Projection lens system
US5404246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1993 |
| Grant date | Apr 4, 1995 |
| Priority date | — |
| Expiry date | Jun 24, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B9/62
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection lens system has a first lens to a sixth lens which are serially arranged in this order from a screen side. The first lens has a meniscus configuration in which a convex surface is directed toward the screen side and the power of the lens changes from positive to negative from the optical axis toward a peripheral portion of the lens. The first lens has two aspherical surfaces. The second lens has a positive power meniscus configuration in which a convex surface is directed toward the screen side. Both surfaces of the second lens are aspherical. The third lens has a positive power meniscus configuration in which a convex surface is directed toward the screen side. The fourth lens is disposed close to the third lens and has two convex surfaces. The fifth lens has a positive power meniscus configuration in which a concave surface is directed toward the screen side. Both surfaces of the fifth lens are aspherical. The sixth lens has a concave surface which has a large curvature directed toward the screen side. The surface of the sixth lens on the screen side is aspherical.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.