CN113066412B - Circuit control method, detection method and preparation method of array substrate - Google Patents

Abstract

The invention provides a circuit control method, a detection method and a preparation method of an array substrate, belongs to the technical field of display, and can solve the problems that an existing OLED display panel is prone to poor display phenomena of bright spot type with lines and bright spot clusters, the poor display phenomena are intelligently detected in a panel detection stage, and repair cannot be carried out. The circuit control method of the array substrate is used for controlling the circuit of the array substrate in the detection stage process of the array substrate; the circuit control method comprises the following steps: writing a turn-off signal into a control end of the pixel circuit to turn off the pixel circuit; an initialization stage: writing a first charge signal to at least a part of the signal lines; writing a first control signal into the control end of the sensing unit, and writing a first sensing signal into the second end of the sensing unit so as to turn off the sensing unit; a detection stage: and writing a second control signal into the control end of the sensing unit to start the sensing unit, and writing the second sensing signal into the pixel voltage output end.

Description

Circuit control method, detection method and preparation method of array substrate

technical field

The invention belongs to the technical field of display, and in particular relates to a circuit control method, a detection method and a display panel preparation method of an array substrate.

Background technique

An organic electroluminescent diode (Organic Light-Emitting Diode; OLED) is a display device with characteristics such as self-luminescence, wide viewing angle, fast response, wide color gamut, high definition and contrast, and can realize flexible display. Therefore, the OLED display panel has strong competitiveness in the display panel of the new era, and is recognized by the industry as the display panel with the most development potential.

In the prior art, in order to ensure the factory yield of the OLED display panel, display inspection is performed before the OLED display panel is shipped from the factory.

The inventor found that the OLED display panel is prone to the bad display phenomenon of the type of bright spots with lines and bright spots. The bad display phenomenon can be found in the CT (cell test) stage and the module detection stage, but at this time the bad display phenomenon is in the module. At this stage, it is impossible to repair or compensate. Even if a defective problem is detected, the OLED display panel has been scrapped, which is not conducive to improving the product yield of the OLED display panel.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a circuit control method for an array substrate that can be used for defect detection in AT detection.

The technical solution adopted to solve the technical problem of the present invention is a circuit control method of an array substrate, which is used to control the circuit of the array substrate during the detection stage of the array substrate; the array substrate includes: a pixel circuit , a signal line and a sensing unit; the pixel voltage output end of the pixel circuit is connected to the light-emitting unit; the first end of the sensing unit is connected to the pixel voltage output end; the circuit control method includes:

writing a shutdown signal to the control terminal of the pixel circuit to turn off the pixel circuit;

Initialization stage: write a first charging signal to at least part of the signal lines; write a first control signal to the control terminal of the sensing unit, and write a first sensing signal to the second terminal of the sensing unit , so that the sensing unit is turned off;

Detection stage: writing a second control signal to the control terminal of the sensing unit to turn on the sensing unit, and writing the second sensing signal to the pixel voltage output terminal.

Optionally, the signal line includes: a data line and a first signal line; the pixel circuit includes: a control module and a driving module; the first end of the control module is connected to the data line, and the second end is connected to the the control terminal of the driving module is connected; the first terminal of the control module is connected to the first signal line, and the second terminal is the output terminal of the pixel voltage;

The writing of the first charging signal to at least part of the signal line includes: writing the first charging signal to one of the first signal line and the data line; and simultaneously, suspending the other.

Further optionally, the writing the first charging signal to at least a part of the signal lines includes: writing the first charging signal to the first signal line; and at the same time, suspending the data line.

Optionally, after the second control signal is written to the control terminal of the sensing unit and maintained for the first period of time, the method further includes:

A second sensing signal is written to the second end of the sensing unit to turn off the sensing unit.

Further optionally, the voltage of the second sensing signal and the second control signal are the same.

Further optionally, the range of the first time period includes 800-1500 microseconds.

Optionally, the circuit control method further includes:

The reset stage: writing a reset signal to the signal line, the sensing unit and the pixel circuit to reset each circuit structure on the array substrate.

The technical solution adopted to solve the technical problem of the present invention is a detection method for an array substrate, including any one of the above circuit control methods.

