阅读说明：本技术 一种液晶显示晶体管半导体层短路的测试方法 (Method for testing short circuit of semiconductor layer of liquid crystal display transistor ) 是由 胡群 郑宇成 骆志锋 于 2020-07-31 设计创作，主要内容包括：本发明公开一种液晶显示晶体管半导体层短路的测试方法,将液晶显示模组初始化并清空存储电容电荷,并对gate线进行逐行扫描。本发明通过将存储电容电荷清空,使得gate线上的高电位通过短路晶体管的位置送到data线上,对该列data线上的晶体管进行充电,使晶体管发光,从而显示出一条纵向的亮线,以此检测出TFT晶体管半导体层的短路漏电问题,实现功能性不良的排查。(The invention discloses a method for testing the short circuit of a semiconductor layer of a liquid crystal display transistor, which initializes a liquid crystal display module, clears the charge of a storage capacitor and scans gate lines line by line. According to the invention, the storage capacitor is emptied of charges, so that a high potential on a gate line is transmitted to a data line through the position of a short-circuit transistor, the transistors on the row of data lines are charged, the transistors emit light, and a longitudinal bright line is displayed, so that the short-circuit leakage problem of a semiconductor layer of the TFT transistor is detected, and the inspection of poor functionality is realized.)

1. A method for testing the short circuit of a semiconductor layer of a liquid crystal display transistor is characterized by comprising the following steps:

step 1: connecting the liquid crystal display module with a test system, and electrifying the test system;

step 2: the testing system sends an instruction to the register through the mipi low-speed mode to initialize the liquid crystal display module;

and step 3: discharging the liquid crystal display module, emptying the charges of storage capacitors of all transistors, and completely closing the Demux switch;

and 4, step 4: the testing system inputs signals to the GIP circuit through the Driver IC, the GIP circuit controls the gate circuit, high potentials are sequentially output to the gate1, the gate2 and the gate N to perform progressive scanning, and whether the liquid crystal display screen has a leakage condition or not is judged simultaneously in the process;

and 5: after scanning the gate lines line by line, issuing an instruction to the liquid crystal display module to enable the liquid crystal display module to enter a sleep mode;

step 6: and powering off the test system, and disconnecting the liquid crystal display module from the test system to finish the test.

2. The method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor according to claim 1, wherein the step 1 of powering up comprises the following specific steps: and sequentially opening the Iovcc voltage, the VSP voltage and the VSN voltage, and then opening a backlight source of the liquid crystal display module to finish the power-on process of the test system.

3. The method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor according to claim 2, wherein the step 7 of powering down specifically comprises the following steps: and powering off the VSN voltage, the VSP voltage and the Iovcc voltage in sequence to finish the powering off process of the test system.

4. The method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor according to claim 1, wherein in the step 4, when a bright spot or a bright line appears on the liquid crystal display screen, the transistor of the liquid crystal display screen is judged to have the short circuit leakage phenomenon; and when no bright spot or bright line appears on the liquid crystal display screen, judging that the transistor of the liquid crystal display screen has no short circuit leakage phenomenon.

5. The method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor according to claim 1, wherein the step 1 comprises mounting the liquid crystal display screen to be tested on a test bracket in a dark box, wherein the test bracket is electrically connected with the test system.

6. The method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor according to claim 5, wherein two sides of the test support are mounted on two side walls of the dark box in a sliding rail manner, and a door leaf is arranged on the dark box.

7. The method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor according to claim 5, wherein a light sensing element group connected with the testing system is arranged on the display surface of the liquid crystal display screen corresponding to the test in the dark box, and an alarm system is arranged on the dark box and comprises a light emitting device and/or a sound emitting device.

8. The method according to claim 7, wherein the light emitting device is an indicator light and the sound generating device is a buzzer.

9. The method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor according to claim 7, wherein the step 4 comprises: when the light sensing element group detects that light appears on the display surface of the liquid crystal display screen, the test system controls the light emitting device to emit red light to give an alarm, and/or the test system controls the light emitting device to emit an alarm; after the line-by-line scanning is finished, the light sensing element group does not detect light, the test system controls the light emitting device to emit green light for prompting, and/or the test system controls the light emitting device to emit prompting sound.

