A touch pressure sensor and a touch pressure switch

Abstract

The present invention discloses a touch pressure sensor, wherein a first electrode layer can form a capacitor with a part touched by a user, thereby locating the area touched by the user; at the same time, when the user presses the touch pressure sensor, the size of the capacitor between the second electrode layer and the third electrode layer can be changed, thereby detecting the size of the user's pressing force. The above-mentioned touch pressure sensor can detect the size of the user's pressing force while locating the user's touched area, thereby reducing the false trigger rate of the touch pressure sensor. At the same time, the above-mentioned signal for locating the user's touched area and the signal for detecting the size of the user's pressing force will be distributed on different signal lines, thereby achieving redundancy of the above-mentioned signals and increasing the reliability of the touch pressure sensor. The present invention also provides a touch pressure switch, which also has the above-mentioned beneficial effects.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a touch pressure sensor and a touch pressure switch. Background Art

[0002] With the continuous advancement of technology and the development of the touch industry in recent years, the application scope of touch sensors is becoming wider and wider.

[0003] At present, touch sensors are usually capacitive touch sensors. Although capacitive touch sensors have the advantages of wear resistance, long life, and low maintenance costs, during the use of capacitive touch sensors, users only need to touch or approach the surface of the capacitive touch sensor with their fingers to activate the touch sensor, which can easily cause false triggering. In some specific application scenarios, such as in-vehicle systems, the hardware security requirements are high. In similar application scenarios, conventional touch sensors in the prior art are no longer applicable.

[0004] Therefore, how to ensure the safety of the touch sensor is an urgent problem that technicians in this field need to solve. Summary of the invention

[0005] An object of the present invention is to provide a touch pressure sensor, which can effectively reduce the false trigger rate of the touch pressure sensor; another object of the present invention is to provide a touch pressure switch, which can effectively reduce the false trigger rate of the touch pressure switch.

[0006] In order to solve the above technical problems, the present invention provides a touch pressure sensor, the touch pressure sensor comprising:

[0007] A first electrode layer, a second electrode layer and a third electrode layer are sequentially arranged at intervals; wherein the first electrode layer includes at least one conductive film layer, and a capacitor is formed between the second electrode layer and the third electrode layer;

[0008] a first isolation layer located between the first electrode layer and the second electrode layer;

[0009] A second isolation layer is located between the second electrode layer and the third electrode layer; wherein an air gap is provided in the second isolation layer.

[0010] Optionally, a cover plate is disposed on a surface of the first electrode layer facing away from the second electrode layer; and a substrate is disposed on a surface of the third electrode layer facing away from the second electrode layer.

[0011] Optionally, an anti-reflection film is provided on a surface of the cover plate facing away from the first electrode layer.

[0012] Optionally, an anti-fingerprint oil coating is provided on a surface of the anti-reflection film on a side facing away from the cover plate.

[0013] Optionally, a surface of the cover plate facing away from the first electrode layer is a rough surface.

[0014] Optionally, the second isolation layer is a second isolation layer made of porous material.

[0015] Optionally, the second isolation layer includes a plurality of spacers, and the air gaps are formed between the spacers.

[0016] Optionally, the first electrode layer includes two conductive film layers, and the two conductive film layers are respectively provided with electrode patterns matching each other.

[0017] The present invention further provides a touch pressure switch, comprising the touch pressure sensor as described in any one of the above items and an MCU electrically connected to the touch pressure sensor.

[0018] A touch pressure sensor provided by the present invention comprises a first electrode layer, a second electrode layer and a third electrode layer which are arranged in sequence and spaced apart; wherein the first electrode layer comprises at least one conductive film layer, and a capacitor is formed between the second electrode layer and the third electrode layer; and a second isolation layer is arranged between the second electrode layer and the third electrode layer, and an air gap is arranged in the second isolation layer. The above-mentioned first electrode layer comprises a conductive film layer, which can form a capacitor with the part touched by the user in the working state, thereby changing the current on the conductive film layer, and the user's touch area can be located by detecting the electrical signal; at the same time, when the user presses the touch pressure sensor, the distance between the second electrode layer and the third electrode layer can be changed, and the size of the capacitance between the second electrode layer and the third electrode layer can be changed, thereby changing the current on the second electrode layer or the third electrode layer, and the size of the user's pressing force can be detected by detecting the electrical signal. Through the above-mentioned touch pressure sensor, the user's touch area can be located while the user's pressing force can be detected, thereby reducing the false trigger rate of the touch pressure sensor. At the same time, the signal for locating the user's touch area and the signal for detecting the user's pressing force are generated by different components. The two signals are distributed on different signal lines, thereby achieving redundancy of the signals and increasing the reliability of the touch pressure sensor.

