Plant growing shelf

Abstract

To provide a plant raising shelf that uses LEDs as a light source, and can suppress variations of plant growth while keeping the value of PPFD to a certain value or more at a high level.SOLUTION: A plant raising shelf 200 comprises: a plurality of shelf parts capable mounting plants; and LED illuminations 300 each of which has a plurality of LEDs which is arranged on a ceiling part of at least one shelf space out of a plurality of shelf spaces defined by the plurality of shelf parts. Regarding a virtual plane in the shelf space illuminated by the LED illuminations 300 which includes points apart by 50 mm in the central axis direction of each of the plurality of LEDs, an average of photosynthesis photon flux density (PPFD) per unit W number is 2.0 μ mol m-2 s-1 W-1 or more, and the plurality of LEDs is arranged such that variations of PPFD become less than 0.4 in standard deviation when standardized by the average value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to plant growing shelves. [Background technology]

[0002] In order to ensure stable growth of vegetables and other plants, plants are cultivated in plant cultivation factories. Methods for cultivating plants in plant cultivation factories can be broadly divided into two types: one in which only artificial light from a lighting device is irradiated instead of sunlight, and another in which sunlight and artificial light are used in combination. An example of a lighting device that generates artificial light is a bar-type lighting device in which LED bars with multiple LEDs are arranged at equal intervals, as described in Patent Document 1.

[0003] The amount of light irradiating the plant's growing surface is usually evaluated by measuring the photosynthetic photon flux density (PPFD), which is the density of photon flux in the wavelength range of 400nm to 700nm that is effective for photosynthesis. Increasing PPFD generally increases growth rate, so lighting devices that can increase PPFD are being developed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-118957 Summary of the Invention [Problem to be solved by the invention]

[0005] However, it was discovered that simply increasing the PPFD using bar-type lighting devices results in variations in plant growth rates, resulting in a decrease in the quality rate, which is the percentage of good plants produced. This problem is thought to be caused by the plants not receiving light evenly. To solve this problem, it is conceivable to use surface-emitting organic electroluminescent (EL) lighting to irradiate the plants, but EL lighting has low luminous efficiency and high running costs, making it unsuitable for use in plant cultivation factories where cost-effectiveness is required.

[0006] One aspect of an embodiment of the present disclosure has been made against this background, and aims to provide a plant cultivation shelf that uses LEDs as a light source and can suppress variation in plant growth while maintaining a high level of PPFD value above a certain level, and a plant factory that uses this plant cultivation shelf. [Means for solving the problem]

[0007] According to one aspect of a plant growing shelf according to an embodiment of the present disclosure, the plant growing shelf comprises: a plurality of shelves on which plants can be placed; an LED light having a plurality of LEDs arranged on a ceiling portion of at least one shelf space among a plurality of shelf spaces defined by the plurality of shelf portions; A plant growing shelf comprising: The average photosynthetic photon flux density (PPFD) per unit wattage is 2.0 μmol m for a virtual surface in the shelf space illuminated by the LED lighting, including points 50 mm apart in the direction of the central axis of each of the plurality of LEDs. -2 ·s -1 ·W -1 The LEDs are arranged so that the variation in PPFD is less than 0.4 in terms of standard deviation when normalized by the average value.

[0008] According to another aspect of the plant growing shelf according to an embodiment of the present disclosure, the plant growing shelf comprises: a plurality of shelves on which plants can be placed; An LED lighting sheet, A substrate film; a metal wiring portion for supplying power formed on a surface of the substrate film; a plurality of LEDs electrically connected to the metal wiring portion and disposed on one surface of the substrate film in a planar and dispersed manner with a predetermined distance between each other; LED lighting sheet with A plant growing shelf comprising: The LED illumination sheet is disposed on the ceiling of at least one shelf space among the plurality of shelf spaces defined by the plurality of shelf sections so as to illuminate the at least one shelf space; The LED lighting sheet has an average photosynthetic photon flux density (PPFD) per unit wattage of 2.0 μmol m for a virtual plane in the shelf space illuminated by the LED lighting, including points 50 mm apart in the direction of the central axis of each of the plurality of LEDs. -2 ·s -1 ·W -1 The plurality of LEDs are provided so that the variation in PPFD is less than 0.4 in terms of standard deviation when normalized by the average value.

[0009] According to another aspect of the plant growing shelf according to an embodiment of the present disclosure, the plant growing shelf comprises: a plurality of shelves on which plants can be placed; an LED light having a plurality of LEDs arranged on a ceiling portion of at least one shelf space among a plurality of shelf spaces defined by the plurality of shelf portions; A plant growing shelf comprising: The average photosynthetic photon flux density (PPFD) per unit wattage is 2.0 μmol m for a virtual surface in the shelf space illuminated by the LED lighting, including points 50 mm apart in the direction of the central axis of each of the plurality of LEDs. -2 ·s -1 ·W -1 That's all, The plurality of LEDs are arranged so that the illumination range in the virtual plane illuminated by any one of the plurality of LEDs overlaps with the illumination range in the virtual plane illuminated by the LED located at the shortest distance from the any one of the plurality of LEDs adjacent to the any one of the LEDs.

[0010] According to yet another aspect of the plant growing shelf according to an embodiment of the present disclosure, the plant growing shelf comprises: a plurality of shelves on which plants can be placed; an LED light having a plurality of LEDs arranged in a grid pattern on a ceiling portion of at least one shelf space among the plurality of shelf spaces defined by the plurality of shelf portions; A plant growing shelf comprising: The average photosynthetic photon flux density (PPFD) per unit wattage is 2.0 μmol m for a virtual surface in the shelf space illuminated by the LED lighting, including points 50 mm apart in the direction of the central axis of each of the plurality of LEDs. -2 ·s -1 ·W -1 That's all, The distance L between any one of the plurality of LEDs and the farthest LED among the eight LEDs located in the vicinity of the any one of the LEDs dis [mm] are arranged to satisfy the following formula: TIFF0007752926000001.tif6150 where α is half the directivity angle of the LED.

[0011] According to one aspect of a plant cultivation factory according to an embodiment of the present disclosure, the plant cultivation factory includes any one of the plant cultivation shelves described above. [Effects of the Invention]

[0012] According to one aspect of a plant cultivation shelf according to an embodiment of the present disclosure, the plant cultivation shelf is equipped with an LED light or an LED illumination sheet having a plurality of LEDs, and the average photosynthetic photon flux density (PPFD) per unit wattage is 2.0 μmol m for an imaginary plane within the shelf space illuminated by the LED lights, the imaginary plane including points spaced 50 mm apart along the central axis of each of the plurality of LEDs. -2 ·s -1 ·W -1As a result, it is possible to provide a high level of PPFD not previously available at low running costs. Furthermore, 1) the standard deviation of PPFD is less than 0.4 when normalized by the average value, 2) the multiple LEDs are arranged so that the irradiation range in the virtual plane illuminated by any one of the multiple LEDs overlaps with the irradiation range in the virtual plane illuminated by the LED located at the shortest distance among the multiple LEDs adjacent to that LED, or 3) the separation distance L between any one of the multiple LEDs and the farthest LED among the LEDs located in the 8 nearest neighborhoods of that LED is less than 0.4. dis [mm] is the half value of the LED beam angle, and the formula TIFF0007752926000002.tif6150, the LEDs are arranged to reduce variations in light irradiation on the virtual plane. Therefore, the plant cultivation shelf according to the embodiment of the present disclosure can reduce variations in plant growth.

