Patent Publication Number: US-2021190341-A1

Title: Humidifier for preventing pollution of humidifying water

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 U.S.C. § 119(a) of a Korean patent application number 10-2019-0169726, filed on Dec. 18, 2019 in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     The disclosure relates to a humidifier. More particularly, the disclosure relates to an evaporative humidifier. 
     2. Description of the Related Art 
     Types of humidifiers include a heating type that boils water with electricity to discharge it as steam, an ultrasonic type that vibrates water with ultrasonic waves to create water droplets, and a combined type that combines heating and ultrasonic types, and an evaporate type that naturally evaporates by blowing wind through a fan to a humidification device moistened with water. 
     Unlike the ultrasonic method, which has a disadvantage that various particles dissolved in water can be sprayed into the air together with water, the evaporation method has an advantage that sprayed moisture is relatively clean since it evaporates only pure water. 
     However, in the case of the conventional evaporative humidifier, since the water stored in the humidifier is continuously used, components dissolved in the water such as ionic components, organic substances, or the like, are concentrated, and microorganisms, or the like, are proliferated, and as a result of the water contamination, the humidifier may be incrusted with slime or may cause an odor. 
     In order to prevent this, the humidifier needs to be frequently cleaned, but users feel inconvenient to frequently perform cleaning the humidifier, and thus users do not perform cleaning often. 
     SUMMARY 
     The disclosure provides a humidifier that prevents pollution of a circulating water tank by automatically discharging water in the circulating water tank that supplies water to a humidifying member according to predetermined conditions. 
     The disclosure provides a humidifier that can maintain clean internal environment by performing purification of humidified water, sterilization treatment of humidified water, discharge of humidified water with concentrated foreign substances, or the like. 
     In particular, the disclosure discloses a specific control method of various components provided in the humidifier described above. 
     According to an embodiment of the disclosure, a humidifier includes a humidifying member, a storage water tank, a circulating water tank, a residual water tank, a supply pump configured to, based on an operating mode of the humidifier being humidity mode, supply water in the storage water tank to the circulating water tank, a circulating pump configured to supply water in the circulating water tank to the humidifying member, a fan configured to provide wind to the humidifying member to which the water is supplied, evaporate the water supplied to the humidifying member, and discharge the water to the outside of the humidifier, an internal pipe configured to form a flow pass through which water not evaporated in the humidifying member is returned to the circulating water tank, a drainage member configured to selectively discharge water in the circulating water tank to the residual water tank, and a controller configured to, based on a water level in the storage water tank being greater than or equal to a predetermined low water level, operate the humidifier in humidity mode, and based on the water level in the storage water tank being less than the predetermined low water level while the humidifier is operating in the humidify mode, stop the humidify mode based on at least one of a water level in the circulating water tank and a water level in the residual water tank. 
     According to an embodiment of the disclosure, a humidifier includes a humidifying member, a storage water tank, a circulating water tank, a residual water tank, a supply pump configured to, based on an operating mode of the humidifier being humidity mode, supply water in the storage water tank to the circulating water tank, a filter configured to purify water supplied from the storage water tank to the circulating water tank, a circulating pump configured to supply the water in the circulating water tank to the humidifying member, a fan configured to provide wind to the humidifying member to which the water is supplied, evaporate the water supplied to the humidifying member, and discharge the water to the outside of the humidifier, an internal pipe configured to form a flow pass through which water not evaporated in the humidifying member is returned to the circulating water tank, a drainage member configured to selectively discharge the water in the circulating water tank to the residual water tank, and a controller configured to, based on the water level in the circulating water tank being less than a predetermined low water level, control the supply pump such that water in the storage water tank is supplied to the circulating water tank through the filter, identify whether the filter needs to be replaced based on a time taken for the water level in the circulating water tank to reach a predetermine high water level, and provide a notification related to the replacement of the filter based on the identification result. 
     According to an embodiment of the disclosure, a humidifier includes a humidifying member, a storage water tank, a circulating water tank, a residual water tank, a sterilization treatment unit configured to sterilize water in the circulating water tank, a supply pump configured to, based on an operating mode of the humidifier being humidity mode, supply water in the storage water tank to the circulating water tank, a circulating pump configured to supply the water in the circulating water tank to the humidifying member, a fan configured to provide wind to the humidifying member to which the water is supplied, evaporate the water supplied to the humidifying member, and discharge the water to the outside of the humidifier, an internal pipe configured to form a flow pass through which water not evaporated in the humidifying member is returned to the circulating water tank, a drainage member configured to selectively discharge the water in the circulating water tank to the residual water tank, and a controller configured to, while an operating mode of the humidifier is in the humidity mode, based on a water level in the circulating water tank being greater than or equal to a predetermine high water level, control the sterilization treatment unit to sterilize the water in the circulating water tank, and control the circulating pump to supply the sterilized water to the humidifying member. 
