Air cleaner

An air cleaner that is capable of efficiently and effectively purifying and humidifying air. An air flow passage from air filters (4, 5) to a blower (8) is branched to first and second air flow passages (31, 32), and then these air flow passages join. A humidifying filter (14) is disposed in the first air flow passage (31), and a movable plate (35) for opening and closing the humidifying filter is disposed in the second air flow passage (32). The air cleaner comprises a control part (40) for controlling the opening and closing operation of the movable plate (35) and the rotating operation of the blower (8). A recess containing the air filters (4, 5) is formed in the front of the body (2) of the air cleaner. An air flow passage extending from under the recess to the back of the recess and bent upward is horizontally partitioned into upper and lower parts by a partition wall (27) to form the first air flow passage (31) and the second flow passage (32) in this order from the bottom. The movable plate (35) is a flat plate rotated around a pivotal axis (36) formed along one lateral side.

TECHNICAL FIELD

The present invention relates to an air cleaner for cleaning air in a room, and more particularly to an air cleaner that has a humidifying function as well.

BACKGROUND ART

Various matters such as dust, pollen, tobacco smoke, breathed-out air and the like that are disagreeable or harmful to the human body are contained in air in a room (room air). Especially, in recent years, because houses are often closed completely, such harmful matters easily collect in a room. Accordingly, conventionally, windows of a room are sometimes opened for spontaneous ventilation. However, as a matter of fact, it is hard to carry out spontaneous ventilation as desired in an area where air pollution is serious, at home or in an office if there is a family member or a colleague who is suffering from hay fever. In such situation, an air cleaner that has an air cleaning function to clean room air is generally becoming widespread.

Generally, an air cleaner is equipped with an air filter on the front of its main body, and an air flow passage in which a blower is disposed is formed inside the main body. The air flow passage extends from an opening of the main-body front to an outlet of an upper portion of the main body. Such an air cleaner sucks room air, that is, outside air into the air flow passage through the air filter as the blower rotates, and sends out the sucked air into the room, that is, the outside through the outlet. Here, harmful matters contained in the air are caught, adsorbed, or decomposed by the air filter to be removed so that the air is cleaned.

Further, for the purpose of adjusting room air to obtain a more comfortable condition, some air cleaners have a humidifying function besides the air cleaning function. In an air cleaner having the humidifying function, a humidifying filter that contains water is so disposed as to close a portion of the sectional region of the air flow passage, and part of the air that is cleaned by the air filter absorbs water when it goes through the humidifying filter, thereby the air is humidified (e.g., see patent document 1).[Patent document 1]: JP-A-2006-46729

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

In the conventional air cleaner having an air humidifying function described above, both the capability of cleaning air and the capability of humidifying air directly depend on an air flow amount, that is, a rotation speed of the blower. In other words, if the air flow amount, that is, the rotation speed of the blower is raised, both capabilities increase at the same time, and to the contrary, if the air flow amount, that is, the rotation speed of the blower is lowered, both capabilities fall at the same time. Accordingly, for example, if humidity is low and it is desired to powerfully operate the humidifying function, the rotation speed of the blower is increased to raise the humidifying power. However, because only part of the air flowing though the air flow passage passes through the humidifying filter, the humidifying efficiency is not very good. If the rotation speed of the blower is excessively increased, noise is generated.

To remove such disadvantages, if the humidifying filter is so disposed as to close substantially the entire portion of the sectional region of the air flow passage, almost all the air flowing through the air flow passage passes through the humidifying filter, thereby the humidifying efficiency rises. In a case where it is desired to operate only the air cleaning function because the humidity is sufficiently high to an agreeable extent but the air is dirty, the rotation speed of the blower is raised to increase the air cleaning power. However, here, because the humidifying power also increases invariably following the raised air cleaning power, the humidity rises unnecessarily to an uncomfortable level. If the rotation speed of the blower is lowered, the humidity is kept at an agreeable level. However, the air cleaning function does not work so sufficiently as needed.

The present invention has been made to cope with the conventional problems, and it is an object of the present invention to provide an air cleaner that is capable of cleaning and humidifying air efficiently and effectively.

