KR102377465B1 - Display device and fabrication method thereof - Google Patents

Abstract

Embodiments of the present invention relate to a display device that does not require a repair line for welding. A display device according to an embodiment of the present invention includes scan lines to which scan signals are supplied, data lines to which data voltages are supplied, reference voltage lines to which a reference voltage is supplied, and the scan lines, the data lines, and Among the reference voltage lines, a pixel includes a same scan line, a same data line, and a plurality of sub-pixels connected to the same reference voltage line.

Description

DISPLAY DEVICE AND FABRICATION METHOD THEREOF}

Embodiments of the present invention relate to a display device.

Recently, various flat display devices have been developed that can reduce the weight and volume, which are disadvantages of cathode ray tubes. These flat panel displays include liquid crystal displays, field emission displays, and organic light emitting displays.

A flat panel display device includes a display panel including data lines, gate lines, a plurality of pixels formed at the intersection of the data lines and the gate lines, a gate driver that supplies gate signals to the gate lines, and data to the data lines. It includes a data driver that supplies voltages. Each of the plurality of pixels receives a data voltage from the data line when a gate signal is supplied from the gate line, and emits light with a predetermined brightness according to the data voltage. For example, each pixel of a liquid crystal display device drives the liquid crystal of the liquid crystal layer according to the electric field of the data voltage supplied to the pixel electrode and the common voltage supplied to the common electrode, thereby transmitting light incident from the backlight unit to achieve a predetermined brightness. It can emit light. Additionally, each pixel of the organic light emitting display device can control the current flowing to the organic light emitting diode according to the data voltage supplied to the gate electrode of the driving transistor, thereby causing the organic light emitting diode to emit light at a predetermined brightness.

Meanwhile, during the manufacturing process of a flat panel display device, defects such as pixels operating as bright points or dark points may occur due to substances such as foreign substances. In this case, a method of repairing defective pixels through a laser process is known.

Figure 1 is an example diagram showing a method of repairing a defective pixel using pixels adjacent to it. In Figure 1, the second pixel (P2) is defective, and the first and third pixels (P1 and P3) are normal. Additionally, Figure 1 illustrates that the pixels P1, P2, and P3 are pixels of an organic light emitting display device.

Referring to FIG. 1, each of the pixels P1, P2, and P3 includes a driving transistor (DT) and an organic light emitting diode (OLED). The first pixel (P1) is connected to the second pixel (P2) through the repair line (RL), and the second pixel (P2) is connected to the third pixel (P3) through the repair line (RL). The repair line (RL) is cut in the cutting area (CA), and when the cutting area (CA) is welded with a laser, the repair line (RL) can be connected to the cutting area (CA).

If the driving transistor (DT) of the second pixel (P2) does not operate normally due to a defect, cutting between the organic light emitting diode (OLED) and the driving transistor (DT) of the second pixel (P2) is performed using a laser. )do. Then, the cut area CA of the repair line RL extending from the third pixel P3 is welded using a laser. Because of this, the repair line RL is connected at the cut area CA, so the organic light emitting diode OLED of the second pixel P2 can be connected to the third pixel P3. Accordingly, since the organic light emitting diode (OLED) of the second pixel (P2) can receive driving current from the driving transistor (DT) of the third pixel (P3), the second pixel (P2) can be repaired. However, when repairing a defective pixel as shown in FIG. 1, there is a problem in that a repair line RL for welding must be additionally designed.

Embodiments of the present invention provide a display device that does not require a repair line for welding.

A display device according to an embodiment of the present invention includes scan lines to which scan signals are supplied, data lines to which data voltages are supplied, reference voltage lines to which a reference voltage is supplied, and the scan lines, the data lines, and Among the reference voltage lines, a pixel includes a same scan line, a same data line, and a plurality of sub-pixels connected to the same reference voltage line.

An embodiment of the present invention includes a pixel including a plurality of sub-pixels connected to the same scan line, the same data line, and the same reference voltage line. As a result, in an embodiment of the present invention, when one of a plurality of subpixels is defective, the pixel can be repaired by cutting the defective subpixel using a laser. That is, the embodiment of the present invention has the advantage of not having to design a repair line for welding because the pixel can be simply repaired using only laser cutting.

Additionally, an embodiment of the present invention converts first digital video data into second digital video data by adding predetermined compensation data to the first digital video data to be supplied to the pixel including the defective subpixel. As a result, the embodiment of the present invention can uniformly match the luminance of a pixel including a defective subpixel with the luminance of a pixel including a plurality of subpixels that normally emit light.

1 is an example diagram showing a method of repairing a defective pixel using pixels adjacent to it.
Figure 2 is a block diagram showing a display device according to an embodiment of the present invention.
FIG. 3 is a block diagram showing an example of the timing control unit of FIG. 2.
Figure 4 is a circuit diagram showing the pixel of Figure 2 in detail.
FIGS. 5A and 5B are exemplary diagrams showing laser cutting positions when the first subpixel of FIG. 4 is defective.
Figure 6 is another circuit diagram showing the pixel of Figure 2 in detail.
7 is a flowchart showing a method of manufacturing a display device according to an embodiment of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. Like reference numerals refer to substantially the same elements throughout the specification. In the following description, if it is determined that a detailed description of a known function or configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Additionally, the component names used in the following description may have been selected in consideration of ease of specification preparation, and may be different from the component names of the actual product.

