Multimedia projection system with image quality correction
US5975704A · kind A · utility
11Cited by
8References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 25, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Feb 25, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3185
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multimedia projector comprises a optical frame that mounts, from back to front, a light source, a back fresnel lens, a back polarizer, an LCD display object, a front polarizer, a front fresnel lens, and a front lens group for projecting images formed by the LCD display object. To provide contrast adjustment, a contrast adjustment mechanism is attached to the back polarizer to permit the manual selective tilting of the back polarizer about an axis extending perpendicular to the front polarizer, in order to optimize contrast of images projected by the front lens group.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.