CN111817698A

CN111817698A - Prevent mistake and touch switch based on hall effect

Info

Publication number: CN111817698A
Application number: CN201910290208.4A
Authority: CN
Inventors: 王学新; 王海风; 钱宇杰
Original assignee: Shanghai Yihe Automobile Technology Co ltd
Current assignee: Shanghai Yihe Automobile Technology Co ltd
Priority date: 2019-04-11
Filing date: 2019-04-11
Publication date: 2020-10-23

Abstract

The invention discloses a false touch prevention switch based on a Hall effect, which belongs to the field of electrical equipment and comprises a panel, a middle shell and a bottom shell; a touch control capacitance film is laid on the bottom surface of the panel, the panel is connected to the upper part of the middle shell in a sliding mode, and the sliding direction of the panel is parallel to the up-down direction of the middle shell; the bottom shell is arranged at the lower part of the middle shell, a PCBA is arranged in the middle shell, a Hall sensor is arranged on the PCBA, and a magnet is arranged on a panel above the Hall sensor; and the middle shell is provided with an elastic component for resetting the panel after being pressed down. The invention has reasonable design and convenient manufacture and use, and can effectively reduce the production cost.

Description

Prevent mistake and touch switch based on hall effect

Technical Field

The invention relates to the field of electrical equipment, in particular to a false touch prevention switch based on a Hall effect.

Background

With the increasing requirements of people on the interior of automobiles, the concept of the capacitive switch gradually becomes popular. The excellent appearance effect can give people strong scientific and technological sense and aesthetic feeling, so the capacitance switch is strongly pursued by consumers.

But the corresponding problems also arise: the capacitive switch is difficult to design for preventing false touch. The traditional switch is operated by pressing and needs a certain force to trigger. The capacitance switch is triggered by the change of capacitance value, and can be triggered as long as a human body touches the capacitance switch. The capacitive switch in the current market can be triggered only by touching of a human body, and the triggering principle also directly causes the problem of easy false triggering. The switch is triggered whenever the user's hand, elbow, etc. inadvertently touches the switch. This is clearly unacceptable for car switches, and false triggering of functions that are not activated can even affect the safety of the vehicle. The requirement of host factories for preventing the capacitors from being touched by mistake is higher and higher.

The current capacitive switch error-touch prevention strategy is as follows: a hand touching the panel causes a change in capacitance value; pressing the panel with hand to provide certain force; when the two points are satisfied at the same time, the corresponding key function is triggered.

For force detection, the conventional anti-false-touch switch mainly detects whether a panel has corresponding pressing force through a microswitch and provides hand feeling feedback. The specific structure of the existing anti-false-touch switch is shown in fig. 1, and comprises three major components: the first component consists of a panel 1, a capacitance film 2 and a sliding block 3; the component II consists of a microswitch 4, a PCB5, a middle shell 6 and a bottom shell 7; a third component, a balance spring 8; the sub parts of each component do not move, and the three components move independently; the panel 1 is provided with a plurality of keys; the first component can move up and down through the sliding block 3 and the second component, and the uniformity of movement is ensured by four guide ribs 81, as shown in fig. 2; the balance spring 8 is used to make the panel 1 sink uniformly, so as to prevent the panel 1 from deflecting and jamming caused by the larger panel 1.

The triggering of the above-mentioned false-touch-prevention switch needs to satisfy two conditions at the same time:

1. a finger touches a certain functional key to cause the capacitance change of the capacitance film 2;

2. the finger presses the panel 1, and the slide block 3 triggers the micro switch 4 to send out a signal.

When the user uses the touch panel, firstly, the user touches the panel 1, firstly, the capacitive film 2 identifies which functional key the user presses, then, when the user presses down with force, the first component moves downwards, and the slide block 3 triggers the micro switch 4 in the second component. And when the product simultaneously receives the correct capacitance change and the trigger signal of the microswitch 4, judging that the user clicks the corresponding function key. The requirement of capacitance and force is met at the same time, so that the function of preventing mistaken touch is achieved. As shown in fig. 3, the motion trace of the panel 1 is shown in the initial position with the dotted line and the pressed position with the solid line, and when the side edge is pressed, the whole panel 1 moves downward.

