CN113108817A

CN113108817A - PCB capacitive sensor and intelligent door lock control switch

Info

Publication number: CN113108817A
Application number: CN202110452620.9A
Authority: CN
Inventors: 黎同辉; 王国强; 张志航
Original assignee: Yuanfeng Technology Co Ltd
Current assignee: Yuanfeng Technology Co Ltd
Priority date: 2021-04-26
Filing date: 2021-04-26
Publication date: 2021-07-13

Abstract

The invention discloses a PCB capacitive sensor and an intelligent door lock control switch, wherein the PCB capacitive sensor comprises an induction layer, a dielectric layer and a protective layer which are stacked together at the upper layer and the lower layer, the induction layer and the protective layer are respectively positioned at the upper side and the lower side 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 and used for generating induction capacitance; the protective layer comprises a signal shielding net which is laid on the substrate and used for preventing interference signals from entering the sensing layer; the PCB capacitive sensor with the structure effectively reduces the volume of the sensor, thereby reducing the requirement on the internal space of the vehicle door handle, providing more reasonable and wider design space for the vehicle door handle and enabling the size of the vehicle door handle to be more exquisite and small; in addition, because the PCB capacitive sensor is provided with the protective layer for preventing interference signals, the signal to noise ratio of the PCB capacitive sensor can be effectively improved, so that the touch sensing distance is longer, and the false triggering probability is effectively reduced.

Description

PCB capacitive sensor and intelligent door lock control switch

Technical Field

The invention relates to the technical field of touch type electric heating sensors, in particular to a PCB (printed circuit board) capacitive sensor and an intelligent door lock control switch for an automobile virtual key.

Background

With the development of science and technology, automobile smart keys have been gradually converted from traditional physical keys to virtual keys. The carrier of the virtual key is usually a product such as a mobile phone, a bracelet, a watch and the like. The user need not to carry the entity key again, only needs to activate virtual key on the cell-phone APP can unblock, start the vehicle, and possesses more function than the entity key, functions such as share.

The currently common virtual keys are divided into the following types based on radio frequency signals: cloud key, bluetooth key, NFC key, UWB key etc.. The product form-based classification is as follows: the intelligent wearing class such as cell-phone, wrist-watch, bracelet, glasses.

The door lock matched with the virtual key is generally provided with a touch switch, when an electronic terminal such as a mobile phone approaches a door, after identification through identity authentication, the door lock control system sends an unlocking signal, the door lock is still in a closed state, when a palm of a user approaches or touches a door handle, the touch switch sends the unlocking signal, and the door lock is opened. As shown in fig. 8 and 9, the touch sensor of the existing door handle 1 ' mainly includes a metal insert 2', which has a poor signal-to-noise ratio and a short sensing distance, and in addition, since the metal insert 2' has a relatively large volume, a suitable installation space needs to be designed for the door handle 1 ', which limits the space design of the door handle 1 ', and moreover, the touch sensor of the metal insert type is easily affected by factors such as rain water, and has a relatively high misrecognition ratio.

Disclosure of Invention

The present invention is directed to provide a PCB capacitive sensor with small size, good interference immunity and longer touch sensing distance to solve the above-mentioned technical problems.

Another object of the present invention is to provide an intelligent door lock control switch for an automobile virtual key, so as to reduce the influence on the space design of an automobile door handle and improve the anti-interference performance and the sensing distance.

In order to achieve the purpose, the invention discloses a PCB capacitive sensor which comprises an induction layer, a dielectric layer and a protective layer which are overlapped at the upper part and the lower part, wherein the induction layer and the protective layer are respectively positioned at the upper side and the lower side of the dielectric layer; the induction layer comprises a conductive metal induction sheet laid on the substrate and used for generating induction capacitance; the protective layer comprises a signal shielding net which is laid on the substrate and used for preventing interference signals from entering the sensing layer.

Preferably, the induction sheet is a copper sheet.

Preferably, the signal shielding net is a copper wire grid.

Preferably, the duty ratio of the copper wire grid is 1/4-1/3.

Preferably, the substrate comprises one or more layers of PP material media.

Preferably, the thickness of the substrate is d, and d is more than or equal to 1.2 mm.

Preferably, the length and the width of the induction sheet are a and b respectively, wherein a is more than or equal to 10mm, and b is more than or equal to 13 mm.

The invention also discloses an intelligent door lock control switch for the automobile virtual key, which comprises the PCB capacitive sensor which is arranged in a door handle of the automobile and is used for detecting a door opening touch signal, wherein the door handle is a non-conductive material body.

