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Software Patent Abstract
Digital-imaging based code symbol reading system employing an event-driven
multi-tier modular software architecture and supporting automatic
operating system login and loading of a bar code symbol reading
application.
Software Patent Claims
1. A digital-imaging based code symbol reading system comprising:
a housing having a light transmission window; a digital image formation
and detection subsystem, disposed in said housing, and having (i)
image formation optics for projecting a field of view (FOV) through
said light transmission window and upon an object to be imaged in
said FOV, and (ii) an area-type image detecting array for detecting
imaged light reflected off the object during illumination operations
in an image capture mode in which rows of sensor elements in said
area-type image detecting array are enabled so as to detect one
or more 2D digital images of the object formed on said area-type
image detecting array; an illumination subsystem, disposed in said
housing, and having an illumination array for producing and projecting
a field of illumination through said light transmission window and
within said FOV during the image capture mode; an illumination control
subsystem disposed in said housing, for controlling the operation
of said illumination subsystem during said image capture mode; an
image capturing and buffering subsystem disposed in said housing,
for capturing and buffering said one or more 2D digital images detected
by said image formation and detection subsystem; a digital image
processing subsystem disposed in said housing, for processing said
one or more 2D digital images captured and buffered by said image
capturing and buffering subsystem, so as to read one or more 1D
and/or 2D code symbols graphically represented therein, and producing
symbol character data representative of said read one or more 1D
and/or 2D code symbols; an input/output subsystem for transmitting
said output data to an external host system or other information
receiving or responding device; a system control system for controlling
and/or coordinating the operation of said subsystems above; and
a computing platform for supporting the implementation of one or
more of said subsystems above, and including (i) memory for storing
at least one code symbol reading application, and (ii) a microprocessor
for running at least one code symbol reading application; and wherein
said memory comprises a memory architecture that supports a multi-tier
modular software architecture characterized by an Operating System
(OS) Layer having automatic login, and an Application Layer in which
at least one said code symbol reading application is automatically
run, and being responsive to the generation of a triggering event
within said digital-imaging based code symbol reading system.
2. The digital-imaging based code symbol reading system of claim
1, wherein said multi-tier modular software architecture is further
characterized a System CORE (SCORE) layer disposed between said
Application Layer and said OS Layer.
3. The digital-imaging based code symbol reading system of claim
2, wherein said computing platform further comprises Flash ROM for
storing at least one code symbol reading application, and RAM for
storing said one or more 2D digital images captured and buffered
by said image capturing and buffering subsystem.
4. The digital-imaging based code symbol reading system of claim
1, wherein said FOV is projected through said light transmission
window and upon an object to be imaged in said FOV.
5. The digital-imaging based code symbol reading system of claim
1, wherein said housing contains all of said subsystems.
6. The digital-imaging based code symbol reading system of claim
1, wherein said memory maintains system parameters used to configure
said functions of said digital image capture and processing system.
7. The digital-imaging based code symbol reading system of claim
1, wherein said computing platform implements said digital image
processing subsystem, said input/output subsystem and said system
control subsystem.
8. The digital-imaging based code symbol reading system of claim
2, wherein said OS Layer includes one or more software modules selected
from the group consisting of an OS kernal module, an OS file system
module, and device driver modules; wherein said SCORE Layer includes
one or more of software modules selected from the group consisting
of a tasks manager module, an events dispatcher module, an input/output
manager module, a user commands manager module, the timer subsystem
module, an input/output subsystem module and an memory control subsystem
module; wherein said Application Layer includes one or more software
modules selected from the group consisting of a code symbol decoding
module, a function programming module, an application events manager
module, a user commands table module, and a command handler module.
9. The digital-imaging based code symbol reading system of claim
2, wherein, prior to capturing one or more digital images of the
object, said microprocessor rapidly initializes said micro-computing
platform by performing the following operations: (1) accessing one
or more software modules from said OS layer and executing code contained
therein; (2) accessing one or more software modules from said SCORE
layer and executing code contained therein; and (3) accessing one
or more software modules from said Application Layer and executing
code contained therein.
10. The digital-imaging based code symbol reading system of claim
1, wherein said field illumination comprises narrow-band illumination
produced from an array of light emitting diodes (LEDs).
11. The digital-imaging based code symbol reading system of claim
1, wherein said digital image processing subsystem processes said
one or more digital images, so as to read one or more code symbols
graphically represented therein, and producing output data in the
form of symbol character data representative of said read one or
more code symbols.
12. The digital-imaging based code symbol reading system of claim
11, wherein each said code symbol is a bar code symbol selected
from the group consisting of a 1D bar code symbol, a 2D bar code
symbol, and a data matrix type code symbol structure.
13. The digital-imaging based code symbol reading system of claim
1, said computing platform implements said digital image processing
subsystem, said input/output subsystem and said system control subsystem,
and wherein said Application Layer includes said one or more libraries
and said one or more libraries include one or more software modules
selected from the group consisting of a code symbol decoding module,
a function programming module, an application events manager module,
a user commands table module, and a command handler module.
14. The digital-imaging based code symbol reading system of claim
1, which further comprises an automatic object detection subsystem
for automatically detecting the presence of the object in said FOV,
and in response thereto, generating a trigger signal indicative
of a triggering event.
15. The digital-imaging based code symbol reading system of claim
14, wherein an IR object detection software driver, located within
said OS Layer, is installed automatically.
16. The digital-imaging based code symbol reading system of claim
1, which further comprises a trigger manually actuatable by an operator
of said digital image capturing and processing system so as to generate
a trigger signal indicating a triggering event.
Software Patent Description
RELATED CASES
[0001] This application is a Continuation of U.S. application Ser.
No. 10/893,800 filed Jul. 16, 2004; which is a Continuation of U.S.
application Ser. No. 10/712,787 filed Nov. 13, 2003, now U.S. Pat.
No. 7,128,266 B2; each said application being assigned to Metrologic
Instruments, Inc. and incorporated herewith.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to hand-supportable and portable
area-type digital bar code readers having diverse modes of digital
image processing for reading one-dimensional (1D) and two-dimensional
(2D) bar code symbols, as well as other forms of graphically-encoded
intelligence.
[0004] 2. Brief Description of the State of the Art
[0005] The state of the automatic-identification industry can be
understood in terms of (i) the different classes of bar code symbologies
that have been developed and adopted by the industry, and (ii) the
kinds of apparatus developed and used to read such bar code symbologies
in various user environments.
[0006] In general, there are currently three major classes of bar
code symbologies, namely: one dimensional (1D) bar code symbologies,
such as UPC/EAN, Code 39, etc.; 1D stacked bar code symbologies,
Code 49, PDF417, etc.; and two-dimensional (2D) data matrix symbologies.
[0007] One Dimensional optical bar code readers are well known
in the art. Examples of such readers include readers of the Metrologic
Voyager.RTM. Series Laser Scanner manufactured by Metrologic Instruments,
Inc. Such readers include processing circuits that are able to read
one dimensional (1D) linear bar code symbologies, such as the UPC/EAN
code, Code 39, etc., that are widely used in supermarkets. Such
1D linear symbologies are characterized by data that is encoded
along a single axis, in the widths of bars and spaces, so that such
symbols can be read from a single scan along that axis, provided
that the symbol is imaged with a sufficiently high resolution along
that axis.
[0008] In order to allow the encoding of larger amounts of data
in a single bar code symbol, a number of 1D stacked bar code symbologies
have been developed, including Code 49, as described in U.S. Pat.
No. 4,794,239 (Allais), and PDF417, as described in U.S. Pat. No.
5,340,786 (Pavlidis, et al.). Stacked symbols partition the encoded
data into multiple rows, each including a respective 1D bar code
pattern, all or most of all of which must be scanned and decoded,
then linked together to form a complete message. Scanning still
requires relatively high resolution in one dimension only, but multiple
linear scans are needed to read the whole symbol.
[0009] The third class of bar code symbologies, known as 2D matrix
symbologies offer orientation-free scanning and greater data densities
and capacities than their 1D counterparts. In 2D matrix codes, data
is encoded as dark or light data elements within a regular polygonal
matrix, accompanied by graphical finder, orientation and reference
structures. When scanning 2D matrix codes, the horizontal and vertical
relationships of the data elements are recorded with about equal
resolution.
[0010] In order to avoid having to use different types of optical
readers to read these different types of bar code symbols, it is
desirable to have an optical reader that is able to read symbols
of any of these types, including their various subtypes, interchangeably
and automatically. More particularly, it is desirable to have an
optical reader that is able to read all three of the above-mentioned
types of bar code symbols, without human intervention, i.e., automatically.
This is turn, requires that the reader have the ability to automatically
discriminate between and decode bar code symbols, based only on
information read from the symbol itself. Readers that have this
ability are referred to as "auto-discriminating" or having
an "auto-discrimination" capability.
[0011] If an auto-discriminating reader is able to read only 1D
bar code symbols (including their various subtypes), it may be said
to have a 1D auto-discrimination capability. Similarly, if it is
able to read only 2D bar code symbols, it may be said to have a
2D auto-discrimination capability. If it is able to read both 1D
and 2D bar code symbols interchangeably, it may be said to have
a 1D/2D auto-discrimination capability. Often, however, a reader
is said to have a 1D/2D auto-discrimination capability even if it
is unable to discriminate between and decode 1D stacked bar code
symbols.
[0012] Optical readers that are capable of 1D auto-discrimination
are well known in the art. An early example of such a reader is
Metrologic's VoyagerCG.RTM. Laser Scanner, manufactured by Metrologic
Instruments, Inc.
[0013] Optical readers, particularly hand held optical readers,
that are capable of 1D/2D auto-discrimination and based on the use
of an asynchronously moving 1D image sensor, are described in U.S.
Pat. Nos. 5,288,985 and 5,354,977, which applications are hereby
expressly incorporated herein by reference. Other examples of hand
held readers of this type, based on the use of a stationary 2D image
sensor, are described in U.S. Pat. Nos. 6,250,551; 5,932,862; 5,932,741;
5,942,741; 5,929,418; 5,914,476; 5,831,254; 5,825,006; 5,784,102,
which are also hereby expressly incorporated herein by reference.
[0014] Optical readers, whether of the stationary or movable type,
usually operate at a fixed scanning rate, which means that the readers
are designed to complete some fixed number of scans during a given
amount of time. This scanning rate generally has a value that is
between 30 and 200 scans/sec for 1D readers. In such readers, the
results the successive scans are decoded in the order of their occurrence.
