KR102028996B1 - Organic light emitting diode display device and method for driving the same - Google Patents

Abstract

The present invention provides an organic light emitting diode that simplifies the structure of subpixels and realizes a high resolution display panel by compensating an image voltage charged in each subpixel of a display panel while driving adjacent subpixels to share a switching element. A display device and a driving method thereof, wherein a plurality of sub-pixels arranged in a horizontal direction share at least one switching element for receiving an emission control signal and respond to an emission control signal supplied through the shared switching element A display panel configured to display an image with a compensation data voltage; A gate driver driving the gate line and the light emission control lines of the display panel; A data driver for driving data lines of the display panel; A power supply unit supplying a high potential and a low potential voltage to power lines of the display panel and a reference voltage to a compensation power line; And a timing controller for aligning the image data from the outside with the driving of the display panel and supplying the image data to the data driver and controlling the gate and the data driver to display the image by the compensation data voltage compensated by the reference voltage. It is characterized by one.

Description

Organic light emitting diode display and its driving method {ORGANIC LIGHT EMITTING DIODE DISPLAY DEVICE AND METHOD FOR DRIVING THE SAME}

The present invention provides an organic light emitting diode that simplifies the structure of subpixels and realizes a high resolution display panel by compensating an image voltage charged in each subpixel of a display panel while driving adjacent subpixels to share a switching element. A display device and a driving method thereof.

Recently, flat panel displays are emerging as liquid crystal displays, field emission displays, plasma display panels, and organic light emitting diode displays. Emitting Display). Among them, the organic light emitting diode display is a self-luminous device that emits an organic light emitting layer by recombination of electrons and holes.

Each of the plurality of sub pixels constituting the organic light emitting diode display includes an organic light emitting diode composed of an organic light emitting layer between an anode and a cathode, and a pixel circuit driving each organic light emitting diode independently.

The pixel circuit includes a plurality of switching transistors, at least one capacitor, and a driving transistor. The plurality of switching transistors charge the data signal to the capacitor in response to the scan signal generated every horizontal period. In addition, the driving transistor adjusts the gray level of each pixel by adjusting the magnitude of the current supplied to the organic light emitting diode so as to correspond to the magnitude of the image voltage charged in the capacitor in response to a separate sensing signal.

Since the conventional pixel circuits configured as described above require a plurality of switching transistors, at least one capacitor, and a driving transistor, pixel circuits having a complicated structure have to be repeatedly arranged in the pixel regions of the matrix form. Therefore, there is a limit in simplifying the pixel structure in the related art, and there was a limit in designing and implementing a high resolution panel, and a load due to a complicated pixel structure was also required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, while compensating the image voltage charged in each sub-pixel of the display panel while allowing adjacent sub-pixels to be driven by sharing a switching element, thereby simplifying the structure of the sub-pixels and increasing the resolution. An object of the present invention is to provide an organic light emitting diode display and a method of driving the same.

In the organic light emitting diode display according to the embodiment of the present invention for achieving the above object, a plurality of sub-pixels arranged horizontally adjacent to each other and share at least one switching element for receiving the emission control signal A display panel configured to display an image at a compensation data voltage in response to a light emission control signal supplied through the switching element; A gate driver driving the gate line and the light emission control lines of the display panel; A data driver for driving data lines of the display panel; A power supply unit supplying a high potential and a low potential voltage to power lines of the display panel and a reference voltage to a compensation power line; And a timing controller for aligning the image data from the outside with the driving of the display panel and supplying the image data to the data driver and controlling the gate and the data driver to display the image by the compensation data voltage compensated by the reference voltage. It is characterized by one.

At least one pixel circuit of the plurality of horizontally adjacent sub-pixels includes first and second switching elements, a light emission control switching element, a driving switching element, and first and second capacitors. The at least one other subpixel sharing the light emission control switching element is configured to include only the first and second switching elements, the driving switching element, and the first and second capacitors.

The first switching element is turned on in response to a scan signal supplied through the gate line, so that the data voltage from the data line is converted into an output terminal of the first switching element, a gate terminal of the driving switching element, and the first capacitor. The second switching element is turned on according to a scan signal of a current stage or a scan signal of a previous stage, and the source terminal of the driving switching element and the light emitting diode are connected to each other. And a light emission control switching element that is turned on according to a light emission control signal to connect the high potential voltage to a drain electrode of the drive switching element, and the drive switching element switches light emission control to the drain electrode. When the high potential voltage is supplied through the device to the light emitting diode according to the voltage level of the first node The amount of light emitted by the light emitting diode is controlled by controlling the amount of current supplied.

