System and method of optical reading employing virtual scan lines

• US 7,721,966 B2
• Filed: 10/17/2005
• Issued: 05/25/2010
• Est. Priority Date: 10/18/2004
• Status: Active Grant

• Current Assignee: Datalogic Adc, Inc. (Datalogic S.p.A.)
• Original Assignee: Datalogic Scanning Incorporated (Datalogic S.p.A.)
• Inventors: Rudeen, Robert W., Olmstead, Bryan L.
• Primary Examiner(s): Le; Thien M.
• Assistant Examiner(s): Mai; Thien T
• Application Number:
  US11/252,997
• Publication Number:
  US 20060081712A1
• Time in Patent Office: 1,681 Days
• Field of Search: 235/462.25, 235/462.31, 235/462.2, 235/462.45, 235/462.21, 235/462.14, 235/462.39, 235/462.09, 235/462.1, 235/462.11, 235/462.01, 235/462.08, 235/454, 235/472.01, 235/472.02, 235/462.44
• US Class Current: 235/462.21
• CPC Class Codes: G06K 2207/1011 Aiming
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence

Abstract

Optical reading system and methods having multiple modes of operation, for example: omnidirectional and single-code picking; fixed and handheld reading; 1D and 2D code reading. In one configuration, an image-based system obtains input data via an area sensor (e.g., a 2D COD array) with only data corresponding to a pattern of virtual scan lines being stored and processed. A user may implement different operating modes such as a first mode reading codes in any location or orientation and a second mode reading only a code oriented along a particular virtual scan line or group thereof. Alternately, the data reader is operable to switch between handheld mode selecting a first pattern of virtual scan lines to process and/or decode and a fixed mode selecting a second pattern of virtual scan lines to process and/or decode. Virtual scan patterns in either mode can change from frame to frame.

Claims

1. A method for reading one out of a plurality of optical codes present in a scan region, using a data reader, comprising the steps of:

the data reader projecting a visible aiming pattern into the scan region;

acquiring an image of the entire scan region into a sensor array including at least a first optical code and a second optical code;

by operation of a user, aligning the aiming pattern onto the first optical code;

processing a portion of the image of the scan region along a pattern of virtual scan lines to locate both the first and second optical codes at any position(s) within the scan region;

the data reader determining if the aiming pattern intersects either one of the optical codes;

if the aiming pattern is determined by the data reader to intersect the first optical code and to not intersect the second optical code, acknowledging and transmitting data acquired from the first optical code and not acknowledging and not transmitting data acquired from the second optical code.

2. A method according to claim 1 wherein the step of processing a portion of the image comprises storing only a selected portion of data comprised of only selected points of the image corresponding to the pattern of virtual scan lines.

3. A method according to claim 1 further comprising an operator positioning the aiming pattern onto the optical code.

4. A method according to claim 1 wherein the step of processing a portion of the image comprises picking off only a selected portion of data comprised of only selected points of the image corresponding to a pattern of virtual scan lines without storing all of the points of the image.

5. A method according to claim 4 further comprising decoding the selected portion of data after determining if the aiming pattern intersects the first optical code and prior to transmitting.

6. A method according to claim 4 further comprising decoding the selected portion of data after transmitting.

7. A method according to claim 4 further comprising decoding the selected portion of data prior to determining if the aiming pattern intersects the first optical code.

8. A method according to claim 1 further comprising illuminating the optical code with an illumination source, wherein the aiming pattern is generated by a light source separate from the illumination source.

9. A method according to claim 1 wherein the aiming pattern is selected from the group consisting of:

an aiming spot, a two-dimensional image, an aiming line segment, a geometric pattern, a logo image.

10. A method according to claim 1 wherein the virtual scan lines forms a pattern selected from the group consisting of:

a raster pattern, an asterisk pattern, a multiple raster with lines at varying angles, an omnidirectional pattern, a single line pattern, a band of a plurality of generally parallel lines.

11. A method according to claim 1 wherein the method for optical reading comprises a handheld mode of operation, wherein the operator aims a handheld data reader at the optical code for positioning the aiming pattern onto the optical code.

12. A method according to claim 1 wherein the method for optical reading comprises a fixed mode of operation, wherein the operator moves an item bearing the optical code within the scan region for positioning the aiming pattern onto the optical code.

13. A method according to claim 1 further comprising selectively switching between (a) a first mode of operation wherein an optical code is acknowledged and transmitted only if the aiming pattern is determined to intersect the optical code and (b) a second mode of operation wherein an optical code is acknowledged and transmitted regardless of whether the aiming pattern is determined to intersect the optical code.

14. A method according to claim 13 further comprising switching to the first mode of operation upon actuation of a switch by the operator.

15. A method according to claim 13 wherein the data reader comprises a portable unit selectively operable in a fixed mode and a handheld mode of operation.

16. A method according to claim 13 wherein the data reader comprises a portable unit operable in a fixed mode and a handheld mode, the method further comprising

sensing whether the data reader has been grasped by the operator;

switching to the first mode of operation upon sensing that the data reader has been grasped by the operator.

17. A method according to claim 13 further comprising projecting the aiming pattern only when operating in the first mode of operation and not the second mode of operation.

