Active matrix display device and method of driving such
US5684501A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1995 |
| Grant date | Nov 4, 1997 |
| Priority date | — |
| Expiry date | Mar 10, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/043
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an active matrix display device having an army of electro-optic, e.g. liquid crystal, display elements (12) which are each connected in series with a two-terminal non-linear device (15), such as a MIM type thin film diode, between associated row and column address conductors (16,17), and are driven by a circuit, (20,22) to produce a display effect by applying a selection signal to each row address conductor in turn and data signals to the column address conductors, a selection signal comprising a voltage pulse signal whose magnitude is increased gradually and in a controlled fashion to a maximum selection voltage amplitude is used so as to reduce the extent of ageing in the non-linear devices and differential ageing effects on display elements driven to different levels over a period of use by reducing peak currents flowing through the non-linear devices. The rising edge of the selection pulse signal is suitably shaped, for example by ramping or stepping, for this purpose. When using a five level row drive waveform comprising positive and negative selection signals and a reset signal, the reset selection signal can be shaped in this way, preferably together with the selection si…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.