Line focus barcode scanner

• US 5,914,477 A
• Filed: 06/26/1996
• Issued: 06/22/1999
• Est. Priority Date: 06/26/1996
• Status: Expired due to Term

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Wang, Mark Shi
• Primary Examiner(s): Hajec, Donald
• Assistant Examiner(s): Rodriguez, Douglas X.
• Application Number:
  US08/669,759
• Time in Patent Office: 1,091 Days
• Field of Search: 235/462, 235/472, 235/454, 235/466, 235/462.1, 235/462.32, 235/462.33, 235/472.01
• US Class Current: 235/462.1
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources

Abstract

A barcode scanner includes a light source for producing a scan line of light on a 2-D barcode along one of the two axes thereof. The scan line is scanned across the barcode along the other axis to effect a scanning band extending over the barcode in both of the two axes. Light reflected from the barcode is collected with a photodetector array to produce signals which are processed for decoding the barcode in both axes.

Claims

1. A barcode scanner for decoding a 2-D barcode having data symbols along first and second orthogonal axes, comprising:

means for producing a scan line of light on said barcode along said second axis;

means for scanning said scan line across said barcode along said first axis to effect a scanning band extending over said symbols in both of said first and second axes;

means for collecting light reflected from said barcode due to said scan line, and including an array of photodetectors aligned for detecting said reflected scan line and producing an array of signals corresponding to said array of photodetectors; and

means for processing said reflected scan line signals for decoding said barcode in both said first and second axes.

2. A scanner according to claim 1 wherein said scan line is straight, and said photodetectors are correspondingly linearly aligned.

3. A scanner according to claim 2 wherein said photodetectors are coaxially aligned in a row for receiving said reflected scan line along said second axis.

4. A scanner according to claim 3 wherein said processing means are operatively joined to said photodetector array and configured for processing said reflected scan line signals in parallel.

5. A scanner according to claim 3 wherein said photodetectors are rectangular in configuration with relatively long and narrow sides, and are coaxially stacked together along said long sides thereof.

6. A scanner according to claim 5 wherein said collecting means further comprise a collection lens and cooperating collection aperture for focusing said reflected scan line on said photodetector array, and said collection aperture is rectangular for matching said rectangular photodetectors.

7. A scanner according to claim 3 wherein said scan line producing means comprise:

a light source; and

a focusing lens optically aligned between said light source and said scanning means for focusing said scan line on said barcode.

8. A scanner according to claim 7 wherein said scan line producing means further comprise a plurality of adjoining light sources for producing a corresponding plurality of light beams collectively defining said scan line.

9. A scanner according to claim 8 wherein said focusing lens is optically aligned with said adjoining light sources for focusing each of said light beams at corresponding spots on said barcode to collectively define said scan line along said second axis as a dotted line.

10. A scanner according to claim 9 wherein said plurality of light sources and photodetectors are configured in a one-to-one correspondence so that said light beams from each of said light sources are reflected from said barcode for detection by a corresponding one of said photodetectors.

11. A scanner according to claim 10 wherein said light sources comprise an array of laser diodes.

12. A scanner according to claim 7 wherein said scan line producing means further comprise a cylindrical lens optically cooperating with said focusing lens to focus light from said light source along said second axis as a continuous scan line.

13. A scanner according to claim 12 wherein said focusing and cylindrical lenses are separate and distinct.

14. A scanner according to claim 13 wherein said light source is effective to produce a single light beam for spreading in said cylindrical lens to effect said scan line.

15. A scanner according to claim 14 wherein said light source is a laser.

16. A method of decoding a 2-D barcode having data symbols along first and second orthogonal axes, comprising:

producing a scan line of light on said barcode along said second axis;

scanning said scan line across said barcode along said first axis to effect a scanning band extending over said symbols in both of said first and second axes;

collecting light reflected from said barcode due to said scan line, and including an array of photodetectors aligned for detecting said reflected scan line and producing an array of signals corresponding to said array of photodetectors; and

processing said reflected scan line signals for decoding said barcode in both said first and second axes.

17. A method according to claim 16 further comprising producing a plurality of adjoining light beams to collectively define said scan line as a dotted line.

18. A method according to claim 17 further comprising collecting light from said barcode in said photodetectors in a one-to-one correspondence with said plurality of light beams.

19. A method according to claim 16 wherein said scan line is continuous.

20. A method according to claim 19 further comprising focusing a single light beam in a spot on said barcode along said first axis, and in a line along said second axis to define said scan line.

21. A barcode scanner for decoding a two-dimensional barcode having a plurality of data symbols varying in width and spacing along both first and second orthogonal axes, comprising:

means for producing a scan line of light on said barcode along said second axis;

means for scanning said scan line across said barcode along said first axis to effect a scanning band extending over said symbols in both of said first and second axes;

means for collecting light reflected from said barcode due to said scan line, and including an array of photodetectors aligned for detecting said reflected scan line and producing an array of signals corresponding to said array of photodetectors; and

means for processing said reflected scan line signals for decoding said barcode symbols of varying width and spacing in both said first and second axes.

22. A method of decoding a two-dimensional barcode having a plurality of data symbols varying in width and spacing along both first and second orthogonal axes, comprising:

producing a scan line of light on said barcode along said second axis;

scanning said scan line across said barcode along said first axis to effect a scanning band extending over said symbols in both of said first and second axes;

collecting light reflected from said barcode due to said scan line, and including an array of photodetectors aligned for detecting said reflected scan line and producing an array of signals corresponding to said array of photodetectors; and

processing said reflected scan line signals for decoding said barcode symbols of varying width and spacing in both said first and second axes.