KR20210110231A - Laundry treating apparatus - Google Patents

Abstract

Disclosed is a laundry treatment apparatus capable of accurately measuring the temperature of a drum. The laundry treatment apparatus of the present disclosure includes: a tub; the drum rotatably provided in the tub; an induction heater fixed to the tub while being spaced apart from the drum to heat the drum; a first circuit including a first coil installed in the tub; a power supply unit for applying AC power to the first coil; and a second circuit installed on the drum; and a second circuit installed in the drum and including a second coil disposed at a position overlapping with the first coil in the longitudinal direction of the central axis of rotation of the drum, and a thermistor whose resistance varies according to temperature.

Description

Clothes processing equipment {LAUNDRY TREATING APPARATUS}

The present disclosure relates to a laundry treatment apparatus.

In general, the clothes treatment apparatus may include a washing machine, a dryer, and an apparatus for refreshing clothes. The washing machine may be a washing machine combined with a drying function.

In a washing machine, a drum accommodating laundry is rotatably provided in a tub that provides a space for storing water. Through holes are formed in this drum, so that water in the tub flows into the drum. When the drum is rotated in this state, the laundry in the drum flows and the contamination of the laundry is removed.

Such a washing machine is also provided with a heater for heating the water in the tub. The heater is operated in a state submerged in water in the tub, so it is common to directly heat the water. However, since this type of heater must always be operated in a state of being submerged in water for safety reasons, it can be used for heating water in the tub. It is not suitable for heating purposes.

Recently, a washing machine in which a drum is heated by an induction heating system has been used. Such a washing machine may be configured to have a heat sensor disposed between the drum and the tank (or tub) to sense the temperature of water or air in the tank.

In this way, the temperature of the drum is inevitably estimated based on the temperature of water or air. However, the temperature of the drum is sensitively changed according to the output of the induction heating system, but the temperature of water or air fluctuates slowly, so the heat sensor The value sensed by the Drum may not accurately reflect the temperature fluctuation of the drum.

Meanwhile, US Patent Application Laid-Open Publication No. US 2018/0148886 discloses a method of estimating a temperature using a characteristic change of a drum according to temperature, in particular, an inductance change.

1 shows a resonant circuit for using this method.

Referring to FIG. 1 , the driving of the power device Q1 is turned off near the zero crossing of the grid voltage by using the resonance circuit 2 , and at this time, the resonance frequency is used using the autonomously resonant voltage. (f _res ) can be measured.

)을 이용하여 인덕턴스(L_eq)를 도출할 수 있다.Using the resonant frequency (f _res ) measured in this way, the relation between the resonant frequency and the inductance and capacitance (

) can be used to derive _{the inductance (L eq ).}

Here, as the temperature increases, the relative magnetic permeability increases and the inductance L _eq also increases. Therefore, the temperature of the drum (load; 1) can be estimated through the change in inductance (L _{eq ) according to the temperature change.}

FIG. 2 shows a voltage waveform when measuring the resonance frequency, and FIG. 3 shows an enlarged view of part A of FIG. 2 .

Referring to FIG. 2 , it can be seen that the _{resonance frequency (f res} ) changes by about 0.015% when the load temperature changes by 1°C. That is, it can be seen that the variation _{of the resonance frequency f res} according to the temperature change is too small to estimate the temperature using the resonance frequency.

That is, referring to FIG. 3 , it can be seen that the portion of the waveform W after the circuit is turned off is small enough to measure the fluctuation.

In addition, _{the change in the inductance (L eq} ) fluctuates by 0.03%/°C. That is, it can fluctuate by 0.03% depending on the temperature. In addition, the capacitance (C _{eq ) in the resonant frequency (f res} ) calculation formula should be 0.003% or less depending on the dispersion of the parts and the dispersion according to the temperature.

4 is a graph illustrating a relationship between a temperature and a resonance frequency when estimating the temperature using the resonance frequency.

Due to the circumstances described above, when the temperature is estimated using the resonant frequency, an error of the estimated temperature may occur by about ±10°C or more. However, in order to be applied to general washing machine products, accuracy within ±5°C is required.

In addition, there is a problem in that the power of the circuit must be turned off for a predetermined time in order to measure the resonance frequency (fres).

Therefore, an improvement or a new method for estimating the temperature of the drum accurately by solving these problems is required.

US Patent Application Publication No. US 2018/0148886

SUMMARY OF THE INVENTION The present disclosure aims to solve the above and other problems.

Another object of the present invention is to provide a laundry treatment apparatus, such as a dryer, a washing machine, a washing machine combined dryer, or an apparatus for refreshing clothes, which can accurately estimate the temperature of the drum.

Another object may be to provide a laundry treatment apparatus capable of heating a drum with an induction heater and accurately estimating the temperature of the drum.

Another object of the present invention is to provide a laundry treatment apparatus capable of accurately estimating the temperature of the drum by minimizing the influence of the magnetic field generated by the induction heater.

Another object of the present invention is to provide a laundry treatment apparatus capable of accurately estimating the temperature of the drum regardless of the distance between the load (drum) and the tub.

Another object may be to provide a laundry treatment apparatus capable of estimating the temperature of a rotating load (drum).

Another object of the present invention is to provide a laundry treatment apparatus capable of continuously estimating the temperature without turning off a power device for estimating the temperature.

Another object of the present invention is to provide a laundry treatment apparatus that minimizes vibration due to unbalance even when a drum including a device for estimating temperature rotates at a high speed.

According to an aspect of the present disclosure, a laundry treatment apparatus includes a first circuit including a first coil, and a second circuit including a second coil and a thermistor.

The resistance of the thermistor changes according to temperature, and the current value of the second coil changes according to the change in resistance of the thermistor. The resistance of the thermistor may change according to the temperature of the drum.

The thermistor may include an NTC thermistor whose resistance decreases when the temperature increases. The resistance of the sub-characteristic thermistor may decrease when the ambient temperature increases. The resistance of the sub-characteristic thermistor may decrease when the temperature of the drum increases.

The thermistor may include a PTC thermistor whose resistance increases when the temperature increases. The resistance of the positive thermistor may increase as the ambient temperature increases. The resistance of the positive thermistor may increase when the temperature of the drum increases.

The second circuit may be provided to be movable with respect to the first circuit. The second circuit may be provided to be movable with respect to the first coil.

The laundry treatment apparatus includes a drum. The drum may be rotatably provided.

The laundry treatment apparatus may further include a tub accommodating the drum.

The drum may be rotatably provided in the tub.

