Optical mouse with limited wavelength optics

• US 8,847,888 B2
• Filed: 12/18/2007
• Issued: 09/30/2014
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bohn, David
• Primary Examiner(s): Cheng, Joe H
• Assistant Examiner(s): CRAWLEY, KEITH L
• Application Number:
  US11/959,449
• Publication Number:
  US 20090153486A1
• Time in Patent Office: 2,478 Days
• Field of Search: 345163-166
• US Class Current: 345/166
• 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
• CPC Class Codes: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence

Abstract

Various embodiments of optical mice are disclosed that facilitate off-surface detection while also providing high-contrast images of a tracking surface. In one embodiment, an optical mouse comprises a light source configured to emit light having a wavelength in or near a blue region of a visible light spectrum toward a tracking surface, an image sensor, and an optical band pass filter configured to pass the light having the wavelength in or near the blue region of the visible light spectrum emitted by the light source while filtering red and infrared wavelengths. Further, the mouse also comprises a controller configured to receive image data from the image sensor and to identify a tracking feature in the image data. The band pass filter prevents ambient light in the filtered wavelengths from reaching the image sensor, and thereby facilitates off-surface detection, while the blue color of the incident light and band pass filter provides a high-contrast image for motion tracking.

Claims

1. An optical mouse, comprising:

a body having a bottom surface comprising a location at which light can pass through;

a light source configured to emit light having a wavelength within a range of 400-490 nm toward a tracking surface;

an image sensor configured to receive light passing through the bottom surface at the location configured to pass light;

an optical band pass filter disposed optically between the tracking surface and the image sensor and configured to pass the light having the wavelength within the range of 400-490 nm emitted by the light source and exclude wavelengths from outside of the range of 400-490 nm such that all ambient light and all reflected light from the light source that passes through the bottom surface of the mouse to the image sensor is filtered by the band pass filter; and

a controller configured to receive image data from the image sensor and to identify a tracking feature in the image data.

2. The optical mouse of claim 1, wherein the controller is configured to detect an off-surface condition based upon an amount of light reaching the image sensor.

3. The optical mouse of claim 1, wherein the band pass filter comprises a window positioned in an opening of the bottom surface of the mouse.

4. The optical mouse of claim 1, wherein the band pass filter comprises one or more of a coating on a lens disposed optically between the tracking surface and the image sensor and a coating on the image sensor.

5. The optical mouse of claim 1, wherein the optical mouse has a specular architecture.

6. The optical mouse of claim 1, wherein the optical mouse has an oblique architecture.

7. The optical mouse of claim 1, wherein the light source is configured to emit white light.

8. The optical mouse of claim 1, wherein the light source is configured to emit blue light.

9. The optical mouse of claim 1, wherein the image sensor is configured to have a higher quantum yield in the range of 400-490 nm than outside of the range of 400-490 nm.

10. An optical mouse, comprising:

a body having a bottom surface comprising a location configured to pass light;

a light source configured to emit light having a wavelength within a range of 400-490 nm toward a tracking surface;

a collimating lens disposed between the light source and the tracking surface to collimate light within the range of 400-490 nm from the light source;

an image sensor;

an optical band pass filter disposed optically between the tracking surface and the image sensor and configured to pass light within the range of 400-490 nm and exclude wavelengths from outside of the range of 400-490 nm such that all ambient light and all reflected light from the light source that passes through the bottom surface of the mouse to all areas of the image sensor is filtered by the band pass filter; and

a controller configured to detect an off-tracking-surface condition of the mouse based upon an amount of light that reaches the image sensor.

11. The optical mouse of claim 10, wherein the mouse has a specular optical architecture.

12. The optical mouse of claim 10, wherein the mouse has an oblique optical architecture.

13. The optical mouse of claim 10, wherein the band pass filter comprises a window that forms a portion of the bottom surface of the mouse at the location configured to pass light.

14. The optical mouse of claim 10, wherein the band pass filter comprises one or more of a coating on a lens disposed optically between the tracking surface and the image sensor and a coating on the image sensor.

15. The optical mouse of claim 10, wherein the image sensor is configured to have a higher quantum yield in the range of 400-490 nm than outside of the range of 400-490 nm.

16. In an optical mouse comprising a light source and an image sensor, a method of operating the mouse, comprising:

illuminating a tracking surface with light from the light source having a wavelength within a range of 400-490 nm;

passing light reflected by the tracking surface toward the image sensor through a location in a bottom surface of the mouse;

filtering light to block light outside the range of 400-490 nm while passing the light having the wavelength within the range of 400-490 nm emitted by the light source such that all ambient light and all reflected light from the light source that passes through the bottom surface of the mouse to all areas of the image sensor is filtered by a band pass filter;

detecting an off-surface condition based upon a total light intensity on the image sensor dropping below a preselected threshold; and

changing an operating condition of the mouse upon detecting the off-surface condition.

17. The method of claim 16, wherein changing an operating condition of the mouse comprises switching the mouse to a low-power mode.

18. The method of claim 16, wherein changing an operating condition of the mouse comprises ceasing a tracking of motion of the mouse.

19. The method of claim 18, further comprising detecting an on-surface condition and then resuming tracking of motion of the mouse.

20. The method of claim 16, wherein the image sensor is configured to have a higher quantum yield in the range of 400-490 nm than outside of the range of 400-490 nm.