Oblique access to image data for reading bar codes

• US 5,831,674 A
• Filed: 10/04/1995
• Issued: 11/03/1998
• Est. Priority Date: 06/10/1994
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Metanetics Corporation
• Inventors: Ju, Paul P., Wang, Ynjiun P.
• Primary Examiner(s): Garber, Wendy
• Assistant Examiner(s): Ho, Tuan V.
• Application Number:
  US08/538,834
• Time in Patent Office: 1,126 Days
• Field of Search: 348/294, 348/300, 348/301, 348/302, 348/303, 348/304, 348/308, 245/462
• US Class Current: 348/302
• 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 addressable to enable readout of randomly selected image data from any one or more individual sensor cells, for any selected image area (13), or for the entire image area (15). 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 area (13) may be used by the address unit (20) to provide address signals representative of the location of a specific sensor cell or area (13) of the array including image data of interest. 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 portion of the image area at an output port (34). Simplified readout can be provided for oblique line components of images. Differing input bus widths enable different levels of cell or line selection.

Claims

1. An oblique access image sensor array system, enabling readout on a single-coordinate sequential basis of image data for an oblique line component of a two-dimensional image area including an optically readable code, comprising:

a location signal source arranged to provide location signals representative of the location of said optically readable code within said image area;

a two-dimensional array of image sensor cells positioned in rows and columns and arranged to provide image data representative of said image area;

an address unit responsive to said location signals to provide two-coordinate address signals for row and column locations of sensor cells representative of image area components of said oblique line component, said oblique line component positioned obliquely to said rows and columns;

at least one readout circuit coupled to said array and responsive to said two-coordinate address signals to selectively designate an oblique series of said cells at row and column intersections representative of the location of said oblique line component;

at least one sampling device coupled to said array and arranged to access image data for said oblique line component as available at cells in said oblique series of cells; and

an output circuit coupled to each said sampling device and arranged to provide single-coordinate output signals representative of image data read sequentially from said oblique series of cells, said output signals not including information as to the two-coordinate addresses of said cells from which the image data was accessed.

2. An oblique access image sensor array system as in claim 1, wherein said output device is an amplifier arranged to provide said output signals representative of said oblique line section as a series of image data values not accompanied by information as to the angular orientation of said oblique line component.

3. An oblique access image sensor array system as in claim 1, including horizontal and vertical readout circuits responsive to said address signals to respectively selectively designate rows and columns of said cells in order to designate said row and column intersections representative of the location of said oblique line component.

4. An oblique access image sensor array system as in claim 1, including a plurality of sampling devices, one coupled to each column of image sensor cells of said array.

5. An oblique access image sensor array system as in claim 1, wherein said array of image sensor cells comprises an array of photodiode devices and said readout circuit comprises a shift register type circuit.

6. An oblique access image sensor array system as in claim 1, wherein said location signal source is a bar code location system arranged to make available to said address unit location signals representative of the position of a bar code image within said image area.

7. An oblique access image sensor array system, enabling an oblique line component of a two-dimensional optically readable code to be read out sequentially as a horizontal line of image data, comprising:

a location signal source arranged to provide location signals representative of the location of said optically readable code within said image area;

a two-dimensional array of image sensor cells positioned in vertical rows and horizontal columns and arranged to provide image data representative of an image area containing an image of said optically readable code positioned obliquely to said rows and columns;

an address unit responsive to said location signals to provide two-coordinate address signals for vertical and horizontal coordinates of the location within said image area of said oblique line component, said oblique line component positioned obliquely to said rows and columns;

at least one readout circuit coupled to said array and responsive to said two-coordinate address signals to selectively designate an oblique series of said cells at vertical row and horizontal column intersections representative of the location of said oblique line component;

at least one sampling device coupled to said array and arranged to access image data for said oblique line component as available at cells in said oblique series of cells at said vertical row and horizontal column intersections; and

an output circuit coupled to each said sampling device and arranged to provide output signals representative of image data read sequentially from said oblique series of cells without accompanying two-coordinate address information and thereby representative of said oblique line component rotated to a horizontal alignment.

8. An oblique access image sensor array system as in claim 7, including two readout circuits responsive to said address signals to each selectively designate one of two intersecting lines of said cells, and wherein said at least one sampling device is arranged to access image data for said oblique line component which is available at cells at the intersections of said intersecting lines.

9. An oblique access image sensor array system as in claim 7, wherein said address unit is arranged to provide address signals representative of the location of said oblique line component, which comprises an oblique line component of predetermined length, inclination and curvature.

10. An oblique access image sensor array system as in claim 7, wherein said array of image sensor cells comprises an array of photodiode devices and said readout circuit comprises a shift register type circuit.

11. An oblique access image sensor array system as in claim 7, wherein said location signal source is a bar code location system arranged to provide location signals representative of the position of a bar code image within said image area.

12. An oblique access image sensor array system as in claim 7, wherein said address unit is arranged to provide address signals representative of the location of an oblique line component which is aligned with the top edge of said image portion containing the image of said optically readable code, said image portion being obliquely aligned within said image area covered by said array.

13. An oblique access image sensor array system as in claim 12, wherein said address unit is arranged to provide address signals representative of the locations of additional oblique line components in order to provide output signals representative of complete image data for said image portion containing the image of said optically readable code.

14. An oblique access method, for accessing image data representative of an optically readable code, comprising the steps of:

(a) providing image data for an image area represented by an array of rows and columns of image sensor cells, said image area including an image portion containing an image of said code which is positioned obliquely to said rows and columns;

(b) providing location signals representative of the location of said image portion within said image area;

(c) providing, in response to said location signals, two-coordinate address signals for row and column locations of sensor cells representative of a first oblique line component of said image portion containing said code image, said first oblique line component positioned obliquely to said rows and columns;

(d) utilizing said address signals to read image data out of an oblique series of said image sensor cells at row and column intersections representative of the location of said first oblique line component;

(e) utilizing said step (d) image data to provide single-coordinate output signals representative of said image data provided sequentially without inclusion of information as to the original two-coordinate addresses of said image data; and

(f) utilizing said output signals to decode said optically readable code.

15. An oblique access method as in claim 14, wherein said optically readable code is a 2-D bar code including rows of spaced bar elements extending at an oblique angle to said rows of sensor cells, and wherein in step (b) said location signals represent the location of a first oblique line component extending at an oblique angle so as to cross a plurality of said bar elements.

16. An oblique access method as in claim 14, additionally including the following step between steps (d) and (e):

(x) repeating steps (c) and (d) for a plurality of additional oblique line components, each said additional oblique line component successively laterally spaced from said first oblique line component.