JP2755200B2 - Composite filter and air purifier using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite filter for collecting and deodorizing dust through air, and more particularly to a composite filter having a combination of different types of filters.

[0002]

2. Description of the Related Art As a filter for purifying air, a filter in which a deodorizing filter using an adsorptive filter medium such as activated carbon and a dust collecting filter using a nonwoven fabric or the like are recently assembled and provided. I have.

[0003] In this filter, fine dust in the air is collected and removed by a dust collecting filter, and the odor in the air is removed by adsorption by an adsorptive filter medium. For this reason, clean air without odor is obtained, and is used for air purifiers and the like used in ordinary households. In addition, since the filters can be handled integrally while using different types of filters, it is convenient to use.

[0004]

As described above, a composite filter is expensive because it uses a combination of different types of filters as described above, but is often used only once because it cannot be restored to the initial state by washing or cleaning.

[0005] By the way, different types of filters used for the composite filter have different lifespans.

For example, a deodorizing filter using an adsorptive filter medium is expensive but has a long life, and a dust collecting filter is inexpensive but has a short life.

[0007] If the composite filter is disposable in accordance with the life of the dust collecting filter, an expensive deodorizing filter whose life has not been reached is wasted and wasteful, resulting in high running costs.

[0008] Further, if the composite filter is disposable in accordance with the life of the deodorizing filter having a long life, the dust collection filter will continue to be used many times as long as the life of the filter. A problem arises in that the resistance increases and the load on the fan increases.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide a composite filter in which different kinds of filters used for the composite filter can be used while being disposable according to their life without impairing the integral handling of the composite filter. The purpose is to provide.

[0010]

In order to achieve the above object, a composite filter according to the present invention is provided with a filter body containing an adsorptive filter medium and an intake side and an exhaust side of the filter body. Combination with a bag-shaped filter having a bag shape or a tubular shape provided with a filter body having a dust collection filter sheet on the front and back and an inlet / outlet of the filter body provided, and a filter sheet applied to the intake side of the filter body is provided more than the filter body. Its main feature is that it has a short life.

The dust collecting filter sheet is made of a non-woven fabric, and the dust collecting filter on the exhaust side can be made thinner than the dust collecting filter sheet on the intake side.

It is preferable that the surface of the dust-collecting filter sheet on the intake side is provided with a color pattern or character corresponding to the degree of contamination that requires replacement of the dust-collecting filter sheet.

[0013] More preferably, the color of the pattern or character is color-coded with a plurality of colors corresponding to different types of stains.

[0014] It is also preferable that the filter body is further combined with a resin sheet that is sandwiched in a folded state, slipped into the bag-shaped filter, and then removed.

It is also preferable that one filter body is provided with a combination of bag-shaped filters corresponding to a multiple of the life of the filter body relative to the bag-shaped filter.

An air purifying apparatus according to the present invention is an air purifying apparatus to which any one of the above-mentioned composite filters is attached so as to be detachable, and determines at least the life of the filter having the shorter life based on the driving time of the fan. And a warning means for warning at least replacement of the filter having the shorter life based on the life determination of the determination means.

[0017]

According to the above-mentioned structure of the main feature of the composite filter of the present invention, the bag-shaped filter can be freely inserted and removed from the filter body by the access opening of the filter body provided therein, and the filter body is housed in the bag-shaped filter. Then, these can be handled and used as a single unit in the same way as conventional ones, and when used, attached to the equipment to be used so that the dust collection filter sheet on the intake side and the dust collection filter sheet on the exhaust side correspond to each other It should be done. In particular, in the filter body and the bag-shaped filter, which are different types of filters, the dust-collecting filter sheet of the bag-shaped filter on the suction side of the filter body has a shorter life than the filter body,
Although it is necessary to replace the filter more frequently than the filter body, it is located on the intake side and is easy to see, so it is possible to determine the life due to dirt, which is convenient and depends on the number of bag-like filters that have a short life. Since the life of the filter body can be determined, it is convenient, and each can be properly used without wasting its life.

