Projection lens system
US4948237A · kind A · utility
17Cited by
3References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1988 |
| Grant date | Aug 14, 1990 |
| Priority date | — |
| Expiry date | Apr 29, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a projection system wherein an optical system comprising a first lens for correcting a spherical aberration dependent on the aperture length, a second lens for enlargement and a third lens for correcting a field curvature, projects an image reproduced on a CRT having a curved phosphor surface, onto a screen, the third lens is spaced from the CRT so that the region of the phosphor surface which again totally reflects a light which has been totally reflected by a screen-side surface of the third lens is limited to the edge portion of an effective region of the phosphor surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.