JP2001062230A - Air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cleaner capable of preventing the operation of a fan caused by transient dirt and noise. SOLUTION: A motor M for driving a fan, a motor control circuit 1 for controlling the operation of the motor M, a dirt detecting part 2, a human body sensitive sensor 4 and a control circuit 5 for controlling the motor control circuit 1 based on the output signal of the human sensitive sensor 4 and the output signal OH, OM and OL of the dirt detecting part 2 when automatic mode is selected by an operation switch SW are provided. The dirt detecting part 2 is provided with a signal processing circuit 3 for outputting the output signal OH, OM and OL in accordance with the dirt of air based on the input from a dust sensor 2a and a gas sensor 2b. The control circuit 5 controls the motor control circuit 1 so that the fan is driven for delay time later when detected output is inputted from the dirt detecting part 2 after lapse of a specified time after detecting no human movement by the human body sensitive sensor 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifier for purifying air.

[0002]

2. Description of the Related Art Conventionally, there has been provided a dust sensor for detecting dust (particles) such as house dust (dust, dust, etc.) and pollen particles in order to detect air contamination, and a fan arranged in a housing. There is provided an air purifier capable of selecting an automatic mode in which the state is switched based on a detection output of a dust sensor. As this type of automatic mode, for example, the rotation speed of the fan is set to low speed, medium speed,
There is a mode in which switching is performed in three steps at high speed. In addition, an automatic mode in which the rotation speed of the fan is switched in three steps of low speed, medium speed, and high speed according to the magnitude relationship between the detection output of the dust sensor and the three thresholds, and the detection output of the dust sensor exceeds the minimum threshold An air purifier that allows the user to select between an automatic mode that drives the fan at a low speed regardless of the size of the dust detection output and prevents the fan speed from shifting to high or medium speed. Provided. In addition, there has been proposed a sensor which includes a gas sensor for detecting an odorous gas component such as cigarette smoke in addition to a dust sensor, and which can select an automatic mode for switching a fan state based on a detection output of the gas sensor.

[0003]

The air purifier as described above is often used in an automatic mode when used in a room requiring quietness, such as a bedroom or a study.
By the way, dust in a room floats in the air during the activity of a person, but when the activity of the person stops, the movement of the air decreases, and the suspended dust gradually falls (settling phenomenon occurs). Therefore, for example, when the automatic mode in which the rotational speed of the fan is switched in three stages of low speed, medium speed, and high speed is selected in the air purifier installed in the bedroom, the detection level of the dust sensor before bedtime is smaller than the minimum threshold. Even if the fan is stopped because it is too small, the dust detected by the dust sensor exceeds the minimum threshold value due to the dust that gradually falls after going to bed (such dust is transient dirt), and the fan operates at a low speed. Was sometimes driven. Further, when the fan is operated, the surrounding air is taken in, the detection level is increased, and the fan is switched from the low speed to the medium speed.

Further, for example, even in a study or the like, after a person is seated and the movement is reduced, the fan may be operated at a low speed due to a temporary dirt. Further, there is a disadvantage that the fan is started even when a transient noise that exceeds the threshold value occurs in the detection output of the dust sensor.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an air purifier that can prevent a fan from being operated due to transient dirt or noise. .

[0006]

According to a first aspect of the present invention, there is provided a fan driving device for driving a fan which is disposed in a housing and which sucks in and blows out external air. Air purifying means for purifying the air sucked into the air, a dirt detecting unit for obtaining a detection output corresponding to the dirt of the air, a human sensor for detecting the motion of a person in the detection area, and a human sensor by the human sensor. Control means for controlling the fan driving device such that when a detection output is input from the dirt detection unit after a specified time has passed after the movement is no longer detected, the fan is driven with a predetermined delay time. In the state where the motion of the person is not detected by the human sensor,
When a detection output due to transient dirt or noise that does not need to drive the fan is generated from the dirt detection unit, it is possible to prevent the fan from being driven immediately.

A second aspect of the present invention is characterized in that, in the first aspect of the present invention, the rotation speed of the fan can be switched in a plurality of steps.

According to a third aspect of the present invention, in the second aspect of the present invention, the fan driving device can switch the rotational speed of the fan at least in three stages of a low speed mode, a medium speed mode, and a high speed mode, and When the fan drive is controlled with a delay time, the fan drive is controlled so that the fan is driven in the low-speed mode.Therefore, when the fan is used in a room where quietness is required, such as a bedroom or study, It is possible to prevent the fan from being driven immediately when a detection output due to transient dirt or noise that does not need to be driven is generated from the dirt detection unit, and to maintain quietness.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the control means controls the fan driving device so that the fan is driven in the low-speed mode with a delay of the delay time, and then the low-speed mode is kept constant. Since the fan drive device is controlled so as to be maintained for a long time, the quietness can be more reliably maintained.

A fifth aspect of the present invention, in the third aspect of the present invention, further comprises an operation section for switching and setting the rotation speed of the fan at least in three stages of a low speed mode, a medium speed mode, and a high speed mode. When a mode other than the low-speed mode is set by the operation unit, the fan driving device is controlled so that the fan is driven in the low-speed mode for a certain time when the fan driving device is controlled with the delay time. , It is possible to more surely keep quiet.

According to a sixth aspect of the present invention, in the first to fifth aspects of the present invention, the dirt detecting section includes a dirt sensor comprising at least one of a dust sensor for detecting dust and a gas sensor for detecting odor component gas. And a signal processing circuit for obtaining a detection output corresponding to air contamination based on the detection output of the contamination sensor.

According to a seventh aspect of the present invention, there is provided a fan driving device for driving a fan provided in a housing to suck in and blow out external air, air purifying means for purifying the air sucked into the housing, and air. A dirt detection unit that obtains a detection output according to the dirt of the light, a light-dark sensor that obtains a binary output according to the lightness / darkness with respect to the reference value of the surrounding brightness, and the output of the light-dark sensor is defined as a dark level. Control means for controlling the fan driving device such that the fan is driven with a delay of a predetermined delay time when a detection output is input from the dirt detection unit after a lapse of time. Yes, after the surroundings have darkened, it is necessary to prevent the fan from being driven immediately when a detection output is generated from the dirt detection unit due to transient dirt or noise that does not require driving the fan. Can.

According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the rotation speed of the fan can be switched in a plurality of steps.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, the fan driving device can switch the rotation speed of the fan at least in three stages of a low speed mode, a medium speed mode, and a high speed mode, and When the fan drive is controlled with a delay time, the fan drive is controlled so that the fan is driven in the low-speed mode.Therefore, when the fan is used in a room where quietness is required, such as a bedroom or study, It is possible to prevent the fan from being driven immediately when a detection output due to transient dirt or noise that does not need to be driven is generated from the dirt detection unit, and to maintain quietness.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the control means controls the fan driving device so that the fan is driven in the low-speed mode with a delay of the delay time, and then the low-speed mode is kept constant. Since the fan drive device is controlled so as to be maintained for a long time, the quietness can be more reliably maintained.

