Plant cultivation equipment

Abstract

To provide a plant cultivation device comprising an illumination apparatus that suppresses an occurrence of illuminance unevenness.SOLUTION: A plant cultivation device 1 comprises an illumination apparatus 10. The illumination apparatus comprises: LED light sources 13; an LED substrate 12 on which the LED light sources are mounted; and shades 14 covering the LED light sources and the LED substrate. The shade has a curved reflection surface 15 which has the positions of the LED light sources as a focal point and includes a quadratic curve on a vertical cross section passing the LED light sources, and the LED light sources are arranged while directing an irradiation direction toward the reflection surfaces of the shades.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a plant cultivation device used in a plant factory, and more particularly to a plant cultivation device equipped with lighting equipment using an LED light source. [Background technology]

[0002] Plant cultivation using facilities such as plant factories utilizes plant cultivation devices that use lighting equipment. Plant cultivation devices are devices that grow plants using only artificial light, such as fluorescent tubes, or devices that control plant growth by supplementing lack of sunlight during the day with artificial light or by intentionally extending the hours of sunlight. Most of the lighting devices installed in conventional plant cultivation devices use fluorescent tubes, which are covered with shades and attached to the shelves or pillars of the plant cultivation device (see, for example, Patent Document 1). In recent years, there has been a shift from fluorescent tubes to LED light sources as the light source for lighting devices.

[0003] Since fluorescent tubes emit light in all directions, conventional plant cultivation devices have placed shades above the fluorescent tubes to reflect the emitted light downward and illuminate the plants being cultivated. On the other hand, when using LED light sources as lighting, the light emitted from LED light sources has directionality, so as in the plant cultivation device 101a shown in Figure 7(a), an LED light source 113a is placed so that its radiation direction is directed toward plants 133a in a cultivation tank 130.

[0004] However, the LED light source 113a is designed to irradiate only a certain range at a predetermined irradiation angle (also called a directivity angle). Therefore, when the irradiation angle Ra of the LED light source 113a is approximately 60 degrees, uneven illuminance occurs near the panel surface of the cultivation tank 130, as shown in Figure 7(a). In other words, there are areas where the irradiation ranges from adjacent LED light sources 113a overlap and areas where they do not, resulting in areas with high and low illuminance. Therefore, in the case of short seedlings (plants 133a), uneven light exposure occurs, resulting in differences in their growth.

[0005] To solve this problem, if an LED light source 113b with an irradiation angle Rb of approximately 120 degrees is used as in the plant cultivation device 101b shown in Fig. 7(b), uneven illuminance can be suppressed near the panel of the cultivation tank 130. However, uneven illuminance occurs near the LED light source 113b, and for tall plants 133b in the harvesting stage, uneven light is received in the upper parts, resulting in differences in growth.

[0006] There are two possible solutions to this problem. The first solution is to increase the number of LED light sources 113b to eliminate uneven illuminance. The second solution is to install the LED light sources 113 even higher so that uneven illuminance does not occur even at the top of the plants 133b during the harvest season.

[0007] In the first proposed solution, increasing the number of LED light sources 113b increases power consumption and heat generation. This increases the air conditioning load required to remove the generated heat. In a plant factory where plants are grown, the power consumption increases for both lighting and air conditioning equipment. Therefore, the first proposed solution poses the problem of increased plant cultivation costs.

[0008] The second solution has the advantage of easily leveling out uneven illuminance by increasing the installation height while keeping the number of LED light sources 113b constant. However, increasing the installation height of the LED light sources 113b reduces illuminance, which can slow plant growth and reduce quality. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-182998 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made to solve the above-mentioned problems, and has an object to provide a plant cultivation device equipped with lighting equipment that suppresses the occurrence of uneven illuminance. [Means for solving the problem]

[0011] The above-mentioned problem is solved by the plant cultivation device of the present invention, which is a plant cultivation device equipped with a lighting device, the lighting device including an LED light source, an LED substrate on which the LED light source is mounted, and a shade covering the LED light source and the LED substrate, the shade having a curved reflective surface that includes a quadratic curve with a focus at the position of the LED light source in a vertical cross section passing through the LED light source, and the LED light source is irradiated in a direction that is parallel to the axis of the shade. The aforementioned Positioned towards a reflective surface , and irradiating the cultivated plants with parallel light reflected by the reflecting surface. This is solved by:

