KR102467998B1 - Sensor for detecting pressrue - Google Patents

Abstract

A pressure sensor according to an embodiment of the present invention is made of a conductive fiber and includes a plurality of signal electrodes disposed in a first region and a plurality of wiring electrodes disposed in a second region and connected to the plurality of signal electrodes. It includes a first electrode layer, an elastic dielectric layer disposed on the first region, and a second electrode layer disposed on the elastic dielectric layer and made of conductive fibers.

Description

Pressure detection sensor {SENSOR FOR DETECTING PRESSRUE}

The present invention relates to a pressure sensor and a pressure sensing device including the same.

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, there is a demand for a technology for determining 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 a human body touches the pressure sensor, the capacitance of the pressure sensor changes even though pressure is not substantially applied. In this way, the touch of the human body may act as noise of 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 is made of a conductive fiber and includes a plurality of signal electrodes disposed in a first region and a plurality of wiring electrodes disposed in a second region and connected to the plurality of signal electrodes. It includes a first electrode layer, an elastic dielectric layer disposed on the first region, and a second electrode layer disposed on the elastic dielectric layer and made of conductive fibers.

A supporting substrate disposed on the second region may be further included.

The supporting substrate may be disposed on a side surface of the elastic dielectric layer on the plurality of wire electrodes, and the hardness of the supporting substrate may be greater than that of the elastic dielectric layer.

The plurality of wiring electrodes may be buried by the supporting substrate.

Bending may occur between the plurality of signal electrodes and the plurality of wire electrodes.

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

The second electrode layer may be connected to ground.

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 sensing sensor is made of a conductive fiber, and a plurality of signal electrodes disposed in a first area and a plurality of signal electrodes disposed in a second area. A first electrode layer including a plurality of wiring electrodes connected to the first electrode layer, an elastic dielectric layer disposed on the first region, and a second electrode layer disposed on the elastic dielectric layer and made of conductive fibers.

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 the embodiment of the present invention can prevent noise caused by a human body touch or pressure applied to a wire electrode.

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 a bottom view of a pressure sensing sensor according to another embodiment of the present invention.
5 is a top view of a pressure sensing sensor according to another embodiment of the present invention.
6 is a cross-sectional view of a pressure sensing sensor according to another embodiment of the present invention.
7 and 8 are cross-sectional views of a pressure sensor according to another embodiment of the present invention.
9 is a cross-sectional view of a pressure sensing sensor according to another embodiment of the present invention.
10 is a cross-sectional view of a pressure sensing sensor according to another embodiment of the present invention.
11 is a side view of a pressure sensitive chair according to one embodiment of the present invention.
12 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.

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 printed circuit board (140).

Here, the first electrode layer 110 includes a plurality of signal electrodes 112 disposed in the first region 10 and a plurality of wiring electrodes disposed in the second region 20 and connected to the plurality of signal electrodes 112 ( 114). Also, the elastic dielectric layer 120 and the second electrode layer 130 are disposed on the first region 10 , that is, the signal electrode 112 of the first electrode layer 110 . Here, since the area for sensing the pressure is the area where the plurality of signal electrodes 112 are disposed, that is, the first area 10, in this specification, the first area 10 may be used interchangeably with the sensing area, and the second area The area 20 may be used interchangeably with the non-sensing area.

At this time, each wiring electrode 114 is connected to a signal electrode of a signal processing unit (not shown) through a copper wiring of the printed circuit board 140, and the wiring drawn out from the second electrode layer 130 is connected to the printed circuit board 140. It may be connected to the ground electrode of the signal processing unit (not shown) through the ground of the . A target for pressure sensing, for example, a human body, may be set to be disposed on the second electrode layer 130 . Here, the printed circuit board 140 may be a rigid printed circuit board or a flexible printed circuit board. At this time, the printed circuit board 140 extends on the surface on which the first electrode layer 110 is disposed, and a wire drawn out from the second electrode layer 130 penetrates the elastic dielectric layer 120 to form a ground of the printed circuit board 140. can be connected to Alternatively, the printed circuit board 140 extends on the surface on which the second electrode layer 130 is disposed, and the plurality of wiring electrodes 114 of the first electrode layer 110 penetrate the elastic dielectric layer 120 to form a printed circuit board ( 140) may be connected to the copper wiring. Alternatively, the printed circuit board 140 is disposed on the side of the elastic dielectric layer 120, and the plurality of wiring electrodes 114 of the first electrode layer 110 are connected to copper wiring on one side of the printed circuit board 140, , The wire drawn out from the second electrode layer 130 may be connected to the ground on the other side of the printed circuit board 140 .