Optionally, the detection method also includes:

In the detection stage: detecting the voltage of the signal line of the array substrate and the pixel voltage of the pixel voltage output terminal;

Perform optical imaging according to the voltage difference between the voltage of the signal line and the pixel voltage; the optical imaging brightness is related to the voltage difference;

According to the optical imaging result, the defective position of the array substrate is determined.

The technical solution adopted to solve the technical problem of the present invention is a preparation method of a display panel, including:

An array substrate is prepared; the array substrate includes: a pixel circuit, a signal line, a light-emitting unit and a sensing unit; the pixel voltage output end of the pixel circuit is connected to the light-emitting unit; the first end of the sensing unit is connected to the The pixel voltage output terminal is connected;

The array substrate is detected according to any one of the above detection methods.

Description of drawings

FIG. 1 is a schematic diagram of a circuit structure of an array substrate according to an embodiment of the present invention;

2 is a circuit timing diagram of a circuit control method for an array substrate according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the detection result of the VIOS system of the detection method according to the embodiment of the present invention.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1:

In the prior art, after the array substrate, display panel, display module and other display product structures are prepared, they need to be inspected to discover defects in time, repair them in time, and improve the ex-factory yield of the display product structure. Among them, in the array test (Array Test; AT) stage, the array substrate can be tested by the VIOS (voltage imaging optical subsystem; voltage imaging optical subsystem) system to detect whether each signal line in the array substrate has a short circuit or open circuit phenomenon, but It is not possible to detect the bad display phenomenon of the type of bright dots with line dots in the array substrate.

This embodiment provides a circuit control method for an array substrate, which can be used to control the circuit of the array substrate during the detection stage of the array substrate. The circuit control method provided in this embodiment is particularly suitable for circuit control of the OLED display array substrate during detection of the OLED display array substrate. The array substrate may include pixel circuits, signal lines, sensing units, light-emitting units, and the like. The pixel voltage output end of the pixel circuit is connected with the light emitting unit; the first end of the sensing unit is connected with the pixel voltage output end. The pixel circuit may include: a control module and a driving module; the first end of the control module is connected to the data line Vdata, the second end is connected to the control end of the driving module; the first end of the control module is connected to the first signal line VDD, The second terminal is the pixel voltage output terminal. The signal lines may include a data line Vdata, a first signal line VDD, a gate line, a sensing line Sense, and the like. In the array substrate, the pixel circuit can be controlled through the gate line, the first signal line VDD, the data line Vdata, etc., so as to control the display light-emitting unit to perform light-emitting display. In addition, the sensing unit can sense the pixel voltage of the pixel voltage output terminal of the pixel circuit, and output it through the sensing line Sense, so as to compensate the pixel circuit according to the sensed pixel voltage and ensure that each pixel of the entire array substrate is Uniform display of cells.

The circuit control method provided by this embodiment includes an initialization phase and a detection phase, which may specifically include:

Write a shutdown signal to the control terminal of the pixel circuit to turn off the pixel circuit.

Initialization stage: write the first charging signal to at least part of the signal lines; write the first control signal to the control terminal of the sensing unit, and write the first sensing signal to the second terminal of the sensing unit, so that the sensing unit off.

The detection stage: writing a second control signal to the control terminal of the sensing unit to turn on the sensing unit, and writing the second sensing signal to the pixel voltage output terminal.

The circuit control method provided in this embodiment is used to control the circuit of the array substrate in the AT stage, so as to use the VIOS system to detect the array substrate, thereby realizing the detection of the bad display phenomenon of the bright spot with line bright spot cluster type of the array substrate. Specifically, when the array substrate is detected, the voltage of each signal line of the array substrate and the pixel voltage at the pixel voltage output end of the pixel circuit can be detected by the VIOS system. Among them, the VIOS system can detect the average voltage of the signal line and the pixel voltage in each pixel circuit in the array substrate, and perform optical imaging according to the voltage difference between the pixel voltage and the average voltage of the signal line. Therefore, the poor display phenomenon of the bright spot strip line bright spot cluster type of the array substrate is found.