[0012] In the plant cultivation device of the present invention configured as described above, light from the LED light source is emitted toward the curved reflective surface of the shade, which encompasses a quadratic curve. The LED light source is not directed directly toward the plants. Therefore, light is emitted as parallel rays from the reflective surface of the shade toward the plants. This suppresses uneven illuminance in the space where plants are cultivated (hereinafter sometimes referred to as the plant growth space), eliminating uneven growth from the seedling stage to the harvesting stage and enabling efficient lighting.

[0013] In addition, a preferred configuration for the above-mentioned cultivation device is that the LED substrate is formed in an elongated shape, multiple LED light sources are arranged in a linear line along the LED substrate, and the shade extends along the direction in which the multiple LED light sources are arranged. By arranging the LED light sources in a straight line, light can be irradiated onto the long and narrow cultivation tank, enabling efficient lighting.

[0014] Furthermore, a preferred configuration for the above-mentioned plant cultivation device is that the plurality of LED light sources are arranged in two rows on the LED substrate, the reflective surface of the shade has a first region and a second region, the first region and the second region are arranged in positions that are linearly symmetrical with respect to the center line of the reflective surface, the plurality of LED light sources arranged in the first row are arranged with their irradiation direction facing the first region, and the plurality of LED light sources arranged in the second row are arranged with their irradiation direction facing the second region.

[0015] Since LED light sources emit light at a specific angle, it is best to use multiple LED light sources to illuminate the entire reflective surface of the shade. For example, by arranging LED light sources with an approximately 90-degree beam angle on the LED board and arranging them so that each one faces a different area of ​​the reflective surface, it is possible to emit a wider, parallel beam of light toward the plants compared to arranging the LED light sources in a single row.

[0016] The above problem is solved by a plant cultivation device according to the present invention, which is a plant cultivation device equipped with a lighting device, the lighting device including an LED light source, an LED substrate on which the LED light source is mounted, and a shade covering the LED light source and the LED substrate, the shade having a curved reflective surface that includes a quadratic curve with a focus at the position of the LED light source in a vertical cross section passing through the LED light source, the LED light source is arranged such that its irradiation direction is directed toward the reflective surface of the shade, the LED substrate is formed elongated, a plurality of the LED light sources are arranged linearly along the LED substrate, and the plurality of LED light sources are arranged in three rows on the LED substrate, the reflective surface of the shade has a first region, a second region, and a third region, the first region and the second region are arranged in positions that are linearly symmetrical with respect to the center line of the reflective surface, the third region is located between the first region and the second region, the plurality of LED light sources arranged in the first row are arranged so that their irradiation direction faces the first region, the plurality of LED light sources in the second row are arranged so that their irradiation direction faces the second region, and the plurality of LED light sources in the third row are arranged so that their irradiation direction faces the third region.

[0017] Furthermore, a preferred configuration for the above-mentioned plant cultivation device is that the plurality of LED light sources are arranged in a row on the LED substrate, and the LED substrate is arranged so that the irradiation direction of the LED light sources is inclined at a predetermined angle from the vertical direction in the longitudinal cross section. When multiple LED light sources are arranged in a row on an LED board, if the LED light sources are arranged so that their irradiation direction is facing upwards, the brightest part of the emitted light will be reflected straight off the ceiling surface of the shade and return to the LED board, creating a shadow.By arranging the LED board so that the irradiation direction is tilted at a certain angle from the vertical, the reflected light of the brightest part of the light will avoid the LED board and reach the plants.

[0018] Furthermore, a preferred configuration of the above-mentioned plant cultivation device is that the LED substrate on which the LED light source is mounted is attached rotatably around an axis that is perpendicular to the longitudinal section and passes through the LED substrate. Furthermore, a preferred configuration of the above-described plant cultivation device is that it includes a housing that surrounds the LED board and rotates together with the LED board around the axis. Light reflected by the shade may be blocked by the LED board, creating a shadow. Although light reaches the shaded areas due to scattered light reflected from the floor and other surfaces, this can leave uneven illuminance with localized differences in light intensity. By rotating the LED board and the housing that surrounds it and adjusting the light reflected from the shade's reflective surface, it is possible to alleviate uneven illuminance that occurs below the LED board, for example, or move the shaded area. In other words, the position of the light can be adjusted to provide the appropriate illuminance to suit the position and height of plants, which vary depending on their growth stage.

