KR100755143B1 - Refrigerator for wireless power transmission to sensor for detecting condition of stored food - Google Patents

Abstract

A refrigerator capable of wirelessly supplying energy to a sensor for detecting conditions of stored foods is provided to measure data of the conditions of the stored foods, and to control inside temperature of the refrigerator to be suitable for long period storage of the foods by wirelessly transmitting and receiving energy between a sensor unit and a refrigerator main body. A refrigerator capable of wirelessly supplying energy to a sensor for detecting conditions of stored foods comprises an energy transmission unit(230), an energy reception unit(130) and a sensor unit(110). The energy transmission unit is installed in the refrigerator, receives energy from an outside power supply(300) and transmits it wirelessly. The energy reception unit is installed in a food container(100), and receives wirelessly transmitted energy. The sensor unit is installed in the food container, electrically coupled to the energy reception unit so as to measure at least one selected from salinity, acidity or temperature.

Description

Refrigerator for wirelessly supplying energy to sensors for detecting food storage status {Refrigerator for Wireless Power Transmission to Sensor for Detecting Condition of Stored Food}

1 is a schematic configuration diagram of an embodiment of a refrigerator according to the present invention;

2 is a perspective view of the embodiment of FIG. 1,

3 is a partial cross-sectional view seen from the line A-A of FIG.

<Explanation of symbols for main parts of the drawings>

50: food 100: food container

110 sensor unit 111 measuring electrode

112: measuring circuit 120: data transmitting unit

130: energy receiving unit 200: refrigerator

210: data receiver 220: controller

230: energy transmission unit 300: external power

The present invention relates to a refrigerator for wirelessly supplying energy to a sensor for detecting food storage conditions, and more particularly, energy required by a sensor installed in a food container to measure salinity, acidity or temperature of the food contained in the food container. The present invention relates to a refrigerator having wirelessly increased the convenience of use.

Refrigerators are widely used for the storage of food. The refrigerator has a general function of keeping the inside at a low temperature below room temperature in order to improve the storage of food. However, as living standards and diets are diversified, there is a need for refrigerators with additional functions besides simple storage. For example, for foods whose storage properties are determined by salinity, such as salted foods, the storage temperature should be changed according to salinity, and for fermented foods such as fermented foods, fermentation degree should be controlled. .

Salted food is a generic name for foods that have increased shelf life by adding salt, and typically include pickles, ham, bacon, kimchi, pickled radish, and salted fish. However, since salt intake is not good for health, recent salt foods are usually made by reducing the amount of salt, so salt storage alone is not perfect for improving storage. Salinity is important in salted foods because the storage temperature is determined by the salinity of the food.

Fermented foods are foods made by fermentation of microorganisms such as lactic acid bacteria and yeast, and the acidity and taste change as fermentation proceeds. In addition, the temperature suitable for fermentation is different depending on the type of microorganisms fermenting, and the taste is different for each person, so even the same fermented food may have a different degree of fermentation. Since fermented foods often change in acidity as the fermentation progresses, the degree of fermentation can often be determined by measuring the acidity of the food.

On the other hand, in the case of fermented foods such as kimchi and fermented foods, the speed of fermentation varies according to salinity and temperature, and the progress of fermentation can be known by measuring acidity. In addition, the acidity should be measured to determine the degree of fermentation, and then the storage temperature should be reset if necessary for further fermentation.

In addition, since fermentation is often accompanied by exotherm, it is necessary to check whether the temperature of the food has reached the target storage temperature.

Therefore, if a refrigerator for storing food is normally provided with means for measuring the storage state of the food, that is, salinity, acidity and temperature, it is possible to create an optimal storage condition.

Looking at the way of measuring salinity representatively in the storage state of such food, as described below are largely known three.

The first is the refractive index measurement method, when the light generated from the laser module is irradiated to the light-transmitting measurement object, the light is refracted. The refractive index changes according to the salinity of the measurement object, so the salinity of the measurement object is calculated using this. .

