KR20190066802A - Light Emitting Display Device - Google Patents

Abstract

Provided is an electroluminescent display device. The electroluminescent display device includes: a display panel; a data driving unit; a scan driving unit; a pixel sensing circuit unit; and a compensation value generating unit. The display panel is configured to display an image. The data driving unit is configured to supply a data signal to the display panel. The scan driving unit is configured to supply a scan signal to the display panel. The pixel sensing circuit unit acquires a sensing value through reference lines of pixels included in the display panel. The compensation value generating unit is configured to prepare a compensation value for a pixel sensed on the basis of the sensing value and a compensation value for a pixel that is not sensed on the basis of an interpolation. The pixel sensing circuit unit is configured to simultaneously sense N (N is an integer of 2 or more) pixels, and change a position of a sensed object for at least one pixel. According to the present invention, even when the compensation value is prepared by using the interpolation, accuracy of compensation can be improved.

Description

[0001] The present invention relates to an electroluminescent display device,

The present invention relates to an electroluminescent display device.

As the information technology is developed, the market of display devices, which is a connection medium between users and information, is getting larger. Accordingly, the use of display devices such as an electroluminescence display (OLED), a liquid crystal display (LCD), and a plasma display panel (PDP) is increasing.

Among the above-described display devices, the electroluminescent display device includes a display panel including a plurality of sub-pixels, a driver for driving the display panel, and a power supply for supplying power to the display panel. The driving unit includes a scan driver for supplying a scan signal (or a gate signal) to the display panel, and a data driver for supplying a data signal to the display panel.

In an electroluminescence display device, when a scan signal, a data signal, or the like is supplied to sub-pixels arranged in a matrix form, the light emitting diode of the selected sub-pixel emits light, thereby displaying an image. The electroluminescence display device has various advantages such as being displayed on a next generation display device because it displays an image based on light generated from a light emitting diode included in a sub pixel.

The electroluminescence display device performs an image display operation for displaying an image and an external compensation operation for compensating the display panel. The external compensation operation senses the current or voltage in order to compensate for deterioration of elements such as the driving transistor and the light emitting diode in the sub-pixel, judges the degree of deterioration based on the sensed current or voltage, compensates the data signal and the like Method. However, in the conventional external compensation method, continuous research is required to apply a more effective compensation method.

The present invention for solving the above problems of the background art is to improve and lower the tact time required for preparing the sensing value and the compensation value even if the size of the display panel increases and the number of pixels increases. In addition, the present invention provides a compensating scheme which is capable of sensing a low current, improving the compensation accuracy even when a compensating value is provided using the interpolation method, and also making the display panel large-sized / high-resolution.

According to an aspect of the present invention, there is provided an electroluminescent display device including a display panel, a data driver, a scan driver, a pixel sensing circuit, and a compensation value generator. The display panel displays the image. The data driver supplies a data signal to the display panel. The scan driver supplies a scan signal to the display panel. The pixel sensing circuit part acquires the sensing value through the reference lines of the pixels included in the display panel. The compensation value generator provides compensation values for the sensed pixels on the basis of the sensing values and compensates for the unsensitized pixels based on the sensing value and the interpolation method. The pixel sensing circuit part simultaneously senses N (N is an integer of 2 or more) pixels, and changes the position of the sensing object by at least one pixel.

The pixel sensing circuit unit may group the sensing groups by N (N is an integer equal to or greater than two) pixels in the display panel, and may move the sensing groups in a superposition or non-overlapping manner in units of K (K is an integer of 1 or more) frames.

The pixel sensing circuit includes a switch unit having switches connected at one end to reference lines; A mux portion having muxes corresponding to the number of switches, one input and one output; An input / output control unit connected to an output terminal of the muxes; And a current-to-voltage converting unit having an input terminal connected to an output terminal of the input / output control unit.

At least one of the two output nodes of the mux can be changed.

The current-voltage conversion unit includes an integration circuit unit and a comparison circuit unit arranged in pairs at the output terminal of the input / output control unit, and only one of the integration circuit unit and the comparison circuit unit can be selectively operated.

The input / output control unit may change its output path so that the sensing value output through the output terminal of the muxes is transferred to one input terminal of the integration circuit unit and the comparison circuit unit.

The integration circuit section operates when performing initial compensation for the entire screen of the display panel, and the comparison circuit section can operate when the display panel is updated and compensated after the initial compensation is completed.

The input / output control unit can control the wiring so that the output terminals of the mux unit are integrated into L (L is an integer of 2 or more).

The scan driver may include a drive mode selector for outputting a signal output from the shift register directly or by replacing one scan signal with I (I is an integer equal to or greater than 2).

The scan driver may include a block shifter for shifting a scan signal output from the drive mode selector to an upper scan line or a lower scan line.

The present invention has the effect of improving and decreasing the tact time required for setting the sensing value and the compensation value even if the size of the display panel increases and the number of pixels increases. Further, the present invention can reduce the time required for preparing the sensing value and the compensation value, which is advantageous in making the display panel large-sized and high-resolution. In addition, since the present invention performs group sensing after grouping pixels of a display panel, it is possible to sense a low current. In addition, since the present invention performs group sensing and moves a group, compensation accuracy can be improved even if a compensation value is provided using an interpolation method. In addition, since the present invention simultaneously groups a plurality of pixels, it is possible to mitigate white noise that individually affects the reference lines required for sensing.

