Circuit for detecting vertical mis-registration in a flying spot scanner
US3976832A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 30, 1975 |
| Grant date | Aug 24, 1976 |
| Priority date | — |
| Expiry date | Jul 30, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/38
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention concerns a circuit for detecting vertical mis-registration in a flying spot scanner of the kind in which each film frame is scanned by at least two interlaced fields. For proper vertical registration each line of each field should fall midway between two adjacent lines of the other field. This means that, on average, the mean video signal value of each line of one field should equal the mean video signal value of the two adjacent lines of the other field. Our invention detects whether this is so by forming the difference between the means video signal values of each line of one field with that of the two adjacent lines of the other field, and summing over a number of lines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.