WO2022172909A1 - Plant growing facility, plant cultivation method, led lighting device for plant growth, shelf plate for plant growth shelf, and shelf for plant growth - Google Patents

Abstract

This plant growing facility (90) has a first growth region (80A) and a second growth region (80B). The first growth region (80A) has a first lighting device (20A) which emits light with a color temperature of 4,500-5,500 K, and the second growth region (80B) has a second lighting device (20B) which emits light with a color temperature of 2,500-3,500 K.

Description

Plant growing facility, plant growing method, LED lighting device for plant growing, shelf plate for plant growing shelf, and plant growing shelf

The present disclosure relates to a plant growing facility, a plant growing method, a plant growing LED lighting device, a plant growing shelf board, and a plant growing shelf.

　In recent years, the demand for lighting equipment that uses LEDs, which consume less power, as light sources has increased in place of conventional fluorescent lamps, high-pressure sodium lamps, etc., as lighting equipment used in plant growing factories.

As an example of a plant growing factory using a lighting device using an LED as a light source, there is known a plant growing apparatus in which a plurality of straight tube type plant growing lights using an LED as a light source are arranged on a shelf board of a plant growing shelf. (See Patent Document 1, for example).

An LED lighting device for growing plants, in which a plurality of LED chips are arranged on a flexible circuit board to form a planar light source, has also been proposed (see Patent Document 2, for example).

JP 2008-118957 A JP 2013-251230 A

The present disclosure provides a plant cultivating facility, a plant cultivating method, a plant cultivating LED lighting device, a plant cultivating shelf board, and a plant cultivating shelf that can improve plant production.

A plant growing facility according to the present embodiment is a plant growing facility having a first growing area and a second growing area, wherein the first growing area emits light having a color temperature of 4500 K or more and 5500 K or less. The second growth area has a second lighting device that emits light having a color temperature of 2500K or more and 3500K or less.

In the plant growing facility according to the present embodiment, the radiant flux in the wavelength range of 400 nm to 499 nm is B, the radiant flux in the wavelength range of 500 nm to 599 nm is G, and the radiant flux in the wavelength range of 600 nm to 699 nm is R. , the emission spectrum of the light emitted by the first lighting device satisfies the relationships 0.54 ≤ B/G ≤ 0.72 and 0.59 ≤ R/G ≤ 0.77, and the The emission spectrum of the light emitted by the second lighting device may satisfy the relationships of 0.26≦B/G≦0.44 and 0.89≦R/G≦1.17.

In the plant growing facility according to the present embodiment, the first lighting device may be a lighting device for raising seedlings, and the second lighting device may be a lighting device for cultivation.

A method for cultivating a plant according to the present embodiment is a method for cultivating a plant, comprising a seedling raising step of illuminating the plant with light having a color temperature of 4500 K or more and 5500 K or less; and a cultivation step of illuminating.

In the plant cultivation method according to the present embodiment, the radiant flux in the wavelength range of 400 nm or more and 499 nm or less is B, the radiant flux in the wavelength range of 500 nm or more and 599 nm or less is G, and the radiant flux in the wavelength range of 600 nm or more and 699 nm or less is When R, the emission spectrum of the light used in the seedling raising step satisfies the relationships 0.54 ≤ B / G ≤ 0.72 and 0.59 ≤ R / G ≤ 0.77, and in the cultivation step The emission spectrum of the light used may satisfy the relationships of 0.26≦B/G≦0.44 and 0.89≦R/G≦1.17.

The method for cultivating a plant according to the present embodiment may include a planting step of planting the plant between the seedling-raising step and the cultivating step.

An LED lighting device for growing plants according to the present embodiment is an LED lighting device for growing plants in which a plurality of LED chips are arranged, and the color temperature of the light from the LED chips is 4500 K or more and 5500 K or less. There, let B be the radiant flux in the wavelength range of 400 nm or more and 499 nm or less, let G be the radiant flux in the wavelength range of 500 nm or more and 599 nm or less, and let R be the radiant flux in the wavelength range of 600 nm or more and 699 nm or less. The emission spectrum of the irradiated light satisfies the relationships of 0.54≦B/G≦0.72 and 0.59≦R/G≦0.77.

In the LED lighting device for cultivating plants according to the present embodiment, the thickest portion has a thickness of 5 mm or less, and includes a substrate film and a metal wiring portion formed on the surface of the substrate film, and the plurality of LED chips may be mounted on the metal wiring portion.

The LED lighting device for growing plants according to the present embodiment may be a lighting device for raising seedlings.

A shelf board for a plant growing shelf according to the present embodiment includes a substrate and an LED lighting device for plant growing according to the present embodiment attached to the substrate.

The plant cultivating shelf according to the present embodiment is a plant cultivating shelf, and includes a shelf plate, and the shelf plate is attached to the lower surface side of a substrate. The LED lighting device for growing plants according to the present embodiment. It has

In the plant growing shelf according to the present embodiment, the LED lighting device for plant growing may be further arranged on the side surface of the shelf board.

According to this embodiment, the production of plants can be improved.

FIG. 1 is a schematic perspective view showing a plant growing facility according to one embodiment. FIG. 2 is a schematic perspective view showing a first cultivating shelf and a second cultivating shelf according to one embodiment. FIG. 3 is a schematic diagram showing an LED lighting module according to one embodiment. FIG. 4 is a plan view showing an LED lighting sheet according to one embodiment. FIG. 5A is a plan view showing a modification of the LED lighting sheet. FIG. 5B is a plan view showing a modification of the LED lighting sheet. FIG. 6A is a graph showing the relationship between time and voltage when a constant voltage is applied from the control unit to the LED lighting sheet. FIG. 6B is a graph showing the relationship between time and voltage when pulses are applied to the LED lighting sheet as a comparative example. FIG. 7 is a cross-sectional view (cross-sectional view taken along line VII-VII in FIG. 4) showing an LED lighting sheet according to one embodiment. FIG. 8 is a diagram showing the emission spectrum of light from the LED chips of the first LED lighting sheet. FIG. 9 is a diagram showing the emission spectrum of light from the LED chips of the second LED lighting sheet. 10(a)-(h) are cross-sectional views showing a method for manufacturing an LED lighting sheet according to one embodiment. FIG. 11A is a diagram showing a modified example of a plant growing shelf. FIG. 11B is a diagram showing a modification of the plant growing shelf. FIG. 12 is a graph comparing the leaf thickness of the plant at the time of planting, the fresh weight of the plant at the time of planting, and the plant height of the plant at the time of planting for Example 1, Comparative Example 1, and Comparative Example 2, respectively. FIG. 13 is a graph comparing the fresh weight of plants after planting for each of Example 1, Comparative Example 1 and Comparative Example 2. FIG. FIG. 14 is a graph comparing the fresh weight of plants after planting in Example 2, Comparative Example 3 and Comparative Example 4, respectively.

The plant growing facility according to the present embodiment has a first growing area and a second growing area. Among these, the first growth region has a first lighting device that illuminates light with a color temperature of 4500K or more and 5500K or less, and the second growth region has a second lighting device that irradiates light with a color temperature of 2500K or more and 3500K or less. 2 lighting devices.

In the plant growing facility according to the present embodiment, the first growing area has a first lighting device that emits light with a color temperature of 4500K or more and 5500K or less. The second growth area has a second lighting device that emits light with a color temperature of 2500K or more and 3500K or less. Therefore, the plant can be grown by moving it to an optimum light source depending on the growing stage of the plant. As a result, it is possible to increase the amount of plants grown, and to obtain plants with a good yield. For example, during the seedling-raising period, which is the first stage of plant growth, the first lighting device irradiates the plant with light having a color temperature of 4500K or more and 5500K or less. In addition, during the cultivation period, which is the latter stage of plant growth, the second lighting device irradiates the plants with light having a color temperature of 2500K or more and 3500K or less. This allows plants to grow under an appropriate light source. Moreover, this embodiment is more effective when applied to leafy vegetables among plants.

The plant cultivation method according to the present embodiment includes a seedling raising step of illuminating the plants with light having a color temperature of 4500K or more and 5500K or less, and a cultivation step of illuminating the plants with light having a color temperature of 2500K or more and 3500K or less.

By irradiating the plants with light with a color temperature of 4500K or more and 5500K or less during the seedling-raising period, which is the first stage of plant growth, the plants can grow compactly and robustly. As a result, after the seedling-raising period is completed, it is possible to prevent the strains from collapsing when the plant is planted, and to prevent the work efficiency of planting from being lowered. In addition, by suppressing the collapse of the stock at the time of fixed planting, the growth of the plant can be prevented from stagnation. Furthermore, by irradiating the plants with light having a color temperature of 4500 K or more and 5500 K or less during the seedling-raising period, it is possible to reduce variations in plant growth. As a result, the size and quality of plants to be grown can be kept within a certain standard range, and the number of nonconforming products can be reduced.

In addition, by irradiating the plants with light having a color temperature of 2500K or more and 3500K or less during the cultivation period, which is the latter stage of plant growth, the growth of the plants can be accelerated and the number of days of plant cultivation can be reduced. Thereby, the production amount of plants per unit area can be improved. Since the cultivation period is a stage in which the plant grows large, a larger space is required in the plant growing facility compared to the seedling-raising period. Therefore, by accelerating the growth of plants and reducing the number of days of the cultivation period, the production cycle of plants can be dramatically improved. Thereby, the production amount per unit area of the plant can be increased.

In the plant growing facility according to the present embodiment, the radiant flux in the wavelength range of 400 nm to 499 nm is B, the radiant flux in the wavelength range of 500 nm to 599 nm is G, and the radiant flux in the wavelength range of 600 nm to 699 nm is R. and At this time, the emission spectrum of the light emitted by the first lighting device satisfies the relationships of 0.54≦B/G≦0.72 and 0.59≦R/G≦0.77. The emission spectrum of light emitted by the second lighting device satisfies the relationships of 0.26≦B/G≦0.44 and 0.89≦R/G≦1.17. As a result, during the seedling raising period, the plants can be grown compactly and robustly, and a decrease in planting work efficiency can be suppressed. In addition, during the cultivation period, by accelerating the growth of plants and reducing the number of days for plant cultivation, the production amount of plants per unit area can be improved.

