Method and apparatus for attenuating a light beam
US5394263A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1993 |
| Grant date | Feb 28, 1995 |
| Priority date | — |
| Expiry date | Apr 28, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/11
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A light valve for attenuating a collimated light beam contains a focusing lens, a light vane and motor control. The focusing lens contains a focal length and lens diameter. The focusing lens focuses a collimated light beam to generate a light cone such that the dimensions of the light cone are based on the diameter and focal length of the focusing lens. The light vane deflects light within the light cone. The motor is controlled to position the light vane to attenuate the light within the light cone by placing the light vane in at least one position ranging from a zero stop attenuation position to a full stop attenuation position. For a single degree of light vane rotation into the light cone, the light beams is attenuated by three percent. In the zero stop position, the light vane is parallel to an edge of the light cone so that no light is attenuation. In the full stop position, the light vane is located thirty degrees, relative to the zero stop position, into the light cone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.