Means for Solving the Problem

To achieve the object, an air cleaner according to the present invention sucks outside air through an air filter following rotation of a blower disposed in an air flow passage, cleans the sucked air, and sends out the cleaned air to the outside, wherein an air flow passage that extends from the air filter to the blower branches off into a first air flow passage and a second air flow passage which join with each other again; a humidifying filter that contains water and is disposed in the first air flow passage; a movable plate that is disposed in the second air flow passage to open and close the second air flow passage; and a control portion that controls open and close operation of the movable plate and rotation operation of the blower.

According to this structure, in a state where the movable plate closes the second air flow passage, air cleaned by the air filter flows into the first air flow passage, passes through the humidifying filter, absorbs water from the humidifying filter when passing through the humidifying filter so that the air is humidified, then the air is sent out to the outside. Thus, here, not only the air cleaning but also the humidifying is efficiently carried out. To the contrary, in a state where the movable plate opens the second air flow passage, most of the air cleaned by the air filter flows out through the second air flow passage, and part of the air is humidified by the humidifying filter and flows out through the first air flow passage, the air flowing through the second air flow passage and the air flowing through the first air flow passage join with each other and is sent out to the outside. Thus, here, the humidifying is carried out at low efficiency, and the air cleaning is chiefly performed.

The air cleaner described above may be so structured as to comprise: a recess portion that is formed at a front of a main body and houses the air filter; and an air flow passage that extends inward (toward the inner part of the main body) from an lower portion of the recess portion, turns upward, and leads to the blower, and the air flow passage is partitioned into upper and lower portions to form a first air flow passage and a second air flow passage in order from the bottom, wherein the movable plate is a curved plate that is curved into an arc shape about a pivotal shaft extending along a right-to-left direction and rotates about the pivotal shaft, the movable plate rotates to the most forward position to close the second air flow passage, and rotates to the most backward position not only to open the second air flow passage and but also to close the join opening of the first air flow passage.

According to this structure, in a state where the movable plate closes the second air flow passage, air cleaned by the air filter flows into the first air flow passage, passes through the humidifying filter, absorbs water from the humidifying filter when passing through the humidifying filter so that the air is humidified, then the air is sent out to the outside. Thus, here, not only the air cleaning but also the humidifying is efficiently carried out. To the contrary, in a state where the movable plate opens the second air flow passage and closes the join opening of the first air flow passage, the air cleaned by the air filter flows not into the first air flow passage but into the second air flow passage, and is sent out to the outside. Thus, here, the humidifying is hardly carried out, and the air cleaning is chiefly performed.

Advantages of the Invention

In the air cleaner according to the present invention, the movable plate is opportunely opened and closed, thereby it is possible to adjust the humidifying efficiency. As a result of this, it is possible to efficiently carry out both the air cleaning and the humidifying.

LIST OF REFERENCE SYMBOLS

FIRST EMBODIMENT

Hereinafter, a first embodiment of an air cleaner according to the present invention is described in detail with reference to drawings. The air cleaner described here is an air cleaner with a humidifying function, and also, an example of an air cleaner that has further an ion emission function besides the humidifying function is explained.FIG. 1is a front perspective view showing an appearance of an air cleaner according to the present invention.FIGS. 2 and 3are side views showing an internal structure of the air cleaner, in whichFIG. 2shows a state where a movable plate closes a second air flow passage, andFIG. 3shows a state where the movable plate opens the second air flow passage.

An air cleaner1in the present embodiment is placed on a suitable position of a floor or hung on a wall of a room before it is used, and its housing is generally composed of a main body2and a front panel3. The main body2has a shape obtained by vertically setting a substantially flat box as a whole, and has in its front an air filter housing portion that is deeply recessed into a rectangular shape. In this air filter housing portion, a deodorization filter4and a dust filter5as air filters are housed in order from the front-side opening with one laid on the other.

The deodorization filter4includes a rectangular frame, a polyester nonwoven fabric mounted on the frame, active carbon evenly disposed on the fabric, and further a polyester nonwoven fabric covered over the active carbon. The deodorization filter4serves as an adsorptive that adsorbs odor contents in the air such as acetaldehyde, ammonia, acetic acid and the like. On the other hand, the dust filter5is what is called a HEPA (High Efficiency Particulate Air) filter, and has a filter medium that is folded and includes an aggregate formed of a polyester/vinylon nonwoven fabric that is joined with a melt-blow nonwoven fabric to which electromagnetic treatment is applied, antibacterial sheets which are formed of a fabric treated with hydroxyapatite, covered over the upper and lower surfaces of the folded filter medium, and bonded to the folded filter medium by thermo-compression bonding, and frames that are formed of a hot-melt nonwoven fabric and are welded to the antibacterial sheets. The dust filter5serves as a filter that catches fine dust.