1 is a schematic block diagram of an organic light emitting display device.
2 is a schematic circuit configuration diagram of a subpixel.
Fig. 3 is a circuit example configuration showing a part of Fig. 2; Fig.
4 is a view for explaining an external compensation method according to an experimental example;
5 is a graph exemplarily showing compensation values provided by external compensation according to an experimental example.
6 is a diagram briefly explaining an operation of a circuit for performing external compensation according to an experimental example;
7 is a first exemplary view for explaining an external compensation method according to an embodiment of the present invention.
8 is a graph exemplarily showing a compensation value provided by the external compensation of FIG.
9 is a second exemplary view for explaining an external compensation method according to an embodiment of the present invention.
10 is a graph exemplarily showing the compensation value provided by the external compensation of FIG.
11 is a diagram briefly explaining an operation of a circuit for performing external compensation according to an embodiment of the present invention.
12 is a circuit diagram of a pixel sensing circuit according to an embodiment of the present invention.
13 is a circuit diagram of a scan driver according to an embodiment of the present invention.
14 to 25 are views for explaining a method of driving an apparatus for an external compensation method according to an embodiment of the present invention.
26 is a diagram illustrating a signal transmission system according to a position of a pixel sensing circuit;
Fig. 27 is an example of movement of a sensing group; Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The electroluminescent display device described below may be implemented as a television, a video player, a personal computer (PC), a home theater, a smart phone, an augmented / virtual reality device (AR / VR) The electroluminescent display device described below will be described with reference to an organic light emitting display device implemented on the basis of an organic light emitting diode (light emitting device). However, the electroluminescent display device described below may be implemented based on inorganic light emitting diodes.

The thin film transistor of the electroluminescence display device described below may be referred to as a source electrode, a drain electrode, a drain electrode, and a source electrode, depending on the type, except for the gate electrode. However, .

FIG. 1 is a schematic block diagram of an organic light emitting display device, FIG. 2 is a schematic circuit configuration diagram of a subpixel, and FIG. 3 is a circuit configuration diagram illustrating a part of FIG.

1, the organic light emitting display includes a timing control unit 180, a data driving unit 130, a scan driving unit 140, a display panel 110, and a power supply unit 160.

The timing controller 180 receives a data enable signal, a vertical synchronous signal, a horizontal synchronous signal, a driving signal including a clock signal, and the like in addition to the data signal DATA from an image processing unit (not shown). The timing controller 180 generates a gate timing control signal GDC for controlling the operation timing of the scan driver 140 and a data timing control signal DDC for controlling the operation timing of the data driver 130 based on the drive signal. .

The data driver 130 samples and latches the data signal DATA supplied from the timing controller 180 in response to the data timing control signal DDC supplied from the timing controller 180 and outputs the digital data signal as a gamma reference voltage Converts it into an analog data signal (or data voltage) and outputs it. The data driver 130 outputs the data signal DATA through the data lines DL1 to DLn. The data driver 130 may be formed in the form of an IC (Integrated Circuit).

The scan driver 140 outputs a scan signal in response to the gate timing control signal GDC supplied from the timing controller 180. The scan driver 140 outputs a scan signal through the scan lines GL1 to GLm. The scan driver 140 is formed in the form of an IC (Integrated Circuit) or a gate in panel (a method of forming a transistor by a thin film process) on the display panel 110.

The power supply unit 160 outputs a high-potential voltage and a low-potential voltage. The high-potential voltage and the low-potential voltage output from the power supply unit 160 are supplied to the display panel 110. The high potential voltage is supplied to the display panel 110 through the first power supply line EVDD and the low potential voltage is supplied to the display panel 110 through the second power supply line EVSS.

The display panel 110 displays an image based on the data signal DATA supplied from the data driver 130, the scan signal supplied from the scan driver 140, and the power supplied from the power supplier 160. The display panel 110 includes sub-pixels SP that emit light and operate to display an image.

The subpixels SP include a red subpixel, a green subpixel, and a blue subpixel or a white subpixel, a red subpixel, a green subpixel, and a blue subpixel. A white subpixel, a red subpixel, a green subpixel and a blue subpixel are defined as one pixel. If there is no white subpixel, the red subpixel, the green subpixel, and the blue subpixel are one pixel.

As shown in FIG. 2, one sub-pixel is located at a crossing region of the data line DL1 and the scan line GL1, and includes a programming portion SC for setting the gate-source voltage of the driving transistor DR And an organic light emitting diode (OLED). The organic light emitting diode (OLED) includes an anode (ANO), a cathode (CAT), and an organic light emitting layer interposed between the anode (ANO) and the cathode (CAT). The anode ANO is connected to the driving transistor DR.

The programming unit SC may be implemented with a transistor unit (transistor array) including at least one switching transistor and at least one capacitor. The transistor portion is implemented based on a CMOS semiconductor, a PMOS semiconductor, or an NMOS semiconductor. The transistors included in the transistor unit may be implemented as p-type or n-type. In addition, the semiconductor layer of the transistors included in the transistor portion of the subpixel may include amorphous silicon, polysilicon, or an oxide.