By the way, one of the main challenges facing plant growing facilities that use artificial light to grow plants is to improve profitability. Factors for improving profitability include, for example, selection of cultivation targets with a high unit price, promotion of growth to grow large crops in a short period of time, and reduction of costs such as initial costs and running costs. For example, as a proposal for promoting growth by promoting photosynthesis, there is a growth control technology using two types of LED chips, a red LED chip and a blue LED chip. However, when using two types of LED chips, it is necessary to prepare two types of LED chips, making it difficult to reduce costs. Moreover, in recent years, it has been proved that even leafy vegetables absorb green light and carry out photosynthesis. For this reason, a white LED chip is sufficient as a light source, and it is desired to grow plants efficiently by an LED lighting device using a mass-produced white LED chip. On the other hand, according to the present embodiment, the first lighting device emits light with a color temperature of 4500K or higher and 5500K or lower, and the second lighting device emits light with a color temperature of 2500K or higher and 3500K or lower. Irradiate. Therefore, mass-produced white LED chips can be used as the LED chips, so that the cost of the LED lighting device can be reduced.

An embodiment will be specifically described below with reference to the drawings. Each figure shown below is shown typically. Therefore, the size and shape of each part are appropriately exaggerated for easy understanding. In addition, it is possible to modify and implement as appropriate without departing from the technical idea. In addition, in each figure shown below, the same code|symbol is attached|subjected to the same part and detailed description may be partially abbreviate|omitted. In addition, numerical values such as dimensions and material names of each member described in this specification are examples as an embodiment, and are not limited to these, and can be appropriately selected and used. In this specification, terms specifying shapes and geometrical conditions, such as parallel, orthogonal, and perpendicular terms, not only have strict meanings but also include substantially the same states.

(Plant growing facility and plant growing shelf)
FIG. 1 is a diagram schematically showing the configuration of a plant growing facility 90 according to this embodiment. A plant growing facility 90 according to the present embodiment includes a first growing shelf 80A and a second growing shelf 80B. Of these, the first growing shelf 80A is a plant growing shelf for growing plants in the seedling-raising period, which is the early stage of plant growing, and the second growing shelf 80B is for plants in the growing period, which is the late stage of plant growing. It is a growing shelf for growing plants. In this case, the first cultivating shelf 80A and the second cultivating shelf 80B have shelves with the same space, but the present invention is not limited to this. The first growing shelf 80A for growing seedlings with relatively small plants may be smaller than the second growing shelf 80B for growing relatively large plants. Further, the inter-shelf distance (vertical distance) of the first cultivating shelf 80A may be smaller than the inter-shelf distance of the second cultivating shelf 80B. In this embodiment, the first cultivating shelf 80A corresponds to the first cultivating area, and the second cultivating shelf 80B corresponds to the second cultivating area. However, not limited to this, both the first growing area and the second growing area may be arranged on one growing shelf. For example, the first growing area may be arranged in the upper part (lower part) of one growing shelf, and the second growing area may be arranged in the lower part (upper part). Hereinafter, the first cultivating shelf 80A and the second cultivating shelf 80B are also collectively referred to as the cultivating shelves 80A and 80B.

In this specification, the seedling-raising period is the early stage of plant growth, and refers to the period after sowing until the plant reaches a certain weight. When a plant is planted permanently, the raising seedling period means the period until planting. The cultivation period is the latter stage of plant growth, and refers to the period from the time the plant grows to a certain weight to the time the plant is harvested. When a plant is permanently planted, the cultivation period refers to the period after it is permanently planted. Fixed planting refers to planting a plant in a field (second growth area) where the plant is cultivated until harvest. Also, raising seedlings, fixed planting, and cultivating mentioned above are collectively referred to as cultivating.

As shown in FIG. 1, the plant growing facility 90 is a plant growing factory using artificial light. This plant growing facility 90 comprises a building 91 that accommodates a first growing shelf 80A and a second growing shelf 80B. In addition, in this specification, a plant growing facility is a concept including a plant growing system, a plant growing room, a plant growing factory, etc. in addition to the plant growing factory.

Next, the first cultivating shelf 80A and the second cultivating shelf 80B will be further described with reference to FIG. In the present embodiment, the first growing shelf 80A for the seedling growing period has a first LED lighting sheet (first lighting device) 20A that emits light with a color temperature of 4500K or more and 5500K or less. The second growing shelf 80B for the cultivation period has a second LED lighting sheet (second lighting device) 20B that emits light with a color temperature of 2500K or more and 3500K or less. Hereinafter, the first LED lighting sheet 20A and the second LED lighting sheet 20B are also collectively referred to as the LED lighting sheets 20A and 20B.

Also, let B be the radiant flux in the wavelength range of 400 nm or more and 499 nm or less, let G be the radiant flux in the wavelength range of 500 nm or more and 599 nm or less, and let R be the radiant flux in the wavelength range of 600 nm or more and 699 nm or less. At this time, the emission spectrum of the light emitted from the first LED lighting sheet 20A satisfies the relationships of 0.54≦B/G≦0.72 and 0.59≦R/G≦0.77. Moreover, the emission spectrum of the light emitted from the second LED lighting sheet 20B satisfies the relationships of 0.26≦B/G≦0.44 and 0.89≦R/G≦1.17.

As shown in FIG. 2, the first LED lighting sheet 20A is electrically connected to a control unit 40 that controls the first LED lighting sheet 20A. The first LED lighting sheet 20A and the controller 40 constitute a first LED lighting module 10A. A control unit 40 for controlling the second LED lighting sheet 20B is electrically connected to the second LED lighting sheet 20B. A second LED lighting module 10B is configured by the second LED lighting sheet 20B and the control unit 40 . Hereinafter, the first LED lighting module 10A and the second LED lighting module 10B are also collectively referred to as the LED lighting modules 10A and 10B.

As shown in FIG. 2, each of the first cultivating shelf 80A and the second cultivating shelf 80B includes a plurality of (four) pillars 82 and a plurality of pillars 82 vertically spaced apart from each other along the pillars 82. and a substrate 81 of A culture medium area for cultivating plants PL is provided on the upper surface of each substrate 81 except for the substrate 81 on the uppermost stage. The bottom surface of each substrate 81 except for the bottom substrate 81 constitutes a ceiling surface for the substrates 81 positioned below the substrate 81, and the LED lighting sheets 20A and 20B are arranged in parallel. In this case, the control unit 40 is arranged at a location sufficiently distant from each of the LED lighting sheets 20A and 20B. Therefore, there is little possibility that the heat from the control unit 40 causes variation in growth between the plant PL located near the control unit 40 and the plant PL located far from the control unit 40 . Further, the board 81 and the LED lighting sheets 20A and 20B attached to the lower surface side of the board 81 constitute a shelf board 83 for a plant growing shelf. Alternatively, the board 81 and the LED lighting modules 10A and 10B attached to the lower surface of the board 81 constitute a shelf board 83 for growing plants. In the present embodiment, a plant-growing facility 90 provided with such a plant-growing shelf plate 83 (Fig. 2), plant-growing shelves 80A and 80B (Fig. 2), and plant-growing shelves 80A and 80B (Fig. 1) is also provided.

As will be described later, the LED lighting sheets 20A and 20B according to this embodiment have flexibility and lightness. Therefore, attachment of the LED lighting sheets 20A and 20B to the lower surface of each substrate 81 can be performed more easily than attachment by a conventional straight tube type illumination device or the like. Furthermore, since the LED lighting sheets 20A and 20B have flexibility, the LED lighting sheets 20A and 20B can be attached to ceiling surfaces having various sizes and shapes. As a result, the LED lighting sheets 20A and 20B according to the present embodiment can be applied to various growing shelves 80A and 80B and plant growing facilities 90.

In addition, the LED lighting sheets 20A and 20B are thinner than conventional straight tube lighting devices. As a result, the space between substrates 81 in the vertical direction can be narrowed, and the number of substrates 81 included in each of the growing racks 80A and 80B can be increased. As a result, the yield of plants PL per unit area can be increased.

(LED lighting module and LED lighting sheet for growing plants)
Next, configurations of the LED lighting modules 10A and 10B and the LED lighting sheets 20A and 20B according to the present embodiment will be described with reference to FIGS. 3 to 9. FIG.

As shown in FIG. 3, the plant growing LED lighting modules 10A and 10B according to the present embodiment are installed in a plant growing facility 90 (FIG. 1) using artificial light to grow plants. As described above, the LED lighting modules 10A and 10B include the LED lighting sheets 20A and 20B for growing plants, and the controller 40 electrically connected to the LED lighting sheets 20A and 20B. .

As shown in FIG. 4, the LED lighting sheets 20A and 20B are so-called planar light source sheets, and a plurality of LED chips 21 are arranged on the light emitting surface side of the sheet surface (the side facing the plant direction when used). It is. By using such direct-type LED lighting sheets 20A and 20B, the irradiation light from the LED chip 21 passes through the light-emitting surface as it is and reaches the plant directly below. As a result, the amount of light can be increased to promote the growth of plants, and the thickness of the entire sheet can be reduced to make it difficult for shadows on the sides of the LED chips 21 to occur. Although FIG. 4 shows an example of the direct type LED lighting sheets 20A and 20B, the present invention is not limited to this, and an edge light type LED lighting sheet with a light guide plate or the like interposed may be used. An edge-light type LED lighting sheet tends to suppress variations in the amount of light emitted from the light-emitting surface.