According to an eleventh aspect of the present invention, in the ninth aspect of the present invention, there is provided an operation unit for setting the rotational speed of the fan at least in three stages of a low speed mode, a medium speed mode, and a high speed mode, and the control means comprises: When a mode other than the low-speed mode is set by the operation unit, the fan driving device is controlled so that the fan is driven in the low-speed mode for a certain time when the fan driving device is controlled with the delay time. , It is possible to more surely keep quiet.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) As shown in FIG. 1, an air purifier of the present embodiment operates in an operation mode (automatic mode, low-speed mode,
A medium speed mode, a high speed mode) and a sirocco fan 2 disposed in the housing 20 (see FIGS. 6 to 9).
A motor M as a fan driving device for driving the two fans F (see FIGS. 6 to 9), a motor control circuit 1 for controlling the operation of the motor M, and a dirt detecting unit 2 for obtaining a detection output corresponding to the dirt of air. A human sensor 4 for detecting the movement of a person in a detection area formed in front of the housing 20; an output signal of the human sensor 4 and an output signal OH of the dirt detector 2;
A control circuit 5 for controlling the motor control circuit 1 based on OM and OL. Here, the dirt detection unit 2
Is a dust sensor 2a that detects dust (particles) such as house dust and pollen, a gas sensor 2b that detects an odorous component gas such as cigarette smoke, and an air dirt sensor based on inputs from the sensors 2a and 2b. Output signals OH, O according to
And a signal processing circuit 3 for outputting M and OL. Further, when the detection output is input from the dirt detection unit 2 after the specified time T1 has elapsed after the human body detection output from the human sensor 4 disappears, the control circuit 5 drives the fan F with a delay of a predetermined delay time T2. Motor control circuit 1
Is configured to be controlled. Further, the motor control circuit 1 has a function of controlling the operation of the motor M based on the output signals OH, OM, OL of the dirt detection unit 2 and the output signal of the control circuit 5.

By the way, as shown in FIGS. 6 to 9, the air purifier having the above-described circuit configuration has a housing 20.
A grill 27 is detachably attached to the front portion of the housing 20 to form an outer shell.
And a motor M are housed therein. Air suction portions 28a and 28b for sucking air by the rotation of the fan F are provided at one side portion and the rear portion of one side portion of the housing 20, respectively.
Is provided on the other side of the housing 20, and an air blowing section 19 for blowing air by rotation of the fan F is provided. In the housing 20, an air suction portion 28 is provided.
a, 28b house dust (for example,
A discharge electrode block 23 for generating plasma for charging dust, pollen, etc., and decomposing odorous component gases into odorless components;
Downstream (ie, between the discharge electrode block 23 and the fan F), a filter block 24 that adsorbs house dust and pollen charged by the discharge electrode block 23 and adsorbs odorous component gas is stored. I have. The filter block 24 is, for example, a dust collection filter (for example, a so-called HEP) for adsorbing charged house dust or pollen.
A filter) and activated carbon that adsorbs odorous component gas, a dust collection filter and a deodorizing filter, or other configurations.

Therefore, in the air purifier of the present embodiment, by rotating the fan F, the air suction portion 2
8a and 28b, air is sucked from the discharge electrode block 2
The air that has been cleaned by passing through the filter block 3 and the filter block 24 is blown out from the air blowing unit 19. An air inlet 41 for the dust sensor 2a is provided on the front side of the housing 20, and the air inlet 41 is adapted to remove house dust, pollen, and the like riding on the air sucked into the air suction unit 28a. It is desirable to provide at a position where detection is easy. That is, it is desirable that the air introduction part 41 be provided near the air suction part 28a or the air suction part 28b. In the present embodiment, the discharge electrode block 23
The filter block 24 and the filter block 24 constitute an air purifying means for purifying the air sucked into the housing 20. Further, the motor control circuit 1 and the control circuit 5 constitute control means.

As shown in FIG. 9, an operation switch SW, a human sensor 4, a gas sensor 2b, and a light emitting diode LED1 for displaying operation described later are provided in the housing 20.
6, a circuit board 40 on which the LED 4 and the like are mounted is also provided. As shown in FIG.
An operation panel 26 provided with light-transmitting windows LE1 to LE4 of the LED 4 is provided. The air purifier of the present embodiment has a degree of air contamination based on the output signal of the dust sensor 2a (amount of dust (mg) in 1 m ³ of air).
Is digitally displayed by a numeral (see FIG. 9).
(See FIG. 9) and a level display unit 24 (see FIG. 9) for displaying the level of the odor based on the output signal of the gas sensor 2b. Here, the dirt display 50 is provided near each of the display units 22 and 24.
24, a nameplate indicating the display content of each is provided. Further, the stain display body 50 is rotatable in a plane including the display surface.

A stand 21 is attached to the housing 20. This stand 21 is shown in FIG.
6 is detachable with respect to the lower surface side of the housing 20 and the left side surface side of the housing 20 in the same figure, and by attaching a stand 21 as shown in FIGS. The vertical position may be used, or the stand 20 may be used in a horizontal position in which the longitudinal direction of the housing 20 is changed to the left-right direction instead of the mounting position. When used in the horizontal orientation, the dirt display 50 is rotated 90 degrees (FIG. 9 shows the dirt display 50 rotated 90 degrees from the state of FIG. 6), and a nameplate or the like is attached. You can fix it.

Hereinafter, the dirt detector 2, the fan control circuit 1,
Each of the control circuits 5 will be specifically described.

The dirt detector 2 has a circuit configuration as shown in FIG. 2, and the signal processing circuit 3 changes the output signals OH, OM, OL based on the output signals of the sensors 2a, 2b. Has become. That is, the signal processing circuit 3 includes comparators CP1 to CP3 that compare the output signal of the dust sensor 2a with the thresholds set by the first threshold setting unit 31 including the series circuit of the resistors R1 to R4. . In addition, the signal processing circuit 3 includes comparators CP4 to CP6 that compare the output signal of the gas sensor 2b with the thresholds set by the second threshold setting unit 32 including a series circuit of the resistors R6 to R9. Further, the signal processing circuit 3 includes AND elements AN7 to AN14 and an OR element Or.
15 to 17, and AND elements AN18 and AN19. The output signal of the OR element Or15 is
H, the output signal of the AND element AN18 is the output signal O
M, the output signal of the AND element AN19 is the output signal O
L. The dirt detecting unit 2 outputs the output signals OH, OM, O based on the output signals of the dust sensor 2a and the gas sensor 2b which have exceeded the upper threshold.
L is determined.

