TW201735777A - Illumination device for plant cultivation, plant cultivation device, plant cultivation method - Google Patents

Abstract

An illumination device for plant cultivation, having: a plurality of LEDs which are arranged more densely in at least one of the two end sections of an LED layout range extending in a first direction than in the center part; and a diffusion part for causing light emitted towards a plant from the plurality of LEDs to diffuse.

Description

Lighting device for plant cultivation, plant cultivation device, plant cultivation method

FIELD OF THE INVENTION The present disclosure relates to a lighting device, a plant cultivation device, and a plant cultivation method for plant cultivation.

BACKGROUND OF THE INVENTION A lighting device for plant cultivation having a straight tube fluorescent lamp or an illumination unit in which light-emitting diodes are arranged in a straight line is known. Advanced technical literature

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2015-136357 (Patent Document 2) Japanese Laid-Open Patent Publication No. 2014-166179

SUMMARY OF THE INVENTION Problems to be Solved by the Invention However, in a conventional illumination device for plant cultivation, it is difficult to illuminate a plurality of plants with a uniform light amount distribution. For example, in the conventional illumination device for plant cultivation, it is difficult to illuminate the plant located at the end among a plurality of plants arranged in a straight line with the same amount of light as the plant at the center.

Therefore, on the one hand, the object of the present invention is to achieve uniformity of the amount of light irradiated to a plurality of plants. Method of solving the problem

According to one aspect, there is provided an illumination device for plant cultivation, comprising: a plurality of LEDs, wherein at least one of both end portions of the LED arrangement range that is arranged to extend in the first direction is closer to the central portion; and the diffusion portion Light emitted from a plurality of the aforementioned LEDs toward the plant direction is diffused. Effect of the invention

The amount of light that can be irradiated to a plurality of plants can be uniformized.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

[First Embodiment] Fig. 1 is a perspective view schematically showing an example of a plant cultivation apparatus 1. FIG. 2 is a front view schematically showing an example of the plant cultivation apparatus 1. FIG. 3 is a perspective view showing a relationship between the conveying device 6 and the cultivation tray 4. 4A is a plan view of an example of the cultivation tray 4. Fig. 4B is a plan view of the cultivation tray 4A of another example. Hereinafter, the three axes orthogonal to the X, Y, and Z axes shown in Fig. 1 are appropriately used for explanation. Further, the Z direction corresponds to the height direction (up and down direction) of the plant cultivation apparatus. In addition, in the following description, the X direction is the left-right direction. Further, in Fig. 1 (the same as Fig. 5 and the like), the lighting fixture 5 is simply displayed in a rectangular cross-sectional shape, but the cross-sectional shape is arbitrary (for example, refer to Fig. 7).

The plant cultivation apparatus 1 is disposed in a plant cultivation room, for example, in the clean room 51. The plant cultivation apparatus 1 includes a cultivation stand 2, a cultivation unit 3, a conveyance device 6, and a lifting mechanism 16.

The cultivation unit 3 is attached to the cultivation stand 2 in a plurality of stages in the height direction, and is arranged in parallel in each of the two stages. Further, the number of stages in the height direction or the number of rows of the cultivation units 3 in each stage is arbitrary. Further, the cultivation gantry 2 may be provided with a plurality of passages in the Y direction or the X direction.

The plant cultivation apparatus 1 is used, for example, in hydroponic cultivation. The cultivated plant is suitable for, for example, leafy vegetables, and plants other than leafy vegetables may be cultivated. Furthermore, leafy vegetables include lettuce, spinach, small pineapple, lettuce, and watercress. Plants other than leafy vegetables include, for example, strawberries, tomatoes, and the like.

The cultivation stand 2 has a skeleton structure and includes a plurality of pillars 2a at intervals in the X direction and the Y direction. The pillar 2a extends in the Z direction and is supported on the ground E. The plurality of pillars 2a adjacent to each other in the Y direction are connected to each other via the first beam 2b at a plurality of points. The first beam 2b and the pillar 2a are fixed by, for example, a screw, a rivet or the like.

As shown in FIG. 2, the plurality of second beams 2c are interposed in the height direction with respect to the two pillars 2a adjacent in the X direction in the X direction. The pillar 2a and the second beam 2c are fixed by, for example, a screw, a rivet or the like. As will be described later, the cultivation tray 4 and the lighting fixture 5 are supported by a plurality of second beams 2c.

Each of the cultivating units 3 includes a cultivating tray 4 (an example of a tray) and a luminaire 5 (an example of an illuminating device for plant cultivation) disposed above the cultivating tray 4. Hereinafter, unless otherwise mentioned, the configuration of one cultivation unit 3 will be described as a representative, but the others are also the same.

The cultivation tray 4 is placed on the transporting device 6. As shown in FIG. 3, the cultivation tray 4 is supported by the second beam 2c via the conveyance tool 6. The cultivation tray 4 can be carried into the cultivation stand 2 or carried out from the cultivation stand 2 using the transfer tool 6 as needed.

The cultivation tray 4 has a long form in the X direction, and has a cultivation container 4a and a lid body 4b as shown in Fig. 3 .

The cultivation container 4a is in the form of a barrel having an opening at the upper portion (a shape in which the cross section on the YZ surface is concave and closed on both sides in the X direction), and the main body of the cultivation tray 4 is formed. Liquid fertilizer or circulating liquid fertilizer is stored in the cultivation container 4a.

The lid body 4b has a rectangular flat shape and covers an opening in the upper portion of the cultivation container 4a. As shown in FIG. 3 and FIG. 4A, in the lid body 4b, hose insertion holes 4c through which the liquid fertilizer hose 8 can be inserted are formed on both sides in the X direction. In the lid body 4b, in a region between the hose insertion holes 4c on both sides in the X direction, a plurality of pot insertion holes 4d are formed linearly at intervals in the X direction. In Fig. 4A, the number of the pot insertion holes 4d is eight, but is not limited thereto, and may be, for example, ten. Further, as shown in FIG. 4B, the pot insertion hole 4d may be formed in two rows or more in a zigzag manner in a zigzag manner.

Each of the plurality of pot insertion holes 4d may be embedded in a cup-shaped cultivation pot 9 which is planted with the plant S which has been seeded. Further, since the upper edge of the cultivation pot 9 is hung on the edge of the pot insertion hole 4d, when the lid body 4b is lifted, the cultivation pot 9 is also lifted. Further, depending on the type of the plant S, a plate (not shown) for preventing the leaves of the growing plant S from falling down between the lids 4b of the two cultivation units 3 adjacent to each other in the Y direction may be provided.

As shown in FIG. 3, the cultivation pot 9 has a bottomed cylindrical shape having an opening at the upper end, and has a wedge-shaped outer peripheral surface whose upper end is wider than the lower end. The cultivation pot 9 has a structure in which a sponge (not shown) can be inserted, and the sponge is a culture site in which a plant S, for example, a lettuce seedling, which has been planted for a predetermined period of time, is planted. For example, a cubic urethane sponge can also be used for the sponge. Further, a longitudinal slit 9a having a width in which a plurality of plants can extend can be formed in the circumferential direction around the lower portion of the cultivation pot 9. Further, a plurality of holes (not shown) for discharging water or the like may be formed at the bottom of the cultivation pot 9.