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.

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 metal wire may have a diameter of 10 μm to 100 μm. If the diameter of the metal wire is less than 10㎛, the strength of the metal wire is weak and it may be difficult to process the fabric. If the diameter of the metal wire exceeds 100㎛, 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, a precipitation hardening stainless alloy, or the like. 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.

In particular, according to an embodiment of the present invention, the elastic dielectric layer 120 and the second electrode layer 130 are disposed on the signal electrode 112 of the first electrode layer 110, and the elastic dielectric layer 120 and the second electrode layer ( 130) does not overlap with the wiring electrode 114 of the first electrode layer 110, only the pressure applied on the region where the signal electrode 112 is disposed, that is, the first region 10 is sensed, Pressure applied to the region where the wire electrode 114 is disposed, that is, the second region 20 may not be sensed. Accordingly, even if pressure is applied to the wire electrode 114 that is the non-sensing region 20, the capacitance does not change, and thus noise caused by the wire electrode 114 can be reduced.

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 formed 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. 4 and 5, a pattern 112-1 is formed on each signal electrode 112 of the first electrode layer 110, and a pattern 112-1 is formed on the second electrode layer 130. 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 112-1 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.

Meanwhile, according to an embodiment of the present invention, the pressure sensor 100 may further include a support substrate for supporting the wiring electrode 114 of the first electrode layer 110 .

6 is a cross-sectional view of a pressure sensing sensor according to another embodiment of the present invention. Redundant descriptions of the same contents as those of FIGS. 1 to 5 are omitted.

Referring to FIG. 6 , 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 130 disposed on the elastic dielectric layer 120 . ), a printed circuit board 140, and a support base 150.

Here, the supporting substrate 150 is disposed on the side surface of the elastic dielectric layer 120 on the second region 20, that is, the plurality of wiring electrodes 114, and the hardness of the supporting substrate 150 is the hardness of the elastic dielectric layer 120. can be bigger

As such, if the supporting base material 150 does not have elasticity, even if pressure is applied to the region where the wiring electrode 114 is disposed, that is, the second region 20, the thickness of the supporting base material 150 does not change. The capacitance does not change. Accordingly, noise caused by the wiring electrode 114 can be reduced.

7 and 8 are cross-sectional views of a pressure sensor according to another embodiment of the present invention. Redundant descriptions of the same contents as those of FIGS. 1 to 6 are omitted.

7 and 8 , 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), a printed circuit board (140), and a support base (150).

Here, the elastic dielectric layer 120 and the second electrode layer 130 are disposed only in the first region 10 . Accordingly, even if pressure is applied to the region where the wire electrode 114 is disposed, that is, the second region 20, the capacitance does not change, and thus noise caused by the wire electrode 114 can be fundamentally blocked.

In this case, the plurality of wiring electrodes 114 may be buried in the supporting substrate 150 . Here, the supporting substrate 150 may include an insulating material. For example, the supporting substrate 150 may be an insulating adhesive or insulating tape having a greater hardness than the wiring electrode 114 . Accordingly, the plurality of wire electrodes 114 can have appropriate strength and can be protected from the external environment.

9 is a cross-sectional view of a pressure sensing sensor according to another embodiment of the present invention. Redundant descriptions of the same contents as those of FIGS. 1 to 8 are omitted.