[0015] Imaging-based bar code symbol readers have a number advantages
over laser scanning based bar code symbol readers, namely: they
are more capable of reading stacked 2D symbologies, such as the
PDF 417 symbology; more capable of reading matrix 2D symbologies,
such as the Data Matrix symbology; more capable of reading bar codes
regardless of their orientation; have lower manufacturing costs;
and have the potential for use in other applications, which may
or may not be related to bar code scanning, such as OCR, security
systems, etc
[0016] Prior art imaging-based bar code symbol readers suffer from
a number of additional shortcomings and drawbacks.
[0017] Most prior art hand held optical reading devices can be
reprogrammed by reading bar codes from a bar code programming menu
or with use of a local host processor as taught in U.S. Pat. No.
5,929,418. However, these devices are generally constrained to operate
within the modes in which they have been programmed to operate,
either in the field or on the bench, before deployment to end-user
application environments. Consequently, the statically-configured
nature of such prior art imaging-based bar code reading systems
has limited their performance.
[0018] Prior art imaging-based bar code symbol readers with integrated
illumination subsystems also support a relatively short range of
the optical depth of field. This limits the capabilities of such
systems from reading big or highly dense bar code labels.
[0019] Prior art imaging-based bar code symbol readers generally
require separate apparatus for producing a visible aiming beam to
help the user to aim the camera's field of view at the bar code
label on a particular target object.
[0020] Prior art imaging-based bar code symbol readers generally
require capturing multiple frames of image data of a bar code symbol,
and special apparatus for synchronizing the decoding process with
the image capture process within such readers, as required in U.S.
Pat. Nos. 5,932,862 and 5,942,741 assigned to Welch Allyn, Inc.
[0021] Prior art imaging-based bar code symbol readers generally
require large arrays of LEDs in order to flood the field of view
within which a bar code symbol might reside during image capture
operations, oftentimes wasting large amounts of electrical power
which can be significant in portable or mobile imaging-based readers.
[0022] Prior art imaging-based bar code symbol readers generally
require processing the entire pixel data set of capture images to
find and decode bar code symbols represented therein.
[0023] Many prior art Imaging-Based Bar Code Symbol Readers require
the use of decoding algorithms that seek to find the orientation
of bar code elements in a captured image by finding and analyzing
the code words of 2-D bar code symbologies represented therein.
[0024] Some prior art imaging-based bar code symbol readers generally
require the use of a manually-actuated trigger to actuate the image
capture and processing cycle thereof.
[0025] Prior art imaging-based bar code symbol readers generally
require separate sources of illumination for producing visible aiming
beams and for producing visible illumination beams used to flood
the field of view of the bar code reader.
[0026] Prior art imaging-based bar code symbol readers generally
utilize during a single image capture and processing cycle, and
a single decoding methodology for decoding bar code symbols represented
in captured images.
[0027] Some prior art imaging-based bar code symbol readers require
exposure control circuitry integrated with the image detection array
for measuring the light exposure levels on selected portions thereof.
[0028] Also, many imaging-based readers also require processing
portions of captured images to detect the image intensities thereof
and determine the reflected light levels at the image detection
component of the system, and thereafter to control the LED-based
illumination sources to achieve the desired image exposure levels
at the image detector.
[0029] Prior art imaging-based bar code symbol readers employing
integrated illumination mechanisms control image brightness and
contrast by controlling the time the image sensing device is exposed
to the light reflected from the imaged objects. While this method
has been proven for the CCD-based bar code scanners, it is not suitable,
however, for the CMOS-based image sensing devices, which require
a more sophisticated shuttering mechanism, leading to increased
complexity, less reliability and, ultimately, more expensive bar
code scanning systems.
[0030] Prior art imaging-based bar code symbol readers generally
require the use of tables and bar code menus to manage which decoding
algorithms are to be used within any particular mode of system operation
to be programmed by reading bar code symbols from a bar code menu.
[0031] Finally, as a result of limitations in the mechanical, electrical,
optical, and software design of prior art imaging-based bar code
symbol readers, such prior art readers generally (i) fail to enable
users to read high-density 1D bar codes with the ease and simplicity
of laser scanning based bar code symbol readers, and also 2D symbologies,
such as PDF 417 and Data Matrix, and (ii) are incapable of use in
OCR and OCV, security applications, etc.
[0032] Thus, there is a great need in the art for an improved method
of and apparatus for reading bar code symbols using image capture
and processing techniques which avoid the shortcomings and drawbacks
of prior art methods and apparatus.
OBJECTS AND SUMMARY OF THE PRESENT INVENTION
[0033] Accordingly, a primary object of the present invention is
to provide a novel method of and apparatus for enabling the reading
of 1D and 2D bar code symbologies using image capture and processing
based systems and devices, which avoid the shortcomings and drawbacks
of prior art methods and apparatus.
[0034] Another object of the present invention is to provide a
novel hand-supportable digital Imaging-Based Bar Code Symbol Reader
capable of automatically reading 1D and 2D bar code symbologies
using the state-of-the art imaging technology, and at the speed
and with the reliability achieved by conventional laser scanning
bar code symbol readers.
[0035] Another object of the present invention is to provide a
novel hand-supportable digital Imaging-Based Bar Code Symbol Reader
that is capable of reading stacked 2D symbologies such as PDF417,
as well as Data Matrix.
[0036] Another object of the present invention is to provide a
novel hand-supportable digital Imaging-Based Bar Code Symbol Reader
that is capable of reading bar codes independent of their orientation
with respect to the reader.
[0037] Another object of the present invention is to provide a
novel hand-supportable digital Imaging-Based Bar Code Symbol Reader
that utilizes an architecture that can be used in other applications,
which may or may not be related to bar code scanning, such as OCR,
OCV, security systems, etc.
[0038] Another object of the present invention is to provide a
novel hand-supportable digital Imaging-Based Bar Code Symbol Reader
that is capable of reading high-density bar codes, as simply and
effectively as "flying-spot" type laser scanners do.
[0039] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader capable of
reading 1D and 2D bar code symbologies in a manner as convenient
to the end users as when using a conventional laser scanning bar
code symbol reader.
[0040] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader having a Multi-Mode
Bar Code Symbol Reading Subsystem, which is dynamically reconfigured
in response to real-time processing operations carried out on captured
images.
[0041] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader having an
integrated LED-Based Multi-Mode Illumination Subsystem for generating
a visible narrow-area illumination beam for aiming on a target object
and illuminating a 1D bar code symbol aligned therewith during a
narrow-area image capture mode of the system, and thereafter illuminating
randomly-oriented 1D or 2D bar code symbols on the target object
during a wide-area image capture mode of the system.
[0042] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
an integrated Multi-Mode Illumination Subsystem which generates
a visible narrow-area illumination beam for aiming onto a target
object, then illuminates a 1D bar code symbol aligned therewith,
captures an image thereof, and thereafter generates a wide-area
illumination beam for illuminating 1D or 2D bar code symbols on
the object and capturing an image thereof and processing the same
to read the bar codes represented therein.
[0043] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
automatic object presence and range detection to control the generation
of near-field and far-field wide-area illumination beams during
bar code symbol imaging operations.
[0044] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
a CMOS-type image sensing array using global exposure control techniques.
[0045] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
a CMOS-type image sensing array with a band-pass optical filter
subsystem integrated within the hand-supportable housing thereof,
to allow only narrow-band illumination from the Multi-Mode Illumination
Subsystem to expose the CMOS image sensing array.
[0046] Another object of the present invention is to provide a
hand-supportable imaging-based auto-discriminating 1D/2D bar code
symbol reader employing a Multi-Mode Image-Processing Based Bar
Code Symbol Reading Subsystem dynamically reconfigurable in response
to real-time image analysis during bar code reading operations.
[0047] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
a continuously operating Automatic Light Exposure Measurement and
Illumination Control Subsystem.
[0048] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
a Multi-Mode LED-Based Illumination Subsystem.
[0049] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader having 1D/2D
auto-discrimination capabilities.
[0050] Another object of the present invention is to provide a
method of performing auto-discrimination of 1D/2D bar code symbologies
in an Imaging-Based Bar Code Symbol Reader having both narrow-area
and wide-area image capture modes of operation.
[0051] Another object of the present invention is to provide a
method of and apparatus for processing captured images within an
Imaging-Based Bar Code Symbol Reader in order to read (i.e. recognize)
bar code symbols graphically represented therein.
[0052] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
helically-sweeping feature-extraction analysis on captured 2D images
of objects, referenced from the center thereof.
[0053] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
simple image processing operations applied in an outwardly-directed
manner on captured narrow-area images of objects bearing 1D bar
code symbols.
[0054] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
an integrated LED-based Multi-Mode Illumination Subsystem with far-field
and near-field illumination arrays responsive to control signals
generated by an IR-based Object Presence and Range Detection Subsystem
during a first mode of system operation and a System Control Subsystem
during a second mode of system operation.
[0055] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reading System employing
an integrated LED-Based Multi-Mode Illumination Subsystem driven
by an Automatic Light Exposure Measurement and Illumination Control
Subsystem responsive to control activation signals generated by
a CMOS image sensing array and an IR-based Object Presence and Range
Detection Subsystem during object illumination and image capturing
operations.
[0056] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
a CMOS image sensing array which activates LED illumination driver
circuitry to expose a target object to narrowly-tuned LED-based
illumination when all of rows of pixels in said CMOS image sensing
array are in a state of integration, thereby capturing high quality
images independent of the relative motion between said bar code
reader and the target object.
[0057] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Reading System, wherein
the exposure time of narrow-band illumination onto its CMOS image
sensing array is managed by controlling the illumination time of
its LED-based illumination arrays using control signals generated
by an Automatic Light Exposure Measurement and Illumination Control
Subsystem and a CMOS image sensing array while controlling narrow-band
illumination thereto by way of a band-pass optical filter subsystem.
[0058] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Reading System employing
a mechanism of controlling the image brightness and contrast by
controlling the time the illumination subsystem illuminates the
target object, thus, avoiding the need for a complex shuttering
mechanism for CMOS-based image sensing arrays employed therein.
[0059] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader employing
a Multi-Mode Image-Processing Bar Code Symbol Reading Subsystem
that automatically switches its modes of reading during a single
bar code symbol reading cycle, and a plurality of different bar
code symbology decoding algorithms are applied within each mode
of reading.
[0060] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader, wherein the
Multi-Mode Image-Processing Symbol Reading Subsystem has a first
multi-read (e.g. Omniscan/ROI-Specific) mode of operation, for adaptively
processing and decoding a captured high-resolution image in a high-speed
manner, applying adaptive learning techniques.
