Non-inductive electrostatic discharge device and vehicle-mounted human-machine interaction device

Abstract

The embodiment of the application discloses a non-inductive static electricity discharge device and a vehicle-mounted man-machine interaction device. The non-inductive static electricity discharge device is installed on a shell of an electronic device. At least one side edge area of the shell is provided with a mounting groove and a first grounding end. The non-inductive static electricity discharge device comprises: a conductive unit, which is arranged in the mounting groove and connected with the first grounding end. The conductive unit is used for providing a discharge path for a living body when the living body touches the conductive unit. The discharge current of the discharge path is less than the perception current threshold of the living body. The non-inductive static electricity discharge device does not need an additional power supply. The static electricity is discharged non-inductively only by arranging the conductive unit. The structure is simple.

Description

Technical Field

[0001] This invention relates to the field of electrostatic protection technology, and in particular to a non-inductive electrostatic discharge device and a vehicle-mounted human-machine interaction device. Background Technology

[0002] Static electricity is ubiquitous in daily life and industrial production, affecting human comfort and the safety of electronic devices. One of the main sources of static electricity in the human body is the friction and separation between clothing and skin or underwear, a process that conforms to the basic physical laws of triboelectric effect. In dry environments, especially when the relative humidity is below 30%, the triboelectric charge between clothing and the human body is difficult to dissipate through the humid air, leading to a sharp increase in static voltage. Typical measured data show that when the relative humidity is 10%-20%, the static voltage of the human body can reach 15,000V to 35,000V when walking on a synthetic fiber carpet while wearing synthetic fiber clothing; 10,000V to 20,000V when sitting on a polyurethane foam chair while wearing a sweater; and 15,000V to 25,000V when taking off a polyester coat. Even slight friction in a normal sitting posture can generate a static voltage of 3,000V to 8,000V.

[0003] To address the issue of static electricity in the human body, various solutions have been developed in existing technologies. Corded anti-static wrist straps are a widely used electrostatic protection method in industrial environments. Their basic structure consists of a conductive wristband and a grounding cable, with a 1MΩ current-limiting resistor connected in series to ground the human body. However, in automotive driving scenarios, drivers frequently perform actions such as steering, shifting gears, and operating the central control panel, making this solution unsuitable for everyday driving. Cordless anti-static wrist straps utilize the principle of corona discharge to neutralize static electricity. They ionize the air through a high-field region around a pointed conductor, neutralizing the static electricity through an ion flow. However, the discharge efficiency of this solution is significantly affected by the geometry of the pointed end and air humidity, and the initial discharge current is relatively large under high static voltage, still resulting in a sensation of electric shock. Anti-static coating technology involves coating conductive or semi-conductive materials onto surfaces that come into direct contact with the hands or body, such as steering wheels, seat fabrics, and gear shift levers, to reduce surface resistivity, allowing static charges generated by friction to be distributed over a larger area or dissipated through contact conduction. However, this solution's coating wears down significantly over time and lacks a clear grounding discharge path, resulting in inconsistent effectiveness. The in-vehicle ion generator ionizes air molecules using a high-voltage generator to produce N2. + and O2 - The positive and negative ion pairs, represented by the electric field, allow ions to migrate to the surface of a charged body for neutralization. However, this method requires continuous power supply, produces trace amounts of ozone byproducts, and requires a certain response time from power-on to reaching the target ion concentration, making it impossible to achieve instant release upon contact. Summary of the Invention

[0004] This invention provides a non-sensory electrostatic discharge device and an in-vehicle human-machine interaction device to safely discharge carried electrostatic charges in a non-sensory manner.

[0005] According to one aspect of the present invention, a non-inductive electrostatic discharge device is provided, which is mounted on the housing of an electronic device, wherein at least one side edge region of the housing has a mounting groove and a first grounding terminal, the non-inductive electrostatic discharge device comprising: A conductive unit is disposed in the mounting groove and connected to the first grounding terminal; the conductive unit is used to provide a discharge path for the organism when it is touched, and the discharge current of the discharge path is less than the sensing current threshold of the organism.

[0006] Optionally, the conductive unit includes a conductive tube and at least one second grounding terminal, wherein the equivalent resistance value from any position of the conductive tube to the first grounding terminal and / or the second grounding terminal ranges from 100MΩ to 200MΩ.

[0007] Optionally, the volume resistivity range of the conductive tube material is [range missing]. The distance from any position of the conductive tube to the grounding terminal ranges from 10cm to 30cm, and the effective cross-sectional area of ​​the conductive tube ranges from 0.01. Up to 0.02 .

