Ultra-thin image projection system
US7714943B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 2006 |
| Grant date | May 11, 2010 |
| Priority date | — |
| Expiry date | Feb 26, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3129
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An ultra-thin rear projection display system (RPDS) is disclosed. The system uses a small flat mirror, a small non-rotationally symmetric mirror and a larger non-rotationally symmetric mirror to achieve a D-to-d ratio of around 11:1 while rendering a significantly distortion free image on the screen. The first two mirrors are significantly smaller than the size of the screen, while the third mirror is significantly larger than the first two mirrors but smaller than the screen. In one embodiment, the lens and light engine are positioned horizontally to one side and, in another example, the lens and light engine are positioned vertically, projecting downwards. In one example, an image processor is used to correct for the remaining distortions. In another example, the system is adapted such that the light rays forming the projected image are within a certain range of angles such that a TIR Fresnel lens could be used to collimate the image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.