Anti-electromagnetic interference liquid crystal display screen circuit system

Abstract

The utility model relates to the technical field of liquid crystal screens, in particular to an anti-electromagnetic interference liquid crystal display screen circuit system which comprises a liquid crystal display screen circuit, a liquid crystal shell and a communication interface shell which are connected with one another, and a power supply end, an enabling end and an RGB (red, green and blue) signal end of a liquid crystal display screen and the liquid crystal display screen circuit are connected with a digital GND (ground) through wires. The digital GND is connected with the 0V circuit; a first discharge tube is arranged between the power supply end, the enabling end and the digital GND and between the RGB signal end and the digital GND; the liquid crystal shell and the communication interface shell are respectively connected with a power supply protection ground wire terminal through wires, and the power supply protection ground wire terminal is connected with the 0V line through a second discharge tube. According to the system, interference signals on the GND can be discharged in time, and the phenomenon of blurred screen or splash screen is avoided; and electromagnetic interference can be successfully introduced into the ground in a small-impedance loop by bypassing a sensitive device, so that the stable operation of the whole system is ensured.

Description

Technical Field

[0001] This utility model relates to the field of liquid crystal display technology, and in particular to a liquid crystal display circuit system that is resistant to electromagnetic interference. Background Technology

[0002] Existing LCDs typically use TFT screens, which have high ESD requirements. The discharge circuits of existing communication interfaces mostly use RC connections or TVS diodes with capacitors to connect the metal casing to the internal GND. Static electricity generated at the interface is injected into the internal digital GND through RC (10M / 1nF) or TVS diodes and capacitors, and then discharged to the 0V line through the capacitor next to the isolation power supply. The LCD screen ground is directly connected to the internal GND.

[0003] Because of their large size, LCD screens are susceptible to interference from ambient radiation, leading to charge accumulation. This charge typically travels to the internal digital ground plane (GND), causing system interference. Specifically, the currently used RC and diode-capacitor solutions have the following problems: They introduce electrostatic interference into the internal GND because the internal GND is connected to the LCD screen's ground, and the 0V discharge capacitor is far from the interference injection point. Furthermore, the interference signal attenuates as it propagates through the ground within the board, failing to dissipate the interference signal on the GND in time. This results in simultaneous interference to the internal signals of the LCD screen (power supply, enable, and RGB signals), causing screen flickering or distortion.

[0004] Therefore, the leakage path of the existing solution will inevitably pass through some components, which will inevitably affect some of their functions. For touch screens, the most direct impact is on the display.

[0005] Therefore, a new technical solution is urgently needed to solve the above-mentioned technical problems. Utility Model Content

[0006] The purpose of this utility model is to overcome the problems of the prior art and provide an anti-electromagnetic interference liquid crystal display circuit system to solve the technical problems of the prior art being unable to discharge the interference signal on GND in time, which causes the signals inside the liquid crystal screen (power supply, enable, RGB signal) to be interfered with at the same time, resulting in screen distortion or flickering; and the existing discharge path passing through some components, which will affect some of their functions.

[0007] The above objectives are achieved through the following technical solutions:

[0008] An electromagnetic interference-resistant liquid crystal display circuit system includes an interconnected liquid crystal screen circuit, a liquid crystal housing, and a communication interface housing. The power supply terminal, enable terminal, RGB signal terminal of the liquid crystal screen, and the liquid crystal screen circuit are connected to a digital GND via wires, and the digital GND is connected to the 0V line. A first discharge tube is also provided between the power supply terminal, the enable terminal, the RGB signal terminal, and the digital GND. The liquid crystal housing and the communication interface housing are respectively connected to a power protection ground terminal via wires, and the power protection ground terminal is connected to the 0V line via a second discharge tube.

[0009] Furthermore, a capacitor is provided between the digital GND and the 0V line.

[0010] Furthermore, the capacitor is a 2200pF capacitor.

[0011] Furthermore, the first discharge tube is model JEB05C.

[0012] Furthermore, the second discharge tube is model P3100SC.

[0013] Furthermore, the communication interface housing is a metal housing.