[0008] Optionally, the outer diameter of the conductive tube ranges from 2.0 mm to 5.0 mm, and the thickness of the conductive layer of the conductive tube ranges from 0.1 mm to 0.5 mm. Alternatively, the inner diameter of the conductive tube ranges from 1.0 mm to 4.5 mm, and the thickness of the conductive layer of the conductive tube ranges from 0.1 mm to 0.5 mm; Alternatively, the outer diameter of the conductive tube is in the range of 2.0 mm to 5.0 mm, and the inner diameter of the conductive tube is in the range of 1.0 mm to 4.5 mm.

[0009] Optionally, the conductive tube includes a support layer, a conductive layer, and an insulating layer, wherein the support layer, the conductive layer, and the insulating layer are arranged sequentially from the inside to the outside; The outer diameter of the conductive tube ranges from 2.0 mm to 5.0 mm, the thickness of the insulating layer ranges from 0.05 mm to 0.2 mm, and the thickness of the conductive layer ranges from 0.1 mm to 0.5 mm. Alternatively, the thickness of the conductive layer ranges from 0.1 mm to 0.5 mm, the inner diameter of the conductive tube ranges from 1.0 mm to 4.5 mm, and the thickness of the insulating layer ranges from 0.05 mm to 0.2 mm.

[0010] Optionally, the conductive unit includes a plurality of second grounding terminals, which are equally spaced along the length of the conductive tube.

[0011] Optionally, the surface of the conductive tube protrudes relative to the surface of the housing, and the protrusion ranges from 0.2 to 0.5 mm.

[0012] According to another aspect of the present invention, an in-vehicle human-machine interaction device is provided, including a display screen and a non-sensory electrostatic discharge device as described in any embodiment of the present invention, mounted on the bezel of the display screen.

[0013] Optionally, the display screen bezel includes a metal frame and a first grounding terminal, the metal frame being connected to the first grounding terminal, and the conductive unit being connected to the metal frame.

[0014] Optionally, the mounting slot is located in the metal frame below the display screen.

[0015] The technical solution of this invention involves a conductive unit disposed within the mounting slot of the electronic device's housing and connected to a first grounding terminal. When a living organism carrying static electricity touches the device, the static charge carried by the organism can form a static discharge path through the conductive unit and the first grounding terminal. Furthermore, the discharge current can be controlled below the biological's sensing current threshold, thus completing static discharge while avoiding the electric shock sensation caused by static electricity and improving the user's touch experience. This invention requires no external power supply; it achieves non-intrusive static discharge simply by setting up the conductive unit, resulting in a simple structure.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a non-inductive electrostatic discharge device provided in an embodiment of the present invention; Figure 2 It is an equivalent circuit diagram for the discharge of static electricity from the human body; Figure 3 This is a schematic diagram of the residual static voltage decay curve under different conductor resistances provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the discharge current decay curve under different conductor resistances provided in an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the dual-objective trade-off between the resistance value of the conductive tube and the peak current and discharge time provided in an embodiment of the present invention. Figure 6 This is a cross-sectional schematic diagram of a conductive tube provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of a multi-point grounding electrostatic discharge path provided in an embodiment of the present invention; Figure 8 This is a structural schematic diagram of an in-vehicle human-machine interaction device provided in an embodiment of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] Figure 1 This is a schematic diagram of a non-inductive electrostatic discharge device provided in an embodiment of the present invention. The device is installed on the housing of an electronic device 10. At least one edge region of the housing has a mounting groove 101 and a first grounding terminal, as shown below. Figure 1 As shown, the device includes: a conductive unit 110, which is disposed in the mounting groove 101 and connected to the first grounding terminal; the conductive unit 110 is used to provide a discharge path for the organism when it is touched by the organism, and the discharge current of the discharge path is less than the organism's sensing current threshold.

[0022] The electronic device 110 can be a terminal with a display screen, such as a mobile phone, tablet, or laptop. A non-contact electrostatic discharge device is installed on the edge of the electronic device 10's casing, in the area most frequently touched by the user's fingers during daily use. A mounting groove 101 is provided on the casing edge for embedding the conductive unit 110. A first grounding terminal is located inside the casing, connected to the ground wire of the electronic device 10, and the conductive unit 110 is connected to the first grounding terminal. The conductive unit 110 can be a conductive tube made of a high-resistance conductive material. When high-voltage electrostatic discharge occurs, the high impedance of the conductive unit 110 clamps the instantaneous peak current to the milliampere level. When bio-touch occurs, i.e., a human finger carrying electrostatic discharge touches the conductive unit 110, the equivalent capacitance of the human body and the high resistance inside the conductive unit 110 form a first-order RC discharge circuit, creating an electrostatic discharge path between the human body, the conductive unit 110, and the first grounding terminal. The biological sensing current threshold refers to the minimum current value that, under given conditions, can cause any sensation when current passes through a living organism. It typically ranges from 0.5mA to 1mA and varies from person to person. The biological sensing current threshold can also be called the human body sensing current threshold. By setting the resistance value of the conductive unit 110, the discharge current of the discharge path can be made less than the biological sensing current threshold, so that the biological touch will not feel the electric shock, thus achieving imperceptible discharge.

