KR20210059077A - Apparatus for testing display panel and method for testing display panel - Google Patents

Abstract

According to the present invention, an inspection device inspects a display panel including a light emitting element and a transistor which transmits a driving current to the light emitting element. The inspection device on the display panel includes: a voltage supply unit receiving input power through an input terminal, generating a first initialization power source for initializing the transistor and a second initialization power source for initializing a light emitting device, and supplying the first and second initialization power sources to the display panel; a current measuring unit for measuring the current flowing through the input terminal; and a setting unit which adjusts voltage levels of the first and second initialization power sources based on the measured current. According to the present invention, it is possible to prevent damage to the display panel due to a short circuit of wires in the display panel.

Description

Display panel inspection device and inspection method {APPARATUS FOR TESTING DISPLAY PANEL AND METHOD FOR TESTING DISPLAY PANEL}

The present invention relates to a display panel inspection apparatus and inspection method.

The display device may include a display panel, and the display panel may include light-emitting elements, transistors, and wires. A short may occur between wirings that transmit the same or similar voltage among wirings included in the display panel. In this case, due to a voltage difference between the wirings, a current is generated between wirings in which a short circuit occurs, and damage (eg, a horizontal line defect, etc.) may occur on the display panel.

An object of the present invention is to provide an apparatus for inspecting a display panel capable of preventing damage to a display panel due to short circuits of wirings in the display panel.

In an apparatus for inspecting a display panel according to an exemplary embodiment of the present invention, in an inspection apparatus for inspecting a display panel including a light-emitting element and a transistor for transmitting a driving current to the light-emitting element, an input power is received through an input terminal, A voltage supply unit for generating a first initialization power for initializing the transistor and a second initialization power for initializing the light emitting device, respectively, and supplying the first and second initialization powers to the display panel, through the input terminal A current measuring unit that measures a flowing current, and a setting unit that adjusts voltage levels of the first and second initialization power sources based on the measured current.

In an embodiment, the apparatus for inspecting the display panel further includes a storage unit including a reference lookup table (LUT), wherein the reference lookup table is 2 It may include voltage levels of initialization power supplies.

In one embodiment, the voltage supply unit includes a voltage controller that generates a voltage control signal based on the reference lookup table, and the voltage control signal includes first to fourth set values, and the first and second 3 set values indicate voltage levels of the first initialization power, the second and fourth set values indicate voltage levels of the second initialization power, and the first and second set values according to the first and second set values A difference between voltage levels of the second initialization power supplies may be maximum, and a difference between voltage levels of the first and second initialization power supplies may be minimum according to the third and fourth set values.

In an embodiment, the voltage supply unit supplies the first and second initialization powers to the display panel based on the input power and the first and second set values in a first mode, and a second In the mode, the first and second initialization powers may be supplied to the display panel based on the input power and the third and fourth set values.

In an embodiment, the current measuring unit may measure a first current flowing through the input terminal in a first mode, and measure a second current flowing through the input terminal in a second mode.

In an embodiment, the setting unit generates a LUT control signal based on the comparison result signal and a comparison unit that generates a comparison result signal based on the first current, the second current, and a preset reference value. And a LUT control signal generation unit providing the LUT control signal to the storage unit, wherein the comparison result signal includes first and second sub-comparison result signals, and the LUT control signal is the first and second sub LUT control signals, and the second sub-LUT control signal may include preset LUT offset data.

In one embodiment, the comparison unit generates the first sub-comparison result signal when the difference between the value of the first current and the value of the second current is less than the reference value, and the LUT control signal generation unit, The first sub-LUT control signal may be provided to the storage unit based on the first sub-comparison result signal.

In an embodiment, the storage unit may store the reference lookup table as a lookup table of the display panel based on the first sub-LUT control signal.

In an embodiment, the comparison unit generates the second sub-comparison result signal when the difference between the value of the first current and the value of the second current is greater than or equal to the reference value, and the LUT control signal generation unit The second sub-LUT control signal may be provided to the storage unit based on the second sub-comparison result signal.

In an embodiment, the storage unit may update the reference lookup table by applying the LUT offset data to the reference lookup table based on the second sub-LUT control signal.

In one embodiment, supply of the first and second initialization powers of the voltage supply unit based on the updated reference lookup table until a difference between the value of the first current and the value of the second current is less than the reference value , And repeating the measurement of the first and second currents of the current measuring unit, and when the difference between the value of the first current and the value of the second current becomes smaller than the reference value, the comparison unit is the first sub-comparison A result signal is generated, and the LUT control signal generator provides the first sub-LUT control signal to the storage unit based on the first sub-comparison result signal, and the storage unit is based on the first sub-LUT control signal. Thus, the updated reference lookup table may be stored as a lookup table of the display panel.

In an embodiment, the setting unit may further include a memory including the reference value and the LUT offset data.

In the inspection method of a display panel according to an embodiment of the present invention, in the inspection method of a display panel including a light-emitting element and a transistor for transmitting a driving current to the light-emitting element, in a power supply unit, the input power supplied through an input terminal is On the basis of, supplying a first initialization power for initializing the transistor and a second initialization power for initializing the light emitting device to the display panel, a state in which the first and second initialization powers are applied to the display panel The method may include measuring a current flowing through the input terminal of the power supply unit, and adjusting voltage levels of the first and second initialization power sources based on the measured current.

In an embodiment, supplying the first initialization power and the second initialization power to the display panel includes generating a voltage control signal based on a reference lookup table, wherein the reference lookup table is the first And voltage levels of the second initialization power, the voltage control signal including first to fourth set values, the first and third set values represent voltage levels of the first initialization power, and the second The second and fourth set values represent voltage levels of the second initialization power, and the first and second set values have a maximum difference in voltage levels between the first and second initialization power sources included in the reference lookup table. Each is selected from a level of the first initialization power and a level of the second initialization power, and the third and fourth set values are a difference between voltage levels of the first and second initialization powers included in the reference lookup table. It may be selected from the minimum level of the first initialization power and the level of the second initialization power, respectively.