In a configuration in which the dust-collecting filter sheet is a non-woven fabric and the exhaust-side dust collecting filter is thinner than the intake-side dust collecting filter sheet, a low-cost non-woven fabric material is used, and the exhaust-side dust collecting filter is used. By further reducing costs by making the sheet thinner than that on the intake side, the thick dust collection filter sheet on the intake side efficiently collects fine dust in the air for deodorization processing at the next filter body. While keeping the dust in the air unaffected,
Fine dust is collected by the thin dust collecting filter sheet on the exhaust side, clean air can be obtained, and the life of the filter body can be prevented from being shortened by the collection of fine dust.

In a configuration in which a color pattern or text corresponding to the degree of contamination that requires replacement of the dust collection filter sheet is provided on the surface of the dust collection filter sheet on the suction side, the pattern or text on the dust collection filter sheet on the suction side is provided. It is convenient to determine whether or not the life of the bag-shaped filter has been reached by checking whether or not the surface of the uncoated portion has become dirty until the color of the pattern or character is substantially equal to the color of the pattern or character. Even if the surface of the dust collecting filter sheet is covered with a front panel such as an air purifying device, the dust collecting filter sheet is opened by opening the front panel.

In a configuration in which the color of a pattern or a character is color-coded with a plurality of colors corresponding to different types of stains, the life of the bag-shaped filter can be determined according to the different types of stains.

In a configuration in which the filter main body is sandwiched in the folded state, the resin sheet is slid into the bag-shaped filter, and then the resin sheet is further removed, the filter main body is sandwiched when the filter body is inserted into the bag-shaped filter. Since the resin sheet is in contact with the inner surface of the bag-shaped filter so that the filter body does not come into direct contact, even if the bag-shaped filter and the filter body are easily caught, they can be slid without being caught by both contacts. After the sliding, the resin sheet in the folded state can be easily pulled out by pulling one end of the resin sheet.

In a configuration in which one filter body is combined with a number of bag filters equal to a multiple of the life of the filter body with respect to the bag filter, the bag filter having a shorter life than the filter body has a shorter life than the filter body. The filter body will reach the end of its life if the bag filters are used for the number of combinations even though it is frequently replaced and used, so it is easy to know the life of the filter body and prevent its overuse. it can.

In the above configuration of the air purifying apparatus of the present invention, when any one of the above composite filters is detachably mounted and used, the life of at least the shorter side filter is determined by the judging means based on the driving time of the fan. The warning means warns at least the replacement of the filter having the shorter life based on the determination of the life of the determination means, so that the user can mistakenly or miss the replacement time of the filter having the shorter life. This can be avoided, and the life of the long-life filter can be accurately determined based on the number of used short-life filters and replaced.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a composite filter of the present invention and an air purifier to which the filter is detachably mounted will be described with reference to the drawings.

As shown in FIGS. 1 to 4, the composite filter A of this embodiment comprises a filter body 2 containing an adsorptive filter medium 1 made of granular or fibrous activated carbon and the like.
Dust filter sheet 3 attached to the intake side and exhaust side of the
And a bag-like filter 6 having a bag-like shape or a tubular shape having a front and back surface 4 and an opening 5 for the filter body 2.

The filter body 2 is a rectangular flat body, as shown in FIG.
As shown in FIGS. 3 and 4, the frame 11 has a lattice-shaped frame 11 having a large number of windows 11 a, and the adsorptive filter medium 1 is accommodated in the window 11 a of the frame 11. Are closed by a synthetic resin net 12 applied to the front and back. However, it goes without saying that various structures and forms can be adopted in which air can pass through the enclosed adsorptive filter medium 1 such as a case where the adsorptive filter medium 1 is accommodated in a bag made of a net material and sealed. The shape of the filter main body 2 can also be set variously depending on the application.

The frame 11 does not break due to natural handling of foamed resin or the like, and is lightweight and convenient to use. The shape of the window 11a may be any shape. However, it is preferable that the window 11a be provided in a larger and denser shape because the passage area through which the air passes through the adsorptive filter medium 1 of the filter body 2 increases.

The dust-collecting filter sheets 3 and 4 may be made of any material as long as they can collect fine dust in the passing air. In this embodiment, a non-woven fabric made of synthetic resin fibers is used. The dust collecting filter sheet 3 is made thicker, and the dust collecting filter sheet 4 on the exhaust side is made thinner to increase the dust collecting efficiency on the intake side. On the exhaust side, it passes through the dust collecting filter sheet on the intake side and the adsorptive filter medium 1. The remaining and mixed fine dust can be finally collected and removed.