The LED lighting sheets 20A and 20B are provided with a flexible wiring board 30 and a plurality of LED chips 21 regularly arranged on the flexible wiring board 30. By using such a flexible wiring board 30, it is possible to obtain the LED lighting sheets 20A and 20B having a relatively large sheet surface area. In general, in a plant growing facility such as a plant growing factory or a plant growing shelf, a plurality of LED lighting sheets 20A and 20B are arranged and used. In this case, if the positions of the adjacent LED lighting sheets 20A and 20B vary, the amount of light varies, which may reduce the yield of plants. The LED lighting sheets 20A and 20B having a relatively large sheet surface area can reduce the number of LED lighting sheets 20A and 20B to be used. As a result, it is possible to suppress variations in the amount of light due to the arrangement of the plurality of LED lighting sheets 20A and 20B. Although FIG. 4 shows an example of the LED lighting sheets 20A and 20B provided with the flexible wiring board 30, it is not limited to this, and an LED lighting sheet provided with a rigid wiring board may be used. An LED lighting sheet with a rigid wiring board has high resistance to stress and is less likely to break. In FIG. 4, illustration of a light-reflective insulating protective film 34 and a transparent protective film 35, which will be described later, is omitted.

In this case, the LED chips 21 are arranged inside the flexible wiring board 30 in a grid pattern in plan view. That is, the LED chips 21 are arranged in multiple rows and columns in a matrix, and N rows R of LED chips 21 connected in series are arranged. For example, in FIG. 4, 14 (M=14) LED chips 21 are connected in series along the first arrangement direction (X direction) of the LED chips 21 . Further, the row R having the 14 LED chips 21 is arranged in 10 rows (N=10) in parallel along the second arrangement direction (Y direction) of the LED chips 21 . Note that the number of LED chips 21 to be arranged is not limited to this. Specifically, 10 or more and 14 or less (14≧M≧10) LED chips 21 are arranged in series in the first arrangement direction (X direction), and this row R is the second arrangement of the LED chips 21. It is preferable to arrange 4 or more and 10 or less (10≧N≧4) rows in parallel in the direction (Y direction). By arranging ten or more LED chips 21 in series, the LED chips 21 can be arranged at short intervals along the first arrangement direction (X direction). As a result, in-plane variations in the illuminance of the LED lighting sheets 20A and 20B can be suppressed, and variations in the light applied to the plants can be suppressed. By arranging 14 or less LED chips 21 in series, power consumption can be reduced, and running costs such as utility costs in the plant growing facility 90 can be reduced. Further, by arranging four or more rows of the LED chips 21 in parallel in the second arrangement direction (Y direction) of the LED chips 21, even if a specific LED chip 21 is damaged, the LED chips 21 in the other rows can be suppressed. Moreover, it is possible to prevent the illuminance of the entire LED lighting sheets 20A and 20B from being extremely lowered. In addition, by limiting the range where the illuminance of the LED lighting sheets 20A and 20B has decreased, the range in which nonconforming products may occur can be limited, and a reduction in yield can be suppressed. In addition, when the LED lighting sheets 20A and 20B are of the direct type, there is an increased risk of damage due to erroneous strong contact with the LED chips 21 during installation or cleaning. It is important from the viewpoint of risk management. Further, by arranging the LED chips 21 in 10 or less rows in parallel, power consumption can be reduced, and running costs such as utility costs in the plant growing facility 90 can be reduced.

The LED lighting sheets 20A and 20B have a plurality of metal wiring portions 22, and the plurality of metal wiring portions 22 are arranged along the first arrangement direction (X direction). A plurality of metal wiring portions 22 arranged along the first arrangement direction (X direction) correspond to the respective rows R of the LED chips 21 . The LED chips 21 are arranged so as to straddle a pair of metal wiring portions 22 adjacent to each other in the X direction. Each terminal (not shown) of the LED chip 21 is electrically connected to a pair of metal wiring portions 22, respectively. The plurality of metal wiring portions 22 constitute a power feeding portion to the LED chips 21, and by supplying power to the plurality of metal wiring portions 22, all the LED chips 21 arranged in the row R are lit. . In addition, the plurality of metal wiring portions 22 constitute a part of a metal wiring portion 32 to be described later.

The interval Px between the LED chips 21 in the first arrangement direction (X direction) is preferably 37 mm or more and 50 mm or less. Moreover, it is preferable that the interval Py between the LED chips 21 in the second arrangement direction (Y direction) is set to 37 mm or more and 100 mm or less. By setting the interval between the LED chips 21 within the above range, the brightness of the LED lighting sheets 20A and 20B is uniform in the plane, and the variation in the light irradiated to the plants is suppressed, and the consumption of the LED lighting sheets 20A and 20B. Electricity can be saved.

The thickness of the thickest portion of the LED lighting sheets 20A and 20B is preferably 5 mm or less. By reducing the thickness of the LED lighting sheets 20A and 20B in this way, it is possible to narrow the vertical interval between the substrates 81 (FIG. 2) on which the LED lighting sheets 20A and 20B are installed. As a result, the number of substrates 81 per growing shelf 80A, 80B (FIG. 2) for each plant can be increased. As a result, the yield of plants per unit area can be increased. In addition, when the plants and the LED lighting sheets 20A and 20B are close to each other, variations in the relatively strong light emitted to the plants can be further suppressed.

The arrangement of the LED chips 21 is not limited to the grid point shape in plan view, and may be arranged in a zigzag pattern in plan view as shown in FIG. 5A. Moreover, the LED chips 21 do not have to be arranged uniformly within the surfaces of the LED lighting sheets 20A and 20B. For example, the density of the LED chips 21 may be increased in the periphery of the LED lighting sheets 20A and 20B. Specifically, as shown in FIG. 5B, the LED chips 21 are arranged in a grid pattern in the central portion (lower portion of FIG. 5B) of the LED lighting sheets 20A and 20B, and the peripheral edge portions of the LED lighting sheets 20A and 20B ( 5B), the LED chips 21 may be arranged in a zigzag pattern. This suppresses a decrease in the luminance of the LED lighting sheets 20A and 20B at the peripheral edges of the LED lighting sheets 20A and 20B, makes the luminance of the LED lighting sheets 20A and 20B uniform in the plane, and causes variations in the light irradiated to the plants. can be suppressed.

The overall shape of the LED lighting sheets 20A and 20B is rectangular in plan view, but the size and planar shape of the LED lighting sheets 20A and 20B are not particularly limited. Since the LED lighting sheets 20A and 20B have a high degree of freedom in size and shape processing, it is possible to flexibly respond to various demands related to this point. In addition, by taking advantage of its flexibility, it is possible to attach it not only to a flat installation surface but also to installation surfaces of various shapes. Moreover, the LED lighting sheets 20A and 20B themselves have rigidity. For this reason, for example, by bending the LED lighting sheets 20A and 20B into a cylindrical shape so that the LED chips 21 are on the outside, the LED lighting sheets 20A and 20B alone can be illuminated without an installation surface.

In FIG. 4, the length Lx of the LED lighting sheets 20A and 20B in the first arrangement direction (X direction) is preferably 500 mm or more and 700 mm or less, more preferably 550 mm or more and 650 mm or less. The length Ly of the LED lighting sheets 20A and 20B in the second arrangement direction (Y direction) is preferably 300 mm or more and 500 mm or less, more preferably 350 mm or more and 450 mm or less. By setting the size of the LED lighting sheets 20A and 20B within the above range, the LED lighting sheets 20A and 20B can be adapted to a general substrate 81 (FIG. 2) for growing plants, and the dead space of the substrate 81 can be reduced. can be reduced. In addition, since the size of each of the LED lighting sheets 20A and 20B is not excessively large, when a specific LED chip 21 is damaged, the other LED chips 21 are minimized from being affected. . As a result, it is possible to prevent the illuminance of the entire shelf plate 83 (FIG. 2) for growing plants from being extremely lowered, and to limit the range in which the illuminance is lowered.

Next, the control unit 40 will be explained. As shown in FIG. 3, the control unit 40 supplies power to the LED lighting sheets 20A and 20B and controls light emission of the LED lighting sheets 20A and 20B. The control unit 40 is detachably connected to the LED lighting sheets 20A, 20B via a first connector 44A provided on the LED lighting sheets 20A, 20B. That is, the control unit 40 is configured separately from the LED lighting sheets 20A and 20B, and is externally connected to the LED lighting sheets 20A and 20B. That is, the controller 40 is not integrated with the LED lighting sheets 20A and 20B. As a result, the control unit 40 serving as a heat source can be separated from the LED lighting sheets 20A and 20B, and the heat from the control unit 40 can be prevented from affecting the growth of plants.

The control unit 40 also has a power input unit 41 , an AC/DC converter (driver) 42 and a PWM control unit 43 . Among them, the power input unit 41 is supplied with an AC voltage having an arbitrary voltage of 100V to 240V, for example. The AC/DC converter 42 converts an AC voltage of 100V to 240V into a constant voltage (for example, 44V) DC voltage. The PWM control section 43 arbitrarily changes the pulse width of the constant voltage waveform from the AC/DC converter 42 to perform light control of the LED chips 21 of the LED lighting sheets 20A and 20B. That is, the PWM control section 43 also serves as a dimming control section that controls dimming of the LED lighting sheets 20A and 20B. A constant voltage output from the PWM control unit 43 is applied to the LED lighting sheets 20A and 20B via the first connector 44A.

By applying a constant voltage to the LED lighting sheets 20A and 20B from the PWM control unit 43 of the control unit 40, unlike the case where the rectified pulse voltage is applied directly to the LED lighting sheets 20A and 20B, the LED chips 21 can be dimmed. That is, the PWM controller 43 can arbitrarily control the illuminance of the LED chip 21 by appropriately changing the duty ratio of the DC voltage from the AC/DC converter 42 . For example, as shown in FIG. 6A, the PWM control unit 43 reduces the illuminance of the LED chip 21 by suppressing the duty ratio of the constant voltage from the AC/DC converter 42 from 100% (solid line) to 50% (dotted line). can be lowered.