Further, in order to efficiently increase the yield of plants, it is desirable to increase the number of plants cultivated in one cultivation tray 4. However, for the growth of plants, a moderate width is required, for example, between adjacent cultivation pots 9 so that adjacent plants do not overlap between the leaves when growing. For example, in the case of leafy vegetables such as lettuce or Komatsu, it takes about 15 cm for the adjacent cultivation pots. Therefore, the interval L between the plurality of pot insertion holes 4d (refer to FIGS. 4A and 4B) can be appropriately adjusted in accordance with the plant species to be cultivated. For example, in order to correspond to various plant species, a plurality of types of lids 4b having different intervals L between the plurality of pot insertion holes 4d are prepared.

Further, one end side of the cultivation container 4a of the cultivation tray 4 in the X direction is surrounded by a wavy line having a cross section of Fig. 2 to form a liquid fertilizer introduction region 4e. The liquid fertilizer is supplied to the liquid fertilizer introduction region 4e through the liquid fertilizer hose 8 inserted into the hose insertion hole 4c on one end side of the lid body 4b. Further, in the bottom portion on the other end side in the X direction of the cultivation container 4a, as shown in a partially cutaway cross section in Fig. 2, a liquid fertilizer discharge hole 4f is formed. A liquid amount adjuster 10 is attached to the liquid fertilizer discharge hole 4f and its periphery, and the liquid amount adjuster 10 is for adjusting the liquid amount so that the liquid fertilizer in the cultivation container 4a of the cultivation tray 4 does not exceed the set height.

The lighting fixture 5 illuminates the plants in the cultivation tray 4. The plants in the cultivation tray 4 are grown by the illumination from the lighting fixture 5. The lighting fixture 5 extends in the X direction in accordance with the shape of the above-described cultivation tray 4 having a long X direction. For example, the length of the lighting fixture 5 in the X direction is 1000 mm or more, for example, about 1250 mm. The lighting fixture 5 arranges a plurality of LEDs 50 (refer to FIG. 8) that can emit light downward (plant direction) in the X direction. As shown in FIG. 5, the lighting fixture 5 has an elongated shape along the cultivation tray 4. An electric wire 15 for supplying electric power is connected to one end of the lighting fixture 5. The lighting fixture 5 is supported by the second beam 2c via a lifting mechanism 16 which will be described later. Further details of the lighting fixture 5 are made later.

The conveyance tool 6 is used to mount the cultivation tray 4, and the conveyance of the cultivation tray 4 is facilitated. As shown in FIG. 3, the conveyance tool 6 is placed on the rail 7, and the rail 7 is spanned over the second beam 2c of the plurality of cultivation stands 2 adjacent in the Y direction. The conveyance tool 6 slides on the rail 7 and is movable in the Y direction. The rail 7 may have, for example, a quadrangular cross section, and two of the second beams 2c are mounted in parallel in the Y direction with a space therebetween.

The lifting mechanism 16 allows the lighting fixture 5 to move up and down. Here, an example of the elevating mechanism 16 will be described with reference to FIGS. 2 and 5. FIG. 5 is a perspective view schematically showing an example of the elevating mechanism 16.

In the first embodiment, as an example, as shown in FIG. 5, the elevating mechanism 16 is provided in a manner common to the two lighting fixtures 5 adjacent in the Y direction.

The elevating mechanism 16 has a plurality of folding arms 16a which are supported by the second beam 2c having a T-shaped cross section at the upper end and are expandable and contractible in the Z direction. The folded portion in the middle of the plurality of arms 16a is rotatably connected to each other through the beam 16b. The lower end of each of the plurality of arms 16a is supported by a shaft 16c having an inverted T-shaped cross section.

At the lower end of the plate piece 16c, a support member 16d capable of simultaneously supporting two lighting fixtures 5 adjacent in the Y direction is attached to a plurality of places. The support 16d is, for example, a recess formed in the center, and the plate 16c is fixed in the recess by screws, rivets or the like. The plate 16c is located between the two lighting fixtures 5 adjacent in the Y direction. Cables 17 are mounted on both sides of the sheet 16c in the X direction. As shown in FIG. 2, the cable 17 extends upward from the plate piece 16c, and is connected to both ends of the coil spring 19 by a pulley 18 that is rotatably attached to the second beam 2c. The coil spring 19 urges the plate 16c and the lighting fixture 5 upward through the cable 17.

The lifting mechanism 16 is driven, for example, manually. When the elevating mechanism 16 is folded, the two lighting fixtures 5 adjacent in the Y direction rise at the same time. On the other hand, when the elevating mechanism 16 is deployed, the two lighting fixtures 5 adjacent in the Y direction are simultaneously lowered. The elevating mechanism 16 transmits the direction in which the elevating mechanism 16 is folded (the direction in which the arm 16a contracts in the Z direction) by the coil spring 19 and the cable 17 as described above. On the other hand, the elevating mechanism 16 is locked by a fastener (not shown) so as not to be deformed in the direction in which the elevating mechanism 16 is folded. The user can change the state of the elevating mechanism 16 by changing the position of the fastener, and can change the height of the two lighting fixtures 5 adjacent in the Y direction within a predetermined range.

According to the support structure of the lighting fixture 5 shown in FIG. 2 and FIG. 5, the two lighting fixtures 5 adjacent to each other in the Y direction can be raised and lowered simultaneously by the elevating mechanism 16. As a result, the height of the lighting fixture 5 can be changed in accordance with the growth of the plant, and by simultaneously raising the two lighting fixtures 5 adjacent in the Y direction, the work of loading and unloading the cultivation tray 4 can be easily performed. Further, in the modified example, the elevating mechanism 16 may be provided for each lighting fixture 5. In this case, each of the lighting fixtures 5 can be lifted up and down individually by the corresponding lifting mechanism 16.

In addition, the configuration of the plant cultivation apparatus 1 shown in FIG. 1 to FIG. 5 is only one example, and various changes can be made. For example, the transport device 6 may be omitted. At this time, the cultivation tray 4 can also be directly supported by the second beam 2c. Further, the lifting mechanism 16 can also be realized by other mechanisms. For example, the lifting mechanism 16 may also be of a type that can be driven by an actuator (such as an electric motor) or the like. Further, the elevating mechanism 16 may be provided in a state common to three or more lighting fixtures 5 adjacent in the Y direction, or may be provided in a state common to two or more lighting fixtures 5 adjacent in the X direction.

Next, the relationship between the lighting fixture 5 of the first embodiment and the cultivation tray 4 will be described with reference to Fig. 6 .

Fig. 6 is a side view schematically showing the relationship between the lighting fixture 5 and the cultivation tray 4 when viewed in the Y direction. Here, the relationship between the lighting fixture 5 of one set and the cultivation tray 4 is demonstrated, but other groups may be the same.