The dust collecting filter sheets 3 and 4 on the intake side and the exhaust side having different thicknesses are formed by seam welding while leaving one side serving as the inlet / outlet 5, making use of the fact that these are made of synthetic resin fibers. Thus, the filter main body 2 is formed into a bag having a size that allows the filter main body 2 to be taken in and out of the port 5 with a little margin. Reference numeral 13 denotes a seam welded portion.

Since the bag-like filter 6 can be freely inserted into and removed from the filter body 2 through the opening 5 of the filter body 2 provided in the bag-like filter 6, as shown in FIGS. , The filter body 2 and the bag-shaped filter 6 can be handled and used as an integral body in the same manner as the conventional one. In this embodiment, a lid piece 5a is integrally formed from one side of the inlet / outlet port 5 of the bag-shaped filter 6 so as to extend from the side of the dust-collecting filter sheet 4 so as to be easily handled as an integral body. After the filter main body 2 is inserted into the filter 6, the cover piece 5a is folded into the access port 5 and closed. If it is difficult to stabilize the lid piece 5a in the folded state,
It is preferable to provide a fastener such as a magic zipper or a hook at the tip end of the opening and the other edge of the opening 5.

When the composite filter A is used, the dust collecting filter sheet 3 on the intake side and the dust collecting filter sheet 4 on the exhaust side
May be attached to a device to be used such as the air purifier B of the present embodiment shown in FIG.

Further, there is a difference in the service life between the filter body 2 and the bag-shaped filter 6, which are different types of filters of the present embodiment. Specifically, the life of the filter body 2 is about two years, whereas the life of the bag-shaped filter 6 is about half a year. Thus, even if there is a difference in the service life between the filter body 2 and the bag-shaped filter 6, the filter body 2 is taken out of the bag-shaped filter 6, separated from each other, and only the end of the life is replaced with a new one. By combining them, they can be properly used without excessive use and wasteful disposal by using each of them for their entire life.

Further, in the case of this embodiment, a low cost non-woven fabric material is used for the dust collecting filter sheets 3 and 4, and the dust collecting filter sheet 4 on the exhaust side is made thinner than that on the intake side. At the intake side, fine dust in the air is efficiently collected by the thick dust-collecting filter sheet 3 so that the fine dust in the air does not affect the deodorizing treatment in the next filter body 2 while the exhaust air is exhausted. Fine dust is finally collected by the thin dust collecting filter sheet 4 on the side, clean air without odor is obtained, and the life of the filter body 2 can be prevented from being shortened by the collection of fine dust.

In this embodiment, a color pattern 14 corresponding to the degree of contamination that requires replacement of the dust filter sheets 3 and 4 is provided on the surface of the dust filter sheet 3 on the intake side as shown in FIG. Have been. However, it is not limited to the pattern 14 and may be a character. These may be printed or attached separately. In addition, any method that can be used, such as partially depositing and forming colored fibers, can be adopted.

In this manner, the life of the bag-shaped filter 6 depends on whether the surface of the dust-collecting filter sheet 3 on the intake side on which the pattern 14 is not applied is stained until the color of the pattern 14 becomes substantially equal. It is convenient because it can be determined whether or not the pressure has reached the maximum value. Even if the surface of the dust collecting filter sheet 3 on the intake side is covered with the front panel 22 of the equipment used, such as the air cleaner B, this front panel Since it is opened by opening the opening 22, there is an advantage that it is easy to confirm.

Moreover, the pattern 14 is color-coded with a plurality of colors corresponding to different types of stains. For example, assuming a living room of a general household, the left portion 14a of the pattern 14 is colored brown corresponding to dirt due to cigarette smoke, and the right portion is colored gray corresponding to normal dirt. However, when the type of dirt differs depending on the environment in which the air purifier B is used, coloring may be devised in accordance with the dirt. Various stain marks corresponding to various stains can be created, and selected and pasted as necessary.

According to such color coding, the life of the bag-shaped filter 6 can be determined according to different types of dirt, and even if the life of the filter 6 reaches the end of its life, excessive use can be prevented. it can.