However, the above solutions have great limitations at the same time. Since there is only one microswitch 4, it is necessary to ensure that the entire panel 1 is lowered uniformly to successfully trigger the microswitch 4, and the panel 1, once slightly deflected, will not trigger the microswitch 4 (the point at which the microswitch 4 is pressed does not have sufficient stroke or sufficient pressing force).

In addition, the reason why the conventional anti-false-touch switch does not adopt a plurality of micro switches 4 is that the plurality of micro switches 4 cause the problems of disordered hand feeling (after some places are pressed down, a plurality of micro switches 4 are sequentially triggered to cause multiple hand feelings), overlarge anti-false-touch force (the trigger forces of the plurality of micro switches 4 are overlapped), and the like. Only one microswitch 4 can be used at present.

In summary, the panel 1 in the conventional anti-false-touch switch is difficult to ensure the uniformity of the movement thereof, and the panel 1 is easy to deflect during the movement process to cause the blocking. To ensure the uniformity of the movement of the panel 1, the panel 1 must satisfy the following conditions:

1. the panel 1 can not be overlarge, the small-sized panel 1 can be directly kept uniform by the guide ribs 81, the middle-sized panel 1 can be kept uniform by the balance springs 8, but once the panel 1 is irregular or the length of the panel 1 exceeds 80mm, the movement uniformity is extremely difficult to ensure;

2. the shape of the panel 1 cannot be too complex, and once the panel has an acute angle or a slender structure, clamping stagnation is easily caused;

3. the precision of the die is high enough, the uniform descending is ensured mainly by the four guide ribs 81 and the balance spring 8, the clamping stagnation is caused when any deformation and dimension of the product are not in place, and the guide ribs 81 are matched very accurately, so that the requirements for the die and suppliers are correspondingly increased, and the cost of the product is directly increased; meanwhile, the yield of the panel 1 is low, and the existing product design has extremely high precision requirements, so slight differences caused by humidity, temperature and injection molding can cause clamping stagnation, and the instability of part batches can cause defective products extremely; moreover, the panel 1 has poor environmental impact resistance, and once the panel 1 touches the surrounding environment, or dust, foreign matter, etc. enter the periphery of the panel 1, the panel 1 may not be uniformly lowered.

Disclosure of Invention

Aiming at the problems that the mistaken touch prevention switch in the prior art has more limitations on a panel and high requirements, the invention aims to provide the mistaken touch prevention switch based on the Hall effect.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a false touch prevention switch based on a Hall effect comprises a panel, a middle shell and a bottom shell; a touch control capacitance film is laid on the bottom surface of the panel, the panel is connected to the upper part of the middle shell in a sliding mode, and the sliding direction of the panel is parallel to the up-down direction of the middle shell; the bottom shell is arranged at the lower part of the middle shell, a PCBA is arranged in the middle shell, a Hall sensor is arranged on the PCBA, and a magnet is arranged on a panel above the Hall sensor; and the middle shell is provided with an elastic component for resetting the panel after being pressed down.

Furthermore, a sliding block is installed on the panel, and a sliding groove matched with the sliding block is formed in the middle shell.

Preferably, the slider is located above the elastic member.

Preferably, the top of the middle shell is open, the panel is provided with a downward surrounding edge, the sliding block is installed on the bottom surface of the panel, and the elastic component is installed inside the middle shell.

Preferably, the magnet is mounted at a lower end of the slider.

Preferably, at least two hall sensors are installed on the PCBA at intervals, and a corresponding number of magnets are installed on the panel.

Preferably, the elastic component is a silica gel pad, a spring or a spring sheet.

Preferably, the bottom shell is detachably connected with the middle shell.

