Illumination of displays with control which switches illuminator in response to changes in the display
US5363223A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1992 |
| Grant date | Nov 8, 1994 |
| Priority date | — |
| Expiry date | Nov 27, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2330/021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A problem arises in electronic equipment incorporating a display, such as an LCD display, which is not intrinsically illuminated. The present invention provides a controlled backlight for such displays, and is particularly useful in battery-powered equipment where power consumption must be kept to a minimum. The circuitry comprises a display 1 controlled via a conventional display driver 6 from other equipment (not shown) such as a microprocessor. Whenever the display is changed a signal is sent also to a timer circuit 7 which triggers, and passes a control signal to an electronic switch 4 which in turn passes power from a battery 3 to a lamp 2. The lamp 2 is arranged to illuminate the display 1. After a preset period, the timer circuit 7 sends a further control signal to the switch 4 to switch lamp 2 off.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.