JP2015123386A - Air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable air cleaner capable of restraining the dust concentration from suddenly increasing from a comparatively low state, and capable of preventing the air volume from being reduced by false recognition of cleanliness when the cleanliness of air is low.SOLUTION: The air cleaner 10 comprises a fan, a dust sensor 60, a determination part 52a, a storage part 51 of a determination result of the determination part and a fan control part 52e. The determination part determines a cleanliness degree of the air by distinguishing between a first cleanliness degree and a second-fourth cleanliness degree higher in the dust concentration than the first cleanliness degree by using an output signal of the dust sensor. A fan control part controls the fan so that a rotation speed becomes larger than when storing the first cleanliness degree when storing the second-fourth cleanliness degree in the storage part. The determination part respectively executes first determination processing of time preference when storing the first cleanliness degree in the storage part and second determination processing of accuracy preference when storing the second-fourth cleanliness degree in the storage part, as a determination of the cleanliness degree of the air.

Description

  The present invention relates to an air cleaner provided with a dust sensor.

  It has a dust sensor that detects dust, determines the cleanliness of the air based on the detection value of the dust sensor within the determination time, and controls the air volume of the fan to pass air through the air purifier filter based on the cleanliness of the air Air purifiers to perform are known. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2001-87613), air cleanliness is determined based on the number of pulses per unit time of a signal indicating that a dust sensor has detected dust. An air cleaner is disclosed that controls a fan so that the lower the cleanliness, the greater the air volume.

  In such an air cleaner, by increasing the determination time, in other words, by increasing the number of detection values of the dust sensor used for the determination, noise and the concentration of dust in the air to be detected by the dust sensor are reduced. The influence of uniformity or the like on the determination of air cleanliness can be reduced. Therefore, basically, the air cleanliness can be determined more accurately by taking a longer determination time.

  However, if the judgment time is lengthened, there is a possibility that the change in the air cleanliness cannot be immediately grasped even though the dust concentration increases in the air clean target space and the air cleanliness starts to decrease. . In particular, when it is determined that the air is relatively clean and the fan is operated in a state where the air volume is relatively small, since the amount of air led to the air cleaning filter is small, there is a change in the cleanliness of the air. Before it is grasped, the dust concentration in the target space for air purification increases rapidly, which may adversely affect the comfort of the user of the air cleaner.

  On the other hand, emphasizing the quick determination of air cleanliness, if the determination time is shortened, the accuracy of air cleanliness decreases, so air cleanliness is erroneously determined, Actually, there is a possibility that the air flow control of the fan is not optimally performed, for example, control for reducing the air flow of the fan is performed even though the air cleanliness is low.

  An object of the present invention is an air purifier that controls the air volume of a fan that guides air to an air cleaning filter in accordance with the cleanliness of the air that is grasped using the detection value of a dust sensor, and the dust concentration is A highly reliable air purifier that can prevent a sudden rise from a relatively low state and can prevent the air volume from being reduced due to misrecognition of air cleanliness when the air cleanliness is low. Is to provide.

  An air cleaner according to a first aspect of the present invention includes a fan having a variable rotation speed, a dust sensor, a determination unit, a storage unit, and a fan control unit. The fan generates an air flow so that air passes through the air cleaning filter. The dust sensor detects dust in the air. The determination unit uses the detection value of the dust sensor to determine the air cleanliness level by distinguishing at least a first cleanness level and a second cleanliness level in which the dust concentration is higher than the first cleanliness level. In the storage unit, the determination result of the determination unit is updated and written and stored. The fan control unit is configured such that the rotational speed when the second cleaning degree is stored as the determination result in the storage unit is larger than the rotational speed when the first cleaning degree is stored as the determination result in the storage unit. To control the fan. A determination part performs a 1st determination process and a 2nd determination process as determination of the cleanliness degree of air, respectively. The first determination process is executed when the first cleanliness level is stored as a determination result in the storage unit. In the first determination process, the determination time has priority over the determination accuracy. The second determination process is executed when the second cleanliness level is stored as a determination result in the storage unit. The second determination process has a longer determination time than the first determination process, and is superior to the first determination process in determination accuracy.

  Here, when the degree of air cleanliness is recognized as the first degree of cleanliness, the first determination process prioritizing the determination time is executed as the determination of the degree of air cleanliness. For this reason, when the air cleaning degree is determined to be a relatively clean first cleaning degree and the fan is operated at a relatively low rotational speed, if the concentration of dust in the air increases, the air purifying process is performed by the first determining process. Deterioration of the degree is recognized promptly. And it controls rapidly so that the rotation speed of a fan may become large according to the deterioration of the cleanliness degree of air. Therefore, when the air is determined to be relatively clean, it is possible to suppress a sudden increase in the concentration of dust in the air.

  In addition, here, when the degree of air cleanliness is recognized as the second degree of cleanliness with a relatively high dust concentration, the second determination process with priority given to the determination accuracy is performed as the determination of the degree of air cleanliness. Therefore, improper control of the fan air volume, such as a reduction in the fan air volume due to erroneous recognition of the degree of air purification, despite the fact that the concentration of dust in the air is high, can be prevented.

  The air cleaner which concerns on the 2nd viewpoint of this invention is an air cleaner which concerns on a 1st viewpoint, Comprising: A dust sensor detects a dust at a fixed time interval. The determination unit uses more dust sensor detection values than the first determination process in the second determination process so that the determination time of the second determination process is longer than the determination time of the first determination process.

  Here, in the second determination process, determination of the degree of air purification is performed based on more detection values of the dust sensor than in the first determination process. Therefore, in the second determination process, it is possible to determine the degree of cleanliness of the air with higher accuracy than in the first determination process.

  The air cleaner which concerns on the 3rd viewpoint of this invention is an air cleaner which concerns on a 1st viewpoint, Comprising: A determination part is air using the moving average value of the calculated value calculated using the detected value of a dust sensor. Determine the degree of cleanliness. The determination unit makes the moving average time in the second determination process longer than the moving average time in the first determination process so that the determination time of the second determination process is longer than the determination time of the first determination process.

  Here, in the second determination process, the determination of the degree of air cleaning is performed based on the moving average value of the moving average time longer than that in the first determination process. Therefore, in the second determination process, it is possible to determine the degree of cleanliness of the air with higher accuracy than in the first determination process.

  The air cleaner which concerns on the 4th viewpoint of this invention is an air cleaner which concerns on a 3rd viewpoint, Comprising: The 1st cleanliness degree is memorize | stored in the memory | storage part at the time of starting of the said air cleaner. The determination unit is a case where the first determination process is performed at the time of starting the air cleaner, and when the detection values of the dust sensors corresponding to the moving average time in the first determination process have not yet been acquired, The first determination process is performed using detection values of a quantity of dust sensors corresponding to a time shorter than the moving average time in the first determination process.

  Here, when the air cleaner is activated and the detection value of the dust sensor corresponding to the moving average time in the first determination process has not yet been acquired, it is used in the normal first determination process. The degree of cleanliness of air is determined using detection values of a small number of dust sensors. Therefore, when the concentration of dust is relatively high and the user activates the air cleaner in anticipation of prompt removal of dust, the degree of air purification is immediately determined, which improves the degree of air purification. It is easy to be done.

  The air cleaner which concerns on the 5th viewpoint of this invention is an air cleaner which concerns on either of the 1st viewpoint to the 4th viewpoint, Comprising: The 1st cleanness degree is in the cleanliness degree of the air determined by the determination part. The cleanliness level of air with the lowest dust concentration.

  Here, when it is determined that the concentration of dust in the air is the lowest in the set degree of air cleanliness, it is possible to suppress a sudden increase in the concentration of dust in the air.

  The air cleaner which concerns on the 6th viewpoint of this invention is an air cleaner which concerns on either of the 1st viewpoint to the 5th viewpoint, Comprising: The writing prohibition part which prohibits the writing to a memory | storage part is further provided. The writing prohibition unit prohibits writing the first cleanness degree as the determination result in the storage unit for a predetermined period when the second cleanness degree is written as the determination result in the storage unit.

  Here, in the transition state in which the dust concentration gradually decreases, the determination of the degree of air cleaning frequently changes between the first degree of cleaning and the second degree of cleaning, and the rotational speed of the fan frequently It is possible to suppress switching.

  The air cleaner which concerns on the 7th viewpoint of this invention is an air cleaner which concerns on either of the 1st viewpoint to the 6th viewpoint, Comprising: The 1st determination process which prohibits a determination part performing a 1st determination process A prohibition unit is further provided. The first determination processing prohibition unit prohibits the determination unit from executing the first determination process for a predetermined period when the first cleanness degree is updated and written as a determination result in the storage unit. While the first determination process is prohibited by the first determination process prohibition unit, the determination unit performs the second determination process according to the degree of air cleanliness even if the first cleanness degree is stored as a determination result in the storage unit. Run as a decision.

  Here, when the air cleaning degree stored in the storage unit is updated to the first cleaning degree, it is prohibited to perform the first determination process as the air cleaning degree determination process for a predetermined period. Therefore, when the dust concentration is in a transition state where the concentration gradually decreases, the accuracy of the air cleanliness suddenly decreases, and the fan must be operated at a relatively high rotational speed. It is possible to avoid a state where the rotational speed of the motor is lowered.

  The air cleaner which concerns on the 8th viewpoint of this invention is an air cleaner which concerns on a 1st viewpoint, Comprising: The determination part is the magnitude of the value based on the calculated value calculated using the detected value of a dust sensor, and a threshold value Are compared to determine the degree of air cleanliness. The threshold value is changed between the first determination process and the second determination process.

  Here, since the threshold value is changed in consideration of the type of determination processing, it is easy to accurately determine the degree of air cleanliness.

  The air cleaner which concerns on the 9th viewpoint of this invention is an air cleaner which concerns on a 1st viewpoint, Comprising: A determination part is the magnitude of the value based on the calculated value calculated using the detected value of a dust sensor, and a threshold value Are compared to determine the degree of air cleanliness. The threshold is changed according to the number of rotations of the fan at the time of determination by the determination unit.

  When the rotational speed of the fan changes, the amount of air passing through the dust sensor changes, and the calculated value calculated using the detection value of the dust sensor changes even though the dust concentration is the same. There is a case. Here, since the threshold value is changed in consideration of this, it is easy to accurately determine the degree of air cleanliness.

  The air cleaner which concerns on the 10th viewpoint of this invention is an air cleaner which concerns on a 1st viewpoint, Comprising: The determination part calculates the value which deducted the offset value from the calculated value calculated using the detected value of a dust sensor. Used to determine the degree of air cleanliness. The offset value is set for each of the first determination process and the second determination process.

  Here, since the offset value is prepared for each of the first determination process and the second determination process, it is easy to accurately determine the degree of air cleanliness.

  Note that the offset value can be simply expressed as the degree of cleanliness of the air using the detection value of the dust sensor (first) in the state where the air is clean (the state where there is almost no dust in the air). Or 2) a value obtained when a calculated value for the determination process is calculated. When the air is clean, the dust sensor should detect little dust. However, even if the air is clean, the dust sensor may recognize that dust has been detected depending on the usage state of the dust sensor. The offset value is used to correct this. In other words, the offset value is a reference value for determining the degree of air cleanliness.

  The air cleaner which concerns on the 11th viewpoint of this invention is an air cleaner which concerns on a 10th viewpoint, Comprising: An offset value is further set according to the rotation speed of the fan at the time of determination by a determination part.

  Here, since the offset value is individually prepared according to the rotational speed of the fan, it is easy to accurately determine the degree of air cleanliness.

  An air cleaner according to a twelfth aspect of the present invention is the air cleaner according to any one of the first to eleventh aspects, wherein the dust sensor has a small particle diameter and a particle diameter smaller than that of the small dust. Detects large dust so that it can be distinguished. In the case where the determination unit determines the air cleaning degree using the detection value related to the small dust of the dust sensor, the first determination process or the second determination is performed based on the air cleaning degree stored as a determination result in the storage unit. Judgment processing is performed. The determination unit always performs the first determination process when determining the degree of air cleanup using the detection value related to the large dust of the dust sensor.

  Here, for small dust, the determination unit switches between the first and second determination processes, whereas for large dust that is floating in the air for a relatively short time, the determination unit Always performs the first determination process with priority on the determination time. Therefore, it is easy to collect large dust.

  In the air cleaner according to the first aspect of the present invention, when the air cleanliness level is recognized as the first cleanliness level, the first determination process prioritizing the determination time is executed as the determination of the air cleanliness level. For this reason, when the air cleaning degree is determined to be a relatively clean first cleaning degree and the fan is operated at a relatively low rotational speed, if the concentration of dust in the air increases, the air purifying process is performed by the first determining process. Deterioration of the degree is recognized promptly. And it controls rapidly so that the rotation speed of a fan may become large according to the deterioration of the cleanliness degree of air. Therefore, when the air is determined to be relatively clean, it is possible to suppress a sudden increase in the concentration of dust in the air. In addition, here, when the degree of air cleanliness is recognized as the second degree of cleanliness with a relatively high dust concentration, the second determination process with priority given to the determination accuracy is performed as the determination of the degree of air cleanliness. Therefore, improper control of the fan air volume, such as a reduction in the fan air volume due to erroneous recognition of the degree of air purification, despite the fact that the concentration of dust in the air is high, can be prevented. As a result, a highly reliable air cleaner is realized.