The second chloride ion (Cl ^-) concentration of the measurement method, the object to be measured on is then treated with a reagent containing ions (Ag ^+), and calculating the concentration of the chloride ions over the amount of silver chloride (AgCl) which is precipitated, and the value It is a way to calculate salinity from.

The third method is an electrical conductivity measurement method, in which the electrical conductivity is changed according to the ion concentration of the measurement target. A pair of electrodes are brought into contact with the measurement target, a voltage is applied to the electrodes, and the salinity is measured by measuring current. to be.

Among them, the refractive index measurement method has a problem that the refractive index of the measurement object is affected by temperature as well as salinity, and thus must be compensated by separately measuring the change in refractive index according to the temperature. In addition, the refractive index measurement method is widely used to measure the salinity of seawater, and it is known that it is almost impossible to apply to foods in which various components are mixed. Chlorine ion concentration measurement method has a disadvantage that it is difficult to apply when the measuring object is a food because the reagent to be toxic can be toxic, and the measurement process is complicated and time-consuming. Therefore, recently, salinity sensors of the conductivity measurement method that can measure the salinity at a low cost within a short time have been developed.

Conventional techniques are known in which a salinity sensor, an acidity sensor and other necessary sensors of the electrical conductivity measurement method are selectively implanted in a refrigerator. Refrigerators according to the prior art control the refrigeration temperature based on the storage state of the food measured by various sensors including the salinity sensor, that is, salinity, acidity or temperature. However, refrigerators according to the prior art have a problem as described below.

If the food is usually stored directly in the refrigerator, it is inconvenient to put it in and take out, so that food is stored in a separate container and then stored in the refrigerator. In particular, fermented foods containing liquid ingredients such as kimchi are absolutely necessary for such a container.

On the other hand, since the salinity measuring device, in particular, the salinity sensor of the electrical conductivity measurement method should be in physical contact with the object to be measured, the refrigerators of the prior art are equipped with various sensors in the container. However, in order for a user to take food out of the container, the container needs to be removed from the refrigerator, and in particular, a means for supplying power to a sensor that requires electric energy to measure storage conditions, such as a salinity sensor of electric conductivity measurement method, is provided. Should be provided.

However, the refrigerators according to the prior art do not present a specific means for supplying electrical energy to the sensor. However, in consideration of the conventional electrical connection means, it is possible to assume techniques such as connecting the wires from the controller of the refrigerator to the sensor of the container or forming contact terminals in the refrigerator and the container, respectively. First, when the sensor and the refrigerator of the container is directly connected by the wire, the range in which the container can be moved is severely limited, so the practicality is significantly reduced. Next, when contact terminals are installed at the end viewed from the container side and the refrigerator side of the upper conductor, and each contact terminal is electrically connected when the container is accommodated in the refrigerator, the inside of the humid refrigerator In the environment of the contact terminal is easy to corrode, so durability is poor. In addition, since the container is not normally fixed to the refrigerator, the energy supply also becomes unstable unless a separate means for stably maintaining the contact point is provided. In addition, every time the container is put in the refrigerator, the position of the container must be accurately adjusted so that the contact terminals of the container and the refrigerator correspond to each other.

The present invention has been made to solve the problems of the prior art as described above, in order to measure the storage state such as salinity, acidity or temperature of the stored food, even if the container containing the food is often put in or taken out of the refrigerator An object of the present invention is to provide a refrigerator capable of stably providing power to a sensor installed in a container.

Another object of the present invention is to provide a refrigerator capable of reliable energy transmission even in a humid environment.

Other objects, specific advantages and novel features of the invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings.

In order to achieve the above object, a refrigerator according to the present invention is a refrigerator for storing food contained in a food container, the energy transmission unit installed in the refrigerator, electrically connected to an external power source, and wirelessly transmitting energy; And an energy receiving unit installed in the container and receiving energy transmitted wirelessly, and a sensor unit installed in the food container and electrically connected to the energy receiving unit to measure at least one selected from salinity, acidity or temperature of the food. do.

