KR20200076196A - Display Device And Driving Method Thereof - Google Patents

Abstract

The present invention relates to a display device and includes: a pixel array connected to share one data line with neighboring sub-pixels; a data driver that supplies image data of each sub-pixel through a data channel in an image display mode and receives sensing data of each sub-pixel through a sensing channel in a sensing mode; and a multiplexer connecting the pixel array and the data driver according to a multiplexer signal. The multiplexer connects the data channel of the data driver and the N^th data line to output the image data to the N^th data line connected to an N^th sub-pixel in the image display mode, and connects the sensing channel of the data driver and the N+1^th data line to sense the N^th subpixel through the N+1^th data line connected to the N+1^th subpixel in the sensing mode, thereby reducing the number of channels of the data driver.

Description

Display device and driving method thereof

The present invention relates to a display device and a driving method thereof.

2. Description of the Related Art Display devices are widely used in portable computers such as notebook computers, PDAs, and mobile phone terminals, as well as desktop computer monitors, due to their advantages in miniaturization and light weight.

Among the display devices, an active matrix type organic light emitting display device includes an organic light emitting diode (hereinafter referred to as "OLED") that emits light by itself, and has a fast response speed, light emission efficiency, luminance and It has a wide viewing angle and is widely used.

The display device includes a display panel including pixels arranged in a matrix, a gate driver outputting a scan signal, and a data driver outputting a data signal. The pixels of the display panel include OLEDs and thin film transistors (TFTs) for controlling the driving current flowing through the OLEDs. As the driving time increases, the electrical characteristics of the pixel change, resulting in image quality deterioration. Accordingly, a function of sensing and compensating the current of the pixel is performed.

In order to sense the electrical characteristics of a pixel, the data driver senses the current of each pixel through a sensing line. Since one sensing line is allocated for each pixel, as many as the number of pixels arranged in the horizontal line, the sensing line needs to have a corresponding number of sensing channels. Accordingly, as the number of sensing lines increases due to an increase in resolution and panel size, the number of channels of the data driver increases accordingly.

The present invention provides a display device capable of reducing the number of channels of the data driver.

A display device according to an exemplary embodiment of the present invention includes a pixel array connected such that neighboring sub-pixels share one data line with each other; A data driver that supplies image data of each sub-pixel through a data channel in an image display mode and receives sensing data of each sub-pixel through a sensing channel in a sensing mode; And a multiplexer connecting the pixel array and the data driver according to a multiplexer signal, wherein the multiplexer is the data driver to output image data to an Nth data line connected to an Nth subpixel in the image display mode. In order to connect the data channel and the Nth data line, and sense the Nth subpixel through the N+1 data line connected to the N+1 subpixel in the sensing mode, the sensing channel of the data driver and Connect the N+1 data line.

The multiplexer may include a data multiplexer TFT that receives the multiplexer signal in the image display mode and connects the Nth data line and the data channel; And a sensing multiplexer TFT that receives the multiplexer signal in the sensing mode and connects the N+1 data line and the sensing channel.

The data multiplexer TFT includes a gate electrode to which the multiplexer signal is input, a first electrode connected to the data channel, and a second electrode connected to the Nth data line connected to the Nth sub-pixel.

The sensing multiplexer TFT includes a gate electrode to which the multiplexer signal is input, a first electrode connected to the sensing channel, and a second electrode connected to the N+1 data line connected to the Nth sub-pixel.

The data multiplexer TFT includes: a first data multiplexer TFT that outputs image data of red (R) sub-pixels; A second data multiplexer TFT that outputs image data of the green (G) sub-pixel; And a third data multiplexer TFT that outputs image data of blue (B) sub-pixels.

The first data multiplexer TFT, the second data multiplexer TFT, and the third data multiplexer TFT are sequentially turned on.

The data driving unit outputs image data of the red (R) sub-pixel, image data of the green (G) sub-pixel, and image data of the blue (B) sub-pixel through one data channel in the image display mode.

The sensing multiplexer TFT includes: a first sensing multiplexer TFT that outputs sensing data of a red (R) sub-pixel; A second sensing multiplexer TFT that outputs sensing data of the green (G) sub-pixel; And a third sensing multiplexer TFT that outputs sensing data of the blue (B) sub-pixel.

The first sensing multiplexer TFT, the second sensing multiplexer TFT, and the third sensing multiplexer TFT are sequentially turned on.

In the sensing mode, the data driver senses the sensing data of the red (R) subpixel, the sensing data of the green (G) subpixel, and the sensing data of the blue (B) subpixel through one sensing channel.

The N+1 data line is connected to the N+1 sub-pixel and the N-th sub-pixel, and transmits image data to an N+1 sub-pixel connected to the N+1 data line in the image display mode. In the sensing mode, sensing data of an Nth sub-pixel connected to the N+1 data line is output.

The Nth sub-pixel includes a switch TFT turned on in the sensing mode to connect the sensing terminal of the N-th sub-pixel to the N+1 data line.

The Nth sub-pixel includes: a light emitting element; And a gate electrode to which a data voltage is applied and a source electrode to be connected to the anode of the light emitting device, to control a current applied to the light emitting device according to a voltage difference between a gate and a source; The switch TFT includes a gate electrode receiving a sensing mode selection signal, a first electrode connected to a power line connecting the source electrode of the driving TFT and the anode of the light emitting device, and the N+1 data line. It includes a second electrode.

The display device of the present invention can reduce the number of channels of the data driver by providing a multiplexer such that sensing data input from a plurality of sensing lines is input to a single sensing channel of the data driver.

The display device of the present invention connects adjacent sub-pixels so as to share one data line with each other, and sequentially senses sub-pixels for each data line in the sensing mode, but senses data as the data line of the sub-pixel currently being sensed. The next data line, which is a data line that is not supplied and sensed, is used as a sensing line. Accordingly, the sensing line, which was provided to directly sense the OLED current in the existing pixel array, can be deleted.

