Patent Publication Number: US-2021185955-A1

Title: Cultivation Device

Description:
TECHNICAL FIELD 
     The present invention relates to a cultivation device used in an artificial light plant factory. 
     BACKGROUND ART 
     Plant factories are attracting attention as a solution to problems such as food shortages due to global population growth and a decrease in agricultural production due to a decrease in rural population with aging in developed countries such as Japan. 
     Plant factories are roughly divided into two types: fully artificial light type and sunlight utilization type. In the fully artificial light type, the plants are cultivated using only an artificial light source without using sunlight in an isolated environment. In the sunlight utilization type, which is based on utilization of sunlight in an environment isolated to a greenhouse, the plants are cultivated using light supplement with artificial light or high temperature control technology in summer. 
     In a general fully artificial light type plant factory, a plurality of multi-stage cultivation shelves including artificial light sources in each stage are arranged in a cultivation room in an isolated environment, and air conditioners and the like are installed on the ceiling or the upper side of the cultivation room. Since the temperature of each cultivation shelf rises due to waste heat when the artificial light source is turned on, the air in the cultivation room is circulated by an air conditioner, and the temperature and humidity are controlled to be uniform among the cultivation shelves (see Patent Document 1). 
     Further, in order to control the amount of nutrient solution supplied to the plant, a circulation type nutrient solution supply device is used (see Patent Document 2).
     Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2002-291349   Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2005-21065   

     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     Although attempts are made to uniformly control the cultivation environment in the cultivation room by using the air conditioner as described above, difference in the temperature and humidity between the cultivation shelf installed near the air conditioner and the cultivation shelf installed far away from the air conditioner is actually generated. In addition, difference in the temperature and humidity is also generated in the vertical direction of the cultivation shelves. 
     In addition, even if a certain amount of nutrient solution is constantly supplied to the plant by the circulation type nutrient solution supply device, the water temperature of the nutrient solution rises due to the waste heat during the period when the artificial light sources are turned on, and gradually drops during the period when the artificial light sources are turned off, thereby not becoming constant. 
     Thus, in the cultivation room of a conventional plant factory, there is generated unevenness in air temperature and humidity depending on the location, and change in temperature of the nutrient solution with time. Since the growth rate of plants is affected by changes in air temperature, humidity, or nutrient solution temperature, such local changes or changes over time in the cultivation environment lead to a decrease in the productivity of the plant factory. 
     Therefore, an object of the present invention is to maintain a substantially constant cultivation environment depending on the location or time in a plant factory. 
     Means for Solving the Problems 
     The present invention relates to a cultivation device used in an artificial light plant factory, the device including: a cultivation room having a closable inside; a plurality of cultivation chambers defined by dividing the cultivation room in the vertical direction at predetermined intervals; an air circulation device that supplies air adjusted to a predetermined condition to each of the plurality of cultivation chambers at a predetermined flow velocity, and collects and circulates the supplied air from the plurality of cultivation chambers; and a nutrient solution circulation device that supplies nutrient solution adjusted to a predetermined condition to each of the plurality of cultivation chambers at a predetermined flow velocity, and collects and circulates the supplied nutrient solution from the plurality of cultivation chambers. 
     Further, it is preferable to supply the air adjusted to the predetermined condition to each of the plurality of cultivation chambers at a flow velocity of a set value that is changeable. 
     Further, it is preferable to supply the nutrient solution adjusted to the predetermined condition to each of the plurality of cultivation chambers at a flow velocity of a set value that is changeable. 
     Further, it is preferable that a flow direction of the nutrient solution supplied to the cultivation chamber by the air circulation device and the nutrient solution circulation device is along a transverse direction of the cultivation chamber. 
     Further, it is preferable that a flow direction of the air supplied to the cultivation chamber by the air circulation device and the nutrient solution circulation device is along a transverse direction of the cultivation chamber. 
     Further, it is preferable that a flow direction of the air supplied to the cultivation chamber by the air circulation device and the nutrient solution circulation device is along from an upper side to a lower side of the cultivation chamber. 
     Further, it is preferable that the cultivation device includes a plurality of rectangular cultivation plates, wherein the plurality of cultivation plates are arranged in the cultivation chamber so that the transverse direction of the cultivation plates is along a longitudinal direction of the cultivation chamber. 
     Further it is preferable that the cultivation device includes a nutrient solution tray arranged in the cultivation chamber, and used for causing nutrient solution to flow therein, wherein the nutrient solution tray is configured with a rectangular tray that is substantially the same size as the cultivation plate and on which the cultivation plate can be arranged, and the plurality of rectangular trays are arranged in the cultivation chamber so that the transverse direction of the rectangular trays is along the longitudinal direction of the cultivation chamber. 
     Further, it is preferable that the nutrient solution tray includes an inclined surface inclining at a predetermined angle in the transverse direction of the cultivation chamber so that a downstream side of the nutrient solution flow is lower. 
     Further, it is preferable that the cultivation chamber is configured with a box-shaped member, has a chamber opening for inserting and removing the cultivation plate and a chamber lid that can open and close the chamber opening, on one end side in the longitudinal direction of the cultivation chamber, and is kept by closing the chamber opening with the chamber lid. 
     Further, it is preferable that the cultivation device further includes a transport mechanism for transporting the cultivation plate, wherein the transport mechanism has: a transporter being provided in the cultivation chamber, and being used for transporting the cultivation plate in the longitudinal direction of the cultivation chamber; and an elevator being provided adjacent to the side of the cultivation chamber where the chamber opening is provided, and being used for inserting and removing the cultivation plate through the chamber opening and for transporting the cultivation plate in the vertical direction. 
     Further, it is preferable that: the elevator is provided in the cultivation room; and the cultivation room has a cultivation room opening for inserting and removing the cultivation plate, and a cultivation room lid that can open and close the cultivation room opening, on one end side in the longitudinal direction, the one end side having the elevator provided thereon. 
     Further, it is preferable that: the nutrient solution tray arranged in the cultivation chamber and used for causing the nutrient solution to flow therein is configured with a rectangular tray that is substantially the same size as the cultivation plate and on which the cultivation plate can be arranged; and the transport mechanism transports the cultivation plate and the rectangular tray in a state where the cultivation plate is arranged on the rectangular tray. 