Figure 2 is a block diagram showing a display device according to an embodiment of the present invention. Referring to FIG. 2, a display device according to an embodiment of the present invention includes a display panel 10, a data driver 20, a scan driver 30, a timing controller 40, and a digital data converter 50. .

A display device according to an embodiment of the present invention may include any display device that supplies data voltages to pixels through line sequential scanning, which sequentially supplies scan signals to scan signals. The display device according to an embodiment of the present invention is preferably implemented as an Organic Light Emitting Display, but is not limited thereto, and may include a Liquid Crystal Display or a Field Emission Display. , may be implemented as one of the electrophoresis displays. Although the present invention is exemplified in the following embodiments where the display device is implemented as an organic light emitting display device, it should be noted that the display device of the present invention is not limited to an organic light emitting display device.

The display panel 10 includes data lines (D1 to Dm, m is a positive integer of 2 or more), reference voltage lines (R1 to Rm), scan lines (S1 to Sn, n is a positive integer of 2 or more), and Sensing signal lines (SEN1 to SENn) are formed. The data lines (D1 to Dm) and the reference voltage lines (R1 to Rm) may be formed to intersect the scan lines (S1 to Sn) and the sensing signal lines (SEN1 to SENn). The data lines (D1 to Dm) and the reference voltage lines (R1 to Rm) may be formed parallel to each other. The scan lines (S1 to Sn) and the sensing signal lines (SEN1 to SENn) may be formed parallel to each other. Meanwhile, the sensing signals supplied to the sensing signal lines (SEN1 to SENn) may be the same as the scan signals supplied to the scan lines (S1 to Sn), in which case the sensing signal lines (SEN1 to SENn) are omitted. It can be.

Each of the pixels (P) of the display panel 10 is one of the data lines (D1 to Dm), one of the reference voltage lines (R1 to Rm), one of the scan lines (S1 to Sn), and the sensing signal lines (SEN1 to SENn). Each pixel P of the display panel 10 may include a plurality of subpixels. In the embodiment of the present invention, each of the pixels P includes two sub-pixels SP1 and SP2 as shown in FIG. 2, but it should be noted that the present invention is not limited thereto. That is, in an embodiment of the present invention, each pixel P may include three or more subpixels. In addition, in FIG. 2, two sub-pixels (SP1, SP2) are arranged vertically, but it should be noted that the display is not limited thereto. That is, the two sub-pixels SP1 and SP2 can be arranged left and right as shown in FIGS. 4 and 6.

The two sub-pixels SP1 and SP2 may be connected to the same data line, the same reference voltage line, the same scan line, and the same sensing signal line. Because of this, the two sub-pixels (SP1, SP2) receive the same data voltage, the same reference voltage, the same scan signal, and the same sensing signal. Accordingly, the two sub-pixels SP1 and SP2 may emit light with the same brightness.

Meanwhile, in an embodiment of the present invention, when a defect occurs in one of the two sub-pixels SP1 and SP2, the sub-pixel in which the defect occurs is made to not emit light. In an embodiment of the present invention, since the pixel P includes two sub-pixels (SP1, SP2), even if one of the two sub-pixels (SP1, SP2) is defective and does not emit light, the other one is normally It can emit light. A detailed description of the pixels P of the display panel 10 will be described later in conjunction with FIGS. 4 and 6.

The data driver 20 includes at least one source drive integrated circuit (hereinafter referred to as “IC”) 21 and a sensing unit 22. In FIG. 2 , one source drive IC 21 is illustrated for convenience of explanation, but the present invention is not limited thereto, and the data driver 20 may include a plurality of source drive ICs 21 .

The source drive IC 21 is connected to the data lines D1 to Dm and supplies data voltages. Specifically, the source drive IC 21 receives digital video data and a source timing control signal (DCS) from the timing control unit 40. The source drive IC 21 converts digital video data into a data voltage according to the source timing control signal (DCS) and supplies it to the data lines (D1 to Dm).

The source drive IC 21 converts the first digital video data DATA1 or the second digital video data DATA2 into data voltages and supplies them to the data lines D1 to Dm during the display period. Each of the first digital video data (DATA1) and the second digital video data (DATA2) is data supplied to cause the organic light emitting diode of the pixel (P) to emit light.

Additionally, the source drive IC 21 converts the third digital video data DATA3 into data voltages and supplies them to the data lines D1 to Dm during the sensing period. The third digital video data (DATA3) is data for sensing the source voltage of the driving transistor of the pixel (P) during the sensing period.

