Bar code reading apparatus having one-dimensional image sensor and digital digitizer

• US 7,077,317 B2
• Filed: 12/23/2002
• Issued: 07/18/2006
• Est. Priority Date: 09/03/1996
• Status: Expired due to Fees

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Longacre, Andrew Jr., Hussey, Robert M., Ehrhart, Michael A., Koziol, Thomas J.
• Primary Examiner(s): LE, THIEN MINH
• Application Number:
  US10/328,939
• Publication Number:
  US 20030146283A1
• Time in Patent Office: 1,303 Days
• Field of Search: 23546201-46245, 235/472.01, 235/472.02, 235/454, 235/455, 235/494
• US Class Current: 235/454
• CPC Class Codes: G06K 17/0022 arrangements or provisious for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 2207/1017 Programmable
• CPC Class Codes: G06K 7/10544 by scanning of the records by radiation in the optical part of the electromagnetic spectrum
• CPC Class Codes: G06K 7/10821 further details of bar or optical code scanning devices
• 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
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1491 the method including a reconstruction step, e.g. stitching two pieces of bar code together to derive the full bar code

Abstract

There is provided a bar code reading apparatus having a one-dimensional image sensor. The bar code reading apparatus can include a one-dimensional image sensor comprising a certain number of pexels, an analog-to-digital converter coupled to the sensor, and a processor coupled to the analog-to-digital converter. The analog-to-digital converter in one embodiment can be configured to convert the analog intensity value for each pixel into a digital value represented by an N-bit value, where N is an integer greater than 1. The processor in one embodiment can be configured to extract information encoded in a bar code.

Claims

1. An apparatus for decoding a bar code, comprising:

a hand held housing;

a one dimensional image sensor comprising pixels for capturing image data along a scanning line oriented across a width of a bar code, the captured image data comprising an analog intensity value for each of a plurality of said pixels;

an analog-to-digital converter coupled to the sensor, the analog-to-digital converter configured to convert the analog intensity value for each pixel of the plurality of pixels into a digital value represented by an N-bit value, where N is an integer greater than 1; and

a processor coupled to the analog-to-digital converter, the processor configured to decode the plurality of N-bit values to extract information encoded in the bar code, wherein

said one dimensional image sensor is encapsulated in said hand held housing.

2. The apparatus of claim 1, wherein said one dimensional image sensor comprises a single row of pixels.

3. The apparatus of claim 1, wherein said hand held housing is a gun style hand held housing.

4. The apparatus of claim 1, further comprising a trigger and a light generating assembly including a laser, said light generating assembly directing laser light toward said bar code, said laser light being reflected from said bar code.

5. The apparatus of claim 4, wherein said apparatus is controlled so that said generated image data is representative of said reflected laser light reflected from said bar code.

6. The apparatus of claim 4, wherein said one dimensional image sensor senses laser light generated by said light generating assembly and reflected from said bar code.

7. The apparatus of claim 1, further comprising an aiming light source, said apparatus being configured so that said aiming light source is disabled on receipt of a user initiated and processor recognizable command.

8. The apparatus of claim 1, further comprising an aiming light source, said apparatus being configured so that said aiming light source is disabled on receipt of a user-initiated command input into said apparatus by a reading of a programming bar code symbol.

9. The apparatus of claim 1, wherein said apparatus comprises a memory, said memory storing decoding parameters.

10. The apparatus of claim 1, wherein said apparatus includes an onboard display.

11. The apparatus of claim 1, wherein said apparatus includes an onboard display, and wherein said apparatus is configured to operate in a mode in which said apparatus displays on said display a current version of a software program resident in said apparatus.

12. The apparatus of claim 1, wherein N=8.

13. The apparatus of claim 1, wherein said image sensor is provided on an integrated circuit chip which does not integrate said analog-to-digital converter.

14. A bar code reading device for decoding information encoded in a bar code, comprising:

a one dimensional image sensor comprising light sensitive pixels, the one dimensional image sensor generating an output signal indicative of said bar code, said output signal comprising an analog intensity value for each of a plurality of said light sensitive pixels;

a housing shaped to be fitted into a human hand, wherein said bar code reading device is configured so that said image sensor is supported within said housing;

an analog-to-digital converter coupled to said one dimensional image sensor, the analog to digital converter configured to convert the analog intensity value for each of said plurality of pixels into a digital pixel value represented by an N-bit value, where N is an integer greater than 1;

a memory coupled to the analog-to-digital converter, the memory having at least M memory locations for storage of image data, wherein M is of a size suitable to store a plurality of said N-bit values corresponding to said plurality of light sensitive pixels of said one dimensional image sensor, wherein said bar code reading device is configured to store into said memory at least a first block of image data, the first block of image data representing light incident on said plurality of light sensitive pixels of said one dimensional image sensor and comprising one of said N-bit value representations for each of said plurality of light sensitive pixels, wherein each of said M memory locations is of suitable size to store one of said N-bit values, wherein said bar code reading device is further configured so that a plurality of bar code symbology decoding programs are stored in said memory; and

a processor coupled to said memory, said processor configured to read the plurality of N-bit values from the memory, wherein said processor is further configured to process said plurality of N-bit values to decode the information encoded in said bar code.

