Device for illuminating an auxiliary track of a motion picture film
US4942566A · kind A · utility
1Cited by
3References
16Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 20, 1988 |
| Grant date | Jul 17, 1990 |
| Priority date | — |
| Expiry date | Jun 20, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B31/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser diode (4) emits a beam which is reflected by a plane mirror (12) and by a spherical focusing mirror (2) in order to form a beam (40) which is focused on a read window which is a segment of a read line (6). Said line extends transversely relative to a film (16) running over a drum (20) which rotates about an axis (22). The window occupies the width of the soundtrack on the film. The light passing through said soundtrack is received by a photo cell (34) which provides the sound signal. The invention is particularly applicable to sound motion pictures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.