When the high potential voltage is supplied to the drain electrode of the driving switching element through the light emitting control switching element, the at least one other sub-pixel sharing the light emitting control switching element of the adjacent pixel, The amount of light emitted by the light emitting diode is controlled by controlling the amount of current supplied to the light emitting diode according to the voltage level of one node.

The driving period for each frame or the horizontal period of one horizontal line of each sub-pixel may be driven by being divided into an initialization period, a sampling period, a data injection period, and a light emission period, or an initialization period, a sampling period, It is characterized by being driven into a data injection period and a light emission period.

In addition, the driving method of the organic light emitting diode display according to the embodiment of the present invention for achieving the above object is to provide at least one switching element for receiving a light emission control signal of a plurality of sub-pixels arranged horizontally adjacent to each other A method of driving an organic light emitting diode display device having a display panel configured to display an image at a compensation data voltage in response to a light emission control signal supplied through the shared switching element. Driving control lines; Driving data lines of the display panel; Supplying a high potential and a low potential voltage to the power lines of the display panel and supplying a reference voltage to the compensation power line; And controlling the data driver to align image data from the outside to the data driver in order to drive the display panel and to display the image by the compensation data voltage compensated by the reference voltage. .

At least one pixel circuit of the plurality of horizontally adjacent sub-pixels includes first and second switching elements, a light emission control switching element, a driving switching element, and first and second capacitors. The at least one other subpixel sharing the light emission control switching element includes only the first and second switching elements, the driving switching element, and the first and second capacitors.

The first switching element is turned on according to a scan signal supplied through the gate line, so that the data voltage from the data line is commonly shared between the output terminal of the first switching element, the gate terminal of the driving switching element, and the capacitor. The second switching element is turned on according to a scan signal of a current stage or a scan signal of a previous stage to supply the reference voltage to the first node connected to a source terminal of the driving switching element and a light emitting diode. The light emission control switching device is turned on according to a light emission control signal to connect the high potential voltage to the drain electrode of the driving switching device, and the driving switching device connects the light emission control switching device to the drain electrode. When a high potential voltage is supplied through the gate, the light emitting diode is supplied to the light emitting diode according to the voltage level of the first node. By controlling the amount of current it is characterized in that adjusting the amount of light emitted by the LED.

When the high potential voltage is supplied to the source electrode of the driving switching element through the light emitting control switching element that shares the light emitting control switching element of the adjacent pixel, the at least one subpixel shares the light emitting control switching element. The amount of light emitted by the light emitting diode is controlled by controlling the amount of current supplied to the light emitting diode according to the voltage level of one node.

The driving period for each frame or the horizontal period of one horizontal line of each sub-pixel may be driven by being divided into an initialization period, a sampling period, a data injection period, and a light emission period, or an initialization period, a sampling period, It is characterized by being driven into a data injection period and a light emission period.

The organic light emitting diode display and the method of driving the same of the present invention having the above characteristics compensate for the image voltage charged in each sub-pixel of the display panel while allowing sub-pixels adjacent to each other to be driven by sharing a switching element. These structures can be simplified and a high resolution display panel can be designed and implemented. In addition, the simplified pixel structure can reduce the load on each sub-pixel.

1 is a block diagram illustrating an organic light emitting diode display according to an exemplary embodiment of the present invention.
FIG. 2 is an equivalent circuit diagram of a plurality of subpixels adjacent to each other of the display panel illustrated in FIG. 1.
3 is a waveform diagram illustrating a method of driving an organic light emitting diode display according to the present invention;
4 is a timing diagram showing the amount of voltage change for each of the first and second nodes when the pixel circuit of each sub-pixel is driven.

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

1 is a block diagram illustrating an organic light emitting diode display according to an exemplary embodiment of the present invention. FIG. 2 is an equivalent circuit diagram of a plurality of subpixels adjacent to each other of the display panel illustrated in FIG. 1.

In the organic light emitting diode display illustrated in FIG. 1, a plurality of sub-pixels P arranged in a horizontally adjacent manner share at least one switching element for receiving the emission control signals EM1 through EMn and share a shared switching element. A display panel 1 configured to display an image at a compensation data voltage in response to the emission control signals EM1 to EMn supplied through the display panel 1; A gate driver 2 driving the gate lines GL1 to GLn and the emission control lines EL1 to ELn of the display panel 1; A data driver 3 driving the data lines DL1 to DLm of the display panel 1; A power supply unit 4 for supplying the high potential and low potential voltages VDD and VSS to the power lines PL1 to PLm of the display panel 1 and the reference voltage Vini to the compensation power line CPL. ); And the gate and data driver so that the image data from the outside is aligned with the driving of the display panel 1 to be supplied to the data driver 3 and the image is displayed by the compensation data voltage compensated by the reference voltage Vini. The timing control part 5 which controls (2,3) is provided.

