Culture device and control method

Abstract

This culture device comprises: a humidification device that heats a container containing water with a heater to humidify a culture chamber; and a control unit that controls the heater. When the difference between a target humidity and a measured humidity of the culture chamber is equal to or greater than a first threshold value, the control unit performs first humidification control in which the heater is controlled on the basis of a target water temperature and a measured water temperature of the water. When the difference is less than the first threshold value, the control unit performs second humidification control in which the heater is controlled on the basis of the target humidity and the measured humidity.

Description

Culture apparatus and control method

[0001] This disclosure relates to a culture apparatus and a control method.

[0002] Conventional culture apparatuses for culturing cells, microorganisms, and other culture targets have been known (see Patent Document 1). This culture apparatus is equipped with a humidifier that adjusts the humidity of the culture chamber to a state suitable for culture. This humidifier adjusts the humidity of the culture chamber by evaporating water in an evaporating dish placed inside the culture chamber.

[0003] Japanese Patent Publication No. 2017-201886

[0004] In the technical field related to the culture apparatus described above, there is a need for a culture apparatus and control method that can stably humidify the culture chamber in a short amount of time.

[0005] This disclosure is made in view of these circumstances and aims to provide a culture apparatus and control method that can humidify a culture chamber in a short time.

[0006] One embodiment of the culture apparatus according to this disclosure comprises a humidifier that heats a container of water with a heater to humidify the culture chamber, and a control unit that controls the heater, wherein the control unit performs a first humidification control that controls the heater based on the target water temperature and the measured water temperature when the difference between the target humidity and the measured humidity of the culture chamber is greater than or equal to a first threshold, and performs a second humidification control that controls the heater based on the target humidity and the measured humidity when the difference is less than the first threshold.

[0007] One embodiment of the control method relating to this disclosure is a control method for a humidifier that humidifies a culture chamber by heating a container containing water with a heater, comprising the steps of: obtaining the measured water temperature of the water; obtaining the measured humidity of the culture chamber; performing a first humidification control, which controls the heater based on the target water temperature and the measured water temperature, if the difference between the target humidity and the measured humidity is greater than or equal to a first threshold; and performing a second humidification control, which controls the heater based on the target humidity and the measured humidity, if the difference is less than the first threshold.

[0008] According to this disclosure, a culture apparatus and control method are provided that can stably humidify a culture chamber in a short amount of time.

[0009] Figure 1 is a perspective view of a culture apparatus according to an embodiment of the present disclosure. Figure 2 is a cross-sectional view of the culture apparatus. Figure 3 is a functional block diagram of the humidifier. Figure 4A is a flowchart of the humidification control process. Figure 4B is a flowchart of the first humidification control process. Figure 4C is a flowchart of the second humidification control process. Figure 5 is a graph showing the relational equation for obtaining the target water temperature. Figure 6 is a diagram showing the changes in humidity and water temperature during humidification control.

[0010] The culture apparatus according to this disclosure will be described below with reference to the drawings. The same reference numerals will be used for the same components. The information described below, along with the attached drawings, is for illustrative purposes only and does not represent the only possible embodiment.

[0011] [Embodiment] A culture apparatus 1 according to an embodiment of this disclosure will be described with reference to Figures 1 to 6.

[0012] Figure 1 is a perspective view of the culture apparatus 1. Figure 2 is a cross-sectional view of the culture apparatus 1. Specifically, Figure 2 is a cross-sectional view showing the central part of the culture apparatus 1 in the left-right direction, cut by planes parallel to the front-back and up-down directions.

[0013] In describing the structure of the culture apparatus 1 below, the Cartesian coordinate system (X, Y, Z) shown in each figure may be used. The X direction corresponds to the front-to-back direction of the culture apparatus 1. The X-direction + side is the front side of the culture apparatus 1. The X-direction - side is the rear side of the culture apparatus 1.

[0014] Furthermore, the Y direction refers to the left-right and width directions of the culture device 1. The Y-direction + side is the left side when viewing the culture device 1 from the front. The Y-direction - side is the right side when viewing the culture device 1 from the front.

[0015] The Z direction is the vertical and height direction of the culture device 1. The Z+ side is the upper side of the culture device 1. The Z- side is the lower side of the culture device 1. Note that the directions of the culture device 1 are not limited to the Cartesian coordinate system (X, Y, Z) shown in each figure.

[0016] The culture apparatus 1 is an apparatus for culturing culture objects such as cells and microorganisms. The culture apparatus 1 includes a box body 101, an inner door 102, and an outer door 103. Note that in FIG. 1, the inner door 102 is omitted.

[0017] The box body 101 is in a box shape having a culture chamber 101d inside. Specifically, as shown in FIG. 2, the box body 101 includes an inner box 101a, an outer box 101b, and a heat insulating material 101c.

[0018] The inner box 101a is formed of a metal plate and is in a box shape with an open front surface. A space surrounded by the inner box 101a constitutes the culture chamber 101d.

[0019] The outer box 101b is formed of a metal plate and is in a box shape with an open front surface. The outer box 101b is arranged so as to cover the outer surface of the inner box 101a. The heat insulating material 101c is provided between the inner box 101a and the outer box 101b.