Preferably, an electronic function device is further arranged on the dielectric layer on one side where the sensing piece and/or the signal shielding net are/is located, and the electronic function device is electrically connected with the sensing piece through a signal line.

Preferably, a functional circuit board is further arranged in the door handle, an electronic functional device is arranged on the functional circuit board, and the electronic functional device is electrically connected with the sensing piece through a signal line.

When the intelligent door lock control switch for the automobile virtual key disclosed by the invention is installed on an automobile, the intelligent door lock control switch has the following beneficial technical effects:

1. the touch signal of the vehicle door handle is detected through the PCB capacitive sensor, the PCB capacitive sensor comprises three material layers which are laminated together and respectively comprise an induction layer, a dielectric layer and a protective layer, and compared with the touch sensor with the traditional metal plug-in structure, the size of the sensor is effectively reduced, so that the requirement on the internal space of the vehicle door handle is reduced, more reasonable and wider design space is provided for the vehicle door handle (particularly a hidden door handle), and the size of the vehicle door handle can be more exquisite and small;

2. because the PCB capacitive sensor is provided with the protective layer for preventing interference signals, the signal-to-noise ratio of the PCB capacitive sensor can be effectively improved, so that the touch sensing distance is longer, and the false triggering probability is effectively reduced.

Drawings

Fig. 1 is an exploded schematic view of an installation structure of an intelligent door lock control switch according to an embodiment of the present invention.

Fig. 2 is a schematic longitudinal sectional view of the installation structure of the smart door lock control switch of fig. 1.

Fig. 3 is a schematic perspective view of a PCB capacitive sensor according to an embodiment of the invention.

Fig. 4 is a schematic perspective view of a PCB capacitive sensor according to another view of the embodiment of the invention.

Fig. 5 is an exploded view of the PCB capacitive sensor of fig. 3.

Fig. 6 is a schematic diagram of an electrical connection structure of the intelligent door lock control switch according to an embodiment of the present invention.

Fig. 7 is a schematic diagram of an electrical connection structure of an intelligent door lock control switch according to another embodiment of the present invention.

Fig. 8 is an exploded view of a mounting structure of a touch control switch of a door handle in the prior art.

Fig. 9 is a schematic longitudinal sectional view of the mounting structure of the door handle touch control switch of fig. 8.

Detailed Description

In order to explain technical contents, structural features, and objects and effects of the present invention in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

The embodiment discloses an intelligent door lock control switch for an automobile virtual key, which is used for controlling opening and closing of a door lock in cooperation with the virtual key. As shown in fig. 1 and 2, the intelligent door lock control switch includes a PCB capacitive sensor 2 disposed in a door handle 1 of an automobile for detecting a door opening touch signal, the door handle 1 is a non-conductive material, and when the PCB capacitive sensor 2 detects the touch signal touching the door handle 1, the intelligent door lock controller sends an unlocking signal to unlock a door lock. In this embodiment, as shown in fig. 3 to 5, the PCB capacitive sensor 2 includes a sensing layer P1, a dielectric layer P0 and a protective layer P2 stacked together, the sensing layer P1 and the protective layer P2 are respectively located at the upper and lower sides of the dielectric layer P0, the dielectric layer P0 includes a non-conductive dielectric substrate 21 to provide support for the sensing layer P1 and the protective layer P2, and to enable a stable dielectric constant to be provided between the sensing layer P1 and the protective layer P2. The sensing layer P1 includes a conductive metal sensing piece 20 laid on the dielectric layer P0 for generating a sensing capacitance, i.e. a sensing capacitance is generated between the palm and the sensing piece 20 when the finger is close to the door handle 1. The protective layer P2 includes a signal shielding mesh 22 laid on the substrate 21 for preventing interference signals from entering the sensing layer P1.

In the above embodiment, since the PCB capacitive sensor 2 for detecting a touch signal includes three material layers stacked together, namely, the sensing layer P1, the dielectric layer P0 and the protective layer P2, compared with a touch sensor of a conventional metal insert 2' (as shown in fig. 8 and 9), the size of the sensor is effectively reduced, so that the requirement on the internal space of the door handle 1 is reduced, a more reasonable and wider design space is provided for the door handle 1 (especially a hidden door handle), and the size of the door handle 1 can be made more compact and smaller. Moreover, due to the arrangement of the protective layer P2, the signal-to-noise ratio of the PCB capacitive sensor 2 can be effectively improved, so that the touch sensing distance is longer, and the probability of false triggering is effectively reduced.