  In the air cleaner according to the second and third aspects of the present invention, it is possible to determine the degree of cleanliness of air in the second determination process with higher accuracy than in the first determination process.

  In the air cleaner according to the fourth aspect of the present invention, when the concentration of dust is relatively high and the user activates the air cleaner in anticipation of quick removal of dust, the degree of air purification is immediately determined. Therefore, it is easy to improve the degree of cleanliness of the air.

  In the air cleaner according to the fifth aspect of the present invention, when the concentration of dust in the air is determined to be the lowest among the set air cleanliness, the concentration of dust in the air rapidly increases. This can be suppressed.

  In the air cleaner according to the sixth aspect and the seventh aspect of the present invention, the rotational speed of the fan can be appropriately controlled in the transition state in which the dust concentration gradually decreases from the relatively high state.

  In the air cleaner according to the eighth aspect to the eleventh aspect of the present invention, it is easy to accurately determine the degree of air purification.

  In the air cleaner according to the twelfth aspect of the present invention, it is easy to collect large dust.

It is an appearance perspective view of an air cleaner concerning one embodiment of the present invention. It is the figure which showed the main structures relevant to the air purifying function and humidification function of the air cleaner of FIG. It is a schematic block diagram of the air cleaner of FIG. It is a threshold when the determination part of the control part of a control unit memorize | stores in the threshold value memory area of the memory | storage part of the control unit of the air cleaner of FIG. It is a threshold when the determination part of the control part of a control unit memorize | stores in the threshold value memory | storage area | region of the memory | storage part of the control unit of the air cleaner of FIG. It is the graph which showed the change with respect to the density | concentration [microgram / m < ³ >] of dust of the L level signal ratio calculated using the detected value of the dust sensor of the air cleaner of FIG. The case where the rotational speed of the fan is the rotational speed N1 (less than the reference value Nb) and the case where the rotational speed of the fan is the rotational speed N2 (more than the reference value Nb) are drawn. It is a graph for demonstrating the update process of the offset value used for the determination process of the determination part by the offset update part of the air cleaner of FIG. In particular, here, the type of determination process performed by the determination unit is the second determination process, and the offset value update process is described for the condition that the determination target is a small dust. It is a graph for doing. The horizontal axis indicates time, and the vertical axis indicates the value of the L level signal ratio. The thick line in the figure shows the time change of the offset value. It is a flowchart for demonstrating determination of the cleanliness degree of the air regarding a large dust of the determination part of the air cleaner of FIG. It is a flowchart (the 1) for demonstrating the determination of the cleanliness degree of the air regarding a small dust of the determination part of the air cleaner of FIG. It is a flowchart (the 2) for demonstrating the determination of the cleanliness degree of the air regarding a small dust of the determination part of the air cleaner of FIG. It is a flowchart (the 3) for demonstrating the determination of the cleanliness degree of the air regarding a small dust of the determination part of the air cleaner of FIG. It is a flowchart for demonstrating the update process of the cleanliness degree of the air memorize | stored in the cleanliness degree storage area by the writing part of the air cleaner of FIG. Moreover, it is a flowchart for demonstrating the process of the improvement determination prohibition part and 1st determination process prohibition part of the air cleaner of FIG. 1 relevant to this update process.

  An air cleaner 10 according to an embodiment of the present invention will be described with reference to the drawings. In addition, the air cleaner 10 is only an example of the air cleaner which concerns on this invention, and can be suitably changed in the range which does not deviate from the summary of this invention.

(1) Overall Configuration FIG. 1 is a schematic external perspective view of an air cleaner 10 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a main configuration related to the air purifying function and the humidifying function of the air purifier 10 housed in the air purifier 10. FIG. 3 is a schematic block diagram of the air cleaner 10.

  An outline of the air cleaner 10 will be described below. In the following description, there may be used words indicating directions such as “up”, “down”, “left”, “right”, “front (front)”, “back (back)”. The expressions are based on the directions shown in FIG. 1 unless otherwise specified.

  The air cleaner 10 is a floor-standing apparatus as shown in FIG. The air cleaner 10 is installed in an air cleaning target space. The air cleaner 10 has an air cleaning function for removing dust in the air from the air taken into the apparatus. Moreover, the air cleaner 10 has a humidification function which humidifies the air after removing dust.

  As shown in FIGS. 1 to 3, the air cleaner 10 mainly includes a housing 11, an air cleaning unit 20, a humidifying unit 30, a fan 40, a control unit 50, and a dust sensor 60.

(2) Detailed Configuration (2-1) Housing The housing 11 accommodates the air cleaning unit 20, the humidification unit 30, the fan 40, the control unit 50, the dust sensor 60, and the like inside.

  The housing 11 is formed with a suction port 12 and an air outlet 13 (see FIG. 1). The air in the target space for air cleaning is taken in from the suction port 12 and supplied to the air cleaning unit 20. The air after the dust is removed (after being further humidified during the humidifying operation) blows out from the air outlet 13 into the air-cleaning target space.

(2-2) Air Purifying Unit The air purifying unit 20 is a unit for removing dust in the air and adsorbing and decomposing odor components in the air.

  As shown in FIG. 2, the air cleaning unit 20 mainly includes a prefilter 21, a HEPA filter 22, and a deodorizing element 23. The pre-filter 21, the HEPA filter 22, and the deodorizing element 23 are arranged in this order from the front side to the back side in the housing 11. The air taken in from the suction port 12 of the housing 11 is first sent to the air cleaning unit 20, and passes through the air cleaning unit 20 in the order of the pre-filter 21, the HEPA filter 22, and the deodorizing element 23.

  The pre-filter 21 is a filter for capturing relatively large dust in the air. The HEPA (High Efficiency Particulate Air) filter 22 is an example of an air cleaning filter. The HEPA filter 22 captures fine dust in the air that has passed through the pre-filter 21. Dust in the air is mainly removed by the prefilter 21 and the HEPA filter 22.

  The deodorizing element 23 contains activated carbon or the like and adsorbs and decomposes odors and harmful gases in the air that have passed through the prefilter 21 and the HEPA filter 22.

(2-3) Humidification unit The humidification unit 30 is a unit for supplying water to the air passing through the humidification unit 30 and humidifying it.

  The humidification unit 30 is disposed on the back side of the air purification unit 20 in the housing 11. The humidifying unit 30 is disposed on the downstream side of the air cleaning unit 20 in the air flow direction in the housing 11 generated by operating the fan 40.

  The humidification unit 30 mainly has a water tray 31 and a humidification rotor 32 (see FIG. 2). The water tray 31 is a storage container that stores water (water for humidification) to be supplied to the air that has passed through the air cleaning unit 20. A water tank (not shown) for supplying water to the water tray 31 is provided in the housing 11. The humidification rotor 32 is configured to be rotatable by a motor 32a (see FIG. 3). The humidification rotor 32 mainly includes a water pumping unit (not shown) that pumps up the water in the water tray 31 and a humidification filter (not shown) that adsorbs the water pumped up by the water pumping unit.

  The function of the humidification rotor 32 will be briefly described. When the motor 32a (see FIG. 3) is rotated, the water pumping unit of the humidification rotor 32 rotates and pumps the water in the water tray 31. The water pumped up by the water pumping unit is supplied to the humidifying filter of the humidifying rotor 32 that is also rotating. The humidification filter to which water is supplied by the pumping unit is in a state of adsorbing moisture. Part of the air that has passed through the air cleaning unit 20 passes through the rotating humidifying filter. The air passing through the humidifying filter that has adsorbed moisture is humidified by supplying water from the humidifying filter. As described above, the humidification rotor 32 humidifies the air that has passed through the air cleaning unit 20.

(2-4) Fan The fan 40 is attached to the back side of the housing 11. The fan 40 is disposed on the downstream side of the humidification unit 30 in the air flow direction in the housing 11 generated by operating the fan 40.

  The fan 40 has a function of taking the air in the air cleaning target space into the housing 11 through the suction port 12 and allowing the air cleaning unit 20 and the humidification unit 30 to pass through. That is, the fan 40 generates an air flow so that air passes through the air cleaning unit 20 including the HEPA filter 22 as an air cleaning filter and the humidification unit 30. Further, the fan 40 has a function of discharging the air after passing through the air cleaning unit 20 and the humidifying unit 30 to the outside of the housing 11 through the air outlet 13.

  The fan 40 is a sirocco fan. When the impeller 41 (see FIG. 2) of the fan 40 is rotated by the fan motor 40a (see FIG. 3), the air that has passed through the air cleaning unit 20 and the humidifying unit 30 is sucked into the fan 40 from the front side. Then, the traveling direction is changed upward (see FIG. 2), and the air is blown upward from the air outlet 13 provided in the upper portion of the housing 11.

  The fan 40 has a variable rotation speed. In other words, the fan motor 40a has a variable rotation speed. The fan motor 40a is controlled by a fan control unit 52e (see FIG. 3) of the control unit 50 described later.

(2-5) Dust Sensor The dust sensor 60 is a sensor that detects dust in the air. Specifically, the dust sensor 60 takes air from the space to be detected by the dust sensor 60, in other words, from the space to be cleaned of the air cleaner 10 into the internal space of the dust sensor 60, and passes through the internal space together with the air. It is a sensor that detects dust.

  The dust sensor 60 is provided on the side surface side (here, the right side surface) of the housing 11. The dust sensor 60 takes in air into the dust sensor 60 via an air intake hole 71a (see FIG. 1) formed on the right side surface of the housing 11, and detects dust passing through the inside together with air.

  The dust sensor 60 detects dust passing through the internal space by the following method and transmits a signal indicating detection / non-detection of the dust to the control unit 50.

  The dust sensor 60 includes a light emitting element (not shown) and a light receiving element. The light emitting element projects light into an internal space through which air to be detected passes. The light receiving element is disposed at a position where it does not directly receive the light emitted from the light emitting element. However, the light receiving element is disposed at a position where it can receive light scattered upon hitting dust when the air passing through the internal space contains dust. The dust sensor 60 outputs an H level (high level) signal when the light receiving element is not receiving light, and outputs an L level (low level) signal when the light receiving element is receiving light. The dust sensor 60 transmits an H level signal or an L level signal to the control unit 50 as a detection value every 80 μsec. The control unit 50 determines the degree of cleanliness of air using the detection value of the dust sensor 60 (output signal of the dust sensor 60). The determination of the air cleanliness of the control unit 50 will be described later.

  As in Patent Document 1 (Japanese Patent Laid-Open No. 2001-87613), the dust sensor 60 is configured to remove dust in the air based on the intensity of scattered light received by the light receiving element, small dust having a small particle size, and small dust. And large dust particles having a particle diameter larger than that of the dust are detected in a distinguishable manner. However, the method by which the dust sensor 60 detects small dust having a small particle size and large dust so as to be distinguishable is not limited thereto, and other methods may be used. Here, the small dust means dust having a particle diameter of 1 μm or more and less than 3 μm, and the large dust means dust having a particle diameter of 3 μm or more.

  The dust sensor 60 outputs an H level signal or an L level signal for dust having a particle size of 1 μm or more, and further outputs an H level signal or an L level signal for dust having a particle size of 3 μm or more. Then, the control unit 50 that has received the signal from the dust sensor 60 uses the output signal for the dust having a particle size of 1 μm or more and the output signal for the dust having a particle size of 3 μm or more to reduce the small dust (particle size). The degree of air cleanliness is determined with respect to dust having a particle size of 1 μm or more and less than 3 μm and large dust (dust having a particle size of 3 μm or more). That is, the dust sensor 60 detects dust in the air so that small dust and large dust can be distinguished. The dust sensor 60 itself detects small dust (dust having a particle size of 1 μm or more and less than 3 μm) and large dust (particle size). However, the control unit 50 that has received the output signal from the dust sensor 60 only needs to be able to distinguish between detection of small dust and detection of large dust. However, the present invention is not limited to this, and the dust sensor 60 itself may be configured to output a signal related to dust having a particle diameter of 1 μm or more and less than 3 μm and a signal related to dust having a particle diameter of 3 μm or more.

  It should be noted that the dust sensor 60 is in a state in which electricity is supplied to the air cleaner 10 (a state in which the air cleaner 10 is connected to a power source), even if the air cleaner 10 is not in operation (air Even if the fan 40 of the cleaner 10 is not in operation, dust in the air is detected.

(2-6) Control Unit The control unit 50 is a unit for controlling the movement of the air cleaner 10.