When the touch panel is used, whether a user touches the panel is firstly confirmed according to the capacitance value change condition of the touch capacitor film; then, whether the user continues to press the panel is confirmed through the voltage change condition of the Hall sensor; only if both are "yes", it is determined that the user's intention is to change the switch state.

By adopting the technical scheme, due to the use of the magnet and the Hall sensor, the stroke displacement of the magnet (panel) can be detected through the Hall voltage change of the Hall sensor; due to the characteristics of the magnet and the Hall sensor, the micro stroke of the magnet can be detected; the sensitivity of the Hall sensor can be set to meet the use requirements under different conditions; the scheme has higher requirements on the uniformity of panel movement, so that the requirements on the dimensional accuracy of each part are not high, and the reduction of the production cost and the use failure rate are facilitated;

drawings

FIG. 1 is a schematic structural diagram of a mis-touch prevention switch in the prior art;

FIG. 2 is a cross-sectional view of the anti-false touch switch of FIG. 1;

FIG. 3 is a schematic diagram of a movement trace of a panel of the anti-false touch switch shown in FIG. 1;

FIG. 4 is a schematic structural view of the present invention;

FIG. 5 is a schematic view of a magnet, a Hall sensor and a PCBA board in the present invention;

FIG. 6 is a graph of the performance of a linear Hall sensor;

FIG. 7 is a cross-sectional view of the Hall-effect based anti-false-touch switch of FIG. 4;

fig. 8 is a schematic diagram of a movement trace of the hall effect based false touch prevention switch shown in fig. 4 when the panel does not uniformly descend.

In the figure, 1-panel, 2-touch control capacitance film, 3-slide block, 4-microswitch, 5-PCBA, 6-middle shell, 7-bottom shell, 8-balance spring, 81-guide rib, 9-magnet, 10-Hall sensor, 11-elastic component.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example one

As shown in fig. 4, the mis-touch preventing switch based on the hall effect comprises a panel 1, a middle shell 6 and a bottom shell 7; the bottom surface of the panel 1 is laid with a touch control capacitance film 2, the panel 1 is connected to the upper part of the middle shell 6 in a sliding way, and the sliding direction of the panel 1 is parallel to the up-down direction of the middle shell 6; the bottom shell 7 is arranged at the lower part of the middle shell 6, the PCBA5 is arranged in the middle shell 6, the Hall sensor 10 is arranged on the PCBA5, and the magnet 9 is arranged on the panel 1 above the Hall sensor 10; the middle case 6 is provided with an elastic member 11 for restoring the panel 1 after being pressed down.

As can be seen from fig. 6, the hall sensor 10 generates different voltage signals under different magnetic field strengths; as shown in fig. 5, the magnet 9 provides a magnetic field, and the hall sensor 10 senses the magnitude of the magnetic field. Therefore, when the user presses the panel 1 to cause displacement, the position of the magnet 9 changes, and the magnetic flux passing through the hall sensor 10 also changes correspondingly, so that the output voltage value of the hall sensor 10 changes, and whether the panel 1 is displaced can be judged by detecting the voltage change of the hall sensor 10.

According to the scheme, the mode that the action condition of the panel 1 is detected through the stress condition of the microswitch 4 in the prior art is changed into the mode that the action condition of the panel 1 is detected through the voltage change of the Hall sensor 10. The advantage is that, due to the characteristics of the magnet 9 and the hall sensor 10, very small strokes of the panel 1 can also be detected, so that the sensitivity of the hall sensor 10 can be adjusted to meet the requirements of different customers; the panel 1 does not have the requirement of pressing force due to the non-contact characteristic of the magnet 9 and the Hall sensor 10; meanwhile, the present invention does not require the panel 1 to move uniformly, as shown in fig. 8, when the panel 1 moves obliquely, as long as the panel 1 has displacement and can satisfy the voltage change of the hall sensor 10.