[0023] The technical solution of this invention involves a conductive unit disposed within the mounting slot of the electronic device's housing and connected to a first grounding terminal. When a living organism carrying static electricity touches the device, the static charge carried by the organism can form a static discharge path through the conductive unit and the first grounding terminal. Furthermore, the discharge current can be controlled below the biological's sensing current threshold, thus completing static discharge while avoiding the electric shock sensation caused by static electricity and improving the user's touch experience. This invention requires no external power supply; it achieves non-intrusive static discharge simply by setting up the conductive unit, resulting in a simple structure.

[0024] In some alternative embodiments of the present invention, the conductive unit includes a conductive tube and at least one second grounding terminal, wherein the equivalent resistance value from any position of the conductive tube to the first grounding terminal or the second grounding terminal ranges from 100MΩ to 200MΩ.

[0025] The equivalent resistance from any point on the conductive tube to the first or second grounding terminal can be simply referred to as the conductive tube resistance. If the conductive tube resistance is too low, the discharge current increases, exceeding the human body's perception current threshold, resulting in pain when touching the tube during discharge. If the conductive tube resistance is too high, the electrostatic discharge path is almost completely blocked, preventing the static electricity from being discharged and causing the charge to remain on the body. A conductive tube resistance ranging from 100MΩ to 200MΩ effectively limits the discharge current to below the human body's perception current threshold, achieving a painless touch, while also effectively discharging the static charge from the body to the ground.

[0026] Specifically, such as Figure 2 As shown, when a human finger is at When in constant contact with the surface of the conductive tube, the equivalent capacitance of the human body Through the resistance of the conductive tube The charge is discharged to the ground. This is a first-order RC discharge process, described by the following differential equation: (1) Initial conditions: ,in This is the initial static voltage of the human body.

[0027] The residual static voltage as a function of time is obtained by solving: (2) Among them, residual static voltage refers to the static voltage remaining on the human body at time t during the discharge process that has not yet been discharged. Time constant. Defined as: (3) The decay function of the discharge current over time: (4) in, This is the peak discharge current, also known as the initial discharge current, which can be understood as the maximum discharge current at the very first instant of discharge. Discharge current. It refers to the magnitude of the current flowing from the human body through the conductive tube to the ground at every moment after the finger touches it.

[0028] The initial discharge current is: (5) The discharge current is less than the human body's current perception threshold, which satisfies: (6) in The threshold for human body to perceive current.

[0029] Taking a static voltage of 15kV for the human body as the worst-case scenario, and substituting it into equations (5) and (6): (7) That is, the resistance of the conductive tube Must be greater than This ensures that the peak current is below the human body's current perception threshold even under the worst operating conditions.

[0030] Assume the safe residual voltage is When the residual voltage is below the safe level, electrostatic discharge has no substantial impact on the human body or electronic equipment. The time required for discharge to the safe voltage can be obtained from equation (2): (8) For the discharge time to be sufficient, it must be much shorter than the typical dwell time of a finger touching the screen a single time. This ensures that all static electricity is discharged in a single touch. (9) The formula for calculating the electrostatic energy stored in the human body is as follows: (10) by , For typical operating conditions, the values ​​of typical operating conditions are substituted into equation (10): ; The worst working conditions Substitute the numerical values ​​into equation (10): ; This energy is the total energy that the conductive tube needs to absorb and dissipate in a single discharge.

[0031] Resistance value of the conductive tube Two objectives must be met: Objective 1 (Security): Minimize ,Right now ; Objective 2 (Performance): Minimize ,Right now ; ; ; There is a contradiction between objective 1 and objective 2; increasing the resistance of the conductive tube... It can reduce peak current but prolong discharge time, and vice versa. Therefore, conductive tubes There exists a feasible interval.

[0032] The lower limit of the resistance of the conductive tube is determined according to formula (5): ; Considering manufacturing tolerances (±20%), temperature drift (resistance variation can reach ±30% within the range of -40°C to +85°C), and aging allowance, a safety factor is used. Therefore, the lower limit of the design resistance of the conductive tube can be determined as follows: ; Determine the upper limit of resistance based on objective 2, using typical operating conditions. , Substituting into equations (8) and (9): ; ; ; Take a conservative margin and assume .

[0033] Therefore, the recommended design range for the resistance of the conductive tube is: (11) Recommended nominal resistance design value for conductive tubes The reasons are as follows: The peak current safety margin is sufficient: ; The peak discharge current under the worst operating conditions is only the current threshold that the human body can perceive. 30%.

