JP2001062231A - Air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cleaner capable of surely actuating even at an working environment low in air pollution. SOLUTION: The air cleaner is provided with a dust sensor 1a, a gas sensor 1b and an ultraviolet sensor 1c. In each threshold value set circuit 31a-31c, three step threshold value in accordance with the degree of the air pollution are set for each sensor 1a-1c, and the threshold value is lowered when the state in which the detecting signal of each sensor 1a-1c becomes less than a prescribed detecting level continues over a fixed time. Comparator circuits 32a-32c compare respectively the detecting signal of each sensor 1a-1c and the threshold value set by each of threshold value set circuit 31a-31c, and a signal treating circuit 33 generates an output signal in accordance with the degree of the air pollution, and a fan control circuit 34 controls the operation mode of the fan 18 in accordance with the operation of an operation switch SW and the output of the signal processing circuit 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an air purifier.

[0002]

2. Description of the Related Art An air purifier of this type includes an outer shell provided with an air intake port and an air outlet port communicating with the outside, and an air intake for sucking air from the outside into the outer shell through the air intake port. Means, an air purifying means provided in an air flow path between the air intake port and the air blowing port, for purifying air passing through the flow path, detecting air dirt, and detecting according to the degree of dirt. A dirt sensor that generates a signal, and a plurality of thresholds indicating the degree of dirt are set, and an air flow control unit that gradually increases the air flow of the intake unit when a detection signal of the dirt sensor exceeds each threshold. was there.

[0003]

In the above-described air purifier, a gas sensor or a dust sensor is generally used as a dirt sensor, and the gas sensor detects a hydrogen gas component contained in cigarette smoke. Some of the dirt sensors use an ultraviolet sensor called a quick sensor. The ultraviolet sensor detects, for example, ultraviolet light emitted from a lighter or a match flame used for smoking.

Since the amount of dust generated during smoking is large and the amount of hydrogen gas contained in the smoke of cigarettes increases, the detection signal of a gas sensor or a dust sensor increases, and the air volume control means reduces the air volume level of the intake means. Can be higher. However, when smoke is not smoked, the generated dust and hydrogen gas components are reduced, and the gas sensor and the dust sensor are difficult to react. Further, as described above, since the ultraviolet sensor detects ultraviolet light emitted from the lighter or the flame of the match, the ultraviolet sensor did not react when cigarettes were not smoked.

[0005] By the way, many people who are interested in air pollution do not smoke, and many people are sensitive to air pollution. In addition, since the rooms used by such people are more thoroughly cleaned and the degree of air pollution is often lower than in a general use environment, the detection signal of the dirt sensor is small and the air volume of the intake means is high. In many cases, the level did not shift to the level, and the user was sometimes dissatisfied.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide an air purifier that can be easily operated even in a use environment in which air is less contaminated.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, there is provided an outer shell provided with an air intake port and an air outlet port communicating with the outside, and an air intake port from the outside. Air intake means for sucking air into the outer shell through the air; air purification means provided in an air flow path between the air intake port and the air discharge port for purifying air passing through the flow path; And a control means for operating the suction means at a predetermined air flow rate when the contamination degree detected by the contamination sensor exceeds a contamination threshold, and the contamination degree detected by the contamination sensor does not exceed a predetermined detection level. A threshold setting means for setting the threshold to a value with a lower contamination level when the state continues for a predetermined time or more, wherein the air contamination level is low and the contamination level detected by the dirt sensor is detected. If the state does not exceed the Le is continued for a certain time, the threshold setting means is reduced the threshold, even if the lower the detected contamination of dirt sensor, the control unit is easy to operate the suction means. Therefore, even in a usage environment where the degree of air pollution is low such that the user does not smoke, the control means can automatically operate the suction means, which is convenient for users who are sensitive to air pollution. Becomes

According to a second aspect of the present invention, in the first aspect of the present invention, the dirt sensor comprises at least one or more of a gas sensor, an ultraviolet sensor, and a dust sensor. It has the same function as.

