Display device

Abstract

To provide a display device that can reduce the time of sensing operation without deteriorating the accuracy of luminance compensation.SOLUTION: A display device includes: a pixel array having a plurality of pixels each including a plurality of sub-pixels, and a gate line shared by the plurality of sub-pixels; a gate driving portion supplying a gate signal to the plurality of sub-pixels through the gate line; a data driving portion supplying a data signal to each of the plurality of sub-pixels through a data line; a control portion selecting any sub-pixel from the plurality of sub-pixels included in the pixel on the basis of deterioration information of the sub-pixels and supplying the data signal from the data driving portion to the selected sub-pixel; and a compensation portion acquiring a property of the selected sub-pixel.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a display device. [Background technology]

[0002] Display devices such as organic EL displays periodically sense pixel characteristic values ​​to compensate for fluctuations in luminance due to pixel degradation and the like.

[0003] Patent Document 1 discloses a display device that senses the characteristic value of a drive transistor from each of the sub-pixels in each pixel that shares a gate line and a reference line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Korean Patent Publication No. 10-2018-0130207 Summary of the Invention [Problem to be solved by the invention]

[0005] When sub-pixels share a gate line and a reference line, the sub-pixels cannot be sensed simultaneously, and therefore, a long sensing time may be required to compensate for the luminance difference between the sub-pixels.

[0006] The present invention has been made in view of the above-mentioned problems, and has an object to provide a display device that can shorten the time for a sensing operation without reducing the accuracy of luminance compensation. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a display device including: a pixel array having a plurality of pixels, each including a plurality of sub-pixels, and a gate line shared by the plurality of sub-pixels; a gate driver that supplies gate signals to the plurality of sub-pixels via the gate line; a data driver that supplies data signals to each of the plurality of sub-pixels via a data line; a control unit that selects one of the plurality of sub-pixels included in the pixel based on degradation information of the sub-pixel, and supplies the data signal to the selected sub-pixel from the data driver; and a compensation unit that acquires characteristics of the selected sub-pixel. [Effects of the Invention]

[0008] According to the present invention, the time required for the sensing operation can be reduced without reducing the accuracy of luminance compensation between sub-pixels. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a schematic configuration of a display device according to a first embodiment. [Figure 2] FIG. 4 is a diagram illustrating an operation for sensing the characteristics of a pixel included in the display device in the first embodiment. [Figure 3] FIG. 2 is a block diagram showing a schematic configuration of a compensation unit in the first embodiment. [Figure 4] 5A and 5B are diagrams illustrating an example of a process in which a control unit selects sub-pixels to be subjected to sensing in the first embodiment. [Figure 5] 4 is a flowchart showing steps executed by the display device in the first embodiment. [Figure 6] FIG. 10 is a diagram illustrating an example of a process in which a control unit selects a sub-pixel to be sensed in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Elements having common functions throughout the drawings will be designated by the same reference numerals, and duplicate descriptions may be omitted or simplified.

[0011] [First embodiment] 1 is a block diagram showing a schematic configuration of a display device 10 according to this embodiment. The display device 10 includes a control unit 11, a data driver 12, a gate driver 13, a compensation unit 14, and a display panel 15.

[0012] The control unit 11 receives a data signal DATA from a video processing unit (not shown). The control unit 11 also receives a data enable signal, a vertical synchronization signal, a horizontal synchronization signal, a clock signal, and the like (hereinafter, these signals are referred to as "drive signals TSS") from the video processing unit. The control unit 11 generates a control signal CTL for controlling the compensation unit 14. The control unit 11 also receives accumulated data CNT for each pixel from the compensation unit 14. The accumulated data CNT may include the number of times a data signal is input to each of the multiple subpixels included in the pixel (the number of times light is emitted) and the luminance value of the light emitted from the subpixel based on the data signal. The control unit 11 estimates the characteristics of each subpixel based on the accumulated data CNT. Specifically, the control unit 11 uses the accumulated data CNT to determine the most deteriorated subpixel from the multiple subpixels included in each pixel. The control unit 11 generates a control signal DCS for driving the data driver 12 and a control signal GCS for driving the gate driver 13 based on the accumulated data CNT and the drive signal TSS. The control unit 11 transmits a data signal DATA and a control signal DCS to the data driver 12. The control unit 11 also transmits a control signal GCS and a control signal CTL to the gate driver 13 and the compensation unit 14, respectively.

[0013] The data driver 12 receives a data signal DATA and a control signal DCS from the control unit 11. The data driver 12 converts the data signal DATA into an analog data voltage for each row using the control signal DCS. The control signal DCS may include a source start pulse signal, a source shift clock signal, a source output enable signal, and the like. The source start pulse signal controls the timing of the start of data sampling in the source driver integrated circuits (not shown) included in the data driver 12. The source shift clock signal is used to control the timing of data sampling in each of the source driver integrated circuits. The source output enable signal controls the output timing of the signal from the data driver 12.

[0014] The data driver 12 is electrically connected to each of the pixels P11 to Pmn included in the display panel 15 via data lines DL1 to DLn. The data driver 12 supplies data voltages to each of the pixels P11 to Pmn via the data lines DL1 to DLn. Each of the data lines DL1 to DLn includes a plurality of signal lines. Each of the signal lines is connected to a plurality of sub-pixels included in each of the pixels P11 to Pmn. The conversion period and output period of the data driver 12 to the data voltages can be changed by modulating the output width of the data enable signal and the output width of the source output enable signal. The data driver 12 continuously supplies data voltages to each of the pixels P11 to Pmn via the data lines DL1 to DLn in synchronization with the output timing of gate signals described below. The plurality of data voltages supplied to the pixels P11 to Pmn correspond to the luminance of the pixels P11 to Pmn, respectively. Each of the data lines DL1 to DLn can include a plurality of data lines depending on the number of sub-pixels included in each of the pixels P11 to Pmn.

