Indicia reading terminal having multiple exposure periods and methods for same

• US 8,295,601 B2
• Filed: 08/12/2009
• Issued: 10/23/2012
• Est. Priority Date: 08/12/2009
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Bremer, Edward C., Havens, William H., Feng, Chen, Wang, Ynjiun P.
• Primary Examiner(s): Bali, Vikkram
• Application Number:
  US12/540,214
• Publication Number:
  US 20110038563A1
• Time in Patent Office: 1,168 Days
• Field of Search: 382/181, 382/313
• US Class Current: 382/181
• CPC Class Codes: G06K 2207/1011 Aiming
• CPC Class Codes: G06K 2207/1013 Multi-focal
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10752 Exposure time control
• CPC Class Codes: H04N 25/533 by using differing integration times for different sensor regions

Abstract

There is described an image reading terminal having an image sensor array including a plurality of pixels, a first optical assembly for focusing imaging light rays onto a first set of pixels of an image sensor array and a second optical assembly for focusing imaging light rays onto a second set of pixels of the image sensor array. The first set of pixels and the second set of pixels of the image sensor array can have different exposure settings in a single exposure period for the image sensor array. In one embodiment, the indicia reading terminal can be adapted to process image data corresponding to pixels of the image sensor array for attempting to decode a decodable indicia.

Claims

1. An image reading terminal comprising:

a two dimensional image sensor array extending along an image plane, said two dimensional image sensor array comprising a plurality of pixels;

a hand held housing encapsulating said two dimensional image sensor array;

a first optical assembly for focusing imaging light rays onto a first set of pixels of said two dimensional image sensor array, wherein the first set of pixels comprise pixels of a plurality of rows of pixels of the two dimensional image sensor array, wherein said first set of pixels have a first exposure time for receiving said imaging light rays transmitted by said first optical assembly;

a second optical assembly for focusing imaging light rays onto a second set of pixels of said two dimensional image sensor array, wherein the second set of pixels comprises pixels of a plurality of rows of pixels of the two dimension image sensor array wherein said second set of pixels have a second different exposure time of a duration different from a duration of the first exposure time for receiving said imaging light rays transmitted by said second optical assembly;

wherein a portion of said first exposure time and a portion of said second exposure time are concurrent;

a memory capable of storing a frame of image data, said frame of image data representing light incident on said image sensor array; and

a CPU capable of addressing said memory, wherein said CPU is adapted to attempt to decode a decodable indicia represented in said frame of image data.

2. The image reading terminal of claim 1, wherein said first exposure time and said second exposure time have a concurrent start time or overlap within a single exposure period for the image sensor array.

3. The image reading terminal of claim 1, wherein said first exposure time and said second exposure time represent independent exposure or gain settings for the first set of pixels and the second set of pixels, respectively.

4. The image reading terminal of claim 1, wherein said first exposure time and said second exposure time maintain a substantially constant brightness or a substantially balanced brightness for pixels in the first set of pixels and the second set of pixels, respectively.

5. The image reading terminal of claim 1, wherein the first set of pixels is larger than the second set of pixels, wherein the first set of pixels is larger than 90%, larger than 70% or larger than 50% of the image sensor array, wherein the first set of pixels are respectively contiguous in the image sensor array, and wherein the second set of pixels are respectively contiguous in the image sensor array.

6. The image reading terminal of claim 1, wherein the first set of pixels and the second set of pixels comprise 100%, less than 50%, less than 25%, less than 5% or less than 0.5% of pixels in the image sensor array.

7. The image reading terminal of claim 1, comprising an image sensor array control circuit configured set said first exposure time and said second different exposure time within a frame time of a frame rate of the image reading terminal.

8. The image reading terminal of claim 7, wherein a blanking time is added to the frame time when one of said first exposure time or said second different exposure time exceed the frame time.

9. The image reading terminal of claim 8, wherein said frame rate of the image reading terminal decreases as a vertical blanking time increases.

10. The image reading terminal of claim 1, said first optical assembly to include a center optical axis and a first imaging lens, said second optical assembly to include a center optical axis and a second imaging lens, wherein said first imaging lens of said first optical assembly has a shorter focal length than the second imaging lens of said second optical assembly.

11. The image reading terminal of claim 1, wherein the first set of pixels and the second set of pixels comprise a plurality of rows, a plurality of columns, a single row, a single column, a partial row or a partial column in the image sensor array.

12. The image reading terminal of claim 1, wherein said first optical assembly and said image sensor array define a first field of view, and wherein said second optical assembly and said image sensor array define a second field of view, and wherein said terminal includes a first aiming pattern generator and a second aiming pattern generator, the first aiming pattern generator capable of projecting an aiming pattern at a prescribed location for said first field of view through a range of terminal to target distances, the second aiming pattern generator capable of projecting an aiming pattern at a prescribed location in said second field of view through a range of terminal to target distances.

13. The image reading terminal of claim 1, wherein the image sensor array comprised a Bayer pattern or a monocolor sensor.

14. An indicia reading terminal comprising:

a two dimensional image sensor array comprising a plurality of pixels;

a hand held housing encapsulating said two dimensional image sensor array;

an image sensor array control circuit to control a first exposure time for a first set of pixels of the plurality of pixels and a second different exposure time for a second different set of pixels of the plurality of pixels of the image sensor array, the first exposure time and the second exposure time having different durations, wherein the first set of pixels comprise pixels of a plurality of rows of pixels of the two dimensional image sensor array, wherein the second set of pixels comprise pixels of a plurality of rows of pixels of the two dimensional image sensor array, wherein a portion of the first exposure time and a portion of the second different exposure time are concurrent, wherein;

an image sensor array readout control circuit to output image data of the first set of pixels and the second set of pixels;

a memory capable of storing said image data; and

a CPU capable of addressing said memory, wherein said CPU is adapted to attempt to decode a decodable indicia represented in said image data.

15. The indicia reading terminal of claim 14, wherein the image data is a frame of image data representing light incident on the plurality of pixels of said image sensor array, wherein the first exposure time and said second exposure time overlap or concurrently start in a frame time.

16. The indicia reading terminal of claim 14, wherein said first exposure time and said second exposure time represent independent exposure or gain settings for the first set of pixels and the second set of pixels, respectively.

17. The indicia reading terminal of claim 14, wherein said first exposure time and said second exposure time maintain a substantially constant brightness or a substantially balanced brightness for pixels in the first set of pixels and the second set of pixels, respectively.

18. The indicia reading terminal of claim 14, comprising:

a first optical assembly to focus imaging light rays onto a first set of pixels of said two dimensional image sensor array; and

a second optical assembly to focus imaging light rays onto a second set of pixels of said two dimensional image sensor array, wherein the first set of pixels and the second set of pixels are respectively contiguous in the image sensor array.

19. An image reading terminal comprising:

a two dimensional image sensor array extending along an image plane, said two dimensional image sensor array comprising a plurality of pixels;

an image sensor array control circuit to read out a frame of data from said plurality of pixels;

a first set of pixels and a second different set of pixels comprise the plurality of pixels of the image sensor array, wherein the first set of pixels and the second set of pixels each have different exposure times, the different exposure times being different durations, wherein the first set of pixels comprise pixels of a plurality of rows of pixels of the two dimensional image sensor array, wherein the second set of pixels comprises pixels of a plurality of rows of pixels of the two dimension image sensor array, wherein a portion of the different exposure times are concurrent; and

a CPU capable of receiving the frame of data, wherein said CPU is adapted to attempt to decode a decodable indicia represented in said frame of data.

20. The image reading terminal of claim 19, wherein the frame of data represents light incident on the plurality of pixels of said image sensor array.