[0020] The culture chamber 101d has an opening 101e on the front surface. The culture chamber 101d is vertically partitioned by a plurality of shelves 101f.

[0021] The inner door 102 is supported by the front end of the inner box 101a in a state where the opening 101e can be opened and closed. Further, the outer door 103 is supported by the front end of the outer box 101b in a state where the opening 101e can be opened and closed. Note that the culture apparatus 1 does not necessarily have to include the inner door 102.

[0022] The culture apparatus 1 has a packing 104 on the outer peripheral edge of the inner side surface of the outer door 103. Further, the culture apparatus 1 has covers 105 on the back surface and the bottom surface of the outer box 101b.

[0023] The culture apparatus 1 has a machine room 106 for arranging various devices between the back surface of the outer box 101b and the cover 105. Further, the culture apparatus 1 has an electrical component box 107 in the machine room 106. Furthermore, the culture apparatus 1 has the control device 3 and other electrical components (not shown) in the electrical component box 107. Note that the culture apparatus may have a machine room above the outer box. In this case, the machine room is provided between the top surface of the outer box and a cover covering the top surface.

[0024] The culture apparatus 1 includes a vertically extending duct 108 in a culture chamber 101d. The duct 108 is detachably attached to the rear side wall of the inner box 101a. A gas passage 109 is formed inside the duct 108. The duct may be provided on the left side wall and / or the right side wall of the inner box 101a.

[0025] The culture apparatus 1 includes a blower 110 in the gas passage 109. The blower 110 sucks air into the gas passage 109 from a suction port 108a formed at an upper portion of the duct 108. This air passes through the gas passage 109 and is blown out into the culture chamber 101d from an air outlet 108b provided at a lower portion of the duct 108. Accordingly, air is forcibly circulated within the culture chamber 101d.

[0026] The culture apparatus 1 includes a gas supply device 111 on the duct 108. The gas supply device 111 is configured to control O in the culture chamber 101d ２ gas concentration, N ２ concentration, and CO ２ adjustment gas for adjusting gas concentration (O ２ gas, N ２ gas, and CO ２ gas) is supplied to the culture chamber 101d.

[0027] The culture apparatus 1 includes, in the culture chamber 101d, a temperature sensor (not shown) for measuring the temperature of the culture chamber 101d, and a concentration sensor (not shown) for measuring the gas concentration in the culture chamber 101d. The temperature sensor and the concentration sensor may be installed at appropriate positions in the culture chamber.

[0028] The culture apparatus 1 includes an ultraviolet irradiation device 112 provided on the duct 108, which irradiates ultraviolet rays to sterilize air in the culture chamber 101d.

[0029] The culture apparatus 1 includes culture chamber heaters 113 for adjusting the temperature of the culture chamber 101d on the respective back surfaces (surfaces on the outer box side) of the right side wall, left side wall, rear wall, top wall, and bottom wall of the inner box 101a. It should be noted that the culture chamber heaters do not need to be provided on all wall portions constituting the inner box 101a.

[0030] In FIG. 1, only the culture chamber heater 113 installed on the rear wall is shown. The operation of the culture chamber heater 113 is controlled by the control device 3.

[0031] The culture apparatus 1 has an evaporative humidifier 114. The humidifier 114 humidifies the culture chamber 101d. The operation of the humidifier 114 is controlled by the control device 3. In this embodiment, the culture apparatus 1 has only an evaporative humidifier 114 as a humidifier. However, the culture apparatus may have a humidifier of another type (for example, a steam supply type) in addition to the evaporative humidifier 114.

[0032] The control device 3, as an example, has a configuration in which a processor, a volatile memory (e.g., RAM), and a non-volatile memory (e.g., HDD, SSD, or Flash ROM) are connected via a bus. The control device 3 may also consist of a single-chip LSI or the like. For example, the control device 3 executes the control processing of the humidifier 114 by having the processor read a program stored in non-volatile memory (not shown) into a buffer memory (not shown) and execute it. Such a control device 3 is an example of a control unit.

[0033] As shown in Figures 2 and 3, the humidifier 114 includes a container 114a, a water temperature sensor 114b, a humidity sensor 114c, and a heater 114d.

[0034] Container 114a is a container for storing water for humidification. Container 114a has an open top. Container 114a is installed in the culture chamber 101d. Specifically, container 114a is installed on the top surface of the bottom of the inner box 101a. The water contained in container 114a evaporates and humidifies the culture chamber 101d.

[0035] The water temperature sensor 114b detects information regarding the temperature of the water in the container 114a (hereinafter referred to as "water temperature information"). The water temperature sensor 114b sends the detected water temperature information to the control device 3.

[0036] The water temperature sensor 114b is an example of a first detection unit and is installed inside the container 114a. The installation position of the water temperature sensor 114b is not particularly limited. The water temperature sensor 114b may be installed in a position where it can detect the temperature of the water inside the container 114a.

[0037] The humidity sensor 114c detects information regarding the humidity of the culture chamber 101d (hereinafter referred to as "humidity information"). The humidity sensor 114c sends the detected humidity information to the control device 3.

[0038] The humidity sensor 114c is an example of a second detection unit and is located inside the culture chamber 101d. In this embodiment, the humidity sensor 114c is located inside the duct 108. However, the installation location of the humidity sensor 114c is not particularly limited. The humidity sensor 114c may be located in a position from which humidity information can be acquired.

