JP7266168B2 - refrigerator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a refrigerator for long-term storage of foods, especially vegetables.

In recent years, not only has the storage temperature of refrigerators diversified, but there has also been a growing interest in environmental considerations and economic efficiency. There is a need for a function to eliminate In particular, in order to maintain the freshness of vegetables, a method is adopted in which the inside of the vegetable compartment is kept almost completely sealed, and cool air circulates around the circumference of the container for indirect cooling. ing. However, the humidity control is a random control, and depending on the amount and type of vegetables stored, it is difficult to maintain the high humidity required for long-term storage.

In order to solve the problem of maintaining a high humidity state in the vegetable compartment, there is a system in which the actual atmospheric humidity in the vegetable compartment is detected and humidity is controlled by spraying water from a humidifying device according to the result (see, for example, Patent Documents 1).

FIG. 7 shows a longitudinal sectional view of a vegetable compartment of a conventional refrigerator described in Patent Document 1. As shown in FIG. In FIG. 7, the refrigerator compartment 2 and the vegetable compartment 3 are partitioned by a partition wall 4, and the inside of the vegetable compartment 3 is hermetically sealed by a vegetable compartment door 3a. A humidity sensor 26 is embedded in the vegetable compartment 3 side of the partition wall 4 to detect the humidity in the vegetable compartment 3 . A humidifier 20 composed of an ultrasonic vibrator 21 and a water storage tank 25 is also embedded in the partition wall 4 on the side of the vegetable compartment 3 . It will be sprayed. With such a configuration, the humidity in the vegetable compartment 3 is detected by the humidity sensor 26, and when the humidity is low, it is determined that the condition is not favorable for the vegetables, and the humidifier 20 is operated to increase the humidity in the vegetable compartment 3. Maintain high humidity.

JP-A-2006-46768

An object of the present disclosure is to provide a refrigerator capable of improving the freshness preservation performance of food by detecting the moisture content of the surface of the food itself and judging the freshness state of the food itself from the increase/decrease rate.

A refrigerator according to the present disclosure includes a storage chamber , a storage container provided in the storage chamber , a water content detection means for detecting the water content of food inside the storage container , and a freshness keeping device for humidifying the inside of the storage container. and the freshness preserving device is characterized by humidifying the inside of the storage container based on the detection result of the moisture content detection means.

Since the refrigerator of the present disclosure can directly detect the moisture content of the food itself in the storage chamber , it is possible to judge the freshness of the food with high accuracy, and the freshness keeping device provides a refrigerator with improved food freshness performance. can do.

BRIEF DESCRIPTION OF THE DRAWINGS Longitudinal sectional view of a refrigerator according to Embodiment 1 of the present invention FIG. 1 is a configuration diagram of moisture content detection means of a refrigerator according to Embodiment 1 of the present invention; FIG. 1 is a vertical cross-sectional view of a vegetable compartment of a refrigerator according to Embodiment 1 of the present invention; FIG. 2 is a diagram showing the absorption spectrum difference of spinach by the infrared spectrometer of the refrigerator according to Embodiment 1 of the present invention; FIG. 4 is a graph showing the relationship between the weight reduction rate of spinach in the refrigerator and the amount of change in the output of the water content detection means according to the first embodiment of the present invention; A longitudinal sectional view of a vegetable compartment of a refrigerator according to Embodiment 2 of the present invention Vertical cross-sectional view of the vegetable compartment of a conventional refrigerator

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a vertical cross-sectional view of a refrigerator according to Embodiment 1 of the present invention, FIG. 2 is a block diagram of moisture content detection means of the refrigerator according to Embodiment 1, and FIG. 3 is a vegetable compartment of the refrigerator according to Embodiment 1. FIG. 4 is a longitudinal sectional view, FIG. 4 is a diagram showing the absorption spectrum difference of spinach by the infrared spectroscope of the refrigerator according to the first embodiment, and FIG. is a diagram showing the relationship between the amount of change in the output of the .

