KR102401421B1 - Curvature adjusting organic light emitting diode display and drving method thereof - Google Patents

Abstract

In the embodiment, the display panel 116 including the driving switch DR for controlling the current on the organic light emitting diode (OLED) senses at least one of the threshold voltage and the mobility of the driving switch DR to output a sensing signal a compensation circuit 130 to control a sensing operation of the compensation circuit 130 and a timing controller 123 for generating compensation data based on the sensing signal, and a curvature of the display panel in response to a curvature control signal from the outside A motor control unit 220 for controlling the motor assembly 240 for controlling and outputting a compensation control signal to the timing controller, the timing controller 123 responds to the compensation control signal, It is possible to provide a curvature variable organic light emitting diode display for controlling a sensing operation.

Description

Curvature variable organic light emitting diode display and driving method thereof {CURVATURE ADJUSTING ORGANIC LIGHT EMITTING DIODE DISPLAY AND DRVING METHOD THEREOF}

The present invention relates to an organic light emitting diode display device and a driving method thereof, and more particularly, to an organic light emitting diode display device having a variable curvature of the display device and a driving method thereof.

Recently, various flat panel displays (FPDs) capable of reducing weight and volume, which are disadvantages of cathode ray tubes, have been developed. Such flat panel displays include a liquid crystal display (hereinafter referred to as "LCD"), a field emission display (FED), a plasma display panel (hereinafter referred to as "PDP"), and an electric field. There is a light emitting device (Electroluminescence Device) and the like.

PDP is attracting attention as a display device that is light, thin, and most advantageous for a large screen because of its simple structure and manufacturing process. TFT LCD to which a thin film transistor (hereinafter referred to as "TFT") is applied as a switching element is the most widely used flat panel display element, but since it is a light emitting element, it has a narrow viewing angle and low response speed. In contrast, the electroluminescent device is largely divided into an inorganic light emitting diode display device and an organic light emitting diode display device according to the material of the light emitting layer. It has great advantages in luminance and viewing angle.

The organic light emitting diode display controls the current flowing from the drain to the source of the driving transistor by controlling the voltage between the gate terminal and the source terminal of the driving transistor.

The current flowing from the drain to the source of the driving transistor emits light while flowing to the organic light emitting diode, and the degree of light emission can be controlled by controlling the amount of current.

At this time, since the current of the organic light emitting diode is greatly affected by the threshold voltage (Vth) and mobility of the driving transistor, it is necessary to accurately measure the threshold voltage (Vth) and the mobility to compensate for them. Research on the subject is being actively conducted.

Also, a curved display device, which has been recently developed, refers to a display device that is curved by a certain curvature so that the distance between the display device and a user at the center of the display device is constant, unlike a general flat panel display. In addition, since the display characteristics or the user's screen immersion level change according to the bending characteristics of the curved display device or the curvature or radius of curvature of the curved surface, the optimal curvature was discussed, and the curvature of the curved display device was adjusted in real time within a certain range. Coordination techniques are being developed.

However, when the curvature of the display device is adjusted at the same time as the characteristic sensing of the driving transistor and the organic light emitting diode, an error occurs during characteristic sensing due to the tension action of the driving circuit connected to the display panel, and compensation for these errors is not appropriate. There is a problem in that an image defect occurs because it is not performed.

A curvature variable organic light emitting diode display device that prevents an error in characteristic sensing due to the tension action of the driving circuit when the characteristic sensing of the driving switch and the organic light emitting diode and the curvature of the display device are adjusted at the same time A driving method may be provided.

In the embodiment, the display panel 116 including the driving switch DR for controlling the current on the organic light emitting diode (OLED) senses at least one of the threshold voltage and the mobility of the driving switch DR to output a sensing signal a compensation circuit 130 to control a sensing operation of the compensation circuit 130 and a timing controller 123 for generating compensation data based on the sensing signal, and a curvature of the display panel in response to a curvature control signal from the outside A motor control unit 220 for controlling the motor assembly 240 for controlling and outputting a compensation control signal to the timing controller, the timing controller 123 responds to the compensation control signal, It is possible to provide a curvature variable organic light emitting diode display for controlling a sensing operation.

In another embodiment, the compensation control signal includes a compensation progress enable signal and a compensation progress disallow signal, and the timing controller 123 provides a sensing stop signal, a sensing start signal and sensing to the compensation circuit based on the compensation control signal. It is also possible to provide a curvature variable organic light emitting diode display for outputting any one of the resume signals.

In this way, when the characteristic sensing of the driving switch (DR) and the organic light emitting diode (OLED) and the curvature of the display device are adjusted at the same time, it solves the problem of an error occurring during characteristic sensing due to the tension action of the driving circuit, thereby accurately compensating for characteristics. By performing it, the quality of the image can be improved.

In addition, the motor assembly 240 adjusts the curvature of the display panel 100 during a time period after the output of the compensation progress prohibition signal from the motor control unit 220 and before the output of the compensation progress enable signal, so that the display panel It is possible to prevent an error in a sensing signal due to tension and stress at an electrical connection portion between the display panel 100 and the compensation circuit 130 due to the bending of 100 .

In another embodiment, the sensing operation is a curvature variable organic light emitting diode display device that is performed at at least one time among power on, off, and driving of the curvature variable organic light emitting diode display device. may provide.

In addition, when the timing controller 123 receives the compensation progress disabling signal, it outputs a sensing stop signal to the compensation circuit 130 , and starts playing after the sensing start signal is output and before the sensing stop signal is output. A curvature-variable organic light emitting diode display device for storing a first sensing signal input during a period of time. In addition, the timing controller 124 controls the position of the gate line or the position of the data line corresponding to the driving switch DR of the display panel 100 and the organic light emitting diode (OLED) sensed from the sensing start signal to the sensing stop signal. Based on the information, the compensation circuit 130 may be controlled so that the compensation circuit 130 performs a sensing operation from an area that is not sensed.

In another embodiment, when the timing controller 123 receives the compensation progress enable signal, it outputs a sensing resume signal to the compensation circuit 130 and stores the first sensing signal and the sensing resume signal. It is also possible to provide a curvature variable organic light emitting diode display that generates compensation data based on the second sensing signal input after the output. Upon resumption of the sensing operation of the compensation circuit 130 , at least one of the driving switch DR corresponding to the remaining area of the display panel 100 and the characteristics of the organic light emitting diode OLED is sensed, and the timing controller 124 ) generates compensation data based on the sensed data and provides the compensation data to the display panel 100 to compensate for variations in characteristics between the driving switch DR and the organic light emitting diode OLED.

In another embodiment, the motor assembly 240 is configured to adjust the curvature of the display panel 116 for a time period after the output of the compensation progress disallow signal from the motor control unit 220 and before the output of the compensation progress enable signal A curvature variable organic light emitting diode display may be provided. That is, the motor control unit 220 controls the motor assembly 240 during the time period between the timing controller's output of the compensation progress disallow signal and the compensation progress allow signal output time, and the motor assembly 240 includes the manpower unit 250 . It is possible to vary the curvature of the display panel 100 through the control of . Through this, it is possible to temporally separate the curvature variable time point and the sensing time point to prevent a sensing error and signal distortion caused by the curvature variable time point.

In another embodiment, the display panel 116 further includes an attractive force unit 250 fixed to a specific area at the rear of the display panel 116 to apply an attractive force to the specific area, and the motor assembly 240 includes the attractive force unit 250 . ) may be provided with a variable curvature organic light emitting diode display for applying or releasing an attractive force, wherein at least two motor assemblies 240 are provided at the rear of the display panel 116 , and each motor assembly 240 . It is also possible to provide a curvature-variable organic light emitting diode display device that adjusts the curvature of the display panel 116 by independently adjusting the rotation amount of the motor included in the display panel. In addition, the timing controller 123 that has received the compensation progress disabling signal may provide a curvature variable organic light emitting diode display for outputting a sensing start signal to the compensation circuit 130 after receiving the compensation proceeding permit signal. there is also

In another embodiment, the display panel 116 senses in response to a sensing control signal and a scan switch SW that applies a sensing voltage on a data line or the compensation data to a first node in response to a scan pulse. A sensing switch SEW for applying a reference voltage on the line Sk to a second node and a storage capacitor Cst connected between the first and second nodes N1 and N2, the driving switch DR ) is a curvature variable organic light emitting diode display that controls the current of the organic light emitting diode (OLED) connected to the second node (N2) by the voltage between the first and second nodes (N1, N2). may be And during the initialization period, the scan switch and the sensing switch are turned on, the sensing voltage from the data line is charged to the first node through the scan switch, and the reference voltage from the sensing line is the sensing switch is charged to the second node through , and during the source follower driving period, the sensing line is floated, the scan switch and the sensing switch are kept turned on, and the second node is charged by the current flowing through the driving switch Thus, it is possible to provide a curvature variable organic light emitting diode display that increases the voltage of the second node and detects the voltage on the second node through the sensing line during a threshold voltage detection period. According to the threshold voltage detection, the sensing line Sk is electrically connected to the ADC 220 by the Sam signal, and the voltage on the second node N2 is detected and converted into a digital signal. Then, when the compensation data signal Vd to be supplied to the data line Dm is generated during the characteristic compensation of the driving switch and the organic light emitting diode characteristic sensing period, the detected threshold voltage Vth of the driving switch DR is used. The threshold voltage Vth of the driving switch DR may be compensated.