Fig. 6 shows the plant placement range R1 on the cultivation tray 4 and the LED arrangement range R2 of the lighting fixture 5. Further, Fig. 6 shows a center line CL for indicating the reference position in the X direction. Hereinafter, the side (the far side) which is away from the center line CL in the X direction is "outside". Here, the plant placement range R1 is a range of the X direction as shown in FIG. 4A (and FIG. 4B), and is set to each of the pot insertion holes 4d of the cultivation tray 4 which is the outermost side in the X direction. The range between the center positions. Further, similarly, the LED arrangement range R2 is set to a range between the center positions of the LEDs 50 on the outermost side in the X direction (refer to FIG. 8).

As described above, the lighting fixture 5 and the cultivation tray 4 extend in the X direction and face each other in the Z direction. Both the lighting fixture 5 and the cultivation tray 4 are arranged slightly parallel to the X direction. Further, the lighting fixture 5 and the cultivation tray 4 are disposed such that the center of the X direction is located on the center line CL. That is, the centers of the plant placement range R1 and the LED arrangement range R2 in the X direction slightly coincide. Furthermore, the so-called "slightly consistent" is intended to allow a certain degree of error. In fact, it is difficult to make the centers of the plant placement range R1 and the LED arrangement range R2 correctly coincide with each other due to errors in configuration or manufacturing tolerances, and it is not meaningful to make them correctly coincide.

The LED configuration range R2 is preferably as shown in Fig. 6, extending to the outside of the plant placement range R1. In the example shown in FIG. 6, the LED arrangement range R2 is on both sides in the X direction, and extends a predetermined distance Δx0 to the outside than the plant placement range R1. The predetermined distance Δx0 is preferably in the range of 20 to 30 mm. In this case, in the X direction, both ends of the plant placement range R1 and the outer side thereof are more likely to ensure the necessary amount of light from the lighting fixture 5.

The lighting fixture 5 is separated from the cultivation tray 4 by a distance H3 in the Z direction. That is, the lighting fixture 5 is disposed above the upper surface (plant placement surface) on the cultivation tray 4 by a distance H3. The distance H3 indicates the height of the lighting fixture 5 to the cultivation tray 4. Therefore, the following description of "adjusting the height of the lighting fixture 5" is synonymous with "adjusting the distance H3" by the lifting mechanism 16. An example of the method of adjusting the distance H3 is related to the plant cultivation method and will be described later. Further, in the first embodiment, an example is that the distance H3 is adjusted by moving the lighting fixture 5 up and down. However, in the modified example, the distance H3 may be adjusted by moving the cultivation tray 4 up and down.

Next, the structure of the lighting fixture 5 of the first embodiment will be described with reference to Figs. 7 and 8 . Here, the lighting fixture 5 in the plant cultivation apparatus 1 will be described as a representative, but the other lighting fixtures 5 in the plant cultivation apparatus 1 are also the same.

Fig. 7 is a cross-sectional view along the line A-A of Fig. 6. Fig. 8 is a view showing the angle of view of arrow B of Fig. 6, showing the internal configuration (LED configuration) of the lighting fixture 5 in a perspective manner. In addition, in FIG. 8, the illustration of the wiring etc. on the board|substrate 56 is abbreviate. 9A and 9B show two examples of variations of the pitch d1. In FIGS. 9A and 9B, the horizontal axis represents the position in the X direction, and the vertical axis represents the pitch d1, and the display pitch d1 changes. In FIGS. 9A and 9B, the outermost positions x3 and x4 corresponding to the position x0 of the center line CL and the LED arrangement range R2 are displayed on the horizontal axis.

As shown in FIGS. 7 and 8 , the lighting fixture 5 includes a plurality of LEDs 50 , a cover 54 (an example of a diffusing portion), a substrate 56 , and a heat radiating portion 58 .

The plurality of LEDs 50 are arranged in a row in the X direction as shown in FIG. The number of the plurality of LEDs 50 is determined by, for example, the relationship between the distance d1 and the length of the lighting fixture 5 in the X direction. The number (22) shown in Fig. 8 is an example, and a larger number of LEDs 50 can be actually arranged.

In the first embodiment, an example in which a plurality of LEDs 50 have the same outer shape and characteristics. The color of light from the plurality of LEDs 50 is arbitrary, and in the first embodiment, white is exemplified.

As shown in FIG. 8, the plurality of LEDs 50 are arranged densely at the both end portions of the luminaire 5 in the X direction than at the central portion of the luminaire 5 in the X direction. That is, the pitch d1 between the LEDs 50 in the X direction is not fixed, and the distance d1 between the both end portions is also smaller than the distance d1 between the center portions. Both ends of the illuminating device 5 in the X direction are portions including the outermost LEDs 50 in the X direction, and are portions within a predetermined range Δx1 on both sides of the LED arrangement range R2. The predetermined range Δx1 is a range including two or more LEDs 50. The central portion of the illuminating device 5 in the X direction is a portion that does not include both end portions of the illuminating device 5 in the X direction, and is a portion including the center line CL.

For example, the pitch d1 may be a value α within a predetermined range Δx1 on both sides of the LED arrangement range R2 as shown in FIG. 9A, and a value β (>α) in other ranges (including the center portion). The value α may correspond to, for example, a configurable minimum pitch, and the value β may be, for example, 10 mm or less. Further, as another example, the pitch d1 may be a value α at the outermost side of the LED arrangement range R2, a value β at the center of the LED arrangement range R2, and a value from the center toward the outer side as shown in FIG. 9B. β gradually changes to a value α. Further, in another example, although not shown, the pitch d1 may be a value α at the outermost side of the LED arrangement range R2, and may be directed toward the center portion within a predetermined range Δx1 on both sides of the LED arrangement range R2. The value β gradually increases.

The cover 54 is formed of a resin material or glass. The cover 54 has a protective function of covering a plurality of LEDs 50. Further, the cover 54 has a function of diffusing light emitted from a plurality of LEDs 50 downward (in the direction of the plant). The cover 54 is preferably formed to have a high light transmittance and to efficiently diffuse light. For example, the cover 54 has a total light transmittance of 60% or more, and preferably has a total light transmittance of 70% or more. Further, the light diffusing coefficient of the cover 54 is 0.2 or more, preferably 0.3 or more, and more preferably 0.5 or more. The cover 54 may be a glass (glazed glass) having fine irregularities formed on its surface, or a plastic material (translucent plastic material) or acrylic material having a fine uneven surface treatment. Alternatively, the cover 54 may be formed by applying a diffusion sheet or a diffusion film to a transparent glass or a transparent plastic. The diffusion sheet may be, for example, a sheet having fine irregularities formed on its surface, a milky white sheet, or the like.

