KR102651624B1 - Glass component, the sensing device including the same and container - Google Patents

Abstract

A glass composition according to an embodiment includes a glass frit; and carbon microcoil powder mixed with the glass frit, wherein the glass frit is included in an amount of 90 to 99% by weight, and the carbon microcoil (CMC) powder is included in an amount of 1 to 10% by weight.

Description

Glass composition, sensing device and container comprising the same {GLASS COMPONENT, THE SENSING DEVICE INCLUDING THE SAME AND CONTAINER}

The present invention relates to a glass composition, and particularly to a glass composition that can detect the state of a material and generates heat when certain conditions are met, and a sensing device and container containing the same.

In recent years, as automobiles have become popular, the spread of automobiles is rapidly occurring across various classes and age groups, and this technological trend in the automobile industry is moving away from the traditional mechanical perspective such as engines, etc., and electronicizing each system for driver convenience. and is gradually transforming into intelligence.

Recently, as part of the electronicization and intelligence of automobiles, technology for vehicle rain sensors has been developed to automatically control the operation of vehicle wipers according to the amount of rainfall. In rainy weather, the vehicle rain sensor detects the amount of rain even if the driver does not operate the wipers. It detects and automatically controls the operation of the wiper.

A conventional vehicle rain sensor is an optical conduction device that installs a light emitting part and a light receiving part inside the windshield of a car and determines the amount of rainfall using the change in light intensity of the light receiving part caused by a change in the refractive index of light caused by rain drops. method was mainly used.

However, the conventional optical conduction type rain sensor has a complicated structure and installation and expensive parts, which increases production costs and has poor measurement accuracy because the measurement area is small and is greatly affected by contaminants. There was a problem.

Therefore, to solve this problem, a capacitive rain sensor has recently been developed that detects rainfall using the change in capacitance of a condenser installed inside the windshield of a car. The configuration and sensing principle of a rain sensor using this capacitive sensor is disclosed in detail in [Document 1] below.

However, even in the case of the rain sensor disclosed in [Document 1], when the vehicle is exposed to a high frequency (RF) environment such as a wireless communication area, noise generated by the external high frequency (hereinafter referred to as 'high frequency noise') There is a problem in that sensing precision is deteriorated due to the influence.

In addition, recently, as in [Document 2], a plurality of condensers are used to detect all rainfall, high-frequency noise, and wiper noise, and when calculating the actual rainfall, the high-frequency noise and wiper noise are removed from the detected rainfall, thereby eliminating the conventional method. A rain sensor for vehicles is being developed that can detect rainfall significantly more stably and precisely than capacitive rain sensors for vehicles based on technology.

However, the capacitive sensor as described above has low sensitivity, so its application is extremely limited, and it is vulnerable to high temperatures and external environmental pollution.

[Document 1] Republic of Korea Patent No. 10-781744 (registration notice on December 4, 2007)

[Document 2] Republic of Korea Patent No. 10-0943401 (registration notice on February 12, 2010)

In an embodiment of the present invention, a glass composition capable of directly detecting a change in the state of a substance at a high temperature or the temperature of a corrosive chemical substance and a sensing device including the same are provided.

Additionally, an embodiment of the present invention provides a glass composition that is resistant to corrosive chemicals, contamination, and high temperatures, and a sensing device and container including the same.

Additionally, in an embodiment of the present invention, a glass composition having linear response characteristics according to temperature changes and a sensing device including the same are provided.

The technical challenges to be achieved in the proposed embodiment are not limited to the technical challenges mentioned above, and other technical challenges not mentioned are clear to those skilled in the art from the description below. It will be understandable.

A glass composition according to an embodiment includes a glass frit; and carbon micro coil (CMC, Carbon Micro Coil) powder mixed with the glass frit, wherein the glass frit is contained in an amount of 90 to 99 wt%, and the carbon micro coil powder is contained in an amount of 1 to 10 wt%.

In addition, the glass composition further includes 1% by weight or less of a binder.

Additionally, the glass frit includes silicon oxide or silicon oxide and at least one of sodium carbonate, alumina, and borosilicate.

Additionally, the carbon fine coil powder is included in 7% by weight in the glass composition.

Meanwhile, the sensing device according to the embodiment includes an insulating layer; an electrode disposed on the insulating layer; and a reaction layer disposed on the insulating layer, wherein the reaction layer is composed of a glass composition including a glass frit and carbon fine coil powder.

Additionally, the glass composition includes 90 to 99% by weight of the glass frit and 1 to 10% by weight of the carbon fine coil powder.

Additionally, the reaction layer has a thickness (mm) of 0.5 to 1.5 and is disposed on the insulating layer.

Additionally, the glass frit includes silicon oxide or silicon oxide and at least one of sodium carbonate, alumina, and borosilicate.

In addition, it is electrically connected to the electrode and further includes a driving unit that processes a detection signal transmitted through the electrode.

Additionally, the driving unit is disposed under the insulating layer and further includes a via that penetrates the insulating layer and has one end connected to the electrode and the other end connected to the driving unit.

In addition, the electrode includes a first electrode portion disposed at an edge area of the insulating layer, and a second electrode portion extending in the longitudinal direction of the insulating layer from one end of the first electrode portion, and the first electrode portion and the second electrode portion The internal angle between the two electrode portions has an obtuse angle.

In addition, the driving unit includes a first frequency generator that outputs a first frequency having an oscillation frequency corresponding to a change in the capacitance value transmitted through the electrode, and a second frequency generator that outputs a second frequency corresponding to a preset reference oscillation frequency. It includes a two-frequency generator, a difference frequency generator that outputs a difference value between the first frequency and the second frequency, and a filter that filters the difference value output through the difference frequency generator within a preset filtering area.

Additionally, the filtering area of the filter is set based on a first threshold for a change in the capacitance value of the reactive layer depending on the state of the sensing object.

Additionally, the driver distinguishes the object that generated the difference value based on the first threshold and a second threshold for changes in the capacitance value for materials other than the sensing object.

Additionally, the first frequency has a frequency corresponding to the amount of change in the inductance value of the carbon fine coil constituting the glass composition and the capacitance value of the capacitor connected to the carbon fine coil.

Additionally, it is a container including an accommodating part, and includes a body that constitutes the accommodating part and heats an object contained in the accommodating part, and the body is made of the glass composition.

