JPH05237322A - Air cleaner - Google Patents

Abstract

PURPOSE:To prevent malfunction based on fine particles stuck to the detection means of the degree of pollution by changing over a flow path by the selection means thereof so that the air clarified by a clarification means is introduced into the detection means of the degree of pollution. CONSTITUTION:When the clean air passed through a filter 4 is introduced into a duet sensor 6 provided as the detection means of the degree of pollution by changing over a solenoid valve 8 provided in a housing 1 as the selection means of a flow path in a proper time, fine particles stuck on the inner surface of a dust sensor 6 are removed by the clean air. In other words, when a time for changing over the solenoid valve 8 is suitably set, fluctuation of sensitivity of the dust sensor 6 is diminished in a long period and malfunction is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifier that purifies air taken into a housing and then discharges the air.

[0002]

2. Description of the Related Art Generally, as an air purifier of this type,
A housing that has an opening for an intake port and an exhaust port, and a fan that forms an air flow from the intake port to the exhaust port in the housing, and a purification that purifies air in a flow path between the intake port and the exhaust port And means are provided. Also,
A pollution degree detecting means for detecting the pollution degree of the indoor air is provided in the housing so that the automatic operation can be performed when the pollution degree of the indoor air becomes high. The output of the pollution degree detection means is used during operation to control the air blowing capacity of the fan according to the degree of air pollution. An air filter is generally used as the purifying means, but a purifying means using another purifying means is also provided. As the contamination degree detecting means, a means for detecting the contamination degree based on a change in optical physical quantity (amount of transmitted light or amount of scattered light) is used. For example, while irradiating light from a light projecting element to a specific area where air is introduced, airborne particles (dust and cigarette smoke) in the air
The light receiving element detects the amount of transmitted light or the amount of scattered light according to the concentration of the light receiving element, and determines the contamination degree based on the change in the output level of the light receiving element.

[0003]

By the way, the amount of fine particles adhering to the contamination degree detecting means increases with time. Therefore, when the pollution degree detecting means for detecting the amount of transmitted light is used, the sensitivity of the pollution degree detecting means increases with the lapse of time, and the operation is performed even when the air is not polluted. The problem arises. Also, when using a pollution degree detection means of the type that detects the amount of scattered light,
With the passage of time, the sensitivity of the pollution degree detecting means decreases, which causes a problem of not operating even if the air is contaminated.

The present invention is intended to solve the above problems, and an object of the present invention is to provide an air purifier which prevents malfunction due to fine particles adhering to pollution degree detecting means.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a housing in which an intake port and an exhaust port are opened, a fan for forming an air flow from the intake port to the exhaust port, and a flow path between the intake port and the exhaust port. A purification means for purifying the air in the interior, and a pollution degree detection means arranged in the flow path between the air supply port and the purification means for detecting the degree of contamination of the air based on the change of the optical physical quantity due to the contamination. The air purifier provided has a common configuration.

According to the first aspect of the invention, in order to achieve the above object, the flow path is so arranged that the air after the purification process by the purifying means is returned to the air supply side of the pollution degree detecting means and introduced into the pollution degree detecting means. A flow path selecting means for selectively opening one of the recirculation path and the air supply port separately formed is provided. According to the second aspect of the invention, the cleaner means is provided which can remove the dirt adhering to the contamination degree detecting means.

According to the third aspect of the present invention, the return passage is formed separately from the above flow passage so that the air after the purification treatment by the purifying means is returned to the air supply side of the pollution degree detecting means and introduced into the pollution degree detecting means. And an output of the pollution degree detecting means in a state where the clean air passing through the return path is introduced into the pollution degree detecting means. And a notification unit for notifying a change in sensitivity of the contamination degree detection unit based on the value.

