KR102399309B1 - Driving method, controller, driving circuit, display panel, and display device - Google Patents

Abstract

The present embodiments relate to a driving method, a controller, a driving circuit, a display panel, and a display device, even if the characteristics of transistors in each sub-pixel change in a direction that cannot be compensated or compensated properly (eg, a negative direction) , to a driving method, a controller, a driving circuit, a display panel, and a display device that enable normal characteristic compensation. According to the present exemplary embodiments, it is possible to increase the compensation performance of the transistor, thereby improving the image quality.

Description

Driving method, controller, driving circuit, display panel and display device {DRIVING METHOD, CONTROLLER, DRIVING CIRCUIT, DISPLAY PANEL, AND DISPLAY DEVICE}

The present embodiments relate to a driving method, a controller, a driving circuit, a display panel, and a display device.

As the information society develops, the demand for a display device for displaying an image is increasing in various forms, and in recent years, various display devices such as a liquid crystal display device, a plasma display device, and an organic light emitting display device are utilized.

In a display panel of such a display device, circuit elements such as transistors are arranged for each sub-pixel.

On the other hand, as the driving time of the transistor in each sub-pixel increases, degradation may proceed, and thus its intrinsic characteristics (eg, threshold voltage, mobility, etc.) may change.

Transistors may have different degrees of deterioration due to a difference in driving time, which may result in a characteristic deviation between transistors. This may cause luminance non-uniformity of the display panel, which may result in deterioration of image quality.

Accordingly, a technology has been developed for sensing the characteristics of the transistors in each sub-pixel and compensating for the characteristic deviation between the transistors.

However, when the characteristics of the transistors in each sub-pixel change in a direction in which compensation is impossible or compensation cannot be performed properly, there may be a problem in that characteristic compensation is not normally performed.

Against this background, the present embodiments provide a driving method, a controller, a driving circuit, a display panel and display is provided.

In addition, in the present embodiments, when white driving is performed by combining only subpixels of three colors among subpixels of four colors, the characteristics of transistors in the subpixels that are not driven during white driving cannot be compensated or compensation is not possible properly. Disclosed are a driving method, a controller, a driving circuit, a display panel and a display device capable of preventing in advance a phenomenon that cannot be changed in an impossible direction.

In addition, the present exemplary embodiments provide a driving method, a controller, a driving circuit, a display panel, and a display device capable of expanding the range of compensating characteristics of a transistor.

According to the present exemplary embodiments, a display panel in which a plurality of data lines and a plurality of gate lines are disposed and a plurality of subpixels are arranged, a data driving circuit driving the plurality of data lines, and a gate driving the plurality of gate lines It is possible to provide a display device including a driving circuit, and a controller for controlling the data driving circuit and the gate driving circuit.

In such a display device, the plurality of subpixels may include a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel.

The display device includes a first white driving method for emitting light of three subpixels among a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel during white driving during a first period can be driven by

During a second period after the first period, the display device is driven in a second white driving method in which the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel emit light during white driving. can do.

According to the first white driving method, a current-voltage transfer characteristic or a threshold voltage of a transistor in one subpixel that does not emit light during white driving may shift from an initial state to a negative direction during the first period.

A current-voltage transfer characteristic or a threshold voltage of a transistor in one subpixel that does not emit light during the first period and emits light during the second period may shift in a positive direction toward an initial state during the second period.

Each of the plurality of subpixels of the display device includes an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first transistor electrically connected between a first node of the driving transistor and a data line, and a second of the driving transistor It may include a second transistor electrically connected between the node and the sensing line, and a capacitor electrically connected between the first node and the second node of the driving transistor.

In addition, the display device may further include a sensing unit electrically connectable to the sensing line, and a switch electrically connecting the sensing line and the sensing unit.

During the sensing period in which the characteristics of the driving transistor or the threshold voltage are sensed, the sensing line may have a voltage increase from the reference voltage. By checking this phenomenon, the presence or absence of a sensing operation can be checked.

Looking at the outer region of the display panel for easy identification, the sensing line may be disposed adjacent to the data line.

The controller of the display device is configured to control a sub-pixel or region including a driving transistor that is not driven according to the first white driving method and whose characteristic or threshold voltage is shifted in a negative direction based on sensed data on the characteristics or threshold voltage of the driving transistor. can be detected.

The controller of the display device may change from the first white driving method to the second white driving method based on sensing data for the characteristics of the driving transistor or the threshold voltage.

According to the present exemplary embodiments, a display panel in which a plurality of data lines and a plurality of gate lines are disposed and a plurality of subpixels are arranged, a data driving circuit driving the plurality of data lines, and a gate driving the plurality of gate lines A method of driving a display device including a driving circuit and a controller for controlling the data driving circuit and the gate driving circuit may be provided.

The driving method includes: white driving in a first white driving method in which three subpixels among a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel emit light; changing the driving method from the first white driving method to the second white driving method; and second white driving for emitting light of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel It may include the step of driving white in this way.

In the present embodiments, a first color subpixel emitting light of a first color, a second color subpixel emitting light of a second color, a third color subpixel emitting light of a third color, and a fourth color subpixel It is possible to provide a display panel including a fourth color sub-pixel that emits light.

In such a display panel, three of the first color sub-pixel, the second color sub-pixel, the third color sub-pixel, and the fourth color sub-pixel may emit light during the first period when the white driving is performed.

In such a display panel, during a second period after the first period, the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel may emit light when the white driving is performed.

The present embodiments include a digital-to-analog conversion circuit for converting image data into a data voltage, and an output circuit for outputting a data voltage to each of the first data line, the second data line, the third data line, and the fourth data line. It is possible to provide a driving circuit comprising the.

In this driving circuit, the first data line is electrically connected to the first color subpixel, the second data line is electrically connected to the second color subpixel, and the third data line is electrically connected to the third color subpixel. connected, and the fourth data line may be electrically connected to the fourth color subpixel.

The output circuit of the driving circuit may output a corresponding data voltage to each of three data lines among the first data line, the second data line, the third data line, and the fourth data line during the first period during the white driving. can

The output circuit of the driving circuit may output a corresponding data voltage to each of the first data line, the second data line, the third data line, and the fourth data line during the second period after the first period during the white driving.

The present embodiments may provide a controller including a white driving controller for controlling the white driving method and a data output unit for supplying image data according to the white driving method.

The white driving control unit of the controller is configured to emit light of three subpixels of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel during the white driving period during the first period. 1 The white driving method can be controlled by the white driving method.

The white driving control unit of the controller is configured to emit light of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel during white driving for a second period after the first period. The method can be controlled as a white driving method.

According to the present embodiments, even if the characteristics of the transistors in each sub-pixel change in a direction that cannot be compensated or compensated properly, characteristic compensation can be normally performed, and thereby, a driving method capable of improving image quality , a controller, a driving circuit, a display panel, and a display device may be provided.

In addition, according to the present embodiments, when white driving is performed by combining subpixels of three colors among subpixels of four colors, the characteristics of transistors in the subpixels that are not driven during white driving cannot be compensated or compensation is not possible. It is possible to provide a driving method, a controller, a driving circuit, a display panel, and a display device that can prevent a change in a direction that cannot be done properly in advance and can improve image quality through this.