According to a third aspect of the present invention, in the first aspect of the invention, the dirt sensor comprises at least one or a plurality of a gas sensor, an ultraviolet sensor, and a dust sensor. When the value exceeds the detection level, the threshold setting means returns the threshold value to the initial setting value, and when the contamination of the air becomes severe and the degree of contamination detected by the contamination sensor exceeds the detection level, the threshold value is set to the initial setting value. , The intake means can be prevented from frequently operating due to the low threshold value.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the threshold value setting means holds the current threshold value even when the intake means stops, and stops when the intake means operates again. It can be operated at the time threshold.

According to a fifth aspect of the present invention, in the first aspect of the present invention, a holding means for holding a current threshold value when the power is turned off is provided, and when the power is restored, the operation is performed with the threshold value when the power is turned off. it can.

[0012]

Embodiments of the present invention will be described with reference to the drawings. First, the structure of the air purifier A will be described. As shown in FIGS. 4 to 6, the air cleaner A has an outer shell 10 in which a grill 12 is detachably attached to a front surface of a housing 11. On one side of the grill 12, there is provided a grid portion 13 penetrating the grill 12, and on a portion of the back surface of the housing 11 on the side of the grid portion 13, there is provided a grid portion 14 communicating with the outside. Part 1
An air intake 15 is formed from 3 and 14. Further, a lattice portion 16 communicating with the outside is formed at a portion of the back surface of the housing 11 opposite to the lattice portion 14, and an air outlet 17 for blowing purified air from the lattice portion 16 to the outside is formed. .

Inside the outer shell 10, fans 18 and 18 such as a sirocco fan for sucking air from the outside into the outer shell 10 through the lattice portions 13 and 14 are provided.
A motor 19 for rotating the fans 18 and 18 and a pre-filter 28 and a filter 20 provided in an air flow path between the air intake 15 and the air outlet 17 for purifying air passing through the flow path are provided. It is stored. The filter 20 is disposed in the housing 11 on the upstream side of the flow of wind to the fan 18. The filter 20 is, for example, a plasma filter (plasma HEPA (High Efficie
ncy Particulate Air Filter), which has a plasma deodorant and activated carbon inside. A plasma electrode unit 27 is provided on the upstream side of the filter 20, and a pre-filter 28 is provided on the upstream side of the plasma electrode unit 27. Here, the fan 18, 18 and the motor 19 constitute an intake unit, and the filter 20, the plasma electrode unit 27 and the pre-filter 28 constitute an air purifying unit. It should be noted that the filter 20 is not limited to the above-described plasma filter, and various known filters may be used.

Here, a stand mounting portion 21 for horizontal installation is provided on one side of the rear surface of the housing 11 provided with the lattice portion 14 constituting the air intake port 15. Also,
Lower surface of housing 11 (lower surface in vertical position)
Is provided with a stand mounting portion 22 for a vertical installation, and when used in a vertical installation, a stand 23 is attached to the stand mounting portion 22 for a vertical installation. In the case of installation and use, the stand 23 is attached to the stand attachment portion 21 for use.

A power supply circuit 24 is provided at a position corresponding to a lower portion in the housing 11 in a vertically placed posture. An optical dust sensor 1a for detecting dust (dust) such as house dust and pollen particles and a circuit board 25 are provided at a position corresponding to an upper portion in the housing 11 in a vertically placed posture. Are arranged side by side in the short width direction with the dust sensor 1 a facing the air intake port 15.

The circuit board 25 has a specific gas (eg, hydrogen gas) contained in an odorous gas component such as cigarette smoke.
, An ultraviolet sensor 1c for detecting, for example, ultraviolet rays emitted from a lighter or a match flame, an operation switch for sequentially switching the operation mode of the fan 18 according to the operation, and an operation display. Components such as light emitting diodes LED1 to LED4 are mounted, and the circuit board 25 and the dust sensor 1a are electrically connected via a connector (not shown). At the end of the circuit board 25 opposite to the dust sensor 1a, there is provided a display unit 30 for displaying the degree of contamination by dust detected by the dust sensor 1a and the degree of contamination in the room detected by the gas sensor 1b. The display unit 30 is rotatably inserted into the hole 25a of the circuit board 25.
Here, the operation mode of the fan 18 includes each of the sensors 1a to 1a.
The operation state of the fan 18 (stop,
(Low speed, medium speed, high speed), a low speed mode in which the fan 18 rotates at a low speed, a medium speed mode in which the fan 18 rotates at a medium speed, and a high speed mode in which the fan 18 rotates at a high speed. There are two modes.