     According to an embodiment of the disclosure, a humidifier includes a humidifying member, a storage water tank, a circulating water tank, a residual water tank, a supply pump configured to, based on an operating mode of the humidifier being humidity mode, supply water in the storage water tank to the circulating water tank, a circulating pump configured to supply the water in the circulating water tank to the humidifying member, a fan configured to provide wind to the humidifying member to which the water is supplied, evaporate the water supplied to the humidifying member, and discharge the water to the outside of the humidifier, an internal pipe configured to form a flow pass through which water not evaporated in the humidifying member is returned to the circulating water tank, a drainage member configured to selectively discharge water in the circulating water tank to the residual water tank, and a controller is configured to, based on a water level in the circulating water tank being identified to be less than the predetermined low water level while a water level in the storage water tank being greater than or equal to a predetermined low water level, control the supply pump to supply the water in the storage water tank to the circulating water tank such that the water level in the circulating water tank reaches a predetermined high water level, and based on the water level in the circulating water tank being identified to be less than the predetermined low water level while the water level in the storage water tank is less than the predetermined low water level, provide a notification related to replenishment of water, and wherein a volume of water corresponding to the predetermined low water level in the storage water tank is greater than or equal to a volume of water corresponding to the predetermined high water level in the circulating water tank. 
     According to an embodiment of the disclosure, a humidifier includes a humidifying member, a storage water tank, a circulating water tank, a residual water tank, a supply pump configured to, based on an operating mode of the humidifier being humidity mode, supply water in the storage water tank to the circulating water tank, a circulating pump configured to supply the water in the circulating water tank to the humidifying member, a fan configured to provide wind to the humidifying member to which the water is supplied, evaporate the water supplied to the humidifying member, and discharge the water to the outside of the humidifier, an internal pipe configured to form a flow pass through which water not evaporated in the humidifying member is returned to the circulating water tank, a drainage member configured to selectively discharge water in the circulating water tank to the residual water tank, and a controller configured to, based on the humidity mode being stopped, control the drainage member to discharge the water in the circulating water tank to the residual water tank. 
     The humidifier according to the disclosure includes a residual water tank, thereby preventing humidification by mixing the remaining water used for humidification with the water accommodated in the storage water tank, and increasing a cleaning interval of the humidifier by suppressing contamination of a humidifying member. 
     Also, the humidifier according to the disclosure provides optimal automatic control related to a start and stop of humidity mode on a structure using all of a storage water tank, a circulating water tank and a residual water tank. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view illustrating a configuration of a humidifier according to an embodiment of the disclosure; 
         FIG. 2  is a block diagram illustrating a functional configuration of a humidifier according to an embodiment of the disclosure; 
         FIG. 3  is a flowchart illustrating an operation in humidity mode of a humidifier according to an embodiment of the disclosure; 
         FIG. 4  is an algorithm illustrating an example of an operation of a humidifier for discharging water accommodated in a circulating water tank to a residual water tank; 
         FIG. 5  is an algorithm illustrating an example of an operation of a humidifier for stopping humidity mode depending on a condition; 
         FIG. 6  is a view illustrating a configuration of a humidifier including a filter according to an embodiment of the disclosure; 
         FIG. 7  is a view illustrating a configuration of a humidifier including a sterilization treatment unit according to an embodiment of the disclosure; 
         FIG. 8  is a flowchart illustrating an operation of a humidifier that performs sterilization in humidity mode; 
         FIG. 9  is an algorithm illustrating an example of an operation of a humidifier using a kit that performs sterilization treatment based on electrolysis; 
         FIG. 10  is an algorithm illustrating an example of an operation of a humidifier that performs a sterilization treatment according to sterilization mode; 
         FIG. 11  is an algorithm illustrating an operation of a humidifier capable of maximizing use of water accommodated in a storage water tank according to an embodiment of the disclosure; 
         FIGS. 12A and 12B  are algorithms illustrating an operation of a humidifier after humidity mode is stopped with respect to a storage water tank and a residual water tank are of a separate type and an integrated type; 
         FIG. 13  is a view illustrating a detailed configuration of a humidifier according to various embodiments of the disclosure; and 
         FIG. 14  is a block diagram functionally illustrating a configuration of a humidifier according to various embodiments of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Before specifically describing the disclosure, a method for demonstrating the disclosure and drawings will be described. 
     Terms used in the disclosure and claims were selected from general terms in consideration of functions in various embodiments of the disclosure. However, these terms may vary depending on the intention of those skilled in the art, legal or technical interpretation, and an emergence of new technologies. Also, there may be some terms arbitrarily selected by an applicant. Such terms may be construed according to meanings defined in the present specification, and may also be construed based on general contents of the present specification and a typical technical concept in the art unless the terms are not specifically defined. 
     Also, the same reference numerals or symbols described in the attached drawings denote parts or elements that actually perform the same functions. For convenience of descriptions and understanding, the same reference numerals or symbols are used and described in different exemplary embodiments. In other words, although elements having the same reference numerals are all illustrated in a plurality of drawings, the plurality of drawings do not mean one exemplary embodiment. 
     In addition, in order to distinguish between the components, terms including an ordinal number such as “first”, “second”, etc. may be used in the present specification and claims. The ordinal numbers are used in order to distinguish the same or similar elements from one another, and the use of the ordinal number should not be understood as limiting the meaning of the terms. For example, used orders, arrangement orders, or the like of elements that are combined with these ordinal numbers may not be limited by the numbers. The respective ordinal numbers are interchangeably used, if necessary. 