[0013] The plant cultivation factory according to the embodiment of the present disclosure is equipped with plant cultivation shelves that provide such effects, and is therefore able to produce evenly grown plants more efficiently than before. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram illustrating a configuration of a plant cultivation factory according to an embodiment. [Figure 2] 1 is a perspective view showing a state in which a plant is placed on a plant growing shelf according to one embodiment. FIG. [Figure 3] FIG. 1 is a perspective view of a plant growing shelf according to one embodiment. [Figure 4] 1 is a schematic configuration diagram of an LED lighting device according to an embodiment. [Figure 5] 1 is a diagram illustrating an example of the arrangement of LED chips in an LED illumination sheet according to an embodiment of the present invention; [Figure 6]6A and 6B are diagrams showing the results of simulations of the illuminance distribution of a conventional bar-type LED lighting device, in which Fig. 6A shows the arrangement of the LED bars, Fig. 6B shows the illuminance distribution on a plane 50 mm away from the plane on which the LED bars are installed, and Fig. 6C shows the illuminance distribution on a plane 100 mm away from the plane on which the LED bars are installed. [Figure 7] 7A and 7B are diagrams showing simulation results of the illuminance distribution of an LED lighting device according to one embodiment, in which Fig. 7A is a diagram showing the arrangement of an LED sheet in which LEDs are dispersed, Fig. 7B is a diagram showing the illuminance distribution on a plane 50 mm away from the plane on which the LED sheet is provided, and Fig. 7C is a diagram showing the illuminance distribution on a plane 100 mm away from the plane on which the LED sheet is provided. [Figure 8] FIG. 1 is an explanatory diagram for explaining a technical concept regarding the arrangement of light sources. [Figure 9] 9A and 9B are plan views showing modified examples of the LED illumination sheet. [Figure 10] FIG. 6 is a cross-sectional view of FIG. 5 . [Figure 11] FIG. 2 is a perspective view of the back side of an LED illumination sheet according to one embodiment. [Figure 12] 12A to 12E are diagrams illustrating a method for manufacturing an LED illumination sheet according to one embodiment. [Figure 13] 13A to 13C are diagrams showing examples of installation of an LED illumination sheet according to one embodiment, and show views from the direction of arrow A in FIG. 2 after the LED illumination sheet has been installed on a plant cultivation shelf. [Figure 14] FIG. 1 is a perspective view showing an example of installation of an LED illumination sheet according to one embodiment. [Figure 15] FIG. 10 is a perspective view showing an example of attachment of a reflective sheet according to a modified embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] In order to explain the present invention in more detail, the following description will be given of an embodiment of the present invention with reference to the accompanying drawings. Identical or similar components are designated by identical or similar reference numerals, and redundant explanations will be omitted. Note that the drawings are not drawn to scale in order to clearly explain the present invention.

[0016] 1. Plant cultivation factories and plant cultivation shelves The configuration of the plant cultivation factory and the plant cultivation shelves will be described with reference to Figures 1 to 3. Figure 1 is a schematic diagram showing the configuration of a plant cultivation factory 100. The plant cultivation factory 100 comprises a building 101 and a plurality of plant cultivation shelves 200 arranged inside the building 101. As shown in Figure 2, plant cultivation trays (pallets) 201 are placed on the plant cultivation shelves 200, and plants PL are housed in the plant cultivation trays 201. Parameters such as temperature and humidity are controlled by a control device (not shown) so that the space in the building 101 where the plant cultivation shelves 200 are arranged becomes an environment suitable for growing the plants PL.

[0017] As shown in FIG. 2 or 3 , each plant cultivation shelf 200 is formed by assembling a plurality of rectangular or cylindrical pipe members 211, 212 and a plurality of connecting members 213 connecting the pipe members 211, 212. The pipe members 211, 212 may have other shapes, and the connecting members 213 may have different shapes accordingly. The pipe members 211, 212 and the connecting members 213 are made of, for example, steel or resin. Of the pipe members 211, 212, the horizontally arranged pipe member 211 is used as a shelf portion 220 on which a plant cultivation tray 201 is placed. However, although the plant cultivation tray 201 can physically be placed on the uppermost pipe member 211 of the horizontally arranged pipe members 211, it is intended that the plant cultivation tray 201 is not actually placed on the uppermost pipe member 211, and the uppermost pipe member 211 is used only as a ceiling portion. Of the pipe members 211, 212, each vertically arranged pipe member 212 has a first engagement portion 214 on its upper side and a second engagement portion 215 on its lower side. Furthermore, all horizontally arranged pipe members 211 except the lowest one also have a third engagement portion 216 along the longitudinal direction of the periphery of the plant cultivation shelf 200. The size of the plant cultivation shelf 200 is, for example, 1200 mm wide, 400 mm deep, and 1500 mm high. With this size, three shelf spaces, each 1200 mm wide, 400 mm deep, and approximately 500 mm high, are formed by the horizontally arranged pipe members 211 and the vertically arranged pipe members 212. Each shelf space is defined by a ceiling, four sides, and a bottom. The plant cultivation shelf does not necessarily have to be assembled using pipe-shaped members, but may be assembled using other members, such as plate-shaped members.

[0018] An LED lighting sheet 300 is provided above each shelf space. The LED lighting provided above each shelf space is not limited to sheet-shaped, and may be in other forms, such as panel-shaped LED lighting.

[0019] One control unit 400 is provided for each plant cultivation shelf 200. The control unit 400 collectively controls the power supply to the multiple LED illumination sheets 300 provided on the corresponding plant cultivation shelf 200.

[0020] 2. LED lighting devices and LED lighting sheets The configurations of the LED lighting device and the LED lighting sheet will be described below with reference to Figures 4 to 11. As shown in Figure 4, the LED lighting device 500 includes LED lighting sheets 300, 700 and a control unit 400. The term "LED" includes both inorganic and organic types.

[0021] As shown in FIG. 4 , the control unit 400 includes a power plug 410, an AC / DC converter 420, and a PWM control unit 430. The power plug 410 receives an AC voltage, for example, a voltage between 100 V and 240 V. The AC / DC converter 420 converts the AC voltage into a predetermined DC voltage, for example, 50 V. The PWM control unit 430 pulses the DC voltage supplied from the AC / DC converter 420 by high-speed switching at a constant cycle. Because of this high-speed switching, a DC voltage is output from the PWM control unit 430. By changing the duty ratio as desired, the DC voltage supplied to the LED illumination sheet 300 can be controlled to a desired voltage, for example, 44 V. The voltage output from the PWM control unit 430 is applied to the LED illumination sheet 300 via a connector 440.

[0022] The LED lighting sheet 300 in Fig. 4 includes a flexible wiring substrate 310, a connector 320, a power supply line 330, a current control unit 340, a metal wiring unit 350, an LED chip 360, and a connector 325. The size of the LED lighting sheet 300 (flexible wiring substrate 310) is, for example, Lx = 600 mm and Ly = 400 mm (see Fig. 5), but other sizes are also possible. Furthermore, the shape of the sheet may be a quadrangle other than a rectangle, a shape other than a quadrangle, or a three-dimensional shape.

[0023] 5, a plurality of LED chips 360 are arranged in a grid or array in a plan view. More specifically, 140 LED chips 360 are arranged on a flexible wiring substrate 310 at a pitch of, for example, Px = Py = 40 mm. The 14 LED chips 360 arranged along the first arrangement direction (X direction) are electrically connected in series via metal wiring parts 350 to form a row R. The arrangement of the LED chips 360 does not necessarily have to be in a grid or array form, as long as the distance between each LED chip 360 is approximately equal.

