KR100590063B1 - A light emitting device, and a method for driving a display panel - Google Patents

Abstract

The present invention relates to an organic EL light emitting display device and a display panel driving method thereof. According to the present invention, there is provided a light emitting display device comprising: a display panel configured to emit light by emitting a plurality of pixels respectively connected to a plurality of data lines and a scan line; A scan driver for sequentially applying a selection signal to the plurality of scan lines, respectively; A data driver for applying a data voltage corresponding to an image signal to each pixel selected by the plurality of scan lines; A temperature sensor for detecting an external temperature; And a driving controller driving the data driver and the scan driver in accordance with an initial driving current raised corresponding to the temperature detected by the temperature sensor. According to the present invention, since the initial current or power supply voltage applied to the organic EL light emitting display device is raised to increase the temperature of the display panel and then driven normally, the brightness of the display panel does not fall during initial driving in a cold external environment.

Light emitting display, organic EL, panel, initial driving, temperature

Description

A light emitting device and a method for driving a display panel

1 is a diagram showing the light emission principle of an organic EL.

2 is a schematic block diagram of an organic EL display device according to an embodiment of the present invention.

3 is a diagram illustrating an organic EL display panel using an active driving method using a thin film transistor (TFT) according to an embodiment of the present invention.

4 is a schematic structural diagram of a light emitting display device according to an embodiment of the present invention.

5 is a schematic diagram of a light emitting display device according to another embodiment of the present invention.

6 is a flowchart illustrating a display panel driving method of a light emitting display device according to an exemplary embodiment of the present invention.

The present invention relates to a light emitting display device and a display panel driving method thereof, and more particularly, to an organic EL light emitting display device and a display panel driving method thereof.

An organic electroluminescence (EL) display device is a device for displaying an image by controlling an amount of current flowing through these organic materials by dividing an organic material emitting light when the current flows into pixels in a matrix form. Such an organic EL display device is expected to be a next generation display device due to advantages such as low voltage driving, light weight, wide viewing angle, and high speed response.

1 is a diagram showing the light emission principle of organic EL, respectively.

In general, an organic EL display device is a display device for electrically exciting a fluorescent organic compound to emit light, and is capable of displaying an image by driving voltage or current by driving N × M organic light emitting cells. As shown in FIG. 1, the organic light emitting cell structure has a structure of an indium tin oxide (ITO) pixel electrode, an organic thin film, and a metal layer, and the organic thin film has a good balance between electrons and holes to improve light emission efficiency. In order to achieve this, a multi-layered structure including an emitting layer (EML), an electron transport layer (ETL), and a hole transport layer (HTL) is formed, and a separate electron injection layer (EIL) is used. ) And a hole injecting layer (HIL).

As such a method of driving the organic light emitting cell, there are a simple matrix method and an active matrix method using a TFT. In the simple matrix method, the anode and the cathode are orthogonal and the line is selected and driven, whereas the active driving method is a driving method in which a TFT and a capacitor are connected to respective pixel electrodes to maintain a voltage by capacitor capacitance.

However, the conventional organic EL light emitting display device has a problem in that the brightness of the display panel may drop early in driving in a cold external environment.

An object of the present invention for solving the above problems is to provide a light emitting display device and a display panel driving method thereof in which the brightness of the display panel does not fall during the initial driving in a cold external environment.

As a means for achieving the above object, the light emitting display device according to the present invention,

A display panel configured to emit light by emitting a plurality of pixels respectively connected to the plurality of data lines and the scan lines;

A scan driver for sequentially applying a selection signal to the plurality of scan lines, respectively;

A data driver for applying a data voltage corresponding to an image signal to each pixel selected by the plurality of scan lines;

A temperature sensor for detecting an external temperature; And

A driving control unit driving the data driving unit and the scan driving unit according to an initial driving current raised corresponding to the temperature detected by the temperature sensor;

Characterized in that it comprises a.

Here, the driving controller increases the initial driving current corresponding to the warm-up data according to the temperature detected by the temperature sensor, and the warm-up data may be data patterns that are preset according to the detected temperature, and the warm-up The data may be data patterns in which the initial driving time varies depending on the detected temperature.

The driving controller may input an initial driving current corresponding to a full write signal according to the temperature detected by the temperature sensor to the data driver.

The driving control unit may increase the initial driving current to increase the temperature of the display panel and then normally drive the display panel.