     The singular expression also includes the plural meaning as long as it does not differently mean in the context. The terms “include”, “comprise”, “is configured to,” etc., of the description are used to indicate that there are features, numbers, steps, operations, elements, parts or combination thereof, and they should not exclude the possibilities of combination or addition of one or more features, numbers, steps, operations, elements, parts or a combination thereof. 
     In the exemplary embodiment of the present disclosure, the term “module,” “unit,” or “part” is referred to as an element that performs at least one function or operation, and may be implemented with hardware, software, or a combination of hardware and software. In addition, a plurality of “modules,” a plurality of “units,” a plurality of “parts” may be integrated into at least one module or chip except for a “module,” a “unit,” or a “part” which has to be implemented with specific hardware, and may be implemented with at least one processor (not shown). 
     Terms such as ‘front’, ‘rear’, ‘upper’, ‘lower’, ‘upper part’ and ‘lower part’ used in this disclosure are defined based on the drawings, and the shape and position of each component is not limited thereto. 
     Also, when any part is connected to another part, this includes a direct connection and an indirect connection through another medium. Further, when a certain portion includes a certain element, unless specified to the contrary, this means that another element may be additionally included, rather than precluding another element. 
       FIG. 1  is a view illustrating a configuration of a humidifier according to an embodiment of the disclosure. 
     Referring to  FIG. 1 , a humidifier  100  according to an embodiment of the disclosure may include a humidifying member  110 , a storage water tank  120 , a circulating water tank  130 , and a residual water tank  140 . In addition, the humidifier  100  may further include a fan  115 , a supply pump  125 , a circulating pump  135 , and a drainage member  136 , or the like. 
     The humidifying member  110  may include a humidifying element implemented in a structure in which water is absorbed and the absorbed water is easily evaporated. Specifically, water is sprayed to the humidifying member  110  from a distributor  111  shown in  FIG. 1 , and wind generated by a rotation of the fan  115  may be provided to the humidifying member  110 . In this case, water sprayed on the humidifying member  110  may evaporate and be discharged to the outside of the humidifier  100 . 
     The humidifying member  110  may be included in a humidifying member case. In this case, the humidifying member case may be detachable to the humidifier  100 . 
     The storage water tank  120  is formed to accommodate a certain amount of water. The water in the storage water tank  120  may be water filled in the storage water tank  120  by a user. For this operation, the storage water tank  120  may be formed to be detachable to the humidifier  100 . 
     Alternatively, the water in the storage water tank  120  may be water supplied from a separate external device connected to the storage water tank  120 . 
     The circulating water tank  130  may be connected to the storage water tank  120  to receive water from the storage water tank  120 . 
     Regarding the above, the supply pump  125  is a configuration for supplying the water accommodated in the storage water tank to the circulating water tank  130 . Referring to  FIG. 1 , the storage water tank  110  and the supply pump  125  may be connected by a pipe  11 , and the supply pump  125  and the circulating water tank  120  may be connected by a pipe  12 . 
     The circulating pump  135  is a configuration for supplying water accommodated in the circulating water tank  130  to the humidifying member  110 . The circulating pump  135  and the humidifying member  110  (and/or the distributor  111 ) may be connected through a pipe  13 . 
     Specifically, the water accommodated in the circulating water tank  130  may be provided to the distributor  111  by the circulating pump  135 , and the distributor  111  may supply the provided water to the humidifying member  110 . 
     Referring to  FIG. 1 , the humidifier  100  may include an internal pipe  14  that forms a flow passage through which water not vaporized in the humidifying member is recovered to the circulating water tank  130 . In other words, some of the water supplied from the circulating water tank  130  to the humidifying member  110  may be recovered to the circulating water tank  130 . 
     The residual water tank  140  is a tank for accommodating discharged residual water when residual water remaining in the circulating water tank  130  is discharged. The water accommodated in the residual water tank  140  may be thrown out by the user. For this operation, the residual water tank  140  may be formed to be detachably attached to the humidifier  100 . 
     Regarding the above, the drainage member  136  may selectively discharge water accommodated in the circulating water tank to the residual water tank. The drainage member  136  may be implemented as a valve controlled by simply opening/closing, a pump that moves water based on power, or the like. 
     The circulating water tank  130  and the drainage member  136  may be connected through a pipe  15 , and the drainage member  136  and the residual water tank  140  may be connected through a pipe  16 . 
       FIG. 2  is a block diagram illustrating a functional configuration of a humidifier according to an embodiment of the disclosure. 
     Referring to  FIG. 2 , the humidifier  100  may include a water level sensor  121  for measuring a water level in the storage water tank, a water level sensor  131  for measuring a water level in the circulating water tank, and a water level sensor for measuring a water level in the residual water tank  141 . 
     Each of the sensors  121 ,  131 , and  141  described above may be implemented with various types of sensors for measuring the water level in the tanks. As an example, each of the water level sensors  121 ,  131  and  141  may include a low water level sensor and a high water level sensor, but is not limited thereto. 
     In addition, referring to  FIG. 2 , the humidifier  100  may include a controller  150  for controlling various configurations of the humidifier  100 . 
     The controller  150  may control the operation of the humidifier  100  based on at least one of whether at least one of the humidifying member  110 , the storage water tank  120 , and the residual water tank  130  is attached or detached, and the water level in water tanks  120 ,  130  measured through the water level sensors  121 ,  131 , and  141 . 