10. The method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor according to claim 9, wherein the step 4 further comprises the step of judging whether the liquid crystal display screen has the electric leakage condition according to the prompt of an alarm system by a tester.

Technical Field

The invention relates to the field of liquid crystal display, in particular to a method for testing a short circuit of a semiconductor layer of a liquid crystal display transistor.

Background

After the liquid crystal display module is produced, the picking work of the functional defects is required. The prior art lights up a pure color display picture and some complex display pictures (color pictures) in a progressive scanning manner to check whether functional defects exist. The operating principle of progressive scanning is as follows: when the first row is scanned, the gate1 is powered on, the pixel transistors in the first row are turned on, the IC outputs voltage to charge the cst1, then the gate1 outputs low level to turn off the pixel transistors, and the like, the gate2, the gate3 and the like are displayed line by line until each row of the liquid crystal display module is checked, so that whether the liquid crystal display module has functional defects or not is detected. However, in this test method, the pixel transistors in the entire row are turned on, so that defects such as bright spots and bright lines caused by short-circuit and leakage of the TFT transistors cannot be detected, the liquid crystal display module cannot be detected comprehensively, and certain potential defects exist.

Accordingly, the prior art is deficient and needs improvement.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for testing the short circuit of a semiconductor layer of a liquid crystal display transistor.

The technical scheme of the invention is as follows: the method for testing the short circuit of the semiconductor layer of the liquid crystal display transistor comprises the following steps:

step 1: connecting the liquid crystal display module with a test system, and electrifying the test system;

step 2: the testing system sends an instruction to the register through the mipi low-speed mode to initialize the liquid crystal display module;

and step 3: discharging the liquid crystal display module, emptying the charges of storage capacitors of all transistors, and completely closing the Demux switch;

and 4, step 4: the testing system inputs signals to the GIP circuit through the Driver IC, the GIP circuit controls the gate circuit, high potentials are sequentially output to the gate1, the gate2 and the gate N to perform progressive scanning, and whether the liquid crystal display screen has a leakage condition or not is judged simultaneously in the process;

and 5: after scanning the gate lines line by line, issuing an instruction to the liquid crystal display module to enable the liquid crystal display module to enter a sleep mode;

step 6: and powering off the test system, and disconnecting the liquid crystal display module from the test system to finish the test.

Further, the step 1 of powering up includes the specific steps of: and sequentially opening the Iovcc voltage, the VSP voltage and the VSN voltage, and then opening a backlight source of the liquid crystal display module to finish the power-on process of the test system.

Further, the step 7 of powering down specifically comprises the following steps: and powering off the VSN voltage, the VSP voltage and the Iovcc voltage in sequence to finish the powering off process of the test system.

Further, in the step 4, when a bright spot or a bright line appears on the liquid crystal display screen, it is determined that the transistor of the liquid crystal display screen has a short-circuit leakage phenomenon; and when no bright spot or bright line appears on the liquid crystal display screen, judging that the transistor of the liquid crystal display screen has no short circuit leakage phenomenon.

Further, step 1 includes that the liquid crystal display screen to be tested is installed on a test support in the dark box, and the test support is electrically connected with the test system.

Furthermore, the two sides of the test support are arranged on the two side walls of the dark box in a sliding rail mode, and a door leaf is arranged on the dark box.

Furthermore, a light sensing element group connected with the testing system is arranged on the display surface of the liquid crystal display screen in the dark box corresponding to the test, and an alarm system is arranged on the dark box and comprises a light-emitting device and/or a sound-generating device.

Further, the light emitting device is an indicator light, and the sounding device is a buzzer.

Further, the step 4 comprises: when the light sensing element group detects that light appears on the display surface of the liquid crystal display screen, the test system controls the light emitting device to emit red light to give an alarm, and/or the test system controls the light emitting device to emit an alarm; after the line-by-line scanning is finished, the light sensing element group does not detect light, the test system controls the light emitting device to emit green light for prompting, and/or the test system controls the light emitting device to emit prompting sound.