[0015] The data driver 12 is electrically connected to each of the pixels P11 to Pmn via the reference lines RL1 to RLn. The data driver 12 supplies a predetermined reference voltage to each of the pixels P11 to Pmn via the reference lines RL1 to RLn. By supplying the data voltage and the reference voltage to the pixels P11 to Pmn, the pixels P11 to Pmn emit light with accurate brightness, and their characteristics can be accurately acquired (sensed). In addition, the data driver 12 acquires sensing data Sdata of a plurality of sub-pixels included in each of the pixels P11 to Pmn via the reference lines RL1 to RLn. Acquisition of the sensing data Sdata will be described later. The data driver 12 transmits the acquired sensing data Sdata to the compensation unit 14.

[0016] The gate driver 13 receives a control signal GCS from the control unit 11. The gate driver 13 is electrically connected to the pixels P11 to Pmn via the gate lines GL1 to GLm. The gate driver 13 outputs a gate signal to each of the gate lines GL1 to GLm based on the control signal GCS. The output gate signal is transmitted to the pixels P11 to Pmn via the gate lines GL1 to GLm.

[0017] The gate driver 13 may include internal circuits (not shown), such as a level shifter, a shift register, a delay circuit, and a flip-flop. The gate driver 13 continuously generates control signals, such as a gate start pulse signal, a gate shift clock signal, and a gate output enable signal, in response to a control signal GCS. The gate start pulse signal controls the start timing of the operation of a gate driver integrated circuit (not shown) included in the gate driver 13. The gate shift clock signal is a signal commonly input to the gate driver integrated circuits and controls the shift timing of a scanning signal (gate signal). The gate output enable signal specifies timing information for the gate driver integrated circuit. The gate driver 13 continuously generates gate signals by shifting the gate start pulse signal in response to the gate shift clock signal. The gate driver 13 supplies the generated gate signals to each of the gate lines GL1 to GLm. The gate signals supplied via the gate lines GL1 to GLm activate each of the multiple pixels P11 to Pmn. The gate driver 13 controls the output width of the gate signals based on the output widths of the data enable signal and the gate output enable signal.

[0018] The gate driver 13 supplies a power supply voltage VDD to the pixels P11 to Pmn via the power supply lines PL1 to PLm. The gate driver 13 also supplies a power supply voltage VSS to the pixels P11 to Pmn. The pixels P11 to Pmn, which receive gate signals from the gate driver 13, emit light in accordance with the power supply voltages VDD, VSS and data voltage.

[0019] The compensator 14 receives the data signal DATA from the image processor. The compensator 14 generates cumulative data CNT based on the data signal DATA. The cumulative data CNT may include information about the cumulative total (counting value) of the input values ​​of the data signal DATA to each subpixel. That is, the cumulative data CNT may be a value obtained by adding up the data signals up to the time when they are supplied to the subpixels based on a predetermined formula. The compensator 14 supplies the generated cumulative data CNT to the controller 11 in response to a control signal CTL from the controller 11. The compensator 14 also receives sensing data Sdata from the data driver 12. The sensing data Sdata may include a current value flowing through the driving transistor DT. The compensator 14 generates compensation data Cdata based on the sensing data Sdata. The compensation data Cdata is a data signal in which non-uniformity in brightness between the subpixels is compensated for. The compensator 14 supplies the compensation data Cdata to the data driver 12. The operation of the compensator 14 will be described later.

[0020] The display panel 15 forms the display image of the display device 10. The display panel 15 includes a plurality of pixels P11 to Pmn. The pixels P11 to Pmn are arranged in a matrix in each pixel region defined by the intersection of gate lines GL1 to GLm extending in the row direction from the gate driver 13 and data lines DL1 to DLn (m and n are positive integers, the same applies below) extending in the column direction from the data driver 12. A pixel array is formed in the display panel 15 by arranging the pixels P11 to Pmn in a matrix.

[0021] Fig. 2 is a diagram showing a configuration for sensing the characteristics of the pixels P11 to Pmn included in the display device of this embodiment, and shows a circuit diagram of pixels P11 and P12 which are part of the pixels P11 to Pmn.

[0022] Each of the pixels P11 and P12 includes four subpixels. The four subpixels emit light of different colors. In this embodiment, the pixel P11 includes subpixels SP11(R), SP11(W), SP11(B), and SP11(G), which correspond to red, white, blue, and green, respectively. Similarly, the pixel P12 includes subpixels SP12(R), SP12(W), SP12(B), and SP12(G), which correspond to red, white, blue, and green, respectively. The four subpixels SP11(R), SP11(W), SP11(B), and SP11(G) included in the pixel P11 share the gate line GL1 and the reference line RL1. The four subpixels SP12(R), SP12(W), SP12(B), and SP12(G) included in the pixel P12 share the gate line GL1 and the reference line RL2. That is, all of the subpixels SP11 included in the pixel P11 and all of the subpixels SP12 included in the pixel P12 are connected to a common gate line GL1.

[0023] Each of the subpixels SP11 included in the pixel P11 shown in FIG. 2 includes switching transistors ST1 and ST2, a driving transistor DT, a capacitor Cst, and a light-emitting element LED. The gate of the switching transistor ST1 is connected to a gate line GL1. The drain or source of the switching transistor ST1 is connected to a data line DL1. The source or drain of the switching transistor ST1 is connected to the gate of the driving transistor DT and one end of the capacitor Cst. The drain or source of the driving transistor DT is connected to a power supply line PL1. The source or drain of the driving transistor DT is connected to the other end of the capacitor Cst, the drain or source of the switching transistor ST2, and the anode of the light-emitting element LED. The gate of the switching transistor ST2 is connected to the gate line GL1. The source or drain of the switching transistor ST2 is connected to a reference line RL1. A power supply voltage VSS is supplied to the cathode of the light-emitting element LED. The light-emitting element LED may be an organic light-emitting diode (OLED).