[0061] Another object of the present invention is to provide such
a hand-supportable Imaging-Based Bar Code Symbol Reader with a Multi-Mode
Image-Processing Bar Code Symbol Reading Subsystem having a first
multi-read (e.g. Omniscan/ROI-Specific) mode of operation, wherein
if during the Omniscan Mode of operation, code fragments associated
with a PDF417 bar code symbol are detected within a ROI in a captured
(narrow or wide) area image, but processing thereof is unsuccessful,
then the Multi-Mode Image-Processing Symbol Reading Subsystem will
automatically (i) enter its ROI-Specific Mode of operation described
above, and then (ii) immediately commence processing of the captured
image at the ROI specified by ROI coordinates acquired by feature
vector analysis during the Omniscan Mode of operation.
[0062] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader with a Multi-Mode
Image-Processing Bar Code Symbol Reading Subsystem having a first
multi-read (e.g. Omniscan/ROI-Specific) mode of operation, which
offers an OmniScan Mode of operation to initially and rapidly read
1D bar code symbologies, and various kinds of 2D bar code symbologies
whenever present in the captured image, and whenever a PDF417 symbology
is detected (through its code fragments), the Multi-Mode Bar Code
Symbol Reading Subsystem of the present invention can automatically
switch (on-the-fly) to its ROI-specific Mode of operation to immediately
process high-resolution image data at a specific ROI (at which there
is a high likelihood of a bar code symbol present).
[0063] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader, wherein its
Multi-Mode Image-Processing Symbol Reading Subsystem has a second
multi-read (e.g. NoFinder/ROI-Specific) mode of operation, for adaptively
processing a captured high-resolution image in a high-speed manner,
applying adaptive learning techniques.
[0064] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader, wherein the
Multi-Mode Image-Processing Symbol Reading Subsystem has a second
multi-read (e.g. NoFinder/ROI-Specific) mode of operation, and wherein
if during the NoFinder Mode of operation, code fragments associated
with a PDF417 bar code symbol are detected within the captured wide-area
image, but decode processing thereof is unsuccessful, then the Multi-Mode
Image-Processing Symbol Reading Subsystem will automatically (i)
enter its ROI-specific mode of operation described above, and then
(ii) immediately commence processing of the captured wide-area image
at a ROI specified by y coordinates corresponding to the wide-area
image processed during the NoFinder Mode of operation.
[0065] Another object of the present invention is to provide such
a hand-supportable Imaging-Based Bar Code Symbol Reader, wherein
its Multi-Mode Image-Processing Symbol Reading Subsystem has a second
multi-read (e.g. NoFinder/ROI-Specific) mode of operation, and wherein
the No-Finder Mode can rapidly read 1D bar code symbologies whenever
they are presented to the bar code symbol reader, and then whenever
a 2D (e.g. PDF417) symbology is encountered, the bar code symbol
reader can automatically switch its method of reading to the ROI-specific
Mode and use features collected from a narrow (or wide) area image
processed during the No-Finder Mode, so as to immediately process
a specific ROI in a captured wide-area image frame, at which there
is a high likelihood of a bar code symbol present, and to do so
in a highly targeted manner.
[0066] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader, wherein the
Multi-Mode Image-Processing Bar Code Reading Subsystem has a third
multi-read (e.g. NoFinder/Omniscan/ROI-Specific) mode of operation,
for adaptively processing a captured high-resolution image in a
high-speed manner, applying adaptive learning techniques.
[0067] Another object of the present invention is to provide such
a hand-supportable Imaging-Based Bar Code Symbol Reader, wherein
the Multi-Mode Image-Processing Symbol Reading Subsystem has a third
multi-read (e.g. NoFinder/Omniscan/ROI-Specific) mode of operation,
and wherein if during the NoFinder Mode of operation, code fragments
associated with a PDF417 bar code symbol are detected within the
captured narrow-area image, but processing thereof is unsuccessful,
then the Image Formation and Detection Subsystem (i) automatically
captures a wide-area image, while the multi-mode image-processing
symbol reading subsystem (ii) automatically enters its Omniscan
Mode of operation described above, and then (iii) immediately commences
processing of the captured wide-area image at a plurality of parallel
spatially-separated (e.g. by 50 pixels) virtual scan lines, beginning
at a start pixel and start angle specified by x and/or y coordinates
of code fragments detected in the narrow-area image processed during
the NoFinder Mode of operation; and, if the Omniscan Mode does not
successfully read a bar code symbol within the ROI, then the Multi-Mode
Image-Processing Symbol Reading Subsystem (i) automatically enters
its ROI-specific mode of operation described above, and then (ii)
immediately commences processing of the captured wide-area image
at a ROI specified by the x,y coordinates corresponding to code
fragments detected in the wide-area image processed during the Omniscan
Mode of operation.
[0068] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader, wherein the
Multi-Mode Image-Processing Symbol Reading Subsystem has a third
multi-read (e.g. NoFinder/Omniscan/ROI-Specific) mode of operation,
and wherein the No-Finder Mode can rapidly acquire 1D bar code symbologies
whenever they are presented to the bar code symbol reader, and then
whenever a 2D symbology is encountered, the bar code symbol reader
can automatically switch its method of reading to the OmniScan Mode,
collected features on processed image data, and if this reading
method is not successful, then the bar code reader can automatically
switch its method of reading to the ROI-Specific Mode and use features
collected during the Omniscan Mode to immediately process a specific
ROI in a captured image frame, at which there is a high likelihood
of a bar code symbol present, and to do so in a highly targeted
manner.
[0069] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader having an
integrated Multi-Mode Illumination Subsystem that supports an optical
depth of field larger than conventional imaging-based bar code symbol
readers.
[0070] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader having a Depth
of Field (DOF) of about 0 mm to 200 mm (face to 8'') for 13.5 mil
bar code symbols, wherein the resolution varies as function of object
distance, it can decode 5 mil codes somewhere, its optics can resolve
4 mil codes somewhere, and it has a 45.degree. Field of View (FOV).
[0071] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem, which uses a set of features
and constructing a feature vector to determine a region of interest
that may contain a bar code.
[0072] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem which uses multiple, adaptive
thresholds to determine and mark regions of interest (ROIs).
[0073] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem, which uses several image
processing methods to determine bar code orientation in a hierarchical
scheme.
[0074] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having A Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem, which uses several different
scan-data filtering techniques to generate bar-space counts.
[0075] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having A Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem which uses bar and space
stitching for correcting perspective and projection transforms,
and also decoding damaged labels.
[0076] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem, which uses incremental
processing of image data while an image is being progressively acquired.
[0077] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem, which uses low-rise histogram
analysis to determine bright spots in captured images.
[0078] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem, which detects all 1D symbologies
and PDF417 omnidirectionally.
[0079] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having A Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem which decodes UPC/EAN, 1205,
C128, C39, C93, CBR omnidirectionally.
[0080] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem, which uses low incidence
of "false-positives"
[0081] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem, which works with images
stored in memory during a snap-shot mode of operation.
[0082] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem which works with images
acquired progressively during an incremental mode of operation.
[0083] Another object of the present invention is to provide an
Imaging-Based Bar Code Symbol Reader having a Multi-Mode Image-Processing
Based Bar Code Symbol Reading Subsystem which operates on captured
high-resolution images having an image size of 32768.times.32768
pixels.
[0084] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Symbol Reader which is simple
to use, is inexpensive to manufacture, requires as few elements
as possible, has a small as possible form factor, employs no moving
elements (i.e. no dynamic focus, and no zoom), and employs all spherical
surfaces and common glasses.
[0085] Another object of the present invention is to provide a
low-cost, high-resolution Imaging-Based Bar Code Symbol Reader for
omni-directional reading of regular 1D bar codes and two-dimensional
bar codes, such as the PDF417 symbology.
[0086] Another object of the present invention is to provide such
an Imaging-Based Bar Code Symbol Reader having target applications
at point of sales in convenience stores, gas stations, quick markets,
and liquor stores, where 2D bar code reading is required for age
verification and the like.
[0087] Another object of the present invention is to provide an
improved Imaging-Based Bar Code Symbol Reading Engine for integration
into diverse types of information capture and processing systems,
such as bar code driven portable data terminals (PDT) having wireless
interfaces with their base stations, reverse-vending machines, retail
bar code driven kiosks, and the like.
[0088] Another object of the present invention is to provide a
novel method of and apparatus for enabling global exposure control
in an Imaging-Based Bar Code Symbol Reader using a CMOS image sensing
array.
[0089] Another object of the present invention is to provide a
hand-supportable Imaging-Based Bar Code Reading System that employs
a novel method of illumination, which automatically reduces noise
in detected digital images caused by specular reflection during
illumination and imaging operations.
[0090] Another object of the present invention is to provide a
novel method of and system for producing a composite DOF plot that
completely theoretically characterizes the Depth of Field (DOF)
of the image formation optics employed in an Imaging-Based Bar Code
Symbol Reader.
[0091] These and other objects of the present invention will become
more apparently understood hereinafter and in the Claims to Invention
appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS OF PRESENT INVENTION
[0092] For a more complete understanding of how to practice the
Objects of the Present Invention, the following Detailed Description
of the Illustrative Embodiments can be read in conjunction with
the accompanying Drawings, briefly described below.