In the display panel 1, a plurality of sub-pixels P are arranged in a matrix form in each pixel area to display an image, and each sub-pixel P is independent of the light emitting diode OLED and the light emitting diode OLED. A pixel circuit for driving is provided. In detail, each sub-pixel P as shown in FIG. 2 has a gate line GL, a data line DL, a compensation power line CPL, a light emission control line EL, and a power line PL. And a light emitting diode (OLED) equivalently represented by a diode connected between the pixel circuit and the low potential voltage (VSS). Here, the high potential voltage VDD has a higher voltage level than the low potential voltage VSS. The low potential voltage VSS may be a ground or ground voltage.

At least one pixel circuit among the sub-pixels P adjacent to each other in the horizontal direction includes the first and second switching elements T1 and T2, the light emission control switching element ET, the driving switching element DT, and the first and second pixel circuits. It is comprised with the 2nd capacitors C1 and C2. On the other hand, at least one other subpixel sharing the light emission control switching element ET of the adjacent pixel includes the first and second switching elements T1 and T2, the driving switching element DT, and the first and second capacitors ( It may be configured with only C1, C2).

The first and second switching elements T1 and T2, the light emission control switching element ET, and the driving switching element DT may be configured as NMOS transistors or PMOS transistors. An example in which T1 and T2, the light emission control switching element ET, and the driving switching element DT are NMOS transistors will be described.

The first switching element T1 is turned on or turned off according to a scan signal supplied through the gate line GLn, and at turn-on, the data voltage from the data line DL is turned on to the first node N1. Supply. The first node N1 is a node in which the output terminal of the first switching element T1 and the gate terminal of the driving switching element DT are connected in common. The first switching element T1 is turned on in the initialization period and the sampling period during every horizontal period (initialization period, sampling period, data injection period, light emission period) and is connected between the data line DL and the first node N1. Form a current path.

The second switching element T2 is turned on or turned off according to the scan signal of the current stage or the previous stage scan signal, and the source terminal and the light emission of the driving switching element DT at the turn-on time. The diode OLED is supplied to the connected second node N2. The second switching device T2 supplies the reference voltage Vini to the second node N2 so that the data voltage can be compensated by being turned on in the sampling period and the light emission period in every horizontal period.

The light emission control switching element ET is turned on or off according to the light emission signal EM, and connects the high potential voltage source VDD with the drain electrode of the driving switching element DT at turn-on.

The driving switching device DT is supplied with the high potential voltage VDD to the source electrode through the light emission control switching device ET, and measures the amount of current supplied to the light emitting diode OLED according to the voltage level of the first node N1. By controlling, the amount of light emitted by the light emitting diode OLED is adjusted.

The light emitting diode OLED includes an organic layer formed between an anode electrode and a cathode electrode connected to a pixel circuit. An operation sequence and a light emission process of the pixel circuit and the light emitting diode OLED will be described in detail later with reference to the accompanying driving waveform diagram.

As described above, at least one other sub-pixel sharing the emission control switching element ET of the adjacent pixel includes the first and second switching elements T1 and T2, the driving switching element DT, and the first. And only the second capacitors C1 and C2, and supply the high potential voltage source VDD to the drain electrode of the driving switching element DT through the light emission control switching element ET of the adjacent pixel. Thus, when the emission control switching device ET is shared through the pixel structure shown in FIG. 2 of the present invention, the high potential voltage source VDD is not affected without affecting the voltage levels of the gate terminal and the source terminal that determine the amount of current. Only the light emission timing supplied can be controlled in the same way.

The gate driver 2 receives a scan signal in response to a gate control signal GVS from the timing controller 5, for example, a gate start pulse GSP and a gate shift clock GSC. For example, the gate voltage of the low logic is sequentially generated, and the pulse width of the scan signal is controlled according to a gate output enable (GOE) signal. The scan signals are sequentially supplied to the gate lines GL1 to GLn. Here, a gate off voltage (eg, a high logic gate voltage) is supplied to a period when the scan signal is not supplied to the gate lines GL1 to GLn.

