KR20180043914A - Display device and its driving method - Google Patents

Abstract

According to an embodiment of the present invention, provided is a display device and a driving method thereof, wherein the display device is capable of removing S multiplexers and sensing voltage switching lines in a floating state and reducing volume and manufacturing costs of a data driving unit. The data driving unit of the present invention generates an X signal for controlling a connection of a sensing line for receiving a sensing voltage by using signals of a data voltage switching line for supplying a data voltage. According to an embodiment of the present invention, the display device and the driving method thereof can control a sensing section by a signal generated by passing control signals of two conventional data line switching multiplexers through a NAND gate. Accordingly, the number of pins may be reduced by removing all of conventional three pins for sensing control. Therefore, a chip integration (CI) effect and a chip size reduction effect may be achieved.

Description

DISPLAY DEVICE AND ITS DRIVING METHOD [0002]

One example of the present invention relates to a display device and a driving method thereof.

BACKGROUND ART [0002] A lot of related technologies are being developed in the field of display devices for displaying visual information as images or images in an information society. The display device includes a display panel having a display area provided with pixels for displaying an image and a non-display area disposed at a periphery of the display area and not displaying an image, a gate driver for inputting a gate signal to the pixels, A plurality of source drive integrated circuits (hereinafter referred to as "ICs ") to be input, and a timing controller for inputting signals for controlling gate drive units and a plurality of source drive ICs.

The source driver ICs are included in the data driver, and the data driver is provided with data voltage switching lines including switching elements for inputting data voltages from the source driver IC to the pixels during a display period. During a display period, a display multiplexer (hereinafter referred to as "D multiplexer") supplies a signal to the switching elements to supply data voltages to the pixels.

There is a display device in which physical characteristics of pixels are different from each other in a display device and a physical characteristic of the pixels is sensed using a sensing interval between display periods. A representative example of such a display device is an organic light emitting diode (OLED) display device. The data driver generates sensing data using the sensing voltage sensed from the pixels in the sensing period, and supplies the sensed data to the timing controller.

In the conventional data driver, sensing voltage switching lines including switching elements for each color of a pixel are provided in order to receive a sensing voltage from the pixels during a sensing period. During a sensing period, a sensing signal is supplied from a sensing multiplexer (S multiplexer) connected to each of the sensing voltage switching lines to the pixels of the color to be sensed by the switching devices, And supplies no voltage to the switching elements in the pixels of different colors. Accordingly, in the case of a general display device having RGB color pixels, sensing voltage is supplied from the pixels during the sensing period using three S multiplexers and three sensing voltage switching lines.

However, in order to perform sensing for each color, additional sensing voltage switching lines are provided for each color of the pixel, so that sensing voltage switching lines connected to pixels of different colors during sensing of pixels of a specific color, The S multiplexers connected to the switching lines are in a floating state. In addition, a large number of S multiplexers and sensing voltage switching lines are provided in the data driver to increase the volume and manufacturing cost of the data driver.

One example of the present invention is to provide a display device and a driving method thereof that can remove the sensing voltage switching lines and S multiplexers in a floating state and reduce the volume and manufacturing cost of the data driver.

A display device according to an exemplary embodiment of the present invention includes a display panel provided with pixels for displaying an image, a data driver for supplying a data voltage to the pixels and receiving a sensing voltage from the pixels, a data driver for supplying a data driver control signal to the data driver And a timing controller for receiving sensing data based on the sensing voltage from the data driver. The data driver of the present invention generates an X signal for controlling connection of a sensing line for receiving a sensing voltage using signals of a data voltage switching line for supplying a data voltage.

According to an embodiment of the present invention, there is provided a method of driving a display device, including: receiving a sensing voltage from pixels displaying an image by a data driver; receiving a sensing data based on a sensing voltage from a data driver; Supplying a driver control signal, and supplying the data voltage to the pixels by the data driver. The step of receiving the sensing voltage from the pixels displaying the image by the data driver of the present invention includes using the signals of the data voltage switching line for supplying the data voltage to generate the X signal controlling the connection of the sensing line for receiving the sensing voltage .

The display device and the driving method thereof according to an exemplary embodiment of the present invention integrate the sensing control of each pixel of each color into three signals to reduce the number of lines. The present invention eliminates sensing voltage switching lines and S multiplexers in a floating state, and can reduce the volume and manufacturing cost of the data driver. In addition, there is an effect of reducing the size of the bezel by reducing the number of sensing control lines. Specifically, two lines are reduced, and the width of the bezel can be reduced by about 0.3 mm.