[0034] The discharge time under typical operating conditions is: ; The discharge time under typical operating conditions is much shorter than the time a finger remains in contact with the surface. .

[0035] Engineering safety margin quantification: defining the sensing current margin coefficient With discharge time margin coefficient : (12a) (12b) Engineering design requirements (That is, under the worst operating conditions, the peak discharge current does not exceed 1 / 3 of the human body's perceptible current threshold), in the resistance of the conductive tube. , The safety margin is sufficient.

[0036] Figure 3 This is a schematic diagram of the residual static voltage decay curve under different conductor resistances provided in an embodiment of the present invention, where the vertical axis represents the residual static voltage V(t), in V; the horizontal axis represents the discharge time t, in ms; as shown... Figure 3 As shown, multiple curves correspond to the residual static voltage decay curves for different conductor resistances, which can be obtained according to formulas (2) and (3). When the conductor resistance is 10MΩ, 30MΩ, 50MΩ, 100MΩ, 200MΩ, and 500MΩ, the discharge times are 1ms, 3ms, 5ms, 10ms, 20ms, and 50ms, respectively, as shown in Table 1. The initial static voltage is 5000V, and the gray dashed line in the figure represents the safe residual voltage. The baseline. Figure 4This is a schematic diagram of the discharge current decay curve under different conductor resistances provided in an embodiment of the present invention. The initial static voltage is 15kV; the vertical axis represents the discharge current in mA, and the horizontal axis represents the discharge time t in ms; as shown... Figure 4 As shown in Table 1, when the resistance of the conductive tube is 10MΩ, 30MΩ, 50MΩ, 100MΩ, 200MΩ and 500MΩ respectively, the discharge current is 1.5mA, 0.5mA, 0.3mA, 0.15mA, 0.07mA and 0.03mA respectively; it can be obtained according to formula (3) and formula (2). The red dotted line in the figure is the biological perception current threshold, and the light green filled area is the safe area where the human body does not perceive it; this figure is used to characterize the exponential decay characteristics of the discharge current over time under different discharge resistances, and to intuitively compare the influence of different conductive tube resistances on the decay of the discharge current. Figure 5 This is a schematic diagram illustrating the dual-objective trade-off between the resistance value of the conductive tube and the peak current and discharge time in an embodiment of the present invention; the horizontal axis represents the resistance of the conductive tube, in MΩ; the left vertical axis represents the peak discharge current, in mA; the right vertical axis represents the time to discharge to the safe voltage, in ms; as shown... Figure 5 As shown, curve 1 shows the trend of peak discharge current with the resistance of the conductive tube, and curve 2 shows the trend of discharge safety time with the resistance of the conductive tube; the red dashed line in the figure represents the biological sensing current threshold; the light green filled area represents the recommended design range of the conductive tube resistance, 100-200MΩ. Figure 5 This demonstrates the contradictory constraint relationship between the peak discharge current and the discharge time.

[0037] Table 1. Performance Comparison of Resistivity of Different Conductor Tubes Table 1 shows the electrostatic discharge performance of the conductive tube under different resistances, simulating the electrostatic discharge conditions of the human body, and comparing the discharge time, peak current, safe discharge time, and current margin. (The last sentence appears to be incomplete and possibly refers to a different topic.) Under certain conditions, the greater the resistance of the conductive tube, the longer the RC time constant. The larger the value, the higher the peak discharge current under 15kV conditions. The smaller the value, the longer the safe discharge time from 5kV to 100V. The longer the time, the higher the ratio of peak current to threshold current. The lower the resistance, the better. When the resistance of the conductive tube is 30MΩ, the ratio of the peak current to the human body's perceived current threshold is 100%, which can be used as a reference critical resistance value. If the resistance is too small, the discharge peak current will be too large. If the resistance is too large, the electrostatic discharge time will be too long and the discharge capacity will be insufficient.

[0038] In some optional embodiments of the present invention, the volume resistivity of the conductive tube material ranges from [value missing]. The distance from any position of the conductive tube to the first grounding terminal and / or the second grounding terminal ranges from 10cm to 30cm, and the effective cross-sectional area of ​​the conductive tube ranges from 0.01. Up to 0.02 .

[0039] Among them, the volume resistivity of the conductive tube material determines the resistance per unit length of the conductive tube; the distance from any position of the conductive tube to the first grounding terminal and / or the second grounding terminal can be simply referred to as the effective conductive length; the effective cross-sectional area of ​​the conductive tube can be called the effective conductive cross-sectional area; and the resistance of the conductive tube... Based on the volume resistivity of the conductive tube material The effective conductive length L and the effective conductive cross-sectional area A are jointly determined, and follow the macroscopic form of Ohm's law: (13) Among them, the volume resistivity of the conductive tube material The unit is The effective conductive length L can be the effective path length of the current flowing along the length of the conductive tube, that is, the path length measured along the tube from the touch contact point to the nearest grounding terminal, in cm. The effective conductive cross-sectional area A is the effective cross-sectional area of ​​the conductive layer perpendicular to the current direction, in cm. .

