High efficiency linear light source
US5442533A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1994 |
| Grant date | Aug 15, 1995 |
| Priority date | — |
| Expiry date | Jun 22, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/02815
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A linear light source for a film scanner includes an elongated light integrating cavity, formed within a light integrator, having diffusely reflective walls. Light is introduced into the cavity through an input port, and an output scan line of diffuse light is produced through an exit slit which is generally parallel to the longitudinal axis of the integrating cavity. The scan line of light is directed on film to be scanned in a stripe of illumination. The scan line of the illuminated film stripe is imaged onto a tri-linear CCD array for conversion of color intensity modulated pixels into scan line data sets. The linear light beam is reflected from a source region within the integrating cavity visible through the exit slit. In order to make the brightness profile of the linear light beam more uniform and avoid position dependent signal level drop outs, sharp angle joints in the source region are replaced by arcuate sections. Particularly the right angle junctions of an interior longitudinal baffle with light integrator end walls are replaced by arcuate sections in the source region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.