Food freshness detection device and food storage

Abstract

To provide a food freshness detection device capable of assisting a user in determining a freshness state of food regardless of the type of food.SOLUTION: A food freshness detection device comprises a light-emitting unit 20 that is a light irradiation unit for irradiating target food with light, and an imaging unit 14 that captures an image of the food. The light irradiation unit irradiates the food by switching between a first irradiation light and a second irradiation light that can excite fluorescence in the food and has a specific wavelength that is less intense than the first irradiation light. The imaging unit 14 captures a first image that captures the fluorescence emitted by the food irradiated with the first irradiation light, and a second image that captures reflected light from the food of the second irradiation light. The food freshness detection device further comprises an image generation unit 634 that generates a single food freshness image based on the first image and the second image.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a food freshness detection device and a food storage facility. [Background technology]

[0002] It is known that a refrigerator judges the freshness of vegetables from the color of the vegetables placed in the vegetable compartment by irradiating the vegetables with ultraviolet light or short-wavelength visible light from a light source installed in the vegetable compartment of the refrigerator body, and visually comparing the autofluorescence of the vegetables that is generated by the irradiation through a colorimetric window installed in the vegetable compartment (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-300351 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology disclosed in Patent Document 1, when trying to visually determine the freshness of food based on its fluorescence state, the fluorescent substances differ depending on the type of food, and the color and intensity of the fluorescence change, etc. Also, the intensity and range of the fluorescence differ depending on the size of the food (size, thickness, etc.). For this reason, it is difficult for users to easily and accurately determine the freshness of food by visual inspection.

[0005] The present disclosure has been made to solve such problems. Its purpose is to provide a food freshness detection device and a food storage facility that can assist a user in determining the freshness state of a food item, regardless of the type and size of the food item. [Means for solving the problem]

[0006] The food freshness detection device of the present disclosure includes a light irradiation unit that irradiates light onto a target food, and an imaging unit that captures an image of the food, wherein the light irradiation unit irradiates the food by switching between a first irradiation light and a second irradiation light having a specific wavelength that is lower in intensity than the first irradiation light and is capable of exciting fluorescence in the food, and the imaging unit captures a first image that captures the fluorescence emitted by the food irradiated with the first irradiation light and a second image that captures the light of the second irradiation light reflected by the food, and further includes an image generation unit that generates a single food freshness image from the first image and the second image.

[0007] A food storage facility according to the present disclosure includes the above-described food freshness detection device and a main body having a storage chamber in which the food is stored. Effect of the Invention

[0008] The food freshness detection device and food storage facility according to the present disclosure have the advantage of being able to assist a user in determining the freshness state of a food item, regardless of the type and size of the food item. [Brief description of the drawings]

[0009] [Figure 1] 1 is a front view of a refrigerator equipped with a food freshness detection device according to a first embodiment. [Diagram 2] 1 is a cross-sectional view of a refrigerator equipped with a food freshness detection device according to a first embodiment. [Diagram 3] 2 is a cross-sectional view of a vegetable compartment of the refrigerator according to the first embodiment. FIG. [Figure 4] 1 is a block diagram showing a configuration of a control system of a refrigerator equipped with a food freshness detection device according to a first embodiment. [Diagram 5] FIG. 2 is a diagram showing an example of a food freshness image according to the first embodiment. [Figure 6] 4 is a flow chart showing an example of an operation of the food freshness detection device according to the first embodiment. FIG. [Figure 7] 2 is a diagram showing an example of a configuration for implementing the functions of a control device of a refrigerator equipped with a food freshness detection device according to the first embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The embodiment for implementing the food freshness detection device and food storage according to the present disclosure will be described with reference to the attached drawings. In each drawing, the same or corresponding parts are given the same reference numerals, and duplicated descriptions are appropriately simplified or omitted. In the following description, for convenience, the positional relationship of each structure may be expressed based on the illustrated state. Note that the present disclosure is not limited to the following embodiments, and it is possible to freely combine each embodiment and modified example, modify any component of each embodiment and modified example, or omit any component of each embodiment and modified example, within the scope of the gist of the present disclosure.

[0011] Embodiment 1 A first embodiment of the present disclosure will be described with reference to Figs. 1 to 7. Fig. 1 is a front view of a refrigerator equipped with a food freshness detection device. Fig. 2 is a cross-sectional view of a refrigerator equipped with a food freshness detection device. Fig. 3 is a cross-sectional view of a vegetable compartment of the refrigerator. Fig. 4 is a block diagram showing the configuration of a control system of a refrigerator equipped with a food freshness detection device. Fig. 5 is a diagram showing an example of a food freshness image. Fig. 6 is a flow diagram showing an example of an operation equipped with a food freshness detection device. Fig. 7 is a diagram showing an example of a configuration for realizing the functions of a control device of a refrigerator equipped with a food freshness detection device.

[0012] A refrigerator 1 will be taken as an example of a food storage facility equipped with a food freshness detection device according to this embodiment. The food freshness detection device may be provided in a food storage facility without a refrigeration or freezing function, instead of in a refrigerator 1. The food freshness detection device may also be configured to be used alone. As shown in FIG. 2, refrigerator 1 equipped with a food freshness detection device according to this embodiment includes a heat-insulating box 90. Heat-insulating box 90 has an outer box, an inner box, and a heat insulating material. The outer box is made of, for example, steel. The inner box is made of, for example, resin. The inner box is disposed inside the outer box. The heat insulating material is, for example, urethane foam or vacuum heat insulating material. The heat insulating material is filled in the space between the outer box and the inner box.

