Optical sensor for pointing device with conical disks and single photodetector

An input device having a movable ball and having two rollers biased against said ball, comprising:

• a first conical shaped encoder connected to said first roller;
• a second conical shaped encoder connected to said second roller;
• a light emitter placed to direct light at said first and second encoders;
• first and second light sensors mounted on a single semiconductor chip located adjacent to said first and second encoders, and positioned such that light from said light emitter is directed at and interacts with said first encoder and is received by said first sensor, and directed at and interacting with said second encoder and is received by said second sensor;
• wherein said encoders alternately block and let light pass through as they rotate with said respective roller;
• wherein said single semiconductor chip is mounted in a vertical plane tangent to both said conical shaped encoders;
• wherein said first and second rollers contact said ball at two points 90 degrees apart;
• and
• wherein said conical shaped encoders are conical with an angle of 45 degrees from a shaft connecting each to a respective one of said first and second rollers.

An input device having a movable ball and having two rollers biased against said ball, comprising:

• a first conical shaped encoder connected to said first roller;
• a second conical shaped encoder connected to said second roller;
• a light emitter placed to direct light at said first and second encoders;
• first and second light sensors mounted on a single semiconductor chip located adjacent to said first and second encoders, and positioned such that light from said light emitter is directed at and interacts with said first encoder and is received by said first sensor, and directed at and interacting with said second encoder and is received by said second sensor;
• wherein said encoders comprise reflective structures configured to selectively reflect light from said light emitter towards said sensors;
• wherein said single semiconductor chip is mounted in a position ranging from horizontally flat to a vertical plane tangent to both said conical shaped encoders, at an angle in said range relative to said reflected light;
• wherein said first and second rollers contact said ball at two points 90 degrees apart;
• and
• wherein said conical shaped encoders are conical with an angle of 45 degrees from a shaft connecting each to a respective one of said first and second rollers.