[0014] This invention provides an anti-electromagnetic interference liquid crystal display circuit system. By connecting the power supply protective ground terminal FG to the liquid crystal screen casing, it can effectively reduce the impact of spatial radiation on the liquid crystal. According to the connection structure provided by this system, interference signals on GND can be discharged in a timely manner, avoiding screen flickering or distorted display phenomena. Furthermore, it successfully bypasses sensitive components, introducing electromagnetic interference into the ground through a low-impedance loop, ensuring the stable operation of the entire system. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the electromagnetic interference resistant liquid crystal display circuit system described in this utility model. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0017] like Figure 1As shown, this solution provides an electromagnetic interference-resistant liquid crystal display circuit system, including an interconnected liquid crystal screen circuit, a liquid crystal housing, and a communication interface housing. The power supply terminal (3.3V), enable terminal (EN), RGB signal terminal (IO), and the liquid crystal screen circuit are connected to a digital GND via wires. The digital GND is connected to the 0V line. A first discharge tube is also provided between the power supply terminal (3.3V), the enable terminal (EN), the RGB signal terminal (IO), and the digital GND. The first discharge tube quickly responds to interference signals to prevent serious impact on the internal structure of the liquid crystal screen. The liquid crystal housing and the communication interface housing are respectively connected to the power protection ground terminal (FG) via wires, forming a discharge path independent of the internal GND. The power protection ground terminal (FG) is connected to the 0V line via a second discharge tube. The second discharge tube can accurately identify high-voltage pulse interference on the FG line and discharge most of the electromagnetic interference from the FG line to the 0V line.

[0018] It should be noted that the communication interface housing in this embodiment is a metal housing to enable electrical connection.

[0019] As an optimization of this solution, a capacitor is provided between the digital GND and the 0V line to form an isolation circuit for filtering out high-frequency noise.

[0020] Specifically, the capacitor is a 2200pF capacitor. The main function of the 2200pF capacitor in this system is to suppress electromagnetic interference through high-frequency filtering and ground potential communication, while balancing the AC and DC signals in the circuit.

[0021] In this embodiment, the first discharge tube is model JEB05C, with a discharge threshold of 5V, a response time of ≤1ns, a surface mount package, and is connected in parallel between the signal line and digital GND, with a line impedance of ≤0.05Ω. This discharge tube has a low discharge threshold (5V) and can quickly respond to interference signals, preventing serious impact on the internal structure of the LCD screen.

[0022] In this embodiment, the second discharge tube is model P3100SC, with a discharge threshold of 3000V and a response time of ≤10ns. Because the discharge tube has a high discharge voltage and fast response speed, it can accurately identify high voltage pulse interference on the FG line and discharge most of the electromagnetic interference from the FG line to the 0V line.

[0023] As a further optimization of this embodiment, this solution also provides two filtering schemes, corresponding to the cases where FG is connected to external ground and the cases where it is not connected, as follows:

[0024] When connected to ground, this solution can directly guide interference signals to ground when connected to FG, and at the same time guide interference from the input 0V line to ground through P3100SC.

[0025] Without grounding, all interference signals will be absorbed by 0V, and most electromagnetic signals will also be absorbed.

[0026] The above description is only for illustrating the embodiments of this utility model and is not intended to limit this utility model. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An electromagnetic interference resistant liquid crystal display screen circuit system comprising a liquid crystal screen circuit, a liquid crystal housing and a communication interface housing connected to each other, characterized in that, The power supply end 3.3V, the enable end (EN), the RGB signal end (IO) of the liquid crystal display screen and the liquid crystal screen circuit are connected with the digital GND through wires, and the digital GND is connected with the 0V line; the power supply end 3.3V, the enable end (EN) and the RGB signal end (IO) are further provided with the first discharge tube between the digital GND; the liquid crystal shell and the communication interface shell are respectively connected with the power supply protection ground terminal (FG) through wires, and the power supply protection ground terminal (FG) is connected with the 0V line through the second discharge tube.

2. The electromagnetic interference resistant liquid crystal display screen circuit system of claim 1, wherein, The digital GND and the 0V line are provided with a capacitor.

3. The electromagnetic interference resistant liquid crystal display screen circuit system of claim 2, wherein, The capacitor is a 2200pF capacitor.

4. The electromagnetic interference resistant liquid crystal display screen circuit system of claim 1 or 2, wherein, The model of the first discharge tube is JEB05C.

5. The circuit system of claim 4 or the liquid crystal display screen against electromagnetic interference, characterized in that, The model of the second discharge tube is P3100SC.

6. The electromagnetic interference resistant liquid crystal display screen circuit system of claim 1, wherein, The communication interface shell is a metal shell.

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