[0039] The heater 114d is located between the inner box 101a and the outer box 101b. Specifically, the heater 114d is located below the bottom of the inner box 101a.

[0040] The heater 114d heats the container 114a under the control of the control device 3. When the container 114a is heated by the heater 114d, the water inside the container 114a evaporates, and the culture chamber 101d is humidified.

[0041] Furthermore, the culture apparatus 1 has an operating device 115 on the front of the outer door 103. The operating device 115 receives input from the user for instructions to start and stop the culture apparatus 1, to set the operating mode, and to input various setting values ​​for the culture chamber 101d.

[0042] The various settings for culture chamber 101d are: culture chamber 101d set temperature (in other words, target temperature), culture chamber 101d set humidity (in other words, target humidity), O ２ The set concentration of the gas, and CO ２ This includes the gas concentration settings. The operating device 115 has a display unit (not shown) that displays the status of the culture apparatus 1.

[0043] The control device 3 controls the blower 110, gas supply device 111, culture room heater 113, humidifier 114, and the like based on information obtained from the operating device 115 and the sensors provided in the culture apparatus 1.

[0044] The culture apparatus 1 according to this embodiment, having the basic configuration described above, controls the operation of the humidifier 114 in order to stably humidify the culture chamber 101d in a short time. The control method of the humidifier 114 will be described below.

[0045] (Overview of Humidification Control) First, an overview of humidification control will be provided. Humidification control is performed by the control device 3. In humidification control, the control device 3 switches between the first humidification control and the second humidification control.

[0046] The control device 3 performs the first humidification control when the difference between the target humidity and the humidity of the culture chamber 101d (i.e., the humidity difference) is greater than or equal to the first threshold. In the first humidification control, the control device 3 controls the heater 114d based on the target water temperature of the water in the container 114a and the actual temperature of the water in the container 114a.

[0047] The method for obtaining the target water temperature will be described later. The water temperature in container 114a is the water temperature information obtained from the water temperature sensor 114b.

[0048] On the other hand, if the humidity difference is less than the first threshold, the control device 3 performs a second humidification control. In the second humidification control, the control device 3 controls the heater 114d based on the target humidity of the culture chamber 101d and the humidity of the culture chamber 101d.

[0049] The target humidity for culture room 101d is the set humidity set by the control device 115. The humidity for culture room 101d is the humidity information obtained from the humidity sensor 114c.

[0050] (Details of Humidification Control) Next, an example of humidification control will be described with reference to Figures 4A to 4C. Figure 4A is a flowchart of the humidification control process. Figure 4B is a flowchart of the first humidification control process. Figure 4C is a flowchart of the second humidification control process. The main component of each process shown in Figures 4A to 4C is the control device 3.

[0051] (Step S101) In step S101 of Figure 4A, the control device 3 acquires setting information. The setting information includes the target temperature of the culture chamber 101d (hereinafter simply referred to as "target temperature"), the target humidity of the culture chamber 101d (hereinafter simply referred to as "target humidity"), and the target water temperature of the water in the container 114a.

[0052] The target temperature and target humidity are information input from the operating device 115 and stored in the control device 3's storage device (for example, RAM, HDD, SSD, or Flash ROM).

[0053] The target water temperature of the water in container 114a (hereinafter simply referred to as "target water temperature") is obtained based on the target temperature and target humidity.

[0054] Here, we will explain how the control device 3 obtains the target water temperature. The control device 3 obtains the target water temperature based on a pre-established relationship between the target temperature, target humidity, and target water temperature.

[0055] This relationship is pre-stored in the storage device (for example, RAM, HDD, SSD, or Flash ROM) that constitutes the control device 3.

[0056] The following describes the relationship for obtaining the target water temperature. This relationship is determined experimentally. Figure 5 is a graph showing the relationship for obtaining the target water temperature. Figure 5 shows four curves L1 to L4. The relationship is a linear function obtained by linearly approximating curves L1 to L4.

[0057] The vertical axis of Figure 5 represents the humidity in culture room 101d (hereinafter simply referred to as "humidity"). The horizontal axis of Figure 5 represents the temperature of the water in container 114a (hereinafter simply referred to as "water temperature").

[0058] Curve L1 shows the relationship between humidity and water temperature when the target temperature of culture room 101d is 37°C. Curve L2 shows the relationship between humidity and water temperature when the target temperature of culture room 101d is 42°C.

[0059] Furthermore, curve L3 shows the relationship between humidity and water temperature when the target temperature of culture chamber 101d is 50°C. Curve L4 shows the relationship between humidity and water temperature when the target temperature of culture chamber 101d is 60°C. Note that the curves in Figure 5 are not limited to the four curves described above. Curves may be provided in any number corresponding to the temperatures that can be set as target temperatures.

[0060] Here, we will explain how to obtain curve L1. Curve L1 shows the relationship between humidity and water temperature when the target temperature of the culture chamber 101d is set to 37°C and the humidity of the culture chamber 101d is increased from 80% RH to 95% RH by the humidifier 114.