In an embodiment, the supplying of the first initialization power and the second initialization power to the display panel may include, in a first mode, based on the input power and the first and second set values, from the power supply unit. And supplying the first and second initialization powers to the display panel, and measuring a current flowing through the input terminal of the power supply unit comprises: in the first mode, the input terminal is It may include measuring the first current flowing through.

In an embodiment, the supplying of the first initialization power and the second initialization power to the display panel may include, in a second mode, based on the input power and the third and fourth set values, from the power supply unit. And supplying the first and second initialization powers to the display panel, and measuring a current flowing through the input terminal of the power supply unit comprises: in the second mode, the input terminal is It may further include measuring the second current flowing through.

In one embodiment, the adjusting of the voltage levels comprises comparing a difference between the value of the first current and the value of the second current with a preset reference value, and the value of the first current and the second current When the difference between the values of is less than the reference value, storing the reference lookup table as a lookup table of the display panel may be included.

In one embodiment, the adjusting of the voltage levels comprises comparing a difference between the value of the first current and the value of the second current with a preset reference value, and the value of the first current and the second current When the difference between the values of is greater than or equal to the reference value, updating the reference lookup table by applying preset LUT offset data to the reference lookup table.

In an embodiment, supplying the input power until a difference between the value of the first current and the value of the second current becomes smaller than the reference value, and supplying the first and second initialization power to the display panel. Supplying, measuring the current, and repeating the step of adjusting the voltage levels, and when the difference between the value of the first current and the value of the second current becomes smaller than the reference value, the update The reference lookup table may be stored as a lookup table of the display panel.

The apparatus for inspecting a display panel according to the present invention may adjust voltage levels of the first and second initialization power sources based on a current flowing through an input terminal of a voltage supply unit supplying first and second initialization powers to the display panel. have. Accordingly, damage to the display panel caused by a short circuit between the first and second initialization power lines included in the display panel before shipment of the display panel can be prevented in advance.

1 is a diagram illustrating an apparatus for inspecting a display panel according to an exemplary embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a display device including a display panel inspected by the inspection device of FIG. 1.
3 is a circuit diagram illustrating an example of a pixel included in the display device of FIG. 2.
4A and 4B are diagrams for explaining an inspection method of the inspection apparatus of FIG. 1.
5 is a flowchart illustrating a method of inspecting a display panel according to an exemplary embodiment of the present invention.
6 is a flowchart illustrating a method of inspecting a display panel according to another exemplary embodiment of the present invention.

In the present invention, various modifications may be made and various forms may be applied, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific form disclosed, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing each drawing, similar reference numerals have been used for similar elements. In the accompanying drawings, the dimensions of the structures are shown to be enlarged than actual for clarity of the present invention. Terms such as first and second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance the possibility of the presence or addition.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a diagram illustrating an apparatus for inspecting a display panel according to an exemplary embodiment of the present invention, FIG. 2 is a diagram illustrating an example of a display device including a display panel inspected by the inspection apparatus of FIG. 1, and FIG. 3 is 2 is a circuit diagram illustrating an example of a pixel included in the display device of FIG. 2, and FIGS. 4A and 4B are diagrams illustrating an inspection method of the inspection device of FIG. 1.

Referring to FIG. 1, the test apparatus 100 supplies a first power VDD, a second power VSS, a first initialization power Vint1, and a second initialization power Vint2 to the display panel DP. In addition, it is possible to check whether there is a short circuit between the first initialization power line and the second initialization power line included in the display panel DP.

Depending on whether the first and second initialization power lines are shorted, the inspection apparatus 100 stores a reference lookup table (LUT) as a lookup table of the display panel DP or a reference lookup table (LUT). May be updated and stored as a lookup table of the display panel DP. The lookup table of the display panel DP includes a first power supply VDD, a second power supply VSS, a first initialization power supply Vint1, and a second initialization power supply Vint2 according to driving conditions of the display panel DP. ) Voltage levels (or information about them).

Hereinafter, the basic configuration of the display panel DP will be described, and then the inspection apparatus 100 according to the configuration of the display panel DP will be described. 2 to 4B may be referred to to describe the display panel DP.

Referring to FIG. 2, the display device 200 includes a display panel DP, a timing controller 210, a scan driver 220, a data driver 230, a light emission control driver 240, and a voltage generator 250. ) Can be included.

The display panel DP includes scan lines S0, S1, S2, ..., Sn, data lines D1, D2, ..., Dm, and emission control lines E1, E2, ... , En), a first initialization power line L1, a second initialization power line L2, and pixels PX11, PX12, ..., PX1m, PX21, PX22, ..., PX2m, ..., PXn1, PXn2, ..., PXnm) may be included. Each pixel may be connected to a first initialization power line L1, a second initialization power line L2, a corresponding scan line, a corresponding data line, and a corresponding emission control line. Each pixel may receive a data voltage in response to a scan signal and emit light in response to the data voltage.

The timing controller 210 may supply a control signal, an image signal, and the like necessary for the scan driver 220, the data driver 230, and the emission control driver 240.

In embodiments, the timing controller 210 may generate a voltage control signal for controlling the operation of the voltage generator 250 based on the lookup table. The lookup table may be preset by the inspection apparatus 100 of FIG. 1, and may be included in the timing controller 210 or previously stored. A first power supply VDD, a second power supply VSS, a first initialization power supply Vint1, and a second initialization power supply Vint2 based on the voltage control signal generated by the voltage generator 250 by the voltage control signal. The voltage levels of can be adjusted.

The scan driver 220 may supply scan signals to the scan lines S0, S1, S2, ..., Sn based on the control signal provided from the timing controller 210. For example, the scan driver 220 may sequentially supply scan signals having a turn-on level pulse to the scan lines S0, S1, S2, ..., Sn.

The data driver 230 may supply data voltages to the data lines D1, D2, ..., Dm based on a control signal and an image signal provided from the timing controller 210. For example, the data driver 230 may generate analog data voltages based on a digital image signal and supply data voltages to the data lines D1, D2, ..., Dm.