The sensing unit 22 is connected to the reference voltage lines (R1 to Rm). The sensing unit 22 supplies a reference voltage to the reference voltage lines (R1 to Rm) during the display period. The reference voltage is a voltage for initializing the source electrode of the driving transistor of the pixel (P). The sensing unit 22 supplies a precharging voltage to the reference voltage lines (R1 to Rm) during the sensing period and then senses the source voltage of the driving transistor. The precharging voltage is also a voltage for initializing the source electrode of the driving transistor of the pixel (P). The sensing unit 22 converts the sensed voltage into sensing data (SD), which is digital data, using an analog to digital converter and outputs it to the digital data conversion unit 50.

The scan driver 30 includes a scan signal driver and a sensing signal driver. The scan signal driver is connected to the scan lines (S1 to Sn) and supplies scan signals. Specifically, the scan signal driver supplies scan signals to the scan lines S1 to Sn according to the scan timing control signal SCS input from the timing control unit 40. The scan signal driver may sequentially supply scan signals to the scan lines (S1 to Sn) during the display period and may supply a scan signal to one scan line during the sensing period.

The sensing signal driver is connected to the sensing signal lines (SEN1 to SENn) and supplies scan signals. Specifically, the sensing signal driver supplies sensing signals to the sensing signal lines (SEN1 to SENn) according to the scan timing control signal (SCS) input from the timing control unit 40. The sensing signal driver sequentially supplies sensing signals to the sensing signal lines (SEN1 to SENn) during the display period, and may supply a sensing signal to one of the sensing lines during the sensing period.

The timing control unit 40 receives first digital video data (DATA1) from the digital data conversion unit 50. The timing control unit 40 generates timing control signals to control the operation timing of the source drive IC 21 and the scan driver 30. The timing control signals include a data timing control signal (DCS) for controlling the operation timing of the source drive IC 21 and a scan timing control signal (SCS) for controlling the operation timing of the scan driver 30.

The timing control unit 40 outputs the first digital video data DATA1 and the data timing control signal DCS generated according to the timing of the first digital video data DATA1 to the data driver 20 during the display period. The timing control unit 40 sends the third digital video data (DATA3) stored in the internal memory during the sensing period and a data timing control signal (DCS) generated according to the timing of the third digital video data (DATA3) to the data driver 20. Output as The timing control unit 40 outputs a scan timing control signal (SCS) to the scan driver 30.

Meanwhile, in an embodiment of the present invention, when a defect occurs in one of the two sub-pixels SP1 and SP2, the defective sub-pixel (hereinafter referred to as “defective sub-pixel”) is made to not emit light. In the pixel P containing a defective subpixel, only one subpixel emits light, while in the pixel P containing no defective subpixel, two subpixels SP1 and SP2 emit light. Accordingly, the luminance of the pixel P including the defective subpixel becomes lower than the luminance of the pixel P including the two normally emitting subpixels SP1 and SP2.

The timing control unit 40 is configured to uniformly match the luminance of the pixel P including the defective subpixel with the luminance of the pixel P including the two normally emitting subpixels SP1 and SP2. It may include a data conversion unit that converts the first digital video data (DATA1) to be supplied to the pixel (P) including the second digital video data (DATA2). In this case, the timing control unit 40 outputs the second digital video data (DATA2) and the data timing control signal (DCS) generated according to the timing of the second digital video data (DATA2) to the data driver 20 during the display period. do. A detailed description of the data conversion unit of the timing control unit 40 will be described later in conjunction with FIG. 3.

The digital data converter 50 receives digital video data (DATA) from the outside. Additionally, the digital data conversion unit 50 receives sensing data (SD) from the sensing unit 22. The digital data converter 50 may calculate threshold voltage compensation data that can compensate for the threshold voltage of the driving transistor of each pixel (P) from the input sensing data (SD). The digital data converter 50 may convert the digital video data (DATA) into first digital video data (DATA1) by applying threshold voltage compensation data to the digital video data (DATA). The digital data conversion unit 50 outputs first digital video data DATA1 to the timing control unit 40. The digital data conversion unit 50 may be included in the timing control unit 50.

FIG. 3 is a block diagram showing an example of the timing control unit of FIG. 2. Referring to FIG. 3, the timing control unit 40 equalizes the luminance of the pixel P including a defective subpixel and the luminance of the pixel P including two normally emitting subpixels SP1 and SP2. In order to do this, it may include a data conversion unit 41 and a memory 42 that convert the first digital video data DATA1 to be supplied to the pixel P including the defective subpixel.

The memory 42 stores coordinate data CD including the coordinate value of the pixel P including the defective subpixel and compensation data AD for compensating the first digital video data DATA1. The memory 42 outputs coordinate data (CD) and compensation data (AD) to the data conversion unit 41.

