Low power pixel-based visual display device having dynamically changeable number of grayscale shades
US5691745A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 6, 1995 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | Jan 6, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2330/02
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An inexpensive, low power visual display device has m n-bit/pixel frame buffers that hold m sets of pixel data, where m>1, and an n-bit controller for switching among the m n-bit/pixel frame buffers at a selected rate during a display cycle. The controller outputs a composite stream of the m sets of pixel data. A display having a matrix of pixels is coupled to the controller to receive the composite stream. The pixels are turned on and off in response to the composite stream of pixel data. Individual pixels have a grayscale shade reflecting an average duration that the individual pixel is on. The visual display device produces m.times.(2.sup.n -1)+1 grayscale shades, including white. The multi-buffer display device can be optimized in a manner which reduces power consumption or increases the number of gray scale colors in comparison to prior art single frame buffer visual display devices. A method for operating visual display devices is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.