According to the present invention, since the sensor unit installed in the food container can be wirelessly supplied with energy, even if the food container is frequently taken out of the refrigerator or put in the refrigerator, the data regarding the storage state of the food can be stably measured. Is increased.

In the refrigerator according to the present invention, the energy transmission unit includes a first coil that receives energy from an external power source and generates a magnetic field change, and the energy receiver includes a second coil that generates induction electromotive force according to the magnetic field change. Can be used to supply energy wirelessly. At this time, if the second coil is formed by printing a metal material on the surface of the food container, the manufacturing process is simplified.

In the refrigerator according to the present invention, the energy transmission unit includes a magnetron for generating electromagnetic waves by receiving energy from an external power source, and the energy receiving unit includes an electromagnetic wave receiver for receiving the electromagnetic waves and converting them into energy. Energy can be supplied wirelessly. If the energy transmitter includes an ultrasonic transmitter for generating ultrasonic waves by receiving energy from an external power source, and the ultrasonic receiver includes an ultrasonic receiver for receiving ultrasonic waves and converting them into energy, the energy may be transmitted and received wirelessly through the ultrasonic waves. have. In addition, when the energy transmission unit includes a light source that receives energy from an external power source and emits light, and the energy receiving unit includes a photovoltaic cell that receives light to generate electromotive force, the energy may be transmitted and received wirelessly using photovoltaic power. have.

Meanwhile, the refrigerator according to the present invention further includes a capacitor installed in the food container and electrically connected to the energy receiving unit, and the sensor unit is configured to receive energy from the capacitor, so that energy supply to the sensor unit can be made stable. Do.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the refrigerator according to the present invention.

1 is a schematic configuration diagram of an embodiment of a refrigerator according to the present invention, FIG. 2 is a perspective view of the embodiment of FIG. 1, and FIG. 3 is a partial sectional view seen from the line A-A of FIG. 2.

The food container 100 is for directly receiving the food 50 to be stored. Although the food contained in the food container can measure salinity, acidity or temperature even if it is a solid material, it is particularly preferable to include liquid components such as pickles and kimchi so as to easily measure the salinity by an electrical conductivity measurement method.

The sensor unit 110 is installed in the food container 100. The sensor unit 110 is for measuring at least one selected from the storage state of the food, that is, salinity, acidity or temperature, the sensor unit 110 of the present embodiment is composed of a salinity sensor for measuring salinity in an electrical conductivity method. . The salinity sensor 110 applies a voltage to the food 50 to be measured, and then finally measures salinity by measuring the amount of current passing through the food 50. Accordingly, the salinity sensor 110 preferably includes a measuring electrode 111 and a measuring circuit 112.

The measuring electrode 111 is for flowing a current through the food 50, and a pair is provided. Since the measuring electrode 111 should be able to directly contact the food 50 accommodated in the food container 100, the measuring electrode 111 is installed to be exposed to the inside of the food container 100. In more detail with respect to a specific position where the measuring electrode 111 is installed, the measuring electrode 111 may be installed at each of the lower end of the opposite side wall of the food container 100, respectively, the bottom surface of the food container 100 A pair may be installed side by side, or a pair may be installed side by side at the bottom of one side wall of the food container 100. That is, the measuring electrode 111 may be in direct contact with the food contained in the food container, no matter where it is installed. However, in order to prevent damage by friction in the process of cleaning the food container 100, the measuring electrode 111 is preferably embedded so that only one surface thereof is exposed to the bottom plate or sidewall of the food container 100. On the other hand, since the measuring electrode 111 is in direct contact with the food 50, it may be corroded by the electrolyte contained in the food. Therefore, the measuring electrode 111 is preferably manufactured by plating a base metal, such as copper and nickel, with platinum to have corrosion resistance.