In addition, a display device and a driving method thereof according to an exemplary embodiment of the present invention can control a sensing period using a signal generated by passing two control signals of a conventional data line switching multiplexer through a NAND gate. Accordingly, the number of pins can be reduced by removing all three pins (PIN) for conventional sensing control. As a result, there is an effect of chip integration (CI) and a reduction in chip size.

1 is a circuit diagram showing a conventional data driver.
2 is a block diagram of a display device according to an exemplary embodiment of the present invention.
3 is a circuit diagram of a pixel according to an example of the present invention.
4 is a circuit diagram illustrating a data driver according to an exemplary embodiment of the present invention.
5 is a circuit diagram illustrating a data driver and pixels according to an exemplary embodiment of the present invention.
6 is a waveform diagram illustrating signals in one sensing frame according to a method of driving a display device according to an exemplary embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. Like reference numerals refer to like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Where the terms "comprises," "having," "consisting of," and the like are used in this specification, other portions may be added as long as "only" is not used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

In the case of a description of a temporal relationship, for example, if the temporal relationship is described by 'after', 'after', 'after', 'before', etc., May not be continuous unless they are not used.

The first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

The terms "X-axis direction "," Y-axis direction ", and "Z-axis direction" should not be construed solely by the geometric relationship in which the relationship between them is vertical, It may mean having directionality.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, May refer to any combination of items that may be presented from more than one.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

In the display device of the present invention, the physical characteristics of each of the pixels are different, and there is a display device that senses physical characteristics of the pixels using a sensing interval between display periods. A representative example of such a display device is an organic light emitting diode (OLED) display device. Therefore, the following description will focus on the case where the display device according to the embodiment of the present invention is an organic light emitting display device.

Before describing an embodiment of the present invention, a conventional data driver will be described, and embodiments of the present invention will be described in detail with reference to differences from a conventional data driver. 1 is a circuit diagram showing a conventional data driver.

The conventional data driver includes a plurality of channels Ch_1 to Ch_4, a reference voltage line Ref, reference voltage switching lines REF_SW1 and REF_SW2, sensing voltage switching lines SMUX1 to SMUX3, (D_SW1, D_SW2).

The plurality of channels Ch_1 to Ch_4 are output terminals of a plurality of source drive integrated circuits (hereinafter referred to as "IC") included in the data driver. In FIG. 1, only four channels among the plurality of channels Ch_1 to Ch_4 are shown. Each of the channels Ch_1 to Ch_4 outputs data voltages generated by the source drive IC.

The reference voltage line Ref is connected to the sensing lines connected to the respective pixels. The reference voltage line Ref supplies the reference voltage REF to the respective sensing lines in the display period. The reference voltage REF is a reference voltage for comparison with the sensing voltage sensed by the pixel. The reference voltage REF is supplied to all the pixels at the same magnitude. In the sensing period, the data driver receives the sensing voltage from the sensing lines. Accordingly, the reference voltage line Ref is disconnected from the sensing lines in the sensing period.

The reference voltage switching lines REF_SW1 and REF_SW2 connect the reference voltage line Ref to the respective sensing lines in the display period. The reference voltage switching lines REF_SW1 and REF_SW2 block the connection between the reference voltage line Ref and the sensing lines in the sensing period. To this end, the reference voltage switching lines REF_SW1 and REF_SW2 are connected to the reference voltage line Ref and the respective sensing lines through a switching element. The switching elements can be implemented with transistors (e. G., MOSFETs can be used). In this case, the reference voltage switching lines REF_SW1 and REF_SW2 may be connected to the gate terminals of the respective switching elements. In addition, the reference voltage line Ref may be connected to the drain terminal of each switching element, and each sensing line may extend from the source terminal of each switching element.

In FIG. 1, two reference voltage switching lines REF_SW1 and REF_SW2 are used. In this case, when the switching element of the first reference voltage switching line REF_SW1 is turned on in a certain display period, the switching element of the second reference voltage switching line REF_SW2 is turned on in the next display period - You can turn it on. Thus, deterioration of the switching element can be prevented.

The sensing voltage switching lines SMUX1 to SMUX3 are connected to the channels Ch_1 to Ch_4 and respective sensing lines through switching devices. The switching elements can be implemented with transistors (e. G., MOSFETs can be used). In this case, the sensing voltage switching lines SMUX1 to SMUX3 may be connected to the gate terminals of the respective switching elements. In addition, the channels Ch_1 to Ch_4 may be connected to the drain terminals of the respective switching elements, and each of the sensing lines may extend from the source terminal of each of the switching elements.

