Intensity flattener for optical mouse sensors
US6819314B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 8, 2002 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Jun 24, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0317
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for flattening the illumination intensity over an optical sensor is disclosed. The intensity of light off the axis from a lens is less than the light on axis by a factor of cos4&thgr;, where &thgr; is the angle from the lens exit pupil to the off-axis point. Light from the lens incident upon the optical sensor therefore will not be uniform in intensity. Light-blocking patches are placed over the areas of the optical sensor where light intensity needs to be reduced to achieve uniform illumination intensity across the entire optical sensor. Areas of the optical sensor that fall closest to the axis of the lens receive the greatest intensity of light due to the rule of cos4&thgr;, and therefore will require more light-blocking patches than areas of the optical sensor further away from the lens axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.