The operation of the signal processing circuit 3 will be described.
For example, assuming that the dust sensor 2a outputs an output signal having a level higher than the threshold value of the comparator CP2 and lower than the threshold value of the comparator CP1, the output signals of the comparators CP2 and CP3 are at “H” level, and the output signal of the comparator CP1 is It becomes "L" level. Then, the output signal of the AND element AN7 becomes “L” level and the output signal of the AND element AN8 becomes “H” level. The output signals of the AND elements A7 and AN8 change the output signal of the AND element A11 to "H" level and the output signal of the AND element AN12 to "L" level.

On the other hand, for example, assuming that the gas sensor 2b outputs an output signal having a level larger than the threshold value of the comparator CP6 and smaller than the threshold value of the comparator CP5, the output signal of the comparator CP6 becomes "H" level, Output signal is "L"
Become a level. Then, the output signals of the AND elements AN9 and AN10 become “L” level. The output signals of the AND elements AN9 and AN10 are used to generate the AND element A1.
3 goes low, and the output signal of the AND element AN14 goes high.

Therefore, the OR elements Or15, Or1
6 and Or17 output signals are respectively “L” level and “L” level.
Then, the output signal of the AND element AN18 becomes “H” level and the output signal AN becomes “H” level.
The output signal of D element AN19 goes to "L" level. As a result, an output signal of a level larger than the threshold value of the comparator CP2 (the second largest threshold value among the three threshold values) and smaller than the threshold value of the comparator CP1 (the largest threshold value among the three threshold values) is output from the dust sensor 2a. Is larger than the threshold value of the comparator CP6 (the minimum threshold value among the three threshold values) from the gas sensor 2b.
P5 threshold (the second largest of the three thresholds)
If an output signal of a smaller level is output,
The output signals OH, OM, OL of the dirt detector 2 are respectively "
L level, H level, and L level.In the present embodiment, the dust sensor 2a and the gas sensor 2
b, the dirt sensor is composed of only the dust sensor 2a. When the dirt sensor is composed of only the dust sensor 2a, the output signals OH, OM, OL of the signal processing circuit 3 of the dirt detector 2 are at "L" level, respectively. The "H" level and the "L" level are set, and the fan F is rotated at a medium speed.
In the case of using only b, the output signals OH, OM, OL of the signal processing circuit 3 of the dirt detection unit 2 become "L" level, "L" level, "H" level, respectively, and the fan F operates at a low speed. Rotated.

Next, the motor control circuit 1 will be described.

As shown in FIG. 3, the motor control circuit 1 operates the fan F in accordance with the output signal OH, OM, OL of the signal processing circuit 3 or the output signal of the control circuit 5 (stop, low speed, medium speed). Speed, high speed), a low speed mode in which the fan F rotates at a low speed, a medium speed mode in which the fan F rotates at a medium speed, and a high speed mode in which the fan F rotates at a high speed. The above-mentioned operation switch SW is connected. That is, the motor control circuit 1 is provided with the counter 11 that switches among the output signals AUTO, LOW, MID, HIGH, and OFF by operating the operation switch SW. Here, the output signals AUTO, LOW, MID, HIGH,
OFF is set to AUT every time the operation switch SW is operated.
O → LOW → MID → HIGH → OFF → AUTO → ...
In this order, only one output signal goes high. Further, the motor control circuit 1 receives the AUTO signal at one input terminal and receives the output signals OL, OM, and OH of the dirt detection unit 2 at the other input terminal, respectively. AND elements AN30, AN31, AN32 And the light-emitting diodes LED1, LED2, LED3, and LED for operation display described above.
4 and an AC power source V composed of a motor M and a commercial power source, respectively.
s and triacs TRC1 and TRC inserted between
2, TRC3 and each triac TRC1, TRC2,
Photocouplers PC1 and TR1 that turn on and off each of TRC3
PC2 and PC3. The operation switch S
The W operation unit 12 (see FIG. 6) is provided on the front side of the housing 20 (see FIG. 6).

The operation of the motor control circuit 1 will be described. When the operation switch SW is operated only once, the output signal AUTO of the counter 11 becomes "H" level, so that the light emitting diode LED1 is turned on. Here, when the light emitting diode LED1 is turned on, it is displayed that the operation mode of the fan F is the automatic mode. Thereafter, when the operation switch SW is operated, the output signal LOW of the counter 11 becomes “H” level.
D2 lights up, the photocoupler PC1 turns on, the triac TRC1 turns on, and the motor M rotates at a low speed (that is, the fan F 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 F is the low-speed mode. Further, when the operation switch SW is operated thereafter, the output signal MID of the counter 11 becomes "H" level, so that the light emitting diode LED3 is turned on, the photocoupler PC2 is turned on, the triac TRC2 is turned on, and the motor M is turned on. The fan rotates at a medium speed (that is, the fan F 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 F is the medium speed mode. Next, when the operation switch SW is operated, the output signal HIGH of the counter 11 becomes "H" level, so that the light-emitting diode LED4 is turned on and the photocoupler PC3 is turned on to activate the triac TR.
C3 is turned on, and the motor M rotates at high speed (that is, the fan F rotates at high speed). Here, the light emitting diode L
When the ED 4 is turned on, it is displayed that the operation mode of the fan F is the high-speed mode. Subsequently, when the operation switch SW is operated, the output signal of the counter 11 is turned off.
When the signal goes high, another output signal AU
Since TO, LOW, MID, and HIGH are all at the “L” level, the rotation of the motor M is stopped (that is, the rotation of the fan F is stopped).

Next, the control circuit 5 will be described.

As shown in FIG. 4, the control circuit 5 outputs the output of the human sensor 4 to the analog switch AS1 and the inverter I.
Two timer circuits 51 and 5 input via NV1
2 is provided. Here, the analog switch AS
1 turns on when the output signal AUTO of the counter 11 of the motor control circuit 1 shown in FIG.
Turn off when level. In addition, each timer circuit 51,5
2, when the human body detection output from the human sensor 4 is input, the output signals O1 and O3 are output for specified times T1 and T1 ', respectively.
(T1 ′ = T1 in this embodiment) only “H”
Level, and the output signal O
1, O3 are set to the "L" level, and the output signals O2,
O4 is set to the "H" level. However, the human sensor 4 detects a slight movement of a person and continuously obtains an output.
When the human body detection output by the human sensor 4 is input again during the counting of the specified times T1 and T1 '(before the timer is up), the count is reset and the specified times T1 and T1 are reset.
The counting of 1 'is started again (retrigger method). Therefore, each of the timer circuits 51, 52
When the motion of the person is no longer detected by the human sensor 4, the output signals O1 and O1 are output after the specified times T1 and T1 '.
3 goes low and the output signals O2 and O4 go high. Here, the output signal O1 of the timer circuit 51
Is input to the terminal LO of the motor control circuit 1 shown in FIG. Note that the timer circuits 51 and 52 do not need to adopt the retrigger method.

