Display device, electro-optical element driving method and electronic equipment
View Patent ↗The present invention permits a capacitance value of an electro-optical element such as organic EL element to be arbitrarily set without changing the light extraction efficiency of a pixel. That is, the present invention permits a capacitance value Coled of an organic EL element ( 21 ) to be arbitrarily set by adjusting the light emission area of the organic EL element ( 21 ) without changing the light extraction efficiency of a pixel ( 20 ) in an organic EL display device. The organic EL display device has the pixels ( 20 ) arranged in a matrix form. A light extraction opening ( 56 ) is formed on the surface of the pixel with a light-shielding film (black matrix) ( 57 ). The light extraction opening ( 56 ) has an opening area smaller than the light emission area of the organic EL element ( 21 ).
1. A display device comprising:
a plurality of pixels arranged in a matrix form, a given pixel comprising:
an electro-optical element having a light emission area, the light emission area being larger than that of an other electro-optical element of an other of the plurality of pixels;
a drive transistor configured to drive the electro-optical element;
a holding capacitor configured to hold an input signal voltage for supply to the drive transistor; and
a light-shielding layer having an opening as a light extraction area,
wherein the light extraction area is smaller than the light emission area of the electro-optical element,
wherein a capacitance of the electro-optical element is larger than a capacitance of the holding capacitor.
2. The display device according to claim 1 , wherein the capacitance of the electro-optical element is larger than a capacitance of the other electro-optical element.
3. The display device according to claim 1 , wherein a color of the electro-optical element is different from a color of the other electro-optical element.
4. The display device according to claim 2 , wherein a color of the electro-optical element is different from a color of the other electro-optical element.
5. The display device according to claim 1 , wherein the pixel has a different film thickness from the other pixel.
6. The display device according to claim 2 , wherein the pixel has a different film thickness from that of the other pixel.
7. An display driving method for driving an electro-optical element to emit light, wherein a plurality of pixels are arranged in a matrix form, and a given pixel comprises the electro-optical element, the electro-optical element having a light emission area larger than that of an other electro-optical element of an other of the plurality of pixels, the method comprising:
holding a voltage to be supplied to a drive transistor in a holding capacitor; and
supplying a current corresponding to the voltage held by the holding capacitor from the drive transistor to the electro-optical element,
wherein a light-shielding layer has an opening as a light extraction area,
wherein the light extraction area is smaller than the light emission area of the electro-optical element, and
wherein a capacitance of the electro-optical element is larger than a capacitance of the holding capacitor.
8. The display driving method according to claim 7 , wherein the voltage is to be supplied to a gate of the drive transistor.
9. The display driving method according to claim 7 , wherein the holding capacitor is connected between the gate and a connection node on a source side of the drive transistor.
10. The display driving method according to claim 8 , wherein the holding capacitor is connected between the gate and a connection node on a source side of the drive transistor.
11. The display driving method according to claim 10 , wherein the electro-optical element is connected to the connection node on the source side.
12. The display driving method according to claim 7 , wherein the capacitance of the electro-optical element is larger than a capacitance of the other electro-optical element.
13. The display driving method according to claim 7 , wherein a color of the electro-optical element is different from a color of the other electro-optical element.
14. The display driving method according to claim 8 , wherein a color of the electro-optical element is different from one of another electro-optical element.
15. The display driving method according to claim 7 , further comprising:
outputting light from the electro-optical element via the light extraction area.
16. The display driving method according to claim 12 , further comprising:
outputting light from the electro-optical element via the light extraction area.
17. The display driving method according to claim 13 , further comprising:
outputting light from the electro-optical element via the light extraction area.
18. The display driving method according to claim 14 , further comprising:
outputting light from the electro-optical element via a light extraction area.
19. The display device according to claim 7 , wherein the pixel has a different film thickness from that of the other pixel.