[0013] The front surface (front face) of the insulated box 90 is open. A storage space is formed inside the insulated box 90. The storage space is a space in which stored items such as food are stored. The storage space formed inside the insulated box 90 is divided by one or more partition members into a plurality of storage chambers for storing and preserving food.

[0014] In the configuration example described here, as shown in Fig. 1 and Fig. 2, refrigerator 1 is provided with a plurality of storage compartments, namely, refrigerator compartment 100, switchable compartment 200, ice making compartment 300, vegetable compartment 400, and freezer compartment 500. These storage compartments are arranged in four vertical tiers inside insulated box 90.

[0015] The refrigerator compartment 100 is disposed on the topmost level inside the insulated box 90. In the configuration example described here, as shown in Fig. 2, a plurality of shelves are provided inside the refrigerator compartment 100. The inside of the refrigerator compartment 100 is vertically divided into a plurality of spaces by these shelves.

[0016] The switchable compartment 200 is disposed on one of the left and right sides below the refrigerator compartment 100. The temperature zone within the switchable compartment 200 can be selectively switched to any one of a plurality of temperature zones. The plurality of temperature zones selectable as the temperature zone within the switchable compartment 200 include, for example, a freezing temperature zone, a refrigerated temperature zone, a chilled temperature zone, and a soft freezing temperature zone. The freezing temperature zone is, for example, a temperature zone of about -18°C. The refrigerated temperature zone is, for example, a temperature zone of about 3°C. The chilled temperature zone is, for example, a temperature zone of about 0°C. The soft freezing temperature zone is, for example, a temperature zone of about -7°C.

[0017] Ice making compartment 300 is disposed adjacent to the side of switchable compartment 200. Ice making compartment 300 is disposed in parallel with switchable compartment 200. In other words, ice making compartment 300 is disposed below refrigerator compartment 100 on the other side, either left or right.

[0018] The vegetable compartment 400 is disposed below the switchable compartment 200 and the ice-making compartment 300. For example, vegetables, fruits, large-capacity plastic bottles, etc. are stored in the vegetable compartment 400. The freezer compartment 500 is disposed below the vegetable compartment 400. The freezer compartment 500 is disposed at the bottom level of the insulated box 90. The freezer compartment 500 is used when storing items in a frozen state for a relatively long period of time.

[0019] A refrigerator compartment door 7 for opening and closing the refrigerator compartment 100 is provided at the front portion of the refrigerator compartment 100. The refrigerator compartment door 7 is, for example, a double-door revolving door. The double-door refrigerator compartment door 7 is made up of a right door 7a and a left door 7b. An operation panel 6 is provided on the outer surface of the refrigerator compartment door 7. In the configuration example shown in FIG. 1, the operation panel 6 is provided on the left door 7b.

[0020] In the configuration example described here, each of the switchable compartment 200, ice making compartment 300, vegetable compartment 400, and freezer compartment 500 is opened and closed by a drawer-type door. These drawer-type doors can slide in the depth direction of the refrigerator 1 along rails formed horizontally on the left and right inner wall surfaces of each storage compartment. A user of the refrigerator 1 in this embodiment can open and close the switchable compartment 200, ice making compartment 300, vegetable compartment 400, and freezer compartment 500 by sliding the drawer-type doors back and forth.

[0021] A switchable compartment storage case 201 capable of storing food and the like is stored inside the switchable compartment 200 and can be pulled out freely. A vegetable compartment storage case 401 capable of storing food and the like is stored inside the vegetable compartment 400 and can be pulled out freely. Similarly, a freezer compartment storage case 501 capable of storing food and the like is stored inside the freezer compartment 500 and can be pulled out freely.

[0022] The switchable compartment storage case 201 is supported by a frame provided on the door that opens and closes the switchable compartment 200. The switchable compartment storage case 201 is pulled out in conjunction with the door that opens and closes the switchable compartment 200. The vegetable compartment storage case 401 is supported by a frame provided on the door that opens and closes the vegetable compartment 400. The vegetable compartment storage case 401 is pulled out in conjunction with the door that opens and closes the vegetable compartment 400. Similarly, the freezer compartment storage case 501 is supported by a frame provided on the door that opens and closes the freezer compartment 500. The freezer compartment storage case 501 is pulled out in conjunction with the door that opens and closes the freezer compartment 500.

[0023] Also, inside the vegetable compartment 400, a vegetable compartment upper storage case 402 is provided. The vegetable compartment upper storage case 402 is placed on top of the vegetable compartment storage case 401. The vegetable compartment storage case 401 and the vegetable compartment upper storage case 402 are examples of cases in which food is placed. Similarly, inside the freezer compartment 500, a freezer compartment upper storage case 502 is provided. The freezer compartment upper storage case 502 is placed on top of the freezer compartment storage case 501.

[0024] The number of storage compartments provided in refrigerator 1, the arrangement of the storage compartments, the configuration of the doors for opening and closing the storage compartments, the number and configuration of the cases in the storage compartments, etc. are not limited to the examples described above. For example, the door for opening and closing refrigerator compartment 100 may be a sliding type. Also, the doors for opening and closing switchable compartment 200, ice-making compartment 300, vegetable compartment 400, and freezer compartment 500 may be rotating type. Two or more of each of switchable compartment storage case 201, vegetable compartment storage case 401, freezer storage case 501, upper vegetable compartment storage case 402, and upper freezer compartment storage case 502 may be provided.