[0061] Figure 5 shows three points P1 to P3 plotted on curve L1. Point P1 shows the relationship between humidity and water temperature when the target temperature of the culture chamber 101d is set to 37°C and the humidity of the culture chamber 101d is raised to 80% RH by the humidifier 114.

[0062] Furthermore, point P2 shows the relationship between humidity and water temperature when the target temperature of the culture chamber 101d is set to 37°C and the humidity of the culture chamber 101d is raised to 90% RH by the humidifier 114.

[0063] Furthermore, point P3 shows the relationship between humidity and water temperature when the target temperature of the culture chamber 101d is set to 37°C and the humidity of the culture chamber 101d is raised to 95% RH by the humidifier 114. The number of points P used to obtain curve L1 is not particularly limited.

[0064] Then, curve L1 can be obtained from points P1 to P3 as described above. By approximating this curve L1 with a linear function, a relational expression for obtaining the target water temperature when the target temperature is set to 37°C can be derived. The method for obtaining curves L2 to L4 is the same as the method for obtaining curve L1 described above.

[0065] The control device 3 applies the target temperature and target humidity to the relational expression derived as described above to obtain the target water temperature. For example, if the target temperature is 37°C and the target humidity is 90%RH, the control device 3 obtains 34°C as the target water temperature (i.e., the water temperature in Figure 5) based on the linear function obtained from the curve L1 in Figure 5.

[0066] Note that the target water temperature may differ from the final water temperature of the water in container 114a (hereinafter referred to as the "final water temperature"). The final water temperature refers to the temperature of the water in container 114a when the humidity in the culture chamber 101d reaches the target humidity due to humidification control.

[0067] The reason the target water temperature differs from the final water temperature is that variations in individual culture devices (such as leaks) and the effects of water evaporation from the culture medium cause the final water temperature to change. From this perspective, the target water temperature can be considered as a provisional target water temperature, or a temperature close to the final water temperature.

[0068] (Step S102) In step S102 of Figure 4A, the control device 3 acquires status information. The status information includes the temperature of the water in the container 114a (hereinafter referred to as "measured water temperature") and the humidity of the culture chamber 101d (hereinafter referred to as "measured humidity").

[0069] The measured water temperature is the water temperature information detected by the water temperature sensor 114b. Therefore, the control device 3 acquires the measured water temperature (i.e., water temperature information) from the water temperature sensor 114b.

[0070] Furthermore, the measured humidity is the humidity information detected by the humidity sensor 114c. Therefore, the control device 3 acquires the measured humidity (i.e., humidity information) from the humidity sensor 114c.

[0071] (Step S103) In step S103 of Figure 4A, the control device 3 determines whether the difference between the target humidity and the measured humidity (i.e., the humidity difference) is greater than or equal to a first threshold. In other words, the control device 3 determines whether the measured humidity is greater than or equal to a first threshold than the target humidity.

[0072] The "first threshold" is a predetermined value used to determine whether to switch between the first and second humidification control modes when the measured humidity is lower than the target humidity.

[0073] If the humidity difference is greater than or equal to the first threshold (YES in step S103), the control device 3 proceeds to step S104.

[0074] On the other hand, if the humidity difference is not equal to or greater than the first threshold (NO in step S103), the control device 3 proceeds to step S105.

[0075] Thus, in step S103, the control device 3 decides whether to perform the first humidification control or the second humidification control.

[0076] (Step S104) In step S104 of Figure 4A, the control device 3 performs the first humidification control. After performing the first humidification control, the control device 3 proceeds to step S106. The first humidification control will be described later.

[0077] (Step S105) In step S105 of Figure 4A, the control device 3 performs the second humidification control. After performing the second humidification control, the control device 3 proceeds to step S106. The second humidification control will be described later.

[0078] (Step S106) In step S106 of Figure 4A, the control device 3 determines whether or not the conditions for terminating humidification control (hereinafter referred to as "termination conditions") have been met.

[0079] Here, a situation in which the termination condition is met is, for example, when a command to terminate humidification control is input from the operating device 115. Another situation in which the termination condition is met is, for example, when cell culture has been completed.

[0080] If the termination condition is met (YES in step S106), the control device 3 terminates the humidification control.

[0081] Furthermore, if the termination condition is not met ("NO" in step S106), the control device 3 returns the control process to step S102. Thereafter, the control device 3 repeatedly performs steps S102 to S106 until the termination condition is met in step S106.

[0082] (First Humidification Control) Next, with reference to Figure 4B, the first humidification control performed in step S104 of Figure 4A will be described. Figure 4B is a flowchart of the process for the first humidification control.

[0083] (Step S201) In step S201 of Figure 4B, the control device 3 determines whether the difference between the target humidity and the measured humidity (i.e., the humidity difference) is greater than or equal to the second threshold. In other words, the control device 3 determines whether the measured humidity is lower than the target humidity by the second threshold or more.

[0084] The "second threshold" is a predetermined value used to determine the switching between the first and second humidification stages of the first humidification control when the measured humidity is lower than the target humidity. The first and second humidification stages will be described later.

[0085] The second threshold is a value greater than the first threshold used in step S103 of Figure 4A.

[0086] If the humidity difference is greater than or equal to the second threshold (YES in step S201), the control device 3 proceeds to step S202. The processes from step S202 to step S205 are performed in the first humidification stage of the first humidification control.