The emission control driver 240 determines the emission period of the pixels PX11, PX12, ..., PX1m, PX21, PX22, ..., PX2m, ..., PXn1, PXn2, ..., PXnm. The emission control signals may be supplied to the emission control lines E1, E2, ..., En. For example, each pixel includes a light emission control transistor, and emission control may be performed by determining whether or not current flows to the light emitting element is determined according to the on/off of the emission control transistor.

The voltage generator 250 generates a first power source VDD and a second power source VSS based on the voltage control signal and input power Vin provided from the timing controller 210, and generates first and second power sources. The fields VDD and VSS may be provided to the display panel DP. In addition, the voltage generator 250 generates a first initialization power supply Vint1 and a second initialization power supply Vint2, and sets the first and second initialization power supplies Vint1 and Vint2 to the first and second initialization power supplies, respectively. It can be provided to the lines L1 and L2.

Referring to FIG. 3, the pixel PXij may include transistors T1 to T7, a storage capacitor Cst, and a light emitting device LD. The transistors T1 to T7 may be P-type transistors, but are not limited thereto.

One electrode of the first transistor T1 may be connected to the fifth transistor T5, the other electrode may be connected to one electrode of the sixth transistor T6, and the gate electrode may be connected to the storage capacitor Cst. The first transistor T1 may control an amount of current flowing from the first power source VDD to the second power source VSS through the light emitting element LD based on a potential difference between the gate electrode and the source electrode.

One electrode of the second transistor T2 may be connected to the data line Dj, the other electrode may be connected to one electrode of the first transistor T1, and the gate electrode may be connected to the current scan line Si.

One electrode of the third transistor T3 is connected to the other electrode of the first transistor T1, the other electrode is connected to the gate electrode of the first transistor T1, and the gate electrode is currently connected to the scan line Si. I can.

One electrode of the fourth transistor T4 is connected to the gate electrode of the first transistor T1, the other electrode is connected to the first initialization power line L1, and the gate electrode is connected to the previous scan line S(i-1). )).

One electrode of the fifth transistor T5 may be connected to the first power source VDD, the other electrode may be connected to one electrode of the first transistor T1, and the gate electrode may be connected to the emission control line Ei.

One electrode of the sixth transistor T6 is connected to the other electrode of the first transistor T1, the other electrode is connected to one electrode of the light emitting element LD, and the gate electrode is connected to the emission control line Ei. have.

One electrode of the seventh transistor T7 may be connected to one electrode of the light emitting element LD, the other electrode may be connected to the second initialization power line L2, and the gate electrode may be connected to the current scan line Si. .

One electrode of the storage capacitor Cst may be connected to the first power source VDD, and the other electrode may be connected to the gate electrode of the first transistor T1.

One electrode (for example, an anode electrode) of the light emitting device LD may be connected to the other electrode of the sixth transistor T6, and the other electrode (for example, a cathode electrode) may be connected to the second power source VSS. have.

The voltage level of the first power VDD may be higher than the voltage level of the second power VSS.

The first initialization power Vint1 supplied to the first initialization power line L1 may have a voltage level for initializing the gate electrode of the first transistor T1. For example, the first initialization power supply Vint1 may have a voltage level lower than the data voltage (eg, the data voltage of the highest gray level).

The second initialization power Vint2 supplied to the second initialization power line L2 may have a voltage level for initializing the light emitting device LD. For example, the second initialization power Vint2 may have a voltage level higher than the voltage level of the second power VSS.

2 and 3, the voltage generator 250 may control the voltage level of the second power source VSS based on a voltage control signal provided from the timing controller 210. In this case, the voltage level of the second power source VSS is determined according to the voltage control signal, and thus, a power voltage difference is adjusted to reduce power consumption. However, as the voltage level of the second power source VSS is varied, the voltage levels of the first and second initialization power sources Vint1 and Vint2 may also vary. In some cases, a difference between voltage level values of the first and second initialization power sources Vint1 and Vint2 may increase. At this time, when there is a short between the first initialization power line L1 supplied with the first initialization power Vint1 and the second initialization power line L2 supplied with the second initialization power Vint2, the first And a current I_over between the first and second initialization power lines L1 and L2 due to the difference between the voltage level values of the second initialization power supplies Vint1 and Vint2, and damages the display panel DP. (For example, bad horizontal lines, etc.) may occur.

In order to prevent such damage to the display panel DP, before shipment of the display panel DP, the inspection apparatus 100 (see FIG. 1) measures the current flowing through the input terminal of the voltage supply unit 120 (see FIG. 1). Thus, it may be determined whether there is a short circuit between the first initialization power line L1 and the second initialization power line L2. When a current I_over occurs between the first and second initialization power lines L1 and L2, the amount of current flowing through the input terminal of the voltage supply unit 120 (refer to FIG. 1) increases. Reference) may determine whether there is a short circuit between the first and second initialization power lines L1 and L2 based on the amount of current flowing through the input terminal. When it is determined that there is no short circuit between the first and second initialization power lines L1 and L2, the test apparatus 100 (refer to FIG. 1) displays the reference lookup table LUT (refer to FIG. 1) on the display panel DP. ) Can be saved as a lookup table. On the other hand, when it is determined that there is a short circuit between the first and second initialization power lines L1 and L2, the inspection apparatus 100 updates the reference lookup table LUT (refer to FIG. 1) to update the display panel DP. ) Can be saved as a lookup table.

For example, referring to FIGS. 4A and 4B, a first lookup table TABLE1 of FIG. 4A represents an example of a reference lookup table LUT, and a second lookup table TABLE2 of FIG. 4B is an inspection device ( 100 (refer to FIG. 1) may show an example of the updated reference lookup table (LUT).

The first look-up table TABLE1 and the second look-up table TABLE2 may include a first power supply VDD according to driving conditions A, B, C, D, and E of the display panel DP based on temperature, illuminance, and the like. The voltage level values of the second power supply VSS, the highest grayscale data voltage Vdata, the first initialization power Vint1, and the second initialization power Vint2 may be included. As the driving condition changes from E to A, the voltage level of the second power supply VSS increases, and accordingly, the voltage levels of the first and second initialization power supplies Vint1 and Vint2 may also change.

