Quality assessment system

Abstract

This system provides a quality assessment system that can accurately acquire temperature information of the environment in which an object is placed, as well as the quality of the object itself. [Solution] The quality determination system according to the present invention comprises a quality indicator 100 and a determination device 200. The quality indicator 100 comprises a time-temperature indicator 110 and a unique ID unit 120 from which the unique ID information of the object is read. The unique ID information includes information that identifies the object and data obtained from the time-temperature indicator 110 of the object. The determination device 200 comprises an information acquisition unit 420 that acquires the color density of the time-temperature indicator 110 linked to the acquired unique ID information, a time-color density calculation unit 510 that calculates the amount of change in the color density of the time-temperature indicator 110 and the elapsed time from a starting date and time, and a temperature calculation unit 520 that uses the rate of change in color density, the amount of change in color density and the elapsed time to determine multiple combinations of temperature and time of the environment in which the object is thought to have been placed during the elapsed time.

Description

Technical Field

[0001] The present invention relates to a quality determination system for determining the quality of an object, and particularly to a quality determination system using a time-temperature indicator.

Background Art

[0002] A quality determination system is used to determine the quality of an object. Some quality determination systems utilize a time-temperature indicator that changes color according to the temperature of the exposed environment and the exposed time. Examples of conventional techniques for determining the quality of an object are described in Patent Documents 1 to 3.

[0003] The quality visualization device described in Patent Document 1 includes an ink information acquisition unit that acquires color information of a temperature-indicating ink from a target product with the temperature-indicating ink whose color changes according to the history of temperature and time, an integrated temperature calculation unit that calculates an integrated temperature from the acquired color information based on information on the correspondence between the color information of the temperature-indicating ink and the integrated temperature of the temperature-indicating ink, and a quality calculation unit that calculates an index of the quality of the target product from the calculated integrated temperature based on information on the correspondence between the integrated temperature and an index of the quality of the target product, and visualizes the quality of a target product whose quality changes according to the history of temperature and time.

[0004] The reading processing device described in Patent Document 2 includes an acquisition unit that acquires a captured image of a display device provided with two or more color display units, and an estimation unit that estimates the elapsed time since the display device began to be exposed to a predetermined environmental temperature based on the captured image acquired by the acquisition unit. The colors of each of the two or more color display units fade with the passage of time at different fading rates according to the ambient temperature when irradiated with light in a predetermined wavelength band.

[0005] The instant noodle ready-to-eat indicator sticker described in Patent Document 3 has a backing that is adjusted so that it changes color at just the right time considering heat conduction. It can be attached to the lid of instant noodles or pre-installed, making it easy to indicate the ready-to-eat time from when hot water is poured into the instant noodles until they are ready to eat.

[0006] The technologies described in Patent Documents 1 to 3 utilize a time-temperature indicator that changes color according to the temperature and duration of exposure to the environment. Based on the color information of the time-temperature indicator, the temperature information of the environment in which the object is placed is determined, and the quality of the object is judged. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2020-003834 [Patent Document 2] Japanese Patent Publication No. 2019-207179 [Patent Document 3] Japanese Patent Publication No. 2006-292704 [Overview of the project] [Problems that the invention aims to solve]

[0008] Some time-temperature indicators change color according to the Arrhenius equation, that is, they change color according to the Arrhenius-type temperature dependence. Because the color change rate of this time-temperature indicator is slower at lower temperatures and faster at higher temperatures, it changes to the same color density even for multiple different combinations of the ambient temperature in which the object is placed and the time it has been held at that temperature. In other words, even if the time-temperature indicator changes to the same color density, the ambient temperature and time in which the object has been placed may not be the same. For this reason, in conventional techniques that use time-temperature indicators that change color according to the Arrhenius-type temperature dependence to determine the quality of an object, it is difficult to accurately determine the temperature information of the environment in which the object is placed and to accurately determine the quality of the object when the ambient temperature in which the object is placed fluctuates.

[0009] The objective of the present invention is to provide a quality determination system that can acquire temperature information of the environment in which an object is placed and the quality of the object with high accuracy. [Means for solving the problem]

[0010] The quality determination system according to the present invention comprises a quality indicator that indicates the quality of an object and a determination device. The quality indicator comprises a time-temperature indicator whose color density changes according to changes in temperature and time, and a unique ID unit from which unique ID information of the object is read. The unique ID information includes information that identifies the object and data obtained by reading the time-temperature indicator for the object. The determination device comprises an information storage unit that stores the unique ID information and stores the color density of the time-temperature indicator linked to the unique ID information, a first storage unit that pre-stores correlation data between the color density and time shown by the time-temperature indicator for multiple temperatures, an image acquisition unit that acquires an image of the time-temperature indicator and reads the unique ID unit, an information acquisition unit that acquires the unique ID information from the information storage unit based on the unique ID unit read by the image acquisition unit, and acquires the color density of the time-temperature indicator linked to the acquired unique ID information from the information storage unit, and acquires the unique ID information from the information storage unit The system includes: a time color density calculation unit that determines the starting date and time and the color density of the time temperature indicator at the starting date and time from the acquired unique ID information, and calculates the amount of change in the color density of the time temperature indicator and the elapsed time from the starting date and time from the color density of the time temperature indicator and the date and time of acquisition of this color density obtained by the information acquisition unit; and a temperature calculation unit that uses the rate of change in color density obtained from the correlation data stored in the first storage unit and the amount of change in the color density of the time temperature indicator and the elapsed time calculated by the time color density calculation unit to determine a plurality of combinations of temperature and time of the environment in which the object is thought to have been placed during this elapsed time. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a quality determination system that can acquire temperature information of the environment in which an object is placed and the quality of the object with high accuracy. [Brief explanation of the drawing]