[0087] On the other hand, if the humidity difference is not equal to or greater than the second threshold ("NO" in step S201), the control device 3 proceeds to step S206. Steps S206 to S209 are processes performed in the second humidification stage of the first humidification control.

[0088] The following describes the processes performed in the first humidification stage of the first humidification control, followed by a description of the processes performed in the second humidification stage of the first humidification control.

[0089] (Step S202) In step S202 of Figure 4B, the control device 3 sets the first target water temperature to the target water temperature. The first target water temperature is a value that is a first predetermined value higher than the target water temperature obtained in step S101 of Figure 4A.

[0090] The target water temperature obtained in step S101 in Figure 4A is sometimes referred to as the reference target water temperature. Subsequently, the control device 3 proceeds to step S203.

[0091] (Step S203) In step S203 of Figure 4B, the control device 3 determines whether the measured water temperature is less than the first target water temperature. The measured water temperature is the water temperature obtained in step S102 of Figure 4A.

[0092] If the measured water temperature is below the first target water temperature (YES in step S203), the control device 3 proceeds to step S204.

[0093] On the other hand, if the measured water temperature is not below the first target water temperature (NO in step S203), the control device 3 proceeds to step S205.

[0094] Thus, in step S202, the control device 3 decides whether to turn the heater 114d ON or OFF.

[0095] (Step S204) In step S204 of Figure 4B, the control device 3 turns on the heater 114d.

[0096] If the heater 114d is already in the ON state, the control device 3 maintains the ON state of the heater 114d. If the heater 114d is in the OFF state, the control device 3 switches the state of the heater 114d from the OFF state to the ON state.

[0097] Furthermore, the control device 3 controls the output of the heater 114d to a level corresponding to the first target water temperature. As a result, the water in the container 114a is heated by the heater 114d with an amount of heating corresponding to the first target water temperature.

[0098] As described above, in this example, when the measured water temperature is lower than the first target water temperature, the control device 3 turns on the heater 114d to heat the water in the container 114a. Thereafter, the control device 3 ends the control process of FIG. 4B, and advances the control process to step S106 of FIG. 4A.

[0099] (Step S205) Next, in step S205 of FIG. 4B, the control device 3 turns off the heater 114d.

[0100] Note that when the heater 114d is already in an off state, the control device 3 maintains the off state of the heater 114d. Further, when the heater 114d is in an on state, the control device 3 switches the state of the heater 114d from the on state to the off state. As a result, the water in the container 114a is no longer heated by the heater 114d.

[0101] As described above, in this example, when the measured water temperature is equal to or higher than the first target water temperature, the control device 3 turns off the heater 114d and does not heat the water in the container 114a. Such a configuration suppresses excessive heating of the water in the container 114a.

[0102] Thereafter, the control device 3 ends the control process of FIG. 4B, and advances the control process to step S106 of FIG. 4A.

[0103] FIG. 6 is a diagram showing an example of changes in measured humidity and measured water temperature in humidification control. The horizontal axis of FIG. 6 represents time. The vertical axis of FIG. 6 represents measured water temperature and measured humidity. The dotted line α in FIG. 6 １ shows the change in the measured water temperature. The solid line α in FIG. 6 ２ shows the change in the measured humidity.

[0104] The first humidification stage of the above-described first humidification control is performed in the period T of FIG. 6 １ repeatedly. In other words, the first humidification stage of the first humidification control starts at time t in FIG. 6 ０ and ends at time t １

[0105] From time t ０ to time t １ ​Up to this point, the difference between the target humidity and the measured humidity (i.e., the humidity difference) is greater than or equal to the second threshold. The control device 3 controls the humidity at time t ０ From time t １ During this period, if the measured water temperature is below the first target water temperature, the heater 114d is turned ON.

[0106] Meanwhile, the control device 3 controls time t ０ From time t １ During this period, if the measured water temperature exceeds the first target water temperature, the heater 114d is turned OFF. Through this control, the measured water temperature converges to the first target water temperature.

[0107] And then, at time t １ In this state, the difference between the target humidity and the measured humidity (i.e., the humidity difference) falls below the second threshold. In other words, the measured humidity no longer satisfies the second condition. As a result, the control device 3 terminates the first humidification stage of the first humidification control.

[0108] The measured water temperature is as shown in Figure 6, at time t ０ From time t １ During this period, the water temperature rises at a nearly constant rate towards the first target temperature. Furthermore, the measured humidity, as shown in Figure 6, at time t ０ From time t １ During this period, the humidity rises at a nearly constant rate towards the target level.

[0109] Next, referring again to Figure 4B, the processes performed in the second humidification stage of the first humidification control will be described. The processes in steps S206 to S209 in Figure 4B are the processes performed in the second humidification stage of the first humidification control.

[0110] (Step S206) In step S206 of Figure 4B, the control device 3 sets the second target water temperature to the target water temperature. The second target water temperature is a second predetermined value higher than the target water temperature (i.e., the reference target water temperature) obtained in step S101 of Figure 4A.

[0111] The second predetermined value is smaller than the first predetermined value used in step S202. In other words, the second target water temperature is lower than the first target water temperature set in step S202.

