JPH11201892A - Air-cleaning machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain constantly fixed output under the same concentration by compensating for the reduction in detection sensitivity with time of a dust sensor. SOLUTION: An air-cleaning machine is provided with a pseudo dust concentration information member 6 for giving constant pseudo dust concentration information to a dust sensor 1, a drive means 7 for moving the pseudo dust concentration information member 6 to a standby position and a detection position for permitting detection by the dust sensor 1, and a variable amplification means 8 for amplifying a dust concentration signal Vs from the dust sensor 1. A control part 5 moves the pseudo dust concentration information member 6 from a standby position to a detection position by the drive means 7 and controls the amplification factor of a variable amplification means 8 based on the pseudo dust concentration information being obtained by detection using the dust sensor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifier, and more particularly to an air purifier with improved dust concentration detection accuracy.

[0002]

2. Description of the Related Art FIG. 1 shows a basic configuration of a conventional air purifier. The illustrated air purifier includes a dust sensor 1 for detecting a dust concentration in an atmosphere, a display unit 2 for notifying a user of a current operation state of the air purifier, and an operation for the user to operate the air purifier. A control unit that controls the air purifying unit 4 based on the operation information from the operation unit 3 and the dust concentration information from the dust sensor 1, converts the operation state of each unit into display information, and sends the display information to the display unit 2. And 5.

FIG. 2 shows the appearance of the dust sensor 1. The dust sensor 1 has a dust passage hole 1a, and detects dust concentration by allowing air containing dust to pass therethrough.

FIG. 3 shows an internal circuit configuration of the dust sensor 1. In the dust sensor 1, the light emission control unit 9 controls light emission of the light emission unit 10 in response to a clock pulse input from the outside. The light emitting unit 10 and the light receiving unit 11 constitute a reflection type optical system. The light emitted from the light emitting unit 10 is applied to the dust passing through the dust passage hole 1a.
Receives light and converts the amount of dust into a current value.

Next, the current signal from the light receiving unit 11 is converted into a voltage signal by a photoelectric voltage conversion unit 12, amplified by an amplifying unit 13, and peak-held by a peak holding unit 14 to obtain a maximum value component of the voltage signal. Output as dust concentration signal.

Here, the dust concentration N and the output voltage Vs are:
It can be expressed by the following equation. Vs = K × N where K is a dust detection coefficient.

Further, the dust detection coefficient K can be expressed by the following equation using the light emission intensity α of the light emitting element, the light receiving sensitivity β of the light receiving element, and a constant P. K = P × α × β ...

[0008]

Therefore, when the light emitting element and the light receiving element are used for detecting the dust concentration, the electric characteristics of the element itself deteriorate with time, and the light emitting surface of the dust and the dirt component contained in the dust and the dust component contained in the element are deteriorated. Due to the attachment to the light receiving surface, the light emission intensity α and the light receiving sensitivity β decrease, the dust detection coefficient K decreases, and the dust concentration signal under the same dust concentration decreases compared to the initial state. This is shown in FIG.

That is, in the conventional air purifier shown in FIG. 1, what was detected in the initial state as shown by the solid line in FIG. The output drops. Therefore, the signal component has changed from Vs to Vs' in the figure, resulting in a decrease in the signal component. If the control is performed based on this, the detection sensitivity of the dust decreases over time, and even if the atmosphere is dirty, it is determined that the atmosphere is not dirty.

SUMMARY OF THE INVENTION It is an object of the present invention to compensate for a decrease in the detection sensitivity of a dust sensor over time so that a constant output is always obtained at the same density.

[0011]

According to the present invention, a pseudo dust concentration information member 6 for giving constant pseudo dust concentration information to the dust sensor 1, and the pseudo dust concentration information member 6 is provided with a standby position and a dust sensor. And a driving unit 7 for moving to a detection position at which detection is possible, and detecting the dust from the dust sensor 1 based on the pseudo dust concentration information obtained by detecting the pseudo dust concentration information member 6 with the dust sensor 1. The controller 5 corrects the density signal.

When the dust concentration signal from the dust sensor 1 is amplified by the variable amplification means 8, the amplification factor of the variable amplification means 8 is controlled based on the pseudo dust concentration information detected and detected by the dust sensor 1. This can compensate for a decrease in detection sensitivity. In this case, even if the pseudo dust concentration information member 6 is moved from the standby position to the detection position by the driving means 7 and corrected immediately before the air purifier starts the air cleaning operation, the air cleaning operation of the air purifier may be performed. The correction may be performed by moving the pseudo dust concentration information member 6 from the standby position to the detection position at regular intervals.