The laundry treatment apparatus may include a cabinet. The cabinet may form an exterior of the laundry treatment apparatus. The cabinet may accommodate the tub.

The first coil may be installed in the tub. The first circuit may be installed in the tub.

The first coil may be installed inside the cabinet. The first circuit may be installed in a cabinet.

The second circuit is arranged on the drum.

The second coil may be disposed at a position overlapping the first coil in the longitudinal direction of the central axis of rotation of the drum.

The second coil may be installed at a position passing the shortest distance from the first coil according to the rotation of the drum. The second coil may be installed at a position where a straight line passing through the first coil and orthogonal to the rotation center line of the drum meets the drum.

The second circuit may be installed on an outer surface of the drum.

The laundry treatment apparatus may include a lifter provided on an inner surface of the drum.

The second circuit may be installed at a position corresponding to the lifter. The second circuit may be installed at a position corresponding to the lifter on the outer surface of the drum. The second circuit may be installed on an outer surface of a portion of the drum where the lifter is disposed. The second circuit may be installed on the inner surface of the drum in a portion of the drum where the lifter is disposed.

The drum may include an extended cylindrical body and a through hole formed in the body.

The laundry treatment apparatus may include a non-magnetic balance maintaining unit. The balance maintaining unit may be provided on the drum. The balance maintaining unit may be provided in the lifter. The balance maintaining unit may be provided in the lifter.

The second circuit and the balance maintaining unit may be arranged at regular intervals along the circumferential direction of the drum.

The balance maintaining unit may include one or more balance maintaining units. The second circuit and the one or more balance maintaining units may be arranged at regular intervals.

The lifter may include a plurality of lifters arranged at regular intervals along the circumferential direction of the drum.

The lifter may include a plurality of lifters. The plurality of lifters may be arranged at regular intervals along the circumferential direction of the drum.

The second circuit may be installed at a position corresponding to any one of the plurality of lifters. The second circuit may be installed on an outer surface of a portion of the drum on which the one lifter is disposed.

The balance maintaining part may be provided at a position corresponding to the other lifters among the plurality of lifters. The balance maintaining part may be provided inside the remaining ribter.

The laundry treatment apparatus includes an induction heater that heats the drum. The induction heater may generate a magnetic field. The induction heater heats the drum using a magnetic field.

The induction heater may be spaced apart from the drum. The induction heater may be installed in the tub. The induction heater may be fixed to the tub.

The induction heater may be disposed inside the case or on an inner wall. In a laundry treatment apparatus such as a dryer without a tub, it may be disposed inside a case or on an inner wall.

The first coil may be installed on an opposite side of the induction heater. The first coil may be installed on the opposite side of the induction heater with respect to the center of the tub. The first coil may be installed on the opposite side of the induction heater with respect to the center of the drum.

The first coil may be installed within a range of ±60 degrees from a point opposite to the induction heater with respect to the center of the tub.

The induction heater may be disposed at a position spaced apart from the drum at an upper side, a lower side, or a right side of the drum inside the case in a tubless laundry treatment apparatus such as a dryer. In this case, the first circuit including the first coil may be positioned opposite to the induction heater. Alternatively, it may be fixed to be spaced apart from the drum at positions spaced apart by a predetermined distance with respect to the drum rotation direction.

A size of the first coil may be greater than a size of the second coil. The first coil may occupy a larger area than the area occupied by the second coil in the circumferential direction of the drum.

The laundry treatment apparatus may include a power supply unit for applying power to the first coil.

The power supply may apply AC power to the first coil. The power supply may apply a resonant frequency.

The first circuit may include a capacitor. The capacitor may be connected in parallel with the first coil.

The laundry treatment apparatus may include a control unit.

The control unit may be connected to the first circuit. The controller may estimate the temperature of the drum. The controller may estimate the temperature of the drum based on a resistance value of the thermistor.

The laundry treatment apparatus may include a current sensing unit. The current sensing unit may be connected in series with the first coil. The current sensing unit may be connected in series with the power supply unit.

The laundry treatment apparatus may include a voltage sensing unit. The voltage sensing unit may be connected in parallel with the first coil. The voltage sensing unit may be connected in parallel with the power supply unit.

The controller may estimate the temperature of the drum based on the measured impedance. The measured impedance may be defined as a value obtained by dividing a voltage value detected by the voltage sensing unit by a current value detected by the current sensing unit.

The controller may compensate an error based on the measured impedance and the equivalent impedance of the first and second circuits. The equivalent impedance of the first and second circuits may be an equivalent impedance at a resonant frequency.

The power supply may change the applied frequency when the resonance frequency of the measured impedance is different from the resonance frequency of the equivalent impedance.

When the phase angle of the measured impedance is different from the phase angle of the equivalent impedance, the controller may compensate for the phase angle error by using the rotation angle of the drum.

According to an aspect of the present disclosure, the temperature of the load (drum) of the rotating induction heater may be estimated using the NTC.

That is, a sensing coil (first coil) and a capacitor are configured in parallel to form a primary side (first circuit), and a secondary side (second circuit) is configured with an NTC and a second coil, and the first coil is used for sensing. The temperature of the drum can be estimated using the voltage/current value of the NTC.

At this time, the primary side (first circuit) is attached in the opposite direction to the heater coil so as to minimize the magnetic effect with the induction heater coil, and the secondary side (second circuit) consists of three parts located inside the load (drum). It can adhere closely to the outer surface of one of the lifters.

To balance the high-speed rotating load (drum), a non-magnetic material that can balance the weight of the load (drum) can be attached inside or outside the other two lifters.

Therefore, the phase, frequency, and magnitude of _{the equivalent impedance (Z eq} ) are derived using the voltage and current values sensed from the primary side, _{and the R ntc} value of the NTC and the load (drum) using this temperature can be estimated.

As a specific example for this, a temporary example of the present disclosure includes a cabinet; a drum rotatably provided in the cabinet for accommodating an object to be treated (eg, clothes); an induction heater spaced apart from the drum and disposed inside or on an inner wall of the cabinet to heat the drum; a first circuit disposed at a position spaced apart from the induction heater inside the cabinet or on an inner wall and including a first coil; a second coil disposed on the drum and disposed at a point in the drum region that overlaps the first coil and the drum in the rotational direction of the drum when the drum rotates; It provides a laundry treatment apparatus including a circuit.

A laundry treatment apparatus according to another embodiment of the present disclosure includes: a tub; a drum rotatably provided in the tub and accommodating an object; an induction heater fixed to the tub while being spaced apart from the drum to heat the drum; a first circuit installed in the tub and including a first coil; a second coil installed on the drum and positioned to pass through a point in the region of the drum overlapping to interact within the circumferential extent of the first coil and the drum upon rotation of the drum and the temperature of the drum in the second coil and a second circuit having a thermal variable resistance unit that transmits at least one of a voltage and a current value according to .

Another embodiment of the present disclosure is connected to the first circuit using at least one of a voltage and a current value according to the temperature of the drum received by the interaction between the second coil and the first coil. It may include a control unit for estimating the temperature of the drum.

In addition, the first circuit may further include a capacitor connected in parallel with the first coil.

In addition, the laundry treatment apparatus may include: a power supply unit; a current sensing unit connected in series with the first coil; and a voltage sensing unit connected in parallel with the first coil.

In addition, the power supply may apply a resonant frequency.

In addition, the capacitor may be for increasing the resolution of the value related to the temperature of the drum received through the second coil.

Also, the sensing unit may be an NTC that outputs a resistance value that changes according to a temperature as a voltage value.

In addition, the size of the first coil may be larger than the size of the second coil.

In addition, the first coil may be installed on the tub on the opposite side of the induction heater.

In addition, the first coil may be installed in a range of ±60 degrees from the opposite side of the induction heater on the tub.

In addition, the second coil may be installed at a position passing the shortest distance from the first coil according to the rotation of the drum.

In addition, the second circuit may be installed on the outer surface of the drum.

In addition, the laundry treatment apparatus may further include a balance maintaining unit installed at a position equal to an angle of the drum with respect to a position to which the second circuit is attached.

In addition, the control unit compares the impedance obtained by sensing the voltage and current values transmitted from the second coil by the interaction of the first coil with the equivalent impedance of the first and second circuits to determine the resistance value of the NTC and The temperature of the drum can be estimated.

As another specific example for this, the present invention includes a tub, a drum rotatably provided in the tub and accommodating an object, and an induction heater fixed to the tub while being spaced apart from the drum to heat the drum In the laundry treatment apparatus, a first circuit installed in the tub and including a first coil and a drum installed in the drum and overlapped to interact within a circumferential range of the drum when the drum rotates with the first coil Estimating the temperature of the drum using a second circuit including a second coil positioned to pass the point and a sensing unit that transmits at least one of a voltage and a current value according to the temperature of the drum to the second coil A method of controlling a laundry treatment apparatus, the method comprising: driving the laundry treatment apparatus; sensing an output value of the sensing unit through the first circuit; calculating an equivalent impedance of the first circuit; matching the impedance measured as an output value of the sensing unit with a resonance frequency of the equivalent impedance; matching the impedance measured as the output value of the sensing unit and the phase angle of the equivalent impedance; and estimating the temperature of the drum through the sensing unit based on the magnitude of the equivalent impedance.

The matching of the resonant frequency may include: obtaining an error by comparing the impedance measured as an output value of the sensing unit with the resonant frequency of the equivalent impedance; and compensating for an error in the inductance value of the first coil.

In addition, the matching of the phase angles may include: obtaining an error by comparing an impedance measured as an output value of the sensing unit with a phase angle of the equivalent impedance; and compensating for an error in the phase angle using the rotation angle of the drum.

The driving of the laundry treatment apparatus may include heating and rotating the drum; and applying a voltage of a resonant frequency to the first circuit.

Also, the driving of the laundry treatment apparatus may include aligning the first coil with the first coil.

In another embodiment of the present disclosure, a fixing unit such as a cabinet and a rotating unit rotating with respect to the fixed unit are provided, and a first circuit including a first coil is disposed in the fixed unit, and the rotating unit is connected to the first coil. A second coil disposed at a corresponding position and a second circuit electrically connected to the second coil and including a second circuit including a thermal variable resistance unit in which the internal resistance changes according to the temperature of the rotating part and the flowing current or voltage value is changed Provided is a laundry treatment apparatus configured to determine a temperature of the rotating unit based on a current value or a voltage value of a first coil corresponding to a current value or a voltage value of the second coil.

The fixing part may be an inner wall of the cabinet or any position inside the cabinet, and may be a tub disposed inside the cabinet to accommodate the rotating part.

In a dryer or clothes treatment apparatus without a tub, the first circuit may be disposed on an inner wall of the cabinet at a lower portion or a side surface of the rotating unit.

The rotating unit includes a drum arranged to rotate inside the cabinet or the tub. The second circuit is disposed on the drum, and may be disposed on an outer surface or an inner surface of the drum.

The laundry treatment apparatus may include a lifter disposed inside the drum, and the second circuit may be disposed in a drum area corresponding to the lifter. The second circuit may be disposed on an outer surface of the drum corresponding to the lifter or an inner surface of the drum on which the lifter is mounted.

The first coil and the second coil are arranged to overlap each other with respect to the drum rotation direction. The thermal variable resistance unit of the second circuit may be disposed in a drum area corresponding to the lifter or a drum area corresponding to the induction heater.

The first coil may be configured to be greater than or equal to the second coil. For example, the first coil may be configured to be larger than the second coil. Even if the first coil and the second coil have the same size, the number of turns of the coil of the first coil may be increased by the number of turns of the coil of the second coil.

A distance between the first coil and the second coil may be 28 mm to 30 mm.

The drum temperature may specify a frequency between the first coil and the second coil, and may be estimated through the magnitude of the impedance at the specified frequency.

The first coil may be disposed at a position opposite to the induction heater with respect to the drum rotation axis, and may be disposed at a position within 90 degrees in both directions from a position 180 degrees opposite to the induction heater.

The rotating unit may dispose the balance weight at a position spaced apart from the second coil, and a laundry treatment apparatus having a rotating unit rotating at a low speed, such as a dryer, may not include the balance weight.

According to at least one of the embodiments of the present disclosure, the temperature of the drum may be estimated using the characteristics of the thermistor whose resistance changes according to the temperature.

According to at least one of the embodiments of the present disclosure, the temperature may be estimated irrespective of an interval that is structurally generated due to a drum and a tub.

According to at least one of the embodiments of the present disclosure, the temperature may be estimated even under a condition in which the load (drum) rotates.

In addition, by including an NTC thermistor, the effect of inductance/capacitance distribution on temperature estimation can be reduced.

In addition, continuous temperature estimation can be performed without turning off the power device for temperature estimation. Accordingly, it is possible to improve the performance of the laundry treatment apparatus.

1 is a resonant circuit for using a method of estimating a temperature using an inductance change.
FIG. 2 shows a voltage waveform when the resonance frequency is measured in the resonance circuit of FIG. 1 .
FIG. 3 shows an enlarged view of part A of FIG. 2 .
4 is a graph illustrating a relationship between a temperature and a resonance frequency when estimating the temperature using the resonance frequency.
5 is a perspective view of a laundry treatment apparatus according to an embodiment of the present disclosure;
6 is a cross-sectional view of a laundry treatment apparatus according to an embodiment of the present disclosure.
7 is a conceptual diagram in which a separate type induction heater module is mounted on a tub.
8 is a circuit diagram illustrating a circuit configuration of a laundry treatment apparatus according to an exemplary embodiment of the present disclosure.
9 is a schematic diagram illustrating an installation position of a circuit configuration of a laundry treatment apparatus according to an embodiment of the present disclosure;
10 is a schematic diagram illustrating an example of installation of a first coil and a second coil of a laundry treatment apparatus according to an embodiment of the present disclosure;
11 is a graph illustrating a relationship between an impedance phase angle and a frequency of the laundry treatment apparatus according to an exemplary embodiment of the present disclosure.
12 is a graph illustrating a relationship between an impedance magnitude and a frequency of the laundry treatment apparatus according to an exemplary embodiment of the present disclosure.
13 is a graph illustrating a relationship between an impedance phase angle and a frequency under simulation conditions.
14 is a graph showing the relationship between impedance magnitude and frequency under simulation conditions.
15 is a graph illustrating a change in a resistance value according to a temperature of an NTC.
16 is a flowchart illustrating a method of controlling a laundry treatment apparatus according to an exemplary embodiment of the present disclosure.

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

The suffixes "module" and "part" for the components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have a meaning or role distinct from each other by themselves.

In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed in the present specification is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present disclosure , should be understood to include equivalents or substitutes.

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

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

It is also understood that when an element, such as a layer, region, or module, is referred to as being “on” another element, it may be directly on the other element or intervening elements may exist in between. There will be.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

Furthermore, although each drawing is described for convenience of description, it is also within the scope of the present invention that those skilled in the art implement other embodiments by combining at least two or more drawings.

The laundry treatment apparatus of the present disclosure may correspond to a washing machine (dryer-integrated washing machine) in which a washing machine, a dryer, and a dryer are integrated. Hereinafter, as a laundry treatment apparatus of the present disclosure, a laundry apparatus will be described as a representative example. However, the laundry treatment apparatus of the present disclosure is not limited thereto.

Hereinafter, a laundry treatment apparatus according to an embodiment of the present disclosure will be described with reference to FIGS. 5 to 7 .

5 is a perspective view illustrating the outside of a washing machine according to an embodiment of the present disclosure; 6 is a cross-sectional view illustrating the inside of a washing machine according to an embodiment of the present disclosure. 7 is a conceptual diagram in which a separate type induction heater module is mounted on a tub.

A washing machine according to an embodiment of the present disclosure may include a tub 20 and a drum 30 . The washing machine may further include a cabinet 10 forming an exterior. The washing machine may further include an induction heater 70 provided to heat the drum 30 .

The tub 20 may be provided inside the cabinet 10 . The tub 20 may provide an accommodation space. The tub 20 may have an opening in the front. The tub 20 may accommodate washing water. The tub 20 may be provided to accommodate the drum 30 .

The drum 30 may be rotatably provided inside the tub 20 . The drum 30 may be provided in the accommodation space of the tub 20 . The drum 30 may accommodate laundry. An opening may be provided at the front of the drum 30 . Laundry may be introduced into the drum 30 through the opening.

A through hole 30h may be formed in the circumferential surface of the drum 30 so that air and washing water may communicate between the tub 20 and the drum 30 . Hereinafter, the circumferential surface of the drum 30 is also referred to as a body of the drum 30 . The body of the drum 30 may extend in a cylindrical shape.

The drum 30 may be made of a conductor. The body of the drum 30 may be made of a conductor. The body of the drum 30 may be made of metal.

The induction heater or IH module 70 may heat the drum 30 . The induction heater 70 may generate a magnetic field. The induction heater 70 may be provided to heat the drum 30 using a magnetic field.

The induction heater 70 may be provided on the outer peripheral surface of the tub 20 . The induction heater 70 may be provided on the tub 20 . The induction heater 70 may be fixed to the tub 20 . The induction heater 70 may be spaced apart from the drum 30 .

The tub 20 and the drum 30 may be formed in a cylindrical shape. The inner and outer peripheral surfaces of the tub 20 and the drum 30 may be formed in a substantially cylindrical shape.

Meanwhile, a laundry treatment apparatus such as a dryer may not include a tub. The induction heater 70 may be provided in the cabinet. The induction heater 70 may be disposed inside the cabinet or on the inner wall. The induction heater 70 may be spaced apart from the drum 30 and fixed to the cabinet 10 .

6 shows a washing machine in a form in which the drum 30 is rotated with respect to a rotation axis parallel to the ground. Unlike the drawings, the drum 30 and the tub 20 may have a tilting shape inclined to the rear. The rotating shaft of the drum 30 may pass through the rear surface of the washing machine. That is, a straight line extending from the rotation shaft 42 of the driving unit 40 may pass through the rear surface of the washing machine.

The washing machine may further include a driving unit 40 provided to rotate the drum 30 inside the tub 20 . The driving unit 40 may include a motor 41 . The motor 41 may include a rotation shaft 42 . The rotating shaft 42 may be connected to the drum 30 to rotate the drum 30 in the tub 20 .

The motor 41 may include a stator and a rotor. The rotor may be connected to the rotation shaft 42 .

The driving unit 40 may include a spider 43 . The spider 43 is a configuration that connects the drum 30 and the rotation shaft 42 and can be said to be a configuration for uniformly and stably transmitting the rotational force of the rotation shaft 42 to the drum 30 .

The spider 43 may be coupled to the drum 30 in the form of being at least partially inserted into the rear wall of the drum 30 . To this end, the rear wall of the drum 30 may be formed in a shape recessed into the drum 30 . In addition, the spider 43 may be coupled to the drum 30 in the form of being further inserted into the drum 30 at the center of rotation of the drum 30 .

A lifter 50 may be provided inside the drum 30 . A plurality of lifters 50 may be provided along the circumferential direction of the drum 30 . The lifter 50 may perform a function of stirring the laundry. For example, as the drum 30 rotates, the lifter 50 lifts the laundry upward.

The laundry moved to the upper part is separated from the lifter 50 by gravity and falls to the lower part. Washing may be performed by the impact force caused by the falling of such laundry. Agitation of laundry can enhance drying efficiency.

The lifter 50 may be formed by extending from the rear end of the drum 30 to the front end. Laundry may be evenly distributed back and forth in the drum 30 .

The induction heater 70 is a device for heating the drum 30 .

As shown in FIG. 7 , the induction heater 70 may include a coil 71 that generates a magnetic field by receiving a current. The coil 71 may generate an eddy current in the drum 30 .

The induction heater 70 may include a heater cover 72 accommodating the coil 71 . Hereinafter, the structure of the induction heater 70 and the principle that the induction heater 70 heats the drum 30 will be omitted.

In the washing machine, the coil 71 heats the drum 30 to increase the temperature inside the drum 30 as well as the drum 30 itself. The induction heater 70 may heat the wash water in contact with the drum 30 through the heating of the drum 30 . The induction heater 70 may heat the laundry in contact with the inner peripheral surface of the drum 30 . The induction heater 70 may heat the laundry that is not in contact with the inner peripheral surface of the drum 30 by increasing the temperature inside the drum 30 .

The induction heater 70 may enhance the washing effect by increasing the washing water, laundry, and the ambient temperature inside the drum 30 . The induction heater 70 may dry the laundry by increasing the laundry, the drum 30 and the ambient temperature inside the drum 30 .

7 illustrates that the induction heater 70 is provided on the upper side of the tub 20 , the induction heater 70 is provided on at least one surface of the upper side, lower side, and both sides of the tub 20 . it is not The induction heater 70 may be installed at a position higher than the maximum water level that the wash water stored in the tub 20 can have.

The induction heater 70 is provided on one side of the outer circumferential surface of the tub 20, and the coil 71 is provided by winding the induction heater 70 in the cover 72 at least once along the surface adjacent to the tub 20. can

The induction heater 70 may generate an eddy current in the drum 30 by emitting an induced magnetic field directly to the outer circumferential surface of the drum 30 , and as a result, may directly heat the outer circumferential surface of the drum 30 .

The laundry treatment apparatus according to an embodiment of the present disclosure may have the same configuration as the control unit (not shown, the control unit 85 of FIG. 8 ) for controlling the output of the induction heater 70; to be described) may be included. The controller 85 may control on/off and output of the induction heater 70 .

The induction heater 70 may receive power by being connected to an external power supply source and an electric wire. Alternatively, the induction heater 70 may be connected to the controller 85 for controlling the operation of the washing machine to receive power. The induction heater 70 may receive power from anywhere as long as it can supply power to the internal coil 71 .

When electric power is supplied to the induction heater 70 and AC current flows through the coil 71 provided in the induction heater 70 , the drum 30 is heated.

If electric power is supplied to the induction heater 70 and the drum 30 does not rotate, only a portion of the surface of the drum 30 is heated, so that some surface may be overheated and the remaining surface of the drum 30 is not heated or heated. can be small In addition, heat may not be smoothly supplied to the laundry accommodated in the drum 30 .

When the induction heater 70 is operated, the control unit 85 may rotate the drum 30 through the motor 41 of the driving unit 40 . The controller 85 may cause the induction heater 70 to operate when the drum 30 rotates.

If all surfaces of the outer peripheral surface of the drum 30 can face the induction heater 70 , the speed at which the motor 41 of the driving unit 40 rotates the drum 30 may be any speed.

Meanwhile, as the drum 30 rotates, all surfaces of the drum 30 may be heated, and the laundry inside the drum 30 may be evenly exposed to heat.

Accordingly, in the laundry treatment apparatus according to an embodiment of the present disclosure, the induction heater 70 evenly heats the outer circumferential surface of the drum 30 even if the induction heater 70 is installed in one place rather than at the upper, lower, and both sides of the outer circumferential surface of the tub 20 . can do.

According to an embodiment of the present disclosure, the induction heater 70 can heat the drum 30 to a high temperature within a very short time. The induction heater 70 can heat the drum 30 to a target temperature within a very short time. The induction heater 70 can heat the drum 30 to 120 degrees Celsius or more within a very short time.

When the induction heater 70 is driven in a state in which the drum 30 is stationary or at a very slow rotation speed, a specific part of the drum 30 may be overheated very quickly. When the induction heater 70 is driven in a state in which the drum 30 is stopped or at a very slow rotation speed, heat may not be sufficiently transferred from the heated drum 30 to the laundry.

The correlation between the rotational speed of the drum 30 and the driving of the induction heater 70 may be very important. It may be more advantageous to rotate the drum 30 and drive the induction heater 70 than to drive the induction heater 70 and rotate the drum 30 .

8 is a circuit diagram illustrating a circuit configuration of a washing machine according to an embodiment of the present disclosure. In addition, Figure 9 is a schematic diagram showing an installation position of the circuit configuration of the washing machine according to an embodiment of the present disclosure.

Hereinafter, a circuit configuration of a laundry treatment apparatus according to an embodiment of the present disclosure will be described in detail with reference to FIGS. 8 and 9 .

In the laundry treatment apparatus according to an embodiment of the present disclosure, the first circuit 80 is installed in the tub 20 and includes the first coil 82 , and is installed in the drum 30 and rotates when the drum 30 rotates. It may include a second circuit 90 including a second coil 92 positioned to pass through a point where it interacts with the first coil 82 and a thermistor 91 whose resistance varies according to temperature.

As such, the second coil is installed on the drum 30 and, upon rotation of the drum 30 , within the region of the drum 30 overlapping with the first coil 82 to interact within the circumferential extent of the drum 30 . It can be positioned past the point.

In addition, the washing machine according to an embodiment of the present disclosure is connected to the first circuit 80 and is connected to the temperature of the drum 30 transmitted by the interaction between the second coil 92 and the first coil 82 . It may include a controller (MCU) 85 for estimating the temperature of the drum 30 using the associated value.

Meanwhile, a laundry treatment apparatus such as a dryer may not include a tub. The first circuit 80 may be disposed inside or on the inner wall of the cabinet 10 at a position where it can interact with the second coil according to the rotational position of the drum.

As shown in FIG. 8 , the first circuit 80 may further include a capacitor C connected in parallel to the first coil 82 .

The laundry treatment apparatus may include a current sensing unit 84 connected in series with the first coil 82 and a voltage sensing unit 83 connected in parallel with the first coil 82 .

The thermistor 91 may be an NTC-thermistor (Negative Temperature Coefficient-thermic resistor) whose resistance decreases as the temperature increases. Hereinafter, the NTC-thermistor is also briefly referred to as NTC.

The resistance value of the NTC may be referred to as Rntc. The NTC may have a resistance value Rntc that exponentially decreases according to the temperature of the load (drum). Hereinafter, the thermistor 91 and the NTC 91 will be described using the same reference numerals.

In this way, the second circuit 90 installed in the drum 30 has at least one of a voltage value and a current value (hereinafter, a voltage value and/or a current value and It will be expressed together.) can be printed.

The output voltage value and/or current value of the NTC 91 may be transmitted to the second coil 92 . Thereafter, this value may be transmitted to the first circuit 80 by the interaction between the first coil 82 and the second coil 92 . That is, the first coil 82 and the second coil 92 interact with each other to transmit a current that fluctuates according to a change in the resistance of the NTC 91 to the first coil 82 of the first circuit 80 . have. In this case, the interaction may be an electromagnetic induction phenomenon in which current/voltage is induced between the first coil 82 and the second coil 92 .

The controller 85 may estimate the resistance value of the NTC 91 by using the impedance obtained by sensing the voltage and current values obtained at this time. The controller 85 may estimate the temperature of the drum 30 from the estimated resistance value of the NTC 91 .

The controller 85 may compensate an error in the resistance value of the NTC 91 by comparing the impedance obtained by sensing the voltage and current values with the equivalent impedance of the first and second circuits 90 viewed from the capacitor. Through this, it is possible to compensate for the error in the temperature of the drum 30 estimated.

The process of estimating the temperature of the drum 30 will be described later in detail.

The power supply unit 81 of the first circuit 80 may apply a resonant frequency. This resonant frequency may be the same as the frequency of a signal induced to the primary coil 82 through the secondary coil 92 .

Impedance can be defined as the ratio of AC voltage and current applied to a reference point or a specific object. An alternating signal, such as an AC voltage, has a phase. In order to compare the phases, it may be necessary for the two signals to have the same frequency. This is because comparing the phases may not be meaningful if the frequencies are different.

Therefore, in order to compare the measured impedance and the equivalent impedance, it may be necessary to compare the (resonant) frequency and then compare the phase angle.

Meanwhile, the capacitor C may increase the resolution (degree of change; degree of discrimination) of a value related to the temperature of the drum 30 received through the second coil 92 .

For example, in the case of a washing machine combined with drying, a gap between the first coil 82 and the second coil 92 may occur due to a structural gap between the drum 30 and the tub 20 . The distance between the first coil 82 and the second coil 92 may be, for example, 28 mm to 30 mm. Accordingly, the mutual inductance M between the first coil 82 and the second coil 92 may be reduced.

Due to this, a change in the resistance value of the NTC 91 may not be significantly observed in the first circuit 80 . The capacitor C may compensate for a phenomenon in which a change in the resistance value of the NTC 91 may not be significantly observed in the first circuit 80 .

Referring to FIG. 9 , the first coil 82 may be installed on the tub 20 on the opposite side of the coil 71 of the induction heater 70 .

In addition, the first coil 82 may be installed on the tub 20 within a range of ±60 degrees from the opposite side of the coil 71 of the induction heater 70 .

That is, in the case of a washing machine combined with drying, the first coil 82 may be installed in the tub 20 . The first coil 82 may be positioned on the tub 20 in a direction opposite to the coil 71 of the induction heater 70 . Accordingly, the influence of the magnetic field generated in the coil 71 of the induction heater 70 on the first coil 82 may be minimized.

Meanwhile, the first coil 82 may be installed within a range between positions of adjacent lifters indicated by dotted lines in FIG. 9 . That is, the first coil 82 may be installed on the tub 20 in a range within ±60 degrees from the opposite side of the coil 71 of the induction heater 70 . Accordingly, the influence of the magnetic field generated in the coil 71 of the induction heater 70 on the first coil 82 may be minimized. For this reason, it is possible to avoid interference of the first coil 82 with other structures that may be provided under the tub 20 , such as a washing heater other than the induction heater 70 .

The second coil 92 may be installed at a position passing the shortest distance from the first coil 82 according to the rotation of the drum 30 . That is, when the drum 30 rotates, the second coil 92 installed on the drum 30 may pass through the position of the shortest distance from the first coil 82 .

In addition, the second circuit 90 including the second coil 92 may be installed on the outer surface of the drum 30 .

In the case of a washing machine combined with drying, the second circuit 90 including the NTC 91 and the second coil 92 may be installed outside the drum 30 at the lifter position of the load drum 30 . have. Here, the dotted line in FIG. 9 indicates the position of the lifter.

When the second coil 92 is installed inside the drum 30 , current may not be transmitted to the first coil 82 due to the material characteristics of the load (drum) 30 .

On the other hand, the balance maintaining unit 93 may be provided at a position that divides the circular angle of the drum 30 into equal parts with respect to the position where the second circuit 92 of the drum 30 is attached.

For example, in the case of a washing machine combined with drying, it may be necessary to maintain a weight balance when rotating at a high speed.

At this time, for example, when the lifter is located at a position where the angle of the drum 30 is divided into three equal parts, and the second circuit 90 is provided at any one position, the balance maintaining unit 93 is provided in the other two parts. can be installed.

For example, since the dryer may not rotate at a high speed, the balance maintaining unit 93 for maintaining the weight balance may not be installed.

10 is a schematic diagram illustrating an example of installation of a first coil and a second coil of a laundry treatment apparatus according to an embodiment of the present disclosure;

Referring to FIG. 10 , the size of the first coil 82 may be greater than the size of the second coil 92 . That is, in consideration of the rotation of the load (drum) 30, the size of the first coil 82 acting as a sensing coil to maintain a constant inductance (L1, L2, M) value even during the rotation of the drum 30 is a signal It may be advantageous to be designed to be larger than the size of the second coil 92 to transmit.

In addition, depending on the applied washing machine and the interval between the first coil 82 and the second coil 92, the number of turns of the first coil 82 and the parallel capacitor C will optimize the value. may need

Meanwhile, the temperature error can be minimized by compensating for the error using the rotation angle information of the drum 30 .

Hereinafter, a process of estimating the temperature of the drum 30 using the circuit configuration of the washing machine according to an embodiment of the present invention shown in FIG. 8 will be described in detail.

Equation 1 is a calculation expression representing the equivalent impedance Zeq seen from the first circuit 80 (primary side). More specifically, Equation 1 is a calculation expression representing the equivalent impedance Zeq of the first and second circuits 80 and 90 viewed from the capacitor C. As shown in FIG. The explanation in terms of the equivalent impedance Zeq of the first and second circuits 80 and 90 shown in FIG. 8 is as follows.

In Equation 1, L1 is the inductance of the first coil 82, L2 is the inductance of the second coil 92, and M is the mutual inductance. ω represents the (resonant) frequency, and C represents the capacitance of the capacitor of the first circuit 80 .

_{Referring to Equation 1, the equivalent impedance (Z eq} ) of the first and second circuits 80 and 90 at the resonant frequency is briefly summarized as the following equation.

Referring to Equation 1 or Equation 2 as above, the equivalent impedance Zeq of the first and second circuits 90 viewed from the capacitor C varies greatly according to the change in Rntc, which is the resistance value of the NTC 91 . it can be seen that That is, the equivalent impedance Zeq is proportional to the resistance Rntc of the NTC 91 .

11 is a graph illustrating a relationship between an impedance phase angle and a frequency. 12 is a graph showing the relationship between impedance magnitude and frequency.

11 and 12 , it can be seen that the temperature estimation of the temperature estimation circuit using the NTC 91 is sufficiently possible.

As can be seen in FIGS. 11 and 12 , it can be seen that both the phase angle and the magnitude of the equivalent impedance Zeq seen from the primary side (the first circuit) 80 change significantly.

At this time, as in FIG. 11 , when the interval between the primary side (first circuit; 80) and the secondary side (second circuit; 90) is changed, the impedance phase angle is changed to specify the frequency to be measured. . As such, in order to compare two impedances, it may be necessary to specify a frequency.

Also, as shown in FIG. 12 , the temperature may be estimated by measuring the magnitude of the impedance at the frequency specified above.

At this time, it can be seen that the magnitude of the impedance changes 100 times from 200Ω to 20 kΩ, which may mean that the discrimination power for temperature estimation is sufficient.

Hereinafter, a temperature estimation process under specific simulation conditions will be described with reference to FIGS. 13 and 14 .

13 is a graph illustrating a relationship between an impedance phase angle and a frequency under simulation conditions. Also, FIG. 14 is a graph showing the relationship between impedance magnitude and frequency under simulation conditions. 15 is a graph illustrating a change in a resistance value according to an NTC temperature.

At this time, the case of the primary side coil turn ratio of the first coil 82 and the second coil 92 is 5 to 5 (5:5), and the interval between the first circuit 80 and the second circuit 90 is applied. The conditions for the case of 30mm apply.

When a specific inductance (L1, L2, M) value for simulation is applied, and the distance between the primary side (first circuit; 80) and the secondary side (second circuit; 90) is 30 mm, Equation 2 becomes as follows are sorted out

As shown in FIGS. 13 and 14 , the Rntc value of the NTC 91 can be derived using the phase of the equivalent impedance Zeq and the impedance magnitude at a specific frequency.

At this time, as shown in FIG. 15 , it can be seen that the Rntc value of the NTC 91 varies from 200 to 1000 Ω, and at this time, the temperature of the NTC varies from 100 to 150 ˚C.

As described above, according to the present invention, the temperature of the drum 30 can be estimated with sufficient accuracy using the circuit shown in FIG. 8 .

According to such an embodiment of the present disclosure, accurate temperature estimation may be possible using the characteristic of the NTC resistance that exponentially decreases with temperature.

In addition, it may be possible to estimate the temperature regardless of an interval that is structurally generated due to the drum and the tub.

In addition, accurate temperature estimation may be possible even under a rotating load (drum) condition.

Also, since the temperature is estimated using the NTC resistance, the influence on the inductance/capacitance distribution may be small.

For temperature estimation, continuous temperature estimation is possible without turning off the power device, so high efficiency can be achieved when product is applied.

16 is a flowchart illustrating a method of controlling a laundry treatment apparatus according to an exemplary embodiment of the present disclosure.

According to an embodiment of the present disclosure, the temperature of the drum 30 of the washing machine may be estimated using the circuit as described with reference to FIG. 8 .

That is, by the interaction between the first coil 82 included in the first circuit 80 and the second coil 92 included in the second circuit 90 , the voltage received from the second coil 92 and By comparing the impedance obtained by sensing the current value and the equivalent impedance of the first and second circuits 80 and 90 viewed from the first circuit 80, the resistance value of the NTC 91 and the temperature of the drum 30 can be estimated have.

Hereinafter, a process of estimating the temperature of the drum 30 of the laundry treatment apparatus using the first circuit 80 and the second circuit 90 will be described in detail with reference to FIGS. 8 and 16 together.

First, a step ( S10 ) of driving the laundry treatment apparatus may be performed. In this case, as mentioned above, the laundry treatment apparatus may correspond to a laundry apparatus (dryer-integrated washing machine) in which a washing machine, a dryer, and a dryer are integrated. Hereinafter, as a laundry treatment apparatus of the present invention, a washing machine will be described as a representative example. However, the laundry treatment apparatus of the present invention is not limited thereto.

Driving the laundry treatment apparatus (S10) may include a process of heating and rotating the load (drum; drum; 30) (S11).

In addition, the step of driving the laundry treatment apparatus ( S10 ) may include a process ( S12 ) of applying a resonant frequency to the power supply unit 81 of the first circuit (primary side) 80 .

In addition, the operation of the laundry treatment apparatus ( S10 ) may include aligning the first coil (primary coil) 82 and the second coil (secondary coil) 92 . The process of aligning the first coil (primary coil) 82 and the second coil (secondary coil) 92 may be performed automatically or manually in the washing machine. Also, in some cases, the process of aligning the first coil (primary coil) 82 and the second coil (secondary coil) 92 may be omitted.

When the process of aligning the first coil (primary coil; 82) and the second coil (secondary coil; 92) is performed, the process of heating and rotating the load (drum; drum; 30) after this alignment process The process (S11) may be performed.

Thereafter, the step S20 of sensing the output value of the second circuit 90 through the first circuit 80 may be performed. In this case, the second circuit 90 may include the thermistor 91 . The thermistor 91 may be an NTC thermistor 91 .

The resistance of the NTC 91 may be changed by heating the drum 30 . Such a change in resistance may follow the graph shown in FIG. 15 . A change in the curve in this graph may vary according to the NTC 91 .

When the resistance of the NTC 91 changes and the drum 30 rotates, the output current (and/or voltage) of the NTC 91 may be transmitted to the first coil 82 through the second coil 92 . There is (S21). That is, the output current (and/or voltage) by Rntc, which is the resistance value of the NTC 91 on the secondary side, may be transmitted to the first coil 82 .

Accordingly, the first circuit 80 may sense the current (and/or voltage) reflecting Rntc ( S22 ).

Then, using the current (and/or voltage) value reflecting the sensed Rntc, calculating the equivalent impedance of the first and second circuits 80 ( S30 ) may be performed.

Calculating the equivalent impedance ( S30 ) may include determining the magnitude and phase angle of the equivalent impedance Zeq.

As mentioned above, impedance can be defined as the ratio of AC voltage and current applied to a reference point or a specific object. An alternating signal, such as an AC voltage, has a phase. In order to compare the phases, it may be necessary for the two signals to have the same frequency. This is because comparing the phases may not be meaningful if the frequencies are different.

Therefore, in order to compare the measured impedance and the equivalent impedance, it may be necessary to compare the (resonant) frequency and then compare the phase angle.

First, the steps ( S40 and S41 ) of matching the impedance measured as an output value of the second circuit 90 with the resonance frequency of the equivalent impedance Zeq may be performed.

At this time, the steps (S40 and S41) of matching the resonance frequencies include the steps of obtaining an error by comparing the impedance measured as the output value of the second circuit 90 with the resonance frequency of the equivalent impedance Zeq (S40); Compensating for an error in the inductance value of one coil 82 ( S41 ) may be included.

That is, if an error occurs by comparing the impedance measured as the output value of the second circuit 90 and the resonance frequency of the equivalent impedance Zeq, the error in the inductance value L1 of the first coil 82 can be compensated. . In this case, the error value may include a capacitance value (C).

In this way, the applied frequency applied to the power supply unit 81 of the primary side 80 may be changed according to the compensated error value.

Next, steps ( S50 and 51 ) of matching the phase angle of the impedance measured as the output value of the second circuit 90 and the equivalent impedance Zeq may be performed.

That is, the steps (S50, S51) of matching the phase angles include the steps of obtaining an error by comparing the phase angle of the equivalent impedance Zeq with the impedance measured as the output value of the second circuit 90 (S50) and the drum ( The step of compensating for the error of the phase angle using the rotation angle of 30) (S51) may be included.

That is, if an error occurs by comparing the phase angle of the impedance measured as the output value of the second circuit 90 and the equivalent impedance Zeq, compensation for the error using the rotation angle of the load (drum) 30 can be performed. have.

By this process, when the frequency and phase angle of the impedance and the equivalent impedance Zeq match, the step of estimating the temperature of the drum 30 through the thermistor (NTC) 91 with the magnitude of the equivalent impedance Zeq (S60) ) can be done.

In this case, the compensation of the error using the rotation angle of the load (drum) 30 may be applied to the step (S60) of estimating the temperature of the drum 30 through the thermistor (NTC) 91 with the magnitude of the equivalent impedance Zeq. .

Any or other embodiments of the present disclosure described above are not mutually exclusive or distinct. Certain embodiments or other embodiments of the disclosure described above are not mutually exclusive or distinct from each other. Any or all elements of the embodiments of the disclosure described above may be combined with another or combined with each other in configuration or function).

For example, it means that configuration A described in a specific embodiment and/or drawing may be combined with configuration B described in another embodiment and/or drawing. That is, even if the combination between the configurations is not directly described, it means that the combination is possible except when it is explained that the combination is impossible (For example, a configuration “A” described in one embodiment of the disclosure and the drawings). and a configuration "B" described in another embodiment of the disclosure and the drawings may be combined with each other. Namely, although the combination between the configurations is not directly described, the combination is possible except in the case where it is described that the combination is impossible).

The above detailed description should not be construed as restrictive in all respects and should be considered as illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention (although embodiments have been described with reference to a number of illustrative embodiments) thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope of the principles of this disclosure. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art).

Claims (19)

tub;
a drum rotatably provided in the tub;
an induction heater fixed to the tub while being spaced apart from the drum to heat the drum;
a first circuit including a first coil installed in the tub;
a power supply unit for applying AC power to the first coil; and,
a second circuit installed on the drum; as a second circuit including a second coil disposed at a position overlapping with the first coil in a longitudinal direction of a rotational central axis of the drum, and a thermistor whose resistance changes according to temperature clothes processing equipment.
According to claim 1,
and the thermistor includes an NTC thermistor whose resistance decreases when a temperature increases.
According to claim 1,
and the second coil is installed at a position where a straight line passing through the first coil and orthogonal to a rotation center line of the drum meets the drum.
According to claim 1,
and the second circuit is installed on an outer surface of the drum.
5. The method of claim 4,
Further comprising a lifter provided on the inner surface of the drum,
The second circuit is installed on an outer surface of a portion of the drum on which the lifter is disposed.
6. The method of claim 5,
The drum is
an elongated cylindrical body; and,
and a through hole formed in the body.
6. The method of claim 5,
The lifter includes a plurality of lifters arranged at regular intervals along the circumferential direction of the drum,
The second circuit is installed on an outer surface of a portion of the drum on which any one of the plurality of lifters is disposed,
and a non-magnetic balance maintaining unit provided inside the other lifters among the plurality of lifters.
According to claim 1,
It is provided adjacent to the drum, and further comprises one or more non-magnetic balance maintaining parts,
The second circuit and the one or more balance maintaining units are arranged at regular intervals along a circumferential direction of the drum.
According to claim 1,
The first coil is installed on an opposite side of the induction heater with respect to the center of the tub.
10. The method of claim 9,
The first coil is installed within a range of ±60 degrees from a point opposite to the induction heater with respect to the center of the tub.
According to claim 1,
The first coil occupies an area larger than an area occupied by the second coil in a circumferential direction of the drum.
According to claim 1,
The first circuit is
The laundry treatment apparatus further comprising a capacitor connected in parallel with the first coil.
According to claim 1,
and a controller connected to the first circuit and configured to estimate the temperature of the drum based on a resistance value of the thermistor.
14. The method of claim 13,
a current sensing unit connected in series with the first coil; and,
The laundry treatment apparatus further comprising a voltage sensing unit connected in parallel with the first coil.
15. The method of claim 14,
The control unit may be configured to estimate the temperature of the drum based on a measured impedance defined as a value obtained by dividing the voltage value detected by the voltage sensing unit by the current value detected by the current sensing unit.
16. The method of claim 15,
and the power supply unit applies a resonant frequency.
17. The method of claim 16,
The controller is configured to estimate the temperature of the drum by compensating for an error based on the measured impedance and the equivalent impedance at the resonant frequencies of the first and second circuits.
18. The method of claim 17,
The power supply changes an applied frequency when a resonance frequency of the measured impedance is different from a resonance frequency of the equivalent impedance.
18. The method of claim 17,
The control unit may be configured to compensate for an error in the phase angle by using a rotation angle of the drum when the phase angle of the measured impedance is different from the phase angle of the equivalent impedance.

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