When the characteristic sensing of the driving switch and organic light emitting diode and the curvature of the display device are adjusted at the same time, the problem of errors occurring during characteristic sensing due to the tension action of the driving circuit is solved, and the quality of the image is improved by accurately performing characteristic compensation. can be improved

1 is a view showing the structure of an organic light emitting diode.
2 is a circuit diagram equivalently showing one pixel in an organic light emitting diode display according to an embodiment of the present invention.
3 is a block diagram illustrating an organic light emitting diode display device according to an embodiment of the present invention.
4 is a diagram illustrating a pixel structure according to an embodiment of the present invention.
5 is a waveform diagram illustrating voltage waveforms on first and second nodes during threshold voltage sensing. 6 to 8 are diagrams illustrating an operation of a pixel during threshold voltage sensing.
9A is a waveform diagram for compensating for characteristics of a driving switch and for sensing characteristics of an organic light emitting diode;
9B is another waveform diagram illustrating characteristic compensation of a driving switch and sensing of characteristics of an organic light emitting diode.
10 to 18 are diagrams illustrating an operation of a pixel when characteristics of a driving switch are compensated and characteristics of an organic light emitting diode are sensed.
10 is a diagram illustrating an operation of a pixel in a first initialization period.
11 is a diagram illustrating an operation of a pixel during a characteristic compensation period of a driving switch.
12 is a diagram illustrating an operation of a pixel in a second initialization period.
13 and 14 are diagrams illustrating the operation of the pixel during the organic light emitting diode characteristic tracking period, and FIG. 15 is a current voltage graph of the organic light emitting diode and the driving switch.
16 is a diagram illustrating an operation of a pixel in a third initialization period.
17 is a diagram illustrating an operation of a pixel during an organic light emitting diode characteristic sensing period.
18 is a diagram illustrating an operation of a pixel during an organic light emitting diode characteristic detection period.
19 is a block diagram illustrating an internal structure of a data driving circuit according to an embodiment of the present invention.
20 is an exemplary diagram of a shape of a curved display device.
21 is a block diagram illustrating the configuration of a curvature variable display device according to functions according to an embodiment of the present invention.
22 is a cross-sectional view illustrating a curvature adjusting device and a curvature variable display device according to a first embodiment of the present invention.
23A and 23B are cross-sectional views illustrating a curvature adjusting device and a curvature variable display device according to a second embodiment of the present invention.
24 is a flowchart illustrating the relationship between the compensation circuit operation and the curvature variable operation of the display device.
25 and 26 are block diagrams of each component for the compensation circuit operation and the curvature variable operation of the display device.
27 to 29 are signal flow charts illustrating the relationship between the compensation circuit operation and the curvature variable operation of the display device.

Hereinafter, a curvature variable 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 drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numbers refer to like elements throughout.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout. The sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of description.

Reference to an element or layer to another element or “on” or “on” includes not only directly on the other element or layer, but also with other layers or other elements interposed therebetween. do. On the other hand, reference to an element "directly on" or "directly on" indicates that there are no intervening elements or layers.

Spatially relative terms "below, beneath", "lower", "above", "upper", etc. are one element or component as shown in the drawings. and can be used to easily describe the correlation with other devices or components. The spatially relative term should be understood as a term including different directions of the device during use or operation in addition to the directions shown in the drawings. For example, when an element shown in the figures is turned over, an element described as "beneath" or "beneath" another element may be placed "above" the other element. Accordingly, the exemplary term “below” may include both directions below and above.

The terminology used herein is for the purpose of describing the embodiments, and thus is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprise” and/or “comprising” refers to the presence of one or more other components, steps, operations, and/or elements mentioned. or addition is not excluded.

<Structure of organic light emitting diode>

1 is a view showing the structure of an organic light emitting diode.

The organic light emitting diode display may include an organic light emitting diode as shown in FIG. 1 .

The organic light emitting diode may include an organic compound layer (HIL, HTL, EML, ETL, EIL) formed between the anode electrode and the cathode electrode. The organic compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL) and an electron injection layer (Electron Injection layer, EIL) may be included. When a driving voltage is applied to the anode and cathode electrodes, holes passing through the hole transport layer (HTL) and electrons passing through the electron transport layer (ETL) are moved to the light emitting layer (EML) to form excitons, and as a result, the light emitting layer (EML) is produces visible light. In addition, in the organic light emitting diode, the type and concentration of the dopant of the light emitting layer (EML) are varied according to the color to be displayed. Blue) may be provided, and additionally, a white organic light emitting diode having a structure in which the R light emitting layer, the G light emitting layer, and the B light emitting layer are selectively stacked may be provided. The organic light emitting diode display device arranges the pixels including the organic light emitting diode in a matrix form and controls the brightness of the pixels selected by the scan pulse according to the gray level of digital video data. Such an organic light emitting diode display device is divided into a passive matrix method and an active matrix method using a TFT as a switching element. Among them, the active matrix method selects a pixel by selectively turning on the TFT, which is an active element, and maintains the light emission of the pixel with a voltage maintained in a storage capacitor.

<Equivalent circuit diagram of active matrix pixel>

2 is a circuit diagram equivalently showing one pixel in an organic light emitting diode display according to an embodiment of the present invention.

Referring to FIG. 2 , the pixels of the organic light emitting diode display according to the embodiment of the present invention include an organic light emitting diode (OLED), a data line (D) and a gate line (G) crossing each other, and the pixel on the gate line (G). A scan switch (SW) for sequentially transferring data to pixels in a scan pulse (SP), a driving switch (DR) that generates a current by a voltage between the gate and source terminals, and a drive switch (DR) for storing data and maintaining it for a certain time A storage capacitor Cst is provided. The scan switch SW and the driving switch DR may be formed of an N-type MOS-FET. As described above, a structure composed of two transistors (SW, DR) and one capacitor (Cst) can be simply referred to as a 2T-1C structure. The scan switch SW is turned on in response to the scan pulse SP from the gate line G to conduct a current path between its source electrode and the drain electrode. During the ON time period of the scan switch SW, the data voltage from the data line D passes through the source electrode and drain electrode of the scan switch SW to the gate electrode of the driving switch DR and the storage capacitor ( Cst) is applied. The driving switch DR controls the current flowing through the organic light emitting diode OLED according to the difference voltage Vgs between its gate electrode and the source electrode. The storage capacitor Cst maintains the voltage supplied to the gate electrode of the driving switch DR constant for one frame period by storing the data voltage applied to one electrode of the storage capacitor Cst. The organic light emitting diode OLED implemented with the structure shown in FIG. 1 is connected between the source electrode of the driving switch DR and the low potential driving voltage source VSS. The current flowing through the organic light emitting diode (OLED) is proportional to the brightness of the pixel, which is determined by the gate-source voltage of the driving switch (DR). The brightness of the pixel shown in FIG. 2 is proportional to the current flowing through the organic light emitting diode (OLED) as shown in Equation 1 below.

