CN108351142B

CN108351142B - Refrigerator with a door

Info

Publication number: CN108351142B
Application number: CN201680062343.8A
Authority: CN
Inventors: 柴田舞子; 松木真理子; 内田毅; 伊藤敬
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2015-10-30
Filing date: 2016-10-18
Publication date: 2020-05-12
Anticipated expiration: 2036-10-18
Also published as: TWI614470B; DE112016004985T5; SG11201803423SA; NZ740530A; WO2017073406A1; TW201730492A; JP2017083121A; JP6176308B2; CN108351142A; AU2016344962B2; HK1252238A1; AU2016344962A1

Abstract

Provided is a refrigerator capable of promoting photosynthesis of vegetables and fruits during preservation by utilizing a circadian rhythm of a plant and also considering a state of stomata of the plant. Therefore, the refrigerator (1) is provided with: a light emitting unit (14) which can irradiate visible light into the interior of a storage chamber (500) for storing food; and a control unit (8) that controls the operation of the light-emitting unit so that a visible light irradiation step in which light containing visible light is irradiated from the light-emitting unit and a non-irradiation step in which light containing visible light is not irradiated from the light-emitting unit are alternately repeated. The light emitting section includes: a 1 st light source (16a) for irradiating light having a 1 st wavelength in the visible light region as a center wavelength; and a 2 nd light source (16b) for irradiating light having a 2 nd wavelength different from the 1 st wavelength in the visible light region as a center wavelength. The control unit controls the light emitting unit so that, in the visible light irradiation step, a 1 st irradiation step of irradiating light from both the 1 st and 2 nd light sources and a 2 nd irradiation step of irradiating light from only the 1 st light source are performed.

Description

Refrigerator with a door

Technical Field

The present invention relates to a refrigerator.

Background

Among conventional refrigerators, the following are known: a portion of a vegetable room is provided with a container for mainly containing vegetables, a low-light irradiation device is disposed above the container, the low-light irradiation device is a semiconductor light emitting element that emits light having a wavelength in the visible light range, and the semiconductor light emitting element is a red LED that outputs light having a wavelength of about 660nm (see, for example, patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2002-267348

Disclosure of Invention

However, in the conventional refrigerator disclosed in patent document 1, vegetables such as leafy vegetables (vegetables) and fruits are continuously irradiated with red light for 1 day and 24 hours. On the other hand, plants such as vegetables perform activities such as photosynthesis in a cycle of about 24 hours. This periodic activity is called the circadian rhythm. In photosynthesis using solar energy, the brightness of light has a large influence on the circadian rhythm. In addition, in natural light, the wavelength of light also changes significantly in accordance with the lapse of 1 day. Therefore, in a state where red light of the same wavelength is continuously irradiated, vegetables and fruits such as leafy vegetables (vegetables) cannot efficiently utilize the energy of the irradiated light. Specifically, in photosynthesis, stomata of vegetables and fruits are not sufficiently opened, and carbon dioxide required for photosynthesis cannot be sufficiently obtained, and therefore, the efficiency of photosynthesis may be reduced.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a refrigerator capable of promoting photosynthesis of vegetables and fruits such as vegetables (particularly, leafy vegetables) during preservation by using the circadian rhythm of plants and also taking into consideration the state of stomata of the plants.

The refrigerator according to the present invention includes: a storage chamber for storing food; a light emitting unit capable of irradiating visible light to the inside of the storage chamber; and a control unit that controls an operation of the light emitting unit so that a visible light irradiation step of irradiating the light including visible light from the light emitting unit and a non-irradiation step of not irradiating the light including visible light from the light emitting unit are alternately repeated, the light emitting unit including: a 1 st light source for emitting light having a 1 st wavelength in a visible light region as a center wavelength; and a 2 nd light source that emits light having a 2 nd wavelength different from the 1 st wavelength in a visible light region as a center wavelength, wherein the control unit controls the light emitting unit so that a 1 st emission step of emitting light from both the 1 st light source and the 2 nd light source and a 2 nd emission step of emitting light from only the 1 st light source are performed in the visible light emission step.

The refrigerator according to the present invention has an effect of promoting photosynthesis of vegetables and fruits such as vegetables (particularly leaf vegetables) during storage by utilizing the circadian rhythm of plants and taking into account the state of stomata of the plants.

Drawings

Fig. 1 is a front view of a refrigerator according to embodiment 1 of the present invention.

Fig. 2 is a longitudinal sectional view of a refrigerator according to embodiment 1 of the present invention.

Fig. 3 is a view showing the part of the vegetable compartment of fig. 2 enlarged.