Further, according to the present exemplary embodiments, it is possible to provide a driving method, a controller, a driving circuit, a display panel, and a display device capable of expanding the range of compensating characteristics of a transistor and improving image quality.

1 is a system configuration diagram of a display device according to the present exemplary embodiment.
2 is a circuit diagram of a sub-pixel of a display device according to the present exemplary embodiment.
3 is a diagram illustrating a display panel according to the present exemplary embodiment and four sub-pixels arranged thereon.
4 is an example of four sub-pixels arranged in a display panel according to the present exemplary embodiment.
5 to 7 are examples of the first white driving method of the display device according to the present exemplary embodiment.
8 is a view for explaining a change in characteristics of a transistor according to the first white driving method of the display device according to the present exemplary embodiment.
9 is a diagram illustrating white driving control of the display device according to the present exemplary embodiment.
10 is a diagram illustrating a change in characteristics of a transistor according to a white driving control of a display device according to the present exemplary embodiment.
11 is a diagram illustrating color coordinate maintenance characteristics according to white driving control of the display device according to the present exemplary embodiment.
12 is a diagram for explaining a method of detecting a negative shift region using sensing data for white driving control of a display device according to the present exemplary embodiments.
13 is a diagram illustrating a sensing and compensation circuit of a display device according to example embodiments.
14 is a diagram for explaining a threshold voltage sensing principle of a display device according to the present exemplary embodiment.
15 is a timing diagram for threshold voltage sensing driving of the display device according to the present exemplary embodiment.
16 is a diagram illustrating an off-sensing timing of a display device according to example embodiments.
17 is a diagram illustrating a transistor compensation region of a display device according to example embodiments.
18 is a flowchart illustrating a method of driving a display device according to the present exemplary embodiment.
19 is a diagram schematically illustrating a data driving circuit according to the present embodiments.
20 is a diagram schematically illustrating a controller according to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It should be understood that each component may be “interposed” or “connected”, “coupled” or “connected” through another component.

1 is a system configuration diagram of a display device 100 according to the present exemplary embodiment.

Referring to FIG. 1 , in the display device 100 according to the present exemplary embodiments, a plurality of data lines DL and a plurality of gate lines GL are disposed, and a plurality of data lines DL and a plurality of The display panel 110 in which a plurality of sub-pixels SP defined by the gate lines GL of It includes a gate driving circuit 130 for driving the gate lines GL, and a controller 140 for controlling the data driving circuit 120 and the gate driving circuit 130 .

The controller 140 supplies various control signals DCS and GCS to the data driving circuit 120 and the gate driving circuit 130 to control the data driving circuit 120 and the gate driving circuit 130 .

The controller 140 starts scanning according to the timing implemented in each frame, and converts the input image data input from the outside according to the data signal format used by the data driving circuit 120 to output the converted image data. and control the data operation at an appropriate time according to the scan.

The controller 140 may be a timing controller used in a typical display technology or a control device that further performs other control functions including a timing controller.

The controller 140 may be implemented as a component separate from the data driving circuit 120 , or may be implemented as an integrated circuit together with the data driving circuit 120 .

The data driving circuit 120 drives the plurality of data lines DL by supplying a data voltage to the plurality of data lines DL. Here, the data driving circuit 120 is also referred to as a source driving circuit.

The data driving circuit 120 may be implemented by including at least one source driver integrated circuit (SDIC).

Each source driver integrated circuit SDIC may include a shift register, a latch circuit, a digital to analog converter (DAC), an output buffer, and the like.

Each source driver integrated circuit SDIC may further include an analog-to-digital converter (ADC) in some cases.

The gate driving circuit 130 sequentially drives the plurality of gate lines GL by sequentially supplying a scan signal to the plurality of gate lines GL. Here, the gate driving circuit 130 is also referred to as a scan driving circuit.

The gate driving circuit 130 may be implemented by including at least one gate driver integrated circuit (GDIC).

Each gate driving circuit integrated circuit GDIC may include a shift register, a level shifter, and the like.

The gate driving circuit 130 sequentially supplies a scan signal of an on voltage or an off voltage to the plurality of gate lines GL under the control of the controller 140 .

When a specific gate line is opened by the gate driving circuit 130 , the data driving circuit 120 converts the image data DATA received from the controller 140 into an analog data voltage to generate a plurality of data lines DL. ) is supplied.

As shown in FIG. 1 , the data driving circuit 120 may be located only on one side (eg, upper or lower side) of the display panel 110 , and in some cases, the display panel ( 110) may be located on both sides (eg, upper and lower).

The gate driving circuit 130 may be located only on one side (eg, left or right) of the display panel 110 as shown in FIG. 1 , and in some cases, the display panel according to a driving method, a panel design method, etc. It may be located on both sides of 110 (eg, left and right).

The display device 100 according to the present embodiments may be an organic light emitting display device, a liquid crystal display device, a plasma display device, or the like.

When the display device 100 according to the present exemplary embodiment is an organic light emitting display device, each sub-pixel SP arranged on the display panel 110 includes an organic light emitting diode (OLED) which is a self-light emitting device and an organic light emitting diode (OLED). , and a circuit element such as a driving transistor for driving an organic light emitting diode (OLED).

The type and number of circuit elements constituting each sub-pixel SP may be variously determined according to a provided function and a design method.

2 is a circuit diagram of a sub-pixel SP of the display device 100 according to the present exemplary embodiment.

Referring to FIG. 2 , in the display device 100 according to the present exemplary embodiments, each sub-pixel SP includes an organic light emitting diode (OLED), a driving transistor (DRT) for driving the organic light emitting diode (OLED), and , the first transistor T1 electrically connected between the first node N1 of the driving transistor DRT and the data line DL, the second node N2 of the driving transistor DRT and the sensing line SL It may be implemented by including a second transistor T2 electrically connected therebetween, and a capacitor Cst electrically connected between the first node N1 and the second node N2 of the driving transistor DRT.

The organic light emitting diode (OLED) may include a first electrode (eg, an anode electrode or a cathode electrode), an organic light emitting layer, and a second electrode (eg, a cathode electrode or an anode electrode).

The first electrode of the organic light emitting diode OLED may be electrically connected to the second node N2 of the driving transistor DRT. A ground voltage EVSS may be applied to the second electrode of the organic light emitting diode OLED.

The driving transistor DRT drives the organic light emitting diode (OLED) by supplying a driving current to the organic light emitting diode (OLED).

The driving transistor DRT has a first node N1 , a second node N2 , and a third node N3 .

The first node N1 of the driving transistor DRT is a node corresponding to a gate node and may be electrically connected to a source node or a drain node of the first transistor T1 .

The second node N2 of the driving transistor DRT may be electrically connected to the first electrode of the organic light emitting diode OLED, and may be a source node or a drain node.

The third node N3 of the driving transistor DRT is a node to which the driving voltage EVDD is applied, and may be electrically connected to a driving voltage line (DVL) that supplies the driving voltage EVDD, and has a drain. It can be a node or a source node.

The first transistor T1 may receive the first scan signal SCAN1 as a gate node through the gate line to be controlled on/off.