According to an embodiment of the present invention, by providing a glass composition using glass frit and carbon fine coil powder, an industrial sensing device capable of directly detecting changes in the state of matter at high temperatures or the temperature of corrosive chemicals can be provided. .

In addition, according to an embodiment of the present invention, by using a glass frit that is durable against contamination and high temperature, it can replace existing household temperature sensors or heaters, and can be applied to various applications that require increased proximity sensitivity.

In addition, according to an embodiment according to the present invention, in the case of a conventional temperature sensor (Thermistor, Thermocouple), the change according to temperature is not linear, and in the case of a conventional Resistance Temperature Detector (RTD) using platinum, the price is high. Although there were high disadvantages, by applying the glass composition according to the present invention, it is possible to provide a temperature sensor that changes linearly with temperature, thereby improving product reliability.

1 is a flowchart showing a method for manufacturing a glass composition according to an embodiment of the present invention in process order.
Figure 2 is a diagram showing carbon fine coil powder 1 according to an embodiment of the present invention.
Figure 3 is a diagram showing a glass composition 3 according to an embodiment of the present invention.
Figure 4 is a diagram showing the operating principle of a sensor using the glass composition 3 according to an embodiment of the present invention.
Figure 5 is a diagram explaining the capacitor function of the carbon microcoil according to an embodiment of the present invention.
Figure 6 is a diagram showing the reactivity evaluation of the glass composition 3 according to an embodiment of the present invention.
Figure 7 is a diagram showing the evaluation of reactivity according to the content of carbon fine coil powder (1) and the thickness of the glass composition (3) according to an embodiment of the present invention.
Figure 8 is a side view showing a rain sensor mounted on the windshield of a vehicle according to an embodiment of the present invention.
FIG. 9 is a cross-sectional view showing the detailed structure of the rain sensor shown in FIG. 8.
FIG. 10 is a plan view of the sensing electrode shown in FIG. 8.
Figure 11 shows the characteristics of carbon microcoils according to an embodiment of the present invention.
FIG. 12 is a diagram showing the configuration of the driving unit 24 shown in FIG. 8.
13 to 15 are diagrams showing changes in difference frequency values according to the first embodiment of the present invention.
Figure 16 is a diagram showing the change in difference frequency value according to the second embodiment of the present invention.
Figures 17 to 19 are graphs showing the changing characteristics of carbon microcoils according to an embodiment of the present invention.
Figure 20 is a flowchart for step-by-step explaining the detection method of the detection device according to an embodiment of the present invention.
Figure 21 is a view showing a container made of the glass composition 3 of the present invention.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted. The suffixes “module” and “part” for components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in themselves. Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and all changes included in the spirit and technical scope of the present invention are not limited. , should be understood to include equivalents or substitutes.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

1 is a flowchart showing a method for manufacturing a glass composition according to an embodiment of the present invention in process order.

Referring to FIG. 1, in order to manufacture the glass composition 3, a mixing process of the raw materials constituting the glass composition 3 is first performed (step 1).

The mixing process of the raw materials may largely include a raw material weighing process and a mixing process.

First, in order to mix the raw materials, the raw materials constituting the glass composition 3 are weighed according to an appropriate mixing ratio.

At this time, the raw materials constituting the glass composition (3) include glass frit (2) and carbon fine coil powder (1). The glass frit (2) combines with the carbon fine coil powder (1) during the firing process of the glass composition (3), and removes the carbon from the external environment within a range below the reaction temperature of the carbon fine coil powder (1). Protects carbon fine coils grown by fine coil powder (1).

The glass frit 2 may contain various metal oxides depending on the intended use. Preferably, the glass frit 2 may include silicon oxide, which is the main component of glass, or alternatively, it may be made of a mixture of the silicon oxide and at least one of sodium carbonate, alumina, and borosilicate.

Additionally, the glass composition 3 may include a metal oxide selected from the group consisting of lead oxide, tellurium oxide, bismuth oxide, zinc oxide, tungsten oxide, silicon oxide, and mixtures thereof.

As an example, the glass frit 2 is a lead oxide-silicon oxide-tellurium oxide-zinc oxide system (PbO-SiO2-TeO2-ZnO), a silicon oxide-tellurium oxide-bismuth oxide-zinc oxide-tungsten oxide system. (SiO2-TeO2-Bi2O3-ZnO-WO3), lead oxide-silicon oxide-tellurium oxide-bismuth oxide-zinc oxide-tungsten oxide (PbO-SiO2-TeO2-Bi2O3-ZnO-WO3), lead oxide-tel oxide It may be a rurium-bismuth oxide system (PbO-TeO2-Bi2O3), or a silicon oxide-tellurium oxide-bismuth oxide-zinc oxide-tungsten oxide system (SiO2-TeO2-Bi2O3-ZnO-WO3).

The glass frit 2 can be manufactured from the above-described metal oxides using a conventional method. For example, it can be manufactured by mixing the above-described metal oxides in a specific composition. At this time, the mixing may be performed using a ball mill or planetary mill. At this time, the mixed composition can be melted at 900°C-1300°C and quenched at 25°C. In addition, the result obtained by the above-described quenching can be pulverized using a disk mill, planetary mill, etc. to produce the glass composition 3 according to an embodiment of the present invention.

At this time, in the mixing ratio of the glass composition (3), the glass frit (2) may be included within 90 to 99% by weight.

Next, prepare the carbon fine coil powder (1) constituting the glass composition (3). The carbon fine coil powder (1) includes carbon fine coils.

Figure 2 is a diagram showing carbon fine coil powder 1 according to an embodiment of the present invention.

Referring to FIG. 2, the carbon fine coil powder (1) is an amorphous carbon fiber that contains carbon fine coils that are not straight but curled like a pig's tail, and have a unique structure that fiber materials cannot have. In addition, the carbon microcoil has super elasticity that can be stretched to a length of more than 10 times the original coil length.

The morphology of the carbon microcoil has a 3D-helical/spiral structure, and the crystal structure is amorphous.

In other words, the carbon microcoils as described above are formed by growing carbon fibers into a coil shape, and thus have a cross-sectional structure in the form of carbon fibers grown into a coil shape.

Here, the carbon microcoil has different properties from carbon nanotubes. That is, the carbon nanotube has a hexagonal shape of carbon connected in the form of a nanotube.