Equation 1

는 구동 스위치(DR)의 이동도 및 기생용량에 의해 결정되는 상수값을 각각 의미한다. 수학식 1과 같이, 유기발광다이오드(OLED)의 전류(Ioled)는 구동 스위치(DR)의 문턱전압(Vth)에 크게 영향 받는다는 것을 알 수 있다. 따라서 전체 영상 이미지의 균일도는 구동 스위치(DR)의 특성 편차, 즉 이동도와 문턱전압의 편차에 의해 좌우된다. 유기발광다이오드 표시장치를 위한 구동 스위치(DR)는 비정질 실리콘(s-Si) 또는 저온 다결정 실리콘(LTPS) 기반에서 제작할 수 있다. 비정질 실리콘 구동 스위치는 특성이 매우 균일하지만 문턱전압 이동 등의 안정성의 문제가 있다. 그리고 이동도가 낮아서 구동 회로를 패널 위에 직접 하기가 어렵다. 이에 반해 저온 다결정 실리콘 구동 스위치는 상대적으로 안정성이 높고 이동도가 높지만, 그레인 경계의 불규칙성으로 인해 문턱전압과 이동도 특성에 대한 화소 간 편차가 크다. 또한 구동 스위치(DR)의 문턱 전압 및 이동도 특성뿐만 아니라 유기발광다이오드(OLED)의 열화 정도에 따라서 전류(Ioled)는 영향을 받을 수 있다. 따라서 보상 구동을 통해 구동 스위치(DR)의 문턱 전압 및 이동도 특성을 보상한 경우에도 유기발광다이오드(OLED)의 열화에 의해 이미지 스티킹이 발생할 수 있으므로 유기발광다이오드(OLED)의 열화 정보를 추출하여 이를 보상할 수 있다. 그리고 유기발광다이오드(OLED)의 열화 정보를 추출할 때 추출된 정보에 구동 스위치(DR)의 열화 특성이 포함될 수 있어 유기발광다이오드(OLED)의 열화 정보를 정확히 검출하는데 한계가 있다. 따라서 유기발광다이오드(OLED)의 열화 정보 추출 시 구동 스위치(DR)의 특성을 제거할 수 있다.Here, 'Vgs' is the difference voltage between the gate voltage Vg and the source voltage Vs of the driving switch DR, 'Vdata' is the data voltage, 'Vinit' is the initialization voltage, 'Ioled' is the driving current, 'Vth' is the threshold voltage of the drive switch (DR),

denotes a constant value determined by the mobility and the parasitic capacitance of the driving switch DR, respectively. As shown in Equation 1, it can be seen that the current Ioled of the organic light emitting diode OLED is greatly affected by the threshold voltage Vth of the driving switch DR. Accordingly, the uniformity of the entire video image is affected by the characteristic deviation of the driving switch DR, that is, the deviation between the mobility and the threshold voltage. The driving switch DR for the organic light emitting diode display may be manufactured based on amorphous silicon (s-Si) or low-temperature polycrystalline silicon (LTPS). Although the amorphous silicon driving switch has very uniform characteristics, there is a problem in stability such as threshold voltage shift. And it is difficult to directly build the driving circuit on the panel due to the low mobility. On the other hand, low-temperature polycrystalline silicon driving switches have relatively high stability and high mobility, but there is a large deviation between pixels in threshold voltage and mobility characteristics due to irregularity of grain boundaries. In addition, the current Ioled may be affected by the threshold voltage and mobility characteristics of the driving switch DR as well as the degree of deterioration of the organic light emitting diode OLED. Therefore, even when the threshold voltage and mobility characteristics of the driving switch DR are compensated through compensation driving, image sticking may occur due to the deterioration of the organic light emitting diode (OLED), so the deterioration information of the organic light emitting diode (OLED) is extracted. can compensate for this. In addition, when the deterioration information of the organic light emitting diode (OLED) is extracted, deterioration characteristics of the driving switch DR may be included in the extracted information, so that there is a limitation in accurately detecting deterioration information of the organic light emitting diode (OLED). Accordingly, when the deterioration information of the organic light emitting diode (OLED) is extracted, the characteristic of the driving switch DR may be removed.

<Block diagram of organic light emitting diode display device>

3 is a block diagram illustrating an organic light emitting diode display device according to an embodiment of the present invention.

Referring to FIG. 3 , the organic light emitting diode display 100 according to an embodiment of the present invention may include a panel assembly 210 and a curvature adjusting device 200 . In addition, the panel assembly 210 may include a system board 123 , a display panel 116 , a gate driving circuit 118 , a data driving circuit 120 , and a timing controller 124 .

The system board 123 may supply a timing signal including a vertical/horizontal synchronization signal, a dot clock signal, and a data enable signal, digital video data, and a power voltage Vcc to the timing controller 124 . The system board 123 may include a scaler circuit to adjust the resolution of digital video data to be supplied to the timing controller 124 . The system board 123 may transmit a timing signal and digital video data to the timing controller 124 through a low voltage differential signaling (LVDS) interface. In addition, the system board 123 receives a curvature variable signal from an external control device, for example, a remote controller (not shown) according to a user command, and adjusts the curvature to the curvature adjusting device 200 based on the received curvature variable signal. signal can be provided.

When the curvature of the panel assembly 210 is adjusted, the curvature adjusting device 200 transmits a compensation control signal to the timing controller 124 so that the timing controller 124 performs the driving switch DR and the organic control on the display panel 116 . It is possible to determine whether to sense the characteristic of the light emitting diode (OLED).

The display panel 116 corresponds to each other on a one-to-one basis to form m pairs of m data lines D1 to Dm, k sensing lines S1 to Sk, and n gate lines G1 to Gn and j. Pixels 122 formed at intersections of sensing control lines SC1 to SCj may be provided. Signal lines supplying the first driving power Vdd and the signal wirings supplying the second driving power Vss to each of the pixels 122 may be formed on the display panel 116 . Here, the first driving power Vdd and the second driving power Vss may be generated from the high potential driving voltage source VDD and the low potential driving voltage source VSS, respectively. The gate driving circuit 118 may generate a scan pulse SP in response to the gate control signal GDC from the timing controller 124 and sequentially supply the scan pulses SP to the gate lines G1 to Gn. Also, the gate driving circuit 118 may be controlled from the timing controller 124 to output the sensing control signal SCS, and a sensing switch in each pixel may be controlled by the sensing control signal SCS. It has been described that the gate driving circuit 118 outputs both the scan pulse SP and the sensing control signal SCS, but is not limited thereto, and is controlled by the timing controller 124 to generate the sensing control signal SCS. A separate sensing switch control driver capable of outputting may be provided. The data driving circuit 120 may be controlled by a data control signal DDC from the timing controller 124 and output a data voltage to the data lines D1 to Dm and a sensing voltage to the sensing lines S1 to Sk. can Each of the data lines D1 to Dm may be respectively connected to each pixel 122 to apply a data voltage to each of the pixels 122 . Each of the sensing lines S1 to Sk may be connected to the pixel 122 to supply a sensing voltage and measure the sensing voltage on the sensing lines S1 to Sk. Specifically, by supplying the initialization voltage using one sensing line S1 to Sk, the sensing voltage using charging and floating as the initialization voltage can be detected. Although it has been described that the data driving circuit 120 can output or detect the data voltage and the sensing voltage, the present invention is not limited thereto, and a separate driver capable of outputting or detecting the sensing voltage may be provided.

<Pixel structure>

4 is a diagram illustrating a pixel structure according to an embodiment of the present invention.

The pixel 122 described in the present invention may refer to any one of red, green, blue, and white, and this may be separately referred to as a sub-pixel. The sub-pixel 122 may include a scan switch SW, a driving switch DR, a sensing switch SEW, an organic light emitting diode OLED, and a storage capacitor Cst. The scan switch SW is controlled by the scan pulse SP on the gate line Gn and is a transistor for supplying data on the data line Dm to the sub-pixel 122 , and includes the data line Dm and the first It may be connected between the nodes N1. The driving switch DR is a transistor that regulates the current flowing in the organic light emitting diode OLED by the voltage between the first node N1 and the second node N2, which is its gate-source, and has a gate terminal It may be connected to the first node N1 , a source terminal may be connected to the second node N2 , and a drain terminal may be connected to the first driving power source Vdd. The sensing switch SEW is a transistor that initializes the second node N2 to detect the threshold voltage of the driving switch DR through the sensing line Sk, and controls sensing on the sensing control line SCj. It is controlled by the signal SCS and may be connected between the second and third nodes N2 and N3 . The anode terminal of the organic light emitting diode OLED may be connected to the second node N2 , and the cathode terminal may be connected to the second driving power source Vss. The storage capacitor Cst may be connected between the first and second nodes N1 and N2 , that is, between the gate and the source terminal of the driving switch DR.