The output signal O4 of the timer circuit 52 is input to one input terminal of the control circuit 5, and the output signal OH of the signal processing circuit 3 (dirt detector 2) shown in FIG. AND element AN to which OM and OL are respectively input
40, AN41, AN42, and each AND element AN40,
It has delay timer circuits 53, 54, 55 connected to the output terminals of AN41, AN42, respectively, and the output signals of each of the delay timer circuits 53, 54, 55 are supplied to the terminal HI of the motor control circuit 1 shown in FIG. , MI, LO. Here, each of the delay timer circuits 53, 54, 55 is provided with an AND element AN40,
When the output signals of AN41 and AN42 become "H" level, delay times T2, T2 'and T2 "(in this embodiment, T2
= T2 '= T2 ") and delay the output signal by"
H ”level.

The operation in the automatic mode is summarized in FIG.
become that way. Here, FIG. 5A shows the detection state of the human sensor 4, FIG. 5B shows the detection state of the dust sensor 2a,
(C) is the detection state of the gas sensor 2b, (d) is the fan F
Are shown, respectively. In the example shown in FIG. 5, the output signal of the gas sensor 2b shown in FIG. 5C does not exceed any threshold set by the second threshold setting unit 32 shown in FIG.

Firstly, the movement of people by the human sensor 4 at time t ₁ as shown in FIG. 5 (a) is detected, the output signal O1 of the timer circuit 51 of the control circuit 5 becomes "H" level Therefore, the photocoupler PC1 of the motor control circuit 1
Is turned on, the triac TRC1 is turned on, and the motor M rotates at low speed, so that the two fans F start rotating at low speed (see FIG. 5D). Thereafter, the fan F after the movement of people at time t ₂ is not detected as shown in FIG. 5 (a) is stopped. Then, the output signal O4 of the timer circuit 52 of the control circuit 5 from the movement of people in the time t ₂ is no longer detected after a lapse the predetermined time T1 has become the "H" level (not shown), Fig. 5 the output signal of the dust sensor 2a at time t ₃ as shown in (b) is first shown in FIG. 2
Exceeds the threshold value determined by the potential of the connection point between the resistors R3 and R4 of the threshold setting unit 31 of FIG.
Since H, OM, and OL become “L” level, “L” level, and “H” level, respectively, the output signals of the AND elements AN40, AN41, and AN42 of the control circuit 5 shown in FIG. The signal goes to the “L” level and the “H” level, and the “H” level output signal is input from the AND element AN42 to the delay timer circuit 55, and the terminal LO of the motor control circuit 1 goes to the “H” level after a delay time T2. , And the low-speed rotation of the fan F is started (see FIG. 5D).

When the air purifier of the present embodiment is installed in a room requiring quietness, such as a bedroom or a study, and the automatic mode is selected by the operation switch SW,
In a state where the motion of the person is not detected by the human sensor 4 (for example, at the time of going to bed or sitting), the dirt detecting unit 2 generates a detection output due to transient dirt or noise that does not need to drive the fan F. In this case, it is possible to prevent the fan F from being immediately driven.

(Embodiment 2) As shown in FIG. 10, the air purifier of the present embodiment
A light / dark sensor 6 is provided which can obtain a binary output according to light / dark with respect to a reference value of ambient brightness. Here, the brightness sensor 6 is a sensor that generates a binary output according to the magnitude relationship between the detected brightness and the reference value. In the air purifier according to the present embodiment, the air suction portions 28 a and 28 b are provided on the lower surface side and the front surface side of the housing 20, respectively, and the air blowing portion 29 is provided on the upper surface side of the housing 20. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The basic circuit configuration of the air purifier of this embodiment is substantially the same as that of the first embodiment. Instead of the motion sensor 4 and the control circuit 5 of the first embodiment, a light / dark sensor 6 as shown in FIG. , A control circuit 5 'is adopted, and illustration and description of the same components as those in the first embodiment are omitted.

Hereinafter, the control circuit 5 'will be described.

As shown in FIG. 11, the control circuit 5 'includes a timer circuit 57 to which the output of the light / dark sensor 6 is input via the analog switch AS11, the inverter INV11, and the differentiation circuit 56. Here, the analog switch AS11 turns on when the output signal AUTO of the counter 11 of the motor control circuit 1 shown in FIG. 3 is at "H" level, and turns off when it is at "L" level. When a signal output from the differentiation circuit 56 is input when the output from the light / dark sensor 6 changes from “H” level (bright level) to “L” level (dark level), the timer circuit 57 outputs The signal O13 is set to “H” level for a specified time T1, and after the specified time T1, the output signal O13 is set to “L” level and the output signal O14 is set to “H” level.

The control circuit 5 'includes a timer circuit 57.
Are input to one input terminal and output signals OH, OM, OL of the signal processing circuit 3 (dirt detection unit 2) shown in FIG. 2 are input to the other input terminal. AN42 and each AND element AN4
0, AN41, AN42, and delay timer circuits 53, 54, 55 respectively connected to the output terminals of the motor control circuit 1 shown in FIG. The signals are input to terminals HI, MI, and LO. Here, each of the delay timer circuits 53, 54, 55 is connected to an AND element AN4.
0, AN41 and AN42 become “H” level, the delay time T2, T2 ′, T2 ”(in this embodiment, T2
2 = T2 ′ = T2), and the output signal is set to “H” level.

The operation in the automatic mode is summarized in FIG.
It looks like 1. Here, FIG. 11A shows the detection state of the light / dark sensor 6, FIG. 11B shows the detection state of the dust sensor 2a,
(C) is the detection state of the gas sensor 2b, (d) is the fan F
Are shown, respectively. In the example shown in FIG. 11, the output signal of the gas sensor 2b shown in FIG. 11C does not exceed any of the thresholds set by the threshold setting unit 32 shown in FIG.

First, as shown in FIG.
₁₁The output signal of the light / dark sensor 6 is at "H" level
("Bright") to "L" level ("Dark")
The signal output from the differentiating circuit 56 is
When input, the output signal O13 of the timer circuit 57 becomes "
H ”level, after the specified time T1 has elapsed
The output signal O14 of the circuit 57 becomes “H” level, and FIG.
At time t as shown in FIG. ₁₂Dust sensor 2a
Output signal of the first threshold setting unit 31 shown in FIG.
Exceeds the threshold determined by the potential at the connection point between R3 and resistor R4
And the output signals OH, OM, OL of the dirt detector 2
The “L” level, “L” level, and “H” level
Therefore, each AND element AN4 of the control circuit 5 'shown in FIG.
0, the output signals of AN41 and AN42 are “L” level,
It becomes L level and “H” level, and the AND element AN4
2 to “H” level output signal to delay timer circuit 55
The input of the motor control circuit 1 is delayed by the delay time T2.
The child LO becomes “H” level, and the low-speed rotation of the fan F opens.
(See FIG. 11D).