The measuring circuit 112 is a circuit for applying a voltage to the measuring electrode 111 and measuring a current flowing through the food 50. The measuring circuit 112 is embedded in the food container 100 or selectively placed at an arbitrary position outside the food container. Is installed. The conductive wire 111a for connecting the measuring circuit 112 and the measuring electrode 111 may be formed to be embedded in the food container 100, as shown in FIG. It may be formed by printing a metal material. If the conductive line 111a is formed by printing, the manufacturing process may be simplified and the manufacturing cost may be lowered. The measurement circuit 112 outputs data regarding the storage state of the food, that is, salinity data, and transmits the data to the controller 220 of the refrigerator 200. Here, the refrigerator 200 includes a double door type as shown in FIG. 2, as well as a one door type, a sliding door type, a curtain door type ( Curtain Door Type), regardless of its size, even the size of a large refrigerator such as Walk In Type (Walk In Type). In this case, the salinity data may be an amount of current flowing through the measuring electrode 111, or may be a salinity converted from the amount of current. In the latter case, the circuit module necessary for converting salinity should be included in the measuring circuit 112. In any case, the detailed configuration of the measurement circuit 112 can be implemented by conventional circuit design techniques, and thus detailed description thereof will be omitted.

The controller 220 determines the state of the food 50 from the salinity data received from the measuring circuit 112 of the salinity sensor 110 and controls the temperature inside the refrigerator to a value suitable for storing the food. The proper storage temperature according to the salinity data is input to the controller 220 in advance. When the salinity data transmitted by the salinity sensor 110 to the control unit 220 is the amount of current, the control unit 220 may include a circuit module for converting salinity so that the control unit 220 may convert the amount of current into a salinity. Even in this case, the circuit module for converting salinity can be implemented by a circuit design technique applied to a conventional salinity measuring apparatus. In addition, specific methods and algorithms for controlling the temperature inside the refrigerator through the obtained salinity data may be implemented by conventional techniques. On the other hand, it is not necessary to know the exact salinity of food to control the temperature of the refrigerator, and if only the data for estimating salinity can be obtained, temperature control is sufficient, so that a separate circuit for converting the amount of current into salinity is measured. The circuit 112 or the controller 220 does not have to be provided. However, when it is necessary to guide the user through the display device to guide the measured salinity value to the user, a circuit for converting salinity data into an accurate salinity value is any one of the measuring circuit 112 or the controller 220. It is preferably included optionally.

The energy transmitter 230 is installed in the refrigerator 200, is electrically connected to the external power source 300 to receive electric energy, and wirelessly transmits the supplied energy. Here, the external power source 300 refers to a power source outside the refrigerator to which the conventional refrigerator receives electric energy.

The energy receiver 130 is installed in the food container 100 and receives energy transmitted wirelessly and supplies energy to the sensor unit 110.

The energy transmission unit 230 and the energy receiving unit 130 will be described in detail a method of transmitting and receiving energy wirelessly.

First, using an induced electromotive force, the primary coil is formed in the energy transmitter 230, the secondary coil is formed in the energy receiver 130. When the primary coil receives electric energy from the external power source 300 and causes a magnetic field change, the secondary coil generates an induced electromotive force under the influence of the magnetic field change by the primary coil, and the sensor unit 110 generates the secondary coil. Receive energy from In this case, the secondary coil may be formed by printing a metal material on the surface of the food container 100. Forming a secondary coil by printing has the advantage of simplifying the manufacturing process.

Second is to use the electromagnetic wave, the magnetron is included in the energy transmission unit 230, the energy receiver 130 includes an electromagnetic wave receiver. The magnetron receives electrical energy from the external power source 300 to radiate electromagnetic waves, and converts the electromagnetic waves received by the electromagnetic wave receiver into electrical energy and supplies them to the sensor unit 110.

