Patent Publication Number: US-11649583-B2

Title: Laundry treating apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/751,291, filed on Jan. 24, 2020, which claims the benefit of the Korean Patent Application No. 10-2019-0085057, filed on Jul. 15, 2019. The disclosures of the prior applications are incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a laundry treating apparatus. 
     BACKGROUND 
     Generally, a laundry treating apparatus includes various types such as a washing machine for laundry washing, a washing machine for drying, and a refresher for refresh. 
     In a laundry treating apparatus, washing means a process of removing contaminants on clothes by using mechanical action of water and detergent, and drying means a process of removing water contained in laundry. 
     In a washing process, if washing is performed using washing water of high temperature, more detergents may be dissolved, whereby contaminants on laundry may be removed more easily and at the same time, laundry may be sterilized. Therefore, it is preferable to wash laundry put in the laundry treating apparatus by increasing a temperature of washing water within the range that deformation (for example, shrinkage, distortion, waterproof failure) of the laundry is not generated. 
     In the related art, it is general that the laundry treating apparatus is externally supplied with hot water to increase a temperature of washing water which is in contact with laundry, or hot water is supplied to a tub by allowing washing water to be in contact with a hot wire provided in the laundry treating apparatus. 
     In the case that the laundry treating apparatus is externally supplied with hot water, an external boiler should be driven separately, whereby a problem occurs in that energy is consumed. In the case that the laundry treating apparatus is supplied with hot water by a hot wire provided therein, the hot wire should continuously be sunk in the washing water, whereby there is a structural limitation in that a separate path should be provided below the tub. 
     Meanwhile, it is general that a hot-air drying system for drying laundry by heating the air that circulates the tub and an external circulating path is used in the drying process, and the hot wire is arranged on the path, through which the air circulates, to heat the air. 
     A gas heater or an electric heater, which can heat a hot wire, is required to use the aforementioned hot-air drying system, however, the gas heater has a problem in stability and exhaust gas, and the electric heater has problems in that particles such as scales may be accumulated and too much energy is consumed. 
     In addition to the aforementioned hot-air drying system, there is a low temperature dehumidification drying system based on a heat pump. The heat pump is reversely uses a cooling cycle of an air conditioner, and therefore requires an evaporator, a condenser, an expansion valve and a compressor in the same manner as the air conditioner. The condenser is used in an indoor system of the air conditioner to cool the indoor air, whereas the heat pump based drying system dries laundry by heating the air in the evaporator. However, the heat pump has problems in that it has a volume greater than that of the other hot-air supply structure, and has a more complicated structure and a higher production cost than the other hot-air supply structure. 
     Moreover, since the hot-air drying system and the low temperature dehumidification drying system are indirect drying systems based on the air, if laundry is entangled or contains much water, a problem occurs in that a drying time may become longer. 
     In such various laundry treating apparatuses, the electric heater, the gas heater and the heat pump have their respective advantages and problems as heating means. In this respect, as new heating means that can emphasize the advantages and complement the problems, concepts (Japanese registered patent No. JP2001070689 and Korean registered patent No. KR10-922986) for a laundry treating apparatus using induced heating are provided. 
     However, such prior arts disclose only basic concepts in which a washing machine performs induced heating, but do not suggest detailed induced heating modules and detailed methods or elements for connection and action relation with basic elements of the laundry treating apparatus, efficiency enhancement and stability. 
     A coil is wound in an induction heating module provided in the laundry treating apparatus such as a washing machine and a drying machine, and heat may be transferred to a heating target (a drum of the washing machine) by an induced current generated by applying a current to the coil. 
     In this case, the induction heating module needs a structure for discharging heat generated from the coil, and if the heat is not discharged actively, degradation of the coil may be generated and therefore may be one factor of performance deterioration of the induction heating module. 
     Since the induction heating module used for a general cooking machine includes a cooling fan for cooling heat generated from the coil, a duct, etc., the above problem may be solved. However, the cooling fan, the duct, etc. used for the general cooking machine cannot be applied to the induction heating module provided in the laundry treating apparatus such as a washing machine and a drying machine due to spatial and positional restrictions. 
     Therefore, it is required to provide various and detailed technical spirits for efficiency enhancement and safety in the laundry treating apparatus to the induced heating principle is applied. 
     SUMMARY 
     Accordingly, the present disclosure is directed to a laundry treating apparatus that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
     An object of the present disclosure is to provide a laundry treating apparatus that can heat washing water or dry washing targets by directly heating a drum. 
     Another object of the present disclosure is to provide a laundry treating apparatus that can prevent a temperature of a coil from being excessively increased in an induction heating module. 
     Still another object of the present disclosure is to provide a laundry treating apparatus that can enhance durability and efficiency of an induction heating module by making sure of a structure for active discharge of heat generated from a coil. 
     Further still another object of the present disclosure is to provide a laundry treating apparatus in which respective elements of an induction heating module are coupled with each other while making sure of a space for discharging heat generated from a coil. 
     Further still another object of the present disclosure is to provide a laundry treating apparatus that can reduce a drying time for washing targets by directly heating a drum. 
     Further still another object of the present disclosure is to provide a laundry treating apparatus that enhances drying efficiency by allowing a center and front and rear of a drum to be uniformly heated. 
     Further still another object of the present disclosure is to provide a laundry treating apparatus that prevents detachment of components for forming an induction heating module even in case of vibration of a tub by making sure of stable joint of the induction heating module and attenuates noise. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a laundry treating apparatus according to an exemplary embodiment of the present disclosure comprises a cabinet, a drum provided inside the cabinet and formed of a metal material for accommodating a treatment target, and an induction module spaced apart from an outer circumferential surface of the drum at a predetermined interval, inducing and heating the drum, wherein the induction module includes a base housing for accommodating a coil, and a cover housing forming a moving space of heat generated from the coil, jointed to an upper portion of the base housing, the cover housing includes a through portion for discharging the heat by passing through the cover housing up and down, and the cover housing forms a section upwardly inclined toward the through portion to move the heat generated from the coil along the inclined section and discharge the heat to the through portion. 
     Preferably, the through portion may be provided at the uppermost end of the induction module, and may be formed at a center of the cover housing. 
     Also, the induction module may further include a permanent magnet housing provided between the base housing and the cover housing and provided with a holder in which a permanent magnet is accommodated. 
     Preferably, the permanent magnet housing may include a connector for connecting the holder, and the connector may connect an upper portion of the holder. 
     The connector may be spaced apart from the base housing to form a space for discharge of the heat generated from the coil, and the holder may include an opening portion into which the permanent magnet is inserted, and a barrier extended from a circumference of the opening portion to a lower portion of the opening portion, accommodating the permanent magnet. 
     The holder may further include supports inwardly protruded from a lower front end of the barrier, supporting the permanent magnet, and the permanent magnet housing may include a through portion communicated with the through portion of the cover housing, and may form a section upwardly inclined toward the through portion of the permanent magnet housing. 
     Also, the inclined section of the cover housing may be formed to be steeper than the inclined section of the permanent magnet housing, the base housing may form a section upwardly inclined toward the through portion of the permanent magnet housing, and the inclined section of the cover housing may be formed to be steeper than the inclined section of the base housing. 
     Also, the base housing and the permanent magnet housing may be formed to be bent at the same curvature. 
     Meanwhile, the laundry treating apparatus according to the exemplary embodiment of the present disclosure further comprises a tub for accommodating the drum, wherein the base housing is fixed to the tub while adjoining an outer circumferential surface of the tub. 
     Also, a laundry treating apparatus according to the exemplary embodiment of the present disclosure comprises a cabinet, a drum provided inside the cabinet and formed of a metal material for accommodating a treatment target, and an induction module spaced apart from an outer circumferential surface of the drum at a predetermined interval, inducing and heating the drum, wherein the induction module includes a base housing for accommodating a coil, and a cover housing forming a moving space of heat generated from the coil, jointed to an upper portion of the base housing, the cover housing includes a through portion for discharging the heat by passing through the cover housing up and down, and the base housing and the cover housing are formed to be bent, and the heat generated from the coil moves along a bent surface of the cover housing and then is discharged to the through portion. 
     Preferably, the induction module may further include a permanent magnet housing provided between the base housing and the cover housing and provided with a holder for accommodating a permanent magnet. 
     Also, the permanent magnet housing and the base housing may be formed to be bent at the same curvature to correspond to the outer circumferential surface of the drum. 