The switching transistor is turned on in response to the scan signal from the scan line GL1, thereby applying the data voltage from the data line DL1 to one electrode of the capacitor. The driving transistor DR generates a driving current corresponding to the magnitude of the voltage charged in the capacitor and regulates a light emission amount of the organic light emitting diode OLED. The amount of light emitted from the organic light emitting diode OLED is proportional to the amount of driving current supplied from the driving transistor DR.

However, when the driving transistor DR operates for a long time, there is a problem that the threshold voltage Vth moves in a specific direction. Also, the driving transistor DR may exhibit different threshold voltage characteristics due to process variations or the like occurring in the manufacturing process. Therefore, a circuit for compensating the threshold voltage of the driving transistor DR and the organic light emitting diode OLED is further added to the programming portion SC. In this way, a circuit added to the programming unit SC and an external device interlock with each other and compensate for an element causing a deviation in a threshold voltage, such as a driving transistor DR and an organic light emitting diode (OLED) Also. Hereinafter, an example of a programming unit SC having a circuit added for external compensation will be described.

2 and 3, the programming section SC further includes a sensing transistor ST and a reference line VREF (or a sensing line). The sensing transistor ST is connected between the source electrode of the driving transistor DR and the anode electrode of the organic light emitting diode OLED (hereinafter referred to as a sensing node). The sensing transistor ST supplies the initialization voltage (or sensing voltage) transmitted through the reference line VREF to the sensing node of the driving transistor DR or the voltage of the sensing node of the driving transistor DR or the voltage of the reference line VREF Or to sense the current.

In the switching transistor SW, the first electrode is connected to the first data line DL1, and the second electrode is connected to the gate electrode of the driving transistor DR. The first electrode of the driving transistor DR is connected to the first power supply line EVDD and the second electrode of the driving transistor DR is connected to the anode electrode of the organic light emitting diode OLED. In the capacitor Cst, the first electrode is connected to the gate electrode of the driving transistor DR, and the second electrode is connected to the anode electrode of the organic light emitting diode OLED. In the organic light emitting diode OLED, an anode electrode is connected to the second electrode of the driving transistor DR, and a cathode electrode is connected to the second power supply line EVSS. The sensing transistor ST has a first electrode connected to the reference line VREF and a second electrode connected to the anode electrode of the organic light emitting diode OLED and the second electrode of the driving transistor DR.

The operation time of the sensing transistor ST may be similar to or different from that of the switching transistor SW according to an external compensation algorithm (or a configuration of a compensation circuit) provided outside the pixel. For example, the first scan line GL1a (or scan line) connected to the gate electrode of the switching transistor SW and the first scan line GL1b (or the sensing line) connected to the gate electrode of the sensing transistor ST are common As shown in FIG. As another example, the gate electrode of the switching transistor SW may be connected to the first scan line GL1a, and the gate electrode of the sensing transistor ST may be coupled to the first scan line GL1b. In this case, the first scan line GL1a and the first scan line GL1b are separated to transmit different scan signals.

The reference line VREF may be coupled to the pixel sensing circuitry configured for external compensation. The pixel sensing circuit unit can sense the pixels and generate the sensing value (sensing result value) or the like during the non-display period of the image or the N frames (N is an integer of 1 or more). In addition, the compensation target according to the sensing value may be a digital data signal, an analog data signal, gamma, or the like. The pixel sensing circuit for generating the sensing value may be implemented in the interior of the data driver, in the timing controller, or in a separate circuit.

3, a sub-pixel of a 3T (Capacitor) structure including a switching transistor SW, a driving transistor DR, a capacitor Cst, an organic light emitting diode OLED, and a sensing transistor ST However, if the compensation circuit CC is added, it may be composed of 3T2C, 4T2C, 5T1C, 6T2C, and the like.

Hereinafter, an external compensation scheme of the embodiment will be described in which the external compensation scheme of the experimental example is considered and further improved.

<Experimental Example>

FIG. 4 is a diagram for explaining an external compensation method according to an experimental example, FIG. 5 is a graph illustrating an exemplary compensation value provided by external compensation according to an experimental example, and FIG. In order to simplify the operation of the circuit.

As shown in FIGS. 4 to 6, the external compensation method according to the experimental example senses all the pixels PIX included in the display panel 110 to obtain a sensing value, PIX). In FIG. 4A, "SEN" means the sensing value of the sensed pixels SP, and "RCMP" means the compensation value of the pixels PIX provided based on the sensing value. Quot; ixj pixel PNL " in Fig. 4 (b) denotes the number of all the pixels PIX included in the display panel 110, and "ixj sensing data" Quot; ix j compensation data "means a compensation value for all the pixels PIX.

As described above, if a compensation value is provided for compensation of the driving transistors and the like based on the sensing values of the bar pixels PIX having different threshold voltage characteristics in each display panel 110, As shown in Fig.