When the variable amplifying means 8 is not used, a correction value of the dust concentration signal is obtained by calculation by the control unit 5. Also in this case, every time the air purifier starts the air purifying operation,
Alternatively, the correction is made by moving the pseudo dust concentration information member 6 from the standby position to the detection position at regular intervals during the air cleaning operation.

[0014]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 5 shows the structure of an air purifier according to the present invention. This air purifier includes a dust sensor 1 for detecting a dust concentration in an atmosphere, a display unit 2 for notifying a user of a current operation state of the air purifier, and an operation unit 3 for the user to operate the air purifier. The control unit 5 controls the air cleaning means 4 based on the operation information from the operation unit 3 and the dust concentration information from the dust sensor 1, and converts the operation state of each unit into display information and sends it to the display unit 2. A pseudo dust concentration information member 6 for giving constant pseudo dust concentration information to the dust sensor 1, and a movement of the pseudo dust concentration information member 6 between a standby position and a detection position where the dust sensor 1 can detect the pseudo dust concentration information member 6. And a variable amplifying means 8 for amplifying the dust concentration signal Vs from the dust sensor 1.

Further, as a function of the control unit 5, the dust concentration signal Vs from the dust sensor 1 is corrected based on the pseudo dust concentration information obtained by detecting the pseudo dust concentration information member 6 by the dust sensor 1, and A function of compensating for the deterioration of the detection sensitivity of the dust sensor 1 over time is added.

The operation of this air purifier will be described. The dust concentration signal Vs from the dust sensor 1 is amplified by the variable amplifying means 8 and input to the control unit 5 as the dust concentration signal Vr, and the concentration in the atmosphere is detected. Is done.

In FIG. 5, when the control unit 5 receives an operation start signal from the operation unit 3, it drives the driving means 7 to move the pseudo dust concentration information member 6 as shown in the timing chart of FIG. As shown in FIG.
Moves to the detection position where it can be detected, ie, the dust passage hole 1a
Insert it inside.

In this state, the pseudo dust concentration information member 6 reflects the light from the light emitting section 10 shown in FIG.
An output Vs corresponding to a certain dust concentration N0 can be obtained from the dust sensor 1. Thus, the pseudo dust concentration information member 6 is moved to the detection position, and the output Vs
Then, the air cleaning operation by the air cleaning means 4 is started.

At this time, the read output Vs is compared in advance with the reference output value Vs0 operated in the initial state in the initial state by the control unit 5, and the control unit 5 calculates the correction coefficient A based on the following equation. I do.

A = Vs0 ÷ Vs ...

Further, the relational expression with the dust concentration N0 can be expressed by the following expressions based on the above expression, and the correction coefficient A becomes as follows.

Vs0 = K0 × N0 Vs = K × N0 A = K0 ÷ K where K0 is a dust detection coefficient in an initial state, and K is a dust detection coefficient after a change with time. .

Therefore, the constants have a relationship of K0> K, and normally Vs0> Vs. However, in the air purifier shown in FIG. 5, the correction coefficient A obtained by the control unit 5 by the equation is variable-amplified. The control unit 5 outputs a gain control signal to be used as the gain of the means 8 to control the variable amplifying means 8.

As a result, the dust concentration signal Vs at the dust concentration N input to the control unit 5 is corrected by multiplying Vs by the correction coefficient A, and the corrected dust concentration signal Vr at the dust concentration N is obtained. Becomes like the following equation.

Vr = A × Vs = K0 ÷ K × Vs = K0 × N

As is apparent from this equation, the dust detection coefficient of the dust concentration signal Vr obtained by correcting the dust concentration signal Vs of the dust sensor 1 is not the dust detection coefficient K reduced with the lapse of time but the dust detection coefficient in the initial state. K0 which is the dust detection coefficient
Thus, the same output as in the initial state can be obtained at an arbitrary dust concentration N, and is not affected by the deterioration of the dust detection coefficient K.

In the above example, just before the air purifier starts the air cleaning operation, the correction is performed by moving the pseudo dust concentration information member 6 from the standby position to the detection position by the driving means 7. As shown in the timing chart of FIG. 8, during the air cleaning operation of the air purifier, the pseudo dust concentration information member 6 is moved from the standby position to the detection position by the driving means 7 at regular intervals to perform the correction. You may. When the variable amplifying means 8 is not used, the correction value of the dust concentration signal may be obtained by calculation by the control unit 5.

