Organic light emitting display device

Patent metadata

Field	Value
Publication number	US-9837021-B2
Application number	US-201514738622-A
Country	US
Kind code	B2
Filing date	Jun 12, 2015
Priority date	Jun 26, 2014
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

An organic light emitting display device includes an (i−1)th pixel, an i-th pixel, and an (i+1)th pixel, each including an organic light emitting diode and a driving transistor to control a driving current flowing through the organic light emitting diode. A first node of the i-th pixel, to which a control electrode of the driving transistor of the i-th pixel is connected, is initialized to an initialization voltage in synchronization with an (i−1)th scan signal applied to the i-th pixel, and an anode of the organic light emitting diode of the i-th pixel is initialized to the initialization voltage in synchronization with an i-th scan signal applied to the (i+1)th pixel.

First claim

What is claimed is:

1. An organic light emitting display device comprising:
an (i−1)th pixel connected to an (i−1)th scan line;
an i-th pixel connected to an i-th scan line; and
an (i+1)th pixel connected to an (i+1)th scan line,
wherein the “i” is a natural number equal to or greater than 2,
each of the (i−1)th pixel, the i-th pixel, and the (i+1)th pixel comprises an organic light emitting diode, a driving transistor configured to control a driving current flowing through the organic light emitting diode, and a first initialization transistor,
a first node of the i-th pixel, to which a control electrode of the driving transistor of the i-th pixel is connected, is configured to be initialized to an initialization voltage of the i-th pixel in synchronization with an (i−1)th scan signal applied to the i-th pixel, and
the first initialization transistor of the (i+1)th pixel is connected to an anode of the organic light emitting diode of the i-th pixel, and the first initialization transistor of the (i+1)th pixel is configured to apply the initialization voltage of the (i+1)th pixel to the anode of the organic light emitting diode of the i-th pixel in synchronization with an i-th scan signal.

2. The organic light emitting display device of claim 1 , wherein:
the i-th pixel further comprises a second initialization transistor, the first initialization transistor and the second initialization transistor of the i-th pixel are connected between an i-th initialization line configured to be applied with the initialization voltage of the i-th pixel and the first node of the i-th pixel in series,
the first and second initialization transistors of the i-th pixel configured to apply the initialization voltage of the i-th pixel to the first node of the i-th pixel in response to the (i−1)th scan signal applied to an i-th dummy scan line.

3. The organic light emitting display device of claim 2 , wherein a first node of the (i+1)th pixel, to which a control electrode of the driving transistor of the (i+1)th pixel is connected, is configured to be initialized to the initialization voltage of the (i+1)th pixel in synchronization with the i-th scan signal applied to the (i+1)th pixel.

4. The organic light emitting display device of claim 3 , wherein:
the (i+1)th pixel further comprises a second initialization transistor, the first initialization transistor and the second initialization transistor of the (i+1)th pixel are connected between an (i+1)th initialization line applied with the initialization voltage of the (i+1)th pixel and the first node of the (i+1)th pixel in series,
a second node of the (i+1)th pixel, which is connected to the anode of the organic light emitting diode of the i-th pixel, is defined between the first and second initialization transistors of the (i+1)th pixel,
the first initialization transistor of the (i+1)th pixel is configured to apply the initialization voltage of the (i+1)th pixel to the second node of the (i+1)th pixel in response to the i-th scan signal applied to the (i+1)th pixel, and
the anode of the organic light emitting diode of the i-th pixel is connected to the second node of the (i+1)th pixel.

5. The organic light emitting display device of claim 2 , wherein:
a second node of the i-th pixel, which is connected to the anode of the organic light emitting diode of the (i−1)th pixel, is defined between the first and second initialization transistors of the i-th pixel, and
the anode of the organic light emitting diode of the (i−1)th pixel is configured to be initialized to the initialization voltage of the i-th pixel in synchronization with the (i−1)th scan signal applied to the i-th pixel.

6. The organic light emitting display device of claim 5 , wherein the second initialization transistor of the i-th pixel comprises two transistors connected between the second node of the i-th pixel and the first node of the i-th pixel.

7. The organic light emitting display device of claim 2 , wherein the i-th pixel comprises:
a switching transistor comprising an input electrode connected to a k-th (k is a natural number equal to or greater than 1) data line, an output electrode connected to an input electrode of the driving transistor, and a control electrode connected to the i-th scan line applied with the i-th scan signal;
a storage capacitor connected between the first node and a power source line;
a first control transistor comprising an input electrode connected to an output electrode of the driving transistor, an output electrode connected to the first node, and a control electrode connected to the i-th scan line applied with the i-th scan signal; and
a second control transistor comprising an input electrode connected to the output electrode of the driving transistor, an output electrode connected to the anode of the organic light emitting diode, and a control electrode connected to an i-th light emitting line.

8. The organic light emitting display device of claim 7 , wherein the i-th pixel further comprises a third control transistor comprising an input electrode connected to the power source line, an output electrode connected to the input electrode of the driving transistor, and a control electrode connected to the i-th light emitting line.

9. The organic light emitting display device of claim 8 , wherein a period in which the (i−1)th scan signal applied to the i-th dummy scan line is activated corresponds to an initialization period, a period in which the i-th scan signal applied to the i-th scan line is activated corresponds to a data write-in period after the initialization period, and the storage capacitor is configured to be charged with a voltage corresponding to a data signal applied to the k-th data line during the data write-in period.

10. The organic light emitting display device of claim 9 , wherein a period in which a light emitting control signal applied to the i-th light emitting line is activated corresponds to a light emitting period after the initialization period, and the organic light emitting diode of the i-th pixel is configured to emit a light in response to the voltage charged in the storage capacitor during the light emitting period.

11. The organic light emitting display device of claim 7 , wherein a channel part of the driving transistor is disposed between the input electrode of the driving transistor and the output electrode of the driving transistor, disposed on a same layer as the input and output electrodes of the driving transistors, and overlapped with the control electrode of the driving transistor.

12. The organic light emitting display device of claim 11 , wherein the storage capacitor comprises:
a first electrode disposed on a first insulating layer that covers the input electrode, the output electrode, and the channel part of the driving transistor; and
a second electrode disposed on a second insulating layer that covers the first electrode and is connected to the power source line.

13. The organic light emitting display device of claim 12 , wherein the driving transistor further comprises a floating electrode disposed on a same layer as the first electrode and overlapped with the control electrode of the driving transistor.

14. The organic light emitting display device of claim 13 , wherein the control electrode of the driving transistor is disposed on a same layer as the second electrode.

15. The organic light emitting display device of claim 14 , wherein:
the i-th pixel comprises a first connection electrode to connect the control electrode of the driving transistor and the first electrode of the storage capacitor,
the first connection electr

Assignees

• Samsung Display Co Ltd

Inventors

• Lee Jeongho
• Kwon Dohyun
• Sim Su-Yeon
• Yoon Ju-Won
• Lee Gichang
• Lee Seungmin
• Lee Iljeong
• Im Choongyoul

Classifications

• G09G3/3233 Primary

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

• 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

• G09G2310/0262

  The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes · CPC title

• G09G2300/0819

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

• G09G2310/0251

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