The data conversion unit 41 receives first digital video data (DATA1) and coordinate data (CD) from the memory 42. The data conversion unit 41 provides first digital video data (DATA1) to be supplied to the pixel (P) including the defective subpixel according to the coordinate value of the pixel (P) including the defective subpixel included in the coordinate data (CD). ) is converted. In particular, since the luminance of the pixel P including the defective subpixel is lower than the luminance of the pixel P including the two normally emitting subpixels SP1 and SP2, the data converter 41 uses Equation By adding predetermined compensation data (AD) to the first digital video data (DATA1) to be supplied to the pixel (P) including the defective sub-pixel as shown in 1, the first digital video data (DATA1) is converted into second digital video data. It can be converted to (DATA2). The data conversion unit 41 outputs the second digital video data (DATA2) to the data driver 20.

In Equation 1, DATA1(x,y) is the first digital video data to be supplied to the pixel (P) of (x,y) coordinates, CD is compensation data, and DATA2(x,y) is (x,y) coordinates. This means the second digital video data to be supplied to the pixel (P) of . The compensation data (CD) is data for uniformly matching the luminance of the pixel (P) including the defective subpixel with the luminance of the pixel (P) including the two normally emitting subpixels (SP1 and SP2). It can be determined in advance through experimentation.

Meanwhile, when there is no defective subpixel, the memory 42 does not store the coordinate value of the pixel P including the defective subpixel. Accordingly, when there is no defective subpixel, the data conversion unit 41 outputs the first digital video data DATA1 as is to the data driver 20.

As discussed above, the embodiment of the present invention adds compensation data (CD) to the first digital video data (DATA1) to be supplied to the pixel (P) including the defective subpixel, thereby generating the first digital video data (DATA1). ) is converted into second digital video data (DATA2). As a result, the embodiment of the present invention can uniformly match the luminance of the pixel P including the defective sub-pixel with the luminance of the pixel P including the two sub-pixels SP1 and SP2 that normally emit light. .

FIG. 4 is a circuit diagram showing the pixel of FIG. 2 in detail. Referring to FIG. 4, each of the pixels P includes two subpixels, that is, first and second subpixels SP1 and SP2.

The first and second subpixels SP1 and SP2 are connected to the same scan line, the same sensing signal line, the same data line, and the same reference voltage line. For example, the first and second sub-pixels (SP1, SP2) have a k-th (k is a positive integer satisfying 1≤k≤n) scan line (Sk), and a k-th sensing signal line as shown in FIG. 4. (SENk), the jth (j is a positive integer satisfying 1≤j≤m) data line (Dj), and the jth reference voltage line (Rj). Because of this, the first and second subpixels SP1 and SP2 receive the same scan signal, the same sensing signal, the same data voltage, and the same reference voltage. Accordingly, the first and second subpixels SP1 and SP2 emit light with the same brightness.

The first and second subpixels SP1 and SP2 are connected to different high potential voltage lines. For example, as shown in FIG. 4, the first sub-pixel (SP1) is connected to the ith high potential voltage line (VDDLi), and the second sub-pixel (SP2) is connected to the i+1 high potential voltage line (VDDLi+1). can be connected to.

As discussed above, the pixel P according to the embodiment of the present invention includes first and second subpixels (SP1, SP2) connected to the same scan line, the same sensing signal line, the same data line, and the same reference voltage line. ) includes. As a result, in an embodiment of the present invention, when any one of the first and second sub-pixels SP1 and SP2 is defective, the defective sub-pixel is cut using a laser as shown in FIGS. 5A and 5B, thereby cutting the pixel P ) can be repaired. That is, the embodiment of the present invention has the advantage that the pixel P can be easily repaired using only laser cutting, and there is no need to design a repair line for welding.

Hereinafter, embodiments of the first and second subpixels SP1 and SP2 will be looked at in conjunction with FIG. 4 .

First, the first sub-pixel SP1 includes a first driving transistor DT1, first and second transistors T1 and T2, a first capacitor C1, and a first organic light-emitting diode OLED1. .

The first driving transistor DT1 controls the amount of current supplied to the first organic light emitting diode OLED1 according to the voltage of the gate electrode. The gate electrode of the first driving transistor (DT1) is connected to the source electrode of the first transistor (T1), the source electrode is connected to the anode electrode of the first organic light emitting diode (OLED1), and the drain electrode is supplied with a high potential voltage. It can be connected to the i-th (i is a positive integer) high potential voltage line (VDDi).

The first organic light emitting diode (OLED1) emits light according to the amount of current supplied through the first driving transistor (DT1). The anode electrode of the first organic light-emitting diode (OLED1) is connected to the source electrode of the first driving transistor (DT1), and the cathode electrode is connected to the low-potential voltage line (VSSL) to which a low-potential voltage lower than the high-potential voltage is supplied. You can.

The first transistor T1 is turned on by the scan signal of the kth scan line Sk and supplies the data voltage of the jth data line Dj to the gate electrode of the first driving transistor DT1. The gate electrode of the first transistor (T1) is connected to the kth scan line (Sk), the source electrode is connected to the gate electrode of the first driving transistor (DT1), and the drain electrode is connected to the jth data line (Dj). It can be.

The second transistor T2 connects the jth reference voltage line Rj to the source electrode of the first driving transistor DT1 in response to the sensing signal of the kth sensing signal line SENk. The gate electrode of the second transistor (T2) is connected to the kth sensing signal line (SENk), the source electrode is connected to the source electrode of the first driving transistor (DT1), and the drain electrode is connected to the jth reference voltage line (Rj). can be connected to.