The dust sensor 1 in the grill 12
a and the operation panel 29
Are provided, and lattice holes 29a and 29b are formed in portions of the operation panel 29 corresponding to the dust sensor 1a and the gas sensor 1b, respectively. Here, the holes 29a provided corresponding to the dust sensors 1a are opened near the lattice portion 13 constituting the air intake port 15, and house dust riding on air sucked near the air intake port 15 is provided. The dust sensor 1a can easily detect dust such as dust and pollen particles. A hole 2 is provided in a portion of the operation panel 29 corresponding to the ultraviolet sensor 1c.
9c is formed, and the ultraviolet sensor 1c is exposed from the hole 29c. The operation switch SW can be operated from the front side of the operation panel 29. The operation switch SW is provided on the circuit board 25.
1 to LED4 and the display unit 30 so that they can be visually recognized from the front of the operation panel 29.
-The part of the operation panel 29 corresponding to the LED 4 and the display unit 30 is transparent or translucent, or can be visually recognized by forming an opening. In this embodiment, the degree of contamination of the air (for example, the amount of dust (mg) in 1 m ³ of air) based on the detection signal of the dust sensor 1a.
Digital display unit 30a composed of, for example, a 7-segment LED or a liquid crystal display, and a level display unit 30b composed of, for example, a plurality of light emitting elements for displaying the odor level based on the detection signal of the gas sensor 1b
Constitute the display unit 30.

Since the display unit 30 is rotatably attached to the circuit board 25, the display unit 30 is rotated with the grill 12 removed, so that the housing 11 can be placed vertically or horizontally. The display unit 30 can be rotated to keep the display direction constant at all times even when the display unit 30 is installed. Further, there are two types of operation panel 29 detachably provided on the grill 12 for vertical installation and horizontal installation, and the direction of the description and the like is different between vertical installation and horizontal installation. Operation panel 2 according to installation condition
By using No. 9, the direction of the description character becomes the correct direction in both the vertical and horizontal arrangements.

Here, when the fan 18 rotates, the lattice 1
The air is sucked in from the air intake port 15 composed of 3 and 14, and relatively large dust in the air is first removed by the pre-filter 28. The air that has passed through the pre-filter 28 becomes positive ions through the plasma electrode unit 27, and the positive ions are charged to dust particles, and the dust is adsorbed on the filter 20, which is a negative electrode. Further, the odor components in the air are decomposed into odorless components by plasma generated in the plasma space or the surface of the filter 20, and the remaining odor components are adsorbed by activated carbon, so that the odor components in the air can be plasma deodorized. . The air purified in this way is discharged from the outlet 17 to create indoor circulating air, thereby purifying the indoor air.

Next, a control section (control means) 2 for controlling the operation state (stop, low speed, medium speed, high speed) of the fan 18 in accordance with the operation of the operation switch SW and the detection signals of the sensors 1a to 1c. explain. In this embodiment, the fan 1
Although the air volume of the fan 8 is switched to three stages (low speed, medium speed, and high speed), the air volume of the fan 18 is not limited to three stages, but may be switched to, for example, four stages or other.

As shown in FIG. 1, the control unit 2 includes, for example, threshold setting circuits (threshold setting means) 31a to 31 for setting three threshold values in accordance with the degree of air contamination for each of the sensors 1a to 1c.
31c, and each sensor 1a-1c for each sensor 1a-1c.
Circuits 32a-32 which compare the detection signal of the threshold value with the threshold value set by the corresponding threshold value setting circuits 31a-31c.
c, a signal processing circuit 33 for generating output signals OH, OM, OL corresponding to the degree of air contamination based on the output signals of each of the comparison circuits 32a to 32c, an operation of the operation switch SW and an output of the signal processing circuit 33. A fan control circuit 34 for generating a control signal for controlling the air volume of the fan 18 according to the signal;
A drive circuit 35 for driving the motor 19 according to a control signal of the fan control circuit 34. Here, FIGS. 2 and 3 show specific circuit diagrams of the control unit 2. FIG. 2 and 3
For simplicity, a case will be described in which a dust sensor 1a and a gas sensor 1b are provided.