     Meanwhile, the laundry treating apparatus may further comprise a tub for accommodating the drum, wherein the base housing may be fixed to the tub by being coupled with an outer circumferential surface of the tub. 
     The respective features of the aforementioned embodiments may complexly be embodied in the other embodiments unless the features are conflict with or exclusive from the other embodiments. 
     According to the present disclosure, it is possible to heat washing water or dry washing targets by directly heating a drum of the laundry treating apparatus. Also, it is possible to prevent a temperature of a coil from being excessively increased in an induction heating module. 
     Also, it is possible to enhance durability and efficiency of an induction heating module by making sure of a structure for active discharge of heat generated from a coil of the induction heating module. 
     Also, it is possible to enhance drying efficiency by allowing a center and front and rear of a drum to be uniformly heated. It is also possible to prevent detachment of components for forming an induction heating module even in case of vibration of a tub by making sure of stable joint of the induction heating module and attenuate noise. 
     It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG.  1    illustrates a whole configuration of a laundry treating apparatus; 
         FIGS.  2 A and  2 B  illustrate a front view and a side view of an induction module and a drum; 
         FIGS.  3 A and  3 B  are upper views illustrating an arrangement structure of a coil and a permanent magnet; 
         FIG.  4 A  illustrates coils having the same curvature radius in a curved line, and  FIG.  4 B  illustrates inner and outer coils having different curvature radiuses in a curved line; 
         FIGS.  5 A- 5 C  are graphs illustrating temperature increase rates per position of a drum according to shapes of a base housing provided with a coil; 
         FIGS.  6 A- 6 D  illustrate a top view, side views, and a bottom view of a base housing; 
         FIG.  7    is a perspective view illustrating a coupling relation among a tub, a base housing and a cover; 
         FIG.  8 A  illustrates a rear view and a side view of a cover, and  FIG.  8 B  illustrates a section of a permanent magnet holder; 
         FIG.  9    is an exploded perspective view illustrating another embodiment of an induction module; 
         FIG.  10    is a bottom perspective view illustrating a permanent magnet housing; 
         FIG.  11    is a plane view illustrating a permanent magnet housing of  FIG.  10   ; 
         FIG.  12    is a longitudinal sectional view illustrating an induction module of  FIG.  9   ; 
         FIG.  13    is a coupled perspective view illustrating a base housing and a permanent magnet housing of  FIG.  9   ; 
         FIG.  14    is a plane view illustrating coupling of a cover and a permanent magnet of  FIG.  9   ; and 
         FIGS.  15  and  16    are cut perspective views illustrating a modified example of a cover housing of  FIG.  9   . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. 
     However, spirits of the present disclosure are not limited to embodiments which are suggested, and it should be understood that other embodiments that may be regarded by the person with ordinary skill in the art to which the present disclosure pertains as embodiments within the same or equivalent range of the present disclosure belong to the scope of the present disclosure. 
     Also, since the elements described hereinafter are intended to describe one embodiment of the present disclosure, it should be understood that the corresponding elements are not intended to restrict the scope of the present disclosure. 
     Meanwhile, terms expressed in this specification are the same as general meaning understood by the person with ordinary skill in the art to which the present disclosure pertains, but should be interpreted as meaning defined in this specification if the terms are different from meaning defined in this specification. 
     In the elements described hereinafter, the expression that an element is “connected” with another element or an element is “provided” in another element may mean that the element may directly be connected or coupled with or provided in another element, a third element may be interposed between the corresponding elements. 
     A preferred embodiment of a laundry treating apparatus according to the present disclosure will be described. First of all, a whole configuration of the laundry treating apparatus  1  will be described. 
     The laundry treating apparatus of this embodiment may include a cabinet  1000  forming an external appearance, a tub  2000  provided inside the cabinet, and a drum  3000  rotatably provided inside the tub  2000 , accommodating laundry, drying targets or refresh targets. The shown embodiment relates to a washing machine, in which washing water is stored in the tub  2000  and therefore washing may be performed through the drum provided inside the tub  2000 . 
     If the laundry treating apparatus of this embodiment is applied to a drying machine, drying targets may be accommodated in the drum, and in this case, the tub may be omitted. 
       FIG.  1    illustrates a whole configuration of a laundry treating apparatus. The laundry treating apparatus  1  may include a cabinet  1000  forming an external appearance of the laundry treating apparatus  1 , provided with an inlet  1100  through which laundry may be inserted, a tub  2000  located inside the cabinet  1000  and provided with an opening  2200  communicated with the inlet  1100 , a drum  3000  provided inside the tub  200  and formed of a metal material, accommodating laundry therein, a door  6000  hinge-coupled with the cabinet  1000  to enable insertion and ejection of laundry, and an induction module  5000  for heating the drum  3000  by means of a magnetic field. 
     The tub  2000  may be located inside the cabinet  1000  by a spring provided on an upper surface inside the cabinet  1000  and a damper  1200  provided on a lower surface inside the cabinet  1000 . 
     Also, the tub  2000  may be fixed to the lower surface inside the cabinet  1000  by a rear support (not shown) bent and extended from the rear of the tub  2000  to the lower portion of the tub and a suspension (not shown) connected with the rear support and provided with a spring and a damper. In this case, the rear of the tub  2000  may be provided to be inclined at a predetermined angle inside the cabinet  1000 . 
     The drum  3000  may rotatably be provided inside the tub  2000 , and at this time, a driver  4000  for rotating the drum  300  may be provided at the rear of the tub  2000 . If the drum  3000  moves inside the tub  2000  while being rotated, vibration is delivered to the tub  2000 . Therefore, structures provided in the tub  2000  are also vibrated, and a detailed description for problems and solutions according to vibration will be described later. 
     Meanwhile, the tub  2000  may be provided with a water supply pipe  8000  if washing water is supplied thereto. The water supply pipe  8000  may be provided to be communicated with the tub  2000  by passing through a detergent box D provided in the cabinet  1000 . This is to allow a detergent used for washing to be supplied to the tub  2000  together with washing water when the washing water is supplied to the tub  2000 . 
     Also, the tub  2000  may further be provided with a drainage pipe  7000  for discharging washing water stored therein to the outside. If drainage starts, the washing water is drained from the lower portion of the tub and then discharged to the outside of the laundry treating apparatus  1  through the drainage pipe  7000  by a drainage pump (not shown). 
     In case of the laundry treating apparatus  1  having a washing function, since it is required to perform washing by enhancing a temperature of the washing water within the range that permanent damage (for example, shrinkage, distortion, loss of waterproof function, etc.) is not caused, depending on laundry, a heating structure for enhancing the temperature of the washing water is required. 
     Both the laundry treating apparatus  1  having a washing function and a drying function and the laundry treating apparatus  1  having only a drying function need a heating structure for drying of laundry. 
     Therefore, the laundry treating apparatus includes an induction module  5000  that may be used to heat washing water or for drying. 
     The principle of heating the drum  3000  using the induction module  5000  will be described with reference to  FIGS.  2 A and  2 B . 
     The induction module  5000  is mounted onto an outer circumferential surface of the tub  2000 , and serves to heat a circumferential surface of the drum  3000  through a magnetic field generated as a current is applied to a coil  5150  in which a wire  5151  is wound (refer to  FIGS.  3 A and  3 B  for shapes of the wire and the coil). 
     However, as described above, since the tub may be omitted in case of a drying machine for which washing based on water is not performed, the induction module of the drying machine may substitute for the tub as a frame or bracket for holding the induction module is provided. The frame or the bracket may be an element for fixing the induction module to the drum at a predetermined interval like the tub. 
     The wire  5151  may be formed of a core wire and a coating covering the core wire. The core wire may be a single core wire. A plurality of core wires may be entangled to form one core wire. Therefore, a thickness or core diameter of the wire  5151  may be determined by the core wire and a coating thickness. 
     A method for heating the drum  3000  through the coil  5150  will be described. An alternating current of which phase is changed flows to the coil  5150  arranged at an outside of the circumferential surface of the drum  3000 , and the coil  5150  forms a radial alternating current magnetic field in accordance with Ampere&#39;s circuit law. 
     This alternating current magnetic field is concentrated on the drum  3000  made of a conductor having high magnetic permeability. In this case, magnetic permeability means a level of a medium magnetized for a given magnetic field. At this time, an eddy current is formed in the drum  3000  in accordance with Faraday&#39;s law of induction. This eddy current flows along the drum  3000  made of a conductor and then is switched to Joule&#39;s heat by resistance of the drum  3000 , whereby an inner wall of the drum  3000  is directly heated. 
