Mist generating device and plant cultivation device

Abstract

A mist generator 20 for use in a plant cultivation apparatus comprises: an ultrasonic vibration part 22 for applying ultrasonic vibrations to a liquid; a liquid supply part for supplying a liquid to the ultrasonic vibration part 22; a reception part 27 for receiving at least one of information related to the growth state of a plant and information related to the dryness of the root of the plant; and a control part 28 that controls the mist generation amount on the basis of at least one of the information related to the growth state of the plant, and the information related to the dryness of the root of the plant which are received by the reception part 27.　Since this mist generator 20 comprises the reception part 27 and control part 28, the mist generator can respond to changes in conditions that accompanies plant growth and the like.

Description

[Technical Field]

[0001] The present invention relates to a mist generating device and a plant cultivation device. [Background technology]

[0002] Hydroponic cultivation, which is a method of cultivating plants without the need for soil, has been widely known. Another type of hydroponic cultivation is spray hydroponic cultivation, which generates a mist of water or liquid fertilizer and supplies it to plants. A device for carrying out this cultivation is also known (see, for example, Patent Document 1).

[0003] Fig. 10 is a diagram illustrating a conventional plant cultivation device 900. As shown in Fig. 10, the conventional plant cultivation device 900 includes a cultivation container 901, a plant support means 903 that supports a plant 905 with its roots 905 exposed to air, and a liquid fertilizer supply means 904 that intermittently supplies liquid fertilizer to the roots 905a. The liquid fertilizer supply means 904 includes a body 914 that has an electric control mechanism built in, and a liquid chamber 916. An ultrasonic vibrator 915 is disposed within the liquid chamber 916. In the plant cultivation device 900, liquid fertilizer supplied from a liquid fertilizer tank 917 to the liquid chamber 916 is converted into mist by the ultrasonic vibrator 915, and the mist is supplied to the roots 905a from a spray nozzle 918.

[0004] This configuration reduces the amount of water and liquid fertilizer required, allowing plants to be cultivated efficiently. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 60-19032 Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional plant cultivation devices and the liquid fertilizer supply means (mist generating devices) used therein have the problem that they cannot respond to changes in conditions that accompany plant growth (for example, changes in the amount of water or liquid fertilizer required).

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a mist generating device that can respond to changes in conditions associated with plant growth, etc., and a plant cultivation device equipped with such a mist generating device. [Means for solving the problem]

[0008] The mist generating device of the present invention is a mist generating device for use in a plant cultivation device, and is characterized by comprising an ultrasonic vibration unit that imparts ultrasonic vibrations to a liquid, a liquid supply unit that supplies liquid to the ultrasonic vibration unit, a receiving unit that receives at least one of information regarding the growth status of the plant and information regarding the dryness state of the roots of the plant, and a control unit that controls the amount of mist generated based on at least one of the information regarding the growth status of the plant and information regarding the dryness state of the roots of the plant received by the receiving unit.

[0009] The plant cultivation device of the present invention comprises the mist generating device of the present invention, a plant holding means for holding a plant, and at least one of a growth status detection means for detecting the growth status of the plant and a dryness status evaluation means for evaluating the dryness status of the roots of the plant, and is characterized in that the amount of mist generated is controlled based on at least one of information regarding the growth status of the plant detected by the growth status detection means and information regarding the dryness status of the roots evaluated by the dryness status evaluation means. [Effects of the Invention]

[0010] The mist generating device of the present invention comprises a receiving unit that receives at least one of information regarding the growth status of a plant and information regarding the dryness state of the plant's roots, and a control unit that controls the amount of mist generated based on at least one of the information regarding the growth status of a plant and information regarding the dryness state of the plant's roots received by the receiving unit, and is therefore a mist generating device that can respond to changes in conditions associated with plant growth, etc.

[0011] The plant cultivation device of the present invention comprises the mist generating device of the present invention and at least one of a growth status detection means for detecting the growth status of a plant and a dryness status evaluation means for evaluating the dryness status of the plant's roots, and controls the amount of mist generated based on at least one of the information on the plant's growth status detected by the growth status detection means and the information on the root dryness status evaluated by the dryness status evaluation means, thereby becoming a plant cultivation device that can respond to changes in conditions accompanying plant growth, etc. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a plant cultivation device 100 according to a first embodiment. FIG. [Figure 2] 2 is a diagram for explaining an ultrasonic vibration unit 22 according to the first embodiment. FIG. [Figure 3] 1 is a block diagram of a mist generating device 20 according to a first embodiment. [Figure 4] FIG. 10 is a diagram illustrating a plant cultivation device 102 according to a second embodiment. [Figure 5] FIG. 10 is a diagram illustrating a plant cultivation device 104 according to a third embodiment. [Figure 6] FIG. 10 is a diagram illustrating a plant cultivation device 106 according to a fourth embodiment. [Figure 7] FIG. 10 is a diagram for explaining a plant cultivation device 108 according to a fifth embodiment. [Figure 8] FIG. 10 is a diagram illustrating a plant cultivation device 110 according to a sixth embodiment. [Figure 9] FIG. 10 is a diagram for explaining a plant cultivation device 112 according to a modified example. [Figure 10] FIG. 1 is a diagram illustrating a conventional plant cultivation device 900. DETAILED DESCRIPTION OF THE INVENTION

[0013] The mist generating device and plant cultivation device of the present invention will be described below based on the embodiments shown in the drawings. The drawings are schematic diagrams and do not necessarily accurately reflect the actual structure or configuration. The embodiments described below do not limit the invention according to the claims. Furthermore, not all of the elements and combinations thereof described in each embodiment are necessarily essential to the present invention. In the following description, the same reference numerals are used across embodiments for components that can be considered substantially equivalent, and repeated explanations will be omitted.