<Threshold voltage compensation>

5 is a waveform diagram illustrating voltage waveforms on first and second nodes when sensing a threshold voltage, and FIGS. 6 to 8 are diagrams illustrating an operation of a pixel when sensing a threshold voltage.

The threshold voltage of the driving switch DR may be sensed and compensated through the following process.

(1) Initialization period: t1

5 and 6, in the initialization period t1, the scan switch SW and the sensing switch SEW are turned on, and the sensing voltage Vsen from the data line Dm is the scan switch SW. is charged to the first node N1 through . In addition, the storage capacitor Cst is initialized to the voltage difference between the first and second nodes N1 and N2, that is, Vsen-Vref. At this time, the organic light emitting diode OLED does not emit light by the reference voltage Vref supplied to the second node N2 through the sensing switch SEW.

(2) Source follower operation period: t2

5 and 7, in the source follower driving period t2, the sensing line Sk is floating, the scan switch SW and the sensing switch SEW are kept turned on, and the storage capacitor CSt A current flows in the driving switch DR using the high potential power Vdd as an energy source by the stored voltage, that is, the voltage Vgs between the gate and the source terminal of the driving switch DR. In addition, as the current flowing through the driving switch DR charges the second node N2 , the voltage on the second node N2 increases. At this time, since Vgs of the driving switch DR decreases, the current flowing through the driving switch DR also decreases. In addition, when Vgs reaches the threshold voltage of the driving switch DR, no current flows through the driving switch DR, so that the voltage on the second node N2 is constantly maintained.

(3) Threshold voltage detection period: t3

Next, referring to FIGS. 5 and 8 , in the threshold voltage detection period t3 , the sensing line Sk is electrically connected to the ADC 220 by the Sam signal, and the voltage on the second node N2 is detected and digital changed to a signal. Then, when the compensation data signal Vd to be supplied to the data line Dm is generated during the characteristic compensation of the driving switch and the organic light emitting diode characteristic sensing period, the detected threshold voltage Vth of the driving switch DR is used. The threshold voltage Vth of the driving switch DR may be compensated.

<Characteristic compensation of driving switch and organic light emitting diode characteristic sensing-First embodiment>

9A is a waveform diagram when characteristics of a driving switch are compensated and characteristics of an organic light emitting diode are sensed, and FIGS. 10 to 18 are diagrams illustrating an operation of a pixel when characteristics of a driving switch are compensated and characteristics of an organic light emitting diode are sensed.

The mobility characteristic of the driving switch DR and the characteristic of the organic light emitting diode may be sensed and compensated through the following process.

(1) First initialization period: t1

10 is a diagram illustrating an operation of a pixel in a first initialization period.

9A and 10 , in the first initialization period t1 , the scan switch SW and the sensing switch SEW are turned on, and the compensation data voltage Vd from the data line Dm is applied to the scan switch ( SW) is charged to the first node N1, and in response to the initialization control signal Spre, the reference voltage Vref from the sensing line Sk is applied to the second node N2 through the sensing switch SEW. is charged In addition, the storage capacitor Cst is initialized to the voltage difference between the first and second nodes N1 and N2, that is, Vd-Vref. At this time, the organic light emitting diode OLED does not emit light by the reference voltage Vref supplied to the second node N2 through the sensing switch SEW. The compensation data voltage vd becomes the sum voltage of the data voltage Vdata and the threshold voltage DR_Vth of the driving switch DR.

(2) Characteristic compensation period of the drive switch: t2

11 is a diagram illustrating an operation of a pixel during a characteristic compensation period of a driving switch.

Subsequently, referring to FIGS. 9A and 11 , in the characteristic compensation period t2 of the driving switch, the scan switch SW remains turned on and the sensing switch SEW is turned off, and the voltage Vd stored in the storage capacitor Vst is -Vref), a current flows in the driving switch DR, and this current charges the second node N2. In this case, the degree of increase of the voltage on the second node N2 may vary according to the mobility characteristic of the driving switch DR. Specifically, when the mobility characteristic of the driving switch DR is excellent, the current flow is excellent and the voltage on the second node N2 rises rapidly, and when the mobility characteristic of the driving switch DR is not excellent, the current flow is excellent. This is so bad that the voltage on the second node N2 rises slowly. Accordingly, the amount of increase in the voltage on the second node N2 varies according to the mobility characteristic of the driving switch DR, and accordingly, the voltage stored in the storage capacitor Cst, that is, between the gate and the source terminal of the driving switch DR. The degree of decrease of the voltage (Vgs) of As described above, since the amount of increase of the voltage on the second node N2 varies depending on the characteristics of the driving switch DR, the characteristics of the driving switch DR are reflected in Vgs and thus the mobility characteristics of the driving switch DR. will compensate

(3) Second initialization period: t3

12 is a diagram illustrating an operation of a pixel in a second initialization period.

Subsequently, referring to FIGS. 9A and 12 , in the second initialization period t3 , the scan switch SW maintains turned on, the sensing switch SEW is turned on, and in response to the initialization control signal Spre, the sensing line ( The reference voltage Vref from Sk) is charged in the second node N2 through the sensing switch SEW. At this time, since the voltage on the first node N1 is also reduced by the amount of the decrease in the voltage on the second node N2 according to the coupling of the storage capacitor Cst, Vgs of the driving switch DR is maintained without change. In addition, the organic light emitting diode OLED does not emit light by the reference voltage Vref supplied to the second node N2 through the sensing switch SEW.

(4) organic light emitting diode characteristic tracking (tracking) period: t4

13 and 14 are diagrams illustrating the operation of the pixel during the organic light emitting diode characteristic tracking period, and FIG. 15 is a current voltage graph of the organic light emitting diode and the driving switch.

Subsequently, referring to FIGS. 9A , 13 , 14 and 15 , in the organic light emitting diode characteristic tracking period t4 , the scan switch SW is turned on and the sensing switch SEW is turned off. At this time, the compensation data voltage Vd from the data line Dm is supplied to the first node N1 through the scan switch SW, and a current flows through the driving switch SW according to the source follower driving, and this current charges the second node N2. In addition, the second node N2 is charged and the Vgs of the driving switch DR decreases as the voltage of the second node N2 increases. And when the voltage of the second node N2 reaches the operating voltage of the organic light emitting diode OLED, as shown in FIG. 13 , the organic light emitting diode OLED is turned on, a current flows through the organic light emitting diode OLED, and the organic light emitting diode The OLED emits light, and since the voltage of the second node N2 is kept constant, Vgs of the driving switch SW also maintains a constant voltage.

At this time, the sensed second node N2 voltage varies according to the Vgs of the driving switch DR. According to the sensing waveform shown in FIG. 15, the current flowing in the driving switch DR moves from the high side to the low side according to the source follower driving, and the current flowing through the organic light emitting diode (OLED) is the current in the state where no current flows. While changing in a flowing state, it moves in the same direction as the current flowing through the driving switch DR. As described above, while the current flowing through the organic light emitting diode OLED and the current flowing through the driving switch DR move to meet each other, the operating voltage Voled of the organic light emitting diode OLED is tracked. At this time, Vgs of the generated driving switch DR is a value reflecting the operating voltage Voled of the organic light emitting diode OLED. Accordingly, the Vgs is information reflecting the operating voltage Voled of the organic light emitting diode (OLED). In addition, as the organic light emitting diode (OLED) deteriorates, the threshold voltage of the organic light emitting diode (OLED) may increase, and accordingly, the operating voltage (Voled) of the organic light emitting diode (OLED) also increases, so that the driving switch (DR) Vgs of can be a smaller value. In addition, depending on the deterioration of the driving switch DR, the characteristic graph may change from a solid line to a dotted line or from a dotted line to a solid line in the graph of FIG. The voltage of Vgs of the driving switch DR may also be changed at a point where the currents meet each other. Accordingly, although deterioration information of the driving switch DR may be reflected in Vgs, the characteristics of the driving switch DR are compensated in advance in the aforementioned characteristic compensation period t2 of the driving switch, so the organic light emitting diode characteristic tracking period t4 ), it is possible to minimize the reflection of the characteristics of the driving switch DR in Vgs of the driving switch DR, and to maximize the reflection of characteristic information of the organic light emitting diode (OLED).

