Zoom light apparatus
US4293892A · kind A · utility
40Cited by
1References
28Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 18, 1979 |
| Grant date | Oct 6, 1981 |
| Priority date | — |
| Expiry date | Dec 18, 1999 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21W2131/406
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A zoom lighting device for projecting a generally rectangular illumination pattern whose size can be selectively changed. The device comprises a paraboloidal reflector and an artificial light source which cooperate to provide a collimated to nearly collimated beam of light which is circular in cross-section. The circularly-shaped light beam is intercepted by a pair of movably mounted crossed lenticular screens that are optically structured to change the circularly-shaped beam to a diverging generally rectangularly-shaped beam whose angles of divergence can be selectively changed by moving the screens relative to one another.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.