  The control unit 50 is a microcomputer having a memory such as a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory). The control unit 50 includes a storage unit 51 that stores various types of information and a control unit 52 that executes various types of control.

  As shown in FIG. 3, the control unit 50 is mainly electrically connected to the dust sensor 60, the fan motor 40a, the motor 32a, and the operation unit 55. The operation unit 55 functions as an input unit that receives various commands from the user (for example, an operation / stop command for the air purifier 10 and an execution / stop command for the humidification operation). In addition, the operation unit 55 functions as a display unit that displays an operation state of the air purifier 10 using an LED (Light Emitting Diode) or the like.

  Hereinafter, the storage unit 51 and the control unit 52 will be described in detail.

(2-6-1) Storage Unit The storage unit 51 stores a program to be executed by the control unit 52 and various information. For example, the storage unit 51 includes a cleanness storage area 51a, a threshold storage area 51b, and an offset value storage area 51c as areas for storing information. Details of the cleanliness degree storage area 51a, the threshold value storage area 51b, and the offset value storage area 51c will be described below.

(2-6-1-1) Clean Degree Storage Area The clean degree storage area 51a is updated with the determination result of the determination unit 52a of the control unit 52 described later, that is, the degree of cleanliness of air determined by the determination unit 52a. Written and stored. The content stored in the cleanliness storage area 51a is updated by writing the determination result of the determination unit 52a by the writing unit 52b described later.

  Until the air cleaner 10 is operated and the determination unit 52a determines the air cleanliness level, the cleanliness storage area 51a stores the first cleanness degree P1 as the initial setting of the air cleanliness level. Has been. That is, when the air cleaner 10 is started, the first cleanness degree P1 is stored in the cleanness degree storage area 51a. When the operation of the air cleaner 10 is stopped, the content stored in the cleanliness storage area 51a is reset, and the first cleanness P1 as the initial setting is written again.

(2-6-1-2) Threshold Storage Area The threshold storage area 51b stores a threshold used when the determination unit 52a described later determines the degree of air cleanliness. How the threshold value is used when the degree of air cleanliness is determined will be described later.

  In the threshold value storage area 51b, a threshold value used when the determination unit 52a executes a first determination process described later (see FIG. 4) and a threshold value used when the determination unit 52a executes a second determination process described later (see FIG. 5). ) Are stored.

  The threshold used when the determination unit 52a executes the first determination process stored in the threshold storage area 51b is an improvement used when the determination unit 52a determines whether or not the degree of cleanliness of air with respect to large dust has improved. There are thresholds for determination 1 to 3 (SA11, 12, 13) (see FIG. 4A). Moreover, when the determination part 52a determines whether the degree of cleanliness of air deteriorated with respect to large dust, the threshold value stored when the determination part 52a performs the 1st determination process memorize | stored in the threshold value storage area 51b. There are deterioration determination thresholds 1 to 3 (SC11, 12, 13) to be used (see FIG. 4B). Moreover, when the determination part 52a determines whether the cleanliness degree of air deteriorated regarding the small dust, the threshold value stored when the determination part 52a performs the 1st determination process memorize | stored in the threshold value storage area 51b. There are threshold values for deterioration determination 1 to 3 (SD11, 12, 13) to be used (see FIG. 4B).

  The threshold value used when the determination unit 52a executes the second determination process regarding small dust, which is stored in the threshold storage area 51b, is an improvement used when the determination unit 52a determines whether or not the degree of cleanliness of the air has improved. There are thresholds for determination 1 to 3 (LB11, 12, 13, 21, 22, 23) (see FIGS. 5A and 5B). The threshold value used when the determination unit 52a executes the second determination process for small dust, which is stored in the threshold storage area 51b, is a deterioration used when the determination unit 52a determines whether or not the degree of cleanliness of air has deteriorated. There are thresholds for determination 1 to 3 (LD11, 12, 13, 21, 22, 23) (see FIGS. 5C and 5D). In addition, LB11,12,13 (refer Fig.5 (a)) and LD11,12,13 (refer FIG.5 (c)) rotate the fan 40 when the determination part 52a performs determination of the cleanliness degree of air. When the number is less than a reference value Nb (for example, 800 rpm), the improvement determination thresholds 1 to 3 and the deterioration determination thresholds 1 to 3 for the second determination process are used. LB21,22,23 (refer FIG.5 (b)) and LD21,22,23 (refer FIG.5 (d)) have the rotation speed of the fan 40 when the determination part 52a performs determination of the cleanliness degree of air. The threshold values for improvement determination 1 to 3 and the threshold values for deterioration determination 1 to 3 for the second determination process when the reference value is Nb or more.

  The improvement determination threshold value 1, the improvement determination threshold value 2, and the improvement determination threshold value 3 are such that the air cleanliness degree is set to a first cleanness degree P1, a second cleanness degree P2, and a third cleanness degree P3, which will be described later, respectively. This is a threshold value used to determine whether or not the improvement has occurred. Whether the deterioration determination threshold value 1, the deterioration determination threshold value 2, and the deterioration determination threshold value 3 have deteriorated to a second cleanness degree P2, a third cleanness degree P3, and a fourth cleanness degree P4, respectively, described later. This is a threshold value used to determine whether or not. Of the first to fourth cleaning degrees P1 to P4, the first cleaning degree P1 is the air cleaning degree with the lowest dust concentration. The larger the number, the higher the degree of cleanliness of the air, the higher the dust concentration, and the fourth cleanness level P4 is the cleanliness level of the air having the highest dust concentration among the first to fourth cleanliness levels P1 to P4. It is.

  Each threshold stored in the threshold storage area 51b will be further described.

  SA11, 12, and 13 in FIG. 4A have a relationship of SA11 <SA12 <SA13. SC11, 12, 13 and SD11, 12, 13 in FIG. 4B have a relationship of SC11 <SC12 <SC13, SD11 <SD12 <SD13, SC11 <SD11, SC12 <SD12, and SC13 <SD13. Further, SA11, 12, 13 and SC11, 12, 13 have a relationship of SA11 <SC11, SA12 <SC12, and SA13 <SC13.

  LB11,12,13 of Fig.5 (a) has the relationship of LB11 <LB12 <LB13. The LBs 21, 22, and 23 in FIG. 5B have a relationship of LB21 <LB22 <LB23. The LDs 11, 12, and 13 in FIG. 5C have a relationship of LD11 <LD12 <LD13. The LDs 21, 22, and 23 in FIG. 5D have a relationship of LD21 <LD22 <LD23. Also, LB11, 12, 13, 21, 22, 23 and LD11, 12, 13, 21, 22, 23 include LB11 <LD11, LB12 <LD12, LB13 <LD13, LB21 <LD21, LB22 <LD22, and LB23. <There is a relationship of LD23.

  Furthermore, LB11, 12, 13, 21, 22, and 23 have a relationship of LB11> LB21, LB12> LB22, and LB13> LB23. LD11, 12, 13, 21, 22, and 23 have a relationship of LD11> LD21, LD12> LD22, and LD13> LD23. As shown in FIG. 6, the above relationship is the dust concentration when the rotational speed of the fan 40 is the rotational speed N1 (less than the reference value Nb) and when the rotational speed is N2 (more than the reference value Nb). And the L level signal ratio calculated by the calculation section 52aa of the determination section 52a described later (the ratio of the time during which the dust sensor 60 outputs the L level signal in the predetermined determination time) is different. It is.

(2-6-1-3) Offset value storage area The offset value storage area 51c is a storage area for storing an offset value used when the determination unit 52a described later determines the degree of air cleanliness. The offset value is a reference value for determining the degree of air cleanliness. How the offset value is used when the determination unit 52a determines the degree of cleanliness of air will be described later.

  The offset value storage area 51c stores offset values according to the following three types of conditions.

  1) The type of the determination process performed by the determination unit 52a is the first determination process, and the dust for which the determination unit 52a performs the degree of air purification is large dust.

  2) When the type of the determination process performed by the determination unit 52a is the first determination process, and the dust for which the determination unit 52a performs the degree of air purification is small dust.

  3) When the type of the determination process performed by the determination unit 52a is the second determination process, and the dust for which the determination unit 52a performs the degree of air purification is small dust.

  The offset value stored in the offset value storage area 51c is appropriately calculated and updated by an offset value updating unit 52f of the control unit 52 described later. A method of calculating and updating the offset value by the offset value updating unit 52f will be described later.

(2-6-2) Control Unit The control unit 52 executes the program stored in the storage unit 51 to control the air cleaner 10. Specifically, the control unit 52 moves the respective parts of the air cleaner 10 such as the fan motor 40a and the motor 32a based on various commands input to the operation unit 55, detection results of the dust sensor 60, and the like. To control.

  For example, the fan control unit 52e described later of the control unit 52 drives the fan motor 40a when the operation unit 55 receives an operation command for the air cleaner 10. For example, the control part 52 will drive the motor 32a, if the operation part 55 receives the execution command of humidification operation.

  The control unit 52 includes a determination unit 52a, a writing unit 52b, an improvement determination prohibition unit 52c, a first determination processing prohibition unit 52d, a fan control unit 52e, and an offset value update unit 52f as functional units. Details of the determination unit 52a, the writing unit 52b, the improvement determination prohibiting unit 52c, the first determination processing prohibiting unit 52d, the fan control unit 52e, and the offset value updating unit 52f will be described below.

(2-6-2-1) Determination Unit The determination unit 52a determines the degree of air cleanliness using the detection value of the dust sensor 60. The determination unit 52a compares the value based on the calculated value calculated using the detection value of the dust sensor 60 (the output signal of the dust sensor 60) with the threshold value stored in the threshold value storage area 51b. Determine the cleanliness of the air.

  More specifically, the determination unit 52a calculates the offset stored in the offset value storage area 51c from the calculated value obtained as a ratio of the time during which the dust sensor 60 outputs the L level signal in the predetermined determination time. The degree of cleanliness of the air is determined by comparing the value calculated by subtracting the value with the threshold value stored in the threshold value storage area 51b.

  In addition, the cleanliness degree of air is determined by distinguishing into four stages of first to fourth cleanliness levels P1 to P4. Among the four levels of cleanliness, the first cleanliness P1 is the cleanliness of air with the lowest dust concentration. The larger the number, the higher the degree of cleanliness of the air, the higher the dust concentration, and the fourth cleanness level P4 is the cleanliness level of the air having the highest dust concentration among the first to fourth cleanliness levels P1 to P4. It is.

  The determination unit 52a includes a calculation unit 52aa and a comparison determination unit 52ab as sub function units. Hereinafter, the calculation unit 52aa and the comparison determination unit 52ab will be described.

(2-6-2-1-1) Calculation Unit The calculation unit 52aa calculates a ratio of the time during which the dust sensor 60 outputs the L level signal to the predetermined determination time (referred to as L level signal ratio). To do. The calculation of the L level signal ratio by the calculating unit 52aa is possible even if the air cleaner 10 is not in operation if power is supplied to the air cleaner 10 (if the dust sensor 60 detects dust). Executed.

  The calculation unit 52aa calculates the L level signal ratio using the detection value of the dust sensor 60 related to the large dust and calculates the L level signal ratio using the detection value of the dust sensor 60 related to the small dust. Do different processing. For each case, specific processing executed by the calculation unit 52aa will be described.

(A) Calculation of L level signal ratio using detection value of dust sensor related to large dust The calculation unit 52aa is a detection value of the dust sensor 60 related to large dust (a signal related to dust having a particle size of 3 μm or more of the dust sensor 60). Is used to calculate the ratio (L level signal ratio) of the output time of the L level signal of the dust sensor 60 in the predetermined determination time (first moving average time). Here, the L level signal ratio calculated using the detection value of the dust sensor 60 regarding the large dust is referred to as a large dust L level signal ratio RL. Below, the calculation process of the large dust L level signal ratio RL by the calculation part 52aa is demonstrated concretely.

  The control unit 50 receives an H level signal or an L level signal for dust having a particle size of 3 μm or more from the dust sensor 60 every 80 μsec.

  The calculation unit 52aa calculates the number of times that the control unit 50 receives the H level signal and the L level signal for the dust having a particle size of 3 μm or more in the immediately preceding 1 ms every 1 ms (1000 μs). And compare. And the calculation part 52aa judges that the dust sensor 60 transmitted the signal of the level with the larger frequency | count about the 1 ms. For example, if the calculation unit 52aa receives the H level signal 3 times and the L level signal 9 times in the immediately preceding 1 ms, the dust sensor 60 determines that the L level signal has been transmitted for this 1 ms. To do. This process executed by the calculation unit 52aa every 1 msec is called sampling.