[0040] For the conductive layer structure of the pipe wall, let the average diameter of the conductive layer be... If the thickness of the conductive layer is t, then the effective conductive cross-sectional area is: (14) in, The outer diameter of the conductive tube. Let be the inner diameter of the conductive tube, and let be the average diameter, which is the arithmetic mean of the outer and inner diameters of the conductive tube. (15) When the conductive tube is a solid cylindrical structure (with only the outer surface being an insulating layer or conductive material covering the entire cross-section), the cross-sectional area is: (14a) The preferred structure of this scheme is a conductive layer on the pipe wall. Equation (13) is an expression for the cross-sectional area of ​​the annulus, which holds true for any wall thickness t.

[0041] Substituting equation (14) into equation (13), we obtain the equation for the resistance of the conductive tube: (16) The volume resistivity of the conductive tube material is: (17) Assuming the outer diameter of the conductive tube conductive layer thickness : ; ; Assuming the total length of the conductive tube Longest leakage path (When a second grounding terminal is set, the discharge path of the far-end touch point is the entire tube length). Among them, the longest discharge path refers to the longest physical distance along the tube body from any finger touch position on the conductive tube to the nearest grounding terminal.

[0042] Substituting into equation (16), if the volume resistivity of the selected conductive tube material is... The resistance of the conductive tube is: ; This value is far beyond the recommended range (100-200 MΩ), indicating that the resistivity of the conductive tube material must be reduced to an even lower level when a second grounding terminal is installed. If the bulk resistivity of the conductive tube material is adjusted... The resistance of the conductive tube is: ; It is still slightly above the upper limit of the recommended range (200MΩ), and can be further optimized by the following measures: shortening the longest discharge path. ; Reduce the volume resistivity of the conductive tube material Increase the thickness t of the conductive layer.

[0043] If the conductive unit is only installed on the lower side of the electronic device's casing, the longest discharge path should be selected. The volume resistivity of conductive tube material : ; The solution is close to the lower limit of the recommended range and is therefore feasible. Adjusting the volume resistivity of the conductive tube material is another option. to The resistance of the conductive tube can be obtained. It is located in the center of the recommended range.

[0044] Therefore, the distance from any position of the conductive tube to the first grounding terminal and / or the second grounding terminal ranges from 10cm to 30cm, and the volume resistivity of the conductive tube material ranges from [missing value]. The effective cross-sectional area of ​​the conductive tube is in the range of 0.01. Up to 0.02 Based on the volume resistivity of the conductive tube material, any one of the following can be selected: carbon black-filled silicone rubber, carbon fiber-filled polymer, metal oxide-coated conductive material, or conductive polymer material.

[0045] Preferably, the conductive tube is made of carbon black-filled silicone rubber, with a bulk resistivity of... The carbon black content can be precisely controlled within a certain range, and the silicone rubber substrate performs excellently in automotive environments (temperature resistance from -50℃ to +200℃, UV resistance, and ozone resistance).

[0046] In some optional embodiments of the present invention, the outer diameter of the conductive tube ranges from 2.0 mm to 5.0 mm, and the thickness of the conductive layer of the conductive tube ranges from 0.1 mm to 0.5 mm. Alternatively, the inner diameter of the conductive tube ranges from 1.0 mm to 4.5 mm, and the thickness of the conductive layer of the conductive tube ranges from 0.1 mm to 0.5 mm; Alternatively, the outer diameter of the conductive tube may range from 2.0 mm to 5.0 mm, and the inner diameter of the conductive tube may range from 1.0 mm to 4.5 mm.

[0047] The inner diameter of the conductive tube can be determined based on the outer diameter of the conductive tube and the thickness of the conductive layer of the conductive tube. Similarly, the outer diameter of the conductive tube can be determined based on the inner diameter of the conductive tube and the thickness of the conductive layer of the conductive tube. The thickness of the conductive layer of the conductive tube can also be determined based on the outer diameter of the conductive tube and the inner diameter of the conductive tube. Thus, the average diameter can be determined according to formula (15), and the effective conductive cross-sectional area can be determined according to formula (14).

[0048] Figure 6 This is a schematic cross-sectional view of a conductive tube provided in an embodiment of the present invention, such as... Figure 6 As shown, in some optional embodiments of the present invention, the conductive tube includes a support layer 1113, a conductive layer 1112, and an insulating layer 1111. The support layer 1113, the conductive layer 1112, and the insulating layer 1111 are arranged sequentially from the inside to the outside. The outer diameter of the conductive tube ranges from 2.0 mm to 5.0 mm, the thickness of the insulating layer ranges from 0.05 mm to 0.2 mm, and the thickness of the conductive layer ranges from 0.1 mm to 0.5 mm. Alternatively, the thickness of the conductive layer may range from 0.1 mm to 0.5 mm, the inner diameter of the conductive tube may range from 1.0 mm to 4.5 mm, and the thickness of the insulating layer may range from 0.05 mm to 0.2 mm.