     Effects of the Invention 
     According to the present invention, since the air circulation device supplies air to each of the plurality of cultivation chambers arranged in the vertical direction in the closed cultivation room, a uniform cultivation environment can be provided regardless of location in the cultivation room, and since air and nutrient solution always adjusted to a predetermined condition are supplied to the cultivation chamber in the cultivation room and collected therefrom in a short time, the environment in the cultivation room can be kept almost constant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  A functional block diagram showing a configuration of a cultivation device according to a first embodiment of the present invention; 
         FIG. 2  A diagram showing the appearance of the cultivation device according to the first embodiment; 
         FIG. 3  A diagram showing the inside of the cultivation device according to the first embodiment; 
         FIG. 4  A schematic cross-sectional view of a cultivation room included in the cultivation device according to the first embodiment as viewed from the longitudinal direction; 
         FIG. 5A  An explanatory diagram of a cultivation plate and a cultivation tray arranged in the cultivation device according to the first embodiment; 
         FIG. 5B  An explanatory diagram of an artificial light source included in the cultivation device according to the first embodiment; 
         FIG. 6  An explanatory diagram of an air circulation device included in the cultivation device according to the first embodiment; 
         FIG. 7  An explanatory diagram of a nutrient solution circulation device included in the cultivation device according to the first embodiment; 
         FIG. 8  A functional block diagram showing a configuration of a cultivation device according to a second embodiment of the present invention; 
         FIG. 9  A diagram showing the appearance of the cultivation device according to the second embodiment; 
         FIG. 10  A schematic cross-sectional view of a cultivation room included in the cultivation device according to the second embodiment as viewed from the longitudinal direction; 
         FIG. 11  An explanatory diagram of an air circulation device included in the cultivation device according to the second embodiment; 
         FIG. 12  A schematic view for explaining the configuration of the transport mechanism according to the second embodiment; 
         FIG. 13A  An explanatory diagram of a method of transporting a cultivation plate using the transport mechanism according to the second embodiment; 
         FIG. 13B  An explanatory diagram of a method of transporting a cultivation plate using the transport mechanism according to the second embodiment; 
         FIG. 13C  An explanatory diagram of a method of transporting a cultivation plate using the transport mechanism according to the second embodiment; 
         FIG. 13D  An explanatory diagram of a method of transporting a cultivation plate using the transport mechanism according to the second embodiment; 
         FIG. 13E  An explanatory diagram of a method of transporting a cultivation plate using the transport mechanism according to the second embodiment; 
         FIG. 13F  An explanatory diagram of a method of transporting a cultivation plate using the transport mechanism according to the second embodiment; and 
         FIG. 13G  An explanatory diagram of a method of transporting a cultivation plate using the transport mechanism according to the second embodiment. 
     
    
    
     PREFERRED MODE FOR CARRYING OUT THE INVENTION 
     Preferred embodiments of the cultivation device of the present invention is described blow with reference to the drawings. The cultivation device of the present invention is used in an artificial light plant factory, and is suitably used in a plant factory having a large production scale where it has conventionally been difficult to govern the cultivation environment. 
     First Embodiment 
     A cultivation device  1 A of a first embodiment is described with reference to  FIGS. 1 to 7 . 
       FIG. 1  is a functional block diagram showing the configuration of the cultivation device  1 A of the present invention. The cultivation device  1 A includes a cultivation room  10 A, a plurality of cultivation chambers  20 A, an air circulation device  30 , a nutrient solution circulation device  40 , an operation unit  50 , a control unit  60 , and a display unit  70 . 
     As shown in  FIG. 2 , the cultivation room  10 A includes a rectangular parallelepiped outer wall having a closable inside, and can maintain a cultivation environment independent from the environment (temperature and humidity) in the work room of the plant factory in which the cultivation device  1 A is arranged. As the material of the outer wall, it is preferable to use a heat insulating material not to be affected by the environment in the work room outside the cultivation room  10 A.  FIG. 3  shows the cultivation device  1 A in a state where the outer wall of the cultivation room  10 A is removed. 
       FIG. 4  shows a schematic cross-sectional view of the cultivation room  10  of the present invention as viewed from the longitudinal direction. 
     As shown in  FIG. 4 , the plurality of cultivation chambers  20 A are defined by dividing the cultivation room  10 A in the vertical direction by shelf boards  111  at predetermined intervals, and each of them has a substantially rectangular parallelepiped shape. The plurality of cultivation chambers  20 A can be configured by providing an exterior on a conventionally known multi-stage cultivation shelf. In this embodiment, the cultivation chamber  20 A is configured by providing an exterior (outer wall of the cultivation room  10 A) on a five-stage cultivation shelf  100 . 
     In each cultivation chamber  20 A, a plurality of nutrient solution trays  210  and cultivation plates  220  as shown in  FIG. 5A  are arranged so that the transverse direction of them is along the longitudinal direction of the cultivation chamber  20 A, as shown in  FIG. 5B . The nutrient solution tray  210  has substantially the same size as the rectangular cultivation plate  220 , and is configured with a rectangular tray into which the cultivation plate  220  can be arranged so as to be fitted. In this embodiment, 16 nutrient solution trays  210  having a size of about 30 cm×120 cm, each of which has the cultivation plate  220  fitted therein, are arranged in each cultivation chamber  20 A (see  FIG. 5B ). 
     It should be noted that the shape of the cultivation chamber  20 A is preferably a long shape in which the length in the longitudinal direction is more than twice the length in the transverse direction so that the cultivation chamber  20 A is suitably used in a plant factory having a large production scale. In this embodiment, the length in the transverse direction: the length in the longitudinal direction=1:5. However, the size of the cultivation chamber  20 A (the number of cultivation plates  220  arranged in the cultivation chamber  20 A) is not limited to the size of the above-described embodiment. 
     Further, in this embodiment, the nutrient solution tray  210  and the cultivation plate  220  are rectangular, but the present invention is not limited to this and they may be square. In the case of a square, one side of the square cultivation plate  220  is arranged along the longitudinal direction of the cultivation chamber  20 A. 
     Thus, in the state where the nutrient solution tray  210  is arranged, each of the plurality of cultivation chambers  20  is in a closed or semi-closed state. 
     Further, in the nutrient solution tray  210 , a discharge port  211  (see  FIG. 4 ) for discharging the supplied nutrient solution is formed on one end side (downstream side of the nutrient solution flow) in the longitudinal direction. Further, the nutrient solution tray  210  includes an inclined surface that inclines at a predetermined angle (for example, about 1 degree) in the transverse direction of the cultivation chamber  20 A so that the downstream side of the nutrient solution flow is lower. This can create a unidirectional flow at a predetermined flow velocity according to the supply flow rate without stagnancy of the supplied nutrient solution in the nutrient solution tray  210 . Further, a nutrient solution collection pipe  470  to be described below is arranged below the discharge port  211  (see  FIG. 4 ). 
     The nutrient solution tray  210  does not have to have a size corresponding to one cultivation plate  220 , and may be configured so that a plurality of cultivation plates  220  can be arranged in one nutrient solution tray  210 . 
     Further, as shown in  FIG. 5B , artificial light sources  230  are arranged above each cultivation chamber  20 A, and a dimmer  231  for dimming the artificial light source  230  is connected. In this embodiment, two artificial light sources  230  are arranged along the longitudinal direction of the nutrient solution tray  210  and the cultivation plate  220  (the transverse direction of the cultivation chamber  20 A). As the artificial light source  230 , an LED that consumes less power and can be configured to be thin is suitably used. Moreover, a fluorescent lamp may be used as an artificial light source. 
