Light beam scanning system
US4143403A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 8, 1977 |
| Grant date | Mar 6, 1979 |
| Priority date | — |
| Expiry date | Mar 8, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04767
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Scanning lines are formed by deflecting a light beam with a rotating multi-face mirror. A light detecting means is placed within the field of deflected light at a position corresponding to the initial part of the scanning lines and the light beam deflected by each face of the rotating multi-face mirror is detected by the light detecting means causing it to produce a signal which is applied to a video clock pulse generator to stop its oscillation. When the light detecting means no longer detects the light beam it stops producing said signal and the video clock pulse generator begins producing clock pulses a short fixed time thereafter and in this manner the beginning points of the effective scanning lines are maintained in alignment regardless of angular imperfections in the rotating multi-face mirror or fluctuations in its speed of rotation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.