The deodorization filter4and the dust filter5housed in the air filter housing portion are held by a filter hold frame6that is mounted on an opening of the air filter housing portion so that the air filters are prevented from coming off the air filter housing portion. The filter hold frame6has a substantially rectangular shape and a plurality of air flow openings that are arranged into a matrix shape.

At the front of the main body2in which the deodorization filter4and the dust filter5are housed and the filter hold frame6is mounted, the front panel3is mounted with a given gap away from the front of the main body2and completely covers all of the deodorization filter4, the dust filter5and the filter hold frame6. The front panel3is supported by the main body2by engaging a hook (not shown), which is bent from an upper portion of the front panel3toward the main body2, with an upper portion of the main body2, and both of its right and left lower portions are fixed by an engagement portion7. The gaps between the back surface of the front panel3and the front surface of the main body2are opened to the outside through the right, left and lower portions, and outside air is introduced through the gaps.

In the main body2, a blower8is disposed in a portion behind the air filter housing portion with a partition wall21arranged between the air filter housing portion and the blower8. The blower8is composed of a fan motor9and a fan10, the front side of the blower8is covered by the partition wall21, the lower side is covered by a partition wall22, and the rear side is covered by a partition wall23. The fan motor9is fixed to the front-side partition wall21, and a plurality of air flow openings that are opened to the blower8are formed through the rear-side partition wall23. Although a turbo-fan is used as the fan10, the kind of the fan is not limited to this. It is also possible to use a propeller fan or a cross-flow fan. The turbo-fan is devised to have a large thickness compared with the fan diameter so that noise level is reduced. As the fan motor9, it is preferable to use a DC motor for easy control.

Besides, the main body2is provided with a first outlet11that is formed through an upper portion of the main body2facing the upper portion of the blower8and is opened upward, a second outlet12that is opened front upward, and an operation and indication portion13that includes operation buttons for turning on and off a power supply and for carrying out operation settings, an indication lamp for indicating operation conditions and the like.

As the blower8is driven, that is, the fan10is rotated by the fan motor9, outside air, that is, room air is introduced into the main body2from the gaps between the main body2and the front panel3. The introduced air reaches the air filters4and5through the air flow openings of the filter hold frame6, and cleaned by the deodorization filter4and the dust filter5into air that has no odor and dust. The cleaned air reaches the rear wall25of the main body2through an opening24that is formed under the partition wall21arranged behind the air filter housing portion, turns upward through a passage formed between the partition wall23and the rear wall25, and is sucked into the center of the fan10through the air flow openings of the partition wall23. The air sucked into the center of the fan10passes through gaps between the fan blades, is sent out from the circumference of the fan10, guided upward and sent out through the first outlet11and the second outlet12into the outside, that is, the room. Thus, the air flow goes through the air flow passages.

In the present embodiment, the air flow passage that extends from the opening24formed under the partition wall21arranged behind the air filter housing portion toward the inner part of the main body2along the partition wall22is partitioned by a partition wall27into upper and lower portions to form a first air flow passage31and a second air flow passage32in order from the bottom. In other words, the air flow passage that extends from the air filter to the blower8branches off into the first air flow passages31,32and join with each other at an inward position.

A humidifying filter14is so disposed in the first air flow passage31as to close almost whole portion of the sectional region of the first air flow passage31. Specifically, a removable tray15is housed from one side portion into a lower portion of the main body2, and water is poured into the tray15to a predetermined water level. The humidifying filter14is formed of a water absorbent that is folded zigzag, inserted into the tray15with the lower portion immersed in the water, sucks up water from the tray15and contains it. A water supply tank16holding water is connected to the tray15, and water is opportunely supplied to the tray15. The water supply tank16is removably housed in a portion of the side of the main body2where the tray15is housed.

