液晶表示装置

Liquid crystal display device

Abstract

【課題】液晶表示パネルに組み込んだ光検知部により液晶の劣化を防止した液晶表示装置 を提供すること。 【解決手段】TFT基板2と対向電極26を有するCF基板25との間に液晶層14が設 けられた液晶表示パネルと、光センサを有する光検知部LS1と、照光手段とを備えた液 晶表示装置1において、光検知部LS1はTFT基板の表示領域の外周縁部に配置され、 光センサとしてTFTを用い、TFTのソース・ドレイン電極S L 、D L 間にコンデンサ Cを接続し、コンデンサを第1、第2スイッチ素子SW1、SW2を介して第1、第2基 準電圧源V SP 、V SM 、及び対向電極に接続し、所定のフレーム期間毎に短時間スイッ チ素子を順次切換え作動させて基準電圧源からの基準電圧をコンデンサに印加して充電し 、スイッチ素子をオフにしてから所定時間後のコンデンサの電圧から外光を検知する。 【選択図】図10
<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device in which deterioration of a liquid crystal due to a light sensing component built in a liquid crystal display panel is prevented. <P>SOLUTION: The liquid crystal display device 1 has: a liquid crystal display panel which has a liquid crystal layer 14 provided between a TFT substrate 2 and a CF substrate 25 having a counter electrode 26; a light sensing component LS1 having a photosensor; and a means for illuminating light. The light sensing component is arranged at the periphery of the TFT substrate's display area and uses a thin film transistor as photosensor. A capacitor C is connected between source and drain electrodes SL, DL for such TFT photosensor. The capacitor is connected via first and second switch elements SW1, SW2 to first, second standard voltage sources V<SB>SP</SB>, V<SB>SM</SB>. and a counter electrode. The switch elements are successively changed over to actuate for a short time in every prescribed frame period to apply the standard voltage from the standard voltage source to the capacitor and to charge the capacitor. External light is detected from the voltage of the capacitor after the prescribed time since the switch elements are turned off. <P>COPYRIGHT: (C)2007,JPO&INPIT

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Patent Citations (1)

    Publication numberPublication dateAssigneeTitle
    WO-03050602-A1June 19, 2003Mitsubishi Denki Kabushiki KaishaAfficheur a cristaux liquides reflechissant

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Cited By (2)

    Publication numberPublication dateAssigneeTitle
    JP-2009116205-AMay 28, 2009Sony Corp, ソニー株式会社Display device, display control method and electronic device
    US-8552967-B2October 08, 2013Japan Display West Inc.Display device, display control method, and electronic apparatus