[0025] The refrigerator 1 includes a compressor 2, a cooler 3, a blower fan 4, and an air duct 5 as a cooling mechanism for cooling each storage compartment. The compressor 2 and the cooler 3, together with a condenser and a throttling device (not shown), constitute a refrigeration cycle circuit. The compressor 2 compresses and discharges the refrigerant in the refrigeration cycle circuit. The condenser condenses the refrigerant discharged from the compressor 2. The throttling device expands the refrigerant flowing out from the condenser. The cooler 3 cools the air supplied to each storage compartment by the refrigerant expanded by the throttling device. The compressor 2 is disposed at the lower part on the rear side of the refrigerator 1, for example, as shown in FIG. 2.

[0026] Air passage 5 is for supplying air cooled by the refrigeration cycle circuit to each storage compartment. Air passage 5 is formed inside heat-insulating box 90. Air passage 5 is arranged, for example, on the rear side of refrigerator 1. Cooler 3 constituting the refrigeration cycle circuit is installed in air passage 5. Also installed in air passage 5 is blower fan 4 for sending air cooled by cooler 3 to each storage compartment.

[0027] When the blower fan 4 operates, the air cooled by the cooler 3, i.e., the cold air, is sent through the air passage 5 to the freezer compartment 500, the switchable compartment 200, the ice-making compartment 300, and the refrigerator compartment 100. This cools the interiors of the freezer compartment 500, the switchable compartment 200, the ice-making compartment 300, and the refrigerator compartment 100. In addition, the cold air returning from the refrigerator compartment 100 is introduced into the vegetable compartment 400 through an air passage (not shown). This cools the interior of the vegetable compartment 400. The air that has passed through the vegetable compartment 400 is returned to the air passage 5 in which the cooler 3 is installed. The air returned to the air passage 5 is cooled again by the cooler 3 and circulates inside the refrigerator 1.

[0028] In addition, dampers (not shown) are provided at locations midway from air passage 5 to each storage compartment. The amount of cool air supplied to each storage compartment is adjusted by changing the open / close state of each damper. The amount of cool air supplied to each storage compartment is also adjusted by controlling the operation of blower fan 4. In addition, the temperature of the air supplied to each storage compartment is adjusted by controlling the output of compressor 2.

[0029] A thermistor (not shown) is installed in each storage compartment. This thermistor detects the temperature inside each storage compartment. The damper, blower fan 4, and compressor 2 described above are controlled based on the detection result of this thermistor. The damper, blower fan 4, and compressor 2 are controlled so that the temperature inside each storage compartment becomes a preset set temperature. The refrigeration cycle circuit including the compressor 2 and cooler 3, the blower fan 4, the air duct 5, and the damper provided as described above are one example of a cooling means for cooling the inside of the storage compartment.

[0030] The refrigerator 1 according to this embodiment also includes a control device 600. The control device 600 is provided, for example, at an upper part on the rear side of the refrigerator 1 as shown in Fig. 2. The control device 600 has a function of controlling the compressor 2, which is an example of a cooling means, the blower fan 4, a damper, and the like.

[0031] Fig. 3 is an enlarged cross-sectional view of the periphery of vegetable compartment 400 included in refrigerator 1 according to embodiment 1. In Fig. 3 and the following description, the door that opens and closes vegetable compartment 400 is referred to as vegetable compartment door 9 with a reference symbol. Vegetable compartment storage case 401 is supported by the frame of vegetable compartment door 9. When vegetable compartment door 9 is pulled forward, vegetable compartment storage case 401 and upper vegetable compartment storage case 402 placed on vegetable compartment storage case 401 are pulled forward in conjunction with vegetable compartment door 9. When vegetable compartment door 9 is pulled out and only upper vegetable compartment storage case 402 is slid backward, only vegetable compartment storage case 401 is pulled forward together with vegetable compartment door 9.

[0032] As shown in FIG. 3, the refrigerator 1 is equipped with a door open / close detection switch 10 and a vegetable compartment thermistor 11. The door open / close detection switch 10 is for detecting the open / close state of the vegetable compartment door 9. The door open / close detection switch 10 is an example of a door open / close detection means for detecting the open / close state of the door of the storage compartment equipped in the refrigerator 1. The door open / close detection switch 10 is provided, for example, at a position facing the vegetable compartment door 9 on the edge of the opening on the front side of the vegetable compartment 400. The vegetable compartment thermistor 11 is provided on the back part of the vegetable compartment 400. The vegetable compartment thermistor 11 detects the temperature inside the vegetable compartment 400. The vegetable compartment thermistor 11 is an example of a temperature detection means for detecting the temperature of the storage compartment equipped in the refrigerator 1.

[0033] A light emitting unit 20 and an imaging unit 14 are provided on the ceiling of the vegetable compartment 400. The light emitting unit 20 is a light emitting unit that irradiates light onto food that is the subject of freshness detection. The imaging unit 14 is, for example, a camera that captures an image of the food.

[0034] The light-emitting unit 20 includes a first light source 21 and a second light source 22. Each of the first light source 21 and the second light source 22 is, for example, an LED. The light-emitting unit 20 includes a drive circuit (not shown) for driving each of the LEDs of the first light source 21 and the second light source 22 to emit light. The first light source 21 is a light source that emits a first irradiation light. The second light source 22 is a light source that emits a second irradiation light.

