WO2007124116A2 - Procédé et appareil de réglage dynamique et adaptatif des paramètres d'un système numérique de capture et de traitement d'images - Google Patents

Procédé et appareil de réglage dynamique et adaptatif des paramètres d'un système numérique de capture et de traitement d'images Download PDF

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Publication number
WO2007124116A2
WO2007124116A2 PCT/US2007/009763 US2007009763W WO2007124116A2 WO 2007124116 A2 WO2007124116 A2 WO 2007124116A2 US 2007009763 W US2007009763 W US 2007009763W WO 2007124116 A2 WO2007124116 A2 WO 2007124116A2
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WO
WIPO (PCT)
Prior art keywords
illumination
digital
subsystem
code symbol
image capture
Prior art date
Application number
PCT/US2007/009763
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English (en)
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WO2007124116A3 (fr
Inventor
Anatoly Kotlarsky
Ka Man Au
Michael Veksland
Xiaoxun Zhu
Mark Meagher
Timothy Good
Richard Hou
Daniel Hu
Original Assignee
Metrologic Instruments, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US11/408,268 external-priority patent/US7464877B2/en
Priority to EP07755869.0A priority Critical patent/EP2038812A4/fr
Application filed by Metrologic Instruments, Inc. filed Critical Metrologic Instruments, Inc.
Priority to US11/880,087 priority patent/US8042740B2/en
Priority to US11/900,651 priority patent/US7954719B2/en
Priority to US11/977,430 priority patent/US7614560B2/en
Priority to US11/977,413 priority patent/US7546952B2/en
Priority to US11/977,432 priority patent/US7878407B2/en
Priority to US11/977,422 priority patent/US7731091B2/en
Priority to US11/978,525 priority patent/US7575170B2/en
Priority to US11/978,521 priority patent/US7661597B2/en
Priority to US11/978,535 priority patent/US7571858B2/en
Priority to US11/978,522 priority patent/US7588188B2/en
Priority to US11/978,943 priority patent/US7665665B2/en
Priority to US11/980,329 priority patent/US20080249884A1/en
Priority to US11/978,951 priority patent/US7775436B2/en
Priority to US11/980,080 priority patent/US7784698B2/en
Priority to US11/980,192 priority patent/US7806336B2/en
Priority to US11/980,317 priority patent/US7770796B2/en
Priority to US11/980,083 priority patent/US7784695B2/en
Priority to US11/980,078 priority patent/US7806335B2/en
Priority to US11/980,084 priority patent/US7793841B2/en
Priority to US11/978,981 priority patent/US7762465B2/en
Priority to US11/980,319 priority patent/US8172141B2/en
Publication of WO2007124116A2 publication Critical patent/WO2007124116A2/fr
Priority to US12/283,439 priority patent/US20090134221A1/en
Publication of WO2007124116A3 publication Critical patent/WO2007124116A3/fr

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Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
    • G06K7/10554—Moving beam scanning
    • G06K7/10594—Beam path
    • G06K7/10683—Arrangement of fixed elements
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K17/00—Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
    • G06K17/0022—Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations arrangements or provisious for transferring data to distant stations, e.g. from a sensing device
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
    • G06K7/10712—Fixed beam scanning
    • G06K7/10722—Photodetector array or CCD scanning
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
    • G06K7/10712—Fixed beam scanning
    • G06K7/10722—Photodetector array or CCD scanning
    • G06K7/10732—Light sources
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
    • G06K7/10712—Fixed beam scanning
    • G06K7/10722—Photodetector array or CCD scanning
    • G06K7/10752—Exposure time control
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
    • G06K7/10712—Fixed beam scanning
    • G06K7/10762—Relative movement
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
    • G06K7/10792—Special measures in relation to the object to be scanned
    • G06K7/10801—Multidistance reading
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
    • G06K7/10821—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices
    • G06K7/10851—Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
    • G06K7/10821—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices
    • G06K7/10861—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices sensing of data fields affixed to objects or articles, e.g. coded labels
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K2207/00—Other aspects
    • G06K2207/1011—Aiming
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K2207/00—Other aspects
    • G06K2207/1017—Programmable