[0012] [Figure 1A]This figure shows an example of the structure of a quality indicator. [Figure 1B] This figure shows examples of other configurations for quality indicators. [Figure 2] This diagram shows an example of the configuration of a judgment device. [Figure 3] This figure shows an example of the correlation data between color density and time stored in the first memory unit. [Figure 4] This figure shows an example of quality-time correlation data stored in the second memory unit. [Figure 5A] This figure shows the relationship between elapsed time (number of days elapsed) and accumulated temperature for multiple combinations of temperature and time in the environment in which the object being judged is thought to have been placed. [Figure 5B] This diagram shows the relationship between elapsed time (number of days elapsed) and accumulated temperature for multiple combinations of temperature and time in the environment where the object being judged is thought to be placed, and it represents a limited range of accumulated temperature. [Figure 6] This diagram illustrates the relationship between elapsed time (number of days) and the ripeness of fruits and vegetables, showing the combinations of ambient temperature and time that result in the maximum accumulated temperature and the combinations that result in the minimum accumulated temperature. [Figure 7] This diagram shows the elapsed time (number of days) and the number of days it takes for produce to reach its peak ripeness, for both the combination of ambient temperature and time that results in the maximum accumulated temperature and the combination that results in the minimum accumulated temperature. [Modes for carrying out the invention]

[0013] In this invention, a time-temperature indicator is used in which the color density changes in accordance with changes in the temperature and time of the environment in which the object to be judged is placed. By using the rate of change in the color density of the time-temperature indicator, the calculated amount of change in color density, and the elapsed time, multiple different combinations of temperature and time in the environment in which the object is thought to be placed can be determined, thereby enabling high-precision acquisition of the temperature of the environment in which the object is placed and the quality of the object, even when the temperature of the environment in which the object is placed fluctuates.

[0014] Hereinafter, a quality determination system according to an embodiment of the present invention will be described with reference to the drawings. In the following examples, as an example, an object for which quality is determined is a fresh fruit and vegetable, and an example in which the quality is the ripeness of the fresh fruit and vegetable will be described. However, the present invention is not limited to foods such as fresh fruits and vegetables, and objects whose quality changes according to Arrhenius-type temperature dependence can be targeted. Objects whose quality changes according to Arrhenius-type temperature dependence include, in addition to foods such as fresh fruits and vegetables, for example, pharmaceuticals and chemical products.

[0015] The quality of the object can be arbitrarily determined according to the object. For example, the quality of fresh fruits and vegetables is the ripeness and freshness of fresh fruits and vegetables, the quality of pharmaceuticals is the efficacy of pharmaceuticals, and the quality of chemical products is the strength of chemical products.

[0016] In the following examples, an object for which quality is determined is referred to as a determination object.

[0017] In the drawings referred to in this specification, the same or corresponding components are denoted by the same reference numerals, and repeated descriptions of these components may be omitted.

Example

[0018] The quality determination system according to this embodiment includes a quality indicator and a determination device. An example of the quality indicator 100 will be described using FIGS. 1A and 1B, and an example of the determination device 200 will be described using FIG. 2.

[0019] <Quality Indicator> FIG. 1A is a diagram showing an example of the configuration of the quality indicator 100.

[0020] The quality indicator 100 may be installed directly on the object to be judged, or it may be installed adjacent to the object to be judged. For example, the quality indicator 100 may be installed directly on the object to be judged by being attached to it or printed on it. The quality indicator 100 may take the form of a label or a card. In this embodiment, as an example, an example in which the quality indicator 100 is attached to the object to be judged will be described.

[0021] The quality indicator 100 includes a time-temperature indicator 110 whose color density changes in response to changes in temperature and time, and a unique ID unit 120, and represents the quality of the object to be judged. The time-temperature indicator 110 and the unique ID unit 120 are placed on a base material which is a non-printable area 130.

[0022] The time-temperature indicator 110 is coated with thermochromic ink and changes color according to changes in temperature and time. The temperature of the environment in which the time-temperature indicator 110 is placed, i.e., the temperature of the environment in which the object to be judged is placed, can be calculated from the color change of the thermochromic ink. The time-temperature indicator 110 can have any shape.

[0023] The discoloration state of the time-temperature indicator 110 is expressed using color density, which represents the degree of color intensity as a percentage. In this example, the color density of the time-temperature indicator 110 is set to 0% at the time of harvesting of the produce being judged. The upper limit of the color density is 100%.

[0024] The unique ID section 120 is the part from which the unique ID information of the object to be judged, to which the time-temperature indicator 110 is attached, is read, and is composed of, for example, a code or string of characters. The judgment device 200 can obtain the unique ID information of the object to be judged by reading the unique ID section 120.

[0025] The unique ID information is information about each individual object to be judged, and includes information that identifies the object to be judged and data obtained in the past about the object to be judged. The information that identifies the object to be judged is, for example, the number assigned to the object to which the time-temperature indicator 110 is attached, the name of the object to be judged, variety, species, manufacturing information, and production information. The data obtained in the past about the object to be judged is, for example, data obtained when the time-temperature indicator 110 was read in the past, and includes the date and time and location where this data was obtained, and the color density of the time-temperature indicator 110 that was read.

[0026] As described later, the unique ID information is stored in the information storage unit 310 of the memory device 300 provided by the determination device 200. The unique ID information stored in the information storage unit 310 is updated as needed.

[0027] Figure 1A shows an example where the unique ID part 120 is a QR code (registered trademark). The QR code is standardized by ISO / IEC 18004, among others. Other codes besides QR codes, such as PDF417, DataMatrix, Maxicode, and AztecCode, can also be used for the unique ID part 120.

[0028] Figure 1B shows an example of another configuration of the quality indicator 100. The quality indicator 100 may comprise multiple time-temperature indicators 110 having different color change characteristics from one another. Figure 1B shows an example in which the quality indicator 100 comprises two time-temperature indicators 110a and 110b having different color change characteristics from one another.

[0029] In this embodiment, the time-temperature indicator 110 changes color according to the Arrhenius equation shown in equation (1) below, specifically, the time-temperature indicator 110 changes color according to the Arrhenius-type temperature dependence. In equation (1), A is the frequency factor, Ea is the activation energy, R is the gas constant, and T is the absolute temperature.