  Furthermore, the calculation unit 52aa uses the sampling result every 1 msec, and the time when the dust sensor 60 is determined to have transmitted the L level signal every 500 msec (0.5 sec) in the immediately preceding 500 msec. The ratio (hereinafter referred to as a unit time calculation value) is calculated. Further, the calculation unit 52aa calculates a moving average value as a large dust L level signal ratio RL every 500 milliseconds using a unit time calculated value for the first moving average time. Here, the first moving average time is 8 seconds. More specifically, the calculation unit 52aa uses 16 unit time calculated values (e1, e2,..., E16) for eight seconds, each having a unit time of 500 msec. As the level signal ratio RL, a moving average value (e1 + e2 +... + E16) / 16 is calculated.

  When calculating the large dust L level signal ratio RL, the calculation unit 52aa calculates the first time if the number of detection values of the dust sensor 60 corresponding to the first moving average time has not yet been acquired. The large dust L level signal ratio RL is calculated using the detection values of a number of dust sensors corresponding to a time shorter than the moving average time. The case where the detection values of the dust sensor 60 corresponding to the first moving average time are not yet acquired is, for example, a case immediately after the air cleaner 10 is connected to the power source. For example, the detection value of the dust sensor 60 corresponding to the first moving average time has not yet been acquired, and the calculation unit 52aa calculates the unit time calculation value (e1, 4 seconds, 500 msec as the unit time). If only e2,..., e8) have been calculated yet, the calculation unit 52aa assumes that the remaining unit time calculation values are all 0 and sets the moving average value (e1 + e2 +... + e8) / 16. The large dust L level signal ratio RL is calculated.

(B) Calculation of L level signal ratio using detection value of dust sensor related to small dust The calculation unit 52aa calculates a detection value of the dust sensor 60 related to the small dust (a signal related to dust having a particle diameter of 1 μm or more from the dust sensor 60, And the ratio of the output time of the L level signal of the dust sensor 60 in the predetermined determination time (first moving average time and second moving average time) using a signal related to dust having a particle size of 3 μm or more (L level). Signal ratio). The first moving average time is 8 seconds as described above, and the second moving average time is 40 seconds longer than the first moving average time. Here, the ratio of the output time of the L level signal of the dust sensor 60 in the first moving average time calculated using the detection value of the dust sensor 60 related to small dust is the first dust L level signal ratio RS1. Call. Further, the ratio of the output time of the L level signal of the dust sensor 60 in the second moving average time calculated using the detection value of the dust sensor 60 related to small dust is referred to as a second small dust L level signal ratio RS2. .

  As described above, the small dust is dust having a particle diameter of 1 μm or more and less than 3 μm. On the other hand, the dust sensor 60 outputs a signal related to dust having a particle diameter of 1 μm or more and a signal related to dust having a particle diameter of 3 μm or more. Therefore, the calculation unit 52aa calculates the L level signal ratio using the detection value of the dust sensor regarding small dust as follows.

  First, the calculation unit 52aa uses a signal related to dust having a particle diameter of 1 μm or more, the ratio of the output time of the L level signal of the dust sensor 60 to the first moving average time (referred to as r11), and the second moving average. The ratio of the output time of the L level signal of the dust sensor 60 in the time (referred to as r12) is calculated. At the same time, the calculation unit 52aa uses a signal related to dust having a particle size of 3 μm or more to calculate the ratio of the output time of the L level signal of the dust sensor 60 to the first moving average time (referred to as r31) and the second The ratio of the output time of the L level signal of the dust sensor 60 in the moving average time (referred to as r32) is calculated. The calculation of r11 by the calculation unit 52aa is the same as the calculation process of the large dust L level signal ratio RL in the above (a) except that the signal used is different. The calculation of r12 by the calculation unit 52aa is the same as the calculation process of the large dust L level signal ratio RL of (a) except that the signal used and the moving average time are different. The calculation of r32 by the calculation unit 52aa is the same as the calculation process of the large dust L level signal ratio RL in (a) except that the moving average time is different. The calculation of r31 by the calculation unit 52aa is the same as the calculation process of the large dust L level signal ratio RL in the above (a).

  Next, the calculation unit 52aa subtracts r31 from r11 to calculate the ratio of the output time of the L level signal of the dust sensor 60 to the first moving average time for dust having a particle size of 1 μm or more and less than 3 μm. That is, the calculation unit 52aa calculates the first small dust L level signal ratio RS1 by subtracting r31 from r11. Further, the calculation unit 52aa subtracts r32 from r12 to calculate the ratio of the output time of the L level signal of the dust sensor 60 to the second moving average time for dust having a particle size of 1 μm or more and less than 3 μm. That is, the calculation unit 52aa calculates the second small dust L level signal ratio RS2 by subtracting r32 from r12.

(2-6-2-1-2) Comparison Determination Unit The comparison determination unit 52ab is a value calculated by subtracting the offset value stored in the offset value storage area 51c from the L level signal ratio calculated by the calculation unit 52aa. Is compared with the threshold value stored in the threshold value storage area 51b. Furthermore, the comparison determination unit 52ab determines the degree of air cleanliness based on the comparison result. The determination of the degree of air purification by the comparison determination unit 52ab is performed at intervals of 500 milliseconds while the air cleaner 10 is operating (when the fan 40 is operating).

  The comparison determination unit 52ab determines the degree of cleanliness of air with respect to large dust (using the detection value of the dust sensor 60 related to large dust) and uses the detection value of the dust sensor 60 regarding small dust. B) When determining the degree of air cleanliness, different processing is performed. In each case, the determination performed by the comparison determination unit 52ab will be described.

(A) Judgment of the degree of air cleanness related to large dusts When the comparison determination unit 52ab determines the degree of air cleanup using the detection value of the dust sensor 60 related to large dusts, a first determination process that prioritizes the determination time. I do. In other words, the comparison determination unit 52ab performs a short-time determination process that prioritizes the determination time when determining the degree of air cleanliness using the detection value of the dust sensor 60 related to large dust.

  Specifically, the comparison determination unit 52ab determines the degree of cleanliness of air related to large dust as follows.

  First, the comparison / determination unit 52ab subtracts the offset value stored in the offset value storage area 51c from the most recently calculated large dust L level signal ratio RL. The offset value used here is the first determination process stored in the offset value storage area 51c and executed by the determination unit 52a, and the determination unit 52a is a target for the degree of air purification. This is an offset value when the dust is large dust.

  Next, the comparison determination unit 52ab compares the value calculated by subtracting the offset value from the most recently calculated large dust L level signal ratio RL with the threshold value stored in the threshold value storage area 51b. The threshold used here is a threshold for large dust stored in the threshold storage area 51b (see FIG. 4). Moreover, the threshold value used here is the threshold values for improvement determination 1 to 3 (SA11, 12, 13) when it is determined that the air cleanliness level has been improved, and the air cleanliness level has deteriorated. In the case of determination, the threshold values for deterioration determination are 1 to 3 (SC11, 12, 13).

  When the comparison determination unit 52ab prohibits the later-described improvement determination prohibition unit 52c from determining whether or not the degree of cleanliness of the air has improved, the most recently calculated large dust L level signal ratio Processing for comparing the value obtained by subtracting the offset value from RL with the threshold value for improvement determination is not performed.

  Specific processing for comparing the value obtained by subtracting the offset value from the most recently calculated large dust L level signal ratio RL and the threshold by the comparison determination unit 52ab, and processing for determining the degree of air cleanliness using the comparison result Will be described later.

(B) Determination of the degree of air cleanliness regarding small dust When the comparison determination unit 52ab determines the degree of air cleanliness using the detection value of the dust sensor 60 regarding small dust, it is stored in the cleanliness storage area 51a. Different determination processes are performed according to the degree of cleanliness of the air.

  When the first cleaning degree P1 is stored in the cleaning degree storage area 51a, the comparison determination unit 52ab performs a first determination process that gives priority to the determination time over the determination accuracy in principle. However, even if the first cleanness level P1 is stored in the cleanness level storage area 51a, the first determination processing prohibition unit 52d described later executes the first determination processing as the determination processing of the air cleanliness level related to small dust. Is prohibited, the comparison determination unit 52ab executes the second determination process as determination of the degree of air cleanliness.

  On the other hand, the comparison determination unit 52ab, rather than the first determination process, when the cleaning degree storage area 51a stores a cleaning degree other than the first cleaning degree P1 (second to fourth cleaning degrees P2 to P4). The second determination process with a longer determination time and better determination accuracy than the first determination process is performed. In other words, the second determination process is executed by the comparison determination unit 52ab when a cleanness level other than the first cleanness level P1 (second to fourth cleanness levels P2 to P4) is stored in the cleanness level storage area 51a. This is a long-time determination process that prioritizes determination accuracy and has a longer determination time than the first determination process.

  In the first determination process and the second determination process, the L level signal ratio used for the determination is the first small dust L level signal ratio RS1 whose moving average time is the first moving average time, or It differs in whether the moving average time is the second small dust L level signal ratio RS2 which is the second moving average time. In other words, more detection values of the dust sensor 60 are used in the second determination process than in the first determination process. Further, the threshold value used for the determination is different between the first determination process and the second determination process.

  Specifically, the comparison determination unit 52ab determines the degree of cleanliness of air related to small dust as follows.

  When performing the first determination process, the comparison determination unit 52ab subtracts the offset value stored in the offset value storage area 51c from the most recently calculated first dust L level signal ratio RS1. The offset value used here is the first determination process stored in the offset value storage area 51c and executed by the determination unit 52a, and the determination unit 52a is a target for the degree of air purification. This is an offset value when the dust is small dust.

  Next, the comparison determination unit 52ab performs the first determination process for small dust, which is stored in the threshold value storage area 51b, with a value obtained by subtracting the offset value from the first calculated small dust L level signal ratio RS1. Compare with the threshold value. Note that the comparison determination unit 52ab executes the first determination process as the degree of air cleanliness regarding small dust when the first degree of cleanness P1 is stored in the degree of cleanness storage area 51a as described above. . Therefore, the comparison / determination unit 52ab does not determine that the degree of air purification has improved. Therefore, the comparison determination unit 52ab compares the value obtained by subtracting the offset value from the most recently calculated first dust L level signal ratio RS1 with the deterioration determination thresholds 1 to 3 (SD11, 12, 13) ( (Refer FIG.4 (b)).

  Specific processing for comparing the value obtained by subtracting the offset value from the most recently calculated first dust L level signal ratio RS1 and the threshold by the comparison determination unit 52ab, and the degree of cleanliness of the air using the comparison result This determination process will be described later.

  When the comparison determination unit 52ab performs the second determination process, the comparison determination unit 52ab subtracts the offset value stored in the offset value storage area 51c from the most recently calculated second dust L level signal ratio RS2. . The offset value used here is the second determination process that is stored in the offset value storage area 51c and executed by the determination unit 52a, and the determination unit 52a is the target on which the degree of air cleaning is performed. This is an offset value when the dust is small dust.

  Next, the comparison determination unit 52ab performs the second determination process for small dust, which is stored in the threshold value storage area 51b, by subtracting the offset value from the most recently calculated second small dust L level signal ratio RS2. Compare with the threshold value. The threshold value used here differs depending on whether the rotation speed N of the fan 40 when the comparison determination unit 52ab calls the threshold value is less than the reference value Nb or more than the reference value Nb (see FIG. 5). Moreover, the threshold value used here is the threshold values for improvement determination 1 to 3 (LB11, 12, 13, 21, 22, 23) when it is determined that the degree of cleanliness of the air has been improved. When it is determined that the degree has deteriorated, the threshold values for deterioration determination are 1 to 3 (LD11, 12, 13, 21, 22, 23).

  When the comparison determination unit 52ab described later prohibits the determination of whether or not the improvement determination prohibition unit 52c has improved the degree of cleanliness of the air, the second small dust L level calculated most recently is used. Processing for comparing the value obtained by subtracting the offset value from the signal ratio RS2 with the threshold value for improvement determination is not performed.

  Specific processing for comparing the value obtained by subtracting the offset value from the most recently calculated second dust L level signal ratio RS2 and the threshold by the comparison determination unit 52ab, and the degree of cleanliness of the air using the comparison result This determination process will be described later.

(2-6-2-2) Writing Unit The writing unit 52b updates and writes the determination result of the determination unit 52a in the cleanliness degree storage area 51a of the storage unit 51. When the determination unit 52a determines the air cleanliness level for small dust and the air cleanliness level for large dust, the writing unit 52b displays the determination result of the determination unit 52a as the cleanliness storage area 51a. Whether to update and write will be described later.

(2-6-2-3) Improvement Determination Prohibition Unit The improvement determination prohibition unit 52c is an example of a write prohibition unit that prohibits writing to the cleanliness storage area 51a of the storage unit 51.

  When the degree of air cleanliness stored in the cleanliness storage area 51a is rewritten, the improvement determination prohibition unit 52c starts from a predetermined period (for example, from the time when the air cleanliness stored in the cleanness storage area 51a is rewritten). 60 seconds), it is prohibited that the determination unit 52a determines whether or not the degree of air purification has improved. Therefore, when the second to fourth cleaning degrees P2 to P4 are written as the determination result of the determination unit 52a in the cleanness degree storage area 51a, the determination unit 52a has the air cleanliness level of the first cleanness degree P1 for a predetermined period. It is not determined that there is. As a result, when the second to fourth cleanliness levels P2 to P4 are written as the determination results of the determination unit 52a in the cleanliness storage area 51a, the writing unit 52b sets the first determination result of the determination unit 52a as the first determination result. Writing the cleanness level P1 to the cleanness level storage area 51a is prohibited for a predetermined period.