1 to 3, the heat insulating box body 101 of the refrigerator 100 includes an outer box 102 mainly using steel plates, an inner box 103 made of resin such as ABS, and a space between the outer box 102 and the inner box 103. The space is filled with a foamed heat insulating material such as rigid urethane foam, which is insulated from the surroundings and divided into a plurality of storage compartments.

A refrigerating chamber 104 as a first storage chamber is provided at the top, and a switching chamber 105 as a fourth storage chamber and an ice making chamber 106 as a fifth storage chamber are arranged horizontally below the refrigerating chamber 104. are provided side by side, a vegetable compartment 107 as a second storage compartment is provided below the switching compartment 105 and the ice making compartment 106, and a freezer compartment 108 is arranged at the bottom as a third storage compartment. It has become.

The refrigerating compartment 104 is normally set to a temperature of 1° C. to 5° C., which is the lowest temperature that does not freeze for refrigerated storage. The freezer compartment 108 is set in a freezing temperature range, and is normally set at −22° C. to −15° C. for frozen storage. It may be set at a low temperature of °C. In addition to the refrigerating temperature range set between 1°C and 5°C, the vegetable temperature range set between 2°C and 7°C, and the freezing temperature range normally set between -22°C and -15°C, It is possible to switch to a preset temperature range between the refrigeration temperature range and the freezing temperature range. The switching compartment 105 is a storage compartment provided with an independent door provided side by side with the ice making compartment 106, and is often provided with a drawer type door.

In the present embodiment, the switching compartment 105 is a storage compartment including the temperature range of refrigeration and freezing. The storage compartment may be specialized for switching only the temperature zone between refrigeration and freezing. Alternatively, a storage room fixed to a specific temperature zone may be used.

The ice-making chamber 106 makes ice with an automatic ice-making machine (not shown) installed in the upper part of the room with water sent from a water storage tank (not shown) in the refrigerating room 104, and an ice storage container (not shown) arranged in the lower part of the room. (not shown).

The top surface of the heat-insulating box 101 has a stepped recess toward the back of the refrigerator 100. A machine room 101a is formed in this stepped recess to accommodate a compressor 109 and a dryer for removing moisture. (not shown) and other high pressure side components of the refrigeration cycle are housed. That is, the machine room 101a in which the compressor 109 is installed is formed by cutting into the uppermost rear region in the refrigerating room 104. As shown in FIG.

In the present embodiment, regarding the essential part of the invention described below, a machine room is provided in the lowermost storage room rear region of the heat insulating box body 101, which has been conventionally common, and the compressor 109 is installed therein. It may be applied to the type of refrigerator that is arranged. Also, the refrigerator 100 may have a so-called mid-freezer configuration in which the freezer compartment 108 and the vegetable compartment 107 are interchanged.

Next, a cooling chamber 110 for generating cool air is provided behind the vegetable compartment 107 and the freezing compartment 108, and between the vegetable compartment 107 and the cooling compartment 110 or between the freezing compartment 108 and the cooling compartment 110, heat insulation is provided. and a rear partition wall 111 configured to separate each room from the heat-insulating air passage.

A cooler 112 is disposed in the cooling chamber 110. In the space above the cooler 112, cold air cooled by the cooler 112 is supplied to the refrigerator chamber 104, the switching chamber 105, the ice making chamber 106, and the vegetables. A cooling fan 113 for blowing air to the chamber 107 and the freezer chamber 108 is arranged, and a glass tube radiant is provided in the lower space of the cooler 112 for defrosting frost and ice adhering to the cooler 112 and its surroundings during cooling. A heater 114 is provided, and a drain pan 115 for receiving defrosted water generated during defrosting is provided below the heater 114. A drain tube 116 penetrates from the deepest part of the heater 114 to the outside of the refrigerator. 117 are configured.