[0035] As described above, vegetables, fruits, etc. are stored in the vegetable compartment 400. When light of a specific wavelength is irradiated onto vegetables, fruits, etc., fluorescent substances contained in these foods, such as chlorophyll and polyphenols, absorb the light and emit fluorescence. Vegetables, fruits, etc. are examples of foods that absorb light of a specific wavelength and emit fluorescence. Thus, foods that are targets of freshness detection have the property of absorbing light of a specific wavelength and emitting fluorescence. The first irradiation light irradiated from the first light source 21 and the second irradiation light irradiated from the second light source 22 have different intensities of light of a specific wavelength that can excite the fluorescence of the target foods. That is, the first irradiation light has a first intensity of light of a specific wavelength. The second irradiation light has a second intensity of light of a specific wavelength. The second intensity is lower than the first intensity.

[0036] Specifically, for example, the first irradiation light is ultraviolet light in the UV-A region having a wavelength of 320 nm or more and 400 nm or less, or blue light having a wavelength of 400 nm or more and 500 nm or less. On the other hand, the second irradiation light is, for example, white light. That is, the second irradiation light is, for example, visible light including light having a wavelength in the range of 400 nm or more and 800 nm or less. Note that the second intensity may be 0. That is, the second irradiation light may not include light of the specific wavelength described above. On the other hand, the first intensity is not 0. That is, the first irradiation light includes light of the specific wavelength described above. The specific wavelength in the present disclosure does not have to be one wavelength, and may include multiple wavelengths. Also, the specific wavelength may include a continuous wavelength in a certain range.

[0037] The light-emitting unit 20 can individually change the on / off state of each of the first light source 21 and the second light source 22. Therefore, by turning on the first light source 21 and turning off the second light source 22, the light-emitting unit 20 can irradiate the above-mentioned first irradiation light. Also, by turning off the first light source 21 and turning on the second light source 22, the light-emitting unit 20 can irradiate the above-mentioned second irradiation light. In this way, the light-emitting unit 20, which is a light irradiating unit, can irradiate food by switching between the first irradiation light and the second irradiation light.

[0038] The bottom surface of upper vegetable compartment storage case 402 is covered with anti-reflection sheet 15. Anti-reflection sheet 15 prevents light emitted from light-emitting unit 20 from being reflected by upper vegetable compartment storage case 402. This prevents light reflected by upper vegetable compartment storage case 402 from affecting the captured image of imaging unit 14.

[0039] The reflection-suppressing sheet 15 is, for example, a matte black resin sheet, that is, a matte surface. Instead of the reflection-suppressing sheet 15, the surface of the upper vegetable compartment storage case 402 may be painted or treated to suppress reflection, or the upper vegetable compartment storage case 402 itself may be made of a material capable of suppressing reflection.

[0040] Here, if upper vegetable storage case 402 is made transparent, it is convenient because the food stored in vegetable storage case 401 below can be seen through upper vegetable storage case 402 even when upper vegetable storage case 402 is closed. When upper vegetable storage case 402 is transparent, it is preferable to use a transparent or semi-transparent anti-reflection sheet 15. Alternatively, it is preferable to apply a coating or treatment that can suppress reflection without impairing the transparency of the bottom surface of upper vegetable storage case 402 as much as possible.

[0041] In addition, it is preferable to form an uneven surface on the bottom of upper vegetable storage case 402 so that food in upper vegetable storage case 402 does not roll or move due to the impact when vegetable compartment door 9 is opened or closed. The size of the uneven surface may be fine or coarse. In other words, the bottom surface of upper vegetable storage case 402 may be roughened to increase friction between the case bottom and food. Alternatively, one or both of the recesses and protrusions on the case bottom may be used to prevent food in the case from rolling or moving.

[0042] Next, referring to FIG. 4, a configuration relating to the control of refrigerator 1, which is a food storage equipped with a food freshness detection device according to this embodiment, will be described. In the configuration example described here, operation panel 6 includes operation section 6a and display section 6b as shown in FIG. 4. Operation section 6a is an operation switch for setting the cold storage temperature of each storage compartment, etc. Display section 6b is a liquid crystal display section for displaying various information such as the temperature of each storage compartment. Operation panel 6 may include a touch panel that serves both operation section 6a and display section 6b. Operation section 6a outputs a signal according to the operation of operation section 6a by a user to control device 600. Furthermore, control device 600 outputs a display signal to display section 6b of operation panel 6 to control the operation of display section 6b.

[0043] As shown in FIG. 4, the control device 600 includes, as its functions, a cooling control unit 610, a communication unit 620, an irradiation control unit 631, an imaging control unit 632, an image storage unit 633, an image generation unit 634, a food detection unit 635, and a freshness determination unit 636. The control device 600 receives signals from thermistors that detect the temperature inside each storage compartment, including the crisper thermistor 11. The cooling control unit 610 of the control device 600 controls the compressor 2, the blower fan 4, and the like, based on the input signals, so that the temperature inside each storage compartment is maintained at a set temperature. The control device 600 including the cooling control unit 610 is an example of a control unit that controls the cooling means. Note that FIG. 4 illustrates only the crisper thermistor 11 among the thermistors in each storage compartment.

[0044] The irradiation control unit 631 controls the irradiation of light from the light emitting unit 20. More specifically, the irradiation control unit 631 controls the turning on and off of each of the first light source 21 and the second light source 22. The imaging control unit 632 controls the imaging operation of the imaging unit 14. The imaging unit 14 captures a first image and a second image under the control of the imaging control unit 632. As described below, the first image is an image of fluorescence emitted by food irradiated with the first irradiation light. Also, the second image is an image of reflected light of the second irradiation light by the food.

[0045] The user stores food items to be subjected to freshness detection in upper vegetable compartment storage case 402. Then, the user operates operation unit 6a of operation panel 6, for example, to perform settings for freshness detection. When the user inputs an instruction to detect the freshness of the food items, control device 600 causes the food freshness detection device provided in refrigerator 1 to start detecting the freshness of the food items. The instruction to detect the freshness of the food items can be input, for example, by the user pressing a freshness detection start button provided on operation unit 6a of operation panel 6.

