Method of and apparatus for testing a two dimensional pattern
US4006296A · kind A · utility
9Cited by
6References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 26, 1975 |
| Grant date | Feb 1, 1977 |
| Priority date | — |
| Expiry date | Jun 26, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/18
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of and apparatus for testing a two dimensional pattern uses a pair of pick-up devices for scanning a reference pattern and the pattern to be tested. The reference pattern is modified relative to the test pattern and includes three types of pattern traces, i.e. narrow black traces, narrow bright traces and intermediate wide grey traces. The pattern is tested by means of the narrow traces only thereby minimizing positioning and scanning problems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.