[0019] Furthermore, a preferred configuration for the above-mentioned plant cultivation device is one in which the device is equipped with an air conditioning device, which has an air conditioning duct arranged below the LED board, and in the air conditioning duct, an air outlet through which air is blown toward the reflective surface is formed on the reflective surface side of the shade. By providing an outlet formed on the reflective surface that blows air toward the reflective surface, the cool air blown from, for example, an air conditioner, is agitated using the reflector. Since the cool air does not directly hit the plants, it is less likely to impede plant growth. [Effects of the Invention]

[0020] According to the plant cultivation device of the present invention, it is possible to provide a plant cultivation device equipped with lighting equipment that suppresses the occurrence of uneven illuminance. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of a plant cultivation device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the plant cultivation device taken along line II-II in FIG. 1. [Figure 3] 3 is a cross-sectional view showing the lighting device, and is a partially enlarged view showing a portion A of FIG. 2 in an enlarged manner. [Figure 4] FIG. 10 is a cross-sectional view showing another example of a lighting device. [Figure 5] FIG. 10 is a cross-sectional view showing another example of the plant cultivation device. [Figure 6] FIG. 10 is a cross-sectional view showing another example of the plant cultivation device. [Figure 7] 1A and 1B are explanatory diagrams of a plant cultivation device equipped with conventional lighting equipment using an LED light source, where (a) shows the illumination angle of the LED light source at approximately 60 degrees, and (b) shows the illumination angle at approximately 120 degrees. DETAILED DESCRIPTION OF THE INVENTION

[0022] The configuration of a plant cultivation device 1 according to one embodiment of the present invention (hereinafter referred to as the present embodiment) will be described below with reference to Figures 1 to 6. In the following embodiments, identical or similar components are denoted by common reference symbols, and the scales of these drawings have been appropriately changed for ease of understanding.

[0023] 1, in the present embodiment, the direction in which the lighting device 10 and the cultivation tank 30 extend (arrow X direction) in the plant cultivation device 1 is the longitudinal direction of the plant cultivation device 1, and the direction of arrow Y extending laterally relative to the arrow X direction is the width direction. The direction perpendicular to the arrow X direction and the arrow Y direction is the height direction, the arrow Z direction is the upward direction (upper side), and the opposite direction is the downward direction (lower side).

[0024] <<Plant cultivation equipment>> The plant cultivation device 1 of this embodiment is a device for hydroponically cultivating plants 33 in a plant factory, and is composed of a cultivation tank 30, a lighting device 10 installed in the cultivation tank 30, and an air conditioning device 20. Cultivation panels 32 float in the cultivation tank 30, and the panels are replaced as the plants 33 grow. The lighting device 10 is installed to illuminate the cultivation panels 32 and plants 33 floating in the cultivation tank 30.

[0025] The cultivation tank 30 is a long and narrow tank extending vertically (in the direction of arrow X in Figure 1), and is filled with a hydroponic nutrient solution 31. The cultivation panel 32 is made up of multiple replaceable panels and is capable of floating and moving. Each cultivation panel 32 is a component on which multiple seedlings are planted at regular intervals (plant spacing), and which supports the grown plants 33. In a plant factory, cultivation panels 32 formed with various plant spacings are prepared according to the type or growth of the plants 33. The cultivation panels 32 are made using, for example, a foam material so that they float in the hydroponic nutrient solution 31, but may also be made from hollow resin, wood, etc. The surface of the cultivation panel 32 has a high light reflectivity and also functions as a reflector that reflects the light from the lighting device 10, shining light onto the plants from below.