Definitions

  • 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 (I D) and two-dimensional (2D) bar code symbols, as well as other forms of graphically-encoded intelligence.
  • 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.
  • bar code symbologies there are currently three major classes of bar code symbologies, namely: one dimensional (I D) bar code symbologies, such as UPC/EAN, Code 39, etc.; I D stacked bar code symbologies, Code 49, PDF417, etc.; a ' nd two-dimensional (2D) data matrix symbologies.
  • I D one dimensional
  • 2D two-dimensional
  • One Dimensional optical bar code readers are well known in the art. Examples of such readers include readers of the Metrologic Voyager® Series Laser Scanner manufactured by Metrologic Instruments, Inc. Such readers include processing circuits that are able to read one dimensional (I D) linear bar code symbologies, such as the UPC/EAN code, Code 39, etc., that are widely used in supermarkets. Such 1 D 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.
  • I D linear bar code symbologies such as the UPC/EAN code, Code 39, etc.
  • the third class of bar code symbologies known as 2D matrix symbologies offer orientation-free scanning and greater data densities and capacities than their ID counterparts.
  • 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.
  • the horizontal and vertical relationships of the data elements are recorded with about equal resolution.
  • 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.
  • an auto-discriminating reader is able to read only I D bar code symbols (including their various subtypes), it may be said to have a I D 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 I D and 2D bar code symbols interchangeably, it may be said to have a 1 D/2D auto-discrimination capability. Often, however, a reader is said to have a 1 D/2D auto-discrimination capability even if it is unable to discriminate between and decode 1 D stacked bar code symbols.
  • Optical readers that are capable of I D auto-discrimination are well known in the art.
  • An early example of such a reader is Metrologic's VoyagerCG® Laser Scanner, manufactured by Metrologic Instruments, Inc.
  • Optical readers particularly hand held optical readers, that are capable of 1 D/2D auto- discrimination and based on the use of an asynchronously moving I D image sensor, are described in US Patent Nos. 5,288,985 and 5,354,977, which applications are hereby expressly incorporated herein by reference.
  • 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 1 D readers. In such readers, the results the successive scans are decoded in the order of their occurrence.
  • 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
  • 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.
  • 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.
  • 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 US Patent Nos. 5,932,862 and 5,942,741 assigned to Welch Allyn, Inc.
  • 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 larges amounts of electrical power which can be significant in portable or mobile imaging-based readers.
  • 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.
  • some prior art imaging systems use the inherent programmable (pixel) windowing feature within conventional CMOS image sensors to capture only partial image frames to reduce pixel data set processing and enjoy improvements in image processing speed and thus imaging system performance.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.
  • an imaging-based bar code symbol reader having a 2D image sensor with a field of view (FOV) and also a pair of LEDsmounted about a I D (i.e. linear) image sensor to project a pair of light beams through the FOV focusing optics and produce a pair of spols on a target surface supporting a I D bar code, thereby indicating the location of the FOV on the target and enable the user to align the bar code therewithin.
  • I D i.e. linear
  • an imaging-based bar code symbol reader having a 2D image sensor with a field of view (FOV) and also apparatus for marking the perimeter of the FOV, using four light sources and light shaping optics (e.g. cylindrical lens).
  • FOV field of view
  • a hand-held imaging- based bar code symbol reader having a 2D image sensor with a field of view (FOV) and also a laser light source and fixed lens to produce a spotter beam that helps the operator aim the reader at a candidate bar code symbol.
  • FOV field of view
  • the spotter beam is also used measure the distance to the bar code symbol during automatic focus control operations supported within the bar code symbol reader.
  • an imaging-based bar code symbol reader comrpising a 2D image sensor with a field of view (FOV), a user display for displaying a visual representation of a dataform (e.g. bar code symbol), and visual guide marks on the user display for indicating whether or not the dataform being imaged is in focus when its image is within the guide marks, and out of focus when its image is within the guide marks.
  • FOV field of view
  • a system for reading 2D images comprising a 2D image sensor, an array of LED illumination sources, and an image framing device which uses a VLD for producing a laser beam and a light diffractive optical element for transforming the laser beam into a plurality of beamlets having a beam edge and a beamlet spacing at the 2D image, which is at least as large as the width of the 2D image.
  • a portable imaging assembly comprising a 2D image sensor with a field of view (FOV) and also a set of LEDs and a lens array which .produces a cross-hair type illumination pattern in the FOV for aiming the imaging assembly at a target.
  • FOV field of view
  • a portable imaging assembly comprising a 2D image sensor with a field of view (FOV), and a viewing assembly having a pivoting member which, when positioned a predetermined distance from the operator's eye, provides a view through its opening which corresponds to the target area (FOV) of the imaging assembly, for displaying a visual representation of a dataform (e.g. bar code symbol).
  • FOV field of view
  • a portable imaging and illumination optics assembly having a 2D image sensor with a field of view (FOV), an array of LEDs for illumination, and an aiming or spotting light (LED) indicating the location of the FOV.
  • FOV field of view
  • LED aiming or spotting light
  • a portable imaging device comprising a 2D image sensor with a field of view (FOV), and first and second sets of targeting LEDs and first and second targeting optics, which produces first and second illumination targeting patterns, which substantially coincide to form a single illumination targeting pattern when the imaging device is arranged at a "best focus" position.
  • FOV field of view
  • a portable imaging and illumination optics assembly comprising a 2D image sensor with a field of view (FOV), an array of LEDs for illumination, and an aiming pattern generator including at least a point-like aiming light source and a light diffractive element for producing an aiming pattern that remains approximately coincident with the FOV of the imaging device over the range of the reader-to-target distances over which the reader is used.
  • FOV field of view
  • aiming pattern generator including at least a point-like aiming light source and a light diffractive element for producing an aiming pattern that remains approximately coincident with the FOV of the imaging device over the range of the reader-to-target distances over which the reader is used.
  • Correa et al disclosed an imaging engine comprising a 2D image sensor with a field of view (FOV) and an aiming pattern generator using one or more laser diodes and one or more light diffractive elements to produce multiple aiming frames having different, partially overlapping, solid angle fields or dimensions corresponding to the different fields of view of the lens assembly employed in the imaging engine.
  • the aiming pattern includes a centrally- located marker or cross-hair pattern.
  • Each aiming frame consists of four corner markers, each comprising a plurality of illuminated spots, for example, two multiple spot lines intersecting at an angle of 90 degrees.
  • prior art imaging-based bar code symbol readers generally: (i) fail to enable users to read high-density I D 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 (iii) have not enabled end-users to modify the features and functionalities of such prior art systems without detailed knowledge about the hard-ware platform, communication interfaces and the user interfaces of such systems.
  • control operations in prior art image-processing bar code symbol reading systems have not been sufficiently flexible or agile to adapt to the demanding lighting conditions presented in challenging retail and industrial work environments where 1 D and 2D bar code symbols need to be reliably read.
  • a primary object of the present invention is to provide a novel method of and apparatus for enabling the reading of 1 D 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.
  • Another object of the present invention is to provide a novel hand-supportable digital imaging- based bar code symbol reader capable of automatically reading I D 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.
  • 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.
  • 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.
  • Another object of the present invention is to provide a hand-supportable imaging-based bar code symbol reader capable of reading 1 D 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.
  • 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.
  • 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 I D bar code symbol aligned therewith during a narrow-area image capture mode of the system, and thereafter illuminating randomly-oriented 1 D or 2D bar code symbols on the target object during a wide-area image capture mode of the system.
  • 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 I D bar code symbol aligned therewith, captures an image thereof, and thereafter generates a wide-area illumination beam for illuminating I D or 2D bar code symbols on the object and capturing an image thereof and processing the same to read the bar codes represented therein.
  • 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.
  • Another object of the present invention is to provide such a hand-supportable imaging-based bar code symbol reader employing a CMOS-type image sensing array using global exposure control techniques.
  • Another object of the present invention is to provide such 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.
  • Another object of the present invention is to provide a hand-supportable imaging-based auto- discriminating 1 D/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.
  • 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.
  • 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.
  • Another object of the present invention is to provide a hand-supportable imaging-based bar code symbol reader having 1 D/2D auto-discrimination capabilities.
  • Another object of the present invention is to provide a method of performing auto-discrimination of 1 D/2D bar code symbologies in an imaging-based bar code symbol reader having both narrow-area and wide-area image capture modes of operation.
  • 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.
  • 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.
  • 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 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.
  • 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.
  • Another object of the present invention is to provide a hand-supportable imaging-based bar code symbol reader, 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 the CMOS image sensing array while controlling narrow-band illumination thereto by way of a band-pass optical filter subsystem.
  • Another object of the present Invention is to provide a hand-supportable imaging-based bar code symbol reader 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.
  • 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 x 32768 pixels.
  • 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.
  • 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.
  • PDT portable data terminals
  • Another object of the present invention is to provide a hand-supportable semi-automatic imaging— based bar code reading system wherein an LED-based illumination subsystem automatically illuminates a target object in a narrow-area Field of illumination while a multi-mode image formation and detection (IFD) subsystem captures a narrow-area image of an aligned I D bar code symbol therein, and when manually switched into a wide-area illumination and image capture mode by a trigger switch, the LED- based illumination subsystem illuminates the target object in a wide-area field of illumination, while the multi-mode IFD subsystem captures a wide-area image of randomly-oriented I D or 2D code symbols thereon.
  • IFD image formation and detection
  • Another object of the present invention is to provide a hand-supportable imaging-based bar code symbol reader employing a multi-mode illumination subsystem enabling narrow-area illumination for aiming at a target object and illuminating aligned I D bar code symbols during the narrow-area image capture mode, and wide-area illumination for illuminating randomly-oriented I D and 2D bar code symbols during the wide-area image capture mode.
  • 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 during bar code symbol imaging operations.
  • Another object of the present invention is to provide a hand-supportable imaging-based bar code symbol reader employing a CMOS-type image sensor using global exposure techniques.
  • 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.
  • Another object of the present invention is to provide a hand-supportable imaging-based auto- discriminating I D/2D bar code symbol reader employing a multi-mode image processing bar code symbol reading subsystem having a plurality of modes of operation which are dynamically reconfigurable in response to real-time image analysis.
  • Another object of the present invention is to provide a hand-supportable digital imaging-based bar code reading system wherein, during each imaging cycle, a single frame of pixel data is automatically detected by a CMOS area-type image sensing array when substantially all rows of pixels therein are in a state of integration and have a common integration time, and then pixel data is transmitted from said CMOS area-type image sensing array into a FIFO buffer, and then mapped into memory for subsequent image processing.
  • Another object of the present invention is to provide a hand-supportable digital image-processing based bar code symbol reading system employing an image cropping zone (ICZ) framing and post-image capture cropping process.
  • ICZ image cropping zone
  • Another object of the present invention is to provide hand-supportable digital imaging-based bar code symbol reading system employing a high-precision field of view (FOV) marking subsystem employing automatic image cropping, scaling, and perspective correction.
  • FOV field of view
  • Another object of the present invention is to provide a digital image capture and processing engine employing a high-precision field of view (FOV) marking subsystem employing automatic image cropping, scaling, and perspective correction.
  • FOV field of view
  • Another object of the present invention is to provide a digital image capture and processing engine employing optical waveguide technology for the measuring light intensity within central portion of FOV of the engine for use in automatic illumination control of one or more LED illumination arrays illuminating the field of the view (FOV) of the system.
  • Another object of the present invention is to provide a digital image-processing based bar code symbol reading system that is highly flexible and agile to adapt to the demanding lighting conditions presented in challenging retail and industrial work environments where 1 D and 2D bar code symbols need to be reliably read.
  • Another object of the present invention is to provide a novel method of dynamically and adaptively controlling system control parameters (SCPs) in a multi-mode image capture and processing system, wherein (i) automated real-time exposure quality analysis of captured digital images is automatically performed in a user-transparent manner, and (ii) system control parameters (e.g. illumination and exposure control parameters) are automated reconfigured based on the results of such exposure quality analysis, so as to achieve improved system functionality and/or performance in diverse environments.
  • SCPs system control parameters
  • SCPs system control parameters
  • SCPs include, for example: the shutter mode of the image sensing array employed in the system; the electronic gain of the image sensing array; the programmable exposure time for each block of imaging pixels within the image sensing array; the illumination mode of the system (e.g. ambient/OFF, LED continuous, and LED strobe/flash); automatic illumination control (i.e. ON or OFF); illumination field type (e.g. narrow-area near-field illumination, and wide-area far-field illumination, narrow-area field of illumination, and wide-area field of illumination); image capture mode (e.g. narrow-area image capture mode, wide-area image capture mode); image capture control (e.g. single frame, video frames); and automatic object detection mode of operation (e.g. ON or OFF).
  • illumination mode of the system e.g. ambient/OFF, LED continuous, and LED strobe/flash
  • illumination field type e.g. narrow-area near-field illumination, and wide-area far-field illumination, narrow-area field of illumination, and
  • Another object of the present invention is to provide an image capture and processing system, wherein object illumination and image capturing operations are dynamically controlled by an adaptive control process involving the real-time analysis of the exposure quality of captured digital images and the reconfiguration of system control parameters (SCPs) based on the results of such exposure quality analysis.
  • SCPs system control parameters
  • Another object of the present invention is to provide an image capture and processing engine, wherein object illumination and image capturing operations are dynamically controlled by an adaptive control process involving the real-time analysis of the exposure quality of captured digital images and the reconfiguration of system control parameters (SCPs) based on the results of such exposure quality analysis.
  • SCPs system control parameters
  • Another object of the present invention is to provide an automatic imaging-based bar code symbol reading system, wherein object illumination and image capturing operations are dynamically controlled by an adaptive control process involving the real-time analysis of the exposure quality of captured digital images and the reconfiguration of system control parameters (SCPs) based on the results of such exposure quality analysis.
  • SCPs system control parameters
  • Another object of the present invention is to provide a digital image capture and processing engine which is adapted for POS applications, wherein its illumination/aiming subassembly having a central aperture is mounted adjacent a light transmission (i.e. imaging) window in the engine housing, whereas the remaining subassembly is mounted relative to the bottom of the engine housing so that the optical axis of the camera lens is parallel with respect to the light transmission aperture, and a field of view (FOV) folding mirror is mounted beneath the illumination/aiming subassembly for directing the FOV of the system out through the central aperture formed in the illumination/aiming subassembly.
  • FOV field of view
  • Another object of the present invention is to provide an automatic imaging-based bar code symbol reading system supporting a presentation-type mode of operation using wide-area illumination and video image capture and processing techniques.
  • Another object of the present invention is to provide such an automatic imaging-based bar code symbol reading system, wherein its image-processing based bar code symbol reading subsystem carries out real-time exposure quality analysis of captured digital images in accordance with the adaptive system control method of the present invention.
  • Another object of the present invention is to provide an automatic imaging-based bar code symbol reading system supporting a pass-through mode of operation using narrow-area illumination and video image capture and processing techniques, as well as a presentation-type mode of operation using wide-area illumination and video image capture and processing techniques.
  • Another object of the present invention is to provide such an automatic imaging-based bar code symbol reading system, wherein an automatic light exposure measurement and illumination control subsystem is adapted to measure the light exposure on a central portion of the CMOS image sensing array and control the operation of the LED-based multi-mode illumination subsystem in cooperation with the multi-mode image processing based bar code symbol reading subsystem, carrying out real-time exposure quality analysis of captured digital images in accordance with the adaptive system control method of the present invention.
  • Another object of the present invention is to provide such automatic imaging-based bar code symbol reading system, wherein a narrow-area field of illumination and image capture is oriented in the vertical direction with respect to the counter surface of the POS environment, to support the pass-through mode of the system, and an automatic IR-based object presence and direction detection subsystem which comprises four independent IR-based object presence and direction detection channels.
  • Another object of the present invention is to provide such automatic imaging-based bar code symbol reading system, wherein the automatic IR-based object presence and direction detection subsystem supports four independent IR-based object presence and direction detection channels which automatically generate activation control signals for four orthogonal directions within the FOV of the system, which signals are automatically received and processed by a signal analyzer and control logic block to generate a trigger signal for use by the system controller.
  • Another object of the present invention is to provide a price lookup unit (PLU) system employing a digital image capture and processing subsystem of the present invention identifying bar coded consumer products in retail store environments, and displaying the price thereof on the LCD panel integrated in the system.
  • PLU price lookup unit
  • Fig. I A is a rear perspective view of the hand-supportable digital imaging-based bar code symbol reading device of the first illustrative embodiment of the present invention
  • Fig. 1 B is a front perspective view of the hand-supportable digital imaging-based bar code symbol reading device of the first illustrative embodiment of the present invention
  • Fig. 1C 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;
  • Fig. 1 D 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;
  • Fig. 1 E 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
  • Fig. 2Al 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. IA through I E, 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.
  • 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
  • an Automatic Light Exposure Measurement and Illumination Control Subsystem for controlling the operation of the LED- Based Multi-Mode Illumination Subsystem
  • an Image Capturing and Buffering Subsystem for capturing and buffering 2-D images detected by the Image Formation and Detection Subsystem
  • 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 1 D and 2D bar code symbols represented
  • 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
  • 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. 2M;
  • Fig. 2B is a schematic diagram representative of a system implementation for the hand- supportable digital imaging-based bar code symbol reading device illustrated in Figs. 2A through 2L2, 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 X 1024 7-bit 6 micron pixel size) CMOS image sensor array running at 25Mhz 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 lOOMhz external bus speed, (ii) an expandable (e.g. 7+ megabyte) Intel J3 Asynchronous 16-bit Flash memory, (iii) an 16 Megabytes of 100 MHz SDRAM, (iv) an Xilinx Spartan Il FPGA FIFO 39 running at 50Mhz clock frequency and 60MB/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
  • 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;
  • 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;
  • Fig. 3C is a schematic representation showing the geometrical layout of the optical components used within the hand-supportable digital imaging-based bar code symbol 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 filler 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;
  • Fig. 3 E 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 symbol 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;
  • Fig. 3Fl 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 1280x1024 pixel resolution (1/2" format), 6 micron pixel size, 13.5 Mhz clock rate, with randomly accessible region of interest (ROI) window capabilities);
  • the image sensing array employed therein e.g. a Motorola MCM20027 or National Semiconductor LM9638 CMOS 2-D image sensing array having a 1280x1024 pixel resolution (1/2" format), 6 micron pixel size, 13.5 Mhz clock rate, with randomly accessible region of interest (ROI) window capabilities
  • 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 symbol reading device, shown in relation to the image formation lens assembly, and the image sensing array employed therein;
  • Fig. 4A 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 symbol reading device of the present invention;
  • Fig. 5 A 1 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 symbol 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 symbol reading device,
  • 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 symbol reading device
  • Fig. 5A2 is a 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 symbol 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);
  • Fig. 5 A3 is a 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 symbol 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);
  • Fig. 5A4 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; Fig.
  • 6 A 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 symbol reading device of the present invention;
  • Fig. 6B 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;
  • Figs. 6Cl and 6C2 taken together, 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. 6B employed in the hand-supportable digital imaging-based bar code symbol reading device of the present invention;
  • Fig. 6D 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 symbol 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;
  • Fig. 6El and 6E2 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 symbol reading device of the illustrative embodiments;
  • Fig. 7 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;
  • Fig. 8 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;
  • DMA direct memory access
  • Fig. 9 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;
  • Fig. I O 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 Narrow-Area Illumination Task module, the Metroset Task module, the Application Events Manager module, the User Commands Table module, the Command Handler module, Plug-In Controller, and Plug-In Libraries and Configuration Files, all residing within 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 in operable communication with the Plug-In Controller, the Linux File System module, and Device Drivers modules residing within the Linux Operating System (OS) layer of the software architecture, and in operable communication with an external Development Platform via standard or proprietary communication interfaces;
  • Figs. 1 1 A and 1 1 B provide a table listing the primary Programmable Modes of Bar Code Reading Operation supported within the hand-supportable Digital Imaging-Based Bar Code Symbol Reading Device of the present invention, namely:
  • FIG. 12A is a first perspective view of a second illustrative embodiment of the portable POS digital imaging-based bar code 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;
  • Fig. 12B 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;
  • Fig. 12C 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;
  • Fig. 13 is a perspective view of a third illustrative embodiment of the digital imaging-based bar code 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;
  • PDTs wireless portable data terminals
  • reverse-vending machines retail product information kiosks and the like
  • Fig. 14 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;
  • Fig. 15 is a perspective view of the wireless bar code-driven portable data terminal of Fig. 14 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;
  • Fig. 16 is a side view of the wireless bar code-driven portable data terminal of Figs. 14 and 15 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;
  • POS point of sale
  • Fig. 17 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. 14, 15 and 16, shown interfaced with possible host systems and/or networks;
  • Fig. 18 is a schematic block diagram representative of a system design for the hand-supportable digital imaging-based bar code symbol reading device according to an alternative embodiment of the present invention, wherein the system design is similar to that shown in Fig. 2Al , except that the Automatic Light Exposure Measurement and Illumination Control Subsystem is adapted to measure the light exposure on a central portion of the CMOS image sensing array and control the operation of the LED-Based Multi-Mode Illumination Subsystem in cooperation with a software-based illumination metering program realized within the Multi-Mode Image Processing Based Bar Code Symbol Reading Subsystem, involving the real-time analysis of captured digital images for unacceptable spatial-intensity distributions;
