Quality determining system

Abstract

The present invention provides a quality determining system capable of acquiring temperature information of an environment in which an object is placed, and the quality of the object, with high accuracy. The quality determining system of the present invention is provided with a quality indicator (100) and a determining device (200). The quality indicator (100) is provided with a time-temperature indicator (110) and a unique ID unit (120) from which unique ID information of the object is read. The unique ID information includes information identifying the object and data acquired from the time-temperature indicator (110) of the object. The determining device (200) comprises: an information acquiring unit (420) that acquires the color density of the time-temperature indicator (110) associated with acquired unique ID information; a time-color density calculating unit (510) that calculates an amount of change in the color density of the time-temperature indicator (110) and the elapsed time from a date and time serving as a starting point; and a temperature calculating unit (520) that uses a rate of change in the color density, the amount of change in the color density, and the elapsed time to obtain a plurality of combinations of the time and temperature of the environment in which it can be considered that the object has been placed during the elapsed time.

Description

Quality Determination System

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

[0002] A quality determination system is used to determine the quality of an object. There is a quality determination system that utilizes 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-sensitive ink from a target product with the temperature-sensitive ink whose color changes according to the history of temperature and time, an integrated temperature calculation unit that calculates the integrated temperature from the acquired color information based on the information on the correspondence between the color information of the temperature-sensitive ink and the integrated temperature of the temperature-sensitive ink, and a quality calculation unit that calculates the quality index of the target product from the calculated integrated temperature based on the information on the correspondence between the integrated temperature and the quality index of the target product, and visualizes the quality of the 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 cup ramen eating time display seal described in Patent Document 3 has the backing paper of the seal adjusted so that the color changes at just the right time considering heat conduction, and is pasted on the lid of cup ramen or used after being pre-attached, so as to easily display the eating time from when the hot water of the cup ramen is poured until it is ready.

[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.

[0007] Japanese Patent Publication No. 2020-003834, Japanese Patent Publication No. 2019-207179, Japanese Patent Publication No. 2006-292704

[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.

[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 in association with 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 a plurality of 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 associated with 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.

[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.

[0012] This figure shows an example of the configuration of a quality indicator. This figure shows an example of the configuration of a quality indicator. This figure shows an example of the configuration of a judgment device. This figure shows an example of correlation data between color density and time stored in the first memory unit. This figure shows an example of correlation data between quality and time stored in the second memory unit. 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 to be judged is thought to be placed. 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 to be judged is thought to be placed, and shows a limited range of accumulated temperature. This figure shows the relationship between elapsed time (number of days elapsed) and the ripeness of fruits and vegetables for the combination of ambient temperature and time in which the accumulated temperature is maximum and the combination of ambient temperature and time in which the accumulated temperature is minimum. This figure shows the relationship between elapsed time (number of days elapsed) and the number of days it takes for fruits and vegetables to reach their peak ripeness for the combination of ambient temperature and time in which the accumulated temperature is maximum and the combination of ambient temperature and time in which the accumulated temperature is minimum.

[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] The following describes a quality determination system according to an embodiment of the present invention with reference to the drawings. In the following embodiment, as an example, the object to be judged for quality is fresh produce, and the quality is the ripeness of the fresh produce. However, the present invention is not limited to food products such as fresh produce, but can also be used for articles whose quality changes according to an Arrhenius-type temperature dependence. Articles whose quality changes according to an Arrhenius-type temperature dependence include, in addition to food products such as fresh produce, for example, pharmaceuticals and chemical products.

[0015] The quality of an object can be arbitrarily determined depending on the object. For example, the quality of fresh produce is its ripeness and freshness, the quality of pharmaceuticals is its effectiveness, and the quality of chemical products is their strength, etc.

[0016] In the following examples, the object whose quality is to be determined is referred to as the object to be judged.

[0017] In the drawings referenced herein, identical or corresponding components are denoted by the same reference numeral, and repeated descriptions of these components may be omitted.

[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 Figures 1A and 1B, and an example of the determination device 200 will be described using Figure 2.

[0019] <Quality Indicator> Figure 1A shows 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 accordance with 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 arranged 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 in accordance with changes in temperature and time. From the color change of the thermochromic ink, 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. 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 that is the object to be 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 storage 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). QR codes are 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 a plurality of time-temperature indicators 110 having different color change characteristics. Figure 1B shows an example in which the quality indicator 100 comprises two time-temperature indicators 110a and 110b having different color change characteristics.