In addition, the gate driver 2 sequentially generates emission control signals EM of high or low logic and supplies them to respective emission control lines EL1 to ELn. In this case, the emission control signal EM sequentially outputs a period in which a current flows through the light emitting diode OLED, that is, a period in which an image is displayed and the high-potential voltage source VDD drives the drain switching element DT. The period supplied to the electrode is adjusted.

The data driver 3 uses the source start pulse SSP, the source shift clock SSC, and the like among the data control signals DVS from the timing controller 5. The digital image data Data input from the digital signal is converted into an analog voltage, that is, an analog data voltage. In this case, the data driver 3 converts the digital image data to an analog data voltage using a gamma voltage set divided to correspond to grayscale values of the digital image data. The data voltage is supplied to each of the data lines DL1 to DLm in response to a source output enable (SOE) signal. In detail, the data driver 3 latches the digital image data Data input according to the SSC, and then 1s every 1 horizontal period in which the gate-on signal is supplied to each gate line GL1 to GLn in response to the SOE signal. The data voltage for the horizontal line is supplied to each of the data lines DL1 to DLm.

The timing controller 5 aligns the image data RGB input from the outside according to the size and resolution of the display panel 1 and supplies the aligned digital image data Data to the data driver 3. The timing controller 5 may use synchronization signals input from the outside, for example, a dot clock DCLK, a data enable signal DE, a horizontal synchronization signal Hsync, a vertical synchronization signal Vsync, and the like. The gate and data control signals GVS and DVS are generated and supplied to the gate driver 2 and the data driver 3, respectively.

3 is a waveform diagram illustrating a method of driving an organic light emitting diode display according to the present invention. 4 is a timing diagram illustrating a voltage change amount of each of the first and second nodes when the pixel circuit of each sub-pixel is driven.

Referring to FIGS. 3 and 4, each sub-pixel frame period or one horizontal line driving period is divided into an initialization period, an sampling period, a data injection period, and an emission period, or 2 Through the 3 to 3 horizontal periods, it may be driven into an initial period, an sampling period, a data injection period, and a light emission period. At this time, initialization can also be performed using the previous horizontal period.

First, the first and second switching elements T1 and T2 are turned on in the initialization period S1. In this initialization period S1, the first and second nodes N1 and N2 are initialized to a preset reference voltage Vini.

In the sampling period S2, the emission control switching device ET and the driving switching device DT are turned off and supplied to the first node N1 through the data voltage first switching device T1. As the current flowing through the driving switching element DT flows into the second node N2, the threshold voltage Vth of the driving switching element DT is sensed. At this time, the voltage level of the second node N2 converges to "VDD-Vth" at the reference voltage Vini.

In the data injection period S3, a data voltage is injected into the first node N1, and since the second node N2 is in a floating state, the data voltage is increased by the changed voltage to maintain the sampling value of the previous period.

In the light emission period S4, the light emission control switching element ET and the driving switching element DT are turned on. The driving transistor DT supplies a driving current to the light emitting diode OLED according to the voltage level of the first node N1 injected in the previous period.

As described above, in the organic light emitting diode display and the driving method thereof, the light emission control switching element ET is formed only in at least one sub-pixel P of the sub-pixels P arranged in the horizontal direction. . In addition, the remaining at least one adjacent pixel may be configured to include only the first and second switching elements T1 and T2, the driving switching element DT, and the capacitor C by sharing the emission control switching element ET. have. Thus, when the emission control switching device ET is shared through the pixel structure shown in FIG. 2 of the present invention, the sub-pixels adjacent to only the emission timing to which the high potential voltage source VDD is supplied without affecting the data voltage level. Can be controlled in the same way.

Accordingly, in the present invention, the sub-pixels adjacent to each other are driven by sharing a switching element while compensating the image voltage charged in each sub-pixel with a reference voltage, thereby simplifying the structure of the sub-pixels and designing and implementing a high-resolution display panel. have. In addition, the simplified pixel structure can reduce the load on each sub-pixel.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention It will be apparent to those skilled in the art.

