JP7632302B2 - Heating device and dryer equipped with heating device - Google Patents

Description

The present disclosure relates to a heating device that heats an object to be heated using microwaves, and a dryer equipped with the heating device.

One example of a heating device is a clothes dryer that heats and dries clothes. One method for speeding up the drying performance of a clothes dryer or a washer-dryer is to use microwaves as a heat source for heating the moisture in the clothes (see, for example, Patent Document 1). According to this method, microwaves are irradiated onto the clothes to directly heat the moisture in the clothes, allowing the moisture in the clothes to evaporate quickly, so that the clothes can be dried in a short time compared to conventional hot air drying using a heater or heat pump.

Figure 11 is a block diagram of a conventional clothes dryer described in Patent Document 1. This clothes dryer includes a microwave irradiation unit 101 that irradiates microwaves onto clothes, a clothes compartment 102 that stores clothes, a blower 103 that takes in outside air into the clothes compartment 102 and blows out the air from the clothes compartment 102, a heater 104 for drying clothes, a microwave control unit 105 that controls the microwave irradiation unit 101, a microwave reflection detection unit 106 that senses the state of microwave reflection, and a control circuit 107 that controls the microwave control unit 105.

A clothes dryer of this configuration can shorten the drying time of clothes by using microwaves to directly heat the water adhering to the clothes fibers, especially when the moisture content of the clothes is approximately 30% or less.

JP 2008-000249 A

However, in conventional clothes dryers, if the clothes stored in the clothes compartment 102 have metal parts such as buttons or zippers, the electric field strength of the microwaves in the clothes compartment 102 may become strong and cause sparks. To deal with this, technology capable of detecting the occurrence of sparks is essential.

The present disclosure provides a technology for detecting the occurrence of sparks in a heating device that heats an object by irradiating electromagnetic waves.

The heating device of the present disclosure comprises a heating chamber that contains an object to be heated, an irradiation unit that irradiates electromagnetic waves into the heating chamber, and a first electromagnetic wave shield for suppressing electromagnetic waves leaking from the heating chamber. It also comprises a receiving unit that receives the electromagnetic waves, and a detection unit that detects electromagnetic waves generated by sparks generated in the heating chamber due to the irradiation of the electromagnetic waves in the electromagnetic waves received by the receiving unit. Furthermore, the detection unit detects the electromagnetic waves amplified within the space of the first electromagnetic wave shield.

According to the present disclosure, the detection unit of the heating device can more accurately detect the occurrence of sparks within the heating chamber by detecting electromagnetic waves amplified within the space of the first electromagnetic wave shield.

FIG. 1 is a vertical sectional view that shows a schematic configuration of a drum type washer-dryer for illustrating a heating device according to a first embodiment. FIG. 2 is a configuration diagram of the heating device according to the first embodiment. FIG. 3 is a configuration diagram of the heating device according to the first embodiment. FIG. 4 is a graph illustrating the frequency and intensity of the electromagnetic wave received by the microwave receiving unit of the heating device according to the first embodiment. FIG. 5 is a schematic diagram for explaining the conditions under which electromagnetic wave resonance occurs in the heating device according to the first embodiment. FIG. 6 is an explanatory diagram showing the relationship between the frequency and attenuation of electromagnetic waves to water in the heating device according to the first embodiment. FIG. 7 is a configuration diagram of a heating device according to the second embodiment. FIG. 8 is an explanatory diagram showing the relationship between the intensity of electromagnetic waves inside and outside the electromagnetic wave shield of the heating device according to the second embodiment. FIG. 9 is a configuration diagram of a heating device according to the third embodiment. FIG. 10 is a diagram showing another configuration of the heating device according to the third embodiment. FIG. 11 is a block diagram of a conventional clothes dryer.

Below, embodiments of the present disclosure will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of matters that are already well known or duplicate explanations of substantially identical configurations may be omitted. This is to avoid making the following explanation unnecessarily redundant and to make it easier for those skilled in the art to understand.

It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter described in the claims.

(First embodiment)
In the first embodiment, the heating device will be described as a washer/dryer that heats and dries laundry such as clothes. Alternatively, the heating device may be a clothes dryer or a device that heats something other than laundry.

Figure 1 is a vertical cross-sectional view showing a schematic configuration of a drum type washer-dryer 60 for explaining a heating device according to a first embodiment. The left side will be described as the front, the right side as the rear, the upper side as the top, and the lower side as the bottom. The drum type washer-dryer 60 of this embodiment has the function of washing and drying laundry such as clothes, and can function as a washing machine that performs only the washing function, a dryer that performs only the drying function, and a washer-dryer that performs both the washing and drying functions.

The drum type washer-dryer 60 has a function of irradiating microwaves, a type of electromagnetic wave, to the laundry in the drum to heat it. First, the basic configuration and operation of the drum type washer-dryer 60 will be described, and then the details of the first electromagnetic wave shield, which is used to suppress leakage of microwaves from the housing when irradiating microwaves in the drum type washer-dryer 60, will be described.

The drum type washer-dryer 60 includes a water tub 2, which is a heating chamber formed in a cylindrical shape with a bottom, in which wash water is stored. The water tub 2 is supported in a housing 1 (main body) so that it can swing freely by a damper 4 provided below it. A drum 3, which contains laundry such as clothes to be dried, is provided rotatably in the water tub 2. This drum 3 is also formed in a cylindrical shape with a bottom. The drum 3 is provided so that its axis of rotation is horizontal. In another example, the drum 3 may be provided so that its axis of rotation is inclined upward from the horizontal, or so that its axis of rotation is vertical. In this embodiment, the heating chamber is described as the water tub 2 including the drum 3, but only the drum 3 may be the heating chamber.

A drive motor 6 is attached to the back of the water tub 2. This drive motor 6 rotates the drum 3 in the forward and reverse directions around the rotation axis. The drum type washer-dryer 60 agitates, beats, washes, rinses, and dries the laundry contained in the drum 3 by rotating the drum 3 driven by the drive motor 6.

An opening 19 and a door 5 for opening and closing the opening 19 are provided on the front of the housing 1, facing the open ends of the drum 3 and the water tub 2. A user can load and unload laundry into and from the drum 3 by opening the door 5.

The water tank 2 has a front water tank part 2a with a water tank opening 2c provided in a position facing the opening 19 of the housing 1, and a rear water tank part 2b provided behind the front water tank part 2a. An elastic cylindrical water seal gasket 23 is provided to connect the edge of the water tank opening 2c of the front water tank part 2a to the edge of the opening 19 around the entire circumference. When the user closes the door body 5, the water seal gasket 23 is pressed by the door body 5 and elastically deforms, ensuring watertightness of the water tank 2 against the outside of the machine.