1, 2, 4A, and 4B, it is assumed that the display device 200 drives the display panel DP based on the first look-up table TABLE1. As the driving condition changes from E to A, the voltage of the second power VSS applied to the display panel DP changes from -4V to -2V, and the first and second initialization power supplies Vint1 and Vint2 The voltages of can also be varied from -4V and -3.5V to -3V and -1.5V, respectively. In this case, a difference between voltage level values of the first and second initialization power sources Vint1 and Vint2 may increase from 0.5V to 1.5V. When there is a short circuit between the first and second initialization power lines L1 and L2, a current I_over (refer to FIG. 3) occurs, and accordingly, damage to the display panel DP may occur.

Accordingly, before shipment of the display panel DP, the inspection apparatus 100 may update the first lookup table TABLE1 to the second lookup table TABLE2 and store it as a lookup table of the display panel DP. In this case, as the voltage of the second power VSS applied to the display panel DP is varied from -4V to -2.2V, the voltages of the first and second initialization powers Vint1 and Vint2 are -4V, respectively. And -3.5V to -3.1V and -1.7V. In this case, the maximum voltage difference between the first and second initialization power supplies Vint1 and Vint2 in the second lookup table TABLE2 (that is, the voltage of the first and second initialization power supplies Vint1 and Vint2 under the driving condition A). Difference) may decrease from 1.5V to 1.4V compared to the first lookup table TABLE1. Accordingly, when the display device 200 drives the display panel DP according to the second lookup table TABLE2 compared to the first lookup table TABLE1, the first and second initialization power supplies according to the driving condition The voltage difference between the voltages Vint1 and Vint2 decreases, and the amount of current flowing between the first and second initialization power lines L1 and L2 decreases, so that damage to the display panel DP may be prevented. The specific operation of the inspection apparatus 100 will be described later.

Referring back to FIG. 1, the inspection apparatus 100 may perform a reference lookup table according to whether a short circuit between the first and second initialization power lines L1 and L2 included in the display panel DP (refer to FIG. 2 ). The reference lookup table (LUT) is stored as a lookup table of the display panel (DP) without adjusting the voltage levels included in the LUT, or by adjusting the voltage levels included in the reference lookup table (LUT). May be updated, and the updated reference lookup table LUT may be stored as a lookup table of the display panel DP.

The test apparatus 100 may include a storage unit 110, a voltage supply unit 120, a current measurement unit 130, and a setting unit 140.

The storage unit 110 may include a reference lookup table (LUT). For example, the reference lookup table LUT is substantially the same as or similar to the first lookup table TABLE1 described with reference to FIG. 4A, and the first power supply VDD, the second power supply VSS, and the first initialization power supply Voltage levels of (Vint1) and second initialization power (Vint2) may be included.

The voltage supply unit 120 may receive input power Vin through an input terminal. The voltage supply unit 120 is a first initialization power source for initializing the gate electrode of the first power source VDD, the second power source VSS, and the first transistor T1 (refer to FIG. 3) based on the input power Vin. A second initialization power source Vint2 for initializing Vint1 and the light emitting device LD (refer to FIG. 3) may be generated. The voltage supply unit 120 may supply the first power VDD, the second power VSS, the first initialization power Vint1, and the second initialization power Vint2 to the display panel DP.

In one embodiment, the voltage supply unit 120 may include a voltage control unit 121. The voltage control unit 121 may receive information on the reference lookup table LUT from the storage unit 110. The voltage controller 121 may generate a voltage control signal based on the reference lookup table. Based on the voltage control signal, the voltage supply unit 120 controls voltage levels of the first power VDD, the second power VSS, the first initialization power Vint1, and the second initialization power Vint2 (or , Variable).

In an embodiment, the voltage supply unit 120 may control the first power VDD to have a fixed voltage level based on the voltage control signal. For example, referring to FIG. 4A, the voltage of the first power source VDD may be 4V. That is, the voltage level of the first power VDD may not be varied.

In an embodiment, based on the voltage control signal, the voltage supply unit 120 includes the minimum and maximum voltages among voltage level values of the second power VSS included in the reference lookup table LUT. You can control to have levels. For example, referring to FIG. 4A, the minimum value of the voltage level of the second power source VSS may be -4V, and the maximum value may be -2V.

Also, the voltage level of the first initialization power Vint1 and the voltage level of the second initialization power Vint2 may be determined according to the voltage level of the second power VSS. Accordingly, the voltage control signal corresponds to the second power supply VSS having the maximum voltage level, the first set value for the voltage level of the first initialization power supply Vint1 and the voltage of the second initialization power supply Vint2 It may include a second set value for the level. Similarly, the voltage control signal corresponds to the second power supply VSS having the minimum voltage level, and the third set value for the voltage level of the first initialization power supply Vint1 and the voltage of the second initialization power supply Vint2 It may include a fourth set value for the level.

Specifically, the first initialization power Vint1 may have a voltage level lower than the data voltage applied to the display panel DP.

In an embodiment, the first initialization power Vint1 may have a voltage level lower than the data voltage of the highest grayscale applied to the display panel DP. Here, the data voltage of the highest gray level applied to the display panel DP may be determined based on a difference between the voltage level of the first power VDD and the voltage level of the second power VSS. Since the first power VDD has a fixed voltage level and the second power VSS has a variable voltage level, the voltage of the first initialization power Vint1 is based on the voltage level of the second power VSS. The level can be determined. For example, referring to FIG. 4A, when the voltage of the first power supply VDD is 4V and the voltage of the second power supply VSS is -2V, which is the maximum value, the highest grayscale data applied to the display panel DP The voltage can be 1.5V. The voltage of the first initialization power supply Vint1 is 4.5V lower than the data voltage of the highest grayscale, and may be -3V. As another example, when the voltage of the first power VDD is 4V and the voltage of the second power VSS is -4V, which is the minimum value, the data voltage of the highest grayscale applied to the display panel DP may be 0.5V. . The voltage of the first initialization power supply Vint1 may be 4.5V lower than the data voltage of the highest grayscale, and may be -4V, which is the minimum value.

