JP6735478B2 - Water content sensor and clothes dryer - Google Patents

Description

The present invention relates to a water content sensor and a clothes drying device.

2. Description of the Related Art Conventionally, for example, a clothes drying device that dries clothes (object) dried in an indoor space is known to include a water content sensor that detects the water content of the object. Then, the clothes drying device may detect the water content of the object with the water content sensor and adjust the dehumidification strength based on the detection result of the water content sensor. As the moisture content sensor, for example, an infrared moisture meter that measures the moisture content by utilizing infrared absorption by moisture is known (see, for example, Patent Document 1).

JP-A-5-118984

By the way, in order to enable more efficient clothes drying, it is desired to detect the water content according to the situation of the target object.

Therefore, the present invention is to provide a water content sensor and a clothes drying device that enable efficient clothes drying by detecting the water content of an object according to the situation.

In order to achieve the above object, a water content sensor according to one embodiment of the present invention is a water content sensor that emits light to an object and detects the water content of the object based on reflected light from the object. Then, the detection light including the first wavelength band whose absorption by water is larger than a predetermined value, and the reference light including the second wavelength band whose absorption by water is equal to or less than the predetermined value are directed toward the object while scanning. A light emitting unit that emits light, a first light receiving unit that receives the detection light reflected by the object and converts it into a first electric signal, and a reference light that receives the reference light reflected by the object and converts it into a second electric signal. Two light receiving parts, an arithmetic processing part for calculating the signal ratio of the first electric signal and the second electric signal, and a distribution of a plurality of detection positions of the signal ratio in the scanning range of the detection light and the reference light emitted by the light emitting part. And a light source control unit that controls based on the ratio.

A clothes drying device according to an aspect of the present invention includes the moisture content sensor, and a drying control unit that controls drying conditions based on the moisture content detected by the moisture content sensor.

The water content sensor and the clothes drying/dehumidifying machine according to the present invention enable efficient clothes drying by detecting the water content of the object according to the situation.

FIG. 1 is a perspective view showing a schematic configuration of a clothes drying device according to an embodiment. FIG. 2 is a control block diagram of the clothes dryer according to the embodiment. FIG. 3 is a schematic diagram showing a configuration of a water content sensor and an object according to the embodiment. FIG. 4 is a block diagram showing a control configuration of the water content sensor according to the embodiment. FIG. 5 is a diagram showing absorption spectra of water and water vapor. FIG. 6 is an explanatory diagram showing a scanning range of the scanning module according to the embodiment. FIG. 7A is a conceptual diagram of the detection range adjustment mechanism according to the embodiment. FIG. 7B is a conceptual diagram of the detection range adjusting mechanism according to the embodiment. FIG. 8 is an explanatory diagram showing the relationship between the distribution of the plurality of detection positions P in the scanning range A and the water content according to the embodiment. FIG. 9A is a conceptual diagram of a detection range adjusting mechanism according to the first modification. FIG. 9B is a conceptual diagram of the detection range adjusting mechanism according to the first modification. FIG. 10 is an explanatory diagram showing the relationship between the distribution of a plurality of detection positions in the scanning range and the water content according to the second modification. FIG. 11 is an explanatory diagram showing the relationship between the distribution of a plurality of detection positions in the scanning range and the water content according to Modification 3. FIG. 12 is a graph showing the relationship between the rate of change in the normalized signal ratio and the dryness.

Hereinafter, a clothes dryer and a water content sensor according to an embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement of constituent elements, connection forms, and the like shown in the following embodiments are examples and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, the constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as arbitrary constituent elements.

In addition, each drawing is a schematic view, and is not necessarily strictly illustrated. Therefore, for example, the scales and the like in the drawings do not necessarily match. Further, in each of the drawings, the substantially same components are designated by the same reference numerals, and duplicate description will be omitted or simplified.

(Embodiment)
[Clothes dryer]
First, the clothes drying apparatus 100 according to the embodiment will be described.

FIG. 1 is a perspective view showing a schematic configuration of a clothes drying device 100 according to an embodiment.

As shown in FIG. 1, the clothes drying apparatus 100 sucks indoor air to dehumidify the air, and blows the indoor air again to dry the object 2 that has been dried indoors. Here, the object 2 is, for example, clothing, if not particularly limited. Examples of the object 2 other than clothes include bedding such as sheets and pillow covers.

The clothes drying apparatus 100 includes a main body 101 having a substantially rectangular parallelepiped shape, and a lid portion 102 that opens and closes at the upper portion of the main body 101. An air blower 103 (see FIG. 2) that is exposed when the lid 102 is opened is provided on the upper portion of the main body 101. The blower unit 103 blows the wind W to the space 3 in the room to dry the target object 2 existing in the space 3. The space 3 is a space (free space) between the clothes drying device 100 and the object 2, and contains moisture (water vapor). The space 3 is an external space of the main body 101 of the clothes drying apparatus 100.

A suction port 104 for taking in outside air is provided on the upper part of the main body 101 at a position apart from the lid 102. A flow path that guides air from the suction port 104 to the blower unit 103 is formed inside the main body 101, and a dehumidifying unit 105 (see FIG. 2) that dehumidifies the air is provided in the flow path. There is. The lid 102 is provided with a water content sensor 1 for detecting the water content of the object 2.

FIG. 2 is a control block diagram of clothes drying apparatus 100 according to the embodiment. As shown in FIG. 2, the clothes drying device 100 includes a dehumidifying unit 105, a blower unit 103, a water content sensor 1, and a drying control unit 106.

