Opto sensor signal detector
US6297859A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1999 |
| Grant date | Oct 2, 2001 |
| Priority date | — |
| Expiry date | Jun 30, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/31
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection display comprises a display device forming an image for projection onto a display screen. A photo sensor is adjacent to the display screen and generates a first signal responsive to a level of the projected image illumination incident on the photo sensor. A detector is coupled to receive the first signal and generates an output signal indicative of detecting the first signal. A source of a predetermined detection threshold value is coupled to the detector for determining a threshold at which the detection of the first signal occurs. Wherein the first signal exceeds the predetermined detection threshold value, the detector detects and generates the output signal indicative of signal detection, and generates a second signal for coupling to the source to change the predetermined detection threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.