KR102517690B1 - Sensor for detecting pressrue - Google Patents

Abstract

A pressure sensor according to an embodiment of the present invention includes a first electrode layer made of conductive fibers, an elastic dielectric layer disposed on the first electrode layer, a second electrode layer disposed on the elastic dielectric layer and made of conductive fibers, and the first electrode layer disposed on the first electrode layer. A first electrode layer and a signal transfer unit connected to the second electrode layer, wherein the signal transfer unit includes a first metal electrode connected to the first electrode layer, a second metal electrode connected to the second electrode layer, and the first metal electrode. and an insulating layer disposed between the electrode and the second metal electrode, and at least one of the first metal electrode and the second metal electrode has a mesh structure.

Description

Pressure detection sensor {SENSOR FOR DETECTING PRESSRUE}

The present invention relates to a pressure sensing sensor.

Recently, with the development of electronic technology and information communication technology, the field of health care (Health Care) is rapidly developing. That is, there is a demand for a health management system capable of measuring a person's body condition using biometric information, and in particular, a technology for obtaining biometric information using a chair mainly used in daily life is being developed. For example, a technology is being developed to determine the weight, age, posture, and the like of a seated person by mounting a sensor for detecting pressure in a chair.

A typical pressure sensor may have a structure in which a lower electrode, an elastic dielectric layer, and an upper electrode are sequentially stacked. In such a pressure sensor, the thickness of the elastic dielectric layer changes according to the change in the pressure applied on the upper electrode, the capacitance changes according to the change in the thickness of the elastic dielectric layer, and the pressure applied on the upper electrode according to the change in capacitance will yield

However, when such a pressure sensor is shaken or an electromagnetic wave is formed around the pressure sensor, the capacitance of the pressure sensor changes even though no pressure is substantially applied. Changes in the external environment, such as shaking or electromagnetic waves, may act as noise in the pressure sensor.

A technical problem to be achieved by the present invention is to provide a pressure sensor that detects pressure according to an applied weight.

A pressure sensor according to an embodiment of the present invention includes a first electrode layer made of conductive fibers, an elastic dielectric layer disposed on the first electrode layer, a second electrode layer disposed on the elastic dielectric layer and made of conductive fibers, and the first electrode layer disposed on the first electrode layer. A first electrode layer and a signal transfer unit connected to the second electrode layer, wherein the signal transfer unit includes a first metal electrode connected to the first electrode layer, a second metal electrode connected to the second electrode layer, and the first metal electrode. and an insulating layer disposed between the electrode and the second metal electrode, and at least one of the first metal electrode and the second metal electrode has a mesh structure.

The first electrode layer may include a plurality of signal electrodes spaced apart at predetermined intervals, and the second electrode layer may be connected to a ground.

The second metal electrode may have a mesh structure.

The second metal electrode may include copper.

The signal transfer unit may include a flexible printed circuit board (FPCB).

The mesh structure may be entirely formed on one of both sides of the FPCB.

An insulating layer disposed under the first electrode layer may be further included.

A pattern matching the arrangement of the plurality of signal electrodes may be formed on the second electrode layer.

The second electrode layer may be formed so as not to be separated from each other by the pattern.

A pressure sensing device according to an embodiment of the present invention is connected to a pressure sensor, a signal processor connected to the pressure sensor, and processing an electrical signal generated by the pressure sensor, and connected to the signal processor, and connected to the signal processor. and a control unit generating a control signal based on a signal processed by the pressure sensor, wherein the pressure sensor includes a first electrode layer made of conductive fibers, an elastic dielectric layer disposed on the first electrode layer, and an elastic dielectric layer disposed on the elastic dielectric layer. A second electrode layer made of fibers, and a signal transfer unit connected to the first electrode layer and the second electrode layer, wherein the signal transfer unit comprises a first metal electrode connected to the first electrode layer and a signal transfer unit connected to the second electrode layer. It includes a second metal electrode and an insulating layer disposed between the first metal electrode and the second metal electrode, wherein at least one of the first metal electrode and the second metal electrode has a mesh structure.

The pressure sensor according to the embodiment of the present invention can accurately detect the pressure according to the applied weight and accurately detect the pressure distribution.