[0014] [Embodiment 1] Fig. 1 is a diagram illustrating a plant cultivation device 100 according to embodiment 1. In Fig. 1, the cultivation container 10, the mist generating device 20 (excluding the housing 29), and the plant holding means 30 are shown in cross-section, while other components are shown as schematic diagrams in which cross-sections are basically omitted. This also applies to drawings illustrating other plant cultivation devices described later. Figure 2 is a diagram for explaining the ultrasonic vibration unit 22 in embodiment 1. Figure 2(a) is a plan view of the ultrasonic vibration unit 22, and Figure 2(b) is a cross-sectional view taken along line AA in Figure 2(a). Fig. 3 is a block diagram of the mist generating device 20 according to embodiment 1. In Fig. 3, of the components of the mist generating device 20, those not directly related to the control unit 28 are omitted from the illustration.

[0015] 1, the plant cultivation device 100 according to the first embodiment comprises a cultivation container 10, a mist generating device 20, a plant holding means 30, a growth status detecting means 40, a dryness state evaluating means 42, a light source 50, a mist removing means 60, and a temperature and humidity adjusting means 62, and cultivates a plant P1. Note that the plant cultivation device 100 also comprises essential components (for example, a power supply that supplies power to each component) in addition to those described above, but these are general components and will not be illustrated or described here.

[0016] The plant P1 in the first embodiment is a seedling of a leafy vegetable (cabbage, lettuce, etc.). Note that the plant P1 being a seedling of a leafy vegetable is merely an example, and the plant cultivation device 100 can also cultivate plants other than leafy vegetables, and the plant P1 can also be cultivated even if it is at a developmental stage other than a seedling.

[0017] The cultivation container 10 is a container that accommodates a plant P1 to be cultivated. The airtightness and light transmittance of the cultivation container 10 can be determined depending on the environment in which the plant cultivation device 100 is used and the type of plant P1. The internal space of the cultivation container 10 is divided by the plant holding means 30 into a first space S1 on the side where the leaves of the plant P1 are present and a second space S2 on the side where the roots of the plant P1 are present.

[0018] The mist generating device 20 is for use in the plant cultivation device 100, and as shown in Figures 1 and 3, includes an ultrasonic vibration unit 22, a liquid container 25, a liquid supply unit 26, a receiving unit 27, a control unit 28, and a housing 29. Note that the receiving unit 27 and the control unit 28, which are present inside the housing 29, are not shown in Figure 1. The mist generating device in this specification can also be referred to as an ultrasonic sprayer.

[0019] The ultrasonic vibration unit 22 applies ultrasonic vibrations to the liquid L. As shown in Fig. 2, the ultrasonic vibration unit 22 has a mesh plate 23 having a plurality of pores formed therein, and an ultrasonic vibration element 24 that vibrates the mesh plate 23. Note that the ultrasonic vibration unit 22 also has electrodes and electric wires in addition to those described above, but as these are general features, illustration and description thereof will be omitted.

[0020] The mesh plate 23 has a thickness in the range of 0.01 mm to 2 mm, and the pore diameter of the pores is in the range of 3 μm to 15 μm. In FIGS. 1 and 2, the thicknesses of the mesh plate 23 and the ultrasonic vibration elements 24 are illustrated thicker than their actual proportions in order to make the structure of the ultrasonic vibration unit 22 easier to understand. The mesh plate 23 can be made of various metals, such as stainless steel. Furthermore, from the viewpoint of prioritizing corrosion resistance against the liquid L, the mesh plate 23 can also be made of resin.

[0021] Liquid container 25 stores liquid L to be supplied to ultrasonic vibration unit 22. Replenishing liquid L in liquid container 25 may be performed by replacing liquid container 25, or may be performed via a pipe or the like (not shown) connected to liquid container 25. Note that liquid L in embodiment 1 is liquid fertilizer in which substances necessary for plant growth are dissolved in water. The components of liquid L can be changed as appropriate depending on the growth of plant P1, and in some cases liquid L may consist of only water.

[0022] Liquid supply unit 26 supplies liquid L to ultrasonic vibration unit 22. Liquid supply unit 26 is, for example, a tubular member filled with a fibrous water-retaining material. A first end of liquid supply unit 26 contacts mesh plate 23 of ultrasonic vibration unit 22, and a second end opposite to the first end contacts liquid L in liquid container 25.

