Patent Description:
Such a touch key structure and an electrical appliance are known from <CIT>. This document refers to a switch module, which is attached to a panel. The switch module comprises a cylinder-shaped conductive elastic body having a vertical through hole formed through the center thereof. The body is mounted on a substrate. A capacitive sensor (not shown) is mounted on the substrate. A LED is mounted on the substrate. A transparent conductive lid covers the vertical through hole and is installed between the conductive elastic body and the panel. The body and the substrate are connected to each other by a thin wire or conductive adhesive agent. A support holder is vertically erected on the substrate such that it is located around the body. The elastic body is mounted on a funnel-shaped reflecting plate.

Electronics are equipped with the touch key configured to replace the traditional mechanical key. The touch key has following advantages over the traditional mechanical key:.

Capacitive touch-sensing key, as the most common touch key, is actually just a small piece of "metal electrode" on the PCB, which forms a sensing capacitor with the surrounding "ground signal". When a finger is close to the area above the electrode, the electric field would be interfered, causing a corresponding change in capacitance. Based on the change in capacitance, whether a human body approaches or touches the touch key can be detected. For the current capacitive touch-sensing key, an insulating cover layer such as glass layer should be placed on the sensing electrode due to safety factor and aesthetics factor etc., and the human finger is coupled with the metal sensing sheet through the cover to make the induced capacitance change (usually several pF). However, in some applications, since wire plug, digital tube, capacitor and LED are on the circuit board, the circuit board cannot be directly mounted under the cove. So that some transfer methods are needed. The most common method is to build a capacitive sensor using a spring. For example, <FIG> shows a capacitive touch sensing key <NUM>' having a capacitive sensor constructed by using the spring, the capacitive touch sensing key <NUM>' includes a touch panel <NUM>', a PCB board <NUM>' and a key support <NUM>'. A space is formed between the touch panel <NUM>' and the PCB board <NUM>' to accommodate components such as the wire plug (not labeled), the digital tube (not labeled), and a spring <NUM>', etc.. PCB board <NUM>' is soldered with the spring <NUM>'. The spring <NUM>' abuts between the touch panel <NUM>' and the PCB board <NUM>' through its both ends.

However, there are many disadvantages to the spring <NUM>', which is taken as a sensing electrode, resisting between the PCB <NUM>' and the touch panel <NUM>':
First, because each key must be equipped with one spring <NUM>', the cost is increased.

Besides, the processes of mounting and soldering the spring <NUM>' on the PCB board <NUM>' are both relatively complicated. The pin of the touch spring <NUM>' should be inserted into the through hole of the PCB board <NUM>', and then the spring <NUM>' is soldered with the PCB board <NUM>' through wave soldering. A lot of labor and fixtures are required, and the process is prone to appear problems such as loosening, skewing, displacement, poor welding, etc., which increases the cost of the process and the difficulty of quality assurance.

In addition, during the complete assembly of the product, the spring <NUM>' is prone to skew as it is compressed and tightened by the panel, which is prone to skew. If it is subjected to large amplitude vibration or impact during use, the spring <NUM>' is easily detached from the installation position, causing the touch function to fail.

In view of this, it is necessary to improve the existing capacitive touch-sensing key to provide a reliable capacitive touch-sensing key further with an easy installation advantage.

The main objective of the present disclosure is to provide a touch key structure and an electrical appliance, which aims to improve a simple and reliable touch key structure to solve the problems of the complex structure and poor stability of the existing capacitive touch-sensing key structure.

In order to achieve the above objective, the present disclosure provides a touch key structure according to claim <NUM>.

The present disclosure further provides an electrical appliance according to claim <NUM>.

In the technical solutions of the present disclosure, a sensing electrode is provided on the circuit board, and a conductive medium is provided between a key area of the touch panel and the sensing electrode. When a user's finger touches or approaches the key area, the finger and the sensing electrode form a capacitance. The capacitance is increased because the conductive medium is provided, and can be sensitively sensed when a finger approaches or touches the key area. Therefore, in the present disclosure, the sensing electrode and the conductive medium are easy to be installed and have good stability after installation, thereby making the touch key structure simple and reliable.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the related art, the drawings used in the embodiments or the related art will be briefly described below. Obviously, the drawings in the following description are only some embodiments of the present invention. It will be apparent to those skilled in the art that other figures can be obtained from the structures illustrated in the drawings without the inventive effort.

