Alignment of the optical and the electrical scan in a scrolling color projector
US6690432B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2001 |
| Grant date | Feb 10, 2004 |
| Priority date | — |
| Expiry date | Jun 25, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3117
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A prism is mounted onto a motor without regard to its rotation angle relative to the motor index. Its position is electronically set later after construction of the optical path. A motor controller is used to control the rotation of the prism. This motor controller keeps the prism spinning at a constant velocity and positions the prism phase (rotation angle versus time). A variable offset is used to position the absolute prism rotation as a function of time. The phase may be advanced or delayed by an operator during set up. Each prism has its own phase. The phase of each prism in the system is set so that the illumination pattern correctly matches the video addressing of the panel. This is a one time set up during construction. The correct positions are set, and stored in non-volatile memory for life.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.