NTC (Negative Temperature Coefficient) detection device for testing liquid crystal display screen

Abstract

An NTC (Negative Temperature Coefficient) detection device for testing a liquid crystal display screen comprises a signal adapter plate, and the signal adapter plate is provided with a first interface used for being electrically connected with a liquid crystal test box; the second interface is used for being electrically connected with a liquid crystal display screen to be tested and is provided with an NTC1 port electrically connected with an NTC in the liquid crystal display screen; the NTC alarm circuit comprises a voltage division circuit formed by a resistor R1 and a resistor R3 which are connected in parallel, one end of the voltage division circuit is electrically connected with the power supply port of the first interface, and the other end of the voltage division circuit is respectively connected with the NTC1 port of the second interface and an alarm; and the alarm is connected with the NTC alarm circuit and outputs an alarm signal when the NTC in the liquid crystal display screen has an open circuit or the voltage value exceeds a set value. By adding the NTC alarm circuit, NTC alarm is directly added on the basis of testing by using the test box, and the function of an NTC thermistor can be monitored while the display function of the liquid crystal display module is tested.

Description

Technical Field

[0001] The utility model specifically relates to an NTC detection device for testing a liquid crystal display screen. Background Art

[0002] At present, the monitoring of ambient temperature or heating temperature parameters of electrical equipment is all collected by NTC thermistors, which convert the temperature change into the change of thermistor resistance value, and then convert it into the change of electrical signal. By processing the electrical signal, the temperature value collected by the thermistor is judged. NTC thermistors have the characteristics of high precision, high sensitivity, ultra-high temperature, long life, etc., and are widely used in monitoring the heating of electrical equipment and monitoring the ambient temperature.

[0003] NTC thermistors are commonly used in automotive display modules or display modules with very strict environmental requirements. Usually, the monitoring of NTC thermistors in the industry is usually done by monitoring the SMT effect and appearance through AOI after SMT is completed to confirm whether there is damage or cold soldering, or adding a multimeter to measure whether the resistance of the NTC thermistor is within the specification. In this process, manpower needs to be increased and there is a certain risk of leakage in the monitoring of NTC thermistors. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model aims to provide an NTC detection device for testing a liquid crystal display screen.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] An NTC detection device for testing a liquid crystal display screen includes a signal adapter board, wherein the signal adapter board is provided with:

[0007] A first interface, used for electrically connecting to a liquid crystal test box;

[0008] The second interface is used to be electrically connected to the liquid crystal display screen to be tested, and has an NTC1 port electrically connected to the NTC in the liquid crystal display screen;

[0009] The NTC alarm circuit includes a voltage divider circuit composed of a resistor R1 and a resistor R3 connected in parallel, one end of the voltage divider circuit is electrically connected to the power supply port of the first interface, and the other end thereof is respectively connected to the NTC1 port of the second interface and the alarm;

[0010] The alarm is connected to the NTC alarm circuit and outputs an alarm signal when the NTC in the LCD display screen has an open circuit or the voltage value exceeds the set value.

[0011] The end connected to the alarm is grounded through a filter capacitor C1.

[0012] The input voltage of the power supply port is 3.3V.

[0013] The model of the alarm is JS5140 voltage alarm.

[0014] The alarm voltage of the alarm is less than 1.2V or greater than 2.0V.

[0015] The ports of the first interface and the second interface are arranged in one-to-one correspondence except the NTC1 port.

[0016] The first interface, the second interface and the NTC alarm circuit are all directly integrated on the signal adapter board.

[0017] The beneficial effects of the utility model are as follows: by adding the NTC alarm circuit, the NTC alarm is directly added on the basis of the test using the test box, and the function of the NTC thermistor can be monitored while testing the display function of the LCD module, effectively preventing mistakes and avoiding the failure of the LCD module with a failed NTC thermistor to be shipped to the client, causing the customer's entire machine to fail to work properly, affecting customer satisfaction, and reducing manpower at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the connection between a conventional LCD test box and an LCD display.

[0019] Figure 2 This is a schematic diagram of the connection between the liquid crystal test box and the liquid crystal display screen proposed by the utility model.