The dehumidifying unit 105 is, for example, a vapor compression heat pump, and dehumidifies the air flowing through the flow path of the main body 101. The air blower 103 blows air dehumidified by the dehumidifier 105 toward the space 3. At least one drying condition such as a blowing range, a blowing direction, a blowing intensity (wind force), and a blowing temperature in the blowing unit 103 can be changed. Details of the water content sensor 1 will be described later.

The drying control unit 106 is composed of a microcontroller. The drying control unit 106 is a non-volatile memory in which a general operation program of the clothes drying apparatus 100 is stored, a volatile memory that is a temporary storage area for executing the program, an input/output port, and a processor that executes the program. And so on.

Specifically, the drying control unit 106 controls the drying condition of the blower unit 103 based on the water content of the object 2 detected by the water content sensor 1. Thereby, an appropriate drying condition is selected according to the water content of the object 2.

[Water content sensor]
Next, an outline of the water content sensor 1 according to the embodiment will be described.

FIG. 3 is a schematic diagram showing the configuration of the water content sensor 1 and the object 2 according to the embodiment. FIG. 4 is a block diagram showing a control configuration of the water content sensor 1 according to the embodiment.

The water content sensor 1 is a water content sensor that emits light to the target object 2 and detects the water content of the target object 2 based on the reflected light from the target object 2.

In the present embodiment, as shown in FIGS. 1 and 2, the water content sensor 1 detects water contained in an object 2 arranged with a space 3 in between.

As shown in FIGS. 1 and 2, the water content sensor 1 includes a housing 10, a light emitting unit 20, a first light receiving module 30, a second light receiving module 40, and a signal processing circuit 50.

Below, each component of the water content sensor 1 will be described in detail.

[Case]
The housing 10 is a housing of the lid 102 in the clothes drying apparatus 100, and houses the light emitting unit 20, the first light receiving module 30, the second light receiving module 40, and the signal processing circuit 50. The housing 10 is made of a light-shielding material. This can prevent external light from entering the housing 10. Specifically, the housing 10 is formed of a resin material or a metal material that has a light shielding property with respect to the light received by the first light receiving module 30 and the second light receiving module 40.

A plurality of openings are provided on the outer wall of the housing 10, and the lens 21 of the light emitting unit 20, the lens 31 of the first light receiving module 30, and the lens 41 of the second light receiving module 40 are provided in these openings. It is installed.

[Light emitting part]
The light emitting unit 20 emits detection light including a first wavelength band in which absorption by water is larger than a predetermined value and reference light including a second wavelength band in which absorption by water is less than or equal to a predetermined value toward the object 2. It is a light emitting part. Specifically, the light emitting unit 20 includes a lens 21, a light source 22, a scanning module 23, and a detection range adjusting mechanism 24.

The lens 21 is a condenser lens that condenses the light emitted by the light source 22 onto the object 2. The lens 21 is a convex lens made of resin, but is not limited to this.

The light source 22 is an LED (Light Emitting Diode) light source that includes a first wavelength band that forms detection light and a second wavelength band that forms reference light, and emits continuous light having a peak wavelength on the second wavelength band side. Specifically, the light source 22 is an LED light source made of a compound semiconductor.

FIG. 5 is a diagram showing absorption spectra of water and water vapor. As shown in FIG. 5, water has absorption peaks at wavelengths of about 1450 nm and about 1940 nm. Water vapor has an absorption peak at a wavelength slightly lower than the absorption peak of water, specifically, at a wavelength of about 1350 nm to 1400 nm and about 1800 nm to 1900 nm.

Therefore, as the first wavelength band forming the detection light, a wavelength band having a high water absorbance is selected, and as the second wavelength band forming the reference light, a wavelength band having a smaller water absorption than the first wavelength band is selected. select. Then, as an example, the average wavelength of the second wavelength band is made longer than the average wavelength of the first wavelength body. Regarding the center wavelength defined by the center value of the wavelength that is half the maximum transmittance of the optical bandpass filter, for example, the center wavelength of the first wavelength band is 1450 nm and the center wavelength of the second wavelength band is 1700 nm. To do.

In this way, since the light source 22 emits light that continuously includes the first wavelength band and the second wavelength band, the object 2 includes the detection light including the first wavelength band that is largely absorbed by water, The reference light including the second wavelength band whose absorption by water is smaller than the first wavelength band is irradiated.

The scanning module 23 scans the light from the light source 22 toward the space 3. Within the scanning range A by the scanning module 23, it is possible to scan the light from the light source 22 and detect the water content at a desired position.

FIG. 6 is an explanatory diagram showing the scanning range A of the scanning module 23 according to the embodiment. Although FIG. 6 shows the case where only one target 2 is included in the scanning range A, a plurality of targets 2 may be included in this scanning range A.

As illustrated in FIG. 6, the scanning module 23 temporarily stops the light from the light source 22 a plurality of times while scanning the scanning range A. At the time of this stop, the water content is detected. The position where the water content is detected is referred to as “detection position P”, and the range where the water content is detected at one detection position is referred to as the “detection range Ra”. Although there are a plurality of detection positions P in the scanning range A, the scanning module 23 can adjust the pitch of the detection positions P. Specifically, the scanning module 23 adjusts the pitch of the detection positions P in the main scanning direction by adjusting the stop timing of light in the main scanning direction. The scanning module 23 also adjusts the sub-scanning interval to adjust the pitch of the detection positions P in the sub-scanning direction.