In particular, the pressure sensor according to an embodiment of the present invention can prevent noise due to shaking of the pressure sensor or noise caused by electromagnetic waves formed around the pressure sensor.

In addition, according to an embodiment of the present invention, it is advantageous to determine the posture because it is detected in units of planes rather than a specific point.

In addition, the pressure sensor according to the embodiment of the present invention can have a large area, and the user does not feel a foreign body sensation. In addition, the pressure sensor according to the embodiment of the present invention has high resolution and is simple to modularize.

1 is a cross-sectional view of a pressure sensing sensor according to an embodiment of the present invention.
2 is a bottom view of a pressure sensing sensor according to an embodiment of the present invention.
3 is a top view of a pressure sensing sensor according to an embodiment of the present invention.
4 is an example of a mesh structure applied to a signal transfer unit of a pressure sensor according to an embodiment of the present invention.
5 is another example of a mesh structure applied to a signal transfer unit of a pressure sensor according to an embodiment of the present invention.
6 is a bottom view of a signal transfer unit of a pressure sensing sensor according to an embodiment of the present invention.
7 is a top view of a signal transmission unit of a pressure sensing sensor according to an embodiment of the present invention.
8 is a bottom view of a pressure sensing sensor according to another embodiment of the present invention.
9 is a top view of a pressure sensing sensor according to another embodiment of the present invention.
10 is a side view of a pressure sensitive chair according to one embodiment of the present invention.
11 is a block diagram of a pressure sensing device built into a pressure sensing chair according to one embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as second and first may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a second element may be termed a first element, and similarly, a first element may be termed a second element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the present application, they should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, but the same or corresponding components regardless of reference numerals are given the same reference numerals, and overlapping descriptions thereof will be omitted.

1 is a cross-sectional view of a pressure sensing sensor according to an embodiment of the present invention, FIG. 2 is a bottom view of a pressure sensing sensor according to an embodiment of the present invention, and FIG. 3 is a pressure sensing sensor according to an embodiment of the present invention. This is a top view of the sensor. 4 is an example of a mesh structure applied to a signal transmission unit of a pressure sensor according to an embodiment of the present invention, and FIG. 5 is a mesh applied to a signal transmission unit of a pressure sensor according to an embodiment of the present invention. Another example of a structure. 6 is a bottom view of the signal transmission unit of the pressure sensor according to an embodiment of the present invention, and FIG. 7 is a top view of the signal transmission unit of the pressure sensor according to an embodiment of the present invention.

1 to 3, the pressure sensor 100 includes a first electrode layer 110, an elastic dielectric layer 120 disposed on the first electrode layer 110, and a second electrode layer disposed on the elastic dielectric layer 120. 130, and a signal transfer unit 140.

Here, the first electrode layer 110 includes a plurality of signal electrodes 112 and a plurality of wiring electrodes 114 connected to the plurality of signal electrodes 112 .

At this time, each wire electrode 114 is connected to the first metal electrode 142 of the signal transfer unit 140, and the wire drawn out from the second electrode layer 130 is the second metal electrode of the signal transfer unit 140 ( 144) are connected. To this end, the signal transfer unit 140 includes the first metal electrode 142, the second metal electrode 144, and the insulating layer 146 disposed between the first metal electrode 142 and the second metal electrode 144. ). In addition, an insulating layer 148 may be further disposed on the second metal electrode 144 . Here, the signal transfer unit 140 may be a rigid printed circuit board or a flexible printed circuit board (FPCB).

In this case, at least one of the first metal electrode 142 and the second metal electrode 144 may have a mesh structure. As shown in FIG. 4 , the mesh structure may be a mesh structure having regular intervals and sizes. Alternatively, the mesh structure may be a mesh structure having a random shape as shown in FIG. 5 . In addition to this, the mesh structure may have a circular shape, an oblique shape, a triangular shape, a polygonal shape, and the like. At this time, the mesh structure may be made of one or more selected from the group consisting of silver (Ag), gold (Au), copper (Cu), and aluminum (Al). The size, shape and material of the mesh structure are not limited thereto and may be variously modified.