Fig. 4 is a diagram showing a structure of a light emitting portion provided in a refrigerator according to embodiment 1 of the present invention.

Fig. 5 is a block diagram showing a configuration of a control system of a refrigerator according to embodiment 1 of the present invention.

Fig. 6 is a timing chart of light irradiation control of each light source provided in the light emitting section of the refrigerator according to embodiment 1 of the present invention.

Fig. 7 is a flowchart showing a flow of light irradiation control of the refrigerator according to embodiment 1 of the present invention.

Fig. 8 is a graph showing an example of comparison of the vitamin C content when cabbage was stored for 3 days under a plurality of light irradiation conditions.

Fig. 9 is a timing chart of light irradiation control of each light source provided in the light emitting portion of the refrigerator according to embodiment 1 of the present invention and an open/close state of the vegetable compartment door.

(description of reference numerals)

1: a refrigerator; 2: a compressor; 3: a cooler; 4: an air supply fan; 5: an air passage; 6: an operation panel; 7: a refrigerating chamber door; 7 a: a right door; 7 b: a left door; 8: a control device; 8 a: a processor (CPU); 8 b: a memory; 9: a vegetable room door; 10: a lower storage box body; 11: an upper storage box body; 12: a door opening and closing detection switch; 13: a thermistor; 14: a light emitting section; 15: an opening part; 16 a: 1 st light source; 16 b: a 2 nd light source; 90: a heat insulation box body; 100: a refrigerating chamber; 200: a switching room; 300: an ice making chamber; 400: a freezing chamber; 500: a vegetable room; 201: a switching room storage box body; 401: a freezing chamber storage box body.

Detailed Description

With reference to the drawings, modes for carrying out the present invention will be described. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and overlapping description is appropriately simplified or omitted. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.

Embodiment 1.

Fig. 1 to 9 are views related to embodiment 1 of the present invention, fig. 1 is a front view of a refrigerator, fig. 2 is a vertical sectional view of the refrigerator, fig. 3 is an enlarged view of a vegetable compartment portion of fig. 2, fig. 4 is a diagram illustrating a structure of a light emitting portion provided in the refrigerator, fig. 5 is a block diagram illustrating a structure of a control system of the refrigerator, fig. 6 is a timing chart illustrating light irradiation control of each light source provided in the light emitting portion of the refrigerator, fig. 7 is a flowchart illustrating a flow of the light irradiation control of the refrigerator, fig. 8 is a diagram illustrating an example of comparison of vitamin C amounts in a case where a cabbage is stored for 3 days under a plurality of light irradiation conditions, and fig. 9 is a timing chart illustrating light irradiation control of each light source provided in the light emitting portion of the refrigerator and an open/closed state of a vegetable compartment door.

In the drawings, the relationship between the size and the shape of each component may be different from the actual components. In addition, the positional relationship (for example, the vertical relationship) between the respective components is, in principle, the positional relationship when the refrigerator is set in a usable state.

(Structure of refrigerator)

As shown in fig. 2, a refrigerator 1 according to embodiment 1 of the present invention includes a heat insulating box 90. The heat insulation box 90 is opened at a front surface (front surface) thereof, and a storage space is formed therein. The heat insulating box 90 has an outer box, an inner box, and a heat insulating material. The outer box is made of steel. The inner box is made of resin. The inner box is arranged at the inner side of the outer box. The heat insulating material is, for example, foamed polyurethane or the like, and fills the space between the outer box and the inner box. The storage space formed inside the heat insulation box 90 is divided into a plurality of storage compartments for storing and preserving foods by 1 or more partitions.

As shown in fig. 1 and 2, the refrigerator 1 includes, for example, a refrigerating compartment 100, a switching compartment 200, an ice-making compartment 300, a freezing compartment 400, and a vegetable compartment 500 as a plurality of storage compartments. These storage compartments are arranged in the heat insulating box 90 so as to have a 4-layer structure in the vertical direction.

The refrigerating compartment 100 is disposed at the uppermost layer of the heat insulating box 90. Switching room 200 is disposed on the left and right sides below refrigerating room 100. Any temperature stage of the plurality of temperature stages can be selected to switch the cold insulation temperature stage of the switching room 200. The plurality of temperature stages that can be selected as the cold insulation temperature stage of the switching room 200 are, for example, a freezing temperature stage (for example, about-18 ℃), a refrigerating temperature stage (for example, about 3 ℃), a cooling (chilled) temperature stage (for example, about 0 ℃), and a soft freezing temperature stage (for example, about-7 ℃). The ice making compartment 300 is disposed adjacent to a side of the switching compartment 200, in parallel with the switching compartment 200, that is, disposed on the other left and right sides below the refrigerating compartment 100.