[0093] FIG. 1A is an rear perspective view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention;
[0094] FIG. 1B is an front perspective view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention;
[0095] FIG. 1C is an elevated left side view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention;
[0096] FIG. 1D is an elevated right side view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention;
[0097] FIG. 1E is an elevated rear view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention;
[0098] FIG. 1F is an elevated front view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention, showing components
associated with its illumination subsystem and its image capturing
subsystem;
[0099] FIG. 1G is a bottom view of the hand-supportable Digital
Imaging-Based Bar Code Symbol Reading Device of the first illustrative
embodiment of the present invention;
[0100] FIG. 1H is a top rear view of the hand-supportable Digital
Imaging-Based Bar Code Symbol Reading Device of the first illustrative
embodiment of the present invention;
[0101] FIG. 1I is a first perspective exploded view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention;
[0102] FIG. 1J is a second perspective exploded view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention;
[0103] FIG. 1K is a third perspective exploded view of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the first
illustrative embodiment of the present invention;
[0104] FIG. 2A1 is a schematic block diagram representative of
a system design for the hand-supportable Digital Imaging-Based Bar
Code Symbol Reading Device illustrated in FIGS. 1A through 1L, wherein
the system design is shown comprising (1) a Multi-Mode Area-Type
Image Formation and Detection (i.e. Camera) Subsystem having image
formation (camera) optics for producing a field of view (FOV) upon
an object to be imaged and a CMOS or like area-type image sensing
array for detecting imaged light reflected off the object during
illumination operations in either (i) a narrow-area image capture
mode in which a few central rows of pixels on the image sensing
array are enabled, or (ii) a wide-area image capture mode in which
all rows of the image sensing array are enabled, (2) a Multi-Mode
LED-Based Illumination Subsystem for producing narrow and wide area
fields of narrow-band illumination within the FOV of the Image Formation
And Detection Subsystem during narrow and wide area modes of image
capture, respectively, so that only light transmitted from the Multi-Mode
Illumination Subsystem and reflected from the illuminated object
and transmitted through a narrow-band transmission-type optical
filter realized within the hand-supportable housing (i.e. using
a red-wavelength high-pass reflecting window filter element disposed
at the light transmission aperture thereof and a low-pass filter
before the image sensor) is detected by the image sensor and all
other components of ambient light are substantially rejected, (3)
an IR-based object presence and range detection subsystem for producing
an IR-based object detection field within the FOV of the Image Formation
and Detection Subsystem, (4) an Automatic Light Exposure Measurement
and Illumination Control Subsystem for controlling the operation
of the LED-Based Multi-Mode Illumination Subsystem, (5) an Image
Capturing and Buffering Subsystem for capturing and buffering 2-D
images detected by the Image Formation and Detection Subsystem,
(6) a Multimode Image-Processing Based Bar Code Symbol Reading Subsystem
for processing images captured and buffered by the Image Capturing
and Buffering Subsystem and reading 1D and 2D bar code symbols represented,
and (7) an Input/Output Subsystem for outputting processed image
data and the like to an external host system or other information
receiving or responding device, in which each said subsystem component
is integrated about (8) a System Control Subsystem, as shown;
[0105] FIG. 2A2 is a schematic block representation of the multi-Mode
Image-Processing Based Bar Code Symbol Reading Subsystem, realized
using the three-tier computing platform illustrated in FIG. 2B;
[0106] FIG. 2B is schematic diagram representative of a system
implementation for the hand-supportable Digital Imaging-Based Bar
Code Symbol Reading Device illustrated in FIGS. 1A through 2A2,
wherein the system implementation is shown comprising (1) an illumination
board 33 carrying components realizing electronic functions performed
by the Multi-Mode LED-Based Illumination Subsystem and the Automatic
Light Exposure Measurement And Illumination Control Subsystem, (2)
a CMOS camera board carrying a high resolution (1280.times.1024
8-bit 6 micron pixel size) CMOS image sensor array running at 25
Mhz master clock, at 7 frames/second at 1280*1024 resolution with
randomly accessible region of interest (ROI) window capabilities,
realizing electronic functions performed by the multi-mode area-type
Image Formation and Detection Subsystem, (3) a CPU board (i.e. computing
platform) including (i) an Intel Sabinal 32-Bit Microprocessor PXA210
running at 200 Mhz 1.0 core voltage with a 16 bit 100 Mhz external
bus speed, (ii) an expandable (e.g. 8+ megabyte) Intel J3 Asynchronous
16-bit Flash memory, (iii) an 16 Megabytes of 100 MHz SDRAM, (iv)
an Xilinx Spartan II FPGA FIFO 39 running at 50 Mhz clock frequency
and 60 MB/Sec data rate, configured to control the camera timings
and drive an image acquisition process, (v) a multimedia card socket,
for realizing the other subsystems of the system, (vi) a power management
module for the MCU adjustable by the system bus, and (vii) a pair
of UARTs (one for an IRDA port and one for a JTAG port), (4) an
interface board for realizing the functions performed by the I/O
subsystem, and (5) an IR-based object presence and range detection
circuit for realizing the IR-based Object Presence And Range Detection
Subsystem;
[0107] FIG. 3A is a schematic representation showing the spatial
relationships between the near and far and narrow and wide area
fields of narrow-band illumination within the FOV of the Multi-Mode
Image Formation and Detection Subsystem during narrow and wide area
image capture modes of operation;
[0108] FIG. 3B is a perspective partially cut-away view of the
hand-supportable Digital Imaging-Based Bar Code Symbol Reading Device
of the first illustrative embodiment, showing the LED-Based Multi-Mode
Illumination Subsystem transmitting visible narrow-band illumination
through its narrow-band transmission-type optical filter system
and illuminating an object with such narrow-band illumination, and
also showing the image formation optics, including the low pass
filter before the image sensing array, for collecting and focusing
light rays reflected from the illuminated object, so that an image
of the object is formed and detected using only the optical components
of light contained within the narrow-band of illumination, while
all other components of ambient light are substantially rejected
before image detection at the image sensing array;
[0109] FIG. 3C is a schematic representation showing the geometrical
layout of the optical components used within the hand-supportable
Digital Imaging-Based Bar Code Reading Device of the first illustrative
embodiment, wherein the red-wavelength reflecting high-pass lens
element is positioned at the imaging window of the device before
the image formation lens elements, while the low-pass filter is
disposed before the image sensor of between the image formation
elements, so as to image the object at the image sensing array using
only optical components within the narrow-band of illumination,
while rejecting all other components of ambient light;
[0110] FIG. 3D is a schematic representation of the image formation
optical subsystem employed within the hand-supportable Digital Imaging-Based
Bar Code Reading Device of the first illustrative embodiment, wherein
all three lenses are made as small as possible (with a maximum diameter
of 12 mm), all have spherical surfaces, all are made from common
glass, e.g. LAK2 (.about.LaK9), ZF10 (=SF8), LAF2 (.about.LaF3);
[0111] FIG. 3E is a schematic representation of the lens holding
assembly employed in the image formation optical subsystem of the
hand-supportable Digital Imaging-Based Bar Code Reading Device of
the first illustrative embodiment, showing a two-piece barrel structure
which holds the lens elements, and a base structure which holds
the image sensing array, wherein the assembly is configured so that
the barrel structure slides within the base structure so as to focus
the assembly;
[0112] FIG. 3F1 is a first schematic representation showing, from
a side view, the physical position of the LEDs used in the Multi-Mode
Illumination Subsystem, in relation to the image formation lens
assembly, the image sensing array employed therein (e.g. a Motorola
MCM20027 or National Semiconductor LM9638 CMOS 2-D image sensing
array having a 1280.times.1024 pixel resolution (1/2'' format),
6 micron pixel size, 13.5 Mhz clock rate, with randomly accessible
region of interest (ROI) window capabilities);
[0113] FIG. 3F2 is a second schematic representation showing, from
an axial view, the physical layout of the LEDs used in the Multi-Mode
Illumination Subsystem of the Digital Imaging-Based Bar Code Reading
Device, shown in relation to the image formation lens assembly,
and the image sensing array employed therein;
[0114] FIG. 3G is a flow chart describing the steps involved in
determining the Depth of Field (DOF) of the image formation optics
assembly employed in the bar code reading system of the present
invention;
[0115] FIG. 4A is a schematic representation of the Depth of Field
Chart used in the design of the image formation optics in the Digital
Imaging-Based Bar Code Reading Device, wherein image formation lens
resolution characteristics are plotted against the pixel limits
of the image sensing array;
[0116] FIG. 4B is graphical chart illustrating the performance
of the image formation optics of the Digital Imaging-Based Bar Code
Reading Device of the present invention, plotting object distance
(centimeters) against MTF values of image formation optics;
[0117] FIG. 4C is a schematic representation illustrating the Depth
of Field of the image formation optics of the Digital Imaging-Based
Bar Code Reading Device of the present invention, measured in millimeters,
and showing the narrowest bar code element dimension that can be
measured over particular regions within its Depth of Field;
[0118] FIG. 4D shows a DOF chart that plots the resolution of the
image formation optics, indicating only the optical performance
of the subsystem;
[0119] FIG. 4E graphically illustrates how to read off the DOF
for a certain mil size code, considering only the optical performance
of the image formation optics of the Image Formation and Detection
Subsystem;
[0120] FIG. 4F shows the 1.4 and 1.6 pixel sampling limits plotted
on the same axes as the optical performance curve for a fixed focal
length reader (as they are functions of object distance);
[0121] FIG. 4G graphically illustrates how to determine the composite
DOF curve of the Image Formation and Detection Subsystem, considering
optical performance and sampling limit together, for the 1.6 pixel
case;
[0122] FIG. 4H graphically illustrates how to read off the DOF
for a certain mil size code, considering optical performance and
sampling limit together, for the 1.6 pixel case;
[0123] FIG. 4I1 through 4I3, taken together, show an exemplary
computer program written in ZPL (Zemax Programming Language) and
capable of generating the composite DOF chart;
[0124] FIG. 5A1 is a schematic representation specifying the range
of narrow-area illumination, near-field wide-area illumination,
and far-field wide-area illumination produced from the LED-Based
Multi-Mode Illumination Subsystem employed in the hand-supportable
Digital Imaging-Based Bar Code Reading Device of the present invention;
[0125] FIG. 5A2 is a table specifying the geometrical properties
and characteristics of each illumination mode supported by the LED-Based
Multi-Mode Illumination Subsystem employed in the hand-supportable
Digital Imaging-Based Bar Code Reading Device of the present invention;
[0126] FIG. 5B is a schematic representation illustrating the physical
arrangement of LED light sources associated with the narrow-area
illumination array and the near-field and far-field wide-area illumination
arrays employed in the Digital Imaging-Based Bar Code Reading Device
of the present invention, wherein the LEDs in the far-field wide-area
illuminating arrays are located behind spherical lenses, the LEDs
in the narrow-area illuminating array are disposed behind cylindrical
lenses, and the LEDs in the near-field wide-area illuminating array
are unlensed in the first illustrative embodiment of the Digital
Imaging-Based Bar Code Reading Device;
[0127] FIG. 5C1 is graphical representation showing the Lambertian
emittance versus wavelength characteristics of the LEDs used to
implement the narrow-area illumination array in the Multi-Mode Illumination
Subsystem of the present invention;
[0128] FIG. 5C2 is graphical representation showing the Lambertian
emittance versus polar angle characteristics of the LEDs used to
implement the narrow-area illumination array in the Multi-Mode Illumination
Subsystem of the present invention;
[0129] FIG. 5C3 is schematic representation of the cylindrical
lenses used before the LEDs in the narrow-area (linear) illumination
arrays in the Digital Imaging-Based Bar Code Reading Device of the
present invention, wherein the first surface of the cylindrical
lens is curved vertically to create a narrow-area (i.e. linear)
illumination pattern, and the second surface of the cylindrical
lens is curved horizontally to control the height of the of the
narrow-area illumination pattern to produce a narrow-area (i.e.