Description of reference numerals in the related art:.

Description of reference numerals in the present disclosure:.

The realization of the objective, functional characteristics, advantages of the present disclosure are further described with reference to the accompanying drawings.

It is to be understood that, all of the directional instructions in the embodiments of the present disclosure (such as up, down, left, right, front, rear. ) can only be used for explaining relative position relations, moving condition of the elements under a special form (referring to figures), and so on, if the special form changes, the directional instructions changes accordingly.

In addition, the descriptions, such as the "first", the "second" in the embodiment of present invention, can only be used for describing the aim of description, and cannot be understood as indicating or suggesting relative importance or impliedly indicating the number of the indicated technical character. Therefore, the character indicated by the "first", the "second" can express or impliedly include at least one character. Besides, the technical solution of each embodiment can be combined with each other, however the technical solution must base on that the ordinary skill in that art can realize the technical solution, when the combination of the technical solutions is contradictory or cannot be realized, it should consider that the combination of the technical solutions does not exist, and is beyond the protection scope of the present disclosure.

The present disclosure provides a touch key structure and an electrical appliance having the touch key structure. The electric appliance may be a cooking appliance, such as a rice cooker, an induction cooker, a cooking machine, a soymilk maker, or the like, and may also be other electric appliance such as an air conditioner, which is not limited in this application. All electrical appliances provided with the touch key structure are within the protection scope of the present disclosure, and the touch key structure provided in the present disclosure will be specifically described below with reference to the drawings. <FIG> are a touch key structure; <FIG> are a touch key structure according to a first embodiment of the present disclosure; <FIG> are a touch key structure; <FIG> are a touch key structure; and <FIG> are a touch key structure.

Referring to <FIG>, the touch key structure <NUM> includes a touch panel <NUM>, a circuit board <NUM>, and a conductive medium <NUM>. The front side of the touch panel <NUM> has a key area for a user to touch (touch or approach) (in most cases, the key area forms a key identification, and the key identification may be a silk screen structure, or a bright area where LED light sees through the key area, etc.). The circuit board <NUM> is provided behind the touch panel <NUM>, and a sensing electrode <NUM> is provided on the circuit board <NUM> corresponding to the key area. The conductive medium <NUM> is provided between the key area and the sensing electrode <NUM>.

During a touch operation, a user's finger approaches or touches the key area, the sensing electrode <NUM> and the finger constitute a capacitor, which is referred to as a "touch capacitor", and the formation process is not described in detail. The conductive medium <NUM> is equivalent to adding a conductor between two electrodes of the touch capacitor, so that the touch capacitor becomes larger and it is easier to detect a finger. Therefore, in the present disclosure, the sensing electrode <NUM> and the conductive medium <NUM> are easy to be installed and have good stability after installation, thereby making the touch key structure <NUM> simple and reliable in structure.

The number and shape of the key area are not limited, and a plurality of the key areas set at a single point can be provided, or the key area can also be a sliding touch area set continuously. A plurality of the key areas, a plurality of the sensing electrodes <NUM> and a plurality of conductive media <NUM> are provided, and the key areas are in a one-to-one correspondence with the sensing electrodes <NUM> and the conductive media <NUM>, and the specific number varies depending on the actual number of key areas. Besides, the relationship between the sensing electrode <NUM>, the conductive medium <NUM>, and the key area is not necessarily one-to-one correspondence, and one sensing electrode <NUM> may correspond to multiple key areas. The fingers are located in different key areas, and the capacitance between the finger and the sensing electrode <NUM> changes to identify different keys.

The material, structure, and shape of the conductive medium <NUM> are also not limited, depending on actual needs or the difficulty, cost, and so on of production and manufacturing. The conductive medium <NUM> may be made of a metal material, and the metal material has a high conductivity, which makes the touch capacitor have a larger capacitance. The conductive medium <NUM> may be a conductive body 3b or a conductive layer 3a. The conductive body 3b may be a metal conductive body 3b or a non-metal + metal mixed conductive body 3b. Alternatively, the conductive layer 3a may be provided through physical means or chemical plating. For example, the conductive layer 3a may be provided through water plating, evaporation, sputtering, electrophoresis, vacuum plating, spray coating, coating, chemical plating, etc. The physical means includes one of spray coating, brush coating, vacuum plating, and the like. Among them, spray coating, brush coating or vacuum plating can be selected, which is low cost and easy to implement.