[0019] The present invention further provides a touch pressure switch, which also has the above-mentioned beneficial effects and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the structure of a touch pressure sensor provided by an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the structure of a specific touch pressure sensor provided by an embodiment of the present invention.

[0023] In the figure: 1. first electrode layer, 2. second electrode layer, 3. third electrode layer, 4. first isolation layer, 5. second isolation layer, 6. air gap, 7. cover plate, 8. substrate. DETAILED DESCRIPTION

[0024] The core of the present invention is to provide a touch pressure sensor. In the prior art, a user only needs to touch or approach the surface of a capacitive touch sensor with a finger to activate the touch sensor, which can easily cause false triggering of the touch sensor, thereby reducing the safety of the touch sensor.

[0025] The touch pressure sensor provided by the present invention includes a first electrode layer, a second electrode layer and a third electrode layer which are arranged in sequence; wherein the first electrode layer includes at least one conductive film layer, and a capacitor is formed between the second electrode layer and the third electrode layer; and a second isolation layer is arranged between the second electrode layer and the third electrode layer, and an air gap is arranged in the second isolation layer. The above-mentioned first electrode layer includes a conductive film layer, which can form a capacitor with the part touched by the user in the working state, thereby changing the current on the conductive film layer, and the user's touch area can be located by detecting the electrical signal; at the same time, when the user presses the touch pressure sensor, the distance between the second electrode layer and the third electrode layer can be changed, and the size of the capacitance between the second electrode layer and the third electrode layer can be changed, thereby changing the current on the second electrode layer or the third electrode layer, and the size of the user's pressing force can be detected by detecting the electrical signal. Through the above-mentioned touch pressure sensor, the user's touch area can be located while the user's pressing force can be detected, thereby reducing the false trigger rate of the touch pressure sensor. At the same time, the signal for locating the user's touch area and the signal for detecting the user's pressing force are generated by different components. The two signals are distributed on different signal lines, thereby achieving redundancy of the signals and increasing the reliability of the touch pressure sensor.

[0026] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a touch pressure sensor provided by an embodiment of the present invention.

[0028] See also Figure 1 In an embodiment of the present invention, the touch pressure sensor includes a first electrode layer 1, a second electrode layer 2 and a third electrode layer 3 which are arranged in sequence; wherein the first electrode layer 1 includes at least one conductive film layer, and a capacitor is formed between the second electrode layer 2 and the third electrode layer 3; a first isolation layer 4 is located between the first electrode layer 1 and the second electrode layer 2; a second isolation layer 5 is located between the second electrode layer 2 and the third electrode layer 3; wherein an air gap 6 is arranged in the second isolation layer 5.

[0029] The first electrode layer 1 is mainly used to sense the user's touch and locate the area touched by the user. Specifically, the first electrode layer 1 includes at least one conductive film layer, which is usually electrically connected to an external power source, and the external power source forms a current on the conductive film layer. Specifically, electrodes are etched on the conductive film layer, and the electrodes are electrically connected to leads. The external power source transmits the current to each electrode through the lead. In the working state, when the user touches or approaches a certain area on the surface of the touch sensor, the electrode located in the area will form a capacitor with the part touched by the user, thereby absorbing a small current on the conductive film layer. At this time, the external power supply will supplement a current to the conductive film layer. By analyzing the current, the area touched or approached by the user can be located. The specific working principle of the touch function in the touch pressure sensor can refer to the prior art and will not be repeated in the embodiments of the present invention.

[0030] At present, the area where the touch sensor needs to be positioned is usually a plane, and accurate positioning of a point in the plane usually requires positioning the position in two directions. Accordingly, in an embodiment of the present invention, the first electrode layer 1 includes two conductive film layers, and the two conductive film layers are respectively provided with mutually matching electrode patterns.

[0031] The two conductive film layers included in the above-mentioned first electrode layer 1 are generally referred to as the first conductive film layer and the second conductive film layer, respectively. Similar to the above-mentioned conductive film layer, a first electrode is etched in the first conductive film layer, and the first electrode is electrically connected to a first lead. The first electrode constitutes a first electrode pattern in the first conductive film layer, and the first lead transmits current from a first direction to the first electrode, so that the first electrode can locate the area touched by the user in the first direction.

[0032] Similar to the first conductive film layer, in an embodiment of the present invention, a second electrode is etched in the second conductive film layer, the second electrode is electrically connected to a second lead, the second electrode forms a second electrode pattern in the second conductive film layer, and the second lead transmits current to the second electrode from a second direction, so that the second electrode can locate the area touched by the user in the second direction.