linear) illumination field;
[0130] FIG. 5C4 is a schematic representation of the layout of
the pairs of LEDs and two cylindrical lenses used to implement the
narrow-area (linear) illumination array employed in the Digital
Imaging-Based Bar Code Reading Device of the present invention;
[0131] FIG. 5C5 is a set of six illumination profiles for the narrow-area
(linear) illumination fields produced by the narrow-area (linear)
illumination array employed in the Digital Imaging-Based Bar Code
Reading Device of the illustrative embodiment, taken at 30, 40,
50, 80, 120, and 220 millimeters along the field away from the imaging
window (i.e. working distance) of the Digital Imaging-Based Bar
Code Reading Device, illustrating that the spatial intensity of
the narrow-area illumination field begins to become substantially
uniform at about 80 millimeters;
[0132] FIG. 5D1 is graphical representation showing the Lambertian
emittance versus wavelength characteristics of the LEDs used to
implement the wide area illumination arrays employed in the Digital
Imaging-Based Bar Code Reading Device of the present invention;
[0133] FIG. 5D2 is graphical representation showing the Lambertian
emittance versus polar angle characteristics of the LEDs used to
implement the far-field and near-field wide-area illumination arrays
employed in the Digital Imaging-Based Bar Code Reading Device of
the present invention;
[0134] FIG. 5D3 is schematic representation of the piano-convex
lenses used before the LEDs in the far-field wide-area illumination
arrays in the illumination subsystem of the present invention,
[0135] FIG. 5D4 is a schematic representation of the layout of
LEDs and plano-convex lenses used to implement the far and narrow
wide-area illumination array employed in the Digital Imaging-Based
Bar Code Reading Device of the present invention, wherein the illumination
beam produced therefrom is aimed by positioning the lenses at angles
before the LEDs in the near-field (and far-field) wide-area illumination
arrays employed therein;
[0136] FIG. 5D5 is a set of six illumination profiles for the near-field
wide-area illumination fields produced by the near-field wide-area
illumination arrays employed in the Digital Imaging-Based Bar Code
Reading Device of the illustrative embodiment, taken at 10, 20,
30, 40, 60, and 100 millimeters along the field away from the imaging
window (i.e. working distance) of the Digital Imaging-Based Bar
Code Reading Device, illustrating that the spatial intensity of
the near-field wide-area illumination field begins to become substantially
uniform at about 40 millimeters;
[0137] FIG. 5D6 is a set of three illumination profiles for the
far-field wide-area illumination fields produced by the far-field
wide-area illumination arrays employed in the Digital Imaging-Based
Bar Code Reading Device of the illustrative embodiment, taken at
100, 150 and 220 millimeters along the field away from the imaging
window (i.e. working distance) of the Digital Imaging-Based Bar
Code Reading Device, illustrating that the spatial intensity of
the far-field wide-area illumination field begins to become substantially
uniform at about 100 millimeters;
[0138] FIG. 5D7 is a table illustrating a preferred method of calculating
the pixel intensity value for the center of the far-field wide-area
illumination field produced from the Multi-Mode Illumination Subsystem
employed in the Digital Imaging-Based Bar Code Reading Device of
the present invention, showing a significant signal strength (greater
than 80 DN);
[0139] FIG. 6A1 is a schematic representation showing the red-wavelength
reflecting (high-pass) imaging window integrated within the hand-supportable
housing of the Digital Imaging-Based Bar Code Reading Device, and
the low-pass optical filter disposed before its CMOS image sensing
array therewithin, cooperate to form a narrow-band optical filter
subsystem for transmitting substantially only the very narrow band
of wavelengths (e.g. 620-700 nanometers) of visible illumination
produced from the Multi-Mode Illumination Subsystem employed in
the Digital Imaging-Based Bar Code Reading Device, and rejecting
all other optical wavelengths outside this narrow optical band however
generated (i.e. ambient light sources);
[0140] FIG. 6A2 is schematic representation of transmission characteristics
(energy versus wavelength) associated with the low-pass optical
filter element disposed after the red-wavelength reflecting high-pass
imaging window within the hand-supportable housing of the Digital
Imaging-Based Bar Code Reading Device, but before its CMOS image
sensing array, showing that optical wavelengths below 620 nanometers
are transmitted and wavelengths above 620 nm are substantially blocked
(e.g. absorbed or reflected);
[0141] FIG. 6A3 is schematic representation of transmission characteristics
(energy versus wavelength) associated with the red-wavelength reflecting
high-pass imaging window integrated within the hand-supportable
housing of the Digital Imaging-Based Bar Code Reading Device of
the present invention, showing that optical wavelengths above 700
nanometers are transmitted and wavelengths below 700 nm are substantially
blocked (e.g. absorbed or reflected);
[0142] FIG. 6A4 is a schematic representation of the transmission
characteristics of the narrow-based spectral filter subsystem integrated
within the hand-supportable Imaging-Based Bar Code Symbol Reading
Device of the present invention, plotted against the spectral characteristics
of the LED-emissions produced from the Multi-Mode Illumination Subsystem
of the illustrative embodiment of the present invention;
[0143] FIG. 7A is a schematic representation showing the geometrical
layout of the spherical/parabolic light reflecting/collecting mirror
and photodiode associated with the Automatic Light Exposure Measurement
and Illumination Control Subsystem, and arranged within the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the illustrative
embodiment, wherein incident illumination is collected from a selected
portion of the center of the FOV of the system using a spherical
light collecting mirror, and then focused upon a photodiode for
detection of the intensity of reflected illumination and subsequent
processing by the Automatic Light Exposure Measurement and Illumination
Control Subsystem, so as to then control the illumination produced
by the LED-based Multi-Mode Illumination Subsystem employed in the
Digital Imaging-Based Bar Code Reading Device of the present invention;
[0144] FIG. 7B is a schematic diagram of the Automatic Light Exposure
Measurement and Illumination Control Subsystem employed in the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the present
invention, wherein illumination is collected from the center of
the FOV of the system and automatically detected so as to generate
a control signal for driving, at the proper intensity, the narrow-area
illumination array as well as the far-field and narrow-field wide-area
illumination arrays of the Multi-Mode Illumination Subsystem, so
that the CMOS image sensing array produces digital images of illuminated
objects of sufficient brightness;
[0145] FIGS. 7C1 and 7C2 set forth a schematic diagram of a hybrid
analog/digital circuit designed to implement the Automatic Light
Exposure Measurement and Illumination Control Subsystem of FIG.
7B employed in the hand-supportable Digital Imaging-Based Bar Code
Symbol Reading Device of the present invention;
[0146] FIG. 7D is a schematic diagram showing that, in accordance
with the principles of the present invention, the CMOS image sensing
array employed in the Digital Imaging-Based Bar Code Reading Device
of the illustrative embodiment, once activated by the System Control
Subsystem (or directly by the trigger switch), and when all rows
in the image sensing array are in a state of integration operation,
automatically activates the Automatic Light Exposure Measurement
and Illumination Control Subsystem which, in response thereto, automatically
activates the LED illumination driver circuitry to automatically
drive the appropriate LED illumination arrays associated with the
Multi-Mode Illumination Subsystem in a precise manner and globally
expose the entire CMOS image detection array with narrowly tuned
LED-based illumination when all of its rows of pixels are in a state
of integration, and thus have a common integration time, thereby
capturing high quality images independent of the relative motion
between the bar code reader and the object;
[0147] FIGS. 7E1 and 7E2, taken together, set forth a flow chart
describing the steps involved in carrying out the global exposure
control method of the present invention, within the Digital Imaging-Based
Bar Code Reading Device of the illustrative embodiment;
[0148] FIG. 8 is a schematic block diagram of the IR-based automatic
Object Presence and Range Detection Subsystem employed in the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the present
invention, wherein a first range indication control signal is generated
upon detection of an object within the near-field region of the
Multi-Mode Illumination Subsystem, and wherein a second range indication
control signal is generated upon detection of an object within the
far-field region of the Multi-Mode Illumination Subsystem;
[0149] FIG. 9 is a schematic representation of the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the present
invention, showing that its CMOS image sensing array is operably
connected to its microprocessor through a FIFO (realized by way
of a FPGA) and a system bus, and that its SDRAM is also operably
connected to the microprocessor by way of the system bus, enabling
the mapping of pixel data captured by the imaging array into the
SDRAM under the control of the direct memory access (DMA) module
within the microprocessor;
[0150] FIG. 10 is a schematic representation showing how the bytes
of pixel data captured by the CMOS imaging array within the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device of the present
invention, are mapped into the addressable memory storage locations
of its SDRAM during each image capture cycle carried out within
the device;
[0151] FIG. 11 is a schematic representation showing the software
modules associated with the three-tier software architecture of
the hand-supportable Digital Imaging-Based Bar Code Symbol Reading
Device of the present invention, namely: the Main Task module, the
CodeGate Task module, the Metroset Task module, the Application
Events Manager module, the User Commands Table module, and the Command
Handler module residing with the Application layer of the software
architecture; the Tasks Manager module, the Events Dispatcher module,
the Input/Output Manager module, the User Commands Manager module,
the Timer Subsystem module, the Input/Output Subsystem module and
the Memory Control Subsystem module residing with the System Core
(SCORE) layer of the software architecture; and the Linux Kernal
module, the Linux File System module, and Device Drivers modules
residing within the Linux Operating System (OS) layer of the software
architecture;
[0152] FIG. 12A is a schematic representation of the Events Dispatcher
software module which provides a means of signaling and delivering
events to the Application Events Manager, including the starting