According to the fourth aspect of the present invention, the contamination degree detection is performed in a state where an optical element that causes a change in the optical physical quantity that is sufficiently larger than a change in the optical physical quantity due to air pollution is arranged in the detection area of the contamination degree detection means. An informing unit is provided for informing the change in the sensitivity of the contamination degree detecting unit based on the output value of the unit.

[0009]

According to the structure of the first aspect, the air cleaned by the purifying means can be introduced into the pollution degree detecting means, so that the dirt adhering to the pollution degree detecting means can be cleaned with almost no suspended fine particles. It can be removed by air. That is, if clean air is introduced into the pollution degree detecting means at appropriate time intervals by switching the flow path by the flow path selecting means, it is possible to suppress the sensitivity change of the pollution degree detecting means, and for a long period of time. It is possible to prevent malfunction.

According to the second aspect of the present invention, the cleaner means is provided to remove the dirt on the pollution degree detecting means, so that the sensitivity change of the pollution degree detecting means can be suppressed over a long period of time. According to the configuration of claim 3, the change in the sensitivity of the pollution degree detecting means is notified based on the output value of the pollution degree detecting means while the clean air after passing through the purifying means is being introduced into the pollution degree detecting means. Therefore, it is possible to notify that the contamination degree detecting means is dirty and prompt cleaning.

According to the fourth aspect of the present invention, the change in sensitivity of the contamination degree detecting means is notified based on the output value of the contamination degree detecting means when the optical element is arranged in the contamination degree detecting means.
Cleaning can be promoted by notifying that the contamination degree detecting means is dirty. Moreover, by disposing the optical element in the contamination degree detecting means, it is possible to determine the sensitivity change of the contamination degree detecting means. The flow path can be simplified as compared with the case where the return path is provided.

[0012]

【Example】

(Embodiment 1) In this embodiment, an example in which a filter is used as the purifying means is shown. As shown in FIG. 1, an intake port 2 and an exhaust port 3 are opened in the housing 1. Intake port 2 and exhaust port 3
A filter 4 which is a purifying means and a fan 5 are arranged in the flow path between and, and the air flow taken from the intake port 2 and formed by the fan 5 from the intake port 2 toward the exhaust port 3 is After being cleaned through the filter 4, the exhaust port 3
Will be discharged from. Between the intake port 2 and the filter 4, a dust sensor 6 as a pollution degree detecting means for detecting the pollution degree of the air taken into the filter 4 is arranged. The dust sensor 6 includes a light emitting element 6a formed of a light emitting diode and a light receiving element 6b formed of a photodiode, which are arranged to face each other, and the amount of transmitted light of air between the light emitting element 6a and the light receiving element 6b. The concentration of airborne particulates in the air is detected based on the change of.

By the way, the housing 1 has a filter 4
A recirculation path 7 is formed for returning the air purified through the air to the intake side of the dust sensor 6. Further, the housing 1 is provided with a solenoid valve 8 as a flow path selecting means for selectively opening the opening on the intake port 2 side of the return path 7 and the intake port 2. Therefore, as shown in FIG. 1, when the intake port 2 is opened by the solenoid valve 8, the air taken in from the intake port 2 passes through the filter 4 through the dust sensor 6 and is then discharged from the exhaust port 3. Will be.
Further, as shown in FIG. 2, when the intake port 2 is closed by the solenoid valve 8, the air in the return passage 7 is sucked, so that the air passing through the filter 4 passes through the return passage 7. It will pass through the dust sensor 6 later. In short, the air that has passed through the dust sensor 6 depending on the position of the solenoid valve 8 is the air that has not been purified by the filter 4 and the air that has passed through the filter 4.
It will be possible to select the air that has passed through the purification process and the air.