However, the carbon microcoils in the present invention have a form in which carbon is grown into micro-unit coils using a catalyst rather than in the form of a carbon-to-carbon structure.

Carbon nanotubes as described above use the characteristic of being a conductor and an insulator depending on the form of bonding of the elements themselves to obtain a specific measurement value by using the change in impedance from a conductor to an insulator.

However, in the case of carbon microcoils, they are in the form of coils made of microscale carbon, and the L characteristics change as the coil expands and contracts due to force or dielectric constant changes, and the C characteristics depending on the distance between each carbon microcoil. As a result, it has the characteristic of changing impedance depending on the interaction between the carbon microcoils.

In other words, the carbon microcoil itself has the properties of a conductor, but the curing agent or epoxy resin as described above has the properties of an insulator, so it has a unique capacitance value internally, and the carbon microcoil is formed by the force or dielectric constant change as described above. When the distance between coils changes, the characteristics of the capacitance value change accordingly.

In other words, the carbon microcoil has L-C-R characteristics, and accordingly has frequency absorption characteristics, heating characteristics when certain conditions are met, proximity sensing characteristics, and temperature characteristics.

Meanwhile, the carbon fine coil powder (1) may be included in an amount of 1 to 10% by weight.

Additionally, the raw materials constituting the glass composition 3 may further include a binder. The binder may be included in the raw materials constituting the glass composition 3 in an amount of 1% by weight or less. The binder may be included in the raw material to increase mixing uniformity between the glass frit 2 and the carbon fine coil powder 1. Additionally, the binder may be selectively removed or its content may be adjusted depending on the mixing state between the glass frit 2 and the carbon fine coil powder 1.

As described above, weighing of raw materials according to the mixing ratio of carbon fine coil powder (1) and glass frit (2) can be performed through electronic balance, EPMA (Electron Probe Micro-Analysis), SEM (Scanning Electron Microscope), and electron microscope. .

Next, when the carbon fine coil powder (1) and the glass frit (2) as described above are weighed, a mixing process of mixing the measured glass frit (2) and the carbon fine coil powder (1) can be performed. .

The mixing process may be performed through a V-Mixer, Ball-Mill, and ultra-vibrating stirrer. Then, when the mixing process is completed, an evaluation process for the mixing process may proceed. The evaluation process can evaluate the mixing state through EPMA (Electron Probe Micro-Analysis), SEM (Scanning Electron Microscope), electron microscope, and particle size analyzer.

Once the raw material mixing process is completed, a process of plate forming the mixed raw materials is performed (step 2).

The plate forming process may include a process of pressing the blended raw materials. The pressing process may be performed by a press or hot press device.

And, the process conditions of the pressing process include a pressure condition between 3 tons and 5 tons, a time condition between 5 minutes and 10 minutes, and a temperature condition of ordinary temperature. When the pressing process is completed, an evaluation process for the pressing process is performed. Evaluation of the pressing process can be conducted through the sintering density that appears as the raw material is pressed and molded into a certain shape through the plate forming process.

When the pressing process proceeds, a processing process for processing the pressed raw material is performed (step 3).

The processing process may include a sintering process of sintering the raw material on which the plate forming process has been performed.

The sintering process may be carried out in a kiln, and may be carried out under sintering conditions including a temperature increase condition of 10°C/min, a sintering temperature condition between 450°C and 700°C, a holding time condition of 1 hour, and an air atmosphere condition. there is.

When the sintering process proceeds, an evaluation process may be performed on the sintering process, and the evaluation process may be performed with the sintering density of the sintered product of the composition through which the sintering process has been performed.

Figure 3 is a diagram showing a glass composition 3 according to an embodiment of the present invention.

Referring to FIG. 3, as shown in (A), in the initial blended and mixed state of the glass composition (3), the raw materials constituting the glass frit (2) and the carbon fine coil powder (1) The constituent raw materials are only mixed.

And, under the above sintering conditions, when the raw materials are sintered at a temperature close to a certain melting point, bonding is achieved at the bonding surface between the glass frit 2 and the carbon fine coil powder 1, or some are deposited to produce a single composition connected to each other.

As described above, when the sintering process proceeds, a reliability evaluation process to evaluate the manufactured glass composition 3 can be performed (step 4).

At this time, the glass composition 3 can be polished before proceeding with the reliability evaluation process, and the polishing process can be optionally skipped.

The reliability evaluation process may be performed through an electrical evaluation process.

That is, in order to electrically evaluate the glass composition 3, a process of measuring the output value of each manufactured glass composition 3 may be performed. At this time, the manufactured glass composition (3) may contain the carbon fine coil powder (1) in different amounts, for example, a general capacitance sensor (0 weight) that does not contain the carbon fine coil powder (1). %), the glass composition (3) containing the carbon fine coil powder (1) at 1% by weight, the glass composition (3) containing the carbon fine coil powder (1) at 5% by weight, and the glass composition (3) containing the carbon fine coil powder (1) at 10% by weight. Electrical evaluation can be performed on the glass composition (3) containing the carbon fine coil powder (1), respectively.

The electrical evaluation can be performed using the output value of a capacitance digital converter that converts the capacitance value into a digital value and outputs it, or an L-C-R meter that can measure L value/C value/R value, respectively.

In addition, the electrical evaluation sets the reference value when a specific sensing object does not exist in the module area including the glass composition 3, and the change value is accordingly set when the specific sensing object enters the module area. , it is possible to proceed with the degree of difference between the reference value and the change value.

Figure 4 is a diagram showing the operating principle of a sensor using the glass composition 3 according to an embodiment of the present invention.

Referring to FIG. 4, the glass composition 3 contains carbon fine coils grown by the carbon fine coil powder 1.

When a sensing object approaches within a certain radius of the glass composition 3 by the carbon fine coil, a magnetic field is generated around the glass composition 3. In addition, the arrangement state of the carbon fine coils included in the glass composition 3 is changed by the magnetic field, and the capacitance value changes accordingly.

At this time, an electrode may be disposed on the surface of the glass composition 3. The electrode is connected to a driving part (described later), and the driving part acquires a change in the capacitance value of the glass composition 3 through the electrode and senses the state of the sensing object accordingly. Here, the state of the sensing object may include the distance to the sensing object, the concentration of the sensing object, the temperature of the sensing object, and the humidity according to the sensing object.