Third, the ultrasonic wave is used, and the ultrasonic transmitter is included in the energy transmitter 230 and the ultrasonic receiver 130 is included in the energy receiver 130. The ultrasonic generator receives electric energy from the external power source 300 to radiate ultrasonic waves, and the ultrasonic receiver receives the ultrasonic waves, converts them into electrical energy, and supplies them to the sensor unit 110.

Fourth, the photovoltaic power is used. The light source is included in the energy transmitter 230, and the photovoltaic cell is included in the energy receiver 130. The light source receives electric energy from the external power source 300 to emit light. When the photovoltaic cell receives the light, electromotive force is generated, and the sensor unit 110 receives energy from the photovoltaic cell.

The energy transmitter 230 and the energy receiver 130 may use any one of the above four methods selectively, as well as use two or more in combination, and the above four methods if the energy can be transmitted and received wirelessly. You can use it even if you don't belong.

In order to improve transmission and reception efficiency, the energy transmission unit 230 and the energy reception unit 130 may be installed to face each other at the closest distance. That is, as shown in Figure 3, if the energy receiving unit 130 is installed on the side of the food container 100, the energy transmitting unit 230 corresponds to the energy receiving unit 130 of the inner wall surface of the refrigerator 200. It is installed at the position. In addition, as shown in Figure 4, if the energy receiving unit 130 is installed on the bottom surface of the food container 100, the energy transmission unit 230 is a shelf of the refrigerator 200 supporting the food container 100. Is installed on.

 On the other hand, when the energy required by the sensor unit 110 is more than the energy supplied by the energy receiving unit 130, or when more stable energy supply is required to install a capacitor in the food container 100 additionally. desirable. The capacitor is electrically connected to the energy receiver 130, receives energy from the energy receiver 130, stores idle energy, and when the sensor 110 needs additional energy, or energy from the energy receiver 130. If it is not supplied to the sensor unit 110 to supply energy to allow the sensor unit to operate normally.

As such, the energy transmission unit 230 and the energy receiving unit 130 are separately installed in the refrigerator 200 and the food container 100, respectively, between the food container 100 and the refrigerator 200, wires, contact terminals, and other physical components. There is no connection. Therefore, even if the food container 100 is taken out from the refrigerator 200, there is no limitation on the moving range of the food container 100. On the other hand, since the energy transmitter 230 and the energy receiver 130 transmit and receive energy wirelessly, when the food container 100 is put back into the refrigerator 200, the energy transmitter 230 is wireless even if no action is taken. Energy receiver 130 may receive the energy transmitted to. Since the transmission of energy is necessary only when the sensor unit 110 needs energy to measure the storage state of the food, the sensor 110 may transmit and receive energy only when the food container 100 is accommodated in the refrigerator 200. Negative storage conditions can be measured. However, if the food container 100 does not deviate more than a predetermined distance from the refrigerator 200 according to a specific method of transmitting and receiving energy by the energy transmitting unit 230 and the energy receiving unit 130, the food container 100 is stored in the refrigerator. Energy transmission and reception may continue after taking out from 200. Furthermore, when the capacitor is additionally provided in the food container 100, the energy supply to the sensor unit 110 may be stabilized despite the interruption of energy transmission and reception.

On the other hand, in order for the refrigerator 200 to properly control the storage temperature, the sensor unit 110 must transmit the measured state of storage of the food to the controller 220 of the refrigerator. In order to transfer data between the control unit 220 and the sensor unit 110 of the refrigerator, the method of directly connecting the wires or connecting the terminals in the food container 100 and the refrigerator 200, respectively. However, there are various problems as in the conventional electrical connection method for transmitting and receiving energy.

Therefore, the data transmission and reception of the sensor unit 110 and the control unit 220 is more preferably performed wirelessly as in the energy supply to the sensor unit.

In order to wirelessly transmit and receive data between the sensor unit and the controller, the food container 100 is provided with a data transmitter 120, and the refrigerator 200 is provided with a data receiver 210.