The first capacitor C1 is formed between the gate electrode and the source electrode of the first driving transistor DT1.

In FIG. 4, the description focuses on the fact that the first driving transistor DT1 and the first and second transistors T1 and T2 are formed of an N-type MOSFET (Metal Oxide Semiconductor Field Effect Transistor), but it should be noted that the transistor is not limited thereto. do. That is, the first driving transistor DT1 and the first and second transistors T1 and T2 may be formed of a P-type MOSFET. Additionally, in FIG. 4, the first transistor T1 is a transistor connected to the kth scan line (Sk), so it can be collectively referred to as a “scan transistor,” and the second transistor (T2) is a transistor connected to the kth sensing signal line (SENk). Since it is a transistor connected to , it can be collectively referred to as a “sensing transistor.”

As described above, the first sub-pixel (SP1) according to an embodiment of the present invention includes a first driving transistor (DT1) for supplying a driving current to the first organic light-emitting diode (OLED1), and a first driving transistor (DT1). ), a first transistor (T1) for supplying a data voltage to the gate electrode of 1 It includes a first capacitor C1 to maintain a voltage difference between the gate electrode and the source electrode of the driving transistor DT1. As a result, the embodiment of the present invention supplies a data voltage for light emission to the gate electrode of the first driving transistor (DT1) and a reference voltage to the source electrode during the display period, thereby setting the first organic light emitting diode (OLED1) to a predetermined level. It can emit light with a brightness of . In addition, an embodiment of the present invention supplies a data voltage for sensing to the gate electrode of the first driving transistor (DT1) and a precharging voltage to the source electrode during the sensing period, so that the first driving transistor (DT1) uses a reference voltage line. The source voltage of (DT1) can be sensed.

Second, the second subpixel SP2 includes a second driving transistor DT1, third and fourth transistors T3 and T4, a second capacitor C2, and a second organic light emitting diode OLED2. Includes.

The second driving transistor DT2 controls the amount of current supplied to the second organic light emitting diode OLED2 according to the voltage of the gate electrode. The gate electrode of the second driving transistor (DT2) is connected to the source electrode of the third transistor (T3), the source electrode is connected to the anode electrode of the second organic light-emitting diode (OLED2), and the drain electrode is supplied with a high potential voltage. It can be connected to the i+1th high potential voltage line (VDDi+1).

The second organic light emitting diode (OLED2) emits light according to the amount of current supplied through the second driving transistor (DT2). The anode electrode of the second organic light emitting diode (OLED2) may be connected to the source electrode of the second driving transistor (DT2), and the cathode electrode may be connected to the low potential voltage line (VSSL).

The third transistor T3 is turned on by the scan signal of the kth scan line Sk and supplies the data voltage of the jth data line Dj to the gate electrode of the second driving transistor DT2. The gate electrode of the third transistor T3 is connected to the kth scan line Sk, the source electrode is connected to the gate electrode of the second driving transistor DT2, and the drain electrode is connected to the jth data line Dj. It can be.

The fourth transistor T4 connects the jth reference voltage line Rj to the source electrode of the second driving transistor DT2 in response to the sensing signal of the kth sensing signal line SENk. The gate electrode of the fourth transistor (T4) is connected to the kth sensing signal line (SENk), the source electrode is connected to the source electrode of the second driving transistor (DT2), and the drain electrode is connected to the jth reference voltage line (Rj). can be connected to.

The second capacitor C2 is formed between the gate electrode and the source electrode of the second driving transistor DT2.

In FIG. 4, the description focuses on the fact that the second driving transistor DT2 and the third and fourth transistors T3 and T4 are formed of an N-type MOSFET (Metal Oxide Semiconductor Field Effect Transistor), but it should be noted that the transistor is not limited thereto. do. That is, the second driving transistor DT2 and the third and fourth transistors T3 and T4 may be formed of a P-type MOSFET. Additionally, in FIG. 4, the third transistor T3 is a transistor connected to the kth scan line Sk, so it can be collectively referred to as a “scan transistor” like the first transistor T1, and the fourth transistor T4 is Since it is a transistor connected to the kth sensing signal line (SENk), it can be collectively referred to as a “sensing transistor” like the third transistor (T3).

In addition, the second sub-pixel (SP2) according to an embodiment of the present invention includes a second driving transistor (DT2) for supplying a driving current to the second organic light-emitting diode (OLED2), and a gate electrode of the second driving transistor (DT2). a third transistor (T3) for supplying a data voltage to the source electrode of the second driving transistor (DT2), a fourth transistor (T4) for supplying a reference voltage or a pre-charging voltage to the source electrode of the second driving transistor (DT2), and a second driving transistor ( It includes a second capacitor (C2) to maintain the voltage difference between the gate electrode and the source electrode of DT2). As a result, the embodiment of the present invention supplies a data voltage for light emission to the gate electrode of the second driving transistor (DT2) and a reference voltage to the source electrode during the display period, thereby setting the second organic light emitting diode (OLED2) to a predetermined level. It can emit light with a brightness of . In addition, an embodiment of the present invention supplies a data voltage for sensing to the gate electrode of the second driving transistor (DT2) and a precharging voltage to the source electrode during the sensing period, thereby driving the second driving transistor using the reference voltage line. The source voltage of (DT2) can be sensed.