The first transistor T1 is turned on by the first scan signal SCAN1 to transfer the data voltage Vdata supplied from the data line DL to the first node N1 of the driving transistor DRT. can

The second transistor T2 is electrically connected between the second node N2 of the driving transistor DRT and the sensing line SL, and receives the second scan signal SCAN2 to the gate node to control ON/OFF. can be

The second transistor T2 is turned on by the second scan signal SCAN2 to transfer the reference voltage Vref supplied to the sensing line SL to the second node N2 of the driving transistor DRT. can

Also, the second transistor T2 may be turned on by the second scan signal SCAN2 to transfer the voltage of the second node N2 of the driving transistor DRT to the sensing line SL.

In other words, the second transistor T2 controls the voltage state of the second node N2 of the driving transistor DRT or senses the voltage of the second node N2 of the driving transistor DRT through the sensing line SL. can be forwarded to

The capacitor Cst is electrically connected between the first node N1 and the second node N2 of the driving transistor DRT, and receives the data voltage Vdata corresponding to the image signal voltage or a voltage corresponding thereto in one frame. You can keep it for a while.

Such a capacitor Cst is not a parasitic capacitor (eg, Cgs, Cgd) which is an internal capacitor existing between the first node N1 and the second node N2 of the driving transistor DRT, but a driving It is an external capacitor intentionally designed outside the transistor (DRT).

Each of the driving transistor DRT, the first transistor T1 , and the second transistor T2 may be an n-type transistor or a p-type transistor.

Meanwhile, the first scan signal SCAN1 and the second scan signal SCAN2 may be separate gate signals. In this case, the first scan signal SCAN1 and the second scan signal SCAN2 may be respectively applied to the gate node of the first transistor T1 and the gate node of the second transistor T2 through different gate lines. there is.

In some cases, the first scan signal SCAN1 and the second scan signal SCAN2 may be the same gate signal. In this case, the first scan signal SCAN1 and the second scan signal SCAN2 may be commonly applied to the gate node of the first transistor T1 and the gate node of the second transistor T2 through the same gate line. .

Each subpixel structure illustrated in FIG. 2 includes three transistors DRT, T1, and T2 and one capacitor Cst, but this is only an example for description and may further include one or more transistors, or In some cases, it may further include one or more capacitors.

Alternatively, each subpixel structure may include only two transistors DRT and T1 and one capacitor Cst without the second transistor T2.

Alternatively, each of the plurality of subpixels may have the same structure, and some of the plurality of subpixels may have a different structure.

3 is a view showing the display panel 110 according to the present embodiments and four sub-pixels SP1, SP2, SP3, and SP4 arranged thereon, and FIG. 4 is the display panel 110 according to the present embodiments. ) is an example of the four sub-pixels SP1, SP2, SP3, and SP4.

The four subpixels SP1, SP2, SP3, and SP4 include a first color subpixel SP1 emitting light of a first color, a second color subpixel SP2 emitting light of a second color, and a third The third color subpixel SP3 emitting the light of the color and the fourth color subpixel SP4 emitting the light of the fourth color.

The first color, the second color, the third color, and the fourth color may be different colors.

For example, as shown in FIG. 4 , the first color may be red, the second color may be green, the third color may be blue, and the fourth color may be white.

That is, the first color subpixel SP1 is a red subpixel R, the second color subpixel SP2 is a green subpixel G, and the third color subpixel SP3 is a blue subpixel B ), and the fourth color subpixel SP4 may be a white subpixel W.

In FIG. 4 , the red subpixel R, the white subpixel W, the green subpixel G, and the blue subpixel B are arranged in the order, but this is only an example and may be arranged in various orders. .

For example, it may be arranged in the order of a red subpixel (R), a green subpixel (G), a white subpixel (W), and a blue subpixel (B), and a red subpixel (R), a green subpixel ( G), the blue sub-pixel (B), and the white sub-pixel (W) may be arranged in the order.

In addition, the sub-pixels R, G, B, and W of the four colors may be regularly arranged in a horizontal direction such that one row (horizontal row)*4 columns (vertical column) becomes one pattern. The sub-pixels R, G, B, and W of the four colors may be regularly arranged in the vertical direction such that 4 rows (horizontal row)*1 column (vertical column) form one pattern. The sub-pixels R, G, B, and W of the four colors may be regularly arranged in a tile form such that 2 rows (horizontal rows)*2 columns (vertical columns) form one pattern. In addition to this, the sub-pixels R, G, B, and W of the four colors may be arranged in various patterns.

5 to 7 are examples of the first white driving method of the display device 100 according to the present exemplary embodiment.

In the display device 100 according to the present exemplary embodiments, when driving white (ie, displaying white), the display device 100 is selected from among the first color subpixel SP1 , the second color subpixel SP2 , and the third color subpixel SP3 . A fourth color subpixel SP4 corresponding to the subpixels of two colors and the white subpixel W may be driven.

As described above, the white driving method in which the subpixels of two colors and the white subpixel W emit light is referred to as a “first white driving method”.

In the case of the first white driving method, the sub-pixel of one color among the sub-pixels R, G, and B of the three colors is not driven and thus does not emit light.

5 to 7 , when white driving is performed in the first white driving method, the subpixel of one color that does not emit light among the subpixels R, G, and B of the three colors is a red subpixel. The first color subpixel SP1 corresponding to the pixel R, the second color subpixel SP2 corresponding to the green subpixel G, or the third color subpixel corresponding to the blue subpixel B (SP3).

Hereinafter, for convenience of explanation, when white driving is performed in the first white driving method, the subpixel of one color that does not emit light among the subpixels R, G, and B of three colors is a green subpixel ( It is assumed that it is the second color subpixel SP2 corresponding to G).

8 is a diagram for explaining a change in characteristics of a transistor in the non-emission subpixel G according to the first white driving method of the display device 100 according to the present exemplary embodiment.

In the transistor in the subpixel, a phenomenon in which a characteristic (characteristic value) or a threshold voltage of the transistor is negatively shifted or positively shifted according to a bias occurs. Here, for example, the transistor in the sub-pixel may be an oxide thin film transistor (TFT).

In addition, the transistor in the sub-pixel is subjected to electrical stress by light, and a phenomenon in which a characteristic or a threshold voltage of the transistor in the sub-pixel is negatively shifted may occur.

For example, when driving white according to the first white driving method, the characteristic or threshold voltage of the driving transistor DRT in the non-emitting green sub-pixel G is the white sub-pixel positioned around the green sub-pixel G. A negative shift phenomenon may occur due to the light emitted from the pixel W and the blue sub-pixel B.

When white driving (driving expressing white) according to the first white driving method is continued, the characteristics or threshold voltage of the driving transistor DRT in the green sub-pixel G that do not emit light during white driving is negatively shifted. Shift) can be even greater.

Referring to the current (I)-voltage (V) transfer graph of the driving transistor DRT in the non-emitting green sub-pixel G in FIG. 8 , the driving transistor DRT in the non-emitting green sub-pixel G is It can be seen that the current-voltage transfer characteristic or the threshold voltage is changed from the initial state t0 to the negative shift state t1 shifted in the negative direction.

