Arrangement and method of imaging one-dimensional and two-dimensional optical codes at a plurality of focal planes

• US 20050006478A1
• Filed: 11/06/2003
• Published: 01/13/2005
• Est. Priority Date: 07/09/2003
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Patel, Mehul
• Granted Patent: US 7,222,793 B2
• Time in Patent Office: Days
• US Class Current: 235/462.240
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10801 Multidistance reading

Abstract

A non-complex imaging arrangement is aligned along an imaging axis. A mirror assembly is configured to reflect an image from an optical axis, which intersects the imaging axis, toward the optics assembly. The imaging arrangement includes at least one fixed image sensor for imaging thereon an optical code or target, such as a one-dimensional or two-dimensional barcode symbol, or label, signature, marking, picture, etc. The imaging arrangement provides an extended working range of approximately 5-102 cm. The imaging arrangement is capable of being incorporated within a barcode imager to provide a non-complex barcode imager having an extended working range which is comparable to or greater than the working ranges of conventional image-based barcode imagers.

Claims

1. An imaging arrangement for imaging an optical code or target at a plurality of focal planes comprising:

at least one image sensor each having at least one row of pixels for obtaining at least one row of pixel data corresponding to an image focused thereon;

an optics assembly having at least one objective lens positioned along an imaging axis of the imaging arrangement for focusing an image of the optical code or target on the at least one image sensor for obtaining at least one row of pixel data corresponding to at least a portion of the optical code or target; and

a mirror positioned adjacent a point defined by an intersection of the imaging axis and the optical axis, wherein the mirror reflects the image received from the optical axis, along the imaging axis toward the optics assembly and the image sensor.

2. The imaging arrangement according to claim 1, wherein the optical code or target is selected from the group consisting of a barcode symbol, a signature, a label, a marking, and a picture.

3. The imaging arrangement according to claim 2, wherein the barcode symbol is one of a one-dimensional and a two-dimensional barcode symbol.

4. The imaging arrangement according to claim 1, wherein the imaging arrangement has a working range of approximately 5 cm to 102 cm.

5. The imaging arrangement according to claim 1, further comprising a motor assembly operatively coupled to the mirror for pivoting the mirror for imaging a field of view.

6. The imaging arrangement according to claim 1, wherein the optics assembly is moved in the range of 0-100 μ

m by an actuator.

7. The imaging arrangement according to claim 1, wherein the lens assembly includes a plurality of optical elements for further focusing the image on the at least one image sensor.

8. The imaging arrangement according to claim 7, wherein the plurality of optical elements are selected from the group consisting of glass, lens, holographic optical elements, plastic, and other transparent materials.

9. The imaging arrangement according to claim 7, wherein the plurality of optical elements overlay at least a portion of the at least one image sensor.

10. The imaging arrangement according to claim 7, further comprising a carrier defining a plurality of openings, wherein each of the plurality of optical elements is disposed within a corresponding one of a plurality of openings defined within a rotatable carrier.

11. The imaging arrangement according to claim 10, wherein one of the plurality of openings is an empty opening and does not include an optical element, and further wherein a motor is operatively coupled to the rotatable carrier for positioning the empty opening or one of the plurality of optical elements along the optical axis.

12. The imaging arrangement according to claim 7, wherein at least one of the plurality of optical elements is configured to move in a direction which is substantially perpendicular to the imaging axis.

13. The imaging arrangement according to claim 1, further comprising an illumination device for illuminating a field of view for the imaging arrangement.

14. The imaging arrangement according to claim 1, wherein a plane of the optical code or target is correlated in space to at least one of the plurality of focal planes.