The second initialization power Vint2 may have a voltage level higher than the voltage level of the second power VSS.

In an embodiment, the second initialization power Vint2 may have a voltage level higher than the voltage level of the second power VSS by a preset value. In an embodiment, when the second power supply VSS has a maximum voltage level among voltage level values of the second power supply VSS included in the reference lookup table LUT, the second initialization power supply Vint2 is the reference The voltage level of the maximum value among voltage level values of the second initialization power Vint2 included in the look-up table LUT may be obtained. For example, referring to FIG. 4A, when the voltage of the second power supply VSS is -2V, which is the maximum value, the voltage of the second initialization power supply Vint2 is 0.5V higher than the voltage of the second power supply VSS. It can be 1.5V. As another example, when the voltage of the second power supply VSS is -4V, which is the minimum value, the voltage of the second initialization power Vint2 may be -3.5V by 0.5V higher than the voltage of the second power supply VSS.

Accordingly, when the second power supply VSS has a maximum voltage level among voltage level values of the second power supply VSS included in the reference lookup table LUT, the first setting for the first initialization power supply Vint1 The voltage difference between the first initialization power Vint1 and the second initialization power Vint2 may be maximized based on the value and the second set value for the second initialization power Vint2. For example, referring to FIG. 4A, when the voltage of the second power supply VSS is -2V, which is the maximum value among voltage level values of the second power supply VSS included in the reference lookup table LUT, the first initialization power supply The voltage of Vint1 may be -3V, and the voltage of the second initialization power Vint2 may be -1.5V. Accordingly, a voltage difference between the first initialization power Vint1 and the second initialization power Vint2 may be 1.5V, which is the maximum voltage difference.

As another example, when the second power supply VSS has the minimum voltage level among voltage level values of the second power supply VSS included in the reference lookup table LUT, the third setting for the first initialization power supply Vint1 The voltage difference between the first initialization power Vint1 and the second initialization power Vint2 may be minimized based on the value and the fourth set value for the second initialization power Vint2. For example, referring to FIG. 4A, when the voltage of the second power supply VSS is -4V, which is the minimum value among voltage level values of the second power supply VSS included in the reference lookup table LUT, the first initialization power supply The voltage of Vint1 may be -4V and the voltage of the second initialization power Vint2 may be -3.5V. Accordingly, a voltage difference between the first initialization power Vint1 and the second initialization power Vint2 may be 0.5V, which is the minimum voltage difference.

In the first mode, the voltage supply unit 120 displays the first and second initialization power sources Vint1 and Vint2 based on the input power Vin and first and second set values included in the voltage control signal. It can be supplied to the panel DP. That is, the voltage supply unit 120 displays the first and second initialization powers Vint1 and Vint2 having the largest difference in voltage levels between the first and second initialization powers Vint1 and Vint2 in the first mode. DP) can be supplied.

The current measuring unit 130 may measure currents I1 and I2 flowing through the input terminal of the voltage supply unit 120.

In the first mode, the current measurement unit 130 controls the input terminal of the voltage supply unit 120 when the voltage supply unit 120 supplies the first and second initialization powers Vint1 and Vint2 to the display panel DP. The first current I1 flowing through may be measured.

In the second mode, the voltage supply unit 120 displays the first and second initialization power sources Vint1 and Vint2 based on the input power Vin and third and fourth set values included in the voltage control signal. It can be supplied to the panel DP. That is, in the second mode, the voltage supply unit 120 displays the first and second initialization powers Vint1 and Vint2 having the minimum difference between the voltage levels of the first and second initialization powers Vint1 and Vint2 in the second mode. DP) can be supplied.

In the second mode, the current measuring unit 130 controls the input terminal of the voltage supply unit 120 when the voltage supply unit 120 supplies the first and second initialization powers Vint1 and Vint2 to the display panel DP. The second current I2 flowing through may be measured.

In an embodiment, the first mode may be after the second mode, but is not limited thereto, and the second mode may be after the first mode.

The current measuring unit 130 may provide the value of the first current I1 measured in the first mode and the value of the second current I2 measured in the second mode to the setting unit 140. Here, in the first mode, the voltage supply unit 120 displays the first and second initialization powers Vint1 and Vint2 having the largest difference between the voltage levels of the first and second initialization powers Vint1 and Vint2 on the display panel ( DP), so when there is a short circuit between the first and second initialization power lines L1 and L2, the amount of current I_over flowing between the first and second initialization power lines L1 and L2 As this increases, the amount of current flowing through the input terminal of the voltage supply unit 120 increases, so the value of the first current I1 may be greater than the value of the second current I2.

The setting unit 140 is based on the first and second currents I1 and I2 measured by the current measuring unit 130, the second power VSS included in the reference lookup table LUT, and the first initialization The reference lookup table LUT may be updated by adjusting voltage levels of the power supply Vint1 and the second initialization power supply Vint2. The setting unit 140 may include a memory 141, a comparison unit 142, and a LUT control signal generation unit 143.

The memory 141 may include a preset reference value Ith and preset LUT offset data Offset.

The comparison unit 142 is based on the value of the first current I1 and the second current I2 provided from the current measuring unit 130 and the reference value Ith provided from the memory 141, and the comparison result signal (CRS) can be created. The comparison result signal CRS may include a first sub-comparison result signal and a second sub-comparison result signal.

The LUT control signal generation unit 143 may generate the LUT control signal LCS based on the comparison result signal (CRS, or first and second sub-comparison result signals) provided from the comparison unit 142. . The LUT control signal LCS may include a first sub-LUT control signal and a second sub-LUT control signal.