In other words, when the sensing object approaches the glass composition 3, an electrostatic induction phenomenon occurs. In addition, the carbon microcoil contained in the glass composition 3 functions as a series/parallel capacitor inside the electrode.

Figure 5 is a diagram explaining the capacitor function of the carbon microcoil according to an embodiment of the present invention.

Referring to FIG. 5, as shown in (A), the carbon microcoil can function as a series capacitor in which a plurality of capacitors are connected in series.

Additionally, as shown in (B), the carbon microcoil may function as a parallel capacitor in which multiple capacitors are connected in parallel.

Figure 6 is a diagram showing the reactivity evaluation of the glass composition 3 according to an embodiment of the present invention.

In Figure 6, the result of comparing the capacitance change value of the capacitance sensor manufactured with the glass composition (3) containing carbon fine coil powder (1) according to an embodiment of the present invention and the capacitance change value of a general capacitance sensor. shows.

For the experiment, four samples were prepared, the first sample consisting of a glass composition (3) containing carbon microcoil powder (1) with A content, the second sample consisting of carbon microcoil powder (1) with B content ) is a glass composition (3) containing, and the third and fourth samples are capacitance sensors that do not contain carbon fine coil powder (1) and have different capacitance characteristics.

The capacitance change values of the first to fourth samples are presented in a table as follows.

sample 1
(CMC Yu #1) sample 2
(CMC Yu #2) sample 3
(CMC Nothing #1) sample 4
(CMC Nothing #2) distance 1 1323 1374 859 897 distance 2 1066 1029 654 672 distance 3 708 687 450 464 distance 4 238 232 153 157 distance 5 32 31 17 17

Referring to Figure 6 and Table 1, it was confirmed that there was a significant difference in the reactivity by distance depending on the presence/absence of the carbon fine coil.

The distances 1 to 5 are expressed in stages from 3 mm to 15 mm, and the reactivity is a value obtained by analog-to-digital conversion of the capacitance change value.

As described above, in the case of a sensor containing a carbon fine coil, the change in capacitance value was about 1.55 times higher than that of the existing sensor, and it was confirmed that a sensor with higher sensitivity could be provided accordingly.

Figure 7 is a diagram showing the reactivity evaluation according to the content of carbon fine coil powder (1) and the thickness (mm) of the glass composition (3) according to an embodiment of the present invention.

Figure 7 shows the results of comparing the capacitance change values that appear as the content of the carbon fine coil powder (1) according to an embodiment of the present invention is changed and the thickness of the glass composition (3) produced accordingly is changed. .

The experimental results are presented in a table as shown in Table 2 below.

3% by weight 5% by weight 7% by weight 0T 29.60 29.60 29.60 0.2T 34.2 35.54 37.20 0.5T 36.13 37.9 39.20 1.0T 32.5 34.53 35.53 1.5T 33.17 33.93 34.43 2.0T 33.93 34.47 34.73

Referring to FIG. 7 and Table 2, it was confirmed that the reactivity was significantly different depending on the presence/absence and corresponding content of the carbon microcoil. In addition, it was confirmed that there was a difference in the reactivity depending on the thickness (mm) of the glass composition (3) manufactured including the carbon fine coil powder (1).

At this time, if the content of the carbon fine coil powder (1) exceeds 10% by weight, it is unsuitable for the manufacturing process due to an increase in viscosity, and accordingly, the content of the carbon fine coil powder (1) was limited to 10% by weight.

As a result of the experiment, the best change in capacitance value was shown when the carbon fine coil powder (1) was included at 7% by weight and the thickness (mm) of the glass composition (3) was 0.5T.

According to an embodiment of the present invention, by providing a glass composition using glass frit and carbon fine coil powder, an industrial sensing device capable of directly detecting changes in the state of matter at high temperatures or the temperature of corrosive chemicals can be provided. .

In addition, according to an embodiment of the present invention, by using a glass frit that is durable against contamination and high temperature, it can replace existing household temperature sensors or heaters, and can be applied to various applications that require increased proximity sensitivity.

In addition, according to an embodiment according to the present invention, in the case of a conventional temperature sensor (Thermistor, Thermocouple), the change according to temperature is not linear, and in the case of a conventional Resistance Temperature Detector (RTD) using platinum, the price is high. Although there were high disadvantages, by applying the glass composition according to the present invention, it is possible to provide a temperature sensor that changes linearly with temperature, thereby improving product reliability.

Hereinafter, a sensing device manufactured using the glass composition 3 manufactured as described above will be described. At this time, the sensing device may include a temperature sensor, a humidity sensor, a proximity sensor, etc. Meanwhile, the description below will take as an example that the sensing device is a rain sensor mounted on a vehicle.

Figure 8 is a side view showing a state in which a rain sensor is mounted on the windshield of a vehicle according to an embodiment of the present invention, Figure 9 is a cross-sectional view showing the detailed structure of the rain sensor shown in Figure 8, and Figure 10 is in Figure 8 This is a top view of the sensing electrode shown.

8 to 10, a rain sensor 20 is mounted on the windshield 10 of the vehicle. The rain sensor 20 is installed to face the windshield 10 of the vehicle, and detects the presence of raindrops falling on the windshield 10 or a change in impedance depending on the amount of raindrops.

The rain sensor 20 forms a detection area at a certain position on the windshield 10 of the vehicle, and accordingly detects information according to the state of raindrops occurring within the detection area.

Referring to FIG. 9, the rain sensor 20 includes a substrate 21, a sensing electrode 22, a reaction layer 23, a driver 24, and a protective layer 25. Here, the reaction layer 23 is composed of the glass composition 3 described above. In other words, the reaction layer 23 may be the glass composition 3.

The rain sensor 20 as described above detects impedance changes depending on the presence or absence of raindrops falling on the windshield 10 in a certain area inside the windshield 10 of the vehicle and provides information for driving the wiper. Here, the impedance change includes the change in capacitance value described above.

The substrate 21 is a base substrate on which the sensing electrode 22, the reaction layer 23, and the driver 24 are mounted.

A sensing electrode 22 is formed on the substrate 21. The sensing electrode 22 is formed on the upper surface of the substrate 21 while being buried by the reaction layer 23. The sensing electrodes 22 are formed in plural pieces and detect impedance that changes as the reaction layer 23 reacts with the material formed on the surface of the reaction layer 23.

Preferably, the sensing electrode 22 may include a first sensing electrode of positive polarity and a second sensing electrode of negative polarity.