The sensing voltage switching lines SMUX1 to SMUX3 control the sensing voltages to be supplied to the channels Ch_1 to Ch_4 of the color to be sensed in the sensing period. For example, when it is desired to sense the sensing voltages of the red pixels, the switching elements in the sensing line connected to the first and fourth channels Ch_1 and Ch_4 are turned on.

The data voltage switching lines D_SW1 and D_SW2 are connected to the channels Ch_1 to Ch_4 and the respective data lines through a switching element. The switching elements can be implemented with transistors (e. G., MOSFETs can be used). In this case, the data voltage switching lines D_SW1 and D_SW2 may be connected to the gate terminals of the respective switching elements. In addition, the channels Ch_1 to Ch_4 may be connected to the drain terminals of the respective switching elements, and each of the data lines may extend from the source terminal of each of the switching elements.

The data voltage switching lines D_SW1 and D_SW2 control to supply the data voltages to the data lines in the display period. For example, when it is desired to supply the data voltages to the red pixels, the switching elements in the data lines connected to the first and fourth channels Ch_1 and Ch_4 are turned on.

In FIG. 1, two data voltage switching lines D_SW1 and D_SW2 are used. In this case, when the switching element of the first data voltage switching line D_SW1 is turned on in a certain display period, the switching element of the second reference voltage switching line D_SW2 may be turned on in the next display period . Thus, deterioration of the switching element can be prevented.

In the conventional data driver, sensing voltage switching lines SMUX1 to SMUX3 are provided for each pixel to receive a sensing voltage from the pixels during a sensing period. During a sensing period, a sensing signal is supplied from a sensing multiplexer (S multiplexer) connected to each of the sensing voltage switching lines to the pixels of the color to be sensed by the switching devices, And supplies no voltage to the switching elements in the pixels of different colors. Accordingly, in the case of a general display device having RGB color pixels, the sensing voltage is supplied from the pixels during the sensing period using three S multiplexers and three sensing voltage switching lines SMUX1 to SMUX3.

However, the sensing voltage switching lines SMUX1 to SMUX3 may be provided for each color of the pixels to sense each color, and during sensing the pixels of a specific color, sensing voltage switching lines SMUX1 To SMUX3 and the S multiplexers connected to the sensing voltage switching lines SMUX1 to SMUX3 of different colors are in a floating state. In addition, a large number of S multiplexers and sensing voltage switching lines SMUX1 to SMUX3 are provided in the data driver, which increases the volume and manufacturing cost of the data driver.

Hereinafter, embodiments of the present invention will be described in detail. 2 is a block diagram of a display device according to an exemplary embodiment of the present invention.

A display device according to an embodiment of the present invention includes a display panel 100, a gate driver 110, a data driver 120, and a timing controller (T-CON) 130.

The display panel 100 includes a display area and a non-display area provided around the display area. The display area is an area where pixels P are provided to display an image. The display panel 100 is provided with gate lines GL1 to GLp, p is a positive integer of 2 or more, data lines DL1 to DLq, q is a positive integer of 2 or more, and sensing lines SL1 to SLq do. The data lines DL1 to DLq and the sensing lines SL1 to SLq may intersect the gate lines GL1 to GLp. The data lines DL1 to DLq and the sensing lines SL1 to SLq may be parallel to each other. The display panel 100 may include a lower substrate on which the pixels P are provided and an upper substrate on which the sealing function is performed. Each of the pixels P may be connected to any one of the gate lines GL1 to GLp and one of the data lines DL1 to DLq and the sensing lines SE1 to SEm. A detailed description of the pixels P will be given later with reference to FIGS. 3 through 5. FIG.

The gate driver 110 receives the gate control signal GCS from the timing controller 130. The gate driver 110 generates gate signals according to the gate control signals GCS and supplies the gate signals to the gate lines GL1 to GLp. The gate driver 110 according to an embodiment of the present invention is provided with a gate in panel (GIP) circuit in a non-display region of the lower substrate. The GIP circuit is embedded in the non-display region of the lower substrate. For example, the GIP circuit may be provided on one side or the other non-display region of the display region, or on both non-display regions of the display region. However, the present invention is not limited to this and any arbitrary And is provided in the non-display area.