The freezing compartment 400 is disposed below the switching compartment 200 and the ice making compartment 300. The freezing chamber 400 is mainly used for freezing and preserving the storage object for a relatively long period of time. Vegetable compartment 500 is disposed at the lowermost layer below freezing compartment 400. The vegetable room 500 is mainly used for storing vegetables, large-sized PET bottles with a large capacity (for example, 2L).

A rotary refrigerating chamber door 7 for opening and closing an opening formed in the front surface of refrigerating chamber 100 is provided. Here, the refrigerating chamber door 7 is of a double-opening type (left-right double-opening type) and includes a right door 7a and a left door 7 b. An operation panel 6 is provided on an outer side surface of a refrigerating chamber door 7 (e.g., a left door 7b) of a front surface of the refrigerator 1. The operation panel 6 includes an operation unit 6a and a display unit 6 b. The operation unit 6a is an operation switch for setting the cooling temperature of each storage room and the operation mode (defrosting mode, etc.) of the refrigerator 1. The display unit 6b is a liquid crystal display for displaying various information such as the temperature of each storage room. The operation panel 6 may also include a touch panel that also serves as the operation unit 6a and the display unit 6 b.

Each of the storage compartments (switching compartment 200, ice making compartment 300, freezing compartment 400, and vegetable compartment 500) other than refrigerating compartment 100 is opened and closed by a drawer-type door. These pull-out type doors can be opened and closed in the depth direction (front-rear direction) of the refrigerator 1 by sliding frames fixedly provided to the doors on rails horizontally formed on the left and right inner wall surfaces of each storage room.

In addition, a switching chamber storage case 201 and a freezing chamber storage case 401 capable of storing food and the like therein are stored in the switching chamber 200 and the freezing chamber 400 so as to be able to be drawn out. Similarly, the upper storage box 11 and the lower storage box 10 capable of storing food and the like therein are stored in the vegetable room 500 so as to be able to be drawn out.

(Cooling mechanism)

The refrigerator 1 includes a refrigeration cycle circuit for cooling air supplied to each storage chamber. The refrigeration cycle includes a compressor 2, a condenser (not shown), an expansion device (not shown), a cooler 3, and the like. The compressor 2 compresses and discharges the refrigerant in the refrigeration cycle. The condenser condenses the refrigerant discharged from the compressor 2. The throttling device expands the refrigerant flowing out of the condenser. The cooler 3 cools the air supplied to each storage chamber by the refrigerant expanded by the throttle device. The compressor 2 is disposed, for example, at a lower portion of the rear surface side of the refrigerator 1.

An air duct 5 is formed in the refrigerator 1, and the air duct 5 supplies the air cooled by the refrigeration cycle to each storage compartment. The air passage 5 is mainly disposed on the rear side in the refrigerator 1. The cooler 3 of the refrigeration cycle is disposed in the air passage 5. Further, an air supply fan 4 is provided in the air duct 5, and the air supply fan 4 supplies the air cooled by the cooler 3 to each storage room.

When the blower fan 4 is operated, the air (cold air) cooled by the cooler 3 is sent to the freezer compartment 400, the switching compartment 200, the ice-making compartment 300, and the refrigerator compartment 100 via the air duct 5, and the storage compartments are cooled. Vegetable compartment 500 is cooled by introducing cool return air from cooling compartment 100 into vegetable compartment 500 via a return air passage for the refrigerating compartment. The cold air having cooled vegetable room 500 is returned to air duct 5 having cooler 3 via the vegetable room return air duct (these return air ducts are not shown). Then, the cooled air is cooled again by the cooler 3, and the cooled air is circulated in the refrigerator 1.

A not-shown air valve is provided at a part of the air passage 5 which extends to each storage chamber. Each air valve opens and closes a portion of the air passage 5 leading to each storage chamber. By changing the open/close state of the air valve, the amount of cold air supplied to each storage chamber can be adjusted. Further, the temperature of the cold air can be adjusted by controlling the operation of the compressor 2.

The refrigeration cycle circuit including the compressor 2 and the cooler 3, the blower fan 4, the air passage 5, and the air valve provided as described above constitute a cooling unit that cools the inside of the storage compartment.