A plurality of LEDs 50 are mounted on the surface of the substrate 56 on the lower side in the Z direction. In the first embodiment, the respective optical axes of the plurality of LEDs 50 are exemplified in the Z direction perpendicular to the surface of the substrate 56. A terminal for connecting to the electric wire 15 or a wiring for supplying electric power to the plurality of LEDs 50 is formed on the substrate 56 (refer to FIG. 10). In the example shown in FIG. 10, the substrate 56 corresponds to the lighting fixture 5 that is long in the X direction, and is divided into two in the X direction. Specifically, the substrate 56 includes a substrate portion 56L on the left side in the X direction and a substrate portion 56R on the right side in the X direction. The substrate portion 56L and the substrate portion 56R are connected in the X direction. The positive electrode terminal 520 and the negative electrode terminal 521 electrically connected to the electric wire 15 (refer to FIG. 6) are formed in the substrate portion 56L. Further, a positive electrode terminal 522 and a negative electrode terminal 523 are formed at the right end of the substrate portion 56L and the left end of the substrate portion 56R. The substrate portion 56L and the positive electrode terminal 522 of the substrate portion 56R are electrically connected to each other via the wiring 528, and the substrate portion 56L and the negative electrode terminal 523 of the substrate portion 56R are electrically connected to each other via the wiring 529. The substrate portion 56L and the substrate portion 56R are formed with a positive electrode side wiring 524 and a negative electrode side wiring 526 which extend in the X direction in the Y direction in the Y direction. A wiring 527 electrically connected to the plurality of LEDs 50 is electrically connected between the positive electrode side wiring 524 and the negative electrode side wiring 526. In this manner, the plurality of LEDs 50 on the substrate 56 are electrically connected to the electric wires 15 through the wiring 524 or the like. According to the substrate 56 shown in FIG. 10, the pitch between the adjacent wirings 527 in the Y direction can be set in accordance with the pitch d1 between the LEDs 50 in the X direction. Therefore, the wiring structure is simple.

The heat radiating portion 58 is formed by, for example, an aluminum plate. The heat radiating portion 58 is provided on the back side of the substrate 56 (opposite to the side on which the plurality of LEDs 50 are mounted). The heat radiating portion 58 takes the heat of the plurality of LEDs 50 and releases it to the outside of the lighting fixture 5.

Next, the light amount distribution characteristic of the lighting fixture 5 on the cultivation tray 4 will be described with reference to Figs. 11 to 15 . In the same manner, the relationship between the lighting fixtures 5 of one set and the cultivation tray 4 will be described as a representative, but the other groups are also the same. The light amount distribution characteristic of the lighting fixture 5 on the cultivation tray 4 is exemplified as being evaluated at a position separated from the lighting fixture 5 by a predetermined distance H1 (refer to FIG. 6). The axis L1 (refer to FIG. 6) is referred to as "reference axis L1", and the axis L1 is parallel to the X direction by a position spaced apart from the lighting fixture 5 by a predetermined distance H1.

Fig. 11 is a view showing an ideal light amount distribution characteristic of the lighting fixture 5 illuminated onto the cultivation tray 4. 11 shows that the position on the set axis L1 is the horizontal axis, and the set light amount is the vertical axis, and the ideal light amount distribution characteristic 70 is displayed. Further, the intensity distribution characteristics of the illumination light can be evaluated by substituting the light amount distribution characteristics in an equivalent manner.

11 shows the position p0 corresponding to the center line CL, the positions p1 and p2 corresponding to both ends of the plant placement range R1, and the positions p3 and p4 corresponding to the outermost positions of the LED arrangement range R2 on the horizontal axis (1st) An example of location). Further, the positions p3 and p4 are positions corresponding to the respective LEDs 50 located on the outermost side in the X direction on the axis L1 of the lighting fixture 5 spaced apart by a predetermined distance H1. That is, the positions p3 and p4 are the respective intersection positions on the axis L1 from the outermost positions x3 and x4 of the LED arrangement range R2 toward the Z direction. Further, in Fig. 11, the positions p5 and p6 at which the predetermined distances Δp are shifted outward at the positions p3 and p4 are displayed on the horizontal axis.

The ideal light amount distribution characteristic is as shown in Fig. 11, and the amount of light between the positions p5 and p6 is fixed in the X direction. The preferred value of the predetermined distance Δp differs depending on the species of the plant S. For example, the predetermined distance Δp is preferably larger for plants of a species having a wider blade than for plants of this type. The predetermined distance Δp is in the range of 10 to 40 mm, preferably in the range of 40 to 60 mm, preferably in the range of 60 to 80 mm.

Fig. 12 is a view showing the arrangement of LEDs of the lighting fixture 5' of the first comparative example. Fig. 13 is an explanatory view showing an overlap of illumination light of a plurality of LEDs 50 of the first comparative example. Fig. 14 is an explanatory view showing an overlap of illumination light of a plurality of LEDs 50 of the first embodiment. Further, in FIGS. 13 and 14, for the sake of explanation, it is easy to display the superimposition, but in actuality, the overlapping of the illumination lights of the plurality of LEDs 50 is more complicated.

Fig. 15 is an explanatory diagram showing the light amount distribution characteristics of the first embodiment. In Fig. 15, the position on the axis L1 is taken as the horizontal axis, and the amount of light taken out is the vertical axis, and the light amount distribution characteristic according to the test result is displayed. Fig. 15 shows, for comparison, the light amount distribution characteristic 71 of the first embodiment, the light amount distribution characteristic 72 of the first comparative example, and the light amount distribution characteristic 73 of the second comparative example. In Fig. 15, similarly to Fig. 11, the position p0 corresponding to the center line CL, the positions p1 and p2 corresponding to both ends of the plant placement range R1, and the outermost position corresponding to the LED arrangement range R2 are displayed on the horizontal axis. Position p3, p4. Further, in the test results shown in Fig. 15, the predetermined distance Δp was 80 mm.

In the lighting fixture 5' of the first comparative example, as shown in Fig. 12, a plurality of LEDs 50 are arranged at equal intervals in the X direction. That is, the pitch d2 between the LEDs 50 in the X direction is fixed. According to the first comparative example, as shown by the light amount distribution characteristic 72, as shown in the light amount distribution characteristic 72, the range corresponding to the both end portions of the illuminating device 5' in the X direction (around the positions p3 and p4) corresponds to the lighting fixture 5 In the range of the central portion of the X direction (around p0), the amount of light from the lighting fixture 5' is remarkably reduced. In other words, the plant in the central portion of the cultivation tray which is long in the X direction is different from the amount of light of the lighting fixture 5' and the plant receiving the lighting fixture 5' at both ends of the cultivation tray. This is because the LED 50 is more directional than the fluorescent lamp (the extent of the regions S1 and S2 shown in FIG. 13 is small) and does not spread. For example, as shown in Fig. 13, the LED 50 on the left side of Fig. 13 is the LED 50 at the end in the X direction, and the end portion W1 on the reference axis L1 (for example, outside the position p3), no light overlap, light amount insufficient. According to the test result shown in FIG. 15, the position (position p3, p4) corresponding to the outermost position of the both ends of the illuminating device 5' in the X direction is compared with the position corresponding to the center portion (for example, the periphery of p0) The position of the maximum amount of light) is reduced by more than 40%.

