Image display device
View Patent ↗The invention provides an image display device that has an especially satisfactory display quality for animated images, and sufficiently suppresses the irregularities of display quality among pixels. The image display device includes a light emitting drive means that drives a light emitting means, based on an analog display signal inputted to the pixels, and a light emitting control switch for controlling a light-on or light-off of the light emitting means on one end of the light emitting drive means in each pixel.
1. An image display device comprising:
a plurality of pixels;
a signal line for inputting a display signal to the plurality of pixels;
a power supply line for supplying power to the plurality of pixels;
each of the plurality of pixels including a first transistor which have a source and a drain one of which is connected to the power supply line and which controls light emission of corresponding one of the plurality of pixels, a second transistor arranged between the drain of the first transistor and a gate thereof, a third transistor which have a source and a drain one of which is connected to the other of the source and the drain of the first transistor, a light emitting device connected to the other of the source and the drain of the third transistor, and a capacitor which have a first end connected to the signal line and a second end connected to the gate of the first transistor;
a first voltage applying circuit for inputting the display signal to the first end of the capacitor in each of the plurality of pixels during write period in order to store a potential difference on the capacitor in accordance with the display signal and a threshold voltage of the first transistor in corresponding one of the plurality of pixels;
a second voltage applying circuit for inputting a predetermined voltage to the first end of the capacitor in each of the plurality of pixels during light-on period.
2. The image display device according to claim 1 , wherein the first voltage applying circuit is an analog signal voltage distribution circuit.
3. The image display device according to claim 1 , wherein the first voltage applying circuit is a DA converter circuit.
4. The image display device according to claim 1 , wherein the second voltage applying circuit is a transistor switch.
5. The image display device according to claim 1 , wherein the second voltage applying circuit is a DA converter circuit.
6. The image display device according to claim 1 , wherein the first voltage applying circuit and the second voltage applying circuit share an identical DA converter circuit.
7. The image display device according to claim 1 , wherein the predetermined voltage has a triangular waveform.
8. The image display device according to claim 1 , wherein the predetermined voltage has a staircase waveform.
9. A driving method for an image display device comprising a plurality of pixels each including a drive transistor controlling light-emission of corresponding one of the plurality of pixels, a light control switch which has one end connected to a drain of the driving transistor, and capacitor which has one end connected to a gate of the driving transistor, the driving method comprising:
a writing step of scanning the plurality of pixels in sequence, inputting a display signal to the other end of the capacitor in the scanned pixel as well as connecting a gate and a drain of the driving transistor in the scanned pixel each other, storing a potential difference on the capacitor in accordance with the display signal and a threshold voltage of the driving transistor, and turning off a light control switch in the other pixels to prevent light-emission of the other pixels;
after the writing step, a light-on step of turning on the light control switch in the plurality of pixels as well as inputting a predetermined voltage to the other end of the capacitor in the plurality of pixels and making the driving transistor in the plurality of pixels control a gradation display.