[0024] Each row R is provided with one current control unit 340, which is electrically connected in series with the LED chips 360 via metal wiring units 350. The current control unit 340 is a functional unit that has the function of keeping the current supplied to the LED chips 360 of the corresponding row constant, and includes, for example, a current regulator IC and a resistor. By connecting a variable resistor in series, the current regulator IC can adjust the current supplied to the corresponding row, and the current supplied from the current control unit 340 (current regulator IC) can be dimmed.

[0025] The LED lighting sheet 300 has a cross-sectional structure as shown in Fig. 10. Fig. 10 is a VV cross-sectional view of Fig. 5. As shown in Fig. 10, the LED lighting sheet 300 has a structure in which a substrate film 311, an adhesive layer 312, a metal wiring portion 313, and a light-reflective insulating protective film 314 are laminated in this order. The substrate film 311, the adhesive layer 312, and the metal wiring portion 313 constitute a flexible wiring substrate 310. An LED chip 360 is mounted on the flexible wiring substrate 310, and the LED chip 360 and the metal wiring portion 313 are electrically connected by a solder portion 317. A transparent protective film 316 is provided to cover the light-reflective insulating protective film 314, the LED chip 360, and the solder portion 317.

[0026] Substrate film 311 is formed from a flexible resin film. In this specification, "flexible" means that it can be bent to a radius of curvature of at least 1 m or less. As the material for substrate film 311, polyimide resin or polyethylene naphthalate can be used, taking into consideration not only flexibility but also heat resistance, insulation, dimensional stability, mechanical strength, and durability.

[0027] The adhesive layer 312 is a layer that bonds the substrate film 311 and the metal wiring portion 313. Various known adhesives, such as resin-based adhesives and acrylic-based adhesives, can be used as appropriate for the adhesive layer 312. The substrate film 311 and the metal wiring portion 313 may be bonded together by a dry lamination method.

[0028] The metal wiring portion 313 is a wiring pattern formed on the surface (the surface on the light-emitting surface side) of the substrate film 311 using a conductive base material such as metal foil. The metal wiring portion 313 is used as the plurality of metal wiring portions 350 described above. The plurality of metal wiring portions 350 includes a first metal wiring portion 350A and a second metal wiring portion 350B located apart from the first metal wiring portion 350A. The metal wiring portion 350 can be made of a thin film made of a metal such as silver or copper that has excellent electrical conductivity and heat dissipation properties.

[0029] The LED chip 360 is disposed between the first metal wiring portion 350A and the second metal wiring portion 350B and is electrically connected to the first metal wiring portion 350A and the second metal wiring portion 350B via the solder portion 317. To suppress heat generation from the LED chip 360, it is preferable to select an LED chip 360 with high luminous efficiency. For example, an LED chip 360 with a luminous efficiency of 150 lm / W or more, or an LED chip 360 with a luminous efficiency of 180 lm / W or more can be used. By adopting LED chips 360 with excellent luminous efficiency, the desired number of photons required for cultivation can be achieved with a smaller number of LED chips. This reduces the number (density) of LED chips 360 mounted and reduces heat generation from the LED chips 360. This reduces variations in plant growth due to heat from the LED chips 360, thereby suppressing yield declines.

[0030] The light-reflective insulating protective film 314 is a layer formed in an area excluding the area where the LED chip 360 is provided and the surrounding area. The light-reflective insulating protective film 314 has sufficient insulating properties and is therefore a resist layer that improves the migration resistance of the flexible wiring board 30, and is also a light-reflecting layer that has light reflectivity that contributes to improving the lighting environment created by the LED illumination sheet 300.

[0031] The light-reflective insulating protective film 314 can be formed from various resin compositions that use a urethane resin, an acrylic urethane resin, or the like as a base resin and further contain a white pigment made of an inorganic filler such as titanium oxide or alumina.

[0032] Furthermore, in order to allow many photons to reach the target plants PL, the light-reflective insulating protective film 314 preferably has a high reflectance for light of any wavelength in the range of 400 nm to 700 nm, which is effective for photosynthesis. The reflectance is preferably, for example, 65% or more, more preferably 70% or more, and even more preferably 80% or more. For example, by incorporating 20 parts by mass or more of titanium oxide per 100 parts by mass of a urethane-based or acrylic urethane-based base resin, the LED illumination sheet 300 can achieve a light reflectance of 75% or more for the light-reflective insulating protective film 314 having a thickness of 8 μm.

[0033] The transparent protective film 316 is formed on the outermost surface of the LED illumination sheet 300 so as to cover the LED chips 360. The transparent protective film 316 is waterproof and transparent. The waterproof property of the transparent protective film 316 prevents water from entering the LED illumination sheet 300 when it is used as a light source for growing plants.

[0034] The transparent protective film 316 can be formed from various resin compositions having an acrylic urethane resin as a base resin, etc. As the base resin of the resin composition used to form the transparent protective film 316, in addition to the acrylic urethane resin, a urethane resin, a polyester resin, a phenol resin, etc. can be appropriately used.

[0035] The waterproofing of the LED lighting sheet 300 provided by the transparent protective film 316 need only be sufficient to prevent deterioration of the LED chips 360 when water for plant growth is sprayed onto the LED lighting sheet 300. For example, the waterproofing may be IPX4 or higher according to the waterproof and dustproof protection standard established by the International Electrotechnical Commission (IEC). To achieve IPX4 waterproofing, the transparent protective film 316 preferably has a certain thickness. For example, the thickness may be 10 μm to 40 μm, or 15 μm to 30 μm, or 20 μm to 25 μm. The thickness of the transparent protective film 316 should be determined with the following in mind: if the transparent protective film 316 is too thick, it will affect the flexibility of the LED lighting sheet 300, making it difficult to bend.

[0036] As shown in FIG. 4, the rows R each including the LED chips 360 and current control units 340 described above are electrically connected in parallel to the control unit 400 via the power supply line 330 and the GND line. Therefore, the current supplied from each current control unit 340 can be made different for each row. For example, the current supplied to the two LED rows R closest to the ends of the LED illumination sheet 300 (the two above and below the sheet) can be made larger than the current supplied to the other LED rows R. This makes it possible to maintain the level of light irradiated to plants PL placed at the ends of the cultivation shelf at the same level as the light irradiated to plants PL placed in areas other than the ends of the cultivation shelf, thereby reducing variation in the growth of the plants PL.

[0037] The power supply line 330 connected to the connector 320 branches into 11 lines, one of which does not supply power to the LED chips 360 of the LED illumination sheet 300 but is connected to a connector 325. The connector 325 is connected to a connector 720 of another LED illumination sheet 700 having the same configuration as the LED illumination sheet 300 via a cable 600 having connectors 610 and 620. With this configuration, the other LED illumination sheets 700 are supplied with the same power as that supplied to the LED illumination sheet 300.

[0038] As described above, by arranging multiple rows R of LED chips 360 in parallel, even if the LED chips 360 in a specific row are damaged, it is possible to prevent the LED chips 360 in other rows from being affected. This prevents the illuminance of the entire LED-illuminated sheet 300 from decreasing drastically. Furthermore, by limiting the area where the illuminance of the LED-illuminated sheet 300 is reduced, the area where non-conforming products may be produced is limited, thereby preventing a decrease in yield. Furthermore, if the LED chips 360 in a specific row are damaged, the amount of current supplied from the current control unit 340 of the adjacent row can be increased to compensate for the decrease in the illuminance of the damaged row.

[0039] In the arrangement example of FIG. 5, the pitch Px between the LED chips 360 is, for example, Px=Py=40 mm, but it may be another value, and Px and Py may take different values.