  • Figs. 19A and 19B taken together, set forth a flow chart illustrating the steps involved in carrying out the adaptive method of controlling system operations (e.g. illumination, image capturing, image processing, etc.) within the multi-mode image-processing based bar code symbol reader system of the illustrative embodiment of the present invention, wherein the "exposure quality" of captured digital images is automatically analyzed in real-time and system control parameters (SCPs) are automatically reconfigured based on the results of such exposure quality analysis;
  • system control parameters SCPs
  • Fig. 19C is a schematic representation illustrating the Single Frame Shutter Mode of operation of the CMOS image sensing array employed within the multi-mode image-processing based bar code symbol reader system of the illustrative embodiment of the present invention, while the system is operated in its Global Exposure Mode of Operation illustrated in Figs. 6D through 6E2;
  • Fig. 19D is a schematic representation illustrating the Rolling Shutter Mode of operation of the CMOS image sensing array employed within the multi-mode image-processing based bar code symbol reader system of the illustrative embodiment of the present invention, while the system is operated according to its adaptive control method illustrated in Figs. 19A through 19B;
  • Fig. 19E is a schematic representation illustrating the Video Mode of operation of the CMOS image sensing array employed within the multi-mode image-processing based bar code symbol reader system of the illustrative embodiment of the present invention, while the system is operated according to its adaptive control method illustrated in Figs. 19A through 19B;
  • Fig. 20 is a perspective view of a hand-supportable image-processing based bar code symbol reader employing an image cropping zone (ICZ) targeting/marking pattern, and automatic post-image capture cropping methods to abstract the ICZ within which the targeted object to be imaged has been encompassed during illumination and imaging operations;
  • ICZ image cropping zone
  • Fig. 21 is a schematic system diagram of the hand-supportable image-processing based bar code symbol reader shown in Fig. 20, shown employing an image cropping zone (ICZ) illumination targeting/marking source(s) operated under the control of the System Control Subsystem;
  • ICZ image cropping zone
  • Fig. 22 is a flow chart setting forth the steps involved in carrying out the first illustrative embodiment of the image cropping zone targeting/marking and post-image capture cropping process of the present invention embodied within the bar code symbol reader illustrated in Figs. 20 and 21 ;
  • Fig. 23 is a perspective view of another illustrative embodiment of the hand-supportable image- processing based bar code symbol reader of the present invention, showing its visible illumination-based Image Cropping Pattern (ICP) being projected within the field of view (FOV) of its Multi-Mode Image Formation And Detection Subsystem;
  • ICP visible illumination-based Image Cropping Pattern
  • Fig. 24 is a schematic block diagram representative of a system design for the hand-supportable digital imaging-based bar code symbol reading device illustrated in Fig. 23, 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 substantially 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.
  • an Image Cropping Pattern Generator for generating a visible illumination-based Image Cropping Pattern (ICP) projected within the field of view (FOV) of the Multi-Mode Area-type Image Formation and Detection Subsystem, (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 measuring illumination levels in the FOV and 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) an Image Processing and Cropped Image Locating Module for processing captured and buffered images to locate the image region corresponding to the region defined by the
  • Fig. 25A is a schematic representation of a first illustrative embodiment of the VLD-based Image Cropping Pattern Generator of the present invention, comprising a VLD located at the symmetrical center of the focal plane of a pair of flat-convex lenses arranged before the VLD, and capable of generating and projecting a two (2) dot image cropping pattern (ICP) within the field of view of the of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • ICP dot image cropping pattern
  • Fig. 25B and 25C taken together provide a composite ray-tracing diagram for the first illustrative embodiment of the VLD-based Image Cropping Pattern Generator depicted in Fig. 33 A, showing that the pair of flat-convex lenses focus naturally diverging light rays from the VLD into two substantially parallel beams of laser illumination which to produce a two (2) dot image cropping pattern (ICP) within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem, wherein the distance between the two spots of illumination in the ICP is a function of distance from the pair of lenses;
  • ICP dot image cropping pattern
  • Fig. 25Dl is a simulated image of the two dot Image Cropping Pattern produced by the ICP Generator of Fig. 25 A, at a distance of 40mm from its pair of flat-convex lenses, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 25D2 is a simulated image of the two dot Image Cropping Pattern produced by the ICP Generator of Fig. 33 A, at a distance of 80mm from its pair of flat-convex lenses, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 25D3 is a simulated image of the two dot Image Cropping Pattern produced by the ICP Generator of Fig. 25 A, at a distance of 120mm from its pair of flat-convex lenses, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 5D4 is a simulated image of the two dot Image Cropping Pattern produced by the ICP Generator of Fig. 25A, at a distance of 160mm from its pair of flat-convex lenses, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 25D5 is a simulated image of the two dot Image Cropping Pattern produced by the ICP Generator of Fig. 25A, at a distance of 200mm from its pair of flat-convex lenses, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 26A is a schematic representation of a second illustrative embodiment of the VLD-based Image Cropping Pattern Generator of the present invention, comprising a VLD located at the focus of a biconical lens (having a biconical surface and a cylindrical surface) arranged before the VLD 1 and four flat-convex lenses arranged in four corners, and which optical assembly is capable of generating and projecting a four (4) dot image cropping pattern (ICP) within the field of view of the of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • ICP dot image cropping pattern
  • Fig. 26B and 26C taken together provide a composite ray-tracing diagram for the third illustrative embodiment of the VLD-based Image Cropping Pattern Generator depicted in Fig. 26A, showing that the biconical lens enlarges naturally diverging light rays from the VLD in the cylindrical direction (but not the other) and thereafter, the four flat-convex lenses focus the enlarged laser light beam to generate a four parallel beams of laser illumination which form a four (4) dot image cropping pattern (ICP) within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem, wherein the spacing between the four dots of illumination in the ICP is a function of distance from the flat-convex lens;
  • ICP dot image cropping pattern
  • Fig. 26Dl is a simulated image of the linear Image Cropping Pattern produced by the ICP Generator of Fig. 26A, at a distance of 40mm from its flat-convex lens, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 26D2 is a simulated image of the linear Image Cropping Pattern produced by the ICP Generator of Fig. 26A, at a distance of 80mm from its flat-convex lens, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem
  • Fig. 26D3 is a simulated image of the linear Image Cropping Pattern produced by the ICP Generator of Fig. 26A, at a distance of 120mm from its flat-convex lens, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 26D4 is a simulated image of the linear Image Cropping Pattern produced by the ICP Generator of Fig. 26A, at a distance of 160mm from its flat-convex lens, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 26D5 is a simulated image of the linear Image Cropping Pattern produced by the ICP Generator of Fig. 26A, at a distance of 200mm from its flat-convex lens, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem;
  • Fig. 27 is a schematic representation of a third illustrative embodiment of the VLD-based Image Cropping Pattern Generator of the present invention, comprising a VLD and a light diffractive optical (DOE) element (e.g. volume holographic optical element) forming an optical assembly which is capable of generating and projecting a four (4) dot image cropping pattern (ICP) within the field of view of the of the Multi-Mode Area-type Image Formation and Detection Subsystem, similar to that generated using the refractive optics based device shown in Fig. 26A;
  • DOE light diffractive optical
  • ICP dot image cropping pattern
  • Fig. 28 is a schematic representation of a digital image captured within the field of view (FOV) of the bar code symbol reader illustrated in Figs. 23 and 24, wherein the clusters of pixels indicated by reference characters (a,b,c,d) represent the four illumination spots (i.e. dots) associated with the Image Cropping Pattern (ICP) projected in the FOV;
  • FOV field of view
  • ICP Image Cropping Pattern
  • Fig. 29 is a flow chart setting forth the steps involved in carrying out the second illustrative embodiment of the image cropping pattern targeting/marking and post-image capture cropping process of the present invention embodied in embodied within the bar code symbol reader illustrated in Figs. 23 and 24;
  • Fig. 30 is a perspective view of the digital image capture and processing engine of the present invention, showing the projection of a visible illumination-based Image Cropping Pattern (ICP) within the field of view (FOV) of the engine, during object illumination and image capture operations;
  • ICP visible illumination-based Image Cropping Pattern
  • Fig. 31 A is a close-up, perspective view of the digital image capture and processing engine of the present invention depicted in Fig. 30, showing the assembly of an illumination/targeting optics panel, an illumination board, a lens barrel assembly, a camera housing, and a camera board, into a an ultra-compact form factor offering advantages of light-weight construction, excellent thermal management, and exceptional image capture performance;
  • Fig. 31 B is a perspective view of the digital image capture and processing engine of Fig. 30;
  • Fig. 32 is a side perspective view of the digital image capture and processing engine of Fig. 30, showing how the various components are arranged with respect to each other;
  • Fig. 33 is an elevated front view of the digital image capture and processing engine of Fig. 30, taken along the optical axis of its image formation optics;
  • Fig. 34 is a bottom view of the digital image capture and processing engine of Fig. 30, showing the bottom of its mounting base for use in mounting the engine within diverse host systems;
  • Fig. 35 is a top view of the digital image capture and processing engine of Fig. 30;
  • Fig. 36 is a first side view of the digital image capture and processing engine of Fig. 30;
  • Fig. 37 is a second partially cut-away side view of the digital image capture and processing engine taken in Fig. 36, revealing the light conductive pipe used to collect and conduct light energy from the FOV of the Multi-Mode Area- Type Image Formation and Detection Subsystem, and direct it to the photo-detector associated with the Automatic Light Exposure Measurement and Illumination Control Subsystem;
  • Fig. 38 is a first cross-sectional view of the digital image capture and processing engine taken in Fig. 36, revealing the light conductive pipe used to collect and conduct light energy from the FOV of the Multi-Mode Area-Type Image Formation and Detection Subsystem;
  • Fig. 39A is a perspective view of the light conductive pipe shown in Figs. 36 and 37;
  • Fig. 39B is a first perspective view of the lens barrel assembly used in the digital image capture and processing engine of Fig. 36;
  • Fig. 39C is a first cross-sectional perspective view of the lens barrel assembly used in the digital image capture and processing engine of Fig. 36;
  • Fig. 39D is a second cross-sectional perspective view of the lens barrel assembly used in the digital image capture and processing engine of Fig. 36, showing the optical lens components used to form construct the image formation optics of the engine;
  • Fig. 39E is a first perspective view of one half portion of the lens barrel assembly used in the digital image capture and processing engine of Fig. 36;
  • Fig. 40 is an exploded, perspective view of the digital image capture and processing engine of Fig. 30, showing how the illumination/targeting optics panel, the illumination board, the lens barrel assembly, the camera housing, the camera board and its assembly pins are arranged and assembled with respect to each other in accordance with the principles of the present invention;
  • Fig. 41 is a perspective view of the illumination/targeting optics panel, the illumination board and the camera board of digital image capture and processing engine of Fig. 40, showing completely assembled with the lens barrel assembly and the camera housing removed for clarity of illustration;
  • Fig. 42 is a perspective view of the illumination/targeting optics panel and the illumination board of the engine of the present invention assembled together as a subassembly using the assembly pins;
  • Fig. 43 is a perspective view of the subassembly of Fig. 42 arranged in relation to the lens barrel assembly, the camera housing and the camera board of the engine of the present invention, and showing how these system components are assembled together to produce the digital image capture and processing engine of Fig. 40;
  • Fig. 44 is a schematic block diagram representative of a system design for the digital image capture and processing engine illustrated in Figs. 40 through 43, 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 ( ⁇ ) a wide-area image capture mode in which substantially all rows of the image sensing array are enabled, (2) a LED-Based Illumination Subsystem for producing a wide area field of narrow-band illumination within the FOV of the Image Formation And Detection Subsystem during the image capture mode, so that only light transmitted from the LED-Based 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.
  • an Image Cropping Pattern Generator for generating a visible illumination-based Image Cropping Pattern (ICP) projected within the field of view (FOV) of the Multi- Mode Area-type Image Formation and Detection Subsystem, (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 measuring illumination levels in the FOV and controlling the operation of the LED-Based Multi-Mode Illumination Subsystem, during the image capture mode, (5) an Image Capturing and Buffering Subsystem for capturing and buffering 2-D images detected by the Image Formation and Detection Subsystem, (6) an Image Processing and Cropped Image Locating Module for processing captured and buffered images to locate the image region corresponding to
  • Fig 45 is a perspective view of an alternative illustrative embodiment of the digital image capture and processing engine shown in Figs. 40 through 43, adapted for POS applications and reconfigured so that the illumination/aiming subassembly shown in Fig 42 is mounted adjacent the light transmission window of the engine housing, whereas the remaining subassembly is mounted relative to the bottom of the engine housing so that the optical axis of the camera lens is parallel with the light transmission aperture, and a field of view (FOV) folding mirror is mounted beneath the illumination/aiming subassembly for directing the FOV of the system out through the central aperture formed in the illumination/aiming subassembly;
  • FOV field of view
  • Fig 46 is a schematic block diagram representative of a system design for the digital image capture and processing engine of the present invention shown in Fig 45, wherein the system design is similar to that shown in Fig 2Al , except that the Automatic Light Exposure Measurement and Illumination Control Subsystem is adapted to measure the light exposure on a central portion of the CMOS image sensing array and control the operation of the LED-Based Multi-Mode Illumination Subsystem in cooperation with a software-based illumination metering program realized within the Multi- Mode Image Processing Based Bar Code Symbol Reading Subsystem, involving the real-time exposure quality analysis of captured digital images in accordance with the adaptive system control method of the present invention, illustrated in Figs. 19A through 19E;
  • Fig. 47 A is a perspective view of an automatic imagi ⁇ g-based bar code symbol reading system of the present invention supporting a presentation-type mode of operation using wide-area illumination and video image capture and processing techniques, and employing the general engine design shown in Fig. 45;
  • Fig. 47B is a cross-sectional view of the system shown in Fig. 47 A;
  • Fig. 48 is a schematic block diagram representative of a system design for the digital image capture and processing engine of the present invention shown in Fig. 47 A, wherein the system design is similar to that shown in Fig. 2Al , except that the Automatic Light Exposure Measurement and Illumination Control Subsystem is adapted to measure the light exposure on a central portion of the CMOS image sensing array and control the operation of the LED-Based Multi-Mode Illumination Subsystem in cooperation with a software-based illumination metering program realized within the Multi- Mode Image Processing Based Bar Code Symbol Reading Subsystem, performing the real-time exposure quality analysis of captured digital images in accordance with the adaptive system control method of the present invention, illustrated in Figs. I9A through 19E;
  • Fig. 49A is a perspective view of an automatic imaging-based bar code symbol reading system of the present invention supporting a pass-through mode of operation using narrow-area illumination and video image capture and processing techniques, as well as a presentation-type mode of operation using wide-area illumination and video image capture and processing techniques
  • Fig. 49B is a schematic representation illustrating the system of Fig. 49A operated in its Pass- Through Mode of system operation;
  • Fig. 49C is a schematic representation illustrating the system of Fig. 49A operated in its Presentation Mode of system operation;
  • Fig. 50 is a schematic block diagram representative of a system design for the digital image capture and processing engine of the present invention shown in Figs. 49A and 49B, wherein the system design is similar to that shown in Fig. 2Al , except for the following differences: (1 ) the Automatic Light Exposure Measurement and Illumination Control Subsystem is adapted to measure the light exposure on a central portion of the CMOS image sensing array and control the operation of the LED-Based Multi- Mode Illumination Subsystem in cooperation with the Multi-Mode Image Processing Based Bar Code Symbol Reading Subsystem, carrying out real-time quality analysis of captured digital images in accordance with the adaptive system control method of the present invention, illustrated in Figs.
  • the narrow-area field of illumination and image capture is oriented in the vertical direction with respect to the counter surface of the POS environment, to support the Pass-Through Mode of the system, as illustrated in Fig. 49B; and (3) the ]R-based object presence and range detection system employed in Fig. 46 is replaced with an automatic IR-based object presence and direction detection subsystem which comprises four independent IR-based object presence and direction detection channels;
  • Fig. 51 is a schematic block diagram of the automatic IR-based object presence and direction detection subsystem employed in the bar code reading system illustrated in Figs. 49A and 50, showing four independent IR-based object presence and direction detection channels which automatically generate activation control signals for four orthogonal directions within the FOV of the system, which are received and processed by a signal analyzer and control logic block;
  • Fig. 52A is a perspective view of a first illustrative embodiment of a projection-type POS image- processing based bar code symbol reading system, employing the digital image capture and processing engine showing in Fig. 45;
  • Fig. 52B is a perspective view of a second illustrative embodiment of a projection-type POS image-processing based bar code symbol reading system, employing the digital image capture and processing engine showing in Fig. 45;
  • Fig. 52C is a perspective view of a third illustrative embodiment of a projection-type POS image- processing based bar code symbol reading system, employing the digital image capture and processing engine showing in Fig. 45;
  • Fig. 53 is a perspective view of a price lookup unit (PLU) system employing a digital image capture and processing subsystem of the present invention identifying bar coded consumer products in retail store environments, and displaying the price thereof on the LCD panel integrated in the system.
  • PLU price lookup unit
  • the hand-supportable Digital lmaging-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.
  • 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.
  • an Input/Output Subsystem 18 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.
  • 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 (2OA, 20B), and generate control activation signals Al 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.
  • 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.
  • image formation camera optics 21 for producing a field of view (FOV) 23 upon an object to be imaged
  • CMOS area-image sensing array 22 for detecting imaged light reflected off the object during illumination and image acquisition/capture operations.
  • 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.
  • Fig. 5A4 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.
  • 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 by the three sets of LED-based illumination arrays 27, 28 and 29 driven by LED driver circuitry 30 associated with the Multi-Mode Illumination Subsystem 14, whereas all other components of ambient light collected by the light collection optics are substantially rejected at the image sensing array 22, thereby providing improved SNR thereat, thus improving the performance of the system.
  • the primary function of the Automatic Light Exposure Measurement and Illumination Control Subsystem 15 is to twofold: ( I ) to measure, in real-time, the power density [joules/cm] of photonic energy (i.e. light) collected by the optics of the system at about its image sensing array 22, and generate Auto-Exposure Control Signals indicating the amount of exposure required for good image formation and detection; and (2) in combination with Illumination Array Selection Control Signal provided by the System Control Subsystem 19, automatically drive and control the output power of selected LED arrays 27, 28 and/or 29 in the Multi-Mode Illumination Subsystem, so that objects within the FOV of the system are optimally exposed to LED-based illumination and optimal images are formed and detected at the image sensing array 22.
  • the primary function of the Image Capturing and Buffering Subsystem 16 is to (1 ) detect the entire 2-D image focused onto the 2D image sensing array 22 by the image formation optics 21 of the system, (2) generate a frame of digital pixel data 31 for either a selected region of interest of the captured image frame, or for the entire detected image, and then (3) buffer each frame of image data as it is captured.
  • a single 2D image frame (31) is captured during each image capture and processing cycle, or during a particular stage of a processing cycle, so as to eliminate the problems associated with image frame overwriting, and synchronization of image capture and decoding processes, as addressed in US Patents Nos. 5,932,862 and 5,942,741 assigned to Welch Allyn, and incorporated herein by reference.
  • the primary function of the Multi-Mode Imaging-Based Bar Code Symbol Reading Subsystem 17 is to process images that have been captured and buffered by the Image Capturing and Buffering Subsystem 16, during both narrow-area and wide-area illumination modes of system operation.
  • image processing operation includes image-based bar code decoding methods illustrated in Fig 2A2, and described in detail in Applicants' WIPO International Publication No. WO 2005/050390, incorporated herein by reference in its entirety.
  • the primary function of the Input/Output Subsystem 18 is to support standard and/or proprietary communication interfaces with external host systems and devices, and output processed image data and the like to such external host systems or devices by way of such interfaces. Examples of such interfaces, and technology for implementing the same, are given in US Patent No. 6,619,549, incorporated herein by reference in its entirety.
  • the primary function of the System Control Subsystem 19 is to provide some predetermined degree of control or management signaling services to each subsystem component integrated, as shown. While this subsystem can be implemented by a programmed microprocessor, in the illustrative embodiment, it is implemented by the three-tier software architecture supported on computing platform shown in Fig. 2B, and as represented in Fig. 10, and detailed in WIPO International Publication No. WO 2005/050390, supra.
  • the primary function of the manually-activatable Trigger Switch 2C integrated with the hand- supportable housing is to enable the user to generate a control activation signal upon manually depressing the Trigger Switch 2C, and to provide this control activation signal to the System Control Subsystem 19 for use in carrying out its complex system and subsystem control operations, described in detail herein.
  • the primary function of the System Mode Configuration Parameter Table 70 is to store (in nonvolatile/persistent memory) a set of configuration parameters for each of the available Programmable Modes of System Operation specified in the Programmable Mode of Operation Table shown in Figs. 1 I A and 1 I B, and which can be read and used by the System Control Subsystem 19 as required during its complex operations.
  • Fig. 2B shows a schematic diagram of a system implementation for the hand-supportable Digital Imaging-Based Bar Code Symbol Reading Device 1 illustrated in Figs. I A through I E.
  • the bar code symbol reading device is realized using a number of hardware component comprising: an illumination board 33 carrying components realizing electronic functions performed by the LED-Based Multi-Mode Illumination Subsystem 14 and Automatic Light Exposure Measurement And Illumination Control Subsystem 15; a CMOS camera board 34 carrying high resolution (1280 X 1024 7-bit 6 micron pixel size) CMOS image sensing array 22 running at 25Mhz master clock, at 7 frames/second at 1280* 1024 resolution with randomly accessible region of interest (ROl) window capabilities, realizing electronic functions performed by the Multi-Mode Image Formation and Detection Subsystem 13; a CPU board 35 (i.e.
  • computing platform including (i) an Intel Sabinal 32- Bit Microprocessor PXA210 36 running at 200 mHz 1.0 core voltage with a 16 bit lOOMhz external bus speed, (ii) an expandable (e.g. 7+ megabyte) Intel J3 Asynchronous 16-bit Flash memory 37, (iii) an 16 Megabytes of 100 MHz SDRAM 38, (iv) an Xilinx Spartan II FPGA FIFO 39 running at 50Mhz clock frequency and 60MB/Sec data rate, configured to control the camera timings and drive an image acquisition process, (v) a multimedia card socket 40, for realizing the other subsystems of the system, (vi) a power management module 41 for the MCU adjustable by the I2C bus, and (vii) a pair of UARTs 42 A and 42B (one for an I RDA port and one for a JTAG port); an interface board 43 for realizing the functions performed by the I/O subsystem 18; and an IR-based object presence and range detection circuit 44
  • the image formation optics 21 supported by the bar code reader provides a field of view of 103 mm at the nominal focal distance to the target, of approximately 70 mm from the edge of the bar code reader.
  • the minimal size of the field of view (FOV) is 62 mm at the nominal focal distance to the target of approximately 10 mm.
  • the depth of field of the image formation optics varies from approximately 69 mm for the bar codes with resolution of 5 mils per narrow module, to 181 mm for the bar codes with resolution of 13 mils per narrow module.
  • the Multi-Mode Illumination Subsystem 14 is designed to cover the optical field of view (FOV) 23 of the bar code symbol reader with sufficient illumination to generate high-contrast images of bar codes located at both short and long distances from the imaging window.
  • the illumination subsystem also provides a narrow-area (thin height) targeting beam 24 having dual purposes: (a) to indicate to the user where the optical view of the reader is; and (b) to allow a quick scan of just a few lines of the image and attempt a super-fast bar code decoding if the bar code is aligned properly.