A controller 8 is housed in, for example, an upper portion of the rear surface side of the refrigerator 1. The control device 8 is provided with a control circuit and the like for performing various controls necessary for the operation of the refrigerator 1. Examples of the control circuit provided in the control device 8 include a circuit for controlling the operation of the compressor 2 and the blower fan 4 and the opening degree of the air valve based on the temperature in each storage room, information input to the operation panel 6, and the like. That is, the control device 8 controls the cooling unit and the like to control the operation of the refrigerator 1. The temperature in each storage chamber can be detected by a thermistor (not shown) or the like provided in each storage chamber.

(Structure of vegetable room)

Fig. 3 is a sectional view of a part of a vegetable compartment 500 provided in the refrigerator 1. The vegetable room 500 is a storage room for storing food, particularly vegetables. The lower storage box 10 is supported by a frame (not shown) of the vegetable compartment door 9. An upper storage case 11 is placed on the upper side of the lower storage case 10. When the vegetable room door 9 is pulled out forward, the lower storage box 10 and the upper storage box 11 are pulled out forward integrally with the vegetable room door 9. When only the upper storage box 11 is slid backward in a state where the vegetable compartment door 9 is pulled out, only the lower storage box 10 is pulled out. In a state where only the lower storage case 10 is pulled out, food can be taken in and out of the lower storage case 10.

The vegetable room 500 is provided therein with a door opening/closing detection switch 12, a thermistor 13, and a light emitting unit 14. The door opening/closing detection switch 12 is used to detect the open/closed state of the vegetable room door 9. The door opening/closing detection switch 12 is provided at a position opposed to the vegetable room door 9 at an edge portion of the front surface opening of the vegetable room 500.

A thermistor 13 and a light emitting unit 14 are mounted on the rear surface in the vegetable room 500. The thermistor 13 detects the temperature inside the vegetable room 500. The light emitting unit 14 can irradiate visible light to the inside of the vegetable room 500 as the storage room. Here, an opening 15 is formed in a portion of the rear surface of the lower storage case 10 facing the light emitting portion 14. The light emitting unit 14 can irradiate the visible light into the lower storage case 10 through the opening 15. In addition, a material having a property of transmitting visible light irradiated from the light emitting section 14 may be used at least in a portion corresponding to the opening 15 of the lower storage case 10.

(Structure of the luminous part)

Next, the structure of the light emitting unit 14 will be further described with reference to fig. 4. As shown in fig. 4, the light emitting unit 14 includes two types of light sources, i.e., a 1 st light source 16a and a 2 nd light source 16 b. As described above, the light emitting unit 14 can emit visible light. Therefore, the light emitting unit 14 includes a visible light source that emits visible light. The 1 st light source 16a and the 2 nd light source 16b are visible light sources.

The 1 st light source 16a irradiates light having the 1 st wavelength as a center wavelength. The 2 nd light source 16b irradiates light having the 2 nd wavelength as a center wavelength. Both the 1 st wavelength and the 2 nd wavelength belong to the visible light region. However, the 2 nd wavelength is different from the 1 st wavelength.

Specifically, the 1 st wavelength as the center wavelength of the 1 st light source 16a is 500nm or more and 700nm or less, preferably 600nm or more and 700nm or less. That is, the light emitted from the 1 st light source 16a is red. Specifically, for example, a red LED can be used as the 1 st light source 16 a.

The 2 nd wavelength, which is the center wavelength of the 2 nd light source 16b, is 400nm or more and 500nm or less. That is, the light emitted from the 2 nd light source 16b is blue. Specifically, for example, a blue LED can be used as the 2 nd light source 16 b.

These 1 st

light source

16a and 2 nd light source 16b are configured to be capable of being independently turned on and off.

(control System of refrigerator)

Fig. 5 is a block diagram showing the structure of the functionality of the control system of the refrigerator 1. In this fig. 5, a part related to the control of the vegetable room 500 is particularly shown. The control device 8 includes, for example, a microcomputer, and includes a processor (CPU, central processing Unit) 8a and a memory 8 b. The control device 8 executes a preset process by executing a program stored in the memory 8b by a processor (CPU)8a, thereby controlling the refrigerator 1.

A detection signal of the temperature inside vegetable room 500 is input from thermistor 13 to control device 8. Further, an operation signal from the operation unit 6a of the operation panel 6 is also input to the control device 8. Further, a detection signal from the door opening/closing detection switch 12 is also input to the control device 8.

The control device 8 executes the following processing in accordance with the inputted signal: the operations of compressor 2, blower fan 4, and the like are controlled so that the inside of vegetable room 500 is maintained at a predetermined temperature. Further, the control device 8 outputs a display signal to the display portion 6b of the operation panel 6.