Meanwhile, by adjusting the organic light emitting diode characteristic tracking period t4, before the organic light emitting diode OLED is turned on, a third initialization period t5 to be described later may be transferred. That is, the second node N2 may be initialized during the third initialization period t5 while the current flowing through the organic light emitting diode OLED and the current flowing through the driving switch DR meet each other. And while the current flowing through the organic light emitting diode OLED and the current flowing through the driving switch DR move to a point where they meet each other, the characteristic information of the organic light emitting diode OLED is continuously reflected in Vgs of the driving switch DR. Therefore, as described above, even if the organic light emitting diode characteristic tracking period t4 is not maintained until the organic light emitting diode (OLED) is turned on, the characteristic information of the organic light emitting diode (OLED) is reflected in Vgs of the driving switch (DR). can

As such, the holding time of the organic light emitting diode characteristic tracking period t4 may be adjusted so that the characteristics of the organic light emitting diode (OLED) are reflected as much as possible or the characteristics of the organic light emitting diode (OLED) are reflected as much as possible compared to the characteristics of the driving switch DR. At this time, the gate pulse modulation technology (GPM) uses a scan pulse (SP) to match the timing of the central axis and the edge of the load of the display panel 116 with another. can As such, the holding time of the organic light emitting diode characteristic tracking period t4 can be adjusted to reflect the characteristics of the organic light emitting diode (OLED) as much as possible. SP) can be applied.

<Characteristic compensation of driving switch and organic light emitting diode characteristic sensing-Second embodiment>

9B is another waveform diagram illustrating characteristic compensation of a driving switch and sensing of characteristics of an organic light emitting diode.

(1) Referring to FIG. 9B , unlike the case in which the scan switch SW is turned on in the organic light emitting diode characteristic tracking period t4 of FIG. 9A , the scan switch SW remains turned off during the third initialization period (t5) It can be turned on only during a partial period. And the sensing switch SEW is turned off. At this time, when the voltage of any one of the first and second nodes N1 and N2 is changed, the voltages of the other nodes also change according to the coupling phenomenon of the storage capacitor Cst, so that Vgs is maintained. Accordingly, the driving switch DR operates in a constant current mode due to the maintenance of the Vgs voltage. And when the second node N2 is charged and the voltage of the second node N2 reaches the operating voltage of the organic light emitting diode OLED as the voltage of the second node N2 is increased, the organic light emitting diode OLED ) is turned on, a current flows in the organic light emitting diode (OLED), the organic light emitting diode (OLED) emits light, and the voltage of the second node (N2) is maintained constant. And when the scan switch SW is turned on before the third initialization period t3, the compensation data voltage Vd from the data line Dm is supplied to the first node N1 again through the scan switch SW. Only the degradation characteristics of the organic light emitting diode (OLED) exist at the Vgs voltage. Accordingly, deterioration information of the organic light emitting diode OLED can be reflected in Vgs of the driving switch DR not only in the source follower driving mode of FIG. 9A but also in the constant current driving mode.

(2) Third initialization period: t5

16 is a diagram illustrating an operation of a pixel in a third initialization period.

Subsequently, referring to FIGS. 9A and 16 , in the third initialization period t5 , the scan switch SW is turned off, the sensing switch SEW is turned on, and in response to the initialization control signal Spre, the sensing line Sk ) from the reference voltage Vref is charged to the second node N2 through the sensing switch SEW. At this time, since the voltage on the first node N1 is also reduced by the amount of the decrease in the voltage on the second node N2 according to the coupling of the storage capacitor Cst, Vgs of the driving switch DR is maintained without change. Accordingly, the operating voltage Voled of the organic light emitting diode OLED stored in the storage capacitor Cst is maintained. In addition, the organic light emitting diode OLED does not emit light by the reference voltage Vref supplied to the second node N2 through the sensing switch SEW.

In this way, the second node N2 is initialized through the third initialization period t5, and Vgs information is reflected to the second node N2 through a process to be described later, and Vgs information is obtained by sensing the second node N2. can be easily detected.

(3) organic light emitting diode characteristic sensing period: t6

17 is a diagram illustrating an operation of a pixel during an organic light emitting diode characteristic sensing period.

Subsequently, referring to FIGS. 9A and 17 , the scan switch SW maintains turn-off, and the sensing switch SEW maintains turn-on. In response to the initialization control signal Spre, the terminal supplying the reference voltage Vref and the sensing line Sk are electrically cut off while the sensing line Sk floats, and by the current flowing through the driving switch DR Since the voltage of the second node N2 is increased and the voltage of the first node N1 is also changed by the amount of voltage change of the second node N2 according to the coupling of the storage capacitor Cst, the voltage of the driving switch DR is Vgs is maintained Accordingly, the operating voltage Voled of the organic light emitting diode OLED stored in the storage capacitor Cst is maintained. In addition, the current flowing through the driving switch DR varies according to the operating voltage Voled of the organic light emitting diode OLED stored in the storage capacitor Cst, and accordingly, the amount of increase in the voltage on the second node N2 is also different. Therefore, the characteristic of the operating voltage Voled of the organic light emitting diode (OLED) is reflected as the voltage on the second node (N2).

(4) organic light emitting diode characteristic detection period: t7

18 is a diagram illustrating an operation of a pixel during an organic light emitting diode characteristic detection period.

Subsequently, referring to FIGS. 9A and 18 , the scan switch SW is turned on and the black data Vblack is supplied to the first node N1 through the data line Dm to completely block the current flowing through the driving switch DR. can break In addition, when the black data Vblack is supplied to the first node N1 , the voltage of the first node N1 decreases, but a capacitor component of the sensing line Sk having a relatively large capacitor capacity compared to the storage capacitor Cst. As a result, the coupling phenomenon of the storage capacitor Cst is not reflected in the second node N2 , and thus the voltage of the second node N2 may not be changed and may be stably maintained. Then, the sensing line Sk is connected to the ADC 220 by the sampling signal Sam, and the voltage on the second node N2 is detected by the ADC 220 to detect the characteristics of the organic light emitting diode.

As described above, deterioration of the organic light emitting diode (OLED) can be compensated by detecting the deterioration characteristic of the organic light emitting diode (OLED) through the external compensation method and reflecting the deterioration characteristic of the organic light emitting diode (OLED) in a data signal.

When sensing an organic light emitting diode (OLED), the influence of external factors such as temperature is large. may occur, but in the method of driving the organic light emitting diode display 100 according to the embodiment of the present invention, the operating voltage Voled of the organic light emitting diode OLED increases by alleviating the mobility component of the driving switch DR. A reflected sensing value can be obtained, and through this, the sensing quality can be improved. In addition, it is possible to reduce the number of memories by internally compensating for the mobility characteristic without having to provide a separate memory for sensing the mobility characteristic of the driving switch DR.

On the other hand, the compensation of the characteristics of the driving switch DR and the organic light emitting diode OLED can be performed when the power of the organic light emitting diode display 100 is turned on, and the driving of the organic light emitting diode display 100 is performed. It may be performed during the period of time, and may be performed for a preset time after turning off the power of the organic light emitting diode display 100 .

In addition, the mobility characteristic of the driving switch DR can be compensated for when the power of the organic light emitting diode display 100 is turned on and during driving of the organic light emitting diode display 100 , and The threshold voltage characteristic may be performed after the power of the organic light emitting diode display 100 is turned off, but is not limited thereto.

As described above, by compensating for the characteristics of the display panel 116 during initial driving and driving of the display device 100 , the image quality can be improved, and sensing data is acquired in advance even after the power is turned off so that when the power is turned on, Quick compensation may be performed based on the stored sensing data.

<Internal structure of data driving circuit>

19 is a block diagram illustrating an internal structure of a data driving circuit according to an embodiment of the present invention.

Referring to FIG. 19 , the data driving circuit 120 includes a sampling switch SW10 for sampling, an initialization switch SW20 for applying a reference voltage Vref, a sensing circuit 131, an analog-to-digital converter (hereinafter, ADC, 132) and a reference voltage generator 133 may be included.

In response to the initialization control signal Spre, the initialization switch SW20 is turned on during the initialization period when sensing the threshold voltage or during the initialization period when the characteristics of the driving switch are compensated and the characteristics of the organic light emitting diode are sensed, and is generated from the reference voltage generator 133. The supplied reference voltage Vref may be supplied to the pixel 122 .