On the other hand, as a means for achieving the above object, the light emitting display device according to the present invention,

A display panel configured to emit light by emitting a plurality of pixels respectively connected to the plurality of data lines and the scan lines;

A scan driver for sequentially applying a selection signal to the plurality of scan lines, respectively;

A data driver for applying a data voltage corresponding to an image signal to each pixel selected by the plurality of scan lines;

A temperature sensor for detecting an external temperature; And

A driving controller which applies a power supply voltage corresponding to the temperature detected by the temperature sensor to the plurality of pixels

Characterized in that it comprises a.

In this case, when the power supply voltage rises, the gray scales of the entirety also increase in proportion.

The driving control unit may increase the power supply voltage to increase the temperature of the display panel and then normally drive the display panel.

On the other hand, as a means for achieving the above object, the display panel driving method of the light emitting display device according to the present invention,

Iii) turning on the power supply;

Ii) detecting the external temperature and the temperature of the display panel;

Iii) raising the temperature of the display panel by raising an initial driving current when the detected temperature is below a predetermined temperature; And

I) normally driving the display panel when the temperature of the display panel rises to a predetermined temperature;

Characterized in that it comprises a.

Here, the step iii) increases the initial driving current corresponding to the pre-stored warm-up data according to the detected temperature, and the warm-up data may be a preset data pattern according to the detected temperature, and the warm-up data May be a data pattern in which the initial driving time varies depending on the detected temperature.

The initial driving current corresponding to the full write signal may be input to the data driver according to the detected temperature.

On the other hand, as a means for achieving the above object, a display panel driving method of a light emitting display device according to the present invention,

In the method of driving a display panel of a light emitting display device having a plurality of pixels, a scan driver and a data driver,

Iii) turning on the power supply;

Ii) detecting the external temperature and the temperature of the display panel;

Iii) raising the temperature of the display panel by raising a power supply voltage when the detected temperature is below a predetermined temperature; And

I) normally driving the display panel when the temperature of the display panel rises to a predetermined temperature;

Characterized in that it comprises a.

In this case, when the power supply voltage rises, the gray scales of the entirety also increase in proportion.

According to the present invention, since the initial current or power supply voltage applied to the organic EL light emitting display device is raised to increase the temperature of the display panel and then driven normally, the brightness of the display panel does not fall during initial driving in a cold external environment.

Hereinafter, a light emitting display device and a display panel driving method thereof according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic block diagram of an organic EL display device according to an embodiment of the present invention.

Referring to FIG. 2, an organic EL display device according to an exemplary embodiment of the present invention includes a video controller 100, a panel controller 200, a power module 300, a scan driver 400, a data driver 500, and an organic EL. It may be made of a panel 600.

In the organic EL display device according to the embodiment of the present invention, a plurality of signals passing through the analog interface and the digital interface are respectively arranged in the organic EL panel 600 by the scan driver 440 and the data driver 500. It is provided in the row direction.

Specifically, various analog signals such as R, G, B signals, and synchronization signals are input to the video controller 100 and then converted into digital signals, and the panel controller 200 controls them to sequentially scan the driver 400. And the data driver 500, the organic EL panel 600 is provided by the scan driver 400 and the data driver 500, and the power supply device 400. An n × m organic light emitting cell is driven by voltage or current by a power supply to represent an image.

3 is a diagram illustrating an organic EL display panel using an active driving method using a TFT according to an embodiment of the present invention.

Referring to FIG. 3, an organic EL display device according to an exemplary embodiment of the present invention includes an organic EL display panel 600, a data driver 400, and a scan driver 500.

The organic EL display panel 600 includes m data lines D1, D2, ..., Dm extending in the column direction, n scan lines S1, S2, ..., Sn extending in the row direction, and n × m. Pixel circuits. The m data lines D1, D2, ..., Dm transfer data signals representing an image signal to the pixel circuits, and the n scan lines S1, S2, ..., Sn transfer respective selection signals to the pixel circuits. . Here, the pixel circuit is formed in one pixel region 610 defined by two neighboring data lines D1, D2,..., And Dm and two neighboring scan lines S1, S2,..., Sn.

The scan driver 400 sequentially applies selection signals to the n scan lines S1, S2,..., And Sn, and the data driver 500 images the m data lines D1, D2,..., And Dm. The data voltage corresponding to the signal is applied.