In the vegetable compartment 107, a lower storage container 119 mounted on a frame attached to a drawer door 118 of the vegetable compartment 107 and an upper storage container 120 mounted on the lower storage container 119 are arranged. A lid body 122 for substantially sealing mainly the upper storage container 120 in a state where the drawer door 118 is closed is held by a first partition wall 123 and the inner box 103 provided in the upper part of the vegetable compartment 107. . When the drawer door 118 is closed, the lid body 122 and the upper storage container 120 are in close contact with each other at the left, right, and deep sides of the upper surface, and substantially in close contact with each other at the front side of the upper surface. Further, the boundary between the left and right bottom sides of the back surface of the upper storage container 120 and the lower storage container 119 is closed to prevent moisture from escaping from the food storage portion within a range where the upper storage container 120 does not come into contact with the upper storage container 120 during its operation.

Between the lid body 122 and the first partition wall 123, an air passage for cold air discharged from the discharge port 124 for the vegetable compartment 107 formed in the inner partition wall 111 is provided. In addition, the water content detection means 131 is embedded in the vegetable compartment 107 side of the first partition wall 123, and in the present embodiment, it is arranged so as to optically face the vegetables stored in the lower storage container 119. . Optically, necessary portions of the lid 122 and the upper storage container 120 may be cut off or made of transparent resin so that infrared light and visible light can be transmitted.

Further, a space is also provided between the lower storage container 119 and the second partition wall 125 below the lower storage container 119 to form a cool air passage. A suction port 126 for the vegetable compartment 107 is provided in the lower part of the inner partition wall 111 provided on the back side of the vegetable compartment 107 for cooling the inside of the vegetable compartment 107 and returning the cool air, which has been heat-exchanged, to the cooler 112. It is

The rear partition wall 111 is composed of a surface made of resin such as ABS, and a heat insulating material made of expanded polystyrene or the like for isolating the air passage and the cooling chamber 110 and ensuring heat insulation. In this embodiment, a freshness keeping device 139 for generating fine particle mist is embedded in a part of the wall surface of the inner partition wall 111 on the side of the vegetable compartment 107 .

Specific examples of the freshness keeping device 139 include an electrostatic atomization method that blows water from the tip of the pin by electrostatic force, an ultrasonic vibration method that atomizes the water by vibration of a piezoelectric element, and a water crushing method that makes water finer by the wind speed of a fan. , a nozzle spraying method that sprays through a fine hole nozzle, etc., and the method can be selected according to the target performance and the allowable installation space. The gap and arrangement with the upper storage container 120 are designed so that the fine particle mist generated by the freshness keeping device 139 is sprayed onto the lower storage container 119 . Also, a damper 145 is embedded in the cool air passage for adjusting the cool air that cools each storage compartment.

As shown in FIG. 2, the water content detection means 131 has a first light emitting element 146 and a second light emitting element 150 that emit infrared wavelengths inside. An object (here a vegetable) is irradiated. Furthermore, the moisture content detection means 131 has a first angle adjusting plate 148 and a second angle adjusting plate 151 that transmit and deflect a specific wavelength, and the light reflected from the object to be measured is are transmitted to the second light receiving element 149 and the second light receiving element 152, respectively. The water content detection means 131 configured in this manner irradiates the vegetable at the position where the measurement object (vegetables) is stored in the vegetable compartment 107 and receives the reflected light from the first light emitting element. 146, the arrangement and shape of the second light emitting element 150, the reflector 147, the first angle adjustment plate 148, the second angle adjustment plate 151, the first light receiving element 149, and the second light receiving element 152 are adjusted, It is embedded in the first partition wall 123 that is the top surface of the vegetable compartment 107 within a range that does not affect the internal volume and case operability.

The operation and function of the refrigerator configured as described above will be described below.