     For this operation, the controller  150  may include a circuit directly/indirectly connected to the water level sensors  121 ,  131 ,  141 , the supply pump  125 , the circulating pump  135 , the drainage member  136 , or the like. In addition, the controller  150  may include at least one processor and a memory. 
     The controller  150  may set/control an operating mode of the humidifier  100 . The operating mode may include a humidity mode (i.e., performing a humidifying operation), a non-humidity mode (i.e., not performing a humidifying operation), or the like. When the humidifier  100  is a humidified air cleaning device including an air cleaning function in addition to the humidifying function, the non-humidity mode may be an air cleaning mode. 
     When the operating mode of the humidifier  100  is humidity mode, the controller  150  may control components of the humidifier  100  to perform various operations for humidification. 
       FIG. 3  is a flowchart illustrating an operation of a humidifier operating in the humidity mode. 
     Referring to  FIG. 3 , when the operating mode of the humidifier  100  is the humidity mode, the controller  150  may control the supply pump  125  to supply water accommodated in the storage water tank  120  to the circulating water tank  130  (S 310 ). 
     In addition, the controller  150  may control the circulating pump  135  to supply water accommodated in the circulating water tank  130  to the humidifying member  110  (S 320 ). Specifically, when the water level in the circulating water tank  130  is less than a predetermined low water level, the controller  150  may control the supply pump  125  to supply the water accommodated in the storage water tank  120  to the circulating water tank  130  such that the water level in the circulating water tank  130  reaches a predetermined high water level. 
     The controller  150  may drive the fan  115  to evaporate water in the humidifying member  110  to discharge it to the outside (S 330 ). In this case, water supplied to the humidifying member  110  but not vaporized may be returned to the circulating water tank  130  through the internal pipe  14 . However, in this case, a concentration of foreign substances/microorganisms of water supplied to the humidifying member  110  but not vaporized may become more than before being supplied to the humidifying member  110 . 
     In this case, the controller  150  may control the drainage member  136  to discharge the water accommodated in the circulating water tank  130  to the residual water tank  140  based on the water level in the circulating water tank  130  (S 340 ). 
     Specifically, when the water level in the circulating water tank  130  has reached a predetermined high water level as a result of supplying the water accommodated in the storage water tank  120  to the circulating water tank  130 , and the water accommodated in the circulating water tank  130  has reached a predetermined low water level as a result of supplying the accommodated water in the humidifying member  110 . 
     Alternatively, when the number of times the supply pump  125  supplies water to the circulating water tank  130  is a predetermined number of times such that the water level in the circulating water tank  130  reaches the predetermined high water level from below the predetermined low water level, and if the water level in the circulating water tank  130  becomes less than the predetermined low water level, the controller  150  may control the drainage member  136  to discharge the water in the circulating water tank  130  to the residual water tank  140 . 
       FIG. 4  is an algorithm illustrating a specific example of the operation of a humidifier for discharging water accommodated in a circulating water tank to a residual water tank. 
     Referring to  FIG. 4 , after the humidity mode is started (S 410 ), a water level in the circulating water tank  130  may be measured in real time in a state in which the number of water supply=0 (S 420 ). 
     When the water level in the circulating water tank  130  is less than the predetermined low water level (S 430 —Y), the operation of the controller  150  may vary depending on whether the number of water supply is N (: predetermined number) times. 
     If the water level in the circulating water tank  130  is less than the predetermined low water level (S 430 —Y), and the number of water supply is not N times (S 440 —N), the controller  150  may control the supply pump  125  such that the water level in the circulating water tank  130  reaches the predetermined high water level (S 450 ). When the supply is finished, the number of water supply may be increased by one (S 460 ). 
     Meanwhile, when the water level in the circulating water tank  130  is less than the predetermined low water level (S 430 —Y), the number of water supply is N times (S 440 —Y), the controller  150  may control the drainage member  136  to discharge the accommodated water to the residual water tank  140  (S 470 ). In this case, the stored number of water supply may be 0 again (S 420 ). 
     According to the embodiments described above that selectively discharging residual water in the circulating water tank  130 , a situation in which residual water enriched with microorganisms/bacteria may be stored for a long period of time in the circulating water tank  130  and left unattended may be automatically prevented. 
     Meanwhile, the controller  150  may operate the humidifier  100  in the humidity mode described above when the water level in the storage water tank  120  is more than the predetermined low water level. Specifically, the controller  150  may start the humidity mode only when the humidifying member case is attached to the humidifier  100  and the water level in the storage water tank  120  is equal to or more than the predetermined low water level. 
     If a user command to start the humidifying operation is input while the water level in the storage water tank  120  is less than the predetermined low water level, the controller  150  may provide a notification of water shortage. 
     Meanwhile, when the humidity mode starts, the controller  150  may control the drainage member  136  to discharge the water in the circulating water tank  130  to the residual water tank  140 , and when the discharge ends, the controller  150  may control the supply pump  125  to supply water to the circulating water tank  130  from the storage water tank  120 . In this case, there is an advantage in that it may be possible to discard the residual water remaining in the existing circulating water tank  130  and use more clean water. 
