KR102612739B1 - Display Device And Driving Method Thereof - Google Patents

Abstract

The present invention relates to a display device, comprising: a pixel array connected so that neighboring sub-pixels mutually share one data line; 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 outputs image data to an N-th data line connected to the N-th sub-pixel in the image display mode. To connect the data channel and the Nth data line, and to sense the Nth subpixel through the N+1th data line connected to the N+1th subpixel in the sensing mode, a sensing channel of the data driver and Connect the N+1 data line.

Description

Display device and driving method thereof {Display Device And Driving Method Thereof}

The present invention relates to a display device and a method of driving the same.

Display devices are widely used in not only desktop computer monitors, but also portable computers such as laptop computers and PDAs, and mobile phone terminals due to their advantage in miniaturization and weight reduction.

Among display devices, the active matrix type organic light emitting display device includes organic light emitting diodes (hereinafter referred to as "OLED") that emit light on their own, and has a fast response speed, luminous efficiency, brightness and It has the advantage of a large viewing angle and is widely used.

The display device includes a display panel including pixels arranged in a matrix, a gate driver that outputs a scan signal, and a data driver that outputs a data signal. The pixels of the display panel include OLED and TFTs (Thin Film Transistors) to control the driving current flowing through the OLED. As the driving time increases, the electrical characteristics of the pixel change, which may lead to image quality deterioration. Accordingly, it performs a function of sensing and compensating the current of the pixel.

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 assigned to each pixel, the number of sensing lines equal to the number of pixels arranged in the horizontal line is required, and the data driver requires a corresponding number of sensing channels. Accordingly, as the number of sensing lines increases due to an increase in resolution and panel size, there is a problem in that the number of channels in the data driver increases accordingly.

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

A display device according to an embodiment of the present invention includes a pixel array connected so that neighboring sub-pixels mutually share one data line; 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 outputs image data to an N-th data line connected to the N-th sub-pixel in the image display mode. To connect the data channel and the Nth data line, and to sense the Nth subpixel through the N+1th data line connected to the N+1th subpixel in the sensing mode, a sensing channel of the data driver and Connect the N+1 data line.

The multiplexer includes a data multiplexer TFT that receives the multiplexer signal in the image display mode and connects the N-th 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 through which the multiplexer signal is input, a first electrode connected to the data channel, and a second electrode connected to the N-th data line to which the N-th subpixel is connected.

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

The data multiplexer TFT includes: a first data multiplexer TFT that outputs image data of a red (R) subpixel; a second data multiplexer TFT that outputs image data of a green (G) subpixel; and a third data multiplexer TFT that outputs image data of a blue (B) subpixel.

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

The data driver outputs image data of the red (R) subpixel, image data of the green (G) subpixel, and image data of the blue (B) subpixel 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) subpixel; a second sensing multiplexer TFT that outputs sensing data of a green (G) subpixel; and a third sensing multiplexer TFT that outputs sensing data of a blue (B) subpixel.

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

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

The N+1-th data line is connected to the N+1-th subpixel and the N-th subpixel, and sends image data to the N+1-th subpixel connected to the N+1-th data line in the image display mode. is applied, and the sensing data of the Nth subpixel connected to the N+1th data line is output in the sensing mode.

The Nth subpixel includes a switch TFT that is turned on in the sensing mode and connects a sensing terminal of the Nth subpixel and the N+1th data line.

The N-th subpixel is a light emitting device; and a driving TFT that includes a gate electrode to which a data voltage is applied and a source electrode connected to the anode of the light emitting device, and controls the current applied to the light emitting device according to the voltage difference between the gate and source. The switch TFT includes a gate electrode that receives 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 first electrode connected to the N+1 data line. Includes a second electrode.

The display device of the present invention can reduce the number of channels in the data driver 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 driver.

The display device of the present invention connects neighboring subpixels to share one data line and sequentially senses the subpixels for each data line in a sensing mode, and transmits sensing data to the data line of the subpixel currently being sensed. The next data line, which is a data line that is not being supplied or sensed, is used as a sensing line. Accordingly, the sensing line provided to directly sense OLED current in the existing pixel array can be deleted.