According to this structure, when the clean air passing through the filter 4 is introduced into the dust sensor 6 by switching the solenoid valve 8 at an appropriate time, the clean air adheres to the inner surface of the dust sensor 6. Fine particles (cotton dust, etc.) can be removed. That is, if the timing of switching the solenoid valve 8 is set appropriately, the fluctuation of the sensitivity of the dust sensor 6 can be reduced over a long period of time. The time interval for switching the solenoid valve 8 can be set based on the usage time and the detection value of the dust sensor 6. When clean air is introduced into the dust sensor 6 with the intake port 2 closed, the air introduced from the exhaust port 3 will be transferred to the dust sensor 6 if the space in front of the filter 4 is closed. Since it is inconvenient to be introduced inside, it is desirable to provide an opening in the space before the filter 4 so that air can be introduced without passing through the dust sensor 6. If the turbulent flow is generated in the clean air in the dust sensor 6 by adjusting the position of the air introduction portion from the return passage 7 to the dust sensor 6, the effect of removing fine particles is further enhanced. Become.

(Embodiment 2) In this embodiment, as shown in FIG. 3, a cleaner 9 as a cleaner means that can be inserted into the inner peripheral surface of a sensor case 6c of a cylindrical dust sensor 6 is provided. Is provided. Cleaner 9
The cleaner body 9a is formed in a cylindrical shape or a rectangular frame shape, and the brush body 9b is attached to the outer peripheral surface of the cleaner body 9a. As the brush body 9b, a double-sided adhesive tape having elasticity based on a sponge body, a sponge body made of adhesive synthetic rubber, or the like can be used. The outer diameter of the cleaner 9 is set to be substantially equal to the inner diameter of the sensor case 6c of the dust sensor 6. The cleaner 9 is driven by the motor of the fan 5 as a drive source, and a mechanism portion for moving the cleaner 9 in the axial direction and the circumferential direction of the dust sensor 9 is provided between the cleaner 9 and the drive source. ..

According to the above construction, if the cleaner 9 is inserted into the dust sensor 6 and rotated at an appropriate time, the fine particles adhering to the inner peripheral surface of the dust sensor 6 can be removed by the brush body 9b. is there. As the brush body 9b,
It is not always necessary to use an adhesive material, and any member can be used as long as it can wipe off dirt on the inner peripheral surface of the dust sensor 6. Further, if the brush body 9 is combined with not only rotation but also movement in the circumferential direction and reciprocating movement in the axial direction, the effect of removing fine particles is further enhanced.
Here, the time interval for using the cleaner 9 may be set based on the operating time and the detection value of the dust sensor 6 as in the first embodiment. Other configurations are similar to those of the first embodiment.

(Embodiment 3) In this embodiment, the degree of dirt inside the dust sensor 6 is detected and the degree of dirt on the dust sensor 6 is reported. That is, in a state where the solenoid valve 8 described in the first embodiment is switched to introduce the clean air that has passed through the return path 7 into the dust sensor 6, as shown in FIG. The change in the sensitivity of the dust sensor 6 is determined by comparing the reference value set by the value generator SG ₁ with the reference value CP ₁ .

A more specific description will be given. The output of the dust sensor 6 is divided by the resistor R and the variable resistor VR and input to the comparator CP ₁ via the switch element SW which is an analog switch. Also, partial pressure value is also input to the other three comparators CP ₂ ~ CP _4. In each of the comparators CP _{1 to} CP ₄ , the reference value generator SG
_The reference value set by _{1 to} SG ₄ is compared with the partial pressure value obtained by dividing the output of the dust sensor 6, and when the partial pressure value exceeds the reference value, the corresponding transistors Q _{1 to} Q ₄ are turned on. Transistors Q ₁ to Q ₄ is if turned on, the display lamp LD ₁ to Ld ₄ made of light-emitting diode connected to the collector of the transistors Q ₁ to Q ₄ is turned, respectively. Here, the reference value of the reference value generator SG ₂ to SG ₄ are set to be sequentially increased, the indicator lamp LD ₂ to Ld ₄ so as to sequentially light up as the output of the dust sensor 6 increases There is. The dust sensor 6 is assumed to have a higher output voltage as the detected pollution level increases. However, when the dust sensor 6 is configured so that the output voltage decreases as the pollution level increases, the reference value generator SG When the partial pressure value is smaller than the reference value set by _{1 to} SG ₄ , the indicator lamp LD ₁
~ LD ₄ lights up so that comparators CP ₁ ~ CP ₄
It goes without saying that the