[0024] Each of the subpixels SP12 included in the pixel P12 shown in Figure 2 has a configuration similar to that of the subpixel SP11. The gate of the switching transistor ST1 is connected to the gate line GL1 shared with the subpixel SP11. The drain or source of the switching transistor ST1 is connected to the data line DL2. The drain or source of the drive transistor DT is connected to the power supply line PL1 shared with the subpixel SP11. The gate of the switching transistor ST2 is connected to the gate line GL1 shared with the subpixel SP11. The source or drain of the switching transistor ST2 is connected to the reference line RL2.

[0025] When a gate voltage is supplied to the gate line GL1, the data voltage Vdata is stored in the capacitor Cst via the data lines DL1 and DL2 and the switching transistor ST1. The data voltage Vdata stored in the capacitor Cst is supplied between the gate and drain or source of the drive transistor DT. A current corresponding to the data voltage Vdata and the power supply voltages VDD and VSS is supplied to the light-emitting element LED via the drive transistor DT. The light-emitting element LED emits light at a brightness corresponding to the supplied current. Furthermore, when a gate voltage is supplied to the gate line GL1, the sensing data Sdata of the subpixel is transmitted to the data driver 12 via the switching transistor ST2 and the reference lines RL1 and RL2.

[0026] 2, a data voltage Vdata of 10V+Vth(R) is applied to the subpixel SP11(R) via the data line DL1, and a data voltage Vdata of 10V+Vth(W) is applied to the subpixel SP12(W) via the data line DL2. A black data voltage corresponding to black is applied to the other subpixels via the data lines DL1 and DL2 as the data voltage Vdata. Here, Vth(R) is the threshold voltage of the drive transistor DT of the subpixel SP11(R), and Vth(W) is the threshold voltage of the drive transistor DT of the subpixel SP12(W). The black data voltage is a voltage that prevents the light-emitting element LED from emitting light, and in this example, the black data voltage is 0V.

[0027] When a gate voltage equal to or greater than the threshold voltage is supplied to the gates of the switching transistors ST1 and ST2 via the gate line GL1, a current corresponding to the data voltage Vdata flows through the drive transistors DT of the subpixels SP11(R) and SP12(W). The current values ​​flowing through the drive transistors DT of the subpixels SP11(R) and SP12(W) are transmitted to the data driver 12 via the reference lines RL1 and RL2 as sensing data Sdata for the subpixels SP11(R) and SP12(W), respectively. When transmitting the sensing data Sdata, the control unit 11 may be configured to change the power supply voltage VSS so that the light-emitting element LED does not emit light. Because a black data voltage (e.g., 0 V) ​​is supplied to the gates of the drive transistors DT of the subpixels other than the subpixels SP11(R) and SP12(W), no current flows through the drive transistors DT. Therefore, only the sensing data Sdata of the subpixel SP11(R), which is one of the four subpixels, is acquired from the pixel P11 via the reference line RL1. Further, from the pixel P12, only the sensing data Sdata of the subpixel SP12(W), which is one of the four subpixels, is acquired via the reference line RL2.

[0028] The data driver 12 includes a switching unit 121. The data driver 12 is connected to the reference lines RL1 and RL2 and the compensation unit 14. The data driver 12 supplies a reference voltage Vref from a reference voltage source 16 to each subpixel via the switching unit 121, the reference lines RL1 and RL2, and the switching transistor ST2. The switching unit 121 electrically connects the data driver 12 to the reference voltage source 16 when the reference voltage Vref is supplied from the reference voltage source 16. Before sensing the characteristics of the subpixels, the data driver 12 initializes each subpixel based on the transmitted reference voltage Vref. The switching unit 121 also electrically connects the data driver 12 to the compensation unit 14 when sensing the characteristics of the subpixels. Sensing data Sdata acquired from the subpixels is transmitted to the compensation unit 14 via the data driver 12.

[0029] 3 is a block diagram showing a schematic configuration of the compensation unit 14 in this embodiment. The compensation unit 14 includes a characteristics calculation unit 141, a characteristics storage unit 142, a first compensation data generation unit 143, a cumulative data generation unit 144, a characteristics estimation unit 145, and a second compensation data generation unit 146.

[0030] The characteristic calculation unit 141 receives sensing data Sdata from the data driver 12. The characteristic calculation unit 141 calculates characteristic values ​​CH11, CH12, ... CHmn of the sub-pixels based on the sensing data Sdata. The characteristic value CH11 is a characteristic value of some of the sub-pixels in the pixel P11, the characteristic value CH12 is a characteristic value of some of the sub-pixels in the pixel P12, and the characteristic value CHmn is a characteristic value of some of the sub-pixels in the pixel Pmn. In this embodiment, the characteristic values ​​may be threshold voltages of the driving transistors DT of the sub-pixels on which the sensing operation is performed. In the example shown in FIG. 2, the characteristic value CH11 is the threshold voltage of the driving transistor DT included in the sub-pixel SP11(R), and the characteristic value CH12 is the threshold voltage of the driving transistor DT included in the sub-pixel SP12(W).

[0031] The characteristic storage unit 142 stores the characteristic values ​​CH11, CH12, ... CHmn received from the characteristic calculation unit 141. The characteristic storage unit 142 transmits the characteristic value CH1 specified by the control signal CTL1 from among the characteristic values ​​CH11, CH12, ... CHmn to the first compensation data generation unit 143. The subpixel associated with the characteristic value CH1 may be the subpixel determined by the control unit 11 to be the most deteriorated of multiple subpixels included in the same pixel.

