Optical reader having reduced specular reflection read failures

• US 20060283952A1
• Filed: 06/02/2006
• Published: 12/21/2006
• Est. Priority Date: 06/03/2005
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Wang, Ynjiun P.
• Granted Patent: US 7,770,799 B2
• Time in Patent Office: Days
• US Class Current: 235/462.10
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10752 Exposure time control
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/12 using a selected wavelength, e.g. to sense red marks and ignore blue marks
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1443 locating of the code in an image
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: H04N 23/10 for generating image signals from different wavelengths
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/42 by switching between different modes of operation using different resolutions or aspect ratios, e.g. switching between interlaced and non-interlaced mode
• CPC Class Codes: H04N 25/532 by controlling global shutters in CMOS SSIS
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors

Abstract

There is provided in one embodiment an optical reader having an image sensor array. In one embodiment, the image sensor array can include a first subset of pixels and a second subset of pixels. The first subset of pixels can be devoid of light polarizing filter elements, and the second subset of pixels can be light polarizing pixels including light polarizing filter elements. An optical reader can be configured to selectively read out image data from an image sensor array'"'"'s light polarizing pixels.

Claims

1. A hand held bar code reading device for reading bar code symbols under specular reflection read conditions, said hand held bar code reading device comprising:

(a) a solid state image sensor array having a plurality of pixels, the plurality of pixels being formed in a plurality of rows of pixels, wherein a first subset of pixels include monochrome pixels and a second subset of said pixels are light polarizing pixels that include light polarizing filter elements that attenuate incident light rays;

(b) an imaging lens focusing an image onto said solid state image sensor array;

(c) a hand held housing encapsulating said imaging lens;

(d) a control circuit communicatively coupled to said solid state image sensor array;

(e) wherein said hand held device operates in a first mode of operation wherein said control circuit selectively reads out image data from said light polarizing pixels and, wherein said control circuit is configured to be at least one of manually or automatically driven into said first mode of operation.

2. The hand held device of claim 1, wherein said hand held device is configured so that said hand held device is automatically driven into said first mode of operation when said control circuit determines a saturation condition.

3. The hand held device of claim 1, wherein said hand held device includes separate reset control lines for facilitating reset of pixels external to said light polarizing pixels independent of a resetting of said light polarizing pixels.

4. A method in support of reading a bar code symbol in specular reflection read conditions, said method comprising the steps of:

(a) including in a subset of pixels of an image sensor array light polarizing pixels, said light polarizing pixels having light polarizing filter elements which attenuate incident light rays;

(b) incorporating said image sensor array in a hand held bar code reader housing in combination with an imaging lens such that an image of said bar code symbol is projected onto said image sensor array;

(c) actuating said image sensor array to read out image data from said array;

(d) processing said image data read out at step (c) to determine whether a saturation condition is present; and

(f) if a saturation condition is determined to be present at step (d) transferring image data selectively corresponding to said light polarizing pixels to a decode circuit.

5. The method of claim 4, wherein said processing step (d) includes the step of attempting to decode utilizing image data other than image data corresponding to said light polarizing pixels.

6. The method of claim 4, wherein said processing step (d) includes the step of analyzing white values.

7. A hand held bar code reading device for reading bar code symbols under specular reflection read conditions, said hand held bar code reading device comprising:

(a) a solid state image sensor array having a plurality of pixels, the plurality of pixels being formed in a plurality of rows of pixels, wherein a first subset of pixels include pixels without light polarizing filter elements and a second subset of said pixels are light polarizing pixels that include light polarizing filter elements that attenuate incident light rays;

(b) an imaging lens focusing an image onto said solid state image sensor array;

(c) a hand held housing encapsulating said solid state image sensor array;

(d) a control circuit communicatively coupled to said solid state image sensor array;

(e) wherein said hand held device is configured to operate in a decode mode of operation in which said control circuit (1) selectively extracts image data corresponding to said light polarizing pixels from a frame of image data including image data corresponding to said pixels without light polarizing elements and image data corresponding to said light polarizing pixels, and (2) transfers said extracted image data corresponding to said light polarizing to a bar code decode circuit.

8. The hand held device of claim 7, wherein said hand held device is configured so that said hand held device commences operation in said decode mode responsively to an attempt to decode utilizing said frame subject to selective extraction of image data corresponding to said light polarizing pixels.