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

The advantages and features of the present specification and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below and will be implemented in various different forms, but the present embodiments only serve to ensure that the disclosure of the present specification is complete, and that common knowledge in the technical field to which this specification pertains is provided. It is provided to fully inform those who have the scope of the invention, and this specification is only defined by the scope of the claims.

The shape, size, ratio, angle, number, etc. disclosed in the drawings for explaining the embodiments of the present specification are illustrative, and the present specification is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. When 'includes', 'has', 'consists of', etc. mentioned in the specification are used, other parts may be added unless '~ only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

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

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

Like reference numerals refer to substantially like elements throughout the specification.

In this specification, the pixel circuit and the gate driver formed on the substrate of the display panel may be implemented as a TFT with an n-type MOSFET (Metal Oxide Semiconductor Field Effect Transistor) structure, but are not limited to this and may also be implemented as a TFT with a p-type MOSFET structure. there is. TFT is a three-electrode device including a gate, source, and drain. The source is an electrode that supplies carriers to the transistor. Within the TFT, carriers begin to flow from the source. The drain is the electrode through which carriers go out of the TFT. That is, the flow of carriers in the MOSFET flows from the source to the drain. In the case of n-type TFT (NMOS), because the carriers are electrons, the source voltage has a lower voltage than the drain voltage to allow electrons to flow from the source to the drain. Since electrons flow from the source to the drain in an n-type TFT, the direction of current flows from the drain to the source. On the other hand, in the case of p-type TFT (PMOS), since the carrier is a hole, the source voltage is higher than the drain voltage so that holes can flow from the source to the drain. In a 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 a MOSFET can change depending on the applied voltage. Accordingly, in the description of the embodiments of the present specification, one of the source and the drain is described as the first electrode, and the other one 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 attached drawings. In the following embodiments, the description will focus on 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 organic light emitting display devices, but can be applied to inorganic light emitting display devices including inorganic light emitting materials.

In the following description, if it is determined that a detailed description of a known function or configuration related to the present specification may unnecessarily obscure the gist of the present specification, the detailed description will be omitted.

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

Referring to FIG. 1, a display device according to an embodiment of the present invention includes a display panel 10 on which subpixels (SP) are formed, image data supplied to the display panel 10 through a channel 14, and each subpixel A data driver 12 that receives sensing data of (SPs), a gate driver circuit 13 for driving the gate lines 15, and a driving timing of the data driver 12 and the gate driver circuit 13. It is provided with a timing controller 11 that controls it.

Subpixels SP are arranged in a matrix form on the display panel 10. The subpixels (SP) can be commonly supplied with high-potential and low-potential driving voltages (EVDD and EVSS) and a reference voltage (Vref). Each subpixel (SP) may include an OLED. OLED, a self-luminous device, includes an anode electrode and a cathode electrode, and an organic compound layer formed between them. Each of the subpixels SP may be one of a red pixel, a green pixel, a blue pixel, and a white pixel. Red pixels, green pixels, blue pixels, and white pixels may constitute one unit pixel for color implementation. The subpixels (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 to match the resolution of the display panel 10 and supplies it to the data driver 12. The timing controller 11 controls the operation timing of the data driver 12 based on timing signals such as the vertical synchronization signal (Vsync), the horizontal synchronization signal (Hsync), the dot clock signal (DCLK), and the data enable signal (DE). A data control signal (DDC) for controlling and a gate control signal (GDC) for controlling the operation timing of the gate driving circuit 13 are generated.

The gate driver 13 may generate a scan signal (SCAN) based on the gate control signal (GDC). The gate driver 13 may supply a scan signal SCAN to the gate line 15 connected to each pixel row in a row sequential manner. This gate driver 13 may be formed directly on the non-display area of the display panel 10 according to the 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 can convert digital video data (RGB) input from the timing controller 11 into image data in the form of analog voltage based on the data control signal (DDC) and output it through the channel 14.

