Optical reader having a plurality of imaging modules

• US 8,074,887 B2
• Filed: 07/22/2005
• Issued: 12/13/2011
• Est. Priority Date: 06/04/2002
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Havens, William H., Barber, Charles P., Gannon, Colleen, Gardiner, Robert C., Hennick, Robert J., Pettinelli, John A. Jr.
• Primary Examiner(s): Walsh, Daniel
• Application Number:
  US11/187,608
• Publication Number:
  US 20050279836A1
• Time in Patent Office: 2,335 Days
• Field of Search: 235/454, 235/462.1, 235/462.11, 235/462.12, 235/462.2, 235/462.21, 235/462.23, 235/462.24, 235/462.32, 235/462.33, 235/462.42, 235/462.45, 235/472, 235/435, 235/455, 235/462.06, 235/462.25, 235/462.41, 235/462.47
• US Class Current: 235/462.45
• CPC Class Codes: G06K 7/10574 Multiple sources
• CPC Class Codes: G06K 7/10584 Source control
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners
• CPC Class Codes: G06K 7/109 adaptations to make the hand-held scanner useable as a fixed scanner
• CPC Class Codes: G06K 7/1098 the scanning arrangement having a modular construction
• 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 7/1417 2D bar codes
• CPC Class Codes: G06V 10/17 using hand-held instruments

Abstract

The invention in one embodiment is an optical reader having a plurality of imaging modules. In one method for operating a multiple imaging module reader of the invention, a second frame of image data captured via actuation of a second imaging module is automatically captured and subjected to decoding in the case an attempt to decode using a frame of image data captured via actuation of a first imaging module fails. In another embodiment, a frame of image data captured via actuation of an image sensor of a first module and actuation of illumination of a second imaging module is subjected to decoding. In another embodiment, frames of image data captured via actuation of image sensors of spaced apart modules are combined. The various modules of a multiple imaging module reader can be adapted to have different best focus positions so that a field depth of the reader is improved.

Claims

1. An optical reader comprising:

a housing defining at least one cavity;

a first imaging module having a first imaging axis and a first best focus distance mounted in said at least one cavity;

a second imaging module having a second imaging axis and a second best focus distance, different from said first best focus distance, said second best focus distance being at least one inch apart from said first best focus distance, said first imaging axis extending from the optical reader in a first direction, said second imaging axis extending from the optical reader in a second direction, the first direction being in diverging relation to the second direction, said second imaging module being mounted in said at least one cavity;

wherein each of said first imaging module and said second imaging module includes an image sensor, a lens assembly for focusing an image of a target onto the image sensor, a support assembly, and at least one illumination light emitting diode for use in providing flood illumination;

a control circuit in communication with each of said first imaging module and said second imaging module;

wherein said control circuit is programmed, in response to a trigger signal, to;

(a) capture a first frame of image data via actuation of said at least one illumination light emitting diode of said first imaging module, and said image sensor of said first imaging module;

(b) determine whether said first frame of image data includes decodable indicia;

(c) automatically subject to a decode attempt a second frame of image data if said determine step (b) indicates that decodable indicia is not or is likely not represented in said first frame of image data, wherein said second frame of image data is captured via actuation of said at least one illumination light emitting diode of said second imaging module, and said image sensor of said second imaging module.

2. The reader of claim 1, wherein said control circuit in determining whether decodable indicia is represented in said first frame of image data attempts to decode decodable indicia represented in said first frame of image data.

3. The reader of claim 1, wherein said control circuit captures said second frame of image data contemporaneously while capturing said first frame of image data.

4. The reader of claim 1, wherein said control circuit in determining whether decodable indicia is represented in said first frame of image data preliminarily evaluates image data of said first frame without attempting to decode decodable indicia represented therein.

5. The reader of claim 4, wherein said control circuit in preliminarily evaluating said image data evaluates said image data to determine whether a saturation condition is present.

6. The reader of claim 1, wherein said first imaging module is a one dimensional imaging module and wherein said second imaging module is a two dimensional imaging module.

7. The reader of claim 1, wherein said first best focus distance and said second best focus distance are fixed best focus distances.

8. The reader of claim 1, wherein said trigger signal is an automatically generated trigger signal generated by decodable indicia being moved in a field of view of said reader.

9. The reader of claim 1, further comprising a trigger, wherein said trigger signal is generated when said trigger is pulled.

10. An optical reader comprising:

a housing defining at least one cavity;

a first imaging module mounted in said at least one cavity;

a second imaging module mounted in said at least one cavity;

wherein each of said first imaging module and said second imaging module includes an image sensor, a support assembly, and at least one illumination light emitting diode;

a control circuit in communication with each of said first imaging module and said second imaging module;

wherein said control circuit is programmed, in response to a trigger signal, to;

(a) capture a first frame of image data and a second frame of image data, wherein said first frame of image data is captured via actuation of said at least one light emitting diode thereby providing flood illumination and said image sensor of said first imaging module, and said second frame of image data is captured via actuation of said at least one light emitting diode thereby providing flood illumination and said image sensor of said second imaging module;

(b) combine said first frame and said second frame to generate a third image representation; and

to

(c) subject said third image representation to a decode attempt, wherein said control circuit in combining said first frame and said second frame identifies a common graphical element commonly represented in said first frame and said second frame of image data.