(2-6-2-4) First determination processing prohibition unit The first determination processing prohibition unit 52d prohibits the determination unit 52a from executing the first determination processing as the determination processing of the degree of cleanliness of air related to small dust. To do. When the first cleaning degree P1 is updated and written as the determination result of the determining part 52a in the cleaning degree storage area 51a (the first cleaning degree P1 is written as an initial setting at the time of reset). The determination unit 52a performs a process for determining the degree of cleanliness of air related to small dust during a predetermined period (for example, 20 minutes from the time when the degree of cleanness of air stored in the cleanness degree storage area 51a is rewritten). Execution of the first determination process is prohibited. When the first determination process prohibition unit 52d prohibits the determination unit 52a from executing the first determination process as the determination process of the degree of air cleanness related to small dust, the determination unit 52a includes the cleanness degree storage area. Even if the first cleanliness degree P1 is stored in 51a, the second determination process is executed as the determination process of the cleanliness degree of air related to small dust.

(2-6-2-5) Fan Control Unit The fan control unit 52e has a stored air cleanliness level based on the determination result of the determination unit 52a stored in the cleanliness storage area 51a of the storage unit 51. The fan 40 is controlled so that the number of revolutions increases as the value decreases. For example, the fan control unit 52e determines the rotational speed when the second to fourth cleaning degrees P2 to P4 are stored as the determination result of the determination unit 52a in the cleanness degree storage area 51a in the cleanness degree storage area 51a. The fan 40 is controlled so that it becomes larger than the rotation speed when the 1st cleanliness degree P1 is memorize | stored as a determination result of the part 52a. More specifically, the fan control unit 52e controls the rotational speed of the fan 40 to M1 to M4, respectively, when the first to fourth cleaning degrees P1 to P4 are stored in the cleaning degree storage area 51a. To do. M1 to M4 have a relationship of M1 <M2 <M3 <M4. That is, the fan control unit 52e controls the fan 40 so that the higher the dust concentration is, the higher the degree of cleanliness of the air (the lower the degree of cleanness of the air), the greater the rotational speed of the fan 40.

(2-6-2-6) Offset Value Update Unit The offset value update unit 52f calculates and updates the offset value stored in the offset value storage area 51c of the storage unit 51.

  The offset value update unit 52f calculates an offset value according to the following three types of conditions, and updates the offset value stored in the offset value storage area 51c. The first condition is a case where the type of the determination process performed by the determination unit 52a is the first determination process, and the dust for which the determination unit 52a performs the degree of air cleaning is large dust. The second condition is a case where the type of the determination process performed by the determination unit 52a is the first determination process, and the dust for which the determination unit 52a performs the degree of air purification is small dust. The third condition is a case where the type of the determination process performed by the determination unit 52a is the second determination process, and the dust for which the determination unit 52a performs the degree of air cleaning is small dust.

  The offset value executed by the offset value updating unit 52f on the condition that the type of the determination process performed by the determination unit 52a is the second determination process and the dust whose target is the degree of air cleaning performed by the determination unit 52a is small dust. The calculation and update processing will be described with reference to FIG. The offset value update process for other conditions is the same as the update process described here, and a description thereof will be omitted.

  FIG. 7 is a graph showing the change over time of the second small dust L level signal ratio RS2. In FIG. 7, the horizontal axis represents time, and the vertical axis represents the value of the L level signal ratio. Further, the thick line in FIG. 7 indicates that the type of the determination process performed by the determination unit 52a calculated by the offset value update unit 52f is the second determination process, and the determination unit 52a performs the air cleanliness. It represents the time change of the offset value for the condition that the dust to be played is small dust.

  In FIG. 7, the time 0 indicates a time when the air purifier 10 is connected to the power source. The offset value is reset to 0 when the air cleaner 10 is disconnected from the power source and no electricity is supplied. Therefore, when the time of FIG. 7 is 0, the offset value is 0. The offset value update unit 52f does not perform offset value update processing for a predetermined data update basic time Tr (for example, 60 minutes) after the air cleaner 10 is connected to the power source.

  When the data update basic time Tr elapses after the air purifier 10 is connected to the power source, the offset value update unit 52f calculates the offset value as follows, and stores the offset value stored in the offset value storage area 51c. Update.

  The offset value update unit 52f is configured to calculate the second small dust L level signal ratio RS2 calculated at intervals of 0.5 seconds from when the air cleaner 10 is connected to the power source until the data update basic time Tr elapses. Among them, the minimum value is calculated as the offset value. Then, the offset value update unit 52f is a second determination process in which the determination process performed by the determination unit 52a stored in the offset value storage area 51c is a second determination process, and the determination unit 52a is a target on which the degree of air cleaning is performed. The offset value for the condition that the dust is small dust is updated to the calculated offset value.

  Thereafter, according to the following two rules, the offset value update unit 52f stores the offset value storage area 51c, and the determination process performed by the determination unit 52a is the second determination process. The offset value is updated for the condition that the dust to be subjected to the degree of air cleaning is small dust.

  1) When the second small dust L level signal ratio RS2 calculated at 0.5 second intervals falls below the offset value stored in the offset value storage area 51c, the offset value update unit 52f The offset value stored in the storage area 51c is immediately updated to the second small dust L level signal ratio RS2.

  2) When the data update basic time Tr has elapsed since the last update of the offset value, the offset value update unit 52f updates the offset value as follows. Note that the case where the data update basic time Tr has elapsed since the last update of the offset value is an interval of 0.5 seconds between the last update of the offset value and the passage of the data update basic time Tr. This is a case where the second small dust L level signal ratio RS2 calculated in (2) does not fall below the offset value stored in the offset value storage area 51c. The offset value update unit 52f includes the second small dust L level signal ratio RS2 calculated at intervals of 0.5 seconds between the last update of the offset value and the elapse of the data update basic time Tr. Thus, the minimum value is calculated as the offset value. Then, the offset value update unit 52f updates the offset value stored in the offset value storage area 51c to the calculated offset value.

(3) Determination of degree of air cleaning by determination unit Hereinafter, determination of the degree of air cleaning by the determination unit 52a will be described with reference to the flowcharts of FIGS. 8 and 9A to 9C.

  The determination unit 52a includes a case where the detection value of the dust sensor 60 regarding large dust is used to determine the degree of air cleaning, and a case where the detection value of the dust sensor 60 regarding small dust is used to determine the degree of air cleaning. The method for determining the degree of cleanliness of air is different. When determining the air cleanliness level using the detection value of the dust sensor 60 related to large dust, using the flowchart of FIG. 8 to determine the air cleanliness level using the detection value of the dust sensor 60 related to small dust. Will be described with reference to the flowcharts of FIGS. In addition, the determination part 52a performs determination regarding large dust and determination regarding small dust in parallel.

(3-1) Determination of the degree of air cleanliness using the detection value of the dust sensor relating to large dust When the air cleaner 10 is connected to the power source, the dust sensor 60 does not start operation. However, even if the fan 40 is not in operation, dust is detected and an H level signal or an L level signal is output to the control unit 50 every 80 μsec.

  As described above, the calculation unit 52aa of the determination unit 52a performs sampling every 1 msec (1000 μsec) (step S11). In other words, the calculation unit 52aa compares the number of times the control unit 50 receives the H level signal and the number of times the L level signal is received for the dust having a particle size of 3 μm or more in the immediately preceding 1 ms for every 1 ms. . And the calculation part 52aa judges that the dust sensor 60 transmitted the signal of the level with the larger frequency | count about the 1 ms.

  Next, in step S12, the calculation unit 52aa calculates the large dust L level signal ratio RL every 500 milliseconds (0.5 seconds) using the sampling result every 1 milliseconds as described above. Thereafter, the process proceeds to step S13.

  In step S13, it is determined whether or not the air cleaner 10 is currently operating. In addition, the air cleaner 10 being in operation is a state in which an operation command for the air cleaner 10 by the user is input to the operation unit 55 and the fan 40 is rotating. If the air cleaner 10 is not in operation, the determination of the degree of air purification is not performed, and the process returns to step S11. On the other hand, if the air cleaner 10 is in operation, the process proceeds to step S14.

  In step S14, the comparison determination unit 52ab determines the type of determination process executed by the determination unit 52a stored in the offset value storage area 51c at this time from the large dust L level signal ratio RL as the first determination process. The determination unit 52a subtracts the offset value when the dust to be subjected to the air cleaning degree is large dust. The comparison determination unit 52ab then subtracts the offset value from the large dust L level signal ratio RL, and the large dust deterioration determination thresholds 1 to 3 (SC11, 12, 13) stored in the threshold storage area 51b. The degree of cleanliness of the air is determined by comparing the size of the air with the size of FIG.

  Specifically, the comparison determination unit 52ab compares the value obtained by subtracting the offset value from the large dust L level signal ratio RL with the deterioration determination thresholds 1 to 3, and calculates the offset value from the large dust L level signal ratio RL. The subtracted values are a) less than the deterioration determination threshold 1, b) the deterioration determination threshold 1 or more and less than the deterioration determination threshold 2, c) the deterioration determination threshold 2 or more and less than the deterioration determination threshold 3, d) the deterioration determination threshold. It is determined which of 3 or more. And the comparison determination part 52ab determines the cleanliness degree of 1 air corresponding to a determination result. The above conditions a) to d) correspond to the air cleanliness levels P1 to P4, respectively. Thereafter, the process proceeds to step S15.

  In step S15, the comparison determination unit 52ab refers to the cleanliness storage area 51a, and the air cleanliness level of 1 determined in step S14 is currently stored in the cleanliness storage area 51a. Determine if it is getting worse. When it is determined that the air quality has deteriorated, the comparison / determination unit 52ab uses the air cleanliness determined in step S14 as a determination result of the air cleanliness using the detection value of the dust sensor 60 for large dust. decide. Thereafter, the process proceeds to an update process of the air cleanliness stored in the cleanliness storage area 51a (see FIG. 10).

  The comparison / determination unit 52ab determines in step S15 that the air cleanliness determined in step S14 is the same as the air cleanliness currently stored in the cleanliness storage area 51a, or the cleanliness storage area 51a. If it is determined that the air cleanliness level is lower than the air cleanliness level stored in step S16, the process proceeds to step S16.

  In step S16, it is determined whether or not improvement determination is prohibited by the improvement determination prohibition unit 52c. That is, in step S16, it is determined whether or not a predetermined time has elapsed since the cleanliness of the air stored in the cleanliness storage area 51a is updated. If improvement determination is prohibited, the process proceeds to step S19. If the improvement determination is not prohibited, the process proceeds to step S17.

  In step S17, the comparison determination unit 52ab uses the first determination process as the type of determination process performed by the determination unit 52a stored in the offset value storage area 51c at this time from the large dust L level signal ratio RL. The determination unit 52a subtracts the offset value when the dust to be subjected to the air cleaning degree is large dust. The comparison determination unit 52ab then subtracts the offset value from the large dust L level signal ratio RL and the large dust improvement determination thresholds 1 to 3 (SA11, 12, 13) stored in the threshold storage area 51b. The degree of air cleanliness is determined by comparing the magnitudes of the size and the size (see FIG. 4A).

  Specifically, the comparison determination unit 52ab compares the value obtained by subtracting the offset value from the large dust L level signal ratio RL with the improvement determination thresholds 1 to 3, and calculates the offset value from the large dust L level signal ratio RL. The subtracted values are a) improvement determination threshold 1 or less, b) improvement determination threshold 1 or more and improvement determination threshold 2 or less, c) improvement determination threshold 2 or more and improvement determination threshold 3 or less, d) improvement determination threshold. It is determined which of 3 or more. And the comparison determination part 52ab determines the cleanliness degree of 1 air corresponding to a determination result. The above conditions a) to d) correspond to the air cleanliness levels P1 to P4, respectively. Thereafter, the process proceeds to step S18.

  In step S18, the comparison determination unit 52ab refers to the cleanliness storage area 51a, and the air cleanliness level of 1 determined in step S17 is currently stored in the cleanliness storage area 51a. Judge whether it is improving or not. If it is determined that the air quality has improved, the comparison / determination unit 52ab uses the air cleanliness determined in step S17 as the determination result of the air cleanliness using the detection value of the dust sensor 60 for large dust. decide. Thereafter, the process proceeds to an update process of the air cleanliness stored in the cleanliness storage area 51a (see FIG. 10).

  The comparison / determination unit 52ab determines that the air cleanliness degree 1 determined in step S18 is the same as the air cleanliness degree currently stored in the cleanness degree storage area 51a, or the cleanness degree storage area 51a. If it is determined that the air cleanliness level is higher than the air cleanliness level stored in step S19, the process proceeds to step S19.