[0040] Here, the technical idea regarding the arrangement of light sources and the characteristic parameters used in the present disclosure will be described with reference to Figs. 6 to 8. In the present disclosure, the characteristic parameter PPFD 50 W is defined and used as follows:

[0041]

number

[0042] PPFD 50 is the PPFD (μmol m) measured on an imaginary plane in a rectangular space that includes a point 50 mm away from each of the LEDs in the direction of the central axis when multiple LEDs are placed on the ceiling of the space. -2·s]. Here, PPFD is a parameter used to evaluate the performance of lighting equipment for plant growth, and is calculated by measuring the number of photons per square meter per second in the wavelength range from 400nm to 700nm. It is generally known that PPFD and plant growth rate are directly correlated (directly proportional), so it is desirable to increase PPFD. Furthermore, the term "ceiling" is not intended to be limited to the ceiling itself, but rather refers to the ceiling itself or the area near the ceiling.

[0043] And PPFD 50 W What is PPFD? 50 This is a parameter or value obtained by dividing by the amount of power P input to the LED, and represents the photosynthetic photon flux density (PPFD) per unit wattage of power input to the LED.

[0044] The present disclosure defines PPFD at a distance of 50 mm as a parameter because it takes into account plant growth conditions and the effective use of the space in which the plants are grown. For example, at a distance of 100 mm from the light source, there is ample space for plants to grow, so discussing PPFD at a distance of 100 mm is meaningless from the perspective of efficient use of the space provided by the plant growth shelf. On the other hand, it has been found that at a distance of 20 mm from the light source, plants grow rapidly due to their proximity to the light source, and the supply of calcium necessary for proper plant growth cannot keep up, resulting in a growth disorder known as tip burn, in which the tips of the plants' leaves become burned. Furthermore, when plants grow close to the light source, such as 20 mm, there is a problem that the air passage, which is important for plant growth, is blocked, causing growth disorders. Therefore, it is best to focus on a distance that allows efficient use of the space provided by the plant growth shelf, prevents tip burn, and ensures a clear air passage. The inventors of the present invention have discovered that such a distance is 50 mm.

[0045] In addition, since PPFD itself is commonly used among those skilled in the art, PPFD at a position 50 mm away is used. 50The meaning of PPFD is easily understood by those skilled in the art. 50 W PPFD 50 This is simply obtained by dividing by the amount of power P input to the LED, and can be easily understood by those skilled in the art.

[0046] Therefore, when growing plants using a plant growing shelf, it is desirable to increase the PPFD at a position 50 mm away from the light source. However, we found that simply increasing the PPFD using conventional bar-type lighting devices results in inconsistent plant growth rates and a decrease in the yield (the percentage of non-defective plants). This issue is explained using Figures 6A to 6C. Figures 6A to 6C are diagrams illustrating the illuminance distribution when light is emitted from an LED bar. Figure 6A shows the layout of the LED bars, and Figures 6B and 6C show simulation results of the illuminance distribution. Figure 6A shows a configuration in which six LED bars, each with 140 LEDs with a beam angle of ±60°, are arranged in parallel, 200 mm apart, in an area 1200 mm long and 1200 mm wide. Figures 6B and 6C show simulation results when each LED is set to emit 100 lm. Figure 6B shows the illuminance distribution within a plane 50 mm away from the LED, and Figure 6C shows the illuminance distribution within a plane 100 mm away from the LED. Comparing Figure 6C and Figure 6B makes it clear that the illuminance variation in Figure 6C is relatively small, while the illuminance variation in Figure 6B is relatively large. Note that there is a direct proportional relationship between illuminance and PPFD, and they can be converted to each other by specifying the color temperature in the case of white light and the wavelength in the case of colored light. Therefore, the PPFD distribution will be similar to that of the illuminance distribution.

[0047] The reason for the large illuminance variation in Figure 6B is explained using Figure 8. In Figure 8, assume that LED1 and LED2, with beam angles of ±60°, are placed 200 mm apart. That is, α = β = 60° and L1 = 200 mm. With L2 = L3 = 50 mm, we focus on a first imaginary plane IP1, located vertically downward from LED1 and LED2 by L2 + L3 = 100 mm. Every point on this imaginary plane IP1 is within the beam angle range. However, when we focus on a second imaginary plane IP2, located vertically downward from LED1 and LED2 by L2 = 50 mm, we see a region below the midpoint between LED1 and LED2 that is not covered by either LED's beam angle range. Based on the Pythagorean theorem, L4 = L5 = approximately 86.5 mm, so the length between the edges of this region, L6, is approximately 27 mm. This central region of the second imaginary plane IP2 represents an area of ​​insufficient illumination, where the light irradiating the plant is weak. As a result, variations in plant growth occur between areas with insufficient illumination and areas with sufficient illumination, resulting in a decrease in the yield rate.

[0048] To prevent such areas of insufficient illumination, it is necessary to minimize illuminance variations. For example, LEDs can be arranged as shown in Figure 5 so that the standard deviation of PPFD variation, normalized by the average value, is less than 0.4. To illustrate this, we performed a simulation using the same 140 x 6 = 840 LEDs used in the previous simulation, with the results shown in Figure 7. In Figure 7A, six LED sheets LS, each measuring 400 mm x 600 mm and with 140 LEDs per sheet distributed in a grid pattern, are arranged adjacently on a flat surface. Therefore, the total area of ​​LED sheets LS1-LS6 is 1200 mm. Figures 7B and 7C show the simulation results when each LED emits 100 lm. Figure 7B shows the illuminance distribution within a plane 50 mm away from the LED, and Figure 7C shows the illuminance distribution within a plane 100 mm away from the LED. 7B and 7C, no significant difference in illuminance distribution is observed. As can be seen by comparing Fig. 6B and Fig. 7B, the variation in illuminance distribution is suppressed in Fig. 7B.

[0049] As such, even when using the same number of LEDs to irradiate light, uniformly distributing the LEDs reduces the variation in illuminance distribution even at short distances from the light source, such as 50 mm, compared to using multiple LEDs densely arranged in a row, such as an LED bar. This reduces variation in plant growth at short distances from the light source.

[0050] The LED arrangement can also be explained from a geometrical perspective as follows. To minimize the variation in plant growth, as suggested by the simulation results in Figure 6, it is preferable to eliminate areas outside the beam angle range of LED1 and LED2. In the example in Figure 8, the separation distance between LED1 and LED2 needs to be less than the critical distance L4 + L5, i.e., less than approximately 173 mm. Applying this critical distance consideration to the arrangement example in Figure 5, it is preferable that the separation distance between the LED chips 360 located diagonally on the LED illumination sheet 300 be less than approximately 173 mm, and that Px = Py = approximately 123 mm (173 / √2). This numerical example is based on LEDs with beam angles of ±60°. Therefore, the required separation distance will change if LEDs with different beam angles are used. If the beam angle range of the LEDs is narrower than ±60°, the distance between the LEDs needs to be less than 173 mm. However, if the beam angle range of the LEDs is wider than ±60°, the distance between the LEDs may be greater than 173 mm. Furthermore, by spacing the plants closer together, but still below the critical distance, more light is irradiated, promoting growth while reducing variability.

[0051] Generally, in order to make the light within the range of the directivity angle of the light source overlap on an imaginary plane 50 mm away from the light source, the distance L between the light sources is dis The light source should be positioned so that [mm] satisfies the following formula:

[0052]

number

[0053] Here, α and β are the angles on one side with respect to the central axis of the light source, i.e., half the beam angle. When α=β, equation (2) becomes as follows:

[0054]

number

[0055] When light sources are arranged in a grid pattern, if the distance between a central light source and the farthest light source among the eight neighboring light sources satisfies equation (3), the light from both light sources will overlap on the virtual plane.