The conductive medium <NUM> is provided in a manner that is not limited, and may be provided on the touch panel or on a mounting structure between the touch panel <NUM> and the circuit board <NUM>. The following describes it in combination with specific embodiments: Referring to <FIG> and <FIG>(in the first embodiment of the present disclosure), the touch key structure <NUM> further includes a support <NUM>, which is provided between the circuit board <NUM> and the touch panel <NUM>. The conductive medium <NUM> is provided on the support <NUM>, and specifically, the support <NUM> is a key support, and the circuit board <NUM> is provided with an LED lamp. The key support is also provided with a cylindrical structure for accommodating LED indicators. The cylindrical structure isolates the LED lights to avoid mutual influence of light between the LED lights, so that the LED lights form an indication identification on the touch panel <NUM>.

Obviously, the support should be made of an insulating material. For example, the support <NUM> may be made of an insulating material with a material resistivity of <NUM>Ω. cm to <NUM>Ω. The conductive medium may be made of a material with a resistivity of less than <NUM>Ω. cm, and may be made of a material with a resistivity of less than <NUM>Ω. The lower the resistivity, the better the conductivity, and the higher the sensitivity of the touch key structure <NUM>.

Referring to <FIG>, the conductive medium <NUM> is a conductive body 3b provided on the support <NUM>. The conductive body 3b can be provided in various shapes and sizes. The conductive body 3b has sufficient conductive medium, so that the touch key structure <NUM> has better touch sensitivity. The conductive body 3b may be a metal conductive body 3b. The conductive body 3b may be reliably installed on the support <NUM>, the conductive body 3b and the support <NUM> are relatively easy to be fixed, and the connection relationship between the conductive body 3b and the support <NUM> is not limited. The conductive body 3b is integrally connected with the support <NUM> through a secondary molding method. Specially, the support <NUM> is injection-molded first, and then the molded support <NUM> is inserted into a mold to form the conductive body 3b, so that the conductive body 3b is integrally connected with the support <NUM>. The conductive body 3b will not be loose due to other mechanical connection methods, which will affect the touch sensitivity of the touch key structure <NUM>, thereby making the touch key structure <NUM> stable and reliable.

Further, referring to <FIG>, the conductive body 3b is installed in the mounting hole <NUM> and at least one end (both ends in the present embodiment) of the conductive body 3b is exposed to the mounting hole <NUM>, such that the conductive body 3b has a sufficient length. The distance between the sensing electrode <NUM> and the touch panel <NUM> is relatively short, thereby making the touch key structure <NUM> more sensitive.

Referring to <FIG>, in the first embodiment of the present disclosure, the conductive medium <NUM> is a conductive layer 3a provided on the support <NUM>. Compared with providing the conductive body 3b on the support, it is easier to provide the conductive layer 3a on the support <NUM>, and there is no problem of assembling and mounting between the conductive body 3b and the support <NUM>. The conductive layer 3a may be formed on the support <NUM> through a physical means such as spray coating, brush coating, or vacuum plating or chemical plating.

Specially, referring to <FIG>, in the present embodiment, the support <NUM> is provided with a mounting hole <NUM>, and the conductive layer 3a is provided in the mounting hole <NUM>. Since the mounting hole <NUM> can form a sealing space by itself or by means of an external fixture, the conductive layer 3a may be provided on the inner wall of the mounting hole <NUM> through vacuum plating. Of course, it is obviously not limited to this, and chemical plating may also be used.

The mounting hole <NUM> may be a blind hole or a through hole. Please refer to <FIG>, the mounting hole <NUM> is a through hole to avoid having an insulator between the key area and the sensing electrode <NUM>, thereby affecting the size of the sensing capacitor and affecting the sensitivity of the touch key structure <NUM>. Referring to <FIG>, the mounting hole <NUM> is a blind hole. That is, only one end of the mounting hole <NUM> is opened. For this reason, when the conductive layer 3a is provided, vacuum plating may be preferentially used.