1 is a view showing a display device according to an exemplary embodiment of the present invention.
FIG. 2 is a view showing a configuration of the display panel of FIG. 1.
3 is a circuit diagram illustrating an embodiment of the multiplexer circuit of FIG. 2.
4 is a circuit diagram illustrating a sub-pixel of a display device according to an exemplary embodiment of the present invention.
5 is a diagram showing the flow of data in the display device of the present invention.
FIG. 6 is a diagram showing the operation principle of the multiplexer circuit and the sub-pixel in the image display mode.
7 is a view showing a driving waveform in the operation of FIG. 6.
8 is a view showing the operating principle of the multiplexer circuit and the sub-pixel in the sensing mode according to the first embodiment of the present invention.
9 is a view showing a driving waveform in the operation of FIG. 8.
10 is a view showing the operating principle of the multiplexer circuit and the sub-pixel in the sensing mode according to the second embodiment of the present invention.
FIG. 11 is a view showing a driving waveform during operation of FIG. 10.

Advantages and features of the present specification, and a method of achieving them will be apparent with reference to embodiments described below in detail together with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments allow the disclosure of the present specification to be complete, and common knowledge in the art to which this specification belongs It is provided to fully inform the person having the scope of the invention, and this specification is only defined by the scope of the claims.

Since the shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for describing the embodiments of the present specification are exemplary, the present specification is not limited to the illustrated items. The same reference numerals refer to the same components throughout the specification. When'include','have','consist of', etc. mentioned in this specification are used, other parts may be added unless'~ only' is used. When a component is expressed as a singular number, the plural number is included unless otherwise specified.

In interpreting the components, it is interpreted as including the error range even if there is no explicit description.

In the case of the description of the positional relationship, for example, if the positional relationship of the two parts is described as'~ on','~ on top','~ on the bottom','~ next to', etc.,'right' Alternatively, one or more other parts may be located between the two parts unless'direct' is used.

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

Throughout the specification, the same reference numerals refer to substantially the same components.

In the present specification, the pixel circuit and the gate driver formed on the substrate of the display panel may be implemented as a TFT of an n-type MOSFET (Metal Oxide Semiconductor Field Effect Transistor) structure, but are not limited thereto and may be implemented as a TFT of a p-type MOSFET structure. have. TFT is a three-electrode device including a gate, a source, and a drain. The source is an electrode that supplies a carrier to the transistor. In the TFT, carriers begin to flow from the source. The drain is an electrode through which the carrier exits from the TFT. That is, the carrier flow in the MOSFET flows from the source to the drain. In the case of an n-type TFT (NMOS), since the carrier is electron, the source voltage has a voltage lower than the drain voltage so that electrons can flow from the source to the drain. Since electrons flow from the source to the drain in the n-type TFT, the direction of the current flows from the drain to the source. In contrast, in the case of the p-type TFT (PMOS), the source voltage is higher than the drain voltage so that holes can flow from the source to the drain because the carrier is a hole. In the p-type TFT, current flows from the source to the drain because holes flow from the source to the drain. It should be noted that the source and drain of the MOSFET are not fixed. For example, the source and drain of the MOSFET can be changed according to the applied voltage. Therefore, in the description of the embodiment of the present specification, any one of the source and the drain is described as the first electrode, and the other of the source and the drain is described as the second electrode.

Hereinafter, embodiments of the present specification will be described in detail with reference to the accompanying drawings. In the following embodiments, the display device will be mainly described with an organic light emitting display device including an organic light emitting material. However, it should be noted that the technical idea of the present specification is not limited to the organic light emitting display device, and can be applied to an inorganic light emitting display device including an inorganic light emitting material.

In the following description, when it is determined that a detailed description of known functions or configurations related to the present specification may unnecessarily obscure the subject matter of the present specification, the detailed description is omitted.

1 is a view showing a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the display device according to an exemplary embodiment of the present invention supplies image data to the display panel 10 through the display panel 10 on which the sub-pixels SP are formed, and the channel 14, and each sub-pixel. The driving timing of the data driver 12 for receiving the sensing data of the (SP), the gate driver circuit 13 for driving the gate lines 15, and the data driver 12 and the gate driver circuit 13 A timing controller 11 for controlling is provided.

Sub-pixels SP are arranged on the display panel 10 in a matrix form. The sub-pixels SP may be commonly supplied with high potential and low potential driving voltages EVDD and EVSS and a reference voltage Vref. Each sub-pixel SP may include an OLED. The self-luminous device, OLED, includes an anode electrode and a cathode electrode, and an organic compound layer formed therebetween. Each of the sub-pixels SP may be one of a red pixel, a green pixel, a blue pixel, and a white pixel. The red pixel, the green pixel, the blue pixel, and the white pixel may constitute one unit pixel for color realization. The sub-pixels SP may include an OLED, a driving TFT DT, at least two switch TFTs, and at least one storage capacitor.

The timing controller 11 rearranges digital video data (RGB) input from the outside according to the resolution of the display panel 10 and supplies it to the data driver 12. The timing controller 11 operates timing of the data driver 12 based on timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a dot clock signal DCLK, and a data enable signal DE. Generates a data control signal (DDC) for controlling and a gate control signal (GDC) for controlling the operation timing of the gate driving circuit (13).

The gate driver 13 may generate a scan signal SCAN based on the gate control signal GDC. The gate driver 13 may supply the scan signal SCAN to the gate line 15 connected to each pixel row in a row sequential manner. The gate driver 13 may be directly formed on a non-display area of the display panel 10 according to a gate-driver in panel (GIP) method.

The data driver 12 supplies image data to the display panel 10 in the image display mode. The data driver 12 may convert digital video data RGB input from the timing controller 11 into image data in analog voltage form based on the data control signal DDC and output it through the channel 14.

