Display device and driving method thereof

Patent metadata

Field	Value
Publication number	US-2016293103-A1
Application number	US-201615083874-A
Country	US
Kind code	A1
Filing date	Mar 29, 2016
Priority date	Apr 2, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A method of driving a display device includes the following steps: a step of applying a first voltage to a drain of the driving transistor from the first power supply line, while applying an initialization voltage lower than the first voltage to a gate of the driving transistor; a step of applying a voltage higher than the initialization voltage lower than the first voltage to the drain of the driving transistor, and applying a voltage based on a video signal to the gate of the driving transistor; and a step of applying the first voltage to a drain of the driving transistor from the first power supply line and supplying a current to the light emitting element while holding the voltage based on the video signal to the gate of the driving transistor.

First claim

What is claimed is:

1 . A method of driving a display device, the display device includes a plurality of pixels, each of the plurality of pixels includes a light emitting element arranged between a first power supply line applied with a first voltage and a second power supply line applied with a second voltage lower than the first voltage, and a driving transistor controlling a current flowing to the a light emitting element and electrically connected to the first power supply line, the method of driving the display device includes the following steps:
a step of applying a first voltage to a drain of the driving transistor from the first power supply line, while applying an initialization voltage lower than the first voltage to a gate of the driving transistor; a step of applying a voltage higher than the initialization voltage and lower than the first voltage to the drain of the driving transistor, and applying a voltage based on a video signal to the gate of the driving transistor; and a step of applying the first voltage to a drain of the driving transistor from the first power supply line and supplying a current to the light emitting element while holding the voltage based on the video signal to the gate of the driving transistor.

2 . The method of driving a display device according to claim 1 , wherein
the step of applying the first voltage to a drain of the driving transistor from the first power supply line while applying an initialization voltage lower than the first voltage to a gate of the driving transistor is performed a plurality of times.

3 . The method of driving a display device according to claim 1 , wherein
the step of applying the first voltage to a drain of the driving transistor from the first power supply line while applying an initialization voltage lower than the first voltage to a gate of the driving transistor, the driving transistor holding a gate-source voltage between the gate and a source of the driving transistor, the gate-source voltage is changed from the initial voltage by amount of a threshold voltage of the driving transistor.

4 . The method of driving a display device according to claim 1 , wherein
after applying the first voltage to a drain of the driving transistor from the first power supply line while applying an initialization voltage lower than the first voltage to a gate of the driving transistor, the initialization voltage lower than the first voltage is applied to the gate of the driving transistor, and a voltage lower than the first voltage and higher than the initial voltage is applied to the drain of the driving transistor.

5 . The method of driving a display device according to claim 1 , wherein
the step of applying a voltage higher than the initialization voltage and lower than the first voltage to a drain of the driving transistor while applying an initialization voltage lower than the first voltage to a gate of the driving transistor is performed a plurality of times.

6 . A method of driving a display device, the display device includes a plurality of pixels, each of the plurality of pixels includes a light emitting element arranged between a first power supply line applied with a first voltage and a second power supply line applied with a second voltage lower than the first voltage, a driving transistor arranged between the light emitting element and the first power supply line, a source of the driving transistor is electrically connected to the light emitting element, a first switch controlling an electrical connection between a gate of the driving transistor and a signal line supplied with a video signal and an initialization voltage, and a second switch controlling an electrical connection between the first power supply line and a drain of the driving transistor, the method of driving the display device includes the following steps:
a step of switching the first switch and the second switch to OFF in a source initialization period and applying a first reset voltage to a drain of the driving transistor; a step of switching the first switch to ON and the second switch to OFF in a gate initialization period following the source initialization period, and applying an initialization voltage higher than the first reset voltage to a gate of the driving transistor from the signal line; a step of switching the first switch and the second switch to ON in an offset cancel period following the gate initialization period, applying an initialization voltage to a gate of the driving transistor, supplying a current to the driving transistor from the first power supply line and shifting a source voltage to a high voltage side; a step of switching the first switch to ON and the second switch to OFF in a video signal writing period following the offset cancel period, applying a video signal to a gate of the driving transistor, and applying a second reset voltage higher than the first reset voltage and lower than a voltage of the first power supply line to a drain of the driving transistor; and a step of switching the first switch to OFF and the second switch to ON in a emission period following the video signal writing period, and supplying a current from the first power supply line to the light emitting element according to a gate voltage of the driving transistor.

7 . The method of driving a display device according to claim 6 , wherein
the step of switching the first switch and the second switch to ON in the offset cancel period following the gate initialization period, applying an initialization voltage to a gate of the driving transistor, and supplying a current to the driving transistor from the first power supply line is performed a plurality of times.

8 . The method of driving a display device according to claim 6 , wherein
the plurality of pixels are arranged in a row direction and a column direction, and an operation in the source initialization period, an operation in the gate initialization period and an operation in the offset cancel period are performed simultaneously on two adjacent rows.

9 . A display device comprising a plurality of pixels, each of the plurality of pixels includes:
a first power supply line applied with a first voltage; a light emitting element arranged between the first power supply line applied with the first voltage and a second power supply line applied with a second voltage lower than the first voltage; a driving transistor arranged between the light emitting element and the first power supply line, a source of the driving transistor is electrically connected to the light emitting element; a first switch controlling an electrical connection between a signal line supplied with a video signal and an initialization voltage, and a gate of the driving transistor; and a second switch controlling an electrical connection between the first power supply line and a drain of the driving transistor, the display device further includes: a driving circuit controlling an ON/OFF operation of the first switch and the second switch, applying a video signal and an initialization voltage to the signal line, and applying a first reset voltage and a second voltage to the driving transistor; a source initialization period for switching the first switch and the second switch to OFF, and applying the first reset voltage to a drain of the driving transistor; a gate initialization period following the source initialization period for switching the first switch to ON and the second switch to OFF, and applying an initialization voltage higher than the first reset voltage to a gate of the driving transistor from the signal line; a first offset cancel period following the gate initialization period for switching the first switch and the second switch to

Assignees

• Japan Display Inc

Inventors

• Kimura Hiroyuki
• PENG Duzen
• Wu Ilin

Classifications

• G09G2310/0254

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• G09G2310/0216

  Interleaved control phases for different scan lines in the same sub-field, e.g. initialization, addressing and sustaining in plasma displays that are not simultaneous for all scan lines · CPC title

• G09G2300/043

  Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver · CPC title

• G09G2300/0842

  forming a memory circuit, e.g. a dynamic memory with one capacitor · CPC title

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title