Time multiplexed gray scale approach
US5652600A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 1994 |
| Grant date | Jul 29, 1997 |
| Priority date | — |
| Expiry date | Nov 17, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2300/0842
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of illuminating an active matrix EL device (AMEL) to provide a gray scale display. The device comprises a first electrode layer comprising an active matrix of individually adjustable pixel electrodes, a second electrode layer, and a thin film EL laminate stack including at least an EL phosphor layer and a dielectric layer, and the stack being disposed between the first and second electrode layers. The gray scale display is illuminated by the steps of, energizing a first set of selected ones of the pixel electrodes with data signals during a first subframe time period. Selected pixels are illuminated by driving the second electrode layer during the first subframe time period a first illuminating signal having predetermined characteristics including frequency, amplitude, wave shape and time duration. Thereafter, a second set of selected ones of the pixel electrodes are energized with data signals during a next subframe time period. Selected pixels are again illuminated during the next time period with an altered illumination applied to the second electrode signal wherein one or more of the predetermined characteristics differ from the first illuminating signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.