JP2018141768A - Moisture amount sensor and clothing dryer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable clothing to be dried efficiently by detecting the moisture amount of an object in accordance with conditions.SOLUTION: Provided is a moisture amount sensor 1 for emitting light to an object 2 and detecting the moisture amount of the object 2 on the basis of reflected light from the object 2, the moisture amount sensor 1 comprising: a light-emitting unit 20 for emitting a detection light that includes a first wavelength band the absorption of which by water is larger than a prescribed value and a reference light that includes a second wavelength band the absorption of which by water is smaller than or equal to the prescribed value toward the object 2 while scanning it; a first light-receiving unit 33 for receiving the detection light reflected by the object 2 and converting it to a first electric signal; a second light-receiving unit 43 for receiving the reference light reflected by the object 2 and converting it to a second electric signal; an arithmetic processing unit 56 for calculating a signal ratio of the first electric signal to the second electric signal; and a light source control unit 51 for controlling the distribution of a plurality of detection positions P of the signal ratio on the basis of the signal ratio in a scanning range A of the detection light and reference light emitted by the light-emitting unit 20.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a moisture sensor and a clothes drying apparatus.

  2. Description of the Related Art Conventionally, for example, a clothing drying apparatus that dries clothing (target object) that has been dried in an indoor space is equipped with a moisture sensor that detects the moisture content of the object. And the clothing drying apparatus may detect the moisture content of a target object with a moisture sensor, and may adjust dehumidification intensity | strength based on the detection result of the said moisture sensor. In addition, as a moisture sensor, for example, an infrared moisture meter that measures moisture content using absorption of infrared rays by moisture is known (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 5-118984

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

  Then, this invention is providing the moisture content sensor and clothing drying apparatus which enable efficient clothing drying by detecting the moisture content of a target object according to a condition.

  In order to achieve the above object, a moisture sensor according to one embodiment of the present invention is a moisture sensor that emits light to an object and detects the moisture content of the object based on reflected light from the object. The detection light including the first wavelength band in which the absorption by water is larger than the predetermined value and the reference light including the second wavelength band in which the absorption by water is equal to or less than the predetermined value are scanned toward the object. A light-emitting unit that emits light, a first light-receiving unit that receives detection light reflected by the object and converts it into a first electric signal, and a first light-receiving unit that receives reference light reflected by the object and converts it into a second electric signal Two light receiving units, an arithmetic processing unit for calculating a signal ratio of the first electric signal and the second electric signal, and a signal range 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 unit A light source control unit that controls based on the ratio.

  Moreover, the clothing drying apparatus which concerns on 1 aspect of this invention is provided with the said moisture content sensor and the drying control part which controls drying conditions based on the moisture content detected with the moisture content sensor.

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

1 is a perspective view showing a schematic configuration of a clothes drying apparatus according to Embodiment 1. FIG. 3 is a control block diagram of the clothes drying apparatus according to Embodiment 1. FIG. It is a schematic diagram which shows the structure and target object of the moisture content sensor which concern on Embodiment 1. FIG. FIG. 3 is a block diagram showing a control configuration of a moisture amount sensor according to Embodiment 1. It is a figure which shows the absorption spectrum of a water | moisture content and water vapor | steam. 6 is an explanatory diagram illustrating a scanning range of the scanning module according to Embodiment 1. FIG. 4 is a conceptual diagram of a detection range adjustment mechanism according to Embodiment 1. FIG. 4 is a conceptual diagram of a detection range adjustment mechanism according to Embodiment 1. FIG. 6 is an explanatory diagram showing a relationship between a distribution of a plurality of detection positions in a scanning range according to Embodiment 1 and a moisture amount. FIG. It is a conceptual diagram of a detection range adjustment mechanism according to Modification 1. It is a conceptual diagram of a detection range adjustment mechanism according to Modification 1. It is explanatory drawing which shows the relationship between the distribution of the several detection position of the scanning range which concerns on the modification 2, and a moisture content. It is explanatory drawing which shows the relationship between distribution of the several detection position of the scanning range which concerns on the modification 3, and a moisture content. It is a graph which shows the relationship between the change rate of a normalization signal ratio, and dryness. It is a graph which shows the distance dependence of a LED light source. It is a graph which shows the temperature dependence of a LED light source. It is a perspective view which shows the heating part which concerns on the modification 6, and a light source. It is a perspective view which shows the heating part which concerns on the modification 7, and a light source. It is a perspective view which shows the heating part and light source which concern on the modification 8. It is a perspective view which shows the cooling part and light source which concern on the modification 9. It is a top view which shows the heating part which concerns on the modification 10, and a light source. It is a perspective view which shows the heating part which concerns on the modification 11, and a light source. It is a perspective view which shows the cooling part and light source which concern on the modification 12. It is a side view which shows the thermoelectric conversion part and light source which concern on the modification 13. It is a schematic diagram which shows the structure of the moisture content sensor which concerns on the modification 14. It is a schematic diagram which shows the structure of the moisture content sensor which concerns on the modification 15.

  Hereinafter, a clothes drying apparatus and a moisture sensor according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component arrangements, connection forms, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. Therefore, for example, the scales and the like do not necessarily match in each drawing. Moreover, in each figure, the same code | symbol is attached | subjected about the substantially same structure, The overlapping description is abbreviate | omitted or simplified.

(Embodiment 1)
[Clothing drying device]
First, clothing drying apparatus 100 according to Embodiment 1 will be described.

  FIG. 1 is a perspective view showing a schematic configuration of a clothes drying apparatus 100 according to the first embodiment.

  As shown in FIG. 1, the clothes drying apparatus 100 sucks room air and dehumidifies it, and blows air again indoors, thereby drying the object 2 dried in the room. Here, the object 2 is, for example, clothing or the like when not particularly limited. Examples of the object 2 other than clothing include bedding such as sheets and pillow covers.