When the air purifier of this embodiment is installed in a room such as a bedroom where quietness is required, and the automatic mode is selected by the operation switch SW, the fan F is driven after the room is darkened. It is possible to prevent the fan F from being immediately driven when a detection output due to transient dirt or noise that does not need to be generated is generated from the dirt detection unit 2.

(Embodiment 3) The basic configuration of the air purifier of the present embodiment is substantially the same as that of Embodiment 1, and each of the delay timer circuits 53 to 5 in the control circuit 5, as shown in FIG.
5 is configured to be input to the terminal LO of the motor control circuit 1. Other configurations are the same as those of the first embodiment, and illustration and description are omitted.

The operation in the automatic mode can be summarized as shown in FIG.
It looks like 4. 14A shows the detection state of the human sensor 4, FIG. 14B shows the detection state of the dust sensor 2a,
(C) is the detection state of the gas sensor 2b, (d) is the fan F
Are shown, respectively. In the example shown in FIG. 14, the output signal of the gas sensor 2b shown in FIG. 14C does not exceed any of the thresholds set by the second threshold setting unit 32 shown in FIG.

Firstly, the time _{t 1} as shown in FIG. 14 (a)
When the human motion is detected by the human sensor 4 at
Since the output signal O1 of the timer circuit 51 of the control circuit 5 becomes “H” level, the photocoupler PC of the fan control circuit 1
1 turns on, the triac TRC1 turns on, and the motor M rotates at a low speed, so that the two fans F start rotating at a low speed (see FIG. 14D). Thereafter, the fan F after the movement of people at time t ₂ as shown in FIG. 14 (a) was not detected is stopped. The output signal O4 of the timer circuit 52 of the control circuit 5 from the longer movement of people at the time t ₂ is detected after the specified time T1 has elapsed "
H "becomes level (not shown), the output signal of the dust sensor 2a at time t ₃ as shown in FIG. 5 (b) and the resistor R3 and the resistor R4 of the first threshold value setting unit 31 shown in FIG. 2 Exceeds the threshold value ThL determined by the potential of the connection point
Output signals OH, OM, OL become "L" level, "L" level, and "H" level, respectively, so that the AND elements AN40, AN41, A of the control circuit 5 shown in FIG.
The output signal of N42 is "L" level, "L" level,
H level, the AND element AN42 outputs “H” level.
The output signal of the level is input to the delay timer circuit 55, and the terminal LO of the fan control circuit 1 is delayed by the delay time T2.
H "level, and the low-speed rotation of the fan F is started (see FIG. 14 (d)). Then, as shown in FIG. 14 (b), the output signal of the dust sensor 2a rises and the signal shown in FIG. When the threshold value ThM determined by the potential of the connection point between the resistor R2 and the resistor R3 of the threshold setting unit 31 is exceeded, the output signals OH, OM, and OL of the dirt detection unit 2 are set to “L” level and “L” respectively.
Since they are at H level and L level, the AND elements AN40, AN41, AN42 of the control circuit 5 shown in FIG.
Become "L" level, "H" level, and "L" level, an "H" level output signal is input from the AND element AN41 to the delay timer circuit 54, and delayed by the delay time T2. Outputs an "H" level output signal. When the output signal of the dust sensor 2a rises and exceeds the threshold value ThH determined by the potential at the connection point between the resistors R1 and R2 of the threshold value setting unit 31 shown in FIG. , OL become “H” level, “L” level, and “L” level, respectively, so that the AND elements AN40, AN41, A of the control circuit 5 shown in FIG.
The output signal of N42 is "H" level, "L" level,
The signal becomes L level, and the output signal of “H” level is input from the AND element AN40 to the delay timer circuit 53, and the output signal of “H” level is output from the delay circuit 53 with a delay of the delay time T2.

When the air purifier according to the present embodiment is installed in a room such as a bedroom or a study where quietness is required, and the automatic mode is selected by the operation switch SW, the human sensor 4 detects a person. After a certain period of time has passed since the movement is no longer detected, the output signal O of the stain detector 2 is output.
When any one of H, OM, OL becomes "H" level, the fan F is rotated at a low speed after the delay time T2 of the delay timer circuits 53 to 55 has elapsed. That is, the fan F
Is rotated at a low speed irrespective of which of the output signals OH, OM, OL of the dirt detector 2 is at the "H" level.

(Embodiment 4) The basic configuration of the air purifier of the present embodiment is substantially the same as that of Embodiment 2 and, as shown in FIG. 15, each of the delay timer circuits 53 to 53 in the control circuit 5 '.
It is characterized in that an output signal of 55 is input to a terminal LO of the motor control circuit 1. The other configuration is the same as that of the second embodiment, so that illustration and description are omitted.

The operation in the automatic mode is summarized in FIG.
It looks like 6. Here, FIG. 16A shows the detection state of the light / dark sensor 6, FIG. 16B shows the detection state of the dust sensor 2a,
(C) is the detection state of the gas sensor 2b, (d) is the fan F
Are shown, respectively. In the example shown in FIG. 16, the output signal of the gas sensor 2b shown in FIG. 16C does not exceed any of the thresholds set by the second threshold setting unit 32 shown in FIG.

First, as shown in FIG.
_{In 11} , when the signal output from the differentiation circuit 56 is input to the timer circuit 57 when the output signal of the light / dark sensor 6 changes from “H” level (“bright”) to “L” level (“dark”) , The output signal O13 of the timer circuit 57 becomes "
H level (not shown), and after the lapse of the specified time T1, the output signal O14 of the timer circuit 57 goes high (not shown), and as shown in FIG.
_{At 12} the output signal of the dust sensor 2a is changed to the first signal shown in FIG.
Exceeds the threshold value ThL determined by the potential of the connection point between the resistor R3 and the resistor R4 of the threshold setting unit 31, the output signals OH, OM, OL of the dirt detection unit 2 are at "L" level and "L", respectively.
Level, the output signals of the AND elements AN40, AN41, AN42 of the control circuit 5 'shown in FIG. 15 become "L" level, "L" level, "H" level, and An "H" level output signal is input from the element AN42 to the delay timer circuit 55, the terminal LO of the fan control circuit 1 becomes "H" level with a delay of the delay time T2, and the low speed rotation of the fan F is started (FIG. 16 (d)). Thereafter, as shown in FIG. 16B, the output signal of the dust sensor 2a rises, and the threshold value Th determined by the potential of the connection point between the resistor R2 and the resistor R3 of the threshold value setting unit 31 shown in FIG.
M, the output signals OH, OM, O of the stain detector 2
Since L becomes "L" level, "H" level, and "L" level, respectively, the output signals of the AND elements AN40, AN41, AN42 of the control circuit 5 'shown in FIG. 15 become "L" level, "H". The output signal of the "H" level is input from the AND element AN41 to the delay timer circuit 54, and is delayed by the delay time T2.
Outputs an "H" level output signal. FIG.
As shown in FIG. 6, when the output signal of the dust sensor 2a further rises and exceeds the threshold value ThH determined by the potential of the connection point between the resistors R1 and R2 of the first threshold value setting unit 31 shown in FIG. 2 are at "H" level, "L" level, and "L" level, respectively, so that each AND element AN4 of the control circuit 5 'shown in FIG.
0, the output signals of AN41 and AN42 are “H” level,
L level and L level, and the AND element AN4
An output signal of “H” level from 0 is input to the delay timer circuit 53 and delayed from the delay circuit 53 by the delay time T2.
An H-level output signal is output.

