Scanning and decoding control for an optical reader

• US 6,698,656 B2
• Filed: 12/21/2000
• Issued: 03/02/2004
• 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., Parker, James A., Pine, Jeffrey, Smith, George S.
• Primary Examiner(s): Le, Thien M.
• Assistant Examiner(s): LE, UYEN CHAU N
• Application Number:
  US09/746,428
• Publication Number:
  US 20030085282A1
• Time in Patent Office: 1,167 Days
• Field of Search: 235/462.01, 235/462.12, 235/462.15, 235/462.45, 235/462.2, 235/462.07, 235/462.16, 235/454, 235/472.01
• US Class Current: 235/462.01
• CPC Class Codes: G06K 17/0022 arrangements or provisions 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

An optical reading system comprising an optical reader and a host processor. In one aspect of the invention, the host processor may be configured to transmit a component control instruction in response to a command input by a user of the host processor to remotely control the reader. The optical reader subsequently receives the transmitted component control instruction and executes the component control instruction substantially on receipt thereof. In one embodiment, execution of the component control instruction by the optical reader has the same effect as the reader trigger being manually pulled by a reader operator.

Claims

1. A method for scanning and decoding at least one optically encoded symbol with an optical reader, the method comprising:

scanning the at least one optically encoded symbol during a scanning time frame to thereby generate a block of scan data;

decoding the block of scan data during a decoding time frame; and

selecting a scanning-decoding tracking option based on a comparison of the scanning time frame with the decoding time frame.

2. The method of claim 1, wherein the selected scanning-decoding tracking option decodes blocks of scan data in consecutive order when the scanning time frame is greater than or equal to the decoding time frame.

3. The method of claim 1, wherein the selected scanning-decoding tracking option decodes blocks of scan data in non-consecutive order when the scanning time frame is less than the decoding time frame.

4. The method of claim 1, wherein the selected scanning-decoding tracking option suspends the step of scanning for a period of time when the scanning time frame is less than the decoding time frame.

5. The method of claim 4, wherein the selected scanning-decoding tracking option suspends the step of scanning to thereby decode blocks of scan data in consecutive order when the scanning time frame is less than the decoding time frame.

6. The method of claim 1, wherein the step of selecting further comprises the step of selecting at least one operating mode, the at least one operating mode providing the optical reader with a plurality of scanning-decoding tracking options.

7. The method of claim 6, wherein the plurality of scanning-decoding tracking options includes a first tracking option for light loading conditions, and a second tracking option for heavy loading conditions.

8. The method of claim 6, wherein the plurality of tracking options include a scan-on-demand option whereby the scanning of a subsequent block of scan data is suspended and restarted as required to prevent an excessive lag time accruing between scanning a block of scan data and the decoding of the block of scan data.

9. The method of claim 6, wherein the plurality of tracking options include a skip-scan option, whereby decoding is performed continuously on a most current complete block of scan data.

10. The method of claim 6, wherein the plurality of tracking options include a decode-on-demand option that alternates between decoding a first scan data memory location and a second scan data memory location.

11. The method of claim 10, wherein the step of decoding is delayed until the scanning of a scan data location is completed.

12. The method of claim 6, wherein the plurality of tracking options include a continuous decoding option employing three scan data memory locations, whereby a scan data memory location having a most current complete block of scan data is decoded.

13. The method of claim 6, wherein the at least one operating mode is a one-shot mode whereby scanning and decoding are discontinued after one decoding attempt, whether the decoding attempt is successful or not.

14. The method of claim 6, wherein the at least one operating mode is a repeat-until-stopped mode, whereby scanning and decoding are discontinued by a command.

15. The method of claim 14, wherein the command is generated by a release of a trigger on the optical reader.

16. The method of claim 6, wherein the at least one operating mode is a repeat-until-done mode, whereby scanning and decoding continue until the at least one optical symbol is decoded successfully.

17. The method of claim 6, wherein the at least one operating mode includes a plurality of autodiscrimination modes, an autodiscrimination mode being selected to optimize data throughput for a predetermined optical reader application.

18. The method of claim 17, wherein the autodiscrimination mode is selected for a 1D decoding operation.

19. The method of claim 17, wherein the autodiscrimination mode is selected for a 2D decoding operation.

20. The method of claim 1, further comprising:

capturing the image of the at least one optically encoded symbol, whereby the at least one optically encoded symbol is converted into a block of scan data;

attempting to decode the block of scan data; and

repeating the steps of capturing and attempting while at least one condition is satisfied.

21. The method of claim 20, wherein the at least one condition includes unsuccessfully decoding the block of scan data.

22. The method of claim 20, wherein the at least one condition includes an actuated trigger on the optical reader.

23. The method of claim 20, wherein the at least one condition includes an indication that the repeat-until-done mode is in effect.

24. The method of claim 20, wherein the step of attempting is repeated after a successful decoding when the at least one optically encoded symbol includes a plurality of optically encoded symbols.

25. The method of claim 1, further comprising selecting an autodiscrimination mode for an optical reader application, the autodiscrimination mode being operative to select an autodiscrimination process during the step of decoding.

26. The method of claim 25, wherein the autodiscrimination mode is operative to select a 1D autodiscrimination process.

27. The method of claim 26, wherein the 1D autodiscrimination process comprises:

calculating activities of the block of scan data to thereby identify candidate symbol regions;

selecting a candidate symbol region of the candidate symbol regions;

defining a first scan line through the centroid of the candidate symbol region, the first scan line defining the direction of highest activity in the candidate symbol region;

calculating first scan line values along the first scan line; and

applying at least one 1D decoding program to the first scan line values until the first scan line values are decoded or determined to be undecodable.