Specifically, the sensing patch 20 is a copper sheet laid on the dielectric layer P0, and the signal shielding mesh 22 is a copper wire mesh laid on the dielectric layer P0. Preferably, the duty cycle of the copper wire grid is 1/4-1/3, preferably 1/3, and the duty cycle is the ratio of the area of the solid line to the area of the empty area under the condition that the solid line and the empty area are uniformly distributed.

More specifically, the substrate 21 at the dielectric layer P0 includes one or more layers of PP material dielectric. Preferably, the thickness of the substrate 21 is d, d is greater than or equal to 1.2 mm.

In addition, in order to effectively ensure the induction strength of the PCB capacitive sensor 2, the length and width of the induction sheet 20 are a and b, respectively, where a is greater than or equal to 10mm, and b is greater than or equal to 13 mm.

As shown in fig. 6 and 7, in specific use, since the PCB capacitive sensor 2 needs to be configured with the corresponding electronic functional device 3 (such as an inductive IC and a resistor) and the signal line 4, the present invention discloses the following two embodiments of the intelligent door lock control switch:

in the first embodiment, as shown in fig. 6, the electronic functional device 3 is disposed on the dielectric layer P0 at the side where the sensing patch 20 and/or the signal shielding net 22 are located. For example, when the electronic function device 3 is disposed on the side of the sensor sheet 20, the upper surface of the dielectric layer P0 includes a first region Q1 and a second region Q2, the sensor sheet 20 is laid in the first region Q1, the electronic function device 3 is mounted in the second region Q2, and the electronic function device 3 is electrically connected to the sensor sheet 20 through the signal line 4. In addition, in order to avoid the noise signal emitted by the electronic functional device 3 from interfering with the sensing strip 20, a signal isolation line 5 (metal grid line) is further disposed between the sensing strip 20 and the electronic functional device 3, and the distance between the signal isolation line 5 and the signal line 4 is ensured to be greater than or equal to 1 mm. When the electronic functional device 3 and the signal line 4 are disposed on one side of the signal shielding net 22, the electronic functional device 3 is electrically connected to the sensing strip 20 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 1 mm. 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 further disposed in the connection path of the signal line 4.

In the second embodiment, as shown in fig. 7, a functional circuit board 6 is further disposed in the door handle 1, the electronic functional device 3 is disposed on the functional circuit board 6, and the electronic functional device 3 is electrically connected to the sensing piece 20 through the signal line 4. In this embodiment, the electronic function device 3 is separately disposed on the functional circuit board 6, so that more electronic function devices 3 can be configured for the intelligent door lock control switch, and the intelligent door lock control switch has more additional functions.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, therefore, the present invention is not limited by the appended claims.

Claims

1. A PCB capacitive sensor is characterized by comprising an induction layer, a dielectric layer and a protective layer which are stacked up and down, wherein the induction layer and the protective layer are respectively positioned on the upper side and the lower side 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 and used for generating induction capacitance; the protective layer comprises a signal shielding net which is laid on the substrate and used for preventing interference signals from entering the sensing layer.

2. The PCB capacitive sensor of claim 1, wherein the sensing piece is a copper sheet.

3. The PCB capacitive sensor of claim 1, wherein the signal shielding mesh is a copper wire mesh.

4. The PCB capacitive sensor of claim 3, wherein the copper wire mesh has a duty cycle of 1/4-1/3.

5. The PCB capacitive sensor of claim 1, wherein the substrate comprises one or more layers of PP material dielectric.

6. The PCB capacitive sensor of claim 1, wherein the substrate has a thickness d ≧ 1.2 mm.

7. The PCB capacitive sensor of claim 1, wherein the length and width of the sensing piece are a, b, a is more than or equal to 10mm, and b is more than or equal to 13 mm.

8. An intelligent door lock control switch for a virtual key of an automobile, comprising the PCB capacitive sensor for detecting a door opening touch signal as claimed in any one of claims 1 to 7 provided in a door handle of the automobile, the door handle being a non-conductive material body.

9. The intelligent door lock control switch for the automobile virtual key as claimed in claim 8, wherein an electronic function device is further arranged on the dielectric layer on the side where the sensing piece and/or the signal shielding net are/is located, and the electronic function device is electrically connected with the sensing piece through a signal line.

10. The switch of claim 8, wherein a functional circuit board is further disposed in the door handle, and an electronic functional device is disposed on the functional circuit board and electrically connected to the sensor strip through a signal line.