Meanwhile, in an embodiment of the present invention, the first and second subpixels (SP1, SP2) use one reference voltage line to apply the source voltage of the first driving transistor (DT1) and the source voltage of the second driving transistor (DT2). Because the voltage is sensed, the average voltage of the source voltage of the first driving transistor (DT1) and the source voltage of the second driving transistor (DT2) is sensed. The digital data converter 50 according to an embodiment of the present invention can calculate threshold voltage compensation data that can compensate for the threshold voltages of the first and second driving transistors DT1 and DT2 using the average voltage. , By converting digital video data (DATA) using threshold voltage compensation data, the threshold voltages of the first and second driving transistors (DT1 and DT2) can be compensated.

Meanwhile, it should be noted that the pixel structure of the first and second sub-pixels SP1 and SP2 of the pixel P according to the embodiment of the present invention is not limited to that shown in FIG. 4. That is, the pixel structure of the first and second sub-pixels SP1 and SP2 of the pixel P according to the embodiment of the present invention can be changed to another known pixel structure within the range that can be changed by a person skilled in the art. Be careful.

FIG. 5A is an example diagram showing a cutting location when the first subpixel of FIG. 4 is defective. In FIG. 5A , when the first sub-pixel (SP1) is defective among the first and second sub-pixels (SP1, SP2) of the pixel (P), the position where the pixel (P) is cut with a laser to repair it is shown. It appears.

Referring to FIG. 5A, when the first sub-pixel (SP1) is defective, the drain electrode of the first driving transistor (DT1), the gate electrode of the first transistor (T1), and the second transistor (T2) are damaged using a laser. Cut the gate electrode. When the drain electrode of the first driving transistor DT1 is disconnected, the connection between the drain electrode of the first driving transistor DT1 and the ith high potential voltage line VDDLi is disconnected. Because of this, since the high potential voltage is not supplied to the drain electrode of the first driving transistor (DT1), the driving current is not supplied to the first organic light emitting diode (OLED1).

When the gate electrode of the first transistor T1 is cut, the connection between the gate electrode of the first transistor T1 and the kth scan line Sk is disconnected. Because of this, since the scan signal is not supplied to the gate electrode of the first transistor (T1), the first transistor (T1) is not turned on. Accordingly, the data voltage of the jth data line Dj is not supplied to the gate electrode of the first driving transistor DT1.

When the gate electrode of the second transistor T2 is cut, the connection between the gate electrode of the second transistor T2 and the kth sensing signal line SENk is disconnected. Because of this, since the sensing signal is not supplied to the gate electrode of the second transistor (T2), the second transistor (T2) is not turned on. Accordingly, the reference voltage or precharging voltage of the jth reference voltage line Rj is not supplied to the source electrode of the first driving transistor DT1.

As discussed above, the embodiment of the present invention uses a laser as shown in FIG. 5A to connect the drain electrode of the first driving transistor (DT1), the gate electrode of the first transistor (T1), and the gate of the second transistor (T2). By cutting the electrode, the first sub-pixel SP1 can be made into a non-emission pixel. In an embodiment of the present invention, even if the first sub-pixel (SP1), which is a defective sub-pixel, is made a non-emission pixel, the pixel (P) can emit light normally because the second sub-pixel (SP2) emits light normally. As a result, the embodiment of the present invention has the advantage of not having to design a repair line for welding because the pixel P can be simply repaired using only laser cutting.

In addition, an embodiment of the present invention uses a laser to cut the drain electrode of the first driving transistor (DT1), the gate electrode of the first transistor (T1), and the gate electrode of the second transistor (T2), as shown in FIG. 5A. In this case, since no voltage is applied to the defective subpixel SP1, it is possible to prevent adjacent pixels from being unspecifically affected by the voltage applied to the defective subpixel SP1.

FIG. 5B is an example diagram showing a laser cutting position when the first subpixel of FIG. 4 is defective. In FIG. 5B, when the first sub-pixel (SP1) is defective among the first and second sub-pixels (SP1, SP2) of the pixel (P), the position where the pixel (P) is cut with a laser to repair is shown. It appears.

Referring to FIG. 5B, when the first sub-pixel SP1 is defective, a laser is used to cut between the drain electrode of the driving transistor DT and the anode electrode of the first organic light-emitting diode OLED1. Because of this, since the driving current is not supplied to the first organic light emitting diode (OLED1), the first organic light emitting diode (OLED1) does not emit light.