First, the operation of the refrigeration cycle will be explained. A refrigerating cycle is operated in response to a signal from a control board (not shown) according to the set temperature in the refrigerator to perform the cooling operation. The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 109 is condensed and liquefied to some extent in a condenser (not shown), and further flows into refrigerant pipes ( (not shown), etc., while preventing dew condensation in the refrigerator 100, it is condensed and liquefied, and reaches a capillary tube (not shown). After that, in the capillary tube, the pressure is reduced while exchanging heat with a suction pipe (not shown) to the compressor 109 to become a low-temperature, low-pressure liquid refrigerant and reach the cooler 112 .

Here, the low-temperature, low-pressure liquid refrigerant exchanges heat with the air in each storage chamber such as the discharge air passage 141 of the freezer compartment 108 conveyed by the operation of the cooling fan 113, and the refrigerant in the cooler 112 evaporates. At this time, cold air for cooling each storage compartment is generated in the cooling compartment 110 .

The low-temperature cold air generated in the cooling chamber 110 is diverted from the cooling fan 113 to the refrigerating chamber 104, the switching chamber 105, the ice making chamber 106, the vegetable chamber 107, and the freezing chamber 108 using air paths and dampers 145. Cool to each target temperature zone.

Refrigerating compartment 104 is cooled to a target temperature by adjusting the amount of cold air with damper 145 using a temperature sensor (not shown) provided in refrigerating compartment 104 . In particular, the temperature of the vegetable compartment 107 is adjusted from 2° C. to 7° C. by the distribution of cold air and the ON/OFF operation of heating means (not shown).

After the refrigerator compartment 104 is cooled, the air in the vegetable compartment 107 is discharged to the vegetable compartment 107 from an outlet 124 for the vegetable compartment 107 formed in the middle of the refrigerator compartment return air path for circulating the air to the cooler 112 . , the outer periphery of the upper storage container 120 and the lower storage container 119 to indirectly cool it, and then return to the cooler 112 again from the suction port 126 for the vegetable compartment 107 .

In this way, the vegetable compartment 107 is set to the optimum temperature for the vegetables. Weight decreases, and leaf vegetables in particular wilt, deteriorating their commercial value.

Next, an example of the absorption spectrum characteristics of vegetables at infrared wavelengths will be described using the graph of the absorption spectrum of spinach obtained by an infrared spectrometer in FIG. 4 . This result was actually measured in a wavelength band of 800 nm to 1700 nm using a general-purpose infrared spectroscope. As a light source for measurement, a halogen lamp or the like is preferable because of the stability of the wavelength output level. In FIG. 4, the one-dot chain line is the characteristic when only the light source is directly input to the spectroscope, and it has a gentle mountain shape in this band, and this characteristic is used as a reference.

Next, the solid line in the graph is the spectroscope output when fresh spinach is irradiated with light from this light source and the reflected light is made incident on the spectroscope. As can be seen from the graph, in the vicinity of the wavelength with the wavelength of 1450 nm as the peak, the output drops significantly with respect to the reference (light source only) (variation: A). This means that fresh vegetables have a lot of moisture, and even the surface of the leaves has a lot of moisture, and this wavelength is absorbed by the moisture and does not return to the spectroscope as reflected light. is also used physicochemically for moisture measurement.

It is generally known that the wavelength of 1940 nm is also a band that absorbs more water, but the wavelength of 1600 nm to 2100 nm is a band that also absorbs components other than water (carbohydrates, starches, sugars, proteins, etc.). There is a possibility that the moisture content of non-mineral vegetables cannot be detected with high accuracy. In addition, as an environment specific to a refrigerator, the inside of the vegetable compartment 107 is generally in a high-humidity state, and the longer the wavelength, the more likely it is to be absorbed by environmental water vapor, and the measurement light may attenuate before reaching the vegetables.

Therefore, the wavelength of the measurement light used by the water content detection means 131, which will be described later, is set to 1450 nm.