  In step S19, the comparison / determination unit 52ab determines the air cleanliness currently stored in the cleanliness storage area 51a as the determination result of the air cleanliness using the detection value of the dust sensor 60 for large dust. . Thereafter, the process proceeds to an update process of the air cleanliness stored in the cleanliness storage area 51a (see FIG. 10).

(3-2) Determination of the degree of air purification using the detection value of the dust sensor relating to small dust When the air cleaner 10 is connected to the power source, the dust sensor 60 does not start operation. Even if dust is detected, an H level signal or an L level signal is output to the control unit 50 every 80 μs.

  As described above, the calculation unit 52aa performs sampling every 1 msec (1000 μsec) (step S21). Specifically, the calculation unit 52aa calculates the number of times the control unit 50 receives the H level signal and the number of times the L level signal is received for the dust having a particle diameter of 3 μm or more in the immediately preceding 1 ms for every 1 ms. Compare And the calculation part 52aa judges that the dust sensor 60 transmitted the signal of the level with the larger frequency | count about the 1 m second regarding the dust with a particle size of 3 micrometers or more. In addition, the calculation unit 52aa compares the number of times the control unit 50 receives the H level signal and the number of times the L level signal is received for the dust having a particle size of 1 μm or more in the immediately preceding 1 msec every 1 msec. . And the calculation part 52aa judges that the dust sensor 60 transmitted the signal of the level with the larger frequency | count about the 1 m second regarding the dust with a particle size of 1 micrometer or more.

  Next, in step S22, the calculation unit 52aa uses the sampling result every 1 msec as described above, and performs the first small dust L level signal ratio RS1 (the first datum) every 500 msec (0.5 sec). The ratio of the output time of the L level signal of the dust sensor 60 in one moving average time) and the ratio of the output time of the L level signal of the dust sensor 60 in the second moving average time RS2 ) And. Thereafter, the process proceeds to step S23.

  In step S23, it is determined whether or not the air cleaner 10 is currently operating. If the air cleaner 10 is not in operation, the determination of the degree of air purification is not performed, and the process returns to step S21. On the other hand, if the air cleaner 10 is in operation, the process proceeds to step S24.

  In step S24, the comparison / determination unit 52ab grasps the rotational speed of the fan 40 controlled by the fan control unit 52e. Thereafter, the process proceeds to step S25.

  In step S25, the comparison determination unit 52ab grasps the current air cleanliness level stored in the cleanliness storage area 51a. Thereafter, the process proceeds to step S26.

  In step S26, the comparison determination unit 52ab determines whether or not the current air cleanliness stored in the cleanliness storage area 51a is the first cleanliness P1. If it is determined that the degree of cleaning is the first degree of cleaning P1, the process proceeds to step S211. If it is determined that the degree of cleaning is other than the first degree of cleaning P1, the process proceeds to step S221.

  In step S211, the first determination process prohibiting unit 52d determines whether or not the first determination process is prohibited as the determination process of the degree of air cleanliness regarding small dust. In other words, in step S211, it is determined whether or not a predetermined period has elapsed since the first cleaning degree P1 is updated and written as the air cleaning degree in the cleaning degree storage area 51a. When the first determination process is prohibited as the determination process of the degree of air cleanliness regarding small dust, the process proceeds to step S221. If the first determination process is not prohibited, the process proceeds to step S212.

  In step S212, the comparison determination unit 52ab determines the type of the determination process executed by the determination unit 52a stored in the offset value storage area 51c at this time from the first small dust L level signal ratio RS1. Therefore, the determination unit 52a subtracts the offset value when the dust to be subjected to the degree of air purification is small dust. The comparison determination unit 52ab then subtracts the offset value from the first small dust L level signal ratio RS1, and the deterioration determination thresholds 1 to 3 (SD11, 12 for the small dust) stored in the threshold storage area 51b. , 13, see FIG. 4 (b)), and the degree of cleanliness of the air is determined. The contents executed by the comparison / determination unit 52ab are the same as those in step S14 described above except that the values used are different, and thus the description thereof is omitted here. When step S212 ends, the process proceeds to step S213.

  In step S213, the comparison / determination unit 52ab determines the current air cleanliness degree stored in the cleanness degree storage area 51a in which the air cleanliness degree 1 determined in step S212 is grasped in step S25 (i.e., It is determined whether or not it is worse than the first cleanliness degree P1). When it is determined that the air quality has deteriorated, the comparison / determination unit 52ab uses the air cleanliness determined in step S212 as a determination result of the air cleanliness using the detection value of the dust sensor 60 for small dust. decide. And it progresses to the update process (refer FIG. 10) of the air cleanliness memorize | stored in the cleanliness memory area 51a.

  In step S213, the comparison / determination unit 52ab determines that the air cleanliness level of 1 determined in step S212 is the same as the air cleanliness level currently stored in the cleanliness storage area 51a (first cleanness level P1). If YES, the process proceeds to step S214.

  In step S214, the comparison / determination unit 52ab determines the air cleanliness currently stored in the cleanliness storage area 51a as the determination result of the air cleanliness using the detection value of the dust sensor 60 for small dust. . And it progresses to the update process (refer FIG. 10) of the air cleanliness memorize | stored in the cleanliness memory area 51a.

  In step S221, it is determined whether or not the rotational speed of the fan determined in step S24 is less than the reference value Nb. If the rotational speed of the fan determined in step S24 is less than the reference value Nb, the process proceeds to step S222. On the other hand, if the rotational speed of the fan ascertained in step S24 is greater than or equal to the reference value Nb, the process proceeds to step S232.

  In step S222, the comparison determination unit 52ab determines the type of the determination process performed by the determination unit 52a stored in the offset value storage area 51c at this time from the second small dust L level signal ratio RS2. Therefore, the determination unit 52a subtracts the offset value when the dust to be subjected to the degree of air purification is small dust. Then, the comparison / determination unit 52ab determines that the value obtained by subtracting the offset value from the second small dust L level signal ratio RS2 and the rotational speed of the fan 40 stored in the threshold storage area 51b is the reference value Nb. The degree of cleanliness of air is determined by comparing the magnitudes of thresholds 1 to 3 for deterioration determination for less than 1 (LD11, 12, 13, see FIG. 5C). The contents executed by the comparison / determination unit 52ab are the same as those in step S14 described above except that the values used are different, and thus the description thereof is omitted here. When step S222 ends, the process proceeds to step S223.

  In step S223, the air level that is determined in step S222 by the comparison / determination unit 52ab using the air cleaning level determined in step S25 is currently stored in the cleaning level storage area 51a. It is determined whether or not the degree of cleanliness is worse. When it is determined that the air quality has deteriorated, the comparison / determination unit 52ab uses the air cleanliness determined in step S222 as the determination result of the air cleanliness using the detection value of the dust sensor 60 for small dust. decide. And it progresses to the update process (refer FIG. 10) of the air cleanliness memorize | stored in the cleanliness memory area 51a.

  In step S223, the comparison determination unit 52ab determines that the air cleanliness level of 1 determined in step S222 is the same as the air cleanliness level currently stored in the cleanness level storage area 51a, or the cleanness level storage area 51a. If it is determined that the air cleanliness level is lower than the air cleanliness level stored in step S224, the process proceeds to step S224.

  In step S224, it is determined whether or not improvement determination is prohibited by the improvement determination prohibition unit 52c. That is, in step S224, it is determined whether or not a predetermined time has elapsed since the cleanliness of the air stored in the cleanliness storage area 51a is updated. If the improvement determination is prohibited, the process proceeds to step S227. If the improvement determination is not prohibited, the process proceeds to step S225.

  In step S225, the comparison determination unit 52ab determines the type of the determination process executed by the determination unit 52a stored in the offset value storage area 51c at this time from the second small dust L level signal ratio RS2. Therefore, the determination unit 52a subtracts the offset value when the dust to be subjected to the degree of air purification is small dust. Then, the comparison / determination unit 52ab determines that the value obtained by subtracting the offset value from the second small dust L level signal ratio RS2 and the rotational speed of the fan 40 stored in the threshold storage area 51b is the reference value Nb. The degree of cleanliness of air is determined by comparing the magnitudes of improvement determination thresholds 1 to 3 for less than 1 (see LB11, 12, 13 and FIG. 5A). The contents executed by the comparison / determination unit 52ab are the same as those in step S17 described above except that the values used are different, and thus the description thereof is omitted here. When step S225 ends, the process proceeds to step S226.

  In step S226, the air cleaning degree determined by step S225 using the air cleaning degree grasped in step S25 by the comparison / determination unit 52ab is currently stored in the cleaning degree storage area 51a. It is judged whether or not the degree of cleanliness is improved. If it is determined that the air quality has improved, the comparison / determination unit 52ab uses the air cleanliness determined in step S225 as a determination result of the air cleanliness using the detection value of the dust sensor 60 for small dust. decide. And it progresses to the update process (refer FIG. 10) of the air cleanliness memorize | stored in the cleanliness memory area 51a.

  In step S226, the comparison / determination unit 52ab determines that the air cleanliness degree 1 determined in step S225 is the same as the air cleanliness degree currently stored in the cleanness degree storage area 51a, or the cleanness degree storage area 51a. If it is determined that the air cleanliness level is higher than the air cleanliness level stored in step S227, the process proceeds to step S227.

  In step S227, the comparison / determination unit 52ab determines the air cleanliness currently stored in the cleanliness storage area 51a as the determination result of the air cleanliness using the detection value of the dust sensor 60 for small dust. . And it progresses to the update process (refer FIG. 10) of the air cleanliness memorize | stored in the cleanliness memory area 51a.

  The processing from step S232 to step S237 is the same as the processing from step S222 to step S237. However, in step S232, unlike step S222, deterioration determination thresholds 1 to 3 (for dust and stored in threshold storage area 51b and for which the rotational speed of fan 40 is greater than or equal to reference value Nb are stored as thresholds. LD 21, 22, 23, see FIG. 5 (d)). Further, in step S235, unlike step S225, the threshold values for improvement determination 1 to 3 (LB21) for small dust and for the rotational speed of the fan 40 greater than or equal to the reference value Nb, stored in the threshold value storage area 51b as threshold values. , 22, 23, see FIG. 5B). Description of the processing from step S232 to step S237 is omitted.

(4) Update process of the degree of cleanliness of air stored in the cleanliness degree storage area Update process by the writing unit 52b of the cleanliness degree of air stored in the cleanness degree storage area 51a, and this update process The processes of the improvement determination prohibition unit 52c and the first determination process prohibition unit 52d will be described with reference to the flowchart of FIG.

  In step S31, the writing unit 52b grasps the cleanliness level of the air currently stored in the cleanliness storage area 51a.

  In step S32, the writing unit 52b determines the air cleanliness determination result using the detection value of the dust sensor 60 for large dust and the determination result of the air cleanliness using the detection value of the dust sensor 60 for small dust. The degree of cleanliness of air having a higher dust concentration is specified as the degree of cleanliness of air for comparison with the degree of cleanliness of air currently stored in the cleanness degree storage area 51a. If both the determination results indicate that the determined air cleanliness level is the same, the air cleanliness for comparing the air cleanliness level with the air cleanliness level currently stored in the cleanliness storage area 51a. Specify as a degree. Then, the writing unit 52b compares the specified air cleanliness level with the air cleanliness level currently stored in the cleanness level storage area 51a, and determines whether they are the same. If it is determined that they are the same, the updating process is terminated, and the process returns to the determination of the degree of air cleanliness (step S11 in FIG. 8 and step S21 in FIG. 9A). If it is determined that they are not the same, the process proceeds to step S33.

  In step S33, the writing unit 52b determines the air cleanliness determination result using the detection value of the dust sensor 60 for large dust and the determination result of the air cleanliness using the detection value of the dust sensor 60 for small dust. Of these, the degree of cleanliness of the air with the higher dust concentration is updated and written in the cleanness storage area 51a as the determination result of the determination unit 52a. Thereafter, the process proceeds to step S34.

  In step S34, the improvement determination prohibition unit 52c prohibits the improvement determination. That is, the improvement determination prohibition unit 52c prohibits the determination unit 52a from determining whether or not the degree of air purification has improved. The improvement determination prohibiting unit 52c starts counting a timer for prohibiting the improvement determination for a predetermined period. Thereafter, the process proceeds to step S35.

  In step S35, it is determined whether or not the air cleaning degree written by the writing unit 52b in the cleaning degree storage area 51a in step S33 is the first cleaning degree P1. When the cleanness level of the air written by the writing unit 52b in the cleanliness storage area 51a is the first cleanliness level P1, the process proceeds to step S36. When the air cleaning degree written by the writing unit 52b in the cleaning degree storage area 51a is other than the first cleaning degree P1, the determination of the air cleaning degree is performed again (step S11 in FIG. 8 and step S21 in FIG. 9A). Return to.