The front part 2a of the tank may be the top part of the tank 2 formed in a cylindrical shape with a bottom. In that case, the rear part 2b of the tank may be the side part and the bottom part of the cylinder. The front part 2a of the tank may include a part of the front of the side part in addition to the top part of the cylinder. In that case, the rear part 2b of the tank may be the remaining part of the rear of the side part of the cylinder and the bottom part. The rear part 2b of the tank may include a part of the side of the top part in addition to the side part and the bottom part of the tank 2. In that case, the front part 2a of the tank may be the remaining part of the top part of the cylinder on the tank opening 2c side. The front part 2a of the tank and the rear part 2b of the tank may be manufactured integrally, or may be manufactured as separate bodies and the tank 2 may be formed by connecting them. When the front part 2a of the tank and the rear part 2b of the tank are manufactured as separate bodies, a water seal packing is provided at the connecting part of the front part 2a of the tank and the rear part 2b of the tank, similar to the water seal packing 23.

A water supply pipe 13 is connected to the top of the water tank 2. A water supply valve 12 is provided midway along the water supply pipe 13. The water supply valve 12 supplies water into the water tank 2 via the water supply pipe 13. A drain pipe 11 is connected to the bottom of the water tank 2. A drain valve 10 is provided midway along the drain pipe 11. The drain valve 10 drains the water in the water tank 2 via the drain pipe 11 to the outside of the machine, which is outside the housing 1.

A damper 4 is provided below the water tub 2. The damper 4 supports the water tub 2 and dampens vibrations of the water tub 2 caused by uneven distribution of laundry in the drum 3 during spin-drying, etc. A fabric amount detector (not shown) is attached to this damper 4. The fabric amount detector detects the amount of displacement of the axis of the damper 4 up and down due to weight changes caused by the clothes in the drum 3. The drum type washer-dryer 60 detects the amount of clothes in the drum 3 based on the amount of displacement detected by the fabric amount detector.

The drum 3 has a drum front part 3a having a drum opening 3c provided at a position facing the opening 19 of the housing 1, and a drum rear part 3b provided behind the drum front part 3a. The drum front part 3a may be the top surface part of the drum 3 formed in a bottomed cylindrical shape. In that case, the drum rear part 3b may be the side surface part and the bottom surface part of the cylinder. The drum front part 3a may include a front part of the side surface part in addition to the top surface part of the cylinder. In that case, the drum rear part 3b may be the remaining part behind the side surface part of the cylinder and the bottom surface part. The drum rear part 3b may include a part of the side side of the top surface part in addition to the side surface part and the bottom surface part of the drum 3. In that case, the drum front part 3a may be the remaining part of the drum opening 3c side of the top surface part of the cylinder. The drum front part 3a and the drum rear part 3b may be manufactured integrally or separately, and the drum 3 may be formed by connecting them.

The drum type washer-dryer 60 includes a circulation air duct 7 that circulates air in the water tub 2 and the drum 3, and a microwave heating device 30 that irradiates microwaves onto the objects to be dried in the drum 3. The microwave heating device 30, which constitutes the heating section that heats the objects to be dried, irradiates microwaves into the drum 3 from a microwave irradiation port 32 provided between the water tub opening 2c of the water tub 2, which is the heating chamber, and the opening 19 of the housing 1, to heat the moisture contained in the objects to be dried in the drum 3.

The circulation duct 7 is configured as an air circulation duct for drying the objects to be dried in the drying process. The air circulation duct includes the water tank 2 and the drum 3. The circulation duct 7 is provided by connecting an outlet 8 (drying air outlet) provided on the bottom surface of the water tank 2 with an exhaust port 9 (drying air exhaust port) provided on the front side of the water tank 2.

The circulating air duct 7 is provided with a lint filter 22, a dehumidifying section 21, a heater 17, and a blower fan 16 from the exhaust port 9 side. The lint filter 22 is a filter having a nylon mesh, and captures lint contained in the air flowing through the circulating air duct 7. The dehumidifying section 21 dehumidifies the air flowing through the circulating air duct 7. The dehumidifying section 21 may be either a water-cooled type or an air-cooled type. The heater 17 heats the air flowing through the circulating air duct 7. The dehumidifying section 21 and the heater 17 may be composed of an evaporating section and a condensing section of a heat pump device. The blower fan 16 circulates the air in the water tank 2 and the drum 3 into the circulating air duct 7.

The heater 17 and the microwave irradiation unit (details will be described later) constitute a heating unit that heats the object to be dried, and electricity is passed through both or either one at the same time. Methods for heating the object to be dried using the heating unit include direct heating using microwaves, indirect heating using a heater or the like to heat the circulating air, or the inner wall of the drum 3, and are not particularly limited. If the object to be dried, such as clothing, has metal buttons or zippers attached thereto and there is a high possibility of sparks occurring, the output of microwaves irradiated from the microwave irradiation unit into the drum 3 is reduced or stopped, and drying is switched to using the heater 17.

An inflow temperature detection unit 18 is provided in the circulating air duct 7. The inflow temperature detection unit 18 detects the temperature of the air flowing into the drum 3. The inflow temperature detection unit 18 is configured, for example, by a thermistor.

A control device 20 is provided in the housing 1. The control device 20 controls the blower fan 16, the heater 17, the microwave irradiation unit, etc. The control device 20 also controls the drive motor 6, the water supply valve 12, the drain valve 10, etc., and sequentially executes each process of cleaning, rinsing, and drying.

The control device 20 is realized in hardware by the CPU, memory, and other LSIs of any computer, and in software by programs loaded into memory. Those skilled in the art will understand that it can be realized in various forms, such as hardware alone or a combination of hardware and software.

Next, the flow of dried air will be explained. When microwaves are irradiated into the drum 3, the moisture contained in the material to be dried is heated and evaporated. When the blower fan 16 is driven, the air, which has become humid due to the evaporated moisture, flows into the circulating air duct 7 through the exhaust port 9 provided in the water tub 2. The air that flows into the circulating air duct 7 is sent by the blower fan 16 towards the dehumidifying section 21 and heater 17. The air passing through the dehumidifying section 21 is cooled and dehumidified. The cooled air is heated by the heater 17.

The air that has passed through the heater 17 passes through the air outlet 8 and is blown out again into the drum 3. Note that a clothes dryer without a washing function does not have a water tub 2 for storing wash water, a water supply valve 12, a water supply pipe 13, a drain valve 10, or a drain pipe 11. The drum 3 functions as a heating chamber, and the connection between the rotating drum 3 and the circulating air passage 7 is configured so that the drum 3 slides on a sealing member such as felt.

In the drum type washer-dryer 60 of this embodiment, microwaves are irradiated into the drum 3, so it is necessary to configure the drum type washer-dryer 60 so that the strength of the electromagnetic waves leaking outside the drum type washer-dryer 60 is equal to or less than the standard value set in the region in which it is used. Therefore, the drum type washer-dryer 60 of this embodiment is provided with a first electromagnetic wave shield to suppress leakage of microwaves irradiated from the microwave irradiation port 32.

