PCB capacitive sensor and smart door lock control switch

Abstract

The invention discloses a PCB capacitance sensor and an intelligent door lock control switch, wherein the PCB capacitance sensor comprises an induction layer, a dielectric layer and a protective layer stacked up and down, the induction layer and the protective layer are respectively located at the upper and lower sides of the dielectric layer, the dielectric layer comprises a substrate of a non-conductive dielectric material; the induction layer comprises a conductive metal induction sheet laid on the substrate for generating an induction capacitance; the protective layer comprises a signal shielding net laid on the substrate for preventing interference signals from entering the induction layer; the PCB capacitance sensor with the above structure effectively reduces the volume of the sensor, thereby reducing the internal space requirement for a door handle, providing a more reasonable and wider design space for the door handle, so that the size of the door handle can be made more delicate and compact; in addition, since the PCB capacitance sensor is provided with a protective layer for preventing interference signals, the signal-to-noise ratio of the PCB capacitance sensor can be effectively improved, thereby making the touch sensing distance longer and effectively reducing the probability of false triggering.

Description

Technical Field

[0001] The present invention relates to the technical field of touch-type electrothermal sensors, and in particular to a PCB capacitance sensor and an intelligent door lock control switch for a virtual key of an automobile. Background Art

[0002] With the development of technology, car smart keys have gradually transformed from traditional physical keys to virtual keys. The carriers of virtual keys are usually mobile phones, bracelets, watches and other products. Users no longer need to carry physical keys, they only need to activate the virtual key on the mobile phone APP to unlock and start the vehicle, and it has more functions than physical keys, such as sharing.

[0003] At present, common virtual keys are divided into the following categories based on radio frequency signals: cloud keys, Bluetooth keys, NFC keys, UWB keys, etc. Based on product form, they are divided into: smart wearables such as mobile phones, watches, bracelets, glasses, etc.

[0004] The car door lock compatible with the virtual key is generally also equipped with a touch switch. When an electronic terminal such as a mobile phone is close to the car door, after identity authentication, the car door lock control system sends an unlock signal. At this time, the door lock is still in a closed state. When the user's palm approaches or touches the door handle, the touch switch sends an unlock signal, and the car door lock opens. Figure 8 and Fig. 9 At present, the touch sensor of the door handle 1' on the car is mainly a metal plug-in 2', which has a poor signal-to-noise ratio and a short sensing distance. In addition, since the metal plug-in 2' is relatively large in size, it is necessary to design a suitable installation space for it on the door handle 1', thereby limiting the space design of the door handle 1'. Moreover, this metal plug-in type of touch sensor is easily affected by factors such as rain, and the misrecognition rate is relatively high. Summary of the invention

[0005] The object of the present invention is to solve the above-mentioned technical problems and provide a PCB capacitive sensor with small size, good anti-interference performance and longer touch sensing distance.

[0006] Another object of the present invention is to provide an intelligent door lock control switch for a car virtual key to reduce the impact on the space design of the car door handle and improve the anti-interference performance and sensing distance.

[0007] In order to achieve the above-mentioned purpose, the present invention discloses a PCB capacitance sensor, which includes a sensing layer, a dielectric layer and a protective layer stacked together, the sensing layer and the protective layer are respectively located on the upper and lower sides of the dielectric layer, the dielectric layer includes a non-conductive dielectric material substrate; the sensing layer includes a conductive metal sensing sheet laid on the substrate for generating a sensing capacitor; the protective layer includes a signal shielding net laid on the substrate for preventing interference signals from entering the sensing layer.

[0008] Preferably, the sensor sheet is made of copper.

[0009] Preferably, the signal shielding mesh is a copper wire mesh.

[0010] Preferably, the duty cycle of the copper wire grid is 1 / 4 to 1 / 3.

[0011] Preferably, the substrate comprises one or more layers of PP material medium.

[0012] Preferably, the thickness of the substrate is d, d≥1.2 mm.

[0013] Preferably, the length and width of the sensor sheet are respectively a, b, a≥10mm, b≥13mm.

[0014] The present invention also discloses an intelligent door lock control switch for a virtual key of a car, which includes a PCB capacitive sensor as described above for detecting a door opening touch signal and is arranged in a door handle of the car, wherein the door handle is a non-conductive material body.

[0015] Preferably, an electronic functional device is further provided on the dielectric layer at a side where the sensing sheet and / or the signal shielding net are located, and the electronic functional device is electrically connected to the sensing sheet via a signal line.