  The clothes drying apparatus 100 includes a substantially rectangular parallelepiped main body 101 and a lid 102 that opens and closes at the top of the main body 101. An air blower 103 (see FIG. 2) that is exposed when the lid 102 is in an open state is provided on the upper portion of the main body 101. The air blowing unit 103 dries the object 2 existing in the space 3 by sending the wind W to the indoor space 3. The space 3 is a space (free space) between the clothes drying apparatus 100 and the object 2 and includes moisture (water vapor). The space 3 is an external space of the main body 101 of the clothes drying apparatus 100.

  In addition, a suction port 104 that takes in outside air is provided at an upper portion of the main body 101 at a position away from the lid 102. A flow path for guiding air from the suction port 104 to the blower 103 is formed inside the main body 101, and a dehumidifying section 105 (see FIG. 2) for dehumidifying the air is provided for the flow path. Yes. The lid 102 is provided with a moisture sensor 1 that detects the moisture content of the object 2.

  FIG. 2 is a control block diagram of the clothes drying apparatus 100 according to the first embodiment. As shown in FIG. 2, the clothes drying apparatus 100 includes a dehumidifying unit 105, a blower unit 103, a moisture amount 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 blowing unit 103 blows air dehumidified by the dehumidifying unit 105 toward the space 3. At least one drying condition such as a blowing range, a wind direction, a blowing intensity (wind force), a blowing temperature, or the like in the blowing unit 103 can be changed. Details of the moisture sensor 1 will be described later.

  The drying control unit 106 includes a microcontroller. The drying control unit 106 includes a nonvolatile 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. Etc.

  Specifically, the drying control unit 106 controls the drying conditions of the blower unit 103 based on the moisture content of the object 2 detected by the moisture sensor 1. Thereby, appropriate drying conditions are selected according to the moisture content of the object 2.

[Moisture sensor]
Next, an outline of the moisture sensor 1 according to Embodiment 1 will be described.

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

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

  In the first embodiment, as shown in FIG. 3 and FIG. 4, the moisture amount sensor 1 detects moisture contained in the object 2 arranged with a space 3 therebetween.

  As shown in FIGS. 3 and 4, the moisture amount 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 moisture content sensor 1 is demonstrated in detail.

[Case]
The housing 10 is a housing of the lid portion 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. Thereby, it can suppress that external light injects into the housing | casing 10. FIG. Specifically, the housing 10 is formed of a resin material or a metal material that has a light shielding property with respect to 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 attached.

[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 equal to or less than 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 adjustment mechanism 24.

  The lens 21 is a condensing lens that condenses the light emitted from the light source 22 onto the object 2. The lens 21 is a resin convex lens, but is not limited thereto.

  The light source 22 is an LED (Light Emitting Diode) light source that emits continuous light having a first wavelength band that forms detection light and a second wavelength band that forms reference light, and 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 moisture and water vapor. As shown in FIG. 5, moisture has absorption peaks at wavelengths of about 1450 nm and about 1940 nm. Water vapor has absorption peaks at wavelengths slightly lower than the absorption peak of moisture, specifically at wavelengths of about 1350 nm to 1400 nm and about 1800 nm to 1900 nm.

  For this reason, a wavelength band with a high water absorbance is selected as the first wavelength band for the detection light, and a wavelength band with a lower water absorbance than the first wavelength band is selected as the second wavelength band for the reference light. select. 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.

  Thus, since the light source 22 irradiates light including the first wavelength band and the second wavelength band continuously, the object 2 has detection light including the first wavelength band that is largely absorbed by water, Reference light including a 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, light from the light source 22 can be scanned to detect the amount of water at a desired position.

  FIG. 6 is an explanatory diagram showing the scanning range A of the scanning module 23 according to the first embodiment. FIG. 6 shows a case where only one object 2 is included in the scanning range A, but a plurality of objects 2 may be included in the scanning range A.

  As shown in FIG. 6, the scanning module 23 temporarily stops the light multiple times while the light from the light source 22 scans the scanning range A. At the time of this stop, the amount of moisture is detected. A position where the moisture amount is detected is “detection position P”, and a range where the moisture amount is detected at one detection position is “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 light stop timing in the main scanning direction. Further, the scanning module 23 adjusts the pitch of the detection positions P in the sub-scanning direction by adjusting the sub-scanning interval.

  The scanning module 23 has a structure that reflects 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. The first mirror and the second mirror reflect light from the light source 22 in a direction corresponding to its own swing angle. The light from the light source is reflected by the second mirror after being reflected by the first mirror. The first mirror and the second mirror swing in the horizontal direction and the vertical direction, respectively, so that the light from the light source 22 is irradiated 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 adopt a structure that scans light by adjusting the posture of the light source 22. Alternatively, the moisture 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 adjustment mechanism 24 controls the size of the spot of the light transmitted through the lens 21 by changing the interval between the lens 21 and the light source 22. This spot is the detection range Ra.

  7A and 7B are conceptual diagrams of the detection range adjustment mechanism 24 according to the first embodiment. FIG. 7A shows a state where the detection range is wide, and FIG. 7B shows a state where the detection range is narrow. Specifically, as shown in FIG. 7A, when the distance between the lens 21 and the light source 22 is shortened (distance d1 shorter than 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 (distance d2 longer than FIG. 7A), the spot of light transmitted through the lens 21 (detection range Ra) is reduced. 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 band pass filter 32, and a first light receiving unit 33.

  The lens 31 is a condensing 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 such that the focal point is located on the light receiving surface of the first light receiving unit 33, for example. The lens 31 is, for example, a resin convex lens, but is not limited thereto.

