Process and apparatus for the preparation of photographic images from transparent masters
US4878111A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 16, 1988 |
| Grant date | Oct 31, 1989 |
| Priority date | — |
| Expiry date | Aug 16, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B27/725
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a process and apparatus for the production of photographic images of transparent masters, the master is reproduced in a first beam path by means of a light source and optical means on photographic material, and in a second beam path for color and contrast correction by means of a CRT controlled by image measuring means and a computer unit as a mask in a coincident manner. The mask is produced by a feedback loop formed by the CRT, master, image measuring unit, computer unit and again the CRT, whereby in particular the geometric image distortions of the CRT are eliminated. In each location of the screen of the CRT, in which the light point is present, the brightness of the image point is calculated and immediately corrected. By the above described measures the effect of any distortion of the CRT is coupled out, whereby a sharper image is obtained. The part of the light of the CRT used for exposure is not weakened by the master. The process is intended primarily for the photographic copying of color slides.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.