The external compensation method according to the experimental example is performed such that the pixel sensing circuit unit 150 sequentially senses through all the reference lines VREF1 to VREF4 to sense all the pixels PIX of the display panel 110 Signals. For example, first to fourth scan signals (Scan1 to Scan4) applied to the first to fourth scan lines GL1 to GL4 are sequentially generated as shown in FIG. 6, such as "Scan1 to Scan4".

However, in the external compensation method according to the experimental example, the sensing and sensing values of all the pixels PIX included in the display panel 110 are extracted and compensation values for all of them are provided. Therefore, as the size of the display panel 110 increases and the number of pixels PIX increases, the time required for sensing increases by a square. Therefore, the external compensation method according to the experimental example is difficult to improve the tact time required for preparing the sensing value and the compensation value, and is disadvantageous when the display panel 110 is large-sized / high-resolution, .

<Examples>

FIG. 7 is a first exemplary view for explaining an external compensation method according to an embodiment of the present invention, FIG. 8 is a graph exemplarily showing a compensation value provided by the external compensation of FIG. 7, and FIG. FIG. 10 is a graph illustrating a compensation value provided by the external compensation of FIG. 9, and FIG. 11 is a graph illustrating a compensation value of the external compensation according to the embodiment of the present invention. Fig. 8 is a diagram for explaining an operation of a circuit for carrying out the present invention.

7 to 11, the external compensation method according to the embodiment of the present invention senses a part of pixels PIX included in the display panel 110 to obtain a sensing value, and based on the sensing value and the interpolation method And compensates for the sensed pixel and the un-sensed pixel. As shown in FIG. 7, by using the interpolation method, a sensing value (point sensing) for one pixel located at a specific point is obtained to acquire a sensing value, or sensing (block sensing) for a plurality of pixels located at a specific point So that the sensing value can be obtained.

In FIG. 7A and FIG. 9A, "SEN" means the sensing value of the sensed pixels PIX (which is the representative sensing value of the surrounding pixels), "RCMP" Means the compensation value of the pixels PIX, and "ICMP " means the compensation value of the pixels PIX provided based on the interpolation method. "I × j pixel PNL" in FIG. 7 (b) and FIG. 9 (b) means the number of all the pixels PIX included in the display panel 110 and "(i / n) sensing data "means a sensing value for the selected pixels PIX, and" (i / n) × (j / n) compensation data "means a compensation value for the selected pixels PIX, "Interpolation compensation data generation" means compensation values prepared by interpolation for unselected pixels (PIX), and "ixj compensation data" means compensation values for all pixels (PIX).

As described above, even if a compensation value is provided to compensate for the sensed values of the bar pixels PIX having different threshold voltage characteristics and the interpolation method, even in a single display panel 110, 8 and Fig. 10, respectively. 5, FIG. 8, and FIG. 10, it can be seen that the difference between the actual compensation value (Real compensation value) and the interpolation compensation value (Interpolation) is not so great even if all subpixels are not actually sensed.

The external compensation method according to the exemplary embodiment of the present invention performs selective sensing only on the selected reference lines VREF1 to VREF4 so that the pixel sensing circuit unit 150 only senses the selected pixels PIX of the display panel 110 The driving signals are provided. For example, first to fourth scan signals (Scan1 to Scan4) applied to the first to fourth scan lines GL1 to GL4 are generated at the same time as "Scan1 to Scan4"

A simple comparison of the embodiments with respect to the experimental example shows that the experimental example requires a long sensing time because it senses all the pixels and provides compensation values. However, the embodiment of the present invention requires a relatively short sensing time compared to the experimental example because it only senses the selected pixels and provides compensation values of pixels not selected by the interpolation method based on the sensed values of the selected pixels.

Therefore, even if the size of the display panel 110 increases and the number of pixels PIX increases, the external compensation method according to the embodiment of the present invention does not increase the time required for sensing to be square. Accordingly, the external compensation method according to the embodiment of the present invention can improve and reduce the tact time required for preparing the sensing value and the compensation value, and is advantageous when the display panel 110 is large-sized / high-resolution .

Hereinafter, a configuration and a driving method of an apparatus for implementing an external compensation scheme according to an embodiment of the present invention will be described.

FIG. 12 is a circuit diagram of a pixel sensing circuit according to an embodiment of the present invention, and FIG. 13 is a circuit diagram of a scan driver according to an embodiment of the present invention.

12, the pixel sensing circuit unit 150 according to the embodiment of the present invention includes a switch unit 151, a mux unit 152, an input / output control unit 153, a current-voltage conversion unit 154, A conversion unit 156, and the like. The number of circuits constituting each of the switch portion 151, the mux portion 152, the input / output control portion 153, and the current / voltage conversion portion 154 included in the pixel sensing circuit portion 150 is larger than that shown in the drawings.

However, in order to facilitate the understanding of the explanation, it should be noted that only the portions for managing the eight reference lines (VREF1 to VREF8) are shown and described. Note also that the circuits not directly related to the embodiment of the present invention are greatly omitted. And the reference lines are connected to pixels including red, green, blue, and white subpixels, respectively, but connected to pixels including red, green, and blue subpixels in the absence of white subpixels.