Returning to the graph in FIG. 4, when the spinach has wilted and the weight reduction rate has reached 30% (that is, the weight is 70% of the initial weight), the result measured by the same measurement method as when it was fresh is the characteristic indicated by the dotted line. is. Although it is not as good as when it is fresh, the output drops (variation: B) with respect to the reference (light source only) near the peak wavelength of 1450 nm. The reason why the drop is not as great as when it is fresh is that it absorbs less water. Therefore, if the correlation between the weight reduction rate and the amount of change in the wavelength of 1450 nm is clarified, the wilting of vegetables can be detected.

Next, the operation of the water content detection means 131 will be described with reference to FIG. When a certain amount of light from the first light emitting element 146 having a wavelength of 1450 nm, which is the measurement light, is incident on the reflecting plate 147 along the path a, it is reflected at a predetermined angle and passes through the path b to reach the object. (vegetables) are irradiated. Subsequently, measurement light other than the amount of light absorbed by the vegetables passes through path c as reflected light, and the measurement light with a wavelength of 1450 nm is incident on the first angle adjustment plate 148 selectively via path d. is taken into the light receiving element 149 of the

Moreover, as shown in FIG. 4, 1330 nm is a wavelength that is not absorbed by water, and the output of the spectroscope does not change whether the vegetables are fresh or wilted. That is, by simultaneously measuring this wavelength as a reference light and determining the difference between the measurement light and the reference light, disturbance factors (disturbance light, measurement distance, reflection angle, etc.) can be eliminated, leading to an improvement in detection accuracy. The reason why the wavelength of the reference light is set to 1330 nm is to bring the wavelength closer to that of the measurement light of 1450 nm so that it is not absorbed by moisture and the fluctuation tendency due to disturbance factors is in the same direction as the measurement light. Returning to FIG. 2, when a certain amount of light is emitted from the second light emitting element 150 having a wavelength of infrared 1330 nm, which is the reference light, the path e→f→g→ h, the reference light with a wavelength of 1330 nm, which is not attenuated by moisture, is taken into the second light receiving element 152 .

A control device (not shown) such as a microcomputer inside the refrigerator 100 performs a difference operation on the reflected light from the measurement light and the reference light measured in this way, and removes errors due to disturbance factors. is determined as the detected moisture content output value. The results for spinach are shown in FIG. In FIG. 5 , the black circle plots are obtained by actually drying the vegetables over time, periodically measuring the weight loss rate with the top pan balance, and measuring the water content with the water content detection means 131 at the same time. Note that the vertical axis of FIG. 5 is numerically corrected to represent the amount of change ΔV from the initial stage so that the correlation with the spectrometer output values of FIG. 4 can be easily understood. As shown in FIG. 5, the characteristic graph is a linear characteristic that descends to the right. That is, it can be seen that when the weight (moisture content) decreases, the amount of change ΔV in the output value of the moisture content detection means 131 also decreases with the variation width indicated by the dotted line.

In the case of vegetables in general, when the rate of weight loss from the initial stage exceeds 10%, it is identified as a withered state that can be discerned with the naked eye. Therefore, in the present embodiment, as shown in FIG. 5, the control device determines that the withered state occurs when .DELTA.V=C after a change over time from the initial stage. The reason why the wilting detection change amount ΔV is set to C here is to avoid judging that the weight reduction rate is not withered at a rate of 10% or more due to variations, which is a safety side.

In addition, in the description of the present embodiment, one water content detection means 131 is used for detection at one point position. Detection accuracy can be improved. In addition, if the infrared wavelengths of the measurement light and reference light used for the moisture content detection means 131 are difficult to pass through packaging materials such as vegetable wraps, the accuracy can be further improved by replacing them with packing materials that allow transmission of that wavelength band. become. Although the measurement light and the reference light of the water content detection means 131 are different light sources, they may be a single light source with a wide band including both wavelengths of 1330 nm and 1450 nm.

Spinach was explained as a typical leaf vegetable, but other vegetables such as Japanese mustard spinach and bok choy may be used. It can be applied by changing the value of C.