     Meanwhile, when the water level in the storage water tank is less than the predetermined low water level in a state in which the humidifier  100  is operated in the humidity mode, the controller  150  may stop the humidity mode based on at least one of the water level in the circulation water tank  130  and the water level in the residual water tank  140 . 
       FIG. 5  is an algorithm illustrating an example of an operation of a humidifier for stopping humidity mode depending on conditions. 
     Referring to  FIG. 5 , after the humidity mode is started (S 510 ), the controller  150  may identify whether the water level in the storage water tank  120  is less than a predetermined low water level based on sensing data of the storage water level sensor  121  (S 520 ). 
     When the water level in the circulating water tank  130  is less than the predetermined low water level (S 530 —Y), while the water level in the storage water tank  120  is less than the predetermined low water level (S 520 —Y), the controller  150  may stop the humidity mode (S 540 ). Meanwhile, the predetermined low water level in S 520  may refer to a target different from the predetermined low water level in S 530 , and each may be independently predetermined from each other. 
     When the water level in the circulating water tank  130  is not less than the predetermined low water level (S 530 —N), but the water level in the residual water tank  140  is more than the predetermined high water level (S 550 —Y), while the water level in the storage water tank  120  is less than the predetermined low water level (S 520 —Y), the controller  150  may stop the humidity mode (S 540 ). 
     In other words, when the circulation water tank  130  is less than the predetermined low water level or the residual water tank  140  is more than the predetermined high water level, while the water level in the storage water tank  129  is less than the predetermined water level, the controller may stop the humidity mode (S 540 ). 
       FIG. 6  is a view illustrating a configuration of a humidifier including a filter according to an embodiment of the disclosure. 
     Referring to  FIG. 6 , the humidifier  100  may further include a filter  160  in addition to the components of  FIG. 1 . 
     The filter  160  is a component for purifying water supplied from the storage water tank  120  to the circulating water tank  130 . The filter  160  may be replaced as a result of being formed in a detachable structure to the humidifier  100 . 
     The filter  160  may remove sludge, bacteria, etc. in water. For example, the filter  160  may include at least one of an ultra-filtration membrane filter, a sediment filter, and an activated carbon filter, but is not limited thereto. 
     When the water level in the circulating water tank  130  is less than a predetermined low water level, the controller  150  of  FIG. 6  may control the supply pump  125  such that the water accommodated in the storage water tank  120  passes through the filter  160  and is supplied to the circulating water tank  130 . 
     In this case, the controller  150  may identify whether the filter  160  needs to be replaced based on a time it takes for the water level in the circulating water tank  130  to reach a predetermined high water level, and may provide a notification related to the replacement of the filter  160  as a result of the identification. 
     For example, when the time it takes for the water level in the circulating water tank  130  to reach the predetermined high water level is more than the predetermined time, the controller  150  may identify that the filter  160  needs to be replaced, and provide a notification that the filter  160  needs to be replaced. In this case, the controller  150  may stop the humidity mode. 
     The predetermined time may be a time required to fill a predetermined high water level in the circulating water tank  130  according to a flow rate of the filter  160  clogged by 70 to 80% compared to the filter  160  in the initial state, but is not limited thereto. 
     Meanwhile, the controller  150  may identify the time taken for the water level in the circulating water tank  130  to reach the predetermined high water level and store the time in a memory, or the like, each time the supply pump  125  supplies the water accommodated in the storage water tank  120  to the circulating water tank  130 . 
     And, based on a changing pattern of the time stored before the time when it is identified that the filter needs to be replaced (depending on the time taken for the water level in the circulating water tank  130  to reach the high water level), the control unit  150  may identify the number of water supply of the supply pump  125  is supplied with water that requires replacement of the filter. 
     Thereafter, the controller  150  may identify whether the filter needs to be replaced based on the identified number of water supply, without measuring the time it takes for the water level in the circulating water tank  130  to reach the high water level each time. 
       FIG. 7  is a view illustrating a configuration of a humidifier including a sterilization treatment unit according to an embodiment of the disclosure. 
     Referring to  FIG. 7 , the humidifier  100  may further include a sterilization treatment unit  170  in addition to the components of  FIG. 1 . 
     The sterilization treatment unit  170  is a configuration for sterilizing the water in the circulating water tank  130 . 
     The controller  150  of the humidifier  100  of  FIG. 7  may control the sterilization treatment unit  130  to sterilize water accommodated in the circulating water tank  130  when the water level in the circulating water tank  139  is more than a predetermined high water level, while the operating mode of the humidifier  100  is humidity mode. In addition, the controller  150  may control the circulating pump  135  to supply the sterilized water to the humidifying member  110 . 
     As a result, it is possible to prevent water in which microorganisms/bacteria have propagated from being circulated through the circulating water tank  130 , the humidifying member  110 , or the like. 
       FIG. 8  is a flowchart illustrating an operation of a humidifier that performs sterilization in humidity mode. Referring to  FIG. 8 , a sterilization treatment step is added in addition to the steps of  FIG. 3 . 
     Referring to  FIG. 8 , the controller  150  may supply water accommodated in the storage water tank to the circulating water tank (S 810 ). 