[0023] The receiving unit 27 and the control unit 28 are actually comprised of a combination of an arithmetic unit, a storage unit, an electronic circuit, wiring, etc., and are housed in a housing 29 .

[0024] The receiving unit 27 receives information regarding the growth status of the plant P1 and information regarding the dryness state of the roots of the plant P1. The receiving unit 27 receives this information from the growth status detection means 40 and the dryness state evaluation means 42. The plant cultivation device 100 may exchange information between the receiving unit 27 and other components via a wired or wireless connection. The receiving unit 27 also receives information regarding at least one of the presence or absence and state of mist from the mist detection means 61.

[0025] The control unit 28 controls the amount of mist generated based on information regarding the growth status of the plant P1 and information regarding the dryness state of the roots of the plant P1 received by the receiving unit 27. The control unit 28 also controls the amount of mist generated based on information regarding at least one of the presence or absence and state of mist. The control unit 28 may have a function of determining how to control the amount of mist generated based on the received information. The control unit 28 controls the amount of mist generated so that the dryness state of the roots becomes the desired dryness. In the plant cultivation device 100, it is preferable to control at least one of the average particle size of the mist, the temperature of the mist, and the atmospheric humidity, in addition to the amount of mist generated.

[0026] The action of "controlling the amount of mist produced so that the roots reach the desired dryness" includes not only the action of controlling the amount of mist produced so that the roots do not dry out for a long period of time (increasing the amount of mist produced), but also the action of reducing the amount of moisture near the roots of plant P1, for example, controlling the amount of mist produced so that the roots dry out to a certain extent when plant P1 enters a developmental stage where it dislikes excess moisture (reducing the amount of mist produced).

[0027] The plant holding means 30 holds the plant P1. In the first embodiment, the plant holding means 30 has a plate-like member 32 formed with a hole 33 for passing the stem (or trunk) of the plant P1 through. The hole 33 may be filled with a support means (sponge, rock wool, etc.) for supporting the plant P1. The plant holding means 30 may further have a pole, net, etc. for supporting the plant P1.

[0028] The growth status detection means 40 detects the growth status of the plant P1. The growth status detection means 40 has, for example, an imaging means and a transmission unit (not shown), and transmits information regarding the growth status of the plant P1 obtained using the imaging means to the receiving unit 27. The growth status detection means 40 may transmit, as the information regarding the growth status of the plant P1, information that serves as material for determining the growth status of the plant P1 (for example, the image or video itself obtained by the imaging means), or may transmit information indicating the growth status of the plant P1 (for example, the result of determining the growth status by analyzing the image or video obtained by the imaging means). The growth status detection means 40 is arranged on the first space S1 side and detects the growth status of the leaves, stems, etc. (so-called above-ground parts) of the plant P1. The plant cultivation device 100 may further include a growth status detection means arranged on the second space S2 side and detecting the growth status of the roots (so-called underground parts) of the plant P1.

[0029] The dryness evaluation means 42 evaluates the dryness of the roots of the plant P1. The dryness evaluation means 42 has, for example, an imaging means and a transmission unit (not shown), and transmits information regarding the dryness of the roots of the plant P1 obtained using the imaging means to the receiving unit 27. The dryness evaluation means 42 may transmit, as the information regarding the dryness of the roots of the plant P1, information that serves as material for evaluating the dryness of the roots of the plant P1 (for example, the image or video itself obtained by the imaging means), or may transmit information evaluating the dryness of the roots of the plant P1 (for example, the result of evaluating the dryness by analyzing the image or video obtained by the imaging means). The dryness evaluation means 42 may also function as a growth status detection means. The dryness evaluation means 42 may further include an illumination means for effectively operating the imaging means.

[0030] The light source 50 emits light for growing the plant P1. The light source 50 can be one that contains light of a wavelength suitable for photosynthesis of the plant P1. From the viewpoint of power consumption, it is preferable to use a light-emitting diode as the light source 50. Note that if the light necessary for growing the plant P1 can be obtained from outside the plant cultivation device 100, the plant cultivation device 100 does not need to be equipped with the light source 50.

[0031] The mist removal means 60 removes mist according to the growth status of the plant P1. The mist removal means 60 has, for example, a suction fan (not shown) and removes the mist by sucking it into the second space S2. The removed mist may be collected and reused after appropriate processing (such as dust removal or sterilization). In this case, the mist removal means 60 can also be said to be a liquid recovery means. The mist removal means 60 may also have a function of ventilating the second space S2.

[0032] The mist detection means 61 detects at least one of the presence or absence and state of mist. The state of mist refers, for example, to the particle size and density of the mist. The mist detection means 61 includes, for example, an imaging means and a transmission unit (not shown), and transmits information regarding at least one of the presence or absence and state of mist obtained by the imaging means to the receiving unit 27. The mist detection means 61 may transmit, as the information regarding at least one of the presence or absence and state of mist, information that serves as material for evaluating the presence or state of mist (for example, the image or video itself obtained by the imaging means), or may transmit information that evaluates at least one of the presence or absence and state of mist (for example, the results of evaluating the presence or state of mist by analyzing the image or video obtained by the imaging means). The mist detection means 61 may also include an illumination means to effectively operate the imaging means.