In addition, the scan driver 330 and / or the data driver 320 may be electrically connected to the organic EL display panel 600, or a tape carrier adhered to and electrically connected to the organic EL display panel 600. The package may be mounted in a chip carrier package (TCP). Alternatively, the display panel 600 may be attached to a flexible printed circuit (FPC) or a film that is adhered to and electrically connected to the display panel 600 in the form of a chip.

In addition, the scan driver 400 and / or the data driver 500 may be directly mounted on the glass substrate of the organic EL display panel 600, or may be formed of the same layers as the scan line, the data line, and the thin film transistor on the glass substrate. It may be replaced with the driving circuit formed or may be directly mounted.

The pixel circuit also includes an organic EL element OLED, two transistors SM and DM and a capacitor Cst. For example, the two transistors SM and DM may be formed as PMOS transistors.

The driving transistor DM has a source connected to the power supply voltage VDD, and a capacitor Cst connected between the gate and the source. The capacitor Cst maintains the gate-source voltage of the driving transistor DM for a predetermined period, and the driving transistor DM corresponds to a voltage held by the capacitor Cst, that is, a voltage between the gate and the source. Output the current. The switching transistor SM transfers the data signal from the data line Dm to the driving transistor DM in response to the selection signal from the current scan line Sn.

The organic EL element OLED has a cathode connected to a reference voltage Vss and emits light corresponding to a current applied through the driving transistor DM. Here, the power source Vss connected to the cathode of the organic EL element OLED is a voltage having a lower level than the power source VDD, and a ground voltage or the like may be used.

4 is a schematic configuration diagram of a light emitting display device according to an exemplary embodiment of the present invention, which includes a display panel 600, a scan driver 400, a data driver 500, a drive controller 700, and a temperature sensor 800. ) And warm up data 900.

Referring to FIG. 4, in the light emitting display device according to an exemplary embodiment of the present invention, the scan driver 400 sequentially applies a selection signal to the plurality of scan lines, and the data driver 500 corresponds to an image signal. The data voltage to be applied is applied to each pixel selected by the plurality of scan lines, and the display panel 600 emits light by displaying a plurality of pixels respectively connected to the plurality of data lines and the scan lines.

The temperature sensor 800 detects an external temperature in a cold environment, and the driving control unit 700 may adjust the data driving unit 500 and the initial driving current corresponding to the temperature detected by the temperature sensor 800. The scan driver 400 is driven.

The driving control unit 700 increases the initial driving current corresponding to the warm-up data 900 according to the temperature detected by the temperature sensor 800. In this case, the warm-up data 900 is preliminarily set according to the detected temperature. The data pattern may be a set data pattern or a data pattern in which an initial driving time varies depending on the detected temperature.

In addition, the driving controller 700 may input an initial driving current corresponding to a full write signal to the data driver 500 according to the temperature detected by the temperature sensor 800.

As a result, the driving controller 700 increases the initial driving current to increase the temperature of the display panel 600 and then normally drives the display panel 600.

5 is a schematic configuration diagram of a light emitting display device according to another embodiment of the present invention, and includes a display panel 600, a scan driver 400, a data driver 500, a drive controller 700, and a temperature sensor ( 800 and the power supply 300.

Referring to FIG. 5, in the light emitting display device according to the present invention, the driving controller 700 applies power voltages VDD and ELVDD corresponding to a temperature detected by the temperature sensor 800 to the plurality of pixels. Except for the points, the description is the same as described in FIG. At this time, when the power supply voltages VDD and ELVDD rise, the overall gray level also rises in proportion.

In addition, the driving controller 700 increases the temperature of the display panel 600 by increasing the power supply voltages VDD and ELVDD, and then drives the display panel 600 normally. ELVDD) is supplied from the power supply 300. For example, the voltage may be increased to a predetermined voltage by the DC / DC converter in the power supply 300.

6 is a flowchart illustrating a display panel driving method of a light emitting display device according to an exemplary embodiment of the present invention.

Referring to FIG. 6, a display panel driving method of a light emitting display device according to an exemplary embodiment of the present invention is a method of driving a display panel of a light emitting display device including a plurality of pixels, a scan driver, and a data driver. Turn on the power (S610).

Thereafter, an external temperature and a temperature of the display panel are detected using a temperature sensor (S620), and when the detected temperature is lower than or equal to a predetermined temperature (S630), the initial driving current or power supply voltages VDD and ELVDD are raised to increase the display temperature. The temperature of the panel is increased (S640).