As a standard for leakage electromagnetic waves, for example, there is the Japanese Industrial Standard "JIS C9250" which specifies microwave ovens with a rated high frequency output of 2kW or less that heat food using electromagnetic waves (microwaves) in the 2.45GHz frequency band, and microwave ovens with additional devices. Section 5.8 of the standard specifies that "the power density of leakage electromagnetic waves measured by the power density test of leakage electromagnetic waves specified in section 8.2.12 of the standard shall be (1) 1mW/ ^cm2 or less when the door is closed, (2) 5mW/ ^cm2 or less when the door is opened to the maximum position just before the oscillation stop device of the oscillator tube operates and fixed, and (3) 5mW/ ^cm2 or less when the oscillation stop device other than the main oscillation stop device is restrained." In addition, the notice on the interpretation of the "Ministerial Ordinance Prescribing Technical Standards for Electrical Appliances and Materials" stipulated in Article 8, Paragraph 1 of the Electrical Appliance and Material Safety Law prescribes almost the same content. It is considered that the same standards as microwave ovens are applicable to washer-dryers.

In addition, the World Health Organization (WHO) has recommended that the guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), which were prepared by experts from various countries on the basis of scientific evidence, be adopted as the exposure limit value for human protection. In these guidelines, the exposure limit value is stipulated as 0.08 W/kg (1 mW/cm ² ). The international standard "IEC 62233" established by the International Electrotechnical Commission (IEC) and the Japanese Industrial Standard "JIS 1912" established based on it stipulate a method for measuring electromagnetic fields related to human exposure from household electrical appliances and similar appliances. In the measurement method stipulated in the standard, the electromagnetic field is measured as a ratio to the exposure limit value by weighting the signal of a sensor that detects the electromagnetic field, and if the exposure limit value stipulated in the ICNIRP guidelines is not exceeded, it is determined that the ICNIRP guidelines are met. The first electromagnetic wave shield is configured to comply with these standards.

In a microwave oven, no large vibrations occur during microwave irradiation, but in the drum type washer-dryer 60 of this embodiment, when the drum 3 is rotated during drying to improve drying efficiency, the drum 3 and water tub 2 vibrate. Therefore, the first electromagnetic shield of the drum type washer-dryer 60 of this embodiment has a structure that can suppress microwaves leaking from gaps even when microwaves are irradiated while the drum 3 and water tub 2 are vibrating. Details will be described later.

Figure 2 is a block diagram of the microwave heating device 30, water tub 2, drum 3, door 5, and control device 20 to explain the heating device according to the first embodiment. The water tub 2, drum 3, and door 5 are shown in the positional relationship seen from the front of the drum-type washer-dryer 60 in Figure 1, looking toward the rear. The position of the microwave irradiation port 32 may be different from that shown in Figure 2, as long as microwaves can be irradiated to the water tub 2, which is the heating chamber. Also, the position of the microwave heating device 30 and control device 20 may be different from that shown in Figure 2, as long as they are outside the first electromagnetic wave shield.

The microwave heating device 30 has a microwave irradiation unit 31, a waveguide 34, a microwave irradiation port 32, a microwave control unit 40, a reflecting unit 33, and a microwave receiving unit 36. The microwave irradiation unit 31 irradiates microwaves. The waveguide 34 guides the irradiated microwaves into the drum 3. The microwave irradiation port 32 is provided in the water tank 2 at the tip of the waveguide 34. The microwave control unit 40 adjusts the output of the microwaves irradiated from the microwave irradiation unit 31. The reflecting unit 33 is provided between the microwave irradiation unit 31 and the microwave irradiation port 32, and reflects a part or all of the microwaves reflected from the drum 3 and irradiates them into the drum 3. The microwave receiving unit 36 is provided inside the first electromagnetic wave shield and receives electromagnetic waves including the microwaves irradiated from the microwave irradiation unit 31 and the electromagnetic waves generated by the spark.

The first electromagnetic shield is formed of a material that contains an electromagnetic shielding material such as a metal that can reflect or absorb microwaves. The first electromagnetic shield includes at least a wall that forms the heating chamber and a door for inserting and removing the object to be heated into the heating chamber. Here, when the heating chamber has a cylindrical shape with a bottom, the wall that forms the heating chamber includes a cylindrical side wall and a bottom surface. In FIG. 2, the first electromagnetic shield is composed of a water tank 2, which is the heating chamber, and a door 5.

In addition, part or all of the drum 3 or the housing 1 may be made of a material containing an electromagnetic wave shielding material to form a first electromagnetic wave shield.

The first electromagnetic wave shield may also include a first choke portion 38 to block, attenuate, or suppress electromagnetic waves leaking from the gap between the water tank 2 and the door body 5. The first choke portion 38 is formed at the contact point between the water tank 2 and the door body 5, and has a high shielding effect against the frequency band of microwaves irradiated by the microwave irradiation portion 31. The first choke portion 38 may employ any choke structure known in the technical field of microwave ovens and the like.

In addition, instead of a choke structure, the first electromagnetic wave shield may be formed from a conductive material such as a metal capable of reflecting the microwaves irradiated from the microwave irradiation section 31, or a dielectric or magnetic material capable of absorbing and attenuating microwaves due to dielectric loss, magnetic loss, etc.

The microwave irradiation unit 31 is a microwave oscillator such as a magnetron, and oscillates electromagnetic waves of a frequency of 2.45 GHz band that can be used by microwave heating devices. Note that the frequency is not limited to the 2.45 GHz band assigned as the ISM (Industry Science Medical) band, and electromagnetic waves of a frequency such as the 915 MHz band may be used. Microwaves adjusted to an arbitrary output by the microwave control device 40 are irradiated from the microwave irradiation unit 31. The irradiated microwaves are irradiated into the rotating drum 3 through the waveguide 34 and the microwave irradiation port 32, and heat the moisture contained in the objects to be dried such as clothes.

Of the microwaves irradiated into the drum 3, a portion of the microwaves that is not absorbed by the moisture contained in the material to be dried returns as reflected waves from the drum 3 to the microwave irradiation section 31 through the microwave irradiation port 32. The microwaves that return to the microwave irradiation section 31 are converted into heat and treated as exhaust heat.

The reflecting section 33 reflects some or all of the reflected waves that are reflected from the drum 3 and travel in a direction returning to the microwave irradiating section 31, and causes them to enter the drum 3 again together with the microwaves irradiated from the microwave irradiating section 31. This reduces energy loss and shortens the drying time.

Figure 3 shows the configuration of a microwave control device 40, a microwave receiving unit 36, and a microwave irradiation unit 31 to explain the heating device according to the first embodiment. The microwave control device 40 is realized by hardware such as a microcomputer, a microcontroller, and an integrated circuit.