[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 represents the frequency factor, Ea represents the activation energy, R represents the gas constant, and T represents the absolute temperature.

[0030]

[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. From a manufacturing process perspective, it is preferable that the thermochromic ink can be printed on 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 frequency factor A being exp(35) and Ea / R being 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 indicate the amount of color change per day.

[0033]

[0034]

[0035]

[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]

[0038] <Determination Device>FIG. 2 is a diagram showing an example of the configuration of the determination device 200. The determination device 200 can be configured by a computer such as a smartphone or a tablet terminal, and includes a storage device 300, a reading device 400, and a processing device 500. The determination device 200 can be connected to the Internet and can be connected to the server 600 via the Internet, for example.

[0039] The storage device 300 is a device that stores various data, and includes an information storage unit 310, a first storage unit 320, and a second storage unit 330.

[0040] As described above, the information storage unit 310 stores unique ID information. The unique ID information is input into the information storage unit 310 as needed by the operation of the user, for example. Further, the information storage unit 310 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 in association with the unique ID information.

[0041] The first storage unit 320 stores in advance the correlation data between the color density indicated by the time temperature indicator 110 and time for a plurality of temperatures. This correlation data can be obtained by experiments conducted in advance, etc.

[0042] FIG. 3 is a diagram showing an example of the correlation data 321 between the color density and time stored in the first storage unit 320. In FIG. 3, the horizontal axis represents time, and the vertical axis represents the color density of the time temperature indicator 110. In FIG. 3, as an example, the correlation data 321 for five temperatures from 10°C to 50°C are shown by calibration curves 322 to 326.

[0043] The second storage unit 330 stores in advance the correlation data between the quality of the determination object and time for a plurality of temperatures. This correlation data can be obtained by experiments conducted in advance, etc.

[0044] FIG. 4 is a diagram showing an example of correlation data 331 of quality and time stored in the second storage unit 330. In FIG. 4, the horizontal axis represents time, and the vertical axis represents the degree of ripeness, which is the quality of the fresh produce. In FIG. 4, as an example, correlation data 331 for five temperatures from 10°C to 50°C are shown by calibration curves 332 to 336.

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

[0046] Returning to the description of the determination device 200 shown in FIG. 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, acquires an image 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, an optical sensor, etc. Also, the image acquisition unit 410 can acquire images related to the determination object, such as the appearance of the determination object, the label attached to the determination object, and the surrounding environment of the determination object.

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

[0050] The information acquisition unit 420 acquires the 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 the information on the color density 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 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, then the color density of the time-temperature indicator 110 at the starting date and time is 0%.

[0056] In this embodiment, 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. The temperature calculation unit 520 may also determine the color change rate k from the Arrhenius equation shown in equation (1).

[0061] Next, the temperature calculation unit 520 uses the determined discoloration rate k and the amount of 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), it is calculated that the object to be judged was stored at an ambient temperature of 29.1°C.

[0067]

[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]

[0075]

[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 simultaneous equations (9) and (10) hold true.

[0077]

[0078]

[0079] Solving this system of equations yields the solutions A = 1.83 and B = 8.17 days. In other words, it is calculated that 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 pattern of the environment in which the object to be judged is thought to have been placed is in two temperature ranges, 45°C and 5°C, the combination 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 Tabg is calculated to be 12.3°C, according to the following formula (11).

[0082]

[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 Tabg 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°C, and the average temperature Tabg 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 Tabg 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, it is assumed 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 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°C).

[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 to be 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 to be 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) as the true value of the cumulative temperature, 523. As shown in Figure 5A, the true value of the cumulative temperature, 523, falls within the cumulative temperature range 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 unit 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 higher accuracy.

[0098] For example, suppose a user stores fresh produce in a refrigerator at 5°C for four days. The user inputs the fact that the item to be judged was stored at 5°C for four 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 the following equation (12).