When the air purifier of the present embodiment is installed in a room such as a bedroom where quietness is required, and the automatic mode is selected by the operation switch SW,
If any one of the output signals OH, OM, OL of the dirt detection unit 2 becomes "H" level after a certain time has passed since the room was darkened, the delay time T of the delay timer circuits 53 to 55 is set.
After elapse of 2, fan F is rotated at a low speed. That is, the fan F outputs the output signals OH, OM, O
Regardless of which L is at the "H" level, the motor is rotated at a low speed.

(Embodiment 5) The basic configuration of the air purifier of this embodiment is substantially the same as that of Embodiment 1, except that the circuit configuration of the control circuit 5 is different. Since they are the same, illustration and description of the same components as those in the first embodiment are omitted.

The control circuit 5 according to the present embodiment is configured as shown in FIG.
As shown in (1), there are provided two timer circuits 51 and 52 to which the output of the human sensor 4 is input via the analog switch AS1 and the inverter INV1. put it here,
The analog switch AS1 is turned on when the output signal AUTO of the counter 11 of the motor control circuit 1 shown in FIG. 3 is at "H" level, and turned off when it is at "L" level. Also,
When the human body detection output from the human sensor 4 is input, each of the timer circuits 51 and 52 sets the output signals O1 and O3 to specified times T1 and T1 '(in the present embodiment, T1 = T1' as in the first embodiment). ), The output signals O1 and O3 are set to the "L" level and the output signals O2 and O4 are set to the "H" level after the specified time T1 has elapsed. However, the human sensor 4 detects a slight movement of a person and continuously obtains an output. Each of the timer circuits 51 and 52 outputs the human body detection output by the human sensor 4 during the counting of the specified time T1. Is reset, the count is reset and the counting of the specified time T1 is started again. Therefore, when the human motion is no longer detected by the human sensor 4, the timer circuits 51 and 52 output the signals O1 and O3 to the "L" level and output signals O2 and O4 to "L" after the specified time T1.
H ”level. Here, each of the timer circuits 51,
The output signals O1 and O3 of the respective 52 are input to the terminal LO of the motor control circuit 1 shown in FIG.

An OR element Or64 to which the output signals OH, OM, OL of the dirt detector 2 are input is input to the control circuit 5.
And an AND element AN63 in which the output signal O4 of the timer circuit 52 is input to one input terminal and the output signal of the OR element Or64 is input to the other input terminal, and a differentiating circuit 58 to which the output signal of the AND element AN63 is input. A timer circuit 59 to which an output signal of the differentiating circuit 58 is input, and a timer circuit 5
9 are input to one input terminal and output signals OH, OM, OL of the signal processing circuit 3 (dirt detection unit 2) shown in FIG. 2 are input to the other input terminal. , AN62, and each A
The output signals of the ND elements AN60, AN61, AN62 are respectively connected to the terminals HI, MI,
The data is input to the LO. Here, when the signal output from the differentiating circuit 58 is input when the output signal of the AND element 63 changes from “L” level to “H” level, the timer circuit 59 changes the output signal O25 for a certain period of time T3. Only after the predetermined time T3, the output signal O25 is set to the "L" level and the output signal O26 is set to the "H" level.

The operation in the automatic mode is summarized in FIG.
It looks like 8. Here, FIG. 18A shows a detection state of the human sensor 4, FIG. 18B shows a detection state of the dust sensor 2a,
(C) is the detection state of the gas sensor 2b, (d) is the fan F
Are shown, respectively. In the example shown in FIG. 18, the output signal of the gas sensor 2b shown in FIG. 18C does not exceed any of the thresholds set by the second threshold setting unit 32 shown in FIG.

[0056] First, the time _{t 1} as shown in FIG. 18 (a)
When the human motion is detected by the human sensor 4 at
Since the output signal O1 of the timer circuit 51 of the control circuit 5 becomes “H” level, the photocoupler PC of the motor control circuit 1
1 turns on, the triac TRC1 turns on, and the motor M rotates at low speed, so that the two fans F start rotating at low speed (see FIG. 18D). Then, when the movement of the person is no longer detected at time t ₂ as shown in FIG. 18 (b), the output signal O2, O4 of the timer circuit 52 and 53 of the control circuit 5 after the specified time T1 has elapsed is "H "level (not shown), the output signal of the dust sensor 2a at time t ₃ as shown in FIG. 18 (c) is between resistors R3 and R4 of the first threshold value setting unit 31 shown in FIG. 2 When the threshold value ThL determined by the potential at the connection point is exceeded, the output signal O of the stain detection unit 2 is output.
H, OM, and OL become “L” level, “L” level, and “H” level, respectively. Then, the output signal of the OR element Or64 of the control circuit 5 shown in FIG. 17 becomes “H” level, the output signal of the AND element AN63 becomes “H” level, and the timer circuit 59 outputs the output signal of the AND element AN63. Is changed from the "L" level to the "H" level, when the signal output from the differentiating circuit 58 is input, the output signal O25 is set to the "H" level for a certain time T3.
When the photocoupler PC1 of the motor control circuit 1 is turned on, the triac TRC1 is turned on, and the motor M rotates at a low speed, the two fans F start rotating at a low speed (FIG. 18).
(D)). Then, the output signal O26 becomes "H" level after the lapse of the predetermined time T3, and thereafter the fan F is rotated based on the output signals OH, OM, OL of the dirt detector 2. In short, for example, the output signals OH, OM, OL of the dirt detection unit 2 are at “L” level and “H”, respectively.
Level, "L" level, the rotation speed of the fan F changes to medium speed, and the output signals OH, O
M and OL are “H” level, “L” level, “
When the L level is reached, the rotation speed of the fan F changes to a high speed.

When the air purifier according to the present embodiment is installed in a room where quietness is required, such as a bedroom or a study, and the automatic mode is selected by the operation switch SW, the human sensor 4 detects a person. After a certain period of time has passed since the movement is no longer detected, the output signal O of the stain detector 2 is output.
Even if any of H, OM, OL goes to "H" level, the fan F rotates at low speed until the output signal O25 of the timer circuit 59 goes from "H" level to "L" level. That is, the fan F outputs the output signal O of the stain detection unit 2.
Regardless of which of H, OM, and OL is at the “H” level, the rotation is performed at a low speed.