The microwave control device 40 includes a spark detection unit 41 and an output adjustment unit 42. These components are realized as hardware by the CPU, memory, and other LSIs of any computer, and as software by programs loaded into memory, but the functional blocks realized by the cooperation of these are depicted here. Therefore, it will be understood by those skilled in the art that these functional blocks can be realized in various ways, such as hardware alone or a combination of hardware and software.

The microwave control device 40 controls the microwave irradiation unit 31 according to instructions from the control device 20 during the washing process, rinsing process, or drying process controlled by the control device 20. The microwave control device 40 heats the washing water during the washing process, heats the rinsing water during the rinsing process, heats the moisture contained in the objects to be dried during the drying process, and heats and sterilizes bacteria attached to the laundry or objects to be dried. To this end, microwaves are irradiated from the microwave irradiation unit 31 into the drum 3. When heating the washing water or rinsing water, microwaves may be irradiated into the water tank 2 in which they are stored.

The spark detection unit 41 can detect the occurrence of a spark within the heating chamber by detecting electromagnetic waves generated by a spark in the electromagnetic waves received by the microwave receiving unit 36. For example, the spark detection unit 41 detects the occurrence of a spark by detecting a change in the intensity of the received electromagnetic waves. In addition, in order to improve the accuracy of spark detection, the occurrence of a spark may be detected by detecting a change in the intensity of the electromagnetic waves at a predetermined frequency. Hereinafter, the electromagnetic waves detected by the spark detection unit 41 as electromagnetic waves generated by a spark from the electromagnetic waves received by the microwave receiving unit 36 will be referred to as spark electromagnetic waves.

First, let's explain the frequency of the electromagnetic waves generated by a spark.

Figure 4 is a graph explaining the frequency and intensity of the electromagnetic waves received by the microwave receiving unit in the heating device of the first embodiment, and explains the relationship between the frequency and intensity of the electromagnetic waves received by the microwave receiving unit 36 when a metal piece is placed in the heating chamber assuming that the clothing has metal such as a button or zipper, microwaves are irradiated from the microwave irradiating unit 31 into the heating chamber, causing sparks. The horizontal axis shows the frequency of the electromagnetic waves, and the vertical axis shows the intensity of the electromagnetic waves.

The electromagnetic waves received by the microwave receiving unit 36 include both the microwaves irradiated from the microwave irradiating unit 31 and the electromagnetic waves generated by sparks caused by the irradiated microwaves. Here, the frequency of the microwaves irradiated from the microwave irradiating unit 31 is in the 2.45 GHz band.

Here, the microwave receiving unit 36 is equipped with a filter having frequency characteristics that block or attenuate the microwaves irradiated from the microwave irradiating unit 31. This filter is, for example, a low-pass filter configured by hardware. As a result, the electromagnetic wave intensity of the frequency band of the microwaves irradiated from the microwave irradiating unit 31 among the electromagnetic waves received by the microwave receiving unit 36 is reduced.

Therefore, in comparison with electromagnetic waves of other frequencies, no peak in the intensity of the electromagnetic waves is detected in the frequency band of the microwaves irradiated from the microwave irradiation unit 31. In addition, the electromagnetic waves generated by the spark have a peak in the intensity of the electromagnetic waves detected in the frequency band of 100 MHz or more, particularly in the range of 100 MHz to 1.5 GHz.

As described above, the frequency of the electromagnetic waves generated by a spark is 100 MHz or higher, and by receiving electromagnetic waves of a different frequency from the microwaves irradiated from the microwave irradiation unit 31 and detecting the change in the intensity of the electromagnetic waves, it is possible to detect the occurrence of a spark.

The electromagnetic waves generated by a spark are not electromagnetic waves with only a specific frequency, but electromagnetic waves with a wide range of frequencies above 100 MHz.

Therefore, the spark detection unit 41 detects the occurrence of a spark by analyzing the frequency of the electromagnetic waves received by the microwave receiving unit 36 and detecting the change in intensity of electromagnetic waves of a frequency different from the microwaves irradiated from the microwave irradiating unit 31 as spark electromagnetic waves.

In addition, the microwave receiving unit 36 may use a filter (low-pass filter, band-stop filter, or high-pass filter) having frequency characteristics that block or attenuate the microwaves irradiated from the microwave irradiating unit 31 to receive only the electromagnetic waves generated from the spark, thereby allowing the spark detection unit 41 to detect the spark electromagnetic waves. In addition, the above-mentioned frequency analysis and a filter may be used in combination. The filter provided in the microwave receiving unit 36 may be provided in the spark detection unit 41.

Next, we will explain the intensity of the electromagnetic waves generated by a spark.

The intensity of the electromagnetic waves generated by the spark is considerably weaker than the intensity of the microwaves irradiated into the heating chamber by the microwave irradiation unit 31, so the irradiated microwaves become noise. Therefore, it may be difficult to detect the electromagnetic waves generated by the spark.

Here, we will explain the resonance phenomenon of electromagnetic waves. As mentioned above, the electromagnetic waves generated by a spark are not electromagnetic waves with only a specific frequency, but electromagnetic waves with a wide range of frequencies above 100 MHz. Therefore, among these electromagnetic waves, those with a certain frequency or higher may cause a resonance phenomenon within the space of the electromagnetic wave shield.

Figure 5 is a schematic diagram illustrating the conditions under which electromagnetic wave resonance occurs in the heating device according to the first embodiment. In general, the resonance phenomenon occurs when the distance between opposing electromagnetic shielding surfaces in the space of the electromagnetic shield satisfies a relationship of an integer multiple of 1/2 the wavelength λ of the electromagnetic wave. Figure 5 shows the resonance phenomenon when the distance between opposing electromagnetic shielding surfaces is 1, 2, and 3 times 1/2 the wavelength λ of the electromagnetic wave.

For example, let Lmax be the maximum straight line length of the x-axis length, y-axis length, and z-axis length that make up the space of the electromagnetic shield. Resonance occurs in short electromagnetic waves generated by a spark, with half the wavelength, λ/2, being less than or equal to Lmax. The resonance phenomenon amplifies the intensity of the electromagnetic waves generated by the spark.

Therefore, the spark detection unit 41 may selectively detect electromagnetic waves at a frequency at which resonance occurs among the electromagnetic waves generated by a spark in accordance with the size of the space in the first electromagnetic wave shield, and detect the spark electromagnetic waves, thereby accurately detecting the occurrence of a spark.

That is, as described above, when the maximum linear length of the x-axis length, y-axis length, and z-axis length constituting the space of the first electromagnetic wave shield is Lmax, the spark detection unit 41 detects electromagnetic waves for which (λ/2)≦Lmax as spark electromagnetic waves. As a result, the spark detection unit 41 can more accurately detect the occurrence of sparks in the heating chamber by detecting the electromagnetic waves generated by sparks that are amplified in the space of the first electromagnetic wave shield as spark electromagnetic waves.