In addition, the data driver 12 according to an embodiment of the present invention may supply sensing voltage data to the display panel 10 in the sensing mode and receive sensing data of each sub-pixel SP. The data driver 12 generates sensing voltage data and outputs it to the display panel 10 to sense the current characteristics of the OLEDs included in each sub-pixel SP. Thereafter, the current applied to the OLED may be sensed and processed as sensing data according to the sensing voltage data.

Here, the timing controller 11 may temporally separate sensing driving in the sensing mode and display driving in the image display mode according to a predetermined control sequence. When driving the display, the timing controller 11 may rearrange video data RGB to match the resolution of the display panel 10 and supply it to the data driver 12. The sensing driving may include driving to sense the current characteristic of the OLED in the display panel 10 and update the compensation value accordingly. The timing controller 11 may sense current characteristics of the OLED through sensing driving and compensate image data input to the display panel 10 according to the sensing result.

2 is a diagram illustrating a configuration of a display panel 10 of a display device according to an embodiment of the present invention, and FIG. 3 is a circuit diagram showing an embodiment of the multiplexer circuit 200 of FIG. 2.

Referring to FIG. 2, the display panel 10 may include a display area AA in which a pixel array is formed, and a multiplexer circuit 200 that time-divisionly outputs image data output from the data driver 12. have.

The display area AA includes a plurality of gate lines 15 arranged in a horizontal direction, j (j is a natural number) data lines DL1 to DLj arranged in a vertical direction, and subpixels connected to the current line and the next line. (SP) may be included. Accordingly, the Nth sub-pixel SP is connected to the Nth data line and the N+1 data line, and neighboring sub-pixels SP can share the data line with each other. Each sub-pixel SP is connected to only the N-th data line in the image display mode and receives image data through the N-th data line. In the sensing mode, it is connected to the Nth data line and the N+1 data line to receive sensing voltage data through the Nth data line and output sensing data through the Nth+1 data line. Each sub-pixel SP includes a plurality of R sub-pixels R for displaying a red image, a plurality of G sub-pixels G for displaying a green image, and a plurality of B sub-pixels for displaying a blue image. It can be divided into (B) and sub-pixels of the same color are connected to the same data line DL.

The data driver 12 includes n output channels DC1 to DCn and n sensing channels SC1 to SCn having a smaller number than j data lines DL1 to DLj arranged in one horizontal line. Each channel may be assigned one channel per unit pixel including the R sub-pixel R, the G sub-pixel G, and the B sub-pixel B. That is, one output channel (DC) and one sensing channel (SC) can be allocated per three sub-pixels.

The data driver 12 converts digital video data (RGB) input from the timing controller 11 into RGB analog data voltages to generate image data, and generates the image data through n output channels DC1 to DCn. It is supplied to the multiplexer circuit 200. The data driver 12 converts digital video data RGB corresponding to sub-pixels SP of one horizontal line into an RGB analog data voltage signal, and consists of j image data for one horizontal line having a smaller number than this. Outputs through n output channels (DC1 to DCn).

In the image display mode, the data driver 12 divides j image data three times during one horizontal period through the multiplexer circuit 200 and sequentially outputs them. For example, the data driver 12 simultaneously outputs R image data among j image data through n output channels DC1 to DCn during the first period of the horizontal period, and then of the j image data G image data is outputted simultaneously through n output channels (DC1 to DCn) during the second period of the horizontal period, and then G image data of the j image data is n for the third period of the horizontal period. Simultaneous output through two output channels (DC1 to DCn).

In the sensing mode, the data driver 12 sequentially outputs j sensing data through the multiplexer circuit 200 three times during one horizontal period, and outputs each sub for the sensing data. The sensing data of the pixel SP is received. The data driver 12 simultaneously outputs sensing data for the R sub-pixel R among j sensing data through n output channels DC1 to DCn during the first period of the horizontal period, and then outputs the data. The sensing data of the R sub-pixel R for the sensed data is received through n sensing channels SC1 to SCn. Subsequently, the G image data among the j image data are simultaneously output through n output channels DC1 to DCn during the second period of the horizontal period, and then the sensing data of each G subpixel R are sensed by n sensing channels. It is received through (SC1 to SCn). Next, the B image data among the j image data are simultaneously output through the n output channels DC1 to DCn during the third period of the horizontal period, and then the n sensing data of each B sub-pixel B is sensed. It is received through channels SC1 to SCn.

The multiplexer circuit 200 selectively connects n output channels DC1 to DCn with j data lines DL1 to DLj to transmit image data or sensing data. Further, n sensing channels SC1 to SCn are selectively connected to j data lines DL1 to DLj to transmit sensing data.

FIG. 3 shows a circuit configuration of the multiplexer circuit 200, and one output channel (for one unit pixel including an R sub-pixel R, a G sub-pixel G, and a B sub-pixel B) DC) and when one sensing channel SC is allocated, the configuration of the multiplexer circuit 200 is disclosed.

Referring to FIG. 3, the multiplexer circuit 200 senses data multiplexer TFTs (RD_TFT, GD_TFT, BD_TFT) and data multiplexers selectively connecting the data channels DC1 and data lines DL1 to DL4 of the data driver 12. And a sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT) that selectively connects the channel SC1 and the data lines DL1 to DL4.

The data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) and the sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT) selectively connect data lines DL1 to DL4 according to the multiplexer clock signals (Mux_R, Mux_G, Mux_B) input from the outside. do. In the image display mode, the data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) connects the data channel DC1 and the Nth data line to output image data to an Nth data line connected to the Nth subpixel, and the sensing mode In the sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT), a sensing channel (SC) and the N+1 data line are used to sense the Nth sub pixel through the N+1 data line connected to the N+1 sub pixel. Connect.

Each sub-pixel (R, G, B) is connected to the N data line and the N+1 data line, and neighboring sub-pixels (SP) share the data line with each other. Each sub-pixel (R, G, B) is connected to only the N-th data line in the image display mode to receive image data through the N-th data line. In the sensing mode, it is connected to the Nth data line and the N+1 data line to receive sensing voltage data through the Nth data line and output sensing data through the Nth+1 data line.