  • the entire field of view is illuminated with a wide- area illumination field 25 or 26 and the image of the entire field of view is acquired by Image Capture and Buffering Subsystem 16 and processed by Multi-Mode Bar Code Symbol Reading Subsystem 17, to ensure reading of a bar code symbol presented therein regardless of its orientation.
  • the interface board 43 employed within the bar code symbol reader provides the hardware communication interfaces for the bar code symbol reader to communicate with the outside world.
  • the interfaces implemented in system will typically include RS232, keyboard wedge, and/or USB, or some combination of the above, as well as others required or demanded by the particular application at hand.
  • the Multi-Mode Image Formation And Detection (IFD) Subsystem 13 has a narrow-area image capture mode (i.e. where only a few central rows of pixels about the center of the image sensing array are enabled) and a wide-area image capture mode of operation (i.e. where all pixels in the image sensing array are enabled).
  • the CMOS image sensing array 22 in the Image Formation and Detection Subsystem 13 has image formation optics 21 which provides the image sensing array with a field of view (FOV) 23 on objects to be illuminated and imaged. As shown, this FOV is illuminated by the Multi-Mode Illumination Subsystem 14 integrated within the bar code reader.
  • FOV field of view
  • the Multi-Mode Illumination Subsystem 14 includes three different LED-based illumination arrays 27, 28 and 29 mounted on the light transmission window panel 5, and arranged about the light transmission window 4A. Each illumination array is designed to illuminate a different portion of the FOV of the bar code reader during different modes of operation. During the narrow-area (linear) illumination mode of the Multi-Mode Illumination Subsystem 14, the central narrow-wide portion of the FOV indicated by 23 is illuminated by the narrow-area illumination array 27, shown in Fig. 3A.
  • the near-field wide-area portion of the FOV is illuminated by the near-field wide-area illumination array 28, shown in Fig. 3A.
  • the far-field wide-area illumination mode of the Multi-Mode Illumination Subsystem 14 which is activated in response to the IR Object Presence and Range Detection Subsystem 12 detecting an object within the far-field portion of the FOV
  • the far-field wide-area portion of the FOV is illuminated by the far-field wide-area illumination array 29, shown in Fig. 3A.
  • the spatial relationships are shown between these fields of narrow-band illumination and the far and near field portions the FOV of the Image Formation and Detection Subsystem 13.
  • the Multi-Mode LED-Based Illumination Subsystem 14 is shown transmitting visible narrow-band illumination through its narrow-band transmission-type optical filter subsystem 4, shown in Fig. 3C and integrated within the hand-supportable Digital Imaging-Based Bar Code Symbol Reading Device.
  • the narrow-band illumination from the Multi-Mode Illumination Subsystem 14 illuminates an object with the FOV of the image formation optics of the Image Formation and Detection Subsystem 13, and light rays reflected and scattered therefrom are transmitted through the high-pass and low-pass optical Filters 4A and 4B and are ultimately focused onto image sensing array 22 to form of a focused detected image thereupon, while all other components of ambient light are substantially rejected before reaching image detection at the image sensing array 22.
  • the red- wavelength reflecting high-pass optical filter element 4A is positioned at the imaging window of the device before the image formation optics 21, whereas the low-pass optical filter element 4B is disposed before the image sensing array 22 between the focusing lens elements of the image formation optics 21.
  • This forms narrow-band optical filter subsystem 4 which is integrated within the bar code reader to ensure that the object within the FOV is imaged at the image sensing array 22 using only spectral components within the narrow-band of illumination produced from Subsystem 14, while rejecting substantially all other components of ambient light outside this narrow range (e.g. 15 nm).
  • these lenses are held together within a lens holding assembly 45, as shown in Fig. 3 E, and form an image formation subsystem arranged along the optical axis of the CMOS image sensing array 22 of the bar code reader.
  • the lens holding assembly 45 comprises: a barrel structure 45Al , 45A2 for holding lens elements 2 I A, 21 B and 21C; and a base structure 45B for holding the image sensing array 22; wherein the assembly is configured so that the barrel structure 45A slides within the base structure 45B so as to focus the fixed-focus lens assembly during manufacture.
  • the lens holding assembly 45 and imaging sensing array 22 are mounted along an optical path defined along the central axis of the system.
  • the image sensing array 22 has, for example, a 1280x1024 pixel resolution (1/2" format), 6 micron pixel size, with randomly accessible region of interest (ROI) window capabilities. It is understood, though, that many others kinds of imaging sensing devices (e.g. CCD) can be used to practice the principles of the present invention disclosed herein, without departing from the scope or spirit of the present invention.
  • the LED-Based Multi-Mode Illumination Subsystem 14 comprises: narrow-area illumination array 27; near-field wide-area illumination array 28; and far-field wide-area illumination array 29.
  • the three fields of narrow-band illumination produced by the three illumination arrays of subsystem 14 are schematically depicted in Fig. 4. As will be described hereinafter, with reference to Figs.
  • narrow-area illumination array 27 can be realized as two independently operable arrays, namely: a near-field narrow-area illumination array and a far-field narrow- area illumination array, which are activated when the target object is detected within the near and far fields, respectively, of the automatic IR-based Object Presence and Range Detection Subsystem 12 during wide-area imaging modes of operation.
  • the first illustrative embodiment of the present invention employs only a single field narrow-area (linear) illumination array which is designed to illuminate over substantially entire working range of the system, as shown in Fig. 4.
  • the narrow-area (linear) illumination array 27 includes two pairs of LED light sources 27Al and 27A2 provided with cylindrical lenses, and mounted on left and right portions of the light transmission window panel 5.
  • the narrow-area (linear) illumination array 27 produces narrow- area illumination field 24 of narrow optical-bandwidth within the FOV of the system.
  • narrow-area illumination field 24 has a height less than 10 mm at far field, creating the appearance of substantially linear or rather planar illumination field.
  • the near-field wide-area illumination array 28 includes two sets of (flattop) LED light sources 28A l and 28 A2 without any lenses mounted on the top and bottom portions of the light transmission window panel 5, as shown in Fig. 1C.
  • the near-field wide-area illumination array 28 produces a near- field wide-area illumination field 25 of narrow optical-bandwidth within the FOV of the system.
  • the far-field wide-area illumination array 29 includes two sets of LED light sources 29Al and 29A2 provided with spherical (i.e. plano-convex) lenses, and mounted on the top and bottom portions of the light transmission window panel 5.
  • the far-field wide-area illumination array 29 produces a far-field wide-area illumination beam of narrow optical-bandwidth within the FOV of the system.
  • the narrow-area (linear) illumination field 24 extends from about 30mm to about 200 mm within the working range of the system, and covers both the near and far fields of the system.
  • the near-field wide-area illumination field 25 extends from about 0 mm to about 100 mm within the working range of the system.
  • the far-field wide-area illumination field 26 extends from about 100 mm to about 200 mm within the working range of the system.
  • the narrow-area illumination array 27 employed in the Multi-Mode LED-Based Illumination Subsystem 14 is optically designed to illuminate a thin area at the center of the field of view (FOV) of the imaging-based bar code symbol reader, measured from the boundary of the left side of the field of view to the boundary of its right side, as specified in Fig.
  • FOV field of view
  • the narrow-area illumination field 24 is automatically generated by the Multi-Mode LED-Based Illumination Subsystem 14 in response to the detection of an object within the object detection field of the automatic IR-based Object Presence and Range Detection Subsystem 12.
  • the object detection field of the I R-based Object Presence and Range Detection Subsystem 12 and the FOV of the Image Formation and Detection Subsystem 13 are spatially co-extensive and the object detection field spatially overlaps the FOV along the entire working distance of the imaging-based bar code symbol reader.
  • the narrow-area illumination field 24, produced in response to the detection of an object, serves a dual purpose: it provides a visual indication to an operator about the location of the optical field of view of the bar code symbol reader, thus, serves as a field of view aiming instrument; and during its image acquisition mode, the narrow-area illumination beam is used to illuminated a thin area of the FOV within which an object resides, and a narrow 2-D image of the object can be rapidly captured (by a small number of rows of pixels in the image sensing array 22), buffered and processed in order to read any linear bar code symbols that may be represented therewithin.
  • the near-field wide-area illumination array 28 employed in the LED-Based Multi-Mode Illumination Subsystem 14 is optically designed to illuminate a wide area over a near-field portion of the field of view (FOV) of the imaging-based bar code symbol reader, as defined in Fig. 4Al .
  • FOV field of view
  • the near-field wide-area illumination field 28 is automatically generated by the LED-based Multi-Mode Illumination Subsystem 14 in response to: ( 1 ) the detection of any object within the near-field of the system by the IR-based Object Presence and Range Detection Subsystem 12; and (2) one or more of following events, including, for example: (i) failure of the image processor to successfully decode process a linear bar code symbol during the narrow-area illumination mode; (ii) detection of code elements such as control words associated with a 2-D bar code symbol; and/or (iii) detection of pixel data in the image which indicates that object was captured in a state of focus.
  • the object detection field of the IR-based Object Presence and Range Detection Subsystem 12 and the FOV of the Image Formation And Detection Subsystem 13 are spatially coextensive and the object detection field spatially overlaps the FOV along the entire working distance of the imaging-based bar code symbol reader.
  • the intensity of the near-field wide-area illumination field during object illumination and image capture operations is determined by how the LEDs associated with the near-field wide array illumination arrays 28 are electrically driven by the Multi-Mode Illumination Subsystem 14.
  • the degree to which the LEDs are driven is determined by the intensity of reflected light measured near the image formation plane by the automatic light exposure and control subsystem 15.
  • the Automatic Light Exposure Measurement and Illumination Control Subsystem 15 will drive the LEDs more intensely (i.e. at higher operating currents).
  • the far-field wide-area illumination array 26 employed in the Multi-Mode LED-based Illumination Subsystem 14 is optically designed to illuminate a wide area over a far-field portion of the field of view (FOV) of the imaging-based bar code symbol reader, as defined in Fig. 4Al .
  • FOV field of view
  • the far-field wide-area illumination field 26 is automatically generated by the LED-Based Multi-Mode Illumination Subsystem 14 in response to: (1) the detection of any object within the near-field of the system by the IR-based Object Presence and Range Detection Subsystem 12; and (2) one or more of following events, including, for example: (i) failure of the image processor to successfully decode process a linear bar code symbol during the narrow-area illumination mode; (ii) detection of code elements such as control words associated with a 2-D bar code symbol; and/or (iii) detection of pixel data in the image which indicates that object was captured in a state of focus.
  • the object detection field of the IR-based Object Presence and Range Detection Subsystem 12 and the FOV 23 of the image detection and formation subsystem 13 are spatially coextensive and the object detection field 20 spatially overlaps the FOV 23 along the entire working distance of the imaging-based bar code symbol reader.
  • the intensity of the far-field wide-area illumination field during object illumination and image capture operations is determined by how the LEDs associated with the far-field wide-area illumination array 29 are electrically driven by the Multi-Mode Illumination Subsystem 14.
  • the degree to which the LEDs are driven is determined by the intensity of reflected light measured near the image formation plane by the Automatic Light Exposure Measurement And Illumination Control Subsystem 15.
  • the Automatic Light Exposure Measurement and Illumination Control Subsystem 15 will drive the LEDs more intensely (i.e. at higher operating currents).
  • the Automatic Light Exposure Measurement and Illumination Control Subsystem i.e. module 15 measures and controls the time duration which the Multi-Mode Illumination Subsystem 14 exposes the image sensing array 22 to narrow-band illumination (e.g. 633 nanometers, with approximately 15 nm bandwidth) during the image capturing/acquisition process, and automatically terminates the generation of such illumination when such computed time duration expires.
  • this global exposure control process ensures that each and every acquired image has good contrast and is not saturated, two conditions essential for consistent and reliable bar code reading
  • the hand-supportable housing of the bar code reader of the present invention has integrated within its housing, narrow-band optical filter subsystem 4 for transmitting substantially only the very narrow band of wavelengths (e.g. 620-700 nanometers) of visible illumination produced from the narrow-band Multi-Mode Illumination Subsystem 14, and rejecting all other optical wavelengths outside this narrow optical band however generated (i.e. ambient light sources).
  • narrow-band optical filter subsystem 4 comprises: red-wavelength reflecting (high-pass) imaging window filter 4 A integrated within its light transmission aperture 3 formed on the front face of the hand- supportable housing; and low pass optica! filter 4B disposed before the CMOS image sensing array 22.
  • optical filters 4A and 4B cooperate to form the narrow-band optical filter subsystem 4 for the purpose described above.
  • the light transmission characteristics (energy versus wavelength) associated with the low-pass optical filter element 4B indicate that optical wavelengths below 620 nanometers are transmitted therethrough, whereas optical wavelengths above 620 nm are substantially blocked (e.g. absorbed or reflected).
  • the light transmission characteristics (energy versus wavelength) associated with the high-pass imaging window filter 4A indicate that optical wavelengths above 700 nanometers are transmitted therethrough, thereby producing a red-color appearance to the user, whereas optical wavelengths below 700 nm are substantially blocked (e.g. absorbed or reflected) by optical filter 4A.
  • spectral band-pass filter subsystem 4 greatly reduces the influence of the ambient light, which falls upon the CMOS image sensing array 22 during the image capturing operations.
  • a optical shutter mechanism is eliminated in the system.
  • the optical filter can reject more than 85% of incident ambient light, and in typical environments, the intensity of LED illumination is significantly more than the ambient light on the CMOS image sensing array 22.
  • the imaging-based bar code reading system of the present invention effectively manages the exposure time of narrow-band illumination onto its CMOS image sensing array 22 by simply controlling the illumination time of its LED-based illumination arrays 27, 28 and 29 using control signals generated by Automatic Light Exposure Measurement and Illumination Control Subsystem 15 and the CMOS image sensing array 22 while controlling illumination thereto by way of the band-pass optical filter subsystem 4 described above.
  • the result is a simple system design, without moving parts, and having a reduced manufacturing cost.
  • band-pass optical filter subsystem 4 is shown comprising a high-pass filter element 4A and low-pass filter element 4B, separated spatially from each other by other optical components along the optical path of the system
  • subsystem 4 may be realized as an integrated multi-layer filter structure installed in front of the image formation and detection (IFD) module 13, or before its image sensing array 22, without the use of the high-pass window filter 4A, or with the use thereof so as to obscure viewing within the imaging-based bar code symbol reader while creating an attractive red-colored protective window.
  • the red-color window filter 4A will have substantially planar surface characteristics to avoid focusing or defocusing of light transmitted therethrough during imaging operations.
  • the primary function of the Automatic Light Exposure Measurement and Illumination Control Subsystem 15 is to control the brightness and contrast of acquired images by (i) measuring light exposure at the image plane of the CMOS imaging sensing array 22 and (ii) controlling the time duration that the Multi-Mode Illumination Subsystem 14 illuminates the target object with narrow-band illumination generated from the activated LED illumination array.
  • the Automatic Light Exposure Measurement and Illumination Control Subsystem 15 eliminates the need for a complex shuttering mechanism for CMOS-based image sensing array 22. This novel mechanism ensures that the imaging-based bar code symbol reader of the present invention generates non-saturated images with enough brightness and contrast to guarantee fast and reliable image-based bar code decoding in demanding end-user applications.
  • the Automatic Light Exposure Measurement and Illumination Control Subsystem 15 measures the amount of light reflected from the target object, calculates the maximum time that the CMOS image sensing array 22 should be kept exposed to the actively-driven LED-based illumination array associated with the Multi-Mode Illumination Subsystem 14, and then automatically deactivates the illumination array when the calculated time to do so expires (i.e. lapses).
  • the Automatic Light Exposure Measurement and Illumination Control Subsystem 15 comprises: a parabolic light-collecting mirror 55 mounted within the head portion of the hand-supportable housing, for collecting narrow-band LED-based light reflected from a central portion of the FOV of the system, which is then transmitted through the narrow-band optical filter subsystem 4 eliminating wide band spectral interference; a light-sensing device (e.g.
  • photo- diode 56 mounted at the focal point of the light collection mirror 55, for detecting the filtered narrowband optical signal focused therein by the light collecting mirror 55; and an electronic circuitry 57 for processing electrical signals produced by the photo-diode 56 indicative of the intensity of detected light exposure levels within the focal plane of the CMOS image sensing array 22.
  • incident narrow-band LED-based illumination is gathered from the center of the FOV of the system by the spherical light collecting mirror 55 and narrow-band filtered by the narrowband optical filter subsystem 4 before being focused upon the photodiode 56 for intensity detection.
  • the photo-diode 56 converts the detected light signal into an electrical signal having an amplitude which directly corresponds to the intensity of the collected light signal.
  • the System Control Subsystem 19 generates an illumination array selection control signal which determines which LED illumination array (i.e. the narrow-area illumination array 27 or the far-field and narrow-field wide-area illumination arrays 28 or 29) will be selectively driven at any instant in time of system operation by LED Array Driver Circuitry 64 in the Automatic Light Exposure Measurement and Illumination Control Subsystem 15.
  • LED Array Driver Circuitry 64 processes the electrical signal from photo-detector 56 and generates an auto exposure control signal for the selected LED illumination array.
  • this auto exposure control signal is provided to the LED array driver circuitry 64, along with an illumination array selection control signal from the System Control Subsystem 19, for selecting and driving (i.e.
  • the illumination array selection control signal is generated by the System Control Subsystem 19 in response to (i) reading the system mode configuration parameters from the system mode configuration parameter table 70, shown in Fig. 2Al , for the programmed mode of system operation at hand, and (ii) detecting the output from the automatic IR- based Object Presence and Range Detection Subsystem 12.
  • LED-based illumination arrays 27, 28 and 29 which can be selected for activation by the System Control Subsystem 19, and the upper and/or lower LED subarrays in illumination arrays 28 and 29 can be selectively activated or deactivated on a subarray-by-subarray basis, for various purposes taught herein, including automatic specular reflection noise reduction during wide-area image capture modes of operation.
  • Each one of these illumination arrays can be driven to different states depending on the auto- exposure control signal generated by electronic signal processing circuit 57, which will be generally a function of object distance, object surface reflectivity and the ambient light conditions sensed at photo- detector 56, and measured by signal processing circuit 57.
  • the operation of signal processing circuitry 57 will now be detailed below.
  • the narrow-band filtered optical signal that is produced by the parabolic light focusing mirror 55 is focused onto the photo-detector Dl 56 which generates an analog electrical signal whose amplitude corresponds to the intensity of the detected optical signal.
  • This analog electrical signal is supplied to the signal processing circuit 57 for various stages of processing.
  • the first step of processing involves converting the analog electrical signal from a current-based signal to a voltage-based signal which is achieved by passing it through a constant-current source buffer circuit 58, realized by one half of transistor Ql (58). This inverted voltage signal is then buffered by the second half of the transistor Ql (58) and is supplied as a first input to a summing junction 59. As shown in Figs.
  • the CMOS image sensing array 22 produces, as output, a digital electronic rolling shutter (ERS) pulse signal 60, wherein the duration of this ERS pulse signal 60 is fixed to a maximum exposure time allowed in the system.
  • the ERS pulse signal 60 is buffered through transistor Q2 61 and forms the other side of the summing junction 59.
  • the outputs from transistors Ql and Q2 form an input to the summing junction 59.
  • a capacitor C5 is provided on the output of the summing junction 59 and provides a minimum integration time sufficient to reduce any voltage overshoot in the signal processing circuit 57.
  • the output signal across the capacitor C5 is further processed by a comparator Ul 62.
  • the comparator reference voltage signal is set to 1.7 volts. This reference voltage signal sets the minimum threshold level for the light exposure measurement circuit 57.
  • the output signal from the comparator 62 is inverted by inverter U3 63 to provide a positive logic pulse signal which is supplied, as auto exposure control signal, to the input of the LED array driver circuit 64.
  • the LED array driver circuit 64 automatically drives an activated LED illuminated array, and the operation of LED array driver circuit 64 depends on the mode of operation in which the Multi-Mode Illumination Subsystem 14 is configured.
  • the mode of operation in which the Multi-Mode Illumination Subsystem 14 is configured at any moment in time will typically depend on (i) the state of operation of the Object Presence and Range Detection Subsystem 12 and (U) the programmed mode of operation in which the entire Imaging-Based Bar Code Symbol Reading System is configured using system mode configuration parameters read from Table 70 shown in Fig. 2Al .
  • the LED array driver circuit 64 comprises analog and digital circuitry which receives two input signals: (i) the auto exposure control signal from signal processing circuit 57; and (ii) the illumination array selection control signal.
  • the LED array driver circuit 64 generates, as output, digital pulse-width modulated (PCM) drive signals provided to either the narrow- area illumination array 27, the upper and/or lower LED sub-array employed in the near-field wide-area illumination array 28, and/or the upper and/or lower LED sub-arrays employed in the far-field wide-area illumination array 29.
  • PCM digital pulse-width modulated
  • the LED array driver circuit 64 will drive one or more of the above- described LED illumination arrays during object illumination and imaging operations.
  • LED illumination array(s) are automatically driven by the LED array driver circuit 64 at an intensity and for duration computed (in an analog manner) by the Automatic Light Exposure and Illumination Control Subsystem 15 so as to capture digital images having good contrast and brightness, independent of the light intensity of the ambient environment and the relative motion of target object with respect to the imaging-based bar code symbol reader.
  • the CMOS image sensing array 22 is operated in its Single Frame Shutter Mode (i.e. rather than its Continuous Frame Shutter Mode) as shown in Fig. 6D, and employs a novel exposure control method which ensure that all rows of pixels in the CMOS image sensing array 22 have a common integration time, thereby capturing high quality images even when the object is in a state of high speed motion.
  • This novel exposure control technique shall be referred to as "the global exposure control method" of the present invention, and the flow chart of Figs. 6El and 6E2 describes clearly and in great detail how this method is implemented in the imaging-based bar code symbol reader of the illustrative embodiment.
  • the global exposure control method will now be described in detail below.
  • Step A in the global exposure control method involves selecting the single frame shutter mode of operation for the CMOS imaging sensing array provided within an imaging-based bar code symbol reading system employing an automatic light exposure measurement and illumination control subsystem, a multi-mode illumination subsystem, and a system control subsystem integrated therewith, and image formation optics providing the CMOS image sensing array with a field of view into a region of space where objects to be imaged are presented.
  • Step B in the global exposure control method involves using the automatic light exposure measurement and illumination control subsystem to continuously collect illumination from a portion of the field of view, detect the intensity of the collected illumination, and generate an electrical analog signal corresponding to the detected intensity, for processing.
  • Step C in the global exposure control method involves activating (e.g. by way of the system control subsystem 19 or directly by way of trigger switch 2C) the CMOS image sensing array so that its rows of pixels begin to integrate photonically generated electrical charge in response to the formation of an image onto the CMOS image sensing array by the image formation optics of the system.
  • Step D in the global exposure control method involves the CMOS image sensing array 22 automatically (i) generating an electronic rolling shutter (ERS) digital pulse signal when all rows of pixels in the image sensing array are operated in a state of integration, and providing this ERS pulse signal to the Automatic Light Exposure Measurement And Illumination Control Subsystem 15 so as to activate light exposure measurement and illumination control functions/operations therewithin.
  • ERS electronic rolling shutter
  • Step E in the global exposure control method involves, upon activation of light exposure measurement and illumination control functions within Subsystem 15, (i) processing the electrical analog signal being continuously generated therewithin, (ii) measuring the light exposure level within a central portion of the field of view 23 (determined by light collecting optics 55 shown in Fig. 6A), and (iii) generating an auto-exposure control signal for controlling the generation of visible field of illumination from at least one LED-based illumination array (27, 28 and/or 29) in the Multi-Mode Illumination Subsystem 14 which is selected by an illumination array selection control signal produced by the System Control Subsystem 19.
  • Step F in the global exposure control method involves using (i) the auto exposure control signal and (ii) the illumination array selection control signal to drive the selected LED-based illumination array(s) and illuminate the field of view of the CMOS image sensing array 22 in whatever image capture mode it may be configured, precisely when all rows of pixels in the CMOS image sensing array are in a state of integration, as illustrated in Fig. 6D, thereby ensuring that all rows of pixels in the CMOS image sensing array have a common integration time.