Claims (10)

A plurality of horizontally adjacent sub-pixels share at least one emission control switching element for receiving the emission control signal and simultaneously display an image at a compensation data voltage in response to the emission control signal supplied through the shared switching element. A display panel formed to display;
A gate driver driving the gate line and the light emission control lines of the display panel;
A data driver for driving data lines of the display panel;
A power supply unit supplying a high potential and a low potential voltage to power lines of the display panel and a reference voltage to a compensation power line; And
And a timing controller for aligning the image data from outside with the driving of the display panel and supplying the image data to the data driver and controlling the gate and the data driver to display the image by the compensation data voltage compensated by the reference voltage. An organic light emitting diode display, characterized in that. The method of claim 1,
At least one sub pixel circuit of the plurality of horizontally adjacent sub pixels is
The first and second switching elements, the light emission control switching element, the driving switching element, and the first and second capacitors,
At least one other subpixel sharing the light emission control switching element of the adjacent subpixel is configured to have the same light emission timing by including only the first and second switching elements, the driving switching element, and the first and second capacitors. Organic LED display. The method of claim 2,
The first switching device
A first signal which is turned on according to a scan signal supplied through the gate line to connect the data voltage from the data line to the output terminal of the first switching element, the gate terminal of the driving switching element, and the first capacitor in common; To the node,
The second switching device is turned on according to a scan signal of a current stage or a scan signal of a previous stage to supply the reference voltage to a second node to which a source terminal of the driving switching element and a light emitting diode are connected.
The light emission control switching element is turned on according to a light emission control signal to connect the high potential voltage with a drain electrode of the driving switching element.
The driving switching device controls the amount of light emitted by the light emitting diode by controlling the amount of current supplied to the light emitting diode according to the voltage level of the first node when the high potential voltage is supplied to the drain electrode through the light emission control switching device. Organic LED display. The method of claim 3, wherein
When the high potential voltage is supplied to the drain electrode of the driving switching element through the light emission control switching element which shares the light emission control switching element of the adjacent sub pixel,
And an amount of light emitted from the light emitting diode is controlled by controlling the amount of current supplied to the light emitting diode according to the voltage level of the first node through a driving switching element. The method of claim 4, wherein
The driving period for each frame or the horizontal period of one horizontal line of each sub-pixel may be driven by being divided into an initialization period, a sampling period, a data injection period, and a light emission period, or an initialization period, a sampling period, An organic light emitting diode display, which is divided into a data injection period and a light emission period. A plurality of horizontally adjacent sub-pixels share at least one emission control switching element for receiving the emission control signal and simultaneously display an image at a compensation data voltage in response to the emission control signal supplied through the shared switching element. In the driving method of an organic light emitting diode display device having a display panel formed to display,
Driving gate lines and emission control lines of the display panel;
Driving data lines of the display panel;
Supplying a high potential and a low potential voltage to the power lines of the display panel and supplying a reference voltage to the compensation power line; And
And controlling the data driver to align the image data from the outside according to the driving of the display panel to supply the data driver to the data driver and to display the image by the compensation data voltage compensated by the reference voltage. Method of driving LED display device. The method of claim 6,
At least one sub pixel circuit of the plurality of horizontally adjacent sub pixels is
The first and second switching elements, the light emission control switching element, the driving switching element, and the first and second capacitors,
At least one other subpixel sharing the light emission control switching elements of the adjacent subpixels includes only the first and second switching elements, the driving switching element, and the first and second capacitors to have the same emission timing. A method of driving an organic light emitting diode display. The method of claim 7, wherein
The first switching device
It is turned on in response to a scan signal supplied through the gate line to transmit a data voltage from the data line to a first node in which the output terminal of the first switching element, the gate terminal of the driving switching element, and the capacitor are commonly connected. Supply,
The second switching device is turned on according to a scan signal of a current stage or a scan signal of a previous stage to supply the reference voltage to a second node to which a source terminal of the driving switching element and a light emitting diode are connected.
The light emission control switching element is turned on according to a light emission control signal to connect the high potential voltage with a drain electrode of the driving switching element.
The driving switching device controls the amount of light emitted by the light emitting diode by controlling the amount of current supplied to the light emitting diode according to the voltage level of the first node when the high potential voltage is supplied to the drain electrode through the light emission control switching device. A method of driving an organic light emitting diode display. The method of claim 8,
When the high potential voltage is supplied to the source electrode of the driving switching device through the light emitting control switching device which shares at least one other subpixel sharing the light emitting control switching device of the adjacent subpixel,
And controlling the amount of light emitted by the light emitting diode according to the voltage level of the first node through a driving switching element. The method of claim 9,
The driving period for each frame or the horizontal period of one horizontal line of each sub-pixel may be driven by being divided into an initialization period, a sampling period, a data injection period, and a light emission period, or an initialization period, a sampling period, A method of driving an organic light emitting diode display, which is divided into a data injection period and a light emission period.

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