     The controller  150  may control the sterilization treatment unit  170  to sterilize the water accommodated in the circulating water tank  130  (S 820 ). Specifically, when the water level in the circulating water tank  130  is more than the predetermined high water level, the controller  150  may stop supplying water to the circulating water tank  130 , while controlling the sterilization treatment unit  170  to sterilize the water accommodated in the circulating water tank  130 . 
     In addition, the controller  150  may control the circulating pump  135  to supply the water in the sterilized circulating water tank  130  to the humidifying member  110  (S 830 ), and control the fan  115  to discharge the water of the humidifying member  110  to the outside by vaporizing the water (S 840 ). Meanwhile, the controller  150  may control the drainage member  136  to discharge the water accommodated in the circulating water tank  130  to the residual water tank  140  based on the water level in the circulating water tank  130  (S 850 ). 
     The sterilization treatment unit  170  may be configured as a kit for performing a sterilization treatment by electrolyzing the water accommodated in the circulating water tank  130  based on an input voltage. In this case, the controller  150  may measure a current according to the voltage input to the kit through an electrode of the kit while the voltage is input to the kit. 
     In addition, when the measured current exceeds a first current while a first voltage is input to the kit, the controller  150  may provide a notification related to replacement of water or replenishment of water included in the circulating water tank  130 . In addition, when the measured current is less than or equal to a second current while a second voltage greater than the first voltage is input to the kit, the controller  150  may provide a notification that the sterilization treatment cannot be performed through the kit. 
       FIG. 9  is an algorithm for explaining an example of a sterilization treatment operation (S 820 ) of a humidifier using a kit that performs sterilization treatment based on electrolysis. 
       FIG. 9  is an algorithm illustrating an example of a sterilization treatment operation of the humidifier using a kit that performs sterilization treatment based on electrolysis (S 820 ). 
     Referring to  FIG. 9 , when the sterilization treatment starts (S 910 ), the controller  150  may input a first voltage to the kit (S 920 ). In this case, the first voltage may be DC 5.4˜6.6 V. 
     If the measured current is greater than the first current (S 930 —Y), the controller  150  may identify that the water accommodated in the circulating water tank  130  is contaminated, and may provide a notification that “water replacement” or “water replenishment” is required (S 940 ). In this case, the controller  150  may terminate the sterilization treatment (electrolysis) through the kit (S 950 ), and may discharge the water accommodated in the circulating water tank  130  to the residual water tank  140 . The first current may be a value corresponding to water having a hardness of 1200 ppm and an electrical conductivity of 1800 μm, for example, 650 mA. 
     Meanwhile, when the measured current is not greater than the first current (S 930 —N), the controller  150  may input a second voltage greater than the first voltage into the kit (S 960 ). In this case, the second voltage may be DC 10 to 14 V. 
     When the measured current is less than or equal to the second current (S 970 —Y), the controller  150  may provide a notification that the sterilization treatment is impossible (S 980 ). The second current may be a value corresponding to water having a hardness of 10 ppm and an electrical conductivity of 15 μm or less, for example, 50 mA. In this case, the controller  150  may stop the sterilization treatment (S 950 ), and may provide a notification related to a “possibility of device failure” or a “necessity of water replacement”. 
     In general, when a lead wire or a terminal configuring a kit or connected to the kit is disconnected, or when water from a reverse osmotic membrane water purifier is supplied in addition to tap water, the measured current may be less than or equal to the second current. In this case, free residual chlorine is not generated by electrolysis, so that a sterilizing effect may not occur. 
     Meanwhile, when the measured current exceeds the second current (S 970 —N), the controller  150  may continue to apply a voltage to the kit to perform the sterilization treatment normally (S 990 ). In addition, the controller  150  may terminate the sterilization treatment after a predetermined sterilization treatment time has passed (S 950 ). 
     Meanwhile, when a user command for the sterilization mode is received, the controller  150  may switch the operating mode of the humidifier  100  to the sterilization mode and perform the sterilization treatment operation. Specifically, when the water level in the storage water tank  120  is more than or equal to the predetermined low water level and the humidifying member case is mounted, the controller  150  may switch the operating mode of the humidifier  100  to the sterilization mode. 
     In this case, the sterilization mode may be a separate mode from the humidity mode, and may be a mode for performing a sterilization treatment in the humidifier  100 . Hereinafter, an example of an operation of the humidifier that performs the sterilization treatment according to the sterilization mode will be described with reference to  FIG. 10 . 
     Referring to  FIG. 10 , the controller  150  may provide the water accommodated in the storage water tank  120  to the circulating water tank  130  (S 1010 ), and control a sterilization treatment unit  170  to sterilize the water accommodated in the circulating water tank  130  (S 1020 ). 
     The controller  150  may supply the sterilized water accommodated in the circulating water tank  130  to the humidifying member  110  (S 1030 ), and discharge the water accommodated in the circulating water tank  130  depending on the water level in the circulating water tank  130  to the residual water tank  140  (S 1040 ). 
     In addition, the controller  130  may control the fan  115  to evaporate water of the humidifying member  110  (S 1050 ). For example, the controller  150  may control the fan  115  to operate for about 30 minutes, and as a result, the humidifying member  110  may be maintained in a dry state. 