of a new task, stopping a currently running task, doing something,
or doing nothing and ignoring the event;
[0153] FIG. 12B is a Table listing examples of System-Defined Events
which can occur and be dispatched within the hand-supportable Digital
Imaging-Based Bar Code Symbol Reading Device of the present invention,
namely: SCORE_EVENT_POWER_UP which signals the completion of system
start-up and involves no parameters;_SCORE_EVENT_TIMEOUT which signals
the timeout of the logical timer, and involves the parameter "pointer
to timer id"; SCORE_EVENT_UNEXPECTED_INPUT which signals that
the unexpected input data is available and involves the parameter
"pointer to connection id"; SCORE_EVENT_TRIG_ON which
signals that the user pulled the trigger switch and involves no
parameters; SCORE_EVENT_TRIG_OFF which signals that the user released
the trigger switch and involves no parameters; SCORE_EVENT_OBJECT_DETECT_ON
which signals that the object is positioned under the bar code reader
and involves no parameters; SCORE_EVENT_OBJECT_DETECT_OFF which
signals that the object is removed from the field of view of the
bar code reader and involves no parameters; SCORE_EVENT_EXIT_TASK
which signals the end of the task execution and involves the pointer
UTID; and SCORE_EVENT_ABORT_TASK which signals the aborting of a
task during execution;
[0154] FIG. 12C is a schematic representation of the Tasks Manager
software module which provides a means for executing and stopping
application specific tasks (i.e. threads);
[0155] FIG. 12D is a schematic representation of the Input/Output
Manager software module (i.e Input/Output Subsystem), which runs
in the background and monitors activities of external devices and
user connections, and signals appropriate events to the Application
Layer, which such activities are detected;
[0156] FIGS. 12E1 and 12E2 set forth a schematic representation
of the Input/Output Subsystem software module which provides a means
for creating and deleting input/output connections, and communicating
with external systems and devices;
[0157] FIGS. 12F1 and 12F2 set forth a schematic representation
of the Timer Subsystem which provides a means for creating, deleting,
and utilizing logical timers;
[0158] FIGS. 12G1 and 12G2 set forth a schematic representation
of the Memory Control Subsystem which provides an interface for
managing the thread-level dynamic memory with the device, fully
compatible with standard dynamic memory management functions, as
well as a means for buffering collected data;
[0159] FIG. 12H is a schematic representation of the User Commands
Manager which provides a standard way of entering user commands,
and executing application modules responsible for handling the same;
[0160] FIG. 12I is a schematic representation of the Device Driver
software modules, which includes trigger switch drivers for establishing
a software connection with the hardware-based manually-actuated
trigger switch employed on the Digital Imaging-Based Bar Code Reading
Device, an image acquisition driver for implementing image acquisition
functionality aboard the Digital Imaging-Based Bar Code Reading
Device, and an IR driver for implementing object detection functionality
aboard the Imaging-Based Bar Code Symbol Reading Device;
[0161] FIG. 13A is an exemplary flow chart representation showing
how when the user points the bar code reader towards a bar code
symbol, the IR device drivers detect that object within the field,
and then wakes up the Input/Output Manager software module at the
System Core Layer;
[0162] FIG. 13B is an exemplary flow chart representation showing
how upon detecting an object, the Input/Output Manager posts the
SCORE_OBJECT_DETECT_ON event to the Events Dispatcher software module;
[0163] FIG. 13C is an exemplary flow chart representation showing
how, in response to detecting an object, the Events Dispatcher software
module passes the SCORE_OBJECT_DETECT_ON event to the Application
Layer;
[0164] FIG. 13D is an exemplary flow chart representation showing
how upon receiving the SCORE_OBJECT_DETECT_ON event at the Application
Layer, the Application Events Manager executes an event handling
routine which activates the narrow-area illumination array associated
with the Multi-Mode Illumination Subsystem, and executes the CodeGate
Task described in FIG. 13E;
[0165] FIG. 13E is an exemplary flow chart representation showing
how what operations are carried out when the CodeGate Task is executed
within the Application Layer;
[0166] FIG. 13F is an exemplary flow chart representation showing
how, when the user pulls the trigger switch on the bar code reader
while the Code Task is executing, the trigger device driver wakes
up the Input/Output Manager at the System Core Layer;
[0167] FIG. 13G is an exemplary flow chart representation showing
how, in response to waking up, the Input/Output Manager posts the
SCORE_TRIGGER_ON event to the Events Dispatcher;
[0168] FIG. 13H is an exemplary flow chart representation showing
how the Events Dispatcher passes on the SCORE_TRIGGER_ON event to
the Application Events Manager at the Application Layer;
[0169] FIG. 13I is an exemplary flow chart representation showing
how the Application Events Manager responds to the SCORE_TRIGGER_ON
event by invoking a handling routine within the Task Manager at
the System Core Layer which deactivates the narrow-area illumination
array associated with the Multi-Mode Illumination Subsystem, cancels
the CodeGate Task, and executes the Main Task;
[0170] FIG. 13J is an exemplary flow chart representation showing
what operations are carried out when the Main Task is executed within
the Application Layer;
[0171] FIG. 13K is an exemplary flow chart representation showing
what operations are carried out when the Data Output Procedure,
called in the Main Task, is executed within the Input/Output Subsystem
software module in the Application Layer;
[0172] FIG. 13L is an exemplary flow chart representation showing
decoded symbol character data being sent from the Input/Output Subsystem
to the Device Drivers within the Linux OS Layer of the system;
[0173] FIG. 13M is a flow chart describing a novel method of generating
wide-area illumination, for use during the Main Task routine so
as to illuminate objects with a wide-area illumination field in
a manner, which substantially reduces specular-type reflection at
the CMOS image sensing array in the Digital Imaging-Based Bar Code
Reading Device of the present invention;
[0174] FIG. 14 is a table listing various bar code symbologies
supported by the Multi-Mode Bar Code Symbol Reading Subsystem module
employed within the hand-supportable Digital Imaging-Based Bar Code
Symbol Reading Device of the present invention;
[0175] FIG. 15 is a table listing the four primary modes in which
the Multi-Mode Bar Code Symbol Reading Subsystem module can be programmed
to operate, namely: the Automatic Mode wherein the Multi-Mode Bar
Code Symbol Reading Subsystem is configured to automatically process
a captured frame of digital image data so as to search for one or
more bar codes represented therein in an incremental manner, and
to continue searching until the entire image is processed; the Manual
Mode wherein the Multi-Mode Bar Code Symbol Reading Subsystem is
configured to automatically process a captured frame of digital
image data, starting from the center or sweep spot of the image
at which the user would have aimed the bar code reader, so as to
search for (i.e. find) one or more bar code symbols represented
therein, by searching in a helical manner through frames or blocks
of extracted image feature data and marking the same and processing
the corresponding raw digital image data until a bar code symbol
is recognized/read within the captured frame of image data; the
ROI-Specific Mode wherein the Multi-Mode Bar Code Symbol Reading
Subsystem is configured to automatically process a specified "region
of interest" (ROI) in a captured frame of digital image data
so as to search for one or more bar codes represented therein, in
response to coordinate data specifying the location of the bar code
within the field of view of the multi-mode image formation and detection
system; the NoFinder Mode wherein the Multi-Mode Bar Code Symbol
Reading Subsystem is configured to automatically process a captured
narrow-area (linear) frame of digital image data, without feature
extraction and marking operations used in the Automatic and Manual
Modes, so as read one or more bar code symbols represented therein;
and the Omniscan Mode, wherein the Multi-Mode Bar Code Symbol Reading
Subsystem is configured to automatically process a captured frame
of digital image data along any one or more predetermined virtual
scan line orientations, without feature extraction and marking operations
used in the Automatic and Manual Modes, so as to read one or more
bar code symbols represented therein;
[0176] FIG. 16 is a exemplary flow chart representation showing
the steps involved in setting up and cleaning up the software sub-Application
entitled "Multi-Mode Image-Processing Based Bar Code Symbol
Reading Subsystem", once called from either (i) the CodeGate
Task software module at the Block entitled READ BAR CODE(S) IN CAPTURED
NARROW-AREA IMAGE indicated in FIG. 13E, or (ii) the Main Task software
module at the Block entitled "READ BAR CODE(S) IN CAPTURED
WIDE-AREA IMAGE" indicated in FIG. 13J;
[0177] FIG. 17A is a summary of the steps involved in the decode
process carrying out by the Multi-Mode Bar Code Symbol Reading Subsystem
of the present invention during its Automatic Mode of operation,
wherein (1) the first stage of processing involves searching for
(i.e. finding) regions of interest (ROIs) by processing a low resolution
image of a captured frame of high-resolution image data, partitioning
the low-resolution image into N.times.N blocks, and creating a feature
vector for each block using spatial-derivative based image processing
techniques, (2) the second stage of processing involves marking
ROIs by examining the feature vectors for regions of high-modulation,
calculating bar code orientation and marking the four corners of
a bar code as a ROI, and (3) the third stage of processing involves
reading any bar code symbols represented within the ROI by traversing
the bar code and updating the feature vectors, examining the zero-crossings
of filtered images, creating bar and space patterns, and decoding
the bar and space patterns using conventional decoding algorithms;
[0178] FIG. 17B is an exemplary flow chart representation of the
steps involved in the image-processing method carried out by the
Multi-Mode Bar Code Symbol Reading Subsystem during its Automatic
Mode of operation;
[0179] FIG. 18A is a graphical representation illustrating the
generation of a low-resolution image of a package label from an
original high-resolution image thereof during the first finding
stage of processing within the Multi-Mode Bar Code Symbol Reading
Subsystem configured in its Automatic Mode of operation;
[0180] FIG. 18B is a graphical representation illustrating the
partitioning of the low-resolution image of the package label, the
calculation of feature vectors using the same, and the analysis
of these feature vectors for parallel lines, during the first finding
stage of processing within the Multi-Mode Bar Code Symbol Reading