On the other hand, the switch element SW is the dust sensor 6
It is turned on upon receiving the output of the timer T that integrates the power feeding time to the. Therefore, the output of the timer T is turned on and the switch element SW is turned on every constant use time, and the output of the dust sensor 6 is input to the comparator CP ₁ . Here, the output of the timer T is configured to reset the timer T via the delay circuit D, and the switch element SW is turned on for the delay time of the delay circuit D. The output of the timer T also controls the solenoid valve 8. When the timer T is turned on, the solenoid valve 8 shuts off the intake port 2 so that clean air flows through the dust sensor 6.
Therefore, the sensitivity of the dust sensor 6 is compared with the reference value of the reference value generating unit SG ₁ every fixed use time (for example, one month). As a result, if the reference value is set to an appropriate value, a change in the sensitivity of the dust sensor 6 (that is, an increase in dirt) can be detected. Since the indicator lamp LD ₁ is turned off when the delay time set by the delay circuit D elapses, it is desirable to provide a circuit for holding the output value of the comparator CP ₁ .

According to the above construction, if the reference values of the variable resistor VR and the reference value generating sections SG _{1 to} SG ₄ are set to appropriate values, the degree of pollution of air during operation is indicated by the indicator lamp. LD
_{2 to} LD ₄ can be displayed, and the degree of contamination of the dust sensor 6 can be detected at regular intervals of use,
Whether or not the dust sensor 6 needs to be cleaned can be informed by the indicator lamp LD ₁ which is an informing means. Other configurations are similar to those of the first embodiment.

(Embodiment 4) In the embodiment 3, by comparing the output value of the dust sensor 6 with the reference value while the clean air is being introduced into the dust sensor 6, the inside of the dust sensor 6 becomes dirty. However, in the present embodiment, a reflector 11 is provided as a standard optical element that reflects the light from the light projecting element 6a of the dust sensor 6 and makes it enter the light receiving element 6b. The dirt of the dust sensor 6 is detected by determining the amount of light received by the light receiving element 6b when the reflector 11 is used. That is, it is utilized that the amount of light reflected by the reflector 11 on the light receiving element 6b decreases as the dust sensor 6 becomes more contaminated. Further, the change in the amount of received light due to the presence or absence of the reflector 11 is set to be sufficiently larger than the change in the amount of received light due to the presence or absence of suspended fine particles, and can be distinguished from the change in the amount of received light due to the suspended fine particles. There is. Here, the reflector 11 is formed of a material to which dirt is unlikely to adhere, and is normally stored so that dirt is unlikely to adhere to it, so that it can be moved to a necessary place only when necessary. ..

That is, as shown in FIG. 5, normally, the reflector 11 is housed in the recess 6d formed in the sensor case 6c of the dust sensor 6, and the solenoid 12 coupled to the reflector 11 is driven by driving the reflector 11. , Reflector 1 as shown in FIG.
1 is projected into the internal space of the sensor case 6c. The position of the reflector 11 in the protruding state is set to a position where the light from the light projecting element 6a can be reflected and incident on the light receiving element 6b. The solenoid 12 is shown in FIG.
As shown in FIG.
4 is straight ahead, and the reflector 11 is coupled to the tip of the drive iron core 14.