Further, the control device 8 outputs a control signal to the light emitting unit 14 to control the light emitting operation of the light emitting unit 14. As described above, the light emitting unit 14 includes the 1 st light source 16a and the 2 nd light source 16 b. The two light sources can be independently turned on and off. The control device 8 can control the lighting and lighting states of the 1 st light source 16a and the 2 nd light source 16b provided in the light emitting unit 14 independently of each other.

(control of the luminous part)

Next, the control of the light emitting operation of the light emitting unit 14 by the control device 8 will be described with reference to fig. 6. The control device 8 controls the operation of the light emitting unit 14 so that a visible light irradiation step of irradiating the light including visible light from the light emitting unit 14 and a non-irradiation step of not irradiating the light including visible light from the light emitting unit 14 are alternately repeated. In the visible light irradiation step, at least one of the 1 st light source 16a and the 2 nd light source 16b is turned on. In the non-irradiation step, neither the 1 st light source 16a nor the 2 nd light source 16b is turned on.

The visible light irradiation step is further divided into two steps. In the visible light irradiation step, the 1 st irradiation step is performed first, and the 2 nd irradiation step is performed next. That is, the controller 8 controls the light emitting unit 14 to perform the 1 st irradiation step and the 2 nd irradiation step in the visible light irradiation step. In the 1 st irradiation step, the control device 8 irradiates light from both the 1 st light source 16a and the 2 nd light source 16 b. That is, both red light and blue light are irradiated. In the 2 nd irradiation step, the controller 8 irradiates light from only the 1 st light source 16a, and the 2 nd light source 16b is turned off. That is, only red light is irradiated, and blue light is not irradiated.

The duration of each step is preset. In this regard, the duration of the 1 st irradiation step is Δ T1, the duration of the 2 nd irradiation step is Δ T2, and the duration of the non-irradiation step is Δ T3.

In this way, the controller 8 controls the light emitting unit 14 so that the 1 st irradiation step, the 2 nd irradiation step, and the non-irradiation step are performed in this order. After the non-irradiation step is completed, the steps are repeated in the order described above from the 1 st irradiation step, which is the visible light irradiation step. Therefore, the time Δ T taken for 1 cycle, which is sequentially performed for each step, is the sum of Δ T1, Δ T2, and Δ T3. The duration of the visible light irradiation step is the sum of Δ T1 and Δ T2.

The control device 8 controls the light emitting unit 14 so that the visible light irradiation step and the non-irradiation step are alternately repeated at a cycle of 24 hours or less. That is, Δ T is set to 24 hours or less. The duration Δ T3 of the non-irradiation step is set to be equal to or shorter than the duration of the visible light irradiation step. That is, the duration Δ T3 of the non-irradiation step is set to be equal to or less than the total time of the duration Δ T1 of the 1 st irradiation step and the duration Δ T2 of the 2 nd irradiation step. Further, the duration Δ T1 of the 1 st irradiation step is set to be equal to or less than the duration Δ T2 of the 2 nd irradiation step. As an example of the duration of each step satisfying the above conditions, specifically, Δ T1 is set to 2 hours, Δ T2 is set to 10 hours, and Δ T3 is set to 8 hours. In this case, Δ T was 20 hours.

A series of flows related to the control of the light emitting unit 14 of the vegetable room 500 provided in the refrigerator 1 configured as described above will be described with reference to a flowchart of fig. 7. When the power supply of the refrigerator 1 is turned on, first, in step S101, the control device 8 turns on the 1 st light source 16a and the 2 nd light source 16b of the light emitting section 14. In the next step S102, the control device 8 resets the value of the timer t for measuring the elapsed time to 0, and starts the counting by the timer.

Then, in the next step S103, the control device 8 checks whether or not the elapsed time T of the timer is Δ T1. If the elapsed time T of the timer has not become Δ T1, the confirmation in step S103 is repeated until the elapsed time T of the timer becomes Δ T1. Then, if the elapsed time T of the timer becomes Δ T1, the process proceeds to step S104. Steps S101 to S103 described above are the 1 st irradiation step.

In step S104, the control device 8 turns off the 2 nd light source 16b of the light emitting unit 14. Therefore, only the 1 st light source 16a is turned on. In the next step S105, the control device 8 resets the value of the timer t for measuring the elapsed time to 0, and starts the counting by the timer.

Then, in the next step S106, the control device 8 checks whether or not the elapsed time T of the timer has become Δ T2. If the elapsed time T of the timer has not become Δ T2, the confirmation in step S106 is repeated until the elapsed time T of the timer becomes Δ T2. Then, if the elapsed time T of the timer becomes Δ T2, the process proceeds to step S107. Steps S104 to S106 described above are the 2 nd irradiation step.