Subsystem during its Automatic Mode of operation;
[0181] FIG. 18C is a graphical representation showing that the
calculation of feature vectors within each block of low-resolution
image data, during the second marking stage of processing within
the Multi-Mode Bar Code Symbol Reading Subsystem, can involve the
use of gradient vectors, edge density measures, the number of parallel
edge vectors, centroids of edgels, intensity variance, and the histogram
of intensities captured from the low-resolution image;
[0182] FIG. 18D is a graphical representation of the examination
of feature vectors looking for high edge density, large number of
parallel edge vectors and large intensity variance, during the second
marking stage of processing within the Multi-Mode Bar Code Symbol
Reading Subsystem during its Automatic Mode of operation;
[0183] FIGS. 18E and 18F set forth graphical representations of
calculating bar code orientation during the second marking stage
of processing within the Multi-Mode Bar Code Symbol Reading Subsystem
operating in its Automatic Mode, wherein each feature vector block,
the bar code is traversed (i.e. sliced) at different angles, the
slices are matched with each other based on "least mean square
error", and the correct orientation is determined to be that
angle which matches the mean square error sense through every slice
of the bar code symbol represented within the captured image;
[0184] FIG. 18F is a graphical representation of calculating bar
code orientation, during the second marking stage of processing
within the Multi-Mode Bar Code Symbol Reading Subsystem operating
in its Automatic Mode;
[0185] FIG. 18G is a graphical representation of the marking of
the four corners of the detected bar code symbol during the second
marking stage of processing within the Multi-Mode Bar Code Symbol
Reading Subsystem operating in its Automatic Mode, wherein such
marking operations are performed on the full high-resolution image
of the parcel, the bar code is traversed in either direction starting
from the center of the block, the extent of modulation is detected
using the intensity variance, and the x,y coordinates (pixels) of
the four corners of the bar code are detected starting from 1 and
2 and moving perpendicular to the bar code orientation, and define
the ROI by the detected four corners of the bar code symbol within
the high-resolution image;
[0186] FIG. 18H is a graphical representation of updating the feature
vectors during the third stage of processing within the Multi-Mode
Bar Code Symbol Reading Subsystem operating in its Automatic Mode,
wherein the histogram component of the feature vector Fv is updated
while traversing the bar code symbol, the estimate of the black-to-white
transition is calculated, and an estimate of narrow and wide elements
of the bar code symbol are calculated;
[0187] FIG. 18I is a graphical representation of the search for
zero crossings during the third stage of processing within the Multi-Mode
Bar Code Symbol Reading Subsystem operating in its Automatic Mode,
wherein the high-resolution bar code image is median filtered in
a direction perpendicular to bar code orientation, the second derivative
zero crossings define edge crossings, the zero-crossing data is
used only for detecting edge transitions, and the black/white transition
estimates are used to put upper and lower bounds on the grey levels
of the bars and spaces of the bar code symbol represented within
the captured image;
[0188] FIG. 18J is a graphical representation of creating bar and
space pattern during the third stage of processing within the Multi-Mode
Bar Code Symbol Reading Subsystem operating in its Automatic Mode,
wherein the edge transition is modeled as a ramp function, the edge
transition is assumed to be 1 pixel wide, the edge transition location
is determined at the subpixel level, and the bar and space counts
are gathered using edge transition data;
[0189] FIG. 18K is a graphical representation of the decode bar
and space pattern during the third stage of processing within the
Multi-Mode Bar Code Symbol Reading Subsystem operating in its Automatic
Mode, wherein the bar and space data is framed with borders, and
the bar and space data is decoded using existing laser scanning
bar code decoding algorithms;
[0190] FIG. 19A is a summary of the steps involved in the image-processing
method carried out by the Multi-Mode Bar Code Symbol Reading Subsystem
during its Manual Mode of operation, wherein (1) the first stage
of processing involves searching for (i.e. finding) regions of interest
(ROIs) by processing a low resolution image of a captured frame
of high-resolution image data, partitioning the low-resolution image
into N.times.N blocks, and creating a feature vector for the middle
block using spatial-derivative based image processing techniques,
(2) the second stage of processing involves marking ROIs by examining
the feature vectors for regions of high-modulation and returning
to the first stage to create feature vectors for other blocks surrounding
the middle block (in a helical manner), calculating bar code orientation
and marking the four corners of a bar code as a ROI, and (3) the
third stage of processing involves reading any bar code symbols
represented within the ROI by traversing the bar code and updating
the feature vectors, examining the zero-crossings of filtered images,
creating bar and space patterns, and decoding the bar and space
patterns using conventional decoding algorithms;
[0191] FIG. 19B is an exemplary flow chart representation of the
steps involved in the image-processing method carrying out by the
Multi-Mode Bar Code Symbol Reading Subsystem during its Manual Mode
of operation;
[0192] FIG. 20A is a summary of the steps involved in the image
processing method carried out by the Multi-Mode Bar Code Symbol
Reading Subsystem during its NoFinder Mode of operation, wherein
the Decoder Module does not employ bar code element finding or marking
techniques (i.e. Finder Module and Marker Module) and directly processes
a narrow-area portion of a captured high-resolution image, starting
from the middle thereof, examines the zero-crossings of the filtered
image, creates bar and space patterns therefrom, and then decodes
the bar and space patterns using conventional decoding algorithms;
[0193] FIG. 20B is an exemplary flow chart representation of the
steps involved in the image-processing method carried out by the
Multi-Mode Bar Code Symbol Reading Subsystem during its NoFinder
Mode of operation;
[0194] FIG. 21A is a summary of the steps involved in the image-processing
method carried out by the Multi-Mode Bar Code Symbol Reading Subsystem
during its OmniScan Mode of operation, wherein the Decoder Module
does not employ bar code element finding or marking techniques (i.e.
Finder Module and Marker Module), assumes the imaged bar code symbol
resides at the center of the captured wide-area high-resolution
image with about a 1:1 aspect ratio, and directly processes the
high-resolution image along a set of parallel spaced-apart (e.g.
50 pixels) virtual scan lines, examines the zero-crossings along
the virtual scan lines, creates bar and space patterns therefrom,
and then decodes the bar and space patterns, with the option of
reprocessing the high-resolution image along a different set of
parallel spaced-apart virtual scan lines oriented at a different
angle from the previously processed set of virtual scan lines (e.g.
0, 30, 60, 90, 120 or 150 degrees);
[0195] FIG. 21B is an exemplary flow chart representation of the
steps involved in the image-processing method carried out by the
Multi-Mode Bar Code Symbol Reading Subsystem during its OmniScan
Mode of operation;
[0196] FIG. 22A is a summary of the steps involved in the image-processing
based bar code reading method carried out by the Multi-Mode Bar
Code Symbol Reading Subsystem of the present invention during its
"ROI-Specific" Mode of operation, designed for use in
combination with the Omniscan Mode of operation, wherein (1) the
first stage of processing involves receiving region of interest
(ROI) coordinates (x1, x2) obtained during the Omniscan Mode of
operation (after the occurrence of a failure to decode), re-partitioning
the captured low-resolution image (from the Omniscan Mode) into
N.times.N blocks, and creating a feature vector for the ROI-specified
block(s) using spatial-derivative based image processing techniques,
(2) the second stage of processing involves marking additional ROIs
by examining the feature vectors for regions of high-modulation
and returning to the first stage to create feature vectors for other
blocks surrounding the middle block (in a helical manner), calculating
bar code orientation and marking the four corners of a bar code
as a ROI, and (3) the third stage of processing involves reading
any bar code symbols represented within the ROI by traversing the
bar code symbol and updating the feature vectors, examining the
zero-crossings of filtered images, creating bar and space patterns,
and decoding the bar and space patterns using conventional decoding
algorithms;
[0197] FIG. 22B is an exemplary flow chart representation of the
steps involved in the image-processing method carried out by the
Multi-Mode Bar Code Symbol Reading Subsystem of the present invention
during its ROI-specific Mode of operation;
[0198] FIG. 23 is a specification of Multi-Mode Bar Code Symbol
Reading Subsystem operated during its first multi-read (Omniscan/ROI-Specific)
mode of operation;
[0199] FIG. 24 is a specification of Multi-Mode Bar Code Symbol
Reading Subsystem operated during its second multi-read (No-Finder/ROI-Specific)
mode of operation;
[0200] FIG. 25 is a specification of Multi-Mode Bar Code Symbol
Reading Subsystem operated during its third multi-read (No-Finder/Omniscan/ROI-Specific)
mode of operation; and
[0201] FIGS. 26A and 26B, taken together, provide a table listing
the primary Programmable Modes of Bar Code Reading Operation within
the hand-supportable Digital Imaging-Based Bar Code Symbol Reading
Device of the present invention, namely: Programmed Mode of System
Operation No. 1--Manually-Triggered Single-Attempt 1D Single-Read
Mode Employing the No-Finder Mode of the Multi-Mode Bar Code Reading
Subsystem; Programmed Mode Of System Operation No. 2--Manually-Triggered
Multiple-Attempt 1D Single-Read Mode Employing the No-Finder Mode
of the Multi-Mode Bar Code Reading Subsystem; Programmed Mode Of
System Operation No. 3--Manually-Triggered Single-Attempt 1D/2D
Single-Read Mode Employing the No-Finder Mode And The Automatic
Or Manual Modes of the Multi-Mode Bar Code Reading Subsystem; Programmed
Mode of System Operation No. 4--Manually-Triggered Multiple-Attempt
1D/2D Single-Read Mode Employing the No-Finder Mode And The Automatic
Or Manual Modes of the Multi-Mode Bar Code Reading Subsystem; Programmed
Mode of System Operation No. 5--Manually-Triggered Multiple-Attempt
1D/2D Multiple-Read Mode Employing the No-Finder Mode And The Automatic
Or Manual Modes of the Multi-Mode Bar Code Reading Subsystem; Programmed
Mode of System Operation No. 6--Automatically-Triggered Single-Attempt
1D Single-Read Mode Employing The No-Finder Mode Of the Multi-Mode
Bar Code Reading Subsystem Programmed Mode of System Operation No.