Due to this negative shift phenomenon, the driving transistor DRT in the green sub-pixel G, which does not emit light when driving in white, is compared to the driving transistor DRT in the sub-pixels R, W, and B, which is driven when driving in white. , a larger current can flow at the same voltage.

Therefore, a luminance deviation may occur between the green sub-pixel G, which is not driven (non-emission) when driving in white, and the sub-pixels R, W, and B, which are driven (light-emitting) when driving in white, resulting in deterioration of image quality. there is.

In addition, due to the negative shift phenomenon, the compensating ability of the corresponding driving transistor DRT may be reduced or compensation may be impossible within a predetermined range. Accordingly, the luminance deviation between the sub-pixels cannot be reduced, which may lead to deterioration of image quality.

Accordingly, the present exemplary embodiments may provide white driving control capable of preventing a negative shift in the characteristic or threshold voltage of the driving transistor DRT in the green sub-pixel G that does not emit light during white driving.

Hereinafter, white driving control according to the present embodiments will be described in detail. However, hereinafter, it will be described as an example that the subpixel that does not emit light during white driving according to the first white driving method is the second color subpixel SP2 corresponding to the green subpixel G.

In this specification, the characteristics of the driving transistor DRT may refer to a current-voltage transfer characteristic, a threshold voltage, etc. of the driving transistor DRT, and in some cases, may refer to the mobility of the driving transistor DRT. there is.

9 is a diagram illustrating white driving control of the display device 100 according to the present exemplary embodiments.

Referring to FIG. 9 , the plurality of sub-pixels arranged on the display panel 110 include a first color sub-pixel SP1 , a second color sub-pixel SP2 , a third color sub-pixel SP3 , and a fourth color sub-pixel SP1 . pixel SP4.

That is, the display panel 110 includes a first color subpixel SP1 that emits light of a first color, a second color subpixel SP2 that emits light of a second color, and a third color subpixel SP2 that emits light of a third color. It includes a third color subpixel SP3 and a fourth color subpixel SP4 emitting light of a fourth color.

In the display device 100 according to the present exemplary embodiments, during the first period, when driving white (driving for white expression), the first color subpixel SP1 , the second color subpixel SP2 , and the third color Driven in the "first white driving method" in which one subpixel (eg, SP1, SP2, or SP3) of the subpixel SP3 and the fourth color subpixel SP4 does not emit light and three subpixels emit light can do.

In the display device 100 according to the present exemplary embodiments, the first color subpixel SP1 and the second color subpixel SP2 during white driving (driving for white expression) during the second period after the first period , the third color subpixel SP3 and the fourth color subpixel SP4 may be driven in a “second white driving method” to emit light.

In the display panel 110 according to the present exemplary embodiments, during the first period, when white is driven (driving for white expression), the first color subpixel SP1 , the second color subpixel SP2 , and the third color One of the sub-pixels SP3 and the fourth color sub-pixel SP4 (eg, SP1, SP2, or SP3) may not emit light and three sub-pixels may emit light.

In the display panel 110 according to the present exemplary embodiments, during the second period after the first period, the first color sub-pixel SP1 and the second color sub-pixel SP2 when white is driven (driving for white expression) , the third color subpixel SP3 and the fourth color subpixel SP4 may both emit light.

According to the above-described white driving control, since the subpixel that did not emit light during white driving during the first period emits light during white driving in the second period after the first period, the driving transistor in the subpixel that did not emit light during the first period (DRT) characteristics or threshold voltage can be normalized by shifting it back to the positive direction. Accordingly, it is possible to effectively compensate for the characteristic of the driving transistor DRT or a positive shift of the threshold voltage, and it can also help to improve image quality.

The subpixels SP1 , SP2 , SP3 , and SP4 of the four colors mentioned above may be as illustrated in FIG. 4 .

That is, the first color subpixel SP1 is a red subpixel R, the second color subpixel SP2 is a green subpixel G, and the third color subpixel SP3 is a blue subpixel B ), and the fourth color subpixel SP4 may be a white subpixel W.

During the first period, when white driving (driving for white expression) is performed according to the first white driving method, as shown in the example of FIG. 5 , red among the subpixels SP1 , SP2 , SP3 , and SP4 of 4 colors The sub-pixel R may be a sub-pixel that does not emit light.

During the first period, when white driving (driving for white expression) is performed according to the first white driving method, as shown in the example of FIG. 6 , green among the subpixels SP1, SP2, SP3, and SP4 of four colors The sub-pixel G may be a sub-pixel that does not emit light.

During the first period, when white driving (driving for white expression) is performed according to the first white driving method, as illustrated in FIG. 7 , blue among the subpixels SP1 , SP2 , SP3 , and SP4 of four colors The sub-pixel B may be a sub-pixel that does not emit light.

As described above, white can be expressed by variously combining sub-pixels of three colors among the sub-pixels R, W, G, and B of the four colors to match the light emitting performance and characteristics of the sub-pixels of each color. .

Meanwhile, the display panel 110 may have a different white driving time for each area.

Accordingly, some areas of the display panel 110 are changed from the first white driving method to be white driven in the second white driving method, and the remaining areas except for some areas in the display panel 110 are to be driven white in the first white driving method. can

In other words, when viewed from a certain point of view, when the display panel 110 is driven in white, the first color subpixel SP1, the second color subpixel SP2, Both the third color subpixel SP3 and the fourth color subpixel SP4 emit light. However, in the remaining area of the display panel 110 , when driving white, the first color subpixel SP1 , the second color subpixel SP2 , and the third color subpixel SP3 according to the first white driving method and only three of the fourth color subpixels SP4 may emit light.

More specifically, in a portion of the display panel 110 , all sub-pixels R, W, G, and B of four colors emit light when driving in white, and in the remaining regions, sub-pixels R of four colors when driving in white. , W, G, B) of one color sub-pixel (eg, R, G, or B) does not emit light, and only sub-pixels of the other three colors may emit light.

As described above, even if the white driving time for each region is different in the display panel 110 , it is possible to provide adaptive white driving control for each region.

However, when viewed from a certain point of view, all regions of the display panel 110 may be driven white by the first white driving method or the second white driving method.

That is, in all areas of the display panel 110 , all sub-pixels R, W, G, and B of four colors emit light or sub-pixels R, W, G, and B of four colors when driving in white. ), subpixels of one color (eg, R, G, or B) do not emit light, and only subpixels of the other three colors can emit light.

Meanwhile, when the green sub-pixel G does not emit light (not driven) during the first period in which the white driving is performed according to the first white driving method, the non-emission time may be different for each green sub-pixel G.

Accordingly, the start time of the second period may be different for each green subpixel G.

For example, the green subpixel G having a longer non-emission time starts the second period earlier than other green subpixels G. That is, the green sub-pixel G having a longer non-emission time may emit light earlier than other green sub-pixels G during white driving.

Meanwhile, during the second period in which the white driving is performed according to the second white driving method, the green subpixel G, which did not emit light during the previous first period, emits light. The shifted characteristic or threshold voltage of the driving transistor DRT is normally changed.

When the characteristics or the threshold voltage of the driving transistor DRT are completely normalized, the green sub-pixel G may not emit light because the second white driving scheme is changed to the first white driving scheme.