When the initial driving current is increased, the initial driving current corresponding to the pre-stored warm-up data is increased according to the detected temperature, and the warm-up data may be a preset data pattern according to the detected temperature. The warm-up data may be data patterns in which an initial driving time varies depending on the detected temperature.

In addition, an initial driving current corresponding to a full write signal may be input to the data driver according to the detected temperature.

In addition, in the case of raising the power supply voltages VDD and ELVDD, when the power supply voltage rises, the overall gradation also increases in proportion. That is, when raising the amount of current, when the power supply voltages VDD and ELVDD are raised, the overall gradation also rises in proportion, so that the gradation is not affected.

Thereafter, when the temperature of the display panel rises to a predetermined temperature, for example, 20 ° C. to 30 ° C. (S650), the display panel is normally driven (S660).

As a result, in the exemplary embodiment of the present invention, the display panel may be normally driven after the temperature of the display panel is increased by raising the initial current or power supply voltage applied to the organic EL light emitting display device.

While the invention has been shown and described in connection with specific embodiments thereof, it will be appreciated that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the claims. Anyone who owns it can easily find out.

According to the present invention, since the initial current or power supply voltage applied to the organic EL light emitting display device is raised to increase the temperature of the display panel and then driven normally, the brightness of the display panel does not fall during initial driving in a cold external environment.

Claims (16)

A display panel configured to emit light by emitting a plurality of pixels respectively connected to the plurality of data lines and the scan lines; A scan driver for sequentially applying a selection signal to the plurality of scan lines, respectively; A data driver for applying a data voltage corresponding to an image signal to each pixel selected by the plurality of scan lines; A temperature sensor for detecting an external temperature; And A driving control unit driving the data driving unit and the scan driving unit according to an initial driving current raised corresponding to the temperature detected by the temperature sensor; Light emitting display device comprising a. The method of claim 1, And the driving controller increases the initial driving current corresponding to the warm-up data according to the temperature detected by the temperature sensor. The method of claim 2, And the warm-up data is a preset data pattern according to the detected temperature. The method of claim 2, And the warm-up data is a data pattern in which an initial driving time varies depending on the detected temperature. The method of claim 1, And the driving controller inputs an initial driving current corresponding to a full write signal to the data driver according to the temperature detected by the temperature sensor. The method of claim 1, And the driving control unit drives the display panel normally after increasing the initial driving current to increase the temperature of the display panel. A display panel configured to emit light by emitting a plurality of pixels respectively connected to the plurality of data lines and the scan lines; A scan driver for sequentially applying a selection signal to the plurality of scan lines, respectively; A data driver for applying a data voltage corresponding to an image signal to each pixel selected by the plurality of scan lines; A temperature sensor for detecting an external temperature; And A driving controller which applies a power supply voltage corresponding to the temperature detected by the temperature sensor to the plurality of pixels Light emitting display device comprising a. The method of claim 7, wherein The light emitting display device as claimed in claim 1, wherein the gray level of the entire gray scale increases in proportion to the power supply voltage. The method of claim 7, wherein And the driving controller is configured to drive the display panel normally after increasing the power supply voltage to raise the temperature of the display panel. In the method of driving a display panel of a light emitting display device having a plurality of pixels, a scan driver and a data driver, Iii) turning on the power supply; Ii) detecting the external temperature and the temperature of the display panel; Iii) raising the temperature of the display panel by raising an initial driving current when the detected temperature is below a predetermined temperature; And I) normally driving the display panel when the temperature of the display panel rises to a predetermined temperature; Display panel driving method of a light emitting display device comprising a. The method of claim 10, And (iv) increasing the initial driving current corresponding to the pre-stored warm-up data according to the detected temperature. The method of claim 11, And the warming-up data is a data pattern preset according to the detected temperature. The method of claim 11, And the warm-up data is a data pattern in which an initial driving time is different depending on the detected temperature. The method of claim 10, And a first driving current corresponding to a full write signal is input to the data driver according to the detected temperature. In the method of driving a display panel of a light emitting display device having a plurality of pixels, a scan driver and a data driver, Iii) turning on the power supply; Ii) detecting the external temperature and the temperature of the display panel; Iii) raising the temperature of the display panel by raising a power supply voltage when the detected temperature is below a predetermined temperature; And I) normally driving the display panel when the temperature of the display panel rises to a predetermined temperature; Display panel driving method of a light emitting display device comprising a. The method of claim 15, The display panel driving method of the light emitting display device, characterized in that when the power supply voltage rises, the overall gray scale also rises in proportion.

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