The switch unit 151 includes first to eighth switches SW1 to SW8 connected at one end to the first to eighth reference lines VREF1 to VREF8 of the display panel 110. [ The reference lines of the switch unit 151 and the display panel 110 may be connected in a 1: 1 ratio. The first to eighth switches SW1 to SW8 switch the pixel sensing circuit part 150 and the first to eighth reference lines VREF1 to VREF8 of the display panel 110 do. When the first to eighth switches SW1 to SW8 are turned on, the pixels connected to the first to eighth reference lines VREF1 to VREF8 can be sensed.

In the figure, one switch is disposed on one reference line. However, this is merely a simplified illustration for explaining a simple function related to sensing. In one reference line, a plurality of switches and a sensing voltage for charging or discharging See that the circuits are further organized and connected. In addition, the switch unit 151 may not be included in the pixel sensing circuit unit 150, but may be disposed on the outside, for example, on the display panel 110.

 The mux part 152 includes first through eighth muxes Mux1 through Mux8 connected to the other end of the first through eighth switches SW1 through SW8. The mux portion 152 and the switch portion 151 may be connected at a ratio of 1: 1. The first to eighth muxes (Mux1 to Mux8) are composed of muxes capable of receiving one input and performing two outputs. The input terminal of the mux is connected to the switch stage and one of the two output terminals is connected to the input terminal of the input / output control unit 153 and the other is connected to the output terminal of another adjacent mux. In the drawing, four reference lines are set as one sensing group, so that the output terminals of the four muxes are integratedly connected to one another. However, this is only one example, and the output stages of the muxes are connected so as to integrate L (L is an integer of 2 or more) corresponding to the driving method.

The first to eighth muxes Mux1 to Mux8 serve as an electrical connection for performing simultaneous sensing on N (N is an integer of 2 or more) pixels by interpolation. The first to eighth muxes Mux1 to Mux8 are configured to enable group sensing by N pixels (N is an integer of 2 or more) pixels, as well as M (M (2 or more integers) to change the wiring node of the output stage.

In addition, since the first to eighth muxes Mux1 to Mux8 can change the connection node of the output stage through the time-divisional control, it is possible to simultaneously detect N (N is an integer of 2 or more) Change is possible. At this time, the position change of the sensing object or the position change (group movement) of the sensing group is possible in units of K (K is an integer of 1 or more) frames. The mux part 152 can not only sense group sensing, individual sensing, and single sensing, but also change the position of a sensing object, and provide a condition for simultaneously grouping a plurality of pixels. Therefore, It is also possible to sense.

In addition, white noise, which individually affects the reference lines, can also be mitigated when grouping multiple pixels simultaneously. In addition, if the sensing group is moved by overlapping, it is possible to improve the compensation accuracy because the occurrence probability of the factors causing the sensing deviation between the groups can be lowered even if the interpolation method is used.

The input / output control unit 153 includes first and second control units CNT1 and CNT2. The first input terminal IN1 and the second input terminal IN2 of the first and second control units CNT1 and CNT2 are connected to the output terminals of the first to eighth muxes Mux1 to Mux8 and the first output terminal OUT1, The second output terminal OUT2 is connected to the first and second integration circuit units CI1 and CI2 of the current-voltage conversion unit 154 and the first and second comparison circuit units CC1 and CC2 separately. The input / output control unit 153 has input terminals less than the number of output terminals of the first to eighth muxes Mux1 to Mux8. That is, the mux section 152 and the input / output control section 153 have a connection relationship of J (J is an integer of 2 or more): 1.

The input / output control unit 153 controls the wiring structure so that the output terminals of the multiplexers 152 are integrated into L (L is an integer of 2 or more). The input / output control unit 153 outputs the sensing value output through the output terminal of the mux part 152 to the first and second integration circuit units CI1 and CI2 included in the current-voltage conversion unit 154, (CC1, CC2). In order to perform such a function, the first and second control units CNT1 and CNT2 each include two input / output terminals, and a selection circuit which can change the output path without outputting the input sensed value to the subsequent stage .

12, the first input IN1 of the first control unit CNT1 is connected to the output terminals of the first to fourth muxes Mux1 to Mux4 and the second input IN2 is connected to the output terminals of the third to sixth muxes Mux1 to Mux4, (Mux3 to Mux6) are connected to the output terminals of the MUX3 to Mux6. That is, the input / output control unit 153 controls the wiring node of the output terminal of the mux part 152 and can change its own output path. As shown in the drawing, the wiring structure is not maintained and changed according to the driving mode.

The current-voltage conversion unit 154 includes first and second integration circuit units CI1 and CI2 and first and second comparison circuit units CC1 and CC2. The input terminals of the first and second integration circuit units CI1 and CI2 and the first and second comparison circuit units CC1 and CC2 are connected to the output terminals of the input / output control unit 153. [ The first and second integration circuit units CI1 and CI2 may be provided with a first voltage source Vref and capacitors C1 and C2 disposed between the input and output output terminals for integrating the sensed values, The second comparison circuit units CC1 and CC2 may be provided with a voltage source Iref or the like for comparison of sensing values. The first integration circuit unit CI1 and the first comparison circuit unit CC1 form a pair and are arranged corresponding to one first control unit CNT1. The first control unit CNT1, the first integration circuit unit CI1, and the first comparison circuit unit CC1 are defined as one sensing block.