The data driver 120 receives the digital video data DATA and the data driver control signal DCS supplied from the timing controller 130. The data driver 120 converts the digital video data DATA into analog data voltages according to the data driver control signal DCS and supplies the analog data voltages to the data lines DL1 to DLq. The data driver 120 may include a plurality of source drive integrated circuits (hereinafter referred to as "source drive ICs").

Each of the source drive ICs may be mounted on each of the flexible films. Each of the flexible films may be provided with a chip on film (COF). The chip-on film may include a base film such as polyimide and a plurality of conductive lead wires provided on the base film. Each of the flexible films can be bent or bent. Each of the flexible films may be attached to a lower substrate of the display panel 100 and a control printed circuit board (C-PCB). In particular, each of the flexible films may be attached on the lower substrate by a TAB (Tape Automated Bonding) method using an anisotropic conductive flame (ACF), whereby the source drive ICs are connected to the data lines DL1 to DLq .

The data driver 120 receives the sensing voltage from the sensing lines SL1 to SLq. Each of the pixels P supplies a sensing voltage reflecting the physical characteristics to the sensing lines. The data driver 120 receives sensing voltages during a sensing period. The data driver 120 generates sensing data SD using the supplied sensing voltages. The data driver 120 supplies sensing data SD to the timing controller 130.

The timing controller 130 is mounted on a control printed circuit board and receives digital video data (DATA) and timing synchronization signals (Timing Signals) from an external system board. Here, the timing synchronization signals include a vertical synchronization signal (Vsync) defining one frame period, a horizontal synchronization signal (Hsync) defining one horizontal period, a data enable signal (Data Enable Signal, DE), and a dot clock (Dot Clock, DCLK) which is a clock signal having a predetermined period. The timing controller 130 receives the sensing data SD from the data driver 120.

The timing controller 130 generates a gate driver control signal GCS for controlling the operation timing of the gate driver 110 based on the timing synchronization signals TS and a data driver control signal GCS for controlling the data driver 120 DCS). The timing controller 130 supplies a gate driver control signal GCS to the gate driver 110 and a data driver control signal DCS to the data driver 120. [ At this time, the timing controller 130 can compensate the difference in the physical characteristics between the pixels P by correcting the data driver control signal DCS using the sensing data SD.

3 is a circuit diagram of a pixel P according to an example of the present invention. The pixel P according to an exemplary embodiment of the present invention includes an organic light emitting diode OLED, a driving transistor DT, first through fifth transistors T1 through T5, and a first capacitor C1.

The anode electrode of the organic light emitting diode OLED is connected to the source terminal of the fourth transistor T4 and the cathode electrode may be connected to a low potential voltage line VSS to which a low potential voltage lower than the high potential voltage is supplied. The organic light emitting diode OLED emits light according to the current supplied through the fourth transistor T4.

More specifically, the organic light emitting diode OLED includes an anode electrode, a hole transporting layer, an organic light emitting layer, an electron transporting layer, and a cathode electrode. . ≪ / RTI > In the organic light emitting diode (OLED), when a voltage is applied to the anode electrode and the cathode electrode, holes and electrons move to the organic light emitting layer through the hole transporting layer and the electron transporting layer, respectively.

The gate terminal of the driving transistor DT is connected to the drain terminal of the second transistor T2 and the first capacitor C1. The drain terminal of the driving transistor DT is connected to a high-potential voltage line VDD to which a high-potential voltage is supplied. The source terminal of the driving transistor DT is connected to the source terminal of the second transistor T2 and the drain terminal of the fourth transistor T4. The driving transistor DT is supplied with the data voltage VDATA stored in the first capacitor C1 and is turned on to supply a current to the fourth transistor T4.

The gate terminal of the first transistor T1 is supplied with the first gate signal G1. The drain terminal of the first transistor T1 is supplied with the data voltage VDATA. The source terminal of the first transistor T1 is connected to the first capacitor C1. The first transistor T1 is turned on by the first gate signal G1 to store the data voltage VDATA in the first capacitor C1.

And the gate terminal of the second transistor T2 is supplied with the second gate signal G2. The drain terminal of the second transistor T2 is connected to the gate terminal of the driving transistor TD and the first capacitor C1. The source terminal of the second transistor T2 is connected to the source terminal of the driving transistor TD and the drain terminal of the fourth transistor T4. The second transistor T2 is turned on by the second gate signal G2 to control the current flowing to the driving transistor TD by controlling the voltage difference between the gate terminal and the source terminal of the driving transistor TD.

