Patent ID: 8736591
Filing Date: 2014-05-27
Classification: G09G

Abstract:
1. A display device, comprising: a plurality of pixels arranged in a matrix, wherein each pixel has a first electrode, a second electrode, a light-transmittive element controlling the amount of transmissive light in response to a voltage difference between the first electrode and the second electrode, and a memory circuit storing the voltage level of the first electrode; a controller refreshing the memory circuit periodically, a plurality of source lines disposed respectively for each column of the plurality of pixels to apply data signals to the plurality of pixels; and a plurality of gate lines disposed respectively for each row of the plurality of pixels to apply control signals to the plurality of pixels to control the application of the data signals, wherein each pixel has a first switch element disposed between a corresponding source line and the first electrode, wherein the first switch element connects the first electrode to the corresponding source line in response to the control signal from a corresponding gate electrode line, and wherein the memory circuit of each pixel comprises: a capacitor storing the voltage level of the first electrode; a second switch element disposed between the first electrode and the capacitor, wherein the second switch element is controlled by the controller to connect the first electrode to the capacitor; a third switch element disposed between the first electrode and the corresponding source line, wherein the third switch element is controlled by the controller to connect the first electrode to the corresponding source line to discharge the first electrode; and a fourth switch element disposed between the first electrode and the third switch element, wherein the fourth switch element has a control terminal connected to a node between the capacitor and the second switch element, and the fourth switch element is conducted in response to a voltage difference between the corresponding source line, which is connected to the fourth switch element via the third switch element, and the control terminal wherein the second switch element is turned on so that the voltage level of the first electrode is stored in the capacitor in a sample period, then in the case where the first electrode has a positive voltage level with respect to the second electrode at a refresh timing, a first predetermined voltage is applied to the second electrode, under a state where the gate line turns off the first switch element, to increase the voltage level of the first electrode by the first predetermined voltage in a precharge period, and finally the third switch element is turned on to discharge the first electrode via the fourth switch element and the third switch element in the refresh period, so that the first electrode has a negative voltage level with respect to the second electrode.