SYSTEM AND METHOD FOR PERFORMING OPTICAL NAVIGATION ON GLASS-LIKE NAVIGATION SURFACES

• US 20090026351A1
• Filed: 07/27/2007
• Published: 01/29/2009
• Est. Priority Date: 07/27/2007
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Itagaki, Nobutaka
• Granted Patent: US 7,525,082 B2
• Time in Patent Office: Days
• US Class Current: 250/206.100
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface

Abstract

A system and method for performing optical navigation addresses M×N photosensitive elements of an image sensor array to capture first frames of image data of a navigation surface when set to a first operational mode such that each of the first frames of image data includes M×N sampled signals, and addresses at most the M×N photosensitive elements of the image sensor array to capture second frames of image data of the navigation surface when set to a second operational mode such that each of said second frames of image data includes less than M×N sampled signals.

Claims

1. A method for performing optical navigation on a navigation surface, said method comprising:

setting an image capturing mode to one of a first operational mode and a second operational mode based on said navigation surface;

electronically capturing said navigation surface using M×

N photosensitive elements of an image sensor array as first frames of image data when said image capturing mode is set to said first operational mode, including addressing said M×

N photosensitive elements such that each of said first frames of image data includes M×

N sampled signals;

electronically capturing said navigation surface using at most said M×

N photosensitive elements of the image sensor array as second frames of image data when said image capturing mode is set to said second operational mode, including addressing at most said M×

N photosensitive elements such that each of said second frames of image data includes less than M×

N sampled signals; and

processing said first and second frames of image data to determine relative displacements using at least some of said first and second frames of image data.

2. The method of claim 1 wherein said electronically capturing said navigation surface using at most said M×

N photosensitive elements as said second frames of image data includes addressing every n^th photosensitive elements of said image sensor array to capture said second frames of image data, where n is an integer greater than one.

3. The method of claim 2 wherein said addressing every n^th photosensitive elements of said image sensor array includes addressing every other photosensitive elements of said image sensor array to capture said second frames of image data.

4. The method of claim 1 wherein said electronically capturing said navigation surface using at most said M×

N photosensitive elements as said second frames of image data includes addressing blocks of said M×

N photosensitive elements of said image sensor array to capture said second frames of image data, each sampled signal of said second frames of image data corresponding to one of said blocks.

5. The method of claim 4 wherein said addressing said blocks of said M×

N photosensitive elements of said image sensor array includes addressing 2×

2 blocks of said M×

N photosensitive elements of said image sensor array to capture said second frames of image data.

6. The method of claim 1 wherein said electronically capturing said navigation surface using at most said M×

N photosensitive elements as said second frames of image data includes addressing a portion of said M×

N photosensitive elements of said image sensor array to capture said second frames of image data.

7. The method of claim 6 wherein said addressing said portion of said M×

N photosensitive elements of said image sensor array includes addressing a 32×

32 pixel portion of said M×

N photosensitive elements of said image sensor array, said image sensor array being a 64×

64 image sensor array.

8. The method of claim 1 wherein said M×

N photosensitive elements of said image sensor array are between 5 μ

m to 20 μ

m in size.

9. The method of claim 1 further comprising injecting ions onto said navigation surface to neutralize micro-particles on said navigation surface.

10. A system for optical navigation, said system comprising:

an image sensor array including M×

N photosensitive elements positioned to receive light reflected from a navigation surface;

a decoding unit operatively connected to said image sensor array to selectively address said M×

N photosensitive elements of said image sensor array;

a mode selector operatively connected to said decoding unit to set an image capturing mode to one of a first operational mode and a second operational mode based on said navigation surface;

a processor operatively connected to said decoding unit and said mode selector to instruct said decoding unit to selectively address said M×

N photosensitive elements of said image sensor array depending on said image capturing mode, said processor being configured to instruct said decoding unit to selectively address said M×

N photosensitive elements of said image sensor array to capture first frames of image data of said navigation surface when said image capturing mode is set to said first operational mode such that each of said first frames of image data includes M×

N sampled signals, said processor further being configured to instruct said decoding unit to selectively address at most said M×

N photosensitive elements to capture second frames of image data of said navigation surface when said image capturing mode is set to said second operational mode such that each of said second frames of image data includes less than M×

N sampled signals; and

an image processing module operatively connected to said image sensor array to receive said first and second frames of image data, said image processing module being configured to correlate said first and second frames of image data to determine relative displacements using at least some of said first and second frames of image data.

11. The system of claim 10 wherein said processor is configured to instruct said decoding unit to address every n^th photosensitive elements of said image sensor array to capture said second frames of image data when said image capturing mode is set to said second operational mode, where n is an integer greater than one.

12. The system of claim 11 wherein said processor is configured to instruct said decoding unit to address every other photosensitive elements of said image sensor array to capture said second frames of image data when said image capturing mode is set to said second operational mode.

13. The system of claim 10 wherein said processor is configured to instruct said decoding unit to address blocks of said M×

N photosensitive elements of said image sensor array to capture said second frames of image data when said image capturing mode is set to said second operational mode, each sampled signal of said second frames of image data corresponding to one of said blocks.

14. The system of claim 13 wherein said processor is configured to instruct said decoding unit to address 2×

2 blocks of said M×

N photosensitive elements of said image sensor array to capture said second frames of image data when said image capturing mode is set to said second operational mode.

15. The system of claim 10 wherein said processor is configured to instruct said decoding unit to address a portion of said M×

N photosensitive elements of said image sensor array to capture said second frames of image data when said image capturing mode is set to said second operational mode.

16. The system of claim 15 wherein said processor is configured to instruct said decoding unit to address a 32×

32 pixel portion of said M×

N photosensitive elements of said image sensor array when said image capturing mode is set to said second operational mode, said image sensor array being a 64×

64 image sensor array.

17. The system of claim 10 wherein said M×

N photosensitive elements of said image sensor array are between 5 μ

m to 20 μ

m in size.

18. The system of claim 10 further comprising an ion generator to inject ions onto said navigation surface to neutralize micro-particles on said navigation surface.

19. A system for optical navigation, said system comprising:

a light source configured to emit light;

an image sensor array including M×

N photosensitive elements positioned to receive the light reflected from a navigation surface;

an ion generator configured to inject ions onto said navigation surface;

a decoding unit operatively connected to said image sensor array to selectively address said photosensitive elements of said image sensor array;

a processor operatively connected to said decoding unit to instruct said decoding unit to selectively address said M×

N photosensitive elements of said image sensor array to capture said navigation surface as frames of image data; and

an image processing module operatively connected to said image sensor array to receive said frames of image data, said image processing module being configured to correlate said frames of image data to determine relative displacements using at least some of said frames of image data.

20. The system of claim 19 wherein said processor is configured to instruct said decoding unit to selectively address said M×

N photosensitive elements of said image sensor array to capture first frames of image data of said navigation surface when an image capturing mode is set to a first operational mode such that each of said first frames of image data includes M×

N sampled signals, said processor further being configured to instruct said decoding unit to selectively address at most said M×

N photosensitive elements to capture second frames of image data of said navigation surface when said image capturing mode is set to a second operational mode such that each of said second frames of image data includes less than M×

N sampled signals.