[0032] Furthermore, in response to a control signal CTL2 from the control unit 11, the characteristic storage unit 142 transmits the characteristic value CH2 specified by the control signal CTL2 from among the stored characteristic values ​​CH11, CH12, ... CHmn to the characteristic estimation unit 145. The pixel associated with the characteristic value CH2 is different from the pixel associated with the characteristic value CH1. Furthermore, the emission color of the sub-pixel associated with the characteristic value CH2 is different from the emission color of the sub-pixel associated with the characteristic value CH1. Furthermore, the characteristic value CH2 may be multiple characteristic values ​​acquired from multiple pixels.

[0033] The first compensation data generator 143 receives the characteristic value CH1 from the characteristic storage unit 142. The first compensation data generator 143 generates first compensation data Cdata1 based on the characteristic value CH1. Specifically, the first compensation data generator 143 detects a change in the threshold voltage of the driving transistor DT from the characteristic value CH1 and compensates for the detected change. The first compensation data Cdata1 may be a data signal corrected based on the characteristic value CH1. The first compensation data generator 143 transmits the first compensation data Cdata1 to the data driver 12.

[0034] The cumulative data generation unit 144 receives a data signal DATA from the video processing unit. The cumulative data generation unit 144 generates cumulative data based on the data signal DATA. Specifically, the cumulative data generation unit 144 measures the counting value of each sub-pixel based on the data signal DATA and stores the counting value as cumulative data CNT11, CNT12, ..., CNTmn. The cumulative data CNT11 is the cumulative data of pixel P11, the cumulative data CNT12 is the cumulative data of pixel P12, and the cumulative data CNTmn is the cumulative data of pixel Pmn. The cumulative data CNT11, CNT12, ..., CNTmn may correspond to degradation information for each sub-pixel.

[0035] The cumulative data generation unit 144 transmits the stored cumulative data CNT11, CNT12, ..., CNTmn to the control unit 11 in response to a control signal CTL3 from the control unit. The control unit 11 estimates changes in the characteristics of each subpixel (e.g., changes in the threshold voltage of the drive transistor) based on the cumulative data CNT11, CNT12, ..., CNTmn received from the cumulative data generation unit 144 and determines the subpixel estimated to be most degraded. Furthermore, in response to a control signal CTL4 from the control unit, the cumulative data generation unit 144 transmits cumulative data CNT1 designated by the control signal CTL4 from among the cumulative data CNT11, CNT12, ..., CNTmn to the characteristic estimation unit 145. The designated cumulative data CNT1 may include counting values ​​of multiple subpixels included in one pixel. Furthermore, the cumulative data generation unit 144 may extract the luminance value of light emitted from each subpixel from the data signal DATA. The cumulative data CNT11, CNT12, ..., CNTmn generated by the cumulative data generating unit 144 may include information on the extracted brightness values. The information on the measured brightness values ​​may correspond to degradation information.

[0036] The characteristic estimation unit 145 receives the characteristic value CH2 specified by the control signal CTL2 from the characteristic storage unit 142. The characteristic estimation unit 145 also receives the cumulative data CNT1 specified by the control signal CTL4 from the cumulative data generation unit 144. The characteristic estimation unit 145 estimates the characteristic value of the sub-pixel based on the characteristic value CH2 and the cumulative data CNT1.

[0037] Specifically, the characteristic estimation unit 145 estimates a change in the characteristic value of a sub-pixel based on the accumulated data CNT1. Here, the pixel associated with the accumulated data CNT1 is the same as the pixel associated with the characteristic value CH1 transmitted to the first compensation data generation unit 143. Furthermore, the sub-pixel associated with the accumulated data CNT1 is different from the sub-pixel associated with the characteristic value CH1 transmitted to the first compensation data generation unit 143.

[0038] Next, the characteristic estimation unit 145 corrects the change in the characteristic value of the sub-pixel calculated from the accumulated data CNT1 based on the characteristic value CH2 to generate an estimated characteristic value EC1. The estimated characteristic value EC1 is the amount of change in the corrected characteristic value for the sub-pixel related to the accumulated data CNT1. The estimated characteristic value EC1 may be the amount of change in the threshold voltage of the drive transistor DT of the sub-pixel related to the accumulated data CNT1. The pixel related to the characteristic value CH2 is different from the pixel related to the accumulated data CNT1. Furthermore, the pixel related to the characteristic value CH2 is selected from pixels arranged near the pixel related to the accumulated data CNT1. Furthermore, the emission color of the sub-pixel related to the characteristic value CH2 is the same as the emission color of the sub-pixel related to the accumulated data CNT1.

[0039] When generating the estimated characteristic value EC1, the characteristic estimation unit 145 may weight the characteristic value CH2 and the accumulated data CNT1 depending on the distance from the subpixel associated with the characteristic value CH2 to the subpixel associated with the accumulated data CNT1. For example, the characteristic estimation unit 145 may assign a relatively greater weight to the characteristic value CH2 the shorter the distance from the subpixel associated with the characteristic value CH2 to the subpixel associated with the accumulated data CNT1. Furthermore, the characteristic estimation unit 145 may assign a relatively greater weight to the accumulated data CNT1 the longer the distance from the subpixel associated with the characteristic value CH2 to the subpixel associated with the accumulated data CNT1. The characteristic estimation unit 145 may generate the estimated characteristic value EC1 based on the weighted accumulated data CNT1 and characteristic value CH2.

[0040] The characteristic estimation unit 145 transmits the generated estimated characteristic value EC1 to the second compensation data generation unit 146.

[0041] The second compensation data generator 146 receives the estimated characteristic value EC1 from the characteristic estimation unit 145. The second compensation data generator 146 generates second compensation data Cdata2 based on the estimated characteristic value EC1. Specifically, the second compensation data generator 146 obtains the amount of change in the threshold voltage of the driving transistor DT from the estimated characteristic value EC1 and compensates for the amount of change. The second compensation data Cdata2 may be a data signal corrected based on the estimated characteristic value EC1. The second compensation data generator 146 transmits the second compensation data Cdata2 to the data driver 12.

