Projection lens device and projector
US7021772B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 7, 2003 |
| Grant date | Apr 4, 2006 |
| Priority date | — |
| Expiry date | Mar 19, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3194
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention provides a lens device and projector in which light passing through liquid crystal panels is projected on a screen using the lens device. The lens device includes a diaphragm mechanism. A telecentric optical system for the display device is provided between the diaphragm mechanism and the liquid crystal panels. An aperture of the diaphragm mechanism is positioned at a location where primary rays that are emitted from the liquid crystal panels parallel to an optical axis intersect with the optical axis. Contrast characteristics of the liquid crystal panels vary depending on angles and directions of incidence of rays of light. The aperture of the diaphragm mechanism is formed in a substantially triangular shape in accordance with the shape of the contrast characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.