     As shown in  FIGS. 2 and 3 , the air circulation device  30  is arranged adjacent to the cultivation shelf  100  on one end side in the longitudinal direction of the cultivation room  10 . The air circulation device  30  supplies the air adjusted to a predetermined condition to each cultivation chamber  20 A at a predetermined flow velocity, collects the air that has passed through the inside of each cultivation chamber  20 A to adjust it to meet the predetermined condition, and repeats this procedure to circulate and supply the air. 
     The configuration of the air circulation device  30  is described below with reference to  FIG. 6 . It is sufficient that the air circulation device  30  has at least a function of adjusting temperature, humidity, carbon dioxide concentration, and air flow velocity (flow rate). In this embodiment, the air circulation device  30  includes: an air sterilizer  310 ; an air conditioner  320  of a direct expansion system (with a method where the air is cooled directly with a refrigerant) that has warming, cooling, and dehumidifying functions; a humidifier  330  with a humidifying function; a carbon dioxide supply device  340  that adjusts the carbon dioxide concentration; a suction pump  350 ; and a compression pump  360 . 
     As a device having a function of adjusting the temperature, a chiller device of an indirect expansion system (with a method where the air is cooled via water with a refrigerant) may be used. 
     Each cultivation chamber  20 A and the air circulation device  30  are connected via an air collection pipe  370 A and an air supply pipe  380 . The air collection pipe  370 A and the air supply pipe  380  extend in the longitudinal direction of the cultivation chamber  20 . A plurality of air collection ports  371  provided at predetermined intervals are formed in the air collection pipe  370 A. Further, the air supply pipe  380  is formed with a plurality of air supply ports  381  provided at predetermined intervals, and these air supply ports  381  are provided with flow regulating valves (not shown). 
     Further, a temperature sensor, a humidity sensor and a carbon dioxide concentration sensor (not shown) are attached to predetermined locations in each cultivation chamber  20 A, and the temperature, humidity and carbon dioxide concentration of the circulating air are monitored. 
     The air collected from each cultivation chamber  20 A by the suction pump  350  via the air collection pipe  370 A is sterilized through the air sterilizer  310  and sent to the air conditioner  320 . In the air conditioner  320 , after temperature adjustment and dehumidification according to the measurement results of the temperature sensor and the humidity sensor, the humidifier  330  humidifies the air. After that, the carbon dioxide supply device  340  supplies carbon dioxide from the carbon dioxide supply source  341  such as a carbon dioxide cylinder according to the measurement result of the carbon dioxide concentration sensor. Then, the compression pump  360  supplies air adjusted to a predetermined condition and a predetermined flow velocity to each cultivation chamber  20 A through the air supply pipe  380 . 
     The set value of the air flow velocity may be fixed or changeable. 
     At this time, as shown in  FIG. 4 , the air flow direction in the cultivation chamber  20 A is along the transverse direction of the cultivation chamber  20 A. As a result, the time from air supply to collection can be shortened as compared with the case where the air is supplied so that the flow direction is along the longitudinal direction of the cultivation chamber  20 A. Therefore, it is possible to reduce changes in the cultivation environment such as temperature, humidity, and carbon dioxide concentration that is generated between the upstream side and the downstream side of the air flow. 
     However, the present invention is not limited to this, and the air flow direction in the cultivation chamber  20 A may be along from the upper side to the lower side of the cultivation chamber  20 A. 
     Here, in this embodiment, one cultivation device  1 A includes one cultivation room  10 A, and one cultivation room  10 A includes a plurality of cultivation chambers  20 A and one air circulation device  30 , in which the air is sent from one air circulation device  30  to the plurality of cultivation chambers  20 A. 
     However, the present invention is not limited to this, and there may be a configuration in which one cultivation device  1 A includes one cultivation room  10 A, and one cultivation room  10 A includes a plurality of cultivation chambers  20 A and a plurality of air circulation devices  30  corresponding to each cultivation chamber  20 , in which the air is sent from the corresponding air circulation device  30  to each of the plurality of cultivation chambers  20 A. In this case, the temperature, humidity, carbon dioxide concentration, flow velocity (flow rate), and the like of the circulating air can be changed for each of the cultivation chambers  20 A. 
     Further, one cultivation device  1 A may include a plurality of cultivation rooms  10 A, and each of the plurality of cultivation rooms  10 A may include a plurality of cultivation chambers  20 A and one air circulation device  30 . 
     Further, one cultivation device  1 A may include a plurality of cultivation rooms  10 A, and each of the plurality of cultivation rooms  10 A may include a plurality of cultivation chambers  20 A and a plurality of air circulation devices  30  corresponding to the respective cultivation chambers  20 . 
     The nutrient solution circulation device  40  is arranged below the cultivation room  10 A as shown in  FIGS. 2 and 3 . The nutrient solution circulation device  40  supplies the nutrient solution adjusted to the predetermined condition to the nutrient solution tray  210  of each cultivation chamber  20 A at a predetermined flow velocity, collects the nutrient solution that has passed through each nutrient solution tray and adjusts it to meet the predetermined condition, and repeats this procedure to circulate and supply the nutrient solution. 
     The configuration of the nutrient solution circulation device  40  is described below with reference to  FIG. 7 . It is sufficient that the nutrient solution circulation device  40  has at least a function of adjusting the temperature of the nutrient solution and nutrients (various straight fertilizer ions such as nitrogen, phosphoric acid, and potassium). In this embodiment, the nutrient solution circulation device  40  includes: a nutrient solution sterilizer  410 ; a nutrient solution tank  420  connected to the city water supply source; a chiller device with warming and cooling functions (not shown); a nutrient supply device  440 ; an oxygen supply device  450  that supplies oxygen to adjust the dissolved oxygen concentration; and a pressure pump  460  for the nutrient solution. 
     Each cultivation chamber  20 A and the nutrient solution circulation device  40  are connected through a nutrient solution collection pipe  470  and a nutrient solution supply pipe  480 . The nutrient solution collection pipe  470  extends in the longitudinal direction of the cultivation chamber  20 A, and is configured so that the nutrient solution discharged from the discharge port of the nutrient solution tray  210  can be collected. Further, the nutrient solution supply pipe  480  also extends in the longitudinal direction of the cultivation chamber  20 , and the nutrient solution supply pipe  480  has a plurality of nutrient solution supply ports  481  formed at predetermined intervals. The nutrient solution supply port  481  may be opened in the nutrient solution supply pipe  480  so as to face downward, but it is preferably opened so as to face the direction along the flow direction of the nutrient solution as in this embodiment (See  FIGS. 4 and 7 ). As a result, the flow velocity of the nutrient solution can be increased for the same supply amount as compared with the case of opening downward. 