The lighting fixture (not shown) of the second comparative example has a straight tube fluorescent lamp instead of a plurality of LEDs. In the second comparative example, as shown by the light amount distribution characteristic 73 in FIG. 15, the range corresponding to both end portions of the X-direction of the straight tube fluorescent lamp (around the positions p3 and p4) is compared with the corresponding straight tube. In the range of the central portion of the fluorescent lamp in the X direction (around p0), the amount of light from the straight tube fluorescent lamp is significantly reduced. This tendency is also remarkable according to Comparative Example 1 described above. This is a large influence of the electrode portion disposed on the end portion of the straight tube fluorescent lamp (the electrode portion disposed in the longer range in the X direction). In the test results shown in FIG. 15, as shown by the light amount distribution characteristic 73, in the position (position p3, p4) corresponding to the outermost position of the both ends of the straight tube fluorescent lamp in the X direction, compared with Corresponding to the position of the central portion (for example, the position of the maximum amount of light around p0), the amount of light is reduced by 60% or more.

In the first comparative example or the second comparative example, as described above, the amount of light is insufficient in the range corresponding to both end portions of the illuminating device in the X direction (around the positions p3 and p4), and therefore, for example, the following is generated. situation. Plants at both ends of the cultivation tray 4 in the X direction are bent and grown in the direction of light (that is, near the central portion of the lighting fixture) in order to receive light. In this case, the plants at both ends in the X direction in the cultivation tray 4 are in a state unsuitable as a product. On the other hand, by reducing the plant placement range R1 in the X direction (for example, the outermost pot insertion hole 4d is not used), the above situation can be avoided, but in this case, a new problem of poor cultivation efficiency occurs.

On the other hand, according to the lighting fixture 5 of the first embodiment, as described above, the plurality of LEDs 50 are disposed closer to each other at the both end portions in the X direction than at the central portion in the X direction. Here, as shown in FIG. 14, the light from the LED 50 is less diffused than the light from the fluorescent lamp, but the distance d1 between the adjacent LEDs 50 becomes smaller, and the respective illumination lights of the adjacent LEDs 50 are formed. Overlapping areas (S3 or S4, etc.). The width of the overlap region in the X direction is such that when the distance from the LED 50 in the Z direction is the same, it becomes wider as the pitch d1 between the two LEDs 50 becomes smaller. That is, the region S3 spreads outward, and the end portion range in which the light does not overlap (refer to the end portion range W1 of FIG. 14) becomes narrow. Therefore, according to the first embodiment, the LEDs 50 are closely arranged at both end portions of the lighting fixture 5, whereby the above problem can be reduced as compared with the first comparative example and the like. In other words, according to the first embodiment, since the LEDs 50 are closely arranged at both end portions of the lighting fixture 5, it is possible to reduce the amount of light of the plants in the central portion of the cultivation tray 4 and the plants at both ends of the cultivation tray 4. The difference in the amount of light of the appliance 5.

Specifically, according to the first embodiment, as shown by the light amount distribution characteristic 71 of FIG. 15, the position (position p3, p4) corresponding to the outermost position of the both ends of the illumination device 5 in the X direction is compared with the corresponding At the central portion position (for example, the position of the maximum amount of light around p0), the amount of light is hardly lowered. Further, according to the first embodiment, the range from the position (position p3, p4) corresponding to the outermost position of the both ends of the illuminating device 5 to the outer positions p5 and p6 is the same as the position corresponding to the central portion. The amount of light is the same. In the test result shown in FIG. 15, the amount of light (minimum value) in the range of the positions p5 and p6 to the outside is decreased with respect to the amount of light at the position corresponding to the central portion (for example, the position of the maximum amount of light around p0). Within 15%. In other words, the light amount at the position (the second position of the second position) at the maximum light amount around p0 is "Umax", and the minimum value of the light amount in the range of the outer positions p5 and p6 is "Umin", Umin/Umax ≧ 0.85. . As described above, according to the first embodiment, it is possible to achieve characteristics close to the ideal light amount distribution characteristics shown in FIG. 11 as compared with the first comparative example and the like. Further, according to the test by the inventors, Umin/Umax ≧ 0.85, but if Umin/Umax ≧ 0.8, it is understood that advantageous effects can be obtained as compared with the first comparative example and the like.

Moreover, in order to improve the cultivation efficiency in the same cultivation equipment, it is desirable to cultivate a large number of plants as much as possible in one cultivation tray 4. Therefore, a mechanism for allowing plants located at both end portions of the cultivation tray 4 to grow in the same manner as plants located at the central portion of the cultivation tray 4 is required. That is, in order to improve the cultivation efficiency, a mechanism capable of achieving characteristics close to the ideal light amount distribution characteristics as shown in Fig. 11 is required.

According to the first embodiment, as described above, the characteristics similar to those of the first comparative example and the like as shown in FIG. 11 can be achieved, and thus the cultivation efficiency can be improved.

Next, referring to Fig. 16, the light diffusion effect by the cover 54 will be described.

Fig. 16 is a view showing the light amount distribution characteristics of the lighting fixture 5 when the cover 54 is not attached. In Fig. 16, the position in the X direction is the horizontal axis, and the amount of light taken out is the vertical axis, and the light amount distribution characteristic of the lighting fixture 5 when the cover 54 is not attached is displayed. In Fig. 16, the light amount distribution characteristic 78 in the range (a range of about 300 mm) corresponding to the central portion of the illumination device 5 in the X direction is shown. Further, the scale along the vertical axis in Fig. 16 is different from Fig. 15. Moreover, the light amount distribution characteristic 78 shown in FIG. 16 is obtained at a position spaced apart from the lighting fixture 5 by a predetermined distance by 180 mm.

As shown in FIG. 16, the light amount distribution characteristic of the luminaire 5 when the cover 54 is not attached has a characteristic that the amount of light has a plurality of peaks (for example, Q1 to Q4) in a part. In particular, it is worth noting that the position p0 located directly below the LED 50 on the center line CL of the illuminating device 5 in the X direction is a minimum value smaller than the periphery. This is because of the strong directivity of the characteristics of the LED 50, and the interference grating occurs. Such a light amount distribution characteristic also occurs in a range corresponding to both end portions of the illuminating device in the X direction. In the cultivation of, for example, leafy vegetables, when a local peak occurs, the color of the leaf partially irradiated to the portion of the strong light is different from the color of the other portions of the blade (for example, yellow, etc.), and it is known that the state of the "leaf edge of the leaf" occurs. . Plants (especially leafy vegetables) in the state of "leaf stalks" may become unsuitable as a product.

In this regard, according to Embodiment 1, as described above, the cover 54 of the lighting fixture 5 diffuses light from the plurality of LEDs 50. Therefore, according to the first embodiment, the local peak due to the interference grating can be suppressed, and the possibility of occurrence of "leaf edge scorch" can be reduced.

Next, a suitable plant cultivation method in the plant cultivation apparatus 1 will be described with reference to Figs. 17 and 18 .

Fig. 17 is a table showing the relationship between the type of plant to be cultivated, the cultivation period, and the distance H4 of the lighting fixture 5 with respect to the plant in the Z direction. The distance H4 of the lighting fixture 5 with respect to the plant has a relationship of H3 = H2 + H4 with respect to the height H2 of the plant S and the above-described distance H3 (refer to Fig. 6). The height H2 and the distance H4 of the plant S are the distances along the Z direction. The type of plant can also be classified according to the name, attributes, characteristics, etc. of the plant. Here, the types of plants are exemplified by names, and there are different types such as lettuce, spinach, kimchi, lettuce, and watercress.