Further, in this embodiment, as shown by the solid line in FIG. 1, the filter body 2 is sandwiched in a folded state, which is slid into the bag-like filter 6 and then removed.
1 is further provided in combination. Therefore, when the filter main body 2 is inserted into the bag-shaped filter 6, the resin sheet 31 sandwiching the filter main body 2 comes into contact with the inner surface of the bag-shaped filter 6 as shown by a virtual line in FIG. Is prevented from directly contacting, even if the bag-shaped filter 6 and the filter main body 2 are easily caught by corners or synthetic resin fibers, they can be slid without being caught by the contact between them, and Is one end 31a of the resin sheet 31 in a folded state.
1 can be easily removed by pulling it with fingers as shown by the arrow in FIG. 1, and there is no inconvenience due to the use of the resin sheet 31.

One filter body 2 has a bag-shaped filter 6
The number of which is a multiple of the life of the filter body 2 with respect to
In the present embodiment, by providing four bag-shaped filters 6 in combination, the bag-shaped filter 6 having a shorter life than the filter body 2 is used more frequently than the filter body 2, but the number of combined filters is smaller. When the bag-shaped filter 6 is completely used, the life of the filter main body 2 also reaches the end of its life. Therefore, the life of the filter main body 2 can be easily known and the excessive use of the filter main body 2 can be prevented.

As shown in FIG. 5, the air purifier B of this embodiment has an intake opening 23 which is largely open at the front surface of the cabinet 21 except for the upper part. A front panel 22 pivotally supported by a shaft 24 is provided. A large number of intake holes 22a are formed in the front panel 22 so as to cover the intake opening 23 and obscure the mounting portion of the composite filter A in this portion without obstructing the intake through the intake opening 23. It is used on a wall.

A rear wall of the cabinet 21 is formed of a thick plate 25, and a motor 27 having a fan 26 directly connected thereto is mounted thereon.
a and a casing 28 forming the exhaust chamber 21b are mounted on the back surface of the rim of the intake opening 23 by welding or the like. The composite filter A is fitted in a frame-like frame portion 28a formed along the intake opening 23 of the casing 28 so as to be detachable in the above-described direction, and the air purifier B is installed by the rotation of the fan 26. The air sucked from the space 32 into the suction chamber 21a through the suction opening 23 passes through the composite filter A. The clean air without odor entering the intake chamber 21a is exhausted to the exhaust chamber 21b, and a number of exhaust holes 21c provided on the upper surface of the cabinet 21.
To the space 32. Thereby, the air in the space 32 can be sequentially cleaned and deodorized. In a wall-mounted state, the exhaust hole 21c is directed downward.

It is to be noted that one or both of the filter body 2 and the bag-like filter 6 can be loaded with sterility and other necessary filter functions.

The air purifier B of this embodiment has an operation panel 33 on the upper part of the front surface of the cabinet 21 and a control unit 34 in the cabinet 21. The control unit 34 shown in FIG.
A microcomputer 35 as shown in FIG.

The microcomputer 35 detects a start signal generated by operating a start key 36 for starting the driving of the fan 26 by the motor 27, and detects the dirt on the bag-shaped filter 6 which is the filter having the shorter life of the composite filter A. Output of the dirt sensor 37, reset key 3
8, a stop signal by operating the stop key 39, and other signals are input, and a fan drive signal for driving the fan 26 from the microcomputer 35, and a power-on display signal based on the operation of the start key 36 , A filter replacement display signal, and other outputs are output to perform various controls of the operation of the air purifier B and various displays corresponding thereto.

The microcomputer 35 has an internal function as a judging means for judging at least the life of the bag-shaped filter 6 having a shorter life based on the driving time of the fan 26, and the life of the judging function. It has at least an internal function as a warning unit that warns by display or the like of replacement of the bag-shaped filter 6 having the shorter life. However, these can also be configured by a hardware circuit, and the specific configuration can be freely designed. Further, the warning means may be configured to give a warning by a buzzer or a sound, or may be made to match the display.

According to such determination and warning, when the composite filter A is detachably mounted and used, the filter, at least on the short side, in this embodiment, based on the driving time of the fan 26, is used by the determination means. The life of the filter 6 is determined, and the warning unit warns the user of the replacement of the bag-shaped filter 6, which is at least the filter with the shorter life, based on the determination of the life of the determination means. It is possible to avoid erroneous or missed replacement time of the bag-shaped filter 6 which is a filter body which is a filter having a long life depending on the number of used bags-filter 6 which is a filter having a short life. 2 can also be determined.

