Piezoelectric device responsive to optical image for generating an electrical signal
US4099206A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1975 |
| Grant date | Jul 4, 1978 |
| Priority date | — |
| Expiry date | Mar 21, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A piezoelectric substrate is subjected to the continuous excitations produced by a high-frequency electric field of fixed radian frequency .alpha. applied between its two opposite faces; high-frequency electrical pulses of radian frequency .alpha..sub.p are applied to the periodic network of conductors illuminated by the image; the electrical conductivity at the surface of the substrate at each point is made a function of the illumination directed towards said point, for example by the application of a photoconducting semi-conductor covering the network or by a substrate whose conductivity is directly modulated by the incident light. The non-linear interaction between the two substrate excitations induces a surface wave whose intensity is modulated by the luminous intensity and which is picked up by the transducers. Application with fixed .alpha..sub.p, to the point by point read-out of a linear optical image and with .alpha..sub.p = .alpha..sub.p (t) to the analysis of its spatial frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.