     Here, in this embodiment, one cultivation device  1 A includes one cultivation room  10 A, and one cultivation room  10 A includes a plurality of cultivation chambers  20 A and one nutrient solution circulation device  40 , in which the nutrient solution is sent from one nutrient solution circulation device  40  to the plurality of cultivation chambers  20 A. 
     Further, the set value of the flow velocity of the nutrient solution may be fixed or changeable. 
     However, the present invention is not limited to this, and there may be a configuration in which one cultivation device  1 A includes one cultivation room  10 A, and one cultivation room  10 A includes a plurality of cultivation chambers  20 A and a plurality of nutrient solution circulation devices  40  corresponding to each cultivation chamber  20 , in which the nutrient solution is sent from the corresponding nutrient solution circulation device  40  to each of the plurality of cultivation chambers  20 A. In this case, the temperature, nutrients, flow velocity and the like of the nutrient solution can be changed for each cultivation chamber  20 A. 
     Further, one cultivation device  1 A may include a plurality of cultivation rooms  10 A, and each of the plurality of cultivation rooms  10 A may include a plurality of cultivation chambers  20 A and one nutrient solution circulation device  40 . 
     Further, one cultivation device  1 A may include a plurality of cultivation rooms  10 A, and each of the plurality of cultivation rooms  10 A may include a plurality of cultivation chambers  20 A and a plurality of nutrient solution circulation devices  40  corresponding to the respective cultivation chambers  20 . 
     Further, a water temperature sensor (not shown) is attached to the nutrient solution tank  420 , and a straight fertilizer sensor SFS for measuring the concentration of various nutrients is attached in the vicinity of the connection port of the nutrient solution tank  420  with the nutrient solution collection pipe  470 . They monitor the water temperature of the nutrient solution in circulation and the concentration of various straight fertilizer ions. The chiller device adjusts the temperature of the nutrient solution according to the measurement result of the water temperature sensor. 
     The nutrient supply device  440  is configured to include a straight fertilizer ion concentration control unit  441 , a straight fertilizer sensor SFS, and a straight fertilizer ion supply plunger  442 . Then, in this nutrient supply device  440 , the straight fertilizer ion concentration control unit  441  drives the straight fertilizer ion supply plunger  442  according to the measurement results of various straight fertilizer sensors SFS to adjust the straight fertilizer ion concentration of the nutrient solution. The straight fertilizer ion concentration of the nutrient solution may be measured using a pH sensor and an EC sensor. 
     The nutrient solution stored in the nutrient solution tank  420  is adjusted to a predetermined water temperature by a chiller device, is adjusted to a predetermined straight fertilizer ion concentration by a nutrient supply device  440 , and is adjusted by the oxygen supply device  450  to have a predetermined amount of dissolved oxygen. After that, the nutrient solution pressure pump  460  supplies the nutrient solution to the nutrient solution trays  210  arranged in each cultivation chamber  20 A through the nutrient solution supply pipe  480 . As shown in  FIG. 4 , the nutrient solution flows through the nutrient solution tray  210  at a predetermined flow velocity along the transverse direction of the cultivation chamber  20 A, is discharged from the discharge port  211  of the nutrient solution tray  210 , and flows into the nutrient solution collection pipe  470 . The nutrient solution collected by the nutrient solution collection pipe  470  connected to each cultivation chamber  20 A is sterilized by the nutrient solution sterilizer  410  and then flows into the nutrient solution tank  420 . 
     At this time, the flow direction of the nutrient solution in the cultivation chamber  20 A is along the transverse direction of the cultivation chamber  20 A. As a result, the time from supply to collection of the nutrient solution can be shortened as compared with the case where the flow direction of the nutrient solution is along the longitudinal direction of the cultivation chamber  20 A. 
     One nutrient solution tank  420  may be provided for each cultivation chamber  20 A, or only one may be provided for each cultivation room  10 . 
     The operation unit  50  is configured with buttons, a keyboard, and the like for setting the inside of the cultivation room  10  to be in a predetermined cultivation environment, and as shown in  FIGS. 1 and 2 , is arranged outside the one end side (the side where the air circulation device  30  is arranged) in the longitudinal direction of the cultivation room  10 . 
     The control unit  60  is arranged inside the cultivation room  10 . The control unit  60  receives signals from the air circulation device  30 , the nutrient solution circulation device  40 , and the operation unit  50  to control the air circulation device  30 , the nutrient solution circulation device  40 , and the display unit  70  to described below, and is configured with, for example, a central processing unit, a computer device including a RAM, a ROM, or the like. 
     The display unit  70  is used for displaying the measurement results monitored by various sensors in each cultivation chamber  20  in the cultivation room  10 , or the predetermined cultivation environment set by the operation unit  50 , and is configured with a liquid crystal panel or the like. As shown in  FIGS. 2 and 3 , the display unit  70  is arranged outside the one end side (the side where the air circulation device  30  is arranged) in the longitudinal direction of the cultivation room  10 . 
     Note that the operation unit  50 , the control unit  60 , and the display unit  70  may be configured separately from the cultivation room  10  instead of being integrally configured with the cultivation room  10 . In that case, a control panel including an operation unit, a control unit, and a display unit may be arranged at a predetermined location in the plant factory, and the control panel may centrally govern the cultivation environment of a plurality of cultivation chambers  20  in each of the plurality of cultivation rooms  10 . 
     According to the cultivation device  1 A of the present invention described above, the following effects are exhibited. 
     (1) The cultivation device  1 A used in an artificial light plant factory includes: a rectangular parallelepiped cultivation room  10 A having a closable inside; a plurality of rectangular parallelepiped cultivation chambers  20 A defined by dividing the cultivation rooms  10 A in the vertical direction at predetermined intervals; an air circulation device  30  which supplies air adjusted to a predetermined condition to each of the plurality of cultivation chambers  20 A at a predetermined flow velocity and collects the supplied air from the plurality of cultivation chambers  20 A to circulate the air; and a nutrient solution circulation device  40  which supplies a nutrient solution adjusted to a predetermined condition to each of the plurality of cultivation chambers  20 A at a predetermined flow velocity and collects the supplied nutrient solution from the plurality of cultivation chambers  20 A to circulate the nutrient solution. 
     As a result, the air is supplied by the air circulation device  30  to each of the plurality of cultivation chambers  20 A arranged in the vertical direction in the closed cultivation room  10 A, so that a uniform cultivation environment can be provided in the cultivation room  10 A regardless of the location. 
     Further, since the cultivation room  10 A has a closable structure, when the cultivation device  1 A of the present invention is arranged in a work room where a person works in a plant factory, the environment inside the cultivation room  10 A and the work room can be set to be independent. Therefore, unlike the work room in a conventional plant factory, it is not necessary for the plants and humans to coexist. This allows the environment in the cultivation room  10 A to be set, for example, to be optimum cultivation conditions for plants, which is not necessarily suitable for the human body. Further, since the cultivation device  1 A of the present invention can independently set the optimum cultivation environment for each device  1 A, it is possible to cultivate plants having different cultivation conditions in one work room of a plant factory. Further, the cultivation room  10 A is made a closed type, so that the temperature and humidity can be governed inside the cultivation room  10 A without affection by the temperature and humidity inside the plant factory. Therefore, since the conditions to govern environment inside the plant factory can be set relaxed, the plant factory can be a larger size. 