That is, during white driving, the first white driving scheme may be changed to the second white driving scheme, and then the first white driving scheme may be changed again.

10 is a diagram illustrating a change in characteristics of a transistor or a threshold voltage according to a white driving control of the display device 100 according to the present exemplary embodiment.

Current-voltage transfer characteristics or threshold voltages of transistors in one subpixel that do not emit light during white driving according to the first white driving method are in a negative shift state t1 shifted from the initial state t0 to a negative direction during the first period ) is changed to

One sub-pixel that did not emit light during the first period emits light during white driving during the second period after the white driving method is changed.

Accordingly, the current-voltage transfer characteristic or threshold voltage of the transistor in one subpixel that did not emit light during the first period shifts in a positive direction from the negative shift state t1 to the initial state t0 during the second period, Ultimately, it may be restored to the initial state t0.

As described above, it is possible to normalize the characteristic or threshold voltage of the driving transistor DRT in the sub-pixel that is in the negative shift state while not emitting light during the first period by shifting it back to the positive direction. Accordingly, it is possible to effectively compensate for the characteristic of the driving transistor DRT or the positive shift of the threshold voltage.

11 is a diagram illustrating color coordinate maintenance characteristics according to white driving control of the display device 100 according to the present exemplary embodiments.

According to the above-described white driving control, a subpixel that did not emit light when driving white during the first period emits light when driving white during the second period, so that the color coordinates of the corresponding subpixel may change, and in this case, image quality problem occurs can do it

Therefore, as shown in FIG. 11 , it is possible to control white driving while maintaining the same color coordinates (color temperature) when driving in the first white driving scheme and the color coordinates in driving in the second white driving scheme. can

For example, the data change process may be performed so that the color coordinates (color temperature) when the first white driving method is driven and the color coordinates (color temperature) when the second white driving method is driven are the same.

As described above, even when a sub-pixel that did not emit light according to the white driving control emits light, the color coordinate (color temperature) is prevented from changing, thereby preventing image quality deterioration due to the white driving control.

12 is a diagram for explaining a method of detecting a negative shift region using sensing data for white driving control of the display device 100 according to the present exemplary embodiments.

Referring to FIG. 12 , the display device 100 may use sensing data to determine whether the white driving method should be changed from the first white driving method to the second white driving method through white driving control.

The display device 100 acquires sensing data to determine the I-V transfer characteristic (or threshold voltage Vth or threshold voltage variation ΔVth) of the driving transistor (DRT) in each sub-pixel through N-th sensing (eg, Vth sensing) do.

Then, after a predetermined time (eg, after generation of the next power-off signal or after a predetermined cumulative driving time (hour) has elapsed), the display device 100 displays each sub-pixel through the N+1th sensing (eg, Vth sensing). Sensing data for understanding the I-V transfer characteristic (or threshold voltage Vth or threshold voltage variation ΔVth) of the internal driving transistor DRT is acquired.

The display device 100 compares the sensed data acquired through the N-th sensing with the sensed data acquired through the N+1-th sensing, and compares the I-V transfer characteristics (or threshold voltage Vth) of the driving transistor DRT in each sub-pixel. Alternatively, a state change (t0→t1) of the threshold voltage change amount ΔVth is calculated, and there is a subpixel in which the I-V transfer characteristic (or the threshold voltage Vth or the threshold voltage change amount ΔVth) of the driving transistor DRT is shifted in a negative direction. The regions A1, A2, A3, A4, A5, and A6 to be used are detected. Here, the detected areas A1, A2, A3, A4, A5, A6 are called negative shift areas.

In other words, the display device 100 is not driven according to the first white driving method ( A sub-pixel that is a sub-pixel (not emitting light) and includes a driving transistor DRT whose characteristic or threshold voltage is shifted in a negative direction is detected. The thus-detected undriven sub-pixels (un-emitted sub-pixels) are sub-pixels located in the detected negative shift regions A1 , A2 , A3 , A4 , A5 , and A6 .

As described above, the display device 100 changes the white driving scheme from the first white driving scheme to the second white driving scheme for the detected negative shift regions A1, A2, A3, A4, A5, and A6, so that white carry out the drive

The display device 100 performs white driving by maintaining the white driving scheme as the first white driving scheme for the remaining regions except for the detected negative shift regions A1 , A2 , A3 , A4 , A5 , and A6 . .

That is, the display device 100 may change from the first white driving method to the second white driving method based on the characteristics of the driving transistor DRT or sensing data of the threshold voltage.

Accordingly, the sub-pixels that are not driven (not light-emitted) according to the first white driving method are driven (light-emitted) when the white is driven.

A process of detecting a sub-pixel that is not driven (not emitting light) according to the first white driving method and includes a driving transistor DRT whose characteristic or threshold voltage is shifted in a negative direction (that is, the negative shift region A1 ) , A2, A3, A4, A5, A6) and the white driving control process such as the white driving method change process may be performed by the controller 140 as the center.

As described above, by accurately detecting the negative shift region and performing white driving for the detected negative shift region, the white driving may be performed by changing the first white driving method to the second white driving method.

As described above, in order to accurately detect the negative shift region, the display device 100 includes a suitable subpixel structure and a sensing and compensation circuit including the same. This will be described with reference to FIG. 13 .

13 is a diagram illustrating a sensing and compensation circuit of the display device 100 according to the present exemplary embodiments.

Referring to FIG. 13 , each of the plurality of subpixels includes an organic light emitting diode OLED, a driving transistor DRT for driving the organic light emitting diode OLED, and a first node N1 of the driving transistor DRT. ) and a first transistor T1 electrically connected between the data line DL, and a second transistor T2 electrically connected between the second node N2 of the driving transistor DRT and the sensing line SL; , a capacitor Cst electrically connected between the first node N1 and the second node N2 of the driving transistor DRT, and the like.

In addition, the display device 100 is configured to sense the voltage of the second node N2 of the driving transistor DRT in each sub-pixel, and includes a sensing unit 1310 electrically connectable to the sensing line SL; , a switch (SAM, also referred to as a sampling switch) electrically connecting the sensing line SL and the sensing unit 1310 may be further included.

One sensing line SL may be disposed in one sub-pixel column.

Alternatively, one sensing line SL may be disposed in every two or more subpixel columns.

For example, one sensing line SL may be disposed in every four subpixel columns. In this case, one sensing line SL includes one node (a node opposite to N2 ) of the first transistors disposed in the first subpixel column including the first color subpixel SP1 and the second color subpixel SP1 . A node (opposite to N2) of the first transistors disposed in the second subpixel column including SP2) and one node of the first transistors disposed in the third subpixel column including the third color subpixel SP3 (a node opposite to N2 ) and one node (a node opposite to N2 ) of the first transistors disposed in the fourth subpixel column including the fourth color subpixel SP4 may be commonly connected.

In addition, the display device 100 applies an additional switch at a desired timing to apply the reference voltage Vref for sensing driving (or display driving) to the second node N2 of the driving transistor DRT in each subpixel at a desired timing. (SPRE, initialization switch) may be further included.

The above-described sensing unit 1310 may sense the voltage of the sensing line SL and output sensing data for the sensed voltage.