[0020] Figure 3 This is a circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] like Figure 1As shown, when testing the LCD screen, the conventional LCD test box will only test the functions of the related screen, such as the output backlight voltage, LCD screen working voltage and display signal, but will not detect the internal NTC. This will cause the LCD display module with failed NTC thermistor to be lost after being shipped to the customer, causing the customer's entire machine to not work properly, affecting customer satisfaction. If the NTC test is to be added, the staff is required to lead out the NTC PIN and use a multimeter to test it separately, which increases the test steps and affects production efficiency.

[0024] like Figure 2 and Figure 3 As shown, the utility model discloses an NTC detection device for testing a liquid crystal display screen, which includes a signal adapter board, and the signal adapter board is provided with:

[0025] A first interface, used for electrically connecting to a liquid crystal test box;

[0026] The second interface is used to electrically connect to the liquid crystal display screen to be tested, and the connection between the two is achieved directly by plugging the connector, and it has an NTC1 port electrically connected to the NTC in the liquid crystal display screen;

[0027] The NTC alarm circuit includes a voltage divider circuit composed of a resistor R1 and a resistor R3 connected in parallel, one end of the voltage divider circuit is electrically connected to the power supply port of the first interface, and the other end thereof is respectively connected to the NTC1 port of the second interface and the alarm;

[0028] The alarm is connected to the NTC alarm circuit and outputs an alarm signal when the NTC in the LCD display screen has an open circuit or the voltage value exceeds the set value.

[0029] The first three can be directly integrated into the signal adapter board, while the alarm can be externally connected or directly integrated into the signal adapter board and set up as needed.

[0030] One end connected to the alarm is grounded through a filter capacitor C1, and interference is absorbed by the filter capacitor C1, making the alarm more accurate and avoiding false alarms caused by interference.

[0031] The input voltage of the power supply port is 3.3V, which cooperates with the output end of the NTC of the liquid crystal display screen through a voltage-dividing resistor. When the voltage value is within the set range, it can work normally. When the voltage exceeds the set value, an alarm is issued to effectively detect whether there is an abnormality in the NTC of the current tested liquid crystal display screen.

[0032] The model of the alarm is JS5140 voltage alarm. The alarm voltage of the alarm is less than 1.2V or greater than 2.0V, and the alarm area can be set as needed.

[0033] The ports of the first interface and the second interface are arranged in one-to-one correspondence except the NTC1 port, which meets the normal test use, that is, a single NTC1 port is added without affecting the normal use of the liquid crystal test box.

[0034] The embodiments should not be regarded as limiting the present invention, but any improvements based on the spirit of the present invention should be within the protection scope of the present invention.

Claims

1. An NTC detection device for testing a liquid crystal display screen, characterized in that: It includes a signal adapter board, and the signal adapter board is provided with: A first interface, used for electrically connecting to a liquid crystal test box; The second interface is used to be electrically connected to the liquid crystal display screen to be tested, and has an NTC1 port electrically connected to the NTC in the liquid crystal display screen; The NTC alarm circuit includes a voltage divider circuit composed of a resistor R1 and a resistor R3 connected in parallel, one end of the voltage divider circuit is electrically connected to the power supply port of the first interface, and the other end thereof is respectively connected to the NTC1 port of the second interface and the alarm; The alarm is connected to the NTC alarm circuit and outputs an alarm signal when the NTC in the LCD display screen has an open circuit or the voltage value exceeds the set value.

2. The NTC detection device for testing a liquid crystal display according to claim 1, characterized in that: The end connected to the alarm is grounded through a filter capacitor C1.

3. The NTC detection device for testing a liquid crystal display according to claim 1, characterized in that: The input voltage of the power supply port is 3.3V.

4. The NTC detection device for testing a liquid crystal display according to claim 1, characterized in that: The model of the alarm is JS5140 voltage alarm.

5. The NTC detection device for testing a liquid crystal display screen according to claim 4, characterized in that: The alarm voltage of the alarm is less than 1.2V or greater than 2.0V.

6. The NTC detection device for testing a liquid crystal display screen according to claim 1, characterized in that: The ports of the first interface and the second interface are arranged in one-to-one correspondence except the NTC1 port.

7. The NTC detection device for testing a liquid crystal display screen according to claim 1, characterized in that: The first interface, the second interface and the NTC alarm circuit are all directly integrated on the signal adapter board.

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