[0100]

[0101] If the ambient temperature remained constant for the remaining six days, the discoloration rate k of the time-temperature indicator 110 would be 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]

[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 six 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]

[0106]

[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 is a diagram showing 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 to be judged is thought to be placed, and it shows 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 of the limited cumulative temperature range 525 (the other extreme) 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 unit 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 in the ripeness of the produce, k', is defined as the daily 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]

[0118] In conventional technology, as explained earlier, assuming that fruits and vegetables are stored at a constant temperature, it is calculated that the fruits and vegetables were 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 formula (17) with the rate of change of ripeness X k'29.1.

[0119]

[0120] Therefore, the ripeness of fruits and vegetables calculated using conventional technology is 12.1%, which is a significant difference 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 formula (18), with the rate of change k'5 at 5°C and the rate of change k'33.7 at 33.7°C.

[0122]

[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 formula (19), with the rate of change k'5 at 5°C and the rate of change k'45 at 45°C.

[0124]

[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 maximum. 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 minimum.

[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 543 falls within the ripeness range 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 subject to evaluation is placed fluctuates, information about the ripeness (i.e., quality) of the subject to evaluation 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 (ripeness) 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 (ripeness) of the object to be judged (fruit and vegetables). 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 to eat 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 subject to evaluation 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 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 k'20 at 20°C, according to the following formula (20).

[0134]

[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 the following equation (21).

[0136]

[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]

[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 edible (20% ripeness) as 20.1 days using the rate of change in ripeness at 20°C k'20, according to the following formula (23).

[0142]

[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 552 of days D for the fruits and vegetables that are the subject of evaluation to reach their optimal eating stage. The upper limit of this range 552 of days D is the number of days D (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 552 of days D is the number of days D (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, representing the true value of ready to eat as 553. As shown in Figure 7, the true value of ready to eat 553 falls within the range 552 of the number of days D until ready to eat.

[0146] In this embodiment, it is possible to determine the range 552 of the number of days D that will reach the peak eating stage, which includes the true value 553 of the peak eating stage. This allows for highly accurate prediction of the ripeness (i.e., quality) of the produce being judged, 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 device 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 the ready to eat range 552, and the true value of the 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 of the described configurations. 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. In addition, it is possible to delete parts of the configuration of each embodiment, or to add or replace other configurations.

[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 unit, 510... Time color density calculation unit, 520... Temperature calculation unit, 522... Range of accumulated temperature, 523... True value of accumulated temperature, 525... Limited range of accumulated temperature, 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. A quality indicator that shows the quality of an object, and a determination device, wherein 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 the unique ID information of the object is read, wherein 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, and an information acquisition unit that, based on the unique ID unit read by the image acquisition unit, acquires the unique ID information from the information storage unit and acquires the color density of the time-temperature indicator linked to the acquired unique ID information from the information storage unit. A quality determination system characterized by comprising: an information storage unit that acquires the unique ID information; a time color density calculation unit that calculates the amount of change in the color density of the time temperature indicator and the elapsed time from the starting date and time, based on the color density of the time temperature indicator and the date and time of acquisition of this color density, acquired 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 in the environment in which the object is thought to have been placed during this elapsed time.

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

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

4. The quality determination system according to claim 1, wherein the unique ID portion is composed of a code or a string.

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

6. The quality determination system according to claim 1, wherein the information acquisition unit acquires information related to the storage of the object as composite information of the object when the image acquisition unit acquires an image of the time temperature indicator, and 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.

7. The quality determination system according to claim 6, comprising 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 held at this temperature as known information, and the temperature calculation unit corrects the composite information of the object using the known information to narrow down a plurality of combinations.

8. A quality determination system according to claim 1, comprising a result display unit, wherein the temperature calculation unit calculates the average temperature of the object during storage for each of the plurality of combinations, and the result display unit displays the average temperature.

9. A quality determination system according to claim 1, comprising a result display unit, wherein the temperature calculation unit calculates the cumulative temperature of the object during storage for each of the plurality of combinations, and the result display unit displays the cumulative temperature.

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

11. A quality determination system according to claim 10, comprising: a quality calculation unit and a result display unit, wherein the quality calculation unit calculates the quality of the object from a plurality of 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, and the result display unit displays the quality of the object calculated by the quality calculation unit.

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

13. A quality determination system according to claim 11, comprising 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, wherein the result display unit displays the future quality of the object predicted by the quality prediction unit.

14. The quality determination system according to claim 13, wherein 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, and the result display unit displays the ambient temperature calculated by the quality prediction unit.

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

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