US 9,812,081 B2
Liquid-crystal display device and method for driving same
Jin Miyazawa, Osaka (JP); Kouji Kumada, Osaka (JP); Noriyuki Tanaka, Osaka (JP); Tatsuhiko Suyama, Osaka (JP); and Takuya Sone, Osaka (JP)
Assigned to Sharp Kabushiki Kaisha, Sakai (JP)
Appl. No. 14/652,178
Filed by Sharp Kabushiki Kaisha, Osaka-shi, Osaka (JP)
PCT Filed Dec. 20, 2013, PCT No. PCT/JP2013/084219
§ 371(c)(1), (2) Date Jun. 15, 2015,
PCT Pub. No. WO2014/103914, PCT Pub. Date Jul. 3, 2014.
Claims priority of application No. 2012-288969 (JP), filed on Dec. 28, 2012.
Prior Publication US 2015/0332651 A1, Nov. 19, 2015
Int. Cl. G09G 3/36 (2006.01)
CPC G09G 3/3648 (2013.01) [G09G 3/3614 (2013.01); G09G 2310/0251 (2013.01); G09G 2320/0204 (2013.01); G09G 2320/046 (2013.01); G09G 2330/027 (2013.01); G09G 2340/0435 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A liquid-crystal display device that displays an image represented by input image data, by applying a voltage corresponding to the input image data, to a liquid crystal layer in a display, the liquid-crystal display device comprising:
a driver that applies the voltage to the liquid crystal layer, the voltage corresponding to the input image data; and
a display controller that controls the driver; wherein
the display includes a plurality of pixel formation portions that hold the voltage to be applied to the liquid crystal layer as a data voltage;
in a pause period of pausing writing of the data voltage into the plurality of pixel formation portions and upon receiving an OFF signal instructing OFF of a power supply of an entirety of the liquid-crystal display device, the display controller controls the driver so that a polarity bias of the voltage applied to the liquid crystal layer is reduced from a time when the OFF signal is input until the power supply is turned off;
the polarity bias of the voltage applied to the liquid crystal layer is a difference between a total sum of a time while a positive data voltage is held in one of the plurality of pixel formation portions and a total sum of a time while a negative data voltage is held in the one of the plurality of pixel formation portions; and
the display controller includes:
a bias movement determiner that determines whether the polarity bias is in an increasing direction or in a decreasing direction at a point of time when the OFF signal is input; and
a balance controller that controls the driver in a case where the bias movement determiner determines that the polarity bias is in the increasing direction, so that the polarity bias is reduced after performing polarity reverse refreshment of writing a data voltage into the plurality of pixel formation portions, the data voltage reversing the polarity of the applied voltage to the liquid crystal layer, and that controls the driver in a case where the bias movement determiner determines that the polarity bias is in the decreasing direction, so that the polarity bias is reduced without performing the polarity reverse refreshment.