The reaction layer 23 is formed on the substrate 21 and buries the upper surface of the substrate 21 and the sensing electrode 22.

Preferably, the reaction layer 23 has a predetermined thickness and is formed on the substrate 21 on which the sensing electrode 22 is formed. The reaction layer 23 is made of a conductive material and has the property of changing impedance according to changes in magnetic field, force, and dielectric constant caused by external materials.

Preferably, the reaction layer 23 includes carbon fine coils having a spring shape, and since this is the glass composition 3 described above, a detailed description thereof will be omitted below.

The reactive layer 23 is a force applied when a specific material contacts the surface of the front glass 10 to which the rain sensor 20 is attached, or a change in impedance of the reactive layer 23 due to the dielectric constant of the specific material. occurs.

Then, the sensing electrode 22 detects the change in impedance of the reaction layer 23, and accordingly transmits a detection signal according to the change in impedance to the driver 24.

The driving unit 24 is formed on the lower surface of the substrate 21, and accordingly detects whether it is raining and the amount of rain according to the detection signal transmitted through the sensing electrode 22, and wipes the wiper according to the detected rain or not and the amount of rain. Generates a control signal to control the operation of.

That is, generally, the REAL TERM of impedance is made up of resistance, the POSITIVE IMAGINARY TERM is inductance, and the NEGATIVE IMAGINARY TERM is made up of capacitance, and is made up of the sum of the resistance, inductance, and capacitance.

Therefore, like general resistors, inductors, and capacitors, the rain sensor 20 also requires a pair of sensing electrodes 22 to detect impedance changes occurring in the reaction layer 23. The sensing electrode 22 optimizes the sensing characteristics of the reactive layer 23 and serves to connect the reactive layer 23 and the driver 24.

Here, when a specific force is applied to the surface of the front glass 10 or a material with a specific dielectric constant comes into contact, the capacitance of the reaction layer 23 increases, and accordingly the resistance and inductance values are as above. Conversely, it decreases with capacitance.

At this time, the sensed impedance value is the sum of the resistance value, inductance value, and capacitance, and accordingly, the impedance value linearly decreases depending on the degree of force or dielectric constant applied to the surface.

At this time, the sensing electrode 22 has a structure as shown in FIG. 11 and is formed on the substrate 21.

The sensing electrode 22 has a first electrode portion formed at an edge area of the substrate 21, extends from one end of the first electrode portion to the central region of the substrate, and has a predetermined inclination angle with respect to one end of the first electrode portion. It includes a second electrode portion.

That is, the state of impedance change occurring in the reaction layer 23 varies depending on the shape of the sensing electrode 22.

Therefore, in the present invention, in order to optimally adjust the impedance change state of the reaction layer 23, the sensing electrode 22 including the first electrode portion and the second electrode portion as described above is formed on the substrate 21. .

Meanwhile, a via 223 is formed in the lower part of one end of the second electrode portion.

The via 223 is formed by filling a through hole penetrating the upper and lower surfaces of the substrate 21 with a metal material.

One end of the via 223 penetrates the substrate 21 and is connected to the sensing electrode 22, and the other end of the via 223 is connected to the driver 24 attached to the lower surface of the substrate 21. do.

Meanwhile, the driver 24 is equipped with an analog front end (AFE), and the sensing electrode 22 is connected to it through the via 223.

At this time, the AFE performs a differential amplification function, and there is a difference in the change state of impedance due to the occurrence of rain depending on whether the differential amplification is positive amplification or negative amplification.

Accordingly, the driver 24 detects the change state of the impedance value based on the reference value according to the differential amplification state, and when the degree of the change state exceeds the threshold, drives the wiper to remove raindrops. do.

Hereinafter, the driving steps of the wiper will be described in more detail.

That is, when raindrops fall, the raindrops exert a certain force on the windshield 10 or cause a change in dielectric constant. Additionally, an impedance change occurs in the reaction layer 23 according to the applied force or change in dielectric constant.

At this time, the amount of change in the impedance may correspond to whether or not it is raining and the amount of rain. That is, the force or dielectric constant applied to the reaction layer 23 increases in proportion to the amount of rainfall, and the amount of impedance change decreases in inverse proportion to the degree of increase in the dielectric constant or force.

As described above, when rainfall occurs, the impedance of the reactive layer 23 changes, and according to the impedance change, an amplitude change for the internal clock of the driver 24 occurs.

In addition, a differential signal according to differential amplification of the AFE of the driver 24 is output according to a change in the amplitude of the internal clock.

Thereafter, when the differential signal is output, the output differential signal is converted into a digital signal and transmitted to the vehicle's main control unit (described later).

The main control unit (not shown) determines whether it is raining and the amount of rain based on the amount of impedance change according to the transmitted digital signal, and when the rain occurs and the resulting rainfall amount exceeds a critical point, a wiper to remove raindrops Activate .

Below, the driving principle of the rain sensor 20 will be described in more detail.

As described above, the sensing electrode 22 is embedded in the reaction layer 23 made of carbon fine coils. At this time, although it is said that the sensing electrode is embedded in the reaction layer, this is only an example, and the sensing electrode 22 may be disposed in a protruding form on the surface of the reaction layer 23.

And, the sensing electrode 22 is connected to the driving unit 24 mounted on the lower part of the substrate 21 through a via 223. At this time, the reaction layer 23 itself can determine whether it is raining and the amount of rain according to the amount of change in impedance, and its measurement sensitivity varies depending on the shape of the sensing electrode 22. Accordingly, in the embodiment, the sensing electrode 22 having the above-described planar shape is formed.

In addition, as described above, impedance is composed of a real part and an imaginary part, and the imaginary part is composed of a positive imaginary part (inductive) and a negative imaginary part (capacitive), and includes the carbon microcoil. The rain sensor 20 measures using two characteristic changes: the positive imaginary part (inductive) and the negative imaginary part (capacitive).

That is, when it rains, the force applied to the windshield 10 of the vehicle varies depending on the amount of rain, and the amount of water (raindrops) present on the windshield 10 also varies.

At this time, the carbon fine coil, as its name suggests, consists of a group of very fine coils and is also a dielectric with a dielectric constant.

At this time, the force is measured through a change in the inductive component, that is, a change in the characteristics of the carbon fine coil, and the amount of water present on the windshield 10 is measured by a capacitive change due to a change in dielectric constant.