For example, we will explain the case where the first electromagnetic wave shield is formed into a substantially right circular cylinder shape. In the right circular cylinder shape, the larger of the maximum diameter of the cross section of the circle and the maximum depth of the cylinder is defined as Lmax. Resonance occurs in electromagnetic waves generated by a spark, where half the wavelength, λ/2, is equal to or less than Lmax. The intensity of the electromagnetic waves generated by the spark is amplified by the resonance phenomenon.

We will now explain the case where the first electromagnetic wave shield is formed substantially in a rectangular parallelepiped shape. Of the three sides that form the rectangular parallelepiped shape, the maximum straight line length is Lmax. A resonance phenomenon occurs in short electromagnetic waves generated by a spark, whose half wavelength, λ/2, is less than or equal to Lmax. The resonance phenomenon amplifies the intensity of the electromagnetic waves generated by the spark.

From the above, the spark detection unit 41 can selectively detect electromagnetic waves at a frequency at which resonance occurs among the electromagnetic waves generated by a spark in accordance with the size of the space in the first electromagnetic wave shield, and detect the spark electromagnetic waves, thereby accurately detecting the occurrence of a spark.

Finally, we will explain the effect that moisture contained in the clothes, which are the objects to be heated, has on the electromagnetic waves generated by sparks during the drying operation of the drum type washer-dryer 60.

Figure 6 is an explanatory diagram showing the relationship between the frequency and attenuation of electromagnetic waves for water in the heating device of the first embodiment. The horizontal axis shows the frequency of the electromagnetic waves, and the vertical axis shows the loss of the electromagnetic waves.

The degree of attenuation by water increases rapidly from frequencies above 5 GHz. Because the intensity of electromagnetic waves generated by sparks is weak, it becomes difficult to detect sparks as the degree of attenuation by moisture in clothing increases. Therefore, the microwave receiving unit 36 may detect sparks more accurately by receiving electromagnetic waves containing frequency components of 10 GHz or less, preferably 5 GHz or less. Furthermore, the spark detection unit 41 may detect sparks more accurately by detecting electromagnetic waves containing frequency components of 10 GHz or less, preferably 5 GHz or less.

That is, the spark detection unit 41 detects electromagnetic waves having a frequency of 10 GHz or less, preferably 5 GHz or less, among electromagnetic waves generated by sparks occurring in a heating chamber constituted by, for example, the water tank 2 or the drum 3. In this way, the spark detection unit 41 can more accurately detect the occurrence of sparks by detecting the spark electromagnetic waves.

When the spark detection unit 41 detects a spark electromagnetic wave, that is, when a spark occurs, the output adjustment unit 42 adjusts the output of the microwaves irradiated from the microwave irradiation unit 31. Specifically, when the spark detection unit 41 detects a spark electromagnetic wave, the output adjustment unit 42 determines that a spark has occurred and reduces the output of the microwaves irradiated from the microwave irradiation unit 31. Alternatively, the output adjustment unit 42 stops the output of the microwaves irradiated from the microwave irradiation unit 31.

This allows accurate detection of sparks occurring inside the drum 3 and reduces or stops the output of microwaves irradiated from the microwave irradiation unit 31. In other words, damage to the object to be dried due to sparks generated by metals or the like contained in the object to be dried inside the drum 3 is prevented.

As described above, according to this embodiment, the drum type washer-dryer 60, which is a heating device, includes a water tub 2 or drum 3, which is a heating chamber that contains clothes, which are objects to be heated, a microwave irradiation unit 31 that irradiates electromagnetic waves into the heating chamber, and a first electromagnetic wave shield for suppressing electromagnetic waves leaking from the heating chamber. It also includes a microwave receiving unit 36 that receives electromagnetic waves, and a spark detection unit 41 that detects electromagnetic waves generated by sparks that are generated in the heating chamber due to the irradiation of electromagnetic waves in the electromagnetic waves received by the microwave receiving unit 36. Furthermore, the spark detection unit 41 is configured to detect electromagnetic waves that are amplified within the space of the first electromagnetic wave shield.

With this configuration, the spark detection unit 41 can more accurately detect the occurrence of sparks within the heating chamber by detecting spark electromagnetic waves within the space of the first electromagnetic wave shield.

Furthermore, the maximum linear length of the x-axis length, y-axis length, and z-axis length that make up the space of the first electromagnetic shield may be Lmax, and the spark detection unit 41 may be configured to detect electromagnetic waves with a wavelength λ of (λ/2)≦Lmax. With this configuration, the spark detection unit 41 can more accurately detect the occurrence of sparks in the heating chamber by detecting the electromagnetic waves that are amplified in the space of the first electromagnetic shield.

The spark detection unit 41 may be configured to detect electromagnetic waves generated by sparks in the heating chamber that have a frequency of 10 GHz or less, preferably 5 GHz or less. This configuration allows for more accurate detection of sparks in the heating chamber.

The first electromagnetic shield may also include at least a wall that defines the heating chamber and a door for inserting and removing the object to be heated into the heating chamber. This configuration optimizes the first electromagnetic shield, and allows the spark detector 41 to detect spark electromagnetic waves within the space of the first electromagnetic shield, thereby more accurately detecting the occurrence of sparks within the heating chamber.

The first electromagnetic shield may also include a first choke portion 38 (first choke structure) that suppresses leakage of electromagnetic waves from the heating chamber. This configuration allows the first electromagnetic shield to be optimally configured, and the spark detection portion 41 can detect spark electromagnetic waves in the space of the first electromagnetic shield, thereby more accurately detecting the occurrence of sparks in the heating chamber.

The microwave irradiation unit 31 may be configured to irradiate the inside of the heating chamber with electromagnetic waves having a frequency of 2.45 GHz or 915 MHz. With this configuration, a heating device can be realized using electromagnetic waves in a usable frequency band.

Second Embodiment
FIG. 7 is a configuration diagram of a microwave heating device 30, a water tank 2, a drum 3, a door body 5, a control device 20, etc., for explaining a heating device according to a second embodiment.

In Fig. 2 showing the heating device according to the first embodiment, the microwave receiving unit 36 is provided inside the first electromagnetic shield including the wall and door body 5 that form the heating chamber, and receives electromagnetic waves within the space of the first electromagnetic shield. Here, the electromagnetic waves irradiated by the microwave irradiating unit 31 are strong, and therefore may become noise when the spark detecting unit 41 detects the spark electromagnetic waves. In other words, this may be a factor that hinders the detection of spark occurrence.