Additionally, the data driver 12 according to an embodiment of the present invention can supply voltage data for sensing to the display panel 10 and receive sensing data of each subpixel (SP) in the sensing mode. The data driver 12 generates voltage data for sensing and outputs it to the display panel 10 to sense the current characteristics of the OLED included in each subpixel SP. Afterwards, the current applied to the OLED can be sensed according to the sensing voltage data and processed as sensing data.

Here, the timing controller 11 can temporally separate sensing driving in the sensing mode and display driving in the image display mode according to a predetermined control sequence. When driving a 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 drive may include driving to sense the current characteristics of the OLED in the display panel 10 and update the compensation value accordingly. The timing controller 11 can sense the current characteristics of the OLED through sensing drive and compensate for the image data input to the display panel 10 according to the sensing result.

FIG. 2 is a diagram showing the configuration of the 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-dividedly outputs image data output from the data driver 12. there is.

The display area (AA) includes a plurality of gate lines 15 arranged in the horizontal direction, j (j is a natural number) data lines (DL1 to DLj) arranged in the vertical direction, and subpixels connected to the current line and the next line. (SP) may be included. Accordingly, the Nth subpixel (SP) is connected to the Nth data line and the N+1th data line, so that neighboring subpixels (SP) can share the data line. Each subpixel (SP) is connected only to the N-th data line in the image display mode and receives image data through the N-th data line. In sensing mode, it is connected to the N-th data line and the N+1-th data line, receives voltage data for sensing through the N-th data line, and outputs sensing data through the N+1-th data line. Each subpixel (SP) includes a plurality of R subpixels (R) for displaying a red image, a plurality of G subpixels (G) for displaying a green image, and a plurality of B subpixels (G) for displaying a blue image. (B) and subpixels 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), which are fewer than the j data lines (DL1 to DLj) arranged in one horizontal line. Each channel may be allocated one channel per unit pixel including an R subpixel (R), a G subpixel (G), and a B subpixel (B). That is, one output channel (DC) and one sensing channel (SC) can be allocated per three subpixels.

The data driver 12 converts digital video data (RGB) input from the timing controller 11 into RGB analog data voltage to generate image data, and transmits the generated 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 the subpixels (SP) of one horizontal line into RGB analog data voltage signals, and configures j pieces of image data for one horizontal line into smaller numbers. It is output through n output channels (DC1 to DCn).

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

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

The multiplexer circuit 200 transfers image data or sensing data by selectively connecting n output channels (DC1 to DCn) with j data lines (DL1 to DLj). In addition, n sensing channels (SC1 to SCn) are selectively connected to j data lines (DL1 to DLj) to transmit sensing data.

Figure 3 shows the circuit configuration of the multiplexer circuit 200, which provides one output channel ( The configuration of the multiplexer circuit 200 is disclosed when allocating DC) and one sensing channel (SC).

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

The data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) and sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT) selectively connect data lines (DL1 to DL4) according to the multiplexer clock signal (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 N-th data line to output image data to the N-th data line connected to the N-th subpixel, and operates in the sensing mode. In order to sense the N-th subpixel through the N+1-th data line connected to the N+1-th subpixel, the sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT) uses a sensing channel (SC) and the N+1-th data line. Connect.

Each subpixel (R, G, B) is connected to the N data line and the N+1 data line, and neighboring subpixels (SP) share the data line. Each subpixel (R, G, B) is connected only to the N-th data line in the image display mode and receives image data through the N-th data line. In sensing mode, it is connected to the N-th data line and the N+1-th data line, receives voltage data for sensing through the N-th data line, and outputs sensing data through the N+1-th data line.

