# US 7,746,317 B2 · Liquid crystal display having a light sensor and driving method thereof for adjusting luminance according to that of ambient light > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,317 B2 - Document ID: US7746317B2 - Status: Granted - Kind: B2 - Application number: 11/645,412 - Filed: 2006-12-26 - Published: 2007-06-28 - Granted: 2010-06-29 - Earliest claimed: 2005-12-23 - Assignees: Innocom Technology (Shenzhen) Co., Ltd.; Innolux Display Corp. - Inventors: Zhan-Wei Fu; Ming-Hung Tsai - Web page: https://patentgrep.com/patent/US7746317B2 ## CPC - G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)} - G09G 2320/0633: by amplitude modulation of the brightness of the illumination source - G09G 2360/144: the light being ambient light - 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 An exemplary liquid crystal display (200) has a liquid crystal panel (240); a gate driving circuit (230) configured for scanning the liquid crystal panel; a data driving circuit (220) configured for providing a plurality of gradation voltages to the liquid crystal panel; a photo sensor (241) configured for measuring a luminance of ambient light and generating a corresponding optical signal; a luminance control circuit (231) for receiving the optical signal from the photo sensor and transferring the optical signal to a measurement signal; a timing control circuit (210) configured for controlling the gate driving circuit and the data driving circuit; and a backlight circuit (270) for driving a light source to emit light beams for illuminating the liquid crystal panel, according to the measurement signal from the luminance control circuit. ## Claims ### Claim 1 A liquid crystal display, comprising: a liquid crystal panel; a gate driving circuit configured for scanning the liquid crystal panel; a data driving circuit configured for providing a plurality of gradation voltages to the liquid crystal panel; a photo sensor configured for measuring a luminance of ambient light and generating a corresponding optical signal; a luminance control circuit for receiving the optical signal from the photo sensor and transferring the optical signal to a measurement signal; a timing control circuit configured for controlling the gate driving circuit and the data driving circuit; and a backlight circuit for driving a light source to emit light beams for illuminating the liquid crystal panel, according to the measurement signal from the luminance control circuit. ### Claim 2 (depends on 1) The liquid crystal display as claimed in claim 1, wherein the photo sensor is formed at the liquid crystal panel. ### Claim 3 (depends on 1) The liquid crystal display as claimed in claim 1, wherein the luminance control circuit is integrated in the gate driving circuit or the data driving circuit. ### Claim 4 (depends on 1) The liquid crystal display as claimed in claim 1, wherein the luminance control circuit comprises a amplify circuit for amplifying the optical signal and transferring the optical signal to an electrical signal and a control circuit receiving the electrical signal to produce a measurement signal. ### Claim 5 (depends on 4) The liquid crystal display as claimed in claim 4, wherein the luminance control circuit further comprises a feedback circuit for feedbacking the actual adjust result of the backlight circuit to the control circuit. ### Claim 6 (depends on 1) The liquid crystal display as claimed in claim 1, wherein the photo sensor is made from amorphous silicon material. ### Claim 7 A driving method for a liquid crystal display, the liquid crystal display comprising a liquid crystal panel, an photo sensor positioned at the liquid crystal panel, a timing control circuit, a luminance control circuit, and a backlight circuit, the driving method comprising: detecting a luminance of ambient light by the photo sensor, generating a corresponding optical signal representing the luminance of the ambient light, and transmitting the optical signal to the luminance control circuit; judging the luminance of the ambient light by the luminance control circuit and sending a measurement signal to the backlight circuit; adjusting the luminance of a light source according to the measurement signal via control by the backlight circuit; and feedbacking the actual luminance of the light source to the luminance control circuit. ### Claim 8 (depends on 7) The driving method as claimed in claim 7, wherein the luminance control circuit comprises a amplify circuit for amplifying the optical signal and transferring the optical signal to an electrical signal and a control circuit receiving the electrical signal to produce a measurement signal. ### Claim 9 (depends on 8) The driving method as claimed in claim 8, wherein the luminance control circuit further comprises a feedback circuit for feedbacking the actual adjust result of the backlight circuit to the control circuit. ### Claim 10 (depends on 9) The driving method as claimed in claim 9, wherein when the amplify circuit of the luminance control circuit receives the luminance signal of the ambient light from the photo sensor, the amplify circuit amplifies and transfers the signal to an electrical signal and sending the electrical signal to the control circuit, after that, the control circuit judges the luminance of the ambient light according to the received electrical signal and sends a measurement signal to the backlight circuit. ### Claim 11 A liquid crystal display, comprising: a liquid crystal panel; a gate driving circuit driven by a power supply to actuate the liquid crystal panel; a data driving circuit driven by said power supply to provide a plurality of gradation voltages to the liquid crystal panel; a sensor configured measuring a light and generating a corresponding signal; a luminance control circuit receiving the signal from the sensor; a timing control circuit controlling the gate driving circuit and the data driving circuit; and a backlight circuit actuated by the power supply to drive a light source to emit light beams for illuminating the liquid crystal panel, according to the signal from the luminance control circuit.