The data transmitter 120 is installed in the food container 100 together with the sensor unit 110 or selectively installed outside the food container, and receives the storage state data from the sensor unit 110 and transmits the data wirelessly. In order to improve reliability of data transmission and to facilitate data transmission in any direction in which the food container 100 is accommodated in the refrigerator 200, a plurality of data transmitters 120 may be installed. If the data transmitter 120 needs energy to transmit data, the energy may be supplied from the energy receiver 130.

The data receiver 210 is installed in the refrigerator 200 and receives salinity data wirelessly transmitted from the data transmitter 120.

Although the data receiver 210 is preferably embedded in the inner side of the refrigerator 200, it may be installed on the outer side of the refrigerator 200 to enable additional data transmission and reception with an external device if necessary to build a home network environment. have. In addition, a plurality of data receivers 210 may be installed to improve the reception rate. The data receiver 210 transmits the received storage state data to the controller 220 of the refrigerator.

Various methods may be applied to the data transmitter 120 and the data receiver 210 to wirelessly transmit and receive the storage state data. However, the data transmitter 120 and the data receiver 210 may be one of the following methods.

The first is Bluetooth. Bluetooth is a low-cost, low-power, short-range wireless solution that is resistant to interference and has good interconnectivity, allowing simultaneous connection between multiple devices. Therefore, it is easy to mount on a mobile terminal or home appliances.

The second is Zigbee. The Zigbee method is a concept that communicates a small amount of information instead of minimizing power consumption, and is used for short-range communication markets such as intelligent home networks and buildings, industrial equipment automation, logistics, environmental monitoring, human interfaces, telematics, and military. Its small size, low power consumption, and low price have recently attracted much attention as a ubiquitous construction solution such as home network.

Third is Radio Frequency Identification (RFID). The RFID method is a contactless recognition system, which is classified into a passive type that operates by receiving energy from a radio wave signal of a reader without an internal power supply and an active type where an RF tag battery is embedded to operate by itself.

When the refrigerator according to the present invention adopts a passive RFID method as a data transmission / reception method, the sensor unit 110 may be operated using energy supplied from a radio signal of a reader. That is, when the data transmitter 120 and the data receiver 210 can perform two-way communication, the data transmitter 120 may also function as the energy receiver 130. Similarly, the data receiver 210 may also function as the energy transmitter 230.

Hereinafter will be described the operation of one embodiment of a refrigerator according to the present invention.

When the user puts the food 50 in the food container 100, the liquid component of the food, in particular, salted food, is in contact with the measuring electrode 111 installed in the food container 100. The food must be in contact with a pair of measuring electrodes. That is, when the measuring electrode 111 is installed at the bottom of the side wall of the food container 100, the salinity may be measured from the result because the current flows only when the amount of food is secured to a certain degree.

The measuring circuit 112 applies a preset voltage to the pair of measuring electrodes 111 and measures a current flowing between the pair of measuring electrodes 111 by the applied voltage. The ratio of the measured current value to the applied voltage value becomes the electrical resistance of the food product 50, from which the electrical conductivity can be calculated.

The measuring circuit 112 transmits the measured salinity data to the data transmitter 120. As described above, the salinity data is data that can finally calculate the salinity value, and may be an amount of current flowing through the measuring electrode 111, an electrical conductivity calculated therefrom, and finally converted from the electrical conductivity. It may be a salinity.

The transmitter 120 wirelessly transmits salinity data.

The power necessary for the operation of the measuring circuit 112 or the data transmitter 120 may be supplied from the energy receiver 130 or the storage battery separately provided in the food container 100. Among these, the energy receiving unit 130 receives energy from the energy transmitting unit 230 by using induced electromotive force, electromagnetic waves, ultrasonic waves, or photovoltaic power, and the battery stores idle energy from the energy receiving unit 130 to the sensor unit 110. Supply.