(Embodiment 6) The basic configuration of an air purifier of this embodiment is substantially the same as that of Embodiment 2, and the control circuit 5 '
Only the circuit configuration of the second embodiment is different, and other configurations are the same as those of the second embodiment. Therefore, illustration and description of the same components as those of the second embodiment are omitted.

The control circuit 5 'according to the present embodiment has the configuration shown in FIG.
As shown in FIG. 9, there is provided a timer circuit 57 to which the output of the light / dark sensor 6 is inputted via the analog switch AS11, the inverter INV11 and the differentiating circuit 56. Here, the analog switch AS11 sets the output signal AUTO of the counter 11 of the motor control circuit 1 shown in FIG.
It turns on when the signal is at H level and turns off when it is at L level.The timer circuit 57 changes the output of the light / dark sensor 6 from "H" level (bright level) to "L" level (dark level). When a signal output from the differentiating circuit 56 is input when the output signal O13 changes, the output signal O13 is output for a specified time T1.
Only after the specified time T1, the output signal O13 is set to "L" level and the output signal O14
Is set to the “H” level.

An OR element Or6 to which the output signals OH, OM, OL of the dirt detector 2 are input is input to the control circuit 5 '.
4, an AND element AN63 in which an output signal O14 of the timer circuit 57 is input to one input terminal and an output signal of an OR element Or64 is input to the other input terminal, and an AND element AN6
A differentiating circuit 58 to which the output signal of the third circuit 3 is inputted;
And an output signal O26 of the timer circuit 59 is input to one input terminal and the signal processing circuit 3 (dirt detection unit 2) shown in FIG.
To which the output signals OH, OM, OL of
D elements AN60, AN61, AN62,
The output signals of the AND elements AN60, AN61, AN62 are connected to the terminals HI, M of the motor control circuit 1 shown in FIG.
The signals are input to I and LO. Here, the timer circuit 59 outputs the output signal of the AND element 63 as “
When a signal output from the differentiating circuit 58 is input when the signal changes from the L level to the “H” level, the output signal O2
5 is set to the “H” level for a predetermined time T3,
After the elapse, the output signal O25 is set to “L” level and the output signal O26 is set to “H” level. The output signal O25 of the timer circuit 59 is inputted to the terminal L0 of the motor control circuit 1.

The operation in the automatic mode is summarized in FIG.
It will be like 0. Here, FIG. 20A shows the detection state of the light / dark sensor 6, FIG. 20B shows the detection state of the dust sensor 2a,
(C) is the detection state of the gas sensor 2b, (d) is the fan F
Are shown, respectively. In the example shown in FIG. 20, the output signal of the gas sensor 2b shown in FIG. 20C does not exceed any of the thresholds set by the second threshold setting unit 32 shown in FIG.

First, as shown in FIG.
_{In 11} , when the signal output from the differentiation circuit 56 is input to the timer circuit 57 when the output signal of the light / dark sensor 6 changes from “H” level (“bright”) to “L” level (“dark”) , The output signal O13 of the timer circuit 57 becomes "
H level (not shown), and the output signal O14 of the timer circuit 57 becomes "H" level (not shown) after the lapse of the specified time T1. Thereafter, as shown in FIG. it exceeds the threshold value ThL determined by the potential at the connection point of the output signal of the dust sensor 2a is a resistor R3 and the resistor R4 of the first threshold value setting unit 31 shown in FIG. 2 at t _12, the output signal OH of the stain detection unit 2, OM and OL become "L" level, "L" level and "H" level, respectively, and the output signal of the OR element Or64 of the control circuit 5 'shown in FIG. The output signal of the AN 63 becomes “H” level, and the timer circuit 59 receives the signal output from the differentiating circuit 58 when the output signal of the AND element AN 63 changes from “L” level to “H” level. And the output Issue O25 only a certain period of time T3 "H"
Level, so the photocoupler P of the motor control circuit 1
C1 turns on and triac TRC1 turns on and motor M
Is rotated at a low speed, the low-speed rotation of the two fans F is started (see FIG. 20D). And the above-mentioned fixed time T3
After the lapse of time, the output signal O26 becomes "H" level, and thereafter, the fan F is rotated based on the output signals OH, OM, OL of the dirt detector 2. In short, for example, the output signals OH, OM, OL of the dirt detection unit 2 are each “L”.
Level, "H" level, and "L" level, the rotation speed of the fan F changes to the medium speed, and the output signals OH, OM, OL of the dirt detector 2 become "H" level, "H", respectively.
When the L level or the L level is reached, the rotation speed of the fan F changes to a high speed.

When the air purifier of the present embodiment is installed in a room such as a bedroom where quietness is required, and the automatic mode is selected by the operation switch SW,
Even if any one of the output signals OH, OM, OL of the dirt detection unit 2 becomes "H" level after the room is darkened and the above-mentioned predetermined time T1 has elapsed, the output signal O25 of the timer circuit 25 is obtained.
Until the level of the fan F changes from the “H” level to the “L” level.
Is rotated at a low speed. That is, the fan F is connected to the dirt detector 2
Of the output signals OH, OM, and OL at "H" level.

In each of the above embodiments, the fan F can be switched in three stages. However, the fan F may be switched in four or more stages.

[0065]

According to the first aspect of the present invention, there is provided a fan driving device for driving a fan which is provided in a housing to suck in and blow out external air, and an air purifying means for purifying the air sucked into the housing. , A dirt detector that obtains a detection output corresponding to air dirt, a human sensor that detects the motion of a person in the detection area, and after a specified time has elapsed since the motion of the person is no longer detected by the human sensor. And control means for controlling the fan driving device so that the fan is driven with a delay of a predetermined delay time when the detection output is input from the dirt detection unit, so that the motion of the human is not detected by the human sensor. In such a situation, it is possible to prevent the fan from being driven immediately when a detection output is generated from the dirt detection unit due to transient dirt or noise that does not require driving the fan. There is an effect that it is.

According to a third aspect of the present invention, in the second aspect of the present invention, the fan driving device can switch the rotation speed of the fan at least in three stages of a low speed mode, a medium speed mode, and a high speed mode. When the fan drive is controlled with a delay time, the fan drive is controlled so that the fan is driven in the low-speed mode.Therefore, when the fan is used in a room where quietness is required, such as a bedroom or study, It is possible to prevent the fan from being driven immediately when a detection output due to transient dirt or noise that does not need to be driven is generated from the dirt detection unit, and to maintain the quietness.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the control means controls the fan driving device such that the fan is driven in the low-speed mode with a delay of the delay time, and then the low-speed mode is kept constant. Since the fan driving device is controlled so as to maintain the time, there is an effect that the quietness can be more reliably maintained.