The initialization control signal Spre for controlling the initialization switch SW20 may be provided from the timing controller 124 .

The sampling switch SW10 is turned on by a high-level sampling signal Sam signal when the threshold voltage is sensed or when the driving switch characteristic compensation and organic light emitting diode characteristic sensing are performed, so that the sensing circuit 131 is connected to the sensing lines S1 to Sk). Enables detection of the sensed voltage on the line.

The sampling signal Sam for controlling the sampling switch SW10 may be provided from the timing controller 124 .

Meanwhile, the sensing lines S1 to Sk may be floated by the low logic signal of the sampling signal Sam and the low logic signal of the initialization control signal Spre.

The ADC 132 may convert the sensing voltage on the sensing lines S1 to Sk detected by the sensing circuit 131 into a digital value and provide it to the memory 134 , and the memory 134 may store the digital value By storing , information on the threshold voltage and mobility of the driving switch DR in the pixel 122 may be stored.

The controller 135 provides information on the threshold voltage and mobility of the driving switch DR in the pixel 122 stored in the memory 134 to the timing controller 124 , and the timing controller 124 provides the data The driver 120 may control to provide the compensated data voltage to the data lines D1 to Dm. Accordingly, image quality may be improved by considering the threshold voltage and mobility of the driving switch DR in the pixel 122 and compensating for the parasitic capacitor Cg on the sensing lines S1 to Sk and non-ideal characteristics of each device.

Meanwhile, the ADC 132 may be a separate configuration separated from the sensing circuit 131 or may be included in the sensing circuit 131 to form a single configuration.

Meanwhile, although it has been described that the data driving circuit 120 includes a circuit for sensing the characteristics of the driving switch DR and sensing the characteristics of the organic light emitting diode (OLED), it is not limited thereto, and sensing the characteristics of the driving switch DR and The organic light emitting diode (OLED) characteristic sensing compensation circuit 130 may be provided on a separate substrate.

The characteristic sensing of the driving switch DR of the organic light emitting diode display device 100 and the characteristic sensing of the organic light emitting diode OLED and a method for compensating them have been described. Hereinafter, the curved function of the organic light emitting diode display 100 will be mainly described.

<Curved variable display device>

Hereinafter, the organic light emitting diode display 100 will be referred to as a curved display device 100 or a variable curvature display device 100 .

20 is an exemplary diagram of a shape of a curved display device.

Referring to FIG. 20 , the curved display device 100 refers to a display or a device including the same that can be bent or bent at a predetermined curvature without special damage through a substrate, unlike a general flat panel display.

Meanwhile, “bending” or “curved” of the curved display device 100 according to an embodiment of the present invention refers to a state in which a flat state is deformed from a flat state to a non-flat state as shown in FIG. A first bending type of bending or partially bending the curved display device 100 in the horizontal or vertical direction as shown in (b) of FIG. 20, and twisting the curved display device 100 as shown in FIG. 20 (c) ) can be broadly classified into a second bending type and the like.

On the other hand, the curved display device to which an embodiment of the present invention is applied is curved while having a certain curvature as a whole in one of the horizontal or vertical directions as shown in FIG. 20(b) rather than twisting as shown in FIG. is more general, but not limited thereto.

In this case, the curvature (R) of the variable curvature display device to which an embodiment of the present invention is applied may be defined as a radius of curvature representing the arc curvature of a circle having a radius R, but is not limited thereto.

21 is a block diagram illustrating the configuration of a variable curvature display device according to functions according to an embodiment of the present invention.

The curvature variable display device 100 according to an embodiment of the present invention includes a panel assembly 210 including a panel 116 and a back cover attached to the rear of the panel 116, and a rotational force of a motor. and a curvature adjusting device 200 for changing the curvature of the display device by using it, and the curvature adjusting device 200 is again fixed to a specific region at the rear of the panel assembly 210 to correspond to the display panel 116 . An attractive force part 250 having a shape of a wire, a bar, etc., that applies an attractive force to an area, and a motor assembly 240 for applying and releasing an attractive force for forming a curved surface to a specific part of the panel 116 by pulling the attractive part and a motor control unit 220 for controlling a rotation amount of a motor included in the motor assembly 240 to change the curvature of the panel 116 .

In addition, the motor assembly 240 is again connected to the motor and the motor shaft of the motor and connected to a reduction unit including a reduction output shaft that provides an output of a rotation speed smaller than the motor rotation speed, and is connected to the reduction output shaft so that the manpower part is wound. may be configured to include a winding part in the form of a wheel or pulley.

<Curvature adjustment device>

The detailed configuration of the curvature adjusting device 200 will be described again in various embodiments below with reference to FIG. 22 .

The motor control unit 220 generates a motor rotation control signal for adjusting the curvature of the panel with a motor included in one or more motor assemblies in response to the curvature variable signal from the system board 123 , and provides it to the corresponding motor to rotate the motor to control In this case, the motor rotation control signal may be different for each motor. That is, by making the rotation amount of the motor of the motor assembly 240 disposed behind the center of the panel 116 larger than the amount of rotation of the motor located behind the edge of the panel, a greater attractive force is applied to the center of the panel 116 . It is the same as being able to reduce the curvature. That is, by allowing the central portion of the panel 116 to be pulled more than the edges, the panel 116 is bent more.

The motor rotation control signal generated by the motor controller 220 and provided to the motor may be, for example, a pulse width modulation (PWM) signal, but is not limited thereto.

The motor controller 220 may be included in the timing controller 124, may be implemented by being included in a main controller or control circuit such as a TV, or may be implemented as an independent controller or control circuit separate from the main controller. will be.

(1) Curved Variable Display Device-First Embodiment

22 is a cross-sectional view illustrating a curvature adjusting device and a curvature variable display device according to a first embodiment of the present invention.

In the variable curvature display device 100 according to the first embodiment, a display panel 116 and a back cover 320 for maintaining and protecting the panel 116 in a flat state are attached to the rear thereof. and three curvature adjusting devices 300 are disposed behind the back cover 320 .

Each of the curvature adjustment devices 300 according to the first embodiment includes a wire 350 as an attractive force part that can pull a portion rearward by providing an attractive force to a specific area of the display panel 116, and the wire connected to the motor. It includes a motor assembly 240 for controlling the degree of pulling of the 350 to the degree of motor rotation, and optionally a fixing part 360 fixed to the back cover 320 and connected to one end of the wire 350 which is a manpower part. may include

In addition, in the curvature adjusting device according to the first embodiment, one wire 350 and a motor assembly 340 are provided in the center rear portion of the display panel 116 , and one wire is respectively provided in the rear portion of the left and right edges of the panel 116 . (350a, 350b) and the motor assembly (340a, 340b) are arranged and shown to be provided with three wires as a whole, but is not limited thereto, and a plurality of wires such as five or seven may be provided.

In addition, although FIG. 22 shows that the curvature adjusting device is disposed only in the central portion of the panel 116 when viewed in the vertical direction, the present invention is not limited thereto, and for example, a plurality of wires and A motor assembly may also be disposed.

The wire 350 that is the attractive part of the curvature adjusting device 300 may be made of a metal material, but is not limited thereto, and the attractive part does not have to be a wire and has a shape of a bar or the like and has a specific region behind the panel 116 . There will be no restrictions on shape and material as long as it can be connected between the motor assembly 240 and provide an attractive or repulsive force to the corresponding panel area.

(2) Curved Variable Display Device-Second Embodiment

23A and 23B are cross-sectional views illustrating a curvature adjusting device and a curvature variable display device according to a second embodiment of the present invention.

In the variable curvature display device 100 according to the second embodiment, a display panel 116 and a back cover 320 for maintaining and protecting the panel in a flat state are attached to the rear thereof, The point including the rear cover 330 is the same as that of the first embodiment, but unlike the first embodiment including three motors, a motor assembly, and the like, in the second embodiment of FIG. 4 , one curvature adjusting device 400 . is provided

On the other hand, in the first embodiment, the curvature of the panel was adjusted by independently controlling a plurality of motor assemblies. However, in the second embodiment, since only one motor and a motor assembly are used, a reinforcement bar ( 460) may be further included.

