KR20150002324A - Organic light emitting diode display device and method for driving the same - Google Patents

Abstract

The present invention relates to an organic light emitting diode display device, which can simplify the structure of subpixels and realize a high-resolution display panel by compensating for a zero-sequence voltage charged in each subpixel of the display panel and enabling the adjacent subpixels to be driven while sharing a switching element, and to a method for driving the same. The organic light emitting diode display device comprises: a display panel having a plurality of subpixels which are horizontally arranged adjacent to each other, share at least one switching element for receiving an emission control signal, and display an image by a compensation data voltage in response to the emission control signal supplied through the shared switching element; a gate driving unit to drive gate lines and emission control lines of the display panel; a data driving unit to drive data lines of the display panel; a power supply unit to supply a reference voltage to a compensation power line while supplying high potential and low potential voltages to power lines of the display panel; and a timing control unit to control the gate and data driving units to display the image by the compensation data voltage compensated by the reference voltage while supplying image data from the outside to the data driving unit by aligning the image data to be suitable for driving of the display panel.

Description

Technical Field [0001] The present invention relates to an organic light emitting diode (OLED) display device,

The present invention provides an organic light emitting diode (OLED) display device capable of simplifying the structure of sub-pixels and realizing a high-resolution display panel by allowing sub-pixels adjacent to each other to be driven by sharing switching elements while compensating image voltages charged in sub- A display device and a driving method thereof.

BACKGROUND ART [0002] Recently, flat panel displays that are emerging include liquid crystal displays (LCDs), field emission displays, plasma display panels, and organic light emitting diodes Emitting Display). Among them, organic light emitting diode display devices are self-luminous devices that emit organic light emitting layers by recombination of electrons and holes, and are expected to be a next generation display device because they have a high brightness, a low driving voltage and an ultra thin film.

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

The pixel circuit includes a plurality of switching transistors, at least one capacitor, and a driving transistor. The plurality of switching transistors charges the data signal to the capacitor in response to the scan signal generated every horizontal period unit. The driving transistor adjusts the gradation 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 thus configured require a plurality of switching transistors and at least one capacitor and a driving transistor, the pixel circuits of a complicated structure are forced to be repeatedly arranged in the pixel regions in the form of a matrix. Therefore, there is a limit in simplifying the pixel structure in the related art, and there is a limitation in designing and implementing a high-resolution panel, and a load due to a complicated pixel structure has also to be reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to simplify the structure of sub-pixels and to reduce the number of sub- And a method of driving the organic light emitting diode display device.

According to another aspect of the present invention, there is provided an organic light emitting diode display device including a plurality of sub-pixels arranged horizontally adjacent to each other and sharing at least one switching device for receiving emission control signals, A display panel configured to display an image with a compensated data voltage in response to a light emission control signal supplied through a switching element; A gate driver for driving gate lines and emission control lines of the display panel; A data driver driving data lines of the display panel; A power supply unit for supplying a high potential and a low potential voltage to the power supply lines of the display panel and supplying a reference voltage to the compensation power supply line; And a timing controller for controlling the gate and the data driver so that the video data from the outside is aligned with driving of the display panel and supplied to the data driver and the image is displayed by the compensated data voltage compensated by the reference voltage .

Wherein at least one of the plurality of horizontally adjacent pixel circuits comprises first and second switching elements, a light emission control switching element, a driving switching element, and first and second capacitors, And at least one other sub-pixel 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.

Wherein the first switching element is turned on according to a scan signal supplied through the gate line so that a data voltage from the data line is applied to the output terminal of the first switching element and the gate terminal of the driving switching element, And the second switching element is turned on according to the scan signal of the present stage or the scan signal of the previous stage to supply the reference voltage to the source terminal of the drive switching element and the light emitting diode And the emission control switching element is turned on according to an emission control signal to connect the high potential voltage to the drain electrode of the driving switching element, and the driving switching element supplies the emission control switching element to the drain electrode, When a high-potential voltage is supplied through the device, the light-emitting diode And the amount of light emitted from the light emitting diode is controlled by controlling the amount of current supplied.

When at least one sub-pixel sharing the emission control switching element of the adjacent pixel is supplied with the high potential voltage through the common emission control switching element to the drain electrode of the driving switching element, The 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 one node.

The driving period of each sub-pixel or the horizontal period of one horizontal line may be divided into an initialization period, a sampling period, a data injection period, and a light emission period, or may be divided into a reset period, a sampling period, A data injection period, and a light emission period.