15. The bar code reading device of claim 14, wherein said processor in processing said plurality of N-bit values utilizes sub pixel interpolation to mark changes in brightness representative of bar code transitions across said bar code.

16. The bar code reading device of claim 14, wherein said bar code reading device is configured so that said analog to digital converter fills a second block of image data into said memory while said processor binarizes M N-bit digital pixel values forming said first block of image data from said memory.

17. The bar code reading device of claim 14, wherein the analog-to-digital converter fills a set of M memory locations storing an oldest block of image data with a newest set of M N-bit digital pixel values representing a newest acquired block of image data such that said oldest block of image data is overwritten.

18. The bar code reading device of claim 14, wherein said bar code reading device further has an address pointer that marks the starting address for overwriting the oldest image data.

19. The bar code reading device of claim 14, wherein said bar code is a ID bar code symbol.

20. The bar code reading device of claim 14, wherein said bar code reading device is configured to generate interrupt signals derived from a stable timing source to accurately locate individual blocks of scanned data and the boundaries between adjacent blocks of scanned data.

21. The bar code reading device of claim 14, wherein said one dimensional image sensor has a single row of pixels.

22. The bar code reading device of claim 14, further comprising an aiming light source, said apparatus being configured so that said aiming light source is disabled on receipt of a user initiated command.

23. The bar code reading device of claim 14, further comprising a trigger and a light generating assembly including a laser, said light generating assembly directing laser light toward said bar code, said laser light being reflected from said bar code.

24. The bar code reading device of claim 23, wherein said bar code reading device is controlled so that said generated image data is representative of said reflected laser light reflected from said bar code.

25. The bar code reading device of claim 23, wherein said one dimensional image sensor senses laser light generated by said light generating assembly and reflected from said bar code.

26. A method for decoding information stored in a bar code, said method comprising the steps of:

providing a hand held optical reader having a one dimensional image sensor, said one dimensional image sensor having a plurality of pixels;

providing a bar code to be read by the optical reader;

imaging said bar code onto the one dimensional image sensor with an optical element

reading a plurality of analog intensity values from the plurality of pixels of the image sensor.

converting each analog intensity value into a digital N-bit pixel value to digitize the image of the bar code;

storing a block of image data comprising a plurality of said N-bit pixel values into a set of memory locations of a memory;

reading the plurality of N-bit pixel values from the memory;

binarizing the N-bit pixel values using sub pixel interpolation to mark changes in brightness representative of bar code transitions across the digitized image of the bar code; and

processing the binarized data to decode the information stored in the bar code.

27. The method of claim 26, wherein said storing each N-bit pixel value into said set of memory locations further comprises reading the N-bit pixel values from another set of memory locations of said memory while storing newly acquired N-bit pixel values into said set of memory locations.

28. The method of claim 26, wherein said storing newly acquired N-bit pixel values into said set of memory locations comprises overwriting an oldest set of N-bit pixel values in the second block of memory.

29. The method of claim 26, further comprising pointing with an address pointer to mark the starting address for overwriting the oldest set of N-bit pixel values before the step of storing each N-bit pixel value into said set of memory locations.

30. The method of claim 26, further comprising timing each new capture of the analog image (a scan, digitization by the analog-to-digital converter, and storage to memory in conjunction with interrupt signals derived from a stable timing source to accurately locate individual blocks of scanned data and the boundaries between adjacent blocks of scanned data.

31. A bar code reading device for use in reading information encoded in a bar code comprising a plurality of bars and spaces, said bar code reading device comprising:

an imaging assembly including a one dimensional image sensor comprising light sensitive pixels, the one dimensional image sensor generating an output signal indicative of said bar code, said output signal comprising an analog intensity value for each of a plurality of said light sensitive pixels, the imaging assembly further including an imaging optics assembly focusing an image of said bar code onto said one dimensional image sensor;

a hand held housing, wherein said bar code reading device is configured so that components of said imaging assembly are supported within said hand held housing;

an analog-to-digital converter coupled to said one dimensional image sensor, the analog to digital converter configured to convert the analog intensity value for each of said plurality of pixels into a digital pixel value represented by an N-bit value, where N is an integer greater than 1;

a memory being of sufficient size to store first and second blocks of image data, each of said first and second blocks of image data representing light incident on said plurality of pixels of said one dimensional image sensor;

a trigger; and

a decode circuit coupled to said memory for reading image data from said memory and processing said image data to produce data indicating relative widths of said bars and spaces of said bar code;

wherein said bar code reading device is configured so that at a time after said trigger is actuated by an operator of said bar code reading device, both of a first block of image data and second block of image data are stored into said memory, wherein said first block of image data represents light incident on said one dimensional image sensor at a first time, T₁, and said second block of image data represents light incident on said one dimensional image sensor at a second time, T₂, wherein T₂ after T₁, and wherein each of said first block of image data and said second block of image data comprises one of said N-bit value representations for each of said plurality of light sensitive pixels.