The first data multiplexer TFT (RD_TFT) connects the output channel (DC1) of the data driver 12 and the data line (DL1) to which the R subpixel (R) is 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 subpixel (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 subpixel (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, the drain electrode is connected to the first data channel (DC1) of the data driver 12, and the source electrode is connected to the first data channel (DC1) of the data driver 12. 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) or sensing data output from the data driver 12 is supplied to the R subpixel (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, the drain electrode is connected to the first data channel (DC1) of the data driver 12, and the source electrode is connected to the first data channel (DC1) of the data driver 12. 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 subpixel (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, the drain electrode is connected to the first data channel (DC1) of the data driver 12, and the source electrode is connected to the first data channel (DC1) of the data driver 12. 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) or sensing data output from the data driver 12 is supplied to the B subpixel (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) where sensing data of the R subpixel (R) is received according to the first multiplexer clock signal (Mux_R). And, the second sensing multiplexer TFT (GS_TFT) has a data line (DL3) through which sensing data of the sensing channel (SC1) and the G subpixel (G) of the data driver 12 are received according to the second multiplexer clock signal (Mux_G). is connected, and the third sensing multiplexer TFT (BS_TFT) is a data line ( Connect 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, 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 subpixel (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, 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 subpixel (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, 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 subpixel (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 first to third data multiplexer TFTs (RD_TFT, GD_TFT, BD_TFT) described above, a plurality of other data multiplexer TFTs connected to each of the remaining output channels (DC2 to DCn). It further includes first to third data multiplexer TFTs (RD_TFT, GD_TFT, BD_TFT), and the other first to third data multiplexer TFTs (RD_TFT, GD_TFT, BD_TFT) are also connected to the above-described 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), a plurality of first to third sensing multiplexer TFTs (RS_TFT, GS_TFT, BS_TFT), and the other first to third sensing multiplexer TFTs (RS_TFT, GS_TFT, BS_TFT) are also connected to the above-described first sensing channel (SC1). It is connected between the corresponding sensing channel and the corresponding data lines in the same way as (GS_TFT, BS_TFT).

Meanwhile, all first data multiplexer TFTs (RD_TFT) and first sensing multiplexer TFTs (RS_TFT) 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 TFT (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_TFT) are commonly supplied with the third multiplexer clock signal (Mux_B).

Figure 4 is a circuit diagram showing a subpixel of a display device according to an embodiment of the present invention.

Referring to FIG. 4, the subpixel (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) may be provided. However, it should be noted that the pixel configuration in 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 switch TFT (SW1, SW2, SW3) may be output from the gate driver 13. The first scan signal (SCAN1) and the second scan signal (SCAN2) may include scan signals for a sensing mode or an 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 the other data line (DLN+1) contains sensing data in the subpixel (SP). This may be the current value flowing through the OLED as it is input.

OLED emits light according to the driving current input from the driving TFT (DT). OLED includes an anode electrode, a cathode electrode, and an organic compound layer located 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 certain period of 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 the 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) can control the driving current input to the OLED according to the gate-source voltage (Vgs) to make the OLED emit light 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, if 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 detected, and if there is no voltage input to the gate electrode, the current of the OLED can be directly detected. You can.

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

The present invention is provided with a multiplexer circuit 200 in the display panel 10 to transmit data through fewer output channels (DC1 to DCn) and sensing channels (SC1 to SCn) than the number of data lines (DL) arranged in a horizontal line. Image display mode and sensing mode can be performed. In the following description, an example will be given where one channel is allocated per unit pixel including an R subpixel (R), a G subpixel (G), and a B subpixel (B).

Referring to FIG. 5, one output channel (DC) and one sensing channel (SC) are allocated to each three subpixels including the R subpixel (R), G subpixel (G), and B subpixel (B). It can be.