[0026] <<Lighting equipment>> Next, the lighting device 10 will be described. In a plant factory, in order to reduce variations in the growth of plants 33 due to bad weather, plants 33 are grown using lighting devices 10 that provide artificial light. In recent years, LED light sources 13 have come to be used as artificial light instead of fluorescent tubes. The lighting device 10 is composed of multiple lighting units 11, and in the lighting device 10 of this embodiment, four lighting units 11 are arranged in parallel. The number of lighting units 11 is just an example, and may be one or five or more according to the width of the cultivation tank 30. The four lighting units 11 can be attached and detached integrally using a support member 36. A side wall 34 is provided on the side of the lighting device 10 to prevent light from the lighting device 10 from leaking outside. As shown in FIGS. 1 and 2 , a gap 34a of several millimeters to several centimeters is formed in the side wall 34 at the boundary with the cultivation tank 30. This gap 34a allows the cool air in the plant cultivation space to escape, thereby suppressing temperature variations within the plant cultivation space.

[0027] Each lighting unit 11 has a plurality of LED light sources 13 arranged in a line and an elongated LED board 12 on which the plurality of LED light sources 13 are mounted. Each lighting unit 11 also has a shade 14 that covers the plurality of LED light sources 13 and the LED board 12 and has a shape that extends along the direction in which the plurality of LED light sources 13 are arranged (vertical direction, arrow X direction).

[0028] The shade 14 has a curved reflective surface 15 that includes a quadratic curve in a vertical cross section including the LED light source 13, more specifically, in a cross section perpendicular to the linear arrangement direction (vertical direction, arrow X direction) of the LED light sources 13. The LED light source 13 is positioned at the focus of the quadratic curve of the reflective surface 15 of the shade 14. Therefore, as shown by the two-dot chain arrow in Figure 2, light emitted from the LED light source 13 is reflected by the reflective surface 15 and reflected toward the plant 33 as parallel rays. Because the light is irradiated onto the plant 33 as parallel rays, the area where it overlaps with the light emitted from the adjacent lighting unit 11 is reduced. This reduces uneven illuminance and uneven growth of the plant 33, even from the seedling stage when the plant is still young to the plant 33 at harvest time. The shade 14 is made of metal or resin with high light reflectivity.

[0029] A highly reflective material may be attached to the inner surface of the shade 14 as the reflective surface 15 of the shade 14 to reduce light loss. Alternatively, a highly reflective material may be attached to the surface of the LED substrate 12 on which the LED light source 13 is mounted, thereby re-reflecting the light reflected by the reflective surface 15 and reducing light loss. Examples of highly reflective materials include aluminum, silver, gold, copper, and cobalt. Alternatively, the highly reflective material may be a highly reflective resin laminate in which highly reflective resin is laminated. Examples of highly reflective resins include resins containing white pigments such as titanium oxide. Furthermore, a highly reflective material may be attached not only to the shade 14 but also to the inner surface of the sidewall 34.

[0030] The LED light sources 13 arranged linearly in each lighting unit 11 of the lighting device 10 will be described in more detail with reference to Figure 3. Compared to fluorescent lamps, incandescent bulbs, etc., LED light sources 13 typically have a narrower illumination angle at which light is emitted, typically designed to be in the range of 30 to 90 degrees, with the front (center) of the LED light source 13 being brighter and becoming darker as it extends outward. The smaller the illumination angle, the greater the difference in illuminance between the front and the outside. In the following, the direction passing through the center of the illumination angle R of the LED light source 13 will be referred to as the illumination direction.

[0031] When using the reflecting surface 15 of the shade 14 to emit parallel beams of light, it is desirable to use LED light sources 13 with a wide beam angle, but LED light sources 13 with a wide beam angle are not common and must be custom-made, which increases costs. Therefore, in this embodiment, the LED light sources 13 are arranged in multiple rows on the LED substrate 12, and the reflecting surface 15 of the shade 14 is divided by the surface from which the LED light sources 13 in each row emit light, thereby making it possible to provide parallel beams of light with a wider width than when the LED light sources 13 are arranged in a single row.

