Variable beamwidth stage light
US4855884A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 2, 1987 |
| Grant date | Aug 8, 1989 |
| Priority date | — |
| Expiry date | Dec 2, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21W2131/406
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A variable beamwidth stage light relying upon an axially movable reflector for changes in beamwidth. The reflector has a plurality of radially outwardly and axially forwardly extending leaves in side-by-side relation to define a bowl-shaped reflector surface. A stationary support flange is in frictional contact with the radially outward surface of each leaf. The reflector leaves are sandwiched between a base member and a ring member at the base of the reflector. A motor driven lead screw is attached to the base member to cause axial movement of the reflector relative to the support flange. The reflector defines a first and a second focal point along the axis of the reflector. A light source is fixed at the first focal point, which remains substantially fixed relative to the base member. Contact of the support flange with the reflector leaves causes the diameter of the reflector leaves to vary as the base member is moved, thereby causing displacement of the second focal point and variation of the bandwidth issuing from the reflector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.