Through research, it is found that the poor display phenomenon of the bright spot strip line bright spot cluster type of the array substrate is caused by the weak migration between the gate electrode and the active layer of the sensing transistor T3 in the sensing unit on the pixel voltage. That is to say, in a plurality of pixel circuits on the same array substrate, even if the same data voltage is written to each pixel circuit, the pixel voltage in the pixel unit where weak migration occurs is the same as the pixel voltage in the pixel unit where weak migration does not occur. different. Therefore, by detecting the voltage (ie, the second sensing signal) written to the pixel voltage output terminal of the pixel circuit via the sensing unit in each pixel unit, the defect of the bright spot strip line bright spot cluster type of the array substrate can be detected. Displays the location of the phenomenon (as shown in Figure 3). However, in the circuit control method provided in this embodiment, each pixel circuit on the array substrate is turned off through circuit control, and the pixel circuit does not output the pixel voltage at the pixel voltage output terminal.

It can be understood that, in this embodiment, the sensing unit generally includes a sensing transistor T3, the on and off of the sensing unit and the control signal written to the control terminal of the sensing unit and the second signal to the sensing unit. It is related to the voltage difference of the sensing signal written at the terminal. Therefore, in this implementation, in the initialization stage, the sensing unit is controlled to be turned off by controlling the pressure difference between the first control signal and the first sensing signal; in the detection stage, the control signal at the control end of the sensing unit (by the first The control signal becomes the second control signal) to control the conduction of the sensing unit, and write the second sensing signal into the state of the pixel voltage output terminal. In this way, it can be determined whether the sensing unit of each pixel unit in the array substrate undergoes weak migration according to the voltage of each pixel voltage output terminal on the array substrate. At the same time, since the pixel circuit is in an off state and no voltage is supplied to the pixel voltage output terminal, the pixel circuit will not affect the detection result.

The circuit control method provided in this embodiment is preferably used in the detection process of the array substrate by the VIOS system. It should be noted that when the VIOS system detects the array substrate, it does not directly detect the value of the pixel voltage in each pixel circuit of the array substrate, but detects the difference between the average voltage passing through the signal line and the pixel voltage of each pixel circuit. Difference, optical imaging is performed directly according to the voltage difference, and the display brightness converted by different voltage differences is different. Therefore, as shown in FIG. 3 , the defective position of the array substrate can be determined according to the abnormal brightness points in the image displayed by the VIOS system when the array substrate is detected. Specifically, in this embodiment, the pixel circuit is controlled to be turned off, and a charging signal is input to at least part of the signal lines. At the same time, a sensing signal is input to the sensing unit through the sensing line Sense, and transmitted to the pixel voltage output terminal, so as to The VIOS system detects the array substrate, and the optical image can be displayed normally.

Optionally, in this embodiment, the signal line includes: a data line Vdata and a first signal line VDD; the pixel circuit includes: a control module and a driving module; the first end of the control module is connected to the data line Vdata, and the second end is connected to the driver the control end of the module is connected; the first end of the control module is connected to the first signal line VDD, and the second end is the pixel voltage output end; writing the first charging signal to at least part of the signal lines includes: writing the first signal line VDD and data to the first signal line VDD One of the lines Vdata is written with the first charging signal; at the same time, the other is left suspended.

In the VIOS system, the display of the electro-optical image is performed according to the voltage difference between the average voltage of the signal line and the pixel voltage. It can be understood that there are many signal lines in the array substrate. In this embodiment, it is only necessary to write charging signals to some of the signal lines. At the same time, suspending the remaining signal lines can avoid affecting the normal charging of the charging signal lines.

Further optionally, in this embodiment, writing the first charging signal to at least part of the signal lines includes: writing the first charging signal to the first signal line VDD; at the same time, suspending the data line Vdata. In this embodiment, the first signal line VDD is connected to the input end of the driving unit of the pixel circuit. Normally, the width of the first signal line VDD is wider, and the signal transmission effect is better. Writing the first charging signal to the signal line VDD can obtain better and more accurate detection results than writing the first charging signal to other signal lines.

Optionally, as shown in FIG. 2 , in this embodiment, after writing the second control signal to the control terminal of the sensing unit and maintaining the first period of time, the method further includes: writing to the second terminal of the sensing unit The second sensing signal is input to turn off the sensing unit.

It can be understood that, in the normal manufacturing process of the display panel, after the array substrate is inspected, other operations are also performed on the array substrate. In this embodiment, the sensing unit may be turned off by writing the second sensing signal to the second end of the sensing unit.

Preferably, the range of the first time period includes 800-1500 microseconds. It can be understood that the duration of the first period of time does not need to be too long as long as it can meet the detection requirements.