[0032] Specifically, as shown in FIG. 3, a plurality of LED light sources 13 arranged in two rows are disposed on the LED substrate 12. The LED light sources 13 have an illumination angle R1 of approximately 90 degrees. The reflecting surface 15 is divided by a center line C into a first region 15a and a second region 15b. The first region 15a and the second region 15b of the reflecting surface 15 are arranged in positions that are symmetrical with respect to the center line C. Of the plurality of LED light sources 13 arranged in two rows, the plurality of LED light sources 13a arranged in the first row are arranged so that their illumination direction is toward the first region 15a of the reflecting surface 15. On the other hand, the plurality of LED light sources 13b arranged in the second row are arranged so that their illumination direction is toward the second region 15b of the reflecting surface 15. In other words, the LED light sources 13a and the LED light sources 13b are arranged at an angle with respect to the center line C so that their illumination ranges do not overlap each other. In this way, by arranging multiple LED light sources 13, it is possible to use the reflecting surface 15 of the shade 14 to emit light over a wide area, and to emit wide parallel light rays toward the plants 33.

[0033] Each lighting unit 11 of the lighting device 10 may have a plurality of LED light sources 13A arranged in three rows on the LED substrate 12, as in the lighting unit 11A shown in FIG. 4. In this case, the LED light sources 13A have an illumination angle R2 of approximately 60 degrees. The reflecting surface 15 is divided into three regions (first region 15Aa, second region 15Ab, and third region 15Ac), and the first region 15Aa and the second region 15Ab are positioned symmetrically with respect to the center line C of the reflecting surface 15. The third region 15Ac is positioned between the first region 15Aa and the second region 15Ab, as shown in FIG. 4.

[0034] Of the three rows of LED light sources 13A, the LED light sources 13Aa in the first row are arranged so that their illumination direction is directed toward the first region 15Aa of the reflecting surface 15. Meanwhile, the LED light sources 13Ab in the second row are arranged so that their illumination direction is directed toward the second region 15b of the reflecting surface 15. The LED light sources 13Ac in the third row, located between the first and second rows of LED light sources 13Aa and 13Ab, are arranged so that their illumination direction is directed toward the third region 15Ac above the LED light source 13c. The LED light sources 13Aa to 13Ac are arranged so that their illumination ranges do not overlap. By arranging the multiple LED light sources 13 in this manner, even when using an LED light source 13A with an illumination angle R2 of approximately 60 degrees, light can be irradiated onto the entire reflecting surface 15 of the shade 14, and parallel light can be irradiated onto plants across the width of the shade 14. Furthermore, increasing the number of rows of LED light sources 13 arranged on the LED substrate 12 enables brighter light to be irradiated onto plants.

[0035] In this embodiment, the LED light source 13 is indirectly illuminated using the reflecting surface 15, and is not directly aimed at the plants. As shown in Figures 7(a) and 7(b), if the LED light source 113 were directly aimed, uneven illuminance would occur depending on the height from the cultivation panel 132, which could result in differences in growth depending on the location of the plant. In the lighting device 10 of this embodiment, the reflecting surface 15 of the shade 14 irradiates the plants with parallel light, thereby preventing uneven illuminance depending on the height from the cultivation panel 132.

[0036] Of the parallel light from the reflecting surface 15, light directed directly above the LED board 12 and the air conditioning duct 21 of the air conditioning equipment 20 (described later) is reflected straight back to the LED board 12. This may result in a shadow below the air conditioning duct 21. Light reflected by the cultivation panel 32 other than directly below the equipment such as the LED board 12 returns to the reflecting surface 15 of the shade 14 and is reflected again, eventually becoming scattered light. The scattered light also reaches the shadowed area below the air conditioning duct 21, but may remain as uneven illuminance where the light intensity varies locally. To eliminate this unevenness in illuminance, it is desirable to be able to adjust the irradiation direction of the LED light source 13 in accordance with the position and height of the plant, which changes depending on the type of plant being cultivated and its growth stage.

[0037] In the lighting device 10A of the plant cultivation device 1A shown in Fig. 5, the LED substrate 12A is provided so as to be rotatable about an axis 16 extending in the longitudinal direction of the LED substrate 12A, in other words, an axis 16 that is perpendicular to the longitudinal section and passes through the LED substrate 12A. The LED substrate 12A can be rotated clockwise or counterclockwise.

