Display device incorporating brightness control and a method of operating such a display
US5122791A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1987 |
| Grant date | Jun 16, 1992 |
| Priority date | — |
| Expiry date | Sep 21, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/0666
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A display device is formed by a matrix of surface-stabilized bi-stable ferroelectric liquid crystal elements each being separately settable by a matrix driver. To provide brightness control or color in the display, all the elements of the matrix are set in accordance with a portion of a signal for display and the amount of light passing through the matrix for that setting is controlled in accordance with the binary significance of the respective portion of the signal. This control is produced by varying one of the activation duration or intensity of a light source, such as sets of fluorescent tubes in accordance with the binary significance of the brightness information in the input signal. Half of the frame time (T) is used for the numerous setting operations on the matrix of elements and half is used for the backlighting operations of the various settings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.