[0033] It should be noted that the first electrode pattern formed by the first electrodes and the second electrode pattern formed by the second electrodes usually need to match each other. The two conductive film layers included in the first electrode layer 1 can achieve accurate positioning of the user touch area.

[0034] In the embodiment of the present invention, a first isolation layer 4 is provided between the first electrode layer 1 and the second electrode layer 2 , and a capacitor is formed between the second electrode layer 2 and the third electrode layer 3 .

[0035] The function of the first isolation layer 4 is to separate the first electrode layer 1 from the second electrode layer 2, and prevent the first electrode layer 1 and the second electrode layer 2 from contacting each other and being electrically connected. The first isolation layer 4 is usually made of an insulating material. The specific function of the first isolation layer 4 is not specifically limited in the embodiment of the present invention, and depends on the specific situation.

[0036] The second electrode layer 2 is usually a grounded electrode layer in the embodiment of the present invention, that is, the second electrode layer 2 is usually grounded in the embodiment of the present invention, and its voltage is usually zero. The second electrode layer 2 is usually composed of a conductive film layer. The specific structure and specific composition of the second electrode layer 2 can refer to the prior art and are not specifically limited in the embodiment of the present invention.

[0037] The second electrode layer 2 is arranged between the first electrode layer 1 and the third electrode layer 3, that is, the third electrode layer 3 is arranged in the second electrode layer 2 and on the side facing away from the first electrode layer 1. In the embodiment of the present invention, a capacitor is formed between the second electrode layer 2 and the third electrode layer 3, that is, in the working state, the second electrode layer 2 and the third electrode layer 3 are usually connected to an external power source. Similar to the second electrode layer 2, the third electrode layer 3 is usually composed of a conductive film layer, but the third electrode layer 3 is usually not grounded.

[0038] In the working state, the capacitance formed between the second electrode layer 2 and the third electrode layer 3 can be used to detect the user's pressing. Usually, the user presses the touch pressure sensor from the direction from the first electrode layer 1 to the second electrode layer 2. Specifically, in the embodiment of the present invention, a second isolation layer 5 is provided between the second electrode layer 2 and the third electrode layer 3; wherein the second isolation layer 5 is provided with an air gap 6.

[0039] The function of the second spacer layer is similar to that of the first spacer layer, and its main function is to separate the second electrode layer 2 from the third electrode layer 3 to prevent the second electrode layer 2 and the third electrode layer 3 from contacting each other and being electrically connected.

[0040] Since the air gap 6 is provided in the second isolation layer 5, the second isolation layer 5 can be deformed when the touch pressure sensor is pressed, so that the distance between the second electrode layer 2 and the third electrode layer 3 changes, thereby affecting the capacitance between the second electrode layer 2 and the third electrode layer 3, so that the current flowing through the second electrode layer 2 and the third electrode layer 3 changes, thereby generating an electrical signal caused by pressure. By detecting the electrical signal, the user's pressure can be detected. Since the second electrode layer 2 is usually a ground electrode layer, the electrical signal caused by pressure is usually transmitted from the third electrode layer 3. In contrast, the electrical signal generated by the user's touch is usually transmitted from the first electrode layer 1.

[0041] It should be noted that the stiffness of the first electrode layer 1, the first spacer layer and the second electrode layer 2 needs to be within an appropriate range, that is, the stiffness of the above structure is not easy to be too large, so that the user needs to use too much force to deform the second spacer layer; and the stiffness of the above structure is not easy to be too small, which causes false triggering.

[0042] As for the specific structure of the second isolation layer 5, two specific solutions are provided in the embodiment of the present invention: First, the second isolation layer 5 is a second isolation layer 5 made of porous material.

[0043] The second isolation layer 5 can be made of a loose porous material, so that the second isolation layer 5 naturally has an air gap 6. When the touch pressure sensor is pressed, the second isolation layer 5 can be deformed, thereby changing the capacitance between the second electrode layer 2 and the third electrode layer 3. The specific material of the second isolation layer 5 made of a loose porous material can refer to the prior art and is not specifically limited in the embodiments of the present invention.

[0044] Secondly, the second isolation layer 5 includes a plurality of spacers, and the air gaps 6 are formed between the spacers.