7--Automatically-Triggered Multi-Attempt 1D Single-Read Mode Employing
The No-Finder Mode Of the Multi-Mode Bar Code Reading Subsystem;
Programmed Mode of System Operation No. 8--Automatically-Triggered
Multi-Attempt 1D/2D Single-Read Mode Employing The No-Finder Mode
and Manual and/or Automatic Modes Of the Multi-Mode Bar Code Reading
Subsystem; Programmed Mode of System Operation No. 9--Automatically-Triggered
Multi-Attempt 1D/2D Multiple-Read Mode Employing The No-Finder Mode
and Manual and/or Automatic Modes Of the Multi-Mode Bar Code Reading
Subsystem; Programmable Mode of System Operation No. 10--Automatically-Triggered
Multiple-Attempt 1D/2D Single-Read Mode Employing The Manual, Automatic
or Omniscan Modes Of the Multi-Mode Bar Code Reading Subsystem;
Programmed Mode of System Operation No. 11--Semi-Automatic-Triggered
Single-Attempt 1D/2D Single-Read Mode Employing The No-Finder Mode
And The Automatic Or Manual Modes Of the Multi-Mode Bar Code Reading
Subsystem; Programmable Mode of System Operation No. 12--Semi-Automatic-Triggered
Multiple-Attempt 1D/2D Single-Read Mode Employing The No-Finder
Mode And The Automatic Or Manual Modes Of the Multi-Mode Bar Code
Reading Subsystem; Programmable Mode of Operation No. 13--Semi-Automatic-Triggered
Multiple-Attempt 1D/2D Multiple-Read Mode Employing The No-Finder
Mode And The Automatic Or Manual Modes Of the Multi-Mode Bar Code
Reading Subsystem; Programmable Mode of Operation No. 14--Semi-Automatic-Triggered
Multiple-Attempt 1D/2D Multiple-Read Mode Employing The No-Finder
Mode And The Omniscan Modes Of the Multi-Mode Bar Code Reading Subsystem;
Programmable Mode of Operation No. 15--Continuously-Automatically-Triggered
Multiple-Attempt 1D/2D Multiple-Read Mode Employing The Automatic,
Manual Or Omniscan Modes Of the Multi-Mode Bar Code Reading Subsystem;
Programmable Mode of System Operation No. 16--Diagnostic Mode Of
Imaging-Based Bar Code Reader Operation; and Programmable Mode of
System Operation No. 17--Live Video Mode Of Imaging-Based Bar Code
Reader Operation;
[0202] FIG. 27A is a schematic representation specifying the four
modes of illumination produced from the Multi-Mode Illumination
Subsystem employed in the second illustrative embodiment of the
Digital Imaging-Based Bar Code Symbol Reader of the present invention,
which supports both near and far fields of narrow-area illumination
generated during the narrow-area image capture mode of its Multi-Mode
Image Formation and Detection Subsystem;
[0203] FIG. 27B is a schematic representation specifying how the
cylindrical beam shaping optics employed within near-field and far-field
narrow-area illumination arrays can be easily tailored to generate
near and far narrow-area illumination fields having geometrical
characteristics that enables (i) simple reading of extended-length
bar code symbols within the far-field region of the FOV of the system,
and also (ii) simple reading of bar code menus with a great degree
of control within the near-field region of the FOV, preferably during
a "Semi-Automatic-Triggered" programmed mode of system
operation;
[0204] FIG. 28 is a schematic representation illustrating the physical
arrangement of LEDs and light focusing lenses associated with the
near and far field narrow-area and wide-area illumination arrays
employed in the Digital Imaging-Based Bar Code Symbol Reading Device
according to the second illustrative embodiment of the present invention;
[0205] FIG. 29A is a first perspective view of a second illustrative
embodiment of the portable POS Digital Imaging-Based Bar Code Symbol
Reading Device of the present invention, shown having a hand-supportable
housing of a different form factor than that of the first illustrative
embodiment, and configured for use in its hands-free/presentation
mode of operation, supporting primarily wide-area image capture;
[0206] FIG. 29B is a second perspective view of the second illustrative
embodiment of the portable POS Digital Imaging-Based Bar Code Reading
Device of the present invention, shown configured and operated in
its hands-free/presentation mode of operation, supporting primarily
wide-area image capture;
[0207] FIG. 29C is a third perspective view of the second illustrative
embodiment of the portable Digital Imaging-Based Bar Code Reading
Device of the present invention, showing configured and operated
in a hands-on type mode, supporting both narrow and wide area modes
of image capture;
[0208] FIG. 30 is a perspective view of a third illustrative embodiment
of the Digital Imaging-Based Bar Code Symbol Reading Device of the
present invention, realized in the form of a Multi-Mode Image Capture
And Processing Engine that can be readily integrated into various
kinds of information collection and processing systems, including
wireless portable data terminals (PDTs), reverse-vending machines,
retail product information kiosks and the like;
[0209] FIG. 31 is a schematic representation of a Wireless Bar
Code-Driven Portable Data Terminal embodying the Imaging-Based Bar
Code Symbol Reading Engine of the present invention, shown configured
and operated in a hands-on mode;
[0210] FIG. 32 is a perspective view of the Wireless Bar Code Driven
Portable Data Terminal of FIG. 31 shown configured and operated
in a hands-on mode, wherein the Imaging-Based Bar Code Symbol Reading
Engine embodied therein is used to read a bar code symbol on a package
and the symbol character data representative of the read bar code
is being automatically transmitted to its cradle-providing base
station by way of an RF-enabled 2-way data communication link;
[0211] FIG. 33 is a side view of the Wireless Bar Code Driven Portable
Data Terminal of FIGS. 31 and 32 shown configured and operated in
a hands-free mode, wherein the Imaging-Based Bar Code Symbol Reading
Engine is configured in a wide-area image capture mode of operation,
suitable for presentation-type bar code reading at point of sale
(POS) environments; and
[0212] FIG. 34 is a block schematic diagram showing the various
subsystem blocks associated with a design model for the Wireless
Hand-Supportable Bar Code Driven Portable Data Terminal System of
FIGS. 31, 32 and 33, shown interfaced with possible host systems
and/or networks.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS OF THE PRESENT
INVENTION
[0213] Referring to the figures in the accompanying Drawings, the
various illustrative embodiments of the hand-supportable imaging-based
bar code symbol reading system of the present invention will be
described in great detail, wherein like elements will be indicated
using like reference numerals.
Hand-Supportable Digital Imaging-Based Bar Code Reading Device
of the First Illustrative Embodiment of the Present Invention
[0214] Referring to FIGS. 1A through 1K, the hand-supportable Digital
Imaging-Based Bar Code Symbol Reading Device of the first illustrative
embodiment of the present invention 1 is shown in detail comprising
a hand-supportable housing 2 having a handle portion 2A and a head
portion 2B that is provided with a light transmission window 3 with
a high-pass (red-wavelength reflecting) optical filter element 4A
having light transmission characteristics set forth in FIG. 6A2,
in the illustrative embodiment. As will be described in greater
detail hereinafter, high-pass optical filter element 4A cooperates
within an interiorly mounted low-pass optical filter element 4B
characterized in FIG. 6A1, which cooperates with the high-pass optical
filter element 4A. These high and low pass filter elements 4A and
4B cooperate to provide a narrow-band optical filter system 4 that
integrates with the head portion of the housing and permits only
a narrow band of illumination (e.g. 633 nanometers) to exit and
enter the housing during imaging operations.
[0215] As best shown in FIGS. 1I, 1J, and 1K, the hand-supportable
housing 2 of the illustrative embodiment comprises: left and right
housing handle halves 2A1 and 2A2; a foot-like structure 2A3 which
is mounted between the handle halves 2A1 and 2A2; a trigger switch
structure 2C which snap fits within and pivots within a pair of
spaced apart apertures 2D1 and 2D2 provided in the housing halves;
a light transmission window panel 5 through which light transmission
window 3 is formed and supported within a recess formed by handle
halves 2A1 and 2A2 when they are brought together, and which supports
all LED illumination arrays provided by the system; an optical bench
6 for supporting electro-optical components and operably connected
an orthogonally-mounted PC board 7 which is mounted within the handle
housing halves; a top housing portion 2B1 for connection with the
housing handle halves 2A1 and 2A2 and enclosing the head portion
of the housing; light pipe lens element 8 for mounting over an array
of light emitting diodes (LEDs) 9 and light pipe structures 10 mounted
within the rear end of the head portion of the hand-supportable
housing; and a front bumper structure 2E for holding together the
top housing portion 2B1 and left and right handle halves 2A1 and
2A2 with the light transmission window panel 5 sandwiched therebetween,
while providing a level of shock protection thereto.
[0216] In other embodiments of the present invention shown in FIGS.
27 through 33 the form factor of the hand-supportable housing might
be different. In yet other applications, the housing need not even
be hand-supportable, but rather might be designed for stationary
support on a desktop or countertop surface, or for use in a commercial
or industrial application.
Schematic Block Functional Diagram as System Design Model for the
Hand-Supportable Digital Image-Based Bar Code Reading Device of
the Present Invention
[0217] As shown in the system design model of FIG. 2A1, the hand-supportable
Digital Imaging-Based Bar Code Symbol Reading Device 1 of the illustrative
embodiment comprises: an IR-based Object Presence and Range Detection
Subsystem 12; a Multi-Mode Area-type Image Formation and Detection
(i.e. camera) Subsystem 13 having narrow-area mode of image capture,
near-field wide-area mode of image capture, and a far-field wide-area
mode of image capture; a Multi-Mode LED-Based Illumination Subsystem
14 having narrow-area mode of illumination, near-field wide-area
mode of illumination, and a far-field wide-area mode of illumination;
an Automatic Light Exposure Measurement and Illumination Control
Subsystem 15; an Image Capturing and Buffering Subsystem 16; a Multi-Mode
Image-Processing Bar Code Symbol Reading Subsystem 17 having five
modes of image-processing based bar code symbol reading indicated
in FIG. 2A2 and to be described in detail hereinabove; an Input/Output
Subsystem 18; a manually-actuatable trigger switch 2C for sending
user-originated control activation signals to the device; a System
Mode Configuration Parameter Table 70; and a System Control Subsystem
18 integrated with each of the above-described subsystems, as shown.
[0218] The primary function of the IR-based Object Presence and
Range Detection Subsystem 12 is to automatically produce an IR-based
object detection field 20 within the FOV of the Multi-Mode Image
Formation and Detection Subsystem 13, detect the presence of an
object within predetermined regions of the object detection field
(20A, 20B), and generate control activation signals A1 which are
supplied to the System Control Subsystem 19 for indicating when
and where an object is detected within the object detection field
of the system.
[0219] In the first illustrative embodiment, the Multi-Mode Image
Formation And Detection (I.E. Camera) Subsystem 13 has image formation
(camera) optics 21 for producing a field of view (FOV) 23 upon an
object to be imaged and a CMOS area-image sensing array 22 for detecting
imaged light reflected off the object during illumination and image
acquisition/capture operations.
[0220] In the first illustrative embodiment, the primary function
of the Multi-Mode LED-Based Illumination Subsystem 14 is to produce
a narrow-area illumination field 24, near-field wide-area illumination
field 25, and a far-field wide-area illumination field 25, each
having a narrow optical-bandwidth and confined within the FOV of
the Multi-Mode Image Formation And Detection Subsystem 13 during
narrow-area and wide-area modes of imaging, respectively. This arrangement
is designed to ensure that only light transmitted from the Multi-Mode
Illumination Subsystem 14 and reflected from the illuminated object
is ultimately transmitted through a narrow-band transmission-type
optical filter subsystem 4 realized by (1) high-pass (i.e. red-wavelength
reflecting) filter element 4A mounted at the light transmission
aperture 3 immediately in front of panel 5, and (2) low-pass filter
element 4B mounted either before the image sensing array 22 or anywhere
after panel 5 as shown in FIG. 3C. FIG. 6A4 sets forth the resulting
composite transmission characteristics of the narrow-band transmission
spectral filter subsystem 4, plotted against the spectral characteristics
of the emission from the LED illumination arrays employed in the
Multi-Mode Illumination Subsystem 14.
[0221] The primary function of the narrow-band integrated optical
filter subsystem 4 is to ensure that the CMOS image sensing array
22 only receives the narrow-band visible illumination transmitted
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