[0112] (Step S207) Next, in step S207 of Figure 4B, the control device 3 determines whether the measured water temperature is less than the second target water temperature. The measured water temperature is the water temperature obtained in step S102 of Figure 4A.

[0113] If the measured water temperature is below the second target water temperature (YES in step S207), the control device 3 proceeds to step S208.

[0114] On the other hand, if the measured water temperature is not below the second target water temperature (NO in step S207), the control device 3 proceeds to step S209.

[0115] Thus, in step S207, the control device 3 decides whether to turn the heater 114d ON or OFF.

[0116] (Step S208) Next, in step S208 of Figure 4B, the control device 3 turns on the heater 114d.

[0117] If the heater 114d is already in the ON state, the control device 3 maintains the ON state of the heater 114d. If the heater 114d is in the OFF state, the control device 3 switches the state of the heater 114d from the OFF state to the ON state.

[0118] Furthermore, the control device 3 controls the output of the heater 114d to a level corresponding to the second target water temperature. As a result, the water in the container 114a is heated by the heater 114d with an amount of heating corresponding to the second target water temperature.

[0119] Furthermore, since the second target water temperature is lower than the first target water temperature, the output of the heater 114d in step S208 of Figure 4B (i.e., the amount of heating) will be smaller than the output of the heater 114d in step S204 of Figure 4B (i.e., the amount of heating).

[0120] In this example, if the measured water temperature is below the second target water temperature, the control device 3 turns on the heater 114d to heat the water in the container 114a. After that, the control device 3 completes the control process shown in Figure 4B and proceeds to step S106 in Figure 4A.

[0121] (Step S209) Next, in step S209 of Figure 4B, the control device 3 turns the heater 114d to the OFF state.

[0122] If the heater 114d is already in the OFF state, the control device 3 maintains the OFF state of the heater 114d. If the heater 114d is in the ON state, the control device 3 switches the heater 114d from the ON state to the OFF state. As a result, the water in the container 114a is no longer heated by the heater 114d.

[0123] Thus, in this example, if the measured water temperature is above the second target water temperature, the control device 3 turns off the heater 114d and does not heat the water in the container 114a. This configuration prevents the water in the container 114a from being heated more than necessary.

[0124] Subsequently, the control device 3 completes the control process shown in Figure 4B and proceeds to step S106 in Figure 4A.

[0125] The second humidification stage of the first humidification control described above is the period T shown in Figure 6. ２ This is repeated. In other words, the second humidification stage of the first humidification control is at time t in Figure 6. １ It starts at time t ２ It will end here.

[0126] Note that time t １ From time t ２ Up to time t, the difference between the target humidity and the measured humidity (i.e., the humidity difference) is less than the second threshold. The control device 3 controls time t １ From time t ２ During this period, if the measured water temperature is below the second target water temperature, the heater 114d is turned ON.

[0127] Meanwhile, the control device 3 controls time t １ From time t ２ During this period, if the measured water temperature exceeds the second target water temperature, the heater 114d is turned OFF. Through this control, the measured water temperature converges to the second target water temperature.

[0128] And then, at time t ２In this state, the humidity difference falls below the first threshold. In this state, the conditions in step S103 of Figure 4A are no longer met. As a result, the control device 3 terminates the second humidification stage of the first humidification control.

[0129] The measured water temperature is as shown in Figure 6, at time t １ From time t ２ During this period, the water temperature decreases towards the second target temperature and is then maintained at the second target temperature. Furthermore, the measured humidity, as shown in Figure 6, at time t １ From time t ２ During this period, the humidity gradually increases towards the target level.

[0130] (Operation and Effects of the First Humidification Control) As described above, in the first humidification control, the control device 3 controls the heater 114d by ON / OFF control based on the target water temperature (specifically, the first target water temperature and the second target water temperature) and the measured water temperature.

[0131] Specifically, the control device 3 heats the water in the container 114a with the heater 114d in the first and second humidification stages of the first humidification control so that the measured water temperature reaches the target water temperature (in this example, the second target water temperature). After the measured water temperature reaches the target water temperature, the control device 3 controls the output of the heater 114d by ON / OFF control to maintain the measured water temperature at the target water temperature.

[0132] This type of first-stage humidification control allows for shortening the humidification time and optimizing the amount of humidification by appropriately changing the target water temperature according to the difference between the target humidity and the measured humidity (i.e., the humidity difference).

[0133] When the measured humidity is far from the target humidity, it is important to quickly bring the measured humidity closer to the target humidity.

[0134] In this example, when the measured humidity is far from the target humidity (i.e., the humidity difference is large), the amount of water evaporation can be increased and the humidifying effect enhanced by setting the target water temperature to a first target water temperature that is a first predetermined value higher than the standard target water temperature.

[0135] Furthermore, when the measured humidity is close to the target humidity (i.e., the humidity difference is small), the amount of water evaporation can be suppressed and the humidification effect can be finely adjusted by setting the target water temperature to a second target water temperature that is lower than the first target water temperature.

[0136] The control device 3 may perform the first humidification control using a single target water temperature. In this case, the target water temperature may be the target water temperature obtained from the relational expression in step S101 of Figure 4A (in other words, the reference target water temperature).