According to another aspect of the present invention, there is provided a method of driving an organic light emitting diode (OLED) display device including a plurality of sub-pixels arranged horizontally adjacent to each other, And a display panel formed to share an image and display an image with a compensated data voltage in response to a light emission control signal supplied through the shared switching element, the method comprising: driving the organic light emitting diode display device, Driving control lines; Driving data lines of the display panel; Supplying a high potential and a low potential voltage to the power supply lines of the display panel and supplying a reference voltage to the compensation power supply line; And controlling the data driver to display image data according to the compensated data voltage compensated by the reference voltage by supplying image data from the outside to the data driver in a manner suitable for driving the display panel, .

Wherein at least one of the plurality of horizontally adjacent pixel circuits comprises first and second switching elements, a light emission control switching element, a driving switching element, and first and second capacitors, And at least one other sub-pixel sharing the light emission control switching element includes only first and second switching elements, a driving switching element, and first and second capacitors.

Wherein 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 commonly connected to the output terminal of the first switching element and the gate terminal of the drive switching element and the capacitor And the second switching element is turned on according to the scan signal of the current stage or the scan signal of the previous stage to supply the reference voltage to the source terminal of the drive switching element and the And the light emission control switching element is turned on according to an emission control signal to connect the high potential voltage to the drain electrode of the driving switching element, and the driving switching element supplies a light emission control switching element to the drain electrode The voltage of the first node is supplied to the light emitting diode, By controlling the amount of current it is characterized in that adjusting the amount of light emitted by the LED.

Wherein at least one sub-pixel sharing the emission control switching element of the adjacent pixel is supplied with the high potential voltage through the emission control switching element shared by the source electrode of the driving switching element, The 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 one node.

The driving period of each sub-pixel or the horizontal period of one horizontal line may be divided into an initialization period, a sampling period, a data injection period, and a light emission period, or may be divided into a reset period, a sampling period, A data injection period, and a light emission period.

The organic light emitting diode display device and the driving method thereof according to the present invention having the above characteristics compensate for the image voltage charged to each sub pixel of the display panel while driving adjacent sub pixels to share the switching device, And a high-resolution display panel can be designed and implemented. In addition, the load imposed on each sub-pixel can also be reduced by the simplified pixel structure.

1 is a block diagram illustrating an organic light emitting diode display device according to an embodiment of the present invention.
Fig. 2 is an equivalent circuit diagram showing a plurality of sub-pixels adjacent to each other of the display panel shown in Fig. 1. Fig.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting diode (OLED) display device.
4 is a timing chart showing voltage variations of the first and second nodes at the time of driving the pixel circuits of the respective sub-pixels.

Hereinafter, an organic light emitting diode display device and a driving method thereof according to an embodiment of the present invention 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 embodiment of the present invention. 2 is an equivalent circuit diagram showing a plurality of sub-pixels adjacent to each other of the display panel shown in Fig.

1, a plurality of sub-pixels P arranged horizontally adjacent share at least one switching element for receiving emission control signals EM1 to EMn, and a common switching element A display panel (1) configured to display an image with a compensated data voltage in response to emission control signals (EM1 to EMn) supplied thereto; A gate driver 2 for driving the gate lines GL1 to GLn and the emission control lines EL1 to ELn of the display panel 1; A data driver 3 for driving the data lines DL1 to DLm of the display panel 1; A power supply unit 4 for supplying the high and low potential voltages VDD and VSS to the power supply lines PL1 to PLm of the display panel 1 and for supplying the reference voltage Vini to the compensation power supply line CPL, ); And the image data from the outside is supplied to the data driver 3 while being aligned with the driving of the display panel 1 and the image is displayed by the compensated data voltage compensated by the reference voltage Vini. And a timing controller 5 for controlling the switches 2 and 3.

The display panel 1 displays a plurality of subpixels P arranged in a matrix form in each pixel region so that each subpixel P has a light emitting diode OLED and the light emitting diode OLED independently And a pixel circuit for driving the pixel circuit. Specifically, 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) connected between the pixel circuit and the low potential voltage (VSS) and equivalently represented by a diode. Here, the high-potential voltage VDD has a voltage level higher than the low-potential voltage VSS. And the low potential voltage VSS may be ground or ground voltage.

At least one pixel circuit among the sub-pixels P adjacent to each other in the horizontal direction includes first and second switching elements T1 and T2, a light emission control switching element ET, a driving switching element DT, And second capacitors C1 and C2. On the other hand, 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 second capacitors C1, and C2.

The first and second switching elements T1 and T2, the emission control switching element ET and the driving switching element DT may be formed of an NMOS transistor or a PMOS transistor. Hereinafter, the first and second switching elements T1, and T2, the 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 off according to a scan signal supplied through the gate line GLn and the data voltage from the turn-on data line DL is applied to the first node N1 Supply. The first node N1 is a node to which the output terminal of the first switching device T1 and the gate terminal of the drive switching device DT are connected in common. The first switching device T1 is turned on during the initialization period and the sampling period in each horizontal period (initialization period, sampling period, data injection period, light emission period), and is turned on between the data line DL and the first node N1 Thereby forming a current path.

