Display apparatus and driving method thereof

A display apparatus comprising:

• plural light emitting devices arranged in a row direction and a column direction, each of which emits light of a color selected from plural kinds of colors;
• a driving circuit connected to each of the plural light emitting devices;
• a scanning line for supplying a selection signal to select the driving circuits in the row direction;
• a light emission control line for supplying a light emission control signal to cause the light emitting devices in the row direction to emit light;
• and
• a data line for supplying a current signal designating brightness of the light emitting device to the selected driving circuits,
• wherein the driving circuit comprises
• a driving transistor which supplies a current to the light emitting device, a first switch having one switch arranged between a gate and a drain of the driving transistor and another switch arranged between the drain of the driving transistor and the data line, with the first switch turned on in response to the selection signal on the scanning line,
• a second switch which is arranged between the drain of the driving transistor and the light emitting device, and is turned on at every end time of the selection signal when the light emission control signal on the light emission control line changes from a first level to a second level,
• a first capacitor, one end of which is connected to the gate of the driving transistor, and a potential of the other end of which is fixed, and
• a second capacitor, one end of which is connected to the gate of the driving transistor, and the other end of which is connected to the light emission control line,
• wherein the two switches in the first switch and the second switch are transistors having a channel polarity opposed to a channel polarity of the driving transistor,
• wherein a capacitance ratio of the second capacitor to the first capacitor varies according to the color of the light emitting device to which the driving circuit is connected, and
• wherein the driving circuit further comprises a third capacitor one end of which is connected to the gate of the driving transistor and the other end of which is connected to the scanning line.

A driving method for a display apparatus which comprises

• plural light emitting devices, arranged in a row direction and a column direction, emitting light of a color selected from plural kinds of colors;
• a driving circuit connected to each of the plural light emitting devices;
• a scanning line for supplying a selection signal to select the driving circuits in the row direction;
• a light emission control line for supplying a light emission control signal to cause the light emitting devices in the row direction to emit light;
• and
• a data line for supplying a current signal designating brightness of the light emitting device to the selected driving circuit,
• the driving circuit comprising a driving transistor which supplies a current to the light emitting device,
• a first switch which has one switch arranged between a gate and a drain and another switch arranged between the drain of the driving transistor and the data line, and is turned on in response to the selection signal,
• a second switch which is arranged between a drain of the driving transistor and the light emitting device, and is turned on in response to the light emission control signal,
• a first capacitor, one end of which is connected to the gate of the driving transistor and a potential of the other end of which is fixed,
• a second capacitor, one end of which is connected to the gate of the driving transistor and the other end of which is connected to the light emission control line, and
• a third capacitor, one end of which is connected to the gate of the driving transistor and the other end of which is connected to the scanning line,
• wherein the two switches in the first switch and the second switch are transistors having a channel polarity opposed to a channel polarity of the driving transistor,
• wherein a capacitance ratio of the second capacitor to the first capacitor varies according to the color of the light emitting device to which the driving circuits are connected,
• the driving method comprising the steps of:
• holding the current signal on the data line as a voltage in the first capacitor of the driving circuit, by turning on the first switch;
• turning on the second switch by changing the light emission control signal from a first level to a second level at every end time of the selection signal, thereby changing a gate-source voltage of the driving transistor to a smaller absolute value via the second capacitor;
• and
• supplying the current from the drain of the driving transistor to the light emitting device according to the changed gate-source voltage by keeping the light emission control signal at the second level.