Optical displacement detection over varied surfaces
First Claim
1. A dark-field optical displacement detection system for use in an optical input device capable of tracking motion of the optical input device relative to a glass surface, a top of the glass surface having features thereon, the dark-field optical displacement detection system comprising:
- an illumination subsystem comprising a light source for illuminating the glass surface;
a lens positioned to collect at least some diffracted light from the features on the top of the glass surface, but not the zero order light reflected from the glass surface, wherein the features are not sufficient to enable tracking movement of the optical input device using conventional methods used for optically rough surfaces; and
a detector optically coupled to the lens to receive the at least some diffracted light wherein the dark-field optical displacement detection system tracks motion relative to the top of the glass surface, and not relative to an optically rough surface underneath the glass surface.
2 Assignments
0 Petitions
Accused Products
Abstract
Embodiments of the present invention enable an optical device to track on a diffusing surface over which a transparent and/or translucent and/or optically smooth surface is placed. Some embodiments are directed towards detecting when an optical device is lifted off the surface it was resting on. Embodiments also include a sensing system that detects the z distance (distance to the tracking surface) and improves image quality by improving the effectiveness of the optical sensor subsystem and/or the illumination subsystem at the detected z distance. Other embodiments include a system and method that enables an optical device to track on a transparent and/or translucent and/or optically smooth surface alone. This may involve dark-field imaging based on certain features (e.g., dirt) already present on the transparent surface. Alternately, this may involve creating features such as droplets, spreading dirt residue, and creating thermal spots, which can be used for tracking.
-
Citations
18 Claims
-
1. A dark-field optical displacement detection system for use in an optical input device capable of tracking motion of the optical input device relative to a glass surface, a top of the glass surface having features thereon, the dark-field optical displacement detection system comprising:
-
an illumination subsystem comprising a light source for illuminating the glass surface; a lens positioned to collect at least some diffracted light from the features on the top of the glass surface, but not the zero order light reflected from the glass surface, wherein the features are not sufficient to enable tracking movement of the optical input device using conventional methods used for optically rough surfaces; and a detector optically coupled to the lens to receive the at least some diffracted light wherein the dark-field optical displacement detection system tracks motion relative to the top of the glass surface, and not relative to an optically rough surface underneath the glass surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. An optical displacement detection system for use in an optical input device capable of tracking on a surface comprising a glass layer having features thereon, and a second layer of a material below the glass layer that scatters at least some light, the optical displacement detection system comprising:
-
a coherent light source for illuminating the glass layer and the second layer by an illumination beam; a lens configured to collect at least some scattered light from the features on top of the glass layer, but not zero order light specularly reflected from the glass layer, and at least some scattered light from the second layer; and a detector optically coupled to the lens for receiving the at least some scattered light from the features on the glass layer and the at least some scattered light from the second layer, wherein the features are not sufficient to enable tracking movement of the optical input device using conventional methods used for optically rough surfaces, wherein the dark-field optical displacement detection system tracks motion relative to the top of the glass surface, and not relative to the second layer underneath the glass layer. - View Dependent Claims (12, 13)
-
-
14. A method for optically detecting displacement on a glass surface and an optically rough surface at different times, the method comprising:
-
at a first time, upon being placed on the glass surface, receiving a signal based upon at least some diffracted light from features on top of the glass a surface, but not zero order light specularly reflected from the glass surface, and detecting displacement relative to the top of the glass surface; and at a second time, upon being placed on the optically rough surface, receiving a signal based upon at least some scattered light from the optically rough surface, and detecting displacement relative to the optically rough surface. - View Dependent Claims (15, 16, 17)
-
-
18. A method for optically detecting displacement on a surface comprising a first layer of a transparent material, and a second layer of a material below the first layer that scatters at least some light, the method comprising:
-
illuminating the first layer and the second layer with a light source; receiving at least some scattered light from certain features on top of the first layer, but not zero order light specularly reflected from the first layer; and detecting displacement based on the received scattered light, wherein the optical input device tracks motion relative to the top of the first layer and not relative to the second layer.
-
Specification