According to one embodiment of the present invention, the wiring electrode 114 drawn out from the first electrode layer 110 is connected to the first metal electrode 142 in the form of a wiring, as illustrated in FIG. 6, and the second electrode layer 130 ) may be connected to the second metal electrode 144 having a mesh structure, as illustrated in FIG. 7 . In this case, the second metal electrode 144 may have a mesh structure formed entirely on one side of the signal transfer unit 140, that is, both sides of the FPCB. As described above, when at least one of the first metal electrode 142 and the second metal electrode 144 has a mesh structure, an electrical signal generated from the first electrode layer 110 or the second electrode layer 130 is transmitted to the first metal electrode layer 110. Not only can it be efficiently transferred to the signal processing unit 200 through the electrode 142 or the second metal electrode 144, but also noise of pressure sensing can be prevented by shielding electromagnetic waves on the pressure sensor 100. In addition, since the mesh structure has excellent adhesion performance with wires, there is an advantage in that the pressure sensor is resistant to shaking.

Meanwhile, according to an embodiment of the present invention, the second metal electrode 144 connected to the second electrode layer 130 is connected to the ground electrode of the signal processing unit 200, and the target of pressure sensing, for example, the human body, It may be set to be disposed on the second electrode layer 130 .

In this way, when the second electrode layer 130 is connected to the ground, even if the human body slightly rubs the second electrode layer 130, since no pressure is substantially applied on the second electrode layer 130, the first electrode layer 110 ) and the capacitance between the second electrode layer 130 does not change. Accordingly, it is possible to prevent noise caused by a human body touch. In particular, when the second metal electrode 144 connecting the wire drawn out from the second electrode layer 130 and the ground electrode of the signal processing unit 200 has a mesh structure, electromagnetic waves on the pressure sensor 100 can be shielded. , noise caused by electromagnetic waves can be prevented.

Meanwhile, the first electrode layer 110 and the second electrode layer 130 are made of conductive fibers. For example, the first electrode layer 110 and the second electrode layer 130 may be made of conductive fabric woven with conductive fibers.

The conductive fiber may be a metal wire or a normal fiber coated with a metal film on the surface. The conductive fibers may be ordinary fibers in which metal particles are dispersed. When the conductive fiber is a metal wire, the diameter of the metal wire may be 10 μm to 100 μm. If the diameter of the metal wire is less than 10 μm, the strength of the metal wire is weak and fabric processing may be difficult. If the diameter of the metal wire exceeds 100 μm, the stiffness of the metal wire is high and the flexibility of the fabric may be reduced. It can cause damage to equipment, and it is easy for users to feel a sense of heterogeneity. In this case, the metal wire may be Cu, Ni, or a stainless alloy. The stainless alloy may be, for example, a martensitic stainless alloy, a ferritic stainless alloy, an austenitic stainless alloy, a two-phase stainless alloy, or a precipitation hardening stainless alloy. When the metal wire is a stainless alloy, corrosion resistance of the pressure sensor 100 may be increased.

When the conductive fiber is a normal fiber coated with a metal film on the surface, the metal film may be formed by a method in which metal particles are coated on the surface of the normal fiber by a plating method or a vapor deposition method. In this case, the metal particles may be Cu, Ni, or a stainless alloy, and the metal film may have a thickness of 1 μm to 50 μm. If the thickness of the metal film is less than 1 μm, the conductivity is low, which may cause loss in signal transmission, and if the thickness of the metal film exceeds 50 μm, the metal film may be easily separated from the surface of the fiber.

In addition, the elastic dielectric layer 120 is a dielectric material made of a material having a restoring force that is elastically deformed when pressure is applied from the outside and returns to its original shape when the pressure is released. The elastic dielectric layer 120 may include, for example, a fiber substrate having random fiber arrangement such as foam, nonwoven fabric, nanoweb, polyurethane, nylon, polyethylene terephthalate, and polyester. fibers or natural fibers, elastomers, rubbers, urethanes, and the like. In this case, the thickness of the elastic dielectric layer 120 may be 50 μm to 300 μm.