[0046] When food freshness detection by the food freshness detection device is started, first, the irradiation control unit 631 turns on the first light source 21 and turns off the second light source 22, and causes the light-emitting unit 20 to irradiate the first irradiation light described above. Then, while the light-emitting unit 20 is irradiating the first irradiation light, the imaging control unit 632 causes the imaging unit 14 to capture an image of the food. The image of the food captured by the imaging unit 14 at this time is the first image described above. The image storage unit 633 stores the first image captured by the imaging unit 14.

[0047] As described above, food that is the subject of freshness detection emits fluorescence when excited by light of a specific wavelength contained in the first irradiation light irradiated from the light-emitting unit 20. The first image captured by the imaging control unit 632 in a state in which the first irradiation light is irradiated from the light-emitting unit 20 is an image capturing the fluorescence emitted by the food irradiated with the first irradiation light.

[0048] Next, the irradiation control unit 631 turns off the first light source 21 and turns on the second light source 22 to cause the light-emitting unit 20 to irradiate the second irradiation light described above. Then, while the light-emitting unit 20 is irradiating the second irradiation light, the imaging control unit 632 causes the imaging unit 14 to capture an image of the food. The image of the food captured by the imaging unit 14 at this time is the second image described above. The image storage unit 633 stores the second image captured by the imaging unit 14. While the light-emitting unit 20 is irradiating the second irradiation light, the second image captured by the imaging control unit 632 is an image of the second irradiation light reflected by the food.

[0049] In this manner, the light emitting unit 20, which is a light irradiating unit, irradiates the food with the first irradiation light and the second irradiation light, the specific wavelength of which has a lower intensity than the first irradiation light, by switching between the first irradiation light and the second irradiation light, the specific wavelength being capable of exciting the fluorescence of the food. The image capturing unit 14 then captures a first image in which the fluorescence emitted by the food irradiated with the first irradiation light is captured, and a second image in which the reflected light of the second irradiation light by the food is captured. The second irradiation light is light that can obtain an image of the food within the range of colors that humans normally see, and is preferably white light as described above. However, the second irradiation light does not have to be white light as long as the type of food captured can be identified when the user checks the image. In addition, the specific wavelength, i.e., the wavelength capable of exciting the fluorescence of the food, is generally a short wavelength. For this reason, it is preferable to make the peak wavelength of the first irradiation light shorter than the peak wavelength of the second irradiation light. Conversely, it is preferable to make the peak wavelength of the second irradiation light longer than the peak wavelength of the first irradiation light. In addition, when one or both of the first irradiation light and the second irradiation light have multiple peak wavelengths, it is preferable that the peak wavelength on the shortest wavelength side of the second irradiation light is longer than the peak wavelength on the longest wavelength side of the first irradiation light.

[0050] The image generating unit 634 generates one food freshness image from the first image and the second image stored in the image storage unit 633. The food freshness image is an image that represents the state of food included in the image, taking into consideration the freshness.

[0051] The fluorescence state of a food changes with the change in freshness of the food. The change in the fluorescence state with the change in freshness of the food differs depending on the type and state of the food. For example, if the food is a cucumber, a fresh one will fluoresce red, and as the freshness decreases, the red fluorescence will decrease. In another example, if the food is a tomato, a fresh one will barely fluoresce, and as the freshness decreases, it will fluoresce pale blue.

[0052] Therefore, when generating a food freshness image, it is necessary to specify the fluorescent color of the target food and the relationship between freshness and fluorescence intensity. The relationship between freshness and fluorescence intensity is whether the higher the freshness, the stronger the fluorescence, and the lower the freshness, the weaker the fluorescence, or whether the higher the freshness, the weaker the fluorescence, and the lower the freshness, the stronger the fluorescence. In the present disclosure, a change in fluorescence intensity is not limited to a case where the wavelength of the fluorescence does not change and the emission intensity at at least a part of the wavelength changes (increases or decreases). In the present disclosure, a change in fluorescence intensity also includes a case where the range of the wavelength of the fluorescence changes, more specifically, a case where the range of the wavelength of the fluorescence emitted at a certain intensity or higher changes (widens or narrows).

[0053] As described above, when the user operates the operation unit 6a of the operation panel 6 to perform settings for freshness detection, the user may input the type of food to be detected (e.g., cucumber, tomato, etc.). The control device 600 stores in advance the fluorescent color and the relationship between the freshness and the intensity of the fluorescent light for each type of food. The image generating unit 634 then identifies the fluorescent color and the relationship between the freshness and the intensity of the fluorescent light for the input type of food from the data stored in the control device 600.

[0054] Alternatively, as shown in Fig. 4, the control device 600 may include a food detection unit 635. The food detection unit 635 detects the type of food from the second image stored in the image storage unit 633. The type of food can be detected from the second image using a known method, such as estimating the type of food from the shape, color, etc. of the food, or using machine learning. Then, the image generation unit 634 identifies the fluorescent color of the detected type of food and the relationship between freshness and fluorescent intensity from the data stored in the control device 600.

[0055] Furthermore, the fluorescent color and the relationship between freshness and fluorescent intensity tend to be similar if the food color is the same. Therefore, instead of inputting the type of food, the user may input the color of the food (green, red, etc.). Alternatively, the food detection unit 635 may detect the color of the food from the second image stored in the image storage unit 633. In this case, the control device 600 stores in advance the fluorescent color and the relationship between freshness and fluorescent intensity for each food color. Then, the image generation unit 634 identifies the fluorescent color and the relationship between freshness and fluorescent intensity of the input or detected food color from the data stored in the control device 600.