A circuit for judging the degree of contamination of the dust sensor 6 is constructed as shown in FIG. That is, similarly to the third embodiment, the output of the dust sensor 6 is the resistance R and the variable resistor VR.
After being divided by and, the voltage is input to the comparator CP ₁ via the switch element SW which is an analog switch. The comparator CP ₁ compares the partial pressure value of the output of the dust sensor 6 with the reference value set by the reference value generator SG _1, and when the partial pressure value exceeds the reference value, the output is inverted. When the output of the comparator CP ₁ is inverted, the transistor Q ₁ is turned on via the latch circuit LH and the indicator lamp LD ₁ is turned on. As a result, the change in the sensitivity of the dust sensor 6 is notified. The inverted state of the output of the comparator CP ₁ is held by the latch circuit LH. The latch circuit LH is reset by operating the switch S.

On the other hand, a timer T ₁ for integrating the energization time of the sensor power supply to the dust sensor 6 and a timer T ₂ triggered by the output of the timer T ₁ being inputted via the differentiating circuit DF ₁ are provided. Therefore, the output is turned on only for the time limit of the timer T ₂ for each integration time of the timer T ₁ . The cumulative time of the timer T ₁ is, for example, 2
It is set to 4 hours, and the time limit of the timer T ₂ is, for example, 1
It is set to minutes. When the output of the timer circuit T ₂ turns on, the transistor Q ₅ turns on and the solenoid 1
2 is energized, and the reflector 11 projects into the sensor case 6c of the dust sensor 6. Further, when the time limit time of the timer circuit T ₂ ends, the transistor Q ₅ is turned off and the reflector 11 returns to the original position. That is, the reflector 11 projects only for one minute every 24 hours of use. Timer T
₂ is reset via the delay circuit D that delays the output of the timer T ₂ , and the timer T ₁ is reset via the differentiating circuit DF ₂ that differentiates the output of the timer T ₂ .

According to the above structure, the reflector 11 projects into the sensor case 6c at regular intervals of use, so that the amount of light changes in the optical path from the light projecting element 6a to the light receiving element 6b via the reflector 11. Can be detected by the comparator CP ₁ , and the change in the sensitivity of the dust sensor 6 can be regularly inspected. Other configurations are similar to those of the first embodiment.

[0026]

According to the first aspect of the present invention, since the air cleaned by the purifying means can be introduced into the pollution degree detecting means, the dirt adhering to the pollution degree detecting means can be cleaned with almost no suspended fine particles. It can be removed by air. That is, if clean air is introduced into the pollution degree detecting means at appropriate time intervals by switching the flow path by the flow path selecting means, it is possible to suppress the sensitivity change of the pollution degree detecting means, and for a long period of time. There is an advantage that malfunction can be prevented.

According to the second aspect of the present invention, since the cleaner means is provided to remove the dirt on the pollution degree detecting means, it is possible to suppress a change in the sensitivity of the pollution degree detecting means over a long period of time. According to the invention of claim 3, the change in sensitivity of the pollution degree detecting means is notified based on the output value of the pollution degree detecting means while the clean air after passing through the purifying means is introduced into the pollution degree detecting means. There is an advantage that it is possible to notify that the contamination degree detection means is dirty and prompt cleaning.

According to the fourth aspect of the present invention, since the change in the sensitivity of the contamination degree detecting means is notified based on the output value of the contamination degree detecting means when the optical element is arranged in the contamination degree detecting means, the contamination degree detecting means There is an advantage that cleaning can be promoted by notifying that it is dirty. Moreover, by disposing the optical element in the contamination degree detecting means, it is possible to determine the sensitivity change of the contamination degree detecting means, so that it becomes possible to provide an optical element in parallel with the contamination degree detecting means to have a self-diagnosis function, There is an advantage that the flow path can be simplified as compared with the case where the return path is provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a first embodiment in use.

FIG. 2 is a cross-sectional view showing a state in which dirt on the dust sensor according to the first embodiment is removed.

FIG. 3 is an exploded sectional view of a main part of the second embodiment.

FIG. 4 is a circuit diagram of a third embodiment.

FIG. 5 is a cross-sectional view of Example 4 during use.