As such, when the elastic dielectric layer 120 is disposed between the first electrode layer 110 and the second electrode layer 130, when pressure is applied on the second electrode layer 130, the thickness (d) of the elastic dielectric layer 120 decreases, and the capacitance between the first electrode layer 120 and the second electrode layer 130 changes. The pressure sensor 100 and the pressure sensing device including the pressure sensor according to an embodiment of the present invention may detect the pressure applied to the second electrode layer 130 based on the capacitance variation.

Meanwhile, according to an embodiment of the present invention, the plurality of signal electrodes 112 are spaced apart at predetermined intervals, and each signal electrode may be connected to each wiring electrode. Accordingly, capacitance change amount can be obtained for each signal electrode, and capacitance change amount distribution on the pressure sensor 100 can be obtained. That is, each signal electrode can act as one sensing point.

In addition, according to an embodiment of the present invention, the second electrode layer 130 is connected as a whole, and the second electrode layer 130 has a pattern 132 matching the arrangement of the plurality of signal electrodes 112 of the first electrode layer 110. ) can be formed. At this time, a plurality of second electrode layers 130 are not separated from each other by the pattern 122 . An empty space may be formed in a part of the second electrode layer 130 due to the pattern 132 formed on the second electrode layer 130 or the empty space may be filled with an insulating material. In this way, when the pattern of the second electrode layer 130 matches the arrangement of the plurality of signal electrodes 112 of the first electrode layer 110, the sensitivity of pressure sensing can be improved for each signal electrode.

According to another embodiment of the present invention, as shown in FIGS. 8 to 9, a pattern 112-1 is formed on each signal electrode 112 of the first electrode layer 110, and the second electrode layer 130 has A pattern 132-1 matching the pattern formed on each signal electrode 112 of the first electrode layer 110 may be further formed. Here, due to the pattern formed on the first electrode layer 110, an empty space may be formed in a part of the first electrode layer 110 or the formed empty space may be filled with an insulating material. In this way, the pattern 112-1 is formed on each signal electrode 112, and the pattern 132-1 is also formed on the second electrode layer 130 to match the pattern 112-1 formed on each signal electrode 112. When is formed, since the amount of capacitance change can be subdivided and sensed, the sensitivity and resolution of pressure sensing can be further improved.

According to another embodiment of the present invention, although not shown, the pressure sensor 100 may further include an insulating layer. The insulating layer may be disposed under the first electrode layer 110 . According to an embodiment of the present invention, the first electrode layer 110 including a plurality of signal electrodes 112 is disposed on the lower surface of the pressure sensor 100, and the second electrode layer 130 connected to the ground detects pressure. When disposed on the upper surface of the sensor 100, that is, the surface on which the target for pressure sensing is placed, when the insulating layer 160 is bonded under the first electrode layer 110, interference between the plurality of signal electrodes 112 is minimized. can do.

Table 1 shows capacitance change amounts of pressure sensors according to Comparative Examples and Examples. The pressure sensing sensor according to the comparative example includes a first electrode layer 110 including a plurality of signal electrodes 112, an elastic dielectric layer 120 on the first electrode layer 110, and a second electrode layer 130 on the elastic dielectric layer 120. Including, the first electrode layer 110 is connected to the signal electrode of the signal processing unit 200 through a wire-shaped metal electrode of the signal transmission unit 140, and the second electrode layer 130 is the signal transmission unit 140 was connected to the ground electrode of the signal processing unit 200 through a metal electrode in the form of a wire. In addition, the pressure sensor according to the embodiment includes a first electrode layer 110 including a plurality of signal electrodes 112, an elastic dielectric layer 120 on the first electrode layer 110, and a second electrode layer on the elastic dielectric layer 120 ( 130), the first electrode layer 110 is connected to the signal electrode of the signal processing unit 200 through a wire-shaped metal electrode of the signal transmission unit 140, and the second electrode layer 130 is a signal transmission unit ( 140) connected to the ground electrode of the signal processing unit 200 through the metal electrode having a mesh structure.