The first and second integration circuit units CI1 and CI2 and the first and second comparison circuit units CC1 and CC2 form a pair but selectively operate according to the compensation use (compensation mode or compensation timing). For example, the first and second integration circuit units CI1 and CI2 operate when the pixels included in the display panel are compensated (initial compensation for the entire screen). The first and second comparison circuit units CC1 and CC2 do not operate when the first and second integration circuit units CI1 and CI2 operate. The first and second comparison circuit units CC1 and CC2 operate when the display panel is updated and compensated after the full screen compensation of the display panel is completed. The first and second integration circuit units CI1 and CI2 do not operate when the first and second comparison circuit units CC1 and CC2 operate.

In the initial compensation, it is good for improving the accuracy of the compensation when performing the update compensation thereafter by sensing all the pixels included in the display panel and preparing a compensation value. The reason for performing the update compensation after performing the initial compensation is that the components included in the display panel deteriorate over time after the initial compensation. Therefore, the initial compensation value prepared through the initial compensation is used as an index or a reference value for providing a compensation value corresponding to the deterioration of the elements when performing the update compensation thereafter.

The analog-to-digital converter 156 converts the sensing value of the analog type transmitted from the current-voltage converter 154 into a digital sensing value. The analog-to-digital converter 156 transmits the sensing value obtained through sensing to the timing controller or the like so as to provide a compensation value based on the sensing value of the digital form. However, if the pixel sensing circuit unit 150 itself provides a compensation value, a processor unit capable of data processing is further provided at the rear end of the analog-to-digital conversion unit 156.

Embodiments of the present invention compensate for pixels that are not sensed based on the interpolation method and can also move the sensing group. In order to move the sensing group, not only the internal operation of the pixel sensing circuit unit 150 but also the configuration of the scan driver should be supported. Therefore, the structure of the scan driver according to the embodiment of the present invention will be described below.

13, the scan driver 140 according to the exemplary embodiment of the present invention includes a shift register unit 141, a drive mode selection unit 142, a block shift unit 143, and a scan signal output unit 144, .

The shift register unit 141 sequentially generates scan signals and outputs the scan signals. The shift register unit 141 sequentially outputs a scan signal of logic high or logic low based on a signal supplied from a timing controller or the like.

The drive mode selection unit 142 includes first to n-th muxes Mux1 to Muxn. The drive mode selection section 142 outputs the signal outputted from the shift register section 141 as it is or the I (I is 2 or more) outputted from the shift register section 141 in response to the two drive mode signals supplied from the outside, (Integer) scan signals into one scan signal and simultaneously outputs the scan signals. For example, when the normal mode signal is supplied, the drive mode selection unit 142 outputs the signal output from the shift register unit 141 as it is. When the sensing mode signal (Sensing) is supplied, the driving mode selection unit 142 outputs the same scan signals as the scan signals output from the first to Mux 4 through the first to fourth muxes Mux1 to Mux4.

The drive mode selection unit 142 is interlocked (synchronized) with the pixel sensing circuit unit. Therefore, the pixel sensing circuitry operates to connect the muxes by the number of scan lines corresponding to the sensing group to be sensed and to output the scan signals. For example, when the pixel sensing circuit unit sets the sensing group in the horizontal and vertical directions on the display panel, the first to fourth muxes Mux1 to Mux4 may receive a scan signal output from the first mux, The same scan signal is output. However, when the pixel sensing circuit unit sets the sensing group to 5 * 5 on the display panel, the first to fifth muxes Mux1 to Mux5 output the same scan signal as the scan signal output from the first mux . Therefore, the wiring structure of the first to nth muxes Mux1 to Muxn included in the driving mode selection unit 142 is also changed according to the driving mode.

The block movement unit 143 moves the scan signal output from the drive mode selection unit 142 to an upper scan line or a lower scan line. The block movement unit 143 also operates in response to two drive mode signals supplied from the outside. When the drive mode selection unit 142 operates in response to the normal mode signal (normal driving), the block movement unit 143 does not perform an operation to move the scan signal. On the other hand, when the drive mode selection unit 142 operates in response to the sensing mode signal (Sensing), the block movement unit 143 moves the scan signal. The block movement unit 143 may also be configured as a mux, but is not limited thereto.

The scan signal output section 144 outputs a scan signal output from the block movement section 143 through each scan line of the display panel. The scan signal output section 144 includes first to nth output circuit sections (Gate1 to Gaten). Although the first to nth output circuit portions (Gate1 to Gaten) are shown as transistors, they are not limited thereto.

Hereinafter, the driving method of the pixel driving circuit unit 150 and the scan driver 140 described with reference to FIGS. 12 and 13 will be described.

FIGS. 14 to 25 are diagrams for explaining a method of driving an apparatus for an external compensation method according to an embodiment of the present invention, FIG. 26 is a diagram for illustrating a signal delivery system according to a position of a pixel sensing circuit unit, 27 is an example of movement of the sensing group.

All. Hereinafter, for the external compensation based on the interpolation method, a sensing group is set to 4 * 4 pixels, and some pixels included in the sensing group are overlapped and the sensing group is moved.

