Device and system for processing image data representing bar codes

• US 7,600,687 B2
• Filed: 05/21/2007
• Issued: 10/13/2009
• Est. Priority Date: 11/05/2004
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Longacre, Andrew Jr., Havens, William H., McCall, Melvin D., Fitch, Timothy R., Robinson, Michael D., Gomez, Garrison, McClaude, Mark A., Sonneville, Eunice, Balschweit, Paul, Biss, Charles E.
• Primary Examiner(s): Lee; Seung H
• Application Number:
  US11/804,990
• Publication Number:
  US 20070278310A1
• Time in Patent Office: 876 Days
• Field of Search: 235/462.25, 235/454, 235/462.01, 235/462.08, 235/462.11, 235/462.12, 235/462.24, 235/462.31, 235/462.46, 235/472.01
• US Class Current: 235/462.25
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G06K 7/089 hand-held scanners
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03

Abstract

A device for processing image data relating to bar codes is described. In one embodiment a bar code verification device is provided having an ergonomic form factor characterized by a domed hand held trigger and a viewing window. The verification device may be disposed in a network that includes a host processor system and other bar code reading devices which may include other bar code verification devices. Processing circuitry for processing image signals corresponding to printed bar codes may be partially disposed within the hand held verification device and partially disposed within a host processor system spaced apart from and associated with the hand held verification device. The hand held verification device may be in wireless communication with the host processor system to which it is associated. The bar code verification system may include signal enhancement modules which interpolate constructed pixel values from actual pixel values and which correct for signal degradation resulting from high frequency spatial sampling.

Claims

1. A device for verification of a bar code disposed on a substrate, said device comprising:

(A) an imaging assembly including a solid state image sensor;

(B) a hand held housing encapsulating a component of said imaging assembly, said hand held housing defining a front surface, a rear surface and side surfaces of said device, wherein walls of said hand held housing extend upward from said substrate when said device is positioned in a position to measure print quality of said bar code;

(C) an illumination assembly at least partially disposed in said housing projecting an illumination pattern onto said substrate;

(D) a window disposed at a front surface of said device, said window being light transmissive to enable an operator to view said bar code when said device is positioned in a position over said bar code;

(E) a trigger disposed on said device, wherein said housing and said trigger are configured in a complementary manner so that an operator grasping said device in a grasping position can actuate said trigger with a digit of a hand that is grasping said device without releasing said device from said hand;

(F) an image capture module incorporated in said device;

(G) a bar code decoding module further incorporated in said device;

(H) a bar code print quality measurement module incorporated in said device;

(I) an interpolation module disposed in said device; and

(J) a high spatial frequency correction module incorporated in said device;

wherein said device is configured so that when said trigger is actuated, said device automatically executes said image capture module, said bar code decoding module and said bar code print quality measurement module, wherein said device when executing said image capture module captures a frame of image data corresponding to said bar code symbol, wherein said device when executing said bar code decoding module processes a frame of image data to determine a decoded out message, and wherein said device when executing said print quality measurement module determines at least one of a print contrast measurement, an edge contrast measurement and a modulation measurement of said bar code symbol; and

wherein said device is further configured so that when said trigger is activated, said reader automatically executes each of said interpolation module and said high spatial frequency error correction module.

2. The device of claim 1, wherein said device is configured so that when said device executes said image capture module, said device automatically compensates captured image data for fixed pattern noise attributable to illumination pattern nonuniformalities.

3. The device of claim 1, wherein said device is configured to operate in a user-selectable calibration mode of operation, wherein said device when operating in said user-selectable calibration mode captures a test frame of image data in such manner that said test frame represents nonuniformalities of said projected illumination pattern projected by said illumination assembly.

4. The device of claim 1, wherein said side surfaces of said housing define contoured side grasping formations, said side grasping formations accommodating an operator'"'"'s hand so that an operator stabilizes said housing on a said substrate by grasping said side grasping formations.

5. The device of claim 1, wherein an upper portion of said housing includes a lip extending outwardly from a major body of said housing, said lip including a surface adapted to engage a digit of a hand of an operator that grasps said device when said operator lifts said device upwardly.

6. A portable data collection device for use in decoding and measuring print quality of a bar code symbol disposed on a substrate, said portable data collection device comprising:

an imaging assembly including a solid state image sensor and an imaging lens focusing an image onto an active surface of said solid state image sensor, said solid state image sensor being selected from the group consisting of;

a one dimensional image sensor having at least one row of photosensitive picture elements and a two dimensional image sensor having a plurality of rows and a plurality of columns of photosensitive picture elements, said sensor configured to output a scan reflectance waveform representative of said bar code symbol;

a hand held housing encapsulating a component of said imaging assembly, said hand held housing defining a front surface, a rear surface, and side surfaces of said device, wherein walls of said hand held housing extend upward from said substrate when said device is positioned in a position to measure print quality of said bar code;

a trigger button disposed on said housing;

a display disposed on said housing;

an image capture module configured to capture at least one frame of image data corresponding to a bar code symbol;

a bar code decoding module configured to process said at least one frame of image data to determine a decoded out message; and

a bar code quality measurement module configured to determine at least one of;

a value of contrast of said bar code symbol, a value of edge contrast of said bar code symbol, a value of modulation of said bar code symbol;

wherein said data collection device is configured, responsive to detecting that said trigger has been actuated, to automatically execute said image capture module, said bar code decoding module, and said bar code print quality measurement module.

7. The data collection device of claim 6, wherein said display is configured to display a scan reflectance profile representative of said scan reflectance waveform.

8. The data collection device of claim 6, further comprising at least one radio frequency transceiver configured to facilitate data communications of said data collection device in a network composed by said portable data collection device, at least one host computer, and zero or more peer data collection devices.

9. The data collection device of claim 6, wherein said bar code quality measurement module is configured to determine said value of contrast of said bar code symbol by determining a difference between a highest peak of said scan reflectance waveform and a lowest peak of said scan reflectance waveform.

10. The data collection device of claim 6, wherein said bar code quality measurement module is configured to determine said value of edge contrast of said bar code symbol by determining a smallest difference between a pair of peaks of said scan reflectance waveform.

11. The data collection device of claim 6, wherein said bar code quality measurement module is configured to determine said value of modulation of said bar code symbol by determining a ratio of a difference between a highest peak of said scan reflectance waveform and a lowest peak of said scan reflectance waveform to a smallest difference between a pair of peaks of said scan reflectance waveform.