Video blink comparator
US4404590A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1981 |
| Grant date | Sep 13, 1983 |
| Priority date | — |
| Expiry date | Aug 6, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/18
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video blink comparator incorporates an optical system for presenting and superimposing a data pattern image and reference pattern image, a video system for generating a video signal for final comparison of the reference image and data image, and a control system for blinking the respective data image and reference image on and off at the same frequency and out of phase so that a video picture formed by the video signal remains constant when the data image and reference image patterns are substantially identical and so that variant elements of the respective patterns blink on and off in the video picture. A lens system is provided spaced from a video camera to provide variable magnification or enlargement of the superimposed pattern images. Universal mounting of components permits sequential scanning of the superimposed image in fractional portions or blocks permitting non-linear distortion introduced during pattern formation. The control system permits variation of a number of blink comparison parameters affording flexibility in its use and application.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.