Display device and method for driving display device
A display device according to one embodiment of the present invention is provided with a plurality of pixels which are arranged as a matrix on a substrate, and each of which is provided with a liquid crystal display element and an organic EL display element. The organic EL display element is provided with a positive electrode and a negative electrode, which are formed so as to be electrically separated from a pixel electrode and a counter electrode of the liquid crystal display element. Each one of the plurality of pixels is provided with: a first transistor which changes the magnitude of a current to be supplied to the organic EL display element on the basis of the potential of a first bus line; a second transistor which electrically separates the first bus line and the pixel electrode from each other on the basis of the potential of a third bus line; and a third transistor which electrically connects the first transistor and the second transistor with the first bus line on the basis of the potential of a second bus line. A method for driving a display device according to one embodiment of the present invention reduces the potential difference between the pixel electrode and the counter electrode before turning off the second transistor during switching from display by means of the liquid crystal display element to display by means of the organic EL display element.
1. A method for driving a display apparatus comprising:
when performing display by an organic EL display element in a display apparatus comprising a liquid crystal display element and the organic EL display element at each one of a plurality of pixels, each of the liquid crystal display element and the organic EL display element being formed on a surface of a substrate comprising a plurality of bus lines,
applying a voltage based on display data being data relating to display in each one of the plurality of pixels between a gate and a source of a first transistor that changes current flowing through the organic EL display element; and
electrically separating the liquid crystal display element from a first bus line to be set to a potential based on the display data by using a second transistor being a field effect transistor comprising a gate being connected to a third bus line, the second transistor being connected to a pixel electrode of the liquid crystal display element, and
when performing display by the liquid crystal display element, electrically connecting the first bus line and the pixel electrode by turning on the second transistor and a third transistor being provided between the second transistor and the first bus line, wherein,
when the first bus line and the pixel electrode are electrically connected, current supply to the organic EL display element from a fourth bus line to supply current to the organic EL display element is stopped by using a current cut-off circuit, the current cut-off circuit being constituted of a field effect transistor comprising a gate connected to the third bus line and being of a channel type different from that of the second transistor, and
in switching from the display by the liquid crystal display element to the display by the organic EL display element, before bringing the second transistor from an ON state to an OFF state:
a potential difference between the pixel electrode and a counter electrode of the liquid crystal display element is reduced by applying substantially a same potential as a potential of the counter electrode to the pixel electrode via the second transistor from the first bus line; and
the source of the first transistor is electrically connected to a cathode of the organic EL display element, the source being connected to an anode of the organic EL display element, thereby decreasing a potential of the source to a predetermined potential before current is supplied to the organic EL display element from the fourth bus line.