Referring to FIG. 9 , 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 130 disposed on the elastic dielectric layer 120 . ), a printed circuit board 140, and an insulating layer 160.

The insulating layer 160 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.

10 is a cross-sectional view of a pressure sensing sensor according to another embodiment of the present invention. Redundant descriptions of the same contents as those of FIGS. 1 to 9 are omitted.

Referring to FIG. 10 , 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 130 disposed on the elastic dielectric layer 120. ), a printed circuit board 140, and an insulating layer 160.

At this time, the first electrode layer 110 including the plurality of signal electrodes 112 and the plurality of wiring electrodes 114 is disposed on the insulating layer 160, and the plurality of signal electrodes 112 and the plurality of wiring electrodes 114 ) may be bent. Accordingly, the plurality of wire electrodes 114 may be disposed on the side surface of the surface to which pressure is applied. Also, the pressure sensor 100 may be embedded in the instrument 200 .

Accordingly, only the pressure applied to the region where the signal electrode 112 is disposed can be sensed, and noise caused by the wiring electrode 114 can be reduced.

Table 1 shows capacitance change amounts of pressure sensors according to Comparative Examples and Examples. In the pressure sensing sensor according to the comparative example, the first electrode layer 110 including the second electrode layer 130 connected to ground, the elastic dielectric layer 120, and the plurality of signal electrodes 112 is sequentially stacked from bottom to top, In the pressure sensor according to the example, a first electrode layer 110 including a plurality of signal electrodes 112, an elastic dielectric layer 120, and a second electrode layer 130 connected to the ground are sequentially stacked from bottom to top. Measurement of the capacitance change in the initial state, that is, a state in which no weight is applied, a state in which a weight of 300g is applied, and a state in which only a hand touches the pressure sensor according to the comparative example and the embodiment did

Experimental example Initial (0g) at hand touch 300g comparative example 131.2pF 142.2pF 159.1pF Example 132.3pF 132.8pF 159.8pF

Referring to Table 1, it can be seen that both Comparative Example and Example showed a similar capacitance change amount of about 29 pF when a weight of 0 g was applied and when a weight of 300 g was applied. However, when only the hand is touched without applying pressure to the top, it can be seen that the capacitance change amount in the comparative example is 11.0 pF, but the capacitance change amount in the embodiment is 0.5 pF. As such, according to an embodiment of the present invention, it can be seen that noise caused by a human body touch can be prevented.

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.

11 is a side view of a pressure-sensing chair according to an embodiment of the present invention, and FIG. 12 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. 11 and 12 , a pressure sensing chair 1000 may include a seat 1100 , armrests 1200 , backrests 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 310 , a control unit 320 and a communication unit 330 . 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 310 is connected to the pressure sensor 100 and may process an electrical signal generated by the pressure sensor 100 . Also, the control unit 320 may be connected to the signal processing unit 310 and generate a control signal based on the signal processed by the signal processing unit 310 . For example, the control unit 320 may control on/off of the pressure sensing device 300 using a result of processing a signal detected by the pressure sensing sensor 100 . As another example, the controller 320 may generate diagnostic information about the seated person's posture by using a result of processing a signal detected by the pressure sensor 100 . As another example, the controller 320 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 330 transmits the control signal generated by the control unit 320 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 and including a plurality of signal electrodes disposed in a first region and a plurality of wiring electrodes disposed in a second region and connected to the plurality of signal electrodes;
an elastic dielectric layer disposed on the first region;
a second electrode layer disposed on the elastic dielectric layer and made of conductive fibers; and
A pressure sensing sensor comprising a supporting substrate disposed on the second region. According to claim 1,
Pressure sensing sensor further comprising an insulating layer disposed under the first electrode layer. According to claim 1,
The support substrate is disposed on the side surface of the elastic dielectric layer on the plurality of wiring electrodes,
The pressure sensing sensor of claim 1, wherein the hardness of the supporting substrate is greater than the hardness of the elastic dielectric layer. According to claim 1,
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. The pressure sensing sensor according to any one of claims 1 to 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 delete delete

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