The multiplexer circuit provided in the display panel includes a data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) that selectively connects the supply channel of the data voltage (Vdata) and the data lines (DL1 to DL4), an output channel of the sensing data (Sen_data), and It includes a sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT) that selectively connects data lines (DL1 to DLj). One data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) and one sensing multiplexer TFT (RS_TFT) can be connected to each of the R subpixel (R) column, G subpixel (G) column, and B subpixel (B) column. there is. The data multiplexer TFT (RD_TFT, GD_TFT, BD_TFT) and sensing multiplexer TFT (RS_TFT, GS_TFT, BS_TFT) selectively connect data lines (DL1 to DL4) according to the multiplexer clock signal (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 subpixel (R) is connected to the first data channel (DC1) according to the first multiplexer clock signal (Mux_R). and the second data multiplexer TFT (GD_TFT) connects the second data line (DL2) to which the first switch TFT (SW1) of the G subpixel (G) is connected to the first data line according to the second multiplexer clock signal (Mux_G). A third data line (DL3) is connected to the channel (DC1), and the third data multiplexer TFT (BD_TFT) is connected to the first switch TFT (SW1) of the B subpixel (B) according to the third multiplexer clock signal (Mux_B). Connect 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, the drain electrode is connected to the first data channel (DC1) of the data driver 12, and the source electrode is connected to the first data channel (DC1) of the data driver 12. 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) or sensing data output from the data driver 12 is supplied to the R subpixel (R) through the first data line (DL1). . R image data (VR) or sensing data applied to the R subpixel (R) is reflected in the gate-source voltage (Vgs) of the driving TFT (DT). The driving TFT (DT) can 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, 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 subpixel (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, the drain electrode is connected to the first data channel (DC1) of the data driver 12, and the source electrode is connected to the first data channel (DC1) of the data driver 12. 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 N-th data line (DLN). . G image data (VR) or sensing data applied to the G subpixel (G) is reflected in the gate-source voltage (Vgs) of the driving TFT (DT). The driving TFT (DT) can 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, 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 subpixel (G) is received by the data driver 12 through the N+1-th 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, the drain electrode is connected to the first data channel (DC1) of the data driver 12, and the source electrode is connected to the first data channel (DC1) of the data driver 12. 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) or sensing data output from the data driver 12 is supplied to the B subpixel (B) through the third data line (DL3). . B image data (VB) or sensing data applied to the B subpixel (B) is reflected in the gate-source voltage (Vgs) of the driving TFT (DT). The driving TFT (DT) can 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, 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 subpixel (B) is received through the first sensing channel (SC1) of the data driver 12 through the fourth data line (DL4). do.

As such, the present invention connects each subpixel to the Nth data line and the N+1th data line, and uses a data multiplexer and a sensing multiplexer to control the connection between each data line and the data driver to perform various modes. You can.

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

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

In the image display mode, the first scan signal (SCAN1) and the second scan signal (SCAN2) are input at high level, and the sensing selection signal (SENSE) is input at low level. Accordingly, the first switch TFT (SW1) and the second switch TFT (SW2) of each subpixel are turned on and the third switch TFT (SW3) is turned off. As the first switch TFT (SW1) is turned on, each subpixel is connected to the first data line (DL1) through the first switch TFT (SW1), and as the second switch TFT (SW2) is turned on, each subpixel is connected to the first data line (DL1) through the first switch TFT (SW1). 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 the 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 to the first data multiplexer TFT (RD_TFT) and the second data multiplexer TFT. (GD_TFT) and the third data multiplexer TFT (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 subpixel (R) is connected to the first data channel ( Connect to DC1). Accordingly, as shown in ① of FIG. 7, R image data VR is supplied to the R subpixel R through the first data line DL1. The R image data (VR) input to the R subpixel (R) is reflected in the gate-source voltage (Vgs) of the driving TFT (DT) to control the driving current input to the OLED. Accordingly, the R subpixel (R) may emit light in the gray scale 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 subpixel (G) is connected to the first data channel ( Connect to DC1). Accordingly, as shown in ② of FIG. 7, G image data (VG) is supplied to the G subpixel (G) through the data line. G image data (VG) input to the G subpixel (G) is reflected in the gate-source voltage (Vgs) of the driving TFT (DT) to control the driving current input to the OLED. Accordingly, the G subpixel (G) may emit light in 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 the third data line to which the first switch TFT (SW1) of the B subpixel (B) is connected to the first data channel (DC1). Connect to Accordingly, as shown in ③ of FIG. 7, B image data (VB) is supplied to the B subpixel (B) through the data line. The B image data (VB) input to the B subpixel (B) is reflected in the gate-source voltage (Vgs) of the driving TFT (DT) to control the driving current input to the OLED. Accordingly, the B subpixel (B) may emit light in the gray level of the B image data (VB).

As described above, 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, and the first data multiplexer TFT (RD_TFT), The second data multiplexer TFT (GD_TFT) and the third data multiplexer TFT (BD_TFT) are sequentially turned on to supply image data (Vdata) to each pixel.