By appropriately adjusting the illuminance of the LED chips 21 in this manner, the illuminance of the LED lighting sheets 20A and 20B can be adjusted according to the growth stage of the plant, and the degree of plant growth can be adjusted. For example, during the seedling raising period or cultivation period, the illuminance of the LED lighting sheets 20A and 20B is reduced at the beginning of the period when the leaves of the plant are small, and the illuminance of the LED lighting sheets 20A and 20B is reduced at the end of the period when the leaves of the plant are large. can be raised. Alternatively, the illuminance of the LED lighting sheets 20A and 20B may be increased during the seedling raising period or during the cultivation period at the beginning of the period when the plant is short, since the distance between the plant and the LED chip 21 is large. Since the distance between the plant and the LED chip 21 is reduced in the latter half of the period when the height of the plant increases, the illuminance of the LED lighting sheets 20A and 20B may be lowered. As another example of adjusting the illuminance of the LED lighting sheets 20A and 20B, the illuminance may be increased for plants that require high illuminance, and may be decreased for plants that can be grown at low illuminance. The illuminance may be increased to accelerate the shipment, and may be decreased to delay the shipment.

Further, by applying a constant voltage from the PWM control unit 43 to the LED lighting sheets 20A and 20B, the integrated amount of light per unit time from the LED lighting sheets 20A and 20B can be increased. That is, for example, the integrated light amount when a constant voltage is applied to the LED lighting sheets 20A and 20B (the area of the shaded portion in FIG. 6A) is compared with the integrated light amount when a pulse voltage is applied as a comparative example (FIG. 6B can be larger than the shaded area of ). Thereby, the luminous efficiency of the light from the LED lighting sheets 20A and 20B can be increased, and the growing efficiency of plants can be improved.

Referring to FIG. 3 again, the LED lighting sheets 20A and 20B are provided with regulators 45. In this case, the regulators 45 are provided corresponding to the respective columns of the LED chips 21. Specifically, ten regulators 45 are provided corresponding to the ten columns of the LED chips 21. . This regulator 45 serves to keep constant the current flowing through the plurality of LED chips 21 in each column. As a result, even if one LED chip 21 is damaged, it is possible to prevent an excessive current from flowing to the LED chips 21 in other columns, thereby preventing the LED chips 21 in other columns from being damaged. As a result, it is possible to prevent the illuminance of the entire LED lighting sheets 20A and 20B from being extremely lowered, and to suppress variations in the light emitted to the plants. In addition, the regulator 45 can control the amount of current controlled by the connected resistance value for each column. can be raised. In this way, the LED lighting sheets 20A and 20B are normally laid together without gaps, thereby ensuring uniformity. On the other hand, even if the LED lighting sheets 20A and 20B are spaced about 5 cm to 10 cm from the viewpoint of cost and ensuring air permeability, the effect of eliminating the seam can be expected.

Furthermore, the LED lighting sheets 20A and 20B are provided with a power supply line 46 branched from the first connector 44A. A second connector 44B is provided on the LED lighting sheets 20A and 20B. The power supply line 46 is not electrically connected to the LED chips 21 of the LED lighting sheets 20A and 20B, and is connected to wiring of another LED lighting sheet 200 having the same configuration as the LED lighting sheets 20A and 20B. are electrically connected. That is, the power supply line 46 is detachably connected to the wiring of the LED lighting sheet 200 via the second connector 44B and the other first connector 44A provided on the other LED lighting sheet 200 . A current from the power supply line 46 is supplied to the other LED lighting sheet 200 via the second connector 44B and the other first connector 44A. Thereby, the LED lighting sheets 20A, 20B and another LED lighting sheet 200 can be connected, and these LED lighting sheets 20A, 20B and the LED lighting sheet 200 can be controlled simultaneously by one control unit 40. By simultaneously controlling the plurality of LED lighting sheets 20A, 20B, 200 by one controller 40, the number of controllers 40, which are sources of heat generation, can be reduced. As a result, variations in plant growth due to the heat from the control unit 40 are less likely to occur, and reduction in yield can be suppressed.

(Each member of the LED lighting sheet)
Next, each member which comprises LED lighting sheet 20A, 20B is demonstrated. As shown in FIG. 7, the LED lighting sheets 20A and 20B include a flexible wiring board 30 and a plurality of LED chips 21 arranged on the flexible wiring board 30. As shown in FIG. Among them, the flexible wiring board 30 has a substrate film 31 having flexibility and a metal wiring portion 32 formed on the surface of the substrate film 31 (the surface on the light emitting surface side). The metal wiring portion 32 is laminated on the substrate film 31 with an adhesive layer 33 interposed therebetween.

Each LED chip 21 is mounted on the metal wiring portion 32 in a conductive manner. In the LED lighting sheets 20A and 20B, since the LED chips 21 are mounted on the flexible wiring board 30, it is possible to arrange the plurality of LED chips 21 at a desired high density.

A light-reflective insulating protective film 34 covers a region of the LED lighting sheets 20A and 20B, excluding a region where the LED chip 21, the regulator 45, the first connector 44A and the second connector 44B are provided, and the peripheral region thereof. formed. This light-reflective insulating protective film 34 is arranged so as to cover the metal wiring portion 32 . The light-reflective insulating protective film 34 has both an insulating function that contributes to improving migration resistance properties of the LED lighting sheets 20A and 20B and a light reflecting function that contributes to improving the light environment created by the LED lighting sheets 20A and 20B. layer. This layer is formed from an insulating resin composition containing a white pigment. A structure without the light-reflective insulating protective film 34 is also possible when the migration resistance and the light-reflecting function can be obtained only with the metal wiring portion 32 described above and the transparent protective film 35 described later.

A transparent protective film 35 is formed so as to cover the light-reflective insulating protective film 34 and the LED chip 21 . The transparent protective film 35 is a resinous film formed on the outermost surface (the surface closest to the light emitting surface) mainly to ensure waterproofness of the LED lighting sheets 20A and 20B.

A solder portion 36 is provided on the metal wiring portion 32 . Each LED chip 21 is electrically connected to the metal wiring portion 32 via a solder portion 36 .

(substrate film)
A flexible resin film can be used for the substrate film 31 . In this specification, "having flexibility" means "having a radius of curvature of at least 1 m or less, preferably 50 cm, more preferably 30 cm, still more preferably 10 cm, and particularly preferably 5 cm. "Things"

As the material for the substrate film 31, a thermoplastic resin with high heat resistance and insulation may be used. Polyimide resin (PI) and polyethylene naphthalate (PEN), which are excellent in heat resistance, dimensional stability when heated, mechanical strength, and durability, can be used as such a resin. Among them, polyethylene naphthalate (PEN), which is improved in heat resistance and dimensional stability by applying heat resistance improvement treatment such as annealing treatment, can also be preferably used. Polyethylene terephthalate (PET), which is improved in flame retardancy by adding a flame retardant inorganic filler or the like, may also be used.

The thickness of the substrate film 31 is not particularly limited. The thickness of the substrate film 31 can be appropriately set from the viewpoints of not becoming a bottleneck as a heat dissipation path, having heat resistance and insulating properties, and balancing manufacturing costs. Specifically, the thickness of the substrate film 31 may be approximately 10 μm or more and 500 μm or less, preferably 50 μm or more and 250 μm or less. Moreover, it is preferable that the thickness is within the above range also from the viewpoint of maintaining good productivity in the case of manufacturing by a roll-to-roll method.

(adhesive layer)
As the adhesive for forming the adhesive layer 33, a known resin-based adhesive can be appropriately used. Among these resin adhesives, urethane-based, polycarbonate-based, silicone-based, ester-based or epoxy-based adhesives can be particularly preferably used.

(Metal wiring part)
The metal wiring portion 32 is a wiring pattern formed on the surface of the substrate film 31 (the surface on the side of the light emitting surface) with a conductive base material such as metal foil. The metal wiring portion 32 is preferably formed on the surface of the substrate film 31 with an adhesive layer 33 interposed therebetween by a dry lamination method. The metal wiring portion 32 includes the plurality of metal wiring portions 22 described above. The multiple metal wiring portions 22 include a first metal wiring portion 22A and a second metal wiring portion 22B spaced apart from the first metal wiring portion 22A. The LED chip 21 is mounted on the first metal wiring portion 22A and the second metal wiring portion 22B, and the LED chip 21 is electrically connected to the first metal wiring portion 22A and the second metal wiring portion 22B. It is The LED chip 21 is lit by power supplied to the first metal wiring portion 22A and the second metal wiring portion 22B.

It is preferable that the metal wiring part 32 has both heat dissipation and electrical conductivity at a high level. For example, copper foil can be used. In this case, heat dissipation from the LED chips 21 is stabilized, and an increase in electrical resistance can be prevented, so that variations in light emission among the LED chips 21 are reduced and stable light emission becomes possible. Also, the life of the LED chip 21 is extended. Furthermore, since deterioration of peripheral members such as the substrate film 31 due to heat can be prevented, the product life of the LED lighting sheets 20A and 20B can be extended. Examples of metals forming the metal wiring portion 32 include metals such as aluminum, gold, and silver, in addition to the above copper.

The thickness of the metal wiring portion 32 may be appropriately set according to the magnitude of withstand current required for the flexible wiring board 30 and the like. However, the thickness of the metal wiring portion 32 is preferably 10 μm or more in order to suppress warping due to heat shrinkage of the substrate film 31 during soldering processing such as a reflow method. On the other hand, the thickness of the metal wiring portion 32 is preferably 50 μm or less, so that the flexible wiring board 30 can maintain sufficient flexibility, and a decrease in handling performance due to an increase in weight can be suppressed.

(solder part)
The solder portion 36 joins the metal wiring portion 32 and the LED chip 21 . This soldering can be performed by either a reflow method or a laser method.

(LED chip)
The LED chip 21 is a light-emitting element utilizing light emission at a PN junction where a P-type semiconductor and an N-type semiconductor are joined. The LED chip 21 may have a structure in which a P-type electrode and an N-type electrode are respectively provided on the upper and lower surfaces of the element, or a structure in which both the P-type electrode and the N-type electrode are provided on one side of the element. can be

As the LED chip 21, it is preferable to select one with high luminous efficiency. Specifically, the LED chip 21 preferably has a luminous efficiency of 150 lm/W or more, and more preferably has a luminous efficiency of 180 lm/W or more. By increasing the luminous efficiency of the LED chips 21 to 150 lm/W or higher, the number (density) of the LED chips 21 mounted can be reduced, and the heat generated by the LED chips 21 due to Joule heat can be reduced. As a result, variations in plant growth caused by the heat from the LED chip 21 are less likely to occur, and a decrease in yield can be suppressed.