The drive circuit 35 has an input terminal t of the motor 19.
1, t2, and t3 and the triacs TRC1, TRC2, and TRC3 inserted between the AC power supply AC, respectively, and one of the triacs TRC1, TRC2, and TRC3 is turned on, and the input terminals t1, t2, and t3 are turned on. When the AC power supply AC is applied between t3 and the input terminal t4, the motor 19 rotates at any one of low, medium, and high rotational speeds.

The fan control circuit 34 includes an operation switch S
The output signals AUTO, LOW, MID,
A counter CT that switches between HIGH and OFF is provided. Here, the output signal AUTO, L of the counter CT is
OW, MID, HIGH, and OFF are the operation switches SW
Every time is operated, AUTO → LOW → MID → HIG
Only one output signal becomes “H” level in the order of H → OFF → AUTO →. Further, the fan control circuit 34 receives an AUTO signal at one input terminal, and outputs the output signals OH and O of the signal processing circuit 33 to the other input terminal.
AND gates AND1, AND to which M and OL are input
2, AND3 and light emitting diode LED1 for operation display
~ LED4, TRIAC TRC1, TRC2, TR
Photocouplers PC1, which turn on / off each of C3
PC2 and PC3.

Here, the operation of the fan control circuit 34 and the drive circuit 35 will be described. When the output signal OFF of the counter CT is at the H level, the operation switch S
When W is operated only once, the output signal A of the counter CT is output.
Since UTO becomes H level, the light emitting diode LED1
Lights up. Here, when the light emitting diode LED1 is turned on, it is displayed that the operation mode of the fan 18 is the automatic mode. When, for example, the output signal OL is input from the signal processing circuit 33 during operation in the automatic mode, AN
The output signal of the D gate AND1 becomes H level and the LED
2 turns on, the photocoupler PC1 turns on, the triac TRC1 turns on, and the motor 19 rotates at a low speed. Here, when the light emitting diode LED2 is turned on, it is displayed that the operation mode of the fan 18 is the low speed mode. As described above, while operating in the automatic mode, the output signals OH, O input from the signal processing circuit 33 are output.
The rotation of the motor 19 is automatically switched between high speed, medium speed and low speed according to M and OL. The fan control circuit 3
When the operation mode of Step 4 is other than the automatic mode, the counter C
Since the output signal AUTO of T goes low and the output signals of the AND gates AND1 to AND3 are forced low, the operation mode of the fan 18 is independent of the output signals OH, OM, OL of the signal processing circuit 33. Forced switching.

After that, when the operation switch SW is operated, the output signal LOW of the counter CT becomes H level, so that the light emitting diode LED1 is turned off, the light emitting diode LED2 is turned on, and the photocoupler PC1 is turned on and the triac is turned on. TRC1 turns on, and the motor 19 rotates at a low speed. Here, when the light emitting diode LED2 is turned on, it is displayed that the operation mode of the fan 18 is the low speed mode. After that, the operation switch S
When W is operated, the output signal MID of the counter CT becomes H
Level, so the light emitting diode LED2 turns off,
The light emitting diode LED3 is turned on, the photocoupler PC2 is turned on, and the triac TRC2 is turned on.
The motor 19 rotates at a medium speed. Here, when the light emitting diode LED3 is turned on, it is displayed that the operation mode of the fan 18 is the medium speed mode. Next, when the operation switch SW is operated, the output signal HI of the counter CT is output.
Since GH becomes H level, the light emitting diode LED3 is turned off, the light emitting diode LED4 is turned on,
The photocoupler PC3 turns on, the triac TRC3 turns on, and the motor 19 rotates at high speed. Here, when the light emitting diode LED4 is turned on, it is displayed that the operation mode of the fan 18 is the high-speed mode. Subsequently, when the operation switch SW is operated, the output signal OFF of the counter CT goes high, and the other output signals AUTO, LOW, MID, and HIGH go low, so that the rotation of the fan 18 stops. .