On the other hand, a movable plate35is disposed in the second air flow passage32to open and close the second air flow passage32. In the present embodiment, the movable plate35is a simple flat plate that is supported at one end of the plate by a pivotal shaft36which is so disposed along a right to left direction as to be in contact with the partition wall22so that the movable plate35rotates about the pivotal shaft36. Rotation driving of the movable plate35is performed by a digital-control motor such as a stepping motor and the like. Accordingly, the rotation position of the movable plate35is always detected.

As shown inFIG. 2, when the movable plate35is rotated to the most forward position, that is, a vertical-direction position by the digital-control motor, the movable plate35completely close the second air flow passage32. In this state, if the blower8is driven, the air cleaned by the air filters flows into the first air flow passage31because the second air flow passage32is closed by the movable plate35, and reaches the humidifying filter14. When the air passes through the humidifying filter14, the air absorbs water from the humidifying filter14to be humidified. Then, the air goes upward through the passage between the partition wall23and the rear wall25, and is finally sent out into the outside through the first outlet11and the second outlet12. Thus, in this case, not only the air cleaning but also the humidifying is efficiently carried out.

To the contrary, as shown inFIG. 3, when the movable plate35is rotated to the most backward position, that is, a horizontal-direction position by the digital-control motor, the movable plate35completely opens the second air flow passage32. In this state, if the blower8is driven, part of the air cleaned by the air filters flows into the second air flow passage32because the second air flow passage32is opened. Of course, part of the air flows into the first air flow passage31because the first air flow passage31is always opened. However, because the humidifying filter14that impedes the air flow is present in the first air flow passage31, the flow amount into the first air flow passage31is much less than that into the second air flow passage32. Accordingly, in this case, most of the air cleaned by the air filters flows out through the second air flow passage32, while only a little part of the air is humidified by the humidifying filter14and flows out through the first air flow passage31. The air flowing through the first air flow passage1and the air flowing through the second air flow passage32join later with each other, flows upward through the passage between the partition wall23and the rear wall25, and is finally sent out to the outside from the first outlet11and the second outlet12. Thus, in this case, the humidifying is carried out at low efficiency, while the air cleaning is chiefly carried out.

As described above, in the air cleaner1according to the present embodiment, because the movable plate35is opportunely driven to open and close the second air flow passage32, the humidifying efficiency can be adjusted, and as a result of this, it is possible to efficiently and effectively carry out both the air cleaning and the humidifying.

Besides, even if the total air flow amount is the same, the ratio of the air flowing into the first air flow passage31to the air flowing into the second air flow passage32changes depending on an open degree of the second air flow passage32, and it is possible to adjust the humidifying efficiency according to the ratio. Accordingly, as rotation positions of the movable plate35driven by the digital-control motor, besides the vertical- and horizontal-direction positions, several other positions between the vertical-direction position and the horizontal-direction position may be used.

In the present embodiment, an ion generator17that generates positive and negative ions at the same time or either one of them separately is disposed between the second outlet12and the blower8. If the ion generator17is driven, ions from the ion generator17are emitted into the air flowing from the fan10to chiefly the second air flow passage12, thereby the cleaned air, and besides, the humidified air contains ions and is sent out into the room from chiefly the second air flow passage12.

In the present embodiment, the movable plate35is a flat plate that rotates about the pivotal shaft36extending along a right to left direction. However, the movable plate35is not limited to such a flat plate, and a flat plate that rotates about a pivotal shaft extending along a vertical direction may be used. Besides, the open and close mechanism of the movable plate35for the second air flow passage12is not limited to the rotational mechanism, and a slide mechanism may be used. The positions where the first and second air flow passages31,32are formed are not limited to the portion under the partition wall21behind the air filter housing portion, specifically, a portion over, or a portion alongside the partition wall21may be used, and the first and second air flow passages31,32may be formed away from each other.

FIG. 4shows a block diagram of a main structure for operation of the air cleaner1. The whole operation of the air cleaner1is controlled by a control portion40. Various sensors such as a temperature sensor41, a humidity sensor42, a dust sensor43, and an odor sensor44are connected to the control portion40. The temperature sensor41detects the temperature of room air. The humidity sensor42detects the humidity of room air. Generally, the temperature sensor41and the humidity sensor42are united with each other. The dust sensor43includes a light emitting device and a light receiving device, and detects particles floating in room air such as dust and the like. The odor sensor44is a semiconductor gas sensor that uses a phenomenon that if gas is adsorbed on the surface of a sensor composed of a metal oxide semiconductor, the resistance value changes. The odor sensor44detects odor in room air. In other words, the dust sensor43and the odor sensor44function as dirt sensors that detect the dirt level of room air. Detected values from the temperature sensor41, the humidity sensor42, the dust sensor43, and the odor sensor44are outputted to the control portion40.

