Color wheel assembly for lighting equipment
US4800474A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 1986 |
| Grant date | Jan 24, 1989 |
| Priority date | — |
| Expiry date | May 15, 2006 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21W2131/406
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lighting fixture includes a source for producing a beam of light and pair of color wheels. Each of the color wheels has a plurality of dichoric filters mounted on the periphery of the wheel with the filters positioned contiguous to each other. The light beam is directed to a focal point. Each of the color wheels can be rotated to place the peripheral dichroic filters in position to intercept the beam. One of the color wheels is equipped with long wave pass dichroic filters while the other color wheel is equipped with short wave pass dichroic filters. By aligning various combinations of these filters, a large number of different colors with different saturations can be produced. The cutoff wavelengths for the dichoric filters are selected to be different at the long and short wavelengths of the filter set, such that there is produced a perceived uniform graduation of colors across the spectrum. Each of the dichroic filters mounted on the color wheels is in a shape of a trapezoid and is mounted adjacent other filters, such that there is no blanking of light or leakage of light in the process of changing from one filter to the next.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.