The scanning module 23 has a structure that reflects the light from the light source 22 and scans the light. Specifically, the scanning module 23 includes a first mirror that swings at a relatively high speed in the horizontal direction (main scanning direction) and a second mirror that swings at a relatively low speed in the vertical direction (sub scanning direction). Have Then, the first mirror and the second mirror reflect the light from the light source 22 in a direction according to its deflection angle. The light from the light source is reflected by the first mirror and then by the second mirror. By swinging the first mirror and the second mirror in the horizontal direction and the vertical direction, respectively, the light from the light source 22 is applied to the space 3 while being scanned in the horizontal direction and the vertical direction (that is, two-dimensionally). The object 2 is scanned.

In addition to the structure that reflects and scans light, the scanning module 23 may have a structure that scans light by adjusting the attitude of the light source 22. Alternatively, the water content sensor 1 itself may be moved to scan the light.

The detection range adjustment mechanism 24 is a mechanism that adjusts the size of the detection range Ra. Specifically, the detection range adjusting mechanism 24 changes the distance between the lens 21 and the light source 22 to control the size of the spot of the light transmitted through the lens 21. This spot is the detection range Ra.

7A and 7B are conceptual diagrams of the detection range adjusting mechanism 24 according to the embodiment. 7A shows a state where the detection range is wide, and FIG. 7B shows a state where the detection range is narrow. More specifically, as shown in FIG. 7A, when the distance between the lens 21 and the light source 22 is shortened (distance d1 shorter than that in FIG. 7B), the spot of light transmitted through the lens 21 (detection range Ra) is large. Become. On the other hand, as shown in FIG. 7B, when the distance between the lens 21 and the light source 22 is increased (the distance d2 is longer than that in FIG. 7A), the spot of light transmitted through the lens 21 (detection range Ra) becomes small. The detection range adjustment mechanism 24 adjusts the size of the detection range Ra by moving at least one of the lens 21 and the light source 22 and adjusting the distance between the lens 21 and the light source 22.

[First light receiving module]
As shown in FIG. 3, the first light receiving module 30 includes a lens 31, a first bandpass filter 32, and a first light receiving unit 33.

The lens 31 is a condenser lens for condensing the reflected light reflected by the object 2 on the first light receiving unit 33. The lens 31 is fixed to the housing 10 so that the focus is located on the light receiving surface of the first light receiving unit 33, for example. The lens 31 is, for example, a resin-made convex lens, but is not limited to this.

The first bandpass filter 32 is a bandpass filter that extracts light in the first wavelength band from reflected light. Specifically, the first bandpass filter 32 is arranged between the lens 31 and the first light receiving unit 33, and is on the optical path of the reflected light that passes through the lens 31 and enters the first light receiving unit 33. It is provided in. Then, the first bandpass filter 32 transmits light in the first wavelength band and absorbs light in other wavelength bands.

The first light receiving unit 33 is a light receiving element that receives the light of the first wavelength band that has been reflected by the object 2 and that has passed through the first bandpass filter 32, and that converts the light into a first electrical signal. The first light receiving unit 33 photoelectrically converts the received light in the first wavelength band to generate a first electric signal according to the amount of received light (that is, intensity). The generated first electric signal is output to the signal processing circuit 50. The first light receiving unit 33 is, for example, a photodiode, but is not limited to this. For example, the first light receiving unit 33 may be a phototransistor or an image sensor.

[Second light receiving module]
The second light receiving module 40 includes a lens 41, a second bandpass filter 42, and a second light receiving section 43.

The lens 41 is a condenser lens for condensing the reflected light reflected by the object 2 on the second light receiving unit 43. The lens 41 is fixed to the housing 10 so that the focus is located on the light receiving surface of the second light receiving unit 43, for example. The lens 41 is, for example, a resin-made convex lens, but is not limited to this.

The second bandpass filter 42 is a bandpass filter that extracts the light in the second wavelength band from the reflected light. Specifically, the second bandpass filter 42 is disposed between the lens 41 and the second light receiving unit 43, and is on the optical path of the reflected light that passes through the lens 41 and enters the second light receiving unit 43. It is provided in. Then, the second bandpass filter 42 transmits light in the second wavelength band and absorbs light in other wavelength bands.

The second light receiving unit 43 is a light receiving element that receives the light of the second wavelength band that is reflected by the object 2 and that has passed through the second bandpass filter 42, and that converts the light into a second electric signal. The second light receiving unit 43 photoelectrically converts the received light in the second wavelength band to generate a second electric signal according to the received light amount (that is, intensity) of the light. The generated second electric signal is output to the signal processing circuit 50. The second light receiving section 43 is a light receiving element having the same shape as the first light receiving section 33. That is, when the first light receiving unit 33 is a photodiode, the second light receiving unit 43 is also a photodiode.

[Signal processing circuit]
The signal processing circuit 50 controls the lighting of the light source 22 of the light emitting unit 20 and processes the first electric signal and the second electric signal output from the first light receiving unit 33 and the second light receiving unit 43, thereby obtaining the water content. Is a circuit for calculating.

The signal processing circuit 50 may be housed in the housing 10 or may be attached to the outer surface of the housing 10. Alternatively, the signal processing circuit 50 may have a communication function such as wireless communication and may receive the first electric signal from the first light receiving unit 33 and the second electric signal from the second light receiving unit 43.

Specifically, as shown in FIG. 4, the signal processing circuit 50 includes a light source control unit 51, a first amplification unit 52, a second amplification unit 53, a first signal processing unit 54, a second signal processing unit 55, and a calculation. The processing unit 56 is provided.

The light source controller 51 is composed of a drive circuit and a microcontroller. The light source control unit 51 includes a nonvolatile memory in which control programs for the light source 22, the scanning module 23, and the detection range adjusting mechanism 24 are stored, a volatile memory that is a temporary storage area for executing the program, an input/output port, It has a processor for executing a program.