  The first band pass filter 32 is a band pass filter that extracts light in the first wavelength band from the reflected light. Specifically, the first band pass filter 32 is disposed 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. Is provided. The first band pass 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 light in the first wavelength band reflected by the object 2 and transmitted through the first band pass filter 32 and converts the light into a first electric signal. The first light receiving unit 33 photoelectrically converts the received light in the first wavelength band to generate a first electrical signal corresponding to the amount of light received (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 thereto. 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 band pass filter 42, and a second light receiving unit 43.

  The lens 41 is a condensing 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 such that the focal point is located on the light receiving surface of the second light receiving unit 43, for example. The lens 41 is, for example, a resin convex lens, but is not limited thereto.

  The second bandpass filter 42 is a bandpass filter that extracts light in the second wavelength band from the reflected light. Specifically, the second band pass 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. Is provided. 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 light in the second wavelength band reflected by the object 2 and transmitted through the second band pass filter 42 and converts the light into a second electric signal. The second light receiving unit 43 photoelectrically converts the received light in the second wavelength band, thereby generating a second electric signal corresponding to the amount of light received (that is, intensity). The generated second electric signal is output to the signal processing circuit 50. The second light receiving unit 43 is a light receiving element having the same shape as the first light receiving unit 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, so that the amount of moisture is increased. 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 an arithmetic operation. A processing unit 56 is provided.

  The light source control unit 51 includes 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 adjustment mechanism 24 are stored, a volatile memory that is a temporary storage area for executing the program, an input / output port, A processor for executing the 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 period. Specifically, the light source control unit 51 outputs a pulse signal having a predetermined frequency (for example, 1 kHz) to the light source 22 to turn on and off the light source 22 at a predetermined light emission cycle.

  The light source controller 51 controls the size of the detection range Ra by controlling the detection range adjustment mechanism 24 and controlling the distance between the light source 22 and the lens 21. 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 of the detection range Ra is detected at a 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, thereby detecting the 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 amplifying unit 52 amplifies the first electric signal output from the first light receiving unit 33 and outputs the amplified first electric signal to the first signal processing unit 54. Specifically, the first amplifying unit 52 is an operational amplifier that amplifies the first electric signal.

  The first signal processing unit 54 is configured by a microcontroller. The first signal processing unit 54 is a non-volatile memory in which a processing program for the first electric signal is stored, a volatile memory that is a temporary storage area for executing the program, an input / output port, a processor for executing the program, and the like Have The first signal processing unit 54 performs a multiplication process with the light emission period of the light source 22 after limiting the passband and correcting the phase delay due to the passband restriction on the first electric signal. The process for the first electric signal is a so-called lock-in amplifier process. Thereby, the noise based on disturbance light can be suppressed from the first electric signal.

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

  The second signal processing unit 55 is configured by a microcontroller. The second signal processing unit 55 includes a nonvolatile memory in which a processing program for the second electric signal is stored, a volatile memory that is a temporary storage area for executing the program, an input / output port, a processor for executing the program, and the like. Have The second signal processing unit 55 performs a multiplication process with the light emission period of the light source 22 after performing the passband restriction and correcting the phase delay due to the passband restriction on the second electric signal. The process for the second electric signal is a so-called lock-in amplifier process. Thereby, the noise based on disturbance light can be suppressed 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 moisture contained in the object 2 based on the ratio (signal ratio) between the voltage level of the first electrical signal and the voltage level of the second electrical 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. The amount of water contained in is detected. A specific method for detecting (calculating) the amount of moisture will be described later.

  The arithmetic processing unit 56 is, for example, a microcontroller. The arithmetic processing unit 56 includes a nonvolatile memory in which a signal processing program 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. The arithmetic processing unit 56 outputs the detected moisture content of the object 2 to the light source control unit 51 from the input / output port. Thereby, the light source control unit 51 can control the distribution of the plurality of detection positions P in the scanning range A based on the moisture amount detected by the arithmetic processing unit 56.

[Signal processing (detection processing)]
Next, 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 amount of component included in the target object 2 by comparing the light energy Pd of the detection light included in the reflected light with 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 expressed by the following (Formula 1).

  (Formula 1) Pd = Pd0 × Gd × Rd × Td × Aad × Ivd

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

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

  Aad is the absorptance of the detection light by the component (moisture) contained in the object 2, and is expressed by the following (Expression 2).

(Formula 2) Aad = 10 ^{−αa × Ca × D}

  Here, αa is a predetermined extinction coefficient, specifically, the extinction coefficient of the detection light by the component (water). Ca is a volume concentration of a component (moisture) 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 target object 2 in which moisture is uniformly dispersed, when light enters the target object 2 and is reflected and emitted from the target object 2, Ca is included in the components of the target object 2. This corresponds to the volume concentration. Further, D corresponds to the optical path length from the reflection inside to the emission from the object 2. For example, when the object 2 is a mesh-like solid such as a fiber or a porous solid such as a sponge, it is assumed that light is reflected on the surface of the solid. In this case, for example, Ca is the concentration of water contained in the liquid phase covering the solid. Moreover, D is the contribution thickness converted as an average thickness of the liquid phase which covers the solid substance.

  Therefore, αa × Ca × D corresponds to the amount of component (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. In addition, since the light absorbency of moisture is extremely small compared with moisture, it can be disregarded.

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

  (Formula 3) Pr = Pr0 * Gr * Rr * Tr * Ivr

  In the present embodiment, the reference light can be regarded as not being substantially absorbed by the component contained in the object 2, so that it corresponds to the moisture absorption rate Aad as can be seen from comparison with (Equation 1). This term is not included in (Equation 3).