In other words, each layer constituting the rain sensor 20 acts as a dielectric with a specific dielectric constant. When it rains as described above, a new dielectric called water exists at the electrode, resulting in a capacitive change. ..

At this time, the real part can be adjusted according to the area of the reaction layer 23, and when it rains, the impedance value changes due to changes in inductive and capacitive values as described above.

Therefore, in the embodiment, whether it is raining and the amount of rain are determined by detecting a change in impedance value according to a change in the inductive and capacitive values of the rain sensor 20 as described above.

Meanwhile, the rain sensor 20 as described above forms an adhesive member (not shown) such as silicon on the inside of the windshield 10, and is mounted on a specific inner area of the front glass 10 by the adhesive member. do. At this time, the rain sensor 20 detects the impedance change by considering the dielectric constant of the adhesive member.

Below, the operation of the driving unit 24 will be described in more detail.

The driving unit 24 is connected to the sensing electrode 22 and generates an oscillation frequency according to the change in impedance of the sensor unit 20 that occurs depending on whether or not there is rain and the amount of rainfall, and generates an oscillation frequency according to the difference between the oscillation frequency and the reference frequency. Determine whether or not it is raining and how much it will rain.

At this time, the driver 24 detects whether the difference frequency between the oscillation frequency and the reference frequency falls within a preset filtering area, and detects whether the difference frequency corresponds to the difference frequency only if the difference frequency exists within the preset filtering area. Outputs digital values.

At this time, although it is said that the above operation is performed by the driver, this is only an example, and the driver can only output digital values according to the detection signal transmitted from the sensing electrode, and a separate main control unit (as shown) (not performed), the following specific detection operations can be performed.

That is, the driving unit 24 may include either a low-pass filter (LPF) or a band-pass filter (BPF) depending on the characteristics of the sensor unit 20.

Additionally, the low-pass filter and the band-pass filter have different filtering frequency ranges.

Figure 11 shows the characteristics of carbon microcoils according to an embodiment of the present invention.

As shown in FIG. 11, the carbon fine coil normally has a first inductance value, and as force or dielectric constant is applied to the carbon fine coil, the inductance value decreases.

The inductance value has different reduction amounts depending on the type of material placed on the carbon microcoil.

That is, the inductance value has a relatively small decrease when rainwater due to rainfall contacts the carbon fine coil, and when a part of the human body such as a person contacts, the inductance value has a higher decrease than when the rainwater contacts the metal. When the substance comes into contact, the amount of reduction is higher than when the rainwater or the human body comes into contact.

FIG. 12 is a diagram showing the configuration of the driving unit 24 shown in FIG. 8.

Referring to FIG. 12, the driver 24 includes a first frequency generator 241, a second frequency generator 242, a difference frequency generator 243, a filter 234, and an analog-to-digital converter 245.

The first frequency generator 241 is connected to the sensor unit 20 and generates a first frequency according to the impedance change of the sensor unit 20.

The first frequency generator 241 may be configured as an LC oscillator circuit.

Preferably, the first frequency generator 241 is configured to use a carbon fine coil and a capacitor constituting the sensor unit 20 to generate an oscillation frequency that changes by changing the inductance value of the carbon fine coil. do.

That is, the first frequency generator 241 uses a carbon fine coil attached to the windshield to oscillate the oscillation frequency by the sensor unit 20.

In other words, the inductance value of the carbon fine coil constituting the sensor unit 20 and the capacitance value of the capacitor determine the oscillation frequency of the first frequency generator 241.

The second frequency generator 242 may be a reference oscillator and generates a second frequency corresponding to the reference oscillator frequency.

At this time, the first frequency generated from the first frequency generator 241 may have a slight change, and accordingly, in the first embodiment of the present invention, the filter 234 is configured as a low-pass filter.

Below, the description will be made assuming that the filter 234 is configured as a low-pass filter.

At this time, in a state where no rainfall occurs in the sensor unit 20, the first frequency generated by the first frequency generator 241 and the second frequency generated by the second frequency generator 242 have the same value. It can be set to:

And, when rainfall occurs in the sensor unit 20, the difference between the first frequency and the second frequency increases according to the amount of rainfall, and the amount of rainfall can be determined based on the increasing difference value.

At this time, if the inductance of the carbon fine coil included in the sensor unit 20 is L and the capacitance of the capacitor is C, the first frequency (ω ₀ ) generated in the first frequency generator 241 is expressed by Equation 1 Same as

And, the first voltage value (V ₀ ) corresponding to the first frequency generated by the first frequency generator 241 is expressed in Equation 2 below.

Additionally, the second voltage value (Vr) corresponding to the second frequency generated by the second frequency generator 242 is expressed in Equation 3 below.

The difference frequency generator 243 is connected to the first frequency generator 241 and the second frequency generator 242, and the first frequency generated by the first frequency generator 241 and the second frequency generator 242 ) outputs a difference value corresponding to the difference in the second frequency occurring in

At this time, the difference value (Vdmod) generated from the difference frequency generator 243 is expressed in Equation 4 below.

Here, the reason why the difference value has the same value as Equation 4 is that, when no rainfall occurs in the sensor unit 20, the first frequency generated by the first frequency generator 241 and the This is because the second frequencies generated from the second frequency generator 242 have the same value.

The filter 234 filters the output value generated from the difference frequency generator 243 and outputs the filtered output value.

At this time, the filter 234 has a filtering area corresponding to a frequency range of a certain size, and the output value of the difference frequency generator 243 is filtered within the filtering area.

Here, the filtering area may be determined by the type of the filter 234 and the change characteristics of the carbon fine coil that appears when rainfall occurs in the sensor unit 20.

The changing characteristics of the carbon microcoils will be described in more detail below.

Meanwhile, the type of the filter 234 may be determined by the structure of the carbon fine coil.

That is, the inductance value of the carbon fine coil changes slightly without changing within a large range depending on whether there is rain and the amount of rain, and the first frequency generated from the first frequency generator 241 according to the slightly changing value. If there is no significant difference from the second frequency generated by the second frequency generator 242, the filter 234 can be configured as a low-pass filter.

Additionally, if the first frequency generated by the first frequency generator 241 is significantly different from the second frequency generated by the second frequency generator 242 due to a change in the inductance value of the carbon microcoil, The filter 234 may be configured as a band-pass filter.