[0038] The irradiation direction of the LED light source 13 can be changed by rotating the LED substrate 12A at any rotation angle θ around the axis 16. By changing the irradiation direction of the LED light source 13 according to the position and height of the plant, for example, the light from the LED light source 13 can be reflected from the side wall 34, etc., making it possible to reduce uneven illumination on the cultivation surface and move shadow areas.

[0039] When there are multiple lighting units 11A, such as the lighting device 10A of the plant cultivation device 1A, it is not necessary to make the rotation angle θ of each LED substrate 12A the same, and the rotation angle θ may be changed for each lighting unit 11A to achieve appropriate illuminance, as shown in Fig. 5. In Fig. 5, the LED substrate 12A of the lighting unit 11A located on the left side is rotated counterclockwise, and the LED substrate 12A of the lighting unit 11A located on the right side is rotated clockwise.

[0040] In this way, by rotating the LED substrate 12 and adjusting the light reflected from the reflecting surface 15 of the shade 14, even if the position or height of the plant changes depending on the type or growth of the plant, it is possible to appropriately apply light with reduced unevenness in illuminance to the plant. In the lighting device 10A of the plant cultivation device 1A shown in Fig. 5, only the LED substrate 12A in each lighting unit 11A is arranged to rotate, but this is just an example, and the LED substrate 12A may rotate together with the air conditioning duct 21. The air conditioning duct 21 also serves as a housing that surrounds the LED substrate 12A. The air conditioning duct 21 has its air passage 22 provided below the LED substrate 12, and is configured to blow air from an air outlet 23 provided on the side of the LED substrate 12A toward the reflective surface 15 of the shade 14 (see also Figs. 3 and 4). By rotating the air conditioning duct 21 together with the LED substrate 12A, the blowing direction of the air ejected from the air outlet 23 can be changed.

[0041] In the embodiment shown in Figures 3 and 4, multiple rows of LED light sources 13 are used. However, increasing the number of LED light sources 13 increases power consumption, installation costs, and heat generation. Therefore, the lighting unit 11 may be constructed by vertically arranging LED light sources 13C with a large illumination angle R in a single row. However, if the LED light sources 13C are arranged in a single row with the illumination direction facing directly upward, the light in the illumination direction will be reflected directly by the ceiling surface of the reflective surface 15 of the shade 14. This reflected light returns to the LED substrate 12 and is blocked by the LED substrate 12 and the air conditioning duct 21 of the air conditioning equipment 20 (described later), creating a shadow. Although scattered light reaches the shaded area, uneven illuminance occurs. Therefore, it is desirable for the light emitted in the illumination direction to avoid the LED substrate 12.

[0042] Another example of the plant cultivation device 1 will be described with reference to Fig. 6. The plant cultivation device 1B shown in Fig. 6 uses an LED substrate 12B on which LED light sources 13B are arranged in a row. The LED light source 13B has an illumination angle R3 of approximately 140 degrees.

[0043] In the plant cultivation device 1B, the LED substrate 12B is installed so that the irradiation direction (indicated by arrow E) of the LED light source 13B is tilted at a predetermined inclination angle β (predetermined angle) from the vertical direction (center line C) in the longitudinal cross section. As a result, the brightest part of the light emitted from the LED light source 13B is reflected downward by the reflecting surface 15 as indicated by arrow F, avoiding the LED substrate 12B. When the irradiation angle R3 of the LED light source 13B is approximately 140 degrees, the inclination angle β should be set to around 20 degrees. The inclination angle β may be adjusted between 10 and 30 degrees to ensure uniform illumination on the cultivation surface depending on the plant being cultivated and its growth rate.

[0044] The shape of the shade 14B in this case will be described. Because the illumination angle R3 of the LED light source 13B is approximately 140 degrees, there is a portion (portion G in FIG. 6) where light from one LED light source 13B is not irradiated. If this non-irradiated portion G were formed as a parabolic surface, as in the shade 14 shown in FIGS. 3 and 4, the amount of light reflected would be small, potentially resulting in uneven illuminance on the cultivation surface below. Therefore, a wall extending in the height direction (Z direction) is provided for portion G. A highly reflective material may be attached to the inside of the wall extending in the height direction to reflect the light from the LED light source 13B. The adjacent lighting unit 11B is then used to illuminate downward. In this way, the bright light irradiated from the LED light source 13B is no longer blocked by the LED board 12B and the air conditioning duct 21, allowing for efficient light irradiation and eliminating uneven illuminance.