[0042] The data driver 12 supplies the first compensation data Cdata1 and the second compensation data Cdata2 to the corresponding subpixels. The first compensation data Cdata1 and the second compensation data Cdata2 compensate for the change in threshold voltage of the driving transistor DT included in each subpixel. Therefore, the display device according to the present invention can make all pixels included in the pixel array emit light with uniform brightness without any variation.

[0043] 4 is a diagram showing an example of the process in which the control unit 11 in this embodiment selects sub-pixels to be sensed. The following description focuses on the process for pixels P11 and P12, but similar processes can be performed for all pixels P11 to Pmn included in the display panel.

[0044] The control unit 11 determines the most degraded subpixel from among the multiple subpixels included in each pixel based on the accumulated data CNT11, CNT12, ..., CNTmn. In the example shown in Figure 4, pixel area PA1a shows the subpixel determined to be the most degraded subpixel in a 6 x 6 pixel area including pixels P11 and P12. In Figure 4, R, W, B, and G represent subpixels corresponding to red, white, blue, and green, respectively. That is, in this example, the most degraded subpixel in pixel P11 is subpixel SP11(R) corresponding to red, and the most degraded subpixel in pixel P12 is subpixel SP12(B) corresponding to blue.

[0045] In this embodiment, for each pixel, the sub-pixels corresponding to red or white are sensed, and then the sub-pixels corresponding to blue or green are sensed. That is, two sensing operations are performed for each pixel, and sensing data Sdata is obtained from each of the two sub-pixels included in each pixel.

[0046] In this example, the subpixel corresponding to red (first emission color) or white (second emission color) is sensed first. The control unit 11 selects the subpixel SP11(R), which is determined to be the most deteriorated subpixel of pixel P11, as the sensing target. On the other hand, the subpixel SP12(B), which does not have red or white as its emission color, is the most deteriorated subpixel of pixel P12. The control unit 11 compares the degree of deterioration of the subpixels SP12(R) and SP12(W) of pixel P12 based on the cumulative data CNT12. In this example, the control unit 11 determines that the subpixel SP12(W) has deteriorated more than the subpixel SP12(R), and selects the subpixel SP12(W) as the sensing target. The control unit 11 performs similar processing on the other pixels, selecting the subpixel corresponding to red or white from each pixel as the sensing target. The pixel area PA1b in FIG. 4 shows an example of the subpixels to be sensed selected by the control unit 11. The pixel area PA1b is the same area as the pixel area PA1a.

[0047] Next, the subpixels corresponding to blue or green within the same pixel region are sensed. The control unit 11 selects the subpixel SP12(B), which is determined to be the most deteriorated subpixel of pixel P12, as the sensing target. Meanwhile, the subpixel SP11(R), which corresponds to red, is the most deteriorated subpixel of pixel P11. The control unit 11 compares the degree of deterioration of the subpixels SP11(B) and SP11(G) of pixel P11 based on the accumulated data CNT11. In this example, the control unit 11 determines that the subpixel SP11(G) is more deteriorated than the subpixel SP11(B), and selects the subpixel SP11(G) as the sensing target. The control unit 11 performs similar processing on the other pixels, selecting the subpixels corresponding to blue or green from each pixel as the sensing target. The pixel region PA1c in FIG. 4 shows the subpixels selected by the control unit 11 as the sensing target. The pixel region PA1c is the same region as the pixel regions PA1a and PA1b.

[0048] In pixel P11, a change in the characteristic value of a subpixel (first subpixel) not selected as a sensing target is estimated based on the accumulated data CNT11 of the first subpixel and the characteristic value obtained through sensing from a subpixel having the same emission color as the first subpixel. To estimate the change in the characteristic value of the first subpixel, the control unit 11 may select the subpixel (second subpixel) located closest to the first subpixel from among multiple subpixels having the same emission color as the first subpixel and whose characteristic values ​​have been obtained through sensing. For example, a change in the characteristic value of subpixel SP11(W) included in pixel P11 (first pixel) is estimated by the compensation unit 14 based on the accumulated data CNT11 for subpixel SP11(W) and the characteristic value of sensed subpixel SP12(W) of pixel P12. A change in the characteristic value of subpixel SP11(B) is estimated by the compensation unit 14 based on the accumulated data CNT11 for subpixel SP11(B) and the characteristic value of sensed subpixel SP12(B). Specifically, the compensation unit 14 uses the characteristic value of the subpixel SP12(W) to correct a change in the characteristic value of the subpixel SP11(W) estimated based on the accumulated data CNT11 for the subpixel SP11(W). Similarly, the compensation unit 14 uses the characteristic value of the subpixel SP12(B) to correct a change in the characteristic value of the subpixel SP11(B) estimated based on the accumulated data CNT11 for the subpixel SP11(B). Similar processing is performed for the other pixels, and the compensation unit 14 estimates changes in the characteristic values ​​of the subpixels not selected for sensing.

[0049] By performing the process shown in FIG. 4 on all pixels included in the display panel 15 and all sub-pixels included in each pixel, it is possible to accurately compensate for luminance non-uniformity across the entire display area of ​​the display device and reduce the time required for the sensing operation.

[0050] If subpixels corresponding to one emission color are selected more than a predetermined percentage within a predetermined range based on accumulated data, the control unit 11 may change the selection of subpixels so that the percentage is not exceeded. For example, if subpixels corresponding to red (first emission color) are selected as sensing targets more than a predetermined percentage within a predetermined pixel range, the control unit 11 may exclude some of the selected subpixels corresponding to red from the sensing targets. Next, the control unit 11 may select subpixels corresponding to white (second emission color) included in the same pixel as the excluded subpixels as sensing targets. Furthermore, when changing the selection of subpixels to be sensed, the control unit 11 may select a pixel including two subpixels with a relatively small difference in the degree of degradation as the target for the change.