  • CMOS image sensing array 22 By enabling all rows of pixels in the CMOS image sensing array 22 to have a common integration time, high-speed "global exposure control" is effectively achieved within the imaging-based bar code symbol reader of the present invention, and consequently, high quality images are captured independent of the relative motion between the bar code symbol reader and the target object.
  • IR-wavelength based Automatic Object Presence and Range Detection Subsystem 12 is realized in the form of a compact optics module 76 mounted on the front portion of optics bench 6, as shown in Fig. IC.
  • the object presence and range detection module 12 of the illustrative embodiment comprises a number of subcomponents, namely: an optical bench 77 having an ultra-small footprint for supporting optical and electro-optical components used to implement the subsystem 12; at least one IR laser diode 78 mounted on the optical bench 77, for producing a low power IR laser beam 79; I R beam shaping optics 80, supported on the optical bench for shaping the IR laser beam (e.g.
  • IR light collection/focusing optics 81 supported on the optical bench 77; an amplitude modulation (AM) circuit 82 supported on the optical bench 77, for modulating the amplitude of the IR laser beam produced from the IR laser diode at a frequency / 0 (e.g.
  • optical detector e.g. an avalanche-type IR photo- detector
  • optical detector 83 mounted at the focal point of the IR light collection/focusing optics 81, for receiving the IR optical signal reflected off an object within the object detection field, and converting the received optical signal 84 into an electrical signal 85
  • an amplifier and filter circuit 86 mounted on the optical bench 77, for isolating the / 0 signal component and amplifying it
  • a limiting amplifier 87 mounted on the optical bench, for maintaining a stable signal level
  • phase detector 88 mounted on the optical bench 77, for mixing the reference signal component / o from the AM circuit 82 and the received signal component f 0 reflected from the packages and producing a resulting signal which is equal to a DC voltage proportional to the Cosine of the phase difference between the reference and the reflected / 0 signals
  • an amplifier circuit 89 mounted on the optical bench 77, for amplifying the phase difference signal
  • range analysis circuitry 93 is to analyze the digital range data from the A/D converter 90 and generate two control activation signals, namely: (i) "an object presence detection” type of control activation signal A
  • Automatic Object Presence and Range Detection Subsystem 12 operates as follows. In System Modes of Operation requiring automatic object presence and/or range detection, Automatic Object Presence and Range Detection Subsystem 12 will be activated at system start-up and operational at all times of system operation, typically continuously providing the System Control Subsystem 19 with information about the state of objects within both the far and near portions of the object detection field 20 of the imaging-based symbol reader. In general, this Subsystem detects two basic states of presence and range, and therefore has two basic states of operation.
  • the IR-based automatic Object Presence and Range Detection Subsystem 12 In its first state of operation, automatically detects an object within the near-field region of the FOV 20, and in response thereto generates a first control activation signal which is supplied to the System Control Subsystem 19 to indicate the occurrence of this first fact. In its second state of operation, the IR-based automatic Object Presence and Range Detection Subsystem 12 automatically detects an object within the far-field region of the FOV 20, and in response thereto generates a second control activation signal which is supplied to the System Control Subsystem 19 to indicate the occurrence of this second fact.
  • control activation signals are used by the System Control Subsystem 19 during particular stages of the system control process, such as determining (i) whether to activate either the near-field and/or far-field LED illumination arrays, and (ii) how strongly should these LED illumination arrays be driven to ensure quality image exposure at the CMOS image sensing array 22.
  • the CMOS image sensing array 22 employed in the digital imaging-based bar code symbol reading device hereof is operably connected to its microprocessor 36 through FIFO 39 (realized by way of a FPGA) and system bus shown in Fig. 2M.
  • SDRAM 38 is also operably connected to the microprocessor 36 by way of the system bus, thereby enabling the mapping of pixel data captured by the CMOS image sensing array 22 into the SDRAM 38 under the control of the direct memory access (DMA) module within the microprocessor 36.
  • DMA direct memory access
  • CMOS image sensing array 22 are automatically mapped (i.e. captured and stored) into the addressable memory storage locations of its SDRAM 38 during each image capture cycle carried out within the hand- supportable imaging-based bar code reading device of the present invention.
  • the CMOS image sensing array 22 sends 7- bit gray-scale data bytes over a parallel data connection to FPGA 39 which implements a FIFO using its internal SRAM.
  • the FIFO 39 stores the pixel data temporarily and the microprocessor 36 initiates a DMA transfer from the FIFO (which is mapped to address OXOCOOOOOO, chip select 3) to the SDRAM 38.
  • the DMA module will contain a 32-byte buffer.
  • the DMA module can be programmed to read data from the FIFO 39, store read data bytes in the DMA's buffer, and subsequently write the data to the SDRAM 38.
  • a DMA module can reside in FPGA 39 to directly write the FIFO data into the SDRAM 38. This is done by sending a bus request signal to the microprocessor 36, so that the microprocessor 36 releases control of the bus to the FPGA 39 which then takes over the bus and writes data into the SDRAM 38.
  • pixel data output from the CMOS image sensing array 22 is stored in the SDRAM 38, and how the microprocessor (i.e. implementing a decode algorithm) 36 accesses such stored pixel data bytes.
  • Fig. 9F represents the memory space of the SDRAM 38.
  • a reserved memory space of 1.3 MB is used to store the output of the CMOS image sensing array 22.
  • This memory space is a 1 : 1 mapping of the pixel data from the CMOS image sensing array 22.
  • Each byte represents a pixel in the image sensing array 22.
  • Memory space is a mirror image of the pixel data from the image sensing array 22.
  • the image pixels are sequentially read out of the image sensing array 22. Although one may choose to read and column-wise or row-wise for some CMOS image sensors, without loss of generality, the row-by-row read out of the data is preferred.
  • the pixel image data set is arranged in the SDRAM 38 sequentially, starting at address OXAOEC0000. To randomly access any pixel in the SDRAM 38 is a straightforward matter: the pixel at row y 1/4 column x located is at address (OXAOEC0000+ y x 1280 + x).
  • each image frame always has a frame start signal out of the image sensing array 22, that signal can be used to start the DMA process at address OXAOEC0000, and the address is continuously incremented for the rest of the frame. But the reading of each image frame is started at address OXAOECOOOO to avoid any misalignment of data. Notably, however, if the microprocessor 36 has programmed the CMOS image sensing array 22 to have a ROl window, then the starting address will be modified to (OXAOECOOOO + 1280 X Ri), where R, is the row number of the top left corner of the ROI.
  • the hand-supportable digital imaging-based bar code symbol reading device of the present invention 1 is provided with a three-tier software architecture comprising the following software modules: (1 ) the Main Task module, the CodeGate Task module, the Metroset Task module, the Application Events Manager module, the User Commands Table module, the Command Handler module, the Plug-In Controller (Manager) and Plug-In Libraries and Configuration Files, each residing within the Application layer of the software architecture; (2) 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, each residing within the System Core (SCORE) layer of the software architecture; and (3) the Linux Kernal module, the Linux File System module, and Device Drivers modules, each residing within the Linux Operating System (OS) layer of the software architecture.
  • the Linux Kernal module the Linux File System module, and Device Drivers modules, each residing within the Linux Operating System (OS) layer of the software architecture.
  • the operating system layer of the imaging-based bar code symbol reader is based upon the Linux operating system, it is understood that other operating systems can be used (e.g. Microsoft Windows, Max OXS, Unix, etc), and that the design preferably provides for independence between the main Application Software Layer and the Operating System Layer, and therefore, enables of the Application Software Layer to be potentially transported to other platforms.
  • the system design principles of the present invention provides an extensibility of the system to other future products with extensive usage of the common software components, which should make the design of such products easier, decrease their development time, and ensure their robustness.
  • the above features are achieved through the implementation of an event-driven multi-tasking, potentially multi-user, Application layer running on top of the System Core software layer, called SCORE.
  • the SCORE layer is statically linked with the product Application software, and therefore, runs in the Application Level or layer of the system.
  • the SCORE layer provides a set of services to the Application in such a way that the Application would not need to know the details of the underlying operating system, although all operating system APIs are, of course, available to the application as well.
  • the SCORE software layer provides a real-time, event-driven, OS-independent framework for the product Application to operate.
  • the event-driven architecture is achieved by creating a means for detecting events (usually, but not necessarily, when the hardware interrupts occur) and posting the events to the Application for processing in real-time manner.
  • the event detection and posting is provided by the SCORE software layer.
  • the SCORE layer also provides the product Application with a means for starting and canceling the software tasks, which can be running concurrently, hence, the multitasking nature of the software system of the present invention.
  • the SCORE layer provides a number of services to the Application layer.
  • the Tasks Manager provides a means for executing and canceling specific application tasks (threads) at any time during the product Application run.
  • the Events Dispatcher provides a means for signaling and delivering all kinds of internal and external synchronous and asynchronous events
  • the Events Dispatcher dispatches them to the Application Events Manager, which acts on the events accordingly as required by the Application based on its current state. For example, based on the particular event and current state of the application, the Application Events Manager can decide to start a new task, or stop currently running task, or do something else, or do nothing and completely ignore the event.
  • the Input/Output Manager provides a means for monitoring activities of input / output devices and signaling appropriate events to the Application when such activities are detected.
  • the Input/Output Manager software module 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.
  • the Input/Output Manager is a high-priority thread that runs in parallel with the Application and reacts to the input/output signals coming asynchronously from the hardware devices, such as serial port, user trigger switch 2C, bar code reader, network connections, etc. Based on these signals and optional input/output requests (or lack thereof) from the Application, it generates appropriate system events, which are delivered through the Events Dispatcher to the Application Events Manager as quickly as possible as described above.
  • the User Commands Manager provides a means for managing user commands, and utilizes the User Commands Table provided by the Application, and executes appropriate User Command Handler based on the data entered by the user.
  • the Input/Output Subsystem software module provides a means for creating and deleting input/output connections and communicating with external systems and devices
  • the Timer Subsystem provides a means of creating, deleting, and utilizing all kinds of logical timers.
  • the Memory Control Subsystem provides an interface for managing the multi-level dynamic memory with the device, fully compatible with standard dynamic memory management functions, as well as a means for buffering collected data.
  • the Memory Control Subsystem provides a means for thread- level management of dynamic memory.
  • the interfaces of the Memory Control Subsystem are fully compatible with standard C memory management functions.
  • the system software architecture is designed to provide connectivity of the device to potentially multiple users, which may have different levels of authority to operate with the device.
  • the User Commands Manager which provides a standard way of entering user commands, and executing application modules responsible for handling the same.
  • Each user command described in the User Commands Table is a task that can be launched by the User Commands Manager per user input, but only if the particular user's authority matches the command's level of security.
  • the Events Dispatcher software module 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, or doing something or nothing and simply ignoring the event.
  • the image processing software employed within the system hereof performs its bar code reading function by locating and recognizing the bar codes within the frame of a captured image comprising pixel data.
  • the modular design of the image processing software provides a rich set of image processing functions, which could be utilized in the future for other potential applications, related or not related to bar code symbol reading, such as: optical character recognition (OCR) and verification (OCV); reading and verifying directly marked symbols on various surfaces; facial recognition and other biometrics identification; etc.
  • the CodeGate Task in an infinite loop, performs the following task. It illuminates a "thin" narrow horizontal area at the center of the f ⁇ eld-of-view (FOV) and acquires a digital image of that area. It then attempts to read bar code symbols represented in the captured frame of image data using the image processing software facilities supported by the Image-Processing Bar Code Symbol Reading Subsystem 17 of the present invention to be described in greater detail hereinafter. If a bar code symbol is successfully read, then Subsystem 17 saves the decoded data in the special Decode Data Buffer. Otherwise, it clears the Decode Data Buffer. Then, it continues the loop.
  • the CodeGate Task routine never exits on its own. It can be canceled by other modules in the system when reacting to other events.
  • the event TRIGGER ON is posted to the application.
  • the Application software responsible for processing this event checks if the CodeGate Task is running, and if so, it cancels it and then starts the Main Task.
  • the CodeGate Task can also be canceled upon OBJECT_DETECT_OFF event, posted when the user moves the bar code reader away from the object, or when the user moves the object away from the bar code reader.
  • the CodeGate Task routine is enabled (with Main Task) when "semi-automatic-triggered" system modes of programmed operation (Modes of System Operation Nos. 1 1 - 14 in Figs. 1 IA-I I B) are to be implemented on the illumination and imaging platform of the present invention.
  • the Narrow-Area Illumination Task is a simple routine which is enabled (with Main Task) when "manually-triggered" system modes of programmed operation (Modes of System Operation Nos. 1 -5 in Figs. I I A-1 1 B) are to be implemented on the illumination and imaging platform of the present invention.
  • this routine is never enabled simultaneously with CodeGate Task.
  • Main Task will typically perform differently. For example, when the imaging-based bar code symbol reader is configured in the Programmable Mode of System Operation No. 12 (i.e. Semi-Automatic- Triggered Multiple-Attempt I D/2D Single-Read Mode) to be described in greater detail hereinafter, the Main Task first checks if the Decode Data Buffer contains data decoded by the CodeGate Task. If so, then it immediately sends the data out to the user by executing the Data Output procedure and exits. Otherwise, in a loop, the Main Task does the following: it illuminates an entire area of the field-of-view and acquires a full-frame image of that area. It attempts to read a bar code symbol the captured image.
  • the Decode Data Buffer contains data decoded by the CodeGate Task. If so, then it immediately sends the data out to the user by executing the Data Output procedure and exits. Otherwise, in a loop, the Main Task does the following: it illuminates an entire area of the field-of-view and acquires a full-frame image
  • the Main Task analyzes the decoded data for a "reader programming" command or a sequence of commands. If necessary, it executes the MetroSelect functionality.
  • the Main Task can be canceled by other modules within the system when reacting to other events.
  • the bar code reader of the present invention can be re-configured using standard Metrologic configuration methods, such as MetroSelec® and MetroSet®. The MetroSelect functionality is executed during the Main Task.
  • the MetroSet functionality is executed by the special MetroSet Task.
  • the Focus RS232 software driver detects a special NULL-signal on its communication lines, it posts the METROSET_ON event to the Application.
  • the Application software responsible for processing this event starts the MetroSet task. Once the MetroSet Task is completed, the scanner returns to its normal operation.
  • the function of the Plug-In Controller (i.e. Manager) is to read configuration files and find plug- in libraries within the Plug-In and Configuration File Library, and install plug-ins into the memory of the operating system, which returns back an address to the Plug-In Manager indicating where the plug-in has been installed, for future access.
  • the Plug-In Development Platform support development of plug-ins that enhance, extend and/or modify the features and functionalities of the image-processing based bar code symbol reading system, and once developed, to upload developed plug-ins within the file system of the operating system layer, while storing the addresses of such plug-ins within the Plug-In and Configuration File Library in the Application Layer. Details regarding the development and installation of plug-ins for the computing platform of the present invention are disclosed in Applicant's International Patent Application Mo. PCT/US2006/048148 filed December 18, 2006, and incorporated herein by reference in its entirety.
  • Modes of System Operation Nos. 6-10 can be readily implemented on the illumination and imaging platform of the present invention by making software system modifications, including for example, the addition of an Auto-Read Task routine to the system routine library (wherein Auto-Read Task could be an infinite loop routine where the primary operations of CodeGate Task and Main Task are sequenced together to attempt first automatic narrow-area illumination and image capture and processing, followed by automatic wide-area illumination and image capture and processing, and repeating the wide- area operation in an infinite loop, until the object is no longer detected within a particular predetermined time period.
  • Auto-Read Task could be an infinite loop routine where the primary operations of CodeGate Task and Main Task are sequenced together to attempt first automatic narrow-area illumination and image capture and processing, followed by automatic wide-area illumination and image capture and processing, and repeating the wide- area operation in an infinite loop, until the object is no longer detected within a particular predetermined time period.
  • the Devices Drivers software modules which includes trigger drivers, provide a means for establishing a software connection with the hardware-based manually-actuated trigger switch 2C employed on the imaging-based device, an image acquisition driver for implementing image acquisition functionality aboard the imaging-based device, and an IR driver for implementing object detection functionality aboard the imaging-based device.
  • the Device Drive software modules include: trigger drivers for establishing a software connection with the hardware-based manually-actuated trigger switch 2C employed on the imaging-based bar code symbol reader of the present invention; an image acquisition driver for implementing image acquisition functionality aboard the imaging-based bar code symbol reader; and an IR driver for implementing object detection functionality aboard the imaging-based bar code symbol reader.
  • the Multi-Mode Bar Code Symbol Reading Subsystem 17 employed within the hand-supportable digital imaging-based bar code symbol reading device of the present invention supports bar code symbologies including: Code 128; Code 39; I2of5; Code93; Codabar; UPC/EAN; Telepen; UK-Plessey; Trioptic; Matrix 2of5; Arili ⁇ e 2of5; Straight 2of5; MSI-Plessey; Codel 1 ; and PDF417.
  • the Multi-Mode Image-Processing Based Bar Code Symbol Reading Subsystem 17 of the illustrative embodiment supports five primary modes of operation, namely: the Automatic Mode of Operation; the Manual Mode of Operation; the ROI-Specific Mode of Operation; the No-Finder Mode of Operation; and Omniscan Mode of Operation. As described in detail in WIPO International Publication No. WO 2005/050390, supra, these modes of operation can be used during the lifecycle of the image-processing based bar code reading process of the present invention.
  • the imaging-based bar code symbol reader of the present invention has at least seventeen (17) Programmable System Modes of Operation, namely: Programmed Mode of.System Operation No. 1— Manually-Triggered Single-Attempt ID 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 I D Single-Read Mode Employing the No-Finder Mode of the Multi-Mode Bar Code Reading Subsystem; Programmed Mode Of System Operation No.
  • these Modes Of System Operation can programmed by reading a sequence of bar code symbols from a programming menu as taught, for example, in US Patent No. 6,565,005, which describes a bar code scanner programming technology developed by Metrologic Instruments, Inc., and marketed under the name MetroSelect® Single Line Configuration Programming Method.
  • GUI MetroSet® Graphical User Interface
  • CLI Command Line Interface
  • the hand-supportable image-processing bar code symbol reader of the present invention can be programmed to operate in any one of a number of different "manually-triggered" modes of system operation, as identified in Mos. I through 5. However, during each of these manually-triggered modes of operation, the image-processing bar code symbol reader controls and coordinates its subsystem components in accordance with a generalized method of manually-triggered operation.
  • the IR-based object presence detection subsystem automatically generates an object detection event, and in response thereto, the multi-mode LED-based illumination subsystem automatically produces a narrow- area Field of narrow-band illumination within the FOV of said image formation and detection subsystem.
  • the image capturing and buffering subsystem automatically captures and buffers a narrow-area digital image of the object using the narrow-area field of narrow-band illumination within the FOV, during the narrow-area image capture mode of said multi-mode image formation and detection subsystem;
  • the image processing bar code symbol reading subsystem automatically processes said I D digital image attempts processes the narrow-area digital image in effort to read a I D bar code symbol represented therein, and upon successfully decoding a I D bar code symbol therein, automatically produces symbol character data representative thereof.
  • the multi-mode LED-based illumination subsystem automatically produces a wide-area field of narrow-band illumination within the FOV of the multi-mode image formation and detection subsystem, (ii) the image capturing and buffering subsystem captures and buffers a wide-area digital image during the wide-area image capture mode of the image capturing and buffering subsystem, and
  • the image processing bar code symbol reading subsystem processes the wide-area digital image in effort to read a 1 D or 2D bar code symbol represented therein, and upon successfully decoding a I D or 2D bar code symbol therein, automatically produces symbol character data representative thereof.
  • the imaging-based bar code symbol reading device of the present invention can have virtually any type of form factor that would support the reading of bar code symbols at diverse application environments.
  • One alternative form factor for the bar code symbol reading device of the present invention is shown in Figs. 2OA through 2OC, wherein a portable digital imaging-based bar code symbol reading device of the present invention 1 " is shown from various perspective views, while arranged in a Presentation Mode (i.e. configured in Programmed System Mode No. 12).
  • the digital imaging-based bar code symbol reading device of the present invention I ', I " can also be realized in the form of a Digital Imaging-Based Bar Code Reading Engine 100 that can be readily integrated into various kinds of information collection and processing systems.
  • trigger switch 2C shown in Fig. 13 is symbolically represented on the housing of the engine design, and it is understood that this trigger switch 2C or functionally equivalent device will be typically integrated with the housing of the resultant system into which the engine is embedded so that the user can interact with and actuate the same.
  • Such Engines according to the present invention can be realized in various shapes and sizes and be embedded within various kinds of systems and devices requiring diverse image capture and processing functions as taught herein.
  • Figs. 14, 15, and 16 show a Wireless Bar Code-Driven Portable Data Terminal (PDT) System 140 according to the present invention which comprises: a Bar Code Driven PDT 150 embodying the Digital Imaging-Based Bar Code Symbol Reading Engine of the present invention 100, described herein; and a cradle-providing Base Station 155.
  • PDT Portable Data Terminal
  • the Digital Imaging-Based Bar Code Symbol Reading Engine 100 can be used to read bar code symbols on packages and the symbol character data representative of the read bar code can be automatically transmitted to the cradle-providing Base Station 155 by way of an RF- cnabl ⁇ d 2-way data communication link 170.
  • robust data entry and display capabilities are provided on the PDT 150 to support various information based transactions that can be carried out using System 140 in diverse retail, industrial, educational and other environments.
  • the Wireless Bar Code Driven Portable Data Terminal System 140 comprises: a hand-supportable housing 151 ; Digital Imaging-Based Bar Code Symbol Reading Engine 100 as shown in Fig. 21, and described herein above, mounted within the head portion of the hand- supportable housing 151 ; a user control console 151 A; a high-resolution color LCD display panel 152 and drivers mounted below the user control console 151 A and integrated with the hand-supportable housing, for displaying, in a real-time manner, captured images, data being entered into the system, and graphical user interfaces (GUIs) generated by the end-user application running on the virtual machine of the wireless PDT; and PDT computing subsystem 180 contained within the PDT housing, for carrying out system control operations according to the requirements of the end-user application to be implemented upon the hardware and software platforms of the wireless PDT 2B of this illustrative embodiment.
  • GUIs graphical user interfaces
  • a design model for the Wireless Hand- Supportable Bar Code Driven Portable Data Terminal System 140 shown in Figs. 31 and 32, and its cradle-supporting Base Station 155 interfaced with possible host systems 173 and/or networks 174 comprises a number of subsystems integrated about a system bus, namely: a data transmission circuit 156 for realizing the PDT side of the electromagnetic-based wireless 2-way data communication link 170; program memory (e.g. DRAM) 158; non-volatile memory (e.g.
  • SRAM Serial Bus
  • a battery power supply circuit 164 is provided for supplying regulated power supplies to the various subsystems, at particular voltages determined by the technology used to implement the PDT device.
  • the Base Station 155 also comprises a number of integrated subsystems, namely: a data receiver circuit 165 for realizing the base side of the electromagnetic-based wireless 2-way data communication link 170; a data transmission subsystem 171 including a communication control module; a base station controller 172 (e.g. programmed microcontroller) for controlling the operations of the Base Station 155.
  • the data transmission subsystem 171 interfaces with the host system 173 or network 174 by way of the USB or RS232 communication interfaces, TCP/IP, AppleTalk or the like, well known in the art.