[0045] <<Air conditioning equipment>> Next, the air conditioner 20 provided in the plant cultivation device 1 of this embodiment will be described with reference to Figs. 2 to 4. In a plant factory, the internal temperature and humidity are controlled, and the air conditioner 20 is provided to adjust them. Adjusting the temperature inside the entire factory would result in high air conditioning costs, so it is desirable to air condition only the plant cultivation environment.

[0046] In the air conditioning device 20 of the plant cultivation device 1 shown in Fig. 2, an air conditioning duct 21 extends from a blower (not shown) and is arranged to extend along the LED board 12 of the lighting device 10. The air conditioning duct 21 is arranged below the LED board 12 and does not directly block the light emitted from the LED light source 13.

[0047] As shown in Figures 3 and 4, air conditioning duct 21 is provided to cover the lower and side portions of LED board 12 with gaps, which serve as air passages 22. Air outlet 23 is located on the reflective surface 15 side of shade 14 and is formed so that air sent from the fan is blown out toward reflective surface 15. The blown out air is agitated when it hits reflective surface 15 of shade 14, as indicated by dashed arrow D in Figures 3 and 4, and moves to the plant growing space below.

[0048] If the air outlet 23 is formed below the air conditioning duct 21, the cold air may directly hit the growing plants. If the cold air is directed at the same leaf surface or stem for a long period of time, the low discharge temperature may damage the part directly hit by the cold air. Furthermore, for plants that have grown tall enough to be harvested, the distance between adjacent plants is small. Therefore, if the cold air is discharged directly toward the plants, turbulence will occur near the plants, resulting in areas where the cold air does not reach. As a result, temperature unevenness may occur, which may lead to inconsistent plant growth. For this reason, it is not desirable to provide an air outlet below the air conditioning duct 21 and direct the cold air directly toward the plants. In the air conditioner 20 of this embodiment, the air outlet is not directly aimed at the plants, preventing the cool air from directly hitting the plants. Furthermore, the air blown out from the air outlet 23 hits the reflective surface 15, is agitated, and moves to the plant growth space below, preventing turbulence near the plants. Furthermore, the air in the plant growth space can escape through the gap 34a between the cultivation tank 30 and the side wall 34. This allows the air to be distributed evenly, preventing temperature variations.

[0049] In addition, the air passing through the air conditioning duct 21 passes around the LED substrate 12, and can therefore also be used to cool the LED substrate 12. In other words, by placing the LED substrate 12 inside the air conditioning duct 21, the cooling effect on the LED substrate 12 is enhanced, which has the effect of extending the lifespan of the LED light source 13 and the LED substrate 12. This air conditioner 20 can also be applied to the plant cultivation devices 1A and 1B shown in FIGS.

[0050] As a measure to reduce uneven illuminance, a highly reflective material may be attached to the outer surface of the air conditioning duct 21. By attaching a highly reflective material to the surface of the air conditioning duct 21, the light reflection efficiency can be increased in combination with the light reflection from the surface of the cultivation panel 32.

[0051] Although the light emitted from the LED light source 13 becomes parallel rays in a cross section of the lighting device 10 in the width direction (Y direction), the light emitted from the LED light source 13 becomes scattered light in the longitudinal direction (X direction) of the lighting device 10. Therefore, when the light reflected by the top surface reaches the surface of the planar cultivation panel 32, all light except for that absorbed by the plants is diffused from the surface of the cultivation panel 32. As a result, the reflected light is made uniform to a certain extent within the plant cultivation space surrounded by the reflective surface 15 of the shade 14, the side wall 34, and the cultivation panel 32, and uneven illuminance occurring in the area shaded by the air conditioning duct 21 can be alleviated.