[First sensing block sensing]

As shown in FIG. 14, pixels PIX included in the horizontal (j) 4 * vertical (i) 4 on the display panel 110 are defined as a first sensing block BL1. 14 and 15, the first sensing block BL1 is sensed through the first to fourth reference lines VREF1 to VREF4. The first to fourth switches SW1 to SW4 of the switch unit 151 are turned on to sense the first sensing block BL1. The first to fourth muxes Mux1 to Mux4 of the mux 152 are selected as one group.

The first control unit CNT1 of the input and output control unit 153 receives the sensing values output from the first through fourth multiplexers Mux1 through Mux4 through the first input IN1 as one value and outputs the first output OUT1 ). The first comparison circuit unit CC1 of the current-voltage conversion unit 154 compares the sensing value transmitted from the first control unit CNT1 and transmits the sensed value to the analog-to-digital conversion unit 156. [ 14, 15, and 16, the scan driver 140 includes a plurality of pixels PIX included in the first sensing block BL1 on the display panel 110, 1 to 4 th scan signals Scan 1 to Scan 4 through the first to fourth scan lines.

[Second sensing block sensing]

As shown in Fig. 17, the pixels PIX included in the horizontal (j) 4 * vertical (i) 4 on the display panel 110 are defined as the second sensing block BL2. The second sensing block BL2 is located at a position where two reference lines have moved to the right side of the first sensing block BL1. As shown in FIGS. 17 and 18, the second sensing block BL2 is sensed through the third to sixth reference lines VREF3 to VREF6. The third to sixth switches SW3 to SW6 of the switch unit 151 are turned on to sense the second sensing block BL2. The third to sixth muxes (Mux3 to Mux6) of the mux portion 152 are selected as one group.

The first control unit CNT1 of the input / output control unit 153 receives the sensing values output from the third through sixth muxes Mux3 through Mux6 through the second input IN2 as one value, ). The first comparison circuit unit CC1 of the current-voltage conversion unit 154 compares the sensing value transmitted from the first control unit CNT1 and transmits the sensed value to the analog-to-digital conversion unit 156. [ 17, 18, and 19, the scan driver 140 includes a plurality of pixels PIX included in the second sensing block BL2 on the display panel 110, 1 to 4 th scan signals Scan 1 to Scan 4 through the first to fourth scan lines.

[Third sensing block sensing]

As shown in Fig. 20, the pixels PIX included in the horizontal (j) 4 * vertical (i) 4 on the display panel 110 are defined as a third sensing block BL3. The third sensing block BL2 is located at a position where two reference lines are moved to the lower side of the second sensing block BL1. As shown in FIGS. 20 and 21, the third sensing block BL3 is sensed through the third to sixth reference lines VREF3 to VREF6. The third to sixth switches SW3 to SW6 of the switch unit 151 are turned on to sense the third sensing block BL3. The third to sixth muxes (Mux3 to Mux6) of the mux portion 152 are selected as one group.

The first control unit CNT1 of the input / output control unit 153 receives the sensing values output from the third through sixth muxes Mux3 through Mux6 through the second input IN2 as one value, ). The first comparison circuit unit CC1 of the current-voltage conversion unit 154 compares the sensing value transmitted from the first control unit CNT1 and transmits the sensed value to the analog-to-digital conversion unit 156. [ 20, 21, and 22, the scan driver 140 includes a plurality of pixels PIX included in the third sensing block BL3 on the display panel 110, 3 through 6th scan signals Scan3 through Scan6 through the third through sixth scan lines.

[Fourth sensing block sensing]

As shown in Fig. 23, the pixels PIX included in the horizontal (j) 4 * vertical (i) 4 on the display panel 110 are defined as the fourth sensing block BL4. The fourth sensing block BL4 is located at a position where two reference lines have moved to the left of the third sensing block BL1. As shown in FIGS. 23 and 24, the fourth sensing block BL4 is sensed through the first through fourth reference lines VREF1 through VREF4. The first to fourth switches SW1 to SW4 of the switch unit 151 are turned on to sense the fourth sensing block BL4. The first to fourth muxes Mux1 to Mux4 of the mux 152 are selected as one group.

The first control unit CNT1 of the input and output control unit 153 receives the sensing values output from the first through fourth multiplexers Mux1 through Mux4 through the first input IN1 as one value and outputs the first output OUT1 ). The first comparison circuit unit CC1 of the current-voltage conversion unit 154 compares the sensing value transmitted from the first control unit CNT1 and transmits the sensed value to the analog-to-digital conversion unit 156. [ 23, 24, and 25, the scan driver 140 includes a plurality of pixels PIX included in the fourth sensing block BL4 on the display panel 110, 3 through 6th scan signals Scan3 through Scan6 through the third through sixth scan lines.

The pixel sensing circuit unit 150 may have a compensation value generating unit capable of calculating a compensation value by itself. However, in the embodiment of the present invention, the pixel sensing circuit unit 150 generates only the sensed value by sensing the pixels, transfers the generated sensed value to the timing controller, and generates the compensation value in the timing controller . That is, the case where the compensation value generating unit is included in the timing control unit will be described as an example.

