Electro-optical mouse with improved resolution for compensation of optical distortion
US4857903A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 6, 1986 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | May 6, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0317
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An electro-optical mouse has a four-quadrant photodetector, each quadrant producing a voltage proportional to the amount of light impinging thereon. The mouse slides over a surface having optically contrasting, i.e. reflecting and nonreflecting, indicia thereon. The position of the mouse relative to a coordinate system in the plane of the surface is determined by projecting light onto the surface and then detecting the amount of light reflected from the surface onto the respective quadrants. The mouse is able to detect within which of four ranges the amount of light impinging on each quadrant lies. A two-bit code indicating the range is generated for each quadrant, thereby forming an eight-bit detector code. In the case where the eight-bit detector code is the same, i.e., ambiguous, for two different positions of the mouse relative to an indicium being optically detected, the true position at a current instant in time is identified by interpolating between the position at a previous instant in time and the position at a subsequent instant in time. This look-ahead routine is performed after the predetermined ambiguous detector code has been recognized and after a determination has b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.