In addition, the display device 100 may further include a memory 1320 and a compensator 1330 electrically connected to the sensing unit 1310 .

The memory 1320 may store sensing data output from the sensing unit 1310 .

The compensator 1330 may use the sensing data output from the sensing unit 1310 or the sensing data stored in the memory 1320 to detect a change in characteristics or threshold voltage of the driving transistor DRT, and based on this, A compensation value for compensating for a characteristic deviation or a threshold voltage deviation between the transistors DRT may be calculated.

The compensator 1330 may detect a negative shift in the characteristics or threshold voltage of the driving transistor DRT when determining a change in characteristics or threshold voltage of the driving transistor DRT by using the sensing data. That is, the negative shift region can be detected.

The compensation unit 1330 may store the calculated compensation value in the memory 1320 .

The compensator 1330 uses the calculated compensation value or the compensation value stored in the memory 1320 to compensate the characteristic deviation or threshold voltage deviation between the driving transistors DRT, the data DATA to be supplied to the source driver integrated circuit SDIC. ) can be changed.

The source driver integrated circuit (SDIC) receives the changed data (DATA) and converts it into a data voltage (Vdata') in the form of an analog voltage through an internal digital-to-analog converter (DAC: DAC), and the corresponding data line (DL) can be output as Accordingly, compensation will be applied.

The compensator 1330 may be a component included in the controller 140 .

The memory 1320 may be a configuration that exists inside or outside the controller 140 .

The sensing unit 1310 and the two switches SPRE and SAM may exist outside the source driver integrated circuit SDIC, but may be included in the source driver integrated circuit SDIC.

The sensing unit 1310 may be implemented as an analog to digital converter (ADC).

By using the above-described sub-pixel structure and the sensing and compensation circuit including the sub-pixel structure, it is possible to accurately sense and compensate the characteristics of each sub-pixel (eg, characteristics of the driving transistor (DRT)), and a negative shift region for white driving control. can also be accurately detected.

14 is a diagram for explaining a threshold voltage sensing principle of the display device 100 according to the present embodiments, and FIG. 15 is a timing diagram for driving the threshold voltage sensing operation of the display device 100 according to the present embodiments. .

14 and 15 , the threshold voltage sensing driving of the driving transistor DRT may be performed through a sensing process including an initialization step S10 , a tracking step S20 , and a sampling step S30 .

The initialization step S10 is a step of initializing the first node N1 and the second node N2 of the driving transistor DRT.

In the initialization step S10 , for example, the first transistor T1 and the second transistor T2 may be turned on, and the initialization switch SPRE may be turned on.

Accordingly, each of the first node N1 and the second node N2 of the driving transistor DRT is initialized to the threshold voltage sensing driving data voltage Vdata and the reference voltage Vref (V1 = Vdata, V2). =Vref).

In the tracking step S20 , the second node N2 of the driving transistor DRT is performed until the voltage of the second node N2 of the driving transistor DRT reaches the threshold voltage Vth or a voltage state reflecting the change thereof. ) is a step of changing the voltage (V2).

That is, the tracking step ( S20 ) is a step of tracking the threshold voltage or the voltage of the second node N2 of the driving transistor DRT capable of reflecting the change thereof.

In the tracking step S20 , the initialization switch SPRE is turned off or the second transistor T2 is turned off, so that the second node N2 of the driving transistor DRT is floated.

Accordingly, the voltage V2 of the second node N2 of the driving transistor DRT increases.

At this time, when the second transistor T2 is in the turned-on state, the voltage of the sensing line SL also increases.

The voltage V2 of the second node N2 of the driving transistor DRT rises and then gradually decreases to saturation.

Here, the time it takes for the voltage V2 of the second node N2 of the driving transistor DRT to rise and then saturate is determined by the threshold voltage of the driving transistor DRT or a change thereof. ), which determines the sensing time.

The saturated voltage of the second node N2 of the driving transistor DRT is the difference (Vdata-Vth) between the data voltage Vdata and the threshold voltage Vth or the difference between the data voltage Vdata and the threshold voltage deviation ΔVth. (Vdata-ΔVth). Here, the threshold voltage Vth may be a positive threshold voltage or a negative threshold voltage.

When the voltage V2 of the second node N2 of the driving transistor DRT is saturated, the sampling step S30 may proceed.

The sampling step S30 is a step of measuring the threshold voltage Vth of the driving transistor DRT or voltages Vdata-Vth and Vdata-ΔVth reflecting the change, and the sensing unit 1310 sends the sensing line SL ) (which may be the voltage of the second node N2 of the driving transistor DRT) is sensed.

In this sampling step S30 , the sampling switch SAM is turned on, and the sensing unit 1310 is connected to the sensing line SL and the voltage of the sensing line SL (the second of the driving transistor DRT). It may be the voltage of the node N2).

The voltage Vsen sensed by the sensing unit 1310 is a voltage Vdata-Vth obtained by subtracting the threshold voltage Vth from the data voltage Vdata or a voltage obtained by subtracting the threshold voltage deviation ΔVth from the data voltage Vdata ( Vdata-ΔVth). Here, Vth may be a positive threshold voltage or a negative threshold voltage.

According to the threshold voltage sensing driving as described above, the sensing unit 1310 converts the sensed voltage Vsen into a digital value for threshold voltage sensing or mobility sensing, and includes the converted digital value (sensing value) It generates and outputs sensing data.

The sensing data output from the sensing unit 1310 may be provided to the compensating unit 1330 .

The compensator 1330 is configured to change (eg, a threshold voltage or a current-voltage transfer characteristic) of the driving transistor DRT in the corresponding sub-pixel or a characteristic change ( For example, a change in threshold voltage or change in current-voltage transfer characteristics) can be identified and a compensation process can be performed.

Here, the change in the characteristics of the driving transistor DRT may mean that the current sensed data is changed based on the previous sensed data or that the current sensed data is changed based on the reference sensed data.

Here, by comparing the characteristics or characteristics change of the driving transistors DRT, the characteristic deviation between the driving transistors DRT can be grasped, and a phenomenon in which the characteristics of the driving transistors DRT are shifted in a negative direction can also be grasped.

The compensation process may include a threshold voltage compensation process for compensating for a threshold voltage deviation between the driving transistors DRT.

The threshold voltage compensation process calculates a compensation value for compensating for a threshold voltage deviation between the driving transistors (DRT), stores the calculated compensation value in a memory, or changes the image data (Data) with the calculated compensation value. may include

According to the above-described sensing method, during a sensing period in which the characteristic or threshold voltage of the driving transistor DRT is sensed, a voltage increase of the sensing line SL may occur in the reference voltage Vref.

This phenomenon is caused by an increase in the voltage of the second node N2 of the driving transistor DRT.

According to the above-described sensing, characteristics of each subpixel (eg, characteristics of a driving transistor (DRT)) can be accurately sensed and compensated, and a negative shift region for white driving control can be accurately detected.

16 is a diagram illustrating an off-sensing timing of the display device 100 according to the present exemplary embodiments.

The threshold voltage sensing operation may be performed after the power-on signal is generated before the display driving starts in earnest, or may be performed while the display is driving.