As described above, in the present embodiment, the vegetable compartment 107 which is a heat-insulated storage compartment, the moisture amount detection means 131 for detecting the moisture amount of the vegetables in the vegetable compartment 107, and the freshness of the vegetables are maintained. A conventional method of estimating the freshness of vegetables from the atmospheric humidity in the vegetable compartment 107 by providing a freshness maintaining device 139 for Instead, the moisture content detection means 131 detects the moisture content of the vegetable surface itself to determine the freshness state, so that the freshness keeping device 139 can be controlled by accurately judging the freshness state of the vegetables, and the freshness preservation quality is further improved. be able to.

In addition, the water content detection means 131 emits an infrared wavelength of a certain intensity, irradiates the vegetables in the vegetable compartment 107, and adopts a non-contact method for measuring the size of the reflected light from the vegetables. Since the infrared wavelength absorption spectrum difference of moisture is applied, the moisture content on the surface of the vegetables can be detected without the moisture content detection means 131 directly touching the vegetables. Installation to a movable storage container, which poses a problem of connection, becomes unnecessary, and the water content detection means 131 can be installed on the main body side, which is easy to connect, with a simple principle configuration of only a light emitting element and a light receiving element.

In addition, the freshness keeping device 139 generates fine particle mist and makes it flow into the vegetable compartment 107 to humidify the vegetables when the weight of the vegetables decreases and the amount of moisture decreases and they begin to deteriorate (wither). It is possible to prevent water puddles in storage containers due to excessive humidification during storage, and problems such as water rot of vegetables associated therewith can be prevented.

In the present embodiment, the vegetable compartment 107 is used as the storage compartment for detecting the amount of moisture in the refrigerator 100. However, a storage compartment with other temperature zones such as the refrigerating compartment 104 or the switchable compartment 105 may be used. In the case of , it is possible to develop various applications for detecting the moisture content of food in the chilled and partial temperature zones where meat, fish, etc. are preserved. In addition, since the water content detection means 131 can measure the water content on the food surface, ie, the degree of dryness, in a non-contact manner, it can be applied as a dryness detection means in a storage device for dried foods and a device for drying dried fruits and the like.

(Embodiment 2)
FIG. 6 is a longitudinal sectional view of a vegetable compartment of a refrigerator according to Embodiment 2 of the present invention. The same reference numerals are given to the same configurations as in the first embodiment, detailed descriptions thereof are omitted, and different portions will be described.

In FIG. 6, a freshness keeping device 139 is embedded in a part of the wall surface of the back partition wall 111 on the side of the vegetable compartment 107 . A plurality of infrared light emitting elements 153 are built in the freshness keeping device 139, and a transmission filter 154 is held on the light emitting side of the infrared light emitting elements 153 by the outer frame. The emitted light from the infrared light emitting element 153 passes through the transmission filter 154 and irradiates the object (vegetables) through the gap between the lower storage container 119 and the upper storage container 120 or through the lower storage container 119. Components are optically designed and optimally placed.

The operation and function of the refrigerator configured as described above will be described below.

Similar to the operation described in the first embodiment, when the moisture detection means 131 determines that the vegetables are in a wilted state, the freshness keeping device 139 starts operating. Specifically, the infrared light emitting element 153 is turned on to emit an infrared wavelength in the range of 700 nm to 2500 nm. A particularly good wavelength is around 850 nm, and the transmission filter 154 may be provided with a band-pass property, or the infrared light emitting element 153 itself may be an LED with a peak of 850 nm.

Here, the biological reaction of vegetables will be explained. Leafy vegetables have stomata, which regulate moisture by respiration and opening and closing actions for taking in and out oxygen and carbon dioxide. In addition, vegetables have the property of closing their stomata as a defensive reaction when exposed to external disturbances such as light and temperature. In particular, it is generally known that irradiation with infrared rays closes the pores and suppresses water evaporation.