[0056] In addition, the distance between the central light source and the light source located farthest out of the 16 light sources outside the 8 neighbors is 2L. dis If the light sources are arranged so that equation (3) is satisfied, the light from both light sources will overlap on the virtual plane, so even if a light source in the row adjacent to the central light source fails, the variation in illuminance can be reduced.

[0057] Alternatively, the area of ​​the illumination range in the virtual plane illuminated by a certain light source may overlap at a certain rate with the area of ​​the illumination range in the virtual plane illuminated by the light source located farthest out of the eight nearest light sources adjacent to that light source or the 16 nearest light sources outside of that. Even when the light sources are arranged so that their illumination areas overlap at a certain rate in this way, it is possible to minimize the occurrence of an area where light is not illuminated when one of the light sources fails.

[0058] The arrangement of the LED chips 360 is not limited to a lattice-like arrangement in a planar view. For example, as in the LED illumination sheet 800 shown in FIG. 9A , the LED chips 360 may be arranged in a staggered arrangement in a planar view. The LED chips do not have to be arranged uniformly within the surface of the LED illumination sheet. For example, the density of the LED chips may be increased at the peripheral edge of the LED illumination sheet. Specifically, as shown in FIG. 9B , the LED chips 360 may be arranged in a lattice-like arrangement at the center of the LED illumination sheet 900 (the lower part of FIG. 9B ) and in a staggered arrangement at the peripheral edge of the LED illumination sheet 900 (the upper part of FIG. 9B ). In this way, in FIG. 9B , the LED surface density, which is the number of LED chips 360 relative to the area of ​​the LED illumination sheet where the LED chips 360 are arranged in a staggered arrangement, is greater than the surface density of the LEDs in the area where the LED chips 360 are arranged in a lattice. This makes it possible to suppress a decrease in brightness of the LED illumination sheet 300 at the peripheral portion of the LED illumination sheet 300 in Figure 5, thereby making the brightness of the LED illumination sheet uniform across the surface and further suppressing variations in the light irradiated to the plants.

[0059] As shown in FIG. 11, the LED illumination sheet 300 has a locking member 370 on the back surface thereof. 11 ~370 55 are provided at regular intervals. The locking members 370 are made of resin or lightweight metal. One end of a connecting member such as an S-hook is engaged with the locking member 370, and the other end of the connecting member is engaged with the plant cultivation shelf 200, thereby providing the LED illumination sheet 300 on the plant cultivation shelf 200. Figure 1 shows the state in which the LED illumination sheet 300 is laid flat on the ceiling portion of each shelf space.

[0060] 3. LED lighting device operation Next, the operation of the LED lighting device 500 will be described. First, the power plug 410 of the LED lighting device 500 is connected to a power source, and a voltage between 100V and 240V is supplied to the power plug 410. Next, the voltage input to the power plug 410 is converted to a predetermined DC voltage, for example, 50V, by the AC / DC converter 42. Next, the DC voltage from the AC / DC converter 42 is pulsed by the PWM control unit 43 at a predetermined duty ratio, for example, 88%, and converted to a DC voltage of 44V. The DC voltage from the PWM control unit 43 is then supplied to the LED lighting sheet 300, and the current control unit 340 of the LED lighting sheet 300 controls the current flowing through each column R of the LED lighting sheet 300 to a desired value. For example, the current flowing through a certain column R is controlled to 70mA. The current flowing through all columns R may be the same, or different currents may flow for each column. For example, the current flowing through the row R closest to the end of the LED illumination sheet 300 may be controlled to 80 mA. When a regulator IC is used as the current control unit 340, such current control can be achieved by varying the resistance value of a resistor externally connected to the regulator IC. This causes the LED chips 360 to emit light, irradiating the light onto the plants PL.

[0061] 4. Manufacturing method of LED lighting sheet Next, a method for manufacturing the LED illumination sheet 300 will be described with reference to FIGS. 12A to 12E.

[0062] First, a substrate film 311 is prepared, and a metal foil 313 such as copper foil, which will be the material for the metal wiring portion 350, is laminated on the surface of the substrate film 311 via an adhesive layer 33 (FIG. 12A). Instead of using the adhesive layer 33, the metal foil 313 may be formed directly on the surface of the substrate film 311 by electrolytic plating or a vapor phase film formation method (sputtering, ion plating, electron beam evaporation, vacuum evaporation, chemical vapor deposition, etc.). Alternatively, the substrate film 311 and the metal foil 313 may be directly welded together.

[0063] Next, an etching mask (not shown) is patterned on the surface of the metal foil 313, and the metal foil 313 located in the area not covered by the etching mask is removed using an immersion liquid, and then the etching mask is removed using an alkaline stripping liquid (FIG. 12B). As a result, the metal foil 313 is formed into the metal wiring portion 350.

[0064] Next, light-reflective insulating protective film 314 is formed by laminating it on metal wiring part 350 (FIG. 12C). The method for forming light-reflective insulating protective film 314 is not particularly limited as long as it is possible to uniformly apply the material resin composition that constitutes light-reflective insulating protective film 314 by any coating means, and methods such as screen printing, offset printing, dip coating, and brush coating can be used. Alternatively, light-reflective insulating protective film 314 may be formed by coating the entire surface with a photosensitive insulating protective film material, exposing only the necessary areas to light through a photomask, and then developing it.

[0065] Next, the LED chip 360, the current control unit 340, and the connectors 320 and 360 are mounted on the metal wiring unit 350 (FIG. 12E). At this time, the LED chip 360 is joined to the metal wiring unit 350 by soldering via the solder unit 317. This joining by soldering can be done by a reflow method or a laser method, or joining by a conductive resin can also be used.

[0066] Next, a transparent protective film 316 is formed to cover the light-reflective insulating protective film 314, the LED chip 360, the current control unit 340, and the connectors 320 and 360 ( FIG. 12E ). This transparent protective film 316 can be formed by a method of spraying a transparent resin composition by a spray process (hereinafter referred to as a “spray coating method”) or a method of forming by a curtain coating method. The transparent protective film 316 can be formed by, for example, spraying a coating liquid for spray coating containing an acrylic polyurethane resin onto a desired region on the flexible wiring substrate 310 using a spray coater to form a coated film. The transparent protective film 316 can be formed by, for example, dropping a coating liquid for curtain coating containing an acrylic polyurethane resin onto a desired region on the flexible wiring substrate 310 using a curtain coater to form a coated film.

[0067] Next, the locking member 370 is attached to the back surface of the LED illumination sheet 300. 11 ~370 55 is fixed by, for example, an adhesive.

[0068] The LED illumination sheet 300 according to this embodiment can be manufactured not only by the method described above, but also by a known method for manufacturing a conventionally known flexible wiring substrate for LED chips or various LED modules in which LED chips are mounted on the substrate.

[0069] 5. Mounting of LED lighting sheet on plant growing shelf Next, with reference to Fig. 1 and Fig. 13 to Fig. 15, we will explain how to attach the LED illumination sheet 300 manufactured as described above to the plant cultivation shelf 200. Fig. 1 shows the LED illumination sheet 300 laid flat on the ceiling of the shelf space. Fig. 13A to Fig. 13C show the LED illumination sheet 300 attached to the plant cultivation shelf 200 as viewed from the direction of arrow A in Fig. 2. Fig. 13A to Fig. 13C and Fig. 15 show the LED illumination sheet 300 attached to the top shelf space, but the LED illumination sheet 300 may also be attached to other shelf spaces in the same way. This will be explained in more detail below.

