Elasto-optic device for spot wobble in a video disc player
US3985952A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 27, 1975 |
| Grant date | Oct 12, 1976 |
| Priority date | — |
| Expiry date | Jan 27, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/09
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An elasto-optic device for providing periodic lateral displacement in a radial tracking servo system for a video disc player. A transparent prism is vibrated in either a flexural or a second harmonic extensional mode by a thin piezoelectric ceramic platelet attached to a side of the prism and energized by an oscillatory signal. Vibration occurs at a natural mechanical resonant frequency of the prism, and a linear strain distribution is established in the prism at its intersection with the path of the optical beam used for reading the record track. The substantially linear strain distribution effects a corresponding localized periodic change in the index of refraction of the prism material to provide lateral optical beam deflection without the use of moving parts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.