Lens-less projection optical system of reflection type
US6513935B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 23, 2001 |
| Grant date | Feb 4, 2003 |
| Priority date | — |
| Expiry date | Jul 23, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3141
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A lens-less projection optical system of the reflection type is provided with four reflecting mirrors, which successively reflect a light flux transmitted through a picture-forming device. The light flux reflected by the fourth reflecting mirrors is projected on the screen. The second reflecting mirror is so situated that its reflecting surface shaped into a convexly curved surface is directed to the light flux reflected from the first reflecting mirror. The third reflecting mirror is so situated that its reflecting surface shaped into a convexly curved surface is directed to the light flux reflected form the second reflecting mirror. The fourth reflecting mirror is so situated that its reflecting surface shaped into a convexly curved surface is directed to the light flux reflected from the third reflecting mirror.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.