  • data transmission and reception circuits 156 and 165 realize the wireless electromagnetic 2-way digital data communication link 170 employed by the wireless PDT of the present invention.
  • Wireless Hand-Supportable Bar Code Driven Portable Data Terminal System 140 each have two primary modes of operation: (1 ) a hands-on mode of operation, in which the PDT 150 or POS Reader 1 " is removed from its cradle and used as a bar code driven transaction terminal or simply bar code symbol reader; and (2) a hands-free mode of operation, in which the PDT 150 or POS Reader 1 " remains in its cradle-providing Base Station 155, and is used a presentation type bar code symbol reader, as required in most retail point-of-sale (POS) environments.
  • POS point-of-sale
  • the trigger switch 2C employed in the digital imaging-based bar code symbol reading device of the present invention can be readily modified, and augmented with a suitable stand-detection mechanism, which is designed to automatically configure and invoke the PDT 150 and its Engine 100 into its Presentation Mode (i.e. System Mode of Operation No. 12) or other suitable system mode when the PDT is placed in its Base Station 155 as shown in Fig. 24. Then when the PDT 150 is picked up and removed from its cradling supporting Base Station 155 as shown in Figs. 22 and 23, the trigger switch 2C and stand-detection mechanism, arrangement can be arranged so as to automatically configure and invoke the PDT 150 and its Engine 100 into a suitable hands-on supporting mode of system operation to enable hands-on mode of operation.
  • a suitable stand-detection mechanism which is designed to automatically configure and invoke the PDT 150 and its Engine 100 into its Presentation Mode (i.e. System Mode of Operation No. 12) or other suitable system mode when the PDT is placed in its Base Station 155 as shown in
  • the trigger switch 2C employed in the POS Digital Imaging Bar Code Symbol Reading Device 1 " can be readily modified, and augmented with stand-detection mechanism, which is designed to automatically configure and invoke the POS Reader I " into its Presentation Mode (i.e. System Mode of Operation No. 12) or other suitable system mode, when the Reader I " is resting on a countertop surface, as shown in Figs. 12A and I 2B. Then when the POS Reader 1 " is picked up off the countertop surface, for use in its hands-on mode of operation, the trigger switch 2C and stand-detection mechanism, arrangement will automatically configure and invoke Reader 1 " into a suitable hands-on supporting mode of system operation, as shown in Fig. 12C.
  • the stand-detection mechanism can employ a physical contact switch, or IR object sensing switch, which is actuated then the device is picked up off the countertop surface. Such mechanisms will become apparent in view of the teachings disclosed herein.
  • Figs. 6D through 6E2 the Global Exposure Control Method of the present invention was described in connection with the automatic illumination measurement and control subsystem of the present invention. Also, an Enhanced Auto-Illumination Control Scheme was described for use in connection with the automatic illumination measurement and control subsystem of the present invention, wherein software-based illumination metering is employed.
  • Figs. 6D through 6E2 the Global Exposure Control Method of the present invention was described in connection with the automatic illumination measurement and control subsystem of the present invention.
  • an Enhanced Auto-Illumination Control Scheme was described for use in connection with the automatic illumination measurement and control subsystem of the present invention, wherein software-based illumination metering is employed.
  • FIGs. 19A and 19B wherein object illumination and image capturing operations are dynamically controlled within the multi-mode image-processing based bar code symbol reader system of the present invention, by analyzing the exposure quality of captured digital images and reconfiguring system control parameters based on the results of such exposure quality analysis.
  • Figs. 19C through I9E illustrate the three basic modes of operation of the CMOS image sensing array employed in the illustrative embodiment, (i.e. Single Frame Shutter Mode, Rolling Shutter Mode and Video Mode), which are dynamically and automatically controlled within the system in accordance with the adaptive system control method of the present invention.
  • SCP System Control Parameters
  • shutter mode of the image sensing array e.g. Single Frame Shutter Mode illustrated in Fig. 27C, and Rolling Shutter Mode illustrated in Fig. 19D;
  • illumination mode e.g., off, continuous and strobe/flash
  • illumination field type e.g. narrow-area near-field illumination, wide-area far-field illumination, narrow-area field of illumination, and wide-area field of illumination
  • image capture mode e.g. narrow-area image capture, and wide-area image capture
  • image capture control e.g. single frame, video frames
  • STEP 2 Illuminate an object using the method of illumination indicated by the Illumination Mode parameter, and capture a digital image thereof.
  • STEP 3 Analyze the captured digital image for exposure quality.
  • exposure quality is a quantitative measure of the quality of the image brightness.
  • Setting system control parameters such as the type and the intensity of the object illumination, value of the image sensor gain, and the type and the value of the image sensor exposure parameters, will affect the image brightness.
  • the value of the exposure quality can be presented in the range from 0 to 100, with 0 being an extremely poor exposure that would generally be fruitless to process (in cases when the image is too dark or too bright), and 100 being an excellent exposure. It is almost always worthwhile to process an image when the value of the exposure quality is close to 100. Conversely, it is almost never worthwhile to process an image when the value of the exposure quality is as low as 0. As will be explained in greater detail below, for the latter case where the computed exposure quality is as low as 0, the system control parameters (SCPs) will need to be dynamically re-evaluated and set to the proper values in accordance with the principles of the present invention.
  • STEP 4 If the exposure quality measured in STEP 3 does not satisfy the Exposure Quality Threshold (EQT) parameters set in STEP 0, then calculate new SCPs for the system and set the SCPR flag to TRUE indicating that system must be reconfigured prior tb acquiring a digital image during the next image acquisition cycle. Otherwise, maintain the current SCPs for the system.
  • EQT Exposure Quality Threshold
  • STEP 5 If barcode decoding is required in the application at hand, then attempt to process the digital image and decode a barcode symbol represented therein.
  • STEP 8 If necessary, transmit the digital image to the host system, or store the image in internal memory.
  • system control process is intended for practice during any "system mode" of any digital image capture and processing system, including the bar code symbol reader of the illustrative embodiments, with its various modes of system operation described in Figs 1 I A and 1 I B.
  • this control method is generally described in Figs. I 9A and 19B, it is understood that its principles will be used to modify particular system control processes that might be supported in any particular digital image capture and processing system.
  • the salient features of this adaptive control method involve using (i) automated real-time analysis of the exposure quality of captured digital images, and (ii) automated reconfiguring of system control parameters (particularly illumination and exposure control parameters) based on the results of such exposure quality analysis, so as to achieve improved system functionality and/or performance in diverse environments.
  • the system in response to a "trigger event" (automatically or manually generated), the system will be able to automatically generate, (i) a narrow-area field of illumination during the narrow-area image capture mode of the system; and if the system fails to read a bar code symbol reading during this mode, then the system will automatically generate (ii) a wide-area field of illumination during its wide-area image capture mode.
  • a "trigger event” automated or manually generated
  • the system in response to a "trigger event” (automatically or manually generated), the system will be able to automatically generate, (i) a narrow-area field of illumination during the narrow-area image capture mode of the system; and if the system fails to read a bar code symbol reading during this mode, then the system will automatically generate (ii) a wide-area field of illumination during its wide-area image capture mode.
  • the adaptive control method described in Figs. 19A and 19B will now be described below as an illustrative embodiment of the control method. It is understood that there are many ways to practice
  • the system control parameters will be configured to implement the selected Programmed Mode of System Operation.
  • the SCPs For System Mode No. 8, the SCPs would be initially configured as follows:
  • the shutter mode parameter will be set to the "single frame shutter mode"(illustrated in Fig. I 9C, for implementing the Global Illumination/Exposure Method of the present invention described in Figs. 6 D through 6E2);
  • the illumination mode parameter will be set to "flash/strobe"
  • the illumination field type will be set to "narrow-area field"
  • the image capture mode parameter will be set to "narrow-area image capture"
  • the image capture control parameter will be set to "single frame"
  • the image processing mode will be set, for example, to a default value
  • the automatic object detection mode will be set to ON. Also, the SCPR flag will be set to its FALSE value.
  • a trigger signal from the system e.g. generated by automatic object detection by IR object presence and range detection subsystem in System Mode No. 8-10, or by manually pulling the activation switch in System Modes 1 1 -12
  • the system will reconfigure itself only if the SCPR flag is TRUE; otherwise, the system will maintain its current SCPs.
  • the SCPR flag will be false, and therefore the system will maintain its SCPs at their default settings.
  • the object will be illuminated within a narrow-field of LED-based illumination produced by the illumination subsystem, and a narrow-area digital image will be captured by the image formation and detection subsystem.
  • the narrow-area digital image will be analyzed for exposure quality (e.g. brightness level, saturation etc.).
  • the system recalculates new SCPs and sets the SCPR flag to TRUE, indicating that the system must be reconfigured prior to acquiring a digital image during the next image acquisition cycle. Otherwise, the SCPs are maintained by the system.
  • EQT exposure quality threshold
  • the system attempts to read a 1 D bar code symbol in the captured narrow-area image.
  • the system if the system is incapable of reading the bar code symbol (i.e. decoding fails), then the system returns to STEP 1 and reconfigures its SCPs if the SCPR flag is set to TRUE (i.e. indicative of unsatisfactory exposure quality in the captured image). In the case of reconfiguration, the system might reset the SCPs as follows:
  • the illumination field type will be set to "narrow-area field"
  • the image capture mode parameter will be set to "narrow-area image capture"
  • the image capture control parameter will be set to "single frame"
  • the system captures a second narrow-area image using ambient illumination and the image sensing array configured in its rolling shutter mode (illustrated in Fig. 19D), and recalculates Exposure Quality Threshold Parameters and if the exposure quality does not satisfy the current Exposure Quality Threshold Parameters, then the system calculates new SCPs (including switching to the wide-area image capture mode, and possibly) and sets the SCPR flag to TRUE. Otherwise, the system maintains the SCPs, and proceeds to attempt to decode a bar code symbol in the narrow-area digital image captured using ambient illumination.
  • the object is illuminated with ambient illumination and captured at STEP 2, and at STEP 3, the captured image is analyzed for exposure quality, as described above.
  • the exposure quality measured in STEP 3 is compared with the Exposure Quality Threshold parameters, and if it does not satisfy these parameters, then new SCPs are calculated and the SCPR flag is set to TRUE. Otherwise the system maintains the SCPs using current SCPs.
  • bar code decoding is attempted, and if it is successful, then at STEPS 7 and 8, symbol character data and image data are transmitted to the host system, and then the system exits the control process at STEP 9. If bar code decoding fails, then the system returns to STEP 1 to repeat STEPS within Blocks Bl and B2 of Figs.
  • the system control parameters will be configured to implement the selected Programmed Mode of System Operation.
  • the SCPs would be initially configured as follows:
  • the shutter mode parameter will be set to the "Video Mode"(illustrated in Fig. 2E);
  • the illumination field type will be set to "wide-area field"
  • the image capture mode parameter will be set to "wide-area image capture"
  • the image processing mode will be set, for example, to a default value
  • the automatic object detection mode will be set to ON.
  • the SCPR flag will be set to its FALSE value.
  • the system Upon the occurrence of a trigger signal from the system (i.e. generated by automatic object detection by IR object presence and range detection subsystem), the system will reconfigure itself only if the SCPR flag is TRUE; otherwise, the system will maintain its current SCPs.
  • the SCPR flag During the first pass through STEP 1, the SCPR flag will be FALSE, and therefore the system will maintain its SCPs at their default settings.
  • the object will be continuously illuminated within a wide-field of LED-based illumination produced by the illumination subsystem, and a wide-area digital image will be captured by the image formation and detection subsystem, while the CMOS image sensing array is operated in its Video Mode of operation.
  • the wide-area digital image will be analyzed for exposure quality (e.g. brightness level, saturation etc.).
  • exposure quality e.g. brightness level, saturation etc.
  • the system recalculates new SCPs and sets the SCPR flag to TRUE, indicating that the system must be reconfigured prior to acquiring a digital image during the next image acquisition cycle while the CMOS sensing array is operated in its Video Mode. Otherwise, the SCPs are maintained by the system.
  • EQT exposure quality threshold
  • the system attempts to read a 1 D bar code symbol in the captured wide-area digital image.
  • the system if the system is incapable of reading the bar code symbol (i.e. decoding fails), then the system returns to STEP 1 and reconfigures its SCPs if the SCPR flag is set to TRUE (i.e. indicative of unsatisfactory exposure quality in the captured image). In the case of reconfiguration, the system might reset the SCPs as follows:
  • the illumination field type will be set to "wide-area field"
  • the image capture mode parameter will be set to "wide-area image capture"
  • the system captures a second wide-area image using continous LED illumination and the image sensing array configured in its Video Mode (illustrated in Fig. 19E), and recalculates Exposure Quality Threshold Parameters and if the exposure quality does not satisfy the current Exposure Quality Threshold Parameters, then the system calculates new SCPs (including switching to the wide-area image capture mode, and possibly) and sets the SCPR flag to TRUE. Otherwise, the system maintains the SCPs, and proceeds to attempt to decode a bar code symbol in the narrow-area digital image captured using continuous LED illumination.
  • the object is illuminated with ambient illumination and captured at STEP 2, and at STEP 3, the captured image is analyzed for exposure quality, as described above.
  • the exposure quality measured in STEP 3 is compared with the Exposure Quality Threshold parameters, and if it does not satisfy these parameters, then new SCPs are calculated and the SCPR flag is set to TRUE. Otherwise the system maintains the SCPs using current SCPs.
  • bar code decoding is attempted, and if it is successful, then at STEPS 7 and 8, symbol character data and image data are transmitted to the host system, and then the system exits the control process at STEP 9. If bar code decoding fails, then the system returns to STEP I to repeat STEPS within Blocks B l and B2 of Figs.
  • the adaptive control method of the present invention described above can be applied to any of the System Modes of Operation specified in Figs. H A and 1 1 B, as well as to any system modes not specifying specified herein.
  • the particular SCPs that will be set in a given system will depend on the structure of and functionalities supported by the system.
  • the subsystems with the system may have a single or multiple modes of suboperation, depending on the nature of the system design.
  • each system will involve the using (i) automated real-time analysis of the exposure quality of captured digital images and (ii) automated reconfiguring of system control parameters (particularly illumination and exposure control parameters) based on the results of such exposure quality analysis, so as to achieve improved system functionality and/or performance in diverse environments.
  • the hand-held image-processing bar code symbol readers described hereinabove employs a narrow-area illumination beam which provides a visual indication to the user on the vicinity of the narrow-area field of view of the system.
  • a narrow-area illumination beam which provides a visual indication to the user on the vicinity of the narrow-area field of view of the system.
  • Fig. 20 shows a hand-supportable image-processing based bar code symbol reader of the present invention I ' employing an image cropping zone (ICZ) framing pattern, and an automatic post-image capture cropping method involving the projection of the ICZ within the field of view (FOV) of the reader and onto a targeted object to be imaged during object illumination and imaging operations.
  • this hand-supportable image-processing based bar code symbol reader 1 ' is similar to the designs described above in Figs. I B through 1 1 B, except that it includes one or more image cropping zone (ICZ) illumination framing source(s) operated under the control of the System Control Subsystem.
  • ICZ image cropping zone
  • these ICZ framing sources are realized using four relative bright LEDs indicating the corners of the ICZ in the FOV, which will be cropped during post-image capture operations.
  • the ICZ framing source could be a VLD that produces a visible laser diode transmitted through a light diffractive element (e.g. volume transmission hologram) to produce four beamlets indicating the corners of the ICZ, or bright lines that appear in the captured image.
  • the ICZ frame created by such corner points or border lines (formed thereby) can be located using edge-tracing algorithms, and then the corners of the ROI can be identified from the traced border lines.
  • the first step of the method involves projecting an ICZ framing pattern within the FOV of the system during wide-area illumination and image capturing operations.
  • the second step of the method involves the user visually aligning the object to be imaged within the ICZ framing pattern (however it might be realized).
  • the third step of the method involves the Image Formation and Detection Subsystem and the Image Capture and Buffering Subsystem forming and capturing the wide- area image of the entire FOV of the system, which embraces (i.e. spatially encompasses) the ICZ framing pattern aligned about the object to be imaged.
  • the fourth step of the method involves using an automatic software-based image cropping algorithm, implemented within the Image-Processing Bar Code Reading Subsystem, to automatically crop the pixels within the spatial boundaries defined by the ICZ, from those pixels contained in the entire wide-area image frame captured at Block B. Due to the fact that image distortion may exist in the captured image of the ICZ framing pattern, the cropped rectangular image may partially contain the ICZ framing pattern itself and some neighboring pixels that may fall outside the ICZ framing pattern.
  • the fifth step of the method involves the Image-Processing Bar Code Reading Subsystem automatically decode processing the image represented by the cropped image pixels in the ICZ so as to read a 1 D or 2D bar code symbol graphically represented therein.
  • the sixth step of the method involves the Image-Processing Bar Code Reading Subsystem outputting (to the host system) the symbol character data representative of the decoded bar code symbol.
  • Another advantage of using the ICZ framing and post-processing pixel cropping method is that the ICZ framing pattern (however realized) does not have to coincide with the field of view of the Image Formation And Detection Subsystem.
  • the ICZ framing pattern also does not have to have parallel optical axes.
  • the only basic requirement of this method is that the ICZ framing pattern fall within the field of view (FOV) of the Image Formation And Detection Subsystem, along the working distance of the system.
  • FIGs. 23 through 29 another novel method of operation will be described for use in a hand-held digital image-processing bar code symbol reader operating during its wide-area image capture modes of operation.
  • the hand-supportable image-processing based bar code symbol reader 1 " is provided with the capacity to generate and project a visible illumination-based Image Cropping Pattern (ICP) 200 within the field of view (FOV) of the reader.
  • ICP visible illumination-based Image Cropping Pattern
  • the operator will align the visibly projected ICP onto the object (or graphical indicia) to be imaged so that the graphical indicia generally falls within, or is framed by the outer boundaries covered by the ICP.
  • the object to be imaged may be perfectly planar in geometry, or it may have a particular degree of surface curvature.
  • the angle of the object surface may also be inclined with respect to the bar code symbol reader, which may produce "keystone" type effects during the projection process.
  • the operator will then proceed to use the reader to illuminate the object using its multi-mode illumination subsystem 14, and capture an image of the graphical indicia and the ICP aligned therewith using the multi-mode image formation and detection subsystem 13.
  • the image After the image has been captured and buffered within the image capturing and buffering system 16, it is then transferred to the ICP locating/finding module 201 for image processing that locates the features and elements of the ICP and determines therefrom an image region (containing the graphical indicia) to be cropped for subsequent processing.
  • the coordinate/pixel location of the ICP elements relative to each other in the captured image are then analyzed using computational analysis to determine whether or not the captured image has been distorted due to rotation or tilting of the object relative to the bar code reader during image capture operations. If this condition is indicated, then the cropped image will be transferred to the image perspective correction and scaling module 202 for several stages of image processing.
  • the first stage of image processing will typically involve correction of image "perspective", which is where the cropped image requires processing to correct for perspective distortion cause by rotation or tilting of the object during imaging. Perspective distortion is also know as keystone effects.
  • the perspective/tilt corrected image is then cropped. Thereafter, the cropped digital image is processed to scale (i.e.
  • the digital image-processing based bar code symbol reader 1 " shown in Fig. 23 is very similar to the system 1 shown in Figs. I B through 1 I B, with the exception of a few additional subcomponents indicated below.
  • the digital imaging-based bar code symbol reading device depicted in Fig. 31 comprises the following system components: a Multi-Mode Area- Type Image Formation and Detection (i.e. Camera) Subsystem 13 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 22 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 substantially all rows of the image sensing array are enabled; a Multi-Mode LED-Based Illumination Subsystem 14 for producing narrow and wide area fields of narrowband illumination within the FOV of the Image Formation And Detection Subsystem 13 during narrow and wide area modes of image capture, respectively, so that only light transmitted from the Multi-Mode Illumination Subsystem 14 and reflected from the illuminated object and transmitted through
  • an Image Cropping Pattern Generator 203 for generating a visible illumination-based Image Cropping Pattern (ICP) 200 projected within the field of view (FOV) of the Multi-Mode Area-type Image Formation and Detection Subsystem 13; an lR-based object presence and range detection subsystem 12 for producing an IR-based object detection field within the FOV of the Image Formation and Detection Subsystem 13: an Automatic Light Exposure Measurement and Illumination Control Subsystem 15 for measuring illumination levels in the FOV and controlling the operation of the LED-Based Multi-Mode Illumination Subsystem 14; an Image Capturing and Buffering Subsystem for capturing and buffering 2-D images detected by the Image Formation and Detection Subsystem 13; an Image Processing and Cropped Image Locating Module 201 for processing captured and buffered images to locate the image region corresponding to the region
  • FIG. 25A through 26D5 there are many possible ways of realizing the Image Cropping Pattern Generator 203 employed in the system of Fig. 23.
  • FIGs. 25A through 26D5 several refractive-based designs are disclosed for generating an image cropping pattern (ICP) 200, from a single two-dot pattern, to a more complex four dot pattern. While the four dot ICP is a preferred pattern, in some applications, the two dot pattern may be suitable for the requirements at hand where I D bar code. symbols are primarily employed.
  • light diffractive technology e.g.
  • volume holograms can be used in conjunction with a VLD and a light focusing lens to generate an image cropping pattern (ICP) having diverse characteristics. It is appropriate at this juncture to describe these various embodiments for the Image Cropping Pattern Generator of the present invention.
  • a first illustrative embodiment of the VLD-based Image Cropping Pattern Generator 2O3A comprising: a VLD 205 located at the symmetrical center of the focal plane of a pair of flat-convex lenses 206A and 206B arranged before the VLD 205, and capable of generating and projecting a two (2) dot image cropping pattern (ICP) 200 within the field of view of the of the Multi- Mode Area-type Image Formation and Detection Subsystem 13.
  • ICP dot image cropping pattern
  • Figs. 25B and 25C a composite ray- tracing diagram is provided for the VLD-based Image Cropping Pattern Generator depicted in Fig. 25A.
  • the pair of flat-convex lenses 206A and 206B focus naturally diverging light rays from the VLD 205 into two substantially parallel beams of laser illumination which to produce a two (2) dot image cropping pattern (ICP) 200 within the field of view (FOV) of the Multi-Mode Area-type Image Formation and Detection Subsystem.
  • ICP dot image cropping pattern
  • FOV field of view
  • Fig. 25Dl through 25D5 are simulated images of the two dot Image Cropping Pattern produced by the ICP Generator 203A of Fig. 25A, at distances of 40mm, 80mm, 120mm, 160mm and 200mm, respectively, from its pair of flat-convex lenses, within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem.
  • a second illustrative embodiment of the VLD-based Image Cropping Pattern Generator of the present invention 203B comprising: a VLD 206 located at the focus of a biconical lens 207 (having a biconical surface and a cylindrical surface) arranged before the VLD 206, and four flat-convex lenses 2O8A, 208B, 208C and 208D arranged in four corners.
  • This optical assembly is capable of generating and projecting a four (4) dot image cropping pattern (ICP) within the field of view of the of the Multi-Mode Area-type Image Formation and Detection Subsystem.
  • ICP dot image cropping pattern
  • 34B and 34C show a composite ray-tracing diagram for the third illustrative embodiment of the VLD-based Image Cropping Pattern Generator depicted in Fig. 26A.
  • the biconical lens 207 enlarges naturally diverging light rays from the VLD 206 in the cylindrical direction (but not the other) and thereafter, the four flat-convex lenses 208A through 208D focus the enlarged laser light beam to generate a four parallel beams of laser illumination which form a four (4) dot image cropping pattern (ICP) within the field of view of the Multi-Mode Area-type Image Formation and Detection Subsystem.
  • ICP dot image cropping pattern
  • Figs. 26Dl through 26D5 are simulated images of the linear Image Cropping Pattern produced by the ICP Generator of Fig. 34 A, at distance of 40mm, 80mm, 120mm, 160mm and 200mm, respectively, from its flat-convex lens, within the field of view of the Multi-Mode Image Formation and Detection Subsystem 13.
  • Fig. 27 a third illustrative embodiment of the VLD-based Image Cropping Pattern Generator of the present invention 203C is shown comprising: a VLD 210, focusing optics 211, and a light diffractive optical element (DOE) 212 (e.g.
  • DOE light diffractive optical element
  • This optical assembly is capable of generating and projecting a four (4) dot image cropping pattern (ICP) within the field of view of the of the Multi-Mode Area-type Image Formation and Detection Subsystem, similar to that generated using the refractive optics based device shown in Fig. 26A.