[0051] Furthermore, when two subpixels have deteriorated to the same degree, the control unit 11 may select the subpixel with the greater maximum luminance as the sensing target. A subpixel having white as its emitting color has a greater maximum luminance than a subpixel having red as its emitting color. A subpixel having green as its emitting color has a greater maximum luminance than a subpixel having blue as its emitting color. For example, when SP12(R) and SP12(W) have deteriorated to the same degree, the control unit 11 may select SP12(W), which has the greater maximum luminance, as the sensing target. When SP11(B) and SP11(G) have deteriorated to the same degree, the control unit 11 may select SP11(G), which has the greater maximum luminance, as the sensing target.

[0052] 5 is a flowchart showing the steps executed by the display device 10 of this embodiment. The following description focuses on the steps executed for pixels P11 and P12.

[0053] In step S501, the control unit 11 selects subpixels to be subjected to sensing. In the examples shown in FIGS. 1 to 4, the control unit 11 selects subpixels that are determined to have relatively large degradation based on the accumulated data CNT11 and CNT12. In the example shown in FIG. 4, the control unit 11 selects subpixels SP11(R) and SP11(G) for pixel P11 based on the accumulated data CNT11. Furthermore, the control unit 11 selects subpixels SP12(W) and SP12(B) for pixel P12 based on the accumulated data CNT12.

[0054] In step S502, the control unit 11 controls the data driver 12 and the gate driver 13 to supply a data signal and a reference voltage Vref to the selected subpixels. In the example shown in FIGS. 1 to 4, the data driver 12 supplies a data voltage Vdata to the subpixels SP11(R), SP11(G), SP12(W), and SP12(B) selected by the control unit 11 via data lines DL1 and DL2 and a switching transistor ST1. The data driver 12 also supplies a black data voltage to subpixels not selected by the control unit 11. In the example shown in FIG. 2, the data driver 12 supplies the reference voltage Vref to the subpixels SP11(R), SP11(W), SP11(B), and SP11(G) included in pixel P11 via a reference line R1 and a switching transistor ST2. The data driver 12 also supplies a reference voltage Vref to the subpixels SP12(R), SP12(W), SP12(B), and SP12(G) included in the pixel P12 via a reference line R2 and a switching transistor ST2.

[0055] In step S503, the control unit 11 controls the data driver 12 to acquire the characteristics of the selected subpixels. In the example shown in FIGS. 1 to 4, the data driver 12 first floats the reference line R1, and then acquires the currents flowing through the driving transistors DT of the selected subpixels SP11(R), SP11(G), SP12(W), and SP12(B) as sensing data Sdata of the subpixels based on the data voltage Vdata. The data driver 12 transmits the acquired sensing data Sdata to the compensation unit 14.

[0056] In step S504, the control unit 11 controls the compensation unit 14 to estimate the characteristics of the subpixels not selected for sensing and generate an estimated characteristic value EC1. In the example shown in FIGS. 1 to 4, the compensation unit 14 estimates the characteristics of the subpixels SP11(W) and SP11(B) not selected based on the accumulated data CNT11 and characteristic value CH2 for the subpixels SP11(W) and SP11(B). The characteristics estimated by the compensation unit 14 correspond to the estimated characteristic value EC1. The estimated characteristic value EC1 may be the amount of change in the threshold voltage of the drive transistor DT of the subpixels SP11(W) and SP11(B). The characteristic value CH2 may be a characteristic value obtained by sensing subpixels arranged near the pixel P11. For example, the characteristic value CH2 may be the threshold voltage of the drive transistor DT obtained by sensing the subpixels SP12(W) and SP12(B). Similarly, the compensation unit 14 estimates the characteristics of the unselected subpixels SP12(R) and SP12(G) based on the accumulated data CNT12 of SP12(R) and SP12(G) and the characteristic value CH2. The estimated characteristic value EC1 may be the amount of change in the threshold voltage of the drive transistor DT of the subpixels SP12(R) and SP12(G). The characteristic value CH2 may be a characteristic value obtained by a sensing operation on a subpixel arranged near the pixel P12. For example, the characteristic value CH2 may be the threshold voltage of the drive transistor DT obtained by a sensing operation on the subpixels SP11(R) and SP11(G).

[0057] In step S505, the control unit 11 controls the compensating unit 14 to generate first compensation data Cdata1. In the example shown in FIGS. 1 to 4, the compensating unit 14 calculates characteristic values ​​CH11 and CH12 from the sensing data Sdata acquired in step S503. Next, the compensating unit 14 supplies the first compensation data Cdata1 as compensated data signals to the data driver 12 based on the calculated characteristic values ​​CH11 and CH12. The data driver 12 supplies the first compensation data Cdata1 to the selected subpixels SP11(R), SP11(G), SP12(W), and SP12(B), respectively.

[0058] In step S506, the control unit 11 controls the compensating unit 14 to generate second compensation data Cdata2. In the example shown in FIGS. 1 to 4, the compensating unit 14 supplies the second compensation data Cdata2 as a compensated data signal to the data driver 12 based on the estimated characteristic value EC1 generated in step S504. The data driver 12 supplies the second compensation data Cdata2 to the unselected subpixels SP11(W), SP11(B), SP12(R), and SP12(G), respectively.

[0059] Changes in the threshold voltage of the drive transistor of each pixel due to aging or other factors can be estimated from the counting value. The threshold voltage of the drive transistor estimated from the counting value may significantly deviate from the actual threshold voltage obtained by the sensing process due to factors such as the usage conditions and environment of the display device. Therefore, in order to accurately compensate for changes in the threshold voltage of the drive transistor, it is desirable to sense all subpixels included in a pixel to obtain their characteristics. However, sensing all subpixels requires a long time to complete. Furthermore, the time required for the sensing process becomes more significant as the resolution of display devices increases. To shorten the time required for the sensing process, it is possible to sense only some of the subpixels included in a pixel using a predetermined pattern. However, the subpixels whose characteristics need to be compensated due to significant degradation may vary from pixel to pixel. Therefore, when selecting subpixels to be sensed using a predetermined pattern, there is a risk that subpixels whose characteristics are most in need of compensation (i.e., subpixels whose characteristics are most significantly degraded) may not be properly sensed.

