Back to results
US 8,570,263 B2Granted
Electronic equipment including LED backlight
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Jun Koyama
Life of this patent
Estimating the term…
Abstract
An object of the present invention is to provide a display device which enables multi-gray scale display without complicating the structure of D/A converter circuit. The measure taken to achieve the object is to use n bit of information among m bit digital video data inputted from external for voltage gray scale method, and (m−n) bit of information for time ratio gray scale.
Claims12
An electronic equipment comprising:
- a display device including a plurality of pixels over a substrate;
- an LED backlight;
- a D/A converter circuit;
- and
- a circuit which converts m-bit digital video data into n-bit digital video data, wherein the m and the n are integers equal to or larger than 2 and satisfy m>n,
- wherein n-bit information out of the m-bit digital video data is used for a voltage gray scale method and (m−n)-bit information is used for a time ratio gray scale method,
- wherein each of a voltage level for the voltage gray scale method is designated as (VH−VL)/2n, where VH is the highest voltage level of voltages inputted to the D/A converter circuit, and VL is the lowest voltage level of voltages inputted to the D/A converter circuit, and
- wherein one frame period includes 2m-n subframe periods.
5 more elements
An electronic equipment comprising:
- a display device including a plurality of pixels over a substrate;
- an LED backlight;
- a D/A converter circuit;
- and
- a circuit which converts m-bit digital video data into n-bit digital video data, wherein the m and the n are integers equal to or larger than 2 and satisfy m>n,
- wherein n-bit information out of the m-bit digital video data is used for a voltage gray scale method and (m−n)-bit information is used for a time ratio gray scale method, and
- wherein each of a voltage level for the voltage gray scale method is designated as (VH−VL)/2n, where VH is the highest voltage level of voltages inputted to the D/A converter circuit, and VL is the lowest voltage level of voltages inputted to the D/A converter circuit.
4 more elements
An electronic equipment comprising:
- a display device including a plurality of pixels over a substrate;
- an LED backlight;
- and
- a D/A converter circuit;
- wherein n-bit information out of m-bit digital video data is used for a voltage gray scale method and (m−n)-bit information is used for a time ratio gray scale method, wherein the m and the n are integers equal to or larger than 2 and satisfy m>n,
- wherein each of a voltage level for the voltage gray scale method is designated as (VH−VL)/2n, where VH is the highest voltage level of voltages inputted to the D/A converter circuit, and VL is the lowest voltage level of voltages inputted to the D/A converter circuit, and
- wherein one frame period includes 2m-n subframe periods.
4 more elements
Dependencies are inferred from the claim text.