The second switching element T2 is turned on or off according to the scan signal of the current stage or the scan signal of the previous stage and the turn-on reference voltage Vini is applied to the source terminal of the drive switching element DT, To the second node N2 to which the diode OLED is connected. The second switching element T2 supplies the reference voltage Vini to the second node N2 so that the data voltage can be compensated for during the sampling period and the light emitting period during each horizontal period.

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

The driving switching element DT is supplied with the high potential voltage VDD through the emission control switching element ET to the source electrode and supplies the amount of current supplied to the light emitting diode OLED according to the voltage level of the first node N1 Thereby controlling the amount of light emitted from the light emitting diode OLED.

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

As described above, the 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 second capacitors C1 and C2 and supplies the high potential source VDD to the drain electrode of the driving switching element DT through the emission control switching element ET of the adjacent pixel which is shared. When the emission control switching element ET is shared through the pixel structure shown in FIG. 2 of the present invention, the high potential voltage source VDD does not affect the voltage levels of the gate terminal and the source terminal, Only the light emission timing to be supplied can be controlled in the same manner.

The gate driver 2 receives the gate control signal GVS from the timing controller 5 in response to a gate start pulse GSP and a gate shift clock GSC, For example, the gate voltage of the row logic) sequentially and controls the pulse width of the scan signal in accordance with a gate output enable (GOE) signal. Then, the scan signals are sequentially supplied to the gate lines GL1 to GLn. Here, a gate-off voltage (for example, a gate voltage of high logic) is supplied during a period in which no scan signal is supplied to the gate lines GL1 to GLn.

Further, the gate driver 2 sequentially generates the light emission control signals EM of high or low logic and supplies the light emission control signals EM to the respective light emission control lines EL1 to ELn. The emission control signal EM sequentially outputted is a period during which a current flows through the light emitting diode OLED, that is, during a period during which an image is displayed, and during the period when the high potential voltage source VDD is applied to the drain Thereby adjusting the period of time that is supplied to the electrode.

The data driver 3 is connected to the timing controller 5 using a source start pulse SSP and a source shift clock SSC among data control signals DVS from the timing controller 5. [ That is, the analog data voltage. At this time, the data driver 3 converts the digital image data Data into the analog data voltage using the subdivided gamma voltage set corresponding to the gray level values of the digital image data Data. In response to a source output enable (SOE) signal, a data voltage is supplied to each data line DL1 to DLm. Specifically, the data driver 3 latches the digital image data Data input in accordance with the SSC, and then, in response to the SOE signal, outputs the gate-on signal to the gate lines GL1 to GLn every 1 horizontal period 1 And supplies the data voltages of the horizontal lines to the data lines DL1 to DLm.

The timing controller 5 aligns image data RGB input from the outside in accordance with the size and resolution of the display panel 1 and supplies the aligned digital image data Data to the data driver 3. The timing control unit 5 uses the sync signals input from the outside, for example, a dot clock DCLK, a data enable signal DE, a horizontal synchronizing signal Hsync, a vertical synchronizing signal Vsync, Gate and data control signals GVS and DVS and supplies them to the gate driver 2 and the data driver 3, respectively.

3 is a waveform diagram for explaining a driving method of the organic light emitting diode display according to the present invention. 4 is a timing chart showing voltage variations of the first and second nodes at the time of driving the pixel circuits of the sub-pixels.

Referring to FIGS. 3 and 4, a frame period or a driving period of one horizontal line for each sub-pixel is divided into an initialization period, a sampling period, a data injection period, and a light emission period, And may be driven by an initialization period (intial), a sampling period, a data injection period (writing), and a light emission period through three horizontal periods. At this time, initialization is possible even using the previous horizontal period.

First, in the initialization period S1, the first and second switching elements T1 and T2 are turned on. 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 light emitting control switching element ET and the driving switching element DT are turned off and supplied to the first node N1 through the data voltage first switching element T1. The current flowing through the driving switching element DT flows into the second node N2 and senses the threshold voltage Vth of the driving switching element DT. At this time, the voltage level of the second node N2 converges to "VDD-Vth" from the reference voltage Vini.

Since the data voltage is injected into the first node N1 during the data injection period S3 and the second node N2 is in the floating state, the voltage value 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 the driving current to the light emitting diode OLED according to the voltage level of the first node N1 that was injected in the previous period.

As described above, the organic light emitting diode display device and the driving method thereof according to the present invention form the light emission control switching element ET only in at least one subpixel P among the subpixels P arranged in the horizontal direction . The remaining at least one adjacent pixel may be configured with only the first and second switching elements T1 and T2, the driving switching element DT and the capacitor C by sharing the light emission control switching element ET. have. In the case of sharing the emission control switching element ET through the pixel structure shown in FIG. 2 of the present invention, only the emission timing at which the high voltage source VDD is supplied without affecting the data voltage level, Can be controlled in the same manner.