In the microwave heating device 30 constituting the heating device according to the second embodiment, as shown in FIG. 7, the microwave receiving unit 36 is provided outside the first electromagnetic shield and receives electromagnetic waves leaked outside the first electromagnetic shield. Since the first electromagnetic shield has a high shielding effect for a specific frequency band, the microwaves irradiated by the microwave irradiating unit 31 have a higher attenuation rate when leaking outside the first electromagnetic shield than the electromagnetic waves generated by the spark. Therefore, outside the first electromagnetic shield, the difference in intensity between the microwaves irradiated by the microwave irradiating unit 31 and the electromagnetic waves generated by the spark becomes smaller. Therefore, by receiving the electromagnetic waves by the microwave receiving unit 36, the microwave detection unit 41 can more accurately detect the electromagnetic waves generated by the spark and detect the occurrence of a spark.

The microwave receiving unit 36 may be provided outside the first electromagnetic shield, and the location of the microwave receiving unit 36 is not particularly limited. For example, the microwave receiving unit 36 may be provided inside the drum type washer-dryer 60, or may be provided separately from the drum type washer-dryer 60. When provided separately from the drum type washer-dryer 60, for example, a mobile terminal or a separate measuring device may be used. The microwave receiving unit 36 and the microwave control device 40 are connected by a wired signal or a wireless signal. The other configurations and operations are the same as those of the first embodiment.

As in the first embodiment, the first electromagnetic wave shield may include a first choke portion 38 to block or attenuate electromagnetic waves leaking from the gap between the door body 5 and the water tank 2. The first choke portion 38 is formed at the contact point between the door body 5 and the water tank 2, and has a high shielding effect against the frequency band of microwaves irradiated by the microwave irradiation portion 31.

The first electromagnetic wave shield using the choke structure has a high shielding effect for a specific frequency band, so that when the microwaves irradiated from the microwave irradiation section 31 leak outside the first electromagnetic wave shield, they are attenuated at a higher rate than the electromagnetic waves generated by a spark.

Therefore, outside the first electromagnetic shield using the choke structure, the difference in intensity between the microwaves irradiated by the microwave irradiation unit 31 and received by the microwave receiving unit 36 and the electromagnetic waves generated by the spark becomes smaller, and the microwave detection unit 41 can detect the spark electromagnetic waves and detect the spark more accurately.

In addition, by providing the first electromagnetic shield and the first choke section 38, it is not necessary to add an attenuator or other components to the microwave receiving section 36. This allows the configuration of the drum type washer-dryer 60 to be simplified, thereby reducing the manufacturing cost and size of the drum type washer-dryer 60. Of course, it is also possible to provide only the first electromagnetic shield.

Figure 8 is an explanatory diagram showing the relationship between the intensity of the electromagnetic waves inside the first electromagnetic shield and the intensity of the electromagnetic waves leaking outside the first electromagnetic shield (leakage electromagnetic waves) in microwaves irradiated from the microwave irradiation unit 31 of the heating device according to the second embodiment. The vertical axis shows the electromagnetic wave intensity of the microwaves. If the electromagnetic wave intensity of the microwaves incident on the drum 3 from the microwave irradiation port 32 is 100%, the intensity of the reflected wave reflected from the drum 3 and returning to the microwave irradiation unit 31 is about 17%, and the intensity of the electromagnetic waves leaking outside the first electromagnetic shield is about 0.0001%.

In this way, the intensity of the leaked electromagnetic waves received by the microwave receiving unit 36 outside the first electromagnetic wave shield is considerably weaker than the intensity of the incident waves, and by installing the microwave receiving unit 36 outside the first electromagnetic wave shield, it becomes easier to detect spark electromagnetic waves.

As described above, according to this embodiment, the microwave receiving unit 36 is provided outside the first electromagnetic shield and is configured to receive electromagnetic waves leaking from the first electromagnetic shield. This allows the microwave receiving unit 36 provided outside the electromagnetic shield to receive electromagnetic waves leaking from the first electromagnetic shield, and the spark detection unit 41 to detect spark electromagnetic waves in the space of the first electromagnetic shield, thereby more accurately detecting the occurrence of sparks in the heating chamber.

The first electromagnetic wave shield may also include a first choke section 38 (first choke structure) that suppresses leakage of electromagnetic waves irradiated from the microwave irradiation section 31 from the heating chamber. This allows the first electromagnetic wave shield to be optimally configured, and the spark detection section 41 to detect spark electromagnetic waves, thereby more accurately detecting the occurrence of sparks.

Third Embodiment
Fig. 9 is a configuration diagram of a microwave heating device 30, a water tank 2, a drum 3, a door body 5, a control device 20, etc., for explaining a heating device according to a third embodiment. In Fig. 7 of the second embodiment, the microwave receiving unit 36 is provided outside the first electromagnetic wave shield and receives electromagnetic waves leaked outside the first electromagnetic wave shield. In the microwave heating device 30 according to the third embodiment, a second electromagnetic wave shield 37 configured to suppress the intrusion of microwaves irradiated from the microwave irradiating unit 31 is provided around the microwave receiving unit 36. The microwave receiving unit 36 is provided inside the second electromagnetic wave shield 37 and receives electromagnetic waves that have intruded into the second electromagnetic wave shield 37.

Because the second electromagnetic shield 37 has a high shielding effect against a specific frequency band, the microwaves irradiated by the microwave irradiator 31 have a higher attenuation rate when penetrating the second electromagnetic shield 37 than the electromagnetic waves generated by the spark. Therefore, inside the second electromagnetic shield 37, the difference in intensity between the microwaves irradiated by the microwave irradiator 31 and the electromagnetic waves generated by the spark becomes smaller. Therefore, by receiving the electromagnetic waves with the microwave receiver 36, the microwave detector 41 can more accurately detect the electromagnetic waves generated by the spark and detect the occurrence of a spark.

The second electromagnetic wave shield 37 may also include a second choke portion 39 at the contact point with the water tank 2. The second choke portion 39 has a high shielding effect against the frequency band of microwaves irradiated by the microwave irradiation portion 31. Any choke structure known in the technical field of microwave ovens and the like may be used as the second choke portion 39.

The second electromagnetic wave shield 37 using a choke structure has a high shielding effect for a specific frequency band, so that when the microwaves irradiated from the microwave irradiation section 31 penetrate into the second electromagnetic wave shield 37, they are attenuated at a higher rate than the electromagnetic waves generated by a spark.

Therefore, inside the second electromagnetic shield 37 using a choke structure, the difference in intensity between the microwaves irradiated by the microwave irradiating unit 31 and the electromagnetic waves generated by the spark, which are received by the microwave receiving unit 36, becomes smaller, and the microwave detection unit 41 can detect the spark electromagnetic waves and detect the spark more accurately.