In Fig. 17, the plant of the type "A" has a value of γ1 when the cultivation period is "initial", a value of γ2 when the cultivation period is "medium", and a value of γ3 when the cultivation period is "final period". Further, the values γ1, γ2, and γ3 are, for example, in the range of 50 to 70 mm, and are γ1 < γ2 < γ3. Therefore, with respect to the plant of the species "A", the distance H4 from the height of the plant to the interval of the lighting fixture 5 becomes larger as the cultivation period reaches the later stage. Hereinafter, the plant cultivation method in which the distance H4 gradually increases as the plant grows is referred to as a "first plant cultivation method". The first plant cultivation method is suitable for plants in which the leaves become large (extending in the XY plane) as they grow. That is, the plant of the type "A" is preferably a plant having a large leaf as it grows, such as spinach.

In addition, even if the plant grows large (the leaves become larger), it must be able to shine throughout the plant. The light from the luminaire 5 is also diffused as described above, so that the distance from the illumination to the object is longer, and the area of the illumination in the object can be increased. According to the first plant cultivation method, the distance H4 between the plant and the lighting fixture 5 becomes longer than that of the plant before growth, so that the plant which grows and the leaves become large can be illuminated.

Further, in the example shown in Fig. 17, the distance H4 of the lighting fixture 5 with respect to the plant is adjusted in three stages in accordance with the cultivation period, but may be two stages (for example, referring to the plant of the category "C" of Fig. 17) ), can also be 4 or more stages.

Further, depending on the type of the plant, the first plant cultivation method described above is not necessarily the most suitable. For example, because of the type of plant, the leaves do not become as large as they grow, but also remain taller and below the fixed width (width in the XY plane). For this type of plant, light that is applied to the first plant cultivation method described above and does not shine on the leaves (light that does not contribute to plant growth) is added. In this example, in the example shown in Fig. 17, for example, the plant of the type "B" has the same distance γ2 as the value γ2 regardless of whether the cultivation period is any of "initial", "interim", and "final period". Hereinafter, the plant cultivation method in which the distance H4 is maintained without changing during the cultivation of the entire plant is referred to as "the second plant cultivation method". The second plant cultivation method is a plant which is suitable for the leaves to grow as they grow up as described above. That is, the plant of the type "B" is preferably a plant in which the leaves are less likely to grow as the leaves grow, such as lettuce.

Fig. 18 is a schematic flow chart of a method of plant cultivation.

When the user adjusts the height of the lighting fixture 5 to the plant S of the type "A", for example, first, the height H2 of the plant S is measured (step S1). Next, the user judges the cultivation period of the current point (step S2). Next, the user determines the distance H4 between the plant S and the cultivation period in accordance with the type "A" based on the predetermined information shown in FIG. 17, for example (step S3). Next, the user determines the distance H3 by the total height H2 obtained in step S2 and the distance H4 determined in step S3 (step S4). Next, the user adjusts the height of the lighting fixture 5 by the lifting mechanism 16 (step S5) to achieve the distance H3 (refer to FIG. 6).

According to the plant cultivation method of the first embodiment, the plant cultivation apparatus 1 of the first embodiment can adjust the height of the lighting fixture 5 to achieve the light, and the cultivation efficiency can be improved in consideration of the type of the plant or the cultivation period.

[Embodiment 2] The plant cultivation apparatus of the second embodiment differs from the plant cultivation apparatus 1 of the above-described first embodiment in that the lighting fixture 5 can be replaced by the lighting fixture 5A. The other configuration of the plant cultivation apparatus of the second embodiment may be simplified or omitted in the same manner as the plant cultivation apparatus 1 of the first embodiment described above. In the lighting fixture 5A, only the LED arrangement is different for the lighting fixture 5 of the first embodiment described above. Hereinafter, the LED arrangement of the lighting fixture 5A will be described.

Fig. 19 is a perspective view showing the internal structure (LED arrangement) of the lighting fixture 5A of the second embodiment, and shows the same angle of view (the arrow angle B of Fig. 6) of the lighting fixture 5A as that of Fig. 8 described above. In FIG. 19, illustration of wirings and the like on the substrate 56 is omitted.

In the same manner as in the first embodiment described above, the plurality of LEDs 50 are closely arranged at both end portions of the luminaire 5A in the X direction with respect to the central portion of the luminaire 5A in the X direction. In addition, the both ends of the illuminating device 5A in the X direction are the portions within the predetermined range Δx1 on both sides of the LED arrangement range R2 as described above. In the second embodiment, the range in which the predetermined range Δx1 includes only two LEDs 50 is exemplified.

In the second embodiment, unlike the first embodiment described above, the pitches d3 and d4 between the LEDs 50 in the X direction are fixed, and the number of rows of the LEDs 50 is "2" in both end portions in the X direction. That is, in the second embodiment, the plurality of LEDs 50 are arranged in one row in the central portion in the X direction, but are arranged in two rows at both end portions in the X direction. Further, in the second embodiment, the plurality of LEDs 50 are arranged in only two rows on the outermost sides of the two sides in the X direction, but may be other aspects. For example, the predetermined range Δx1 may also be a range including four or more LEDs 50. For example, in the example shown in FIG. 20, the two ends of the illumination device 5A in the X direction include four LEDs 50 (that is, the predetermined range Δx1 is a range including four LEDs 50).

Further, the number of rows at both end portions in the X direction and the number of columns in the central portion in the X direction may be any as long as the number of rows of both end portions is larger than the number of columns in the central portion. Therefore, for example, the number of columns at both end portions in the X direction may be "3", and the number of columns in the center portion may be "2". In addition, when both ends of the illuminating device 5A in the X direction include four or more LEDs 50 (that is, the predetermined range Δx1 is a range including four or more LEDs 50), the number of columns at both end portions in the X direction may also change. For example, the position on the outermost side of the both ends in the X direction may be three, and the other positions in the X direction may be two.

According to the second embodiment, the plurality of LEDs 50 are disposed closer to each other in the X-direction of the luminaire 5A than at the central portion of the luminaire 5A in the X direction. Therefore, the same effects as those of the first embodiment described above can be obtained.

Further, in the second embodiment, the pitches d3 and d4 between the LEDs 50 in the X direction are fixed, and are not limited thereto. In the second embodiment, the distances d3 and d4 between the LEDs 50 may be set in the same manner as in the first embodiment described above, and the both ends of the illuminating device 5A in the X direction are set to be closer to the central portion of the luminaire 5A in the X direction. For example, let d3 < d4, the pitch d4 be set in the same manner as the distance d1 between the above-described first embodiment.

Further, in the second embodiment, the LEDs 50 of the two rows are not biased in the X direction and are only displaced in the Y direction. However, the LEDs 50 may be offset not only in the Y direction but also in the X direction.

