Projection image display device and projection optical system for performing extended projection
US8292438B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 2009 |
| Grant date | Oct 23, 2012 |
| Priority date | — |
| Expiry date | Feb 1, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3105
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection image display device includes a light source; an illumination optical system that uniformly irradiates a surface of an image modulating element (primary image surface) with a light beam emitted from the light source; and a projection optical system that performs with respect to a screen (a secondary image surface) extended projection on image information provided at the primary image surface and modulated by the image modulating element. The projection optical system includes a first optical system having a positive refractive power, and a second optical system having a concave reflecting surface. The first optical system has a common optical axis at which all optical components of the first optical system have rotationally symmetric surfaces, and a screen shift function that causes the secondary image surface to be moved by moving at least one of the optical components of the first optical system substantially perpendicularly to the optical axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.