The gate terminal of the third transistor T3 is supplied with the emission signal EM. The drain terminal of the third transistor T3 is connected to the source terminal of the first transistor T1 and the first capacitor C1. The source terminal of the third transistor T3 is supplied with the reference voltage Vref. The third transistor T3 is turned on by the emission signal EM to store the reference voltage Vref in the first capacitor C1.

The gate terminal of the fourth transistor T4 is supplied with the emission signal EM. The drain terminal of the fourth transistor T4 is connected to the source terminal of the driving transistor TD. The source terminal of the fourth transistor T4 is connected to the anode electrode of the organic light emitting diode OLED. The fourth transistor T4 is turned on by the emit signal EM to supply current to the organic light emitting diode OLED.

The gate terminal of the fifth transistor T5 is supplied with the second gate signal G2. The drain terminal of the fifth transistor T5 is connected to the anode electrode of the organic light emitting diode OLED. The source terminal of the fifth transistor T5 is connected to the reference voltage Vref line. The fifth transistor T5 is turned on by the second gate signal G2 to supply the sensing voltage sensed by the organic light emitting diode OLED to the reference voltage Vref line.

The first capacitor C1 is connected between the source terminal of the first transistor T1 and the gate terminal of the driving transistor TD. The first capacitor C1 uses the data voltage VDATA supplied from the first transistor T1 to turn on the driving transistor TD.

When the pixel P is driven in this manner, the data voltage VDATA and the reference voltage Vref must be supplied and the sensing voltage must be supplied. 4 is a circuit diagram illustrating a data driver according to an exemplary embodiment of the present invention. 5 is a circuit diagram showing a data driver and a pixel P according to an example of the present invention.

The data driver according to an exemplary embodiment of the present invention includes a plurality of channels Ch_1 to Ch_4, a reference voltage line Ref, reference voltage switching lines REF_SW1 and REF_SW2, an X signal line X, (D_SW1, D_SW2). A plurality of channels Ch_1 to Ch_4, a reference voltage line Ref, reference voltage switching lines REF_SW1 and REF_SW2, and data voltage switching lines D_SW1 and D_SW2 in the data driver according to an exemplary embodiment of the present invention. Is the same as the configuration and function of the conventional data driver shown in FIG. 1, so that detailed description thereof will be omitted.

The X signal line X is connected to the channels Ch_1 to Ch_4 and the respective sensing lines through a switching element. The switching elements can be implemented with transistors (e. G., MOSFETs can be used). In this case, the X signal line X may be connected to the gate terminal of each switching element. In addition, the channels Ch_1 to Ch_4 may be connected to the drain terminals of the respective switching elements, and each of the sensing lines may extend from the source terminal of each of the switching elements.

The X signal line X controls the sensing voltages to be supplied to all of the channels Ch_1 to Ch_4 in the sensing period. When the X signal flows through the X signal line X, all the switching elements on the X signal line X are turned on to supply the sensing voltages to all the channels Ch_1 to Ch_4.

The data driver according to an exemplary embodiment of the present invention uses signals for controlling the connection of the data voltage switching lines D_SW1 and D_SW2 for supplying the data voltages and generates X signals . That is, there is no need for a separate multiplexer or signal generator for generating the X signal. Also, the X signal can perform all of the roles that the sensing voltage switching lines SMUX1 to SMUX3 perform in the conventional data driver as one signal.

The data driver of the present invention plays the role that the sensing voltage switching lines SMUX1 to SMUX3 perform by using the X signal and controls the sensing voltage switching lines SMUX1 to SMUX3 and the sensing voltage switching lines SMUX1 to SMUX3 A sensing multiplexer (hereinafter referred to as "S multiplexer" Accordingly, one example of the present invention can eliminate the sensing voltage switching lines SMUX1 to SMUX3 and the S multiplexer. Therefore, the volume and manufacturing cost of the data driver can be reduced.

More specifically, the data driver according to an exemplary embodiment of the present invention performs data voltage switching (hereinafter referred to as " data voltage switching ") generated by a display multiplexer (hereinafter referred to as "D multiplexer") that controls connection of data voltage switching lines D_SW1 and D_SW2 Quot; D switching ") signals. ≪ RTI ID = 0.0 >

The two input terminals of the NAND gates are connected to the first data voltage switching line D_SW1 and the second data voltage switching line D_SW2. The output terminal of the NAND gate is connected to the X signal line X. [ As a result, a signal output from the output terminal of the NAND gates is supplied to the X signal line X. [ That is, the NAND gates receive the D switching signals flowing in the first data voltage switching line D_SW1 and the second data voltage switching line D_SW2, and transmit the X signal controlling the sensing line to the X signal line X). Since the X signal line X is controlled to supply the sensing voltages to all the channels Ch_1 to Ch_4 in the sensing period, the NAND gate supplies the X signal to the sensing line.

