Image display device and driving method of image display device

1. An image display device for displaying input image data on a display section formed by arranging pixel circuits in a form of a matrix by driving said pixel circuits by a signal line driving circuit and a scanning line driving circuit via a signal line and a scanning line of said display section, wherein:

said pixel circuits each include

at least a light emitting element,

a driving transistor configured to current-drive said light emitting element by a driving current corresponding to a gate-to-source voltage,

a storage capacitor configured to retain said gate-to-source voltage, and

a writing transistor configured to set a voltage across said storage capacitor by a voltage of said signal line;

said signal line driving circuit includes

a data driver configured to time-division-multiplex and output gradation setting voltages for each unit of a plurality of signal lines after assigning said input image data to said signal lines and generating, for each of said signal lines, said gradation setting voltages sequentially indicating gradations of said pixel circuits connected to the respective signal lines,

a switch circuit for the gradation setting voltages, said switch circuit for the gradation setting voltages distributing an output signal of said data driver to said plurality of signal lines, and

a switch circuit for precharge, said switch circuit for precharge setting at least potential of the corresponding signal lines to a precharge voltage in advance of setting the gate-to-source voltage of the driving transistor when voltage of said signal lines is set to said gradation setting voltages; and

said signal line driving circuit selects and outputs the precharge voltage to each of said signal lines via the switch circuit for precharge to simultaneously set each signal line in advance of sequentially setting said gradation setting voltages, and

wherein the voltage across the storage capacitor is set to the threshold voltage of the driving transistor such that the potential of the plurality of signal lines is simultaneously set to the precharge voltage in advance of setting the gate-to-source voltage of the driving transistor and the gate-to-source voltage of the driving transistors of said pixel circuits are sequentially set to said gradation setting voltages of the respective signal lines.

2. The image display device according to claim 1 , wherein said precharge voltage is an intermediate voltage between a maximum value and a minimum value of said gradation setting voltages.

3. The image display device according to claim 1 , wherein

after raising the voltage across said storage capacitor to more than a threshold voltage of said driving transistor by setting a voltage of one terminal of said storage capacitor to a fixed voltage for threshold voltage correction via said writing transistor, each of said pixel circuits sets said voltage across said storage capacitor to a voltage dependent on the threshold voltage of said driving transistor by discharging the voltage across said storage capacitor via said driving transistor; and

then sets the voltage across said storage capacitor by said gradation setting voltage via said writing transistor, and

said signal line driving circuit includes a switch circuit for the fixed voltage, said switch circuit for the fixed voltage simultaneously setting the voltage of said plurality of signal lines to said fixed voltage for threshold voltage correction when the voltage of said signal lines is set to said precharge voltage.

4. The image display device according to claim 1 , wherein

after raising the voltage across said storage capacitor to more than a threshold voltage of said driving transistor by setting a voltage of one terminal of said storage capacitor to a fixed voltage for threshold voltage correction via said writing transistor, each of said pixel circuits sets said voltage across said storage capacitor to a voltage dependent on the threshold voltage of said driving transistor by discharging the voltage across said storage capacitor via said driving transistor; and

then sets the voltage across said storage capacitor by said gradation setting voltage via said writing transistor, and

by time-division-multiplexing said precharge voltage and said fixed voltage for threshold voltage correction and inputting a result of time-division-multiplexing said precharge voltage and said fixed voltage for threshold voltage correction to said switch circuit for precharge, said signal line driving circuit simultaneously sets the voltage of said plurality of signal lines to said fixed voltage for threshold voltage correction in advance when the voltage of said signal lines is set to said precharge voltage.

5. A driving method of an image display device for displaying input image data on a display section formed by arranging pixel circuits in a form of a matrix by driving said pixel circuits by a signal line driving circuit and a scanning line driving circuit via a signal line and a scanning line of said display section, said pixel circuits each including at least a light emitting element, a driving transistor configured to current-drive said light emitting element by a driving current corresponding to a gate-to-source voltage, a storage capacitor configured to retain said gate-to-source voltage, and a writing transistor configured to set a voltage across said storage capacitor by a voltage of said signal line, said driving method of the image display device comprising:

a data driver processing step of outputting an output signal obtained by time-division-multiplexing gradation setting voltages for each unit of a plurality of signal lines from a data driver after assigning said input image data to said signal lines and generating, for each of said signal lines, said gradation setting voltages sequentially indicating gradations of said pixel circuits connected to the respective signal lines;

a gradation setting voltage distributing step of distributing and outputting the output signal of said data driver to said plurality of signal lines;

a precharge step of setting at least potential of the corresponding signal lines to a precharge voltage in advance of setting the gate-to-source voltage of the driving transistor when voltage of said signal lines is set to said gradation setting voltages by said gradation setting voltage distributing step; and

said signal line driving circuit is configured selects and outputs the precharge voltage to each of said signal lines via the switch circuit for precharge to simultaneously set each signal line in advance of sequentially setting said gradation setting voltages, and

wherein the voltage across the storage capacitor is set to the threshold voltage of the driving transistor such that the potential of the plurality of signal lines is simultaneously set to the precharge voltage in advance of setting the gate-to-source voltage of the driving transistor and the gate-to-source voltage of the driving transistors of said pixel circuits are sequentially set to said gradation setting voltages of the respective signal lines.

6. The image display device according to claim 2 , wherein said intermediate voltage is a function of:

(the maximum value+the minimum value of said gradation setting voltages)/2.

7. The driving method according to claim 5 , wherein said precharge voltage is an intermediate voltage between a maximum value and a minimum value of said gradation setting voltages, and

wherein said intermediate voltage is a function of:

(the maximum value+the minimum value of said gradation setting voltages)/2.