[0049] The conductive tube comprises a support layer 1113, a conductive layer 1112, and an insulating layer 1111. The support layer 1113 is a non-conductive substrate framework that does not participate in electrostatic discharge and only provides structural support. The discharge current of human body static electricity flows through the conductive layer 1112. The insulating layer 1111 wraps around the conductive layer, and it is the insulating layer 1111 that the human hand actually contacts. The insulating layer 1111 is extremely thin, and electrostatic discharge is achieved through capacitive coupling. Human body static electricity is coupled to the inner conductive layer 1112 through the coupling effect of the insulating layer 1111, and then flows to the grounding terminal for discharge through the conductive layer 1112. The inner diameter of the conductive tube can be determined based on its outer diameter, the thickness of the insulating layer, and the thickness of the conductive layer; similarly, the outer diameter of the conductive tube can be determined based on its inner diameter, the thickness of the insulating layer, and the thickness of the conductive layer. When the human body carries static electricity, touching the outermost insulating layer 1111 with a human hand causes the static electricity to capacitively couple to the middle conductive layer 1112 through the thin insulating layer. The conductive layer 1112 flows along the tube and is discharged to the system ground at the first grounding terminal and / or the second grounding terminal. The discharge current is limited by the high resistance of the conductive layer 1112 to below the biological perception current threshold, thus achieving a non-sensory experience.

[0050] As shown in Table 2, the structural dimensions of the conductive tube are as follows: the recommended outer diameter is 3.0 mm, with a range of 2.0-5.0 mm; the recommended inner diameter is 2.4 mm, with an allowable range of 1.0-4.5 mm; the recommended conductive layer thickness is 0.3 mm, with a range of 0.1-0.5 mm; the average diameter of the conductive layer is calculated from the outer and inner diameters, and the recommended value is 2.7 mm; the recommended total length of the conductive tube is 80 cm, with a range of 20-120 cm; the recommended effective conductive length is 20 cm, with a range of 10-30 cm. The effective conductive length can also be referred to as the touch segment length.

[0051] Table 2 Parameter Range of Conductive Pipes The effective conductive length is the distance from any position of the conductive tube to the first grounding terminal and / or the second grounding terminal.

[0052] In some optional embodiments of the present invention, the conductive unit has a plurality of second grounding terminals, which are arranged at equal intervals along the length of the conductive tube.

[0053] The conductive unit includes multiple second grounding terminals. Along the length of the conductive tube, the installation distance between each second grounding terminal is equal, i.e., they are arranged at equal intervals. For example, a single conductive tube with a total length of 80cm can be equipped with three second grounding terminals arranged at equal intervals, dividing the conductive tube into multiple segments. This ensures that the distance along the tube path from any touch point on the conductive tube to the nearest grounding terminal is controlled within 10cm to 30cm, thereby achieving non-inductive electrostatic discharge.

[0054] If multiple second grounding terminals are equally spaced along the length of the conductive tube, the maximum discharge path from any touch point on the conductive tube to the nearest grounding point is shortened to: (18) in, The number of second grounding terminals. The total length of the conductive tube ranges from 20cm to 120cm, with a recommended value of 80cm. The corresponding maximum resistance of the conductive tube is: (19) The volume resistivity of conductive pipe material With geometric parameters remaining constant, the maximum discharge time is: (20) Number of second grounding terminals Optimization criteria: Select criteria that satisfy The minimum integer value is used to minimize the manufacturing complexity of the second grounding terminal while ensuring discharge performance.

[0055] Multiple second grounding terminals are electrically connected to the first grounding terminal of the electronic device via conductive adhesive, metal elastic contacts, or conductive screws, in order to For reference, the requirements are as follows: (Right now This ensures that the grounding connection does not have a measurable impact on discharge performance. The conductive adhesive can be silver-filled conductive silicone. The silver-doped conductive silicone is applied to the end of the conductive tube, pressed against the shell surface, and after curing, it achieves mechanical fixation through adhesive bonding and electrical grounding through the conductive path formed by the silver powder within the adhesive. A beryllium copper / stainless steel spring is installed at the end of the conductive tube, relying on its own elasticity to press against the shell, achieving grounding through metal-to-metal pressure contact. A metal threaded bushing is embedded at the end of the conductive tube, and a conductive screw passes through the bushing and is tightened onto the shell, forming a conductive path between the screw and the conductive tube.