[0070] FIG. 1 shows the state in which the LED illumination sheet 300 is stretched flat in the shelf space of the plant cultivation shelf 200. Specifically, the LED illumination sheet 300 has a locking portion 370 on the back surface thereof. 11 ~370 15 , 370 21 ~370 25 , 370 31 , 370 33 , 370 35 , 370 41 ~370 45 , 370 51 ~370 55 The figure shows a state in which the LED sheet is engaged with the pipe member 211 of the plant cultivation shelf 200 using an S-shaped hook (not shown). If NFSW757G-V2 LED chips manufactured by Nichia Corporation are used and the LED chips are distributed and arranged as taught in the present application, the average photosynthetic photon flux density (PPFD) per unit wattage will be 2.0 μmol m-2 on an imaginary plane in the shelf space illuminated by the LED illumination sheet, including points 50 mm apart in the direction of the central axis of each LED chip. -2 ·s -1 ·W -1 Furthermore, the standard deviation of PPFD normalized by the average value is less than 0.4. These parameters are also achieved when the LED illumination sheet 300 is stretched in a non-planar shape, as follows:

[0071] In all of Examples 1 and 2 and Comparative Examples 1 and 2 described below, the average photosynthetic photon flux density (PPFD) per unit wattage was 2.0 μmol m -2 ·s -1 ·W -1 As mentioned above, there is no difference between this and the comparative example in this respect. The value "2.0" was adopted in order to differentiate it from organic EL lighting. While there are LEDs with a luminous efficiency of 150 [lm / W], the current situation is that the luminous efficiency of organic EL is less than 100 [lm / W]. Therefore, the luminous efficiency of organic EL can be assumed to be two-thirds that of LED. Also, as shown in Table 1 below, the average photosynthetic photon flux density (PPFD) per unit wattage (W) is 3.1 μmol m at 200 mm. -2 ·s -1 ·W -1 or 3.3 μmol m at 50 mm. -2 ·s -1 ·W -1 This is the value for LEDs, which exceeds 3. The value of 2.0 was set to differentiate them from organic EL, which has a luminous efficiency two-thirds that of LEDs. The average photosynthetic photon flux density (PPFD) per unit wattage is 2.0 μmol m -2 ·s -1 ·W -1 This will contribute to reducing running costs.

[0072] FIG. 13A shows the locking portion 370 provided on the back surface of the LED illumination sheet 300. 11 , 370 15 , 370 31 , 370 33 , 370 35 , 370 51 , 370 551 shows a state in which the LED illumination sheet 300 is non-planarly engaged with the corresponding engaging portion 215 or pipe member 211 of the plant cultivation shelf 200 using an S-shaped hook. Because the LED illumination sheet 300 is curved concavely toward the plants PL within the shelf space, the light from the sheet surface of the LED illumination sheet 300 is focused to an area smaller than the area of ​​the sheet surface. Therefore, the variation in PPFD at a predetermined distance from the sheet surface can be reduced compared to the variation in PPFD when the LED illumination sheet 300 is laid flat as shown in FIG.

[0073] FIG. 13B shows the locking portion 370 provided on the back surface of the LED illumination sheet 300. 11 , 370 13 , 370 15 , 370 31 , 370 33 , 370 35 , 370 51 , 370 53 , 370 55 13B shows a state in which the LED-illuminated sheet 300 is non-planarly engaged with the corresponding engaging portion 214 or pipe member 211 of the plant cultivation shelf 200 using an S-shaped hook. As in the case of FIG. 13A, the LED-illuminated sheet 300 is bent concavely toward the plant PL within the shelf space. More specifically, the end of the LED-illuminated sheet 300 is bent concavely, including at least a portion of the LED array 361. In the case of FIG. 13B, as in the case of FIG. 13A, the light from the sheet surface of the LED-illuminated sheet 300 is focused to an area smaller than the area of ​​the sheet surface. Therefore, the variation in PPFD at a predetermined distance from the sheet surface can be reduced compared to the variation in PPFD when the LED-illuminated sheet 300 is laid flat.

[0074] FIG. 13C shows the locking portion 370 provided on the back surface of the LED illumination sheet 300. 11 , 370 13 , 370 15 , 370 31 , 370 33 , 370 35 , 370 51 , 370 53 , 370 55The figure shows a state in which the LED illumination sheet 300 is non-planarly engaged with the pipe member 211 of the plant cultivation shelf 200 using an S-hook. The LED illumination sheet 300 is curved concavely or convexly toward the plants PL within the shelf space. In the concavely curved portion, the light from the sheet surface of the LED illumination sheet 300 is focused to an area smaller than the area of ​​the sheet surface. Therefore, the variation in PPFD at a predetermined distance from the sheet surface can be reduced compared to the variation in PPFD when the LED illumination sheet 300 is laid flat.

[0075] In contrast, in the convexly curved portions, the light from the sheet surface of the LED illumination sheet 300 is diffused over an area larger than the area of ​​the sheet surface. Therefore, the PPFD variation at a predetermined distance from the sheet surface is greater than the PPFD variation when the LED illumination sheet 300 is laid flat. Therefore, the spacing between the LED chips 360 may be narrowed so that the PPFD variation at a predetermined distance from the sheet surface falls within a desired range even when the LED illumination sheet 300 is convexly curved.

[0076] FIG. 14 shows the locking portion 370 provided on the back surface of the LED illumination sheet 300. 11 , 370 15 , 370 33 , 370 51 , 370 55 13C , the LED-illuminated sheet 300 is bent in a concave or convex shape toward the plant PL. As in the case of FIG. 13C , the LED-illuminated sheet 300 may be bent in a convex shape toward the plant PL. As in the case of FIG. 13C , the spacing between the LED chips 360 may be narrowed so that the PPFD variation at a predetermined distance from the sheet surface falls within a desired range, even if the LED-illuminated sheet 300 is bent in a convex shape.

[0077] Note that the LED lighting sheets 300 shown in FIGS. 13A to 13C and FIG. 14 are not necessarily of the same shape when laid flat. The LED lighting sheet 300 can have an appropriate size so that it can be stretched as shown in FIGS. 13A to 13C and FIG. 14.

[0078] 6. Reflective Sheet Next, referring to FIG. 15, a modified embodiment of the plant growing shelf will be described. As shown in FIG. 15, a reflective sheet 260 may be provided on the side of the plant growing shelf 200. The reflective sheet 260 contains a light-reflective material such as an aluminum sheet on the side facing the plant PL. In FIG. 15, the reflective sheet 260 is provided only on the surface along the longitudinal direction of the plant growing shelf 200, but it may also be provided on other side surfaces of the plant growing shelf 200. The visible light reflectivity of the reflective sheet can be, for example, 90% or more. Here, visible light refers to light in the wavelength range of 380 nm to 780 nm in accordance with JIS B7079. When the reflective sheet 260 is provided, a roll screen main body 250 may be provided above the side surface along the longitudinal direction of the plant growing shelf 200 so that the reflective sheet 260 can be pulled out / rolled up in the vertical direction. Alternatively, a curtain rail (not shown) may be provided above the side surface along the longitudinal direction of the plant growing shelf 200 so that the reflective sheet 260 can be spread or folded in the horizontal direction. By providing the plant growing shelf 200 with the reflective sheet 260 in this way, the light quantity at the periphery of the plant growing shelf 200 where the illuminance tends to be weak can be compensated, and the variation in PPFD can be further suppressed.

[0079] 7. Examples Next, the examples of the embodiment of FIG. 1 will be described.