[0060] According to the present invention, only some of the subpixels included in a pixel are sensed. The subpixels to be sensed are those with the most severe degradation of their light-emitting elements, based on accumulated data including counting values. For subpixels that are not sensed, the characteristics estimated from the accumulated data of the subpixels are corrected using characteristic values ​​obtained by sensing subpixels that have the same emission color and are located nearby the subpixels. Therefore, the display device according to the present invention can accurately compensate for non-uniform luminance among the subpixels while shortening the sensing process time.

[0061] [Second embodiment] A display device according to a second embodiment of the present invention will be described with reference to FIG. 6, focusing on differences from the first embodiment.

[0062] 6 is a diagram showing an example of the process in which the control unit in this embodiment selects the sub-pixels to be sensed. This embodiment differs from the first embodiment in that the sensing operation is performed only once for each pixel within a predetermined range. The following description will focus on the process for pixels P11 and P12.

[0063] 6 shows, as an example, the subpixel determined to be the most degraded subpixel in a 6×6 pixel region including pixels P11 and P12. In this example, the most degraded subpixel in pixel P11 is the subpixel SP11(R) corresponding to red, and the most degraded subpixel in pixel P12 is the subpixel SP12(B) corresponding to blue.

[0064] In this embodiment, one subpixel is sensed for each pixel. That is, one sensing operation is performed for each pixel. Specifically, the control unit 11 selects the subpixel SP11(R), which is the most degraded subpixel of pixel P11, as the sensing target. The control unit 11 also selects the subpixel SP12(B), which is the most degraded subpixel of pixel P12. The control unit 11 performs similar processing for the other pixels, selecting subpixels from each pixel. The pixel area PA1e in FIG. 6 shows the subpixels selected by the control unit 11. The pixel area PA1e is the same area as the pixel area PA1d.

[0065] In pixel P11, changes in the characteristic values ​​of SP11(W), SP11(B), and SP11(G), which were not selected as sensing targets, are estimated by the compensation unit 14 based on the accumulated data CNT11 for each subpixel and the characteristic values ​​of sensed subpixels in neighboring pixels. For example, a change in the characteristic value of SP11(W) is estimated by the compensation unit 14 based on the accumulated data CNT11 for SP11(W) and the characteristic value of the sensed subpixel SP21(W). A change in the characteristic value of SP11(B) is estimated by the compensation unit 14 based on the accumulated data CNT11 for SP11(B) and the characteristic value of the sensed subpixel SP12(B). A change in the characteristic value of SP11(G) is estimated by the compensation unit 14 based on the accumulated data CNT11 for SP11(G) and the characteristic value of the sensed subpixel SP13(G). The compensation unit 14 can estimate a change in the characteristic value of SP11(G) based on, for example, the characteristic value of subpixel SP31(G) in addition to the characteristic value of subpixel SP13(G). In this case, the compensation unit 14 can estimate a change in the characteristic value of SP11(G) based on, for example, the average value of the characteristic value of subpixel SP13(G) and the characteristic value of subpixel SP31(G). Similar processing is performed on the other pixels, and the compensation unit 14 estimates the characteristic values ​​of the subpixels that were not selected.

[0066] By performing the above-described process for all pixels included in the display panel 15, the time required for the sensing operation to be performed for the entire display area of ​​the display device can be further reduced.

[0067] If subpixels corresponding to one emission color are selected more than a predetermined percentage within a predetermined range based on accumulated data, control unit 11 may change the selection of subpixels so that the percentage is not exceeded. For example, if subpixels corresponding to red are selected more than a predetermined percentage within a predetermined pixel range, control unit 11 may exclude some of the selected subpixels corresponding to red from the sensing target. Next, control unit 11 may select subpixels corresponding to white, blue, or green that are included in the same pixel as the excluded subpixels. Furthermore, when changing the selection of subpixels, control unit 11 may select subpixels corresponding to the emission color that are selected the least frequently within the predetermined range in place of the excluded subpixels corresponding to red.

[0068] Furthermore, when two or more subpixels have deteriorated to the same extent, the control unit 11 may select the subpixel with the greatest maximum luminance. For example, with respect to the four luminous colors shown in FIG. 2 , red has a higher maximum luminance than blue, green has a higher maximum luminance than red and blue, and white has a higher maximum luminance than green, red, and blue. Therefore, when two or more subpixels have deteriorated to the same extent, the control unit 11 may preferentially select the subpixel having the white luminous color as the sensing target, followed by the subpixel having the green luminous color, and then the subpixel having the red luminous color.

[0069] Furthermore, if a subpixel corresponding to a certain emission color is not selected within a predetermined range, the control unit 11 may change the selection so that subpixels having that emission color within the predetermined range become the sensing targets. For example, if a subpixel having red as its emission color is not selected within a predetermined pixel range, the control unit 11 may exclude some of the selected subpixels having white, blue, and green as their emission colors from the sensing targets. Next, the control unit 11 may select a subpixel corresponding to red that is included in the same pixel as the excluded subpixel. When changing the selection, the control unit 11 may exclude from the sensing targets the subpixel corresponding to the emission color that is most frequently selected within the predetermined range.

[0070] According to this embodiment, it is possible to further reduce the time required for the sensing operation while accurately compensating for non-uniformity in luminance.

[0071] [Other embodiments] In the first and second embodiments, the control unit 11 is described as being configured separately from the compensation unit 14. However, the compensation unit 14 does not have to be provided separately from the control unit 11. For example, the control unit 11 may be configured as a single chip, the compensation unit 14 may be integrated within the chip of the control unit 11, and the control unit 11 may be configured to provide all of the functions of the compensation unit 14.