Meanwhile, in the case of threshold voltage sensing, the sensing operation may be recognized by the user on the screen by the threshold voltage sensing driving data voltage.

Therefore, as shown in FIG. 16 , in consideration of the time for threshold voltage sensing, the threshold voltage sensing operation is performed after the power-off signal is generated so as not to interfere with the user's viewing, an off-sensing process may proceed with

As described above, as the sensing period proceeds after the generation of the power-off signal, it is possible to prevent the threshold voltage sensing operation from interfering with the user's viewing.

17 is a diagram illustrating a transistor compensation region of the display device 100 according to the present exemplary embodiment.

The voltage region (transistor compensation region) for compensating the characteristics or threshold voltage of a transistor (eg, a driving transistor (DRT)) consists of a positive region for compensating for the positively shifted characteristic and a negative region for compensating for the negatively shifted characteristic. can be done

The positive region corresponds to the Vp voltage range, and the negative region corresponds to the Vn voltage range.

The above-described voltage region may be defined by the performance and specifications of the source driver integrated circuit SDIC.

Meanwhile, the voltage region may be designed to be suitable for sensing and compensating for the positively shifted characteristic. Accordingly, the positive region may be larger than the negative region (ie, Vp>Vn).

Since the negatively shifted characteristic of the driving transistor DRT is shifted in the positive direction according to the above-described white driving control, compensation processing may be performed using the positive region.

That is, when the white driving control according to the present exemplary embodiments is used, the compensation characteristic of the transistor optimized for the positive shift can be well utilized, and thus the compensable range can be expanded by further extending the compensable region to the positive region.

18 is a flowchart illustrating a method of driving the display device 100 according to the present exemplary embodiments.

Referring to FIG. 18 , the driving method of the display device 100 according to the present exemplary embodiments includes a first color subpixel SP1 , a second color subpixel SP2 , a third color subpixel SP3 , and a second color subpixel SP3 . White driving in the first white driving method for emitting light of three of the four color subpixels SP4 ( S1810 ), and changing the white driving method from the first white driving method to the second white driving method ( S1820 ) and driving the first color subpixel SP1, the second color subpixel SP2, the third color subpixel SP3, and the fourth color subpixel SP4 with a second white driving method to emit light. (S1830) and the like.

After step S1830 is performed, the white driving method is changed from the second white driving method to the first white driving method, and thereafter, the first color subpixel SP1 , the second color subpixel SP2 , and the third color subpixel A white driving operation ( S1810 ) may be performed in the first white driving method for emitting light of three of the (SP3) and the fourth color subpixels (SP4).

When the above-described driving method is used, since the subpixel that did not emit light during white driving during the first period emits light during white driving in the second period after the first period, the driving transistor in the subpixel that did not emit light during the first period It can be normalized by shifting the characteristic of (DRT) back to the positive direction. Accordingly, it is possible to effectively compensate for the positive shift in the characteristics of the driving transistor DRT, and to improve image quality.

19 is a diagram schematically illustrating the data driving circuit 120 according to the present exemplary embodiment.

Referring to FIG. 19 , the data driving circuit 120 according to the present exemplary embodiments includes a latch circuit 1910 for storing image data DATA and a digital-to-analog conversion circuit 1920 for converting image data into a data voltage. ) and an output circuit 1930 for outputting the data voltage Vdata to each of the first data line DL, the second data line DL, the third data line DL, and the fourth data line DL. and the like.

The latch circuit 1910 may be implemented by including one or two or more latches for each data line (data channel).

The digital-to-analog converter circuit 1920 may be implemented by including a digital to analog converter (DAC) for each data line (data channel).

The output circuit 1930 may be implemented by including an output buffer for each data line (data channel).

The first data line DL1 is electrically connected to the first color subpixel SP1 , the second data line DL2 is electrically connected to the second color subpixel SP2 , and the third data line DL3 is electrically connected to the second color subpixel SP2 . ) may be electrically connected to the third color subpixel SP3 , and the fourth data line DL4 may be electrically connected to the fourth color subpixel SP4 .

The output circuit 1930 includes three of the first data line DL1 , the second data line DL2 , the third data line DL3 , and the fourth data line DL4 when the white driving is performed during the first period. A corresponding data voltage may be output to each of the data lines of .

For example, the first data line DL1 is electrically connected to the red subpixel R, the second data line DL2 is electrically connected to the green subpixel G, and the third data line DL3 is electrically connected to the green subpixel G. ) is electrically connected to the blue sub-pixel B and the fourth data line DL4 is electrically connected to the white sub-pixel W, the output circuit 1930 is configured to perform white driving during the first period; 3 data lines excluding one data line (eg, DL1 or DL2 or DL3) among the first data line DL1, the second data line DL2, the third data line DL3, and the fourth data line DL4 A corresponding data voltage may be output to each of the data lines of .

During a second period after the first period, the output circuit 1930 may be configured to perform a white driving operation on the first data line DL1 , the second data line DL2 , the third data line DL3 , and the fourth data line DL4 . ) can output the corresponding data voltage for each.

When the above-described data driving circuit 120 is used, the sub-pixel that does not emit light during white driving during the first period emits light during white driving in the second period after the first period, so that the sub-pixel that does not emit light during the first period It is possible to normalize the characteristics of the driving transistor (DRT) in the pixel by shifting it back to the positive direction. Accordingly, it is possible to effectively compensate for the positive shift in the characteristics of the driving transistor DRT, and to improve image quality.

Meanwhile, the data driving circuit 120 according to the present exemplary embodiments may further include a sampling switch SAM, an initialization switch SPRE, and a sensing unit 1310 of FIG. 13 .

20 is a diagram schematically illustrating the controller 140 according to the present embodiments.

Referring to FIG. 20 , the controller 140 according to the present embodiments includes a white driving controller 2010 for controlling a white driving method, a data output unit 2020 for supplying image data according to the white driving method, and the like. may include

The white driving control unit 2010 is configured to control the first color subpixel SP1 , the second color subpixel SP2 , the third color subpixel SP3 , and the fourth color subpixel ( SP3 ) and the fourth color subpixel ( SP1 ) during the white driving period during the first period. The first white driving method for emitting light of three sub-pixels among SP4) may be controlled as the white driving method.

The white driving control unit 2010 is configured to control the first color subpixel SP1 , the second color subpixel SP2 , the third color subpixel SP3 and the fourth color subpixel SP1 , the second color subpixel SP3 , and the fourth color subpixel SP1 , during the white driving for the second period after the first period. The second white driving method in which all of the color subpixels SP4 emit light may be controlled as the white driving method.

When the above-described controller 140 is used, since the subpixel that does not emit light when driving white for the first period emits light during white driving in the second period after the first period, the subpixel that did not emit light during the first period It is possible to normalize the characteristics of the driving transistor DRT by shifting it back to the positive direction. Accordingly, it is possible to effectively compensate for the positive shift in the characteristics of the driving transistor DRT, and to improve image quality.

Meanwhile, the controller 140 according to the present embodiments may further include the compensator 1330 of FIG. 13 .

Also, the controller 140 may be included in the data driving circuit 120 of FIG. 19 .