[0137] (Second Humidification Control) Next, with reference to Figure 4C, the second humidification control performed in step S105 of Figure 4A will be described. Figure 4C is a flowchart of the second humidification control process.

[0138] (Step S301) In step S301 of Figure 4C, the control device 3 determines whether the difference between the measured humidity and the target humidity (i.e., the humidity difference) is less than or equal to the third threshold.

[0139] The "third threshold" is the upper limit of the acceptable humidity difference when the humidity in culture room 101d exceeds the target humidity. In other words, even if the humidity in culture room 101d exceeds the target humidity, the excess humidity must be kept below the third threshold.

[0140] If the humidity difference is below the third threshold (YES in step S301), the control device 3 proceeds to step S302.

[0141] On the other hand, if the humidity difference is not below the third threshold (NO in step S301), the control device 3 proceeds to step S304.

[0142] (Step S302) In step S302 of Figure 4C, the control device 3 determines whether the measured water temperature is less than the second target water temperature. The measured water temperature is the water temperature obtained in step S102 of Figure 4A.

[0143] If the measured water temperature is below the second target water temperature (YES in step S302), the control device 3 proceeds to step S303.

[0144] On the other hand, if the measured water temperature is not below the second target water temperature (NO in step S302), the control device 3 proceeds to step S304.

[0145] (Step S303) In step S303 of Figure 4C, the control device 3 switches the control method of the heater 114d to feedback control. In this example, the control device 3 controls the heater 114d by PI control.

[0146] Specifically, the control device 3 controls the heater 114d by PI control based on the target humidity and the measured humidity. The control device 3 acquires the measured humidity. The humidity of the culture chamber 101d used in step S303 is the humidity information acquired from the humidity sensor 114c in step S102 in Figure 4A.

[0147] The control device 3 generates a proportional control output by proportional control (in other words, P control) based on the difference between the target humidity and the measured humidity. The control device 3 also generates an integral control output by integral control (in other words, I control) based on the difference between the target humidity and the measured humidity.

[0148] The control device 3 then generates a heater control output for controlling the output of the heater 114d based on the proportional control output and the integral control output. The control device 3 controls the heater 114d based on the generated heater control output. After that, the control device 3 completes the control process shown in Figure 4C and proceeds to step S106 in Figure 4A.

[0149] As described above, in this example, when the measured humidity is below the third threshold and the measured water temperature is below the second target water temperature, the control device 3 controls the heater 114d by feedback control (PI control in this example).

[0150] Furthermore, the control method for feedback control is not limited to PI control. The control method for feedback control may be, for example, PID control. In the case of PI control, it is possible to stably bring the humidity of the culture chamber 101d closer to the target humidity. On the other hand, in the case of PID control, responsiveness can be further improved.

[0151] (Step S304) In step S304 of Figure 4C, the control device 3 turns the heater 114d OFF. After that, the control device 3 finishes the control process in Figure 4C and proceeds to step S106 of Figure 4A.

[0152] If the heater 114d is already in the OFF state, the control device 3 maintains the OFF state of the heater 114d. If the heater 114d is in the ON state, the control device 3 switches the heater 114d from the ON state to the OFF state. As a result, the water in the container 114a is no longer heated by the heater 114d.

[0153] As described above, in this example, if the measured humidity is not below the third threshold, or if the measured water temperature is not below the second target water temperature, the control device 3 turns off the heater 114d. In other words, the heater 114d does not heat the water in the container 114a. This configuration prevents the water in the container 114a from being heated more than necessary.

[0154] The second humidification control described above is performed during period T in Figure 6. ３ This is repeated. In other words, the second humidification control is performed at time t in Figure 6. ２ It starts at time t ３ It will end at time t. ３ This is the time when the control device 3 terminates the humidification control.

[0155] Furthermore, the control device 3 controls time t ２ From time t ３ During this period, if the measured water temperature is below the second target water temperature, the control device 3 controls the heater 114d by feedback control based on the target humidity and the measured humidity. As a result, the humidity in the culture chamber 101d is maintained at the target humidity.

[0156] Meanwhile, the control device 3 controls time t ２ From time t ３ During this period, if the measured water temperature is not below the second target water temperature, the heater 114d is turned OFF. As a result, the water in container 114a is prevented from being heated more than necessary.

[0157] (Operation and Effects of Second Humidification Control) As described above, the control device 3 performs the second humidification control described above when the difference between the target humidity and the measured humidity (i.e., the humidity difference) is less than the first threshold. In other words, the control device 3 performs the second humidification control when the measured humidity is close to the target humidity.

[0158] In this second humidification control, the control device 3 controls the heater 114d by feedback control (PI control in this example) based on the difference between the target humidity and the measured humidity (i.e., the humidity difference). In other words, in the second humidification control, the control device 3 controls the output of the heater 114d by feedback control so that the humidity difference falls within a predetermined range.

[0159] When the measured humidity is close to the target humidity, fine-tuning the amount of humidification is important. In this example, the control device 3 suppresses overshoot (excessive increase in humidity) by smoothly controlling the output of the heater 114d using feedback control (PI control in this example). As a result, the humidity in the culture chamber 101d can be stably converged to the target humidity.