[0072] Each unit and each step described in each embodiment can be realized by a processor and a memory cooperating with the processor. For example, the processor can read a program stored in the memory, execute the program, and cause each unit to operate as described in each embodiment. The processor can be included in each unit described in each embodiment. The processor can be a CPU or an MPU. Furthermore, the memory cooperating with the processor can be a non-volatile memory.

[0073] The configurations of the components and the contents of the signals described in each embodiment are not limited to those described above and may be changed depending on the application or purpose. Furthermore, configurations and signals that combine the various embodiments are also included in the present invention. In other words, the present invention is not limited to the above-described embodiments and may be modified based on the technical concept of the present invention. For example, the present invention includes a configuration in which the above-described embodiments are organically combined. [Explanation of symbols]

[0074] 10 Display device 11 Control section 12 Data Drive Unit 13 Gate driver 14 Compensation Department 15 Display panel (pixel array) P11, P12 pixels SP11, SP12 subpixels

Claims

1. a pixel array having a plurality of pixels, each of which includes a plurality of sub-pixels, and a gate line shared by the plurality of sub-pixels; a gate driver for supplying gate signals to the plurality of sub-pixels through the gate lines; a data driver for supplying a data signal to each of the plurality of sub-pixels via a data line; a control unit that selects one of the subpixels included in the pixel based on degradation information of the subpixel, and supplies the data signal from the data driver to the selected subpixel; a compensation unit for acquiring characteristics of the selected sub-pixel; Including, the degradation information is cumulative data including information about a cumulative total of input values ​​of data signals supplied to the subpixels, the plurality of sub-pixels have first and second emission colors different from each other, the control unit selects a sub-pixel estimated to be most deteriorated from the plurality of sub-pixels based on the accumulated data, the maximum value of luminance of the first luminescent color, and the maximum value of luminance of the second luminescent color. Display device.

2. Each of the plurality of pixels includes an unselected first subpixel and a selected second subpixel; the compensation unit estimates the characteristic of the first subpixel of the one pixel based on the accumulated data of the first subpixel of the one pixel and the characteristic acquired from the second subpixel of another pixel; The display device according to claim 1 .

3. the first sub-pixel of the one pixel has the same emission color as the second sub-pixel of the other pixel; The display device according to claim 2 .

4. the compensation unit estimates the characteristic of the first subpixel of the one pixel based on the characteristic of the second subpixel of the other pixel that is closest to the first subpixel among the plurality of other pixels; The display device according to claim 3 .

5. the compensation unit further estimates the characteristic of the first subpixel based on the characteristic acquired from the second subpixel. The display device according to claim 4 .

6. the compensation unit further estimates the characteristic of the first subpixel according to a distance from the first subpixel to the second subpixel. The display device according to claim 5 .

7. the compensation unit acquires the characteristics from two sub-pixels among the plurality of sub-pixels. The display device according to claim 1 .

8. When the subpixel with the greatest degradation does not have the first light-emitting color or the second light-emitting color, the control unit compares the accumulated data of the subpixel with the first light-emitting color and the accumulated data of the subpixel with the second light-emitting color, and selects the subpixel with the greatest degradation. The display device according to claim 7 .

9. when it is determined that the first subpixel having the first emission color and the second subpixel having the second emission color have the same degree of deterioration based on the accumulated data, the control unit selects a subpixel having a larger maximum value of luminance from the first subpixel and the second subpixel. The display device according to claim 1 .

10. a pixel array having a plurality of pixels, each of which includes a plurality of sub-pixels, and a gate line shared by the plurality of sub-pixels; a gate driver for supplying gate signals to the plurality of sub-pixels through the gate lines; a data driver for supplying a data signal to each of the plurality of sub-pixels via a data line; a control unit that selects one of the subpixels included in the pixel based on degradation information of the subpixel, and supplies the data signal from the data driver to the selected subpixel; a compensation unit for acquiring characteristics of the selected sub-pixel; Including, the degradation information is cumulative data including information about a cumulative total of input values ​​of data signals supplied to the subpixels, the control unit selects the subpixel estimated to be most deteriorated from the plurality of subpixels based on the accumulated data; the plurality of sub-pixels include a first sub-pixel having a first emission color and a second sub-pixel having a second emission color; When the first subpixels are selected more than a predetermined rate within a predetermined pixel range, the control unit selects pixels within the predetermined pixel range in which the difference in the degree of deterioration between the first subpixels and the second subpixels is relatively small, excludes the first subpixel, which is the subpixel with the greatest deterioration, from among the selected pixels, and selects the second subpixel from among the selected pixels. Display device.

11. When there is an unselected luminescent color within a predetermined pixel range, the control unit selects a subpixel corresponding to the unselected luminescent color instead of the subpixel with the greatest degradation. The display device according to claim 1 .

12. The compensation unit generating a data voltage that compensates for the change in the characteristic of the selected sub-pixel based on the acquired characteristic; generating a data voltage in which the change in the characteristic of the first subpixel is compensated based on the estimated characteristic; The display device according to claim 2 .

13. the data driver supplies a black data voltage corresponding to black to sub-pixels other than the selected sub-pixel when supplying the data signal to the selected sub-pixel; The display device according to claim 1 .

14. the data driver supplies a predetermined reference voltage to the plurality of sub-pixels via a reference line shared by the plurality of sub-pixels before supplying the data signal; the compensation unit acquires the characteristics via the reference line. The display device according to claim 1 .

15. the control unit selects the sub-pixels from all the pixels included in the pixel array, the compensation unit acquires the characteristics from all of the selected sub-pixels, respectively. The display device according to claim 1 .

16. each of the plurality of sub-pixels includes an organic light emitting diode; The display device according to any one of claims 1 to 15.

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