According to the present embodiments, even if the characteristics of the transistors (eg, DRT) in each sub-pixel change in a direction that cannot be compensated or compensated properly, characteristic compensation can be performed normally, thereby improving image quality. It is possible to provide a driving method, the controller 140 , the data driving circuit 120 , the display panel 110 , and the display device 100 that can be improved.

In addition, according to the present embodiments, when white driving is performed by combining subpixels of three colors among subpixels of four colors, the characteristics of transistors in the subpixels that are not driven during white driving cannot be compensated or compensation is not possible. A driving method, the controller 140 , the data driving circuit 120 , the display panel 110 , and the display device 100 that can prevent a change in a direction that cannot be done properly in advance and can improve image quality through this ) can be provided.

In addition, according to the present embodiments, the driving method, the controller 140 , the data driving circuit 120 , and the display panel 110 can expand the range of compensating characteristics of the transistor and thereby improve the image quality. and a display device 100 may be provided.

The above description and the accompanying drawings are merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains can combine configurations within a range that does not depart from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: display device
110: display panel
120: data driving circuit
130: gate driving circuit
140: controller

Claims (17)

a display panel in which a plurality of data lines and a plurality of gate lines are disposed, and a plurality of sub-pixels are disposed;
a data driving circuit for driving the plurality of data lines;
a gate driving circuit for driving the plurality of gate lines; and
a controller for controlling the data driving circuit and the gate driving circuit;
wherein the plurality of subpixels comprises a first color subpixel, a second color subpixel, a third color subpixel and a fourth color subpixel;
During the first period, when driving white,
driving in a first white driving method for emitting light of three subpixels among the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel;
During the second period after the first period, when driving white,
driving the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel in a second white driving method to emit light;
at some point,
In the partial region of the display panel, all of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel are selected according to the second white driving method during white driving. glow,
The remaining area of the display panel includes three of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel according to the first white driving method when the display panel is driven in white. A light-emitting display device. According to claim 1,
wherein the first color subpixel is a red subpixel, the second color subpixel is a green subpixel, the third color subpixel is a blue subpixel, and the fourth color subpixel is a white subpixel;
During the first period, when a white driving device is performed, the red sub-pixel does not emit light. According to claim 1,
wherein the first color subpixel is a red subpixel, the second color subpixel is a green subpixel, the third color subpixel is a blue subpixel, and the fourth color subpixel is a white subpixel;
During the first period, when a white driving device is performed, the green sub-pixel does not emit light. According to claim 1,
wherein the first color subpixel is a red subpixel, the second color subpixel is a green subpixel, the third color subpixel is a blue subpixel, and the fourth color subpixel is a white subpixel;
During the first period, the blue sub-pixel does not emit light when the white driving is performed. delete According to claim 1,
At one point in time, all regions of the display panel are white driven by the first white driving method or the second white driving method. According to claim 1,
Current-voltage transfer characteristics or threshold voltages of transistors in one sub-pixel that do not emit light during white driving according to the first white driving method shift in a negative direction from an initial state during the first period;
A current-voltage transfer characteristic or a threshold voltage of a transistor in one subpixel that does not emit light during the first period and emits light during the second period shifts in a positive direction toward the initial state during the second period. According to claim 1,
Each of the plurality of sub-pixels,
An organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first transistor electrically connected between a first node of the driving transistor and a data line, and an electrical connection between a second node of the driving transistor and a sensing line A second transistor connected to , and a capacitor electrically connected between the first node and the second node of the driving transistor,
a sensing unit electrically connectable to the sensing line; and
The display device further comprising a switch electrically connecting the sensing line and the sensing unit. 9. The method of claim 8,
During a sensing period for sensing the characteristic or threshold voltage of the driving transistor,
The sensing line is a display device in which a voltage rise occurs from a reference voltage. 10. The method of claim 9,
The sensing section is a display device that proceeds after a power-off signal is generated. 9. The method of claim 8,
The controller is
Detecting a sub-pixel or region including the driving transistor that is not driven according to the first white driving method and whose characteristic or threshold voltage is shifted in a negative direction based on sensing data of the characteristics or threshold voltage of the driving transistor display device. 9. The method of claim 8,
The controller is
The display device is configured to change from the first white driving method to the second white driving method based on sensing data on the characteristics of the driving transistor or the threshold voltage. According to claim 1,
The color coordinates when driven by the first white driving method and the color coordinates when driven by the second white driving method are the same. A display panel in which a plurality of data lines and a plurality of gate lines are disposed and a plurality of subpixels are arranged, a data driving circuit driving the plurality of data lines, and a gate driving circuit driving the plurality of gate lines; A method of driving a display device comprising: a controller for controlling the data driving circuit and the gate driving circuit,
white driving in a first white driving method for emitting light of three subpixels among the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel;
changing a white driving scheme from the first white driving scheme to a second white driving scheme; and
driving the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel to emit white light in the second white driving method;
at some point,
In the partial region of the display panel, all of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel according to the second white driving method during white driving glow,
The remaining area of the display panel includes three of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel according to the first white driving method when the display panel is driven in white. A method of driving a display device that emits light only. In the display panel,
The display panel is
a first color subpixel emitting light of a first color;
a second color subpixel emitting light of a second color;
a third color subpixel emitting light of a third color; and
a fourth color subpixel emitting light of a fourth color;
During the first period, when driving in the first white driving method, three of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel emit light;
For a second period after the first period, when driving in a second white driving method, the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel emit light;
at some point,
In the partial region of the display panel, all of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel are selected according to the second white driving method during white driving. glow,
The remaining area of the display panel includes three of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel according to the first white driving method when the display panel is driven in white. A light-emitting display panel. a digital-to-analog conversion circuit for converting image data into data voltage; and
an output circuit for outputting a data voltage to each of the first data line, the second data line, the third data line, and the fourth data line disposed on the display panel;
the first data line is electrically connected to a first color subpixel;
the second data line is electrically connected to a second color subpixel;
the third data line is electrically connected to a third color subpixel;
the fourth data line is electrically connected to a fourth color subpixel;
The output circuit is
During the first period, when driving in the first white driving method, a corresponding data voltage is output to each of three data lines among the first data line, the second data line, the third data line, and the fourth data line do,
For a second period after the first period, when driving in the second white driving method, a corresponding data voltage is output to each of the first data line, the second data line, the third data line, and the fourth data line; ,
The output circuit, at any one point in time,
In the partial region of the display panel, all of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel are selected according to the second white driving method during white driving. light is emitted, and the remaining areas of the display panel display the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel according to the first white driving method when the display panel is driven in white. A driving circuit for outputting the data voltage so that only three of the pixels emit light. a white driving controller for controlling a white driving method of the display panel; and
and a data output unit for supplying image data according to the white driving method;
The white driving control unit,
During the first period, during white driving, a first white driving method of emitting light of three subpixels among a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel is performed in the white driving method; control in a way
a second white driving method in which the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel emit light during a second period after the first period when driving white; Controlled by the white driving method,
The white driving control unit, at a certain point in time,
In the partial region of the display panel, all of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel are selected according to the second white driving method during white driving. light is emitted, and the remaining areas of the display panel display the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel according to the first white driving method when the display panel is driven in white. A controller that controls only 3 of the pixels to emit light.

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