[0033] The temperature and humidity adjusting means 62 adjusts the temperature and humidity. The temperature and humidity adjusting means 62 is, for example, a combination of a heater, a cooler, a humidifier, a dehumidifier, a boiler, a fan, etc. The temperature and humidity adjusting means 62 in the first embodiment mainly adjusts the temperature and humidity of the first space S1, but may also adjust the temperature and humidity of the second space S2. The temperature and humidity adjusting means 62 may also have a function of ventilating the first space S1.

[0034] The effects of the mist generating device 20 and the plant cultivation device 100 according to the first embodiment will be described below.

[0035] The mist generating device 20 of embodiment 1 includes a receiving unit 27 that receives information relating to the growth status of the plant P1 and information relating to the dryness state of the roots of the plant P1, and a control unit 28 that controls the amount of mist generated based on the information relating to the growth status of the plant P1 and information relating to the dryness state of the roots of the plant P1 received by the receiving unit 27, and is therefore a mist generating device that can respond to changes in conditions associated with the growth of the plant P1, etc.

[0036] Furthermore, by using the mist generating device 20 according to the first embodiment in the plant cultivation device 100, it becomes possible to reduce the amounts of water and liquid fertilizer required and cultivate plants efficiently.

[0037] Furthermore, according to the mist generating device 20 of embodiment 1, the ultrasonic vibration unit 22 has a mesh plate 23 having a plurality of pores formed therein and an ultrasonic vibration element 24 that vibrates the mesh plate 23. Therefore, by simply bringing the mesh plate 23 into contact with the liquid L, mist can be ejected by the force of the vibration without the need for a fan or the like, making it possible to achieve a simple and compact structure.

[0038] Furthermore, according to the mist generating device 20 of embodiment 1, the mesh plate 23 has a plate thickness in the range of 0.01 mm to 2 mm and a pore diameter in the range of 3 μm to 15 μm, so that the liquid L can be turned into mist with high efficiency.

[0039] The plant cultivation device 100 according to the first embodiment includes a mist generating device 20, a growth status detection means 40 for detecting the growth status of the plant P1, and a dryness evaluation means 42 for evaluating the dryness of the roots of the plant P1. The amount of mist generated is controlled based on information relating to the growth status of the plant P1 detected by the growth status detection means 40 and information relating to the dryness of the roots evaluated by the dryness evaluation means 42, making the plant cultivation device adaptable to changes in conditions accompanying the growth of the plant P1.

[0040] Furthermore, according to the plant cultivation device 100 of the first embodiment, like the conventional plant cultivation device 900, it is possible to reduce the amounts of water and liquid fertilizer required and to cultivate plants efficiently.

[0041] Furthermore, according to the plant cultivation device 100 of embodiment 1, the amount of mist generated is controlled so that the dryness of the roots reaches the desired dryness, making it possible to supply the required amount of liquid L according to the type and growth status of the plant P1.

[0042] Furthermore, the plant cultivation device 100 according to embodiment 1 is further provided with a mist removal means 60 that removes mist depending on the growth status of the plant P1, thereby making it possible to actively eliminate the situation where excessive mist is present near the roots.

[0043] Furthermore, according to the plant cultivation device 100 of embodiment 1, since it is equipped with a mist detection means 61 that detects at least one of the presence or absence and state of mist, it is possible to detect whether mist is being generated appropriately.

[0044] Furthermore, according to the plant cultivation device 100 of embodiment 1, when the plant cultivation device 100 controls at least one of the average particle size of the mist, the temperature of the mist, and the atmospheric humidity in addition to the amount of mist generated, it becomes possible to more finely adjust the method of supplying the liquid L to the plant P1.

[0045] Furthermore, the plant cultivation device 100 according to the first embodiment is provided with the temperature and humidity adjusting means 62 for adjusting the temperature and humidity, and therefore it is possible to cultivate the plant P1 regardless of the season or the like.

[0046] [Embodiment 2] FIG. 4 is a diagram for explaining the plant cultivation device 102 according to the second embodiment. The plant cultivation device 102 according to the second embodiment basically has the same configuration as the plant cultivation device 100 according to the first embodiment, but differs from the plant cultivation device 100 according to the first embodiment in that it is equipped with two types of mist generation devices.

[0047] As shown in Fig. 4, the plant cultivation device 102 includes, as mist generating devices, a water mist generating device 20a that generates a mist of water and a liquid fertilizer mist generating device 20b that generates a mist of liquid fertilizer. The water mist generating device 20a and the liquid fertilizer mist generating device 20b each have a configuration similar to that of the mist generating device 20 according to the first embodiment, but the liquid La in the water mist generating device 20a is water, and the liquid Lb in the liquid fertilizer mist generating device 20b is liquid fertilizer. The water mist generating device 20a and the liquid fertilizer mist generating device 20b may have differences according to the properties of the liquids to be misted (for example, differences in the constituent material of the mesh plate, the size of the pores, and the frequency of vibration).