Salinity data wirelessly transmitted from the transmitter 120 is received by the data receiver 210 of the refrigerator 200, and the data receiver 210 transmits the received salinity data to the controller 220 of the refrigerator. Then, the controller 220 controls the refrigeration temperature based on the salinity data received.

An embodiment of the present invention described above and illustrated in the drawings should not be construed as limiting the technical idea of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention as long as it will be apparent to those skilled in the art.

As described above, since the refrigerator according to the present invention wirelessly transmits and receives energy between the sensor unit and the refrigerator main body, the food container is not limited to the moving range of the food container even when the food container is taken out of the refrigerator. Even if no action is taken, energy is supplied to the sensor, so data storage status of the food can be measured. Therefore, the control unit of the refrigerator may receive the storage state data and control the temperature inside the refrigerator to an appropriate temperature for long-term storage of the stored salted food.

In addition, since the energy is transmitted and received wirelessly between the sensor unit and the refrigerator main body, reliable energy supply can be achieved regardless of the physical contact state between the sensor unit and the refrigerator, and is not affected by the humid environment inside the refrigerator. Therefore, even if the food container is not precisely positioned at a specific position in the refrigerator, energy supply is possible, which greatly increases the convenience of use.

Claims (7)

delete delete In the refrigerator for storing food contained in a food container, An energy transmission unit installed in the refrigerator and receiving energy from an external power source and transmitting the energy wirelessly; An energy receiving unit installed in the food container and receiving the wirelessly transmitted energy; A sensor unit installed in the food container and electrically connected to the energy receiver to measure at least one selected from salinity, acidity or temperature of the food, The energy transmission unit includes a first coil receiving energy from the external power source to generate a magnetic field change, The energy receiving unit includes a second coil for generating an induced electromotive force in accordance with the change in the magnetic field, The second coil is a refrigerator for wirelessly supplying energy to a food storage state detection sensor, characterized in that formed by printing a metal material on the surface of the food container. In the refrigerator for storing food contained in a food container, An energy transmission unit installed in the refrigerator and receiving energy from an external power source and transmitting the energy wirelessly; An energy receiving unit installed in the food container and receiving the wirelessly transmitted energy; A sensor unit installed in the food container and electrically connected to the energy receiver to measure at least one selected from salinity, acidity or temperature of the food, The energy transmission unit includes a magnetron for generating electromagnetic waves by receiving energy from the external power source, And the energy receiver comprises an electromagnetic wave receiver which receives the electromagnetic wave and converts the electromagnetic wave into electrical energy. In the refrigerator for storing food contained in a food container, An energy transmission unit installed in the refrigerator and receiving energy from an external power source and transmitting the energy wirelessly; An energy receiving unit installed in the food container and receiving the wirelessly transmitted energy; A sensor unit installed in the food container and electrically connected to the energy receiver to measure at least one selected from salinity, acidity or temperature of the food, The energy transmitter includes an ultrasonic transmitter for generating ultrasonic waves by receiving energy from the external power source, The energy receiving unit is a refrigerator for wirelessly supplying energy to a sensor for detecting food storage conditions, characterized in that it comprises an ultrasonic receiver for receiving the ultrasonic wave and converting it into electrical energy. In the refrigerator for storing food contained in a food container, An energy transmission unit installed in the refrigerator and receiving energy from an external power source and transmitting the energy wirelessly; An energy receiving unit installed in the food container and receiving the wirelessly transmitted energy; A sensor unit installed in the food container and electrically connected to the energy receiver to measure at least one selected from salinity, acidity or temperature of the food, The energy transmission unit includes a light source that emits light by receiving energy from the external power source, The energy receiver comprises a photovoltaic cell for generating an electromotive force by receiving the light, the refrigerator for wirelessly supplying energy to the sensor for detecting the food storage state. The method according to any one of claims 3 to 6, And a capacitor installed in the food container and electrically connected to the energy receiver. The sensor unit is a refrigerator for supplying energy wirelessly to the sensor for detecting the food storage state, characterized in that the energy is supplied from the capacitor.

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