     (2) The flow directions of the air and the nutrient solution supplied to the cultivation chamber  20 A, respectively by the air circulation device  30  and the nutrient solution circulation device  40 , are along the transverse direction of the cultivation chamber  20 A. As a result, air and nutrient solution adjusted to a predetermined condition are always supplied to the cultivation chamber  20 A in the cultivation room  10 , flow in the transverse direction of the cultivation chamber  20 A, and are collected in a short time, thereby reducing changes in the cultivation environment between the upstream side and the downstream side. This can reduce changes in the environment (changes in temperature or humidity) with time inside the cultivation room  10 A. As a result, an optimum and uniform cultivation environment for plant growth can be kept, and productivity of the plant factory can be improved. 
     (3) The cultivation device  1 A includes a plurality of rectangular cultivation plates  220 , and the plurality of cultivation plates  220  are arranged in the cultivation chamber  20 A so that the transverse direction is along the longitudinal direction of the cultivation chamber  20 A. This can reduce changes in the cultivation environment even in a long cultivation device  1 A (cultivation chamber  20 A) in which a plurality of cultivation plates  220  can be arranged, because the air and nutrient solution flow in the transverse direction. Therefore, it is possible to efficiently produce a large amount of plants in a cultivation chamber in which the environment is uniformly controlled. 
     (4) The cultivation device  1 A includes a nutrient solution tray  210  for causing the nutrient solution to flow therein, which is arranged in the cultivation chamber  20 , and the nutrient solution tray  210  includes an inclined surface inclining at a predetermined angle in the transverse direction of the cultivation chamber  20 A so that the downstream side of the nutrient solution flow is lower. This can cause the nutrient solution to flow in the transverse direction at a predetermined flow velocity without stagnancy along the transverse direction of the cultivation chamber  20 A. For example, the nutrient solution tray can be configured to be shallower as compared with the case where the nutrient solution flows in the longitudinal direction with an inclination in the longitudinal direction. This can lower the height of the cultivation chamber  20 A to save the space. So, if the cultivation chambers  20 A are arranged in the same space, the number of stages of them can be increased, and this can increase the production amount per unit area. Further, since the plant can be cultivated while the nutrient solution flows at a predetermined flow velocity, the root of the plant can be always kept in contact with the new nutrient solution. Therefore, the growth of plants can be further promoted, and the production efficiency of plants can be improved. 
     (5) The nutrient solution tray of the cultivation device  1 A is configured with a rectangular tray  210 , having substantially the same size as the cultivation plate  220 , on which the cultivation plate  220  can be arranged. The plurality of rectangular trays  210  are arranged in the cultivation chamber  20 A so that the transverse direction is along the longitudinal direction of the cultivation chamber  20 A. As a result, the nutrient solution trays are in a state in which they are partitioned along the transverse direction of the cultivation chamber  20 A, so that the supplied nutrient solution can easily flow along the transverse direction of the cultivation chamber  20 A. 
     Second Embodiment 
     A cultivation device  1 B of a second embodiment is described below with reference to  FIGS. 8 to 13 . 
     The cultivation device  1 B according to the second embodiment is different from the one according to the first embodiment in the configuration of the cultivation room, the configuration of the cultivation chamber, and the configuration of the air collection pipe connecting the cultivation chamber and the air circulation device, and is also different from the first embodiment in that it further includes a transport mechanism for transporting the cultivation plate. In this embodiment, a configuration different from that of the first embodiment is described in detail, and the equivalent configurations are given the same reference numerals and the description thereof is omitted. 
       FIG. 8  is a functional block diagram showing the configuration of a cultivation device  1 B of the present invention.  FIG. 9  is a perspective view showing the cultivation device  1 B. 
     The cultivation device  1 B includes a cultivation room  10 B, a plurality of cultivation chambers  20 B, an air circulation device  30 , a nutrient solution circulation device  40 , an operation unit  50 , a control unit  60 , a display unit  70 , and a transport mechanism  80 . 
     The cultivation room  10 B is configured in a rectangular parallelepiped shape in which a plurality of box-shaped cultivation chambers  20 B are stacked in the vertical direction. As a result, each of the plurality of cultivation chambers  20 B is configured so that the inside can be closed, and can maintain a cultivation environment independent from the environment (temperature and humidity) of the work room of the plant factory in which the cultivation device  1 B is arranged. As the material of the cultivation chamber  20 B, it is preferable to use a heat insulating material not to be affected by the environment in the work room outside the cultivation room  10 B. In this embodiment, the cultivation room  10 B is configured to include a five-stage cultivation chamber  20 B. 
     Further, in a bottom part of one end side in the longitudinal direction of the cultivation room  10 B (the side opposite to the side where the air circulation device  30  is provided), there is provided a cultivation room opening  11  for inserting and removing the nutrient solution tray  210  and the cultivation plate  220 , and a cultivation room lid  12  for opening and closing the opening  11  (see  FIGS. 9 and 12 ). As an example, the cultivation room lid  12  is configured to be openable and closable by an electric-powered hinge  13 . 
     The cultivation room lid  12  is opened only for the time of inserting and removing the nutrient solution tray  210  and the cultivation plate  220 , and is kept closed for the rest of the time, so that the cultivation room  10 B can be kept closed. 
       FIG. 10  shows a schematic cross-sectional view of the cultivation room  10  of the present invention as viewed from the longitudinal direction. 
     The plurality of cultivation chambers  20 B are configured with box-shaped members having closability, and are arranged in multiple stages in the vertical direction in the cultivation room  10 B. That is, the plurality of cultivation chambers  20 B are defined by dividing the cultivation room  10 B in the vertical direction at predetermined intervals by box-shaped members, each of which has a substantially rectangular parallelepiped shape and has closability. 
     Further, the cultivation chamber  20 B includes a chamber opening  21  for inserting and removing the nutrient solution tray  210  and the cultivation plate  220 , and a chamber lid  22  that can open and close the chamber opening  21  (see  FIG. 12 ), on one end side in the longitudinal direction (the side opposite to the side where the air circulation device  30  is provided). As an example, the chamber lid  22  is configured to be openable and closable by an electric-powered hinge  23 . 
     The chamber lid  22  is opened only for the time of inserting and removing the nutrient solution tray  210  and the cultivation plate  220 , and is kept closed for the rest of the time, so that the cultivation chamber  20 B can be kept closed. Thus, it is possible to reduce leakage of air (particularly carbon dioxide) from the cultivation chamber  20 B and mixing of air into the cultivation chamber  20 B as compared with the configuration in which the cultivation chambers are not closed. Therefore, in one cultivation room  10 B, each of the plurality of cultivation chambers  20 B can be independently controlled in different cultivation environments. Moreover, if insects, germs or the like grow in one cultivation chamber  20 B out of a plurality of cultivation chambers  20 B, it is possible to reduce the possibility that contamination such as insects, germs or the like spread to other cultivation chambers  20 B in the same cultivation room  10 B. 