[0048] In the plant cultivation device 102, the amount of water mist generated by the water mist generator 20a and the amount of liquid fertilizer mist generated by the liquid fertilizer mist generator 20b can be controlled independently. Therefore, in the plant cultivation device 102, the ratio of water to liquid fertilizer reaching the plant P1 can be changed without replacing the liquids La and Lb.

[0049] The plant cultivation device 102 according to the second embodiment differs from the plant cultivation device 100 according to the first embodiment in that it is equipped with a mist generating device for water and a mist generating device for liquid fertilizer as mist generating devices, but it is equipped with mist generating devices (mist generating device for water 20a and mist generating device for liquid fertilizer 20b), a growth status detection means 40 that detects the growth status of the plant P1, and a dryness status evaluation means 42 that evaluates the dryness status of the roots of the plant P1, and controls the amount of mist generated based on information on the growth status of the plant P1 detected by the growth status detection means 40 and information on the dryness status of the roots evaluated by the dryness status evaluation means 42, so that like the plant cultivation device 100 according to the first embodiment, it is a plant cultivation device that can respond to changes in conditions accompanying the growth of the plant P1, etc.

[0050] Furthermore, according to the plant cultivation device 102 of the second embodiment, the mist generating devices include a water mist generating device 20a that generates water mist and a liquid fertilizer mist generating device 20b that generates liquid fertilizer mist, and therefore flexible operation is possible, such as optimizing the structure of each mist generating device depending on the liquid used.

[0051] Furthermore, according to the plant cultivation device 102 of embodiment 2, the amount of water mist generated in the water mist generating device 20a and the amount of liquid fertilizer mist generated in the liquid fertilizer mist generating device 20b can be controlled independently, and the ratio of water and liquid fertilizer that reaches the plant P1 can be changed, so it is possible to adjust the concentration of liquid fertilizer supplied to the plant P1 without the need for the trouble of replacing the liquids La and Lb.

[0052] The plant cultivation device 102 according to the second embodiment also has the effects of the plant cultivation device 100 according to the first embodiment other than those described above.

[0053] [Embodiment 3] FIG. 5 is a diagram for explaining the plant cultivation device 104 according to the third embodiment. The plant cultivation device 104 according to the third embodiment basically has the same configuration as the plant cultivation device 100 according to the first embodiment, but the configuration of the plant holding means is different from that of the plant cultivation device 100 according to the first embodiment.

[0054] As shown in Fig. 5, the plant holding means 30a in the plant cultivation device 104 has a root holding member 34 having a porous, honeycomb, or framework structure. As the plant P1 grows, the roots of the plant P1 penetrate the sparsely packed parts of the root holding member 34 and become entangled with the densely packed parts. The root holding member 34 preferably has sufficient strength to be destroyed as needed in accordance with the root growth. The root holding member 34 can be made of, for example, ceramic, paper, etc.

[0055] The plant cultivation device 104 of embodiment 3 differs from the plant cultivation device 100 of embodiment 1 in the configuration of the plant holding means, but is equipped with a mist generating device 20, a growth status detection means 40 that detects the growth status of the plant P1, and a dryness condition evaluation means 42 that evaluates the dryness condition of the roots of the plant P1, and controls the amount of mist generated based on information regarding the growth status of the plant P1 detected by the growth status detection means 40 and information regarding the dryness condition of the roots evaluated by the dryness condition evaluation means 42, so that, like the plant cultivation device 100 of embodiment 1, it is a plant cultivation device that can respond to changes in conditions accompanying the growth of the plant P1, etc.

[0056] Furthermore, according to the plant cultivation device 104 of embodiment 3, the plant holding means 30a has a root holding member 34 having a porous, honeycomb or framework structure, which makes it possible to firmly hold the roots of the plant P1.

[0057] The plant cultivation device 104 according to the third embodiment also has the effects of the plant cultivation device 100 according to the first embodiment other than those described above.

[0058] [Embodiment 4] FIG. 6 is a diagram for explaining the plant cultivation device 106 according to the fourth embodiment. The plant cultivation device 106 of embodiment 4 basically has the same configuration as the plant cultivation device 100 of embodiment 1, but differs from the plant cultivation device 100 of embodiment 1 in that it further includes a water recovery means.

[0059] As shown in FIG. 6 , the plant cultivation device 106 includes a water recovery unit 64 that recovers water from the outside air. The water recovery unit 64 is, for example, a device that recovers moisture from the outside air using a moisture absorbent and temperature changes. The moisture in the outside air can come from any source, including weather conditions, moisture excreted from plant stomata, and moisture contained in human breath. In this specification, "outside air" refers to air outside the plant cultivation device. Therefore, when the plant cultivation device is located indoors, the outside air may also be indoor air. Alternatively, when the outside air is indoor air, an air conditioner may be used as the water recovery unit 64 to recover so-called drain water generated by condensation when cooling the air. The water recovery unit 64 is connected to the liquid container 25 of the mist generating device 20, and the recovered water is transferred to the liquid container 25.