[0030]

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[0031] The time-temperature indicator 110 may be coated with any thermochromic ink, as long as it changes color according to the Arrhenius formula in response to changes in ambient temperature. It is preferable from a manufacturing process standpoint that the thermochromic ink can be printed onto the substrate, which is the non-printable area 130.

[0032] Assume that a time-temperature indicator 110, which changes color according to the Arrhenius equation, with a frequency factor A of exp(35) and Ea / R of 10000, is stored for a total of 10 days: 4 days at 5°C, 3 days at 10°C, and 3 days at 40°C. The color change rates k5, k10, and k40 of the time-temperature indicator 110 at 5°C, 10°C, and 40°C are expressed using equation (1) as shown in equations (2) to (4) below. These color change rates represent the amount of color change per day.

[0033]

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[0034]

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[0035]

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[0036] According to the calculation method shown in equation (5) below, the change in color density ΔV of the time temperature indicator 110 over 10 days is 68.1%.

[0037]

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[0038] <Judgment device> Figure 2 shows an example of the configuration of the determination device 200. The determination device 200 can be configured as a computer such as a smartphone or tablet terminal, and comprises a storage device 300, a reading device 400, and a processing device 500. The determination device 200 can connect to the internet and can connect to a server 600 via the internet, for example.

[0039] The storage device 300 is a device for storing various types of data and comprises an information storage unit 310, a first storage unit 320, and a second storage unit 330.

[0040] As already mentioned, the information storage unit 310 stores unique ID information. This unique ID information is input into the information storage unit 310 as needed, for example, through user operations. The information storage unit 310 also stores the image of the time-temperature indicator 110 acquired by the reading device 400 and the color density of the time-temperature indicator 110 calculated by the time-color density calculation unit 510 of the processing device 500, linking them to the unique ID information.

[0041] The first memory unit 320 pre-stores correlation data between color intensity and time, as indicated by the time-temperature indicator 110, for multiple temperatures. This correlation data can be obtained through experiments conducted in advance.

[0042] Figure 3 shows an example of the correlation data 321 between color density and time stored in the first memory unit 320. In Figure 3, the horizontal axis represents time, and the vertical axis represents the color density of the time-temperature indicator 110. As an example, Figure 3 shows the correlation data 321 for five temperatures from 10°C to 50°C using calibration curves 322 to 326.

[0043] The second memory unit 330 pre-stores correlation data between the quality of the object to be judged and time for multiple temperatures. This correlation data can be obtained through experiments conducted in advance.

[0044] Figure 4 shows an example of quality-time correlation data 331 stored in the second memory unit 330. In Figure 4, the horizontal axis represents time, and the vertical axis represents ripeness, which is the quality of fruits and vegetables. As an example, Figure 4 shows correlation data 331 for five temperatures from 10°C to 50°C using calibration curves 332 to 336.

[0045] The storage device 300 does not necessarily have to be provided in the determination device 200. For example, if the determination device 200 is connected to a server 600 (Figure 2) via a network, the storage device 300 may be provided in this server.

[0046] Returning to the explanation of the determination device 200 shown in Figure 2.

[0047] The reading device 400 includes an image acquisition unit 410 and an information acquisition unit 420.

[0048] The image acquisition unit 410 is composed of an imaging device capable of acquiring and storing optical information, and acquires images of the time-temperature indicator 110 of the quality indicator 100 and reads the unique ID unit 120. The imaging device is, for example, a camera and an optical sensor. The image acquisition unit 410 can also acquire images related to the object to be judged, such as the appearance of the object to be judged, labels attached to the object to be judged, and the surrounding environment of the object to be judged.

[0049] The image of the time temperature indicator 110 acquired by the image acquisition unit 410 is stored in the information storage unit 310 of the storage device 300, linked to unique ID information.

[0050] The information acquisition unit 420 acquires unique ID information from the information storage unit 310 based on the unique ID unit 120 read by the image acquisition unit 410, and also acquires color density information of the time temperature indicator 110 associated with the acquired unique ID information from the information storage unit 310.

[0051] For example, the information acquisition unit 420 obtains the reading date and time of the unique ID unit 120 and the color density of the time-temperature indicator 110 from the unique ID information acquired based on the unique ID unit 120. In this embodiment, for example, if the reading date and time of the unique ID unit 120 is the harvest date and time of the produce that is the object to be judged, the color density of the time-temperature indicator 110 is 0%.

[0052] Furthermore, the information acquisition unit 420 acquires information related to the storage of the object to be judged as composite information of the object to be judged when the image acquisition unit 410 acquires an image of the time temperature indicator 110. This composite information includes information such as the location and time the object to be judged is placed, the temperature and humidity of the environment in which the object to be judged is placed, the weather at the location where the object to be judged is placed, the transportation route if the object to be judged is transported, and production information and inventory information of the object to be judged. The information acquisition unit 420 acquires this composite information from, for example, information provided on the internet or information input by the user into the quality judgment system according to this embodiment.

[0053] The processing unit 500 includes a time-based color density calculation unit 510, a temperature calculation unit 520, an information input unit 530, a quality calculation unit 540, a quality prediction unit 550, and a result display unit 560.

[0054] The time-time color density calculation unit 510 calculates the amount of change in the color density of the time-time temperature indicator 110 and the elapsed time from a starting date and time, based on the color density of the time-time temperature indicator 110 and the date and time of acquisition of this color density, which are acquired by the information acquisition unit 420. Furthermore, the time-time color density calculation unit 510 acquires unique ID information from the information storage unit 310. The starting date and time can be determined from the unique ID information acquired from the information storage unit 310. For example, the harvest date and time of the produce that is the object to be judged can be used as the starting date and time. The color density of the time-time temperature indicator 110 at the starting date and time can also be determined from the unique ID information acquired from the information storage unit 310. Note that the date and time of acquisition of the color density of the time-time temperature indicator 110 is the same as the date and time of reading from the unique ID unit 120.