Ultimately, the embodiment of the present invention uses a laser to cut between the drain electrode of the driving transistor (DT) and the anode electrode of the first organic light-emitting diode (OLED1), as shown in FIG. 5B, thereby forming the first sub-pixel (SP1). It can be made into a light-emitting pixel. In an embodiment of the present invention, even if the first sub-pixel (SP1), which is a defective sub-pixel, is made into a non-emission pixel, the pixel (P) can emit light normally because the second sub-pixel (SP2) emits light normally. As a result, the embodiment of the present invention has the advantage of not having to design a repair line for welding because the pixel P can be simply repaired using only laser cutting.

FIG. 6 is another circuit diagram showing the pixel of FIG. 2 in detail. Referring to FIG. 6, each pixel P includes two subpixels, that is, first and second subpixels SP1 and SP2.

The first and second subpixels SP1 and SP2 are connected to the same high potential voltage line. For example, as shown in FIG. 6 , the first and second subpixels SP1 and SP2 may be connected to the jth high potential voltage line VDDLj. Since the first and second sub-pixels (SP1, SP2) are connected to the same high potential voltage line, the first and second sub-pixels (SP1, SP2) have different high potential voltages, as shown in FIG. Since the number of wires passing through the pixel P can be reduced compared to when connected to a line, the design area of the first and second sub-pixels SP1 and SP2 can be increased, and the aperture ratio can be increased. there is.

The first and second subpixels (SP1, SP2) shown in FIG. 6 are similar to the first and second subpixels (SP1, SP2) shown in FIG. 4, except that the first and second subpixels (SP1, SP2) shown in FIG. 6 are connected to the same high potential voltage line. are substantially the same. Therefore, a detailed description of the first and second subpixels SP1 and SP2 shown in FIG. 6 will be omitted.

In addition, when the first sub-pixel (SP1) among the first and second sub-pixels (SP1, SP2) of the pixel (P) shown in FIG. 6 is defective, a laser is used to repair the pixel (P). The cutting position is also substantially the same as described in conjunction with FIGS. 5A and 5B. Therefore, detailed description thereof will be omitted.

Figure 7 is a flowchart showing a method of manufacturing a display device according to an embodiment of the present invention. Referring to FIG. 7, the method of manufacturing a display device according to an embodiment of the present invention includes first to fifth steps. Hereinafter, a method of manufacturing a display device according to an embodiment of the present invention will be described in detail with reference to FIGS. 4, 5A, 5B, and 7.

First, transistors of pixels (P) are formed on the lower substrate. The pixels P may include first and second sub-pixels SP1 and SP2 connected to the same scan line, the same data line, and the same reference voltage line as shown in FIG. 4 . In this case, as shown in FIG. 4 on the lower substrate, first and second driving transistors (DT1, DT2), first to fourth transistors (T1 to T4), and first and second capacitors (C1, C2) ) can be formed.

Each of the first and second driving transistors DT1 and DT2 and the first to fourth transistors T1 to T4 may include a gate electrode, a source electrode, and a drain electrode. A gate insulating film covering the gate electrode is formed to electrically insulate the gate electrode, source electrode, and drain electrode of each of the first and second driving transistors (DT1, DT2) and the first to fourth transistors (T1 to T4). And, a source electrode and a drain electrode can be formed on the gate insulating film. A protective film may be formed on the gate insulating film, the source electrode, and the drain electrode. (S101)

Second, it is checked whether the transistors of the pixels P are operating normally, and the pixel containing the transistor operating abnormally is determined to be the first defective pixel. It is possible to check whether the transistors are operating normally by flowing current through the test pads provided on the lower substrate. (S102)

Third, the first defective pixel is repaired by cutting the electrodes of the transistors included in the first defective pixel using a laser. For example, if the first sub-pixel is defective as shown in FIG. 5A, the drain electrode of the first driving transistor (DT1), the gate electrode of the first transistor (T1), and the second transistor (T2) are damaged using a laser. The gate electrode may be cut. In addition, when the first defective pixel is the second sub-pixel, the drain electrode of the second driving transistor (DT2), the gate electrode of the third transistor (T3), and the gate electrode of the fourth transistor (T4) are connected using a laser. It can be cut. (S103)

Fourth, organic light emitting diodes of pixels (P) are formed. When the pixels P include first and second sub-pixels SP1 and SP2 as shown in FIG. 4, first and second organic light emitting diodes OLED1 and OLED2 may be formed.