That is, the curvature adjusting device 400 according to the second embodiment includes a reinforcing bar 460 formed on the back cover 320 at the rear of the panel 116 , a fixing part 470 fixed to the upper portion of the reinforcing bar, and a plurality of It is connected to the fixed part and is configured to include a wire 450 as an attraction part whose one end is wound around the motor assembly 440 .

Also, as in the first embodiment, in the second embodiment as well, FIG. 23 shows that the curvature adjusting device is disposed only on the central portion of the panel when viewed in the longitudinal direction, but the present invention is not limited thereto, and for example, the upper and lower portions of the panel. A curvature adjusting device including a reinforcing bar, a fixing part, a wire, a motor assembly, and the like may be disposed on the .

The wire 450, which is the attractive part of the curvature adjusting device according to the second embodiment, may also be made of a metal material, but is not limited thereto. There will be no restrictions on shape and material as long as it can be connected between the motor assembly and provide an attractive or repulsive force to the area of the panel.

In the first embodiment as shown in FIG. 22 , the motor assembly must be fixed to the rear cover because the wire must be pulled to the rear of the panel, but in the second embodiment, one motor assembly pulls or pushes the attractive force connected to the reinforcing bar 460 to form a curved surface It is not necessarily fixed to the rear cover, and may be fixed on the back cover.

In the curvature adjusting device according to the second embodiment as described above, a motor control unit (not shown) calculates the rotation amount of the motor according to a user command, and generates a motor rotation control signal accordingly to provide it to the motor assembly. Then, the motor rotates as much as the motor rotation control signal and the wire is pulled accordingly, and the attractive force is transmitted through the reinforcing bar, thereby bending the entire panel backward. Of course, at this time, the curvature can be arbitrarily adjusted to suit the user's preference by controlling the rotation amount of the motor, and the motor can be reversely rotated to release the tensile force to return to the original planar state.

By using the curvature adjusting device and the curvature variable display device 100 including the same as described above, the curvature of the curved display device 100 can be variably adjusted in real time according to the user's needs, so that the user's preference, user number, and viewing distance are used. There is an effect of providing an optimal viewing environment according to the

<Compensation circuit operation and display device curvature variable operation>

24 is a flowchart illustrating the relationship between the compensation circuit operation and the curvature variable operation of the display device, and FIGS. 25 and 26 are block diagrams of each component for the compensation circuit operation and the display device's curvature variable operation. 27 to 29 are signal flow diagrams illustrating the relationship between the compensation circuit operation and the curvature variable operation of the display device.

Referring to FIG. 24 , the variable curvature display device 100 is configured to 1) start a variable curvature operation, 2) stop sensing, 3) store data, 4) stop the variable curvature operation, 5) resume sensing, 6) generate compensation data, and 7 ), it is possible to perform a curvature variable operation and a sensing and compensation operation by performing the compensation operation.

Referring to FIG. 25 , the curvature variable display device 100 according to the embodiment includes a display panel 100 including a driving switch DR for controlling a current on an organic light emitting diode OLED, and a threshold of the driving switch DR. A compensation circuit 130 for sensing at least one of voltage and mobility and outputting a sensing signal, a timing controller 124 for controlling a sensing operation of the compensation circuit 130 and generating compensation data based on the sensing signal; a motor control unit 22 for controlling the motor assembly 240 for controlling the curvature of the display panel 100 in response to a curvature control signal from the outside and outputting a compensation control signal to the timing controller 124 The timing controller 124 may control the sensing operation of the compensation circuit 130 in response to the compensation control signal.

That is, in the compensation process through sensing the characteristics of the driving switch DR and the organic light emitting diode OLED and generating compensation data using the same, when the power of the display device 100 is turned on, the power is turned off ( Off), it may be performed for a certain period of time and in real time while the display device 100 is being driven. When compensation is made in real time while the power of the display device 100 is turned on and off and driving, a variable curvature operation of the display device 100 may be performed. , and compensation can be resumed when the curvature variable operation is finished.

Specifically, referring to FIGS. 24 to 29 , in response to a sensing start signal of the timing controller 124 , the compensation circuit 130 determines the threshold voltage or mobility of the driving switch DR on the display panel 116 , and the organic light emitting diode. At least one of characteristics of (OLED) may be sensed. In this case, driving switches DR corresponding to each of the plurality of gate lines G and characteristics of the organic light emitting diode OLED may be sequentially sensed. All or at least some of the driving switches DR and the organic light emitting diode (OLED) on the display panel 116 by sensing the characteristics of the driving switches DR and the organic light emitting diode (OLED) from the display panel 116 several times. OLED) characteristics are sensed, and the timing controller 124 receiving the sensing characteristics may supply compensated data to each pixel based on the sensed characteristics. During the sensing process, when a user attempts to change the curvature of the variable curvature display device 100 by using an external control means 125 such as a remote control, the remote control transmits the control signal to the system board 123 based on the user's command. and the system board 123 may transmit the curvature control signal to the motor controller 220 .

At this time, referring to an example of a user's command input to the remote control, which is an example of the external control means 125, according to the user's one-time command input, the curvature-variable display device 100 has a variable curvature until it has a specified curvature. As the user continuously inputs a command (for example, continuously presses the button for changing the curvature of the remote control without breaking), the variable curvature display device 100 continues until the user stops inputting the command. , and the curvature can be varied up to the allowed curvature. However, the user's command input method is not limited thereto, and any case is possible as long as the variable curvature display device 100 can be adjusted to have a flat shape and a curved shape within the allowed curvature.

According to the user's one-time command input (or as the user's continuous commands are input), the motor control unit 220 receiving the curvature control signal may provide a compensation control signal to the timing controller 124 . In this case, the compensation control signal may be a compensation stop signal. In addition, the motor controller 220 may control a change in the curvature of the display device 100 .

The timing controller 124 receiving the compensation control signal, which is the compensation stop signal, transmits a sensing stop signal to the compensation circuit 130 to stop the compensation circuit 130 from sensing the characteristics of the display panel 100 . can

In this case, the timing controller 124 may store information on the position of the gate line or the position of the data line corresponding to the driving switch DR and the organic light emitting diode OLED, the characteristics of which are sensed, and the sensing start signal is then sensed. Data sensed up to the stop signal can be stored separately.

Then, when the curvature variable display device 100 has a specified curvature (or when input of a user command is stopped), the motor control unit 220 may provide a compensation control signal to the timing controller 124 . . In this case, the compensation control signal may be a signal allowing compensation to proceed. In this case, the timing controller 124 may receive the compensation control signal and output a sensing resume signal to the compensation circuit 130 immediately or after a predetermined time so that the compensation circuit 130 resumes sensing. At this time, the timing controller 124 is positioned at the position of the gate line or the data line corresponding to the driving switch DR and the organic light emitting diode OLED of the display panel 100 sensed from the sensing start signal to the sensing stop signal. The compensation circuit 130 may be controlled so that the compensation circuit 130 performs a sensing operation from the non-sensed region based on the information on the .

According to the resumption of the sensing operation of the compensation circuit 130 , at least one of the driving switch DR corresponding to the remaining area of the display panel 100 and the characteristics of the organic light emitting diode OLED is sensed, and the timing controller ( 124 may generate compensation data based on the sensed data and provide it to the display panel 100 to compensate for variations in characteristics between the driving switch DR and the organic light emitting diode OLED.

Meanwhile, as described above, the compensation circuit 130 may be provided as a separate component as well as a component included in the data driving circuit 120 as shown in FIG. 19 .

Also, as shown in FIG. 27 , the compensation control signal may include a compensation progress enable signal and a compensation progress disable signal, and the timing controller 124 sends a sensing stop signal to the compensation circuit 130 based on the compensation control signal. , any one of a sensing start signal and a sensing restart signal may be output. In addition, after receiving the sensing start signal from the timing controller 124 , the compensation circuit 130 performs at least one of a corresponding driving switch DR and an organic light emitting diode (OLED) for each gate line G on the display panel 100 . The characteristic may be sensed and the sensed sensing signal may be provided to the timing controller 124 .