In other words, the type of the filter 234 may be determined by the structure, such as the area of the carbon fine coils constituting the sensor unit 20.

The analog-to-digital converter 245 converts the output value output through the filter 234 into a digital value and outputs it.

13 to 15 are diagrams showing changes in difference frequency values according to the first embodiment of the present invention.

Referring to FIG. 13, when no change in dielectric constant occurs without a specific material contacting the sensor unit 20, the first frequency generated by the first frequency generator 241 and the second frequency generator ( The second frequency occurring at 242) may have the same frequency.

Therefore, in a state where no rainfall occurs, the output value filtered by the filter 234 according to the output value output from the difference frequency generator 243 is almost a DC voltage level.

And, referring to FIG. 14, when a specific material comes into contact with the sensor unit 20, a change in dielectric constant occurs, and when the contact material is rainwater caused by rainfall, the output value filtered by the filter 234 is a preset value. Frequency shift occurs within the filtering area.

In other words, when the inductance value of the carbon fine coil of the sensor unit 20 changes as rainfall occurs, a change in the first frequency generated in the first frequency generator 241 occurs, and accordingly There is a difference between the first frequency and the second frequency.

At this time, the difference frequency between the first frequency and the second frequency increases according to the intensity (amount of rainfall) of the occurring rainfall.

Accordingly, in an embodiment of the present invention, the amount of rainfall can be determined according to the value of the difference frequency between the first frequency and the second frequency. In other words, in an embodiment of the present invention, whether it is raining and the amount of rain are determined according to the amount of change in the frequency domain according to the signal output from the filter 234.

Here, the difference between the first frequency and the second frequency may be caused by rainwater or moisture due to rainfall, or alternatively, it may be caused by other foreign substances.

The foreign substances may include human bodies, paper, stones, and metal substances.

Here, the degree of change in the inductance value of the carbon microcoil due to rainfall is different from that of the change in inductance value due to foreign substances such as the human body, paper, stone, and metal substances.

In other words, the inductance value of the carbon fine coil appears different from the critical point of change caused by the rainfall and the critical point of change caused by foreign substances such as the human body, paper, stone, and metal substances.

Therefore, depending on the change critical point of the inductance value (change characteristic of carbon fine coils), it is possible to distinguish whether the difference between the first frequency and the second frequency is caused by rain or foreign substances.

And, in the embodiment, the filtering area of the filter 234 is determined according to the change characteristics of the carbon fine coil caused by each material, and the difference between the first frequency and the second frequency within the determined filtering area The wiper can be selectively driven only when occurs.

Referring to FIG. 15, when the difference between the first frequency and the second frequency is caused by foreign matter rather than the rain, the difference frequency may have a frequency outside the filtering area of the filter 234.

At this time, since the difference frequency is not included in the filtering area as shown in FIG. 15, the wiper is not driven in this case.

Figure 16 is a diagram showing the change in difference frequency value according to the second embodiment of the present invention.

Referring to FIG. 16, the design of the sensor unit 20 is such that there is a difference between the first frequency and the second frequency when no rainfall occurs, and the degree of increase or decrease in the first frequency when rainfall occurs. When is large, the filter 234 may be configured as a band-pass filter.

At this time, the filtering area of the filter 234 may have a frequency range different from that of the low-pass filter.

In addition, whether it is raining and the amount of rain can be determined according to the degree of movement of the difference frequency that occurs according to the change in the difference frequency within the filtering area.

At this time, when the filter 234 is a band-pass filter, the output value of the difference frequency generator 243 is expressed as Equation 5 below.

Figures 17 to 19 are graphs showing the changing characteristics of carbon microcoils according to an embodiment of the present invention.

Referring to Figure 17, carbon microcoils are connected to each other according to stone, paper, servo motor, mobile phone 1 (power off state), mobile phone 2 (power on state), mobile phone 3 (battery disconnected state), battery, multimeter, and water. It has different change characteristics.

In other words, the carbon microcoil generates different output values depending on the material.

Looking at the change in the output value of the carbon microcoil, even for the same stone, different changes occurred depending on the contact area and direction of contact. As the size of the stone increases, the weight and contact area increase and the output value increases.

Additionally, even when a non-magnetic material such as paper or a magnetic material such as a servomotor comes into contact, a large change in the output value occurred without being affected by the magnetic field.

Referring to Figures 18 and 19, the output value of the carbon microcoil according to the present invention has clearly different characteristics when contacted by the human body and when contacted by water due to rainfall.

In other words, the output value of the carbon fine coil has a negative value when the human body comes into contact with it, and has a positive value when it comes into contact with water such as rainfall.

Therefore, in the present invention, based on the characteristics of the carbon microcoil as described above, the difference between the first frequency generated by the first frequency generator 241 and the second frequency generated by the second frequency generator 242 is caused by contact with the human body. It is possible to clearly distinguish whether it occurred or was caused by rainfall.

Accordingly, in the present invention, the response area of the rain sensor, that is, the filtering area of the filter 234, is determined based on the characteristics of the carbon fine coil that responds to the rainfall.

Therefore, in the present invention, by using the characteristics of the carbon fine coil as described above, the sensor unit 20 can be operated only when rain is detected, and the wiper is not operated when a change is detected by a foreign substance such as a human body. It may not be possible.

In other words, drivers generally operate the rain sensor on automatic, but there are cases where young children touch the rain sensor placed on the front of the windshield out of curiosity, and according to the prior art, in the above case, the rain sensor does not detect the rain sensor. There was a risk of injury to young children as the wipers operated.

However, in the present invention, safety can be further secured by preventing the wiper from operating even if there is a difference between the first frequency and the second frequency in the case where the human body of a child comes into contact as described above.

As described above, in the present invention, whether it is raining and the amount of rain are determined based on the change in oscillation frequency that occurs according to the change in inductance of the carbon microcoil.

Meanwhile, in the conventional technology using the existing optical method, the optical signal recognized by the photodiode is different depending on the external illuminance despite the same amount of rainfall, so an optical sensor must be additionally applied to correct this, and when rainfall progresses, the light signal perceived by the photodiode is different. An additional light sensor must be applied to prevent malfunctions when a certain level of light is emitted, and complementary means are essential to verify malfunctions due to changes in the external environment.