11. The reader of claim 10, wherein said control circuit determines whether decodable indicia is represented in said first frame and said second frame of image data by attempting to decode decodable indicia represented in said first frame and said second frame of image data.

12. The reader of claim 10, wherein said control circuit captures said second frame of image data contemporaneously while capturing said first frame of image data.

13. The reader of claim 10, wherein said control circuit determines whether decodable indicia is represented in said first frame and said second frame of image data by preliminarily evaluating image data of said first frame and said second frame of image data without attempting to decode decodable indicia represented therein.

14. The reader of claim 13, wherein said control circuit in preliminarily evaluating said image data evaluates gray scale pixel values of said image data to determine whether a saturation condition is present.

15. The reader of claim 10, wherein said control circuit in combining said first frame and said second frame of image data determines an area of overlap between said first frame and said second frame of image data.

16. The reader of claim 10, wherein said control circuit in combining said first frame and said second frame of image data generates a signal indicative of a module-to-target distance of at least one of said modules.

17. The reader of claim 10, wherein said control circuit in combining said first frame and said second frame of image data combines said first frame and said second frame in a manner dependent on an angle between imaging axes of said first and said second imaging modules.

18. The reader of claim 10, wherein said first imaging module is configured to have a first best focus distance and second best focus distance, wherein said first best focus distance is at least 1 inch apart from said second best focus distance.

19. The reader of claim 10, wherein said trigger signal is an automatically generated trigger signal generated by decodable indicia being moved in a field of view of said reader.

20. The reader of claim 10, wherein said first imaging module and said second imaging module are disposed in a vertical plane and mounted to a common circuit board.

21. The reader of claim 10, wherein said image sensor of said first imaging module is a one dimensional image sensor.

22. The reader of claim 10, wherein said image sensor of said first imaging module is a two dimensional image sensor.

23. The reader of claim 10, wherein said image sensor of said first imaging module is a two dimensional color image sensor.

24. The reader of claim 10, wherein said image sensor of said first imaging module is a one dimensional image sensor and wherein said image sensor of said second imaging module is a two dimensional image sensor.

25. An reader comprising:

a hand held housing encapsulating a first imaging module, a second imaging module and a control circuit;

said first imaging module having a first imaging axis and a first best focus distance;

said second imaging module having a second imaging axis and a second best focus distance, said second best focus distance being at least one inch apart from said first best focus distance, said first imaging axis extending from the optical reader in a first direction, said second imaging axis extending from the optical reader in a second direction, the first direction being in diverging relation to the second direction;

wherein each of said first imaging module and said second imaging module includes an image sensor having an array of photosensitive elements, a support assembly, and at least one illumination LED;

wherein one of said first imaging module and said second imaging module is a one dimensional imaging module including a linear array of photosensitive elements and one of said first imaging module and said second imaging module is a two dimensional imaging module including a two dimensional color image sensor having a two dimensional array of photosensitive elements,

said control circuit being in communication with each of said first imaging module and said second imaging module;

wherein said control circuit is programmed, in response to receipt of a trigger signal, to;

(a) capture a first frame of image data via actuation of said at least one illumination LED and said image sensor of said first imaging module; and

(b) capture a second frame of image data is via actuation of said at least one illumination LED and said image sensor of said second imaging module; and

(c) subject each of said first frame of image data and said second frame of image data to a decode attempt.

26. The reader of claim 25, wherein said optical reader subjects to a decode attempt said second frame of image data conditionally on the condition that said control circuit determines that said first frame of image data does not include decodable indicia.

27. An optical reader comprising:

an imaging module having an imaging axis, wherein the imaging module includes a two dimensional image sensor having an array of photosensitive elements, and a lens assembly for focusing an image of a target onto the two dimensional image sensor, the imaging module including a first light source spaced a first distance from the imaging axis;

a second light source external to the imaging module spaced a second distance from the imaging axis, the second distance being longer than the first distance;

a hand held housing encapsulating the imaging module and the second light source;

wherein the optical reader in response to receipt of a trigger signal is operative to;

capture a first frame of image data via actuation of the image sensor and the first light source;

capture a second frame of image data via actuation of the image sensor and the second light source without actuation of first light source;

wherein the optical reader is operative to subject each of the first frame of image data and the second frame of image data to a decode attempt; and

wherein the first light source is included in a first set of LEDs spaced a first spacing relative to the imaging axis and the wherein the second light source is included in a second set of LEDs spaced a second spacing relative to the imaging axis, the second spacing being longer than the first spacing, wherein the optical reader responsively to receipt of the trigger signal is operative to capture the first frame of image data via actuation of the image sensor and the first set of LEDs, and the second frame of image data via actuation of the image sensor and the second set of LEDs without actuation of the first set of LEDs.

28. The reader of claim 27, wherein the optical reader is operative so that the second frame of image data is captured responsively to a failure to decode the first frame of image data.

29. The reader of claim 27, wherein the optical reader is operative so that the second frame of image data is captured responsively to a determination that the first frame of image data is saturated.

30. The reader of claim 27, wherein the optical reader includes a second imaging module.

31. The reader of claim 27, wherein the second light source is disposed on a second imaging module.

32. The reader of claim 27, wherein optical reader is operative to capture the second frame prior to capture of the first frame.

33. The reader of claim 27, wherein the optical reader is operative to capture the second frame subsequently to capturing the first frame.