     If the inner wall of the drum  3000  is directly heated, an air temperature inside the drum  3000  and a temperature of laundry which is in contact with the inner wall of the drum  3000  increase together. Therefore, since laundry is capable of being directly heated, the corresponding drying machine enables faster drying than the drying machine, which is an indirect heating system based on the hot-air drying system or the low temperature dehumidification drying method. 
     The laundry treating apparatus  1  having a washing function may heat washing water even without a separate hot wire and a separate path, and the washing water continues to be in contact with the inner and outer walls of the drum  3000 . Therefore, it is possible to heat the washing water more quickly than the heating method using a separate path and a separate hot wire, which are formed below the tub. 
     A preferred embodiment of a shape of the coil will be described with reference to  FIGS.  3 A to  4 B . 
       FIGS.  3 A and  3 B  illustrate an upper surface of a coil  5150  in which the wire  5151  is wound at an outside of a circumferential surface of the tub  2000 .  FIGS.  4 A and  4 B  illustrate various types of coil shapes. 
     The coil  5150  may be provided in all shapes, which can form a coil on the outer circumferential surface of the tub  2000  by means of winding of the wire  5151 , such as a concentric circle, an oval, and a track shape. However, a heating level of the drum  3000  may be varied depending on the wound shape. 
     This is because that a magnetic field delivered toward a central direction of the drum  3000  and a magnetic field delivered to the front and the rear of the drum  3000  are remarkably different from each other in their amount if a curvature radius of a curved portion is formed differently in the inner coil and the outer coil like a shape of the coil disclosed in  FIG.  4 B . 
     In other words, since an area of the coil located near the front and the rear of the drum  3000  is narrow, the amount of a magnetic field delivered to the front of the circumferential surface of the drum  3000  may be relatively small. Since an area of the coil located at the center A of the drum is wide, the amount of a magnetic field delivered to the center of the circumferential surface of the drum  3000  may be relatively large. Therefore, it is difficult to uniformly heat the drum  3000 . 
     Therefore, the wire  5151  may be wound in the coil  5150  such that the coil  5150  may include linear portions  5155 ,  5156  and  5157  and a curved portion  5153  as shown in  FIG.  4 A , and it is preferable that a curvature radius of the wire  5151  that forms the curved portion  5153  is formed equally for the inner coil and the outer coil. 
     It is noted that a corner area in the coil of  FIG.  4 A  and a corner area in the coil of  FIG.  4 B  are remarkably different from each other. 
     The relation between the linear portions  5155 ,  5156  and  5157  and the curved portion  5153  will be described in more detail. The linear portions  5155 ,  5156  and  5157  may include horizontal linear portions  5156  and  5157  including a front linear portion  5156  provided at the front of the outer circumferential surface of the tub  2000  and a rear linear portion  5157  provided at the rear of the outer circumferential surface of the tub  2000 , and a vertical linear portion  5155  formed vertically for the horizontal linear portions  5156  and  5157 . The curved portion  5153  is formed at a point where the horizontal portions  5156   5157  meet the vertical linear portion  5155 . 
     That is, the coil may be formed of the front linear portion  5156 , the rear linear portion  5157 , vertical linear portions  5155  at both sides, and four curved portions  5153  formed among the linear portions  5155 ,  5156  and  5157 , having the same curvature radius. 
     In accordance with the aforementioned configuration, coil both end portions B 1  and B 2  including a coil front end portion adjacent to the front of the tub  2000  and a coil rear end portion adjacent to the rear of the tub, and a horizontal width of the coil center portion A located between the coil both end portions B 1  and B 2  may be formed uniformly. 
     As a result, the amount of a magnetic field radiated toward the front and the rear of the circumferential surface of the drum  3000  from the coil both end portions B 1  and B 2  becomes similar to the amount of a magnetic field radiated toward the center of the circumferential surface of the drum  3000  from the coil center portion A. 
     Therefore, the center and the front and rear of the circumferential surface of the drum  300  may be heated uniformly. 
     A temperature distribution of the drum according to the shape of the coil will be described with reference to  FIGS.  5 A to  5 C . 
     The coil  5150  having different vertical lengths and heating distribution of the circumferential surface of the drum  3000  according to the vertical width of the coil  5150  are shown in  FIGS.  5 A to  5 C . 
     In the graph, a vertical axis displays each position of the drum, wherein ‘1’ indicates the rear of the outer circumferential surface of the drum, ‘5’ indicates the front of the outer circumferential surface of the drum  3000 , and ‘2’ to ‘5’ indicate an interval between the rear of the outer circumferential surface and the front of the outer circumferential surface. Also, a horizontal axis indicates a temperature increase rate of the drum  3000 . 
     Hereinafter, the vertical width of the coil  5150  and the temperature increase rate of the drum  3000  are relatively compared with each other based on each coil  5150  disclosed in  FIGS.  5 A to  5 C .  FIG.  5 A  illustrates that the drum is heated using the coil having the widest vertical width,  FIG.  5 B  illustrates that the drum is heated using the coil having a vertical width of a middle width, and  FIG.  5 C  illustrates that the drum is heated using the coil having the narrowest vertical width. 
     The coil of  FIG.  5 A  indicates a uniform temperature increase rate of the front and rear and the center of the drum  3000  as compared with the other coil, the coil of  FIG.  5 C  has a remarkable difference in a temperature increase rate between the front and rear and the center of the drum  3000 , and the coil of  FIG.  5 B  indicates a difference in a relatively more temperature increase rate. 
     That is, it is noted that the front and rear and the center of the drum  3000  may be heated relatively uniformly as the vertical width of the coil  5150  becomes longer under the assumption that the respectively coils  5150  have the same horizontal width. That is, it is preferable that a long shaft of the coil of an oval or track shape is formed in a front and rear direction of the tub. 
     This case may be interpreted that the coil  5150  is provided on the outer circumferential surface of the tub  2000 . In this case, it is noted that the circumferential surface of the drum  3000  provided in the tub  2000  is heated more uniformly as both end portions B 1  and B 2  of the coil  5150  are provided to be close to the front of the tub  2000 . 
     Meanwhile, if the outmost wire of the horizontal linear portions  5156  and  5157  is provided to be extended to the front and rear of the tub  2000 , the drum  3000  may be heated more uniformly. However, in this case, the magnetic field is too extended to the front and rear, whereby the other elements of the laundry treating apparatus, such as the driver  4000  and the door  6000  may be heated and therefore a problem occurs in that the laundry treating apparatus  1  is damaged. 
     Also, in case of the laundry treating apparatus  1  in which the rear of the tub  2000  is provided to be inclined inside the cabinet  1000 , a problem may occur in that the induction module  5000  and the cabinet  1000  are damaged due to interference between the front upper corner of the induction module  5000  and the upper surface of the cabinet  1  when the tub  2000  is vibrated up and down. If the height of the cabinet  1000  becomes higher in order to solve the problem, there is a limitation in that a compact laundry treating apparatus cannot be embodied. 
     Therefore, the outmost wire of the front linear portion  5156  is spaced apart from the front of the tub  2000  at a predetermined interval, and the outmost wire of the rear linear portion  5157  is spaced from the rear of the tub  2000  at a predetermined interval, wherein the predetermined interval ranges from  10   mm  to  20   mm.    
     The aforementioned element may unnecessarily heat the other element in addition to the drum  3000  or prevent interference between the induction module  5000  and the upper surface inside the cabinet  1000  from occurring and at the same time uniformly heat the outer circumferential surface of the drum  3000 . 
     Moreover, it is preferable that the outmost wire of the vertical linear portion  5155  of the coil  5150  has a length longer than that of the outmost wire of the horizontal linear portion  5156  and  5157 . 
     This case prevents the magnetic field from being radiated in a surrounding direction of the drum  3000  in a too wide range so as not to heat the other elements except the drum  3000 , and may make sure of an arrangement space of a spring or the other element that may be provided on the outer circumferential surface of the tub. 
     At this time, a surface where the coil  5150  is formed by winding of the wire  5151  may be provided as a curved surface corresponding to the circumferential surface of the drum  3000 . In this case, magnetic flux density of the magnetic field toward the drum  3000  may further be enhanced. 
     Moreover, if the induction module  5000  is operated, it is preferable that the drum  3000  is rotated to uniformly heat the circumferential surface of the drum  3000 . 