In one embodiment, the comparison unit 142 is less than the reference value Ith when the difference between the value of the first current I1 and the second current I2 (i.e., I1-I2) is smaller than the reference value Ith (ie, I1- I2<Ith), a first sub-comparison result signal may be generated. In this case, the LUT control signal generation unit 143 may generate a first sub LUT control signal based on the first sub comparison result signal provided from the comparison unit 142 and provide it to the storage unit 110.

In this case, the storage unit 110 may store the reference lookup table LUT as a lookup table of the display panel DP based on the first sub-LUT control signal provided from the LUT control signal generator 143. That is, when the difference between the value of the first current I1 and the value of the second current I2 (i.e., I1-I2) is smaller than the reference value Ith (i.e., I1-I2<Ith), the voltage supply unit 120 ) Supplies the first and second initialization powers Vint1 and Vint2 having the largest difference in voltage levels between the first and second initialization powers Vint1 and Vint2 to the display panel DP, 2 The increase of the current I_over flowing between the initialization power lines L1 and L2 may not be large. Accordingly, the inspection apparatus 100 may store the reference lookup table LUT set to vary the power level of the second power supply VSS as a lookup table of the display panel DP to reduce power consumption.

In one embodiment, the comparison unit 142 is the difference between the value of the first current I1 and the second current I2 (i.e., I1-I2) is greater than or equal to the reference value Ith (i.e., I1-I2Ith), a second sub-comparison result signal may be generated. In this case, the LUT control signal generation unit 143 may generate a second sub-LUT control signal based on the second sub-comparison result signal provided from the comparison unit 142 and provide it to the storage unit 110. In an embodiment, the second sub-LUT control signal may include LUT offset data Offset provided from the memory 141. The LUT offset data Offset may include an offset value for a voltage level of a maximum value among voltage levels of the second power supply VSS included in the reference lookup table LUT.

At this time, the storage unit 110 based on the second sub-LUT control signal provided from the LUT control signal generator 143, the LUT offset data (Offset) included in the second sub-LUT control signal in the reference lookup table (LUT) By applying, it is possible to update the reference lookup table (LUT). That is, when the difference between the value of the first current I1 and the value of the second current I2 (i.e., I1-I2) is greater than or equal to the reference value Ith (i.e., I1-I2Ith), the voltage supply unit 120 ) Supplies the first and second initialization powers Vint1 and Vint2 having the largest difference between the voltage levels of the first and second initialization powers Vint1 and Vint2 to the display panel DP, the test apparatus ( 100) may determine that an increase amount of the current I_over flowing between the first and second initialization power lines L1 and L2 is large. Accordingly, the storage unit 110 applies LUT offset data (Offset) to the voltage level of the maximum value among voltage levels of the second power supply (VSS) included in the reference lookup table (LUT), and the second power supply (VSS) It is possible to reduce the variable range of the voltage levels of. For example, referring to FIGS. 4A and 4B, the storage unit 110 applies LUT offset data included in the second sub-LUT control signal to the first look-up table TABLE1, The lookup table TABLE1 may be updated to the second lookup table TABLE2. For example, the offset value included in the LUT offset data (Offset) may be -0.2V, in this case, the inspection device 100 is the voltage level of the second power source (VSS) included in the reference lookup table (LUT) By applying an offset value of -0.2V included in the LUT offset data (Offset) to the maximum value of -2V, the variable range of voltage levels of the second power supply (VSS) is -4V to -2V (i.e., 2V). In, it can be reduced to -4V to -2.2V (that is, 1.8V). Accordingly, when the voltage of the second power source VSS is the maximum value (that is, in the case of driving condition A), the difference in voltage level between the first and second initialization power sources Vint1 and Vint2 is from 1.5V to 1.4V. As a result, the amount of current I_over flowing between the first and second initialization power lines L1 and L2 may decrease.

Thereafter, based on the updated reference lookup table LUT, the test apparatus 100 has a difference (I1-I2) between the value of the first current I1 and the value of the second current I2 than the reference value Ith. Until it is small (I1-I2<Ith), the supply of the first and second initialization powers of the voltage supply unit 120 and the measurement of the first and second currents I1 and I2 of the current measurement unit 130 are performed. Can repeat. In addition, when the difference (I1-I2) between the value of the first current I1 and the value of the second current I2 becomes smaller than the reference value Ith, the comparison unit 142 generates a first sub-comparison result signal. And, the LUT control signal generation unit 143 generates a first sub-LUT control signal based on the first sub-comparison result signal provided from the comparison unit 142 and provides the first sub-LUT control signal to the storage unit 110, and the storage unit 110 May store the updated reference lookup table LUT, for example, the second lookup table TABLE2 of FIG. 4B as a lookup table of the display panel DP, based on the first sub-LUT control signal. The second power supply VSS and the first and second initialization power supplies Vint1 and Vint2 to minimize damage to the display panel DP due to the current I_over between the first and second initialization power lines L1 and L2 The voltage levels of can be set.

As described with reference to FIGS. 1 to 4B, the test apparatus 100 according to an embodiment of the present invention measures a current flowing through an input terminal of the voltage supply unit 120, and a first And determining whether the second initialization power lines L1 and L2 are short-circuited, and when it is determined that the first and second initialization power lines L1 and L2 are shorted, they are included in the reference lookup table LUT. The updated reference lookup table LUT can be stored as a lookup table of the display panel DP by adjusting the voltage levels of the second power supply VSS, the first initialization power supply Vint1, and the second initialization power supply Vint2. have. Accordingly, the inspection apparatus 100 according to an exemplary embodiment of the present invention provides a short circuit between the first and second initialization power lines L1 and L2 included in the display panel DP before shipment of the display panel DP. Damage that may occur to the display panel DP may be prevented in advance by adjusting voltage levels included in the lookup table of the display panel DP based on whether or not.

5 is a flowchart illustrating a method of inspecting a display panel according to an exemplary embodiment of the present invention.

1 and 5, the inspection method of FIG. 5 may be performed in the inspection apparatus 100 of FIG. 1.