[0045] A plurality of spacers may be provided in the second isolation layer 5, and air gaps 6 are formed between the plurality of spacers, so that the second electrode layer 2, the second spacer layer and the third electrode layer 3 form a structure similar to a resistive touch screen, so that the distance between the second electrode layer 2 and the third electrode layer 3 can be changed. Of course, in the embodiment of the present invention, it is not necessary for the second electrode layer 2 and the third electrode layer 3 to contact each other. Normally, as long as a slight change occurs in the distance between the second electrode layer 2 and the third electrode layer 3, the touch pressure sensor can sense the user's pressure. Specifically, in the embodiment of the present invention, as long as the distance between the second electrode layer 2 and the third electrode layer 3 is close to about 0.02 mm, the touch pressure sensor provided in the embodiment of the present invention can sense the user's pressure.

[0046] A touch pressure sensor provided by an embodiment of the present invention comprises a first electrode layer 1, a second electrode layer 2 and a third electrode layer 3 which are arranged in sequence; wherein the first electrode layer 1 comprises at least one conductive film layer, and a capacitor is formed between the second electrode layer 2 and the third electrode layer 3; and a second isolation layer 5 is arranged between the second electrode layer 2 and the third electrode layer 3, and an air gap 6 is arranged in the second isolation layer 5. The first electrode layer 1 comprises a conductive film layer, which can form a capacitor with the part touched by the user in the working state, thereby changing the current on the conductive film layer, and the user's touch area can be located by detecting the electrical signal; at the same time, when the user presses the touch pressure sensor, the distance between the second electrode layer 2 and the third electrode layer 3 can be changed, and the size of the capacitance between the second electrode layer 2 and the third electrode layer 3 can be changed, thereby changing the current on the second electrode layer or the third electrode layer 3, and the size of the user's pressing force can be detected by detecting the electrical signal. The above touch pressure sensor can detect the size of the user's pressing force while locating the user's touch area, thereby reducing the false trigger rate of the touch pressure sensor. At the same time, the signal for locating the user's touch area and the signal for detecting the user's pressing force are generated by different components. The two signals are distributed on different signal lines, thereby achieving redundancy of the signals and increasing the reliability of the touch pressure sensor.

[0047] The structure of the touch pressure sensor provided by the present invention can be further optimized. For details, please refer to the following invention embodiments.

[0048] Please refer to Figure 2 , Figure 2 A schematic diagram of the structure of a specific touch pressure sensor provided by an embodiment of the present invention.

[0049] Different from the above-mentioned invention embodiment, the present invention embodiment introduces in detail the specific structure of the cover plate 7 in the touch display module on the basis of the above-mentioned invention embodiment. The rest of the contents have been introduced in detail in the above-mentioned invention embodiment and will not be repeated here.

[0050] See also Figure 2 In the embodiment of the present invention, a cover plate 7 is disposed on the surface of the first electrode layer 1 facing away from the second electrode layer 2 ; and a substrate 8 is disposed on the surface of the third electrode layer 3 facing away from the second electrode layer 2 .

[0051] Since the first electrode layer 1 and the third electrode layer 3 are usually provided with a conductive film layer electrically connected to an external power source, in order to effectively protect the entire touch pressure sensor from being easily affected by the external environment and to increase the service life of the touch pressure sensor during use, in the embodiment of the present invention, a cover plate 7 may be provided on the surface of the first electrode layer 1 facing away from the second electrode layer 2; and a substrate 8 may be provided on the surface of the third electrode layer 3 facing away from the second electrode layer 2. That is, the cover plate 7 and the substrate 8 are located at the outermost side of the entire touch pressure sensor, and usually the user will touch or even press the touch pressure sensor from the cover plate 7 side of the touch pressure sensor.

[0052] The substrate 8 and the cover plate 7 are mainly used to protect the touch pressure sensor. In the embodiment of the present invention, there is no specific limitation on the specific material of the substrate 8 and the cover plate 7, as long as they can protect the touch pressure sensor. Usually, the substrate 8 and the cover plate 7 are usually made of plastic film, specifically, PET film layer, PC film layer, etc.

[0053] Since the above-mentioned cover plate 7 is mainly facing the user during use, correspondingly in the embodiment of the present invention, a variety of surface treatments can be performed on the surface of the cover plate 7 facing away from the first electrode layer 1. Specifically, the first surface treatment is to make the surface of the cover plate 7 facing away from the first electrode layer 1 into a rough surface, that is, a plurality of grooves are provided on the surface of the cover plate 7 facing away from the first electrode layer 1. Of course, in the embodiment of the present invention, the grooves are usually formed by performing fine concave-convex processing on the surface of the cover plate 7 facing away from the first electrode layer 1. The grooves are usually very small and cannot be observed by the user with the naked eye. However, the grooves formed by the fine concave-convex processing can make the surface of the cover plate 7 facing away from the first electrode layer 1 become a rough surface. When external light irradiates the surface of the cover plate 7 with a rough surface facing away from the first electrode layer 1, the external light will be scattered instead of specular reflection, thereby avoiding the occurrence of glare.

