# US 10,311,801 B2 · Liquid crystal display device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,311,801 B2
- Document ID: US10311801B2
- Status: Granted
- Kind: B2
- Application number: 14/654,940
- Filed: 2013-12-19
- Published: 2015-12-03
- Granted: 2019-06-04
- Earliest claimed: 2013-01-22
- Assignees: Sharp Kabushiki Kaisha
- Applicants: Sharp Kabushiki Kaisha
- Inventors: Katsuya Otoi
- Web page: https://patentgrep.com/patent/US10311801B2

## CPC

- G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)}
- G09G 3/3426: {the different display panel areas being distributed in two dimensions, e.g. matrix}
- G09G 3/36: using liquid crystals
- G09G 2320/0238: Improving the black level
- G09G 2320/0626: for control of overall brightness
- G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other
- G09G 2360/145: the light originating from the display screen
- G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

It is possible to realize a liquid crystal display device 1 which is provided with a down-converter 7, a local dimming control circuit 8, and an upscaling control circuit 9 including a luminance ratio calculation circuit and a gradation conversion circuit, and thus, capable of processing an image having an image size that is not assumed, and further, reducing a storage area, a processing load and a circuit size.

## Claims

### Claim 1

A liquid crystal display device comprising:
a local dimming control circuit that outputs backlight luminance data in accordance with first-size input image data, and outputs first-size liquid crystal gradation data such that the first-size input image data is reproduced by superimposing the backlight luminance data on the first-size liquid crystal gradation data;
a liquid crystal panel;
a backlight in which a luminance of each region of a plurality of backlight regions is controlled in accordance with the backlight luminance data;
at least one or more down-converters that convert second-size image data, which is larger than the first-size image data, to the first-size image data;
a luminance ratio calculation circuit that calculates a gradation ratio by dividing the first-size liquid crystal gradation data output from the local dimming control circuit by the first-size image data output from the down-converter, each of the data corresponding to a same position on a display face; and
a gradation conversion circuit that calculates second-size liquid crystal gradation data by multiplying a plurality of data, which corresponds to neighboring positions on the display face and selected from the second-size image data in accordance with a reduction rate between the second-size image data and the first-size image data by the gradation ratio at a corresponding position on the display face, wherein
the at least one or more down-converters includes a first down-converter and a second down-converter,
the first-size image data output from the first down-converter is supplied to the local dimming control circuit and the first-size image data output from the second down-converter is supplied to the luminance ratio calculation circuit,
the luminance ratio calculation circuit and the gradation conversion circuit are provided in an upscaling control circuit.

### Claim 2 (depends on 1)

The liquid crystal display device according to claim 1, wherein
a number of the at least one or more down-converters is one, and
the first-size image data output from the down-converter is supplied to the local dimming control circuit and the luminance ratio calculation circuit.

### Claim 3 (depends on 1)

The liquid crystal display device according to claim 1, wherein the luminance ratio calculation circuit, the gradation conversion circuit and the second down-converter are provided in an upscaling control circuit.

### Claim 4 (depends on 1)

The liquid crystal display device according to claim 1, wherein the gradation conversion circuit is provided in an upscaling control circuit.