Experimental example Initial (0g) 300g Change amount when shaken comparative example 124pF 155pF 3pF Example 132pF 165pF 0pF

Referring to Table 1, it can be seen that both Comparative Examples and Examples show similar capacitance changes of 31 pF and 33 pF when a weight of 0 g and a weight of 300 g are applied, respectively. However, when the signal connection part, that is, the printed circuit board is shaken, the amount of capacitance change for the pressure sensor of the comparative example is 3 pF, but the capacitance change amount for the pressure sensor of the embodiment is 0 pF. That is, according to the embodiment of the present invention, it can be seen that the pressure sensing performance of the embodiment in which one metal electrode has a mesh structure is not low compared to the comparative example in which all the metal electrodes of the signal transfer unit are configured in the form of wires. In addition, it can be seen that noise due to vibration can be prevented by being more firmly coupled in the embodiment using the bonding between the wires and the mesh, compared to the comparative example using the bonding between the wires.

A pressure sensor according to an embodiment of the present invention may be applied to a pressure-sensing chair for posture correction, a room-sensing mat, a fall prevention mat, and the like.

10 is a side view of a pressure-sensing chair according to an embodiment of the present invention, and FIG. 11 is a block diagram of a pressure-sensing device built into the pressure-sensing chair according to an embodiment of the present invention.

Referring to FIGS. 10 and 11 , a pressure sensing chair 1000 includes a seat 1100 , armrests 1200 , a backrest 1300 , and legs 1400 . When a person is seated on the seat 1100, the pressure sensing device 300 built into the pressure sensing chair 1000 may detect whether or not the person is seated and measure a relative pressure distribution according to the seated position. The pressure sensing device 300 may detect weight, age, sitting posture, etc. according to the measured pressure distribution.

The pressure sensing device 300 may include a pressure sensing sensor 100 , a signal processing unit 200 , a control unit 310 and a communication unit 320 . The pressure sensor 100 may detect whether a person is seated on the seat 1100 and a relative pressure distribution according to the seated position.

According to an embodiment of the present invention, the pressure sensor 100 may be disposed within the seat 1100 . Also, the signal processor 200 is connected to the pressure sensor 100 and may process an electrical signal generated by the pressure sensor 100 . Also, the control unit 310 is connected to the signal processing unit 200 and can generate a control signal based on the signal processed by the signal processing unit 200 . For example, the controller 310 may control on/off of the pressure sensing device 300 using a result of processing a signal detected by the pressure sensor 100 . As another example, the controller 310 may generate diagnostic information about the seated person's posture using a result of processing a signal detected by the pressure sensor 100 . As another example, the controller 310 may generate an alarm signal for correcting a seated person's posture by using a result of processing a signal detected by the pressure sensor 100 .

Then, the communication unit 320 transmits the control signal generated by the control unit 310 to an external device.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

100: pressure detection sensor
110: first electrode layer
120: elastic dielectric layer
130: second electrode layer
112: signal electrode
114: wiring electrode

Claims (10)

A first electrode layer made of conductive fibers;
an elastic dielectric layer disposed on the first electrode layer;
a second electrode layer disposed on the elastic dielectric layer and made of conductive fibers;
A signal transfer unit connected to the first electrode layer and the second electrode layer, and
A first insulating layer disposed under the first electrode layer,
The signal transfer unit,
A first metal electrode connected to the first electrode layer;
A second metal electrode connected to the second electrode layer, and
A second insulating layer disposed between the first metal electrode and the second metal electrode,
The second metal electrode has a mesh structure,
The second electrode layer is connected to ground through the second metal electrode,
The first electrode layer includes a plurality of signal electrodes spaced apart at predetermined intervals,
A pattern matching the arrangement of the plurality of signal electrodes is formed on the second electrode layer,
The second electrode layer is formed so as not to be separated from each other by the pattern. delete According to claim 1,
The signal transfer unit is a pressure sensing sensor including a flexible printed circuit board (FPCB). According to claim 3,
The mesh structure is entirely formed on at least one of both sides of the FPCB. delete delete The pressure sensor according to any one of claims 1, 3 and 4,
A signal processing unit connected to the pressure sensor and processing an electrical signal generated by the pressure sensor; and
A control unit that is connected to the signal processing unit and generates a control signal based on the signal processed by the signal processing unit.
A pressure sensing device comprising a. delete delete delete

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