Besides, various detection switches such as a tray water level detection switch45, an air filter removal detection switch46, and a tray and water supply tank removal detection switch47are connected to the control portion40. The tray water level detection switch45detects that the water held in the tray15reduces through a usual water level to reach a water-shortage level. If the water in the tray15reaches a water-shortage level, it means a situation that the water supply tank16is empty and water supply is needed. The air filter removal detection switch46detects that the front panel3is removed, further the filter hold frame6, the deodorization filter4, and the dust filer5are removed. The tray and water supply tank removal detection switch47detects that the tray15and the water supply tank16are removed.

Further, various operation buttons48and various indication lamps49that compose the operation and indication portion13are connected the control portion40. As the operation buttons48, there are included a power-supply button for turning on and off the power supply, an air cleaning mode setting button for setting operation modes for the air cleaning function, a humidifying mode setting button for setting operation modes for the humidifying function, an ion emission button for starting and stopping emission of ions and the like. At every time when the air cleaning mode setting button is pressed, the operation mode for air cleaning is changed from automatic air flow amount, small air flow amount, and to large air flow amount. At every time when the humidifying mode setting button is pressed, the operation mode for humidifying is changed from automatic humidifying, weak humidifying, powerful humidifying, and to humidifying stop. Inputs on the operation buttons48according to operation by the user are outputted to the control portion40.

As the indication lamps49, there are included a power-supply indication lamp that goes on and out to indicate on and off of the power supply according to operation of the power-supply button, an air cleaning operation-mode indication lamp that goes on to indicate an operation mode for air cleaning according to operation of the air cleaning mode setting button, a humidifying operation-mode indication lamp that goes on to indicate an operation mode for humidifying according to operation of the humidifying mode setting button, an ion emission indication lamp that goes on and out to indicate on and off of ion emission according to operation of the ion emission button, a humidity indication lamp that indicates the current humidity level, a water supply indication lamp that goes on to demand water supply to the water supply tank16and the like. The indication lamps49go on and out following an instruction from the control portion40. Indication of the humidity indication lamp is based on a detected value from the humidity sensor42. Indication of the water supply indication lamp is carried out in response to a detected output from the tray water level detection switch45.

In addition, there are connected to the control portion40a movable-plate motor drive circuit50that controls rotation driving (open and close operations of the movable plate35) of the digital-control motor which rotates the movable plate35, a fan motor drive circuit51that controls rotation driving (rotation operation of the blower8) of the fan motor9of the blower8, and an ion generator drive circuit52that controls driving of the ion generator17. Based on input operations on the operation buttons48, detected values from the various sensors, and detected outputs from the various detection switches, instructions are transmitted from the control portion40to the movable-plate motor drive circuit50, the fan motor drive circuit51, and the ion generator drive circuit52, thereby the movable plate35, the blower8, and the ion generator17are driven.

SECOND EMBODIMENT

Hereinafter, a second embodiment of an air cleaner according to the present invention is described in detail with reference to drawings. In the present embodiment, the appearance of the air cleaner is the same as that shown in the first embodiment. The internal structure is different from the first embodiment in portions around the movable plate shown inFIGS. 2 and 3of the first embodiment, and the main structure for operation of the air cleaner is the same as the structure shown inFIG. 4described in the first embodiment. Hereinafter, description is carried out focusing on the internal structure portion different from that in the first embodiment. The same members as those in the first embodiment are indicated with the same reference numbers, and detailed description is skipped.

FIGS. 5 and 6are side sectional views showing an internal structure of the air cleaner, in whichFIG. 5shows a state where a movable plate closes the second air flow passage, andFIG. 6shows a state where the movable plate opens the second air flow passage.

A movable plate38that opens and closes the second air flow passage32is disposed in the second air flow passage32. In the present embodiment, the movable plate38is a curved plate that is supported by a pivotal shaft39and curved into an are shape about the pivotal shaft39which is disposed along a right to left direction at a position a little upward from the second air flow passage32so that the movable plate38rotates about the pivotal shaft39. Rotation driving of the movable plate38is performed by a digital-control motor such as a stepping motor and the like. Accordingly, the rotation position of the movable plate38is always detected.