Next, the threshold value setting circuits 31a and 31b, the comparison circuits 32a and 32b, and the signal processing circuit 33 will be described. The threshold setting circuit 31b and the comparison circuit 32b provided corresponding to the gas sensor 1b include a dust sensor 1a.
Has the same configuration as that of the threshold setting circuit 31a and the comparison circuit 32a provided correspondingly, and thus the description thereof is omitted.

The threshold setting circuit 31a operates at a constant control voltage V
cc, a series circuit of voltage dividing resistors R11 to R15, an analog switch AS1 connected in parallel with the high-potential-side voltage dividing resistor R11, and a voltage dividing resistor R1 for dividing the control voltage Vcc.
6, R17, a comparator CP14 for comparing the level of the reference voltage Vref1 divided by the voltage dividing resistors R16, R17 with the detection signal of the sensor 1a, and a comparator CP.
A delay timer T1 composed of an on-delay timer for delaying the output signal of the comparator 14 by a predetermined delay time, an output signal of the comparator CP14 is input to one input terminal, and an output signal of the delay timer T1 is input to the other input terminal. NAN
A NAND gate N11.
Analog switch AS1 according to the output signal of AND11
Turns on / off. Here, when the output signal of the comparator CP14 rises from the L level to the H level, the delay timer T1 starts a timed operation for a fixed time, and generates an H level output signal when the time is up. Note that when the output signal of the comparator CP14 becomes L level during the timed operation, the delay timer T1 stops the timed operation. Thus, when the state where the detection signal of the sensor 1a does not exceed the reference voltage Vref1 continues for a predetermined time or more, the output signal of the delay timer T1 becomes H level.

The comparator 32a includes a comparator CP11 for comparing the voltage V11 at the connection point between the resistors R12 and R13 with the detection signal of the sensor 1a, and resistors R13 and R14.
A comparator CP12 for comparing the level of a voltage V12 at a connection point of the sensor with a detection signal of the sensor 1a, and resistors R14 and R1.
5 and a comparator CP13 for comparing the level of the voltage V13 at the connection point 5 with the detection signal of the sensor 1a.

The signal processing circuit 33 includes an AND gate AND
4, AND5, AND11 to AND14, AND21 to
AND24 and OR gates OR1 to OR3, and the output signal of the OR gate OR1 is the output signal O
H, the output signal of the AND gate AND4 corresponds to the output signal OM, and the output signal of the AND gate AND5 corresponds to the output signal OL.

The operation of the threshold setting circuits 31a and 31b, the comparison circuits 32a and 32b, and the signal processing circuit 33 will be described below. Normally, the detection signals of the sensors 1a and 1b are respectively equal to the reference voltage V which is a predetermined detection level.
Since they are higher than ref1 and Vref2, the output signals of the comparators CP14 and CP24 are also at L level, and the output signals of the delay timers T1 and T2 are also at L level. Therefore,
Since the output signals of the NAND gates NAND11 and NAND21 become H level and the analog switches AS1 and AS2 are closed, the analog switches AS1 and AS2 bypass the voltage dividing resistors R11 and R21, respectively, and reduce the control voltage Vcc to the voltage dividing resistor R12. ~ R15, R22 ~
The voltages V11 to V13 and the voltage V respectively divided by R25
21 to V23 are output as thresholds to the comparison circuits 32a and 32b, respectively (V11>V12> V13, V21>
V22> V23).

For example, if an output signal that is higher than the threshold (voltage V12) of the comparator CP12 and lower than the threshold (voltage V11) of the comparator CP11 is output from the dust sensor 1a,
12, the output signal of CP13 is H level, the comparator C
The output signal of P11 becomes L level. Then, the output signal of the AND gate AND11 goes low, and the output signal of the AND gate AND12 goes high. This AN
A is determined by the output signals of the D gates AND11 and AND12.
The output signal of the ND gate AND13 goes high, and the output signal of the AND gate AND14 goes low.