The light source control unit 51 controls the light source 22 so that turning on and off of the light source 22 is repeated at a predetermined light emission cycle. Specifically, the light source control unit 51 outputs a pulse signal of a predetermined frequency (for example, 1 kHz) to the light source 22 to turn the light source 22 on and off at a predetermined light emission cycle.

Further, the light source control unit 51 controls the detection range adjusting mechanism 24 to control the distance between the light source 22 and the lens 21, thereby controlling the size of the detection range Ra. Further, the light source control unit 51 controls the scanning module 23 to stop the light from the light source 22 at a predetermined pitch while scanning the light from the light source 22, so that the light in the detection range Ra is detected at the plurality of detection positions P. To irradiate. The light source control unit 51 controls at least one of the pitch of the plurality of detection positions P and the size of the detection range Ra based on the amount of water detected by the arithmetic processing unit 56 to detect the detection position within the scanning range A. Control the distribution of P. The distribution control of the detection position P will be described later.

The first amplification unit 52 amplifies the first electric signal output by the first light receiving unit 33 and outputs the first electric signal to the first signal processing unit 54. Specifically, the first amplification unit 52 is an operational amplifier that amplifies the first electric signal.

The first signal processing unit 54 is composed of a microcontroller. The first signal processing unit 54 is a non-volatile memory that stores a processing program for the first electric signal, a volatile memory that is a temporary storage area for executing the program, an input/output port, a processor that executes the program, and the like. Have. The first signal processing unit 54 performs a passband limitation on the first electric signal, corrects a phase delay due to the passband limitation, and then multiplies the light emission period of the light source 22. The process for the first electric signal is a so-called lock-in amplifier process. This makes it possible to suppress the noise due to the ambient light from the first electric signal.

The second amplification section 53 amplifies the second electric signal output from the second light receiving section 43 and outputs the amplified second electric signal to the second signal processing section 55. Specifically, the second amplification unit 53 is an operational amplifier that amplifies the second electric signal.

The second signal processing unit 55 is composed of a microcontroller. The second signal processing unit 55 is a non-volatile memory that stores a processing program for the second electric signal, a volatile memory that is a temporary storage area for executing the program, an input/output port, a processor that executes the program, and the like. Have. The second signal processing unit 55 performs passband limitation on the second electric signal, corrects the phase delay due to the passband limitation, and then performs multiplication processing with the light emission period of the light source 22. The process for the second electric signal is a so-called lock-in amplifier process. This makes it possible to suppress the noise due to the ambient light from the second electric signal.

The arithmetic processing unit 56 detects a component included in the object 2 based on the first electric signal output from the first light receiving unit 33 and the second electric signal output from the second light receiving unit 43. Specifically, the arithmetic processing unit 56 detects the amount of water contained in the object 2 based on the ratio (signal ratio) between the voltage level of the first electric signal and the voltage level of the second electric signal. In the present embodiment, the arithmetic processing unit 56 is based on the first electric signal processed by the first signal processing unit 54 and the second electric signal processed by the second signal processing unit 55, and the object 2 The amount of water contained in is detected. A specific method for detecting (calculating) the amount of water will be described later.

The arithmetic processing unit 56 is, for example, a microcontroller. The arithmetic processing unit 56 has a non-volatile memory in which a signal processing program is stored, a volatile memory which is a temporary storage area for executing the program, an input/output port, a processor for executing the program, and the like. The arithmetic processing unit 56 outputs the detected water content of the object 2 to the light source control unit 51 from the input/output port. As a result, the light source control unit 51 can control the distribution of the plurality of detection positions P within the scanning range A based on the amount of water detected by the arithmetic processing unit 56.

[Signal processing (detection processing)]
Next, the signal processing (dryness detection processing) by the arithmetic processing unit 56 will be described.

In the present embodiment, the arithmetic processing unit 56 detects the component amount contained in the object 2 by comparing the light energy Pd of the detection light included in the reflected light and the light energy Pr of the reference light. The light energy Pd corresponds to the intensity of the first electric signal output from the first light receiving unit 33, and the light energy Pr corresponds to the intensity of the second electric signal output from the second light receiving unit 43.

The light energy Pd is represented by the following (Formula 1).

(Formula 1) Pd=Pd0×Gd×Rd×Td×Aad×Ivd

Here, Pd0 is the light energy of the light of the first wavelength band forming the detection light, of the light emitted by the light source 22. Gd is the coupling efficiency (condensing rate) of the light of the first wavelength band with respect to the first light receiving unit 33. Specifically, Gd corresponds to a proportion of a part of the light emitted from the light source 22 that becomes a part of the component diffusely reflected by the object 2 (that is, the detection light included in the reflected light).

Rd is the reflectance of the detection light by the object 2. Td is the transmittance of the detection light by the first bandpass filter 32. Ivd is the light receiving sensitivity for the detection light included in the reflected light at the first light receiving unit 33.

Aad is the absorptance of detection light by the component (water) contained in the object 2, and is represented by the following (Formula 2).

(Formula 2) Aad=10 ^{−αa×Ca×D}

Here, αa is a predetermined extinction coefficient, specifically, the extinction coefficient of the detection light due to the component (water). Ca is the volume concentration of the component (water content) contained in the object 2. D is a contribution thickness that is twice the thickness of the component that contributes to the absorption of the detection light.