FIG. 8 is a diagram showing the operation principle of the multiplexer circuit and the subpixel in the sensing mode according to the first embodiment of the present invention, and FIG. 9 is a diagram showing the driving waveform during the operation of FIG. 8. The first embodiment of the present invention illustrates a method for sensing the threshold voltage (Vth) of the driving TFT (DT) of the subpixel. The driving waveform in FIG. 9 illustrates a case where both the subpixel (SP) and the multiplexer circuit 200 are composed of N-type TFTs, where the high level is an on level and the low level is an 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 high level and then at a low level. In sensing mode, the sensing selection signal (SENSE) is input at high level. Accordingly, the first switch TFT (SW1) of the subpixel 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 N-th 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, the third switch TFT (SW3) of the subpixel is turned on, so the data line of the neighboring subpixel can be used as a sensing line. Accordingly, by sensing the voltage of the source terminal of the driving TFT (DT) according to the sensing data through the N+1 data line, the sensing data (Sen_DT) of the threshold voltage (Vth) of the driving TFT (DT) can be detected. .

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 to the first data multiplexer TFT (RD_TFT) and The first sensing multiplexer TFT (RS_TFT), the second data multiplexer TFT (GD_TFT), 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 subpixel (R) line, G subpixel (G) line, and B subpixel (B) line are sequentially sensed.

Figure 8 illustrates a case where the first multiplexer clock signal (Mux_R) is input to sense the R subpixel (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 subpixel (R) is connected to the first data channel (DC1). Accordingly, sensing data is supplied to the R subpixel (R) through the first data line (DL1). The second switch TFT (SW2) is initially turned on and then maintained in an off state. Since the source terminal of the driving TFT (DT) is connected to the second data line (DL2) through the third switch TFT (SW3), sensing data according to the Vth of the driving TFT (DT) is transmitted through the second data line (DL2). (Sen_DT) can be detected. Afterwards, sensing data can be detected for the G subpixel (G) and B subpixel (B) in the same manner.

FIG. 10 is a diagram showing the operation principle of the multiplexer circuit and the subpixel in the sensing mode according to the second embodiment of the present invention, and FIG. 11 is a diagram showing the driving waveform during the operation of FIG. 10. The second embodiment of the present invention illustrates a method for sensing the current of the OLED of the subpixel. The driving waveform in FIG. 11 illustrates a case where both the subpixel (SP) and the multiplexer circuit 200 are composed of N-type TFTs, where the high level is an on level and the low level is an 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 subpixel 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 subpixel receives 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, the third switch TFT (SW3) of the subpixel is turned on, so the data line of the neighboring subpixel can be used as a 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 to the first data multiplexer TFT (RD_TFT) and The first sensing multiplexer TFT (RS_TFT), the second data multiplexer TFT (GD_TFT), 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 subpixel (R) line, G subpixel (G) line, and B subpixel (B) line are sequentially sensed. Figure 10 illustrates a case where the first multiplexer clock signal (Mux_R) is input to sense the R subpixel (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 subpixel (R) is connected to the first data channel (DC1). Accordingly, sensing data is supplied to the R subpixel (R) through the first data line (DL1). The second switch TFT (SW2) is maintained in an off state. Sensing data input to the R subpixel (R) is maintained as an input to the gate electrode of the driving TFT (DT), and the driving TFT (DT) supplies 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 to the OLED of the R subpixel (R) through the second data line (DL2) can be detected. Afterwards, sensing data can be detected for the G subpixel (G) and B subpixel (B) in the same manner.

As described above, the present invention can reduce the number of channels in the data driver 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 driver.

The display device of the present invention connects neighboring subpixels to share one data line and sequentially senses the subpixels for each data line in a sensing mode, and transmits sensing data to the data line of the subpixel currently being sensed. The next data line, which is a data line that is not being supplied or sensed, is used as a sensing line. Accordingly, the sensing line provided to directly sense OLED current in the existing pixel array can be deleted.