[0060] The mist generating device 20 in the plant cultivation device 106 generates mist using the water recovered by the water recovery means 64 as part of the liquid L. Note that, in order to prevent the liquid L from being diluted with the water from the water recovery means 64, the plant cultivation device 106 may further include a means for supplying components of liquid fertilizer into the liquid container 25.

[0061] The plant cultivation device 106 of embodiment 4 differs from the plant cultivation device 100 of embodiment 1 in that it further includes a water recovery means, but it also includes a mist generation device 20, a growth status detection means 40 that detects the growth status of the plant P1, and a dryness condition evaluation means 42 that evaluates the dryness condition of the roots of the plant P1, and controls the amount of mist generation based on information regarding the growth status of the plant P1 detected by the growth status detection means 40 and information regarding the dryness condition of the roots evaluated by the dryness condition evaluation means 42, so that, like the plant cultivation device 100 of embodiment 1, it is a plant cultivation device that can respond to changes in conditions accompanying the growth of the plant P1, etc.

[0062] Furthermore, the plant cultivation device 106 according to the fourth embodiment is provided with a water recovery means 64 that recovers water from the outside air, and the mist generating device 20 generates mist using the water recovered by the water recovery means 64 as at least a part of the liquid L, thereby eliminating the need to supply water to the mist generating device 20.

[0063] The plant cultivation device 106 according to the fourth embodiment also has the effects of the plant cultivation device 100 according to the first embodiment other than those described above.

[0064] [Embodiment 5] 7A and 7B are diagrams for explaining a plant cultivation device 108 according to embodiment 5. Fig. 7A is a diagram showing a state before the internal volume of liquid container 25c is reduced, and Fig. 7B is a diagram showing a state after the internal volume of liquid container 25c is reduced. The mist generation device 20c and the plant cultivation device 108 according to the fifth embodiment basically have the same configuration as the mist generation device 20 and the plant cultivation device 100 according to the first embodiment, but differ from the mist generation device 20 and the plant cultivation device 108 according to the first embodiment in that they are intended for use under zero gravity or microgravity.

[0065] The mist generation device 20c is intended for use under zero gravity or microgravity, that is, in a spacecraft or space station. The liquid supply unit in the mist generation device 20c is a liquid container 25c that contains a liquid. In other words, the liquid container 25c also serves as the liquid supply unit. As shown in FIG. 7(a), under zero gravity or microgravity, surface tension causes the liquid L to move along the inner wall surface of the liquid container 25c. For this reason, in the mist generation device 20c, the liquid L is supplied to the mesh plate 23 by flowing along the inner wall surface of the liquid container 25c and the housing 29. In other words, the mist generation device 20c does not require a liquid supply unit (liquid supply unit 26 in the first embodiment) that sucks up the liquid L and supplies it to the mesh plate 23.

[0066] In mist generation device 20c, liquid container 25c may be configured so that its internal volume decreases as the amount of liquid L enclosed therein decreases (see FIG. 7(b)). This can be achieved by making liquid container 25c out of a soft or easily deformable material. Note that such liquid container 25c may be disposable rather than reused after the liquid L inside it has been used up.

[0067] The plant cultivation device 108 is intended for use under zero gravity or microgravity, and is provided with a carbon dioxide detection means 66 for detecting the concentration of carbon dioxide and a carbon dioxide supply means 67 for supplying carbon dioxide. When the plant cultivation device 108 is installed in a location accessible to crew members of a spacecraft or the like, it is preferable to increase the airtightness of the cultivation container 10 to ensure safety.

[0068] The mist generating device 20c of embodiment 5 differs from the mist generating device 20 of embodiment 1 in that it is used under zero gravity or microgravity, but it is equipped with a receiving unit 27 that receives information related to the growth status of the plant P1 and information related to the dryness state of the roots of the plant P1, and a control unit 28 that controls the amount of mist generated based on the information related to the growth status of the plant P1 and information related to the dryness state of the roots of the plant P1 received by the receiving unit 27, and therefore, like the mist generating device 20 of embodiment 1, it is a mist generating device that can respond to changes in conditions accompanying the growth of the plant P1, etc.

[0069] Furthermore, according to the mist generating device 20c of the fifth embodiment, the liquid supply unit is a liquid container 25c that encloses the liquid L, and the liquid L is supplied to the mesh plate 23 along the inner wall surface of the liquid container 25c, so that the mist generating device 20c can be used in zero gravity or microgravity while maintaining a simple structure.

[0070] Furthermore, according to the mist generating device 20c of embodiment 5, when the internal volume of the liquid container 25c decreases as the amount of the enclosed liquid L decreases, it is possible to continue supplying the liquid L to the ultrasonic vibration unit 22 even if the inflow of gas into the liquid container 25c due to the decrease in the liquid L is hindered.