The present invention is one in which sensing voltage is supplied to sensing lines using sensing voltage switching lines SMUX1 to SMUX3 and an S multiplexer that supplies signals to sensing voltage switching lines SMUX1 to SMUX3 The same operation can be performed using an X signal output from one NAND gate. Accordingly, an exemplary embodiment of the present invention provides a concrete method for eliminating the sensing voltage switching lines SMUX1 to SMUX3 and the S multiplexer, but replacing the role of the sensing voltage switching lines SMUX1 to SMUX3 and the S multiplexer.

Preferably, the X signal line X is connected to all the gate terminals of the transistor connected to the sensing line. Accordingly, it is possible to simultaneously supply the X signal to all the gate terminals of the transistor connected to the sensing line.

Conventionally, separate sensing voltage switching lines SMUX1 to SMUX3 and an S multiplexer are provided for each RGB color. However, even when the super-high voltage is supplied for each RGB color, it is not necessary to perform each color until the turn-on of the transistor serving as the switching line of the sensing line connected thereto. In addition, when separate sensing voltage switching lines (SMUX1 to SMUX3) and S multiplexer are provided for each RGB color, the output voltage of the remaining S multiplexers except floating colors is in a floating state.

In the present invention, it is possible to simultaneously supply one X signal to all the gate terminals of the transistor connected to the sensing line, irrespective of RGB colors. The X signal can be used to control all transistors connected to the sensing line. Accordingly, the sensing voltage switching lines SMUX1 to SMUX3 and the S multiplexers can perform the same function using only one signal line. Ultimately, as the number of lines decreases, the width of the bezel can be reduced, and a narrow bezel display device can be realized.

In the present invention, the transistor of the sensing line supplied with the X signal is turned on. In the turn-on transistor, the sensing lines supplied with the X signal are connected to the pixels P and the data driver. Accordingly, the sensing line supplied with the X signal can supply the sensing voltage supplied from the pixels P to the data driver.

The transistor in the sensing line of the present invention blocks the connection between the sensing line and the data driver when the X signal is not supplied and connects the sensing line and the data driver when the X signal is supplied. Accordingly, the sensing line of the present invention can supply the sensing voltage to the data driver only in the sensing period using the X signal.

According to the manner in which the pixel P is connected to the data driver in FIG. 5 and the driving method of the pixel P in FIG. 3 through FIG. 5, the pixels P are supplied with the gate signals G1 and G2 The sensing voltage of the organic light emitting diode OLED is supplied to the reference line Ref serving as a sensing line. Therefore, in the present invention, the sensing line supplied with the X signal can supply the sensing voltage to the data driver when the gate signals G1 and G2 are supplied to the pixels P. Accordingly, in the display period in which the gate signals G1 and G2 are not supplied, the connection between the data driver and the sensing line is cut off to prevent the input of unnecessary signals have.

A driving method of a display device according to an example of the present invention includes the following steps.

First, the data driver 120 receives the sensing voltage from the pixels P for displaying an image. The data driver 120 must supply the data voltage to display the image of the uniform brightness on the display panel 100 after sensing the difference in the physical characteristics between the pixels P and compensating the difference in the characteristics. A sensing voltage representing the characteristics of the pixels P is generated from the pixels P in the sensing period. The data driver 120 receives a sensing voltage through a sensing line in a sensing period. The data driver 120 generates sensing data SD based on the sensing voltage.

Secondly, the timing controller 130 receives the sensing data SD based on the sensing voltage from the data driver 120 and supplies a data driver control signal DCS to the data driver 120. The timing controller 130 controls the data driver 120 to display an image of uniform brightness on the display panel 100 by compensating for the difference in characteristics for each pixel P in the data driver control signal DCS.

Thirdly, the data driver 120 supplies the data voltages to the pixels P. The data driver 120 uses the data driver control signal DCS supplied from the timing controller 130 to compensate for the characteristic difference of each pixel P to display an image of uniform luminance on the display panel 100 .