Further, step 4 also includes that the tester judges whether the liquid crystal display screen has the electric leakage condition according to the prompt of the alarm system.

By adopting the scheme, the storage capacitor is emptied of charges, so that the high potential on the gate line is transmitted to the data line through the position of the short-circuit transistor, the transistors on the row of data lines are charged, the transistors emit light, and a longitudinal bright line is displayed, so that the short-circuit leakage problem of the semiconductor layer of the TFT transistor is detected, and the defective functionality is checked.

Drawings

Fig. 1 is a flow chart of a first embodiment of the present invention.

FIG. 2 is a circuit diagram of the present invention.

Fig. 3 is a flow chart of a second embodiment of the present invention.

Detailed Description

The invention is described in detail below with reference to the figures and the specific embodiments.

Referring to fig. 1, the present invention provides a method for testing a short circuit of a semiconductor layer of a liquid crystal display transistor, comprising the following steps:

step 1: and connecting the liquid crystal display module with the test system, sequentially opening the Iovcc voltage, the VSP voltage and the VSN voltage, and then opening a backlight source of the liquid crystal display module to complete the power-on process of the test system.

Step 2: and the test system sends an instruction to the register through the mipi low-speed mode to initialize the liquid crystal display module.

And step 3: and discharging the liquid crystal display module, emptying the charges of the storage capacitors of all the transistors, and completely closing the Demux switch. And discharging the liquid crystal display module, emptying the capacitor charges of all the transistors, and closing the Demux switch to enable the data lines of all the rows to be in a low potential state, so that the transistors do not display pictures when the gate lines are electrified.

And 4, step 4: the testing system inputs signals to the GIP circuit through the Driver IC, the GIP circuit controls the gate circuit, high potentials are sequentially output to the gate1, the gate2 and the gate N to perform line-by-line scanning, and whether the liquid crystal display screen has a leakage condition or not is judged simultaneously in the process. When a bright spot or a bright line appears on the liquid crystal display screen, judging that the transistor of the liquid crystal display screen has short circuit and leakage; and when no bright spot or bright line appears on the liquid crystal display screen, judging that the transistor of the liquid crystal display screen has no short circuit leakage phenomenon.

And 5: after the gate line is scanned line by line, an instruction is given to the liquid crystal display module, so that the liquid crystal display module enters a sleep mode.

Step 6: and powering off the VSN voltage, the VSP voltage and the Iovcc voltage in sequence to finish the power-off process of the test system, disconnecting the liquid crystal display module from the test system and finishing the test.

Referring to fig. 2, in the first embodiment of the present invention, during the test, the lcd module is placed on the test system, and then the test system is connected, the Iovcc voltage, the VSP voltage, and the VSN voltage are sequentially turned on, and then the backlight of the lcd module is turned on, so as to power on the test system and the lcd module. And then the test system sends an instruction to the register through the mipi low-speed mode, initializes the liquid crystal display module, discharges the liquid crystal display module, empties the capacitor charges of all the transistors, and closes the Demux switch so that each row of data is in a low-potential state. The test system inputs signals to the GIP circuit through the Driver IC, the GIP circuit controls the gate lines and sequentially outputs high potential to each gate, and all transistors are turned on. If the liquid crystal display module has a condition that a transistor semiconductor is short-circuited, the high potential of the corresponding gate can be transmitted to the data line where the transistor is located from the short-circuited position through the opened transistor, all the transistors on the data line are charged, and the transistors are lightened to form a bright line. And the storage capacitors of the transistors on the other data lines are emptied of electric charges, so that a black picture is represented. The tester can judge the position of the short-circuited transistor by observing whether a bright spot or a longitudinal bright line appears on the liquid crystal display module and combining a gate line which is at a high potential when the bright line appears, so as to perform subsequent maintenance and rework. By the method, the leakage defect of the short circuit of the semiconductor layer of the TFT transistor can be effectively detected, and the accuracy and the stability of the test are improved.