[0071] The plant cultivation device 108 according to the fifth embodiment differs from the plant cultivation device 100 according to the first embodiment in that it is used under zero gravity or microgravity, but it is equipped with a mist generating device 20c, a growth status detection means 40 that detects the growth status of the plant P1, and a dryness condition evaluation means 42 that evaluates the dryness condition of the roots of the plant P1, and controls the amount of mist generated based on information on the growth status of the plant P1 detected by the growth status detection means 40 and information on the dryness condition of the roots evaluated by the dryness condition evaluation means 42, so that like the plant cultivation device 100 according to the first embodiment, it is a plant cultivation device that can respond to changes in conditions accompanying the growth of the plant P1, etc.

[0072] Furthermore, the plant cultivation device 108 according to the fifth embodiment is equipped with a carbon dioxide detection means 66 for detecting the concentration of carbon dioxide and a carbon dioxide supply means 67 for supplying carbon dioxide, and therefore is able to cope with a shortage of carbon dioxide that is thought to be likely to occur in environments such as spacecraft and space stations.

[0073] The mist generation device 20c according to the fifth embodiment also has the same effects as the mist generation device 20 according to the first embodiment other than those described above, and the plant cultivation device 108 according to the fifth embodiment also has the same effects as the plant cultivation device 100 according to the first embodiment other than those described above.

[0074] [Embodiment 6] FIG. 8 is a diagram for explaining a plant cultivation device 110 according to the sixth embodiment. The plant cultivation device 110 according to the sixth embodiment basically has the same configuration as the plant cultivation device 100 according to the first embodiment, but differs from the plant cultivation device 100 according to the first embodiment in that it is provided with a sound emitting means.

[0075] As shown in Fig. 8, the plant cultivation device 110 further includes sound emitting means 68 that emits sound toward the plant P1. The sound emitting means 68 is, for example, a speaker. The means for providing information to the sound emitting means 68 to emit sound may be a device integrated with the sound emitting means 68, or may be located outside the sound emitting means 68. The mist generating device 20 controls the amount of mist generated in accordance with the sound (for example, music) emitted by the sound emitting means 68. Although the sound emitting means 68 is arranged in the second space S2 in Fig. 8, it may also be arranged in the first space S1 or outside the cultivation container 10.

[0076] The plant cultivation device 110 of embodiment 6 differs from the plant cultivation device 100 of embodiment 1 in that it is equipped with a sound emission means, but it is equipped with a mist generation device 20, a growth status detection means 40 that detects the growth status of the plant P1, and a dryness condition evaluation means 42 that evaluates the dryness condition of the roots of the plant P1, and controls the amount of mist generation based on information regarding the growth status of the plant P1 detected by the growth status detection means 40 and information regarding the dryness condition of the roots evaluated by the dryness condition evaluation means 42, so that, like the plant cultivation device 100 of embodiment 1, it is a plant cultivation device that can respond to changes in conditions accompanying the growth of the plant P1, etc.

[0077] Furthermore, the plant cultivation device 110 according to the sixth embodiment is further provided with a sound emission means 68 that emits sound toward the plant P1, and the mist generating device 20 controls the amount of mist generated in accordance with the sound emitted by the sound emission means 68, thereby enhancing the effect of sound on the growth of the plant P1.

[0078] The plant cultivation device 110 according to the sixth embodiment also has the effects of the plant cultivation device 100 according to the first embodiment other than those described above.

[0079] Although the present invention has been described based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments. The present invention can be embodied in various forms without departing from the spirit of the present invention, and for example, the following modifications are also possible.

[0080] (1) The shapes, numbers, positions, etc. of the components described in the above embodiments are merely examples and may be changed within the scope that does not impair the effects of the present invention.

[0081] (2) The receiver 27 in the mist generating devices 20, 20a, 20b, and 20c according to the above embodiments receives both information about the growth status of the plant P1 and information about the dryness of the roots of the plant P1, but the present invention is not limited to this. The receiver in the mist generating device of the present invention may receive at least one of information about the growth status of the plant and information about the dryness of the roots of the plant. Furthermore, the control unit 28 in the mist generating devices 20, 20a, 20b, and 20c according to the above embodiments controls the amount of mist generated based on both information about the growth status of the plant P1 and information about the dryness of the roots of the plant P1, but the present invention is not limited to this. The control unit in the mist generating device of the present invention may control the amount of mist generated based on at least one of information about the growth status of the plant and information about the dryness of the roots of the plant.

[0082] (3) In each of the above embodiments, each plant cultivation device includes a growth status detection means 40 that detects the growth status of the plant P1 and a dryness condition evaluation means 42 that evaluates the dryness of the roots of the plant P1, but the present invention is not limited to this. The plant cultivation device of the present invention may include at least one of the growth status detection means 40 and the dryness condition evaluation means 42.