Particularly, the step of the data driver 120 of the present invention receiving the sensing voltage from the pixels P displaying the image may be performed by using the signals of the data voltage switching lines D_SW1 and D_SW2 that supply the data voltage, And generating an X signal that controls connection of a sensing line for receiving a voltage.

The X signal is supplied to the sensing line through the X signal line (X). X signal to perform the same function as the signal supplied using the conventional sensing voltage switching lines SMUX1 to SMUX3 and the S multiplexers. That is, the present invention can perform the step of omitting the conventional sensing voltage switching lines SMUX1 to SMUX3 and the S multiplexers and receiving the sensing voltage using a single signal.

In addition, the step of receiving the sensing voltage of the present invention further includes supplying an X signal to the sensing line using data voltage switching signals generated by a display multiplexer that controls connection of the data voltage switching lines D_SW1 and D_SW2 do.

To this end, the present invention adds a NAND gate. The two input signals supplied from the data voltage switching lines D_SW1 and D_SW2 are input to the input terminals of the NAND gates. The output terminal of the NAND gate is connected to the X signal line X. [ A NAND gate outputs an X signal of a high logic level only when the signals output from the data voltage switching lines D_SW1 and D_SW2 are all at a logic low level. This is the same waveform as the signal supplied using the conventional sensing voltage switching lines SMUX1 to SMUX3 and S multiplexers.

That is, the present invention uses only one NAND gate and X signal line X to supply a signal to the sensing line using conventional sensing voltage switching lines SMUX1 to SMUX3 and S multiplexers And supplies the same signal. Accordingly, the present invention provides a concrete implementation method that can generate signals in the same sensing period while omitting the sensing voltage switching lines SMUX1 to SMUX3 and the S multiplexers.

In supplying the X signal of the present invention to the sensing line, the X signal is simultaneously supplied to all the gate terminals of the transistor connected to the sensing line. In the past, when the sensing lines are connected to the respective pixels, the pixels are classified according to the color and a separate signal is supplied. For example, when a signal is supplied to the sensing lines connected to the RGB pixels, three sensing voltage switching lines SMUX1 to SMUX3 and three S multiplexers are required.

However, even when the sensing voltage is supplied for each color, it is not necessary to supply a separate signal for each color. In view of this point, the present invention provides simultaneous supply of a single X signal to all the gate terminals of the transistor connected to the sensing line, turns on all the sensing lines, connects the pixels P and the data driver in the sensing period So that the sensing voltage can be supplied.

In addition, in the step of receiving the sensing voltage from the pixels P displaying the image, the data driver 120 may supply the sensing voltage supplied from the pixels P using the sensing line supplied with the X signal And supplying the data to the data driver 120.

The X signal is supplied to the gate terminals of the transistors on the sensing line. Accordingly, when the X signal is supplied, the transistors on the sensing line are turned on to connect the pixels P and the data driver 120 to each other. Accordingly, the sensing voltage generated by the pixels P in the sensing period can be transmitted to the data driver 120 using the X signal.

Here, in the step of supplying the sensing voltage supplied from the pixels P to the data driver 120 using the sensing line supplied with the X signal, the sensing line supplied with the X signal is applied to the pixels P And supplies a sensing voltage to the data driver 120 when the signals G1 and G2 are supplied.

When the gate signals G1 and G2 are supplied to the pixels P, the pixels P generate a sensing voltage. That is, the time when the gate signals G1 and G2 are supplied to the pixels P corresponds to the sensing period. Accordingly, in the sensing period, the sensing line is connected to the data driver 120 using the X signal, and the sensing voltage is supplied to the data driver 120. In the display period, the sensing line is connected to the data driver 120 It is possible to prevent unnecessary voltage input.

6 is a waveform diagram illustrating signals in one sensing frame according to a method of driving a display device according to an exemplary embodiment of the present invention. In the present invention, it is assumed that the switching elements are turned on when the input signals are at the low logic level. This is because the switching elements are turned on when the PMOS is low logic level.

A sensing data enable (SDE) signal enables a sensing operation for each color to be started within a sensing period.

Signals of the data voltage switching lines D_SW1 and D_SW2 alternately have low logic levels in one sensing period. In Fig. 6, the switching elements of the first data voltage switching line D_SW1 are driven. As a result, the switching elements can be prevented from deteriorating.

The X signal of the X signal line X has a low logic level in the sensing period. Accordingly, the sensing line can connect the pixels P to the data driver 120 so that the sensing voltage is transmitted to the data driver 120 by the X signal.