[0029]

As described above, according to the present invention, the pseudo dust concentration information member is moved from the standby position to the detection position by the driving means, and the dust concentration information member is detected based on the pseudo dust concentration information detected by the dust sensor. Since the dust concentration signal from the sensor is corrected, it is possible to compensate for a decrease in the detection sensitivity of the dust sensor over time, and to always obtain a constant output under the same concentration.

According to the second aspect of the present invention, the dust concentration signal can be easily corrected by controlling the amplification factor of the variable amplifier.

According to the third aspect of the present invention, the dust concentration signal can be corrected by controlling the amplification factor of the variable amplification means immediately before the air purifier starts the air cleaning operation.

According to the fourth aspect of the present invention, the dust concentration signal can be corrected by controlling the gain of the variable amplifying means at regular intervals during the air cleaning operation.

According to the fifth aspect of the present invention, the dust concentration signal can be corrected by calculation by the control unit without using the variable amplifying means.

According to the sixth aspect of the present invention, the dust concentration signal can be corrected by calculation by the control unit at regular intervals during the air cleaning operation without using the variable amplification means.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a conventional air purifier.

FIG. 2 is an external perspective view of the dust sensor.

FIG. 3 is a block diagram showing an internal circuit configuration of the dust sensor.

FIG. 4 is a graph showing a state of a change in a dust concentration signal from a dust sensor with respect to a dust concentration in the related art.

FIG. 5 is a block diagram showing a configuration example of an air purifier according to the present invention.

FIG. 6 is a diagram illustrating an operation of moving a pseudo dust concentration information member from a standby position to a detection position.

FIG. 7: Immediately before the air purifier starts the air purifying operation,
9 is an operation timing chart in a case where correction is performed by moving a pseudo dust concentration information member from a standby position to a detection position.

FIG. 8 is an operation timing chart in a case where the dummy dust concentration information member is moved from the standby position to the detection position and correction is performed at regular intervals during the air cleaning operation of the air purifier.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dust sensor 2 Display part 3 Operation part 4 Air cleaning means 5 Control part 6 Pseudo dust concentration information member 7 Driving means 8 Variable amplification means

Claims (6)

[Claims] 1. A dust sensor for detecting a dust concentration in an atmosphere, a display unit for notifying a user of a current operation state and the like, an operation unit for a user to operate, and operation information from the operation unit. A control unit for controlling the air cleaning means based on the dust concentration information from the dust sensor and converting the operation state of each unit to display information and sending the display information to the display unit, A pseudo dust concentration information member for providing pseudo dust concentration information of the above, and a driving means for moving the pseudo dust concentration information member to a standby position and a detection position where the dust sensor can detect the pseudo dust concentration information member, The unit corrects the dust concentration signal from the dust sensor based on the pseudo dust concentration information obtained by detecting the pseudo dust concentration information member with the dust sensor. ,Air cleaner. 2. A variable amplification unit for amplifying a dust concentration signal from the dust sensor, wherein the control unit moves the pseudo dust concentration information member from a standby position to a detection position by the driving unit, and The air purifier according to claim 1, wherein an amplification factor of the variable amplifying unit is controlled based on the pseudo dust concentration information obtained by the detection. 3. A variable amplifying unit for amplifying a dust concentration signal from the dust sensor, wherein the control unit causes the driving unit to move the pseudo dust concentration information member from a standby position immediately before starting an air cleaning operation. The air purifier according to claim 1, wherein the air purifier is moved to a detection position, and controls an amplification factor of the variable amplifying unit based on pseudo dust concentration information obtained by detection by the dust sensor. 4. A variable amplification unit for amplifying a dust concentration signal from the dust sensor, wherein the control unit causes the driving unit to move the pseudo dust concentration information member to a standby position at regular intervals during an air cleaning operation. The air purifier according to claim 1, wherein the air purifier is moved to a detection position, and the amplification factor of the variable amplifying unit is controlled based on pseudo dust concentration information detected and detected by the dust sensor. 5. The control unit moves the pseudo dust concentration information member from a standby position to a detection position by the driving unit, and controls the dust sensor based on the pseudo dust concentration information obtained by detection by the dust sensor. 2. The air purifier according to claim 1, wherein the dust concentration signal is corrected by calculation. 6. The control unit moves the pseudo dust concentration information member from a standby position to a detection position by the driving means at regular intervals during the air cleaning operation, and obtains the detection result using the dust sensor. The air cleaner according to claim 1, wherein the dust concentration signal from the dust sensor is corrected by calculation based on the pseudo dust concentration information.