[0080] <Fabrication of LED Lighting Sheet> The growing shelves of Examples 1 and 2 and the growing shelves of Comparative Examples 1 and 2 were prepared as follows.

[0081] <Example 1> A copper foil (35 μm thick) for forming the metal wiring was laminated on one surface of a 560 mm × 390 mm film substrate (polyethylene naphthalate, 50 μm thick). The copper foil for the metal wiring was then etched to form the metal wiring. A 10 μm-thick light-reflective insulating protective film was then formed on the substrate film and metal wiring by screen printing using an insulating ink composed of a urethane-based resin base resin and 20% by weight of titanium oxide. Next, multiple LED chips (NFSW757G-V2, manufactured by Nichia Corporation) were soldered to the metal wiring in 10 rows of 14 chips, with a 40 mm pitch in the X direction and a 35 mm pitch in the Y direction. A transparent protective film covering the insulating protective film and the LED chips was then formed by spray coating. The LED illumination sheet produced as described above had a total luminous flux of 3950 [lm], a total input power of 72 W, and the color temperature of the light emitted from the LED chips was 5000 K. Two of these LED illumination sheets were placed on the underside of the shelf part of a plant cultivation shelf to form the plant cultivation shelf of Example 1. Two of these plates were placed on the underside of the shelf substrate to form the plant cultivation shelf of Example 1.

[0082] <Example 2> A plant cultivation shelf of Example 2 was produced by further providing a light reflecting sheet (see FIG. 15) on the side of a plant cultivation shelf produced in the same manner as in Example 1.

[0083] <Comparative Example 1> Two commercially available LED bar lights ("TECO-L40N1-50NH-T8" (manufactured by Toshin Electric Co., Ltd.)) with an array of straight tube LEDs were placed on the underside of the substrate of the cultivation shelf to form the plant cultivation shelf of Comparative Example 1. In this case, the LED bar lights had a total luminous flux of 2300 [lm], an input power of 46 W, and a color temperature of the emitted light of 5000 K.

[0084] <Comparative Example 2> A plant cultivation shelf of Comparative Example 2 was produced by further providing a light reflecting sheet (see FIG. 15) on the side of a plant cultivation shelf produced in the same manner as in Comparative Example 1.

[0085] Photosynthetic photon flux density (PPFD) was measured for each of the plant growth shelves of Examples 1 and 2 and Comparative Examples 1 and 2. In this case, for Examples 1 and 2, the total input power was adjusted using a dimmer to be equivalent to that of Comparative Examples 1 and 2, and PPFD was measured at multiple locations (24 locations in total) within the area below the LED illumination sheet. For the plant growth shelves of Comparative Examples 1 and 2, PPFD was also measured at multiple locations (24 locations in total) within the same area as in Examples 1 and 2. The photosynthetic photon flux density (PPFD) was measured using a photon meter (LI-COR Photon Sensor LI-190R and Light Meter LI-250A, manufactured by LI-COR, USA). For each of the plant growth shelves of Examples 1 and 2 and Comparative Examples 1 and 2, PPFD was measured at locations 50 mm and 200 mm away from the LED chip, and the value was calculated by dividing the measured value by the input power. In addition, the standard deviation was calculated from the measured PPFD values ​​for each of the points 50 mm and 200 mm away from the LED chip, and this was used as the PPFD variation.

[0086] Next, plants (very early Cisco) were actually cultivated using the plant cultivation shelves of Examples 1 and 2 and Comparative Examples 1 and 2. After that, the amount of the grown plants was measured as fresh weight (g / m 2 ) and divide it by the input power to obtain the live weight per input power (g / m 2 The fresh weight was calculated by measuring the fresh weight of the aboveground parts of each cultivation panel after removing any tip burn (dead leaf tips) from the appearance of the lettuce plants after cultivation was completed, and calculating the weight per square meter. The results of this evaluation are shown in Table 1.

[0087] [Table 1]

[0088] As shown in Table 1 above, when comparing the plant growth shelves of Examples 1 and 2 with those of Comparative Examples 1 and 2, there was no significant difference in PPFD variation at a point 200 mm away from the LED chip, but the PPFD variation increased at a point 50 mm away from the LED chip. Thus, when the LED lighting sheet (Examples 1 and 2) was used, the PPFD variation at a position closer to the light source was reduced compared to when the LED bar light with an array of straight-tube LEDs (Comparative Examples 1 and 2) was used.

[0089] Furthermore, when the plant growth shelves of Examples 1 and 2 were used, the plant fresh weight per input power was increased compared to when the plant growth shelves of Comparative Examples 1 and 2 were used. At a point 50 mm away, Example 1, in which the PPFD variation (standard deviation when normalized by the average value) was 0.35 (<0.4), and Example 2, in which it was 0.23 (<0.3), showed a higher plant fresh weight per input power than Comparative Example 1, in which the variation was 0.83 (≧0.4), and Comparative Example 2, in which the variation was 0.84 (≧0.4), as shown in Table 1, and a significant difference was observed. Furthermore, at a point 50 mm away, Example 1, in which the PPFD variation was 0.35 (<0.4), showed a plant fresh weight per input power of 1.61 g m -2 ·W -1 In Example 2, the PPFD variation was 0.23 (<0.3), and that in Example 2 was 1.67 g m -2 ·W -1 Therefore, the measurement results for Examples 1 and 2 indicate that even better results can be achieved by keeping the variation to less than 0.3. Furthermore, when the plant growth shelves of Examples 1 and 2 were used, a difference in the occurrence of chip burns was observed, unlike when the plant growth shelves of Comparative Examples 1 and 2 were used. As such, when the plant growth shelves of Examples 1 and 2 were used, the variation in PPFD at a point 50 mm away from the LED chip was reduced compared to when the plant growth shelves of Comparative Examples 1 and 2 were used. This reduced the unevenness in light intensity directly below the light source, suppressing the occurrence of chip burns, which increase in direct correlation with light intensity, and reducing the number of defective parts that would have been removed, which is thought to have led to higher productivity.