In addition, the conventional technology using the existing impedance method requires developing separate circuit algorithm software to prevent the rain sensor from reacting at a sensing level above a certain critical point, and detecting a specific level of detection for specific substances (stones, people, metal objects, etc.). A sensing level database must be developed, and the wiper operation must be manually changed when not in operation, so a means of preventing wiper malfunction caused by specific foreign substances approaching the rain sensor rather than changes in the external environment is essential.

However, in the present invention, since the external environment does not have any effect on the characteristics of the rain sensor, an additional correction sensor for characteristic correction is unnecessary, thereby reducing costs.

In addition, in the present invention, it is possible to measure whether or not it is raining and the amount of rain even with a slight change in inductance, so it is possible to detect low levels of rainfall and avoid foreign substances on the windshield in a circuit without applying a separate software algorithm for avoiding foreign substances. can do.

Figure 20 is a flowchart for step-by-step explaining the detection method of the detection device according to an embodiment of the present invention.

Referring to FIG. 20, first, the first frequency generator 241 generates a first frequency according to the inductance value of the carbon microcoil constituting the sensor unit 20 (step 10).

Then, the second frequency generator 242 generates a second frequency corresponding to the preset reference oscillation frequency (step 11).

Subsequently, the difference frequency generator 243 receives the first frequency generated by the first frequency generator 241 and the second frequency generated by the second frequency generator 242, and accordingly generates the first frequency and the second frequency. Outputs the difference between 2 frequencies (12 steps).

Accordingly, the filter 234 filters the output difference frequency and determines whether the difference frequency exists within a preset filtering area (step 13).

And, if the difference frequency exists within a preset filtering area, the analog-to-digital converter 245 generates and outputs an output value corresponding to the difference frequency. Then, the control unit receives the output value and detects whether it is raining and the amount of rainfall accordingly based on the received output value (step 14).

Next, the control unit determines the driving conditions of the wiper based on the detected rainfall amount and controls the wiper to be driven according to the determined driving conditions (step 15).

Meanwhile, if the received difference frequency does not exist within a preset filtering area, the filter 234 does not output an output value corresponding to the received difference frequency and thus ignores the received difference frequency (16 step).

That is, when a difference between the first frequency and the second frequency occurs due to a foreign substance, the difference frequency does not exist within the filtering area, and accordingly, the rain sensor does not respond.

According to an embodiment, when rainfall occurs, the wiper is immediately reacted to and driven under driving conditions according to the amount of rainfall, thereby improving the driver's convenience in rainy weather.

In addition, according to the embodiment, by determining whether it is raining and the amount of rain using a carbon fine coil, it is possible to provide a rain sensor with differentiated characteristics (response characteristics, precision, accuracy, power consumption, miniaturization, etc.) compared to existing optical methods. You can.

Additionally, according to the embodiment, since the external environment does not affect the rain sensor, an additional correction sensor for correcting the characteristics of the rain sensor is unnecessary, thereby reducing costs.

In addition, according to the embodiment, it is possible to measure whether it is raining and the amount of rain even with a slight change in the inductance of the carbon microcoil, so it is possible to detect low level rainfall, and by setting a reaction area to avoid foreign substances, You can prevent situations in which the wipers are activated in advance.

Figure 21 is a view showing a container made of the glass composition 3 of the present invention.

The container has an accommodating space inside and includes a body formed in a portion that receives an electromagnetic field from the outside.

At this time, the body is made of the glass composition (3).

At this time, the glass composition 3 has durability that can withstand temperatures of 700°C or higher. And, the inside of the glass composition 3 contains fine carbon coils in the form of coils. Accordingly, when an electromagnetic field is generated from the outside, the container composed of the glass composition 3 generates Joule heat due to the external electromagnetic field, thereby heating the material contained therein.

The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

Although the above description focuses on the examples, this is only an example and does not limit the examples, and those skilled in the art will understand that there are various options not exemplified above without departing from the essential characteristics of the examples. You will see that variations and applications of branches are possible. For example, each component specifically shown in the examples can be modified and implemented. And these variations and differences related to application should be interpreted as being included in the scope of the embodiments set forth in the appended claims.

1: Carbon fine coil powder
2: Glass frit
3: Glass composition
10: Front glass
20: sensor unit
21: substrate
22: sensing electrode
23: reaction layer
24: driving unit
25: protective layer

Claims (16)

insulating layer;
an electrode disposed on the insulating layer;
a reaction layer disposed on the insulating layer and the electrode; and
It is electrically connected to the electrode and includes a driving unit that processes a detection signal transmitted through the electrode,
The reaction layer includes a glass composition including glass frit and carbon fine coils,
In the total weight of the glass composition, the glass frit is included in 90% by weight to 99% by weight, and the carbon fine coil powder is included in 1% by weight to 10% by weight,
The driving unit,
a first frequency generator outputting a first frequency having an oscillation frequency corresponding to a change in capacitance value transmitted through the electrode;
a second frequency generator outputting a second frequency corresponding to a preset reference oscillation frequency;
a difference frequency generator outputting a difference value between the first frequency and the second frequency;
A filter that filters the difference value output through the difference frequency generator within a preset filtering area,
The filtering area of the filter is,
It is set based on a first threshold for the change in capacitance value of the reaction layer according to the state of the sensing object,
The driving unit,
Distinguishing the object that generated the difference value based on the first threshold and a second threshold for the change in the capacitance value for materials other than the sensing object,
The first frequency is,
Having a frequency corresponding to the amount of change in the inductance value of the carbon fine coil constituting the glass composition and the capacitance value of the capacitor connected to the carbon fine coil,
Sensing device. According to paragraph 1,
The glass composition is,
further comprising 1% by weight or less of a binder,
The glass frit is,
Silicon oxide or silicon oxide containing at least one of sodium carbonate, alumina and borosilicate
Sensing device. According to claim 1 or 2,
The reaction layer is,
It has a thickness (mm) of 0.5 to 1.5 and is disposed on the insulating layer.
Sensing device.
delete According to claim 1 or 2,
The electrode is
Disposed on the insulating layer and comprising a first electrode and a second electrode spaced apart from each other,
Each of the first electrode and the second electrode,
a first portion disposed at an edge area of the upper surface of the insulating layer;
It includes a second part extending from one end of the first part in the longitudinal direction of the insulating layer,
The interior angle between the first part and the second part has an obtuse angle,
Sensing device.
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