[0083] (4) In the above embodiments, the plant cultivation device cultivates leafy vegetables (plant P1), but the present invention is not limited to this. FIG. 9 is a diagram illustrating a plant cultivation device 112 according to a modified example. The plant cultivation device 112 according to the modified example has a configuration basically similar to that of the plant cultivation device 100 according to the first embodiment, but is intended for cultivating relatively small trees. The plant P2 in the first embodiment is a grape seedling. Accordingly, the plant cultivation device 112 includes a cultivation container 12 that is larger (taller) than the cultivation container 10 in the plant cultivation device 100. Furthermore, the plant holding means 30b of the plant cultivation device 112 includes a support 36 for supporting the plant P2. As shown in FIG. 9, the plant cultivation device of the present invention can cultivate grapes in addition to leafy vegetables. Grapes are sensitive to excessive water and are therefore considered suitable for cultivation in the plant cultivation device of the present invention. 9, the plant P2 is a grape seedling, but if each component is large enough, it is possible to cultivate grapes in the plant cultivation device of the present invention even when the grapes have grown to a mature stage and the fruit can be harvested. Although not shown in the drawings, the plant cultivation device of the present invention can also cultivate various other plants, such as melons, watermelons, and strawberries, in addition to those mentioned above.

[0084] (5) In the above embodiments and modifications, one plant cultivation device has been described as cultivating one plant, but the present invention is not limited to this. One plant cultivation device may be configured to cultivate multiple plants. In this case, each component (e.g., mist generating device) constituting the plant cultivation device may be provided one for each plant, or one for multiple plants.

[0085] (6) The mist generating devices 20, 20a, and 20b according to the above-described first to fourth and sixth embodiments include the ultrasonic vibration unit 22 having the mesh plate 23 and the ultrasonic vibration element 24, but the present invention is not limited to this. The mist generating device of the present invention may also be configured differently from the above (for example, a mist generating device in which the ultrasonic vibration element is disposed inside a space that stores liquid). [Explanation of symbols]

[0086] 10, 12...cultivation container, 20, 20c...mist generating device, 20a...mist generating device for water, 20b...mist generating device for liquid fertilizer, 22...ultrasonic vibration unit, 23...mesh plate, 24...ultrasonic vibration element, 25, 25c...liquid container, 26...liquid supply unit, 27...receiving unit, 28...control unit, 29...casing, 30, 30a, 30b...plant holding means, 32...plate-shaped member, 33...hole, 34...root holding member, 36...support, 4 0...growth status detection means, 42...dryness state evaluation means, 50...light source, 60...mist removal means, 61...mist detection means, 62...temperature and humidity adjustment means, 64...water recovery means, 66...carbon dioxide detection means, 67...carbon dioxide supply means, 68...sound emission means, 100, 102, 104, 106, 108, 110, 112...plant cultivation device, L, La, Lb...liquid, P1, P2...plant, S1...first space, S2...second space

Claims

1. A mist generating device for use in a plant cultivation device, an ultrasonic vibration unit that applies ultrasonic vibration to the liquid; a liquid supply unit that supplies liquid to the ultrasonic vibration unit; a receiving unit that receives at least one of information regarding the growth status of a plant and information regarding the dryness state of the roots of the plant; a control unit that controls the amount of mist generated based on at least one of the information about the growth status of the plant and the information about the dryness state of the roots of the plant received by the receiving unit, the ultrasonic vibration unit includes a mesh plate having a plurality of pores formed therein and an ultrasonic vibration element that vibrates the mesh plate; The mist generating device is for use in zero gravity or microgravity, the liquid supply unit is a liquid container that seals the liquid, The mist generating device is characterized in that the liquid is supplied to the mesh plate along the inner wall surface of the liquid container.

2. 2. The mist generating device according to claim 1, wherein the liquid container has an internal volume that decreases as the amount of the liquid contained therein decreases.

3. For use in zero gravity or microgravity, The mist generating device according to claim 1 or 2; a plant holding means for holding a plant; a growth status detection means for detecting a growth status of the plant and / or a dryness status evaluation means for evaluating a dryness status of the roots of the plant; The plant cultivation device is characterized in that the amount of mist generated is controlled based on at least one of information regarding the growth status of the plant detected by the growth status detection means and information regarding the dryness state of the roots evaluated by the dryness state evaluation means.

4. for use in zero gravity or microgravity; 4. The plant cultivation device according to claim 3, further comprising a carbon dioxide gas detection means for detecting a concentration of carbon dioxide gas and a carbon dioxide gas supply means for supplying carbon dioxide gas.

5. a mist generating device including an ultrasonic vibration unit that applies ultrasonic vibrations to a liquid, a liquid supply unit that supplies liquid to the ultrasonic vibration unit, a receiving unit that receives at least one of information on the growth status of a plant and information on the dryness state of the roots of the plant, and a control unit that controls the amount of mist generated based on at least one of the information on the growth status of the plant and the information on the dryness state of the roots of the plant received by the receiving unit; a plant holding means for holding the plant; a growth status detection means for detecting a growth status of the plant and / or a dryness status evaluation means for evaluating a dryness status of the roots of the plant; controlling the amount of mist generated based on at least one of information on the growth state of the plant detected by the growth state detection means and information on the dryness state of the roots evaluated by the dryness state evaluation means; Further comprising a water recovery means for recovering water from the outside air; The plant cultivation device, wherein the mist generating device generates the mist using water recovered by the water recovery means as at least a part of the liquid.

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