In addition, by providing the first electromagnetic shield, the second electromagnetic shield 37, the first choke portion 38, and the second choke portion 39, there is no need to add a component such as an attenuator to the microwave receiving portion 36. This allows the configuration of the drum type washer-dryer 60 to be simplified, thereby reducing the manufacturing cost and size of the drum type washer-dryer 60. Of course, the first electromagnetic shield and the second electromagnetic shield 37 may not be provided with the first choke portion 38 and the second choke portion 39, or may be provided with either the first choke portion 38 or the second choke portion 39.

In addition, the first electromagnetic wave shield may be used to realize the above-mentioned standard regarding leakage electromagnetic waves, and the attenuation rates of the first electromagnetic wave shield and the second electromagnetic wave shield 37 may be set so that the electromagnetic waves generated by a spark have an appropriate electromagnetic wave intensity for reception by the microwave receiving unit 36.

The other configurations and operations are the same as those of the first embodiment. Alternatively, they may be the same as those of the second embodiment. Note that only a portion of the microwave receiving unit 36 may be provided inside the second electromagnetic wave shield 37 to receive electromagnetic waves that have entered the second electromagnetic wave shield 37.

As described above, according to this embodiment, the drum type washer-dryer 60, which is a heating device, is provided with a second electromagnetic wave shield 37 for suppressing the intrusion of electromagnetic waves irradiated from the microwave irradiation unit 31, and the microwave receiving unit 36 is provided inside the second electromagnetic wave shield 37 and is configured to receive electromagnetic waves that intrude into the second electromagnetic wave shield 37.

With this configuration, the microwave receiving unit 36 provided inside the second electromagnetic shield 37 receives electromagnetic waves penetrating into the second electromagnetic shield 37, and the spark detection unit 41 detects spark electromagnetic waves within the space of the first electromagnetic shield, thereby making it possible to more accurately detect the occurrence of a spark.

The second electromagnetic shield 37 may also be provided within the space of the first electromagnetic shield. This allows the microwave receiver 36, which is provided within the space of the first electromagnetic shield and inside the second electromagnetic shield 37, to receive electromagnetic waves penetrating into the second electromagnetic shield 37, and the spark detector 41 to detect the spark electromagnetic waves, thereby making it possible to more accurately detect the occurrence of a spark.

In addition, the second electromagnetic wave shield 37 may include a second choke section 39 (second choke structure) that suppresses the intrusion of electromagnetic waves irradiated from the microwave irradiation section 31. This allows the second electromagnetic wave shield 37 to be optimally configured, and the spark detection section 41 to detect spark electromagnetic waves and more accurately detect the occurrence of sparks.

10, in another configuration of the heating device according to the third embodiment, the microwave receiving unit 36, the second electromagnetic shield 37, and the second choke unit 39 may be provided outside the first electromagnetic shield, and their installation positions are not particularly limited. For example, they may be provided inside the drum type washer-dryer 60, or may be provided separately from the drum type washer-dryer 60. When provided separately from the drum type washer-dryer 60, for example, a mobile terminal or a separate measuring device may be used. The microwave receiving unit 36 and the microwave control device 40 are connected by a wired signal or a wireless signal.

According to this configuration, the first electromagnetic shield and the second electromagnetic shield 37 have a high shielding effect against a specific frequency band, so that, compared to a configuration with only the first electromagnetic shield (see FIG. 7 showing the second embodiment), the microwaves irradiated by the microwave irradiator 31 have a higher attenuation rate when penetrating into the second electromagnetic shield 37 than the electromagnetic waves generated by the spark. Therefore, inside the second electromagnetic shield 37, the difference in intensity between the microwaves irradiated by the microwave irradiator 31 and the electromagnetic waves generated by the spark becomes smaller. Therefore, by receiving the electromagnetic waves with the microwave receiver 36, the electromagnetic waves generated by the spark can be detected more accurately to detect the occurrence of a spark.

As described above, the heating device and the washer-dryer (dryer) equipped with the heating device have been described in the first to third embodiments. That is, by equipping a dryer with the heating device of the first to third embodiments, it is possible to realize a dryer that can more accurately detect the occurrence of sparks.

The present disclosure has been described above based on the first to third embodiments. These embodiments are merely examples, and those skilled in the art will understand that various modifications are possible in the combination of each component and each processing process, and that such modifications are also within the scope of the present disclosure. In other words, the technology in this disclosure is not limited to these, and can also be applied to embodiments in which modifications, substitutions, additions, omissions, etc. have been made. It is also possible to combine each component described in the above embodiments to create a new embodiment.

In addition, any combination of the above components, and conversions of the expressions of this disclosure between methods, devices, systems, recording media, computer programs, etc., are also valid aspects of the present disclosure.

As described above, the heating device in the first disclosure comprises a heating chamber that houses an object to be heated, an irradiation unit that irradiates electromagnetic waves into the heating chamber, and a first electromagnetic wave shield for suppressing electromagnetic waves leaking from the heating chamber. It also comprises a receiving unit that receives the electromagnetic waves, and a detection unit that detects electromagnetic waves generated by sparks generated in the heating chamber due to the irradiation of the electromagnetic waves in the electromagnetic waves received by the receiving unit. Furthermore, the detection unit is configured to detect electromagnetic waves amplified within the space of the first electromagnetic wave shield.

With this configuration, the detection unit of the heating device can more accurately detect the occurrence of sparks within the heating chamber by detecting the electromagnetic waves amplified within the space of the first electromagnetic wave shield.

The heating device in the second disclosure may be configured in the first disclosure such that the maximum straight line length of the x-axis length, y-axis length, and z-axis length that form the space of the first electromagnetic wave shield is Lmax, and the detection unit is configured to detect electromagnetic waves with a wavelength λ of (λ/2)≦Lmax.

With this configuration, the detection unit can more accurately detect the occurrence of sparks within the heating chamber by detecting electromagnetic waves that are amplified within the space of the first electromagnetic wave shield.

The heating device in the third disclosure may be configured in either the first or second disclosure such that the detection unit detects electromagnetic waves generated by sparks within the heating chamber, the electromagnetic waves having a frequency of 5 GHz or less.

This configuration allows for more accurate detection of sparks occurring within the heating chamber.

The heating device in the fourth disclosure may be any one of the first to third disclosures, in which the receiving unit is provided outside the first electromagnetic wave shield and configured to receive electromagnetic waves leaking from the first electromagnetic wave shield.

With this configuration, the receiving unit located outside the first electromagnetic shield receives electromagnetic waves leaking from the first electromagnetic shield, and the detecting unit detects the electromagnetic waves amplified within the space of the first electromagnetic shield, thereby making it possible to more accurately detect the occurrence of sparks within the heating chamber.

The heating device in the fifth disclosure may be any one of the first to fourth disclosures, in which the first electromagnetic shield includes at least a wall forming the heating chamber and a door body for inserting and removing the object to be heated into the heating chamber.