32. The bar code reading device of claim 31, wherein said decode circuit in processing said plurality of N-bit values utilizes sub pixel interpolation to mark changes in brightness representative of bar code transitions across said bar code.

33. The bar code reading device of claim 31, wherein said bar code reading device is configured so that said analog-to-digital converter fills a second block of image data into said memory while the processor binarizes M N-bit digital pixel values forming said first block of image data.

34. The bar code reading device of claim 31, wherein the analog-to-digital converter fills a set of M memory locations storing oldest image data with a newest set of M N-bit digital pixel values representing a newest acquired image such that said oldest image data is overwritten.

35. The bar code reading device of claim 31, wherein said bar code reading device further has an address pointer that marks starting address for overwriting said oldest image data.

36. The bar code reading device of claim 31, wherein the bar code is a ID bar code.

37. The bar code reading device of claim 31, wherein said bar code is a stacked bar code.

38. The bar code reading device of claim 31, wherein said bar code reading device is configured to generate interrupt signals derived from a stable timing source to accurately locate individual blocks of scanned data and the boundaries between adjacent blocks of scanned data.

39. The apparatus of claim 31, wherein said one-dimensional image sensor comprises a single row of pixels.

40. The apparatus of claim 31, further comprising a trigger and a light generating assembly including a laser, said light generating assembly directing laser light toward said linear bar code.

41. The bar code reading device of claim 40, wherein said bar code reading device is controlled so that said image data corresponding to said generated output signal is representative of said reflecte laser light reflected from said bar code.

42. The bar code reading device of claim 40, wherein said one dimensional image sensor senses laser light generated by said light generating assembly and reflected form said bar code.

43. The bar code reading device of claim 33, wherein said hand held housing is shaped to be comfortably fitted into a human hand.

44. A method for decoding a bar code, utilizing a hand held one dimensional bar code reader, the method comprising:

generating image data with a one dimensional image sensor having pixels, the image data comprising a plurality of pixel values along a scanning line oriented across a bar code, the image data comprising an analog intensity value for each of a plurality of the pixels;

converting the analog intensity value for each pixel of the plurality of pixels into a digital value represented by an N-bit value, where N is an integer greater than 1; and

decoding the plurality of N-bit values to extract information encoded in the bar code, wherein said decoding comprises identifying at least one candidate symbol region within a block of image data comprising said plurality of N-bit values.

45. The method of claim 44, wherein said decoding comprises identifying a plurality of candidate symbol regions.

46. The method of claim 44, wherein said decoding comprises identifying a plurality of candidate symbol regions and processing said candidate symbol regions according to a priority rule wherein said candidate symbol regions are prioritized based on which candidate symbol region is closest to a center of a field of view of said reader.

47. The method of claim 44, wherein said one dimensional image sensor comprises a single row of pixels.

48. The method of claim 44, wherein said image sensor is provided on an integrated circuit chip which does not integrate said analog-to-digital converter.

49. An apparatus for decoding a bar code, comprising:

a hand held housing;

a one dimensional image sensor comprising pixels for generated image data along a scanning line oriented across a width of a bar code, the generated image data comprising an analog intensity value for each of a plurality of said pixels;

an analog-to-digital converter coupled to the sensor, the analog-to-digital converter configured to convert the analog intensity value for each pixel of the plurality of pixels into a digital value represented by an N-bit value, where N is an integer greater than 1and wherein said apparatus is configured to store a block of said N-bit values into a memory; and

a processor coupled to the analog-to-digital converter, the processor configured to decode said block of N-bit values to extract information encoded in the bar code, wherein said one dimensional image sensor is encapsulated in said hand held housing, and wherein said decoding includes the step of utilizing a priority rule under which decoding of more centrally located image data is prioritized over decoding of less centrally located image data.

50. The apparatus of claim 49, wherein said one dimensional image sensor comprises a single row of pixels.

51. The apparatus of claim 49, wherein said hand held housing is a gun style hand held housing.

52. The apparatus of claim 49, further comprising a trigger and a light generating assembly including a laser, said light generating assembly directing laser light toward said bar code, said laser light being reflected from said bar code.

53. The apparatus of claim 52, wherein said apparatus is controlled so that said generated image data is representative of said reflected laser light reflected from said bar code.

54. The apparatus of claim 52, wherein said one dimensional image sensor senses laser light generated by said light generating assembly and reflected from said linear bar code.

55. The apparatus of claim 49, further comprising an aiming light source, said apparatus being configured so that said aiming light source is disabled on receipt of a user-initiated command.

56. The apparatus of claim 49, further comprising an aiming light source, said apparatus being configured so that said aiming light source is disabled on receipt of a user-initiated command input into said apparatus by a reading of a programming bar code symbol.

57. The apparatus of claim 49, wherein said apparatus comprises a memory, said memory storing decoding parameters.

58. The apparatus of claim 49, wherein said image sensor is provided on an integrated circuit chip which does not integrate said analog-to-digital converter.

59. The apparatus of claim 49, wherein said processor is further configured to identify at least one candidate symbol region within memory stored image data comprising a plurality of said N-bit values.