Each of the first and second organic light emitting diodes OLED1 and OLED2 may include an anode electrode, an organic light emitting layer, and a cathode electrode. The anode electrode may be connected to the source electrode of the driving transistor through a contact hole penetrating the protective film. An organic light-emitting layer may be formed on the anode electrode, and a cathode electrode may be formed on the organic light-emitting layer. The organic light emitting layer may include a hole transporting layer, an organic light emitting layer, and an electron transporting layer. In this case, when voltage is applied to the anode electrode and the cathode electrode, holes and electrons move to the light-emitting layer through the hole transport layer and electron transport layer, respectively, and combine with each other in the light-emitting layer to emit light. An encapsulation layer may be formed on the cathode electrode. The encapsulation layer serves to prevent oxygen or moisture from penetrating into the organic light emitting layer and the cathode electrode. The encapsulation layer may include at least one organic layer and at least one inorganic layer. (S104)

Fifth, it is checked whether the organic light emitting diodes of the pixels P are lit normally, and the pixel containing the organic light emitting diode that is abnormally lit is determined to be a second defective pixel. By applying predetermined signals through inspection pads provided on the lower substrate, it is possible to check whether the organic light emitting diodes are lit normally. (S105)

Sixth, the second defective pixel can be repaired by cutting the electrodes of the transistors included in the second defective pixel using a laser. For example, if the first sub-pixel is defective as shown in FIG. 5A, the drain electrode of the first driving transistor (DT1), the gate electrode of the first transistor (T1), and the second transistor (T2) are damaged using a laser. The gate electrode may be cut. In addition, when the first defective pixel is the second sub-pixel, the drain electrode of the second driving transistor (DT2), the gate electrode of the third transistor (T3), and the gate electrode of the fourth transistor (T4) are connected using a laser. It can be cut.

Alternatively, the second defective pixel can be repaired by cutting the anode electrode of the organic light emitting diode included in the second defective pixel using a laser. For example, if the first sub-pixel is defective as shown in FIG. 5B, the anode electrode of the first organic light-emitting diode OLED1 may be cut using a laser. Additionally, when the first defective pixel is the second sub-pixel, the anode electrode of the second organic light emitting diode (OLED2) may be cut using a laser. (S106)

As discussed above, the embodiment of the present invention forms pixels P including first and second sub-pixels connected to the same scan line, the same data line, and the same reference voltage line, and pixels P are formed during the manufacturing process. It is determined whether there is a defective pixel among the (P)s, and the pixel can be repaired by cutting the defective pixel using a laser. As a result, the embodiment of the present invention has the advantage of not having to design a repair line for welding because the pixel can be simply repaired using only laser cutting.

Through the above-described content, those skilled in the art will be able to see that various changes and modifications can be made without departing from the technical idea of the present invention. Therefore, the technical scope of the present invention should not be limited to what is described in the detailed description of the specification, but should be defined by the scope of the patent claims.

10: display panel 20: data driver
21: source drive IC 22: sensing unit
30: scan driver 40: timing control unit
41: data conversion unit 42: memory
50: digital data conversion unit P: pixel
SP1: 1st subpixel SP2: 2nd subpixel
DT1: first driving transistor OLED1: first organic light emitting diode
DT2: second driving transistor OLED2: second organic light emitting diode
T1: first transistor T2: second transistor
T3: third transistor T4: fourth transistor

Claims (8)

scan lines to which scan signals are supplied;
data lines to which data voltages are supplied;
Reference voltage lines supplied with a reference voltage; and
A pixel including a plurality of sub-pixels connected to the same scan line, the same data line, and the same reference voltage line among the scan lines, the data lines, and the reference voltage line,
When all of the plurality of subpixels operate normally, each of the plurality of subpixels receives first digital video data, and when one of the plurality of subpixels is a defective subpixel, the remaining subpixels receive the first digital video data. A display device that receives second digital video data having a different value from the first digital video data. According to claim 1,
Further comprising sensing signal lines through which sensing signals are supplied,
A display device wherein the plurality of sub-pixels are connected to the same sensing signal line among the sensing signal lines. According to claim 2,
Further comprising first power voltage lines supplied with a first power voltage,
A display device wherein the plurality of subpixels are connected to the same first power voltage line among the first power voltage lines. According to claim 2,
Further comprising first power voltage lines supplied with a first power voltage,
A display device wherein the plurality of subpixels are connected to different first power voltage lines among the first power voltage lines. According to claim 3 or 4,
Each of the plurality of subpixels,
organic light emitting diode;
a driving transistor connected to the organic light emitting diode and the first power voltage line;
A scan transistor whose gate electrode is connected to the kth (k is a positive integer) scan line, the source electrode is connected to the gate electrode of the driving transistor, and the drain electrode is connected to the jth (j is a positive integer) data line. ;
a sensing transistor whose gate electrode is connected to a kth sensing signal line, a source electrode connected to the source electrode of the driving transistor, and a drain electrode connected to a jth reference voltage line; and
A display device including a capacitor connected to a gate electrode and a source electrode of the driving transistor. According to claim 5,
A display device in which the defective subpixel does not emit light. According to claim 5,
When one of the plurality of subpixels is a defective subpixel,
The connection between the drain electrode of the driving transistor and the first power voltage line is disconnected, the connection between the gate electrode of the scan transistor and the kth scan line is disconnected, and the gate electrode of the sensing transistor and the kth sensing signal line are disconnected. The connection between the display devices is broken. According to claim 2,
a scan signal driver that supplies the scan signals to the scan lines;
a data driver that supplies the data voltages to the data lines and the reference voltage to the reference voltage lines; and
A display device further comprising a sensing signal driver that supplies the sensing signals to the sensing signal lines.

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