[0055] If the starting date and time is the harvest date and time of the produce being judged, the color density of the time-temperature indicator 110 at the starting date and time is 0%.

[0056] In this example, the object to be judged and the time-temperature indicator 110 are stored for a total of 10 days: 4 days at 5°C, 3 days at 10°C, and 3 days at 40°C.

[0057] In this embodiment, the information acquisition unit 420 acquires that the color density of the time temperature indicator 110, which has been stored for a total of 10 days (4 days at 5°C, 3 days at 10°C, and 3 days at 40°C), is 68.1% (see, for example, equation (5)).

[0058] The time-based color density calculation unit 510 then calculates that the change in the color density of the time-based temperature indicator 110 from the starting date and time is 68.1%. The time-based color density calculation unit 510 also calculates that the elapsed time (number of days) from the starting date and time is 10 days.

[0059] The temperature calculation unit 520 determines multiple different combinations of temperature and time in the environment in which the object to be judged is thought to have been (or could have been) placed during the elapsed time calculated by the time color density calculation unit 510.

[0060] First, the temperature calculation unit 520 determines the rate of change in color density at multiple temperatures (color change rate k) from the color density-time correlation data 321 (Figure 3) stored in the first storage unit 320. Alternatively, the temperature calculation unit 520 may determine the color change rate k from the Arrhenius equation shown in equation (1).

[0061] Next, the temperature calculation unit 520 uses the calculated discoloration rate k and the change in color density of the time-temperature indicator 110 and the elapsed time calculated by the time-color density calculation unit 510 to create a system of simultaneous equations. Then, the temperature calculation unit 520 obtains a combination of temperature and time in the environment in which the object to be judged is thought to be placed by finding the solution to the system of simultaneous equations.

[0062] The temperature calculation unit 520 can determine multiple combinations of temperature and time in the environment in which the object to be judged is thought to be located by creating a system of simultaneous equations for each of the multiple temperature patterns of the environment in which the object to be judged is thought to be located, and by finding the solution to each of the created systems of simultaneous equations. A temperature pattern is a group consisting of multiple different temperatures. The multiple temperatures included in each of the multiple temperature patterns can be arbitrarily set as long as they are the temperatures of the environment in which the object to be judged is thought to be (or could have been) located.

[0063] In this way, the temperature calculation unit 520 can derive multiple combinations of temperature and time of the environment in which the object to be judged is thought to have been (or could have been) placed during the elapsed time.

[0064] Furthermore, the temperature calculation unit 520 acquires information about the temperature of the environment in which the object to be judged is stored, such as the maximum temperature, minimum temperature, cumulative temperature, and average temperature, based on the composite information of the object to be judged acquired by the information acquisition unit 420.

[0065] Furthermore, the temperature calculation unit 520 calculates the cumulative temperature and average temperature of the object during storage for each of several combinations of temperature and time in the environment in which the object was thought to have been (or could have been) placed during the elapsed time.

[0066] Here, we consider the case where the object to be judged is stored for 10 days and the temperature of the environment in which the object is placed remains constant. The discoloration rate k (amount of discoloration per day) of the time-temperature indicator 110 is 6.81%, since the change in color density of the time-temperature indicator 110 over 10 days is 68.1%. In this case, as shown in equation (6) using equation (1), the object to be judged is calculated to have been stored at an ambient temperature of 29.1°C.

[0067]

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[0068] In this case, the cumulative temperature over the 10 days of storage is calculated to be 291°C, and the average temperature is calculated to be 29.1°C. These cumulative and average temperatures are the same values ​​as those calculated using conventional techniques that treat the object being judged as having been stored at a constant temperature.

[0069] Next, let's consider the case where the temperature of the environment in which the object being judged is placed fluctuates. If the object being judged is stored for a total of 10 days, consisting of 4 days at 5°C, 3 days at 10°C, and 3 days at 40°C, the cumulative temperature will be 170°C and the average temperature will be 17°C.

[0070] From the above, it can be seen that when the temperature of the environment in which the object being judged is placed fluctuates, the cumulative temperature and average temperature of the environment in which the object being judged is placed will differ significantly from the values ​​calculated by conventional technology.

[0071] In the quality determination system according to this embodiment, even when the temperature of the environment in which the object to be determined is placed fluctuates, information about the temperature of the environment in which the object to be determined is placed and information about the quality of the object to be determined can be obtained with high accuracy.

[0072] In this embodiment, when the temperature of the environment in which the object to be judged is placed fluctuates, the process by which the temperature calculation unit 520 derives multiple combinations of temperature and time in the environment in which the object to be judged is thought to have been (or could have been) placed during the elapsed time will be described.

[0073] First, consider the case where the temperature pattern of the environment in which the object to be judged is thought to be placed consists of two temperature zones: 45°C and 5°C. The temperature calculation unit 520 calculates the holding time at 45°C and 5°C respectively using the following method. The discoloration rates k45 and k5 of the time temperature indicator 110 at 45°C and 5°C are obtained from the correlation data between color density and time 321 (Figure 3). Alternatively, the discoloration rates k45 and k5 can also be obtained using equation (1) as follows.

[0074]

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[0075]

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[0076] If the object to be judged is kept at 45°C for day A and at 5°C for day B, the elapsed time is 10 days, and the change in color density of the time-temperature indicator 110 during this elapsed time is 68.1%, so the following system of equations (9) and (10) holds true.

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[0078]

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[0079] Solving this system of equations yields the solutions A = 1.83 and B = 8.17 days. In other words, the object being judged was stored at 45°C for 1.83 days and at 5°C for 8.17 days.

[0080] Therefore, if the temperature patterns of the environment in which the object to be judged is thought to have been placed are in two temperature ranges, 45°C and 5°C, the combinations of temperature and time in the environment in which the object to be judged is thought to have been placed can be calculated as 1.83 days at 45°C and 8.17 days at 5°C.