As described above, the LED lighting sheets 20A and 20B have the LED chips 21 directly mounted on the metal wiring portions 32 capable of exhibiting high heat dissipation. As a result, even when the LED chips 21 are arranged at a high density, excessive heat generated when the LED chips 21 are turned on is rapidly diffused through the metal wiring portion 32, and the LED lighting sheets 20A and 20B are heated through the substrate film 31. can sufficiently dissipate heat to the outside. As a result, variations in plant growth caused by the heat from the LED chip 21 are less likely to occur, and a decrease in yield can be suppressed.

By the way, in the present embodiment, the LED chips 21 used in the first LED lighting sheet 20A for raising seedlings and the LED chips 21 used in the second LED lighting sheet 20B for cultivation have different optical characteristics. is doing. The LED chips 21 of the first LED lighting sheet 20A and the LED chips 21 of the second LED lighting sheet 20B will be described below.

(LED chip of the first LED lighting sheet)
In the present embodiment, the LED chips 21 of the first LED lighting sheet 20A irradiate light suitable for raising seedlings. In this case, the color temperature of the light from the LED chip 21 is 4500K or more and 5500K or less, preferably 4800K or more and 5200K or less, and more preferably 4900K or more and 5100K or less. Let B be the radiant flux in the wavelength range from 400 nm to 499 nm, G be the radiant flux in the wavelength range from 500 nm to 599 nm, and R be the radiant flux in the wavelength range from 600 nm to 699 nm. At this time, the emission spectrum of the light emitted by the LED chips 21 of the first LED lighting sheet 20A has a relationship of 0.54 ≤ B/G ≤ 0.72 and 0.59 ≤ R/G ≤ 0.77. meet.

As shown in FIG. 8, the emission spectrum S1 of light from the LED chips 21 of the first LED lighting sheet 20A has a first peak P1, a second peak P2, and a third peak P3. ing. The first peak P1 has a center wavelength of 440 nm or more and 460 nm or less. The second peak P2 has a center wavelength of 510 nm or more and 530 nm or less. The third peak P3 has a center wavelength of 610 nm or more and 630 nm or less. That is, the emission spectrum S has a first peak P1 existing in the blue wavelength range, a second peak P2 existing in the green wavelength range, and a third peak P3 existing in the red wavelength range. . The emission spectrum of the light from the LED chip 21 can be measured using a spectral irradiance meter (for example, CL-500A manufactured by Konica Minolta) used for measuring the light source color.

In this case, the relative emission intensity at the center wavelength of the first peak P1 is greater than the relative emission intensity at the center wavelength of the second peak P2, and the relative emission intensity at the center wavelength of the second peak P2 is the third It is larger than the relative emission intensity at the center wavelength of peak P3. That is, in this specification, among the peaks of the emission spectrum S of the light from the LED chip 21, the peak having the highest relative emission intensity is referred to as the first peak P1. A peak having the second highest relative emission intensity is called a second peak P2. A peak having the third highest relative emission intensity is called a third peak P3. Note that the light from the LED chip 21 may include four or more peaks. Since the emission spectrum S of the light from the LED chip 21 has the first peak P1, the second peak P2 and the third peak P3 as described above, the light from the LED chip 21 is white. ing.

As shown in FIG. 8, let B be the radiant flux in the wavelength range of 400 nm or more and 499 nm or less, let G be the radiant flux in the wavelength range of 500 nm or more and 599 nm or less, and let R be the radiant flux in the wavelength range of 600 nm or more and 699 nm or less. Here, the radiant flux B corresponds to an integrated value (area) in the wavelength range of 400 nm or more and 499 nm or less in the emission spectrum S1 of the light from the LED chip 21 . The radiant flux G corresponds to an integrated value (area) in the wavelength range of 500 nm or more and 599 nm or less in the emission spectrum S1 of the light from the LED chip 21 . The radiant flux B corresponds to an integrated value (area) in the wavelength range of 600 nm or more and 699 nm or less in the emission spectrum S1 of the light from the LED chip 21 . The radiant fluxes B, G, and R can be measured by a high-precision light measuring instrument (eg, Light Analyzer LA105 manufactured by Nippon Medical Instruments Manufacturing Co., Ltd.).

At this time, the emission spectrum of the light emitted by the LED chips 21 of the first LED lighting sheet 20A satisfies the relationship 0.54≤B/G≤0.72. The emission spectrum preferably satisfies the relationship 0.57≦B/G≦0.69, and more preferably satisfies the relationship 0.60≦B/G≦0.66. Moreover, the emission spectrum of the light emitted by the LED chips 21 of the first LED lighting sheet 20A satisfies the relationship 0.59≦R/G≦0.77. The emission spectrum preferably satisfies the relationship 0.62≦B/G≦0.74, and more preferably satisfies the relationship 0.65≦B/G≦0.71.

When the LED chips 21 of the first LED lighting sheet 20A satisfy the above optical characteristics, plants can be grown into compact and sturdy seedlings, and damage during planting can be reduced. That is, by setting the color temperature of the light from the LED chip 21 to be 4500 K or more and 5500 K or less, it is possible to keep the fresh weight of the plant low, shorten the height of the plant, and increase the thickness of the leaves of the plant. As a result, the plant can be made firm and sturdy while growing compactly. As a result, when the plant is planted, the plant is less likely to fall down, the work efficiency of planting is reduced, and the growth of the plant is prevented from stagnation. In addition, because of its compact size, it is possible to suppress overlapping of adjacent seedlings even if the seedling-raising period is extended. That is, when the color temperature of the light is 4500K or more and 5500K or less, the seedling raising period can be extended more than usual. In addition, it is possible to reduce variation in the fresh weight of plants at the time of harvesting after the cultivation period, reduce nonconforming products, and improve the yield of plants.

(LED chip of the second LED lighting sheet)
Moreover, the LED chip 21 of the 2nd LED lighting sheet 20B irradiates the light suitable for cultivation. In this case, the color temperature of the light from the LED chip 21 is 2500K or higher and 3500K or lower, preferably 2700K or higher and 3300K or lower, and more preferably 2900K or higher and 3100K or lower. Let B be the radiant flux in the wavelength range from 400 nm to 499 nm, G be the radiant flux in the wavelength range from 500 nm to 599 nm, and R be the radiant flux in the wavelength range from 600 nm to 699 nm. At this time, the emission spectrum of the light emitted by the LED chips 21 of the second LED lighting sheet 20B has a relationship of 0.26≦B/G≦0.44 and 0.89≦R/G≦1.17. meet.

As shown in FIG. 9, the emission spectrum S2 of light from the LED chips 21 of the second LED lighting sheet 20B has a first peak P1, a second peak P2, and a third peak P3. ing. The first peak P1 has a center wavelength of 610 nm or more and 630 nm or less. The second peak P2 has a center wavelength of 440 nm or more and 460 nm or less. The third peak P3 has a center wavelength of 510 nm or more and 530 nm or less. That is, the emission spectrum S2 has a first peak P1 existing in the red wavelength range, a second peak P2 existing in the blue wavelength range, and a third peak P3 existing in the green wavelength range. .

In this case, the relative emission intensity at the center wavelength of the first peak P1 is greater than the relative emission intensity at the center wavelength of the second peak P2, and the relative emission intensity at the center wavelength of the third peak P3 is greater than the second It is smaller than the relative emission intensity at the center wavelength of peak P2. Note that the light from the LED chip 21 may include four or more peaks. Since the emission spectrum S2 of the light from the LED chip 21 has the first peak P1, the second peak P2 and the third peak P3 as described above, the light from the LED chip 21 becomes white. .

As shown in FIG. 9, let B be the radiant flux in the wavelength range of 400 nm or more and 499 nm or less, let G be the radiant flux in the wavelength range of 500 nm or more and 599 nm or less, and let R be the radiant flux in the wavelength range of 600 nm or more and 699 nm or less. Here, the radiant flux B corresponds to an integrated value (area) in the wavelength range of 400 nm or more and 499 nm or less in the emission spectrum S2 of the light from the LED chip 21 . The radiant flux G corresponds to an integrated value (area) in the wavelength range of 500 nm or more and 599 nm or less in the emission spectrum S2 of the light from the LED chip 21 . The radiant flux B corresponds to an integrated value (area) in the wavelength range of 600 nm or more and 699 nm or less in the emission spectrum S2 of the light from the LED chip 21 . Each radiant flux B, G, R can be measured in the same manner as the LED chip 21 of the first LED lighting sheet 20A.

At this time, the emission spectrum of the light emitted by the LED chips 21 of the second LED lighting sheet 20B satisfies the relationship 0.26≤B/G≤0.44. The emission spectrum preferably satisfies the relationship 0.29≦B/G≦0.41, and more preferably satisfies the relationship 0.32≦B/G≦0.38. Moreover, the emission spectrum of the light emitted by the LED chips 21 of the second LED lighting sheet 20B satisfies the relationship 0.89≦R/G≦1.17. The emission spectrum preferably satisfies the relationship 0.94≦B/G≦1.12, and more preferably satisfies the relationship 0.99≦B/G≦1.07.

By satisfying the above optical characteristics for the LED chips 21 of the second LED lighting sheet 20B, the production amount per unit area of plants can be improved. In general, the cultivation period is a stage in which the plant grows larger than the seedling-raising period, and requires more space than the seedling-raising period. According to the present embodiment, since the LED chips 21 of the second LED lighting sheet 20B satisfy the above optical characteristics, it is possible to speed up plant growth, increase the amount of plant growth, and shorten the number of days for plant growth. As a result, the yield of plants in the plant growing facility 90 can be improved. That is, since the light source color of the LED chips 21 of the second LED lighting sheet 20B is a color considered to have good photosynthetic quantum efficiency, it is possible to promote the growth of plants. As a result, the yield of plants in the plant growing facility 90 can be improved. Therefore, it is possible to shorten the growth period, which is the combination of the seedling-raising period and the cultivation period, and to dramatically improve the plant production cycle. By shortening the growing period, the plant production per unit area of the plant growing facility 90 can be improved.