     Meanwhile, the magnetic field formed by the coil  5150  is radiated toward the drum  3000  made of a conductor having high magnetic permeability, whereas the magnetic field is partially radiated in an opposite direction or front and rear of the drum  3000  and toward both sides of the coil  5150 . 
     Therefore, it is required to concentrate the magnetic field generated by the coil  5150  toward the drum  3000 . To this end, the induction module  5000  may further include a permanent magnet  5130 . 
     The embodiment of the permanent magnet and arrangement of the permanent magnet will be described with reference to  FIGS.  3 A and  3 B . 
     The permanent magnet  5130  serves as a shielding member to prevent the other element near the drum  3000  from being heated, and serves to enhance heating efficiency by concentrating the magnetic field generated in the coil  5150  toward the drum  3000 . 
     As shown in  FIGS.  3 A and  3 B , the permanent magnet  5130  may be provided as a bar magnet, and is preferably arranged on the coil  5150  vertically to a length direction of the coil  5150 . This is to cover the inner coil and the outer coil at the same time. 
     The permanent magnet  5130  may be provided with a plurality of bar magnets having the same size, wherein the plurality of permanent magnets  5130  may be arranged to be spaced apart from one another along a length direction of the coil  5150 . 
     In the case that the permanent magnet  5130  is arranged at only a specific position, the amount of the magnetic field radiated toward the drum  3000  is varied depending on each portion of the circumferential surface of the drum  3000 , whereby it is difficult to perform uniform heating. Therefore, in order to uniformly induce the magnetic field generated in the coil  5150  toward the drum  5150 , the plurality of coils  5150  are preferably arranged to be spaced apart from one another along the circumference of the coils  5150 . 
     Moreover, it is preferable that the permanent magnets  5130  are concentrated on the portion of the coil  5150 , which is adjacent to the front and rear of the tub  2000 , if there are the same number of permanent magnets  5130 . 
     In detail, as shown in  FIG.  3 B , the coil  5150  may be categorized into the coil both end portions B 1  and B 2  including the coil front end portion B 1  adjacent to the front of the tub  2000  and the coil rear end portion B 2  adjacent to the rear of the tub  2000  and the coil center portion B 1  located between the coil front end portion B 1  and the coil rear end portion B 2  and formed to be wider than the coil front end portion B 1  and the coil rear end portion B 2 , and the permanent magnets  5130  of the coil center portion A, which are equal to or more than those of the coil front end portion B 1  or the coil rear end portion B 2 , may be arranged. 
     In the coil center portion A, the magnetic field is radiated to be extended to both sides of the coil  5150 . In this case, since the drum  3000  is formed to be wider than the width of the coil center portion A, uniform heating may be made in a width direction of the drum  3000  even though more permanent magnets are not arranged. 
     On the other hand, in the coil front end portion B 1  and the coil rear end portion B 2 , the magnet is radiated to both sides of the coil  5150 . In the coil front end portion B 1 , the magnetic field is radiated to the front of the drum  3000 . In the coil rear end portion B 2 , the magnetic field is radiated to the rear of the drum  3000 . 
     Also, in the coil front end portion B 1  and the coil rear end portion B 2 , density of the coil is relatively low. That is, density of the coil may be lowered at both end portions by a round shape of a corner portion. This is because that the coil cannot be formed in the corner portion theoretically vertically. 
     Therefore, if the same number of permanent magnets  5130  are arranged at each of the coil front end portion B 1 , the coil rear end portion B 2  and the coil center portion A, non-uniform heating may occur in a length direction of the drum  3000 . 
     Therefore, if the same number of permanent magnets  5130  are arranged, it is more preferable that the permanent magnets  5130  are concentrated on both end portions B 1  and B 2  rather than the coil center portion A. That is, the front and rear portions of the drum may uniformly be heated. In the embodiment shown in  FIG.  3 B  rather than the embodiment shown in  FIG.  3 A , the drum may be heated more uniformly, whereby efficiency may be enhanced. 
     In other words, magnetic flux density of the coil both end portions B 1  and B 2  may be enhanced through concentration of the permanent magnets, whereby the drum  30  is uniformly heated in a length direction. 
     In detail, under the same condition, efficiency in the embodiment shown in  FIG.  3 B  may be more enhanced than that in the embodiment shown in  FIG.  3 A . Also, on the assumption of the same number of permanent magnets, it is preferable that a permanent magnet  76  located at the center portion A is located at both end portions B 1  and B 2 , in view of efficiency. Therefore, if total magnetic flux density is determined through the permanent magnet, it is preferable that magnetic flux density at both end portions is greater than that at the center portion. 
     The embodiment directed to a winding shape of the aforementioned coil  5150  and the embodiment directed to arrangement of the permanent magnet  5130  may be embodied in one laundry treating apparatus  1  without being conflicted with each other. In this case, the drum  3000  may be heated more uniformly than the laundry treating apparatus  1  in which each embodiment is embodied. 
     Meanwhile, if the drum  3000  is rotated during washing or drying, vibration is delivered to the tub  2000 , and structures provided in the tub  2000  are also vibrated, whereby noise of the laundry treating apparatus  1  may become serious or durability may be weakened. 
     Also, if the tub  2000  is vibrated, the coil  5150  provided in the tub  2000  is also vibrated, whereby the coil  5150  may be detached or noise may be generated. Therefore, in order to solve this problem, it is preferable that the coil  5150  is provided with robustness in the tub  2000 . To this end, it is preferable that the coil  5150  is provided in the tub  2000  using the induction module  5000 . 
     The induction module  5000  will be described with reference to  FIG.  7   . 
     The induction module  5000  serves as a clamp member for fixing the coil  5150  to the outer circumferential surface of the tub  2000 , and may further include a base housing  5100  provided on the outer circumferential surface of the tub  2000  so as not to detach the coil  5150  even though the tub  2000  is vibrated. 
       FIG.  7    illustrates that the base housing  5100  is provided in the tub  2000 .  FIG.  6 A  illustrates an upper surface of the base housing  510 , and  FIG.  6 D  illustrates a lower surface of the base housing  5100 . 
     First of all, the base housing  5100  will be described with reference to  FIG.  6   . 
     As shown in  FIG.  6 B  and  FIG.  6 C , the base housing  5100  may form a coil slot  5120  narrower than a core diameter of the wire  5151  such that the wire  5151  of the coil  5150  is forcibly fitted into the coil slot  5120 , and the width of the coil slot  5120  may be formed in the range of 93% to 97% of the core diameter of the wire  5151 . 
     If the wire  5151  is forcibly fitted into the coil slot  5120 , the wire  5151  is fixed into the coil slot  5120  even though the tub  2000  is vibrated, whereby the coil  5150  does not move. 
     Therefore, the coil  5150  is not detached from the coil slot  5120 , and movement is restricted, whereby noise, which may occur due to a gap, may be avoided. 
     Moreover, the coil slot  5120  may be formed by a plurality of fixed ribs  5121  upwardly protruded from the base housing  5100 , wherein each fixed rib may be provided with a height greater than the core diameter of the coil  5150 . 
     The fixed rib  5121  should be provided with a height greater than the core diameter of the coil  5150  such that an inner wall of the fixed rib  5121  and both sides of the coil  5150  may be supported by being sufficiently in contact with each other. This feature is related to a melting process of the upper end of the fixed rib  5121 , which will be described later. 
     Since the fixed rib  5121  and the wire  5151  adjacent to the fixed rib  5121  are detachably fixed to each other by the aforementioned feature, shirt-circuit may be avoided. Since it is not required to coat a separate insulating film on the wire  5151  or a thickness of the insulating film may be minimized, the production cost may be reduced. 
     Also, the upper end of the fixed rib  5121  may be melted after the wire  5151  is inserted into the fixed thereto and therefore provided to cover the upper portion of the coil  5150 . That is, the upper end of the fixed rib  5121  may be subjected to a melting process. 
     At this time, it is preferable that the fixed rib  5121  is provided with a height of 1 to 1.5 times of the core diameter of the wire  5151  to cover the upper portion of the coil  5150 . 
     In detail, referring to  FIG.  6 C , if the wire is forcibly fitted into the fixed rib  5121 , the upper surface of the fixed rib  5121  may be pressurized and then melted. Then, as shown in  FIG.  6 C , the melted fixed rib  5121  may partially be spread toward both sides to cover the upper portion of the wire  5151 . At this time, it is preferable that the respective fixed ribs  5121  adjacent to each other by interposing the wire  5151  therebetween may be melted to fully shield the upper portion of the wire  5151  in the coil slot  5120  or may be melted to form an interval narrower than the core diameter of the wire at the upper portion of the wire  5151 . 