     Meanwhile, a capacity of water corresponding to the predetermined low water level in the storage water tank  120  of the humidifier  100  according to an embodiment of the disclosure may be greater than or equal to a capacity of water corresponding to the predetermined high water level in the circulating water tank  130 . As a specific example, the capacity of the water corresponding to the predetermined low water level in the storage water tank  120  may be 1 to 1.2 times the capacity of water corresponding to the predetermined high water level in the circulating water tank  130 . 
     In this case, the controller  150  may perform the operation of  FIG. 11  below. 
     Referring to  FIG. 11 , after the humidity mode is started (S 1110 ), when it is identified that the water level in the circulating water tank  130  is less than the water level in the predetermined low water level (an independent value different from the predetermined low water level in the storage water tank  12 ) (S 1130 —Y), while the water level in the storage water tank  120  is more than or equal to the predetermined low water level (S 1120 —Y), the controller  150  may control the supply pump  125  to supply the water accommodated in the storage water tank  120  such that the water level in the circulating water tank  130  reaches the predetermined high water level, to the circulating water tank  130  (S 1140 ). 
     Meanwhile, when it is identified the water level in the circulating water tank  130  is less than the predetermined low water level (S 1150 —Y), while the water level in the storage water tank  120  is less than the predetermined low water level (S 1120 —N), the controller  150  may provide a notification related to water shortage/water replenishment (S 1160 ). In this case, the controller  150  may stop the humidity mode. 
     In other words, through the embodiment of  FIG. 11 , when water is started to be supplied to the circulating water tank  130  while the water level in the storage water tank  120  is more than or equal to the predetermined low water level, even if the water level in the storage water tank  120  is less than the predetermined water level during supplying the water, the water supply to the circulating water tank  130  may be continued until the water level in the circulating water tank  130  reaches a predetermined high water level (an independent value different from the predetermined high water level in the storage water tank  12 ). 
     As a result, the “water replenishment” may be performed after the water stored in the storage water tank  120  is used to the maximum. 
     With respect to the embodiment of  FIG. 11 , when the humidity mode is stopped while the water level in the storage water tank  120  is less than the predetermined low water level, the controller  150  may control the drainage member  136  to discharge the water accommodated in the circulating water tank  130  to the residual water tank  140 . 
     The operation of the controller  150  may be implemented slightly differently in the case when the storage water tank  120  and the residual water tank  140  are formed separately from each other, and in the case when the both tanks are formed integrally with each other. 
     Specifically, when the storage water tank  120  is formed separately from the residual water tank  140 , the controller  150  may provide a notification that water needs to be replenished when the water level in the circulating water tank  130  is less than the predetermined low water level according to the discharge of water described above, In addition, the controller  150  may provide a notification that the water in the residual water tank needs to be discarded and/or a notification that water needs to be replenished, when the water level in the residual water tank  140  is more than or equal to the predetermined high water level according to the discharge of water described above. 
     Meanwhile, when the storage water tank  120  is formed integrally with the residual water tank  140 , and water overflowing from the residual water tank  140  is formed to be accommodated in the storage water tank  120 , the controller  150  may provide the notification that the water needs to be replenished when the water level in the circulating water tank  130  is less than the predetermined low water level according to the water discharge described above. In addition, the controller  150  may provide the notification that the water needs to be discarded and/or the notification that water needs to be replenished, when the water level in the circulating water tank  130  is less than the predetermined low water level and the water level in the residual water tank  140  is more than or equal to the predetermined high water level. 
     When the storage water tank  120  and the residual water tank  140  are integrally formed, even if the water in the residual water tank  140  overflows, since the overflowed water may be accommodated in an empty space of the storage water tank  120 , the water is not urgent to be immediately discharged. In other words, water discarding and water replacement may be simultaneously performed by the user. 
     Meanwhile, as described through the various embodiments described above, the humidity mode may be stopped for various reasons such as when the water level in the storage water tank  120  is less than the predetermined water level, when a water filter needs to be replaced, when sterilization treatment (ex. electrolysis) is impossible, when the low water level in the circulating water tank is detected, or the like. 
     After the humidity mode is stopped for various reasons as described above, the controller  150  may control the drainage member  136  to discharge the water accommodated in the circulating water tank  130  to the residual water tank  140 . The controller  150  may discharge the water accommodated in the circulating water tank  130  immediately after the humidity mode is stopped, or discharge the water accommodated in the circulating water tank  130  after a certain time (ex. 10 minutes) passes after the humidity mode is stopped 
     As a result, while the humidifying operation is not performed, it may prevent residual water in the circulating water tank  130  from being left in the circulating water tank  130 . 
       FIGS. 12A and 12B  are algorithms illustrating an operation of a humidifier after humidity mode is stopped with respect to a storage water tank and a residual water tank are of a separate type and an integrated type. 
       FIG. 12A  assumes that the storage water tank  120  is formed separately from the residual water tank  140 . 
     Referring to  FIG. 12A , when the humidity mode is stopped ( 1210 ), the controller  150  may discharge the water accommodated in the circulating water tank  130  to the residual water tank  140  (S 1230 ) while the water accommodated in the residual water tank  140  is less than or equal to the predetermined high water level (S 1220 —N). 
     In this case, the controller  150  may discharge the water until the water level in the circulating water tank  140  reaches a predetermined ultra-low water level. In other words, the controller  150  may control the drainage member  136  to discharge the water accommodated in the circulating water tank  130  to the residual water tank  140  until the water level in the residual water tank  140  reaches the predetermined high water level or the water level in the circulation tank reaches the predetermined low water level. 