The gate signals G1 and G2 have a low logic level in the sensing period. The gate signals G1 and G2 generate a sensing voltage for each of the pixels P in the sensing period and supply the sensing voltage to the sensing line.

The emission signal EM has a high logic level in the sensing period. Accordingly, the emission signal EM prevents the data voltage from being supplied to the pixels P in the sensing period. The emission signal EM allows a current to flow through the organic light emitting diode OLED of each of the pixels P in the display period so as to emit light.

The sensing channel select (SCS) signal has a high logic level for each RGB color in the sensing period. The sensing channel selection (SCS) signal is a control signal transmitted from the timing controller 130 to the data driver 120 to select a channel corresponding to a color to be sensed.

The PRE signal has a high logic level at the beginning of the sensing period and the sensing (SEN) signal has a high logic level at the end of the sensing period. The free (PRE) signal and the sensing (SEN) signal are control signals used in sensing. Here, the PRE signal controls the initial period of the sensing period, and the sensing (SEN) signal controls the latter period of the sensing period.

Ultimately, the display device and the driving method thereof according to an exemplary embodiment of the present invention reduce the number of lines by integrating the sensing control of each pixel in each color into one signal. Accordingly, the size of the bezel can be reduced by reducing the number of sensing control lines. Specifically, two lines are reduced, and the width of the bezel can be reduced by about 0.3 mm.

In addition, a display device and a driving method thereof according to an exemplary embodiment of the present invention can control a sensing period using a signal generated by passing two control signals of a conventional data line switching multiplexer through a NAND gate. Accordingly, the number of pins can be reduced by removing all three pins (PIN) for conventional sensing control. As a result, there is an effect of chip integration (CI) and a reduction in chip size.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Accordingly, it should be understood that the above-described embodiments are illustrative and non-restrictive in every respect. The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

100: display panel 110: gate driver
120: Data driver 130: Timing controller
TD: driving transistors T1 to T5: first to fifth transistors
C1: first capacitors Ch_1 to Ch_4: a plurality of channels
Ref: reference voltage line, REF_SW1, REF_SW2: reference voltage switching lines
X: X signal lines D_SW1, D_SW2: Data voltage switching lines

Claims (10)

A display panel provided with pixels for displaying an image;
A data driver for supplying a data voltage to the pixels and receiving a sensing voltage from the pixels;
And a timing controller for supplying a data driver control signal to the data driver and supplying sensing data based on the sensing voltage from the data driver,
The data driver may include:
And generates an X signal for controlling connection of a sensing line for receiving the sensing voltage, using signals of a data voltage switching line supplying the data voltage. The method according to claim 1,
The data driver may include:
Further comprising a NAND gate supplied with data voltage switching signals generated by a display multiplexer that controls connection of a data voltage switching line,
And the NOR gate supplies the X signal to the sensing line. 3. The method of claim 2,
And simultaneously supplies the X signal to all the gate terminals of the transistor connected to the sensing line. The method according to claim 1,
And the sensing line supplied with the X signal supplies the sensing voltage supplied from the pixels to the data driver. 5. The method of claim 4,
And the sensing line supplied with the X signal supplies the sensing voltage to the data driver when a gate signal is supplied to the pixels. A data driver receiving a sensing voltage from pixels displaying an image;
The timing controller receiving sensing data based on the sensing voltage from the data driver and supplying a data driver control signal to the data driver; And
The data driver supplying data voltages to the pixels,
Wherein the step of receiving the sensing voltage from the pixels of the data driver,
And generating an X signal for controlling connection of a sensing line for receiving the sensing voltage, using signals of a data voltage switching line supplying the data voltage. The method as claimed in claim 6, wherein the step of receiving the sensing voltage from the pixels of the data driver,
And supplying the X signal to the sensing line using data voltage switching signals generated by a display multiplexer that controls connection of the data voltage switching line. 8. The method of claim 7, wherein the step of supplying the X signal to the sensing line comprises:
And simultaneously supplying the X signal to all the gate terminals of the transistor connected to the sensing line. The method as claimed in claim 6, wherein the step of receiving the sensing voltage from the pixels of the data driver,
And supplying the sensing voltage supplied from the pixels to the data driver using the sensing line supplied with the X signal. The method of claim 9, wherein the step of supplying a sensing voltage supplied from the pixels to the data driver using the sensing line supplied with the X signal comprises:
Wherein the sensing line supplied with the X signal supplies the sensing voltage to the data driver when a gate signal is supplied to the pixels.

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