Mechanical aperture for controlling illumination level
US5414460A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1993 |
| Grant date | May 9, 1995 |
| Priority date | — |
| Expiry date | Jun 8, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B9/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an illumination system for a film telecine scanner of the type adapted to provide a line of illumination on the image frames of a film which is supported for rapid movement in a film gate of the scanner, an improved light control system for adjusting the amount of light that is delivered from a light source to an integrating cylinder to take into account fluctuations in intensity of the light source and desired intensity changes in the line of illumination upon a change of scene in the image frames of the film as the film is being scanned. The light control system includes aperture defining apparatus for selectively adjusting the amount of light entering said integrating cylinder in response to the commanded light intensity signal within the time span of scanning a single image frame of the film. The aperture setting apparatus comprises a housing containing a continuous, single piece, elongated band having first and second centrally disposed light obstructing or solid band sections formed in parallel planes with respect to one another and first and second light transmitting or cut-out band sections separating the first and second light obstructing band sections and forming end l…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.