Wherein, optionally, the voltages of the second sensing signal and the second control signal are the same. It can be understood that, in this embodiment, the sensing unit generally includes a sensing transistor T3. Taking the sensing transistor T3 as an N-type transistor as an example, when the voltage difference between the control electrode and the input electrode of the sensing transistor T3 is greater than the threshold voltage, the sensing transistor T3 can be turned on. In this embodiment, as long as the pressure difference between the control signal of the sensing unit and the sensing signal is controlled, the working state of the sensing unit can be controlled. In this embodiment, by controlling the voltage of the second sensing signal and the second control signal to be the same, the sensing unit can be controlled to be turned off and the voltage writing to the output terminal of the pixel electrode is stopped.

Preferably, the circuit control method provided in this embodiment further includes: a reset stage: writing a reset signal to the signal line, the sensing unit and the pixel circuit to reset each circuit structure on the array substrate.

Specifically, as shown in FIG. 1 and FIG. 2 , in this embodiment, by writing a low-level signal to each signal line, the storage capacitor C1 in the pixel circuit can be controlled to discharge, so as to eliminate the residual electrical signal of the previous frame.

As shown in FIG. 1 , the pixel circuit of the array substrate may include structures such as a control transistor T1 , a driving transistor T2 and a storage capacitor C1 . Preferably, the control transistor T1 and the driving transistor T2 are N-type transistors. Specifically, as shown in FIG. 2 , in the circuit control method provided by this embodiment, in the initialization stage, a first charging signal (for example, an 8V voltage signal) is written to the first signal line VDD, and at the same time, the data line Vdata is suspended set status. At the same time, write a non-operating voltage (such as -20V voltage signal) to the control electrode G1 of the control transistor T1, and control the control transistor T1 to turn off; the control electrode voltage of the driving transistor T2 is the same as the output terminal voltage of the control transistor T1, and the driving transistor T2 Turn off; write the first control voltage (eg -25V voltage signal) to the control electrode G2 of the sensing transistor T3, write the first sensing voltage (eg -20V voltage signal) to the first electrode of the sensing transistor T3, The sensing transistor T3 is controlled to be turned off. In the detection phase, the voltage supplied to the first signal line VDD remains unchanged, and at the same time, the control transistor T1 is kept in an off state. Continue to write the first sensing voltage to the first electrode of the sensing transistor T3 through the sensing line Sense, and write a second control signal (eg -10V voltage signal) to the control electrode of the sensing transistor T3 to control the sensing transistor T3 on. At this time, the first sensing voltage is written into the pixel voltage output terminal and detected by the VIOS system (the voltage transmitted to the pixel voltage output terminal is lower than the first sensing voltage). The VIOS system detects the average voltage of the first signal line on the array substrate (ie, the first charging voltage) and the voltage difference between the pixel voltage output terminals of each pixel unit, and performs photon imaging display according to the voltage difference. After the first time end, a second sensing voltage (eg -10V voltage signal) is written to the first pole of the sensing transistor T3 through the sensing line Sense, and the sensing transistor T3 is controlled to be turned off, and the detection ends.

It can be understood that, in this embodiment, in the detection stage, the driving transistor T2 is turned off, the sensing transistor T3 is turned on, and the sensing transistor T3 writes the second sensing voltage into the pixel voltage output terminal. It can be understood that, due to the characteristics of the sensing transistor T3, the voltage actually output by the sensing unit is smaller than the first sensing voltage output by the sensing line Sense. If the sensing unit undergoes weak migration, the voltage of the pixel voltage output terminal is equal to the gate voltage of the sensing transistor T3. That is to say, the pixel voltage of the normal pixel unit is different from the pixel voltage of the pixel unit with weak migration, so the brightness of the corresponding different pixel units converted by the VIOS system is also different, so that it can be confirmed whether the array is basically defective. .

Example 2:

This embodiment provides a detection method for an array substrate, including any one of the path control methods provided in Embodiment 1.

Optionally, the detection method provided in this embodiment further includes:

In the detection stage: the voltage of the signal line of the array substrate and the pixel voltage of the pixel voltage output terminal are detected. According to the voltage difference between the voltage of the signal line and the pixel voltage, optical imaging is performed; the optical imaging brightness is related to the voltage difference; according to the optical imaging result, the defective position of the array substrate is determined.

