Hand held bar code reader with improved image capture

• US 7,475,823 B2
• Filed: 05/26/2006
• Issued: 01/13/2009
• Est. Priority Date: 05/26/2006
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Lackemann, Thomas, Brock, Christopher, Pang, Robert James
• Primary Examiner(s): Minh; Le Thien
• Assistant Examiner(s): VO, TUYEN KIM
• Application Number:
  US11/441,727
• Publication Number:
  US 20070272756A1
• Time in Patent Office: 963 Days
• Field of Search: 235/462.25, 235/462.06, 235/462.14, 235/462.24, 235/472, 235/454, 235/462.2, 235/462.26, 235/462.29, 235/472.01
• US Class Current: 235/462.25
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/109 adaptations to make the hand-held scanner useable as a fixed scanner

Abstract

An imaging-based bar code reader that includes an imaging and decoding system. When used on a stand to image documents, typically neither the stand or document is moving. Therefore blurring due to motion is not an issue. A sensor detects when the scanner is mounted to a stand. When commanded to take an image the scanner electronics and software modifies an auto-exposure process to minimize gain and lengthen exposure. This modification results in the scanner that is effective for scanning bar codes and yet also takes excellent pictures when mounted to a stand.

Claims

1. An imaging-based portable reader for reading a target comprising:

a) an imaging and decoding system for imaging a target image and if present decoding a target bar code, the imaging and decoding system including focusing optics and a sensor array, the focusing optics defining a field of view and focusing reflected illumination from an image onto the sensor array; and

b) a monitor for determining if the portable reader is stationary, in a fixed mount mode, or moving with respect to the target, and said imaging and decoding system responds to the monitor by adjusting an exposure period in situations wherein said portable reader is stationary, in a fixed mount mode, or moving with respect to the target such that a first exposure period is provided when said monitor determines that the portable reader is in one of a stationary and fixed mount mode and a second exposure period when said monitor determines that said portable reader is moving, the second exposure period being shorter in duration than said first exposure period to reduce image distortion and/or noise.

2. The imaging-based portable reader of claim 1 wherein the monitor is a combination of a reed switch connected to one of a said reader and a stand for supporting the reader and a magnet connected to the other of said reader and said stand.

3. The imaging-based portable reader of claim 1 wherein said monitor comprises a switch for sensing a presence of a magnet in either a stand for the housing or a housing body.

4. For use with a portable image reader that reads images an apparatus comprising:

a controller executing software for adjusting exposure capture times and signal gain from an imaging circuit during capture of images; and

a monitor for determining a first exposure mode and communicating said first exposure mode to the controller in situations where blurring of images is not of concern due to a fixed relation between the portable image reader and the image and said monitor for determining a second exposure mode and communicating said second exposure mode to the controller in situations where blurring of images is of concern due to a moving relation between the portable image reader and the image, said second exposure mode being shorter in duration than said first exposure mode to reduce image distortion and/or noise.

5. The apparatus of claim 4 wherein said monitor comprises a switch for sensing a presence of a magnet in either a stand for the housing or a housing body.

6. The imaging-based portable reader of claim 4 wherein the monitor is a combination of a reed switch connected to one of a said reader and a stand for supporting the reader and a magnet connected to the other of said reader and said stand.