     However, when the water level in the residual water tank  140  becomes more than or equal to the predetermined high water level due to water discharge (S 1220 —Y), the controller  150  may provide a notification about the discarding of water in the residual water tank  140  (S 1240 ). In this case, the discharge of the water accommodated in the circulating water tank  130  to the residual water tank  140  may be stopped. 
       FIG. 12B  assumes that the storage water tank  120  is formed integrally with the residual water tank  140 , and water overflowing from the residual water tank  140  is formed to be accommodated in the storage water tank  120 . 
     Referring to  FIG. 12B , when the humidity mode is stopped (S 1260 ), the controller  150  may discharge the water accommodated in the circulating water tank  130  to the residual water tank  140  regardless of the water level in the residual water tank  140  (S 1270 ). 
     In other words, the controller  150  may control the drainage member  136  to discharge the water accommodated in the circulating water tank  130  to the residual water tank  140  until the water level in the circulation tank reaches a predetermined low water level, regardless of the water level in the residual water tank  140 . 
     Meanwhile, after the humidity mode is stopped, if it is identified that the water level in the storage water tank  120  is less than the predetermined low water level, the controller  150  may provide a notification that water replenishment is required. 
     Alternatively, after the humidity mode is stopped, when the water level in the storage water tank  120  is less than the predetermined low water level and the water level in the circulating water tank  130  is less than the predetermined low water level, the controller  150  may provide the notification that water replenishment is required. 
     Meanwhile, the various embodiments shown and described through the drawings illustrated above may be independently/selectively applied to the humidifier  100 . In other words, the humidifier  100  to which at least two of the embodiments described above are applied is also included in the technical idea of the disclosure. 
       FIG. 13  is a view illustrating a detailed configuration of a humidifier according to various embodiments of the disclosure. Referring to  FIG. 13 , the humidifier  100  may further include at least one of a filter  160  and a sterilization treatment unit  170  in addition to the components of  FIG. 1 . 
       FIG. 14  is a block diagram functionally illustrating a configuration of a humidifier according to various embodiments of the disclosure. 
     Referring to  FIG. 14 , the humidifier  100  may further include a filter  160 , a sterilization processing unit  170 , an outputter  180 , a communicator  190  or the like, in addition to the components of  FIG. 2 . 
     The outputter  180  is a component for providing a notification to the user. The controller  150  may provide various “notifications” provided through the various embodiments described above through the outputter  180 . 
     In addition, the controller  150  may control the outputter  180  to provide information on the operating mode of the humidifier  100 . For example, when the humidity mode is started, a notification that the humidity mode is currently being performed may be provided through the outputter  180 . 
     For this operation, the outputter  80  may include a display, a speaker, or the like. 
     The communicator  190  is a configuration for performing communication with at least one external apparatus. The communicator  190  may be implemented in various forms such as a Bluetooth module, a Wi-Fi module, an LTE module, a 4G/5G module, an infrared communication module, or the like. 
     As an example, the controller  150  may transmit information on a notification related to “discarding water” or “replacement of water” to a user terminal device (e.g., a smartphone). In this case, the user terminal device may provide the corresponding notification to the user. 
     For example, the controller  150  may transmit information on a current operating mode of the humidifier  100  to the user terminal device. 
     In addition, information on a user command input to the user terminal device may be transmitted to the humidifier  100  through the communicator  190 . In this case, the controller  150  may start/terminate the humidity mode/sterilization mode, etc. according to a user command. 
     Meanwhile, although not shown through  FIG. 14 , the humidifier  100  may additionally include a user inputter for receiving a user command. The user inputter may be implemented as a microphone, a touch screen, a motion sensor, a button, or the like, but is not limited thereto. 
     As an example, when a user command is received to the humidifier  100  through the user inputter, the controller  150  may start/terminate the humidity mode/sterilization mode, etc. according to the user command. 
     Various exemplary embodiments described above may be embodied in a recording medium that may be read by a computer or a similar apparatus to the computer by using software, hardware, or a combination thereof. 
     According to the hardware embodiment, exemplary embodiments that are described in the present disclosure may be embodied by using at least one selected from Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electrical units for performing other functions. 
     In some cases, the embodiments described herein may be implemented by the processor itself. In a software configuration, various embodiments described in the specification such as a procedure and a function may be embodied as separate software modules. The software modules may respectively perform one or more functions and operations described in the present specification. 
     Meanwhile, computer instructions for performing a processing operation in the humidifier  100  according to various embodiments of the disclosure described above may be stored in a non-transitory computer-readable medium. The computer instructions stored in the non-transitory computer-readable medium may allow specific devices described above to perform the processing operation of the humidifier  100  according to various embodiments of the disclosure when executed by the processor of the specific device. 
     The non-transitory computer readable recording medium refers to a medium that stores data and that can be read by devices. In detail, the above-described various applications or programs may be stored in the non-transitory computer readable medium, for example, a compact disc (CD), a digital versatile disc (DVD), a hard disc, a Blu-ray disc, a universal serial bus (USB), a memory card, a read only memory (ROM), and the like, and may be provided. 
     The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.