More specifically, in the object 2 in which water is uniformly dispersed, when light is incident on the object 2 and internally reflected and emitted from the object 2, Ca is included in the components of the object 2. Corresponding to the volume concentration. Further, D corresponds to the optical path length until the light is internally reflected and emitted from the object 2. For example, when the object 2 is a mesh-like solid material such as fibers or a porous solid material such as a sponge, it is assumed that light is reflected on the surface of the solid material. In this case, for example, Ca is the concentration of water contained in the liquid phase covering the solid matter. D is a contribution thickness converted as an average thickness of the liquid phase covering the solid matter.

Therefore, αa×Ca×D corresponds to the component amount (water content) contained in the object 2. From the above, it can be seen that the light energy Pd corresponding to the intensity of the first electric signal changes according to the amount of water contained in the object 2. Since the absorbance of moisture is extremely smaller than that of moisture, it can be ignored.

Similarly, the light energy Pr of the reference light incident on the second light receiving unit 43 is represented by the following (Formula 3).

(Formula 3) Pr=Pr0×Gr×Rr×Tr×Ivr

In the present embodiment, it can be considered that the reference light is not substantially absorbed by the component contained in the target object 2, and therefore, as can be seen by comparison with (Equation 1), it corresponds to the absorption rate Aad due to water. The term to do is not included in (Equation 3).

In (Equation 3), Pr0 is the light energy of the light of the second wavelength band forming the reference light, of the light emitted by the light source 22. Gr is the coupling efficiency (condensing rate) of the reference light emitted from the light source 22 to the second light receiving unit 43. Specifically, Gr corresponds to a proportion of a part of the reference light that becomes a part of the component diffusely reflected by the object 2 (that is, the reference light included in the reflected light). Rr is the reflectance of the reference light by the object 2. Tr is the transmittance of the reference light by the second bandpass filter 42. Ivr is the light receiving sensitivity for the reflected light of the second light receiving unit 43.

In the present embodiment, the light emitted from the light source 22, that is, the detection light and the reference light are emitted coaxially and with the same spot size. Therefore, the detection light coupling efficiency Gd and the reference light coupling efficiency Gr are different from each other. It becomes almost equal. Further, since the peak wavelengths of the detection light and the reference light are relatively close to each other, the reflectance Rd of the detection light and the reflectance Rr of the reference light are substantially equal to each other.

Therefore, the following (Equation 4) is derived by taking the ratio of (Equation 1) and (Equation 3).

(Formula 4) Pd/Pr=Z×Aad

Here, Z is a constant term and is represented by (Equation 5).

(Equation 5) Z=(Pd0/Pr0)×(Td/Tr)×(Ivd/Ivr)

The light energies Pd0 and Pr0 are predetermined as the initial output of the light source 22, respectively. In addition, the transmittance Td and the transmittance Tr are predetermined by the transmission characteristics of the first bandpass filter 32 and the second bandpass filter 42, respectively. The light receiving sensitivity Ivd and the light receiving sensitivity Ivr are predetermined by the light receiving characteristics of the first light receiving unit 33 and the second light receiving unit 43, respectively. Therefore, Z shown in (Equation 5) can be regarded as a constant.

The arithmetic processing unit 56 calculates the light energy Pd of the detection light based on the first electric signal, and calculates the light energy Pr of the reference light based on the second electric signal. Specifically, the signal level (voltage level) of the first electric signal corresponds to the light energy Pd, and the signal level (voltage level) of the second electric signal corresponds to the light energy Pr.

Therefore, the arithmetic processing unit 56 can calculate the absorption rate Aad of the water contained in the object 2 based on (Equation 4). Accordingly, the arithmetic processing unit 56 can calculate the water content based on (Equation 2).

Although humidity (water vapor) is also present in the space 3, it is also assumed that the water absorbs the detection light and the reference light. The signal processing circuit 50 may be provided with a correction unit that corrects the first electric signal and the second electric signal so as to cancel the absorbed portion due to the water vapor.

[Distribution control]
Next, the distribution control of the plurality of detection positions P in the scanning range A based on the detected water content will be described.

First, at the start of water content detection, the light source control unit 51 sets the pitches of the plurality of detection positions P and the size of the detection range Ra as initial values, respectively, and based on them, the detection range adjustment mechanism 24 and the scanning. It controls the module 23. As a result, in the scanning range A, the light having the initial value is scanned while being temporarily stopped at the pitch of the initial value. In the temporarily stopped portion, the reflected light enters the first light receiving unit 33 and the second light receiving unit 43 each time. As a result, the arithmetic processing unit 56 detects the amount of water at each detection position P.

Next, the arithmetic processing unit 56 outputs the detected water content to the light source control unit 51. The light source controller 51 determines the pitch of the plurality of detection positions P and the size of the detection range Ra at the time of the next scanning, based on the water content. The amount of water used for this determination may be in any format that can recognize the change over time in the amount of water within the detection range Ra. For example, the water content used for the determination may be the average value of the water content at the plurality of detection positions P, or the water content at one specific detection position P.

FIG. 8 is an explanatory diagram showing the relationship between the distribution of the plurality of detection positions P in the scanning range A and the water content according to the embodiment. When the water content is large, the object 2 is not so dry and is in a wet state as a whole. That is, since it is not necessary to finely change the drying conditions in the clothes drying device 100, the pitch of the detection positions P is widened and the size of the detection range Ra is also increased. That is, the distribution of the detection positions P is roughened. In other words, the detection density is lowered.

On the other hand, as the water content decreases, the object 2 also partially dries. For this reason, it is desired that the clothes drying device 100 finely change the drying conditions. In order to finely control the drying conditions, it is necessary to make the detection position P fine and increase the number of water content data. From this, as the amount of water decreases, the pitch of the detection positions P is narrowed and the size of the detection range Ra is also reduced. That is, the distribution of the detection positions P is made dense. In other words, the detection density is increased.

