Control device for a display screen and display screen controlled by this device
US4427997A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1981 |
| Grant date | Jan 24, 1984 |
| Priority date | — |
| Expiry date | Dec 8, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2310/0218
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to planar display screens and more particularly to smectic liquid crystal screens. One of the problems of high definition display screens (approximately 100 to 1000 lines and columns) is caused by the devices for controlling the heating current on the lines. The complexity of the installation and costs limit the increase in the definition. The invention arranges the N lines of a screen into .sqroot.N groups of lines supplied at each of their ends by .sqroot.N control devices functioning sequentially, i.e. 2.sqroot.N devices in all. Moreover, each line has a diode placed between the heating resistor and the common point of the circuit. Application to the display of images transmitted in the form of a video signal for television and display peripheral equipment in teletransmission.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.