Referring to fig. 3, the present invention further provides a second embodiment, in the second embodiment, the step 1 further includes installing the liquid crystal display to be tested on a testing bracket in the dark box, and the testing bracket is electrically connected to the testing system. The display surface of the liquid crystal display screen is provided with a light sensing element group connected with the test system when the liquid crystal display screen is tested correspondingly in the dark box, and the dark box is provided with an alarm system which comprises a light emitting device and/or a sound generating device. A closed and dark environment is manufactured through the dark box, so that the light sensing element group can detect the light emitted by the liquid crystal display module, and automatic detection is realized.

The two sides of the test support are arranged on the two side walls of the dark box in a sliding rail mode, and a door leaf is arranged on the dark box. Through the closure of door leaf to prevent that external light source from getting into dark case inside and influencing the detection of light sensing element group. When the door leaf is opened, a tester can pull out the testing support from the door leaf along the sliding rail, so that the liquid crystal display module to be tested is mounted on the testing support, and the testing efficiency is improved. When closing the door leaf, form the dark space in the dark case, can improve the degree of accuracy that light sense component group detected light.

In the embodiment, the light emitting device is an indicator light, such as an LED light, and has low energy consumption and high brightness; the sounding device is a buzzer.

The step 4 comprises the following steps: when the light sensing element group detects that light appears on the display surface of the liquid crystal display screen, the test system controls the light emitting device to emit red light to give an alarm, and/or the test system controls the light emitting device to emit an alarm; after the line-by-line scanning is finished, the light sensing element group does not detect light, the test system controls the light emitting device to emit green light for prompting, and/or the test system controls the light emitting device to emit prompting sound.

And step 4, judging whether the liquid crystal display screen has the electric leakage condition or not by the tester according to the prompt of the alarm system.

When testing, open the door leaf of dark case, pull out the test support along the slide rail from the dark case, will await measuring test liquid crystal display and install on the test support, insert test system. After the test support is pushed into the dark box, the door leaf is closed, the Iovcc voltage, the VSP voltage and the VSN voltage are sequentially opened, the backlight source of the liquid crystal display module is opened, and the test system and the liquid crystal display module are powered on. And then the test system sends an instruction to the register through the mipi low-speed mode, initializes the liquid crystal display module, discharges the liquid crystal display module, empties the capacitor charges of all the transistors, and closes the Demux switch so that each row of data is in a low-potential state. The test system inputs signals to the GIP circuit through the Driver IC, the GIP circuit controls the gate lines and sequentially outputs high potential to each gate, and all transistors are turned on. If the liquid crystal display module has a condition that a transistor semiconductor is short-circuited, the high potential of the corresponding gate can be transmitted to the data line where the transistor is located from the short-circuited position through the opened transistor, all the transistors on the data line are charged, and the transistors are lightened to form a bright line. And the storage capacitors of the transistors on the other data lines are emptied of electric charges, so that a black picture is represented.

When the light sensation component group corresponding to the display surface of the liquid crystal display screen in the dark box detects light rays emitted by bright lines appearing on the liquid crystal display screen, a signal is sent to the test system, the light emitting device controlled by the test system emits red light to give an alarm, and meanwhile, the sound emitting device emits high-frequency alarm sound to prompt a tester that the liquid crystal display module has the defect of transistor semiconductor short circuit. If the light sensing element group does not detect light after the line-by-line scanning is finished, and the test system does not receive signals sent by the light sensing element group, the light-emitting device controlled by the control system sends out green light for prompting, and simultaneously, the low-frequency prompting sound of the device is generated to prompt a tester that the liquid crystal display module is good, and the defect of transistor semiconductor short circuit does not exist.

In summary, in the invention, the storage capacitor is charged to empty, so that the high potential on the gate line is sent to the data line through the position of the short-circuit transistor, the transistors on the row of data lines are charged to emit light, and a longitudinal bright line is displayed, thereby detecting the short-circuit leakage problem of the semiconductor layer of the TFT transistor and realizing the troubleshooting of poor functionality.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.