[0081] In this case, the cumulative temperature S of the object to be judged during storage is calculated to be 123°C, and the average temperature Tavg is 12.3°C, according to the following formula (11).

[0082]

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[0083] Using a similar calculation, if the temperature pattern of the environment in which the object under evaluation was likely placed consists of two temperature zones, 40°C and 10°C, then the object under evaluation was stored at 40°C for 2.93 days and at 10°C for 7.07 days, resulting in a cumulative temperature S of 188 and an average temperature Tavg of 18.8°C. Therefore, the combination of temperature and time in the environment in which the object under evaluation was likely placed is 40°C for 2.93 days and 10°C for 7.07 days.

[0084] If the temperature pattern of the environment in which the object to be judged was likely placed consists of two temperature zones, 35°C and 15°C, then the object to be judged was stored at 35°C for 4.78 days and at 15°C for 5.22 days. The cumulative temperature S during storage is calculated to be 246, and the average temperature Tavg is calculated to be 24.6°C. Therefore, the combination of temperature and time in the environment in which the object to be judged was likely placed is 35°C for 4.78 days and 15°C for 5.22 days.

[0085] If the temperature pattern of the environment in which the object to be judged was likely placed consists of two temperature zones, 30°C and 20°C, then the object to be judged was stored at 30°C for 8.67 days and at 20°C for 1.33 days. The cumulative temperature S during storage is calculated to be 287, and the average temperature Tavg is calculated to be 28.7°C. Therefore, the combination of temperature and time in the environment in which the object to be judged was likely placed is 30°C for 8.67 days and 20°C for 1.33 days.

[0086] In this embodiment, multiple combinations of temperature and time in the environment in which the object to be judged is thought to be placed can be derived in this manner.

[0087] Figure 5A shows the relationship between elapsed time (number of days) t and accumulated temperature S for several combinations of temperature and time in the environment in which the object to be judged is thought to be placed.

[0088] The temperature calculation unit 520 determines the maximum and minimum temperatures of the environment during storage of the object to be judged, based on the composite information of the object to be judged acquired by the information acquisition unit 420. Here, we assume that the maximum temperature is 45°C and the minimum temperature is 5°C.

[0089] The temperature calculation unit 520 determines the cumulative temperature range 522 for the temperature of the environment in which the object to be judged is thought to be (or could potentially be) placed. The cumulative temperature range 522 is defined by the upper and lower limits of the cumulative temperature. Hereinafter, the upper and lower limits will be collectively referred to as extreme values. All cumulative temperatures S calculated by the temperature calculation unit 520 are within the cumulative temperature range 522.

[0090] One extreme value of the cumulative temperature range 522 is the cumulative temperature S when the object to be judged is stored at a constant temperature. Figure 5A shows an example where the upper limit of the cumulative temperature range 522 is the cumulative temperature (291) when the object to be judged is stored at a constant temperature (29.1℃).

[0091] The other extreme value of the cumulative temperature range 522 is the minimum or maximum value of the cumulative temperature S when the temperature pattern of the environment in which the object being judged is thought to be placed falls between the highest temperature (45°C) and the lowest temperature (5°C) of the environment obtained from the composite information of the object being judged. If one extreme value of the cumulative temperature range 522 is the upper limit, the other extreme value is the minimum value of the cumulative temperature S, and if one extreme value is the lower limit, the other extreme value is the maximum value of the cumulative temperature S. Figure 5A shows an example where the lower limit of the cumulative temperature range 522 is the cumulative temperature (123) when the temperature pattern has two temperature bands, 45°C and 5°C.

[0092] As mentioned above, if the object being judged is stored for a total of 10 days—4 days at 5°C, 3 days at 10°C, and 3 days at 40°C—the cumulative temperature is 170°C.

[0093] Figure 5A plots the point where the cumulative temperature over 10 days is 170 (the point representing the actual cumulative temperature), with the true value of the cumulative temperature being 523. As shown in Figure 5A, the true value of the cumulative temperature, 523, falls within the cumulative temperature range of 522.

[0094] In this embodiment, it is possible to determine the range 522 of the accumulated temperature that includes the true value 523 of the accumulated temperature, and even when the temperature of the environment in which the object to be judged is placed fluctuates, information about the temperature of the environment in which the object to be judged is placed can be obtained with high accuracy.

[0095] Returning to the explanation of the processing apparatus 500 shown in Figure 2.

[0096] The information input unit 530 is a component that allows the user to input information related to the storage of the object to be judged as known information and to correct the composite information of the object to be judged. The information related to the storage of the object to be judged is information obtained when the user actually stores the object to be judged, and for example, the actual temperature of the environment in which the object to be judged is placed and the actual time that the object to be judged is held at this ambient temperature.

[0097] The temperature calculation unit 520 corrects the composite information of the object to be judged using known information, and can narrow down and limit the multiple combinations of temperature and time of the environment in which the object to be judged is thought to be located, which are derived by the temperature calculation unit 520. By correcting the composite information of the object to be judged, the temperature calculation unit 520 can limit the range of the accumulated temperature 522 (Figure 5A), and even when the temperature of the environment in which the object to be judged is located fluctuates, it is possible to obtain information about the temperature of the environment in which the object to be judged is located with even greater accuracy.

[0098] For example, suppose a user stores fresh produce in a refrigerator at 5°C for 4 days. The user inputs the fact that the item to be judged was stored at 5°C for 4 days as known information into the information input unit 530.

[0099] When the color density of the time-temperature indicator 110 changes after being stored at 5°C for 4 days, the change in color density ΔV over the remaining 6 days can be calculated to be 66.6%, as shown in equation (12) below.

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[0101] If the ambient temperature remained constant for the remaining six days, the discoloration rate k of the time-temperature indicator 110 is 11.1%. From this, the temperature calculation unit 520 calculates, using equation (13) with equation (1), that the ambient temperature was 33.7°C for the remaining six days.

