Display device, driving method of display device and electronic apparatus
View Patent ↗A display device includes: a pixel array unit in which plural pixels are arranged, each including an electro-optic device, a write transistor writing a video signal, a storage capacitor storing the video signal written by the write transistor and a drive transistor driving the electro-optic device based on the video signal stored in the storage capacitor, which have a function of correcting mobility of the drive transistors; and a scanning circuit giving a write scanning signal to gate electrodes of the write transistors while sequentially scanning respective pixels in the pixel array row by row as well as generating the write scanning signal based on respective timings of rising and falling of one pulse-state power source potential.
1. A display device comprising:
a pixel array unit in which plural pixels are arranged, each pixel including an electro-optic device, a write transistor writing a video signal, a storage capacitor storing the video signal written by the write transistor, and a drive transistor driving the electro-optic device based on the video signal stored in the storage capacitor; and
a scanning circuit configured to provide a write scanning signal to gate electrodes of the write transistors while sequentially scanning respective pixels in the pixel array row by row,
wherein,
the write scanning signal is generated based on respective timings of rising and falling of one pulse-state power source potential in a mobility correction period,
a mobility correction process which corrects variations in mobility of the drive transistors in respective pixels is performed in parallel to the writing of the video signal by the write scanning signal in the mobility correction period,
the pixels have a function of correcting threshold voltage of the drive transistors, and
the scanning circuit allows an amplitude of the write scanning signal given to the gate electrode of the write transistor during the correction of threshold voltage to be smaller than an amplitude of the write scanning signal given to the gate electrode of the write transistor during the correction of mobility.
2. The display device according to claim 1 , wherein the correction of mobility is performed in accordance with magnitude of electric current flowing in the drive transistor during a conductive period of the write transistor.
3. The display device according to claim 2 , wherein the correction of mobility is performed by giving negative feedback to the difference of potentials between gate/source of the drive transistor with a correction amount corresponding to the magnitude of electric current flowing in the drive transistor during the conductive period of the write transistor.
4. The display device according to claim 1 , wherein the correction of threshold voltage is performed by changing a source potential of the drive transistor toward a potential obtained by subtracting the threshold voltage of the drive transistor from a reference potential based on an initialization potential of the gate potential of the drive transistor during the conductive period of the write transistor.
5. The display device according to claim 1 , wherein:
the scanning circuit includes a first buffer circuit outputting the write scanning signal to the gate electrode of the write transistor during the correction of threshold voltage, and a second buffer circuit outputting the write scanning signal to the gate electrode of the write transistor during the correction of mobility,
the first buffer circuit operates by a DC power source potential, and
the second buffer circuit operates by the pulse-state power source potential having a higher voltage value than the DC power source potential.
6. The display device according to claim 1 , wherein the correction of threshold voltage is performed in one horizontal period in which writing of the video signal is performed by the write transistor and plural times over plural horizontal periods preceding to the one horizontal period.
7. A driving method of a display device including (a) a pixel array unit in which plural pixels are arranged, each pixel including (i) an electro-optic device, (ii) a write transistor writing a video signal, (iii) a storage capacitor storing the video signal written by the write transistor, and (iv) a drive transistor driving the electro-optic device based on the video signal stored in the storage capacitor, the method comprising the step of:
generating a write scanning signal given to gate electrodes of the write transistors while sequentially scanning respective pixels in the pixel array row by row,
wherein,
the write scanning signal is generated based on respective timings of rising and falling of one pulse-state power source potential in a mobility correction period,
a mobility correction process which corrects variations in mobility of the drive transistors in respective pixels is performed in parallel to the writing of the video signal by the write scanning signal in the mobility correction period
the pixels have a function of correcting threshold voltage of the drive transistors, and
the scanning circuit allows an amplitude of the write scanning signal given to the gate electrode of the write transistor during the correction of threshold voltage to be smaller than an amplitude of the write scanning signal given to the gate electrode of the write transistor during the correction of mobility.
8. An electronic apparatus comprising:
a display device including
a pixel array unit in which plural pixels are arranged, each pixel including an electro-optic device, a write transistor writing a video signal, a storage capacitor storing the video signal written by the write transistor and a drive transistor driving the electro-optic device based on the video signal stored in the storage capacitor, and
a scanning circuit configured to provide a write scanning signal to gate electrodes of the write transistors while sequentially scanning respective pixels in the pixel array row by row,
wherein,
the write scanning signal is generated based on respective timings of rising and falling of one pulse-state power source potential in a mobility correction period,
a mobility correction process which corrects variations in mobility of the drive transistors in respective pixels is performed in parallel to the writing of the video signal by the write scanning signal in the mobility correction period,
the pixels have a function of correcting threshold voltage of the drive transistors, and
the scanning circuit allows an amplitude of the write scanning signal given to the gate electrode of the write transistor during the correction of threshold voltage to be smaller than an amplitude of the write scanning signal given to the gate electrode of the write transistor during the correction of mobility.