Touch operation signal output device
US6366276B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1998 |
| Grant date | Apr 2, 2002 |
| Priority date | — |
| Expiry date | Jun 10, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0421
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for reliably detecting a touch operation in a touch sensitive control surface, despite the influence of light or the existence of an obstruction. In the touch tracer, LEDs and phototransistors for detecting a touch position on the input pad are arranged to form parallel optical axes in the vertical direction and the horizontal direction. The optical axes of the LEDs and the phototransistors are alternately arranged in opposite directions to the adjacent optical axis. Moreover, the front surface of the phototransistor is closed except for an aperture that forms an optical axis only between opposing LEDs. The apertures are divided in half into top and bottom portions by a light-shielding film. Because of the light-shielding film, the phototransistor does not receive any light interference from the adjacent LED or incidental sunlight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.