The first data multiplexer TFT (RD_TFT) connects the data line DL1 to which the output channel DC1 of the data driver 12 and the R sub-pixel R are connected according to the first multiplexer clock signal Mux_R, and the second The data multiplexer TFT (GD_TFT) connects the output channel DC1 of the data driver 12 and the data line DL2 to which the G sub-pixel G is connected according to the second multiplexer clock signal Mux_G, and the third data multiplexer The TFT (BD_TFT) connects the output channel DC1 of the data driver 12 and the data line DL3 to which the B sub-pixel B is connected according to the third multiplexer clock signal Mux_B.

The gate electrode of the first data multiplexer TFT (RD_TFT) is connected to the signal line to which the first multiplexer clock signal Mux_R is applied, and the drain electrode is connected to the first data channel DC1 of the data driver 12 and the source. The electrode is connected to the first data line DL1. Accordingly, when the first multiplexer clock signal Mux_R is applied, the R image data VR output from the data driver 12 or sensing data is supplied to the R sub-pixel R through the first data line DL1. .

The gate electrode of the second data multiplexer TFT (GD_TFT) is connected to the signal line to which the second multiplexer clock signal Mux_G is applied, and the drain electrode is connected to the first data channel DC1 of the data driver 12 and the source. The electrode is connected to the second data line DL2. Accordingly, when the second multiplexer clock signal Mux_G is applied, the G image data VG or sensing data output from the data driver 12 is supplied to the G sub-pixel G through the second data line DL2. .

The gate electrode of the third data multiplexer TFT (BD_TFT) is connected to the signal line to which the third multiplexer clock signal Mux_B is applied, and the drain electrode is connected to the first data channel DC1 of the data driver 12 and the source. The electrode is connected to the third data line DL3. Accordingly, when the third multiplexer clock signal Mux_B is applied, the B image data VB output from the data driver 12 or sensing data is supplied to the B sub-pixel B through the third data line DL3. .

The first sensing multiplexer TFT (RS_TFT) connects the sensing channel SC1 of the data driver 12 and the data line DL2 receiving the sensing data of the R sub-pixel R according to the first multiplexer clock signal Mux_R. In addition, the second sensing multiplexer TFT (GS_TFT) is a data line DL3 in which sensing data of the sensing channel SC1 and the G sub-pixel G of the data driver 12 are received according to the second multiplexer clock signal Mux_G. And the third sensing multiplexer TFT (BS_TFT) is a data line (receiving sensing data of the sensing channel SC1 and the B sub-pixel B of the data driver 12 according to the third multiplexer clock signal Mux_B ( DL4).

The gate electrode of the first sensing multiplexer TFT (RS_TFT) is connected to the signal line to which the first multiplexer clock signal Mux_R is applied, and the drain electrode is connected to the first sensing channel SC1 of the data driver 12 and the source. The electrode is connected to the second data line DL2. Accordingly, when the first multiplexer clock signal Mux_R is applied, the sensing data Sen_R of the R sub-pixel R is received by the data driver 12 through the second data line DL2.

The gate electrode of the second sensing multiplexer TFT (GS_TFT) is connected to the signal line to which the second multiplexer clock signal (Mux_G) is applied, and the drain electrode is connected to the first sensing channel (SC1) of the data driver 12 and the source. The electrode is connected to the third data line DL3. Accordingly, when the second multiplexer clock signal Mux_G is applied, the sensing data Sen_G of the G sub-pixel G is received by the data driver 12 through the third data line DL3.

The gate electrode of the third sensing multiplexer TFT (BS_TFT) is connected to the signal line to which the third multiplexer clock signal Mux_B is applied, and the drain electrode is connected to the first sensing channel SC1 of the data driver 12 and the source. The electrode is connected to the fourth data line DL4. Accordingly, when the third multiplexer clock signal Mux_B is applied, the sensing data Sen_B of the B sub-pixel B is received by the data driver 12 through the fourth data line DL4.

Although not shown in FIG. 3, the multiplexer circuit 200 includes, in addition to the above-described first to third data multiplexer TFTs (RD_TFT, GD_TFT, BD_TFT), another number of other connected to each of the remaining output channels DC2 to DCn. The first to third data multiplexer TFTs (RD_TFT, GD_TFT, BD_TFT) are further included, and the other first to third data multiplexer TFTs (RD_TFT, GD_TFT, BD_TFT) are also included in the aforementioned first data channel DC1. It is connected between the corresponding output channel and the corresponding data lines in the same manner as the connected first to third data multiplexer TFTs (RD_TFT, GD_TFT, BD_TFT).

In addition, in addition to the first to third sensing multiplexer TFTs (RS_TFT, GS_TFT, BS_TFT), another plurality of first to third sensing multiplexer TFTs (RS_TFT, GS_TFT, connected to each of the remaining sensing channels SC2 to SCn) BS_TFT), and further including the first to third sensing multiplexer TFTs (RS_TFT, GS_TFT, BS_TFT), the first to third sensing multiplexer TFTs (RS_TFT, respectively) connected to the aforementioned first sensing channel SC1. It is connected between the corresponding sensing channel and the corresponding data lines in the same way as GS_TFT and BS_TFT).

Meanwhile, all the first data multiplexer TFTs (RD_TFTs) and the first sensing multiplexer TFTs (RS_TFTs) included in the multiplexer circuit 200 commonly supply the first multiplexer clock signal Mux_R regardless of the sensing channel to which they are connected. Receive. In addition, all the second data multiplexer TFTs (GD_TFT) and the second sensing multiplexer TFTs (RS_TFT) are commonly supplied with the second multiplexer clock signal Mux_G, and all the third data multiplexer TFTs (BD_TFT) and the third sensing multiplexer. TFTs (BS_TFTs) are commonly supplied with a third multiplexer clock signal (Mux_B).