In the inspection method of FIG. 5, the display panel DP including the light-emitting element LD and the first transistor T1 that transmits a driving current to the light-emitting element LD may be inspected. Here, the display panel DP may be substantially the same as the display panel DP included in the display device 200 of FIG. 2.

The inspection method of FIG. 5 includes a first initialization power supply for initializing a transistor (for example, the first transistor T1 of FIG. 3) and a light emitting element ( For example, second initialization power for initializing the light emitting device LD of FIG. 3 may be supplied to the display panel (S510).

Thereafter, the inspection method of FIG. 5 may measure a current flowing through an input terminal of the power supply unit in a state in which the first and second initialization powers are applied to the display panel (S520).

Thereafter, the inspection method of FIG. 5 may adjust voltage levels of the first and second initialization power supplies based on the measured current (S530).

Here, the operation of supplying the first and second initialization power to the display panel (S510), measuring the current flowing through the input terminal of the power supply unit (S520), and adjusting the voltage levels of the first and second initialization power supplies The operation (S530) is described with reference to FIGS. 1 to 4B, respectively, the operation of the voltage supply unit 120, the operation of the current measurement unit 130, and the operation of the setting unit 140 and the storage unit 110, respectively. It can be substantially the same.

6 is a flowchart illustrating a method of inspecting a display panel according to another exemplary embodiment of the present invention.

1 and 6, the inspection method of FIG. 6 may be performed in the inspection apparatus 100 of FIG. 1.

In the inspection method of FIG. 6, the display panel DP including the light-emitting element LD and the first transistor T1 that transmits a driving current to the light-emitting element LD may be inspected. Here, the display panel DP may be substantially the same as the display panel DP included in the display device 200 of FIG. 2.

The inspection method of FIG. 6 may generate a voltage control signal based on a reference lookup table (S610). The reference lookup table may include voltage levels of the first and second initialization power, and the voltage control signal may include first to fourth set values. Here, the reference lookup table, the voltage control signal, and the first to fourth set values are the reference lookup table (LUT), the voltage control signal, and the first to fourth set values described with reference to FIGS. 1 to 4B. It can be substantially the same.

Thereafter, in the inspection method of FIG. 6, in the first mode, the power supply unit may supply the first and second initialization powers to the display panel based on the input power and the first and second set values (S620). have.

In the inspection method of FIG. 6, the first current I1 flowing through the input terminal of the power supply unit may be measured (S630). Here, the first current I1 may be substantially the same as the first current I1 described with reference to FIGS. 1 to 4B.

Thereafter, in the second mode, in the inspection method of FIG. 6, the power supply unit may supply the first and second initialization powers to the display panel based on the input power and the third and fourth set values (S640). have.

In the inspection method of FIG. 6, the second current I2 flowing through the input terminal of the power supply unit may be measured (S650). Here, the second current I2 may be substantially the same as the second current I2 described with reference to FIGS. 1 to 4B.

In an embodiment, the first mode may be after the second mode, but is not limited thereto, and the second mode may be after the first mode.

Thereafter, the inspection method of FIG. 6 may compare the difference (I1-I2) between the value of the first current I1 and the value of the second current I2 and a preset reference value Ith (S660). Here, the operation of comparing the difference (I1-I2) between the values of the first current I1 and the second current (I1-I2) and the reference value Ith (S660) is the operation of the comparison unit 142 described with reference to FIGS. 1 to 4B. May be substantially the same as

In an embodiment, when the difference (I1-I2) between the value of the first current and the value of the second current is smaller than the reference value Ith (I1-I2<Ith), the inspection method of FIG. It may be stored as a lookup table of the display panel (S670).

In one embodiment, when the difference (I1-I2) between the value of the first current and the value of the second current is greater than or equal to the reference value Ith (I1-I2Ith), the inspection method of FIG. By applying the preset LUT offset data, the reference lookup table may be updated (S680). Here, the operation of updating the reference lookup table by applying the preset LUT offset data (S680) is based on the second sub-LUT control signal provided from the LUT control signal generator 143 described with reference to FIGS. 1 to 4B. Thus, the operation of the storage unit 110 to update the reference lookup table LUT by applying the LUT offset data Offset to the reference lookup table LUT may be substantially the same.

Thereafter, the inspection method of FIG. 6 includes generating a voltage control signal (S610) until the difference (I1-I2) between the value of the first current and the value of the second current becomes smaller than the reference value Ith (S610). Supplying first and second initialization powers to the display panel based on the first and second set values (S620), measuring the first current I1 flowing through the input terminal of the power supply unit (S630), Supplying the first and second initialization powers to the display panel based on the third and third set values (S640), measuring the second current I2 flowing through the input terminal of the power supply unit (S650) , And comparing (S660) the difference (I1-I2) between the value of the first current I1 and the value of the second current I2 and the preset reference value Ith (S660), When the difference between the values of the second current I1-I2 becomes smaller than the reference value Ith (I1-I2 <

The detailed description above is intended to illustrate and describe the present invention. In addition, the above-described content is only to show and describe preferred embodiments of the present invention, and as described above, the present invention can be used in various other combinations, changes, and environments, and the scope of the concept of the invention disclosed in the present specification, writing Changes or modifications may be made within the scope of one disclosure and equivalent and/or within the scope of skill or knowledge in the art. Accordingly, the detailed description of the invention is not intended to limit the invention to the disclosed embodiment. In addition, the appended claims should be construed as including other embodiments.