In this embodiment, the count value X of the driving time is determined by the dirt data Y of the bag-shaped filter 6 detected by the dirt sensor 37 so that the life can be accurately determined.
Is corrected so that more accurate judgment can be made.

It is also possible to judge the life of the filter main body 2 and warn of replacement when the life is reached.

The life can be determined only by detecting the dirt by the dirt sensor 37. This dirt can be detected by optically detecting the dirt on the surface of the bag-like filter 6, etc. It can be pasted or printed. According to this, it is easy to detect the degree of contamination even with the filter body 2 or the like.

The specific control of the judgment and the warning display by the microcomputer 35 will be described with reference to FIGS.

When there is a start signal for starting the drive of the fan by operating the start key, the fan drive and warning processing program shown in FIG. 7 is executed. First, the fan is driven and the drive time is counted, and the count value X
Is determined to be greater than or equal to a predetermined maximum value.If the signal is not greater than or equal to the predetermined maximum value, the presence or absence of a stop signal is determined. Stop and return.

In the determination as to whether or not the bag-shaped filter is longer than the predetermined maximum value, it is determined that the bag-shaped filter has reached the end of its life. Warn you to be. If the reset operation is performed after the bag-shaped filter is replaced, or when there is a reset signal generated by detecting that the front panel of the air purifier is opened, the counter and the filter replacement display are reset and the next operation is performed. In preparation for the use of a bag-shaped filter. When a stop signal is generated by operating the stop key, the driving of the fan is stopped.

As shown in FIG. 8, in the count subroutine, while accumulating the time by the counter, this is stored every moment or while updating the count value X at regular time intervals, and the driving of the fan is performed. Holds even if stopped.

Next, reading of the count value X, taking in of the dirt data Y from the dirt sensor, and updating and storing are performed at regular time intervals T, and the dirt is obtained from the difference between the previous dirt data Yn-1 and the present dirt data Yn. The degree of rank y is calculated, and the count value X is multiplied by one of the coefficients 0.7, 1, and 1.3 to correct the count value X, depending on whether the dirt degree rank y is 1 to 3. After that, the corrected count value X is updated and stored, and this is used for the life determination in FIG. Thus, the life of the bag-shaped filter can be more accurately determined.

[0055]

According to the main feature of the composite filter of the present invention, the bag-like filter can be freely put in and taken out of the bag-like filter by the access port of the filter body provided in the bag-like filter. These can be handled and used as a single unit in the same way as conventional ones, and when used, they are mounted on the equipment to be used so that the dust collection filter sheet on the intake side and the dust collection filter sheet on the exhaust side correspond to each other. Just do it. In particular, in the filter body and the bag-shaped filter, which are different types of filters, the dust-collecting filter sheet of the bag-shaped filter on the suction side of the filter body has a shorter life than the filter body,
Although it is necessary to replace the filter more frequently than the filter body, it is located on the intake side and is easy to see, so it is possible to determine the life due to dirt, which is convenient and depends on the number of bag-like filters that have a short life. Since the life of the filter body can be determined, it is convenient, and each can be properly used without wasting its life.

According to the structure in which the dust-collecting filter sheet is made of a nonwoven fabric and the dust-collecting filter sheet on the exhaust side is thinner than the dust-collecting filter sheet on the intake side, a low-cost nonwoven fabric material is used. By further reducing costs by making the dust collection filter sheet thinner than that on the intake side, the thick dust collection filter sheet on the intake side efficiently collects fine dust in the air, and the next filter body The fine dust is collected by the thin dust collecting filter sheet on the exhaust side while keeping the fine dust in the air from affecting the deodorization of the air, and the clean air is obtained, and the life of the filter body is shortened by collecting the fine dust. Can be prevented.

According to the structure in which the surface of the dust collecting filter sheet on the intake side is provided with a color pattern or character corresponding to the degree of contamination that requires replacement of the dust collecting filter sheet, the dust collecting filter sheet on the intake side is provided. This is convenient because it is possible to determine whether or not the life of the bag-shaped filter has expired by checking whether the surface of the portion where no pattern or character has been applied is stained until the color of the pattern or character is substantially equal to the surface. However, even if the surface of the dust collecting filter sheet on the intake side is covered with a front panel of an air cleaning device or the like, there is an advantage that the front panel is opened when the front panel is opened, so that it is easy to confirm.