4 is a circuit diagram illustrating a sub-pixel of a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the sub-pixel SP includes an OLED, a driving TFT (Thin Film Transistor) (DT), a storage capacitor (Cst), a first switch TFT (SW1), a second switch TFT (SW2), and a third A switch TFT (SW3) can be provided. However, it should be noted that the pixel configuration of FIG. 4 is only an example, and the technical idea of the present invention is not limited to the pixel structure.

The first scan signal SCAN1, the second scan signal SCAN2, and the sensing selection signal SENSE input to each of the switch TFTs SW1, SW2, and SW3 may be output from the gate driver 13. The first scan signal SCAN1 and the second scan signal SCAN2 may include a scan signal for sensing mode or image display mode. The data voltage Vdata supplied to the data line DLN includes image data or sensing data, and the sensing data Sen_data output from another data line DLN+1 includes sensing data in the sub-pixel SP. It may be a current value flowing through the OLED as it is input.

The OLED emits light according to the driving current input from the driving TFT (DT). The OLED includes an anode electrode, a cathode electrode, and an organic compound layer positioned between the anode electrode and the cathode electrode. The anode electrode is connected to the second node N2, which is the source electrode of the driving TFT DT. The cathode electrode is connected to the input terminal of the low potential driving voltage (EVSS).

The driving TFT DT controls the driving current input to the OLED according to the gate-source voltage Vgs. The driving TFT DT includes a gate electrode connected to the first node N1, a drain electrode connected to the input terminal of the high potential driving voltage EVDD, and a source electrode connected to the second node N2.

The storage capacitor Cstg is connected between the first node N1 and the second node N2 to maintain the gate-source voltage Vgs of the driving TFT DT for a predetermined time.

The first switch TFT SW1 applies the data voltage Vdata supplied to the data line DLN to the first node N1 in response to the first scan signal SCAN1. The second switch TFT SW2 applies a reference voltage Vref to the second node N2 in response to the second scan signal SCAN2. Accordingly, the voltage difference between the first node N1 and the second node N2, that is, the data voltage Vdata is reflected in the gate-source voltage Vgs of the driving TFT DT. The driving TFT DT may control the driving current input to the OLED according to the gate-source voltage Vgs to emit the OLED at a desired gray level.

The third switch TFT SW3 connects the second node N2 and the data line DLN+1 in response to the sensing selection signal SENSE. Accordingly, when the data voltage Vdata is applied to the gate electrode of the driving TFT DT, the threshold voltage of the driving TFT DT can be sensed. If there is no voltage input to the gate electrode, the current of the OLED can be directly detected. Can.

5 is a diagram showing the flow of data in the display device of the present invention.

The present invention is provided with a multiplexer circuit 200 in the display panel 10 through output channels DC1 to DCn and sensing channels SC1 to SCn that are less than the number of data lines DL arranged in a horizontal line. Video display mode and sensing mode can be performed. In the following description, a case in which one channel is allocated per unit pixel including the R sub-pixel R, the G sub-pixel G, and the B sub-pixel B will be described as an example.

Referring to FIG. 5, one output channel (DC) and one sensing channel (SC) are allocated per three sub-pixels including R sub-pixel (R), G sub-pixel (G), and B sub-pixel (B). Can be.

The multiplexer circuit provided in the display panel includes a data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) and an output channel of sensing data (Sen_data), which selectively connect the supply channels of the data voltage (Vdata) and data lines (DL1 to DL4). And a sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT) that selectively connects the data lines DL1 to DLj. One data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) and one sensing multiplexer TFT (RS_TFT) may be connected to each of the R sub-pixel (R) column, the G sub-pixel (G) column, and the B sub-pixel (B) column. have. The data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) and the sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT) selectively connect the data lines DL1 to DL4 according to the multiplexer clock signals (Mux_R, Mux_G, Mux_B) input from the outside. do.

The first data multiplexer TFT (RD_TFT) connects the first data line DL1 to which the first switch TFT SW1 of the R sub-pixel R is connected according to the first multiplexer clock signal Mux_R, to the first data channel DC1. And the second data multiplexer TFT (GD_TFT) is connected to the second data line DL2 to which the first switch TFT SW1 of the G sub-pixel G is connected according to the second multiplexer clock signal Mux_G. The third data line DL3 connected to the channel DC1 and the third data multiplexer TFT (BD_TFT) connected to the first switch TFT SW1 of the B sub-pixel B according to the third multiplexer clock signal Mux_B Is connected to the first data channel DC1.

The gate electrode of the first data multiplexer TFT (RD_TFT) is connected to the signal line to which the first multiplexer clock signal Mux_R is applied, and the drain electrode is connected to the first data channel DC1 of the data driver 12 and the source. The electrode is connected to the first data line DL1. Accordingly, when the first multiplexer clock signal Mux_R is applied, the R image data VR output from the data driver 12 or sensing data is supplied to the R sub-pixel R through the first data line DL1. . The R image data VR applied to the R sub-pixel R or sensing data is reflected in the gate-source voltage Vgs of the driving TFT DT. The driving TFT DT may control the driving current input to the OLED according to the gate-source voltage Vgs.

The gate electrode of the first sensing multiplexer TFT (RS_TFT) is connected to the signal line to which the first multiplexer clock signal Mux_R is applied, and the drain electrode is connected to the first sensing channel SC1 of the data driver 12 and the source. The electrode is connected to the second data line DL2. Accordingly, when the first multiplexer clock signal Mux_R is applied, the sensing data Sen_R of the R sub-pixel R is received by the data driver 12 through the second data line DL2.