[0102]

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[0103] In this case, the cumulative temperature over 10 days is calculated to be 222°C, and the average temperature is calculated to be 22.1°C.

[0104] If the ambient temperature for the remaining 6 days was in two temperature ranges, 45°C and 5°C, then the following system of equations (14) and (15) holds true, where C is the time the object being judged was kept at 45°C and D is the time it was kept at 5°C.

[0105]

number

[0106]

number

[0107] Solving this system of equations yields the solutions C = 1.83 and D = 4.17 days. This means that the object under evaluation was stored at 45°C for 1.83 days and at 5°C for 4.17 days during the remaining 6 days. Therefore, the object under evaluation was stored at 45°C for 1.83 days and at 5°C for 8.17 days during the 10-day period.

[0108] In this case, the cumulative temperature over 10 days is calculated to be 123°C, and the average temperature is calculated to be 12.3°C.

[0109] Figure 5B shows the relationship between elapsed time (number of days) t and accumulated temperature S for multiple combinations of temperature and time in the environment in which the object being judged is thought to be placed, and illustrates a limited range of accumulated temperature 525.

[0110] In this embodiment, the cumulative temperature range 522 is reduced by the known information entered by the user in the information input unit 530, resulting in a limited cumulative temperature range 525. The upper limit of the limited cumulative temperature range 525 is the cumulative temperature (222) over 10 days when the object to be judged is stored at 5°C for 4 days and at a constant temperature for the remaining 6 days. The lower limit (the other extreme) of the limited cumulative temperature range 525 remains unchanged.

[0111] In this way, by having the user input known information into the information input unit 530 and correcting the combined information, the range of the accumulated temperature 522 can be limited, and the limited range of the accumulated temperature 525 can be calculated. This limited range of the accumulated temperature 525 includes the true value of the accumulated temperature 523 (the point where the accumulated temperature over 10 days is 170).

[0112] In this embodiment, by correcting the composite information of the object to be judged with known information input by the information input unit 530, information about the temperature of the environment in which the object to be judged is placed can be obtained with even higher accuracy, even when the temperature of the environment in which the object to be judged is placed fluctuates.

[0113] Returning to the explanation of the processing apparatus 500 shown in Figure 2.

[0114] The quality calculation unit 540 calculates an estimated value of the quality (ripeness) of the object to be judged (fruit and vegetables) from multiple combinations of ambient temperature and time acquired by the temperature calculation unit 520 and the rate of change of quality (ripeness) of the object to be judged k'. The rate of change of quality k' of the object to be judged can be obtained from the correlation data between quality and time 331 (Figure 4) stored in the second storage unit 330, or from the Arrhenius equation shown in equation (1). Below, as an example, an example of obtaining the rate of change of quality k' of the object to be judged from the Arrhenius equation will be explained.

[0115] Assume that the ripeness of the produce being evaluated changes according to the Arrhenius equation, where frequency factor A is exp(25) and Ea / R is 7500. The rate of change of ripeness k' of the produce is defined as the daily percentage change in ripeness, assuming that the ripeness at the time of consumption is 20%.

[0116] Assume that the produce is stored for a total of 10 days: 4 days at 5°C, 3 days at 10°C, and 3 days at 40°C. Let k'5 be the rate of change in the ripeness of the produce at 5°C, k'10 be the rate of change at 10°C, and k'40 be the rate of change at 40°C. In this case, the ripeness X of the produce can be calculated as 9.81% from the following equation (16) using the rates of change in ripeness X k'5, k'10, and k'40, which were calculated from the Arrhenius equation.

[0117]

number

[0118] In conventional technology, as explained earlier, assuming that fruits and vegetables are stored at a constant temperature, the fruits and vegetables are calculated to have been stored for 10 days at an ambient temperature of 29.1°C. In this case, the ripeness X of the fruits and vegetables can be calculated as 12.1% using the following equation (17) with the rate of change of ripeness X k'29.1.

[0119]

number

[0120] Therefore, the ripeness of fruits and vegetables calculated using conventional technology is 12.1%, which is a significant discrepancy from the actual value (9.81%, which is obtained when the temperature of the environment in which the fruits and vegetables are placed fluctuates).

[0121] In the example shown in Figure 5B, among several combinations of ambient temperature and time, the cumulative temperature S is maximized (S=222) when the produce is stored for a total of 10 days, 4 days at 5°C and 6 days at 33.7°C. In this case, the temperature calculation unit 520 calculates the ripeness of the produce as 11.0% using the following equation (18), with the rate of change k'5 at 5°C and the rate of change k'33.7 at 33.7°C.

[0122]

number

[0123] Furthermore, among several combinations of ambient temperature and time, the cumulative temperature S is minimized (S=123) when the produce is stored for a total of 10 days, consisting of 1.83 days at 45°C and 8.17 days at 5°C. In this case, the temperature calculation unit 520 calculates the ripeness of the produce as 8.77% using the following equation (19), with the rate of change k'5 at 5°C and the rate of change k'45 at 45°C.

[0124]

number

[0125] Figure 6 shows the relationship between elapsed time (number of days) t and the ripeness X of fruits and vegetables, for the combinations of ambient temperature and time that result in the maximum accumulated temperature S, and for the combinations of ambient temperature and time that result in the minimum accumulated temperature S.

[0126] Figure 6 shows the ripeness range 542 for the fruit and vegetable being evaluated after being stored for 10 days. The upper limit of this ripeness range 542 is the ripeness (11.0%) for the combination of ambient temperature and time in which the accumulated temperature S is maximized. The lower limit of this ripeness range 542 is the ripeness (8.77%) for the combination of ambient temperature and time in which the accumulated temperature S is minimized.

[0127] Figure 6 plots the point where the ripeness level after 10 days of storage is 9.81% (representing the actual ripeness), with the true ripeness value being 543. As shown in Figure 6, the true ripeness value of 543 falls within the ripeness range of 542.