Limit rotation positions of the movable plate38are set. As shown inFIG. 5, a protrusion37that protrudes outward from a back edge of the movable plate38hits an end surface of the inner part of the partition wall27, thereby the rotation of the movable plate38is limited to the most forward position, and in this position, the movable plate38closes the second air flow passage32. In this state, if the blower8is driven, the air cleaned by the air filters flows into the first air flow passage31because the second air flow passage32is closed by the movable plate38, and reaches the humidifying filter14. When the air passes through the humidifying filter14, the air absorbs water from the humidifying filter14to be humidified. Then, the air goes upward through the passage between the partition wall23and the rear wall25, and is finally sent out into the outside through the first outlet11and the second outlet12. Thus, in this case, not only the air cleaning but also the humidifying is efficiently carried out.

To the contrary, as shown inFIG. 6, the protrusion37of the movable plate38hits a protrusion piece26that protrudes from the rear wall25, thereby the rotation of the movable plate38is limited to the most backward position, and in this position, the movable plate38opens the second air flow passage32and closes the join opening of the first air flow passage31. In this state, if the blower8is driven, the air cleaned by the air filters does not flow into the first air flow passage31because the join opening of the first air flow passage31is closed by the movable plate38, instead flows into the second air flow passage32because the second air flow passage32is opened. The air is guided by the movable plate38, then flows upward through the passage between the partition wall23and the rear wall25, and is finally sent out to the outside from the first outlet11and the second outlet12. Thus, in this case, the humidifying is hardly carried out, while the air cleaning is chiefly carried out.

As described above, in the air cleaner1according to the present embodiment, because the movable plate35is opportunely driven to open and close the second air flow passage32, the humidifying efficiency can be adjusted, and as a result of this, it is possible to efficiently and effectively carry out both the air cleaning and the humidifying.

Next, an example of driving each of the movable plates35,38, the blower8, and the ion generator17by the control portion40is described below.

In the first and second embodiments, the control portion40adjusts the operation of the blower8, that is, the rotation speed of the fan motor9based on a detected value from at least one of the dust sensor43and the odor sensor44. Specifically, in the humidifying stop mode, when the air cleaning is in operation under the automatic air flow amount mode, the rotation speed of the fan motor9is changed step by step according to detected values from the dust sensor43and the odor sensor44. For example, if it is determined from a detected value that the air is dirty, the fan motor9is rotated at a high speed to produce a large amount of air flow, thereby the air cleaning function is powerfully carried out. If it is determined from a detected value that the air is cleaned, from the view point of curbing noise and power consumption, the rotation speed of the fan motor9is changed to a low speed to produce a small amount of air flow, thereby the air cleaning function is kept at a low level. If it is determined again that the air is dirty, the rotation speed of the fan motor9is changed to a high speed. This operation is repeated. Thus, it is possible to clean room air. Here, during the operation, the movable plates35,38are situated at the position to open the second air flow passage32.

In the first and second embodiments, the control portion40drives the movable plates35to open and close the second air flow passage32based on detected values from the humidity sensor42. Specifically, in a case where the humidifying is in operation under the automatic humidifying mode with a target humidity set, for example, to 60%, if a detected value from the humidity sensor42indicates a humidity of 60% or higher, the movable plate35is rotated to open the second air flow passage32, thereby the humidity efficiency is lowered. On the other hand, if the humidity is lower than 60%, the movable plates35are rotated to close the second air flow passage32, thereby the humidifying efficiency is raised. Thus, it is possible to adjust the humidity of room air to the set target humidity.

Also, the operation of the blower8, that is, the rotation speed of the fan motor9may be adjusted at the same time. Specifically, if a detected value from the humidity sensor42indicates the set target humidity or higher, the movable plates35,38are rotated to open the second air flow passage32, and at the same time, the rotation speed of the fan motor39is lowered, thereby the humidity efficiency is decreased. On the other hand, if the humidity is lower than the target humidity, the movable plates35,38are rotated to close the second air flow passage32, and at the same time, the rotation speed of the fan motor9is increased, thereby the humidifying efficiency is raised. Thus, it is possible to adjust the humidity of room air closer to the target humidity.