18. A method for reading optical codes with a data reader, comprising the steps of:

acquiring an image of an entire scan region into a sensor array;

reading only a selected optical code out of a plurality of optical codes present within the scan region, by the steps of

projecting a visible aiming pattern into the scan region containing at least a first optical code and a second optical code;

by action of an operator, positioning the aiming pattern onto the selected first optical code;

processing a selected portion of data at only selected points along a pattern of virtual scan lines in the scan region and thereby locating both the first and second optical codes;

by action of the data reader, determining if the aiming pattern intersects either of the first and second optical codes that have been located;

if the aiming pattern is determined by the data reader to intersect the first optical code that has been located and not intersect the second optical code, acknowledging and transmitting only the first optical code and not the second optical code, and if the aiming pattern is determined by the data reader to not intersect any optical code that has been located, then not acknowledging and not transmitting any optical code.

19. A method according to claim 18 further comprising decoding the optical code after determining if the aiming pattern intersects the optical code and prior to transmitting.

20. A method according to claim 18 further comprising decoding the optical code after transmitting.

21. A method according to claim 18 further comprising selectively switching between (a) a first mode of operation wherein an optical code is acknowledged and transmitted only if the aiming pattern is determined to intersect the optical code and (b) a second mode of operation wherein an optical code is acknowledged and transmitted regardless of whether the aiming pattern is determined to intersect the optical code.

22. A method according to claim 21 further comprising projecting the aiming pattern only when operating in the first mode of operation and not the second mode of operation.

23. A method according to claim 21 wherein the method comprises reading optical codes with a portable data reader operable in a fixed mode and a handheld mode.

24. A method according to claim 23 further comprising

while operating in the handheld mode, switching between operating in the first mode and operating in the second mode.

25. A method for reading optical codes, comprising the steps of:

acquiring with a data reader an image of a two-dimensional imaging region into a sensor array, wherein the two-dimensional imaging region contains at least a first optical code and a second optical code;

operating in a handheld mode by processing only a selected portion of data at only selected points along a pattern of virtual scan lines consisting of (a) a single virtual scan line or (b) a band of a plurality of generally parallel virtual scan lines;

operating in a fixed mode by processing only a selected portion of data at selected points along a pattern of virtual scan lines arranged in multiple directions about the two dimensional imaging region;

decoding the selected portion of data according to the pattern of virtual scan lines,

wherein the step of operating in a handheld mode further comprises

projecting a visible aiming pattern into the two dimensional imaging region;

by operation of a user, aligning the aiming pattern onto the first optical code;

by action of the data reader, determining if the aiming pattern intersects either of the first and second optical codes;

if the aiming pattern is determined by the data reader to intersect the first optical code and not the second optical code, acknowledging and transmitting data acquired from the first optical code and not from the second optical code, and if the aiming pattern is determined by the data reader to not intersect either the first or second optical codes, then not acknowledging and not transmitting data acquired from the optical codes.

26. A method according to claim 25 further comprising selectively switching between operating in the handheld mode of operation and the fixed mode of operation.

27. A method according to claim 25 further comprising

sensing whether the data reader has been grasped by a user;

switching from the fixed mode to the handheld mode upon sensing that the data reader has been grasped by the user.

28. A method according to claim 25 further comprising

providing the data reader with a switch;

switching from the fixed mode to the handheld mode upon actuation of the switch by a user.

29. A method for reading optical codes with a data reader, comprising the steps of:

acquiring an image of a two-dimensional imaging region into a sensor array;

operating in a handheld mode by generating a visible aiming pattern whereby a user positions the aiming pattern onto an optical code within the imaging region, and storing data at only selected points along a pattern of virtual scan lines determined by the data reader to intersect the aiming pattern and not storing data from virtual scan lines determined by the data reader to not intersect the aiming pattern;

decoding data that has been stored.

30. A method of data reading according to claim 29 further comprising

operating in a fixed mode by storing only a selected portion of data at selected points along a pattern of a plurality of virtual scan lines spanning the two-dimensional imaging region in multiple directions;

selectively switching operation as between the handheld mode and the fixed mode.

31. A method for reading optical symbols with a data reader, comprising the steps of:

acquiring an image of a two-dimensional imaging region into a sensor array;

projecting a visible aiming pattern into the two dimensional imaging region;

operating in a first mode by processing only a selected portion of data at only selected points along a pattern of virtual scan lines arranged in multiple directions about the two-dimensional imaging region;

operating in a second mode by processing only a selected portion of data at only selected points along a pattern of virtual scan lines determined by the data reader to intersect the aiming pattern and not processing along virtual scan lines determined by the data not to intersect the aiming pattern;

decoding the selected portion of data according to the pattern of virtual scan lines.

32. A method for reading optical symbols with a data reader, comprising the steps of:

acquiring, with the date reader, data from a two-dimensional scan region, the two-dimensional scan region containing at least a first optical code and a second optical code;

processing the data to detect the first optical code and the second optical code;

operating in a first mode by transmitting optical codes detected anywhere within the scan region;

operating in a second mode by projecting a visible aiming pattern into the two-dimensional scan region and (a) transmitting the first optical code and not the second optical code if the first optical code is determined by the data reader to intersect the aiming pattern and the second optical code is determined not to intersect, (b) transmitting neither of the optical codes if both the first and second optical codes are determined by the data reader to not intersect the aiming pattern.

33. A method according to claim 32 wherein the step of acquiring comprises acquiring data along a pattern of virtual scan lines within the two-dimensional scan region.

34. A method according to claim 32 wherein the step of acquiring comprises storing only a selected portion of the data comprised of selected points of the data corresponding to a pattern of virtual scan lines.