  • ICP dot image cropping pattern
  • the bar code symbol reader during wide-area imaging operations, projects an illumination-based Image Cropping Pattern (ICP) 200 within the field of view (FOV) of the system, as schematically illustrated in Fig. 28.
  • ICP illumination-based Image Cropping Pattern
  • the operator aligns an object to be imaged within the projected Image Cropping Pattern (ICP) of the system.
  • ICP projected Image Cropping Pattern
  • the bar code symbol reader captures a wide-area digital image of the entire FOV of the system.
  • the bar code symbol reader uses module 201 to process the captured digital image and locate/find features and elements (e.g. illumination spots) associated with the Image Capture Pattern 200 within the captured digital image.
  • features and elements e.g. illumination spots
  • the clusters of pixels indicated by reference characters (a,b,c,d) represent the four illumination spots (i.e. dots) associated with the Image Cropping Pattern (ICP) projected in the FOV.
  • the coordinates associated with such features and elements of the ICP would be located/found using module 201 during this step of the image processing method of the present invention.
  • the bar code symbol reader uses module 201 to analyze the coordinates of the located image features (a,b,c,d) and determine the geometrical relationships among certain of such features (e.g. if the vertices of the ICP have been distorted during projection and imaging due to tilt angles, rotation of the object, etc), and reconstruct an undistorted image cropping pattern (ICP) independent of the object tilt angle (or perspective) computed therefrom.
  • Module 210 supports real-time computational analysis to analyze the coordinates of the pixel locations of the ICP elements relative to each other in the captured image, and determine whether or not the captured image has been distorted due to rotation or tilting of the object relative to the bar code reader during image capture operations.
  • the digital image will be transferred to the image perspective correction and scaling module 202 for several stages of image processing.
  • the first stage of image processing performed by module 202 will typically involve correction of image "perspective", which is where the cropped image requires processing to correct for perspective distortion cause by rotation or tilting of the object during imaging.
  • Perspective distortion is also known as keystone effects.
  • the bar code symbol reader uses module 202 to crops a set of pixels from the corrected digital image, that corresponds to the ICP projected in the FOV of the system.
  • the bar code symbol reader uses module 202 to carry out a digital zoom algorithm to process the cropped and perspective-corrected ICP region and produce a scaled digital image having a predetermined pixel size independent of object distance.
  • This step involves processing the cropped perspective-corrected image so as to scale (i.e. magnify or minify) the same so that it has a predetermined pixel size (e.g. NxM) optimized for image processing by the image processing based bar code symbol reading module 17.
  • a predetermined pixel size e.g. NxM
  • the bar code symbol reader transmits the scaled perspective- corrected digital image to the decode processing module 17 (and optionally, a visual display).
  • the bar code symbol reader decode-processes the scaled digital image so as to read 1 D or 2D bar code symbols represented therein and generate symbol character data representative of a decoded bar code symbol.
  • the input/output subsystem 18 of the bar code symbol reader outputs the generated symbol character data to a host system.
  • Figs. 30 through 44 it is appropriate at this juncture to describe the digital image capture and processing engine of the present invention 220 employing light-pipe technology 221 for collecting and conducting LED-based illumination in the automatic light exposure measurement and illumination control subsystem 15 during object illumination and image capture modes of operation.
  • the digital image capture and processing engine 220 is shown generating and projecting a visible illumination-based Image Cropping Pattern (ICP) 200 within the field of view (FOV) of the engine, during object illumination and image capture operations, as described in connection with Figs. 23 through 29B.
  • ICP visible illumination-based Image Cropping Pattern
  • the digital image capture and processing engine 220 will be embedded or integrated within a host system 222 which uses the digital output generated from the digital image capture and processing engine 220.
  • the host system 222 can be any system that requires the kind of information that the digital image capture and processing engine 220 can capture and process.
  • camera housing 226 has a pair of integrated engine mounting projections 226A and 226B, each provided with a hole through which a mounting screw can be passed to fix the engine relative to an optical bench or other support structure within the housing of the host system or device.
  • optical waveguide 221 is made from a plastic material having high light transmission characteristics, and low energy absorption characteristics over the optical band of the engine (which is tuned to the spectral characteristics of the LED illumination arrays and band-pass filter employed in the engine design).
  • the function of optical waveguide 221 is to collect and conduct light energy from the FOV of the Multi-Mode Area-Type Image Formation and Detection Subsystem 13, and direct it to the photo-detector 228 mounted on the camera board 227, and associated with the Automatic Light Exposure Measurement and Illumination Control Subsystem 15.
  • the optical waveguide 221 replaces the parabolic light collecting mirror 55 which is employed in the system design shown in Fig. 6A.
  • Use of the optical waveguide 221 in subsystem 15 offers the advantage of ultra-small size and tight integration within the miniature housing of the digital image capture and processing engine.
  • the optical waveguide 221 aligns with the photodiode 228 on the camera board which supports subsystem 15, specified in great detail in Figs. 6B through 6C2.
  • FIG. 40 an exploded, perspective view of the digital image capture and processing engine 220 is provided to show how the illumination/targeting optics panel 23, the illumination board 224, the lens barrel assembly 225, the camera housing 226, the camera board 227, and its assembly pins 23 I A through 23 I D are easily arranged and assembled with respect to each other in accordance with the principles of the present invention.
  • the illumination board 224 of the illustrative embodiment supports four (4) LEDs 238A through 238D, along with driver circuitry, as generally taught in Figs. 6Cl and 6C2.
  • illumination/targeting optics panel 223 supports light focusing lenses 239A through 239D, for the LEDs in the illumination array supported on the illumination board 224.
  • Optical principles and techniques for specifying lenses 239A through 239D are taught in Figs. 4B through 4D7, and corresponding disclosure here.
  • a wide-area near/far field LED illumination array is shown used in the digital image capture and processing engine of the illustrative embodiment 220, it is understood that the illumination array can be readily modified to support separate wide-area near field illumination and wide-area far field illumination, as well as narrow-area far and near fields of illumination, as taught in great detail herein with respect to systems disclosed in Figs. 1 through 39C2.
  • the illumination/targeting optics panel 223, the illumination board 224 and the camera board 230 of digital image capture and processing engine 220 are shown assembled with the lens barrel assembly 225 and the camera housing 226 removed for clarity of illustration.
  • the illumination/targeting optics panel 223 and the illumination board 224 are shown assembled together as a subassembly 232 using the assembly pins.
  • the subassembly 232 of Fig. 42 is arranged in relation to the lens barrel assembly 225, the camera housing 226, the camera board 227 and the image processing board 230, showing how these system components are assembled together to produce the digital image capture and processing engine 220 of Fig. 30.
  • the digital image capture and processing engine 220 illustrated in Figs. 40 through 43 is shown comprising: a Multi-Mode Area- Type Image Formation and Detection (i.e. Camera) Subsystem 14 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 22 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 substantially all rows of the image sensing array are enabled; a LED-Based Illumination Subsystem 14 for producing a wide area field of narrow-band illumination within the FOV of the Image Formation And Detection Subsystem 13 during the image capture mode, so that only light transmitted from the LED-Based Illumination Subsystem 14 and reflected from the illuminated object and transmitted through a narrow-band transmission-type optical filter realized within
  • an Image Cropping Pattern Generator 203 for generating a visible illumination-based Image Cropping Pattern (ICP) 200 projected within the field of view (FOV) of the Multi-Mode Area-type Image Formation and Detection Subsystem 13; an 1R-Based Object Presence And Range Detection Subsystem 12 for producing an IR-based object detection field within the FOV of the Image Formation and Detection Subsystem 13; an Automatic Light Exposure Measurement and Illumination Control Subsystem 14 for measuring illumination levels in the FOV and controlling the operation of the LED-Based Multi-Mode Illumination Subsystem 14 during the image capture mode; an Image Capturing and Buffering Subsystem 16 for capturing and buffering 2-D images detected by the Image Formation and Detection Subsystem 13; an Image Processing and Cropped Image Locating Module 201 for processing captured and buffered
  • a Multimode Image-Processing Based Bar Code Symbol Reading Subsystem 17 for processing cropped and scaled images generated by the Image Perspective and Scaling Module 202 and reading I D and 2D bar code symbols represented; and an Input/Output Subsystem 18 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 a System Control Subsystem 19, as shown.
  • FOV folding mirror 236 can help to achieve a wider FOV beyond the light transmission window, while using a housing having narrower depth dimensions.
  • use of the linear optical waveguide 221 obviates the need for large aperture light collection optics which requires significant space within the housing.
  • FIGs. 45 and 46 an alternative embodiment of the digital image capture and processing engine 220 of the present invention is shown reconfigured in such as way that the illumination/aiming subassembly 232 (depicted in Fig. 42) is detached from the camera housing 226 and mounted adjacent the light transmission window 233 of the engine housing 234.
  • the remaining subassembly, including lens barrel assembly 225, the camera housing 226, the camera board 227 and the image processing board 230 is mounted relative to the bottom of the engine housing 234 so that the optical axis of the camera lens assembly 225 is parallel with the light transmission aperture 233.
  • a curved optical waveguide 221 is used to collect light from a central portion of the field of view of the engine, and guide the collected light to photodiode 228 on the camera board 227.
  • a field of view (FOV) folding mirror 236 is mounted beneath the illumination/aiming subassembly 232 for directing the FOV of the system out through the central aperture 237 formed in the illumination/aiming subassembly 232.
  • FOV folding mirror 236 in this design can help to achieve a wider FOV beyond the light transmission window, while using housing having narrower depth dimensions.
  • use of the curved optical waveguide 221 obviates the need for large aperture light collection optics which requires significant space within the housing.
  • a presentation-type imaging-based bar code symbol reading system 300 is shown constructed using the general components of the digital image capture and processing engine of Figs. 45 and 46, with some modifications.
  • the illumination/aiming subassembly 232' of Fig. 52 is mounted adjacent the light transmission window 233' of the system housing 301.
  • the remaining subassembly, including lens barrel assembly 225', the camera housing 226', the camera board 227' and the image processing board 230, is mounted relative to the bottom of the engine housing 234' so that the optical axis of the camera lens is parallel with the light transmission aperture 233'.
  • a field of view (FOV) folding mirror 236' is mounted beneath the illumination/aiming subassembly 232' for directing the FOV of the system out through the central aperture formed in the illumination/aiming subassembly 232.
  • FOV field of view
  • FIGs. 49A, 49B and 49C through 55C4 there is shown an automatic imaging-based bar code symbol reading system of the present invention 400 supporting a pass-through mode of operation illustrated in Fig. 49C using narrow-area illumination and video image capture and processing techniques, and a presentation-type mode of operation illustrated in Fig. 49C using wide-area illumination and video image capture and processing techniques.
  • the POS-based imaging system 400 employs a digital image capture and processing engine similar in design to that shown in Figs. 47A and 47B and that shown in Fig. 2Al , except for the following differences:
  • the Automatic Light Exposure Measurement and Illumination Control Subsystem 15 is adapted to measure the light exposure on a central portion of the CMOS image sensing array and control the operation of the LED-Based Multi-Mode Illumination Subsystem 14 in cooperation with a the Multi- Mode Image Processing Based Bar Code Symbol Reading Subsystem 17 employing software for performing real-time "exposure quality analysis" of captured digital images in accordance with the adaptive system control method of the present invention, illustrated in Figs. 27A through 27E;
  • the substantially-coplanar narrow-area field of illumination and narrow-area FOV 401 are oriented in the vertical direction (i.e. oriented along Up and Down directions) with respect to the counter surface of the POS environment, so as to support the "pass-through" imaging mode of the system, as illustrated in Fig. 49A;
  • IR-based object presence and range detection system 12 employed in Fig. 47A is replaced with an automatic IR-based object presence and direction detection subsystem 12' comprising four independent IR-based object presence and direction detection channels (i.e. fields) 402 A, 402B, 402C and 402D, generated by IR LED and photodiode pairs 12Al , 12A2, 12A3 and 12A4 respectively, which automatically produce activation control signals Al (t), A2(t), A3(t) and A4(t) upon detecting an object moving through the object presence and direction detection fields, and a signal analyzer and control logic block I 2B' for receiving and processing these activation control signals A l (t), A2(t), A3(t) and A4(t), according to Processing Rules 1 through 5 set forth in Fig.
  • an automatic IR-based object presence and direction detection subsystem 12' comprising four independent IR-based object presence and direction detection channels (i.e. fields) 402 A, 402B, 402C and 402
  • this POS-based imaging system supports the adaptive control process illustrated in Fig. I9A through 19E, and in the illustrative embodiment of the present invention, operates generally according to System Mode No. 17, described hereinabove.
  • the "trigger signal" is generated from the automatic IR-based object presence and direction detection subsystem 12'.
  • the trigger signal can take on one or three possible values, namely: (1 ) that no object has been detected in the FOV of the system; (2) that an object has been detected in the FOV and is being moved therethrough in a "Pass-Through” manner; or that an object has been detected in the FOV and is being moved therethrough in a Presentation" manner (i.e. toward the imaging window).
  • trigger signal (1 ) above is deemed a "negative” trigger signal
  • trigger signals (2) and (3) are deemed “positive" trigger signals.
  • the shutter mode parameter will be set to the "Video Mode” (illustrated in Fig. 2E);
  • the illumination field type will be set to "narrow-area field"
  • the image capture mode parameter will be set to "narrow-area image capture"
  • the image processing mode will be set, for example, to a default value
  • the automatic object detection mode will be set to "ON". Also, the SCPR flag will be set to its FALSE value.
  • the SCPs would be initially configured as follows:
  • the shutter mode parameter will be set to the "Video Mode” (illustrated in Fig. 2E);
  • the illumination field type will be set to "wide-area field"
  • the image capture mode parameter will be set to "wide-area image capture"
  • the image processing mode will be set, for example, to a default value; and (10) the automatic object detection mode will be set to "ON". Also, the SCPR flag will be set to its FALSE value.
  • a "positive" trigger signal from subsystem 12' i.e. that an object has been detected in the FOV and is being moved therethrough in a "Pass-Through” manner, or that an object has been detected in the FOV and is being moved therethrough in a Presentation" manner
  • the system will reconfigure itself only if the SCPR flag is TRUE; otherwise, the system will maintain its current SCPs.
  • the SCPR flag will be FALSE, and therefore the system will maintain its SCPs at their default settings.
  • trigger signal (2) was generated, indicative of Pass-Through object detection and movement.
  • the object will be continuously illuminated within a narrow-field of LED-based illumination produced by the illumination subsystem, and a sequence of narrow-area digital images will be captured by the image formation and detection subsystem and buffered to reconstruct 2D images, while the CMOS image sensing array is operated in its Video Mode of operation.
  • the reconstructed digital image will be analyzed for exposure quality (e.g. brightness level, saturation etc.).
  • exposure quality e.g. brightness level, saturation etc.
  • the system recalculates new SCPs and sets the SCPR flag to TRUE, indicating that the system must be reconfigured prior to acquiring a digital image during the next wide- area image acquisition cycle while the CMOS sensing array is operated in its Video Mode. Otherwise, the SCPs are maintained by the system.
  • EQT exposure quality threshold
  • the system attempts to read a 1 D bar code symbol in the captured reconstructed 2D digital image.
  • the system if the system is incapable of reading the bar code symbol (i.e. decoding fails), then the system returns to STEP I and reconfigures its SCPs if the SCPR flag is set to TRUE (i.e. indicative of unsatisfactory exposure quality in the captured image). In the case of reconfiguration, the system might reset the SCPs as follows:
  • the illumination field type will be set to "narrow-area field"
  • the image capture mode parameter will be set to "narrow-area image capture"
  • the image capture control parameter will be set to "video frame”; (9) the image processing mode will be set to the default value; and
  • the system captures a second 2 D image using continous LED illumination and the image sensing array configured in its Video Mode (illustrated in Fig. 19E), and recalculates Exposure Quality Threshold Parameters and if the exposure quality does not satisfy the current Exposure Quality Threshold Parameters, then the system calculates new SCPs and sets the SCPR flag to TRUE. Otherwise, the system maintains the SCPs, and proceeds to attempt to decode a bar code symbol in the 2D reconstructed digital image captured using continuous LED illumination.
  • the object is illuminated using, for example, ambient illumination and captured at STEP 2, and at STEP 3, the captured/ reconstructed 2 D image is analyzed for exposure quality, as described above.
  • the exposure quality measured in STEP 3 is compared with the Exposure Quality Threshold parameters, and if it does not satisfy these parameters, then new SCPs are calculated and the SCPR flag is set to TRUE. Otherwise the system maintains the SCPs using current SCPs.
  • bar code decoding is attempted, and if it is successful, then at STEPS 7 and 8, symbol character data and image data are transmitted to the host system, and then the system exits the control process at STEP 9.
  • the system returns to STEP 1 to repeat STEPS within Blocks Bl and B2 of Figs. 19A and 19B, provided that the automatic trigger signal (2) is still persistent (indicative that the object is still within the field of view of the digital imager).
  • the system will reconfigure the system as determined by the exposure quality analysis performed at STEP B l , and calculations performed at STEP 4.
  • such calculations could involve calculating new SCPs that require adjusting illumination and/or image sensing array parameters during the narrow-area image capture mode, that is, as the analysis of the facts may require, according to the adaptive control process of the present invention. Recycling this control loop will reoccur as long as a bar code symbol has not been successfully read, and the automatic trigger signal (2) is persistently generated by the IR-based automatic object detecting subsystem 12'.
  • Adaptive System Control During Presentation (Camera ⁇ Mode of Operation
  • trigger signal (3) indicative of Presentation object detection and movement
  • the object will be continuously illuminated within a wide-field of LED-based illumination produced by the illumination subsystem, and a sequence of wide-area (2D) digital images will be captured by the image formation and detection subsystem and buffered, while the CMOS image sensing array is operated in its Video Mode of operation.
  • the reconstructed digital image will be analyzed for exposure quality (e.g. brightness level, saturation etc.).
  • exposure quality e.g. brightness level, saturation etc.
  • the system recalculates new SCPs and sets the SCPR flag to TRUE, indicating that the system must be reconfigured prior to acquiring a digital image during the next wide- area image acquisition cycle while the CMOS sensing array is operated in its Video Mode. Otherwise, the SCPs are maintained by the system.
  • EQT exposure quality threshold
  • the system attempts to read a I D bar code symbol in the captured wide-area digital image.
  • the system if the system is incapable of reading the bar code symbol (i.e. decoding fails), then the system returns to STEP 1 and reconfigures its SCPs if the SCPR flag is set to TRUE (i.e. indicative of unsatisfactory exposure quality in the captured image). In the case of reconfiguration, the system might reset the SCPs as follows:
  • the illumination field type will be set to "wide-area field"
  • the image capture mode parameter will be set to "wide-area image capture"
  • the system captures a second 2D image using continuous LED illumination and the image sensing array configured in its Video Mode (illustrated in Fig. 19E), and recalculates Exposure Quality Threshold Parameters and if the exposure quality does not satisfy the current Exposure Quality Threshold Parameters, then the system calculates new SCPs and sets the SCPR flag to TRUE. Otherwise, the system maintains the SCPs, and proceeds to attempt to decode a bar code symbol in the 2D reconstructed digital image captured using continuous LED illumination.
  • the object is illuminated with ambient illumination and captured at STEP 2, and at STEP 3, the captured wide-area image is analyzed for exposure quality, as described above.
  • the exposure quality measured in STEP 3 is compared with the Exposure Quality Threshold parameters, and if it does not satisfy these parameters, then new SCPs are calculated and the SCPR flag is set to TRUE. Otherwise the system maintains the SCPs using current SCPs.
  • bar code decoding is attempted, and if it is successful, then at STEPS 7 and 8, symbol character data and image data are transmitted to the host system, and then the system exits the control process at STEP 9.
  • a first alternative embodiment of a projection-type POS image-processing based bar code symbol reading system 250 is shown employing the digital image capture and processing engine 220 or 220'.
  • system 250 includes a housing 241 which may contain the engine housing shown in Fig. 45, or alternatively, it may support the subassemblies and components shown in Fig. 45.
  • a second illustrative embodiment of a projection-type POS image-processing based bar code symbol reading system 260 is shown employing the digital image capture and processing engine 220 or 220'.
  • system 260 includes a housing 261 which may contain the engine housing shown in Fig. 45, or alternatively, it may support the subassemblies and components shown in Fig. 55Al .
  • a third illustrative embodiment of a projection-type POS image-processing based bar code symbol reading system 270 employing the digital image capture and processing engin2 220 or 220'.
  • system 270 includes a housing portion 271 (containing engine 220 or 220'), and a base portion 272 for rotatably supporting housing portion 271.
  • Housing portion 271 may contain the engine housing shown in Fig. 45, or alternatively, it may support the subassemblies and components shown in Fig. 45.
  • the number of VLDs mounted on the illumination board 224 can be substantially greater than four (4), as shown in the illustrative embodiment in Fig. 45.
  • the exact number of LEDs used in the illumination will depend on the end-user application requirements at hand.
  • the IR-Based Object Presence And Range Detection Subsystem 12 employed therein may be used to detect the range of an object within the FOV
  • the LED-Based Illumination Subsystem 14 may include both long and short range wide-area LED illumination arrays, as disclosed hereinabove, for optimized illumination of long and short range regions of the FOV during image capture operations.
  • a price lookup unit (PLU) system 280 comprising: a housing 281 with mounting bracket; a LCD panel 282; a computing platform 283 with network interfaces etc, and a digital image capture and processing subsystem 220 or 220' of the present invention, for identifying bar coded consumer products in retail store environments, and displaying the price thereof on the LCD panel 282.
  • PLU price lookup unit
  • any image capture and processing system or device that supports an application software layer and at least an image capture mechanism and an image processing mechanism would be suitable for the practice of the imaging-based code symbol reading system of the present invention.
  • image-capturing cell phones, digital cameras, video cameras, and portable or mobile computing terminals and portable data terminals (PDTs) are all suitable systems in which the present invention can be practiced.
  • the application layer of the image-processing bar code symbol reading system of the present invention can be ported over to execute on conventional mobile computing devices, PDAs, pocket personal computers (PCs), and other portable devices supporting image capture and processing functions, and being provided with suitable user and communication interfaces.
  • Possible hardware computing platforms would include such as Palm®, PocketPC®, MobilePC®, J VM®, etc. equipped with CMOS sensors, trigger switches etc.
  • the 3-tier system software architecture of the present invention can be readily modified by replacing the low-tier Linux OS (described herein) with any operating system (OS), such as Palm, PocketPC, Apple OSX, etc.
  • any universal (mobile) computing device can be transformed into an Image Acquisition and Processing System having the bar code symbol reading functionalities of the system described hereinabove.
  • illumination arrays 27, 28 and 29 employed within the Multi-Mode Illumination Subsystem 14 may be realized using solid-state light sources other than LEDs, such as, for example, visible laser diode (VLDs) taught in great detail in WIPO Publication No. WO 02/43195 A2, published on May 30, 2002, assigned to Metrologic Instruments, Inc., and incorporated herein by reference in its entirety as if set forth fully herein.
  • VLDs visible laser diode
  • WO 02/43195 A2 provides diverse methods of and apparatus for eliminating or substantially reducing speckle-noise during image formation and detection when using VLD-based illumination arrays.
  • the wavelengths of illumination produced therefrom may be outside the visible band and therefore include infrared (IR) wavelengths, or combinations of visible and invisible electromagnetic radiation.
  • CMOS image sensing array technology was described as being used in the preferred embodiments of the present invention, it is understood that in alternative embodiments, CCD-type image sensing array technology, as well as other kinds of image detection technology, can be used.
  • the bar code reader design described in great detail hereinabove can be readily adapted for use as an industrial or commercial fixed-position bar code reader/imager, having the interfaces commonly used in the industrial world, such as Ethernet TCP/IP for instance.
  • Ethernet TCP/IP the interfaces commonly used in the industrial world
  • a number of useful features will be enabled, such as, for example: multi-user access to such bar code reading systems over the Internet; control of multiple bar code reading system on the network from a single user application; efficient use of such bar code reading systems in live video operations; web-servicing of such bar code reading systems, i.e. controlling the system or a network of systems from an Internet Browser; and the like.