In this way, the light source control unit 51 determines the pitch of the plurality of detection positions P and the size of the detection range Ra based on the amount of water, so that the distribution of the plurality of detection positions P in the scanning range A is appropriate. Have control over.

[Operation of clothes dryer]
Next, the operation of the clothes drying device 100 will be described.

At the time of drying clothes, the drying control unit 106 of the clothes drying apparatus 100 controls the drying condition of the blower unit 103 based on the water content and coordinates of each detection position P input from the water content sensor 1. Specifically, when the water content of the object 2 is small, the number of data of the water content input from the water content sensor 1 to the drying control unit 106 is also small. Therefore, the drying control unit 106 roughly determines the drying condition of the blower unit 103. On the other hand, when the water content of the object 2 is large, the data quantity of the water content input from the water content sensor 1 to the drying control unit 106 is also large. Therefore, the drying control unit 106 finely determines the drying conditions of the air blowing unit 103.

[Effects]
As described above, the water content sensor 1 according to the present embodiment emits light to the object 2 and detects the water content of the object 2 based on the reflected light from the object 2. The quantity sensor 1 directs detection light including a first wavelength band whose absorption by water is greater than a predetermined value and reference light including a second wavelength band whose absorption by water is less than a predetermined value toward the object 2. Then, the light emitting unit 20 that emits while scanning, the first light receiving unit 33 that receives the detection light reflected by the target object 2 and converts it into the first electric signal, and the reference light that is reflected by the target object 2 are received. , A second light receiving unit 43 for converting into a second electric signal, an arithmetic processing unit 56 for calculating a signal ratio of the first electric signal and the second electric signal, and a scanning range A of the detection light and the reference light emitted by the light emitting unit 20. The light source control unit 51 for controlling the distribution of the plurality of detection positions P of the signal ratio based on the signal ratio.

Further, the clothes drying device 100 according to the present embodiment includes the water content sensor 1, and the drying control unit 106 that controls the drying condition based on the water content detected by the water content sensor 1.

According to this configuration, the light source control unit 51 controls the distribution of the plurality of detection positions P for detecting the signal ratio of the first electric signal and the second electric signal based on the signal ratio (water content). Therefore, it is possible to detect an appropriate amount of water according to the situation of the object 2. Therefore, it is possible to efficiently control the drying condition based on the amount of water detected by the water content sensor 1.

Further, the light source controller 51 controls at least one of the pitch of the plurality of detection positions P of the signal ratio and the size of the detection range Ra at the detection position P in the scanning range A based on the signal ratio.

According to this configuration, in the control of the distribution of the detection positions P, at least one of the pitch of the plurality of detection positions P of the signal ratio and the size of the detection range Ra at the detection positions P is controlled. Control can be performed easily.

The light emitting unit 20 includes a light source 22 and a lens 21, and the light source control unit 51 controls the distance between the light source 22 and the lens 21 to control the size of the detection range Ra.

According to this configuration, since the size of the detection range Ra is controlled by controlling the distance between the light source 22 and the lens 21, it is possible to control the size of the detection range Ra with a simple mechanism. is there.

Further, the light source 22 emits light of continuous wavelengths including a wavelength band that forms the detection light and a wavelength band that forms the reference light, and the light source control unit 51 causes the light source 22 to emit light at a predetermined light emission cycle, and the water content. The sensor 1 processes the first electric signal of the first light receiving unit 33 and outputs the first electric signal to the arithmetic processing unit 56, and the second electric signal of the second light receiving unit 43 to calculate the first electric signal. The second signal processing unit 55 for outputting to the processing unit 56 is provided, and the first signal processing unit 54 performs the passband limitation on the first electric signal and corrects the phase delay due to the passband limitation. , The light emission cycle is multiplied, and the second signal processing unit 55 limits the pass band of the second electric signal and corrects the phase delay due to the pass band limitation, and then multiplies the light emission cycle. Apply processing.

According to this configuration, lock-in amplifier processing can be performed on the first electric signal and the second electric signal, and noise due to ambient light can be suppressed from the first electric signal and the second electric signal. Is.

[Modification 1]
In the above embodiment, the detection range adjusting mechanism 24 controls the size of the detection range Ra by adjusting the relative distance between the light source 22 and the lens 21. In this modification 1, a case will be described in which the detection range adjusting mechanism controls the plurality of lenses to control the size of the detection range Ra.

9A and 9B are conceptual diagrams of a detection range adjusting mechanism 24A according to the first modification. 9A shows a state where the detection range is wide, and FIG. 9B shows a state where the detection range is narrow. More specifically, the light emitting unit 20 has a plurality of lenses 21a and 21b having different curvatures. The detection range adjusting mechanism 24A is a switching mechanism that switches the lenses 21a and 21b at a position facing the light source 22, and is controlled by the light source control unit 51.

When the lenses 21a and 21b are arranged at positions facing the light source 22, the optical axes of the lenses 21a and 21b and the optical axis of the light source 22 coincide with each other. Further, at this position, the distance d3 between the lenses 21a and 21b and the light source 22 is constant.

As shown in FIG. 9A, when the lens 21a having a large curvature is arranged at a position facing the light source 22, the spot of light transmitted through the lens 21a (detection range Ra) becomes large. On the other hand, as shown in FIG. 9B, when a lens 21b having a curvature smaller than that of the lens 21a is arranged at a position facing the light source 22, the spot of light transmitted through the lens 21b (detection range Ra) becomes small. ..

Thus, the light emitting unit 20 includes the light source 22 and the plurality of lenses 21a and 21b, and the light source control unit 51 controls the plurality of lenses 21a and 21b to control the size of the detection range Ra. ..

