Projection type image display apparatus
US7766488B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 15, 2007 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Mar 11, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/317
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection-type image display apparatus for projecting an image, enlargedly, onto a projection surface, comprises: an image display element; a lens group, being disposed behind the image display element, comprising therein, a front lens group made up with a plural number of lenses, including, at least, a refractive lens, having a positive power and being rotationally symmetric in a surface configuration thereof, and a rear lens group made up with a plural number of lenses, including, at least, a lens having a free curved surface configuration and being rotationally asymmetric, thereby emitting the image displayed on the image display element; a reflection mirror for reflecting the light from the lens group, thereby projection onto the projection surface, obliquely; a first mounting base, on which the rear lens group is mounted; and a rod member, which is provided on the mounting base for moving the mounting base.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.