In theses cases, if a detected value from the humidity sensor42indicates that the humidity is changed from a humidity lower than the target humidity to the target humidity or higher, the movable plates35,38are rotated to change the closed state of the second air flow passage32to the opened state, and at the same time, the rotation speed of the fan motor9is changed from a high speed to a low speed. As for the changeover order, it is better to change first the rotation speed of the fan motor9, then to change the rotation positions of the movable plates35,38. If the rotation positions of the movable plates35,38are changed first to open the second air flow passage32, because a large amount of air flows into the second air flow passage32that is opening, a whistling noise is generated.

In the automatic humidifying mode, besides the operation method described above, another method also is possible, in which the movable plates35,38are held at the position to close the second air flow passage32so that the air always flows into the first air flow passage31, and at the same time, the rotation speed of the fan motor9, that is, the air flow amount is controlled, thereby the humidifying efficiency is adjusted.

During the operation in the automatic humidifying mode, in a situation where the humidity does not reach a set target humidity even if a given time elapses, the rotation speed of the fan motor9may be raised by one step. In such a situation, it is high in possibility that the air cleaner1is being operated in a room that has an area larger than that specified in the specification, and it can be thought that the humidifying power is insufficient at the rotation speed set for an area specified in the specification.

In the first embodiment, if the control portion40receives an input operation from the operation button48for an open/close changeover of the movable plate35with respect to the second air flow passage32, the control portion40changes the open/close state of the movable plate35, and at the same time, changes the operation of the blower8, that is, the rotation speed of the fan motor9so that the air flow amount becomes substantially the same before and after the open/close changeover of the movable plate35. Specifically, for example, if it is changed from the state where the air cleaning is being carried out in the humidifying stop mode to the humidifying operation state, the movable plate35rotates to change the state of the second air flow passage32from the opened state to the closed state, thereby the air flow passage is changed from the second air flow passage32to the first air flow passage31. Here, there is no resistance to the air flow in the second air flow passage32that serves as the air flow passage before the changeover, while the humidifying filter14, that is, resistance to the air flow is present in the first air flow passage31that serves as the air flow passage after the changeover. Accordingly, even if the rotation speed of the fan motor9is the same before and after the changeover, the air flow amount becomes different in effect before and after the changeover. To prevent this, when carrying out the changeover, the rotation speed of the fan motor9is so set that the rotation speed at the time when the humidifying operation is carried out with the second air flow passage32closed becomes higher than the speed at the time when the air cleaning operation is carried out with the second air flow passage32opened. Thus, the air flow amount becomes substantially the same before and after the changeover, and as a result of this, the air cleaning power is unchanged. For this purpose, correlation data between the rotation speed of the fan motor9and the air flow amount are obtained in pretests of the air cleaning operation carried out with the second air flow passage32opened and of the humidifying operation with the second air flow passage32closed, and a rotation speed to be set is selected from the data.

However, if the operation is changed from the air cleaning operation to the humidifying operation in the powerful humidifying mode, it means that the user intends to carry out the powerful humidification. Accordingly, in such a case, the fan motor9is rotated at a so high speed as to obtain a large amount of air flow irrespective of the air flow amount before and after the changeover.

In the first embodiment, if the control portion40receives an input operation from the operation button48for an open/close changeover of the movable plate35with respect to the second air flow passage32, the control portion40changes the open/close state of the movable plate35, and at the same time, changes the operation of the blower8, that is, the rotation speed of the fan motor9so that the noise level becomes substantially the same before and after the open/close changeover of the movable plate35. Specifically, for example, if it is changed from the state where the air cleaning is being carried out in the humidifying stop mode to the humidifying operation state, the movable plate35rotates to change the state of the second air flow passage32from the opened state to the closed state, thereby the air flow passage is changed from the second air flow passage32to the first air flow passage31. Here, there is no resistance to the air flow in the second air flow passage32that serves as the air flow passage before the changeover, while the humidifying filter14, that is, resistance to the air flow is present in the first air flow passage31that serves as the air flow passage after the changeover. Accordingly, even if the rotation speed of the fan motor9is the same before and after the changeover, the noise level becomes different in effect before and after the changeover. To prevent this, when carrying out the changeover, the rotation speed of the fan motor9is so set that the rotation speed at the time when the humidifying operation is carried out with the second air flow passage32closed becomes slightly higher than or if necessary equal to the speed at the time when the air cleaning operation is carried out with the second air flow passage32opened. Thus, the noise level becomes substantially the same before and after the changeover, and as a result of this, the use does not feel uncomfortable. For this purpose, correlation data between the rotation speed of the fan motor9and the noise level are obtained in pretests of the air cleaning operation carried out with the second air flow passage32opened and of the humidifying operation with the second air flow passage32closed, and a rotation speed to be set is selected from the data.