In step S107, the control device 8 turns off the 1 st light source 16a of the light emitting unit 14. Therefore, all of the 1 st light source 16a and the 2 nd light source 16b are turned off. Then, the process proceeds to step S108, and the control device 8 resets the value of the timer t for measuring the elapsed time to 0, and starts the counting by the timer.

In the next step S109, the control device 8 checks whether or not the elapsed time T of the timer is Δ T3. If the elapsed time T of the timer has not become Δ T3, the confirmation in step S109 is repeated until the elapsed time T of the timer becomes Δ T3. Then, if the elapsed time T of the timer becomes Δ T3, the process returns to step S101, and the above steps are repeatedly executed. The above steps S107 to S109 are non-irradiation steps.

(function of light irradiation control)

Next, an operation expected by the light irradiation control in the above-described light emitting unit 14 will be described. First, the circadian rhythm of the plant is autonomously maintained for a period of about 24 hours even without providing time information such as a light and dark period of light. However, when vegetables and fruits such as vegetables (particularly vegetables and fruits) are stored in a dark environment without irradiation with light, no photosynthesis is performed, and therefore, effects such as improvement in storage stability and increase in nutrients cannot be obtained. On the other hand, when vegetables and fruits are stored in a bright environment in which light is continuously irradiated, although photosynthesis proceeds, there are cases where a sufficient production of nutrients is not achieved, or the rate of photosynthesis or the photosynthetic capacity is decreased.

Therefore, in the refrigerator 1 of the present invention, as described above, the light emitting portion 14 of the vegetable room 500 alternately and repeatedly performs the visible light irradiation step of irradiating light including visible light and the non-irradiation step of not irradiating light including visible light in the lower storage box 10 of the vegetable room 500.

Therefore, in the lower storage case 10, both a bright period in which the light is irradiated with visible light to provide a bright environment and a dark period in which the light is not irradiated with visible light to provide a dark environment change with time. That is, in the lower storage case 10, an environment simulating a change in light amount in nature due to a rise in the morning and a fall in the evening is realized. Therefore, the plant such as the vegetable and the fruit put in the lower storage case 10 can be promoted to perform the photosynthesis or other activities according to the circadian rhythm.

Here, the photosynthesis reaction of the plant is explained. The photosynthesis reaction can be represented by the following formula (1).

6CO₂+12H₂O+688kcal→C₆H₁₂O₆+6H₂O+6O₂…(1)

In the formula (1), CO₂: carbon dioxide, H₂O: water, 688kcal (kcal): light energy, C₆H₁₂O₆: and (3) glucose.

By the photosynthesis reaction of the formula (1), the plant generates oxygen and sugar from carbon dioxide in the atmosphere and water contained in the plant by using light energy. The reaction is divided into two stages. In the first stage, water is decomposed into hydrogen and oxygen using light energy absorbed by chlorophyll and other pigments contained in leaves and the like, and chemical energy is accumulated by the action of enzyme proteins. In the second stage, glucose is synthesized using electrons, hydrogen ions, and carbon dioxide in the atmosphere. The vegetables having increased glucose content have good storage properties and produce vitamin C from glucose.

In order to perform photosynthesis actively, it is necessary to make the light irradiated into the vegetable room 500 effective for photosynthesis. It is known that the absorption spectrum of chlorophyll has two absorption peaks in red (around 660 nm) and blue (around 450 nm), which are particularly effective for photosynthesis. In addition, for green (500 to 600nm), the absorption rate by chlorophyll is low, but light scattering occurs inside the leaves, so that the frequency of the light scattering meeting chlorophyll becomes high, and the absorption rate of the entire leaves becomes high.

In addition, blue light has the effect of opening the stomata of the plant. Thus, by irradiating light containing blue at the initial stage of the bright period of the irradiation light, the stomata of the vegetables and fruits can be opened. Then, the vegetables and fruits can sufficiently take carbon dioxide in the air and can efficiently perform photosynthesis by continuing the light period after the stomata of the vegetables and fruits are opened. On the other hand, blue light also has the action of promoting germination and flowering. Therefore, in the case of long-term preservation of vegetables and fruits, the time for irradiating with blue light is preferably as short as possible.

Therefore, in the visible light irradiation step for promoting photosynthesis, first, the 2 nd light source 16b is turned on in the 1 st irradiation step to irradiate light including blue, and then the 2 nd light source 16b is turned off in the 2 nd irradiation step to irradiate light not including blue, so that photosynthesis can be performed after the stomata of vegetables and fruits in the lower storage box 10 are opened, and photosynthesis of vegetables and fruits in the lower storage box 10 can be further promoted. In this case, the 1 st irradiation step of irradiating light including blue is made shorter than the 2 nd irradiation step of irradiating light not including blue, so that germination and flowering are not promoted as much as possible and a sufficient stomatal opening effect can be obtained.

