LCD projector with shift and tilt field lens
US5836664A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1997 |
| Grant date | Nov 17, 1998 |
| Priority date | — |
| Expiry date | Apr 16, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/7441
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention includes an invertible and orthoscopic LCD projector having a LCD panel for providing display information that is projected toward a display screen to form a display image. In a preferred embodiment, a converging Fresnel lens is positioned to receive the display information from the LCD panel and form a display object corresponding to the display image. The converging Fresnel lens has an optical center offset from the optical center of the LCD panel in an elevation direction and defines a projection optical axis that extends toward the display screen along an elevation angle in the elevation direction. The Fresnel lens is tilted automatically about a tilt axis transverse to the projection optical axis and the elevation direction by an amount proportional to the elevation angle to cooperate with the offset of the Fresnel lens optical center to form an orthoscopic display image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.