| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of preventing the degradation in an optical sensor element due to application of a voltage of a polarity deviating to a gate electrode using a thin film transistor as an optical sensor. <P>SOLUTION: The liquid crystal display device 1 is provided with: a liquid crystal display panel; a light detection part LS1 which has a TFT optical sensor incorporated to the liquid crystal display panel; an optical sensor reading part Re1 which reads a voltage due to light leak of the TFT optical sensor; and a controller 20 which controls the light detection part and the optical sensor reading part and controls a backlight or the like 24 in accordance with an output of the optical sensor reading part, wherein the light detection part is characterized in that a switching element SW2 is connected between a source line connected with a source electrode S<SB>L</SB>of the TFT optical sensor and a drain line connected with a drain electrode D<SB>L</SB>, and the controller 20 is characterized in that the switching element SW2 is turned on when a gate voltage of the TFT optical sensor is changed and, thereby, the source line and drain line of the TFT optical sensor are connected with a common voltage. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