Therefore, in the present invention, the sub-pixels adjacent to each other are driven by sharing the switching elements while compensating the image voltage charged in each sub-pixel by the reference voltage, thereby simplifying the structure of the sub-pixels and designing and implementing a high- have. In addition, the load imposed on each sub-pixel can also be reduced by the simplified pixel structure.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

Claims (10)

A plurality of sub-pixels arranged horizontally adjacent to each other share at least one switching element for receiving a light emission control signal and are formed to display an image with a compensated data voltage in response to a light emission control signal supplied through the shared switching element Display panel;
A gate driver for driving gate lines and emission control lines of the display panel;
A data driver driving data lines of the display panel;
A power supply unit for supplying a high potential and a low potential voltage to the power supply lines of the display panel and supplying a reference voltage to the compensation power supply line; And
And a timing controller for controlling the gate and the data driver so that the video data from the outside is aligned with driving of the display panel and supplied to the data driver and the image is displayed by the compensated data voltage compensated by the reference voltage And an organic light emitting diode (OLED) display device. The method according to claim 1,
At least one of the plurality of horizontally adjacent sub-pixels
A first switching element, a second switching element, a light emission control switching element, a driving switching element, and first and second capacitors,
Wherein at least one sub-pixel sharing the emission control switching element of the adjacent pixel comprises only first and second switching elements, a driving switching element, and first and second capacitors. . 3. The method of claim 2,
The first switching element
Wherein the data line is turned on in response to a scan signal supplied through the gate line to supply a data voltage from the data line to a gate terminal of the first switching device and a gate terminal of the first switching device, 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 source node of the drive switching device and a second node to which the light emitting diode is connected,
The light emission control switching element is turned on according to an emission control signal to connect the high potential voltage to the drain electrode of the driving switching element,
Wherein the driving switching element controls an amount of light emitted from the light emitting diode by controlling an amount of current supplied to the light emitting diode according to a voltage level of the first node when a high potential voltage is supplied to the drain electrode through the light emission control switching element The organic light emitting diode display device. The method of claim 3,
When at least one other sub-pixel sharing the emission control switching element of the adjacent pixel supplies the high potential voltage to the drain electrode of the driving switching element through the shared emission control switching element,
Wherein an amount of light emitted from the light emitting diode is controlled by controlling an amount of current supplied to the light emitting diode according to a voltage level of the first node through a driving switching element. 5. The method of claim 4,
The driving period of each sub-pixel or the horizontal period of one horizontal line may be divided into an initialization period, a sampling period, a data injection period, and a light emission period, or may be divided into a reset period, a sampling period, A data injection period, and a light emission period of the organic light emitting diode. A plurality of sub-pixels arranged horizontally adjacent to each other share at least one switching element for receiving a light emission control signal and are formed to display an image with a compensated data voltage in response to a light emission control signal supplied through the shared switching element A driving method of an organic light emitting diode display device having a display panel,
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 supply lines of the display panel and supplying a reference voltage to the compensation power supply line; And
And controlling the data driver to display the image by compensating the compensated data voltage by supplying the image data from the outside in accordance with the driving of the display panel and supplying the data to the data driver. A method of driving a light emitting diode display device. The method according to claim 6,
At least one of the plurality of horizontally adjacent sub-pixels
A first switching element, a second switching element, a light emission control switching element, a driving switching element, and first and second capacitors,
And at least one other sub-pixel sharing the emission control switching element of the adjacent pixel includes only first and second switching elements, a driving switching element, and first and second capacitors. Driving method. 8. The method of claim 7,
The first switching element
And a data voltage from the data line is supplied to a gate terminal of the first switching device and a gate terminal of the first switching device and to a first node to which the capacitor is 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 source node of the drive switching device and a second node to which the light emitting diode is connected,
The light emission control switching element is turned on according to an emission control signal to connect the high potential voltage to the drain electrode of the driving switching element,
Wherein the driving switching element controls an amount of light emitted from the light emitting diode by controlling an amount of current supplied to the light emitting diode according to a voltage level of the first node when a high potential voltage is supplied to the drain electrode through the light emission control switching element And a driving method of the organic light emitting diode display device. 9. The method of claim 8,
When at least one sub-pixel sharing the emission control switching element of the adjacent pixel supplies the high potential voltage to the source electrode of the driving switching element through a common emission control switching element,
Wherein the 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 the driving switching element. 10. The method of claim 9,
The driving period of each sub-pixel or the horizontal period of one horizontal line may be divided into an initialization period, a sampling period, a data injection period, and a light emission period, or may be divided into a reset period, a sampling period, A data injection period, and a light emission period of the organic light emitting diode.

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