BeThe support <NUM> includes two convex parts <NUM> protruded towards both sides, the mounting hole <NUM> is penetrated through the two convex parts <NUM>, such that the distance between the conductive medium <NUM> and the sensing electrode <NUM> and the distance between the conductive medium <NUM> and the key area are both small, so that the touch capacitance is sufficiently large and the sensing sensitivity is higher.

Further, in the present embodiment, referring to <FIG>, the outer surfaces of the convex parts <NUM> are all provided with the conductive layer 3a, and enough conductive medium <NUM> can be arranged, so that the touch capacitance is sufficiently large and the sensing sensitivity is higher.

Referring to <FIG> and <FIG>, the conductive medium <NUM> is provided on a rear side of the touch panel <NUM>. In this way, the structure of the support <NUM> can be omitted compared to the first and second embodiments. Obviously, the design is not limited to this. The conductive medium <NUM> may be embedded in the touch panel <NUM>. For example, the touch panel <NUM> is provided in multiple layers, and the conductive medium <NUM> is an intermediate layer provided on the touch panel <NUM>, or a cavity may be formed inside the touch panel <NUM>. The surface of the touch panel <NUM> is provided with an entrance communicating with the cavity, and the conductive medium <NUM> is provided in the cavity from the entrance.

Referring to <FIG>, the conductive medium <NUM> is a conductive body 3b provided on the rear side of the touch panel <NUM>. The conductive body 3b may be fixed to the rear side of the touch panel <NUM> through, for example, screws, buckles, adhesives, and the like. The conductive body 3b is integrally connected with the touch panel <NUM> through secondary molding. Specially, first, the touch panel <NUM> is injection-molded, and then the formed touch panel <NUM> is embedded in a mold to form the conductive body 3b, such that the touch panel <NUM> is integrally connected with the conductive body 3b. The conductive body 3b will not be loosened due to other mechanical connection methods, which will affect the touch sensitivity of the touch key structure <NUM>.

The specific structure or shape of the conductive body 3b is not limited. For example, referring to <FIG>, the conductive body 3b is in a cylindrical shape with openings at both ends, and one end of the conductive body 3b is connected to the touch panel <NUM>, to facilitate the connection between the conductive body 3b and the touch panel <NUM>. Alternatively, referring to <FIG>, the conductive body 3b is in a cylindrical shape with an open end and a closed end, and the closed end of the conductive body 3b is connected to the touch panel <NUM>, such that there is a sufficient area between the conductive body 3b and the sensing electrode <NUM>, which makes the touch capacitance larger. Further, referring to <FIG>, the conductive body 3b is a solid conductive body 3b structure, and one end of the conductive body 3b is connected to the touch panel <NUM>, such that the size of the conductive body 3b is larger, which makes the touch capacitance larger, thereby making the touch key structure <NUM> more sensitive.

Referring to <FIG>, the conductive medium <NUM> is a conductive layer 3a provided on the rear side of the touch panel <NUM>. The conductive layer 3a is easier to combine with the touch panel <NUM> than the conductive body 3b. The conductive layer 3a may be directly formed on the rear side of the touch panel <NUM> through physical means (coating, brushing, and vacuum plating) or chemical plating.

Besides, in order to make the conductive medium <NUM> have a sufficient size in the inner and outer directions, and the distance between the conductive medium <NUM> and the sensing electrode <NUM> is small, so that the sensing sensitivity of the touch key structure <NUM> is high. The areas where the conductive layer 3a is provided are all protruding towards the touch electrode, and the specific shape of protruding structure is not limited. Referring to <FIG>, a cylindrical body 1b with an opening towards the circuit board <NUM> is protruded on the rear side of the touch panel <NUM>, and the conductive layer 3b is provided on an inner side, an outer side, and/or a rear end of the cylindrical body 1b. As shown in <FIG>, the conductive layer 3b is provided on the outer side of the cylindrical body 1b, such that the conductive layer 3a can be provided on the cylindrical body 1b through spraying or brushing, which is convenient for installation. As shown in <FIG>, the conductive layer 3b is provided on the inner side, the outer side, and the rear end surface of the cylindrical body <NUM>, such that the layout area of the conductive layer 3a is large, which makes the touch capacitance larger. As shown in <FIG>, the conductive layer 3b is provided on the inner side of the cylindrical body <NUM>, and the conductive layer 3a can be formed through vacuum plating or chemical plating. Referring to <FIG> and <FIG>, a pillar 1a is protruded on the rear side of the touch panel <NUM>, and the conductive layer 3a is provided on an outer side and/or a rear end surface of the pillar 1a. As shown in <FIG>, the conductive layer 3a is only provided on the outer side of the pillar 1a. As shown in <FIG>, the conductive layer 3a is provided on both the outer side and the end surface of the pillar 1a, and a sufficient number of the conductive media <NUM> can be provided.

