System and method for aiming an optical code scanning device

• US 7,478,753 B2
• Filed: 08/31/2004
• Issued: 01/20/2009
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Hatton, Edward, Patel, Mehul, Trajkovic, Miroslav, Brock, Christopher, Sackett, William
• Primary Examiner(s): Koyama; Kumiko C
• Application Number:
  US10/931,150
• Publication Number:
  US 20060043191A1
• Time in Patent Office: 1,603 Days
• Field of Search: 235/462.06, 235/462.07, 235/462.08, 235/462.09, 235/462.12, 235/462.22, 235/462.31, 235/462.2, 235/462.32
• US Class Current: 235/462.08
• CPC Class Codes: G06K 2207/1011 Aiming
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10801 Multidistance reading
• 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 7/1443 locating of the code in an image

Abstract

A system and method for performing a read operation including acquiring a series of frames of image data; processing a first frame of image data including an array of pixel data acquired while an aiming pattern was generated for determining a location L of at least one pixel of the array of pixel data that corresponds to the aiming pattern; and processing a second frame of image data acquired while the aiming pattern was not generated. The processing of the second frame of image data includes the steps of selecting at least one optical code acquired in the second frame of image data that is located at a respective location; wherein the respective location meets a predetermined condition relative to the determined location L; and providing the selected at least one optical code for further processing in accordance with the read operation.

Claims

1. An optical code scanner system for reading at least one optical code comprising:

an imager module for acquiring a series of at least one frame of image data, image data of respective frames including an array of pixel data corresponding to imaging of a field of view of the imager module;

an aiming assembly having at least one light source for generating at least one beam forming an aiming pattern visible in the field of view;

an aiming controller for controlling the aiming assembly for controlling generation of the aiming pattern during acquisition of at least one frame of image data in response to receipt of an actuation signal indicating initiation of a read operation;

an optical code selector module executable on at least one processor for performing in accordance with a read operation processing of at least a portion of a first frame of image data acquired while the aiming pattern was generated for determining a location of a pixel of the array of pixel data that is a digital representation of a photosensitive sensor pixel as illuminated by the aiming pattern during acquisition of the first frame, wherein the photosensitive sensor pixel is included in the imager module for imaging the field of view of the imager module; and

processing of at least a portion of a second frame of image data of the at least one frame of image data acquired while the aiming pattern was not generated, including selecting at least one optical code acquired in the acquired image data that is located at a respective location, wherein the respective location meets a predetermined condition relative to a second digital representation of the photosensitive sensor pixel in the second frame of image data as determined utilizing the determined location, and providing the selected at least one optical code for further processing in accordance with the read operation, wherein the second frame of image data does not include the image of the aiming pattern.

2. The system according to claim 1, wherein the second frame is acquired after the first frame.

3. The system according to claim 1, wherein the system further comprises a decoder module executable on the processor assembly for performing a decode operation for decoding the selected at least one optical code.

4. The system according to claim 1, wherein for a respective at least one read operation the determined location is stored;

and

the optical code selector module retrieves at least one stored location and calculates a position in accordance with at least one function of the retrieved at least one stored location.

5. The system according to claim 4, wherein the at least one function includes averaging the at least one stored location.

6. The system according to claim 4, wherein for a subsequent read operation the optical code selector module:

processes at least a portion of a first frame of image data acquired while the aiming pattern was generated and determines that the position of the aiming pattern cannot be recovered in the processing of the at least a portion of the first frame of image data;

processes at least a portion of a second frame of image data acquired while the aiming pattern was not generated including selecting at least one optical code acquired in the acquired image data that is located at a respective location, wherein the respective location meets a predetermined condition relative to the calculated location; and

provides the selected at least one optical code for further processing in accordance with the read operation.

7. The system according to claim 4, wherein during a subsequent read operation the optical code selector module processes a frame of image data acquired while the aiming pattern was not generated using the calculated location without processing a frame of image data acquired while the aiming pattern was generated, including selecting at least one optical code acquired in the acquired image data that is located at a second respective location, wherein the second respective location meets a predetermined condition relative to the calculated location.

8. The system according to claim 7, wherein during the subsequent read operation:

the optical code selector module determines if the calculated location is well established;

the frame of image data during subsequent read operation is processed using the calculated location only when the calculated location is determined to be well established, in which case the selected at least one optical code is provided for further processing in accordance with the subsequent read operation; and

when the calculated location is not determined to be well established, during the subsequent read operation a first frame of image data acquired while the aiming pattern was generated is processed for determining a location of at least one pixel of the array of pixel data that corresponds to the aiming pattern; and

a second frame of image data acquired while the aiming pattern was not generated is processed, including selecting at least one optical code acquired in the acquired image data that is located at a respective location, wherein the respective location meets a predetermined condition relative to the determined location, and provides the selected at least one optical code for further processing in accordance with the subsequent read operation.