  In step S36, the first determination process prohibition unit 52d prohibits the determination unit 52a from executing the first determination process as the determination process of the degree of air cleanliness regarding small dust. The first determination processing prohibition unit 52d starts counting a timer for prohibiting the execution of the first determination process as the determination process of the degree of air cleanliness regarding small dust for a predetermined period. Thereafter, the process returns again to the determination of the degree of cleanliness of air (step S11 in FIG. 8 and step S21 in FIG. 9A).

(5) Features (5-1)
The air cleaner 10 according to the present embodiment includes a fan 40 having a variable rotation speed, a dust sensor 60, a determination unit 52a, a storage unit 51, and a fan control unit 52e. The fan 40 generates an air flow so that air passes through the HEPA filter 22 as an example of an air cleaning filter. The dust sensor 60 detects dust in the air. The determination unit 52a uses the detection value of the dust sensor 60 (the output signal of the dust sensor 60) to set the air cleanliness to the first cleanness P1 and the second dust concentration higher than the first cleanliness P1. To the fourth cleaning degree P2 to P4. In the cleanliness degree storage area 51a of the storage unit 51, the determination result of the determination unit 52a is updated and written and stored. The fan control unit 52e has the number of rotations when the second to fourth cleaning degrees P2 to P4 are stored as determination results in the cleanness storage area 51a, and the first cleanliness P1 as the determination result in the cleanness storage area 51a. Is controlled so as to be larger than the rotational speed in the case where is stored. The determination unit 52a performs a first determination process and a second determination process as determinations of the degree of air cleanliness. In particular, when the determination unit 52a determines the degree of air cleaning using the detection value of the dust sensor 60 regarding small dust, the determination unit 52a performs the first determination process according to the degree of cleaning stored in the degree-of-cleaning storage area 51a. The second determination process is executed as determination of the degree of air cleanliness. The first determination process is executed when the first cleanness degree P1 is stored as a determination result in the cleanness storage area 51a. In the first determination process, the determination time has priority over the determination accuracy. The second determination process is executed when the second to fourth cleanliness levels P2 to P4 are stored as the determination results in the cleanliness storage area 51a. The second determination process has a longer determination time than the first determination process, and is superior to the first determination process in determination accuracy.

  Here, when the air cleanliness degree is recognized as the first cleanness degree P1, the first determination process prioritizing the determination time is executed as the determination process of the air cleanliness degree of the small dust. Therefore, when the air cleanliness is determined to be the relatively clean first cleanliness P1 and the fan 40 is operated at a relatively low rotational speed (rotational speed N1), if the concentration of dust in the air increases, The deterioration of the air cleanliness is quickly recognized by the 1 determination process. And it controls rapidly so that the rotation speed of the fan 40 may become large according to the deterioration of the air cleanliness degree. Therefore, when the air is determined to be relatively clean, it is possible to suppress a sudden increase in the concentration of dust in the air.

  In addition, here, when the air cleanliness is recognized as the second to fourth cleanliness P2 to P4 where the dust concentration is relatively high, the second priority is given to the determination accuracy as the determination of the air cleanliness. Judgment processing is executed. Therefore, improper control of the air volume of the fan 40, such as the fact that the air volume of the fan 40 is reduced due to erroneous recognition of the degree of air purification, despite the fact that the concentration of dust in the air is high, can be prevented.

(5-2)
In the air cleaner 10 according to the present embodiment, the dust sensor 60 detects dust at regular time intervals (80 μm). In the first determination process, the determination unit 52a uses the output signal of the dust sensor 60 for the first moving average time (here, 8 seconds). In the second determination process, the determination unit 52a uses the output signal of the dust sensor 60 for the second moving average time (40 seconds here). That is, the determination unit 52a uses more output signals of the dust sensor 60 than the first determination process in the second determination process so that the determination time of the second determination process is longer than the determination time of the first determination process. .

  Here, in the second determination process, the degree of cleanliness of the air is determined based on more output signals (detection values) of the dust sensor 60 than in the first determination process. The influence of the uneven density of dust on the determination accuracy is reduced. Therefore, in the second determination process, it is possible to determine the degree of cleanliness of the air with higher accuracy than in the first determination process.

(5-3)
In the air cleaner 10 according to the present embodiment, the determination unit 52a calculates the unit time calculated value every 0.5 seconds using the detection value of the dust sensor 60 (the dust sensor 60 is at L level for 500 milliseconds). The degree of air cleanliness is determined using the moving average value of the ratio of the time at which the signal is transmitted. The determination unit 52a sets the moving average time in the second determination process (second moving average time) to the movement in the first determination process so that the determination time of the second determination process is longer than the determination time of the first determination process. It is longer than the average time (first moving average time).

  Here, in the second determination process, the determination of the degree of air cleaning is performed based on the moving average value of the second moving average time longer than the first moving average time of the first determination process. Therefore, in the second determination process, it is possible to determine the degree of cleanliness of the air more accurately than in the first determination process by reducing the influence of the noise of the output signal and the nonuniformity of the dust concentration in the air on the determination accuracy. It is.

(5-4)
In the air cleaner 10 according to the present embodiment, the first degree of cleanness P1 is stored in the cleanliness degree storage area 51a of the storage unit 51 when the air purifier 10 is activated. The determination unit 52a performs the first determination process when the air purifier 10 is activated, and the output signals of the dust sensor 60 corresponding to the moving average time (first moving average time) in the first determination process are output. If it has not been acquired yet, the first determination process is performed using a quantity of output signals of the dust sensor 60 corresponding to a time shorter than the moving average time in the first determination process.

  Here, when the air cleaner 10 is activated and the output signals (detection values) of the dust sensors corresponding to the first moving average time have not yet been acquired, they are used in the normal first determination process. The degree of cleanliness of the air is determined using the output signal of the dust sensor 60 having a smaller quantity than that obtained. Therefore, when the concentration of dust is relatively high and the user starts the air cleaner 10 in anticipation of prompt removal of dust, the degree of cleanliness of the air is immediately determined, and the improvement of the degree of cleanliness of the air is improved. Easy to figure out.

(5-5)
In the air cleaner 10 according to the present embodiment, the first cleanliness P1 is the cleanliness of the air having the lowest dust concentration among the cleanliness of the air determined by the determination unit 52a.

  Here, when it is determined that the concentration of dust is the lowest in the set degree of air cleanliness, it is possible to suppress a sudden increase in the concentration of dust in the air.

(5-6)
The air cleaner 10 according to the present embodiment includes an improvement determination prohibition unit 52c as a write prohibition unit that prohibits writing to the cleanliness storage area 51a of the storage unit 51. When the writing unit 52b updates and writes the degree of cleanliness of the air stored in the cleanness degree storage area 51a, the improvement determination prohibition unit 52c thereafter determines for a predetermined period (here, 60 seconds), the determination unit 52a. Prohibits determining that the air cleanliness has improved. As a result, the improvement determination prohibition unit 52c has the first determination result in the cleanness degree storage area 51a for a predetermined period when the second to fourth cleanness degrees P2 to P4 are written as the determination result in the cleanness degree storage area 51a. Writing of the degree of cleanliness P1 is prohibited.

  Here, in the transition state in which the concentration of dust gradually decreases, the determination of the air cleanliness frequently changes between the first cleanliness P1 and the second to fourth cleanliness P2 to P4, It can suppress that the rotation speed of the fan 40 is switched frequently.

(5-7)
The air purifier 10 according to the present embodiment includes a first determination processing prohibition unit 52d that prohibits the determination unit 52a from executing the first determination process as the determination process of the degree of air cleanliness regarding small dust. When the first cleaning degree is updated and written as the determination result in the cleaning degree storage area 51a, the first determination processing prohibiting unit 52d is a predetermined time (20 minutes here) after the first cleaning degree is written, The determination unit 52a prohibits execution of the first determination process as the determination process of the degree of air cleanliness regarding small dust. While the first determination processing prohibition unit 52d prohibits the first determination process as the determination process of the degree of air cleanness related to small dust, the determination unit 52a has the first cleanliness level as the determination result in the cleanness storage area 51a. Even if P1 is stored, the second determination process is executed as determination of the degree of air cleanliness.

  Here, when the air cleanliness stored in the cleanliness storage area 51a is updated to the first cleanness P1, the first determination process is performed as the determination process of the air cleanliness regarding small dust for a predetermined period. Is prohibited. Therefore, in a transition state in which the dust concentration gradually decreases, for example, when the dust concentration is in the vicinity of the determination criterion between the first cleaning degree P1 and the second cleaning degree P2, the air cleaning degree Although the determination accuracy suddenly decreases and the operation of the fan 40 at a relatively high rotational speed is necessary, a state where the rotational speed of the fan 40 is decreased can be avoided.

(5-8)
In the air cleaner 10 according to the present embodiment, the determination unit 52a calculates the first or second small dust L level calculated using the output signal of the dust sensor 60 when determining the degree of air cleanliness regarding small dust. The degree of cleanliness of the air is determined by comparing the value obtained by subtracting the offset value from the signal ratios RS1 and RS2 with the improvement determination thresholds 1 to 3 or the deterioration determination thresholds 1 to 3. The improvement determination thresholds 1 to 3 and the deterioration determination thresholds 1 to 3 are the first determination process (when the value obtained by subtracting the offset value from the first small dust L level signal ratio RS1 is compared with the threshold). The second determination process (when the magnitude of the threshold value is compared with the value obtained by subtracting the offset value from the second small dust L level signal ratio RS2) is changed.

  Here, the improvement determination thresholds 1 to 3 and the deterioration determination thresholds 1 to 3 used for determination are changed in consideration of the type of determination processing, so that it is easy to accurately determine the degree of air cleanliness. It is.

(5-9)
In the air purifier 10 according to the present embodiment, the determination unit 52a calculates the second small dust L level signal ratio RS2 calculated using the output signal of the dust sensor 60 when determining the degree of air purification related to small dust. The degree of cleanliness of the air is determined by comparing the value obtained by subtracting the offset value from the improvement determination thresholds 1 to 3 or the deterioration determination thresholds 1 to 3. The improvement determination thresholds 1 to 3 and the deterioration determination thresholds 1 to 3 are changed according to the rotation speed of the fan 40 at the time of determination by the determination unit 52a.

  When the rotational speed of the fan 40 changes, the amount of air passing through the dust sensor 60 changes, and the second small dust calculated using the detection value of the dust sensor 60 even though the dust concentration is the same. The value of the L level signal ratio RS2 changes. Here, since the air cleanliness is determined in consideration of this, it is easy to accurately determine the air cleanliness.

(5-10)
In the air cleaner 10 according to the present embodiment, the determination unit 52a calculates the first small dust L level signal ratio RS1 calculated using the output signal of the dust sensor 60 when determining the degree of cleanliness of air related to small dust. Alternatively, the degree of air cleanliness is determined using a value obtained by subtracting the offset value from the second small dust L level signal ratio RS2. The offset value is set for each of the first determination process and the second determination process.

  Here, since the offset value is prepared for each of the first determination process and the second determination process, it is easy to accurately determine the degree of cleanliness of the air.

(5-11)
In the air cleaner 10 according to the present embodiment, the dust sensor 60 detects small dust having a small particle size and large dust having a larger particle size than the small dust so as to be distinguishable. When the determination unit 52 a determines the air cleanliness level using the detection value related to the small dust of the dust sensor 60, the determination unit 52 a sets the air cleanliness level stored as a determination result in the cleanliness storage area 51 a of the storage unit 51. Based on this, the first determination process or the second determination process is performed. In other words, the determination unit 52a uses a signal related to dust having a particle size of 3 μm or more from the ratio of the output time of the L level signal to the moving average time calculated using the output signal related to dust having a particle size of 1 μm or more. In the case where the air cleanliness level is determined using a value obtained by reducing the ratio of the output time of the L level signal to the moving average time calculated using the output signal, the cleanness level storage area 51a of the storage unit 51 is used. The first determination process or the second determination process is performed based on the degree of air cleanliness stored as the determination result. The determination unit 52a always performs the first determination process when determining the degree of air cleanliness using the detection value of the large dust of the dust sensor 60.

  Here, for the small dust, the determination unit 52a switches between the first and second determination processes, while the determination is performed for the large dust that is suspended in the air for a relatively short time. The unit 52a always performs the first determination process with priority on the determination time. Therefore, it is easy to collect large dust.

(6) Modifications Modifications of the above embodiment are shown below. In addition, a part or all of the configuration of each modification may be combined with a part or all of the configuration of another modification as long as they do not contradict each other.

(6-1) Modification A
In the above embodiment, the dust sensor 60 outputs, as detection values, an L level signal indicating that dust is detected and an H level signal indicating that dust is not detected. However, the present invention is not limited to this. Not what you want.