The gate electrode of the second data multiplexer TFT (GD_TFT) is connected to the signal line to which the second multiplexer clock signal Mux_G is applied, and the drain electrode is connected to the first data channel DC1 of the data driver 12 and the source. The electrode is connected to the Nth data line DLN. Accordingly, when the second multiplexer clock signal Mux_G is applied, the G image data VG or sensing data output from the data driver 12 is supplied to the G subpixel G through the Nth data line DLN. . The G image data VR applied to the G sub-pixel G or sensing data is reflected in the gate-source voltage Vgs of the driving TFT DT. The driving TFT DT may control the driving current input to the OLED according to the gate-source voltage Vgs.

The gate electrode of the second sensing multiplexer TFT (GS_TFT) is connected to the signal line to which the second multiplexer clock signal (Mux_G) is applied, and the drain electrode is connected to the first sensing channel (SC1) of the data driver 12 and the source. The electrode is connected to the N+1 data line DLN+1. Accordingly, when the second multiplexer clock signal Mux_G is applied, the sensing data Sen_G of the G sub-pixel G is received by the data driver 12 through the N+1 data line DLN+1.

The gate electrode of the third data multiplexer TFT (BD_TFT) is connected to the signal line to which the third multiplexer clock signal Mux_B is applied, and the drain electrode is connected to the first data channel DC1 of the data driver 12 and the source. The electrode is connected to the third data line DL3. Accordingly, when the third multiplexer clock signal Mux_B is applied, the B image data VB output from the data driver 12 or sensing data is supplied to the B sub-pixel B through the third data line DL3. . The B image data VB applied to the B sub-pixel B or sensing data is reflected in the gate-source voltage Vgs of the driving TFT DT. The driving TFT DT may control the driving current input to the OLED according to the gate-source voltage Vgs.

The gate electrode of the third sensing multiplexer TFT (BS_TFT) is connected to the signal line to which the third multiplexer clock signal Mux_B is applied, and the drain electrode is connected to the first sensing channel SC1 of the data driver 12 and the source. The electrode is connected to the fourth data line DL4. Accordingly, when the third multiplexer clock signal Mux_B is applied, the sensing data Sen_B of the B sub-pixel B is received through the fourth data line DL4 to the first sensing channel SC1 of the data driver 12. do.

As described above, the present invention performs various modes by connecting each sub-pixel to the Nth data line and the N+1 data line, and controlling the connection between each data line and the data driver using a data multiplexer and a sensing multiplexer. Can.

The image display mode can be performed by connecting the Nth data line of the sub-pixel to the data channel of the data driver and supplying image data to each data line, and connecting the Nth data line of the sub-pixel to the data channel of the data driver. The threshold voltage of the driving TFT (DT) included in each sub-pixel may be sensed by supplying data for sensing to each data line and connecting the N+1 data line to the sensing channel of the data driver. By connecting the +1 data line to the sensing channel of the data driver, the current of the OLED included in each sub-pixel may be sensed.

FIG. 6 is a diagram showing the operating principle of the multiplexer circuit and the sub-pixel in the image display mode, and FIG. 7 is a diagram showing a driving waveform in the operation of FIG. The driving waveform of FIG. 7 illustrates a case where both the sub-pixel SP and the multiplexer circuit 200 are composed of N-type TFTs, where the high level is on level and the low level is off level.

In the video display mode, the first scan signal SCAN1 and the second scan signal SCAN2 are input at a high level, and the sensing selection signal SENSE is input at a low level. Accordingly, the first switch TFT SW1 and the second switch TFT SW2 of each sub-pixel are turned on and the third switch TFT SW3 is turned off. As the first switch TFT SW1 is turned on, each sub pixel is connected to the first data line DL1 through the first switch TFT SW1, and each sub pixel is turned on as the second switch TFT SW2 is turned on. A reference voltage Vref is input to the pixel. Accordingly, image data Vdata input through the first data line may be input to the gate electrode of the driving TFT DT. Since the third switch TFT SW3 is in an off state, it is not connected to the second data line DL2 for sensing.

In the video display mode, the first multiplexer clock signal (Mux_R), the second multiplexer clock signal (Mux_G), and the third multiplexer clock signal (Mux_B) are sequentially input, such that the first data multiplexer TFT (RD_TFT), the second data multiplexer TFT (GD_TFT), the third data multiplexer TFTs (BD_TFT) are turned on in the order of ①, ②, and ③.

As the first multiplexer clock signal Mux_R is input, the first data multiplexer TFT (RD_TFT) connects the first data line DL1 to which the first switch TFT SW1 of the R sub-pixel R is connected to the first data channel ( DC1). Accordingly, as shown in ① in FIG. 7, R image data VR is supplied to the R sub-pixel R through the first data line DL1. The R image data VR input to the R sub-pixel R is reflected in the gate-source voltage Vgs of the driving TFT DT, so that the driving current input to the OLED is controlled. Accordingly, the R sub-pixel R may emit light with the gray level of the R image data VR.

As the second multiplexer clock signal Mux_G is input, the second data multiplexer TFT (GD_TFT) connects the second data line DL2 to which the first switch TFT SW1 of the G sub-pixel G is connected to the first data channel ( DC1). Accordingly, as shown in ② in FIG. 7, the G image data VG is supplied to the data line as the G sub-pixel G. The G image data VG input to the G sub-pixel G is reflected in the gate-source voltage Vgs of the driving TFT DT, so that the driving current input to the OLED is controlled. Accordingly, the G sub-pixel G may emit light with the gray level of the G image data VG.

As the third multiplexer clock signal Mux_B is input, the third data multiplexer TFT (BD_TFT) connects a third data line to which the first switch TFT SW1 of the B sub-pixel B is connected to the first data channel DC1. Connect to. Accordingly, B image data VB is supplied to the B sub-pixel B through the data line as shown in ③ of FIG. 7. The B image data VB input to the B sub-pixel B is reflected in the gate-source voltage Vgs of the driving TFT DT, so that the driving current input to the OLED is controlled. Accordingly, the B sub-pixel B may emit light with the gray level of the B image data VB.

