Oblique access to image data for reading apparatus

• US 6,343,740 B1
• Filed: 12/17/1997
• Issued: 02/05/2002
• Est. Priority Date: 06/10/1994
• Status: Expired due to Fees

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Ju, Paul P., Wang, Ynjiun P.
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): Lee, Diane I.
• Application Number:
  US08/982,188
• Time in Patent Office: 1,511 Days
• Field of Search: 235/454, 235/436, 235/439, 235/462.08, 235/462.09, 235/462.1, 235/462.11, 235/472.01, 348/301, 348/302, 348/303, 348/304, 348/308, 348/294
• US Class Current: 235/454
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/1456 determining the orientation of the optical code with respect to the reader and correcting therefore
• CPC Class Codes: G11C 7/005 with combined beam-and individual cell access
• CPC Class Codes: G11C 8/12 Group selection circuits, e.g. for memory block selection, chip selection, array selection

Abstract

An image sensor array system is arranged to enable oblique access for readout of image data from a stepped pixel pattern of sensor cells. The stepped pixel pattern represents an oblique line component of an image portion containing a 2-D bar code or other dataform. An obliquely aligned bar code image can thus be read out along oblique lines which follow rows of bar code elements traversing the elements. The sensor array (16) is accessed by horizontal and vertical readout circuits (22 and 24) under the control of address signals from an address unit (20). Location signals, from a source (12), indicative of a selected image portion (39) may be used by the address unit (20) to provide address signals representative of the stepped pixel pattern for a particular oblique line component. Under the control of the address signals, image data from cells at the intersection of array lines and columns are sampled by sampling devices (26-32) and provided as output signals representative of the selected oblique line component. The output signals are then usable for decoding the bar code or other dataform.

Claims

1. An addressable access image sensor array system for reading dataforms, comprising:

a two-dimensional array of randomly accessible image sensor cells arranged to provide corresponding image data representative of an image area including an image of a dataform;

an address circuit, operatively coupled to the two-dimensional array, for providing address signals to the two-dimensional array to access image data from selected image sensor cells included in the two-dimensional array;

a judgment circuit for identifying image sensor cells in the two-dimensional array likely to provide image data representative of the dataform compared with other image sensor cells in the two-dimensional array likely to provide image data representative of portions of the image area other than the image of the dataform, and for providing address information to the address circuit to cause the image sensor cells likely to provide image data representative of the dataform to be selectively accessed for purposes of obtaining image data for decoding the dataform without requiring accessing the other image sensor cells; and

an output for outputting the accessed image data.

2. The system of claim 1, wherein the judgment circuit comprises circuitry for determining a location of the image of the dataform within the image area.

3. The system of claim 1, wherein the judgment circuit comprises circuitry for determining an oblique line component of the image of the dataform.

4. The system of claim 1, wherein the judgment circuit comprises circuitry for determining a boundary of the image of the dataform within the image area.

5. The system of claim 1, comprising a processor operatively coupled to the output for receiving the accessed image data.

6. The system of claim 5, wherein processor is configured to decode dataforms from image data representative thereof.

7. A method for reading dataforms, comprising:

utilizing a two-dimensional array of randomly accessible image sensor cells arranged to provide corresponding image data representative of an image area including an image of a dataform;

utilizing an address circuit, operatively coupled to the two-dimensional array, for providing address signals to the two-dimensional array to access image data from selected image sensor cells included in the two-dimensional array;

identifying image sensor cells in the two-dimensional array likely to provide image data representative of the dataform compared with other image sensor cells in the two-dimensional array likely to provide image data representative of portions of the image area other than the image of the dataform, and providing address information to the address circuit to cause the image sensor cells likely to provide image data representative of the dataform to be selectively accessed for purposes of obtaining image data for decoding the dataform without requiring accessing the other image sensor cells; and

outputting the accessed image data.

8. The method of claim 7, wherein the step of identifying comprises a step of determining a location of the image of the dataform within the image area.

9. The method of claim 7, wherein the step of identifying comprises a step of determining an oblique line component of the image of the dataform.

10. The method of claim 7, wherein the step of identifying comprises a step of determining a boundary of the image of the dataform within the image area.