  In (Expression 3), Pr0 is the light energy of the light in the second wavelength band that forms the reference light among the light emitted from the light source 22. Gr is the coupling efficiency (condensation rate) of the reference light emitted from the light source 22 to the second light receiving unit 43. Specifically, Gr corresponds to the proportion of the portion of the reference light that becomes 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 band pass filter 42. Ivr is the light receiving sensitivity with respect to 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 irradiated coaxially and at the same spot size, so that the detection light coupling efficiency Gd and the reference light coupling efficiency Gr are It becomes almost equal. Further, since the peak wavelengths of the detection light and the reference light are relatively close, the detection light reflectance Rd and the reference light reflectance Rr are substantially equal.

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

  (Formula 4) Pd / Pr = Z × Aad

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

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

  Each of the light energies Pd0 and Pr0 is predetermined as an initial output of the light source 22. Further, the transmittance Td and the transmittance Tr are predetermined by the transmission characteristics of the first band-pass filter 32 and the second band-pass 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 (Expression 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 moisture contained in the target object 2 based on (Equation 4). Thereby, the arithmetic processing part 56 can calculate a moisture content based on (Formula 2).

  In addition, although moisture (water vapor | steam) also exists in the space 3, the case where detection light and reference light are absorbed by water vapor | steam is assumed. A correction unit that corrects the first electric signal and the second electric signal so as to cancel the absorption due to the water vapor may be provided in the signal processing circuit 50.

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

  First, at the start of moisture amount detection, the light source control unit 51 sets the pitch of the plurality of detection positions P and the size of the detection range Ra as initial values, and based on them, the detection range adjustment mechanism 24 and the scanning The module 23 is controlled. Thereby, in the scanning range A, the light having the initial value is scanned while being temporarily stopped at the initial value pitch. In the temporarily stopped portion, the reflected light enters the first light receiving unit 33 and the second light receiving unit 43 each time. Thereby, the amount of moisture at each detection position P is detected by the arithmetic processing unit 56.

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

  FIG. 8 is an explanatory diagram showing the relationship between the distribution of a plurality of detection positions P in the scanning range A according to Embodiment 1 and the amount of moisture. When the amount of moisture 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 change the drying conditions finely in the clothes drying apparatus 100, the pitch of the detection positions P is increased 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, the object 2 is also partially dried as the amount of water decreases. For this reason, it is desired to change the drying conditions finely with the clothes drying apparatus 100. For fine control of the drying conditions, it is necessary to make the detection position P fine and to increase the number of data on the amount of moisture. For this reason, the pitch of the detection positions P is narrowed and the size of the detection range Ra is reduced as the amount of water decreases. That is, the distribution of the detection positions P is made dense. In other words, the detection density is increased.

  Thus, the light source control unit 51 appropriately determines the distribution of the plurality of detection positions P in the scanning range A by determining the pitch of the plurality of detection positions P and the size of the detection range Ra based on the amount of moisture. Is controlling.

[Clothing Dryer Operation]
Next, the operation of the clothes drying apparatus 100 will be described.

  At the time of clothing drying, the drying control unit 106 of the clothing drying apparatus 100 controls the drying conditions of the air blowing unit 103 based on the moisture amount and coordinates of each detection position P input from the moisture amount sensor 1. Specifically, when the moisture content of the object 2 is small, the data amount of the moisture content input from the moisture sensor 1 to the drying control unit 106 is also small. For this reason, the drying control unit 106 roughly determines the drying conditions of the air blowing unit 103. On the other hand, when the amount of moisture in the object 2 is large, the amount of moisture data input from the moisture sensor 1 to the drying control unit 106 is also large. For this reason, the drying control part 106 determines the drying conditions of the ventilation part 103 delicately.

[Effects, etc.]
As described above, according to the moisture amount sensor 1 according to the present embodiment, moisture that emits light to the object 2 and detects the amount of moisture of the object 2 based on the reflected light from the object 2. A detection sensor including a first wavelength band in which absorption by water is greater than a predetermined value and a reference light including a second wavelength band in which absorption by water is equal to or less than the predetermined value. The light emitting unit 20 that emits while scanning, the detection light reflected by the object 2 and the first light receiving unit 33 that converts the detection light into a first electric signal, and the reference light reflected by the object 2 are received. The second light receiving unit 43 for converting to the second electric signal, the arithmetic processing unit 56 for calculating the signal ratio between the first electric signal and the second electric signal, and the scanning range A of the detection light and the reference light emitted by the light emitting unit 20 The distribution of the plurality of detection positions P of the signal ratio is controlled based on the signal ratio That includes a light source control unit 51.

  Moreover, according to the clothing drying apparatus 100 which concerns on this Embodiment, the moisture content sensor 1 and the drying control part 106 which controls drying conditions based on the moisture content detected with the moisture content sensor 1 are provided.

  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 between the first electrical signal and the second electrical 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, the control of the drying conditions based on the moisture content detected by the moisture sensor 1 can be made efficient.

  Further, in the scanning range A, the light source control unit 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 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 size of the detection range Ra by controlling the distance between the light source 22 and the lens 21.

  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, the size of the detection range Ra can be controlled with a simple mechanism. is there.

  The light source 22 emits light having a continuous wavelength 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 period, and the amount of moisture. 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. And a second signal processing unit 55 that outputs to the processing unit 56. The first signal processing unit 54 performs passband limitation on the first electric signal and corrects a phase delay due to the passband limitation. The second signal processing unit 55 performs the multiplication process with the light emission period, performs the passband restriction on the second electric signal and corrects the phase delay due to the passband restriction, and then performs the multiplication with the light emission period. Apply processing.

  According to this configuration, the first electric signal and the second electric signal can be subjected to lock-in amplifier processing, and noise based on disturbance light can be suppressed from the first electric signal and the second electric signal. It is.