The plant circadian rhythm is about a 24-hour period corresponding to the time from morning to night and then to morning. However, the plant circadian rhythm is affected by ambient light and the phase of the rhythm changes. For example, when light is irradiated in a dark environment to make the environment bright, the rhythm phase shifts to the morning side. By utilizing such a feature, the time of the non-irradiation step is made shorter than that of the visible light irradiation step, that is, the dark period in which light is not irradiated is made shorter than the bright period in which light is irradiated, and the period of light irradiation is set to 24 hours or less, whereby the ratio of the time during which the photosynthesis is performed on the vegetables and fruits in the lower storage box 10 during the storage can be increased. Furthermore, by increasing the ratio of time for which photosynthesis is performed during storage, the efficiency of production of nutrients such as sugar and vitamin C in vegetables and fruits can be improved.

Here, with reference to fig. 8, a description will be given of how the amounts of nutrients (vitamin C) contained in vegetables and fruits differ when the vegetables and fruits are stored under a plurality of different light irradiation conditions as described above, by taking a specific comparative example. Fig. 8 is a graph comparing the amount of vitamin C after 3 days of cabbage storage under a plurality of different light irradiation conditions. The initial amount of vitamin C before storage was set to 100, and the amount of vitamin C was expressed by a change ratio. The light irradiation conditions were set to be equal in light intensity, and the color included in the irradiated light and the irradiation time per 1 day were changed.

In the non-irradiation state in which light was not irradiated at all for 1 day, the amount of vitamin C after storage was reduced from the initial one (the leftmost panel in fig. 8). On the other hand, the amount of vitamin C after storage was increased more than the initial amount under the irradiation with light. When the conditions of continuously irradiating light for 1 day were compared with each other, the amount of increase in vitamin C after storage was more in the case of combining red light with blue light (3 rd from left of fig. 8) than in the case of irradiating only red light (2 nd from left of fig. 8).

Further, when light irradiation corresponding to the circadian rhythm is performed while setting a dimming period, which is a period in which light is not irradiated, the result is that the amount of increase in vitamin C after storage is larger (the rightmost graph of fig. 8). Thus, by irradiating light of an appropriate wavelength according to the circadian rhythm of vegetables and fruits, photosynthesis and nutrient production can be efficiently performed, and the effects of improving the storage properties of vegetables and increasing nutrients during storage can be obtained. That is, according to the refrigerator 1 of the present invention, by irradiating light simulating the light activity in the natural world, it is possible to control the activities such as photosynthesis of vegetables and fruits by utilizing the circadian rhythm of the vegetables and fruits, and it is possible to promote the production of nutrients by photosynthesis or suppress excessive transpiration, thereby preserving the vegetables with high quality.

(Another example of control of the light emitting part)

In the control of the light emitting unit 14 described above, it is not particularly mentioned which time zone of 1 day the visible light irradiation step, the non-irradiation step, and the like are performed. Here, as another example of the control of the light emitting unit 14, an example of the control of the light emitting unit 14 in a time period in which the non-irradiation step is performed, or the like, based on the detection result of the open/closed state of the vegetable compartment door 9 will be described with reference to fig. 9.

As described above, the vegetable room door 9 is a door that can open and close the vegetable room 500 as a storage room. The door opening/closing detection switch 12 is a detection unit that detects opening/closing of the vegetable room door 9. The controller 8 counts the number of times the vegetable compartment door 9 is opened and closed, which is detected by the door opening/closing detection switch 12, for each predetermined time, that is, for each preset reference time. The reference time at this time is, for example, the duration Δ T3 of the non-irradiation step. The control device 8 controls the light emitting unit 14 to perform the non-irradiation step in a time zone in which the number of times the vegetable compartment door 9 is opened and closed is equal to or less than a predetermined number of times for each predetermined time.

The door of the refrigerator 1 is opened and closed more often before and after food preparation or shopping, and is not opened and closed while a user is sleeping or going out. Therefore, in daily life, the change in the number of door openings and closings is modeled for 1 day, and can be predicted. Therefore, the control device 8 counts the number of times the vegetable room door 9 is opened and closed, and stores a time zone, not shown, in which the number of times the door is opened and closed per a certain time period is small. Then, the non-irradiation step is started in a time period stored on the next day or later, or 24 hours after the time period is stored, so that the non-irradiation step can be performed in a time period with a small number of times of opening and closing.