(Light-reflective insulating protective film)
As shown in FIG. 7, the light-reflective insulating protective film 34 is a layer formed in a region excluding the region in which the LED chip 21 is provided and its peripheral region. The light-reflective insulating protective film 34 is a so-called resist layer that improves the migration resistance of the flexible wiring board 30 by having sufficient insulating properties. Also, the light-reflective insulating protective film 34 is a light-reflecting layer having light-reflecting properties that contributes to the improvement of the light emission brightness of the light environment created by the LED lighting sheets 20A and 20B.

The light-reflective insulating protective film 34 can be formed from various resin compositions containing a base resin such as a urethane-based resin and a white pigment made of an inorganic filler such as titanium oxide. As the base resin of the resin composition used for forming the light-reflective insulating protective film 34, in addition to urethane resin, acrylic polyurethane resin, polyester resin, phenol resin, and the like can be appropriately used. As the base resin of the resin composition forming the light-reflective insulating protective film 34, it is more preferable to use the same or similar resin as the resin composition forming the transparent protective film 35 as the base resin. As for the transparent protective film 35, it is preferable to use an acrylic polyurethane resin as a main material resin, as will be described later. From this, when the base resin of the resin composition forming the transparent protective film 35 is an acrylic polyurethane resin, the base resin of the resin composition for forming the light-reflective insulating protective film 34 is a urethane-based resin or It is more preferable to use an acrylic polyurethane resin.

Inorganic fillers to be contained as white pigments in the resin composition forming the light-reflective insulating protective film 34 include titanium oxide, alumina, barium sulfate, magnesia, aluminum nitride, boron nitride, barium titanate, kaolin, At least one selected from talc, calcium carbonate, zinc oxide, silica, mica powder, powdered glass, powdered nickel and powdered aluminum can be used.

The thickness of the light-reflective insulating protective film 34 is 5 μm or more and 50 μm or less, more preferably 7 μm or more and 20 μm or less. If the thickness of the light-reflective insulating protective film 34 is less than 5 μm, the light-reflective insulating protective film becomes thin particularly at the edge portion of the metal wiring portion 32, and if the metal wiring cannot be covered and is exposed, The risk that insulation cannot be maintained increases. On the other hand, the thickness of the light-reflective insulating protective film 34 is preferably 50 μm or less from the viewpoint of holding the light-reflective insulating protective film 34 against the curvature of the substrate during handling and transportation.

In addition, the light reflectance of the light-reflective insulating protective film 34 at wavelengths of 400 nm to 780 nm is preferably 65% or more, more preferably 70% or more, and preferably 80% or more. More preferred. In the LED lighting sheets 20A and 20B, for example, 20 parts by mass or more of titanium oxide may be contained with respect to 100 parts by mass of the base resin of urethane or acrylic polyurethane. Thereby, when the thickness of the light-reflective insulating protective film 34 is 8 μm, the light reflectance of the same layer can be made 75% or more.

(transparent protective film)
A transparent protective film 35 is formed on the outermost surfaces of the LED lighting sheets 20A and 20B so as to cover the LED chips 21 . The transparent protective film 35 has waterproofness and transparency. The waterproof property of the transparent protective film 35 can prevent water from entering the device when the LED lighting sheets 20A and 20B are used as a light source for growing plants. If the LED chip 21 is selected to have a high luminous efficiency such as 150 lm/W or more, for example, in the LED lighting sheets 20A and 20B, the damage of a specific LED chip 21 will have a greater impact. . Therefore, it is important from the viewpoint of risk management to make the LED chip 21 as hard to be damaged as possible.

The transparent protective film 35 can be formed from various resin compositions using acrylic polyurethane resin or the like as a base resin. As the base resin of the resin composition used for forming the transparent protective film 35, in addition to acrylic polyurethane resin, urethane resin, polyester resin, phenolic resin, and the like can be appropriately used. As the base resin of the resin composition forming the transparent protective film 35, it is more preferable to use the same or similar resin as the resin composition forming the light-reflective insulating protective film 34 as the base resin. As a specific preferred combination, the base resin of the resin composition forming the light-reflective insulating protective film 34 is a urethane resin, and the same resin forming the transparent protective film 35 is an acrylic polyurethane resin. can.

The thickness of the transparent protective film 35 is 10 μm or more and 40 μm or less, preferably 15 μm or more and 30 μm or less, and more preferably 20 μm or more and 25 μm or less. By setting the thickness of the transparent protective film 35 within the above range, it is possible to maintain good flexibility, thinness, and light weight of the LED lighting sheets 20A and 20B, and good optical properties required for growing plants. In addition, it is possible to provide the LED lighting sheets 20A and 20B with sufficient waterproofness required for growing plants.

The water resistance of the LED lighting sheets 20A and 20B by the transparent protective film 35 makes it possible to suppress deterioration of the LED chips 21 when water for growing plants is sprayed on the LED lighting sheets 20A and 20B. It is not particularly limited as long as it is a degree. As for such water resistance, it is preferable to exhibit IPX4 or more in the waterproof/dustproof protection standard defined by IEC (International Electrotechnical Commission). The waterproofness of IPX4 or higher is such that the LED chip 21 is not adversely affected by splashed water from all directions. Specifically, when water is sprinkled from the water nozzle at a water amount of 10 L / min for 5 minutes in the entire range of ± 180 ° with respect to the normal direction of the LED lighting sheets 20A and 20B, the LED chip 21 is adversely affected. to the extent that it does not affect

(Manufacturing method of LED lighting sheet)
Next, a method for manufacturing the LED lighting sheets 20A and 20B according to this embodiment will be described with reference to FIGS. 10(a) to 10(h).

First, the substrate film 31 is prepared (Fig. 10(a)). Next, on the surface of the substrate film 31, a metal foil 32A such as a copper foil, which is the material of the metal wiring portion 32, is laminated (FIG. 10(b)). The metal foil 32A is adhered to the surface of the substrate film 31 with an adhesive layer 33 such as a urethane-based adhesive. Alternatively, the metal foil 32A may be directly formed on the surface of the substrate film 31 by an electrolytic plating method or a vapor phase film forming method (sputtering, ion plating, electron beam deposition, vacuum deposition, chemical deposition, etc.). Alternatively, the substrate film 31 may be directly welded to the metal foil 32A.

Next, an etching mask 37 patterned into a shape required for the metal wiring portion 32 is formed on the surface of the metal foil 32A (FIG. 10(c)). The etching mask 37 is provided so that the portion corresponding to the wiring pattern of the metal foil 32A, which becomes the metal wiring portion 32, is not corroded by the etchant. The method of forming the etching mask 37 is not particularly limited, and for example, it may be formed by exposing a photoresist or dry film through a photomask and then developing it. Alternatively, an etching mask may be formed on the surface of the metal foil 32A using a printing technique such as an inkjet printer.

Next, the metal foil 32A located at the location not covered with the etching mask 37 is removed with an immersion liquid (FIG. 10(d)). As a result, portions of the metal foil 32A other than the portion that will become the metal wiring portion 32 are removed.

After that, the etching mask 37 is removed using an alkaline stripping solution. Thereby, the etching mask 37 is removed from the surface of the metal wiring portion 32 (FIG. 10(e)).

Subsequently, a light-reflective insulating protective film 34 is laminated on the metal wiring portion 32 (FIG. 10(f)). The formation of the light-reflective insulating protective film 34 is not particularly limited as long as it is a coating means capable of uniformly applying the material resin composition constituting the light-reflective insulating protective film 34. Examples include screen printing, offset printing, and the like. Methods such as dip coater and brush coating can be used. Alternatively, the light-reflective insulating protective film 34 may be formed by coating the entire surface with a photosensitive insulating protective film material, exposing only necessary portions through a photomask, and developing the film.

Next, the LED chip 21, the regulator 45, and the connectors 44A and 44B are mounted on the metal wiring portion 32 (Fig. 10(g)). In FIG. 10(g) and FIG. 10(h), which will be described later, illustration of the regulator 45 and the like is omitted for the sake of clarity. In this case, the LED chip 21 is joined to the metal wiring portion 32 by soldering via the solder portion 36 . The joining by soldering can be performed by a reflow method or a laser method, or by using a conductive resin.

Next, a transparent protective film 35 is formed so as to cover the light-reflective insulating protective film 34, the LED chip 21, the regulator 45, and the connectors 44A and 44B (FIG. 10(h)). This transparent protective film 35 is preferably formed by a method of spraying a transparent resin composition by spraying (hereinafter referred to as "spray coating method") or a method of forming by a curtain coating method. The transparent protective film 35 is formed by the spray coating method, for example, by spraying a coating liquid for spray coating containing an acrylic polyurethane resin onto a desired area on the flexible wiring board 30 with a spray coating machine to form a coating film. can be done by forming The transparent protective film 35 is formed by the curtain coating method, for example, by dropping a coating liquid for curtain coating containing an acrylic polyurethane resin onto a desired region on the flexible wiring substrate 30 using a curtain coating machine to form a coating film. can be done by forming

In addition, the LED lighting sheets 20A and 20B according to the present embodiment are not limited to the method described above. It can also be produced by a known method.

Next, the operation of this embodiment having such a configuration will be described. Specifically, a method of growing plants using the plant growing facility 90 described above will be described.

First, plants are raised using the first growing shelf 80A for the seedling raising period. At this time, plant seeds are sown in the culture medium of the first growing shelf 80A, and after germination, the plants are grown until they reach a certain size (seedling raising step). During this time, the plants are irradiated with light having a color temperature of 4500K or more and 5500K or less by the first LED lighting sheet 20A, and seedlings are raised.

When the plants reach a size suitable for planting, plant them (planting process). In this case, the plant seedlings grown on the first growing shelf 80A are transferred to the culture medium of the second growing shelf 80B for the cultivation period. After planting the plants, the first growing shelf 80A is used again to grow the next plant.

