Laser addressed display
US4093852A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1976 |
| Grant date | Jun 6, 1978 |
| Priority date | — |
| Expiry date | Sep 29, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2360/148
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A photoconductor-switched electroluminescent matrix panel for use in a laser-addressed tactical data display system in which photoconductor elements on the back of a screen are connected in series with electroluminescent display and feedback elements which form the front of the screen and an a-c power supply. The photoconductor has a high dark impedance so that in the initial OFF position insufficient a-c power passes through the electroluminescent elements to cause significant light emission. When the photoconductor is illuminated with a light pulse from a scanning laser beam, the impedance drops sharply so that substantially all of the a-c supply voltage is received by the electroluminescent element thereby causing the element to luminesce. The photoconductivity persists long enough for the electroluminescent emission to build up and sustain the low photoconductor impedance via optical feedback. This ON condition is maintained until the power to the device is interrupted for an erase period long enough for the photoconductivity to decay.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.