On the other hand, for example, from the gas sensor 1b, it is higher than the threshold value (voltage V23) of the comparator CP23, and
Assuming that an output signal having a level lower than the threshold value (voltage V22) of the comparator CP22 is output, the output signal of the comparator CP23 becomes H level,
1 and the output signals of CP22 are respectively at L level. Then, the output signals of the AND gates AND21 and AND22 become L level, respectively. This AND gate AND2
1, AND gate AND in response to the output signal of AND22
23 goes low, and the output signal of AND gate AND24 goes high.

Therefore, the OR gates OR1, OR2,
The output signals of OR3 are L level, H level,
It becomes H level. Then, the output signal of the AND gate AND4 becomes H level, and the AND gate AND5
Becomes an L level. Thus, output signal OM goes high and output signals OH and OL go low. Here, when the fan control circuit 34 is operating in the automatic mode, the output signal of the AND gate AND2 becomes H level, so that the light emitting diode LED3 is turned on, and the photocoupler PC2 is turned on and the triac T
RC2 is turned on, and the motor 19 rotates at a medium speed.

Here, when the degree of air pollution is low, for example, when the detection signal of the dust sensor 1a becomes equal to or lower than the reference voltage Vref1, the output signal of the comparator CP14 becomes H level. When the output signal of the comparator CP14 rises from the L level to the H level, the delay timer T1
Until the delay time elapses, the output signal of the delay timer T1 is at the L level.
The output signal of AND11 is at the H level, and the analog switch AS1 remains closed. Thereafter, when the state where the detection signal of the dust sensor 1a does not exceed the reference voltage Vref1 continues for a certain period of time or more, the output signal of the delay timer T1 is inverted to the H level.
11 becomes L level and the analog switch A
S1 is opened. At this time, the comparators CP11 to CP11
Since the threshold value of CP13, that is, the voltages V11 to V13, is a voltage obtained by dividing the control voltage Vcc by the voltage dividing resistors R11 to R15, the voltages V11 to V13 are lower than usual. Similarly, the detection signal of the gas sensor 1b is changed to the reference voltage Vre.
If the state that does not exceed f2 continues for a certain period of time or more, the output signal of the comparator CP24 becomes H level.
Also attains an H level, so that the NAND gate NA
The output signal of ND11 becomes L level, and analog switch AS2 is opened. At this time, the comparator CP2
1 to CP23, that is, the voltages V21 to V23,
Since the control voltage Vcc is divided by the voltage dividing resistors R21 to R25, the voltages V21 to V23 are lower than those in the normal state.

As described above, when the state where the detection signals of the sensors 1a and 1b do not exceed the reference voltages Vref1 and Vref2, respectively, continues for a certain period of time (that is, the sensors 1a and 1b).
(b) When the state in which the degree of air pollution detected by b does not exceed the predetermined threshold continues for a certain period of time or more), the comparators CP11 to CP11
Since the threshold values of the CPs 13 and CPs 21 to 23 are set to lower values than in the normal state, the sensitivities of the sensors 1a and 1b can be made higher than those in the normal state, and the fan 18 can be easily operated. Therefore, even in a use environment in which the degree of air pollution is low such that the user does not smoke, the control unit 2 can automatically operate the fan 2, which is convenient for a user who is sensitive to air pollution. It will be.

Thereafter, when the detection signal of the dust sensor 1a becomes higher than the reference voltage Vref1, the comparator CP1
4 is at L level and the output signal of the delay timer T1 is at L level, the output signal of the NAND gate NAND11 is at H level, and the analog switch AS1 is closed. At this time, the comparators CP11 to CP13
, That is, the voltages V11 to V13 are controlled by the control voltage Vcc.
Is divided by the voltage dividing resistors R12 to R15, and returns to the initial set value. Similarly, when the detection signal of the gas sensor 1b becomes higher than the reference voltage Vref2, the comparator CP2
4 is at the L level and the output signal of the delay timer T2 is at the L level, the output signal of the NAND gate NAND21 is at the H level, and the analog switch AS2 is closed. At this time, the comparators CP21 to CP23
, That is, the voltages V21 to V23 are equal to the control voltage Vcc.
Is divided by the voltage dividing resistors R22 to R25, and returns to the initial set value.