[Modification 1]
In the first embodiment, the case where the detection range adjustment mechanism 24 controls the size of the detection range Ra by adjusting the relative distance between the light source 22 and the lens 21 is exemplified. In the first modification, a case will be described in which the detection range adjustment mechanism controls the size of the detection range Ra by controlling a plurality of lenses.

  9A and 9B are conceptual diagrams of a detection range adjustment mechanism 24A according to the first modification. FIG. 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 includes a plurality of lenses 21a and 21b having different curvatures. The detection range adjustment mechanism 24 </ b> A is a switching mechanism that switches the lenses 21 a and 21 b at positions facing the light source 22, and is controlled by the light source control unit 51.

  Note that when the lenses 21 a and 21 b are arranged at positions facing the light source 22, the optical axes of the lenses 21 a and 21 b coincide with the optical axis of the light source 22. 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 disposed 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 the lens 21b having a smaller curvature than 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 size of the detection range Ra by controlling the plurality of lenses 21a and 21b. .

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

  Note that any method may be used for controlling 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, a plurality of lenses are arranged along the optical axis of the light source 22, and the light source control unit 51 controls the distance between these lenses to control the size of the detection range Ra. To be included.

[Modification 2]
In the first 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 as an example. 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 will be described.

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

  When the amount of moisture is large, the light source controller 51 widens the pitch of the detection positions P while keeping the detection range Ra constant, thereby reducing 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 moisture amount 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 a detection range adjustment mechanism. That is, the moisture 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 the 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 the plurality of detection positions P in the scanning range A according to the modification 3 and the amount of moisture. In FIG. 11, a two-dot chain line circle in the scanning range A is a detection position P for detecting the amount of moisture. A solid 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 amount of moisture at a plurality of detection positions P in each group as the amount of moisture in the grouped range. That is, one group range R1 can be regarded as a virtual detection position and detection range.

  Then, when the amount of moisture is large, the light source control unit 51 increases the predetermined number of detection positions P in each group to lower 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 reducing the predetermined number of detection positions P in each group as the amount of moisture decreases.

  According to 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 a detection range adjustment mechanism.

[Modification 4]
In the first embodiment, the case where the distribution control of the detection position P is controlled based on the amount of moisture is exemplified. However, it is also possible to control the distribution of the detection position P based on the dryness.

  Specifically, a table showing the relationship between the change rate of the signal ratio (ratio between the voltage level of the first electrical signal and the voltage level of the second electrical signal) and the dryness of the object 2 is stored in the arithmetic processing unit 56 If stored in advance in the nonvolatile 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 indicating the relationship between the change rate of the signal ratio and the dryness Dr. Specifically, the dryness Dr when the weight of the object 2 during drying is W1 and the water content of the object 2 is W2 (corresponding to αa × Ca × D) 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. When the dryness is 100%, the reference signal ratio r when the first electric signal is s1 and the second electric signal is s2 is represented by r = s1 / s2. The rate of change of the signal ratio is indicated by the ratio (standardized signal ratio) R / r between the signal ratio R and the reference signal ratio r. The calibration curve is obtained from the relationship between the ratio R / r and the dryness Dr.

  FIG. 12 is a graph showing the relationship between the change rate (ΔR / r) of the normalized signal ratio and the dryness Dr. As shown in FIG. 12, when the dryness Dr becomes larger than 60%, the rate of change ΔR / r shows a substantially linear change. Therefore, a linear approximation line C between the change rate 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 the calibration curve and stored in advance in the nonvolatile memory of the arithmetic processing unit 56.

  As described above, the arithmetic processing unit 56 calculates the signal ratio between the first electric signal and the second electric signal, and calculates the dryness of the object 2 as the moisture content based on the signal ratio.

  According to this configuration, the distribution control of the detection position 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, the distance from the moisture sensor 1 to the object 2 can be measured by using the second electric signal based on the reference light. is there. For this reason, it is also possible to measure the distance from the moisture sensor 1 at each detection position P, and to control the distribution of the detection positions P based on the change over time of the measured value and the moisture content. That is, the light source control unit 51 determines the signal ratio (moisture amount) at the plurality of detection positions P in the scanning range A and the temporal change (distance change over time) of the second electrical signal at the plurality of detection positions P. Based on this, the distribution of the detection positions P is controlled.

  According to this configuration, even if the distance from the moisture 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, in the scanning range A, it is assumed that a detection position P having a distance that is extremely larger than the other detection positions P occurs from the moisture amount sensor 1. In this case, it can be estimated that the object 2 does not exist at the detection position P. That is, by ignoring the amount of water detected at the detection position P, the number of data used in the clothes drying apparatus 100 can be reduced. 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.

(Embodiment 2)
The LED light source used as the light source 22 has a very large temperature dependency as compared with the distance dependency on the peak wavelength and output of the emission spectrum.

  FIG. 13 is a graph showing the distance dependency of the LED light source. Here, the “distance” is a distance from the light source 22 to the object 2. The detection light output is a voltage level of the first electrical signal output by the first light receiving unit 33 receiving the detection light. The reference light output is a voltage level of the second electric signal output by the second light receiving unit 43 receiving the reference light. The signal ratio is a signal ratio between the first electric signal and the second electric signal. In this case, the distance was varied at a constant temperature, and the first electric signal, the second electric signal, and the signal ratio at each distance were obtained. As shown in FIG. 13, in the LED light source, the detection light output and the reference light output decrease as the distance to the object 2 increases, but the signal ratio is substantially constant. That is, it is understood that there is almost no distance dependency.

  FIG. 14 is a graph showing the temperature dependence of the LED light source. In this case, the first electric signal, the second electric signal, and the signal ratio at each temperature were obtained by changing the temperature at a constant distance. As shown in FIG. 14, in the LED light source, the detection light output decreases as the temperature increases, but the reference light output does not vary as much as the detection light output, and there is a portion that increases depending on the temperature. For this reason, the signal ratio varies greatly with temperature. That is, it can be seen that the temperature dependency is large. As described above, if the temperature dependency is large, the detection result of the moisture amount sensor 1 varies due to temperature fluctuation.