As described above, in the image display mode, the first multiplexer clock signal (Mux_R), the second multiplexer clock signal (Mux_G), and the third multiplexer clock signal (Mux_B) are sequentially input, such that the first data multiplexer TFT (RD_TFT), the first The two data multiplexer TFTs (GD_TFT) and the third data multiplexer TFTs (BD_TFT) are sequentially turned on to supply image data Vdata to each pixel.

8 is a diagram showing the operating principle of the multiplexer circuit and the sub-pixel in the sensing mode according to the first embodiment of the present invention, and FIG. 9 is a diagram showing a driving waveform in the operation of FIG. 8. The first embodiment of the present invention illustrates a method of sensing the threshold voltage Vth of the driving TFT DT of the sub-pixel. The driving waveform of FIG. 9 illustrates a case where both the sub-pixel SP and the multiplexer circuit 200 are composed of N-type TFTs, where the high level is on level and the low level is off level.

In the sensing mode according to the first embodiment, the first scan signal SCAN1 is input at a high level, and the second scan signal SCAN2 is input at a low level after the high level. In the sensing mode, the sensing selection signal SENSE is input at a high level. Accordingly, the first switch TFT SW1 of the sub-pixel is turned on, the second switch TFT SW2 is turned on and then turned off, and the third switch TFT SW3 is turned on. As the first switch TFT SW1 is turned on, sensing data may be input through the Nth data line. When the second switch TFT (SW2) is turned on, the reference voltage (Vref) is input, and then the second switch TFT (SW2) is turned off. Since the third switch TFT (SW3) is turned on, the N+1 data line for sensing is connected to the source terminal of the driving TFT (DT). In the sensing mode, since the third switch TFT (SW3) of the sub-pixel is turned on, data lines of neighboring sub-pixels can be used as the sensing line. Accordingly, the sensing data Sen_DT of the threshold voltage Vth of the driving TFT DT may be sensed by sensing the voltage of the source terminal of the driving TFT DT according to the sensing data through the N+1 data line. .

In the sensing mode according to the first embodiment, the first multiplexer clock signal (Mux_R), the second multiplexer clock signal (Mux_G), and the third multiplexer clock signal (Mux_B) are sequentially input, such that the first data multiplexer TFT (RD_TFT) and The first sensing multiplexer TFT (RS_TFT), the second data multiplexer TFT (GD_TFT) and the second sensing multiplexer TFT (GS_TFT), the third data multiplexer TFT (BD_TFT), and the third sensing multiplexer TFT (BS_TFT) are turned on in this order. That is, the R sub-pixel (R) line, the G sub-pixel (G) line, and the B sub-pixel (B) line are sequentially sensed.

FIG. 8 illustrates a case where the first multiplexer clock signal Mux_R is input to sense the R sub-pixel R line, and the first data multiplexer TFT (RD_TFT) and the first sensing multiplexer TFT (RS_TFT) are connected.

The first data multiplexer TFT (RD_TFT) connects the first data line DL1 to which the first switch TFT SW1 of the R sub-pixel R is connected to the first data channel DC1. Accordingly, sensing data is supplied to the R sub-pixel R through the first data line DL1. The second switch TFT (SW2) is initially turned on and then kept in an off state. Since the source end of the driving TFT DT is connected to the second data line DL2 through the third switch TFT SW3, sensing data according to Vth of the driving TFT DT through the second data line DL2. (Sen_DT) can be detected. Thereafter, the sensing data can be sensed in the same manner for the G sub-pixels G and B sub-pixels B.

FIG. 10 is a diagram showing the operating principle of the multiplexer circuit and the sub-pixel in the sensing mode according to the second embodiment of the present invention, and FIG. 11 is a diagram showing a driving waveform in the operation of FIG. The second embodiment of the present invention illustrates a method of sensing the current of the OLED of the sub-pixel. The driving waveform of FIG. 11 illustrates a case where both the sub-pixel SP and the multiplexer circuit 200 are made of an N-type TFT, where the high level is on level and the low level is off level.

In the sensing mode according to the second embodiment, the first scan signal SCAN1 is input at a high level, the second scan signal SCAN2 is input at a low level, and the sensing selection signal SENSE is input at a high level. Accordingly, the first switch TFT SW1 of the sub-pixel is turned on, the second switch TFT SW2 is turned off, and the third switch TFT SW3 is turned on. Since the first switch TFT (SW1) is turned on and the second switch TFT (SW2) is turned off, the sub-pixel has sensing data input through the first data line DL1 to the gate electrode of the driving TFT (DT). Can be entered. Since the third switch TFT SW3 is turned on, the second data line DL2 for sensing is connected to the source terminal of the driving TFT DT. In the sensing mode, since the third switch TFT (SW3) of the sub-pixel is turned on, data lines of neighboring sub-pixels can be used as the sensing line.

In the sensing mode according to the second embodiment, the first multiplexer clock signal (Mux_R), the second multiplexer clock signal (Mux_G), and the third multiplexer clock signal (Mux_B) are sequentially input, such that the first data multiplexer TFT (RD_TFT) and The first sensing multiplexer TFT (RS_TFT), the second data multiplexer TFT (GD_TFT) and the second sensing multiplexer TFT (GS_TFT), the third data multiplexer TFT (BD_TFT), and the third sensing multiplexer TFT (BS_TFT) are turned on in this order. That is, the R sub-pixel (R) line, the G sub-pixel (G) line, and the B sub-pixel (B) line are sequentially sensed. FIG. 10 illustrates a case in which the first multiplexer clock signal Mux_R is input to sense the R sub-pixel R line, and the first data multiplexer TFT (RD_TFT) and the first sensing multiplexer TFT (RS_TFT) are connected.