Specifically, in the compensation circuit 130 that periodically performs a sensing operation during the T1 time period as shown in FIGS. 27 and 28 , the timing controller 124 performs compensation while the compensation circuit 130 performs the sensing operation. When receiving the disallow signal, the timing controller 124 outputs a sensing stop signal to the compensation circuit 130 . In addition, when the timing controller 124 receives the compensation progress enable signal while the compensation circuit 130 stops the sensing operation, the timing controller 124 sends a sensing resume signal to the compensation circuit 130 . to output And the timing controller 124 generates compensation data based on the sensing signal sensed during T3 after the output of the sensing start signal and the sensing signal sensed for the time period T2, which is a time period before the output of the sensing stop signal, and the sensing resume signal. can

Also, as shown in FIG. 29, when the compensation circuit 130, which periodically performs a sensing operation during the T1 time period, receives a compensation progress disallow signal in a state in which the next sensing operation has not yet been performed, the timing controller 124 does not output a sensing start signal to the compensation circuit 130 (no sensing start signal output), and then outputs a sensing start signal immediately or after a preset time when receiving a compensation progress enable signal after the compensation circuit 130 ) to perform the sensing operation, it is possible to prevent a sensing error due to the curvature variable operation.

On the other hand, as shown in FIGS. 28 and 29 , the motor control unit 220 controls the motor assembly 240 during a time period between the time when the compensation proceeding disallow signal is output and the time when the compensation proceeding permit signal is output, and the motor assembly 240 is a manpower unit. The curvature of the display panel 100 may be varied through the control at 250 .

In addition, as shown in FIG. 29 , the motor control unit 220 controls the motor assembly 240 during a time period between the timing controller's output of the compensation progress disallow signal and the compensation progress allow signal output time, and the motor assembly 240 is a manpower unit. The curvature of the display panel 100 may be varied through the control at 250 . Through this, it is possible to temporally separate the curvature variable time point and the sensing time point to prevent a sensing error and signal distortion caused by the curvature variable time point.

In addition, the sensing operation may be performed at at least one point in time among power on, off, and driving of the variable curvature display device 100 .

As the compensation operation according to the sensing operation is performed when the power of the variable curvature display device 100 is turned on, the driving switch DR and the organic light emitting diode (OLED) changed according to the passage of time and external factors in the power-off state. Since an image can be displayed using compensation data reflecting the characteristics of OLED), image quality can be improved when the initial screen of the display device 100 is driven. In addition, as the compensation operation according to the sensing operation is performed when the variable curvature display device 100 is driven, the driving switch DR and the organic light emitting diode OLED are changed according to internal and external factors such as deterioration at the time of driving. Since an image can be displayed using the compensation data reflecting the characteristics, a high-quality image can be maintained when the display device 100 is driven. In addition, as the sensing operation is performed when the power of the variable curvature display device 100 is turned off, the data sensed at the time of power off when the power is turned on can be directly used to generate compensation data. It is possible to quickly compensate the characteristics of the display panel 100 .

In addition, the timing controller 124 outputs a sensing stop signal to the compensation circuit 130 when receiving the compensation progress disabling signal, and sets the timing between the output of the sensing start signal and before the output of the sensing stop signal. The first sensing signal input during the period may be stored. In addition, the timing controller 124 outputs a sensing resume signal to the compensation circuit 130 when receiving the compensation progress enable signal, and outputs the stored first sensing signal and the sensing resume signal after outputting the second inputted signal. 2 Compensation data may be generated based on the sensing signal.

In addition, the motor assembly 240 adjusts the curvature of the display panel 100 during a time period after the output of the compensation progress prohibition signal from the motor control unit 220 and before the output of the compensation progress enable signal, so that the display panel It is possible to prevent an error in a sensing signal due to tension and stress at an electrical connection portion between the display panel 100 and the compensation circuit 130 due to the bending of 100 .

In addition, the embodiment may further include an attractive force unit 250 fixed to a specific region at the rear of the display panel 100 to apply an attractive force to the specific region, and the motor assembly 240 may include the attractive force unit 250 . At least two or more motor assemblies 240 may be provided at the rear of the display panel 100 and independently control the amount of rotation of a motor included in each motor assembly The curvature of the display panel 100 may be adjusted.

According to the embodiment, when the characteristic sensing of the driving switch and the organic light emitting diode and the adjustment of the curvature of the display device are simultaneously performed, the characteristic compensation is accurately performed by solving the problem that an error occurs during characteristic sensing due to the tension action of the driving circuit. The quality of the image can be improved accordingly.

In the detailed description of the present invention described above, although it has been described with reference to preferred embodiments of the present invention, those skilled in the art or those having ordinary knowledge in the art will It will be understood that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention. Accordingly, the technical scope of the present invention should not be limited to the content described in the detailed description of the specification, but should be defined by the claims.

100 display device, curved display device, curved display device, organic light emitting diode display device
116 display panel
122 pixels
118 gate driving circuit
120 data driving circuit
123 system board
124 timing controller
125 External Control Means
130 compensation circuit
131 sensing circuit
132 analog-to-digital converter
133 Reference voltage generator
134 memory
135 control
200, 300, 400 Curvature Adjuster
220 motor control
240, 340, 440 motor assembly
320 rear back cover
350, 450 wire
460 reinforcement bar
360, 470 fixed part

Claims (11)

a display panel including a driving switch for controlling a current on the organic light emitting diode;
a curvature adjusting device formed under the display panel to control a curvature of the display panel and including at least one motor assembly;
a compensation circuit configured to sense at least one of a threshold voltage and mobility of the driving switch and output a sensing signal;
a timing controller controlling a sensing operation of the compensation circuit and generating compensation data based on the sensing signal;
In response to the curvature control signal from the outside, a motor included in the motor assembly generates a motor rotation control signal for adjusting the curvature of the panel, and provides it to the corresponding motor to control the rotation of the motor and provide a compensation control signal to the timing controller a motor control unit to output;
The timing controller is configured to control a sensing operation of the compensation circuit in response to the compensation control signal. According to claim 1,
The compensation control signal includes a compensation progress permission signal and a compensation progress disallow signal,
The timing controller outputs any one of a sensing stop signal, a sensing start signal, and a sensing restart signal to the compensation circuit based on the compensation control signal. According to claim 1,
The sensing operation is a curvature variable organic light emitting diode display device that is performed at at least one point in time among power on, off, and driving of the variable curvature organic light emitting diode display device. 3. The method of claim 2,
The timing controller is
Curvature for outputting a sensing stop signal to the compensation circuit when receiving the compensation progress disallow signal, and storing the input first sensing signal for a time period between after the output of the sensing start signal and before the output of the sensing stop signal Variable organic light emitting diode display. 5. The method of claim 4,
The timing controller is
Curvature for generating compensation data based on the stored first sensing signal and the second sensing signal input after the output of the stored first sensing signal and the sensing resume signal when the compensation progress enable signal is received Variable organic light emitting diode display. 3. The method of claim 2,
The motor assembly is
A curvature variable organic light emitting diode display device for adjusting the curvature of the display panel during a time period after the output of the compensation proceeding disallow signal from the motor control unit and before the output of the compensation proceeding permit signal. According to claim 1,
It further comprises;
The motor assembly is a curvature variable organic light emitting diode display for applying or releasing an attractive force to the attractive part. According to claim 1,
At least two motor assemblies are provided at the rear of the display panel, and the curvature variable organic light emitting diode display is configured to adjust the curvature of the display panel by independently adjusting a rotation amount of a motor included in each motor assembly. 3. The method of claim 2,
The timing controller receiving the compensation progress disallow signal,
A curvature variable organic light emitting diode display device for outputting a sensing start signal to the compensation circuit after receiving the compensation progress enable signal. According to claim 1,
The display panel is
a scan switch for applying a sensing voltage on a data line or the compensation data to a first node in response to a scan pulse;
a sensing switch for applying a reference voltage on a sensing line to a second node in response to a sensing control signal; and
A storage capacitor connected between the first and second nodes; further comprising,
and the driving switch controls a current of the organic light emitting diode connected to the second node by a voltage between the first and second nodes. 11. The method of claim 10,
During the initialization period, the scan switch and the sensing switch are turned on, the sensing voltage from the data line is charged to the first node through the scan switch, and the reference voltage from the sensing line is transmitted through the sensing switch is charged to the second node,
During the source-follower driving period, the sensing line is floated, the scan switch and the sensing switch are kept turned on, and the second node is charged by the current flowing through the driving switch to increase the voltage of the second node,
A curvature variable organic light emitting diode display device for detecting a voltage on the second node through the sensing line during a threshold voltage detection period.

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