With this configuration, the first electromagnetic wave shield can be optimally configured, and the detection unit can detect the electromagnetic waves that are amplified within the space of the first electromagnetic wave shield, making it possible to more accurately detect the occurrence of sparks within the heating chamber.

The heating device in the sixth disclosure may be any one of the first to fifth disclosures, in which the first electromagnetic wave shield is provided with a first choke structure that suppresses leakage of electromagnetic waves from the heating chamber.

With this configuration, the first electromagnetic wave shield can be optimally configured, and the detection unit can detect the electromagnetic waves that are amplified within the space of the first electromagnetic wave shield, making it possible to more accurately detect the occurrence of sparks within the heating chamber.

The heating device in the seventh disclosure may be configured in any one of the first to third disclosures, further comprising a second electromagnetic wave shield for suppressing the intrusion of electromagnetic waves irradiated from the irradiation unit, and a receiving unit provided inside the second electromagnetic wave shield and configured to receive electromagnetic waves that intrude into the second electromagnetic wave shield.

With this configuration, the receiving unit provided inside the second electromagnetic shield receives electromagnetic waves penetrating the second electromagnetic shield, and the detecting unit detects the electromagnetic waves amplified within the space of the first electromagnetic shield, thereby making it possible to more accurately detect the occurrence of sparks within the heating chamber.

The heating device in the eighth disclosure may be the seventh disclosure, in which a second electromagnetic wave shield is provided within the space of the first electromagnetic wave shield.

With this configuration, the receiving unit, which is provided within the space of the first electromagnetic shield and inside the second electromagnetic shield, receives electromagnetic waves that penetrate into the second electromagnetic shield, and the detecting unit detects the electromagnetic waves that are amplified within the space of the first electromagnetic shield, thereby making it possible to more accurately detect the occurrence of sparks within the heating chamber.

The heating device in the ninth disclosure may be either the seventh or eighth disclosure, in which the second electromagnetic wave shield is provided with a second choke structure that suppresses the intrusion of electromagnetic waves irradiated from the irradiation section.

With this configuration, the second electromagnetic shield can be optimally configured and the detection unit can detect the electromagnetic waves amplified within the space of the first electromagnetic shield, thereby more accurately detecting the occurrence of sparks within the heating chamber.

The heating device in the tenth disclosure may be any one of the first to ninth disclosures, and may be configured such that the irradiation unit irradiates electromagnetic waves having a frequency in the 2.45 GHz band or the 915 MHz band into the heating chamber.

With this configuration, a heating device can be realized using electromagnetic waves in the available frequency band.

The dryer in the eleventh disclosure may be equipped with any one of the heating devices in the first to tenth disclosures.

This configuration provides a dryer that can more accurately detect the occurrence of sparks within the heating chamber.

As described above, the scope of application of the present disclosure is not limited to the drum-type washer-dryers or drum-type dryers described above. For example, it may be applied to vertical washer-dryers or vertical dryers using a line-drying method or a pulsator method other than the drum type. In addition, any heating device that uses electromagnetic waves to heat can be used, and the heating target can be other than clothing.

1 Housing 2 Water tank (heating chamber)
Description of the Reference Signs 2a: front of water tank 2b: rear of water tank 2c: water tank opening 3: drum 3a: front of drum 3b: rear of drum 3c: drum opening 4: damper 5: door 6: drive motor 7: circulation air duct 8: outlet 9: exhaust port 10: drain valve 11: drain pipe 12: water supply valve 13: water supply pipe 16: blower fan 17: heater 18: inlet temperature detector 19: opening 20: control device 21: dehumidifier 22: lint filter 23: water seal packing 30: microwave heating device 31: microwave irradiator (irradiator)
32 Microwave irradiation port 33 Reflection section 34 Waveguide 36 Microwave receiving section (receiving section)
37 Second electromagnetic wave shield 38 First choke portion (first choke structure)
39 Second choke portion (second choke structure)
40 Microwave control device 41 Spark detection unit (detection unit)
42 Output adjustment unit 60 Drum type washer-dryer (dryer)

Claims (10)

A heating chamber that accommodates an object to be heated;
An irradiation unit that irradiates an electromagnetic wave into the heating chamber;
a first electromagnetic wave shield for suppressing electromagnetic waves leaking from the heating chamber;
A receiving unit that receives electromagnetic waves;
A detection unit that detects electromagnetic waves generated by sparks generated in the heating chamber by irradiation of the electromagnetic waves in the electromagnetic waves received by the receiving unit,
the receiving unit is provided outside the first electromagnetic wave shield and receives electromagnetic waves leaking from the first electromagnetic wave shield;
The detection unit detects electromagnetic waves amplified in the space of the first electromagnetic wave shield.
Heating device. A heating chamber that accommodates an object to be heated;
An irradiation unit that irradiates an electromagnetic wave into the heating chamber;
a first electromagnetic wave shield for suppressing electromagnetic waves leaking from the heating chamber;
a second electromagnetic wave shield for suppressing intrusion of electromagnetic waves irradiated from the irradiating unit ;
A receiving unit that receives electromagnetic waves;
A detection unit that detects electromagnetic waves generated by sparks generated in the heating chamber by irradiation of the electromagnetic waves in the electromagnetic waves received by the receiving unit ,
the receiving unit is provided inside the second electromagnetic wave shield and receives electromagnetic waves that enter the second electromagnetic wave shield ;
The detection unit detects electromagnetic waves amplified in the space of the first electromagnetic wave shield .
Heating device. The second electromagnetic shield is provided within a space of the first electromagnetic shield.
The heating device according to claim 2 . The second electromagnetic wave shield includes a second choke structure that suppresses intrusion of electromagnetic waves irradiated from the irradiation unit.
The heating device according to claim 2 or 3 . Among the x-axis length, y-axis length, and z-axis length that form the space of the first electromagnetic wave shield, a maximum straight line length is defined as Lmax,
The detection unit is
The wavelength λ is
(λ/2)≦Lmax,
Detects electromagnetic waves that are
The heating device according to any one of claims 1 to 4 . The detection unit detects electromagnetic waves having a frequency of 5 GHz or less among electromagnetic waves generated by sparks generated in the heating chamber.
The heating device according to any one of claims 1 to 5 . The first electromagnetic wave shield includes at least a wall that forms the heating chamber and a door body for inserting and removing the object to be heated into and from the heating chamber.
The heating device according to any one of claims 1 to 6 . the first electromagnetic wave shield has a first choke structure that suppresses leakage of electromagnetic waves from the heating chamber;
The heating device according to any one of claims 1 to 7 . The irradiation unit irradiates electromagnetic waves having a frequency of 2.45 GHz or 915 MHz into the heating chamber.
The heating device according to any one of claims 1 to 8 . A dryer comprising the heating device according to any one of claims 1 to 9 .

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