     Further, the inner wall of the cultivation chamber  20 B is preferably made of a material having a reflectance of 90% or more from the viewpoint of making the plants efficiently absorb the light. For example, the inner wall of the cultivation chamber  20 B is preferably configured with a mirror surface having a reflectance of about 96% to 97%. 
     In each cultivation chamber  20 B, a plurality of nutrient solution trays  210  and cultivation plates  220  are arranged so that their transverse directions are along the longitudinal direction of the cultivation chamber  20 B, as in the case described in the first embodiment. 
     As in the case described in the first embodiment, the air circulation device  30  is arranged adjacent to the cultivation shelf  100  on one end side in the longitudinal direction of the cultivation room  10 B. The air circulation device  30  supplies the air adjusted to a predetermined condition to each cultivation chamber  20 B at a predetermined flow velocity, collects the air that has passed through the inside of each cultivation chamber  20 B, and adjusts it to meet the predetermined condition, and repeat this procedure to circulate and supply the air. 
     The configuration of the air circulation device  30  is described below with reference to  FIG. 11 . It is sufficient that the air circulation device  30  has at least a function of adjusting temperature, humidity, carbon dioxide concentration, and air flow velocity (flow rate). In this embodiment, the air circulation device  30  includes: an air sterilizer  310 ; an air conditioner  320  of a direct expansion system (with a method where the air is cooled directly with a refrigerant) that has warming, cooling, and dehumidifying functions; a humidifier  330  with a humidifying function; a carbon dioxide supply device  340  that adjusts the carbon dioxide concentration; a suction pump  350 ; and a compression pump  360 . 
     As a device having a function of adjusting the temperature, a chiller device of an indirect expansion system (with a method where the air is cooled via water with a refrigerant) may be used. 
     Each cultivation chamber  20 B and the air circulation device  30  are connected through an air collection duct  370 B and an air supply duct  380 B. The air collection duct  370 B and the air supply duct  380 B extend in the longitudinal direction of the cultivation chamber  20 B, and the air collection duct  370 B and the air supply duct  380 B are arranged adjacent to the cultivation chamber  20 B (see  FIGS. 10 and 11 ). A plurality of air collection ports  371  provided at predetermined intervals are formed in the air collection duct  370 B, and these air collection ports  371  are provided with a fan (not shown) for sucking the air in the cultivation chamber into the air collection duct  370 B. A plurality of air supply ports  381  provided at predetermined intervals are formed in the air supply duct  380 B, and these air supply ports  381  are provided with flow regulating valves (not shown). 
     Further, as in the case described in the first embodiment, a temperature sensor, a humidity sensor and a carbon dioxide concentration sensor (not shown) are attached to predetermined locations in the cultivation chamber  20 B, and the temperature, humidity and carbon dioxide concentration of the circulating air are monitored. 
     The air collected from each cultivation chamber  20 B by the suction pump  350  through the air collection duct  370 B is sterilized through the air sterilizer  310  and sent to the air conditioner  320 . In the air conditioner  320 , after temperature adjustment and dehumidification according to the measurement results of the temperature sensor and the humidity sensor, the humidifier  330  humidifies the air. After that, the carbon dioxide supply device  340  supplies carbon dioxide from the carbon dioxide supply source  341  such as a carbon dioxide cylinder according to the measurement result of the carbon dioxide concentration sensor. Then, the compression pump  360  supplies the air adjusted to a predetermined condition and a predetermined flow velocity to each cultivation chamber  20 B through the air supply pipe  380 . At this time, as shown in  FIG. 10 , the air flow direction in the cultivation chamber  20 B is along the transverse direction of the cultivation chamber  20 B. As a result, the time from air supply to collection can be shortened as compared with the case where the air is supplied so that the flow direction is along the longitudinal direction of the cultivation chamber  20 B. Therefore, it is possible to reduce changes in the cultivation environment such as temperature, humidity, and carbon dioxide concentration that is generated between the upstream side and the downstream side of the air flow. 
     The nutrient solution circulation device  40 , the operation unit  50 , the control unit  60 , and the display unit  70  have the same configurations as those in the first embodiment, and thus the description thereof is omitted. 
     Further, as in the case described in the first embodiment, in this embodiment, one cultivation room  10 B can have a dimmer  231  of the artificial light source  230 , an air circulation device  30 , and a nutrient solution circulation device  40 , each arranged therefor, and the cultivation environment adjusted by these may be the same in each cultivation chamber  20 B. Further, it is also possible to arrange one dimmer  231  and one air circulation device  30  and one nutrient solution circulation device  40  for each cultivation chamber  20 B, so that each of the plurality of cultivation chambers  20 B has a different cultivation environment. 
     The transport mechanism  80  is described with reference to  FIGS. 12 and 13 .  FIG. 12  is a schematic view for explaining the configuration of the transport mechanism  80 , and  FIG. 13  is an explanatory diagram of a transport method of the cultivation plate  220  using the transport mechanism  80 . 
     The transport mechanism  80  is used for transporting the plurality of cultivation plates  220  from outside the cultivation room  10 B to a predetermined position in the cultivation chamber  20 B, and for transporting a plurality of cultivation plates  220  arranged in the cultivation chamber  20 B to take them out to the cultivation room  10 B. As shown in  FIG. 12 , the transport mechanism  80  includes a transporter  810  and an elevator  820 . In this embodiment, as an example, a case is described in which the nutrient solution tray  210  is also transported together with the cultivation plate  220 . 
     The transporter  810  is provided in each of the plurality of cultivation chambers  20 B, to transport the nutrient solution tray  210  and the cultivation plate  220  in the longitudinal direction of the cultivation chamber  20 B. The transporter  810  is configured with a plurality of rollers  811  and a roller support base  812 . The plurality of rollers  811  are arranged so as to come into contact with the back surface of the nutrient solution tray  210  and the roller support base  812  is arranged on the bottom surface in the cultivation chamber  20 B (see  FIG. 10 ). The plurality of rollers  811  are configured with electrically driven rollers and non-driven rollers. The rotation direction and the amount of rotation of the electrically driven rollers are controlled, so that the nutrient solution tray  210  and the cultivation plate  220  can be transported in the longitudinal direction of the cultivation chamber  20 B. It should be noted that all of the plurality of rollers  811  may be configured with electrically driven rollers. 