When the vegetable chamber door 9 is opened and closed in the middle of the non-irradiation process, there is a possibility that the phase of the circadian rhythm of the vegetables and fruits stored may be changed due to the influence of light outside the refrigerator 1. Therefore, by performing the non-irradiation step in a time zone in which the number of times the vegetable chamber door 9 is opened and closed is small, a dark period in which light is not irradiated to vegetables and fruits in the lower storage box 10 can be ensured, and light irradiation control in circadian rhythm can be efficiently performed.

Further, by operating the operation portion 6a of the operation panel 6 provided in the refrigerating chamber door 7, the user can switch between execution and stop of the light irradiation control from the light emitting portion 14 (turning off the light emitting portion 14 all the time). The user can select whether or not to perform control for lighting the light emitting unit 14 using the operation panel 6, and can select to stop and turn off the light emitting unit 14 all the time when vegetables and fruits are not stored or when not used for a long period of time, thereby achieving reduction in energy consumption and providing the same convenience as that of the general refrigerator 1.

In addition, during execution of the light irradiation control, the display unit 6b of the operation panel 6 may display the image "during light irradiation". Further, in the display unit 6b, the "on process" may be displayed on the display unit 6b in the visible light irradiation step (bright period), and the "off process" may be displayed on the display unit 6b in the non-irradiation step (dark period). Further, the display unit 6b may display 1 day by replacing the state of light in the refrigerator (in the vegetable room 500) with light in the natural world. Specifically, for example, "morning" is displayed on the display unit 6b in the 1 st irradiation step, "afternoon" is displayed on the display unit 6b in the 2 nd irradiation step, and "night" is displayed on the display unit 6b in the non-irradiation step, in accordance with the step during the execution in the light irradiation control. By doing so, the state of light in the refrigerator can be reported to the user, and convenience and satisfaction can be improved. In addition, it is possible to prompt the user to notice that unnecessary opening and closing of the door is not performed during the non-irradiation step.

The operation panel 6 is not limited to be provided outside the refrigerator 1, and may be provided inside the refrigerator (in the storage compartment). Further, the communication unit may be provided in the refrigerator 1, and commands may be transmitted to the control device 8 of the refrigerator 1 or information of the refrigerator 1 may be received and displayed by a portable information terminal (a portable telephone including a smartphone, a tablet terminal, or the like) via an electric communication line or the like. That is, the portable information terminal may be provided with one or both of the functions of the operation unit 6a and the display unit 6b of the operation panel 6.

Industrial applicability of the invention

The present invention can be used for a refrigerator that includes a light emitting portion in a storage room for storing food and irradiates visible light from the light emitting portion to the inside of the storage room.

Claims

1. A refrigerator is provided with:

a storage chamber for storing food;

a light emitting unit capable of irradiating visible light to the inside of the storage chamber; and

a control unit that controls the operation of the light emitting unit so that a visible light irradiation step in which light including visible light is irradiated from the light emitting unit and a non-irradiation step in which light including visible light is not irradiated from the light emitting unit are alternately repeated,

the light emitting unit includes:

a 1 st light source for emitting light having a 1 st wavelength in a visible light region as a center wavelength; and

a 2 nd light source for emitting light having a 2 nd wavelength different from the 1 st wavelength in a visible light region as a center wavelength,

the control unit controls the light emitting unit so that, in the visible light irradiation step, a 1 st irradiation step of irradiating light from both the 1 st light source and the 2 nd light source is performed first, and then a 2 nd irradiation step of irradiating light from only the 1 st light source is performed,

the 1 st wavelength is 500nm to 700nm,

the 2 nd wavelength is 400nm to 500 nm.

2. The refrigerator according to claim 1,

the control unit controls the light emitting unit so that the visible light irradiation step and the non-irradiation step are alternately repeated at a cycle of 24 hours or less.

3. The refrigerator according to claim 1 or 2,

the duration of the non-irradiation step is equal to or less than the total time of the duration of the 1 st irradiation step and the duration of the 2 nd irradiation step.

4. The refrigerator according to claim 1 or 2,

the duration of the 1 st irradiation step is equal to or less than the duration of the 2 nd irradiation step.

5. The refrigerator according to claim 1 or 2, further comprising:

a door capable of opening and closing the storage chamber; and

a detection unit which detects opening and closing of the door,

the control unit controls the light emitting unit so that the non-irradiation step is performed in a time period in which the number of times of opening and closing of the door detected by the detection unit per a preset reference time is equal to or less than a preset number of times.