[0016] Preferably, a functional circuit board is further provided in the door handle, and electronic functional devices are provided on the functional circuit board, and the electronic functional devices are electrically connected to the sensor sheet via a signal line.

[0017] When the smart door lock control switch for a virtual key of a car disclosed in the present invention is installed on a car, the following beneficial technical effects are achieved:

[0018] 1. The touch signal of the door handle is detected by a PCB capacitive sensor. The PCB capacitive sensor includes three stacked material layers, namely, a sensing layer, a dielectric layer, and a protective layer. Compared with the touch sensor of the traditional metal plug-in structure, the volume of the sensor is effectively reduced, thereby reducing the internal space requirement of the door handle, providing a more reasonable and wider design space for the door handle (especially the hidden door handle), so that the size of the door handle can be made more delicate and compact;

[0019] 2. Since a protective layer is provided on the PCB capacitive sensor to block interference signals, the signal-to-noise ratio of the PCB capacitive sensor can be effectively improved, thereby making the touch sensing distance longer and effectively reducing the probability of false triggering. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the installation structure decomposition of the intelligent door lock control switch in an embodiment of the present invention.

[0021] Figure 2 for Figure 1 Schematic diagram of the longitudinal section of the installation structure of the intelligent door lock control switch.

[0022] Figure 3 It is a schematic diagram of the three-dimensional structure of the PCB capacitive sensor in one viewing angle in an embodiment of the present invention.

[0023] Figure 4 FIG. 1 is a schematic diagram of the three-dimensional structure of the PCB capacitive sensor in another embodiment of the present invention from another perspective.

[0024] Figure 5 for Figure 3 Schematic diagram of the exploded view of the PCB capacitive sensor.

[0025] Figure 6 The figure is a schematic diagram of the electrical connection structure of the intelligent door lock control switch in one embodiment of the present invention.

[0026] Figure 7 Schematic diagram of the electrical connection structure of the smart door lock control switch in another embodiment of the present invention.

[0027] Figure 8 The present invention is a schematic diagram of the exploded installation structure of a door handle touch control switch in the prior art.

[0028] Fig. 9 for Figure 8 Schematic diagram of the longitudinal section of the installation structure of the touch control switch in the door handle of the vehicle. DETAILED DESCRIPTION

[0029] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0030] This embodiment discloses a smart door lock control switch for a car virtual key, which is used to cooperate with the virtual key to control the opening and closing of the car door lock. Figure 1 and Figure 2The smart door lock control switch includes a PCB capacitance sensor 2 arranged in a door handle 1 of a car for detecting a door opening touch signal. The door handle 1 is a non-conductive material. When the PCB capacitance sensor 2 detects a touch signal of the door handle 1, the smart door lock controller sends an unlocking signal to open the door lock. In this embodiment, Figures 3 to 5 PCB capacitance sensor 2 includes a sensing layer P1, a dielectric layer P0 and a protective layer P2 stacked up and down. The sensing layer P1 and the protective layer P2 are respectively located on the upper and lower sides of the dielectric layer P0. The dielectric layer P0 includes a non-conductive dielectric material substrate 21, which provides support for the sensing layer P1 and the protective layer P2 and ensures that there is a stable dielectric constant between the sensing layer P1 and the protective layer P2. The sensing layer P1 includes a conductive metal sensing sheet 20 laid on the dielectric layer P0, which is used to generate an inductive capacitance, that is, when a finger approaches the door handle 1, an inductive capacitance is generated between the palm and the sensing sheet 20. The protective layer P2 includes a signal shielding net 22 laid on the substrate 21 to prevent interference signals from entering the sensing layer P1.

[0031] In the above embodiment, since the PCB capacitive sensor 2 for detecting touch signals includes three stacked material layers, namely the sensing layer P1, the dielectric layer P0 and the protective layer P2, compared with the traditional metal plug-in 2' (such as Figure 8 and Fig. 9 ) structure, the volume of the sensor is effectively reduced, thereby reducing the internal space requirement of the door handle 1, providing a more reasonable and wider design space for the door handle 1 (especially the hidden door handle), so that the size of the door handle 1 can be made more delicate and compact. Furthermore, due to the provision of the protective layer P2, the signal-to-noise ratio of the PCB capacitive sensor 2 can be effectively improved, thereby making the touch sensing distance longer and effectively reducing the probability of false triggering.

[0032] Specifically, the induction sheet 20 is a copper sheet laid on the dielectric layer P0, and the signal shielding net 22 is a copper wire mesh laid on the dielectric layer P0. Preferably, the duty ratio of the copper wire mesh is 1 / 4 to 1 / 3, preferably 1 / 3, and the duty ratio is the ratio of the solid line area to the empty area when the solid line and the empty area are evenly distributed.

