Method and apparatus for distortion correction in optical projectors
US5355188A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1993 |
| Grant date | Oct 11, 1994 |
| Priority date | — |
| Expiry date | Sep 9, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/132
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projector (100) including an liquid crystal display image source (120), a field lens (126), and a projection lens (128) projects a full-color image by projecting and converging images of multiple liquid crystal displays ("LCDs"). The image is properly positioned without keystoning by tilting the field lens and offsetting the center of the LCD image source from the optical axis (142) of the projection lens. Trapezoidal error is eliminated by maintaining the optical center (156) of the field lens on the optical axis of the projection lens. During focusing, a mounting apparatus (164) adjusts the offset (154) between the center of the LCD and the optical axis of the projection lens for proper convergence of the images and maintains the optical center of the field lens on the optical axis of the projection lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.