It should be noted that the threshold setting circuits 31a, 31
b is the detection signals of the sensors 1a and 1b and the reference voltage Vref1,
Since the thresholds of the comparators CP11 to CP13 and CP21 to 23 are set by comparing the level with Vref2, the current threshold value is maintained even when the motor 19 is stopped (that is, when the intake means is stopped). Holding. If the detection signals from the sensors 1a and 1b do not exceed the reference voltages Vref1 and Vref2 for a certain period of time, the logic of the NAND gates NAND11 and NAND21 of the threshold setting circuits 31a and 31b is inverted. , NAND 21 are stored in a non-volatile memory (flash ROM), and as shown in FIG. 9, the operation power of at least the sensors 1a and 1b and the threshold setting circuits 31a and 31b is
, The current threshold value can be maintained even when the power plug of the air purifier A is unplugged from the outlet. Here, a holding unit that holds the current threshold value when the power is turned off is configured from the nonvolatile memory, the battery B, and the like.

In this embodiment, each threshold setting circuit 31
FIG. 10A and FIG. 10B show that the thresholds corresponding to the sensors 1a and 1b are respectively reduced when the detection signals of the sensors 1a and 1b become equal to or lower than the reference voltages Vref1 and Vref2 for a certain period of time or longer. As shown in
The outputs of the D-gates NAND11 and NAND21 are input to the control terminals of the analog switches AS2 and AS1, respectively, and when the state where the detection signal of one sensor 1a becomes equal to or lower than the reference voltage Vref1 continues for a predetermined time or more, the other sensor 1
a and the other sensor 1
If the state in which the detection signal b becomes equal to or lower than the reference voltage Vref2 continues for a certain period of time or more, the threshold value corresponding to one sensor 1a may be reduced.

Further, when the state where the detection signal of a specific dirt sensor is equal to or lower than the reference voltage continues for a predetermined time or more, the threshold value corresponding to another sensor may be lowered. For example, as shown in FIG. 11, in the above-described circuit of FIG.
comparators CP21 to CP to which the detection signal of b is input
23, the thresholds V21 to V23 are fixed, the output of the NAND gate NAND21 is input to the control terminal of the analog switch AS1, and the analog switch AS1 is turned on / off according to the output of the NAND gate NAND21. Is the reference voltage Vref2
If the following condition continues for a certain time or longer, the threshold value corresponding to another sensor 1a can be reduced.

In the above specific circuit diagram, the case where two sensors 1a and 1b are provided has been described. However, when only one sensor 1a is provided, as shown in FIG. AND gates AND4 and AND of
5, AND11 to AND14, the output signal of the AND gate AND1 corresponds to the output signal OH, the output signal of the AND gate AND4 corresponds to the output signal OM, and the output signal of the AND gate AND5 corresponds to the output signal OL. ing.

In this embodiment, the three sensors of the dust sensor 1a, the gas sensor 1b, and the ultraviolet sensor 1c are combined. However, the present invention is not intended to limit the sensors to the above-mentioned ones. May be.
Also, the number of sensors is not limited to three, and four or more dirt sensors may be used. Further, only one dirt sensor such as the dust sensor 1a, the gas sensor 1b or the ultraviolet sensor 1c may be used, or two dust sensors 1a and 1b may be combined as shown in FIG. As shown in (2), two sensors of the dust sensor 1a and the ultraviolet sensor 1c may be combined.

[0042]

As described above, according to the first aspect of the present invention, there is provided an outer shell provided with an air intake port and an air outlet port respectively communicating with the outside, and air inside the outer shell through the air intake port from the outside. Air purifying means provided in the air flow path between the air intake and the air outlet, and purifying air passing through the flow path, and a dirt sensor for detecting the degree of air pollution, When the degree of contamination detected by the dirt sensor exceeds the threshold value of dirt, control means for operating the intake means at a predetermined air volume, and when the state where the degree of contamination detected by the dirt sensor does not exceed the predetermined detection level continues for a predetermined time or more. A threshold setting means for setting the threshold to a value with a lower degree of contamination, wherein the state in which the degree of contamination of the air is low and the degree of contamination detected by the dirt sensor does not exceed the detection level is maintained for a predetermined time. Subsequently, since the threshold value setting means lowers the threshold value, even when the degree of contamination detected by the dirt sensor is low, there is an effect that the control means can easily operate the intake means, and air such as tobacco is not sucked. Even in an environment where the degree of contamination is low, the control means can automatically operate the suction means, which is convenient for users who are sensitive to air pollution.