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  • Image Processing (AREA)

Abstract

L'invention porte sur un procédé et un appareil de réglage dynamique et adaptatif des paramètres d'un système multimode de capture et de traitement d'images, dans lesquels: (i) l'analyse en temps réel de la qualité d'exposition des images numériques prises se fait automatiquement et de manière transparente pour l'utilisateur, et (ii) les paramètres de commande du système (par exemple de l'eclairage et de l'exposition) sont automatiquement reconfigurés en fonction d'une telle analyse de la qualité d'exposition pour obtenir une fonctionnalité du système et/ou des performances, améliorées, dans différents environnements.
PCT/US2007/009763 2000-11-24 2007-04-20 Procédé et appareil de réglage dynamique et adaptatif des paramètres d'un système numérique de capture et de traitement d'images WO2007124116A2 (fr)

Priority Applications (23)

Application Number Priority Date Filing Date Title
EP07755869.0A EP2038812A4 (fr) 2006-04-20 2007-04-20 Procede et appareil de reglage dynamique et adaptatif des parametres d'un systeme numerique de capture et de traitement d'images
US11/880,087 US8042740B2 (en) 2000-11-24 2007-07-19 Method of reading bar code symbols on objects at a point-of-sale station by passing said objects through a complex of stationary coplanar illumination and imaging planes projected into a 3D imaging volume
US11/900,651 US7954719B2 (en) 2000-11-24 2007-09-12 Tunnel-type digital imaging-based self-checkout system for use in retail point-of-sale environments
US11/977,422 US7731091B2 (en) 2000-11-24 2007-10-24 Digital image capturing and processing system employing automatic object detection and spectral-mixing based illumination techniques
US11/977,413 US7546952B2 (en) 2000-11-24 2007-10-24 Method of illuminating objects during digital image capture operations by mixing visible and invisible spectral illumination energy at point of sale (POS) environments
US11/977,430 US7614560B2 (en) 2000-11-24 2007-10-24 Method of illuminating objects at a point of sale (POS) station by adaptively controlling the spectral composition of the wide-area illumination beam produced from an illumination subsystem within an automatic digital image capture and processing system
US11/977,432 US7878407B2 (en) 2000-11-24 2007-10-24 POS-based digital image capturing and processing system employing automatic object motion detection and spectral-mixing based illumination techniques
US11/978,525 US7575170B2 (en) 2000-11-24 2007-10-29 POS-based digital image capturing and processing system using automatic object detection, spectral-mixing based illumination and linear imaging techniques
US11/978,521 US7661597B2 (en) 2000-11-24 2007-10-29 Coplanar laser illumination and imaging subsystem employing spectral-mixing and despeckling of laser illumination
US11/978,535 US7571858B2 (en) 2000-11-24 2007-10-29 POS-based digital image capturing and processing system using automatic object detection, spectral-mixing based illumination and linear imaging techniques
US11/978,522 US7588188B2 (en) 2000-11-24 2007-10-29 Pos-based digital image capturing and processing system using automatic object detection, spectral-mixing based illumination and linear imaging techniques
US11/978,943 US7665665B2 (en) 2000-11-24 2007-10-30 Digital illumination and imaging subsystem employing despeckling mechanism employing high-frequency modulation of laser diode drive current and optical beam multiplexing techniques
US11/980,319 US8172141B2 (en) 2000-11-24 2007-10-30 Laser beam despeckling devices
US11/980,078 US7806335B2 (en) 2000-11-24 2007-10-30 Digital image capturing and processing system for automatically recognizing objects in a POS environment
US11/978,951 US7775436B2 (en) 2000-11-24 2007-10-30 Method of driving a plurality of visible and invisible LEDs so as to produce an illumination beam having a dynamically managed ratio of visible to invisible (IR) spectral energy/power during object illumination and imaging operations
US11/980,080 US7784698B2 (en) 2000-11-24 2007-10-30 Digital image capturing and processing system for automatically recognizing graphical intelligence graphically represented in digital images of objects
US11/980,192 US7806336B2 (en) 2000-11-24 2007-10-30 Laser beam generation system employing a laser diode and high-frequency modulation circuitry mounted on a flexible circuit
US11/980,317 US7770796B2 (en) 2000-11-24 2007-10-30 Device for producing a laser beam of reduced coherency using high-frequency modulation of the laser diode current and optical multiplexing of the output laser beam
US11/980,083 US7784695B2 (en) 2000-11-24 2007-10-30 Planar laser illumination module (PLIM) employing high-frequency modulation (HFM) of the laser drive currents and optical multplexing of the output laser beams
US11/980,329 US20080249884A1 (en) 2000-11-24 2007-10-30 POS-centric digital imaging system
US11/980,084 US7793841B2 (en) 2000-11-24 2007-10-30 Laser illumination beam generation system employing despeckling of the laser beam using high-frequency modulation of the laser diode current and optical multiplexing of the component laser beams
US11/978,981 US7762465B2 (en) 2000-11-24 2007-10-30 Device for optically multiplexing a laser beam
US12/283,439 US20090134221A1 (en) 2000-11-24 2008-09-11 Tunnel-type digital imaging-based system for use in automated self-checkout and cashier-assisted checkout operations in retail store environments

Applications Claiming Priority (20)

Application Number Priority Date Filing Date Title
US11/408,268 2006-04-20
US11/408,268 US7464877B2 (en) 2003-11-13 2006-04-20 Digital imaging-based bar code symbol reading system employing image cropping pattern generator and automatic cropped image processor
US11/648,759 2006-12-29
US11/648,758 2006-12-29
US11/648,758 US7494063B2 (en) 2003-11-13 2006-12-29 Automatic imaging-based code symbol reading system supporting a multi-tier modular software architecture, automatic illumination control, and video image capture and processing techniques
US11/648,759 US7854384B2 (en) 2003-11-13 2006-12-29 Digital image capture and processing engine employing optical waveguide technology for collecting and guiding LED-based illumination during object illumination and image capture modes of operation
US11/699,746 US7559475B2 (en) 2003-11-13 2007-01-30 Automatic digital-imaging based bar code symbol reading system supporting a pass-through mode of system operation using automatic object direction detection and illumination control, and video image capture and processing techniques
US11/699,761 2007-01-30
US11/699,746 2007-01-30
US11/699,760 2007-01-30
US11/699,761 US7487917B2 (en) 2003-11-13 2007-01-30 Automatic digital-imaging based code symbol reading system supporting pass-through and presentation modes of system operation using automatic object direction detection, narrow-area and wide-area illumination control, and narrow-area and wide-area video image capture and processing techniques
US11/699,760 US7484666B2 (en) 2003-11-13 2007-01-30 Automatic digital-imaging based bar code symbol reading system supporting pass-through and presentation modes of system operation using automatic object direction detection and illumination control, and video image capture and processing techniques
US11/700,400 US7546951B2 (en) 2003-11-13 2007-01-31 Digital image capture and processing system employing real-time analysis of image exposure quality and the reconfiguration of system control parameters based on the results of such exposure quality analysis
US11/700,544 US7543752B2 (en) 2003-11-13 2007-01-31 Digital image capture and processing system employing a multi-mode illumination subsystem adaptable to ambient illumination levels
US11/700,737 US7575167B2 (en) 2003-11-13 2007-01-31 Method of dynamically managing system control parameters in a digital image capture and processing system
US11/700,737 2007-01-31
US11/700,544 2007-01-31
US11/700,543 2007-01-31
US11/700,400 2007-01-31
US11/700,543 US7540425B2 (en) 2003-11-13 2007-01-31 Method of dynamically controlling illumination and image capturing operations in a digital image capture and processing system

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
US11/731,905 Continuation-In-Part US7594608B2 (en) 2000-11-24 2007-03-30 Automatic omnidirectional bar code symbol reading system employing linear-type and area-type bar code symbol reading stations within the system housing
US11/731,866 Continuation-In-Part US7559474B2 (en) 2000-11-24 2007-03-30 Automatic omnidirectional bar code symbol reading system employing linear-type and area-type bar code symbol reading stations within the system housing

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US11/788,769 Continuation-In-Part US7594609B2 (en) 2000-11-24 2007-04-20 Automatic digital video image capture and processing system supporting image-processing based code symbol reading during a pass-through mode of system operation at a retail point of sale (POS) station
US11/880,087 Continuation-In-Part US8042740B2 (en) 2000-11-24 2007-07-19 Method of reading bar code symbols on objects at a point-of-sale station by passing said objects through a complex of stationary coplanar illumination and imaging planes projected into a 3D imaging volume

Publications (2)

Publication Number Publication Date
WO2007124116A2 true WO2007124116A2 (fr) 2007-11-01
WO2007124116A3 WO2007124116A3 (fr) 2008-11-27

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014107431A1 (fr) * 2013-01-07 2014-07-10 Symbol Technologies, Inc. Procédé de décodage de code-barres avec un scanner d'imagerie comprenant une pluralité de capteurs d'objet
CN108924445A (zh) * 2018-08-01 2018-11-30 纳米维景(成都)科技有限公司 基于roi的图像读出电路、图像读出方法及图像探测器
CN111368577A (zh) * 2020-03-28 2020-07-03 吉林农业科技学院 一种图像处理系统
US11372126B2 (en) * 2019-04-04 2022-06-28 The Johns Hopkins University Large volume holographic imaging systems and associated methods
US11531993B2 (en) 2018-09-25 2022-12-20 Capital One Services, Llc Machine learning-driven servicing interface

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6347163B2 (en) * 1994-10-26 2002-02-12 Symbol Technologies, Inc. System for reading two-dimensional images using ambient and/or projected light
US7128266B2 (en) * 2003-11-13 2006-10-31 Metrologic Instruments. Inc. Hand-supportable digital imaging-based bar code symbol reader supporting narrow-area and wide-area modes of illumination and image capture
EP1371010B1 (fr) * 2001-03-08 2008-08-27 Hand Held Products, Inc. Module d'imagerie de lecteur optique

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of EP2038812A4 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014107431A1 (fr) * 2013-01-07 2014-07-10 Symbol Technologies, Inc. Procédé de décodage de code-barres avec un scanner d'imagerie comprenant une pluralité de capteurs d'objet
CN108924445A (zh) * 2018-08-01 2018-11-30 纳米维景(成都)科技有限公司 基于roi的图像读出电路、图像读出方法及图像探测器
US11531993B2 (en) 2018-09-25 2022-12-20 Capital One Services, Llc Machine learning-driven servicing interface
US11715111B2 (en) * 2018-09-25 2023-08-01 Capital One Services, Llc Machine learning-driven servicing interface
US11372126B2 (en) * 2019-04-04 2022-06-28 The Johns Hopkins University Large volume holographic imaging systems and associated methods
CN111368577A (zh) * 2020-03-28 2020-07-03 吉林农业科技学院 一种图像处理系统
CN111368577B (zh) * 2020-03-28 2023-04-07 吉林农业科技学院 一种图像处理系统

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EP2038812A2 (fr) 2009-03-25
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