  In the moisture amount sensor 1 according to Embodiment 2, a temperature holding unit that holds the temperature of the light source 22 provided in the light emitting unit 20 constant is provided. As a result, the temperature of the light source 22 can be kept constant, and the influence of temperature variations on the light source 22 can be reduced. Therefore, the detection result of the moisture sensor 1 can be stabilized, and the detection accuracy can be increased.

  In the following modifications, specific examples of the temperature holding unit will be described. In the following description, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof may be omitted.

[Modification 6]
In Modification 6, a case where the temperature holding unit is a temperature adjusting unit that adjusts the temperature of the light source will be described. The temperature adjustment unit according to Modification 6 is a heating unit that heats the light source. FIG. 15 is a perspective view showing a heating unit and a light source according to Modification 6.

  As shown in FIG. 15, the light source 22 is housed in a metal housing 90 and is packaged in a CAN package. The casing 90 is formed in a cylindrical shape, and light emitted from the light source 22 is emitted from the opening at the tip thereof.

  The heating unit 80 is a heating wire and is wound around the casing 90. When the power of the moisture sensor 1 is turned on, the heating unit 80 is supplied with electric power and heated. For example, the heating unit 80 is set so as to be heated at a maximum temperature in a heatable temperature range of the heating wire. The heating unit 80 can adjust the light source 22 to a constant temperature by heating the housing 90 at a constant temperature. Thereby, the light source 22 is held at a constant temperature. Since the heating wire has a simple configuration as compared with other heating means, it is possible to suppress complication of the configuration of the moisture amount sensor 1.

[Modification 7]
In Modification 7, a heating unit 81 made of a film heater will be described. FIG. 16 is a perspective view showing a heating unit and a light source according to Modification 7.

  As shown in FIG. 16, the heating unit 81 is a flexible film heater and is wound around the casing 90. When the power of the moisture sensor 1 is turned on, the heating unit 81 is supplied with electric power and heated. For example, the heating unit 81 is set so as to be heated uniformly at the maximum temperature in the heatable temperature range of the film heater. The heating unit 81 can adjust the light source 22 to a constant temperature by heating the housing 90 at a constant temperature. Thereby, the light source 22 is held at a constant temperature. Since the film heater is in surface contact with the housing 90, it is possible to improve heat transfer.

[Modification 8]
In Modification 8, a heating unit 82 made of a block heater will be described. FIG. 17 is a perspective view showing a heating unit and a light source according to Modification 8.

  As shown in FIG. 17, the heating unit 82 is a cylindrical heater, and a housing 90 is fitted therein. When the power of the moisture sensor 1 is turned on, the heating unit 82 is supplied with electric power and heated. For example, the heating unit 82 is set so as to be heated uniformly at the maximum temperature in the heatable temperature range of the heater. The heating unit 82 can adjust the light source 22 to a constant temperature by heating the housing 90 at a constant temperature. Thereby, the light source 22 is held at a constant temperature. Since the block-shaped heater is in surface contact with the housing 90, it is possible to improve heat transfer. Moreover, since the block-shaped heater has a larger volume than the heating wire and the film heater, the heat capacity is large. For this reason, it is possible to keep the temperature of the light source 22 constant.

[Modification 9]
In Modification 9, a case where the temperature adjustment unit is a cooling unit that cools the light source will be described. FIG. 18 is a perspective view showing a cooling unit and a light source according to Modification 9. As shown in FIG. 18, the cooling unit 70 includes a cylindrical cooling block 701, and a housing 90 is fitted in a hollow portion of the cooling block 701. A spiral refrigerant pipe 702 through which the refrigerant flows is built in the wall portion of the cooling block 701. Examples of the refrigerant include a liquid such as water and a gas such as a fluorine-based gas. The refrigerant circulates in the refrigerant pipe 702 from a tank (not shown). Specifically, when the power of the moisture sensor 1 is turned on, the cooling unit 70 drives a pump (not shown) to circulate the refrigerant in the refrigerant pipe 702. Thereby, the cooling unit 70 can adjust the light source 22 to a constant temperature by cooling the housing 90 at a constant temperature. Therefore, the light source 22 is held at a constant temperature. Since the cooling block 95 is in surface contact with the housing 90, it is possible to improve heat transfer.

[Modification 10]
In the modified examples 6 to 9, the case where the light source 22 is formed in a CAN package is illustrated. In Modifications 10 to 13, a case will be described in which the light source 22 is an LED light source having a COB (Chip On Board) structure.

  FIG. 19 is a plan view showing a heating unit and a light source according to Modification Example 10. As shown in FIG. 19, the light source 22 is mounted on the substrate 221. The heating unit 83 is a flexible film heater. The heating unit 83 is disposed on the substrate 221 so as to surround the light source 22 in plan view. When the power of the moisture sensor 1 is turned on, the heating unit 83 is supplied with electric power and heated. Note that the heating unit 83 may be provided on the front surface or the back surface of the substrate 221. For example, the heating unit 83 is set to heat the film heater at a maximum temperature in a heatable temperature range of the film heater. The heating unit 83 can adjust the light source 22 to a constant temperature by heating the substrate 221 and the light source 22 at a constant temperature. Thereby, the light source 22 is held at a constant temperature.