[0128] In this embodiment, it is possible to determine the ripeness range 542 that includes the true ripeness value 543, and even when the temperature of the environment in which the produce being judged is placed fluctuates, information about the ripeness (i.e., quality) of the produce being judged can be obtained with high accuracy.

[0129] If the quality calculation unit 540 determines that the calculated quality (ripeness) of the object to be judged does not fall within a predetermined range, it can display a warning about the quality of the object on the result display unit 560. For example, if the quality calculation unit 540 determines that the calculated ripeness of the object to be judged does not fall within the range of ripeness for eating, it can display a warning on the result display unit 560 that the object has not reached its peak eating stage (or has passed its peak eating stage).

[0130] The quality prediction unit 550 predicts the future quality (maturity) of the object to be judged based on the quality of the object to be judged acquired by the quality calculation unit 540 and the rate of change k' of the quality (maturity) of the object to be judged. The rate of change k' of the quality of the object to be judged can be obtained from the quality-time correlation data 331 (Figure 4) stored in the second storage unit 330, or from the Arrhenius equation shown in equation (1). Below, as an example, an example of obtaining the rate of change k' of the quality of the object to be judged from the Arrhenius equation will be explained.

[0131] The quality prediction unit 550 predicts the quality of the object to be judged by, for example, estimating the number of days it takes for the quality to reach a predetermined value when the object is stored under certain temperature conditions, or calculating the ambient temperature conditions necessary for the quality to reach a predetermined value at a desired date and time. This predetermined value for quality can be arbitrarily determined in advance. For example, if the object to be judged is fresh produce and the quality is ripeness, this predetermined value can be set to 20% ripeness, which is the ideal time for eating fresh produce.

[0132] The following describes an example of how the quality prediction unit 550 predicts the quality of an object to be judged, specifically, how the quality prediction unit 550 estimates the number of days it takes for fruits and vegetables to reach their optimal ripeness for consumption.

[0133] If the produce being evaluated is stored for a total of 10 days—4 days at 5°C, 3 days at 10°C, and 3 days at 40°C—then the ripeness X of the produce in this case is 9.81%, as previously explained. In the future, when the produce is to be stored at 20°C, the quality prediction unit 550 calculates the number of days D required for the produce to reach its optimal ripeness (20%) as 18.3 days using the rate of change in ripeness at 20°C k'20, according to the following formula (20).

[0134]

number

[0135] In conventional technology, as already explained, if fresh produce is stored at a constant temperature of 29.1°C for 10 days, the ripeness X of the produce can be determined to be 12.1%. In this case, if the produce is to be stored at 20°C in the future, the number of days D required for the produce to reach its optimal ripeness (20%) can be calculated as 14.2 days using the rate of change in ripeness k'20, as shown in equation (21) below.

[0136]

number

[0137] Therefore, the number of days D required for fruits and vegetables to reach their peak ripeness, calculated using conventional technology, is 14.2 days, which deviates from the actual value (18.3 days) obtained when the temperature of the environment in which the fruits and vegetables are placed fluctuates.

[0138] Next, we will explain an example of the range of days D (the number of days D for which produce reaches a predetermined quality level) when it is ready to eat.

[0139] Assume that the produce subject to evaluation was stored for a total of 10 days: 4 days at 5°C and 6 days at 33.7°C. In this case, as already explained, among the multiple combinations of ambient temperature and time, the cumulative temperature S is the maximum (S=222), and the ripeness of the produce is 11.0%. In the future, when storing produce at 20°C, the quality prediction unit 550 calculates the number of days D for the produce to reach edible (20% ripeness) as 16.1 days using the rate of change in ripeness at 20°C k'20, according to the following formula (22).

[0140]

number

[0141] Assume that the produce subject to evaluation was stored for a total of 10 days: 1.83 days at 45°C and 8.17 days at 5°C. In this case, as already explained, among the multiple combinations of ambient temperature and time, the cumulative temperature S is the minimum (S=123), and the ripeness of the produce is 8.77%. In the future, when storing produce at 20°C, the quality prediction unit 550 calculates the number of days D required for the produce to reach its optimal ripeness (20%) as 20.1 days using the rate of change in ripeness at 20°C k'20, according to the following formula (23).

[0142]

number

[0143] Figure 7 shows the combinations of ambient temperature and time that result in the maximum accumulated temperature S, and the combinations that result in the minimum accumulated temperature S, for the elapsed time (number of days) t and the number of days D required for fruits and vegetables to reach their optimal eating stage.

[0144] Figure 7 shows the range of days D for the fruits and vegetables being judged, which is the number of days until they reach their peak ripeness. The upper limit of this range of days D is 20.1 days for the combination of ambient temperature and time in which the accumulated temperature S is minimized. The lower limit of this range of days D is 16.1 days for the combination of ambient temperature and time in which the accumulated temperature S is maximized.

[0145] Figure 7 plots the point where the number of days D (the number of days D until the produce is ready to eat) for produce to reach a predetermined quality level when stored at 20°C is 18.3 days, with the true value of ready to eat being 553. As shown in Figure 7, the true value of ready to eat, 553, falls within the range of 552 for the number of days D to reach ready to eat.

[0146] In this embodiment, it is possible to determine the range 552 of days D that will reach the peak eating stage, which includes the true value of 553 for peak eating, and to predict the ripeness (i.e., quality) of the produce being judged with high accuracy, even when the temperature of the environment in which the produce is placed fluctuates.

[0147] The result display unit 560 displays the calculation results of the processing unit 500. For example, the result display unit 560 displays the future quality (ripeness) of the produce that is the object to be judged, such as the number of days D until the quality of the produce reaches a predetermined value (ready to eat), and the combination of ambient temperature and time (number of days) until the quality of the produce reaches a predetermined value. The result display unit 560 also displays the cumulative temperature range 522, the true value of the cumulative temperature 523, the limited cumulative temperature range 525, the ripeness range of the produce 542, the true value of the ripeness 543, the number of days to reach ready to eat range 552, and the true value of ready to eat 553.