According to this configuration, since the plurality of lenses 21a and 21b are used to control the size of the detection range Ra, the size of the detection range Ra can be controlled more freely.

Note that any method can be used to control the plurality of lenses as long as the size of the detection range Ra can be controlled by controlling the plurality of lenses. For example, it is also possible to arrange a plurality of lenses along the optical axis of the light source 22 and control the distance between these lenses by the light source control unit 51 to control the size of the detection range Ra. ”.

[Modification 2]
In the above embodiment, the case where the distribution of the detection positions P is controlled by controlling both the pitch of the plurality of detection positions P and the size of the detection range Ra has been described. In the second modification, a case where the light source control unit 51 controls the distribution of the detection positions P by controlling the pitches of the plurality of detection positions P will be described.

FIG. 10 is an explanatory diagram showing the relationship between the distribution of the plurality of detection positions P in the scanning range A and the moisture content according to the second modification. In FIG. 10, the chain double-dashed line circle in the scanning range A indicates a portion in which the light from the light emitting unit 20 is temporarily stopped during scanning, but the water content is not detected. The solid line circle is the detection position P for detecting the water content. The light from the light emitting unit 20 may be temporarily stopped only at the detection position P during scanning.

When the amount of water is large, the light source control unit 51 widens the pitch of the detection positions P while keeping the detection range Ra constant, and lowers the detection density in the scanning range A. Then, the light source control unit 51 increases the detection density in the scanning range A by narrowing the pitch of the detection positions P while keeping the detection range Ra constant as the water content decreases.

According to this configuration, since the distribution of the detection positions P is controlled by controlling the pitch of the detection positions P, the distribution of the detection positions P can be controlled without the detection range adjusting mechanism. That is, the water content sensor 1 can be simplified.

[Modification 3]
In the second modification, the case where the light source control unit 51 controls the distribution of the detection positions P by controlling the pitch of the plurality of detection positions P has been described. In the third modification, a case will be described in which the light source control unit 51 controls a distribution by grouping a plurality of detection positions P into a predetermined number and controlling the predetermined number of detection positions P in each group. ..

FIG. 11 is an explanatory diagram showing the relationship between the distribution of a plurality of detection positions P in the scanning range A and the moisture content according to the third modification. In FIG. 11, the circle of the two-dot chain line in the scanning range A is the detection position P where the water content is detected. The solid line circle indicates a range R1 in which a plurality of detection positions P are grouped.

In this case, the arithmetic processing unit 56 uses the averaged water content at the plurality of detection positions P in each group as the water content in the grouped range. That is, the range R1 of one group can be regarded as a virtual detection position and detection range.

Then, when the water content is large, the light source control unit 51 increases the predetermined number of the detection positions P in each group to reduce the virtual detection density in the scanning range A. Then, the light source control unit 51 increases the virtual detection density in the scanning range A by decreasing the predetermined number of detection positions P in each group as the amount of water decreases.

With this configuration, by controlling the predetermined number of detection positions P in each group, the size of the detection range can be virtually controlled without the detection range adjustment mechanism.

[Modification 4]
In the above-described embodiment, the case where the distribution control of the detection positions P is controlled based on the amount of water has been illustrated. However, it is also possible to control the distribution control of the detection positions P based on the dryness.

Specifically, a table showing the relationship between the change rate of the signal ratio (the ratio between the voltage level of the first electric signal and the voltage level of the second electric signal) and the dryness of the object 2 is stored in the arithmetic processing unit 56. If stored in advance in the non-volatile memory, the arithmetic processing unit 56 can detect the dryness Dr of the object 2 based on the detected signal ratio and the table.

For example, the table is defined by a calibration curve showing the relationship between the rate of change of the signal ratio and the dryness Dr. Specifically, when the weight of the target object 2 during drying is W1 and the moisture content of the target object 2 is W2 (corresponding to αa×Ca×D), the dryness Dr is Dr=W1/(W1+W2 )×100 [%]. The signal ratio R when the first electric signal is S1 and the second electric signal is S2 is represented by R=S1/S2. The reference signal ratio r when the first electric signal is s1 and the second electric signal is s2 when the dryness is 100% is represented by r=s1/s2. The rate of change of the signal ratio is represented by the ratio (normalized signal ratio) R/r of the signal ratio R and the reference signal ratio r. Then, the calibration curve is obtained by the relationship between the ratio R/r and the dryness Dr.

FIG. 12 is a graph showing the relationship between the rate of change (ΔR/r) in the normalized signal ratio and the dryness Dr. As shown in FIG. 12, when the dryness Dr is higher than 60%, the change rate ΔR/r shows a substantially linear change. Therefore, a linear approximation line C between the rate of change ΔR/r when the dryness Dr is 60% or more and the dryness Dr is used as a calibration curve. A table may be created based on this calibration curve and stored in advance in the non-volatile memory of the arithmetic processing unit 56.

In this way, the arithmetic processing unit 56 calculates the signal ratio of the first electric signal and the second electric signal, and calculates the dryness of the object 2 as the water content based on the signal ratio.

With this configuration, the distribution control of the detection positions P can be controlled based on the dryness.

[Modification 5]
Here, since the reference light is not absorbed by water more than the detection light, it is also possible to measure the distance from the water content sensor 1 to the object 2 by using the second electric signal based on the reference light. is there. Therefore, it is also possible to measure the distance from the water content sensor 1 at each detection position P and control the distribution of the detection position P based on the change over time of the measured value and the water content. That is, the light source control unit 51 determines the signal ratio (water content) at the plurality of detection positions P in the scanning range A and the temporal change of the second electric signal at the plurality of detection positions P (distance change with time). Based on this, the distribution of the detection positions P is controlled.