As shown in FIGS. 14 to 26, the pixel sensing circuit unit 150 converts a sensing value sensed by the first through fourth sensing blocks BL1 through BL4 into a sensing value SEN of a digital form, To the control unit 180. The timing controller 180 calculates a compensation value based on the digital sensing value SEN.

The timing controller 180 provides a compensation value for the sensed pixel based on the sensing value SEN and provides a sensing value for the sensed pixel and a compensation value for the unsensitized pixel based on the interpolation method. The timing controller 180 generates and outputs the compensation data signal CDATA based on the compensation value. The data driver 130 then drives the display panel based on the compensation data signal CDATA output from the timing controller 180.

As shown in FIG. 26 (a), the pixel sensing circuit unit 150 may be implemented as a separate independent circuit. In this case, there is a signal line between the pixel sensing circuit unit 150 and the timing control unit 180. The pixel sensing circuit unit 150 transmits the sensing value SEN to the timing controller 180 through the signal line.

As shown in FIG. 26 (b), the pixel sensing circuit unit 150 may be integrated in the data driver 130. In this case, the pixel sensing circuit unit 150 transmits the sensing value SEN to the timing controller 180 through the existing signal line existing between the data driver 130 and the timing controller 180.

As shown in FIG. 27, a selected one of the sensing groups BL1 to BL9 on the display panel 110 can be moved not only up and down, right and left but also obliquely. In the first example, the first sensing block BL1 is movable to the second sensing block BL2 or the third sensing block BL3. Also, the first sensing block BL1 is movable to the fifth sensing block BL5 or the ninth sensing block BL9. In the second example, the ninth sensing block BL9 is movable to the fifth sensing block BL5 or the first sensing block BL1. The ninth sensing block BL9 is movable to the eighth sensing block BL8 or the seventh sensing block BL7. In the first and second examples, non-overlapping movement occurs when the sensing group moves in units of blocks. However, it is needless to say that the sensing group may be moved in the overlapping manner.

As described above, according to the present invention, even when the size of the display panel increases and the number of pixels increases, the tact time required for preparing the sensing value and the compensation value can be improved or decreased. Further, the present invention can reduce the time required for preparing the sensing value and the compensation value, which is advantageous in making the display panel large-sized and high-resolution. In addition, since the present invention performs group sensing after grouping pixels of a display panel, it is possible to sense a low current. In addition, since the present invention performs group sensing and moves a group, compensation accuracy can be improved even if a compensation value is provided using an interpolation method. In addition, since the present invention simultaneously groups a plurality of pixels, it is possible to mitigate white noise that individually affects the reference lines required for sensing.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

130: Data driver 180: Timing controller
140: scan driver 150: pixel sensing circuit
151: switch unit 152:
153: Input / output control unit 154: Current / voltage conversion unit
156: analog-to-digital conversion section 141: shift register section
142: drive mode selection unit 143: block movement unit
144: scan signal output unit 110: display panel

Claims (10)

A display panel for displaying an image;
A data driver for supplying a data signal to the display panel;
A scan driver for supplying a scan signal to the display panel;
A pixel sensing circuit for acquiring a sensing value through reference lines of pixels included in the display panel; And
And a compensation value generator for providing a compensation value for a pixel sensed based on the sensing value and for providing a compensation value for a pixel not sensed based on the sensing value and the interpolation method,
Wherein the pixel sensing circuit part simultaneously senses N (N is an integer of 2 or more) pixels, and changes the position of a sensing object by at least one pixel. The method according to claim 1,
The pixel sensing circuitry
Wherein the grouping of N (N is an integer of 2 or more) pixels is performed on the display panel, and the sensing groups are overlapped or non-overlapping in units of K (K is an integer of 1 or more) frames. The method according to claim 1,
The pixel sensing circuitry
A switch unit having switches connected at one end to the reference lines;
A mux part having muxes corresponding to the number of the switches, the mux part having one input terminal and two output terminals;
An input / output control unit connected to an output terminal of the muxes; And
And a current-to-voltage conversion unit connected to an output terminal of the input / output control unit. The method of claim 3,
The above-
And at least one of the two output terminals is changed. The method of claim 3,
The current-to-
And an integration circuit part and a comparison circuit part arranged in pairs at an output terminal of the input / output control part,
Wherein the integration circuit unit and the comparison circuit unit are selectively operated. 6. The method of claim 5,
The input /
And changes the output path of the mux so that a sensing value output through the output terminal of the muxes is transmitted to one input terminal of the integrating circuit part and the comparing circuit part. 6. The method of claim 5,
Wherein the integration circuit section operates when performing initial compensation for the entire screen of the display panel,
Wherein the comparison circuit unit operates when the display panel is updated and compensated after the initial compensation is completed. 5. The method of claim 4,
The input /
And an output terminal of the mux portion is integrated into L (L is an integer of 2 or more). The method according to claim 1,
The scan driver
And a drive mode selection unit for outputting the signal output from the shift register unit as it is or replacing I (I is an integer of 2 or more) scan signals with one scan signal. 9. The method of claim 8,
The scan driver
And a block shifter for shifting an output path of the scan signal output from the drive mode selector to an upper scan line or a lower scan line.

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