The planted plants are then continued to grow on the second growing shelf 80B for the cultivation period. At this time, the plant is grown on the second growing shelf 80B until it reaches a size suitable for harvesting (cultivating step). During this time, the plants are irradiated with light having a color temperature of 2500K or more and 3500K or less by the second LED lighting sheet 20B, and seedlings are raised.

After that, the plants grown to a certain size on the second growing shelf 80B are harvested. The second growing shelf 80B after harvesting the plants is used again to grow the next plant.

Thus, according to the present embodiment, in the plant growing facility 90, the first growing shelf 80A has the first LED lighting sheet 20A that emits light with a color temperature of 4500K or more and 5500K or less. The second growing shelf 80B has a second LED lighting sheet 20B that emits light with a color temperature of 2500K or more and 3500K or less. As a result, the plant can be grown by moving it to an optimum light source according to the growing stage of the plant. Therefore, the amount of growing plants can be increased, and the plants can be obtained with a good yield. In particular, during the seedling raising period, the first LED lighting sheet 20A irradiates the plants with light having a color temperature of 4500 K or more and 5500 K or less, and during the cultivation period, the second LED lighting sheet 20B irradiates the plants with a color temperature of 2500 K or more and 3500 K or less. of light is applied to the plants. This allows plants to grow under an appropriate light source.

According to the present embodiment, the first LED lighting sheet 20A irradiates the plant with light having a color temperature of 4500K or higher and 5500K or lower during the seedling-raising period, thereby allowing the plant to grow compactly and robustly. As a result, after the seedling-raising period is completed, it is possible to prevent the strains from collapsing when the plants are planted, and to prevent the work efficiency of planting from decreasing. In addition, by suppressing the collapse of the stock at the time of fixed planting, the growth of the plant can be prevented from stagnation. In addition, because of its compact size, it is possible to suppress overlapping of adjacent seedlings even if the seedling-raising period is extended. In addition, by irradiating the plants with light having a color temperature of 4500 K or more and 5500 K or less during the seedling-raising period, it is possible to reduce variations in the growth of the plants. As a result, the size and quality of plants to be grown can be kept within a certain standard range, and the number of nonconforming products can be reduced.

Further, according to the present embodiment, during the cultivation period, the second LED lighting sheet 20B irradiates the plants with light having a color temperature of 2500 K or more and 3500 K or less, thereby accelerating the growth of the plants and reducing the number of days for cultivating the plants. be able to. Alternatively, the yield can be increased even with the same cultivation days. Thereby, the production amount per unit area can be improved. In general, the cultivation period is a stage in which plants grow to a large size, so compared to the seedling-raising period, a large amount of space is required in the plant-growing facility. Therefore, the production cycle can be dramatically improved by increasing the ratio of seedling-raising days and decreasing the ratio of cultivation days even during the same growing period. By accelerating plant growth and reducing the number of days in the cultivation period, the production cycle of plants can be dramatically improved. Thereby, the production amount per unit area of the plant can be increased.

For example, let's consider the production efficiency of a model plant factory where the volume of the nursery space: the volume of the cultivation space = 1:6. The growing method A (seedling raising period: 24 days, cultivation period: 9 days) and the raising method B (seedling raising period: 26 days, cultivation period: 7 days) are assumed to yield the same yield. In that case, the volume ratio required for harvesting is A:B = (1 x 24 + 6 x 9): (1 x 26 + 6 x 7), so A:B = 1.14: 1. By extending the seedling raising period by 2 days and reducing the cultivation period by 2 days, the production efficiency was improved by 14%. In other words, even if the cultivation period is the same, production efficiency is dramatically improved by reducing the ratio of cultivation days.

In the plant growing facility 90 according to the present embodiment, the emission spectrum of the light emitted from the first LED lighting sheet 20A is 0.54≦B/G≦0.72 and 0.59≦R/G≦0. .77. The emission spectrum of the light emitted from the second LED lighting sheet 20B satisfies the relationships of 0.26≦B/G≦0.44 and 0.89≦R/G≦1.17. As a result, during the seedling raising period, the plants can be grown compactly and robustly, and it is possible to prevent the work efficiency of fixed planting from deteriorating. In addition, during the cultivation period, by accelerating the growth of plants and reducing the number of days for plant cultivation, the production amount of plants per unit area can be improved.

Further, according to the present embodiment, since the thickness of the thickest portions of the LED lighting sheets 20A and 20B is 5 mm or less, the distance between the upper and lower substrates 81 of the plant growing shelves 80A and 80B is reduced, and the number of substrates 81 is reduced. can increase the plant yield per unit area.

In addition, in the present embodiment described above, the case where the LED lighting device is a planar light source sheet has been described, but the present invention is not limited to this. For example, although not shown, the LED lighting device may be a straight tube lighting device.

Also, as shown in FIGS. 11A and 11B, the LED lighting sheets 20A and 20B may be arranged not only on the bottom surface of the substrate 81 but also on the side surfaces of the substrate 81. The LED lighting sheets 20A and 20B on the side faces hang down from the substrate 81 located above toward the substrate 81 located below the substrate 81 concerned. In this case, as shown in FIG. 11A, the LED lighting sheets 20A and 20B may reach the substrate 81 located below. Alternatively, as shown in FIG. 11B, the LED lighting sheets 20A and 20B may cover only the upper side of the space located between the upper and lower substrates 81 without reaching the substrates 81 located below. In this way, by further arranging the LED lighting sheets 20A and 20B on the side surface of the substrate 81, the amount of light at the periphery of the substrate 81, which tends to be weak, is compensated for, and the brightness of the LED lighting sheets 20A and 20B is increased in the plane. can be made uniform. As a result, the plant can grow uniformly in the plane, and the yield of the grown plant can be improved.

[Example]
Next, a specific example of this embodiment will be described.

(Creation of LED lighting sheet)
LED lighting sheet A, LED lighting sheet B, and LED lighting sheet C were produced as follows. Of these, the LED lighting sheet A emits light with a color temperature of 3000K, the LED lighting sheet B emits light with a color temperature of 4000K, and the LED lighting sheet C emits light with a color temperature of 5000K. is.

(LED lighting sheet A: 3000K)
On one surface of a 560 mm × 390 mm size film substrate (polyethylene naphthalate, thickness 50 μm), a copper foil (thickness 35 μm) for forming a metal wiring part is laminated, and then the copper foil for metal wiring An etching treatment was performed to form a metal wiring portion. Then, on the substrate film and the metal wiring portion, a 10 μm-thick ink is formed by screen printing using an insulating ink obtained by using a urethane-based resin as a base resin and adding titanium oxide at a rate of 20% by mass with respect to the base resin. A light-reflective insulating protective film was formed. Next, on the metal wiring portion, a plurality of LED chips ("NFSW757G-V2" (manufactured by Nichia Corporation)) are arranged in 10 rows of 14 rows at a pitch of 40 mm in the X direction and a pitch of 35 mm in the Y direction. Mounted by soldering. This LED chip is a top emission type light emitting element, and has a rectangular parallelepiped shape of 3.0 mm (length)×3.0 mm (width)×0.65 mm (height). The light source color of these LED chips is the color of an incandescent bulb, and the color temperature of each is 3000K. Furthermore, a transparent protective film covering the insulating protective film and the LED chip was formed by a spray coating method. The LED lighting sheet produced as described above was designated as LED lighting sheet A. The color temperature of the light emitted by this LED lighting sheet A was 3000K. Let B be the radiant flux in the wavelength range from 400 nm to 499 nm, G be the radiant flux in the wavelength range from 500 nm to 599 nm, and R be the radiant flux in the wavelength range from 600 nm to 699 nm. At this time, the emission spectrum of the light emitted by the LED lighting sheet A satisfied the relationships of B/G=0.348 and R/G=1.031.

(LED lighting sheet B: 4000K)
An LED lighting sheet produced in the same manner as LED lighting sheet A, except that an LED chip with a color temperature of 4000 K ("NFSW757G-V2" (manufactured by Nichia Corporation)) was used. B. The emission spectrum of the light emitted by this LED lighting sheet B satisfied the relationships of B/G=0.494 and R/G=0.815.

(LED lighting sheet C: 5000K)
An LED lighting sheet produced in the same manner as LED lighting sheet A, except that an LED chip with a color temperature of 5000 K ("NFSW757G-V2" (manufactured by Nichia Corporation)) was used. C. The emission spectrum of the light emitted by this LED lighting sheet C satisfied the relationships of B/G=0.631 and R/G=0.683.

The optical properties of the three types of LED lighting sheet A, LED lighting sheet B, and LED lighting sheet C are as follows.

(Influence of color temperature during seedling raising period)
Next, the influence of the color temperature of the light emitted from the LED lighting sheet during the seedling-raising period was investigated as follows.

(Example 1)
A plant (leaf lettuce) was grown using LED lighting sheet C (5000K) during the seedling raising period and using LED lighting sheet A (3000K) during the cultivation period. During this period, the LED lighting sheet C (5000K) and the LED lighting sheet A (3000K) were first placed on the growing shelf for the seedling raising period and the growing shelf for the cultivation period, respectively. Then, plant (leaf lettuce) seeds were sown on a growing shelf for the seedling raising period, and the seedling raising period was completed 24 days after the sowing. Next, the plants were planted on the cultivating shelves for the cultivation period, and the plants were continuously cultivated using the cultivating racks for the cultivation period. Plants were then harvested 34 days after sowing.

(Comparative example 1)
Plants were grown and harvested in the same manner as in Example 1, except that LED lighting sheet B (4000K) was used during the seedling raising period and LED lighting sheet A (3000K) was used during the cultivation period.

(Comparative example 2)
Plants were grown and harvested in the same manner as in Example 1, except that the LED lighting sheet A (3000K) was used during the seedling raising period and the LED lighting sheet A (3000K) was used during the cultivation period.