     As another embodiment, the coil slot  5120  may be melted to cover only the wire  5151  at one side not the wire  5151  at both sides. In this case, all the fixed ribs  5121  should be melted to cover only the wire  5151  inwardly provided among the wires  5151  adjacent thereto, or should be melted to cover only the wire  5151  outwardly provided. 
     In addition to the case that the coil  5150  is forcibly fitted into the coil slot  5120 , the reason why that the upper end of the fixed rib  5121  is melted may physically shield a path through which the wire  5151  may be detached, may prevent noise caused by vibration of the tub  2000  from occurring by preventing the wire  5151  from moving, and may improve durability by allowing a gap between components to be removed. 
     The coil slot  5120  may further include a slot base  5122 , on which the coil  5150  is arranged, below a portion between the fixed ribs  5121 . 
     The slot base  5122  has a lower surface shielded as shown in  FIG.  6 C , and serves to pressurize and fix the coil  5150  together with the fixed rib  5121  which is melted. 
     However, the slot base  5122  may partially be opened. In this case, an open structure provided in the slot base  5122  may be referred to as a through hole or through portion  5170 . 
     In the aforementioned description, the coil  5150  is provided on an upper surface of the base housing  5100 , however, the fixed rib  5151  may be protruded below the base housing  5100  such that the coil  5150  may be provided on a lower surface of the base housing  5100 . In this case, a space formed by the fixed ribs  5121  which are melted serves as the through portion even though a separate through portion is not provided in the slot base  5122 . 
       FIG.  6 D  is a view illustrating the lower surface of the base housing  5100 . As shown, a through portion  5170  that passes through the upper surface may be provided on the lower surface of the base housing  5100 . The through portion  5170  has an open structure to allow the coil  5150  to face the outer circumferential surface of the tub  2000 , and may be formed along a winding shape of the wire  5151 . 
     If the through portion is formed along a winding shape of the wire  5151 , the magnetic field may actively be radiated from the wire  5151  to the drum  3000  to enhance heating efficiency. Since the air may move along an open surface, it is advantageous that the coil  5150  which is overheated may quickly be cooled. 
     Also, referring to  FIG.  6 D , a base support bar  5160  formed on the lower surface of the base housing  5100  to cross the through portion is disclosed, and the base housing  5100  may further include the base support bar  5160 . 
     The base support bar  5160  may be provided in a radiation shape around fixed points  5165  at both sides of the center portion A of the base housing  5100  to enhance a joint force between the outer circumferential surface of the tub  2000  and the base housing  5100 . 
     If base joints  5190  provided at both sides of the base housing  5100  are fixed to tub joints  2100  provided on the outer circumferential surface of the tub, the outer circumferential surface of the tub  2000  is pressurized by the base support bar  5160 . Therefore, the outer circumferential surface of the tub  2000  may be supported more strongly than the case that the lower surface of the base housing  5100  is fully in contact with the outer circumferential surface of the tub  2000  (see  FIG.  7   ). As a result, the base housing  5100  may be neither easily moved nor detached from the outer circumferential surface of the tub  2000  even though the tub  2000  is vibrated. 
     Moreover, in order to improve the joint force between the base housing  5100  and the outer circumferential surface of the tub  2000 , the base housing  5100  may form a curved surface corresponding to the outer circumferential surface of the tub  2000 . 
     On the upper surface of the base housing  5100  in which the wire  5151  is wound, the curved portions of the fixed ribs  5121  may be formed with the same curvature radius to correspond to the feature of the aforementioned coil curved portions  5153  which are formed with the same curvature radius (see  FIGS.  3 A and  3 B ). 
     Meanwhile, as shown in  FIG.  7   , the induction module  5000  may further include a cover  5300  coupled with the base housing  5100  to cover the coil slot  5120 . 
     The cover  5300  is provided to be coupled with the upper surface of the base housing  5300  as shown in  FIG.  7   , and serves to prevent detachment of the coil  5150  and the permanent magnet  5130  from occurring. 
     In detail, a lower surface of the cover  5300  may be formed to be adhered to the upper end of the coil slot  5120  of the base housing  5100 . Therefore, the cover  5300  may be prevented from moving. 
     The cover  5300  will be described in detail with reference to  FIGS.  8 A and  8 B . 
     Referring to  FIG.  8 A , a plurality of reinforcing ribs  5370  downwardly protruded may be provided on the lower surface of the cover  5300 , and may be provided such that the reinforcing ribs  5370  and the upper end of the coil slot  5120  may be adhered to each other. 
     If the lower surface of the reinforcing rib  5370  is adhered to the coil slot  5120 , more pressure may be applied to a narrow area than the case that the lower surface of the cover  5300  is fully adhered to the upper end of the coil slot  5120 . 
     Therefore, since the cover  5300  may be fixed to the outer side of the tub  2000  more stably, noise caused by a gap or detachment of components does not occur. 
     The reinforcing rib  5370  may be provided with a plural number along a length direction of the coil  5150 . Also, the reinforcing rib  5370  may be provided vertically to the length direction of the coil  5150 . Therefore, it is possible to stably fix the coil even without fully pressuring the coil. 
     In this case, a gap space is required between the cover  5300  and the coil  5150 . This is because that the air should preferably move for radiation of heat. Therefore, the gap space is partially filled with the reinforcing rib  5370 . Therefore, a moving space of the air is formed and at the same time the coil may be fixed. 
     Meanwhile, the reinforcing rib  5370  is preferably formed in a single body with the cover  5300 . Therefore, the cover  5300  is coupled with the base housing  5100  and at the same time the reinforcing rib  5370  pressurizes the coil  5150 . Therefore, a means or step for pressurizing the coil  5150  separately is not required. 
     Also, the permanent magnet  5130  may be interposed between the base housing  5100  and the cover  5300 , and the cover  5300  may include a permanent magnet holder  5350  into which the permanent magnet  5130  may be inserted Therefore, if the permanent magnet  5130  is fixed to the cover  5300 , the cover  5300  may be coupled to the base housing  5100  and therefore the permanent magnet  5150  may be fixed to the upper portion of the coil  5150 . 
     The permanent magnet  5130  is preferably arranged at a specific position of the upper surface of the coil  5150  to efficiently concentrate the magnetic field toward the drum  3000 . Therefore, if the permanent magnet  5130  moves in accordance with vibration of the tub  2000 , noise and deterioration of heating efficiency may occur. 
     Therefore, the permanent magnet  5130  may be fixed to the initial position between the base housing  5100  and the cover  5300  by the permanent magnet holder  5350 , whereby heating efficiency may be prevented from being deteriorated. 
     In more detail, the permanent magnet holder  5350  may be formed of both sidewalls downwardly protruded from the lower surface of the cover  5300  and provided to face each other, and may include a lower opening portion  5352  where the lower surface of the permanent magnet  5130  provided in the permanent magnet holder  5350  may face one surface of the coil  5150 . 
     In this case, horizontal movement of the permanent magnet  5130  may be restricted by the both sidewalls, and the lower opening portion  5352  may allow the permanent magnet  5130  to be more adjacent to the upper surface of the coil  5150 . 
     As the permanent magnet  5130  is provided to be more adjacent to the coil  5150 , the magnetic field is guided toward the drum  3000  more intensively, whereby the drum  3000  may be heated stably and uniformly. 
     Also, the permanent magnet holder  5130  may further include an inner sidewall  5354  downwardly protruded from the lower surface of the cover  5300  at one end of the both sidewalls, and a latch  5355  provided with an open surface formed on a surface facing the inner wall and formed such that the permanent magnet  5130  is not detached from the cover  5300 . 
     Since forward and backward movement of the permanent magnet  5130  may be restricted by the inner sidewall  5354  and the latch  5355 , the drum  3000  may be heated stably and uniformly as described above, whereas the permanent magnet  5130  may radiate heat through the open surface if its temperature is increased by the overheated coil  5150 . 
     At this time, the base housing may further include a permanent magnet pressurizer  5357  upwardly protruded from the space where the lower opening portion  5352  is formed, pressurizing the lower surface of the permanent magnet  5130 . The permanent magnet pressurizer  5357  may be provided as a protrusion made of a plat spring or rubber material. 