     The elevator  820  is provided adjacent to the side of the cultivation chamber  20 B where the chamber opening  21  is provided. The elevator  820  inserts and removes the nutrient solution tray  210  and the cultivation plate  220  through the chamber opening  21  and then moves in the vertical direction, to transport the nutrient solution tray  210  and the cultivation plate  220  between the chamber opening  21  and the cultivation room opening  11  provided in the bottom part of the cultivation room  10 B. Further, in this embodiment, the elevator  820  is arranged in the cultivation room  10 B. Therefore, the transport mechanism  80  is controlled so that the cultivation room opening  11  and the chamber opening  21  are not opened at the same time. This can be considered that the inside of the cultivation chamber  20 B is doubly closed, and the closability of the cultivation chamber  20 B can be further improved as compared with the case where the elevator  820  is arranged outside the cultivation room  10 B. Accordingly, it is possible to further reduce the leakage of air (particularly carbon dioxide) from each cultivation chamber  20 B and the mixing of air from outside the cultivation room  10 B. Therefore, in one cultivation room  10 B, each of the plurality of cultivation chambers  20 B can be easily controlled independently in different cultivation environments. In addition, the further enhanced closability can reduce the insects or germs mixing in from outside the cultivation room  10 B. Further, if insects, germs or the like grow in one cultivation chamber  20 B, it is possible to reduce the possibility that contamination of insects, germs or the like spreads to other cultivation chambers  20 B in the same cultivation room  10 B. 
     As shown in  FIG. 12 , the elevator  820  is configured with a loading platform  821 , a support column  822 , a tray receiving plate  823 , and a plurality of rollers  824 . 
     The loading platform  821  is mounted on the support column  822  extending in the vertical direction, and can be electrically moved in the vertical direction. Further, the tray receiving plate  823  for receiving the nutrient solution tray  210  is mounted on the loading platform  821  so as to be slidable in the longitudinal direction of the cultivation chamber  20 B. 
     The tray receiving plate  823  is configured in a forked shape that can be inserted into the spaces on both sides of the roller  811  and the roller support base  812  shown in  FIG. 10 . 
     The plurality of rollers  824  are mounted to the loading platform  821  and are configured with electrically driven rollers and non-driven rollers. The surface formed with the plurality of rollers  824  can be electrically tilted obliquely (see  FIGS. 13F and 13G ). Controlling the rotation direction and amount of rotation of the electrically driven roller, and tilting the surface configured with the plurality of rollers  824  allows the nutrient solution tray  210  and the cultivation plate  220  to be sent out from the loading platform  821  toward the cultivation room opening  11 . It should be noted that all of the plurality of rollers  824  may be configured with electrically driven rollers. 
     Next, with reference to  FIGS. 12 and 13 , a transport method using the transport mechanism  80  of the nutrient solution tray  210  and the cultivation plate  220  is described. Here, a case is described in which the nutrient solution tray  210  and the cultivation plate  220  arranged in the bottom-stage cultivation chamber  20 B in  FIG. 12  are sequentially taken out of the cultivation room  10 B. 
     With the cultivation room lid  12  of the cultivation room  10 B closed, the transporter  810  is arranged at a position in the vicinity of the cultivation chamber  20 B containing what are to be taken out, so as not to interfere with the chamber lid  22  if it opens and closes. In the case of this embodiment, the transporter  810  is arranged below the cultivation chamber  20 B containing what are to be taken out (see  FIG. 12 ). 
     Next, after the chamber lid  22  is opened by the electric-powered hinge  23  from the state shown in  FIG. 12 , the transporter  810  is moved to the vicinity of the lowest end of the chamber opening  21  (see  FIG. 13A ). 
     From the state shown in  FIG. 13A , the tray receiving plate  823  is slid toward the chamber opening  21  (see  FIG. 13B ) and is inserted into the spaces on both sides of the roller  811  and the roller support base  812 . 
     From the state shown in  FIG. 13B , the loading platform  821  is slightly raised together with the tray receiving plate  823 , and the nutrient solution tray  210  and the cultivation plate  220  are loaded on the tray receiving plate  823  (see  FIG. 13C ). 
     From the state shown in  FIG. 13C , after the tray receiving plate  823  is slid toward the loading platform  821  side, the loading platform  821  is moved downward toward the cultivation room opening  11  (see  FIG. 13D ). 
     From the state shown in  FIG. 13D , the loading platform  821  is moved to the cultivation room opening  11  and the chamber lid  22  is closed by the electric-powered hinge  23 , and then the electric drive roller of the plurality of rollers  811  of the transporter  810  is operated, to move all the remaining nutrient solution trays  210  (and cultivation plates  220 ) by one tray length to the chamber opening  21  side. Further, the cultivation room lid  12  is opened by the electric-powered hinge  13  (see  FIG. 13E ). 
     From the state shown in  FIG. 13E , after the cultivation room lid  12  is opened, a plurality of rollers  824  mounted to the loading platform  821  are tilted obliquely, and the electrically driven rollers of the plurality of rollers  824  are driven, so that the nutrient solution tray  210  and the cultivation plate  220  are moved toward the cultivation room opening  11  by the electrically driven rollers and gravity, and are sent out to the outside of the cultivation room  10 B (see  FIG. 13F ). 
     From the state shown in  FIG. 13F , the nutrient solution tray  210  and the cultivation plate  220  are transferred from the vicinity of the cultivation room opening  11  by a person or other transport means, and then the cultivation room lid  12  is closed by the electric-powered hinge  13  and the tilt of the plurality of rollers  824  mounted to the loading platform  821  is moved back (see  FIG. 13G ). 
     Then, the procedure performed in  FIGS. 13A to 13G  is repeated until all the nutrient solution tray  210  and the cultivation plate  220  in the cultivation chamber  20 B at the bottom-stage are taken out. After that, by repeating the same operation in the remaining cultivation chamber  20 B, all the nutrient solution trays  210  and the cultivation plates  220  in the cultivation room  10 B can be taken out from the cultivation room  10 B. 
     In this way, with the cultivation plate  220  arranged on the nutrient solution tray  210 , the transport mechanism  80  can transport one set of the nutrient solution tray  210  and the cultivation plate  220  at a time. In this embodiment, the nutrient solution tray  210  can be collected together with the cultivation plate  220 . Therefore, the nutrient solution tray  210  can be easily cleaned, and the inside of the cultivation chamber  20 B can be kept clean as compared to a case where the nutrient solution tray is kept placed in the cultivation chamber. 
     In addition, when the nutrient solution tray  210  and the cultivation plate  220  are moved from outside the cultivation room  10 B to be arranged in the cultivation chamber  20 B, the procedure in the reverse order of that described above allows a plurality of nutrient solution trays  210  and a plurality of cultivation plates  220  to be sequentially arranged at predetermined positions in the cultivation chamber  20 B. 
     According to the cultivation device  1 B of the present invention described above, the following effects are exhibited in addition to the above-mentioned effects (1) to (4). 