15. A barcode imager for imaging an optical code or target at a plurality of focal planes comprising:

means for initiating an imaging operation for imaging the optical code or target at at least one of the plurality of focal planes; and

an imaging arrangement comprising;

at least one image sensor each having at least one row of pixels for obtaining at least one row of pixel data corresponding to an image focused thereon;

an optics assembly having at least one objective lens positioned along an imaging axis of the imaging arrangement for focusing an image of the optical code or target on the at least one image sensor for obtaining at least one row of pixel data corresponding to at least a portion of the optical code or target; and

a mirror assembly positioned adjacent a point defined by an intersection of the imaging axis and the optical axis, wherein the mirror assembly reflects the image received from the optical axis, along the imaging axis toward the optics assembly and the image sensor.

16. The barcode imager according to claim 15, wherein the optical code or target is selected from the group consisting of a barcode symbol, a signature, a label, a marking, and a picture.

17. The barcode imager according to claim 16, wherein the barcode symbol is one of a one-dimensional and a two-dimensional barcode symbol.

18. The barcode imager according to claim 15, wherein the imaging arrangement has a working range of approximately 5 cm to 102 cm.

19. The barcode imager according to claim 15, wherein the imaging arrangement further comprises a motor assembly operatively coupled to the mirror for pivoting the mirror for imaging a field of view.

20. The barcode imager according to claim 19, wherein the optics assembly is moved in the range of 0-100 μ

m by an actuator.

21. The barcode imager according to claim 15, wherein the lens assembly includes a plurality of optical elements for further focusing the image on the at least one one-dimensional image sensor array.

22. The barcode imager according to claim 21, wherein the plurality of optical elements are selected from the group consisting of glass, lens, holographic optical elements, plastic, and other transparent materials.

23. The barcode imager according to claim 21, wherein the plurality of optical elements overlay at least a portion of the at least one image sensor.

24. The barcode imager according to claim 21, wherein at least one of the plurality of optical elements is configured to move in a direction Which is substantially perpendicular to the imaging axis.

25. The barcode imager according to claim 15, further comprising:

a memory for storing rows of pixel data corresponding to different portions of the optical code or target; and

a processor for processing the stored rows of pixel data.

26. The barcode imager according to claim 15, further comprising means for focusing different sets of the plurality of focal planes on the at least one imager sensor.

27. A method for imaging an optical code or target at a plurality of focal planes comprising the steps of:

initiating an imaging operation for imaging the optical code or target at at least one of the plurality of focal planes onto at least one image sensor via at least one objective lens;

determining whether the optical code or target is one-dimensional or two-dimensional; and

obtaining at least one row of pixel data corresponding to the optical code or target during the imaging operation.

28. The method according to claim 27, further comprising the step of pivoting a mirror to scan the optical code or target wherein it is determined that the optical code or target is two-dimensional.

29. The method according to claim 27, further comprising the steps of:

determining whether at least one row of pixel data can be decoded and/or processed; and

decoding and/or processing a row of pixel data if it is determined that at least one row of pixel data can be decoded and/or processed.

30. The method according to claim 29, further comprising the steps of:

moving the at least one objective lens if it is determined that at least one row of pixel data cannot be decoded and/or processed; and

repeating the initiating, obtaining and determining steps, and one of the decoding and moving steps, until the at least one row of pixel data is decoded and/or processed.

31. The method according to claim 27, further comprising the steps of:

moving the at least one objective lens;

repeating the initiating, obtaining and moving steps, until the at least one objective lens has been moved through every position; and

decoding and/or processing at least one row of obtained pixel data.

32. The method according to claim 27, further comprising the steps of:

storing the row of pixel data;

repeating the initiating and storing steps until a plurality of rows of pixel data corresponding to the optical code or target are stored; and

decoding and/or processing the plurality of stored rows of pixel data.

33. The method according to claim 27, wherein the optical code or target is selected from the group consisting of a barcode symbol, a label, a marking, and a picture.

34. The method according to claim 27, wherein the barcode symbol is one of a one-dimensional and a two-dimensional barcode symbol.

35. The method according to claim 27, further comprising the step of positioning at least one optical element between the at least one objective lens and the at least one one-dimensional image sensor array.