Image projector
US6149276A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1999 |
| Grant date | Nov 21, 2000 |
| Priority date | — |
| Expiry date | Jan 25, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3105
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is provided an image projector including (a) a light source, (b) a reflection mirror for reflecting flux of light emitted from the light source, (c) an image display unit for forming images, and (d) a relay system for transferring the flux of light to the image display unit, the relay system including a relay lens having a first convex surface through which the flux of light enters therein and a second convex surface through which the flux of light exits therefrom, a ratio of a radius of curvature of the first convex surface to a radius of a curvature of the second convex surface being determined in such a manner that aberration out of an optical axis of the relay lens is increased to thereby cause a converging point of the flux of light to displace from a calculated focal distance. For instance, the ratio is determined in the range of about 1:2 to about 1:3. The relay lens preferably has a focal distance in the range of about 40 to 60 mm, and is made of material having an index of refraction in the range of about 1.5 to 1.65. The above-mentioned image projector increases aberration thereof. If a relay lens has greater aberration, a greater amount of flux of light is converge…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.