FIG. 6 is a sectional view showing a state in which dirt on a dust sensor according to a fourth embodiment is detected.

FIG. 7 is an exploded perspective view showing a relationship between a solenoid used in a fourth embodiment and a reflector.

FIG. 8 is a circuit diagram of a fourth embodiment.

[Explanation of symbols]

1 Housing 2 Intake port 3 Exhaust port 4 Filter 5 Fan 6 Dust sensor 7 Reflux path 8 Solenoid valve 9 Cleaner 11 Reflector LD ₁ Indicator light

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[Procedure amendment]

[Submission date] November 9, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003]

By the way, the amount of fine particles adhering to the contamination degree detecting means increases with time. Therefore, when the pollution degree detecting means for detecting the amount of transmitted light is used, the sensitivity of the pollution degree detecting means increases with the lapse of time, and the operation is performed even when the air is not polluted. The problem arises. Also, when using a pollution degree detection means of the type that detects the amount of scattered light,
Sensitivity of pollution degree detection means may decrease with time
Elevated or bought air such driving be contaminated,
There will be a problem of driving even if the air is not polluted . That is, the light emitting element and the light receiving element
When particles adhere to the surface, the sensitivity decreases and the degree of air pollution
Scatter when particles adhere to the wall around the area where
The sensitivity increases with the increase in light.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012]

Example 1 In this example, a filter is used as a purifying means. As shown in FIG. 1, an intake port 2 and an exhaust port 3 are opened in the housing 1. Intake port 2 and exhaust port 3
A filter 4 as a purifying unit and a fan 5 (driven by the motor 10) are provided in a flow path between the air conditioner and the air conditioner, and are taken from the intake port 2 and directed from the intake port 2 to the exhaust port 3 by the fan 5. The air flow thus formed is discharged through the exhaust port 3 after being cleaned through the filter 4. Between the intake port 2 and the filter 4, a dust sensor 6 as a pollution degree detecting means for detecting the pollution degree of the air taken into the filter 4 is arranged. The dust sensor 6 includes a light emitting element 6a formed of a light emitting diode and a light receiving element 6b formed of a photodiode, which are arranged to face each other, and the amount of transmitted light of air between the light emitting element 6a and the light receiving element 6b. The concentration of airborne particulates in the air is detected based on the change of.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

(Embodiment 2) In this embodiment, as shown in FIG. 3, a cleaner 9 as a cleaner means that can be inserted into the inner peripheral surface of a sensor case 6c of a cylindrical dust sensor 6 is provided. Is provided. Cleaner 9
The cleaner body 9a is formed in a cylindrical shape or a rectangular frame shape, and the brush body 9b is attached to the outer peripheral surface of the cleaner body 9a. As the brush body 9b, a double-sided adhesive tape having elasticity based on a sponge body, a sponge body made of adhesive synthetic rubber, or the like can be used. The outer diameter of the cleaner 9 is set to be substantially equal to the inner diameter of the sensor case 6c of the dust sensor 6. The cleaner 9 is driven by the motor of the fan 5 as a drive source, and a mechanism portion for moving the cleaner 9 in the axial direction and the circumferential direction of the dust sensor 6 is provided between the cleaner 9 and the drive source. ..