[0056] The image generating unit 634 detects the intensity of the fluorescence from the color information of the first image using the identified fluorescent color. Next, the image generating unit 634 estimates the freshness of the food from the detected intensity of the fluorescence using the relationship between freshness and the intensity of the fluorescence. Then, the image generating unit 634 processes the second image according to the estimated freshness to generate a food freshness image. The image generating unit 634 changes, for example, one or both of the brightness and saturation of the second image according to the freshness to generate a food freshness image. When changing the brightness according to the freshness, the second image is processed so that the higher the freshness is, the brighter the image becomes, and the lower the freshness is, the darker the image becomes. When changing the saturation according to the freshness, the second image is processed so that the higher the freshness is, the higher the saturation is, and the lower the freshness is, the lower the saturation is.

[0057] In this way, the food freshness detection device is equipped with an information acquisition means for acquiring information about food. The information about food acquired by the information acquisition means is the type, color, shape, etc. of the food. In the above example, the information acquisition means corresponds to the operation unit 6a of the operation panel 6 and the control device 600, or the food detection unit 635. When the operation unit 6a of the operation panel 6 and the control device 600 are the information acquisition means, they acquire information about the food input by the user. When the food detection unit 635 is the information acquisition means, the information acquisition means acquires information about the food from the second image.

[0058] For example, when the first image is an RGB color image, if the food is a cucumber, the intensity of the fluorescence is determined from the magnitude of the R value indicating red. In this case, for example, the average value of the R values ​​of each pixel in the area of ​​the cucumber, which is the target food, in the first image is used to determine the intensity of the fluorescence. In this case, the area of ​​the target food in the first image may be determined using the first image or the second image. When the area of ​​the target food in the first image is determined using the second image, it is assumed that the angle of view of the first image is the same as the angle of view of the second image. Then, it is estimated that the weaker the intensity of the fluorescence, the higher the freshness, and the stronger the intensity of the fluorescence, the lower the freshness. In this case, the image generating unit 634 processes the second image based on the average value of the color information of the pixels in the area of ​​the food in the first image to generate a food freshness image.

[0059] For another example, if the first image is an RGB color image and the food is a tomato, the intensity of the fluorescence is determined from the magnitude of the B value, which indicates blue. In this case, the intensity of the fluorescence is determined, for example, by using the average value of the B values ​​of each pixel in the area of ​​the tomato, which is the target food, in the first image. It is then estimated that the stronger the intensity of the fluorescence, the higher the freshness, and vice versa.

[0060] The image generating unit 634 generates, for example, a gray mask image, which has a higher transparency as the freshness increases and a lower transparency as the freshness decreases. The image generating unit 634 then performs image processing to overlay a gray mask image with a transparency according to the freshness on top of the second image, thereby generating a food freshness image. In the food freshness image generated in this manner, when the freshness is high, the color of the food itself is displayed dark, whereas when the freshness is low, the color of the mask is displayed dark and the food is displayed grayish. FIG. 5 shows an example of a food freshness image in which the food is a cucumber.

[0061] The food freshness image generated by the image generation unit 634 is displayed, for example, on the display unit 6b of the operation panel 6. The refrigerator 1 is an example of a food storage facility equipped with a display unit 6b provided on the main body. In addition to the food freshness image, one or both of the first image and the second image may be displayed on the display unit 6b.

[0062] As shown in FIG. 4, the control device 600 may include a communication unit 620. The communication unit 620 transmits the food freshness image generated by the image generation unit 634 to an external information processing device (not shown). The external information processing device is, for example, a server device, a PC, a mobile information terminal, etc. Examples of the mobile information terminal include a smartphone, a tablet terminal, a smart watch, a smart TV, etc. The communication unit 620 may transmit the food freshness image to the external information processing device at predetermined regular time intervals. Furthermore, the communication unit 620 may display not only the food freshness image, but also one or both of the first image and the second image. One or both of the first image and the second image may be transmitted to the external information processing device.

[0063] The food freshness detection device configured as described above creates a freshness display image by processing the appearance image of the food that the user normally sees, taking into account the freshness detection result. This makes it possible to generate an image that visually shows changes in freshness that are difficult to distinguish from the actual appearance of the food. By displaying such an image, the user can easily determine the freshness state of the food, regardless of the type and size of the food in question. Therefore, it is possible to assist the user in determining the freshness state of the food, regardless of the type and size of the food in question, and food waste can be reduced.

[0064] Next, an operation example of the refrigerator 1 equipped with the food freshness detection device configured as above will be described with reference to FIG. 6. First, in step S101, the user operates the operation unit 6a of the operation panel 6 to input information about the target food by selecting the target food, etc. In the following step S102, when the user presses the freshness detection start button provided on the operation unit 6a of the operation panel 6, in step S103, the irradiation control unit 631 turns on the first light source 21 and turns off the second light source 22, and causes the light emitting unit 20 to irradiate the first irradiation light. Then, in step S104, the image capture control unit 632 causes the image capture unit 14 to capture a first image. The image storage unit 633 stores the first image captured by the image capture unit 14 (step S105).

[0065] Next, in step S106, the irradiation control unit 631 turns off the first light source 21, and further in step S107, turns on the second light source 22 to emit the second irradiation light from the light emitting unit 20. Then, in step S108, the imaging control unit 632 causes the imaging unit 14 to capture a second image. The image storage unit 633 stores the second image captured by the imaging unit 14 (step S109).