[0056] Figure 7 This is a schematic diagram of a multi-point grounding electrostatic discharge path provided by an embodiment of the present invention, such as... Figure 7 As shown, the conductive unit 110 is provided with multiple second grounding terminals, dividing the conductive unit 110 into multiple segments; touch point A and touch point B are the human touch positions. The curve in the figure shows the discharge path of static electricity flowing from the touch point to the nearest grounding point. By shortening the static electricity discharge path through multiple grounding points, the residual static electricity discharge capability of the conductive tube is improved.

[0057] In some alternative embodiments of the present invention, the surface of the conductive tube protrudes relative to the surface of the housing, and the amount of protrusion ranges from 0.2 mm to 0.5 mm.

[0058] The conductive tube is installed in the mounting groove, and the protrusion is defined as the height of the conductive tube surface above the surface of the shell. The protrusion ranges from 0.2 to 0.5 mm, which can provide tactile feedback to the fingers without affecting the appearance.

[0059] Figure 8 This is a structural schematic diagram of an in-vehicle human-machine interaction device provided in an embodiment of the present invention, as shown below. Figure 8 As shown, the in-vehicle human-machine interaction device includes a display screen and a non-sensitive electrostatic discharge device, as described in any embodiment of the present invention, mounted on the bezel of the display screen.

[0060] The display screen can be any one of the following: a central control display screen, an instrument panel display screen, a passenger-side display screen, or a rear-seat entertainment display screen. Figure 8 As shown, the non-contact electrostatic discharge device can be installed on each bezel of the display screen, or on one side of the display screen, such as the bottom bezel. Static electricity is easily generated by the human body in a vehicle environment. When drivers and passengers touch the bezel of the central control display screen with their fingers, the non-contact electrostatic discharge device discharges the static electricity from their bodies, limiting the discharge current to below the human body's perceptible current threshold.

[0061] In some alternative embodiments of the present invention, the display screen bezel includes a metal frame and a first ground terminal, the metal frame being connected to the first ground terminal, and the conductive unit being connected to the metal frame.

[0062] The display screen bezel includes a metal frame and a first grounding terminal. The metal frame is electrically connected to the first grounding terminal. The first grounding terminal is ultimately connected to the vehicle's overall system ground. The conductive unit of the non-inductive electrostatic discharge device is directly electrically connected to the metal frame, so that the conductive unit can be conducted to the first grounding terminal through the metal frame, forming an electrostatic discharge path.

[0063] In some alternative embodiments of the invention, the mounting slot is located in the metal frame below the display screen.

[0064] The lower part of the vehicle display screen is the lower bezel metal frame area that is easily touched by the driver's hand. A mounting slot is located on the lower side of the display screen, and a conductive tube is embedded inside the mounting slot. For example... Figure 8 As shown, when static electricity is generated by the human body or the external environment and comes into contact with the touch area or the frame of the display screen, the static electricity will be directly conducted to the ground through the conductive units 110 arranged around the perimeter; the static electricity is discharged, preventing the static electricity from breaking down the internal circuit of the display screen in the middle, thus achieving electrostatic protection.

[0065] The non-inductive electrostatic discharge device must meet the durability verification requirements of the vehicle environment. This involves sequentially conducting a high-temperature storage test at 85℃ for 1000 hours, a low-temperature storage test at -40℃ for 1000 hours, a temperature and humidity cycle test of -40℃ to 85℃ with 85% relative humidity for 1000 cycles, a 1000-hour xenon lamp ultraviolet aging test under ISO 4892-2 standard, a random vibration test under ISO 16750-3 standard, and a 96-hour neutral salt spray test. Acceptance criteria include that after the tests, the conductive tube shows no cracks, no delamination, no breakage or loosening, no corrosion, the relative change in conductive tube resistance does not exceed 30%, and the grounding contact resistance does not significantly increase, ensuring stable and reliable electrostatic discharge performance throughout the vehicle's entire lifespan.

[0066] Failure Mode and Effects Analysis (FMEA) was conducted on the non-inductive electrostatic discharge device. When mechanical breakage of the conductive tube occurs, the discharge path tends to be interrupted. The impact of this failure can be reduced by designing multiple grounding points, and a pull-out force test of more than 50N is set at the factory for control. If the grounding connection becomes loose, it will cause an increase in the equivalent resistance of the conductive tube and a longer electrostatic discharge time. Metal elastic contact pieces can be used to achieve gap self-compensation and mitigate this failure risk. Aging of the conductive layer will cause material resistivity drift. Accelerated aging tests are needed to ensure that the annual resistance drift of the conductive tube is less than 20%. Surface oil and sweat contamination will increase the surface contact resistance. This can be protected by applying an oleophobic coating with a contact angle greater than 110° to ensure that the device maintains its electrostatic discharge capability as much as possible under various failure conditions.