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

A more specific description will be given. The output of the dust sensor 6 is divided by the resistor R and the variable resistor VR and input to the comparator CP ₁ via the switch element SW which is an analog switch. Also, partial pressure value is also input to the other three comparators CP ₂ ~ CP _4. In each of the comparators CP _{1 to} CP ₄ , the reference value generator SG
_The reference value set by _{1 to} SG ₄ is compared with the partial pressure value obtained by dividing the output of the dust sensor 6, and when the partial pressure value exceeds the reference value, the corresponding transistors Q _{1 to} Q ₄ are turned on. Transistors Q ₁ to Q ₄ is if turned on, the display lamp LD ₁ to Ld ₄ made of light-emitting diode connected to the collector of the transistors Q ₁ to Q ₄ is turned, respectively. Here, the reference value of the reference value generator SG ₂ to SG ₄ are set to be sequentially increased, the indicator lamp LD ₂ to Ld ₄ so as to sequentially light up as the output of the dust sensor 6 increases There is. The dust sensor 6 is assumed to have a higher output voltage as the detected pollution level increases. However, when the dust sensor 6 is configured so that the output voltage decreases as the pollution level increases, the reference value generator SG When the partial pressure value is smaller than the reference value set by _{1 to} SG ₄ , the indicator lamp LD ₁
~ LD ₄ lights up so that comparators CP ₁ ~ CP ₄
It goes without saying that the In addition, each Transis
The collector of data Q ₂ ~Q _4, each triac T
Gates of A _{2 to} TA ₄ are connected, and each indicator lamp LD _{2 to} L
When D ₄ lights up, the corresponding triac TA ₂ ~
TA ₄ is turned on. TRIAC TA
Resistors R ₂ and R ₃ are connected in series to ₂ and TA ₃ ,
Ac TA ₂ and TA ₃ and resistors R ₂ and R ₃ in series
And the TRIAC TA ₄ are connected in parallel with each other.
The motor 10 is connected between the parallel circuit and the power supply AC.
It With this configuration, the amount of air blown by the fan 5 depends on the degree of pollution.
Can be switched.

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (4)

[Claims] 1. A housing for opening an intake port and an exhaust port, a fan for forming an air flow from the intake port to the exhaust port, and a purifying unit for purifying air in a flow path between the intake port and the exhaust port. And a pollution degree detecting means disposed in a flow path between the air supply port and the purifying means for detecting the degree of air pollution based on a change in an optical physical quantity due to the contamination, and the air after the purifying processing by the purifying means. To return to the air supply side of the pollution degree detecting means and introduce it into the pollution degree detecting means by selectively opening either one of the recirculation passage formed separately from the flow passage and the air supply port. An air purifier comprising: a route selecting means. 2. A housing for opening an intake port and an exhaust port, a fan for forming an air flow from the intake port to the exhaust port, and a purifying unit for purifying air in a flow path between the intake port and the exhaust port. And a contamination degree detecting means disposed in the flow path between the air supply port and the purifying means for detecting the degree of air contamination based on the change of the optical physical quantity due to the contamination, and the dirt attached to the contamination degree detecting means. An air purifier comprising: a cleaner unit capable of removing 3. A housing for opening an intake port and an exhaust port, a fan for forming an air flow from the intake port to the exhaust port, and a purifying unit for purifying air in a flow path between the intake port and the exhaust port. And a pollution degree detecting means disposed in a flow path between the air supply port and the purifying means for detecting the degree of air pollution based on a change in an optical physical quantity due to the contamination, and the air after the purifying processing by the purifying means. To return to the air supply side of the pollution degree detecting means and introduce it into the pollution degree detecting means by selectively opening either one of the recirculation passage formed separately from the flow passage and the air supply port. And a notifying unit for notifying a change in sensitivity of the pollution degree detecting unit based on an output value of the pollution degree detecting unit in a state where the clean air passing through the return path is introduced into the pollution degree detecting unit. An air purifier characterized by being provided. 4. A purification means for purifying air in a flow path between an inlet and an exhaust port, a fan forming an air flow from the intake port to the exhaust port, and a housing having the intake port and the exhaust port opened. And a pollution degree detecting means which is disposed in the flow path between the air supply port and the purifying means and detects the degree of air pollution based on the change of the optical physical quantity due to the pollution, and the optical physical quantity due to the air pollution. Notification for notifying the change in sensitivity of the pollution degree detecting means based on the output value of the pollution degree detecting means in a state where the optical element that causes a change in the optical physical quantity sufficiently larger than the change is arranged in the detection area of the pollution degree detecting means An air purifier comprising: