# US 2019/0172384 A1 · Display device

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- Number: US 2019/0172384 A1
- Document ID: US20190172384A1
- Status: Published application
- Kind: A1
- Application number: 16/205,150
- Filed: 2018-11-29
- Published: 2019-06-06
- Earliest claimed: 2017-12-01
- Assignees: Sharp Kabushiki Kaisha
- Applicants: Sharp Kabushiki Kaisha
- Inventors: HAJIME NONOMURA
- Web page: https://patentgrep.com/patent/US20190172384A1

## CPC

- G09G 3/2018: {by time modulation using two or more time intervals}
- G09G 2320/0276: for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
- G09G 2320/064: by time modulation of the brightness of the illumination source
- G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other
- 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

A display device includes an auto current limiter (ACL) circuit and a luminance control circuit. The ACL circuit acquires a first parameter on the basis of luminance-related data of input image data, and then acquires a second parameter by applying a luminance control parameter from the luminance control circuit to the first parameter. The ACL circuit corrects the input image data by a second correction function acquired from the second parameter.

## Claims

### Claim 1

A display device comprising:
a display panel;
a gray-level correction circuit; and
a luminance control circuit which controls luminance of the display panel, wherein
the gray-level correction circuit
acquires a first parameter for generating a first correction function on the basis of luminance-related data of input image data, and
corrects the first parameter on the basis of a luminance control parameter related to control of the luminance of the display panel from the luminance control circuit, acquires a second parameter for generating a second correction function, and corrects a gray level of the input image data on the basis of the second correction function.

### Claim 2 (depends on 1)

The display device according to claim 1, wherein the luminance-related data of the input image data is a lighting rate which is calculated on the basis of a value obtained by dividing a frame luminance, which is a sum of luminances of all of pixels in the display panel based on the input image data for one frame, by a product of the number of all the pixels in the display panel and a gray-level value indicating maximum luminance.

### Claim 3 (depends on 1)

The display device according to claim 1, wherein the luminance control parameter includes a PWM parameter which is supplied from the luminance control circuit to a PWM control circuit to control the luminance of the display panel.

### Claim 4 (depends on 1)

The display device according to claim 1, wherein the luminance control parameter includes a gamma voltage setup value which is supplied from the luminance control circuit to a gamma circuit to control the luminance of the display panel.

### Claim 5 (depends on 1)

The display device according to claim 1, wherein the luminance control circuit corrects the gray level of the input image data if a value of the luminance control parameter is a value which makes a luminance setting for the display panel not less than a prescribed value.