[Modification 11]
FIG. 20 is a perspective view showing a heating unit and a light source according to the eleventh modification. As shown in FIG. 20, the heating unit 84 is a square tube-shaped heater, and is installed on the substrate 221 so that the light source 22 is positioned inside the heater. When the power of the moisture sensor 1 is turned on, the heating unit 84 is supplied with electric power and heated. For example, the heating unit 84 is set so as to be heated at a maximum temperature in a heatable temperature range of the heater. The heating unit 84 can adjust the light source 22 to a constant temperature by heating the substrate 221 and the light source 22 at a constant temperature. Thereby, the light source 22 is held at a constant temperature.

[Modification 12]
FIG. 21 is a perspective view showing a cooling unit and a light source according to Modification 12. As shown in FIG. 21, the cooling unit 71 includes a rectangular tube-shaped cooling block 711, and is installed on the substrate 221 so that the light source 22 is positioned in a hollow portion of the cooling block 711. In the wall portion of the cooling block 711, a spiral refrigerant pipe 712 through which the refrigerant flows is incorporated. Examples of the refrigerant include a liquid such as water and a gas such as a fluorine-based gas. The refrigerant circulates in the refrigerant pipe 712 from a tank (not shown). Specifically, when the power of the moisture sensor 1 is turned on, the cooling unit 70 drives a pump (not shown) to circulate the refrigerant in the refrigerant pipe 702. Thereby, the cooling unit 71 can adjust the light source 22 to a constant temperature by cooling the substrate 221 and the light source 22 at a constant temperature. Therefore, the light source 22 is held at a constant temperature.

[Modification 13]
In Modification 13, a case where a thermoelectric conversion unit is provided as a temperature adjustment unit for the light source 22 having the COB structure will be described. FIG. 22 is a side view showing a thermoelectric conversion unit and a light source according to Modification 13. As shown in FIG. 22, a thermoelectric converter 85, a heat sink 86, and a fan 87 are provided on the back surface of the substrate 221. The thermoelectric conversion unit 85 is a thermoelectric conversion element that converts heat and electricity to each other, and is specifically a Peltier element. The thermoelectric conversion unit 85 is formed in a plate shape and is attached so as to be in surface contact with the back surface of the substrate 221. Further, a heat sink 86 is attached on the opposite side of the thermoelectric converter 85 from the substrate 221 so as to be in surface contact. Further, a fan 86 is provided on the opposite side of the heat sink 86 from the thermoelectric conversion portion 85.

  When a predetermined current flows through the thermoelectric conversion unit 85, the thermoelectric conversion unit 85 heats or cools the substrate 221. It is possible to adjust the heating temperature or the cooling temperature of the thermoelectric converter 85 by adjusting the current. Thereby, the thermoelectric conversion part 85 can heat or cool the board | substrate 221 and the light source 22 at fixed temperature, and can adjust the light source 22 to fixed temperature. Therefore, the light source 22 is held at a constant temperature.

  During cooling, the thermoelectric converter 85 radiates heat from the surface opposite to the substrate 221 through the heat sink 86. Further, when the fan 87 is driven, the heat sink 86 is cooled, and more efficient heat dissipation is possible. During heating, the thermoelectric converter 85 absorbs heat from the surface opposite to the substrate 221 through the heat sink 86. Even in this case, when the fan 87 is driven, the heat sink 86 is warmed, and more efficient heat absorption is possible.

  Here, the case where the temperature adjustment by the thermoelectric conversion unit is performed on the light source 22 having the COB structure is illustrated, but the thermoelectric conversion unit can also be adopted for the light source 22 in a CAN package.

  Further, a temperature sensor may be arranged near the light source 22 and the heating temperature or the cooling temperature by the thermoelectric conversion unit 85 may be feedback controlled based on the detection result of the temperature sensor. In this case, the temperature of the light source 22 can be kept constant more accurately.

[Modification 14]
In Modifications 6 to 13, the temperature adjustment unit that adjusts the temperature of the light source 22 is exemplified as the temperature holding unit. In the modified examples 14 and 15, a heat insulating part that insulates the light source 22 and the outside air is exemplified as the temperature holding part.

  FIG. 23 is a schematic diagram illustrating a configuration of a moisture sensor 1A according to Modification Example 14. As shown in FIG. 23, the moisture sensor 1A is provided with a heat insulating portion 60. The heat insulating part 60 is provided so as to surround the light source 22. The heat insulation part 60 is entirely formed of a material having translucency, and the inside is a vacuum. Thereby, since the light source 22 and the outside air are insulated, the temperature of the outside air is unlikely to affect the light source 22.

  When the light source 22 emits light from a light-off state, the temperature of the light source 22 itself increases. However, the temperature of the light source 22 becomes substantially constant when a certain time elapses after light emission. In this state, if the temperature of the outside air is affected, the temperature of the light source 22 fluctuates. However, as described above, if the light source 22 and the outside air are insulated by the heat insulating portion 60, the light source 22 can be kept at a constant temperature.

[Modification 15]
FIG. 24 is a schematic diagram illustrating a configuration of a moisture sensor 1B according to Modification 15. As shown in FIG. 24, the moisture sensor 1B is provided with a heat insulating portion 61. The heat insulating unit 61 surrounds the light emitting unit 20, the first light receiving module 30, the second light receiving module 40, and the signal processing circuit 50 together with the inner surface of the housing 10 of the moisture sensor 1B. The heat insulating portion 61 is provided so as to surround the light source 22. The heat insulating part 60 is formed of a material having heat insulating properties, and the inside is in a vacuum. Thereby, since the light source 22 and the outside air are insulated, the temperature of the outside air is unlikely to affect the light source 22. In addition, a heat insulating sheet can be attached to the surface of the housing 10 in order to further improve the heat insulating property.

  In addition, in the modified examples 14 and 15, the case where heat insulation was acquired by making the inside of the heat insulation parts 60 and 61 evacuated was illustrated. However, the heat insulating portions 60 and 61 may have any structure as long as heat insulation is obtained without blocking light from the light source 22. For example, the heat insulating portion 60 may be filled with a heat insulating material such as glass wool, urethane foam, or a vacuum heat insulating material so as to secure the optical path of the light source 22.