[0066] Next, in step S111, the image generating unit 634 checks the information about the target food input in step S101 and determines whether the target food is a cucumber. If the target food is a cucumber, the image generating unit 634 performs the process of step S112 and generates a mask image based on the R value of the first image. Then, in step 120, the image generating unit 634 superimposes the generated mask image on the second image to generate a food freshness image.

[0067] On the other hand, if the target food is not cucumber in step S111, the image generation unit 634 determines whether the target food is tomato in step S113. If the target food is tomato, the process of step S114 is performed, and the image generation unit 634 generates a mask image based on the B value of the first image. Then, in step S120, the image generation unit 634 superimposes the generated mask image on the second image to generate a food freshness image. Such target food determination process and mask generation process are performed the same number of times as the number of types of food set in advance.

[0068] The food freshness image generated in step S120 is displayed on the display unit 6b of the operation panel 6 in step S130. When the process of step S130 is completed, the series of processes ends. Note that the order of irradiating the first irradiation light and the second irradiation light and the order of capturing the first image and the second image are not limited to this example. That is, the second irradiation light may be irradiated first to capture the second image, and then the first irradiation light may be irradiated to capture the first image.

[0069] The food freshness detection may not be started by a user operation. In this case, for example, the food freshness detection may be started when the door of the storage compartment in which the target food is stored, the vegetable compartment door 9 in the example described above, is closed by the door open / close detection switch 10 that detects the opening and closing of the vegetable compartment door 9.

[0070] As shown in FIG. 4, the control device 600 may include a freshness determination unit 636. The freshness determination unit 636 determines the freshness of the food based on the color information of the first image. For example, a reference value for dividing the freshness into a plurality of stages such as high, medium, and low is set in advance, and the freshness determination unit 636 determines the stage of the freshness of the food estimated from the color information of the first image. Then, a message according to the freshness determined by the freshness determination unit 636, for example, "Eat it soon" if the freshness is "low", or "Ripe to eat now" if the freshness is "high" or "medium", may be displayed on the display unit 6b or the like together with the food freshness image. In this way, the freshness of the food is determined and a message according to the freshness is conveyed to the user, thereby encouraging the user to use the food appropriately.

[0071] When multiple foods are shown in the first image and the second image, for example, the food detection unit 635 described above may detect each of the multiple foods shown in the first image and the second image. In this case, the food detection unit 635 identifies the area of ​​each of the multiple foods in the first image and the second image. Then, the image generation unit 634 may estimate the freshness of each of the multiple foods individually from the color information in the area of ​​each food in the first image and generate a food freshness image. In this case, one food freshness image including the multiple foods may be generated, or a food freshness image cut out for each of the multiple foods may be generated. If one food freshness image including the multiple foods is generated, the multiple foods are shown in the same arrangement as in the storage state, so that the user can easily understand which food each is. On the other hand, if a food freshness image cut out for each of the multiple foods is generated, the user can easily understand the freshness of each food.

[0072] The transparency of the mask image used to generate the food freshness image may be uniform throughout, or may have a distribution that directly reflects the fluorescence distribution of the first image. By generating a food freshness image using a mask image with uniform transparency throughout, the user can easily grasp the average freshness of the food as a whole. On the other hand, if a food freshness image is generated using a transparency mask image that directly reflects the fluorescence distribution of the first image, the user can grasp partial deterioration of freshness of the food. In this case, the user can make decisions such as discarding only the parts with significantly reduced freshness and using only the remaining parts. Furthermore, the color of the mask image is not limited to gray.

[0073] As in the configuration example described above, the light-emitting unit 20 and the imaging unit 14 may be provided on the ceiling of the storage room in which the target food is stored. This allows the light to be evenly irradiated onto the food in the upper vegetable storage case 402, making it easier to capture the color and fluorescence of the food without bias. Also, an ultraviolet-cutting filter may be provided in front of the lens of the imaging unit 14. This cuts out light with wavelength components different from the fluorescence of the light-emitting unit reflected by the food, and a first image that more clearly captures the fluorescence related to freshness can be obtained.

[0074] FIG. 7 is a diagram showing an example of a configuration for realizing the functions of the control device 600 in this embodiment. The functions of the control device 600 are realized by, for example, a processing circuit. The processing circuit may include a processor 601 and a memory 602. The processing circuit may be dedicated hardware 603. A part of the processing circuit may be formed as the dedicated hardware 603, and the processing circuit may further include the processor 601 and the memory 602. In the example shown in the figure, a part of the processing circuit is formed as the dedicated hardware 603. Also, in the example shown in the figure, the processing circuit further includes the processor 601 and the memory 602.

[0075] The processing circuit, part of which is at least one dedicated hardware 603, may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. If the processing circuit comprises at least one processor 601 and at least one memory 602, the functionality of the control device 600 is realized by software, firmware, or a combination of software and firmware.

[0076] The software and firmware are written as programs and stored in memory 602. The processor 601 realizes the functions of each unit by reading and executing the programs stored in memory 602. The processor 601 is also called a CPU (Central Processing Unit), central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or DSP. The memory 602 corresponds to, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, and EEPROM, or a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD.

[0077] In this way, the processing circuit of the control device 600 can realize each function of the control device 600 by hardware, software, firmware, or a combination of these. When the processing circuit of the control device 600 includes at least the processor 601 and the memory 602, the processor 601 executes a program stored in the memory 602 in the control device 600, and the hardware and software of the control device 600 work together to realize the function of each unit included in the control device 600.