[Embodiment 3] The plant cultivation apparatus of the third embodiment differs from the plant cultivation apparatus 1 of the above-described first embodiment in that the lighting fixture 5 is replaced by the lighting fixture 5B. The other configuration of the plant cultivation apparatus of the third embodiment may be the same as that of the plant cultivation apparatus 1 of the first embodiment described above, and the description thereof will be simplified or omitted. The lighting fixture 5B differs from the lighting fixture 5 of the first embodiment only in the arrangement of the LEDs. Hereinafter, the LED arrangement of the lighting fixture 5B will be described.

Fig. 21 is a perspective view showing the internal structure (LED arrangement) of the lighting fixture 5B of the third embodiment, and shows the same viewing angle (arrow angle B of Fig. 6) as the above-described Fig. 8 for the lighting fixture 5B. In FIG. 21, illustration of wirings and the like on the substrate 56B is omitted. Figure 22 is a cross-sectional view taken along line C-C of Figure 21 . Figure 22 is an optical axis 80 showing the LEDs 50 at the ends.

The plurality of LEDs 50 are different from the first embodiment or the second embodiment described above, and are arranged in the X direction at equal intervals d2 as in the first comparative example. However, in the third embodiment, the optical axis of the LED 50 at both ends in the X direction of the luminaire 5B is outward in the X direction with respect to the optical axis of the LED 50 in the central portion of the luminaire 5B in the X direction. In addition, both ends of the illuminating device 5B in the X direction are the portions within the predetermined range Δx1 on both sides of the LED arrangement range R2 as described above. In the third embodiment, the predetermined range Δx1 is a range including only two LEDs 50.

In the example shown in FIGS. 21 and 22, the substrate 56B is curved upward at the end portions along the bending line 560 in the Y direction. In other words, the substrate 56B is at both end portions in the X direction of the luminaire 5B, and the normal direction is directed outward in the X direction. More specifically, the normal direction of the substrate 56B is the Z direction in the central portion of the illuminating device 5B in the X direction, but both end portions of the illuminating device 5B in the X direction are oriented outward at an inclination angle of the inclination angle θ with respect to the Z direction. The angle θ is in the range of 5 to 20 degrees, preferably in the range of 5 to 10 degrees.

According to the third embodiment, the same effects as those of the first embodiment described above can be obtained. More specifically, the light from the LED 50 is such that the directivity of the light is stronger than that of the fluorescent lamp, and therefore the optical axis faces outward and corresponds to the range of both ends of the illumination device 5B in the X direction (position p3, The amount of light around p4) (refer to Fig. 15) is deliberately increased. As a result, according to the third embodiment, the difference between the amount of light received by the plant in the central portion of the cultivation tray 4 and the amount of light received by the plant at both ends of the cultivation tray 4 from the lighting fixture 5B can be reduced.

Further, in the third embodiment, the optical axis direction of the LED 50 is changed by bending the substrate 56B, but a spacer having an inclination is provided between the flat substrate 56B and the LED 50, whereby the optical axis direction of the LED 50 can also be changed. .

Further, in the third embodiment, the pitch d2 between the LEDs 50 in the X direction is fixed, but is not limited thereto. In the third embodiment, the distance d2 between the LEDs 50 is similar to that of the first embodiment described above, and the central portion of the illuminating device 5B in the X direction is closely arranged at both ends in the X direction of the luminaire 5B. set up. Alternatively, in a region closer to the center portion side than the bending line 560, the pitch d2 between the LEDs 50 may be set smaller toward the outside. In this case, the both ends of the illuminating device 5B in the X direction may be the LEDs 50 including the both ends of the region closer to the central portion than the bending line 560.

Further, in the third embodiment, the number of rows of the LEDs 50 of the lighting fixture 5B and the both ends of the X direction are the same as those of the central portion, but are not limited thereto. In the third embodiment, the number of LEDs 50 in the luminaire 5B may be set in the same manner as in the second embodiment described above, and the both ends of the illuminating device 5B in the X direction are set in comparison with the central portion of the illuminating device 5B in the X direction. . Alternatively, the number of LEDs 50 may be set larger toward the outer side than the curved line 560 in the region on the central portion side. In this case, both ends of the illuminating device 5B in the X direction may be in a range including the LEDs 50 at both ends of the region closer to the central portion than the bending line 560.

The above is a detailed description of the various embodiments, and the invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the invention. Further, all or a plurality of constituent elements of the above-described embodiments may be combined.

For example, in the first embodiment and the second embodiment described above, the plurality of LEDs 50 are disposed in close contact with each other in the X-direction central portion of the luminaires 5 and 5A in the X-direction, but are not limited thereto. For example, the plurality of LEDs 50 may be disposed such that only one of the both end portions in the X direction is closer to the central portion in the X direction. Further, in the third embodiment described above, the plurality of LEDs 50 may have only one end of the both ends in the X direction in the central portion of the X direction of the lighting fixture 5B, and the optical axis is in the X direction. Top up to the outside.

Further, in the above-described first to third embodiments, the light color (wavelength) of the LED 50 is white, but the wavelength of the LED 50 is arbitrary. For example, only a portion of the plurality of LEDs 50 can have different wavelengths. Further, a plurality of LEDs having different wavelengths may be arranged offset with respect to the plurality of LEDs 50 in the Y direction.

Further, in the above-described first to third embodiments, the cover 54 functions as a diffusing portion, but the diffusing portion may be realized by the cover 54. That is, the same diffusion portion may be provided at any position in the optical path from the LED 50 toward the plant S. Further, the cover 54 may be omitted when the leafy vegetables are not cultivated or the like.

1‧‧‧plant cultivation equipment
2‧‧‧Cultivation stand
2a‧‧‧ pillar
2b‧‧‧1st beam
2c‧‧‧2nd beam
3‧‧‧cultivating unit
4,4A‧‧‧cultivation tray
4a‧‧‧Cultivation container
4b‧‧‧ cover
4c‧‧‧Hose insertion hole
4d‧‧‧ potted embedded holes
4e‧‧‧liquid fertilizer introduction area
4f‧‧‧liquid fertilizer drain hole
5,5A,5B‧‧‧Lighting equipment
6‧‧‧Transportation equipment
7‧‧‧ Track
8‧‧‧Liquid hose
9‧‧‧Cultivated potted plants
9a‧‧‧length gap
10‧‧‧Liquid Regulator
15‧‧‧Wire
16‧‧‧ Lifting mechanism
16a‧‧‧arm
16b‧‧‧Liang
16c‧‧‧ plates
16d‧‧‧Support
17‧‧‧ Cable
18‧‧‧ Pulley
19‧‧‧Helical spring
50‧‧‧LED
51‧‧‧Clean room
54‧‧‧ Cover
56,56B‧‧‧Substrate
56L‧‧‧Substrate Department
56R‧‧‧Substrate Department
58‧‧‧ Department of heat dissipation
80‧‧‧ optical axis
520‧‧‧positive terminal
521‧‧‧Negative terminal
522‧‧‧positive terminal
523‧‧‧Negative terminal
524‧‧‧positive side wiring (wiring)
526‧‧‧negative side wiring
527‧‧‧Wiring
528‧‧‧Wiring
529‧‧‧ wiring
CL‧‧‧ center line
D1‧‧‧ spacing Δx1‧‧‧predetermined range
X3, X4‧‧‧LED configuration range R2's outermost position
R2‧‧‧LED configuration range
X, Y‧‧ direction