According to this configuration, even if the distance from the water content sensor 1 to the object 2 (detection position P) changes with time, the distribution of the detection positions P can be controlled in accordance with the change over time. .. For example, it is assumed that a detection position P in which the distance from the water content sensor 1 is extremely larger than the other detection positions P in the scanning range A occurs. In this case, it can be inferred that the target object 2 does not exist at the detection position P. That is, by ignoring the amount of water detected at the detection position P, it is possible to reduce the number of data used in the clothes drying apparatus 100. Further, since the detection position P where the object 2 does not exist can be estimated, the shape of the object 2 can also be estimated.

(Other)
Although the moisture sensor 1 according to the present invention has been described above based on the above-described embodiment and modification, the present invention is not limited to the above-described embodiment and modification.

For example, although the case where the light source 22 is an LED light source has been illustrated in the above embodiment, the light source may be a semiconductor laser element, an organic EL element, or the like.

Further, in the above embodiment, the case where one light source 22 emits continuous light including the first wavelength band that forms the detection light and the second wavelength band that forms the reference light has been described. However, a plurality of light sources may be provided so that one light source emits the detection light and the other light source emits the reference light.

Further, in the above-described embodiment, the case where the light source control unit 51, the first signal processing unit 54, the second signal processing unit 55, and the arithmetic processing unit 56 included in the signal processing circuit 50 are each formed of a dedicated microcontroller is exemplified. As described, the signal processing circuit may be realized by one microcontroller as a whole.

Further, in the above embodiment, the case where the water content sensor 1 is integrally mounted on the clothes drying device 100 is illustrated, but the water content sensor is a dedicated device and can be attached to the clothes drying device 100 afterwards. It may have any configuration. The device to which the water content sensor is attached may be any device as long as it can utilize the water content (dryness) detected by the water content sensor. For example, a dehumidifying device that changes the dehumidifying condition using the amount of water detected by the water content sensor, an analyzer that analyzes the amount of water detected by the water content sensor, and the like can be mentioned.

In addition, it can be realized by making various modifications to those embodiments by those skilled in the art, or by arbitrarily combining the components and functions of the embodiments without departing from the spirit of the present invention. The form is also included in the present invention.

1 Water Content Sensor 2 Object 20 Light-Emitting Units 21, 21a, 21b Lens 22 Light Source 30 First Light-Receiving Module 32 First Bandpass Filter 33 First Light-Receiving Unit 40 Second Light-Receiving Module 42 Second Bandpass Filter 43 Second Light-Receiving Unit 51 light source control unit 54 first signal processing unit 55 second signal processing unit 56 arithmetic processing unit 100 clothes drying device 106 drying control unit A scanning range P detection position Ra detection range

Claims (9)

A moisture sensor that emits light to an object and detects the moisture content of the object based on the reflected light from the object,
A detection light including a first wavelength band whose absorption by water is larger than a predetermined value and a reference light including a second wavelength band whose absorption by water is equal to or less than the predetermined value are emitted toward the object while scanning. A light emitting part,
Receiving the detection light reflected by the object, a first light receiving unit for converting into a first electrical signal,
Receiving the reference light reflected by the object, a second light receiving unit for converting into a second electric signal,
An arithmetic processing unit that calculates a signal ratio of the first electric signal and the second electric signal,
In the scanning range of the detection light and the reference light emitted by the light emitting unit, a light source control unit for controlling the distribution of a plurality of detection positions of the signal ratio based on the signal ratio,
In the scanning range, the light source control unit controls at least one of a pitch of a plurality of detection positions of the signal ratio and a size of a detection range at the detection positions in the control of the distribution. The light source control unit controls the distribution based on a signal ratio at the plurality of detection positions in the scanning range and a temporal change of the second electric signal at the plurality of detection positions. The moisture sensor described. The light emitting unit includes a light source and a lens,
The water amount sensor according to claim 1, wherein the light source control unit controls the size of the detection range by controlling the distance between the light source and the lens. The light emitting unit includes a light source and a plurality of lenses,
The water amount sensor according to claim 1 or 2, wherein the light source control unit controls the size of the detection range by controlling the plurality of lenses. The light source emits light of a continuous wavelength including a wavelength band forming the detection light and a wavelength band forming the reference light,
The light source control unit causes the light source to emit light in a predetermined light emission cycle,
The water content sensor,
A first signal processing unit that processes the first electric signal of the first light receiving unit and outputs the first electric signal to the arithmetic processing unit;
A second signal processing unit for processing the second electric signal of the second light receiving unit and outputting the second electric signal to the arithmetic processing unit;
The first signal processing unit, with respect to the first electric signal, performs a pass band limitation and corrects a phase delay due to the pass band limitation, and then performs a multiplication process with the light emission period,
The third signal processing unit performs passband limitation on the second electric signal, corrects a phase delay due to the passband limitation, and then performs multiplication processing with the light emission period. The water content sensor described in. The water content sensor according to claim 1, wherein the light source control unit controls the distribution by controlling the pitch of the detection positions. The light source control unit controls the distribution by grouping the plurality of detection positions by a predetermined number and controlling a predetermined number of the detection positions in each group. A moisture sensor according to the item. The arithmetic processing unit calculates a signal ratio of the first electric signal and the second electric signal, and calculates the dryness of the object as the water content based on the signal ratio. The water content sensor according to item 1. A water content sensor according to any one of claims 1 to 8,
A drying controller that controls a drying condition based on the water content detected by the water content sensor.

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