[0033] More specifically, the substrate 21 located in the dielectric layer P0 includes one or more layers of PP material dielectric. Preferably, the thickness of the substrate 21 is d, d≥1.2 mm.

[0034] In addition, in order to effectively ensure the sensing strength of the PCB capacitance sensor 2, the length and width of the sensing sheet 20 are respectively a and b, where a≥10 mm and b≥13 mm.

[0035] like Figure 6 and Figure 7In specific use, since it is necessary to configure the PCB capacitance sensor 2 with corresponding electronic functional devices 3 (such as sensing IC and resistor, etc.) and signal lines 4, the present invention discloses the following two implementation modes of the intelligent door lock control switch:

[0036] Implementation method 1: Figure 6 , the electronic functional device 3 is arranged on the side where the sensing sheet 20 and / or the signal shielding net 22 are located on the dielectric layer P0. For example, when the electronic functional device 3 is arranged on the side where the sensing sheet 20 is located, the upper surface of the dielectric layer P0 includes a first area Q1 and a second area Q2, the sensing sheet 20 is laid in the first area Q1, the electronic functional device 3 is installed in the second area Q2, and the electronic functional device 3 is electrically connected to the sensing sheet 20 through the signal line 4. It should also be noted that in order to prevent the noise signal emitted by the electronic functional device 3 from interfering with the sensing sheet 20, a signal isolation line 5 (metal grid line) is also arranged between the sensing sheet 20 and the electronic functional device 3, and it is ensured that the distance between the signal isolation line 5 and the signal line 4 is greater than or equal to 1mm. When the electronic functional device 3 and the signal line 4 are arranged on the side where the signal shielding net 22 is located, the electronic functional device 3 is electrically connected to the sensing sheet 20 located on the other side of the dielectric layer P0 through the signal line 4, and the distance between the signal shielding net 22 and the signal line 4 is greater than or equal to 1mm. In this embodiment, the PCB capacitive sensor 2 and the electronic functional device 3 are located on the same carrier. Preferably, a transient suppression diode TVS for preventing electrostatic shock is also provided in the connection path of the signal line 4 .

[0037] Implementation method 2: Figure 7 A functional circuit board 6 is also provided in the door handle 1, and the electronic functional device 3 is provided on the functional circuit board 6, and the electronic functional device 3 is electrically connected to the sensor sheet 20 through the signal line 4. In this embodiment, the electronic functional device 3 is separately provided on the functional circuit board 6, so that more electronic functional devices 3 can be configured for the smart door lock control switch, so that it has more additional functions.

[0038] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A PCB capacitive sensor, characterized in that: It comprises an induction layer, a dielectric layer and a protective layer stacked up and down, wherein the induction layer and the protective layer are respectively located at the upper and lower sides of the dielectric layer, and the dielectric layer comprises a non-conductive dielectric material substrate; the induction layer comprises a conductive metal induction sheet laid on the substrate for generating an induction capacitor; the protective layer comprises a signal shielding net laid on the substrate for preventing interference signals from entering the induction layer; the induction sheet is copper, and the signal shielding net is a copper wire grid.

2. The PCB capacitive sensor according to claim 1, characterized in that: The duty cycle of the copper wire grid is 1 / 4 to 1 / 3.

3. The PCB capacitive sensor according to claim 1, characterized in that: The substrate includes one or more layers of PP material medium.

4. The PCB capacitive sensor according to claim 1, characterized in that: The thickness of the substrate is d, d≥1.2 mm.

5. The PCB capacitive sensor according to claim 1, characterized in that: The length and width of the induction sheet are respectively a, b, a≥10mm, b≥13mm.

6. An intelligent door lock control switch for a car virtual key, characterized in that: The PCB capacitive sensor according to any one of claims 1 to 5 is arranged in a door handle of a car, wherein the door handle is a non-conductive material body.

7. The intelligent door lock control switch for automobile virtual key according to claim 6, characterized in that: An electronic functional device is also arranged on the dielectric layer at a side where the sensing sheet and / or the signal shielding net are located, and the electronic functional device is electrically connected to the sensing sheet through a signal line.

8. The intelligent door lock control switch for automobile virtual key according to claim 6, characterized in that: A functional circuit board is also arranged in the door handle, and electronic functional devices are arranged on the functional circuit board. The electronic functional devices are electrically connected to the sensor sheet through a signal line.

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