Fig. 1 is a perspective view schematically showing an example of a plant cultivation apparatus. Fig. 2 is a front elevational view showing an example of a plant cultivation apparatus. Fig. 3 is a perspective view schematically showing a relationship between a conveying device and a cultivation tray. 4A is a plan view of an example of a cultivation tray. Fig. 4B is a plan view of a cultivation tray of another example. Fig. 5 is a perspective view schematically showing an example of a lifting mechanism. Fig. 6 is a side view schematically showing a relationship between a lighting fixture and a cultivation tray when viewed in the Y direction. Fig. 7 is a schematic cross-sectional view taken along line A-A of Fig. 6. Fig. 8 is a view showing the arrangement of LEDs of the lighting fixture of the first embodiment. Fig. 9A is an example of a variation of the pitch between LEDs. Fig. 9B is another example showing a variation of the pitch between the LEDs. Fig. 10 is an explanatory diagram showing an example of a structure of a substrate. Fig. 11 is a view showing an ideal light amount distribution characteristic on a cultivation tray caused by a lighting fixture. Fig. 12 is a view showing an arrangement of LEDs of a lighting fixture of a first comparative example. Fig. 13 is an explanatory diagram showing the superposition of illumination light of a plurality of LEDs in the first comparative example. Fig. 14 is an explanatory view showing the superposition of illumination light of a plurality of LEDs of the first embodiment; Fig. 15 is an explanatory diagram showing the light amount distribution characteristics of the first embodiment. Fig. 16 is a view showing the light amount distribution characteristics of the lighting fixture when the cover is not covered. Fig. 17 is an explanatory diagram showing an example of a plant cultivation method. Fig. 18 is a schematic flow chart of a method of plant cultivation. Fig. 19 is a perspective view showing the internal structure (LED configuration) of the lighting fixture of the second embodiment. Fig. 20 is a perspective view showing another example of the internal structure (LED arrangement) of the lighting fixture of the second embodiment. Fig. 21 is a perspective view showing the internal structure (LED configuration) of the lighting fixture 5B of the third embodiment. Figure 22 is a cross-sectional view taken along line C-C of Figure 21 .

5‧‧‧ Lighting fixtures

50‧‧‧LED

56‧‧‧Substrate

CL‧‧‧ center line

D1‧‧‧ spacing

R2‧‧‧LED configuration range

Δx1‧‧‧Predetermined range

X, Y‧‧ direction

X3, X4‧‧‧ IED configuration range R2's outermost position

Claims (20)

A lighting device for plant cultivation, comprising: a plurality of LEDs, wherein at least one of both end portions of the LED arrangement range extending in the first direction is closer than the central portion; and the diffusion portion is configured to obtain a plurality of the aforementioned LEDs The light that is emitted toward the plant spreads. The illuminating device for plant cultivation according to claim 1, wherein a pitch between the plurality of LEDs in the first direction is such that at least one of the both end portions is smaller than the central portion. In the illuminating device for plant cultivation according to claim 2, when the side away from the center portion in the first direction is the outer side, the pitch is smaller as it goes further outward in the first direction. The illuminating device for plant cultivation according to any one of claims 1 to 3, wherein the number of the plurality of LEDs in the first direction is more than at least one of the both end portions than the central portion. The illumination device for plant cultivation according to claim 4, wherein the number of columns in the central portion is 1, and the number of columns in at least one of the both ends is 2. A lighting device for plant cultivation, comprising: a plurality of LEDs disposed in an LED arrangement range extending in a first direction and emitting light in a plant direction, and moving away from the LED arrangement in the first direction When the side of the central portion of the range is the outer side, the amount of light from the plurality of LEDs is different from the light amount distribution characteristic of the plurality of LEDs in the plant direction only by a predetermined distance and along the axis of the first direction. The first position on the shaft is equal to the second position on the shaft, and the first position is the outermost LED corresponding to at least one of the first directions, and the second position corresponds to the center unit. The illuminating device for plant cultivation according to claim 6, wherein the light amount distribution is in a range from the first position on the axis to the outer side of 60 to 80 mm, and is the same as the second position on the axis. . A lighting device for plant cultivation according to claim 6 or 7, wherein the amount of light is the same as the difference of 20% or less. The illumination device for plant cultivation according to any one of claims 6 to 8, wherein at least one of the plurality of LEDs in the first direction at both end portions of the LED arrangement range has an optical axis direction The central portion faces outward in the first direction. The illuminating device for plant cultivation according to any one of claims 6 to 8, wherein the plurality of LEDs are mounted on the substrate, and the substrate is at least one of both ends of the LED arrangement range in the first direction. The normal direction is outward toward the outer side in the first direction. The illumination device for plant cultivation according to any one of claims 6 to 10, wherein the predetermined distance is in the range of 50 to 70 mm. The illuminating device for plant cultivation according to any one of claims 6 to 11, wherein the plurality of LEDs are disposed at least one of both end portions of the LED arrangement range in the first direction, than the center The department is close. A lighting device for plant cultivation, comprising: a plurality of LEDs disposed in an LED arrangement range extending in a first direction; and a diffusion portion for diffusing light emitted from the plurality of LEDs in a plant direction. A plant cultivation apparatus comprising: a tray on which a plant is placed; and an illumination device that includes a plurality of LEDs that emit light in the direction of the plant in an LED arrangement range extending in the first direction, and is spaced apart from the foregoing in the first direction When the side of the central portion of the LED arrangement range is outside, the amount of light from the plurality of LEDs is different from the light amount distribution characteristic of the plurality of LEDs in the plant direction by a predetermined distance and along the axis of the first direction. The first position is the same as the second position on the shaft from the first position on the shaft to the outer side of 60 to 80 mm, and the first position is the outermost LED corresponding to at least one of the first directions. The second position corresponds to the central portion. The plant cultivation apparatus according to claim 14, wherein the LED arrangement range is slightly coincident with the center in the first direction with respect to the plant placement range in the first direction in which the plant is placed on the tray, and extends to It is outside the range of the aforementioned plant placement. The plant cultivation apparatus according to claim 15, wherein the tray has a plurality of holes, the plurality of holes are a plurality of holes along the first direction, and are respectively carried to a plurality of the plants, and the plant placement range is In the first direction, it extends between the center positions of the respective holes at both ends. The plant cultivation apparatus according to claim 15 or 16, wherein the LED arrangement range extends to a range of 20 to 30 mm outside the plant placement range. The plant cultivation apparatus according to any one of claims 14 to 17, further comprising an elevating mechanism that changes a height of said illuminating device to said bracket. The plant cultivation apparatus according to any one of claims 14 to 18, wherein the illumination device and the aforementioned tray are provided in a plurality of arrays. In a cultivation method, a plant is cultivated using an illumination device whose height is changeable with respect to a mounting surface of a plant, wherein the interval between the height of the plant and the illumination device is adjusted to the first interval in the first cultivation period. In the second cultivation period which is later than the first cultivation period, the interval from the height of the plant to the illumination device is adjusted to be a second interval larger than the first interval.