Through the above-described content, those skilled in the art will be able to see 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 content described in the detailed description of the specification, but should be determined by the scope of the patent claims.

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

Claims (15)

a pixel array connected so that neighboring sub-pixels mutually share one data line;
a data driver that supplies image data representing gray levels to each sub-pixel through a data channel in an image display mode, and receives sensing data that senses electrical characteristics from 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,
Connecting the data channel of the data driver and the N-th data line to output image data to the N-th data line connected to the N-th subpixel in the image display mode,
A display device connecting a sensing channel of the data driver and the N+1-th data line to sense the N-th sub-pixel through an N+1-th data line connected to the N+1-th sub-pixel in the sensing mode. According to paragraph 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
A display device including 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 paragraph 2,
The data multiplexer TFT is,
A display device including a gate electrode through which the multiplexer signal is input, a first electrode connected to the data channel, and a second electrode connected to the N-th data line to which the N-th subpixel is connected. According to paragraph 2,
The sensing multiplexer TFT is,
A display device including a gate electrode through which the multiplexer signal is input, a first electrode connected to the sensing channel, and a second electrode connected to the N+1-th data line to which the N-th subpixel is connected. According to paragraph 2,
The data multiplexer TFT is,
a first data multiplexer TFT that outputs image data of a red (R) subpixel;
a second data multiplexer TFT that outputs image data of a green (G) subpixel; and
a third data multiplexer TFT that outputs image data of a blue (B) subpixel;
A display device including a. According to clause 5,
The first data multiplexer TFT, the second data multiplexer TFT, and the third data multiplexer TFT are sequentially turned on. According to clause 6,
The data driver,
A display device that outputs image data of the red (R) subpixel, image data of the green (G) subpixel, and image data of the blue (B) subpixel through one data channel in the image display mode. According to paragraph 2,
The sensing multiplexer TFT is,
A first sensing multiplexer TFT that outputs sensing data of a red (R) subpixel;
a second sensing multiplexer TFT that outputs sensing data of a green (G) subpixel; and
A third sensing multiplexer TFT that outputs sensing data of a blue (B) subpixel;
A display device including a. According to clause 8,
The first sensing multiplexer TFT, the second sensing multiplexer TFT, and the third sensing multiplexer TFT are sequentially turned on. According to clause 9,
The data driver,
A display device that senses sensing data of the red (R) subpixel, sensing data of the green (G) subpixel, and sensing data of the blue (B) subpixel through one sensing channel in the sensing mode. According to paragraph 1,
The N+1 data line is,
The N+1-th subpixel is connected to the N-th subpixel, image data is applied to the N+1-th subpixel connected to the N+1-th data line in the image display mode, and the N+1-th subpixel is connected to the N+1-th data line in the sensing mode. A display device that outputs sensing data from the Nth subpixel connected to the N+1 data line. According to paragraph 1,
The Nth subpixel is,
light emitting device;
A driving TFT that includes a gate electrode to which a data voltage is applied and a source electrode connected to the anode of the light emitting device, and controls the current applied to the light emitting device according to the voltage difference between the gate and source; and
A display device including a switch TFT that is turned on in the sensing mode and connects a power line connecting the source electrode of the driving TFT and the anode of the light emitting device and the N+1th data line. According to clause 12,
The switch TFT is,
A display device including a gate electrode that receives 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 subpixels mutually share one data line. In image display mode, image data representing gray levels is supplied to each subpixel through a data channel, and in sensing mode, each subpixel is connected through a sensing channel. In a method of driving a display device including a data driver that receives sensing data for sensing electrical characteristics from,
Connecting the data channel of the data driver and the N-th data line to output image data to the N-th data line connected to the N-th subpixel in the image display mode; and
Connecting a sensing channel of the data driver and the N+1-th data line to sense the N-th sub-pixel through an N+1-th data line connected to the N+1-th sub-pixel in the sensing mode;
A method of driving a display device including. According to clause 14,
Supplying data for sensing to the Nth subpixel through the Nth data line in the sensing mode; and
Receiving sensing data of the Nth subpixel through the N+1th data line;
A method of driving a display device further comprising:

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