# US 2021/0241718 A1 · Display device, method for displaying image data and mobile terminal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0241718 A1 - Document ID: US20210241718A1 - Status: Published application - Kind: A1 - Application number: 17/115,162 - Filed: 2020-12-08 - Published: 2021-08-05 - Earliest claimed: 2020-02-03 - Assignees: Panasonic Liquid Crystal Display Co., Ltd. - Applicants: Panasonic Liquid Crystal Display Co., Ltd. - Inventors: Masaki TSUBOKURA; Takao IMAOKU; Takashi KATO - Web page: https://patentgrep.com/patent/US20210241718A1 ## CPC - G09G 5/10: Intensity circuits - G09G 2320/066: for control of contrast - G09G 2320/0673: for control of gamma adjustment, e.g. selecting another gamma curve - G09G 2320/0693: Calibration of display systems - G09G 2354/00: Aspects of interface with display user - G09G 2360/144: the light being ambient light - G09G 2380/08: Biomedical applications - 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 for displaying image data includes: a gradation conversion circuit that converts a gradation of input image data; a display panel that displays the image data with the gradation converted by the gradation conversion circuit; an illuminance sensor that detects illuminance of an environment where the display device is placed; and a gamma characteristic corrector that controls a gradation conversion circuit so as to convert the gradation by use of a gamma characteristic corresponding to the detected illuminance. ## Claims ### Claim 1 A display device comprising: a gradation conversion circuit that converts a gradation of input image data; a display panel that displays image data with the gradation converted by the gradation conversion circuit; an illuminance sensor that detects illuminance of an environment where the display device is placed; and a gamma characteristic corrector that controls a gradation conversion circuit so as to convert the gradation by use of a gamma characteristic corresponding to the detected illuminance. ### Claim 2 (depends on 1) The display device according to claim 1, further comprising a storage circuit that holds a first gamma characteristic, wherein the gamma characteristic corrector outputs information on the illuminance detected by the illuminance sensor to the gradation conversion circuit, and the gradation conversion circuit generates a second gamma characteristic corresponding to the illuminance output from the gamma characteristic corrector by referring to the first gamma characteristic held in the storage circuit, and converts the gradation of the image data by use of the generated second gamma characteristic. ### Claim 3 (depends on 1) The display device according to claim 1, wherein the gamma characteristic corrector generates a second gamma characteristic corresponding to the illuminance detected by the illuminance sensor, and outputs the generated second gamma characteristic to the gradation conversion circuit, and the gradation conversion circuit converts the gradation of the image data in accordance with the second gamma characteristic output from the gamma characteristic corrector. ### Claim 4 (depends on 2) The display device according to claim 2, wherein the display panel is a panel that performs gradation conversion on image data input to the display panel in accordance with a gamma characteristic having a gamma value of 2.2, and displays the image data, and the second gamma characteristic is a gamma characteristic having a gamma value different from 2.2. ### Claim 5 (depends on 2) The display device according to claim 2, wherein the second gamma characteristic is a gamma characteristic that defines correspondence between gradation indicated by the input image data and luminance of the display panel, and the second gamma characteristic is a gamma characteristic for correcting a gamma characteristic of the display panel so as to reduce the influence of the illuminance detected by the illuminance sensor on contrast of the display panel. ### Claim 6 (depends on 1) The display device according to claim 1, wherein when power is supplied to the illuminance sensor, or when a structure covering the illuminance sensor is removed and the illuminance sensor is exposed, the gamma characteristic corrector controls the gradation conversion circuit so as to convert the gradation by use of a gamma characteristic corresponding to the illuminance. ### Claim 7 (depends on 1) The display device according to claim 1, further comprising: a storage circuit that holds the first gamma characteristic; and a gamma characteristic switcher that controls switching of the gradation conversion circuit between converting and outputting the gradation of the image data by referring to the first gamma characteristic and outputting the gradation of the image data without the conversion. ### Claim 8 A method for displaying image data, the method comprising: a gradation conversion step of converting a gradation of the image data input into a display device; a display step of displaying the image data with the gradation converted in the gradation conversion step; an illuminance detection step of detecting illuminance of an environment where the display device is placed; and a gamma characteristic correction step of performing control so as to convert the gradation by use of a gamma characteristic corresponding to the detected illuminance. ### Claim 9 A mobile terminal, comprising: a display panel; and an opening and closing unit linked to the display panel so as to be switchable between a first position for exposing a front surface of the display panel and a second position for covering the front surface, wherein the opening and closing unit has at least one luminance sensor that is attached to a surface of the opening and closing unit facing the front surface when at the second position, and that detects luminance of the front surface. ### Claim 10 (depends on 9) The mobile terminal according to claim 9, wherein the opening and closing unit has a plurality of luminance sensors. ### Claim 11 (depends on 9) The mobile terminal according to claim 9, wherein the opening and closing unit has an input device that receives an instruction from a user. ### Claim 12 (depends on 9) The mobile terminal according to claim 9, wherein the opening and closing unit is a cover that covers the front surface when at the second position. ### Claim 13 (depends on 9) The mobile terminal according to claim 9, further comprising: a storage circuit, an output port that outputs data, a conversion module including a conversion circuit that converts data output from the output port into data that can be input to the storage circuit, and then writes the data to the storage circuit. ### Claim 14 (depends on 13) The mobile terminal according to claim 13, wherein the output port includes a first connector attached to a housing of the mobile terminal, the mobile terminal includes a second connector connected to the storage circuit and attached to a housing of the mobile terminal, and the conversion module is connected to the first connector and the second connector. ### Claim 15 (depends on 13) The mobile terminal according to claim 13, further comprising a luminance calibrator that generates a gamma characteristic by performing luminance calibration in accordance with luminance detected by the at least one luminance sensor, and writes the generated gamma characteristic to the storage circuit via the conversion module, wherein the luminance calibrator performs the luminance calibration when the opening and closing unit shifts from the first position to the second position.