However, if the operation is changed from the air cleaning operation to the humidifying operation in the powerful humidifying mode, it means that the user intends to carry out the powerful humidification. Accordingly, in such a case, the fan motor9is rotated at a so high speed as to obtain a large amount of air flow irrespective of the noise level before and after the changeover.

In the first and second embodiments, during the time when an operation mode (e.g., an operation mode to drive the ion generator17), which when a given operation time elapses, is stopped or automatically moves to another operation mode, is carried out, if the control portion40receives a detected output from the tray water level detection switch45, the control portion40does not indicate water supply until the given operation time elapses. When the given operation time elapses, the water supply indication lamp, that is, one of the indication lamps49is turned on to demand water supply to the water supply tank16. Specifically, if the ion emission button, that is, one of the operation buttons48is tuned on, the ion generator17is driven for, for example, a given time of about 15 minutes to emit ions. During the time duration, even if there is a detected output from the tray water level detection switch45, the water supply indication lamp is not turned on immediately. Instead, the driving of the ion generator17is continued until the end of the given time, that is, 15 minutes, and after elapse of the given time, the water supply indication lamp is turned on. This answers the intention of the user who desires the ion emission, and even if there is a detected output from the tray water level detection switch45, at that time, generally, because there is sill some water left in both tray15and water tank16, only a little water, though, there is no problem for the driving of the ion generator17within a limited time.

In the first and second embodiments, if the control portion40receives an input operation for operation stop from the operation button48, the control portion40makes the movable plate35rotate to the most forward position (rotate the movable plate38to the most forward position, that is, the vertical-direction position) and makes the movable plate35keep the most forward position. Specifically, if the power-supply button of the operation buttons48is turned off, the movable plates35,38are rotated to and held at the position to completely close the second air flow passage32irrespective of the air cleaning operation and the humidifying operation. Thus, even if the front panel3is removed and further the air filters are removed, because the second air flow passage32that extends into the inside is closed by the movable plates35,38, inadvertent insertion of fingers and the like can be prevented, which is safe.

From the view point of safety like in the above case, if the control portion40receives a detected output from the air filter removal detection switch46, the control portion40may rotate the movable plate35to the most forward position (rotate the movable plate38to the most forward position, that is, the vertical-direction position) and make the movable plate35keep the position. This is because the second air flow passage32extending into the inside is closed by the movable plates35,38even if the front panel3is removed and further the air filters are removed during the operation. Besides, if the control portion40receives a detected output from the tray and water supply tank removal detection switch47, the control portion40may rotate the movable plate35to the most forward position (rotate the movable plate38to the most forward position, that is, the vertical-direction position) and makes the movable plate35keep the most forward position.

In the first and second embodiments, if the control portion40receives a detected output from the tray water level detection switch45during the humidifying operation, the control portion40turns on the water supply indication lamp of the indication lamps49to demand water supply to the water supply tank16, and continues the humidifying operation. In other words, the humidifying operation is not stopped immediately. Thus, because the air flow into the first air flow passage31continues, if water is not supplied to the water tank16, the humidifying filter14loses water gradually to become dry, accordingly, it is possible to prevent limescale from depositing onto the humidifying filter14, which is sanitary.

In the first and second embodiments, the control portion40adjusts the operation of the blower8, that is, the rotation speed of the fan motor9based on a detected output from the temperature sensor41. Specifically, if a detected output from the temperature sensor41indicates a temperature equal to or lower than a given temperature, the rotation speed set for each of the automatic humidifying mode, the weak humidifying mode, and the powerful humidifying mode is changed step by step. This is because the humidifying performance falls, and changing the rotation speed becomes necessary if the air temperature is low.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

INDUSTRIAL APPLICABILITY

The present invention is useful to an air cleaner with a humidifying function.