In the detection method provided in this embodiment, the voltage of each signal line of the array substrate and the pixel voltage at the pixel voltage output end of the pixel circuit can be detected by the VIOS system. Among them, the VIOS system can detect the average voltage of the signal line and the pixel voltage in each pixel circuit in the array substrate, and perform optical imaging according to the voltage difference between the pixel voltage and the average voltage of the signal line. Therefore, the poor display phenomenon of the bright spot strip line bright spot cluster type of the array substrate is found.

Embodiment 3;

This embodiment provides a preparation method of a display panel, including:

S1. Prepare an array substrate; the array substrate includes: a pixel circuit, a signal line, a light-emitting unit and a sensing unit; a pixel voltage output end of the pixel circuit is connected to the light-emitting unit; a first end of the sensing unit is connected to the pixel voltage output end.

S2. Detecting the array substrate.

Specifically, in this step, the array substrate can be detected according to the detection method provided in Embodiment 2, and the poor display phenomenon of the bright spot with line bright spot cluster type of the array substrate can be found in time.

Optionally, in the preparation method provided in this embodiment, when detecting that the array substrate has the above-mentioned defect, the step of repairing the array substrate may be further included. For details, reference may be made to related materials, which will not be repeated in this embodiment.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, without departing from the spirit and essence of the present invention, various modifications and improvements can be made, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (9)

1. A circuit control method for an array substrate, used for controlling a circuit of the array substrate during a detection stage of the array substrate; the array substrate comprising: a pixel circuit, a signal line and a sensing unit; The pixel voltage output terminal of the pixel circuit is connected to the light-emitting unit; the first terminal of the sensing unit is connected to the pixel voltage output terminal; it is characterized in that, the circuit control method includes: writing a shutdown signal to the control terminal of the pixel circuit to turn off the pixel circuit; Initialization stage: write a first charging signal to at least part of the signal lines; write a first control signal to the control terminal of the sensing unit, and write a first sensing signal to the second terminal of the sensing unit , so that the sensing unit is turned off; detection stage: writing a second control signal to the control terminal of the sensing unit to turn on the sensing unit, and writing the second sensing signal to the pixel voltage output terminal; After the writing of the second control signal to the control terminal of the sensing unit and maintaining the first period of time, the method further includes: A second sensing signal is written to the second end of the sensing unit to turn off the sensing unit. 2. The circuit control method according to claim 1, wherein the signal line comprises: a data line and a first signal line; the pixel circuit comprises: a control module and a driving module; the first signal line of the control module The terminal is connected to the data line, and the second terminal is connected to the control terminal of the driving module; the first terminal of the control module is connected to the first signal line, and the second terminal is the pixel voltage output terminal; The writing of the first charging signal to at least part of the signal line includes: writing the first charging signal to one of the first signal line and the data line; and simultaneously, suspending the other. 3 . The circuit control method according to claim 2 , wherein the writing the first charging signal to at least part of the signal lines comprises: writing the first charging signal to the first signal lines; and simultaneously, Suspend the data line. 4 . The circuit control method of claim 1 , wherein the voltage of the second sensing signal and the second control signal are the same. 5 . 5. The circuit control method according to claim 1, wherein the range of the first time period includes 800-1500 microseconds. 6. The circuit control method according to claim 1, further comprising: The reset stage: writing a reset signal to the signal line, the sensing unit and the pixel circuit to reset each circuit structure on the array substrate. 7 . A method for detecting an array substrate, comprising the circuit control method according to any one of claims 1 to 6 . 8. detection method according to claim 7, is characterized in that, also comprises: In the detection stage: detecting the voltage of the signal line of the array substrate and the pixel voltage of the pixel voltage output terminal; Perform optical imaging according to the voltage difference between the voltage of the signal line and the pixel voltage; the optical imaging brightness is related to the voltage difference; According to the optical imaging result, the defective position of the array substrate is determined. 9. A method for preparing a display panel, comprising: An array substrate is prepared; the array substrate includes: a pixel circuit, a signal line, a light-emitting unit and a sensing unit; the pixel voltage output end of the pixel circuit is connected to the light-emitting unit; the first end of the sensing unit is connected to the The pixel voltage output terminal is connected; The array substrate is inspected according to the inspection method of claim 7 or 8.

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