For each of Example 1, Comparative Example 1, and Comparative Example 2, the leaf thickness (μm) at the time of planting, the fresh weight (g) of the plant at the time of planting, and the plant height (cm) at the time of planting were measured. (See FIG. 12). In addition, the fresh weight (g) of the plants was measured and compared on the 24th day (at the time of planting), 27th day, 31st day, and 34th day (at the time of harvesting) after seeding (see FIG. 13). The fresh weight was calculated by measuring the fresh weight of the above-ground part of the plant for each strain and averaging the results. Table 2 shows the above-ground fresh weight of plants at the time of harvest and the variation (standard deviation) of the above-ground fresh weight of the plants at the time of harvest.

As shown in FIG. 12, the plant of Example 1 had the smallest fresh weight and plant height at the time of planting, followed by the plant of Comparative Example 1, and the plant of Comparative Example 2 was the largest. On the other hand, the thickness of the leaves at the time of planting was the thickest in the plant of Example 1, the thickest in the plant of Comparative Example 2, and the thinnest in the plant of Comparative Example 1. Thus, by using the LED lighting sheet C (5000K) during the seedling-raising period, the plants could be grown into compact and strong seedlings.

　As shown in Fig. 13 and Table 2, the fresh weight at the time of harvest did not differ significantly among the plants of Example 1, Comparative Example 1, and Comparative Example 2. In this way, by using the LED lighting sheet C (5000K) during the seedling raising period, even if the fresh weight is small at the time of planting, the use of the LED lighting sheet A (3000K) during the cultivation period allows the plant to grow. was able to promote

Also, as shown in Table 2 above, the variation in fresh weight at the time of harvest was the smallest for the plant of Example 1, followed by the second smallest for the plant of Comparative Example 1, and the largest for the plant of Comparative Example 2. Thus, by using the LED lighting sheet C (5000K) during the seedling-raising period, it was possible to reduce the variation in fresh weight at the time of harvesting.

(Influence of color temperature during cultivation period)
Next, the influence of the color temperature of the light emitted from the LED lighting sheet during the cultivation period was investigated as follows.

(Example 2)
Similar to Example 1 described above, a plant (leaf lettuce) was actually raised using the LED lighting sheet C (5000K) during the seedling raising period and using the LED lighting sheet A (3000K) during the cultivation period.

(Comparative Example 3)
Plants were grown and harvested in the same manner as in Example 2 except that LED lighting sheet C (5000K) was used during the seedling raising period and LED lighting sheet B (4000K) was used during the cultivation period.

(Comparative Example 4)
Plants were grown and harvested in the same manner as in Example 2 except that the LED lighting sheet C (5000K) was used during the seedling raising period and the LED lighting sheet C (5000K) was used during the cultivation period.

For Example 2, Comparative Example 3, and Comparative Example 4, the fresh weight (g) of the plants was measured and compared on days 24 (at the time of planting), 27 days, 31 days, and 34 days (at the time of harvest) after seeding. (See FIG. 14). The fresh weight was calculated by measuring the fresh weight of the above-ground part of the plant for each strain and averaging the results. Table 3 shows the above-ground fresh weight of the plants at harvest.

　As shown in Fig. 14 and Table 3, the fresh weight at the time of harvest was the largest for the plant of Example 2, the second largest for the plant of Comparative Example 3, and the smallest for the plant of Comparative Example 4. Thus, by using the LED lighting sheet A (3000K) during the cultivation period, the growth of plants could be promoted.

(Change in live weight when the cultivation period is shortened)
Next, the effect of shortening the cultivation period on the fresh weight of plants was investigated as follows.

(Example 3)
A plant (leaf lettuce) was grown using LED lighting sheet C (5000K) during the seedling raising period and using LED lighting sheet A (3000K) during the cultivation period. At this time, first, the LED lighting sheet C (5000K) and the LED lighting sheet A (3000K) were placed on the growing shelf for the seedling raising period and the growing shelf for the cultivation period, respectively. The plants (leaf lettuce) were then sown in growing racks for the growing period. Next, the plants were planted on the cultivating shelves for the cultivation period, and the plants were continuously cultivated using the cultivating racks for the cultivation period.

(Comparative Example 5)
Plants were grown and harvested in the same manner as in Example 3, except that the LED lighting sheet C (5000K) was used during the seedling raising period and the LED lighting sheet C (5000K) was used during the cultivation period.

(Comparative Example 6)
Plants were grown and harvested in the same manner as in Example 3, except that the LED lighting sheet A (3000K) was used during the seedling raising period and the LED lighting sheet A (3000K) was used during the cultivation period.

The plants of Example 3 were cultivated at 3 levels (level 1 to level 3) by changing the number of days of the seedling raising period and the cultivation period. That is, in Level 1, the seedling raising period was set to 24 days, and the cultivation period was set to 9 days (33 days for the growing period). For Level 2, the seedling raising period was 25 days and the cultivation period was 8 days (33 days of growing period). For Level 3, the seedling raising period was 26 days and the cultivation period was 7 days (33 days of growing period). In addition, the plant of Comparative Example 5 was cultivated with a seedling raising period of 24 days and a cultivation period of 9 days (33 days of cultivation period). For Example 3 (Levels 1 to 3) and Comparative Example 5, the fresh weight (g) of the plants at harvest was measured and compared. In addition, for each of Example 3 (Levels 1 to 3) and Comparative Example 6, the projected leaf area (pixels (px)) of plants at the time of planting was measured and compared. The results are shown in Table 4.

As shown in Table 4, the live weight of the plants of Example 3 (levels 1 to 3) at the time of harvest was greater than that of the plants of Comparative Example 5. Moreover, between levels 1 to 3 in Example 3, the live weight did not change significantly. Thus, when the LED lighting sheet A (3000K) was used during the cultivation period, a similar yield could be obtained even if the cultivation period was shortened. In addition, it can be seen that the plants of Example 3 (levels 1 to 3) have reduced variation in fresh weight compared to the plants of Comparative Example 6. Thus, it can be seen that when the LED lighting sheet C (5000K) is used during the cultivation period, variations in plant growth can be reduced. In addition, the projected leaf area at the time of planting was smaller in the plants of Example 3 (levels 1 to 3) than in the plants of Comparative Example 6. That is, it was found that by using the LED lighting sheet C (5000K) during the seedling-raising period, the seedlings can be made compact, and therefore the number of seedling-raising days can be extended.

It is also possible to appropriately combine a plurality of constituent elements disclosed in the above embodiments and modifications as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiments and modifications.

Claims (12)

1. A plant growing facility having a first growing area and a second growing area,
   The first growth region has a first lighting device that emits light having a color temperature of 4500K or more and 5500K or less,
   A plant growing facility, wherein the second growing area has a second lighting device that emits light having a color temperature of 2500K or more and 3500K or less.
2. Let B be the radiant flux in the wavelength range of 400 nm or more and 499 nm or less,
   Let G be the radiant flux in the wavelength range of 500 nm or more and 599 nm or less,
   When the radiant flux in the wavelength range of 600 nm or more and 699 nm or less is R,
   The emission spectrum of the light emitted by the first lighting device satisfies the relationships 0.54 ≤ B/G ≤ 0.72 and 0.59 ≤ R/G ≤ 0.77,
   2. The emission spectrum of the light emitted by the second lighting device according to claim 1, satisfying the relationships of 0.26≦B/G≦0.44 and 0.89≦R/G≦1.17. plant growing facility.
3. The first lighting device is a lighting device for raising seedlings,
   The plant growing facility according to claim 1 or 2, wherein said second lighting device is a lighting device for cultivation.
4. A method for cultivating a plant,
   A seedling raising step of illuminating the plant with light having a color temperature of 4500 K or more and 5500 K or less;
   and a cultivation step of illuminating the plant with light having a color temperature of 2500K or more and 3500K or less.
5. Let B be the radiant flux in the wavelength range of 400 nm or more and 499 nm or less,
   Let G be the radiant flux in the wavelength range of 500 nm or more and 599 nm or less,
   When the radiant flux in the wavelength range of 600 nm or more and 699 nm or less is R,
   The emission spectrum of light used in the seedling raising step satisfies the relationships of 0.54 ≤ B/G ≤ 0.72 and 0.59 ≤ R/G ≤ 0.77,
   Cultivation of the plant according to claim 4, wherein the emission spectrum of the light used in the cultivation step satisfies the relationships of 0.26 ≤ B/G ≤ 0.44 and 0.89 ≤ R/G ≤ 1.17. Method.
6. The plant cultivation method according to claim 4 or 5, comprising a fixed planting step of planting the plant between the seedling raising step and the cultivation step.
7. An LED lighting device for growing plants, in which a plurality of LED chips are arranged,
   The color temperature of the light from the LED chip is 4500K or more and 5500K or less,
   Let B be the radiant flux in the wavelength range of 400 nm or more and 499 nm or less,
   Let G be the radiant flux in the wavelength range of 500 nm or more and 599 nm or less,
   When the radiant flux in the wavelength range of 600 nm or more and 699 nm or less is R,
   An LED lighting device for growing plants, wherein the emission spectrum of the light emitted from the LED chip satisfies the relationships of 0.54≦B/G≦0.72 and 0.59≦R/G≦0.77.
8. The thickness at the thickest part is 5 mm or less,
   8. The LED lighting device for growing plants according to claim 7, comprising a substrate film and a metal wiring portion formed on the surface of said substrate film, wherein said plurality of LED chips are mounted on said metal wiring portion. .
9. The LED lighting device for growing plants according to claim 7 or 8, which is a lighting device for growing seedlings.
10. A shelf board for growing plants,
    a substrate;
    A shelf board for a plant growing shelf, comprising the LED lighting device for plant growing according to any one of claims 7 to 9 attached to the substrate.
11. A plant growing shelf,
    Equipped with a shelf board,
    10. A plant growing shelf comprising the LED lighting device for plant growing according to any one of claims 7 to 9, wherein the shelf board is attached to the lower surface side of a substrate.
12. 12. The plant growing shelf according to claim 11, wherein said plant growing LED lighting device is further arranged on a side surface of said shelf board.
    

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