The first data multiplexer TFT (RD_TFT) connects the first data line DL1 to which the first switch TFT SW1 of the R sub-pixel R is connected to the first data channel DC1. Accordingly, sensing data is supplied to the R sub-pixel R through the first data line DL1. The second switch TFT (SW2) is kept off. The sensing data input to the R sub-pixel R maintains an input state to the gate electrode of the driving TFT DT, so that the driving TFT DT supplies a driving current. Since the source terminal of the driving TFT DT is connected to the second data line DL2 through the third switch TFT SW3, the current flowing through the OLED of the R sub-pixel R through the second data line DL2 Can detect. Thereafter, the sensing data can be sensed in the same manner for the G sub-pixels G and B sub-pixels B.

As described above, the present invention can reduce the number of channels of the data driving unit by providing a multiplexer so that sensing data input from a plurality of sensing lines is input to a single sensing channel of the data driving unit.

The display device of the present invention connects adjacent sub-pixels so as to share one data line with each other, and sequentially senses sub-pixels for each data line in the sensing mode, but senses data as the data line of the sub-pixel currently being sensed. The next data line, which is a data line that is not supplied and sensed, is used as a sensing line. Accordingly, the sensing line, which was provided to directly sense the OLED current in the existing pixel array, can be deleted.

Through the above description, those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical idea of the present specification. Therefore, the technical scope of the present specification is not limited to the contents described in the detailed description of the specification, but should be determined by the scope of the claims.

10: display panel 11: timing controller
12: data driver 13: gate driver
200: multiplexer

Claims (15)

A pixel array connected such that neighboring sub-pixels share one data line with each other;
A data driver that supplies image data of each sub-pixel through a data channel in an image display mode and receives sensing data of each sub-pixel through a sensing channel in a sensing mode; And
And a multiplexer connecting the pixel array and the data driver according to a multiplexer signal,
The multiplexer,
In order to output image data to the Nth data line connected to the Nth sub-pixel in the image display mode, connect the data channel of the data driver and the Nth data line,
In the sensing mode, to sense the Nth subpixel through the N+1 data line connected to the N+1 subpixel, a display device connecting the sensing channel of the data driver to the N+1 data line. According to claim 1,
The multiplexer,
A data multiplexer TFT that receives the multiplexer signal in the image display mode and connects the Nth data line and the data channel; And
And a sensing multiplexer TFT that receives the multiplexer signal in the sensing mode and connects the N+1 data line and the sensing channel. According to claim 1,
The data multiplexer TFT,
And a gate electrode to which the multiplexer signal is input, a first electrode to be connected to the data channel, and a second electrode to be connected to the Nth data line to which the Nth sub-pixel is connected. According to claim 1,
The sensing multiplexer TFT,
A display device including a gate electrode to which the multiplexer signal is input, a first electrode connected to the sensing channel, and a second electrode connected to the N+1 data line to which the Nth sub-pixel is connected. According to claim 2,
The data multiplexer TFT,
A first data multiplexer TFT that outputs image data of red (R) sub-pixels;
A second data multiplexer TFT that outputs image data of the green (G) sub-pixel; And
A third data multiplexer TFT that outputs image data of blue (B) sub-pixels;
Display device comprising a. The method of claim 5,
The first data multiplexer TFT, the second data multiplexer TFT, and the third data multiplexer TFT are sequentially turned on display device. The method of claim 6,
The data driving unit,
A display device that outputs image data of the red (R) sub-pixel, image data of the green (G) sub-pixel, and image data of the blue (B) sub-pixel through one data channel in the image display mode. According to claim 2,
The sensing multiplexer TFT,
A first sensing multiplexer TFT that outputs sensing data of a red (R) sub-pixel;
A second sensing multiplexer TFT that outputs sensing data of the green (G) sub-pixel; And
A third sensing multiplexer TFT that outputs sensing data of the blue (B) sub-pixel;
Display device comprising a. The method of claim 8,
The first sensing multiplexer TFT, the second sensing multiplexer TFT, and the third sensing multiplexer TFT are sequentially turned on. The method of claim 9,
The data driving unit,
In the sensing mode, a display device for sensing the sensing data of the red (R) sub-pixel, the sensing data of the green (G) sub-pixel, and the sensing data of the blue (B) sub-pixel through one sensing channel. According to claim 1,
The N+1 data line,
The N+1 sub-pixel and the N-th sub-pixel are connected, and in the image display mode, image data is applied to the N+1 sub-pixel connected to the N+1 data line, and in the sensing mode, the first A display device that outputs sensing data of an Nth sub-pixel connected to an N+1 data line. According to claim 1,
The Nth sub-pixel,
Light emitting element;
A driving TFT for controlling a current applied to the light emitting device according to a voltage difference between a gate and a source, including a gate electrode to which a data voltage is applied and a source electrode connected to an anode of the light emitting device; And
A display device comprising a switch TFT that is turned on in the sensing mode to connect a source electrode of the driving TFT and an anode of a light emitting element and a switch TFT connecting the N+1 data line. The method of claim 12,
The switch TFT,
A display device including a gate electrode receiving a sensing mode selection signal, a first electrode connected to a power line connecting the source electrode of the driving TFT and the anode of the light emitting device, and a second electrode connected to the N+1 data line. . A pixel array connected so that neighboring sub-pixels share one data line with each other, supply image data of each sub-pixel through a data channel in image display mode, and sense data of each sub-pixel through a sensing channel in sensing mode. In the driving method of a display device including a data driver for receiving,
Connecting the data channel of the data driver and the Nth data line to output image data to an Nth data line connected to an Nth subpixel in the image display mode; And
Connecting the sensing channel of the data driver and the N+1 data line to sense the N-th sub-pixel through the N+1 data line connected to the N+1 sub-pixel in the sensing mode;
Method of driving a display device comprising a. The method of claim 14,
Supplying sensing data to the Nth sub-pixel through the Nth data line in the sensing mode; And
Receiving sensing data of the Nth sub-pixel through the N+1 data line;
Method of driving a display device further comprising a.

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