100: inspection device 110: storage
120: voltage supply unit 121: voltage control unit
130: current measuring unit 140: setting unit
141: memory 142: comparison unit
143: LUT control signal generator DP: display panel

Claims (19)

In an inspection apparatus for inspecting a display panel including a light-emitting element and a transistor for transmitting a driving current to the light-emitting element,
An input power source is received through an input terminal, a first initialization power source for initializing the transistor and a second initialization power source for initializing the light emitting device are respectively generated, and the first and second initialization power sources are applied to the display panel. A voltage supply to supply;
A current measuring unit measuring a current flowing through the input terminal; And
And a setting unit configured to adjust voltage levels of the first and second initialization power sources based on the measured current. The method of claim 1,
Further comprising a storage unit including a reference look up table (Look Up Table: LUT),
The reference lookup table includes voltage levels of the first and second initialization power supplies according to a driving condition of the display panel. The method of claim 2, wherein the voltage supply unit comprises a voltage controller that generates a voltage control signal based on the reference lookup table,
The voltage control signal includes first to fourth set values,
The first and third set values represent voltage levels of the first initialization power, and the second and fourth set values represent voltage levels of the second initialization power,
The difference between voltage levels of the first and second initialization power supplies is maximum according to the first and second set values,
The apparatus for inspecting a display panel, wherein a difference between voltage levels of the first and second initialization power supplies is minimum according to the third and fourth set values. The method of claim 3, wherein the voltage supply unit,
In a first mode, based on the input power and the first and second set values, the first and second initialization powers are supplied to the display panel,
In a second mode, the first and second initialization powers are supplied to the display panel based on the input power and the third and fourth set values. The method of claim 4, wherein the current measuring unit,
In a first mode, a first current flowing through the input terminal is measured,
In a second mode, the apparatus for inspecting a display panel is configured to measure a second current flowing through the input terminal. The method of claim 5, wherein the setting unit,
A comparison unit generating a comparison result signal based on the first current, the second current, and a preset reference value; And
Based on the comparison result signal, comprises a LUT control signal generator for generating a LUT control signal, and providing the LUT control signal to the storage unit,
The comparison result signal includes first and second sub-comparison result signals,
The LUT control signal includes first and second sub-LUT control signals,
The second sub-LUT control signal includes preset LUT offset data. The method of claim 6, wherein the comparison unit generates the first sub-comparison result signal when a difference between the value of the first current and the value of the second current is smaller than the reference value,
The LUT control signal generation unit provides the first sub-LUT control signal to the storage unit based on the first sub-comparison result signal. The apparatus of claim 7, wherein the storage unit stores the reference lookup table as a lookup table of the display panel based on the first sub-LUT control signal. The method of claim 6, wherein the comparison unit generates the second sub-comparison result signal when a difference between the value of the first current and the value of the second current is greater than or equal to the reference value,
The LUT control signal generation unit provides the second sub-LUT control signal to the storage unit based on the second sub-comparison result signal. The apparatus of claim 9, wherein the storage unit updates the reference lookup table by applying the LUT offset data to the reference lookup table based on the second sub-LUT control signal. 11. The method of claim 10, wherein the first and second initialization power supplies of the voltage supply unit based on the updated reference lookup table are applied until a difference between the first current value and the second current value is less than the reference value. Supply, and repeat the measurement of the first and second currents of the current measuring unit,
When the difference between the value of the first current and the value of the second current becomes smaller than the reference value, the comparison unit generates the first sub-comparison result signal, and the LUT control signal generation unit generates the first sub-comparison result signal Provides the first sub-LUT control signal to the storage unit based on, and the storage unit stores the updated reference lookup table as a lookup table of the display panel based on the first sub-LUT control signal, Display panel inspection device. The method of claim 6, wherein the setting unit,
The apparatus for inspecting a display panel, further comprising a memory including the reference value and the LUT offset data. In a method for inspecting a display panel including a light-emitting element and a transistor for transmitting a driving current to the light-emitting element,
Supplying, by a power supply unit, a first initialization power for initializing the transistor and a second initialization power for initializing the light emitting element to the display panel, based on an input power provided through an input terminal;
Measuring a current flowing through the input terminal of the power supply unit while the first and second initialization powers are applied to the display panel; And
And adjusting voltage levels of the first and second initialization power sources based on the measured current. The method of claim 13, wherein supplying the first initialization power and the second initialization power to the display panel comprises:
Generating a voltage control signal based on the reference lookup table,
The reference lookup table includes voltage levels of the first and second initialization power,
The voltage control signal includes first to fourth set values,
The first and third set values represent voltage levels of the first initialization power, and the second and fourth set values represent voltage levels of the second initialization power,
The first and second set values are respectively selected from the level of the first initialization power and the level of the second initialization power in which the difference between the voltage levels of the first and second initialization powers included in the reference lookup table is maximum. And
The third and fourth set values are respectively selected from a level of the first initialization power and a level of the second initialization power in which the difference between the voltage levels of the first and second initialization powers included in the reference lookup table is minimum. That, how to inspect the display panel. The method of claim 14, wherein supplying the first initialization power and the second initialization power to the display panel comprises:
In a first mode, the power supply unit further comprises supplying the first and second initialization powers to the display panel based on the input power and the first and second set values,
Measuring the current flowing through the input terminal of the power supply unit,
And measuring a first current flowing through the input terminal in the first mode. The method of claim 15, wherein supplying the first initialization power and the second initialization power to the display panel comprises:
In a second mode, the power supply unit further comprises supplying the first and second initialization powers to the display panel based on the input power and the third and fourth set values,
Measuring the current flowing through the input terminal of the power supply unit,
In the second mode, the method of inspecting a display panel further comprising measuring a second current flowing through the input terminal. The method of claim 16, wherein adjusting the voltage levels comprises:
Comparing a difference between the value of the first current and the value of the second current with a preset reference value; And
And storing the reference lookup table as a lookup table of the display panel when a difference between the value of the first current and the value of the second current is less than the reference value. The method of claim 16, wherein adjusting the voltage levels comprises:
Comparing a difference between the value of the first current and the value of the second current with a preset reference value; And
If the difference between the value of the first current and the value of the second current is greater than or equal to the reference value, updating the reference lookup table by applying preset LUT offset data to the reference lookup table, How to inspect the display panel. The method of claim 18, further comprising supplying the input power until a difference between the value of the first current and the value of the second current becomes smaller than the reference value, and supplying the first and second initialization power to the display panel Repeating the steps of supplying to, measuring the current, and adjusting the voltage levels; And
And storing the updated reference lookup table as a lookup table of the display panel when a difference between the value of the first current and the value of the second current becomes smaller than the reference value.

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