[0148] Furthermore, the result display unit 560 displays at least one of the cumulative temperature and average temperature of the object during storage for each of the multiple combinations of temperature and time of the environment in which the object to be judged is thought to have been (or may have been) placed during the elapsed time, as calculated by the temperature calculation unit 520.

[0149] Furthermore, if the quality calculation unit 540 determines that the calculated quality (maturity) of the object to be judged does not fall within a predetermined range, the result display unit 560 displays a warning about the quality of the object to be judged.

[0150] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible. For example, the embodiments described above are explained in detail to make the present invention easier to understand, and the present invention is not necessarily limited to embodiments having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add configurations from other embodiments to the configuration of one embodiment. Furthermore, it is possible to delete parts of the configuration of each embodiment, or to add or replace other configurations. [Explanation of Symbols]

[0151] 100...Quality indicator, 110, 110a, 110b...Time and temperature indicator, 120...Unique ID section, 130...Non-printable area, 200...Determination device, 300...Storage device, 310...Information storage section, 320...First storage section, 321...Correlation data between color density and time, 322~326...Calibration curve, 330...Second storage section, 331...Correlation data between quality and time, 332~336...Calibration curve, 400...Reading device, 410...Image acquisition section, 4 20...Information acquisition unit, 500...Processing device, 510...Time color density calculation unit, 520...Temperature calculation unit, 522...Cumulative temperature range, 523...True value of cumulative temperature, 525...Limited cumulative temperature range, 530...Information input unit, 540...Quality calculation unit, 542...Range of ripeness of fruits and vegetables, 543...True value of ripeness, 550...Quality prediction unit, 552...Range of days to reach optimal eating time, 553...True value of optimal eating time, 560...Result display unit, 600...Server.

Claims

1. Quality indicators that show the quality of the object, A judgment device, Equipped with, The aforementioned quality indicator is A time-temperature indicator in which the color density changes according to changes in temperature and time, A unique ID unit from which the unique ID information of the aforementioned object is read, Equipped with, The unique ID information includes information that identifies the object and data obtained by reading the time temperature indicator for the object. The determination device is An information storage unit that stores the aforementioned unique ID information and stores the color density of the time temperature indicator in association with the aforementioned unique ID information, A first storage unit pre-stores correlation data between color density and time shown by the aforementioned time-temperature indicator for multiple temperatures, An image acquisition unit that acquires an image of the aforementioned time temperature indicator and reads the unique ID portion, Based on the unique ID section read by the image acquisition unit, the information acquisition unit acquires the unique ID information from the information storage unit, and also acquires the color density of the time temperature indicator associated with the acquired unique ID information from the information storage unit. A time color density calculation unit obtains the unique ID information from the information storage unit, determines the starting date and time and the color density of the time temperature indicator at the starting date and time from the obtained unique ID information, and calculates the amount of change in the color density of the time temperature indicator and the elapsed time from the starting date and time from the color density of the time temperature indicator obtained by the information acquisition unit and the date and time of acquisition of this color density. A temperature calculation unit obtains multiple combinations of temperature and time in the environment in which the object is thought to have been placed during the elapsed time, using the rate of change in color density obtained from the correlation data stored in the first storage unit and the amount of change in color density of the time temperature indicator and the elapsed time calculated by the time color density calculation unit. Equipped with, A quality determination system characterized by the following features.

2. The aforementioned time-temperature indicator changes color according to the Arrhenius type temperature dependence. The quality determination system according to claim 1.

3. The quality indicator is installed directly on the object, or adjacent to the object. The quality determination system according to claim 1.

4. The aforementioned unique ID portion consists of a code or a string. The quality determination system according to claim 1.

5. The image acquisition unit is composed of an imaging device capable of acquiring and storing optical information. The quality determination system according to claim 1.

6. The information acquisition unit acquires information related to the storage of the object when the image acquisition unit acquires an image of the time temperature indicator, as composite information of the object. The temperature calculation unit acquires information about the temperature of the environment during storage of the object based on the composite information acquired by the information acquisition unit. The quality determination system according to claim 1.

7. The system includes an information input unit in which the user inputs the temperature of the environment in which the object is placed and the time the object is maintained at that temperature as known information. The temperature calculation unit corrects the composite information of the object using the known information and narrows down the number of combinations. The quality determination system according to claim 6.

8. Equipped with a results display unit, The temperature calculation unit calculates the average temperature of the object during storage for each of the multiple combinations, The result display unit displays the average temperature. The quality determination system according to claim 1.

9. Equipped with a results display unit, The temperature calculation unit calculates the cumulative temperature of the object during storage for each of the multiple combinations, The result display unit displays the accumulated temperature. do, The quality determination system according to claim 1.

10. The system includes a second storage unit that pre-stores correlation data between the quality and time of the aforementioned object for multiple temperatures. The quality determination system according to claim 1.

11. Quality calculation unit, The results display unit, Equipped with The quality calculation unit calculates the quality of the object from the multiple combinations acquired by the temperature calculation unit and the rate of change in the quality of the object obtained from the correlation data stored in the second storage unit. The result display unit displays the quality of the object calculated by the quality calculation unit. The quality determination system according to claim 10.

12. If the quality calculation unit determines that the calculated quality of the object does not fall within a predetermined range, it will display a warning about the quality of the object on the result display unit. The quality determination system according to claim 11.

13. The system includes a quality prediction unit that predicts the future quality of the object based on the quality of the object calculated by the quality calculation unit and the rate of change in the quality of the object, The result display unit displays the future quality of the object predicted by the quality prediction unit. The quality determination system according to claim 11.

14. The quality prediction unit calculates the ambient temperature required to bring the quality of the object to a predetermined value at a desired date and time, as a prediction of the future quality of the object. The result display unit displays the ambient temperature calculated by the quality prediction unit. The quality determination system according to claim 13.

15. The determination device is connected to a server via a network, The first storage unit is provided in the server, The quality determination system according to claim 1.

Images