[0067] In some optional embodiments of the present invention, the conductive tube is mounted on the display screen bezel (non-touch area) and is isolated from the capacitive sensing layer of the touch panel by the following: display screen glass thickness. Air gap Horizontal distance from the conductive tube to the edge of the touch panel The coupling capacitance is extremely small. This design does not interfere with touch signals. The conductive tube operates in a purely passive mode, and its response characteristics to external electromagnetic fields can be evaluated using an electrically small antenna model. In the automotive EMI band (150kHz-2.5GHz), the high resistance of the conductive tube results in an extremely low quality factor, rendering it unsuitable for effective radiation or reception.

[0068] The energy dissipated in a single electrostatic discharge in the conductive tube is E. The temperature rise of the conductive tube is calculated using the heat balance equation: ;(twenty one) Where m is the mass of the conductive tube. This is the specific heat capacity of the conductive tube material.

[0069] Taking silicone rubber substrate as an example: The mass of the conductive tube (assuming an outer diameter of 3mm, an inner diameter of 2.4mm, a total length of 80cm, and a density) is given. ): ; Maximum single energy release : ; Considering continuous touch scenarios, let the touch frequency be set. That is, touching once per second, the steady-state thermal equilibrium condition is: ;(twenty two) Where h is the natural convection heat transfer coefficient (for still air). S is the outer surface area of ​​the tube: ; exist At that time, steady-state temperature rise This can be ignored.

[0070] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0071] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A non-inductive electrostatic discharge device, characterized in that, Mounted on the housing of an electronic device, the housing having a mounting groove and a first grounding terminal on at least one side edge region, the non-inductive electrostatic discharge device includes: A conductive unit is disposed in the mounting groove and connected to the first grounding terminal; the conductive unit is used to provide a discharge path for the organism when it is touched, and the discharge current of the discharge path is less than the sensing current threshold of the organism.

2. The non-inductive electrostatic discharge device according to claim 1, characterized in that, The conductive unit includes a conductive tube and at least one second grounding terminal, and the equivalent resistance value from any position of the conductive tube to the first grounding terminal and / or the second grounding terminal ranges from 100MΩ to 200MΩ.

3. The non-inductive electrostatic discharge device according to claim 2, characterized in that, The volume resistivity range of the conductive tube material is: The distance from any position of the conductive tube to the first grounding terminal and / or the second grounding terminal ranges from 10cm to 30cm, and the effective cross-sectional area of ​​the conductive tube ranges from 0.

01. Up to 0.02 .

4. The non-inductive electrostatic discharge device according to claim 3, characterized in that, The outer diameter of the conductive tube ranges from 2.0 mm to 5.0 mm, and the thickness of the conductive layer of the conductive tube ranges from 0.1 mm to 0.5 mm. Alternatively, the inner diameter of the conductive tube ranges from 1.0 mm to 4.5 mm, and the thickness of the conductive layer of the conductive tube ranges from 0.1 mm to 0.5 mm; Alternatively, the outer diameter of the conductive tube is in the range of 2.0 mm to 5.0 mm, and the inner diameter of the conductive tube is in the range of 1.0 mm to 4.5 mm.

5. The non-inductive electrostatic discharge device according to claim 2, characterized in that, The conductive tube includes a support layer, a conductive layer, and an insulating layer, which are arranged sequentially from the inside to the outside. The outer diameter of the conductive tube ranges from 2.0 mm to 5.0 mm, the thickness of the insulating layer ranges from 0.05 mm to 0.2 mm, and the thickness of the conductive layer ranges from 0.1 mm to 0.5 mm. Alternatively, the inner diameter of the conductive tube ranges from 1.0 mm to 4.5 mm, the thickness of the insulating layer ranges from 0.05 mm to 0.2 mm, and the thickness of the conductive layer ranges from 0.1 mm to 0.5 mm.

6. The non-inductive electrostatic discharge device according to claim 2, characterized in that, The conductive unit includes a plurality of second grounding terminals, which are equally spaced along the length of the conductive tube.

7. The non-inductive electrostatic discharge device according to claim 2, characterized in that, The surface of the conductive tube protrudes from the surface of the housing, and the protrusion ranges from 0.2 to 0.5 mm.

8. A vehicle-mounted human-machine interaction device, characterized in that, Includes a display screen and a non-sensitive electrostatic discharge device as described in any one of claims 1 to 7, mounted on the bezel of the display screen.

9. The vehicle-mounted human-machine interaction device according to claim 8, characterized in that, The display screen bezel includes a metal frame and a first grounding terminal. The metal frame is connected to the first grounding terminal, and the conductive unit is connected to the metal frame.

10. The vehicle-mounted human-machine interaction device according to claim 9, characterized in that, The mounting slot is located on the metal frame below the display screen.

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