[0160] Furthermore, the second humidification control described above suppresses large fluctuations in the measured humidity around the target value after it has reached the target humidity. Therefore, the measured humidity can be stabilized near the target humidity. As a result, a stable culture environment can be achieved.

[0161] (Operation and Effects of this Embodiment) As described above, in the culture apparatus 1 according to this embodiment, the humidification control switches between a first humidification control and a second humidification control depending on the difference between the target humidity and the measured humidity. The first humidification control is performed when the measured humidity is far from the target humidity, and can quickly raise the humidity of the culture chamber 101d. The second humidification control is performed when the measured humidity is close to the target humidity, and can smoothly converge the humidity of the culture chamber 101d to the target temperature and maintain that state. Thus, according to this embodiment, the humidity of the culture chamber 101d can converge to the target humidity in a short time, and the humidity of the culture chamber 101d can be stably maintained at the target humidity.

[0162] (Note) If the measured humidity has reached the target humidity, but the measured water temperature deviates by a predetermined temperature or more from the target water temperature obtained in step S101 of Figure 4A, there is a possibility that a discrepancy has occurred between the value detected by the humidity sensor 114c (i.e., the measured humidity) and the actual humidity. In this case, the control device 3 may output information prompting calibration of the humidity sensor 114c. The user can understand from this information that calibration of the humidity sensor 114c is necessary.

[0163] Furthermore, in the above-described embodiment, the culture apparatus 1 has only an evaporative humidifier 114 that humidifies the culture chamber 101d by naturally vaporizing the water in the container 114a. However, the culture apparatus 1 may also be equipped with another humidifier in addition to the humidifier 114 that supplies steam generated by forcibly vaporizing water to the culture chamber 101d.

[0164] All disclosures in the specification, drawings, and abstract contained in the Japanese application No. 2025-057048, filed on 28 March 2025, are incorporated herein by reference.

[0165] The culture apparatus described herein can be used for culturing various types of cells.

[0166] 1. Culture Apparatus 101 Box 101a Inner Box 101b Outer Box 101c Insulation 101d Culture Chamber 101e Opening 101f Shelf 102 Inner Door 103 Outer Door 104 Gasket 105 Cover 106 Machine Room 107 Electrical Box 108 Duct 108a Intake 108b Outlet 109 Gas Passage 110 Blower 111 Gas Supply Device 112 Ultraviolet Irradiation Device 113 Heater for Culture Chamber 114 Humidification Device 114a Container 114b Water Temperature Sensor 114c Humidity Sensor 114d Heater 115 Operating Device 3. Control Device

Claims

1. A culture apparatus comprising: a humidifier that heats a container of water with a heater to humidify a culture chamber; and a control unit that controls the heater, wherein the control unit performs a first humidification control that controls the heater based on the target water temperature and the measured water temperature when the difference between the target humidity and the measured humidity of the culture chamber is greater than or equal to a first threshold; and performs a second humidification control that controls the heater based on the target humidity and the measured humidity when the difference is less than the first threshold.

2. The culture apparatus according to claim 1, wherein the control unit, in the first humidification control, heats the water with the heater so that the measured water temperature reaches the target water temperature, and after the measured water temperature reaches the target water temperature, controls the output of the heater by ON / OFF control so that the measured water temperature is maintained at the target water temperature.

3. The culture apparatus according to claim 1, wherein the control unit acquires the target water temperature based on a relational expression that pre-associates the target temperature of the culture chamber, the target humidity of the culture chamber, and the target water temperature.

4. The culture apparatus according to claim 3, wherein the control unit outputs information prompting calibration of the detection unit that detects information about the measured humidity when the measured humidity has reached the target humidity and the measured water temperature deviates from the target water temperature by a predetermined temperature or more.

5. The culture apparatus according to claim 1, wherein the control unit changes the target water temperature in the first humidification control according to the difference between the target humidity and the measured humidity.

6. The culture apparatus according to claim 4, wherein the control unit obtains a reference target water temperature based on a relational expression that pre-associates the set temperature of the culture chamber, the target humidity of the culture chamber, and the target water temperature of the water, and in the first humidification control, if the difference between the target humidity and the measured humidity is greater than or equal to a second threshold, it sets a first target water temperature higher than the reference target water temperature as the target water temperature, and in the first humidification control, if the difference between the target humidity and the measured humidity is less than a second threshold, it sets a second target water temperature that is greater than or equal to the reference target water temperature and less than the first target water temperature as the target water temperature.

7. The culture apparatus according to claim 1, wherein the control unit controls the output of the heater by feedback control so that the difference between the measured humidity and the target humidity falls within a predetermined range in the second humidification control.

8. The culture apparatus according to claim 7, wherein the control unit, in the second humidification control, turns the heater OFF when the measured water temperature becomes higher than the target water temperature.

9. A control method for a humidifying device that humidifies a culture chamber by heating a container of water with a heater, comprising: a step of obtaining the measured water temperature of the water; a step of obtaining the measured humidity of the culture chamber; a step of performing a first humidification control, which controls the heater based on the target water temperature and the measured water temperature, when the difference between the target humidity and the measured humidity is greater than or equal to a first threshold; and a step of performing a second humidification control, which controls the heater based on the target humidity and the measured humidity, when the difference is less than the first threshold.

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