In this embodiment, the upper end and the lower end of the middle shell 6 are both open; the bottom surface of the panel 1 is also provided with a sliding block 3, the middle shell 6 is provided with a sliding chute matched with the sliding block 3, and meanwhile, in order to reduce weight and material consumption, the sliding block 3 is internally provided with a plurality of cavities; the elastic component 11 is positioned inside the middle shell 6, and the elastic component 11 is positioned below the sliding block 3; the elastic component 11 may be a silicone pad, a spring, or a spring plate, and the present embodiment is preferably a silicone pad, and the silicone pad is installed above the PCBA 5.

Since the upper end of the middle case 6 is open, the panel 1 is provided with a downward skirt to cover the middle case 6 in order to prevent the entrance of dust.

In order to facilitate replacement and maintenance of the components inside the middle housing 6, in the present embodiment, the bottom housing 7 is detachably connected to the middle housing 6 by means of a snap, a thread, or a pin.

In order to make the magnetic flux in the hall sensor 10 sufficiently large, in the present embodiment, the magnet 9 is installed at the lower end of the slider 3 to shorten the distance between the magnet 9 and the hall sensor 10.

When the touch control panel is used, the capacitance value of the touch control capacitance film 2 changes when an operator touches the panel 1 by fingers or other parts; the panel 1 continues to drive the magnet 9 to move downwards, and the voltage of the Hall sensor 10 changes; if both conditions are in effect, it can be determined that the operator's intention is to change the switch state.

Example two

The difference from the first embodiment is that: at least two hall sensors 10 are mounted on the PCBA5 at intervals, as shown in fig. 7, and correspondingly, a corresponding number of magnets 9 are mounted on the panel 1 or the slider 3.

By the arrangement, the dead point problem of the movement of the panel 1 can be solved, the magnet 9 and the Hall sensor 10 are arranged below the dead point of the panel 1, and when the dead point is pressed, the Hall sensor 10 below the dead point can detect the tiny displacement of the panel 1 at the dead point position (under the scheme of the original microswitch, the hand feeling is disordered for preventing multiple triggering, so that only a single micro-motion strategy can be adopted, the dead point position of the panel 1 is pressed, and the movement stroke of the panel 1 is not enough to trigger the microswitch); therefore, the present invention does not particularly limit the shape of the panel 1, and can effectively reduce the precision of the panel 1, improve the production efficiency, and reduce the production cost.

In the invention, the larger the panel 1 is, the more the combination number of the magnets 9 and the Hall sensors 10 is needed to be correspondingly increased, so the size of the panel 1 is not limited.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.

Claims

1. The utility model provides a prevent mistake and touch switch based on hall effect which characterized in that: comprises a panel, a middle shell and a bottom shell; a touch control capacitance film is laid on the bottom surface of the panel, the panel is connected to the upper part of the middle shell in a sliding mode, and the sliding direction of the panel is parallel to the up-down direction of the middle shell; the bottom shell is arranged at the lower part of the middle shell, a PCBA is arranged in the middle shell, a Hall sensor is arranged on the PCBA, and a magnet is arranged on a panel above the Hall sensor; and the middle shell is provided with an elastic component for resetting the panel after being pressed down.

2. The hall effect based false touch prevention switch of claim 1, wherein: the panel is provided with a sliding block, and the middle shell is provided with a sliding groove matched with the sliding block.

3. The hall effect based false touch prevention switch of claim 2, wherein: the slider is located above the elastic component.

4. The hall effect based false touch prevention switch of claim 3, wherein: the top of the middle shell is open, the panel is provided with a downward surrounding edge, the sliding block is installed on the bottom surface of the panel, and the elastic component is installed inside the middle shell.

5. The Hall-effect based false touch prevention switch of claim 4, wherein: the magnet is installed at the lower end of the sliding block.

6. The hall effect based false touch prevention switch of claim 1, wherein: at least two Hall sensors are installed on the PCBA at intervals, and magnets with corresponding numbers are installed on the panel.

7. The hall effect based false touch prevention switch of claim 1, wherein: the elastic component is a silica gel pad, a spring or an elastic sheet.

8. The hall effect based false touch prevention switch of claim 1, wherein: the bottom shell is detachably connected with the middle shell.