[0054] The second surface treatment is to provide an anti-reflection film on the surface of the cover plate 7 facing away from the first electrode layer 1. The anti-reflection film is also called an anti-reflection film, also known as an anti-reflection film. The surface of the cover plate 7 provided with the anti-reflection film can effectively reduce or even eliminate the generation of reflected light, and at the same time can improve the physical properties of the cover plate 7, such as mechanical properties, etc.

[0055] The third surface treatment is to apply an anti-fingerprint oil coating on the surface of the cover plate 7 facing away from the first electrode layer 1. Anti-fingerprint oil is also called anti-fingerprint oil or anti-fingerprint paint, which has the effect of anti-fingerprint and anti-oil pollution. The specific anti-fingerprint oil coating can be divided into oleophilic type and oil-repellent type. The specific type of the anti-fingerprint oil coating is not specifically limited in the embodiment of the present invention.

[0056] Of course, the anti-fingerprint oil coating can be provided on the surface of the anti-reflection film. The above describes three specific methods of surface treatment. In the embodiment of the present invention, only one surface treatment can be performed on the surface of the cover plate 7 facing away from the first electrode layer 1; any two surface treatments can be performed on the surface of the cover plate 7 facing away from the first electrode layer 1 at the same time; three surface treatments can be performed on the surface of the cover plate 7 facing away from the first electrode layer 1 at the same time, and even other types of surface treatments can be performed. The specific content of the surface treatment of the cover plate 7 is not specifically limited in the embodiment of the present invention.

[0057] A touch pressure sensor provided by an embodiment of the present invention can effectively improve the optical performance and structural strength of the touch pressure sensor by performing various surface treatments on the surface of the cover plate 7 facing away from the first electrode layer 1 .

[0058] The embodiment of the present invention further provides a touch pressure switch, which includes the touch pressure sensor as described in any of the above invention embodiments and an MCU electrically connected to the touch pressure sensor. The MCU is mainly used to obtain the above electrical signals generated by user pressing and the electrical signals generated by user touching, and to identify and analyze the two electrical signals.

[0059] The touch pressure sensor provided by the above-mentioned embodiment of the invention can effectively reduce the false trigger rate, and the touch pressure switch provided by the corresponding embodiment of the invention can effectively prevent the occurrence of false triggering.

[0060] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0061] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0062] The above is a detailed introduction to a touch pressure sensor and a touch pressure switch provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A touch pressure sensor, characterized in that: The touch pressure sensor comprises: A first electrode layer, a second electrode layer and a third electrode layer are sequentially arranged at intervals; wherein the first electrode layer includes at least one conductive film layer, and a capacitor is formed between the second electrode layer and the third electrode layer; a first isolation layer located between the first electrode layer and the second electrode layer; a second isolation layer located between the second electrode layer and the third electrode layer; wherein an air gap is provided in the second isolation layer; The second isolation layer is a second isolation layer composed of a porous material; The conductive film layer of the first electrode layer forms a capacitor with the part touched by the user in the working state; when the user presses the touch pressure sensor, the distance between the second electrode layer and the third electrode layer is changed, and the size of the capacitance between the second electrode layer and the third electrode layer is changed, so as to detect the size of the user's pressing force while locating the user's touched area; the signal for locating the user's touched area and the signal for detecting the size of the user's pressing force are distributed on different signal lines; The first electrode layer includes two conductive film layers, and the two conductive film layers are respectively provided with electrode patterns matching each other; The second electrode layer is a ground electrode layer, the electrical signal caused by pressure is transmitted from the third electrode layer, and the electrical signal generated by user touch is transmitted from the first electrode layer.

2. The touch pressure sensor according to claim 1, characterized in that: A cover plate is disposed on a surface of the first electrode layer facing away from the second electrode layer; and a substrate is disposed on a surface of the third electrode layer facing away from the second electrode layer.

3. The touch pressure sensor according to claim 2, characterized in that: An anti-reflection film is disposed on a surface of the cover plate facing away from the first electrode layer.

4. The touch pressure sensor according to claim 3, characterized in that: An anti-fingerprint oil coating is provided on a surface of the anti-reflection film facing away from the cover plate.

5. The touch pressure sensor according to claim 4, characterized in that: The surface of the cover plate facing away from the first electrode layer is a rough surface.

6. A touch pressure switch, characterized in that: The touch pressure switch comprises the touch pressure sensor according to any one of claims 1 to 5 and an MCU electrically connected to the touch pressure sensor.

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