According to a fifth aspect of the present invention, in the third aspect of the present invention, there is provided an operating unit for setting the rotational speed of the fan at least in three stages of a low speed mode, a medium speed mode, and a high speed mode, and When a mode other than the low-speed mode is set by the operation unit, the fan driving device is controlled so that the fan is driven in the low-speed mode for a certain time when the fan driving device is controlled with the delay time. This has the effect that the quietness can be maintained more reliably.

According to a seventh aspect of the present invention, there is provided a fan driving device for driving a fan provided in a housing to suck in and blow out external air, air purifying means for purifying air sucked into the housing, and air A dirt detection unit that obtains a detection output according to the dirt of the light, a light-dark sensor that obtains a binary output according to the lightness / darkness with respect to the reference value of the surrounding brightness, and the output of the light-dark sensor is defined as a dark level. Control means for controlling the fan driving device so that the fan is driven with a delay of a predetermined time when a detection output is input from the dirt detection unit after a lapse of time. Later, the fan can be prevented from being driven immediately when a detection output due to transient dirt or noise that does not need to drive the fan is generated from the dirt detector. That.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, the fan driving device can switch the rotation speed of the fan at least in three stages of a low speed mode, a medium speed mode, and a high speed mode. When the fan drive is controlled with a delay time, the fan drive is controlled so that the fan is driven in the low-speed mode.Therefore, when the fan is used in a room where quietness is required, such as a bedroom or study, It is possible to prevent the fan from being driven immediately when a detection output due to transient dirt or noise that does not need to be driven is generated from the dirt detection unit, and to maintain the quietness.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the control means controls the fan driving device such that the fan is driven in the low-speed mode with a delay of the delay time, and then the low-speed mode is kept constant. Since the fan driving device is controlled so as to maintain the time, there is an effect that the quietness can be more reliably maintained.

According to an eleventh aspect of the present invention, in the ninth aspect of the present invention, there is provided an operating section for setting the rotational speed of the fan at least in three stages of a low speed mode, a medium speed mode, and a high speed mode, and When a mode other than the low-speed mode is set by the operation unit, the fan driving device is controlled so that the fan is driven in the low-speed mode for a certain time when the fan driving device is controlled with the delay time. This has the effect that the quietness can be maintained more reliably.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing a first embodiment.

FIG. 2 is a circuit diagram of a dirt detection unit according to the first embodiment;

FIG. 3 is a circuit diagram of a motor control circuit according to the first embodiment;

FIG. 4 is a circuit diagram of a control circuit of the above.

FIG. 5 is an operation explanatory view of the above.

FIGS. 6A and 6B show the same as above, wherein FIG. 6A is a front view and FIG. 6B is a plan view.

FIG. 7 is a left side view showing the above.

FIG. 8 is a right side view showing the same.

FIG. 9 is a front view of a main part of the above.

10A and 10B show a second embodiment, in which FIG. 10A is a front view, and FIG.
Is a front sectional view, and (c) is a side sectional view.

FIG. 11 is a main part circuit diagram of the same.

FIG. 12 is an operation explanatory view of the above.

FIG. 13 is a main part circuit diagram of a third embodiment.

FIG. 14 is an operation explanatory view of the above.

FIG. 15 is a main part circuit diagram of a fourth embodiment.

FIG. 16 is an operation explanatory view of the above.

FIG. 17 is a main part circuit diagram of a fifth embodiment.

FIG. 18 is an operation explanatory view of the above.

FIG. 19 is a main part circuit diagram of a sixth embodiment.

FIG. 20 is an explanatory diagram of the operation of the above.

[Explanation of symbols]

 Reference Signs List 1 fan control circuit 2 dirt detector 2a dust sensor 2b gas sensor 3 signal processing circuit 4 motion sensor 5 control circuit

Claims (11)

[Claims] 1. A fan drive device disposed in a housing for driving a fan that sucks in and blows out external air, air purifying means for purifying the air sucked into the housing, A dirt detector that can provide a detection output, a human sensor that detects the movement of a person in the detection area, and a detection output from the dirt detector after a specified time has passed since the human sensor is no longer detected by the human sensor. Control means for controlling the fan drive device such that the fan drive device is driven with a delay of a predetermined delay time when inputted. 2. The air purifier according to claim 1, wherein the rotation speed of the fan can be switched in a plurality of stages. 3. The fan driving device is capable of switching the rotation speed of the fan in at least three stages of a low speed mode, a medium speed mode, and a high speed mode, and the control means controls the fan driving device with a delay by the delay time. 3. The air purifier according to claim 2, wherein the fan driving device is controlled so that the fan is driven in a low speed mode. 4. The control means controls the fan driving device such that the fan is driven in the low-speed mode with a delay of the delay time, and then controls the fan driving device such that the low-speed mode is maintained for a predetermined time. The air purifier according to claim 1, wherein: 5. An operation unit for switching and setting the rotation speed of the fan in at least three stages of a low speed mode, a medium speed mode, and a high speed mode, wherein the control unit sets a mode other than the low speed mode by the operation unit. 4. The air purifier according to claim 3, wherein when controlling the fan driving device after the delay time, the fan driving device is controlled so that the fan is driven in the low-speed mode for a fixed time. . 6. A dirt detector comprising: a dirt sensor comprising at least one of a dust sensor for detecting dust and a gas sensor for detecting odor component gas; and a detection corresponding to air dirt based on a detection output of the dirt sensor. The air purifier according to any one of claims 1 to 5, further comprising a signal processing circuit capable of obtaining an output. 7. A fan drive device disposed in the housing for driving a fan that sucks in and blows out external air, an air purifying unit that purifies the air sucked into the housing, and an air purifying unit that responds to contamination of the air. A dirt detection unit for obtaining a detection output, a light / dark sensor for obtaining a binary output corresponding to light / dark with respect to a reference value of ambient brightness, and after a lapse of a specified time from the output of the light / dark sensor to a dark level An air purifier comprising: control means for controlling a fan driving device such that a fan is driven with a delay of a predetermined delay time when a detection output is input from a dirt detection unit. 8. The air purifier according to claim 7, wherein the rotation speed of the fan can be switched in a plurality of stages. 9. The fan driving device is capable of switching the rotation speed of the fan in at least three stages of a low speed mode, a medium speed mode, and a high speed mode, and the control means controls the fan driving device with a delay by the delay time. The air purifier according to claim 8, wherein the fan driving device is controlled so that the fan is driven in the low-speed mode. 10. The control means controls the fan driving device so that the fan is driven in the low-speed mode with a delay of the delay time, and then controls the fan driving device so that the low-speed mode is maintained for a predetermined time. 10. The method according to claim 9, wherein
An air purifier as described. 11. An operation unit for setting the rotation speed of the fan by switching at least three stages of a low speed mode, a medium speed mode, and a high speed mode, wherein the control unit is configured to set a mode other than the low speed mode by the operation unit. 10. The air purifier according to claim 9, wherein when controlling the fan drive device with a delay of the delay time, the fan drive device is controlled such that the fan is driven in the low-speed mode for a fixed time. .