In the present embodiment, this biological reaction of vegetables is used. When the freshness keeping device 139 is operated, the vegetables are irradiated with an infrared wavelength, and in response to the stimulus, the stomata are closed and water transpiration from the vegetables is caused. will be suppressed.

As described above, in the present embodiment, the freshness keeping device 139 has the infrared light emitting element 153 inside, and emits an infrared wavelength from the infrared light emitting element 153 to irradiate the vegetables stored in the vegetable compartment 107. By controlling the stomata of vegetables, the stomata are closed when the weight of the vegetables decreases and the amount of moisture in the vegetables decreases and they begin to deteriorate (wither). The freshness keeping device 139 can be realized at a low cost and with a large degree of installation freedom without requiring a complicated structure. In the first and second embodiments, the content of detecting the wilting state of vegetables and maintaining the freshness of the vegetables has been described. It is possible. Therefore, the freshness keeping device 139 may have a humidity control function that loosens the sealing structure with a damper so that the humidity in the vegetable compartment 107 is slightly lowered when the vegetables are fresh.

As described above, the refrigerator according to the present invention can realize appropriate moisture retention of vegetables in the storage compartment, so it can be applied not only to household or business refrigerators or vegetable storages, but also to vegetables other than vegetables. It can also be applied to applications such as low-temperature distribution including food and warehouses.

100 Refrigerator 101 Insulation Box 102 Outer Box 103 Inner Box 104 Refrigerator Chamber 105 Switching Chamber 106 Ice Making Chamber 107 Vegetable Compartment (Storage Compartment)
108 freezer compartment 109 compressor 110 cooling compartment 111 back partition wall 112 cooler 113 cooling fan 114 radiant heater 115 drain pan 116 drain tube 117 evaporating dish 118 drawer door 119 lower storage container 120 upper storage container 122 lid 123 first partition Wall 124 Discharge port 125 Second partition wall 126 Suction port 131 Moisture content detection means 139 Freshness keeping device 145 Damper 146 First light emitting element (measurement light)
147 Reflector 148 First adjusting plate 149 First light receiving element 150 Second light emitting element (reference light)
151 second adjusting plate 152 second light receiving element 153 infrared light emitting element 154 transmission filter

Claims (7)

a storage room;
a storage container provided in the storage room;
moisture content detection means for detecting the moisture content of the food inside the storage container;
A freshness keeping device that humidifies the inside of the storage container,
The refrigerator according to the present invention, wherein the freshness keeping device humidifies the interior of the storage container based on the detection result of the moisture content detection means. 2. The refrigerator according to claim 1, wherein said freshness keeping device humidifies the interior of said storage container when the amount of change from a reference value is smaller than a predetermined value. 3. The refrigerator according to claim 1, wherein said freshness keeping device emits mist into said storage container. Further comprising an upper storage container provided on the storage container,
A gap between the upper storage container and the storage container is provided on the back side of the storage chamber,
4. The freshness keeping device according to any one of claims 1 to 3, wherein the freshness keeping device is provided at a position facing a gap between the upper storage container and the storage container on the back surface of the storage chamber. refrigerator. The moisture content detection means has a first measurement means and a second measurement means,
The first measuring means measures, as measurement light, infrared rays having a wavelength of 1450 nm that are not absorbed by the food among the infrared rays having a wavelength of 1450 nm emitted by the first light emitting element,
The second measuring means measures, as reference light, infrared rays having a wavelength of 1330 nm that are not absorbed by the food among the infrared rays having a wavelength of 1330 nm emitted by the second light emitting element,
5. The refrigerator according to claim 1, wherein the measurement light and the reference light are measured simultaneously, and the moisture content is detected from a difference between the measurement light and the reference light. 6. The refrigerator according to claim 5, wherein said moisture amount detection means comprises a single light source with a wide band including both wavelengths of said first light emitting element and said second light emitting element. 7. The refrigerator according to any one of claims 1 to 6, wherein the food is vegetables.

Images