Referring to <FIG> and <FIG>, a distance between the conductive medium <NUM> and the sensing electrode <NUM> is d1, and a distance between the conductive medium <NUM> and the touch panel <NUM> is d2. Theoretically, the smaller d1 and d2 indicate that the distance between the conductive medium <NUM> and the sensing electrode <NUM> and the key area is sufficiently small, so that the touch capacitance is small and the sensitivity is high. A sum of d1 and d2 is greater than or equal to <NUM> and less than or equal to <NUM>.

A periphery of the area where the conductive medium <NUM> is laid out is exceeding the sensing electrode <NUM>, such that the conductive medium <NUM> can completely cover the edge of the sensing electrode <NUM>. Obviously, an exceeding size cannot be too large, if it is too large, the distance between adjacent conductive media <NUM> is too small. Therefore, in an embodiment, a periphery of the conductive medium <NUM> is exceeding the sensing electrode <NUM>, and an exceeding size is H, and H is less than or equal to <NUM>.

The conductive medium <NUM> is a conductive layer 3a formed through spraying, and a thickness of the conductive layer 3a is D. Theoretically, the larger D is, the better, but the size of D is also limited by the process. In an embodiment, D is greater than or equal to <NUM> and less than or equal to <NUM>.

In anembodiment, limited by the distance between the touch panel <NUM> and the circuit board <NUM>, a size of the conductive medium is K in a front-rear direction, and K is less than <NUM>.

The conductive medium <NUM> may be a discontinuous structure. For example, the conductive medium <NUM> includes a plurality of sections arranged on the front-rear direction, and may also be a continuous structure. When the conductive medium <NUM> is the continuous structure, the touch capacitance is larger than the discontinuous structure. In the present embodiment, each of the conductive media <NUM> is continuously disposed.

The conductive medium <NUM> is a conductive layer 3a, and the conductive medium <NUM> is made of the material selected from one of nickel powder, aluminum powder, silver powder, and silver copper powder. These metals have good stability and excellent electrical conductivity.

In an embodiment, a support <NUM> is provided between the touch panel <NUM> and the circuit board <NUM>, a mounting hole <NUM> is defined in the support <NUM>, and the conductive medium <NUM> is a conductive layer 3a provided on an inner wall of the mounting hole <NUM>. In the present embodiment, the conductive medium is a conductive paint, and preferably, the resistance value of the conductive paint is controlled between <NUM>. 2Ω and <NUM>. Therefore, the touch key structure <NUM> has proper sensitivity.

Claim 1:
A touch key structure (<NUM>), comprising:
a touch panel (<NUM>), wherein a front side of the touch panel (<NUM>) has a key area for a user to touch;
a circuit board (<NUM>) provided behind the touch panel (<NUM>), wherein the circuit board (<NUM>) is provided with a sensing electrode (<NUM>) corresponding to the key area; and
a conductive medium (<NUM>) provided between the key area and the sensing electrode (<NUM>);
a support (<NUM>) provided between the circuit board (<NUM>) and the touch panel (<NUM>), wherein the support (<NUM>) is provided with a mounting hole (<NUM>), whereby the conductive medium (<NUM>) is a conductive layer (3a) provided on the support (<NUM>);
the conductive layer (3a) is provided on an inner wall of the mounting hole (<NUM>); and
the support (<NUM>) comprises two convex parts (<NUM>) protruded towards both sides, such that the distance between the conductive medium (<NUM>) and the sensing electrode (<NUM>) and the distance between the conductive medium (<NUM>) and the key area are both small, and the mounting hole (<NUM>) is penetrated through the convex parts (<NUM>).