Display device, method for driving display device, and electronic apparatus

Patent metadata

Field	Value
Publication number	US-2016307499-A1
Application number	US-201314650950-A
Country	US
Kind code	A1
Filing date	Oct 30, 2013
Priority date	Dec 26, 2012
Publication date	Oct 20, 2016
Grant date	—

Abstract

Provided is a display device in which a pixel circuit is arranged, the pixel circuit including a P channel type driving transistor that drives a light emitting unit, a sampling transistor that samples a signal voltage, a light emission control transistor that controls light emission/non-light emission of the light emitting unit, a holding capacitor that is connected between a gate electrode and a source electrode of the driving transistor, and holds the signal voltage written by the sampling by the sampling transistor, and an auxiliary capacitor that is connected between the source electrode of the driving transistor and a node having fixed potential, the display device including: a current path that flows a current flowing in the driving transistor in a non-light emission period of the light emitting unit into a predetermined node.

First claim

1 . A display device in which a pixel circuit is arranged, the pixel circuit including
a P channel type driving transistor that drives a light emitting unit, a sampling transistor that samples a signal voltage, a light emission control transistor that controls light emission/non-light emission of the light emitting unit, a holding capacitor that is connected between a gate electrode and a source electrode of the driving transistor, and holds the signal voltage written by the sampling by the sampling transistor, and an auxiliary capacitor that is connected between the source electrode of the driving transistor and a node having fixed potential,
the display device comprising:
a current path that flows a current flowing in the driving transistor in a non-light emission period of the light emitting unit into a predetermined node.

2 . The display device according to claim 1 ,
wherein the current path flows the current flowing in the driving transistor into a node of a cathode electrode of the light emitting unit.

3 . The display device according to claim 2 ,
wherein the current path includes a switching transistor that is connected between a drain electrode of the driving transistor and the node of the cathode electrode of the light emitting unit, and enters a conductive state in the non-light emission period of the light emitting unit.

4 . The display device according to claim 3 ,
wherein the switching transistor is driven by a signal for driving the sampling transistor.

5 . The display device according to claim 3 ,
wherein the switching transistor is driven by a signal different from a signal for driving the sampling transistor.

6 . The display device according to claim 4 ,
wherein a light emission period of the light emitting unit is set as a period from timing when a signal for driving the light emission control transistor becomes active, to timing when the signal for driving the sampling transistor becomes active.

7 . The display device according to claim 5 ,
wherein a light emission period of the light emitting unit is set as a period from timing when a signal for driving the light emission control transistor becomes active, to timing when the signal for driving the switching transistor becomes active.

8 . The display device according to claim 5 ,
wherein the signal for driving the switching transistor enters a non-active state before a writing period of the signal voltage by the sampling transistor starts.

9 . The display device according to claim 1 ,
wherein the sampling transistor, the light emission control transistor, and a switching transistor are configured with P channel type transistors.

10 . The display device according to claim 1 ,
wherein the pixel circuit performs an operation of changing source potential of the driving transistor toward potential obtained by subtracting a threshold voltage of the driving transistor from initial potential of gate potential of the driving transistor as a reference.

11 . The display device according to claim 1 ,
wherein the pixel circuit performs an operation of applying negative feedback to the holding capacitor in a writing period of the signal voltage by the sampling transistor by using a feedback amount according to a current flowing in the driving transistor.

12 . A method for driving a display device,
wherein a pixel circuit is arranged in the display device, the pixel circuit including
a P channel type driving transistor that drives a light emitting unit,
a sampling transistor that samples a signal voltage,
a light emission control transistor that controls light emission/non-light emission of the light emitting unit,
a holding capacitor that is connected between a gate electrode and a source electrode of the driving transistor, and holds the signal voltage written by the sampling by the sampling transistor, and
an auxiliary capacitor that is connected between the source electrode of the driving transistor and a node having fixed potential,
the method comprising: flowing, when driving the display device, a current flowing in the driving transistor in a non-light emission period of the light emitting unit into a predetermined node.

13 . An electronic apparatus comprising a display device in which a pixel circuit is arranged, the pixel circuit including
a P channel type driving transistor that drives a light emitting unit, a sampling transistor that samples a signal voltage, a light emission control transistor that controls light emission/non-light emission of the light emitting unit, a holding capacitor that is connected between a gate electrode and a source electrode of the driving transistor, and holds the signal voltage written by the sampling by the sampling transistor, and an auxiliary capacitor that is connected between the source electrode of the driving transistor and a node having fixed potential,
the display device including
a current path that flows a current flowing in the driving transistor in a non-light emission period of the light emitting unit into a predetermined node.

Assignees

• Sony Corp

Inventors

• Toyomura Naobumi
• Onoyama Yusuke
• Yamashita Junichi

Classifications

• G09G2300/0861

  with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes · CPC title

• G09G2310/0251

  Precharge or discharge of pixel before applying new pixel voltage · CPC title

• G09G2300/0852

  being a dynamic memory with more than one capacitor · CPC title

• G09G3/3266

  Details of drivers for scan electrodes · CPC title

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title