(Other)
As described above, the moisture amount sensor 1 according to the present invention has been described based on the above-described first and second embodiments and modifications. However, the present invention is limited to the above-described first and second embodiments and modifications. is not.

  For example, in the first and second embodiments, the light source 22 is an LED light source. However, the light source may be a semiconductor laser element or an organic EL element. In addition, even if it is other than a LED light source, what is necessary is just to employ | adopt the temperature holding | maintenance part mentioned above in the case of a light source with large temperature dependence.

  In the first embodiment, the case where one light source 22 emits continuous light including the first wavelength band forming the detection light and the second wavelength band forming the reference light has been described as an example. However, a plurality of light sources may be provided so that one light source emits detection light and the other light source emits reference light.

  In the first 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 composed of a dedicated microcontroller is illustrated. As described above, the signal processing circuit may be realized by a single microcontroller as a whole.

  In the first embodiment, the case where the moisture sensor 1 is integrally mounted on the clothing drying apparatus 100 is exemplified. However, the moisture sensor is a dedicated device and is attached to the clothing drying apparatus 100 later. A possible configuration may be used. The device to which the moisture sensor is attached may be any device as long as it can use the moisture amount (dryness) detected by the moisture sensor. For example, a dehumidifying device that changes the dehumidifying condition using the moisture amount detected by the moisture sensor, and an analyzer that analyzes the moisture amount detected by the moisture sensor are included.

  In addition, the embodiment can be realized by arbitrarily combining the components and functions in each embodiment without departing from the scope of the present invention, or a form obtained by subjecting each embodiment to various modifications conceived by those skilled in the art. Forms are also included in the present invention.

1, 1A, 1B Moisture sensor 2 Object 20 Light emitting unit 21, 21a, 21b Lens 22 Light source 30 First light receiving module 32 First band pass filter 33 First light receiving unit 40 Second light receiving module 42 Second band pass filter 43 Second light receiving unit 51 Light source control unit 54 First signal processing unit 55 Second signal processing unit 56 Arithmetic processing units 60 and 61 Heat insulation unit (temperature holding unit)
70, 71 Cooling unit (temperature adjusting unit, temperature holding unit)
80, 81, 82, 83, 84 Heating unit (temperature adjusting unit, temperature holding unit)
85 Thermoelectric converter (temperature adjustment unit, temperature holding unit)
100 Clothes Drying Device 106 Drying Control Unit A Scanning Range P Detection Position Ra Detection Range

Claims (16)

A moisture sensor that emits light to an object and detects the moisture content of the object based on reflected light from the object,
Detection light including a first wavelength band in which absorption by water is greater than a predetermined value and reference light including a second wavelength band in which absorption by water is equal to or less than the predetermined value are emitted while scanning toward the object. A light emitting unit;
A first light receiving unit that receives the detection light reflected by the object and converts it into a first electrical signal;
A second light receiving unit that receives the reference light reflected by the object and converts the reference light into a second electrical signal;
An arithmetic processing unit for calculating a signal ratio between the first electric signal and the second electric signal;
A moisture amount sensor comprising: a light source control unit configured to control distribution of a plurality of detection positions of the signal ratio based on the signal ratio in a scanning range of the detection light and the reference light emitted from the light emitting unit. 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 the detection range at the detection positions in the distribution range in the scanning range. Moisture content sensor. 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 moisture sensor according to claim 2 or 3, wherein the light source control unit controls the size of the detection range by controlling an interval between the light source and the lens. The light emitting unit includes a light source and a plurality of lenses,
The moisture sensor according to claim 2 or 3, wherein the light source control unit controls the size of the detection range by controlling the plurality of lenses. The light source emits light having 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 at a predetermined light emission cycle,
The moisture sensor is
A first signal processing unit that processes the first electrical signal of the first light receiving unit and outputs the processed signal to the arithmetic processing unit;
A second signal processing unit that processes the second electrical signal of the second light receiving unit and outputs the processed signal to the arithmetic processing unit;
The first signal processing unit performs passband limitation on the first electric signal and corrects a phase delay due to the passband limitation, and then performs a multiplication process with the light emission cycle,
The second signal processing unit performs passband limitation on the second electric signal and corrects a phase delay due to the passband limitation, and then performs multiplication processing with the light emission period. Moisture content sensor described in 1. The moisture sensor according to claim 2, wherein the light source control unit controls the distribution by controlling a pitch of the detection positions. The said light source control part groups the said several detection position for every predetermined number, and controls the said distribution by controlling the predetermined number of the said detection positions in each group. Moisture content sensor according to item. The said arithmetic processing part calculates the signal ratio of said 1st electric signal and said 2nd electric signal, and calculates the dryness of the said target object as said moisture content based on the said signal ratio. The moisture sensor according to claim 1. The moisture amount sensor according to claim 1, further comprising a temperature holding unit that holds a temperature of a light source provided in the light emitting unit constant. The moisture sensor according to claim 10, wherein the temperature holding unit is a temperature adjusting unit that adjusts a temperature of the light source. The moisture sensor according to claim 11, wherein the temperature adjustment unit is a heating unit that heats the light source. The moisture sensor according to claim 11, wherein the temperature adjustment unit is a cooling unit that cools the light source. The moisture sensor according to claim 11, wherein the temperature adjustment unit is a thermoelectric conversion unit. The moisture amount sensor according to claim 10, wherein the temperature holding unit is a heat insulating unit that insulates the light source from outside air. The moisture sensor according to any one of claims 1 to 15,
A clothes drying apparatus comprising: a drying control unit that controls a drying condition based on the moisture amount detected by the moisture amount sensor.

Images