According to a second aspect of the present invention, in the first aspect, the dirt sensor comprises at least one or more of a gas sensor, an ultraviolet sensor, and a dust sensor. It has the same effect as.

According to a third aspect of the present invention, in the first aspect, the dirt sensor comprises at least one or more of a gas sensor, an ultraviolet sensor, and a dust sensor,
When the degree of contamination detected by any of the sensors exceeds the above-mentioned detection level, the threshold setting means resets the threshold value to the initial set value. When the threshold value is exceeded, the threshold value is returned to the initial set value, so that it is possible to prevent the intake means from frequently operating due to the low threshold value.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the threshold value setting means holds the current threshold value even when the intake means stops, and stops when the intake means operates again. There is an effect that the operation can be performed with the threshold value of time.

According to a fifth aspect of the present invention, in the first aspect of the present invention, a holding means for holding a current threshold value when the power is turned off is provided, and the power supply can be operated at the power-off threshold value when the power is restored. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a block diagram of an air purifier of the present embodiment.

FIG. 2 is a specific circuit diagram in which part of the above is omitted.

FIG. 3 is a specific circuit diagram in which part of the above is partially omitted.

4A is a front view of the same, and FIG. 4B is a top view of the same.

FIG. 5 is a front view showing a state in which the grill is removed.

FIG. 6 is a side view of the same.

FIG. 7 is a front view showing another air purifier of the above.

FIG. 8 is a front view showing another air purifier of the above.

FIG. 9 is a partially omitted specific circuit diagram showing another circuit configuration of the air purifier of the above.

FIG. 10 is a partially omitted specific circuit diagram showing another circuit configuration of the air purifier of the above.

FIG. 11 is a partially omitted specific circuit diagram showing still another circuit configuration of the air purifier of the above.

FIG. 12 is a partially omitted specific circuit diagram showing still another circuit configuration of the air cleaner of the above.

[Explanation of symbols]

 1a Dust sensor 1b Gas sensor 1c Ultraviolet sensor 18 Fan 31a to 31c Threshold setting circuit 32a to 32c Comparison circuit 33 Signal processing circuit 34 Fan control circuit SW Operation switch

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Sadahiko Wakaba 1048 Kadoma Kadoma, Osaka Pref. Matsushita Electric Works, Ltd. Terms (reference) 3L060 AA05 CC08 CC13 DD05 EE05 4C080 AA05 AA10 BB02 CC01 HH01 JJ01 KK02 MM05 QQ11 QQ17 QQ20 4D058 NA01 NA02 NA07 NA10 SA01

Claims (5)

[Claims] An outer shell provided with an air inlet and an air outlet communicating with the outside, an intake means for sucking air from the outside into the outer shell through the air inlet, an air inlet and an air outlet; An air purifying means provided in the air flow path between the mouth and the air purifying the air passing through the flow path, a dirt sensor for detecting the degree of contamination of the air, and the degree of dirt detected by the dirt sensor determines the threshold of dirt. If it exceeds, the control means for operating the intake means at a predetermined air volume, and if the degree of contamination detected by the dirt sensor does not exceed the predetermined detection level for a certain period of time or more, the threshold value is set to a lower value for the degree of contamination. An air purifier comprising: a threshold setting unit that performs setting. 2. The air purifier according to claim 1, wherein the dirt sensor comprises at least one or more of a gas sensor, an ultraviolet sensor, and a dust sensor. 3. The dirt sensor comprises at least one or more of a gas sensor, an ultraviolet sensor, and a dust sensor, and when the degree of contamination detected by any of the sensors exceeds the detection level, the threshold setting means sets a threshold value. The air purifier according to claim 1, wherein the threshold value is returned to an initial setting value. 4. The air purifier according to claim 1, wherein said threshold value setting means keeps the current threshold value even when the intake means stops. 5. The air purifier according to claim 1, further comprising a holding means for holding a current threshold value when the power is turned off.