     If vibration is delivered to the permanent magnet  5130  in accordance with vibration of the tub  2000 , noise may be generated in the permanent magnet  5130  by a gap that may be formed between the coil slot  5120  at the lower portion and the permanent magnet holder  5350 . 
     Therefore, the permanent magnet pressurizer  5357  may prevent noise from being generated by buffering vibration, and may prevent the permanent magnet  5130  and the permanent magnet holder  5350  from being damaged by vibration by allowing the gap not to be generated. 
     Moreover, the lower end of the permanent magnet holder  5350  may be provided to be adhered to the upper end of the coil slot  5120  to improve a joint force and stably heat the drum  3000 . 
     In this case, since the lower surface of the permanent magnet  5130  may be provided to be more adjacent to the coil  5150  as described above, the drum  3000  may be heated more uniformly, and the lower surface of the permanent magnet  5130  may serve as the reinforcing rib  5370  to enhance adhesion between the cover  5300  and the base housing  5100 . 
     Additionally, if the base housing  5100  is formed in a curved surface corresponding to the outer circumferential surface of the tub  2000 , the cover  5300  may be formed in a curved surface having the same curvature as that of the base housing  5100 . 
     As another embodiment, the permanent magnet holder  5350  may be provided in the base housing  5100 . 
     The base housing  5100  may be formed such that the permanent magnet  5350  may be provided at the upper portion of the fixed rib  5121 . At this time, the permanent magnet pressurizer  5357  may be provided on the lower surface of the cover  5300 . 
     A method for coupling the cover  5300  and the base housing  5100  to the tub  2000  will be described with reference to  FIG.  7   . 
     A joint type of the tub  2000 , the base housing  5100  and the cover  5300  is disclosed in  FIG.  7   . Referring to  FIG.  7   , the tub  2000  discloses the tub joints  2100 , the base housing  5100  discloses the base joints  5190 , and the cover  5300  discloses cover joints  5390 . 
     The tub joint  2100  includes a tub joint hole, the base joint  5190  includes a base joint hole, and the cover joint  5390  includes a cover joint hole, wherein the joint holes may be provided with diameters of the same length, and may be provided such that the tub  2000 , the base housing  5100  and the cover  5300  may simultaneously be jointed by one screw. 
     Therefore, simple assembly may be performed during the manufacturing process, and the cost may be reduced. 
     In addition, the tub joint  2100 , the base joint  5190  and the cover joint  5390  may be provided to avoid joint points at both sides of the coil  5150  to make sure of a joint space if both end portions B 1  and B 2  of the coil are provided to be adjacent to the front and rear of the tub  2000 . 
     Moreover, as shown in  FIG.  8   , the cover  5300  may further cover ribs  5380  downwardly protruded at both corners. This is to allow the cover  5300  to be easily provided in its position of the base housing  5100  and prevent horizontal movement of the cover  5300  from occurring. 
     Meanwhile, as shown in  FIG.  7   , a fan holder  5360  may be formed in the cover  72 . The fan holder  5360  may be formed at the center of the cover  5300 . 
     The air may enter the inside of the cover  5300 , that is, the inside of the induction module through the fan holder. Since a space is formed between the cover  5300  and the base housing  5100  in the induction module, a moving space of the air is formed. A through portion is formed in the base housing. Therefore, the air may cool the coil  5150  in the inner space, and may be discharged to the outside of the induction module through the through portion of the base housing. 
     In this specification, although the induction module  5000  is provided on the outer circumferential surface of the tub  2000 , the induction module  5000  may be provided on the inner circumferential surface of the tub  2000  or the same circumferential surface may be formed together with the outer wall of the tub  2000 . 
     In this case, it is preferable that the induction module  5000  is located to be close to the outer circumferential surface of the drum  3000  if possible. That is, this is because that the magnetic field generated by the induction module  5000  is remarkably reduced as the distance with the coil is increased. 
     As shown in  FIG.  8   , in the aforementioned embodiment, since a plurality of permanent magnet holders  5350  are provided in the cover  5300 , the shape of the cover  5300  is complicated. Therefore, a shape of injection molding for manufacturing the cover  5300  is also complicated. Therefore, the cost of injection molding may be increased, and quality of injection molding may be deteriorated. 
     Also, in the aforementioned embodiment, the permanent magnetic holder  5350  is provided on the bottom of the cover  5300 , and therefore the permanent magnet  5130  is inserted at the side of the permanent magnet holder  5350 . Therefore, it is not easy to arrange the permanent magnet  5130  in the permanent magnet holder  5350 , and if the permanent magnet  5130  is damaged, it is not easy to replace the damaged permanent magnet with a new one. 
     Meanwhile, the cover  5300  may be manufactured by insert injection of the permanent magnet  5130 . However, in this case, if the number of permanent magnets  5130  is increased, manufacturing yield is deteriorated. For example, if the number of permanent magnets  5130  is increased, proper heat transfer is not performed in a portion an interval between the permanent magnets is narrow, whereby sufficient injection may not be performed. In order to solve this problem, if insert injection is performed at high pressure, the permanent magnet  5130  may be damaged in the middle of insert injection. 
     This embodiment suggests an improved induction module. 
     Another embodiment of the induction module according to the present disclosure will be described with reference to  FIGS.  9  and  10   . 
     First of all, a whole structure of the induction module  5000  will be described. 
     The induction module  5000  includes a base housing  5100  in which the coil  5150  is accommodated, a permanent magnet housing  5500  in which the permanent magnet  5130  is accommodated, and a cover housing  5600  for covering the permanent magnet housing  5500 . That is, in this embodiment, the cover of the aforementioned embodiment is divided into the permanent magnet housing  5500  and the cover housing  5600 . Also, the permanent magnet  5130  may be inserted into the permanent magnet housing  5500  from up to down, and the cover housing  5600  is jointed to allow the permanent magnet  5130  not to be detached from the permanent magnet housing  5500 . 
     Hereinafter, each element will be described in detail. 
     First of all, the base housing  5100  will be described. 
     The base housing  5100  has a square shape, preferably a rectangular shape, and the coil  5150  is accommodated in an upper portion of the base housing  5100 . It is preferable that a through portion  5170   a  is provided in the center of the base housing  5100 . 
     The joint  5190  is provided at the corner portion of the base housing  5100 , and it is preferable that the joint  5190  is outwardly protruded from the corner portion. Also, a ring  5102  coupled with a hook  5502  of the permanent magnet housing  5500  is provided at the rim of the base housing  5100 . Preferably, two rings  5102  are provided at both sides of a long side portion of the base housing  5100 . Therefore, a total of four rings  5102  are provided. (A detailed coupling structure will be described later.) 
     Since a structure of the other portion of the base housing  5100  may substantially be similar to the base housing of the aforementioned embodiment, its description will be omitted. 
     Next, the permanent magnet housing  5500  will be described. 
     It is preferable that the shape of the permanent magnet housing  5500  has a shape corresponding to the base housing  5100 . For example, it is preferable that the permanent magnet housing  5500  has a rectangular shape. 
     A holder  5510  in which the permanent magnet  5130  is arranged is provided in the permanent magnet housing  5500 . Also, since it is preferable that the permanent magnet housing  5500  is provided by one component, a connector  5530  for a plurality of holders  5510  with one another is preferably provided. The connector  5530  has a structure which is opened up and down, instead of a structure which is blocked up and down, whereby heat generated from the coil  5150  may move. Therefore, the connector  5530  is preferably provided with a through portion  5520  opened up and down. 
     The holder  5510  may be provided in a plural number, and is preferably provided in a radial direction from the center of the base housing  5100  to the rim of the base housing  5100 . Since the holder  5510  is a portion where the permanent magnet  5130  is mounted, it is preferable that the holder  5510  has a shape corresponding to the permanent magnet  5130 , that is, a rectangular shape having a narrow width. 
     In detail, the holder  5510  may include a long side holder  5510   a , a short side holder  5510   b , and a corner holder  5510   c . The long side holder  5510   a  may be provided in such a manner that two long side holders are respectively provided at both sides near the center of the long side portion of the base housing  5100 . The short side holder  5510   b  may be provided in such a manner that two short side holders are respectively provided at both sides near the center of the short side portion of the base housing  5100 . The corner holder  5510   c  may be provided in such a manner that four corner holders are respectively provided in a corner direction at the center of the long side portion of the base housing  5100 . 
     The through portion  5520  may be provided to up and down open the portion where the holder  5510  is not provided, for example, the space between the holder  5510  and its adjacent holder  5510 . That is, the through portion  5520  is preferably provided in a shape corresponding to the shape of the space between the holder  5510  and its adjacent holder  5510 . Also, since the through portion  5520  may serve to discharge heat generated from the coil  5150 , it is preferable that the through portion  5520  has a wide area if possible within the range that maintains strength of the permanent magnet housing  5500 . 
     In detail, it is preferable that the holder  5510  in which the permanent magnet  5130  is provided has a thickness of 2.0 t, and the connector  5530  for connecting the plurality of holders  5510  with one another has a thickness of 1.5 t. Since the holder  5510  is a portion in which the permanent magnet  5130  is mounted, the holder  5510  may be formed to be thicker than the connector  5530  to maintain rigidity. The connector  5530  may be formed to be thinner than the holder  5510  to maintain a certain distance from the base housing  5100  for supporting the permanent magnet  5130  and at the same time accommodating the coil  5150 . 
     If heat of high temperature is applied to the permanent magnet  5130 , atoms moves chaotically, whereby the permanent magnet  5130  loses magnetism. This could weaken durability of the induction module  5000 . 
     Therefore, a difference in thickness between the holder  5510  and the connector  5530  may prevent the temperature of the permanent magnet  5130  from being increased by heat formed on the lower surface of the permanent magnet housing  500  and generated from the coil  5150 . 
     Meanwhile, the joint  5590  is provided at the corner portion of the permanent magnet housing  5500 . Preferably, the joint  5590  is outwardly protruded from the corner portion. 
     The hook  5502  downwardly extended is provided at the rim of the permanent magnet housing  5500 , and the hook  5502  is inserted into the ring  5102  of the base housing  5100 . 
     Also, a groove  5504  is provided at a predetermined position inside the permanent magnet housing  5500 , and is coupled with a hook  5604  of the cover housing  5600 . (A detailed coupling structure will be described later.) 
     Next, the cover housing  5600  will be described. 
     It is preferable that the cover housing  5600  has a shape corresponding to the permanent magnet housing  5500 . For example, it is preferable that the cover housing  5600  has a rectangular shape. The through portion  5620  may be provided at the center of the cover housing  5600 , and a fan (not shown) may be mounted in the through portion  5620 . The joint  5690  is provided at the corner portion of the cover housing  5600 , and is preferably has a long hole. The hook  5604  coupled with the groove  5504  of the permanent magnet housing  5500  is provided at the lower portion of the cover housing  5600 . (A detailed coupling structure will be described later.) 
     The permanent magnet housing  5500  will be described in more detail with reference to  FIGS.  9  and  10   . 
     Preferably, the holder  5510  for mounting the permanent magnet  5130  has an opened upper portion so that the permanent magnet  5130  may be inserted thereinto from up to down. In this case, it is easy to insert the permanent magnet  5130  to the permanent magnet holder  5510 . It is preferable that the permanent magnet  5130  mounted in the permanent magnet holder  5510  is prevented from being detached by the cover housing  5600  coupled to the upper portion. 
     The holder  5510  will be described in detail. 
     As described above, it is preferable that the permanent magnet  5130  is inserted into the holder  5510  from up to down. Therefore, it is preferable that the holder  5510  is provided with an opening portion  5512   a  at the upper portion and therefore the permanent magnet  5130  is inserted into the opening portion  5512   a . Also, the holder  5510  should have a space to which the permanent magnet  5130  is fixed. Therefore, the holder  5510  has a barrier  5512   a  extended to the lower portion of the opening portion  5512   a , and the permanent magnet  5130  is fixedly supported by the barrier  5512   b . Preferably, a sectional shape of the barrier  5512   b  corresponds to the shape of the permanent magnet  5130 . Also, a support portion  5512   c  for supporting the permanent magnet  5130  so as not to be detached is provided at the front end below the barrier  5512   b . Preferably, the support portion  5512   c  is inwardly protruded from the front end below the barrier  5512   b.    
     Meanwhile, as described above, the permanent magnet housing  5500  has a connector  5530  for connecting the holders  5510 . The connector  5530  is located between the holders  5510  to connect the holders  5510 . The connector  5530  may connect a predetermined position of the barrier  5510   b  of the holder  5510 , for example, the upper portion or the lower portion. 
     However, it is preferable that the connector  5530  connects the upper portion of the holder  5510  to efficiently discharge heat generated from the coil  5150 . This is because that the space S between the holder  5510  and its adjacent holder  5510  becomes a convention current space for discharging heat of the coil  5150 . That is, heat generated from the coil  5150  may be discharged to the upper side of the permanent magnet housing  5500  through the through portion  5520  and the convention current space S. 
     As shown in  FIG.  11   , heat that has passed through each through portion  5520  of the permanent magnet housing  5500  is collected in the through portion  5520   a  at the center. Heat collected in the through portion  5520   a  at the center of the permanent magnet housing  5500  is discharged to the outside through the through portion  5620  at the center of the cover housing  5600 . If a fan (not shown) is provided in the through portion  5620  at the center of the cover housing  5600 , heat radiation effect may be more improved. 
     Meanwhile, it is preferable that heat generated from the coil  5150  is induced to a natural convection current using the shape of the induction module and then discharged to the outside of the induction module. 
     The cover housing  5600  forms a predetermined space to move heat generated from the coil, and is jointed to the upper portion of the base housing  5100 . 
     In detail, the cover housing  5600  includes a through portion  5620  that passes through the cover housing  5600  to discharge the heat, and forms a section upwardly inclined toward the through portion  5620  to allow the heat generated from the coil to move along the inclined section and then to be discharged to the through portion  5620 . 
     That is, a space where the heat may move may be formed by the base housing  5100  and the cover housing  5600 , and the heat generated from the coil accommodated in the base housing  5100  may form an ascending air current, move along an inner surface inclined toward the upper portion of the cover housing  5600  and be discharged to the outside of the induction module  5000  through the through portion  5620 . 
     In order to induce discharge of the heat generated from the coil by means a natural convection current, the through portion  5620  may preferably be provided at the uppermost end of the induction module  5000 , and may be formed at a center portion of the cover housing  5600 . 
     The uppermost end may mean a place where a height difference between the cover housing  5600  and the base housing  5100  is the greatest, and the center portion of the cover housing  5600  may be defined differently depending on a shape of the cover housing  5600 . 
     In this embodiment, the cover housing  5600  may be provided in a rectangular shape that forms two long sides and two short sides, the through portion  5620  may be formed at the center of the cover housing  5600 , and the cover housing  5600  may form a section upwardly inclined from the two long sides toward the through portion  5620 . 
     According to another embodiment of the present disclosure, the cover housing  5620  may be provided in a shape parallel with the two long sides and bent based on a virtual line crossing a center point of the cover housing  5600 , wherein the bent level of the cover housing  5600  may correspond to an outer circumferential shape of the drum. 
     Therefore, the base housing  5100  and the cover housing  5600  may be bent to correspond to the outer circumferential surface of the drum, and the heat generated from the coil may move along the bent surface of the cover housing  5600  and then be discharged to the through portion  5620 . 
     In detail, the permanent magnet housing  5500  provided between the base housing  5100  and the cover housing  5600  may also be bent to correspond to the outer circumferential surface of the drum, whereby the base housing  5100 , the permanent magnet housing  5500  and the cover housing  5600  are formed to be bent with the same curvature, wherein the curvature is preferably the same as a curvature formed by the outer circumferential surface of the drum. 
     A structure for discharging heat generated from the coil  5150  to the outside by a natural convention current will be described with reference to  FIG.  12   . 
     It is preferable that the section C 1  of the base housing  5100  is a curved line. This is because that the drum is heated by the coil  5150 . Therefore, in order to uniformly heat the drum, it is preferable that the base housing  5100  in which the coil  5150  is accommodated substantially has the same curved section as a curvature of the drum and/or the tub. On the other hand, it is preferable that the permanent magnet housing  5500  and the cover housing  5600  have sections C 2  and C 3  upwardly inclined toward the center portion, and it is more preferable that the long side portion is inclined (see  FIG.  9   ). 
     This is because that a space D 2  of a center portion becomes greater than a space D 1  of an outer portion if the permanent magnet housing  5500  and the cover housing  5600  are upwardly inclined. In accordance with characteristic of this shape, heat generated from the coil  5150  is guided to easily move to the natural convection current. 