[0078] In the present disclosure, the embodiments and modifications may be combined in any manner without departing from the spirit of the present disclosure. Examples of various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A light irradiation unit that irradiates light onto a target food; An imaging unit that captures an image of the food, the light irradiating unit irradiates the food with a first irradiation light and a second irradiation light having a specific wavelength capable of exciting fluorescence of the food and having an intensity lower than that of the first irradiation light, by switching between the first irradiation light and the second irradiation light; The imaging unit captures a first image capturing fluorescence emitted from the food irradiated with the first irradiation light and a second image capturing light reflected by the food of the second irradiation light, The food freshness detection device further comprises an image generation unit that generates one food freshness image from the first image and the second image. (Appendix 2) 2. The food freshness detection device according to claim 1, wherein the second irradiation light has a peak wavelength longer than that of the first irradiation light. (Appendix 3) 2. The food freshness detection device according to claim 1, wherein the second irradiation light is white light. (Appendix 4) The food freshness detection device according to any one of claims 1 to 3, wherein the image generation unit processes the second image using color information of the first image to generate the food freshness image. (Appendix 5) The food freshness detection device described in Appendix 4, wherein the image generation unit processes the second image based on an average value of color information of pixels within the food area in the first image to generate the food freshness image. (Appendix 6) Further comprising an information acquisition means for acquiring information about the food, The food freshness detection device of claim 4 or 5, wherein the image generation unit determines color information of the first image to be used when processing the second image to generate the food freshness image based on the acquired information about the food. (Appendix 7) 7. The food freshness detection device according to claim 6, wherein the information acquisition means acquires information about the food from the second image. (Appendix 8) 8. The food freshness detection device according to any one of claims 1 to 7, further comprising a freshness determination unit that determines the freshness of the food based on color information of the first image. (Appendix 9) 9. The food freshness detection device according to any one of claims 1 to 8, further comprising a communication unit that transmits the food freshness image to an external information processing device. (Appendix 10) The food freshness detection device according to claim 9, wherein the communication unit transmits the food freshness image to the information processing device at predetermined regular time intervals. (Appendix 11) 11. The food freshness detection device according to any one of claims 1 to 10, further comprising a display unit for displaying the food freshness image. (Appendix 12) A food freshness detection device according to any one of claims 1 to 11, A food storage facility having a main body formed with a storage chamber in which the food is stored. (Appendix 13) A food freshness detection device according to claim 11; A main body having a storage chamber in which the food is stored; The main body is a food storage facility equipped with the display unit. [Explanation of symbols]

[0079] 1. Refrigerator 2. Compressor 3 Cooler 4 Blower fan 5 Wind path 6 Operation Panel 6a Control section 6b Display section 7 Refrigerator door 7a Right door 7b Left door 9 Vegetable compartment door 10 Door open / close detection switch 11 Vegetable compartment thermistor 14 Imaging unit 15 Anti-reflective sheet 20 Light emitting part 21 1st light source 22 Second light source 90 Insulated box 100 Refrigerator 200 Switch Room 201 Switching room storage case 300 Ice Room 400 Vegetable compartment 401 Vegetable storage case 402 Vegetable compartment upper storage case 500 Freezer 501 Freezer storage case 502 Freezer upper storage case 600 Control device 601 Processor 602 Memory 603 Dedicated Hardware 610 Cooling control unit 620 Communications Department 631 Irradiation control unit 632 Imaging control section 633 Image storage unit 634 Image Generation Unit 635 Food Detection Unit 636 Freshness Determination Department

Claims

1. A light irradiation unit that irradiates light onto a target food; An imaging unit that captures an image of the food, the light irradiating unit irradiates the food with a first irradiation light and a second irradiation light having a specific wavelength capable of exciting fluorescence of the food and having an intensity lower than that of the first irradiation light, by switching between the first irradiation light and the second irradiation light; The imaging unit captures a first image of fluorescence emitted from the food irradiated with the first irradiation light and a second image of light reflected by the food of the second irradiation light, The food freshness detection device further includes an image generation unit that generates one food freshness image from the first image and the second image.

2. The food freshness detection device according to claim 1 , wherein the second irradiation light has a peak wavelength longer than that of the first irradiation light.

3. The food freshness detection device according to claim 1 , wherein the second irradiation light is white light.

4. The food freshness detection device according to claim 1 , wherein the image generation unit processes the second image by using color information of the first image to generate the food freshness image.

5. The food freshness detection device according to claim 4 , wherein the image generation unit processes the second image based on an average value of color information of pixels within the food area in the first image to generate the food freshness image.

6. Further comprising an information acquisition means for acquiring information about the food, The food freshness detection device of claim 4, wherein the image generation unit determines color information of the first image to be used when processing the second image to generate the food freshness image based on the acquired information about the food.

7. The food freshness detection device according to claim 6 , wherein the information acquisition means acquires information about the food from the second image.

8. The food freshness detection device according to claim 1 , further comprising a freshness determination unit that determines the freshness of the food based on color information of the first image.

9. The food freshness detection device according to claim 1 , further comprising a communication unit that transmits the food freshness image to an external information processing device.

10. The food freshness detection device according to claim 9 , wherein the communication unit transmits the food freshness image to the information processing device at predetermined regular time intervals.

11. The food freshness detection device according to claim 1 , further comprising a display unit that displays the food freshness image.

12. The food freshness detection device according to any one of claims 1 to 3, A food storage facility having a main body formed with a storage chamber in which the food is stored.

13. The food freshness detection device according to claim 11, A main body having a storage chamber in which the food is stored; The main body is a food storage facility equipped with the display unit.

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