9. The system according to claim 8, wherein determination if the calculated location is well established includes determining if a difference between a recently calculated location and a previously calculated location are below a predetermined threshold level.

10. The system according to claim 7, wherein during the subsequent read operation the aiming controller immediately controls the aiming assembly to disable generation of the aiming pattern in response to receipt of the actuation signal for acquiring the frame of image data.

11. The system according to claim 7, wherein during the subsequent read operation following acquisition of the frame of image data:

the aiming controller controls the aiming assembly to generate the aiming pattern to acquire a second frame of image data;

the optical code selector module processes at least a portion of the second frame of image data for determining a location of at least one pixel of the array of pixel data that corresponds to the aiming pattern acquired in the second frame of image data;

the optical code selector module compares the location determined for the second frame of image data with the calculated location, and if the difference between the compared values is below a threshold value provides the selected at least one optical code for further processing in accordance with the subsequent read operation; and

otherwise selects at least one optical code acquired in the second frame of image data that is located at a respective location, wherein the respective location for the second frame of image data meets a predetermined condition relative to the determined location, and provides the selected at least one optical code for further processing in accordance with the subsequent read operation.

12. The system according to claim 1, wherein:

the system further comprises a parallax range module which determines a range of locations of at least one pixel of the array of pixel data that corresponds to the aiming pattern in accordance with a range of operational distance values associated with the scanner system; and

for a subsequent read operation the optical code selector module processes at least a portion of a frame of image data acquired while the aiming pattern was not generated and determines a cluster of pixels of the image data acquired during the subsequent read operation that corresponds to the range of locations, including selecting at least one optical code acquired with the image data acquired during the subsequent read operation that is located at a second respective location, wherein the respective location meets a predetermined condition relative to the range of locations, and provides the selected at least one optical code for further processing in accordance with the subsequent read operation.

13. The system according to claim 1, wherein the aiming pattern includes first and second lines forming a crosshair and the determined location is the intersection of the first and second lines of the crosshair.

14. An optical code scanner system for reading at least one optical code comprising:

an imager module for acquiring a series of at least one frame of image data, image data of respective frames including an array of pixel data corresponding to imaging of a field of view of the imager module, wherein a first frame of the at least one frame of the image data includes an image of an aiming pattern and a second frame of the at least one frame of the image data does not include the image of the aiming pattern;

an aiming assembly having at least one light source for generating at least one beam forming the aiming pattern visible in the field of view;

a range finder module for determining at least one distance between the scanner system and at least one optical code being imaged;

a parallax range module for determining a range of a location of a pixel of the array of pixel data that is a digital representation of a photosensitive sensor pixel as illuminated by the aiming pattern during acquisition of the first frame in accordance with the at least one distance determined by the range finder module, wherein the photosensitive sensor pixel is included in the imager module for imaging the field of view of the imager module; and

an optical code selector module executable on at least one processor for processing at least a portion of the first frame of image data acquired during a read operation while the aiming pattern was generated for determining the location of the pixel of the array of pixel data that is a digital representation of a photosensitive sensor pixel as illuminated by the aiming pattern during acquisition of the first frame and selecting at least one optical code acquired in the acquired image data that is located at a respective location, wherein the respective location determined during the read operation meets a predetermined condition relative to a second digital representation of the photosensitive sensor pixel in the second frame of image data as determined utilizing the determined location, and providing the selected at least one optical code for further processing in accordance with the read operation.

15. The system according to claim 14, wherein the aiming pattern includes first and second lines forming a crosshair and determined location L is the intersection of the first and second lines of the crosshair.