[0052] The plant cultivation device 1 according to an embodiment of the present invention has been described above using the drawings. However, the above embodiment is merely an example for easily understanding the present invention and is not intended to limit the present invention. For example, the plant cultivation device 1 has been described as an apparatus for irradiating light onto plants grown hydroponically, but the plant cultivation device 1 may also be used for plants grown in soil on the ground. [Explanation of symbols]

[0053] 1, 1A, 1B, 101a, 101b Plant cultivation equipment 10, 10A lighting equipment 11, 11A, 11B lighting units 12, 12B LED board 13, 13A, 113a, 113b LED light source 13a, 13Aa LED light source in the first row 13b, 13Ab LED light source in the second row 13Ac LED light source in the third row 14 Hat 15 Reflective surface 15a, 15Aa First area 15b, 15Ab second region 15Ac Third area 16 axis 20 Air conditioning equipment 21 Air conditioning duct (enclosure) 22 Air passage 23 Air outlet 30, 130 Cultivation tank 31 Hydroponic nutrient solution 32 Cultivation Panel 33, 133a, 133b plants 34 Side wall 34a Gap 36 Support member C center line R1, R2, R3, Ra, Rb Irradiation angle

Claims

1. A plant cultivation device equipped with lighting equipment, The lighting device comprises: An LED light source; an LED substrate on which the LED light source is mounted; a cover that covers the LED light source and the LED substrate, the shade has a curved reflective surface that includes a quadratic curve having a focus at the position of the LED light source in a vertical cross section passing through the LED light source, The LED light source is arranged with its irradiation direction directed toward the reflecting surface of the shade, and the plant being cultivated is irradiated with parallel light reflected by the reflecting surface.

2. The LED substrate is formed in an elongated shape, The LED light sources are arranged in a line along the LED substrate, The plant cultivation device according to claim 1 , wherein the shade extends along a direction in which the plurality of LED light sources are arranged.

3. The plurality of LED light sources are arranged in two rows on the LED substrate, The reflecting surface of the shade has a first region and a second region, and the first region and the second region are arranged at positions that are line-symmetrical with respect to a center line of the reflecting surface, 3. The plant cultivation device according to claim 2, wherein the plurality of LED light sources arranged in a first row are arranged so that their irradiation direction faces the first area, and the plurality of LED light sources arranged in a second row are arranged so that their irradiation direction faces the second area.

4. the plurality of LED light sources are arranged in a row on the LED substrate; The plant cultivation device according to claim 2, wherein the LED substrate is arranged so that the irradiation direction of the LED light source is inclined at a predetermined angle from the vertical direction in the longitudinal cross section.

5. A plant cultivation device equipped with lighting equipment, The lighting device comprises: An LED light source; an LED substrate on which the LED light source is mounted; a cover that covers the LED light source and the LED substrate, the shade has a curved reflective surface that includes a quadratic curve having a focus at the position of the LED light source in a vertical cross section passing through the LED light source, The LED light source is arranged such that the illumination direction is directed toward the reflective surface of the shade, The LED substrate is formed in an elongated shape, The LED light sources are arranged in a line along the LED substrate, The plurality of LED light sources are arranged in three rows on the LED substrate, the reflecting surface of the shade has a first region, a second region, and a third region, the first region and the second region are arranged at positions that are line-symmetrical with respect to a center line of the reflecting surface, and the third region is located between the first region and the second region, The plant cultivation device is characterized in that the plurality of LED light sources arranged in a first row are arranged so that their irradiation direction is toward the first area, the plurality of LED light sources arranged in a second row are arranged so that their irradiation direction is toward the second area, and the plurality of LED light sources arranged in a third row are arranged so that their irradiation direction is toward the third area.

6. The plant cultivation device according to any one of claims 1 to 5, characterized in that the LED substrate on which the LED light source is mounted is mounted rotatably around an axis that is perpendicular to the longitudinal section and passes through the LED substrate.

7. The plant cultivation device according to claim 6, further comprising a housing that surrounds the LED board and rotates together with the LED board around the axis.

8. Equipped with air conditioning equipment, the air conditioning device has an air conditioning duct arranged below the LED board, The plant cultivation device according to any one of claims 1 to 7, characterized in that in the air conditioning duct, an air outlet through which air is blown out toward the reflective surface is formed on the reflective surface side of the shade.

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