     Therefore, heat generated from the coil  5150  easily and upwardly moves along the inclined section, and is finally discharged to the outside through the through portion  5620  at the center of the cover housing  5600 . If the fan is provided in the through portion  5620  at the center of the cover housing  5600 , heat may be discharged to the outside more effectively. 
     The connector  5530  of the permanent magnet housing  5500  may connect the upper portion of the holder  5510 . This feature in the shape of the connector  5530  may make sure of a moving space of the heat generated from the coil by providing the permanent magnet housing  5500  between the cover housing  5600  and the base housing  5100  and forming a space between the base housing  5100  and the permanent magnet housing  5500 . Therefore, the upper portion of the connector  5530  may be in contact with the inner surface of the cover housing  5600 , and the lower portion of the connector  5530  may be spaced apart from the base housing  5100  at a predetermined interval to make sure of the moving space of the heat. 
     However, this embodiment is not limited to the shape of the connector  5530 . The connector  5530  may connect the lower portion of the holder  5510 . In this structure, the moving space of the heat may be formed between the permanent magnet housing  5500  and the cover housing  5600 . 
     The through portion of the permanent magnet housing  5500  may be provided to be connected with the through portion of the cover housing  5600 , wherein the through portions respectively mean center through portions  5520   a  and  5620  formed at the center of the permanent magnet housing  5500  and the cover housing  5600 . 
     Also, as the permanent magnet housing  5500  forms the section upwardly inclined toward the through portion  5520   a , the heat may move to the through portion  5520  along the inclined section and then be discharged to the outside of the induction module  5000  through the through portion  5620  of the cover housing communicated with the through portion  5520   a.    
     Next, a joint structure of the base housing  5100 , the permanent magnet housing  5500  and the cover housing  5600  will be described. 
     The induction module  5000  uses the induced heating principle. Therefore, a magnetism such as a screw is used, and the joint is located to be adjacent to the coil  5150 . Therefore, abnormal heating may occur in the joint using the screw, etc. If abnormal heating occurs, strength near the screw may partially be weakened, whereby the screw may get loose. Therefore, it is preferable to perform another joint in addition to the joint using the magnetism such as the screw. 
     First of all, the joint structure of the base housing  5100  and the permanent magnet housing  5500  will be described with reference to  FIG.  13   . 
     As described above, the hook  5502  is provided in the permanent magnet housing  5500 , and the ring  5102  is provided in the base housing  5100 . It is preferable that two hooks  5502  are provided at both sides of the long side portion of the base housing  5100 , and the rings  5102  are preferably provided to correspond to the hooks  5502 . The hook  5502  and the ring  5102  are preferably made of a non-magnetic material. 
     Preferably, the hook  5502  includes a vertical portion  5502   a  extended vertically, and a horizontal portion  5502   b  outwardly extended from a front end of the vertical portion  5502   a.    
     The hook  5502  and the ring  5102  are jointed to each other by pushing the hook  5502  of the permanent magnet housing  5500  toward the ring  5102  of the base housing  5100  from up to down. 
     As described above, the base housing  5100  and the permanent magnet housing  5500  are jointed to each other using the hook  5502  and the ring  5102 . Therefore, even though the joint force of the joints  5190  and  5590  jointed by the screw is weakened, the joint of the base housing  5100  and the permanent magnet housing  5500  may be maintained by the hook  5502  and the ring  5102 . 
     The joint structure of the cover housing  5600  and the permanent magnet housing  5500  will be described with reference to  FIG.  14   . 
     The cover housing  5600  is provided with the hook  5604 , and the permanent magnet housing  5500  is provided with the groove  5504 . It is preferable that the hook  5604  is provided to be extended to a bottom direction of the cover housing  5600 . It is also preferable that two hooks  5502  are respectively provided at both sides near the long side portion of the cover housing  5600  and two hooks  5502  are provided at the center portion. The permanent magnet housing  5500  is preferably provided with the groove  5504  corresponding to the hook  5502 . 
     Preferably, the hook  5604  includes a vertical portion  5604   a  extended vertically, and a horizontal portion  5604   b  horizontally extended from a front end of the vertical portion  5604   a . It is preferable that the horizontal portion  5604   b  is extended toward a long side portion of the cover housing  5600 . It is preferable that a plurality of hooks  5604  are provided in the same direction. 
     The hook  5604  of the cover housing  5600  is inserted into the groove  5504  of the permanent magnet housing  5500  and then jointed to the groove  5504 . At this time, the hook  5604  and the groove  5504  are jointed to each other using inclination by pushing the cover housing  5600  from the upper side of the permanent magnet housing  5500  toward a horizontal direction. It is preferable that tolerance generated in an inclined surface after maximum assembly is absorbed by a long hole of the joint  5690 . This is because that a damage is likely to occur if there is no tolerance during joint using a great screw. 
     As described above, the cover housing  5600  and the permanent magnet housing  5500  are jointed to each other using the hook  5604  and the groove  5504 . Therefore, even though the joint force of the joint  5690  is weakened, the joint of the cover housing  5600  and the permanent magnet housing  5500  may be maintained by the hook  5604  and the groove  5504 . 
     It is preferable that the base housing  5100 , the permanent magnet housing  5500  and the cover housing  5600  are jointed using the screw by the joints  5190 ,  5590  and  5690 . Also, it is preferable that the holes of the joints  5190 ,  5590  and  5690  are long holes. 
     Meanwhile, the tub is vibrated during operation of the laundry treating apparatus, particularly washing or dehydrating, whereby the induction module is also vibrated. At this time, if the permanent magnet provided in the induction module is vibrated, noise may be generated or the permanent magnet may be damaged if vibration is serious. Therefore, it is preferable that the permanent magnet  5130  is stably fixed to the permanent magnet holder  5510  of the permanent magnet housing  5500 . 
     The structure of stably fixing the permanent magnet  5130  to the permanent magnet holder  5510  will be described with reference to  FIGS.  15  and  16   . 
     A clamp  5650  for fixing the permanent magnet  5130  is provided at a predetermined position of the cover housing  5600 , particularly at a portion where the permanent magnet  5130  is located. 
     As shown in  FIG.  15   , it is preferable that the clamp  5650  is formed by partially cutting the cover housing  5600  and allowing the cut portion to be downwardly located. The cover housing  5600  is capable of being generally made of a plastic material. If the clamp  5650  is made of a thin plate shape, the clamp  5650  may serve as a plate spring. In this case, since the clamp  5650  has elasticity, the clamp  5650  may absorb impact such as vibration. Also, even though there is assembly tolerance of each portion, the clamp  5650  may absorb such tolerance in accordance with its elasticity. 
     As shown in  FIG.  16   , the clamp  5650  may be formed by vertically protruding the cover housing  5600  from the bottom to the lower portion. In this case, the clamp  5650  has less elasticity. Therefore, in this case, it is preferable that the clamp  5650  fixes the permanent magnet by using assembly tolerance. 
     Advantages of the induction module according to the aforementioned embodiment will be described with reference to  FIG.  9   . 
     According to this embodiment, the permanent magnet housing  5500  for accommodating the permanent magnet  5130  and the cover housing  5600  jointed to the upper portion of the permanent magnet housing  5500  are provided separately. Therefore, the structure of the permanent magnet housing  5500  and the cover housing  5600  may be simplified. 
     Also, since the permanent magnet housing  5500  has not portion covering the upper portion, its structure and shape are relatively simple. Since the cover housing  5600  has no permanent magnet holder, its structure and shape are relatively simple. Therefore, the permanent magnet housing  5500  and the cover housing  5600  may make a simple structure of injection molding, and may minimize a defect during injection molding. 
     Also, the permanent magnet holder  5510  provided in the permanent magnet housing  5500  has a structure in which an upper portion is opened. Therefore, since the permanent magnet  5130  may be inserted into the permanent magnet holder  5510  from up to down, it is easy to mount the permanent magnet in the permanent magnet holder. Therefore, when the permanent magnet  5130  is damaged, the damaged permanent magnet may easily be replaced with a new one. 
     Also, since each of the permanent magnet housing  5500  and the cover housing  5600  may have a structure that may induce a natural convex current, it is easy to discharge heat generated from the coil  5150  to the outside. 
     Also, since the base housing  5100 , the permanent magnet housing  5500  and the cover housing  5600  are jointed by the structure of the hook  5502 , the joint force is increased. 
     It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the spirit and essential characteristics of the invention. Thus, the above embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the invention should be determined by reasonable interpretation of the appended claims and all change which comes within the equivalent scope of the invention are included in the scope of the invention.