28. The method of claim 27, wherein the step of calculating includes converting the first scan line values to a binary representation.

29. The method of claim 27, wherein the steps of calculating and applying are repeated when the first scan line values are determined to be undecodable.

30. The method of claim 29, wherein at least one second scan line is defined before repeating the steps of calculating and applying.

31. The method of claim 27, wherein a 2D autodiscrimination process is performed when the 1D autodiscrimination process is unsuccessful.

32. The method of claim 25, wherein the autodiscrimination mode is operative to select a 2D autodiscrimination process.

33. The method of claim 32, wherein the 2D autodiscrimination process comprises:

identifying at least one finder pattern in the block of scan data; and

decoding the block of scan data based on the identified at least one finder pattern.

34. The method of claim 33, wherein the step of identifying further comprises:

locating the at least one finder pattern;

categorizing the at least one finder pattern as a recognizable type of finder pattern; and

selecting the at least one finder pattern closest to the center of a field of view.

35. The method of claim 34, wherein the step of selecting is repeated when the step of decoding is unsuccessful.

36. An optical reader for scanning and decoding at least one optically encoded symbol, the optical reader comprising:

a scanning component adapted to scan the at least one optically encoded symbol during a scanning time frame to thereby produce a block of scan data;

a decoding component coupled to the scanning component, the decoding component adapted to decode the block of scan data during a decoding time frame; and

a controller coupled to the scanning component and the decoding component, the controller being operative to select a scanning-decoding tracking option based on a comparison of the scanning time frame with the decoding time frame.

37. The optical reader of claim 36, wherein the controller includes a mode selection component, the mode selection component being operative to select operational modes in response to receiving a user selected menu command.

38. The optical reader of claim 37, wherein the operational mode is a scanning-decoding mode.

39. The optical reader of claim 37, wherein the operational mode is an autodiscrimination mode.

40. The optical reader of claim 36, wherein the scanning-decoding tracking option decodes blocks of scan data in consecutive order when the scanning time frame is greater than or equal to the decoding time frame.

41. The optical reader of claim 36, wherein the selected scanning-decoding tracking option decodes blocks of scan data in non-consecutive order when the scanning time frame is less than the decoding time frame.

42. The optical reader of claim 36, wherein the selected scanning-decoding tracking option suspends the scanning of the at least one optically encoded symbol for a period of time when the scanning time frame is less than the decoding time frame.

43. The optical reader of claim 36, wherein the controller includes a microprocessor.

44. The optical reader of claim 36, wherein the controller includes an ASIC.

45. The optical reader of claim 36, wherein the controller includes a hard-wired circuit.

46. The optical reader of claim 36, wherein the decoding component includes an autodiscrimination circuit.

47. The optical reader of claim 46, wherein the autodiscrimination circuit further comprises:

a 1D autodiscrimination component operative to decode 1D optically encoded symbols;

a 2D autodiscrimination component coupled to the 1D autodiscrimination component, the 2D autodiscrimination component being operative to decode 2D optically encoded symbols; and

an autodiscrimination mode selector coupled to the 1D autodiscrimination component and the 2D autodiscrimination component, the autodiscrimination mode selector enabling either the 1D autodiscrimination component or the 2D autodiscrimination component, or both, in response to receiving a user selected menu command.

48. The optical reader of claim 36, wherein the scanning component further comprises:

an illumination assembly operative to illuminate the at least one optically encoded symbol to thereby generate a reflected image;

an imaging assembly coupled to the illumination assembly, the imaging assembly adapted to convert the reflected image into scan data; and

at least one memory location coupled to the imaging assembly, the at least one memory adapted to store a block of scan data.

49. The optical reader of claim 36, further comprising:

a segmented memory including a plurality of memory segments, each memory segment being adapted to store one block of scan data produced by a 1D scan component; and

a pointer memory coupled to the segmented memory, the pointer memory being operative to store an address identifying a location of a memory segment.

50. The optical reader of claim 49, wherein the pointer memory further comprises:

a start scan memory location adapted to store a starting address identifying a location of a most recent complete block of scan data;

an end scan memory location coupled to the start scan memory location, the end scan memory location being adapted to store an ending address identifying a location of a most recent complete block of scan data;

a decode start memory location adapted to store a starting address identifying a location of a block of scan data to be decoded; and

a decode end memory location adapted to store an ending address identifying a location of a block of scan data to be decoded.

51. The optical reader of claim 36, further comprising:

a plurality of memory spaces, each memory space being adapted to store blocks of scan data produced by a 2D scan component; and

a pointer memory coupled to the plurality of memory spaces, the pointer memory being operative to store an address identifying a location of a memory space.

52. The optical reader of claim 51, wherein the pointer memory further comprises:

a current scan pointer memory coupled to the plurality of memory spaces, the current scan pointer memory being adapted to store an address identifying the location of a current block of scan data;

a next scan pointer memory coupled to the plurality of memory spaces, the next scan pointer memory being adapted to store an address identifying the location of the next block of scan data;

a current decode pointer memory coupled to the plurality of memory spaces, the current decode pointer memory being adapted to store an address identifying the location of most recently decoded scan data; and

a next decode pointer memory coupled to the plurality of memory spaces, the next decode pointer memory being adapted to store an address identifying the location of the scan data to be decoded immediately after the most recently decoded scan data.

53. The optical reader of claim 36, wherein the scanning component, the decoding component, and the controller are embodied within a housing, the housing including a portion that is shaped to substantially fit the human hand.