  For example, the dust sensor 60 has the same function as the calculation unit 52aa of the determination unit 52a of the above embodiment, and the large dust L level signal ratio RL, the first small dust L level signal ratio RS1, and the second small dust L. The level signal ratio RS2 may be calculated, and these values may be transmitted to the control unit 50 as detection values.

(6-2) Modification B
In the above embodiment, the calculation unit 52aa calculates the L level signal ratio (the large dust L level signal ratio RL, the first small dust L level signal ratio RS1, and the second small dust L level signal ratio RS2) with respect to the determination time. The comparison determination unit 52ab determines the air cleanliness level by comparing the threshold value calculated by the calculation unit 52aa with the offset value subtracted from the L level signal ratio with respect to the determination time. Is not to be done.

  For example, the calculation unit 52aa uses the output signal of the dust sensor 60 instead of the L level signal ratio with respect to the determination time, and uses the output signal of the dust sensor 60 to determine the concentration of dust (the weight of dust contained in the unit volume of air or the unit volume of air). The number of contained dust etc.) may be calculated, and the comparison / determination unit 52ab may determine the degree of cleanliness of the air by comparing the value obtained by subtracting the offset value from the calculated dust concentration with a threshold value. Further, the calculation unit 52aa calculates the H level signal ratio with respect to the determination time instead of the L level signal ratio with respect to the determination time, and the comparison determination unit 52ab subtracts the offset value from the calculated H level signal ratio. The degree of cleanliness of air may be determined by comparing with a threshold value.

(6-3) Modification C
In the said embodiment, although the determination part 52a determines the cleanliness degree of air in four steps, the 1st-4th cleanliness degree P1-P4, it is not limited to this, The determination part 52a is the cleanliness of air. Any method may be used as long as the degree is determined by dividing it into two or more levels. For example, the determination unit 52a may determine the air cleanliness level in two stages of a first cleanness level P1 and a second cleanness level P2. Moreover, the determination part 52a may determine the air cleanliness degree in five stages.

(6-4) Modification D
In the said embodiment, the fan control part 52e sets the rotation speed of the fan 40 to M1-M4 with respect to the cleanliness degree of the air of the 1st-4th cleanliness P1-P4 memorize | stored in the cleanliness degree storage area 51a, respectively. Although it controls, it is not limited to this. For example, when the second cleanliness degree P2 or the third cleanness degree P3 is stored in the cleanliness degree storage area 51a, the fan control unit 52e may be any of the second and third cleanliness levels P2 and P3. The rotation speed of the fan 40 may be controlled to a certain value larger than M1.

(6-5) Modification E
In the above embodiment, even if the determination unit 52a performs the first determination process (short-term determination process) performed when determining the degree of air cleanliness for large dust, the degree of air cleanliness for small dust is determined. Even in the first determination process (short-time determination process) performed at the time of determination, the moving average time is set to one value (first moving average time), but is not limited thereto. For example, for the short-time determination process of the degree of air cleanness related to large dust, the moving average time may be set to a shorter time (for example, 4 seconds).

(6-6) Modification F
In the embodiment, the calculation unit 52aa moves the L level signal ratio (the large dust L level signal ratio RL, the first small dust L level signal ratio RS1, and the second small dust L level signal ratio RS2) with respect to the determination time. Although it calculates using an average, it is not limited to this. The calculation unit 52aa may calculate the ratio of the L level signal output time of the dust sensor 60 to the determination time by using the output signal of the dust sensor 60 for the determination time instead of as a moving average.

(6-7) Modification G
In the above embodiment, the dust sensor 60 starts detecting dust when electricity is supplied to the air cleaner 10. However, the present invention is not limited to this. Detection may be started. By comprising in this way, it is possible to reduce the power consumption of the air cleaner 10 in operation stop. However, in order to make it easy to accurately determine the degree of air purification immediately after the start of the operation of the air cleaner 10, the dust sensor 60 detects dust while electricity is supplied to the air cleaner 10. It is desirable.

(6-8) Modification H
In the above-described embodiment, the first moving average time is used when the first cleanness degree P1 is stored as the air cleanliness degree in the cleanness degree storage area 51a at the time of determination of the air cleanliness degree related to small dust. When the determination process is executed and the second to fourth cleanliness levels P2 to P4 are stored, the second determination process using the second moving average time is executed, but the present invention is not limited to this. For example, even when the air cleanliness is the second cleanliness P2, if it is desirable to quickly determine the air cleanliness similarly to the first cleanliness P1, the first and second cleanliness P1 , P2 is stored, the first determination process using the first moving average time is executed, and when the third and fourth cleaning degrees P3, P4 are stored, the second moving average time is calculated. The used second determination process may be executed. In this case, different improvement determination thresholds 1 to 3 and deterioration determination thresholds 1 to 3 may be used for the first and second cleanliness levels P1 and P2 in which the rotation speed of the fan 40 is different.

(6-9) Modification I
In the above-described embodiment, the improvement determination prohibition unit 52c as the write prohibition unit prohibits the determination unit 52a from determining whether or not the air cleanliness level has been improved. When any one of the fourth cleaning degrees P2 to P4 is written, the first cleaning degree P1 is prohibited from being written in the cleaning degree storage area 51a for a predetermined period. However, the present invention is not limited to this, and the air cleaner 10 is replaced with the improvement determination prohibiting unit 52c when any one of the second to fourth cleaning degrees P2 to P4 is written in the cleaning degree storage area 51a. In addition, the writing unit 52b may include a write prohibiting unit that directly prohibits the first cleaning degree P1 from being written in the cleaning degree storage area 51a for a predetermined period.

(6-10) Modification J
In the above embodiment, the calculation unit 52aa calculates the L level signal ratios RS1 and RS2 for small dust, and the L level signal occupies the determination time calculated using the output signal for dust having a particle size of 1 μm or more. The calculation of subtracting the ratio of the output time of the L level signal to the determination time calculated using the output signal using the signal related to dust having a particle size of 3 μm or more is performed from the ratio of the output time of Is not to be done. In general, since the number of dust particles having a particle size of 3 μm or more is smaller than that of dust particles having a particle size of 1 μm or more, the calculation unit 52aa is calculated using an output signal relating to dust having a particle size of 1 μm or more. The ratio of the output time of the L level signal in the determination time may be approximated as the L level signal ratios RS1 and RS2 for small dust (dust having a particle diameter of 1 μm or more and less than 3 μm).

(6-11) Modification K
In the above embodiment, the dust sensor 60 detects small dust and large dust in a distinguishable manner, but is not limited to this. For example, the dust sensor may detect dust without distinguishing the size of dust. And only the process similar to the determination of the air cleanliness degree regarding the small dust in the said embodiment is performed, and the determination process of the air cleanliness degree regarding the large dust in the said embodiment does not need to be performed. Further, in this case, the writing unit 52b takes into consideration both the results of the determination of the degree of air cleanness related to small dust and the determination of the degree of air cleanness related to large dust, and the cleanliness storage area 51a There is no need to update. The writing unit 52b determines the contents of the cleanliness storage area 51a when the air cleanliness determined by the determiner 52a is different from the air cleanliness stored in the cleanliness storage area 51a. What is necessary is just to update and write in the air cleanliness degree determined by 52a.

  However, since there is a difference in behavior between large dust and small dust, the dust sensor 60 detects the small dust and large dust in a distinguishable manner as in the above embodiment, and the large dust and small dust are It is desirable that the degree of cleanliness of air be determined by the methods described above.

(6-12) Modification L
In the above-described embodiment, the offset value is prepared for each type of determination process performed by the determination unit 52a and for each size of dust that is determined by the determination unit 52a for determining the degree of air cleanliness. Is not to be done. For example, the offset value may be prepared for each rotation speed of the fan 40 when the determination unit 52a further determines the degree of air cleanliness. This makes it easier to accurately determine the degree of air cleanliness.

(6-13) Modification M
In the said embodiment, although the air cleaner 10 is a floor-standing type air cleaner, it is not limited to this. The air cleaner according to the present invention may be an air conditioner having an air cleaning function.

  An air purifier according to the present invention is an air purifier that controls the air volume of a fan that guides air to an air purifying filter in accordance with the cleanliness of air grasped using a detection value of a dust sensor, It is possible to prevent the concentration of air from rising from a relatively low state, and when the air cleanness is low, it is possible to prevent the air volume from being reduced due to misrecognition of the air cleanliness. Useful as an air purifier.

10 Air Cleaner 22 HEPA Filter (Air Cleaner Filter)
40 Fan 51 Storage unit 52a Determination unit 52c Improvement determination prohibition unit (write prohibition unit)
52d 1st determination process prohibition part 52e Fan control part 60 Dust sensor P1 1st cleaning degree P2 2nd cleaning degree (2nd cleaning degree)
P3 Third degree of cleanliness (second degree of cleanliness)
P4 4th cleaning degree (2nd cleaning degree)

JP 2001-87613 A

Claims (12)

A fan (40) with variable rotation speed for generating an air flow so that air passes through the air cleaning filter (22);
A dust sensor (60) for detecting dust in the air;
Using the detection value of the dust sensor, the degree of air cleanliness is at least a first degree of cleanliness (P1) and a second degree of cleanliness (P2, P3, P4) in which the concentration of dust is higher than the first degree of cleanliness. And a determination unit (52a) that makes a distinction and
A storage unit (51) in which the determination result of the determination unit is updated and written and stored;
The number of rotations when the second cleaning degree is stored as the determination result in the storage unit is larger than the number of rotations when the first cleaning degree is stored as the determination result in the storage unit. A fan control unit (52e) for controlling the fan,
With
The determination unit
When the first cleaning degree is stored as the determination result in the storage unit, a first determination process that prioritizes determination time over determination accuracy,
When the second degree of cleanliness is stored as the determination result in the storage unit, a second determination process that is longer in determination time than the first determination process and superior in determination accuracy than the first determination process is performed. ,
Execute as a judgment of the degree of air cleanliness,
Air cleaner (10). The dust sensor detects dust at regular time intervals,
In the second determination process, the determination unit has more detection values of the dust sensor than the first determination process so that the determination time of the second determination process is longer than the determination time of the first determination process. Use
The air cleaner according to claim 1. The determination unit determines a degree of air cleanliness using a moving average value of calculated values calculated using a detection value of the dust sensor, and the determination time of the second determination process is the first time. The moving average time in the second determination process is longer than the moving average time in the first determination process so as to be longer than the determination time of the determination process.
The air cleaner according to claim 1. The storage unit stores the first degree of cleanliness when the air cleaner is activated,
The determination unit is a case where the first determination process is performed when the air cleaner is activated, and a detection value of the dust sensor having a quantity corresponding to the moving average time in the first determination process has not yet been acquired. In this case, the first determination process is performed using a detection value of the dust sensor corresponding to a quantity shorter than the moving average time in the first determination process.
The air cleaner according to claim 3. The first cleanliness is the cleanliness of air having the lowest dust concentration among the cleanliness of air determined by the determination unit.
The air cleaner according to any one of claims 1 to 4. A write prohibiting unit (52c) for prohibiting writing to the storage unit;
The writing prohibition unit prohibits the first cleaning degree from being written as the determination result to the storage unit for a predetermined period when the second cleaning degree is written as the determination result to the storage unit. ,
The air cleaner according to any one of claims 1 to 5. A first determination processing prohibition unit (52d) for prohibiting the determination unit from executing the first determination process;
The first determination process prohibition unit prohibits the determination unit from executing the first determination process for a predetermined period when the first cleanness degree is updated and written as the determination result in the storage unit. And
While the first determination process is prohibited by the first determination processing prohibition unit, the determination unit is configured to perform the second determination even if the first cleanliness is stored as the determination result in the storage unit. The process is executed as a determination of the degree of air cleanliness,
The air cleaner according to any one of claims 1 to 6. The determination unit determines the degree of cleanliness of the air by comparing a value based on a calculated value calculated using a detection value of the dust sensor and a threshold value,
The threshold value is changed between the first determination process and the second determination process.
The air cleaner according to claim 1. The determination unit determines the degree of cleanliness of the air by comparing a value based on a calculated value calculated using a detection value of the dust sensor and a threshold value,
The threshold is changed according to the number of rotations of the fan at the time of determination by the determination unit.
The air cleaner according to claim 1. The determination unit determines the degree of cleanliness of air using a value obtained by subtracting an offset value from a calculated value calculated using a detection value of the dust sensor,
The offset value is set for each of the first determination process and the second determination process.
The air cleaner according to claim 1. The offset value is further set according to the rotation speed of the fan at the time of determination by the determination unit.
The air cleaner according to claim 10. The dust sensor detects small dust particles having a small particle size and large dust particles having a particle size larger than the small dust,
The determination unit
When determining the air cleanliness level using the detection value related to the small dust of the dust sensor, based on the air cleanliness level stored as the determination result in the storage unit, the first determination process or the Perform the second determination process,
When determining the degree of cleanliness of air using a detection value related to the large dust of the dust sensor, the first determination process is always performed.
The air cleaner according to any one of claims 1 to 11.

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