[0090] 8. Additional Notes Below, some of the various embodiments disclosed in this specification will be summarized. <Appendix 1> The plant growing shelves according to Appendix 1 are: a plurality of shelves on which plants can be placed; an LED light having a plurality of LEDs arranged on a ceiling portion of at least one shelf space among a plurality of shelf spaces defined by the plurality of shelf portions; A plant growing shelf comprising: The average photosynthetic photon flux density (PPFD) per unit wattage is 2.0 μmol m for a virtual surface in the shelf space illuminated by the LED lighting, including points 50 mm apart in the direction of the central axis of each of the plurality of LEDs. -2 ·s -1 ·W -1 The LEDs are arranged so that the variation in PPFD is less than 0.4 in terms of standard deviation when normalized by the average value. <Appendix 2> The plant growing shelf (200) according to Appendix 2 is a plurality of shelves (220) on which plants can be placed; An LED lighting sheet, A substrate film (311), a metal wiring portion (350) for supplying power formed on the surface of the substrate film; a plurality of LEDs (360) electrically connected to the metal wiring portion and arranged on one surface of the substrate film in a planar and dispersed manner with a predetermined distance between each other; An LED lighting sheet (300) equipped with A plant growing shelf comprising: The LED illumination sheet is disposed on the ceiling of at least one shelf space among the plurality of shelf spaces defined by the plurality of shelf sections so as to illuminate the at least one shelf space; The LED lighting sheet has an average photosynthetic photon flux density (PPFD) per unit wattage of 2.0 μmol m for an imaginary plane in the shelf space illuminated by the LED lighting sheet, including points 50 mm apart in the direction of the central axis of each of the plurality of LEDs.-2 ·s -1 ·W -1 The plurality of LEDs are provided so that the variation in PPFD is less than 0.4 in terms of standard deviation when normalized by the average value. <Appendix 3> The plant cultivation shelf (200) according to claim 3 is the plant cultivation shelf according to claim 2, wherein the predetermined range is from 40 mm to 100 mm. <Appendix 4> The plant cultivation shelf (200) according to Supplementary Note 4 is the plant cultivation shelf according to Supplementary Note 2 or 3, wherein the plurality of LEDs are an LED array (361) in which a plurality of LEDs are connected in series and a plurality of LED rows are connected in parallel; The LED array further includes a current control section (340) for at least two of the LED arrays. <Appendix 5> The plant cultivation shelf (200) according to claim 5 is the plant cultivation shelf according to any one of claims 2 to 4, The LEDs are arranged so that the surface density in at least a portion of the area of ​​the LED illumination sheet is higher than the surface density in another portion of the area of ​​the LED illumination sheet. <Appendix 6> The plant cultivation shelf (200) according to claim 6 is the plant cultivation shelf according to any one of claims 2 to 5, The LED illumination sheet is arranged on the ceiling in a non-planar manner. <Appendix 7> The plant growing shelf (200) according to claim 7 is the plant growing shelf according to claim 6, The non-planar shape is a shape having at least one recess or protrusion within the shelf space. <Appendix 8> The plant growing shelf (200) according to claim 8 is the plant growing shelf according to claim 6, The non-planar shape is a shape in which at least a portion of the peripheral edge of the LED illumination sheet, including the LED array, is folded so as to face the interior of the at least one shelf space. <Appendix 9> The plant growing shelf (200) according to claim 9 is the plant growing shelf according to any one of claims 2 to 8, further comprising a reflective sheet (260) that reflects light to the sides of the at least one shelf space. <Appendix 10> The plant growing shelf (200) according to claim 10 is the plant growing shelf according to claim 9, The apparatus further includes a support means (250) provided on the side of a shelf portion located on the ceiling portion, The reflecting sheet is supported by the supporting means. <Appendix 11> The plant cultivation shelf (200) according to Supplementary Note 11 is the plant cultivation shelf according to Supplementary Note 9 or 10, wherein the reflective sheet has a visible light reflectance of 90% or more. <Appendix 12> The plant growing shelf (200) according to claim 12 is the plant growing shelf according to any one of claims 2 to 11, wherein the substrate film is generally white. <Appendix 13> The plant growing shelves according to Appendix 13 are: a plurality of shelves (220) on which plants can be placed; an LED lighting (300) having a plurality of LEDs (360) arranged on the ceiling of at least one shelf space among the plurality of shelf spaces defined by the plurality of shelf sections; A plant growing shelf (200) comprising: The average photosynthetic photon flux density (PPFD) per unit wattage is 2.0 μmol m for a virtual surface in the shelf space illuminated by the LED lighting, including points 50 mm apart in the direction of the central axis of each of the plurality of LEDs. -2 ·s -1 ·W -1 That's all, The plurality of LEDs are arranged so that the illumination range in the virtual plane illuminated by any one of the plurality of LEDs overlaps with the illumination range in the virtual plane illuminated by the LED located at the shortest distance from the any one of the plurality of LEDs adjacent to the any one of the LEDs. <Appendix 14> The plant growing shelf (200) according to Appendix 14 is a plurality of shelves (220) on which plants can be placed; an LED lighting (300) having a plurality of LEDs (360) arranged in a grid pattern on the ceiling of at least one shelf space among the plurality of shelf spaces defined by the plurality of shelf sections; A plant growing shelf (200) comprising: The average photosynthetic photon flux density (PPFD) per unit wattage is 2.0 μmol m for a virtual surface in the shelf space illuminated by the LED lighting, including points 50 mm apart in the direction of the central axis of each of the plurality of LEDs. -2 ·s -1 ·W -1 That's all, The distance L between any one of the plurality of LEDs and the farthest LED among the eight LEDs located in the vicinity of the any one of the LEDs dis [mm] are arranged to satisfy the following formula: TIFF0007752926000007.tif6150 where α is half the directivity angle of the LED. <Appendix 15> A plant factory (100) according to appendix 15 comprises a plant growing shelf according to any one of appendices 1 to 14.

[0091] It should be noted that the present invention can be implemented by combining, modifying, or omitting components of the disclosed embodiments within the scope of the invention. [Explanation of symbols]

[0092] 100: Plant cultivation factory 200: Plant growing shelf 220:Shelf 250: Roll screen main body (support means) 260: Reflective sheet 300: LED lighting sheet (LED lighting) 311: Substrate film 313: Metal wiring section 340: Current control section 360: LED chip 361: LED array 700: LED lighting sheet

Claims

1. a plurality of shelves on which plants can be placed; An LED lighting sheet, a substrate film that is white overall and has light reflectivity; a metal wiring portion for supplying power formed on a surface of the substrate film; a plurality of LEDs electrically connected to the metal wiring portion and disposed on one surface of the substrate film in a planarly dispersed manner with a predetermined distance between each other; An LED lighting sheet equipped with A plant growing shelf comprising: the LED illumination sheet is disposed on a ceiling portion of at least one shelf space among a plurality of shelf spaces defined by the plurality of shelf portions so as to illuminate the at least one shelf space; The LED illumination sheet has an average photosynthetic photon flux density (PPFD) per unit wattage (here, the average PPFD per unit wattage is the average PPFD of one LED illumination sheet provided with the substrate film of 560 mm x 390 mm size divided by the total input power of the one LED illumination sheet) of 2.0 μmol m for a virtual plane in the shelf space illuminated by the LED illumination sheet, the virtual plane including points spaced 50 mm apart in the direction of the central axis of each of the plurality of LEDs. -2 ・s -1 ・W -1 A plant cultivation shelf equipped with the plurality of LEDs so that the variation in PPFD is less than 0.4 in standard deviation when normalized by the average value.

2. 2. The plant growing shelf of claim 1, wherein the predetermined range is from 40 mm to 100 mm.

3. The plurality of LEDs are an LED array in which a plurality of LEDs are connected in series and a plurality of LED rows are connected in parallel, 3. The plant growing shelf of claim 1 or 2, further comprising current control units for at least two of the LED strings.

4. 4. The plant growing shelf according to claim 1, wherein the LEDs are arranged so that the surface density of at least a portion of the area of ​​the LED lighting sheet is higher than the surface density of other portions of the LED lighting sheet.

5. The plant growing shelf according to claim 1 , wherein the LED illumination sheet is arranged on the ceiling portion in a non-planar manner.

6. 6. The plant growing shelf of claim 5, wherein the non-planar shape has at least one recess or protrusion within the shelf space.

7. The plurality of LEDs are an LED array in which a plurality of LEDs are connected in series and a plurality of LED rows are connected in parallel, 6. The plant growing shelf of claim 5, wherein the non-planar shape is a shape in which at least a portion of the periphery of the LED illumination sheet, including the LED array, is folded so as to face the interior of the at least one shelf space.

8. 8. The plant growing shelf of claim 1, further comprising a reflective sheet that reflects light to the sides of the at least one shelf space.

9. The shelf portion is located on the ceiling portion, and a support means is provided on the side of the shelf portion.

9. The plant growing shelf of claim 8, wherein the reflective sheet is supported by the support means.

10. 10. The plant growing shelf according to claim 8, wherein the reflective sheet has a visible light reflectance of 90% or more.

11. A plant factory comprising the plant growing shelf according to any one of claims 1 to 10.

Images