According to the configuration in which the color of the pattern or the character is color-coded by a plurality of colors corresponding to different types of stains, the life of the bag-shaped filter can be determined according to the different types of stains. Can be.

According to the configuration in which the filter main body is sandwiched in the folded state, the resin body is slid into the bag-shaped filter, and the resin sheet is further removed, the filter main body is inserted into the bag-shaped filter. Since the resin sheet sandwiching the filter body comes into contact with the inner surface of the bag-shaped filter and prevents the filter body from coming into direct contact, even if the bag-shaped filter and the filter body are easily caught by each other, they are caught by both contacts. It can be slid in without any trouble, and after it is slid, it can be easily taken out by pulling one end of the folded resin sheet.

According to a configuration in which one filter body is provided with a number of bag filters corresponding to a multiple of the life of the filter body with respect to the bag filter, a bag filter having a shorter life than the filter body is provided. Even though the filter body is replaced and used more frequently than the filter body, the filter body will reach the end of its life if the combined number of bag filters has been used. Can be prevented.

When any of the above composite filters is detachably mounted and used, the judging means judges the life of at least the shorter filter based on the driving time of the fan, and the warning means judges the life of the judging means. Warning of replacement of at least the filter with the shorter life based on the determination of the above, it is possible to prevent the user from erroneously or missing the replacement time of the filter with the shorter life, According to the number of filters used, the life of the filter having the longer life can be accurately determined and replaced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a composite filter according to the present invention in a separated state.

FIG. 2 is a plan view of FIG.

FIG. 3 is a sectional view showing a combination state of the composite filter of FIG. 1;

FIG. 4 is an exploded perspective view of the composite filter of FIG.

FIG. 5 is a sectional view of an air cleaner using the composite filter of FIG. 1;

FIG. 6 is a block diagram of a microcomputer that controls the operation of the air purifier of FIG. 5;

FIG. 7 is a flowchart of operation control performed by the microcomputer of FIG. 6 to drive a fan and issue a warning regarding the life of a filter.

FIG. 8 is a flowchart showing a count processing subroutine of FIG. 7;

[Explanation of symbols]

 Reference Signs List A composite filter B air cleaner 1 adsorptive filter medium 2 filter body 3, 4 dust collecting filter sheet 5 access port 6 bag-shaped filter 14 pattern 31 resin sheet 35 microcomputer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B01D 46/00-46/54

Claims (7)

(57) [Claims] 1. A filter body containing an adsorptive filter medium,
The filter body has a dust-collecting filter sheet attached to the intake side and the exhaust side of the filter body on the front and back, and is combined with a bag-shaped or cylindrical bag-shaped filter provided with an access port for the filter body. Apply to the intake side
A composite filter, wherein the filter sheet has a shorter life than the filter body . 2. The filter according to claim 1, wherein the dust collecting filter sheet is made of a non-woven fabric, and the dust collecting filter on the exhaust side is thinner than the dust collecting filter sheet on the intake side. 3. The composite filter according to claim 1, wherein a color pattern or a character corresponding to the degree of contamination that requires replacement of the dust collection filter sheet is provided on the surface of the dust collection filter sheet on the intake side. 4. The composite filter according to claim 3, wherein the color of the pattern or the character is color-coded by a plurality of colors corresponding to different types of stains. 5. The composite filter according to claim 1, further comprising a resin sheet that sandwiches the filter body in a folded state, slides the filter body into a bag-shaped filter, and then removes the resin sheet. 6. The composite filter according to claim 1, wherein one filter body is combined with a number of bag-shaped filters corresponding to a multiple of the life of the filter body with respect to the bag-shaped filter. 7. An air purifying apparatus to which the composite filter according to claim 1 is detachably mounted, wherein at least the life of the filter having the shorter life is determined based on the driving time of the fan. An air purifying apparatus comprising: a judging means for judging; and a warning means for warning at least replacement of a filter having a shorter life based on the judgment of the life of the judging means.