     (6) The cultivation chamber  20 B of the cultivation device  1 B used in the artificial light plant factory is configured with a box-shaped member, has a chamber opening  21  for inserting and removing the cultivation plate  220  on one end side in the longitudinal direction and a chamber lid  22  that can open and close the opening  21 , and can be kept closed by closing the chamber opening  21  with the chamber lid  22 . This enables each of the plurality of cultivation chambers  20 B to be independently controlled in different cultivation environments in one cultivation room  10 B. Moreover, since a plurality of cultivation chambers  20 B can be environmentally less affected by each other, if insects, germs or the like grow in one cultivation chamber  20 B, it is possible to reduce the possibility that contamination such as insects, germs or the like spread to other cultivation chambers  20 B in the same cultivation room  10 B. 
     (7) The cultivation device  1 B used in the artificial light plant factory further includes a transport mechanism  80  for transporting the cultivation plate  220 . The transport mechanism  80  is provided in the cultivation chamber  20 B, and has: a transporter  810  for transporting the cultivation plate  220  in the longitudinal direction of the cultivation chamber  20 B; and an elevator  820 , which is provided adjacent to the side where the chamber opening  21  of the cultivation chamber  20 B is provided, and is used for inserting and removing the cultivation plate  220  through the chamber opening  21  and transporting it in the vertical direction. This enables the cultivation device  1 B including the cultivation chambers  20 B which are long and stacked in multiple stages to use the transport mechanism  80  to transport the cultivation plate  220  to a desired position. 
     (8) The elevator  820  of the transport mechanism  80  is provided in the cultivation room  10 B. The cultivation room  10 B has a cultivation room opening  11  for inserting and removing the cultivation plate  220  and a cultivation room lid  12  that can open and close the opening  11 , on one end side in the longitudinal direction, where the elevator  820  is provided. This, as well as controlling the transport mechanism  80  so that the cultivation room opening  11  and the chamber opening  21  are not opened at the same time, can further improve the closability of the cultivation chamber  20 B as compared to the case where the elevator  820  is arranged outside the cultivation room  10 B. Accordingly, it is possible to further reduce the leakage of air (particularly carbon dioxide) from each cultivation chamber  20 B and the mixing of air from outside the cultivation room  10 B. Therefore, in one cultivation room  10 B, each of the plurality of cultivation chambers  20 B can be easily controlled independently in different cultivation environments. In addition, the further enhanced closability can reduce the insects or germs mixing in from outside the cultivation room  10 B. 
     (9) The nutrient solution tray of the cultivation device  1 B is configured with a rectangular tray  210  which is substantially the same size as the cultivation plate  220  and in which the cultivation plate  220  can be arranged. The transport mechanism  80  transports the cultivation plate  220  and the rectangular tray  210  in a state where the cultivation plate  220  is arranged on the rectangular tray  210 . Thus, the nutrient solution tray  210  can be collected together with the cultivation plate  220 . Accordingly, the nutrient solution tray  210  can be easily cleaned, and the inside of the cultivation chamber  20 B can be kept clean as compared to a case where the nutrient solution tray is kept placed in the cultivation chamber. 
     Although the preferred embodiment of the cultivation device of the present invention is described above, the present invention is not limited to the above-described embodiment and can be appropriately modified. 
     For example, in each of the above-described embodiments, the flow directions of the air and the nutrient solution supplied to the cultivation chamber are the same, but each supply pipe and each collection pipe may be configured so that the flow directions are opposite. 
     Further, in each of the above-described embodiments, the flow directions of the air and the nutrient solution supplied to the cultivation chamber  20  respectively by the air circulation device  30  and the nutrient solution circulation device  40  are set along the transverse direction of the cultivation chamber  20 , but the present invention is not limited to this. That is, the flow directions of the air and the nutrient solution supplied to the cultivation chamber may be along the longitudinal direction of the cultivation chamber. 
     Further, in each of the above-described embodiments, the configuration, in which the nutrient solution tank is directly connected to the city water supply source and a configuration in which a carbon dioxide cylinder is used as the carbon dioxide supply source, is shown, but the present invention is not limited to this. For example, the plug connected to the city water supply source and the plug connected to the carbon dioxide supply source may be collectively configured as one cultivation device side plug, and this cultivation device side plug may be configured to be connected to a factory side plug provided in the plant factory, which can supply water and carbon dioxide, to supply the water and carbon dioxide to the cultivation device. 
     Further, in each of the above-described embodiments, the configuration is shown in which the operation unit, the control unit, and the display unit are integrally attached to the cultivation device, but the present invention is not limited to this. For example, instead of an operation unit, a control unit, and a display unit provided in each cultivation device, an operation unit, a control unit, and a display unit, which can centrally control a plurality of cultivation devices individually or collectively, may be provided. The operation unit, control unit, and display unit may be provided at a location away from the installation location of the cultivation device. 
     Further, in the above-mentioned second embodiment, the configuration, in which the air collection duct and the air supply duct are provided outside the cultivation chamber in the cultivation room, is described as an example, but the present invention is not limited to this. The air collection duct and the air supply duct may be arranged inside the cultivation chamber or outside the cultivation room if the closability inside the cultivation chamber can be maintained. 
     Further, in the above-mentioned second embodiment, as the method of transporting the cultivation plate, an example, in which the transport mechanism transports the nutrient solution tray together with the cultivation plate, is shown, but the method is not limited to this. The transport mechanism may be configured so that the nutrient solution tray is kept placed in the cultivation chamber and only the cultivation plate is transported. 
     Further, in the above-mentioned second embodiment, the case, in which the transport mechanism transports one set of the nutrient solution tray and the cultivation plate at a time, is shown, but the transport mechanism may be configured to transport a plurality of sets at a time. 
     Further, in the above-mentioned second embodiment, the configuration, in which the elevator of the transport mechanism is arranged in the cultivation room, is shown, but the present invention is not limited to this. The elevator may be arranged outside the cultivation room. 
     Further, in the above-mentioned second embodiment, in the transporter and the elevator of the transport mechanism, the configuration of the roller conveyor system using a plurality of rollers is shown as the transport means in the longitudinal direction of the cultivation chamber, but the present invention is not limited to this. For example, other methods such as a belt conveyor system or a chain conveyor system may be used as the transport means. 
     EXPLANATION OF REFERENCE NUMERALS 
     
         
           1 A,  1 B cultivation device 
           10 A,  10 B cultivation room 
           20 A,  20 B cultivation chamber 
           30  air circulation device 
           40  nutrient solution circulation device 
           50  operation unit 
           60  control unit 
           70  display unit 
           80  transport mechanism 
           100  cultivation shelf 
           210  nutrient solution tray (rectangular tray) 
           220  cultivation plate 
           230  artificial light source 
           370 A air collection pipe 
           370 B air collection duct 
           380  air supply pipe 
           380 B air supply duct 
           420  nutrient solution tank 
           460  nutrient solution pressure pump 
           470  nutrient solution collection pipe 
           480  nutrient solution supply pipe 
           810  transporter 
           820  elevator