Projector and projector accessory
US7185987B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 8, 2004 |
| Grant date | Mar 6, 2007 |
| Priority date | — |
| Expiry date | Mar 26, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N17/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projector for enlarging and projecting the display image on a light valve onto a screen is provided with: an infrared photodetector for photodetecting infrared light that is emitted by an electronic pen that is manipulated on the screen and that is provided with an infrared light emission device and ultrasonic generator; at least two ultrasonic receivers for detecting ultrasonic waves that are emitted by the electronic pen; means for measuring the distance to a screen; and means for supplying coordinate data in which the position of the electronic pen on the screen, which has been calculated based on output of the infrared photodetector, output of the ultrasonic generator, and output of the means for measuring the distance to the screen, has been normalized by the length of a side of a projected rectangular image that has been enlarged and projected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.