US 7,247,835 B2Granted

Optical navigation device, and method for manufacturing same

OwnerKeng Yeam Changinventor

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Abstract

An optical navigation sensor receives light that is produced by a light source and reflected from a surface. The optical navigation sensor has a silicon substrate having a plurality of photo-sensing regions, each of which receives a portion of the reflected light, and each of which provides a pixel of navigation information. At least one layer of material is deposited on the photo-sensing regions of the silicon substrate during a silicon wafer fabrication process. Each layer has a thickness that causes it to serve as an anti-reflection coating and reduce a percentage of light that is reflected away from the photo-sensing regions of the silicon substrate. A circuit biases each of the photo-sensing regions with a current, the current providing a given responsivity, and the current being less than a current that would be required to provide the given responsivity absent the at least one layer of material.

Claims29

Dependent claims

An optical navigation device, comprising:

a light source to produce light for illuminating a surface;
an optical navigation sensor to receive light reflected from the surface, the light reflected from the surface being initially produced by the light source, and the optical navigation sensor having:
a silicon substrate having a plurality of photo-sensing regions, each of which receives a portion of the light reflected from the surface, and each of which provides a pixel of navigation information;
at least one layer of material that was deposited on the photo-sensing regions of the silicon substrate during a silicon wafer fabrication process, wherein each of the at least one layer of material has a thickness that causes the layer of material to serve as an anti-reflection coating and reduce a percentage of light that is reflected away from the photo-sensing regions of the silicon substrate to less than 30%;
and
a circuit to bias each of the photo-sensing regions with a current, the current providing a given responsivity, and the current being less than a current that would be required to provide the given responsivity absent the at least one layer of material.

3 more elements

A method for manufacturing an optical navigation device, comprising:

providing a silicon wafer having a plurality of optical navigation sensors formed thereon, wherein each of the optical navigation sensors has a plurality of photo-sensing regions, and wherein each of the photo-sensing regions provides a pixel of navigation information;
depositing at least one layer of material on the photo-sensing regions of the silicon substrate during a silicon wafer fabrication process, wherein each of the at least one layer of material has a thickness that causes the layer of material to serve as an anti-reflection coating and reduce a percentage of light that is reflected away from the photo-sensing regions of the silicon substrate to less than 30%;
separating each of the optical navigation sensors from the wafer;
mounting a light source and one of the optical navigation sensors in an optical navigation device, with the light source and the one of the optical navigation sensors being positioned to enable light produced by the light source to be reflected from a surface and received by the one of the optical navigation sensors;
and
coupling the one of the optical navigation sensors to a circuit to bias each of its photo-sensing regions with a current, the current providing a given responsivity, and the current being less than a current that would be required to provide the given responsivity absent the at least one layer of material.

3 more elements

Dependencies are inferred from the claim text.