16. A method for reading at least one optical code comprising the steps of:

imaging a field of view including acquiring a series of at least one frame of image data, image data of respective frames including an array of pixel data corresponding to a field of view of the imaging;

generating at least one beam forming an aiming pattern visible in the field of view;

controlling generation of the aiming pattern during acquisition of at least one frame of image data in response to receipt of an actuation signal indicating initiation of a read operation; and

performing a read operation comprising the steps of;

processing at least a portion of a first frame of image data acquired while the aiming pattern was generated for determining a location of a pixel of the array of pixel data that is a digital representation of a photosensitive sensor pixel as illuminated by the aiming pattern during acquisition of the first frame, wherein the photosensitive sensor pixel is included in an imager module for imaging the field of view of the imager module; and

processing at least a portion of a second frame of image data of the at least one frame of image data acquired while the aiming pattern was not generated, wherein the second frame of the image data does not include the image of the aiming pattern, comprising the steps of;

selecting at least one optical code acquired in the acquired image data that is located at a respective location;

wherein the respective location meets a predetermined condition relative to a second digital representation of the photosensitive sensor pixel in the second frame of image data as determined utilizing the determined location; and

providing the selected at least one optical code for further processing in accordance with the read operation.

17. The method according to claim 16, further comprising the steps of:

storing the determined location for a respective at least one read operation;

retrieving at least one stored location; and

calculating a position in accordance with at least one function of the retrieved at least one stored location.

18. The method according to claim 17, wherein the at least one function includes averaging the at least one stored location.

19. The method according to claim 17, further comprising the steps of:

processing a frame of image data acquired while the aiming pattern was not generated during a subsequent read operation using the calculated location without processing a frame of image data acquired while the aiming pattern was generated, comprising the step of;

selecting at least one optical code acquired in the acquired image data that is located at a second respective location, wherein the second respective location meets a predetermined condition relative to the calculated location.

20. The method according to claim 19, further comprising the steps of:

determining if the calculated location is well established;

when the calculated location is determined to be well established;

processing the frame of image data during the subsequent read operation using the calculated location; and

;

providing the selected at least one optical code for farther processing in accordance with the subsequent read operation; and

when the calculated location is not determined to be well established;

processing a first frame of image data acquired while the aiming pattern was generated during the subsequent read operation comprising the steps of;

determining a location of at least one pixel of the array of pixel data that corresponds to the aiming pattern; and

processing a second frame of image data acquired while the aiming pattern was not generated, comprising the steps of;

selecting at least one optical code acquired in the acquired image data that is located at a respective location, wherein the respective location meets a predetermined condition relative to the determined location; and

providing the selected at least one optical code for further processing in accordance with the subsequent read operation.

21. The method according to claim 17, further comprising the steps of:

determining the location of at least one pixel of the array of pixel data for respective subsequent read operations;

storing the respective determined locations as the locations are determined; and

updating calculated location using the most recently stored location.

22. The method according to claim 16, further comprising the steps of:

determining a range of locations of at least one pixel of the array of pixel data that corresponds to the aiming pattern in accordance with a range of operational distance values associated with the imaging; and

processing at least a portion of a frame of image data acquired while the aiming pattern was not generated during a subsequent read operation for determining a cluster of pixels of the image data acquired during the subsequent read operation that corresponds to the range of locations, comprising the steps of;

selecting at least one optical code acquired in the image data acquired during the subsequent read operation that is located at a second respective location, wherein the second respective location meets a predetermined condition relative to the range of locations; and

providing the selected at least one optical code for further processing in accordance with the subsequent read operation.

23. The method according to claim 16, wherein the aiming pattern includes first and second lines forming a crosshair and the determined location is the intersection of the first and second lines of the crosshair.

24. A method for reading at least one optical code comprising the steps of:

imaging with a scanning system a field of view including acquiring a series of at least one frame of image data, image data of respective frames including an array of pixel data corresponding to a field of view of the imaging, wherein a first frame of the at least one frame of the image data includes an image of an aiming pattern and a second frame of the at least one frame of the image data does not include the image of the aiming pattern;

generating at least one beam forming the aiming pattern visible in the field of view;

determining at least one distance between the scanner system and at least one optical code being imaged;

determining a range of a location of at least one pixel of the array of pixel data that is a digital representation of a photosensitive sensor pixel as illuminated by the aiming pattern in accordance with the at least one distance determined during acquisition of the first frame; and

processing at least a portion of the first frame of image data acquired during a read operation while the aiming pattern was generated for determining the location of at least one pixel of the array of pixel data that is the digital representation of the photosensitive sensor pixel as illuminated by the aiming pattern during acquisition of the first frame, comprising the steps of;

selecting at least one optical code acquired in the acquired image data that is located at a respective location, wherein the respective location determined during the read operation meets a predetermined condition relative to a second digital representation of the photosensitive sensor pixel in the second frame of image data as determined utilizing the determined location; and

providing the selected at least one optical code for further processing in accordance with the read operation.

25. The method according to claim 24, wherein the aiming pattern includes first and second lines forming a crosshair and the determined location is the intersection of the first and second lines of the crosshair.