Illumination device

Abstract

To achieve both a reduction in power consumption and an increase in yield.SOLUTION: An illumination device 10 includes a light source 110 for emitting light for plant growth. The light for plant growth includes red light in the range of 610 nm or more and 680 nm or less and far-red light in the range of 685 nm or more and 780 nm or less. The ratio of far-red light irradiance to red light irradiance is 0.94 or more and 2.06 or less.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a lighting device. [Background technology]

[0002] Patent Documents 1 to 3 disclose lighting cultivation methods that utilize red light and far-red light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-46575 [Patent Document 2] JP 2012-39901 A [Patent Document 3] JP 2012-165665 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a lighting device that can achieve both reduced power consumption and improved harvest yield. [Means for solving the problem]

[0005] An illumination device according to one aspect of the present invention includes a light source unit that irradiates light for growing plants, the light including red light in the range of 610 nm or more and 680 nm or less and far-red light in the range of 685 nm or more and 780 nm or less, and a ratio of irradiance of the far-red light to the red light is 0.94 or more and 2.06 or less. Effect of the Invention

[0006] According to the lighting device of the present invention, it is possible to achieve both a reduction in power consumption and an increase in harvest yield. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of an illuminated cultivation system according to an embodiment. [Diagram 2] FIG. 2 is a partially cutaway perspective view of the lighting device according to the embodiment. [Diagram 3] FIG. 3 is a diagram illustrating a spectral distribution of light emitted from the lighting device according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing a spectral distribution of light emitted from the lighting device according to the second embodiment. [Diagram 5] FIG. 5 is a diagram showing the spectral distribution of light emitted from the lighting device according to Comparative Example 1. As shown in FIG. [Figure 6] FIG. 6 is a diagram showing the ratio of irradiance from the lighting devices according to Examples 1 and 2 and Comparative Example 1. In FIG. [Figure 7] FIG. 7 is a diagram for explaining the experimental conditions for cultivation under electric light. [Figure 8] FIG. 8 is a graph showing strawberry harvest yields by month. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the following, a lighting device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement and connection forms of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not described in the independent claims will be described as optional components.

[0009] In addition, each figure is a schematic diagram and is not necessarily illustrated precisely. Therefore, for example, the scales in each figure do not necessarily match. In addition, in each figure, substantially the same configurations are given the same reference numerals, and duplicated explanations are omitted or simplified.

[0010] In addition, in this specification, terms indicating the shape of elements and numerical ranges are not expressions that only express a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

[0011] In addition, in this specification, ordinal numbers such as "first" and "second" do not refer to the number or order of components, unless otherwise specified, but are used for the purpose of avoiding confusion between and distinguishing between components of the same type.

[0012] (Embodiment) [Lighted cultivation system] First, an overview of an illuminated cultivation system 1 according to the present embodiment will be described with reference to FIG.

[0013] The electric lighting cultivation system 1 shown in Fig. 1 is a system for cultivating a plant 2 by irradiating the plant 2 with light. The growth of the plant 2 can be promoted and / or inhibited by the light, and the harvest time and yield can be adjusted.

[0014] The plant 2 may be an edible plant such as a vegetable or fruit, an ornamental plant, or an industrial plant. For example, the plant 2 may be a strawberry. Alternatively, the plant 2 may be a chrysanthemum.

[0015] The electric cultivation system 1 is used in greenhouses such as vinyl greenhouses or plastic greenhouses, plant factories, etc. The electric cultivation system 1 cultivates a plurality of plants 2 planted in a greenhouse, for example. As shown in FIG. 1, the electric cultivation system 1 includes a plurality of lighting devices 10.

[0016] Each of the lighting devices 10 can emit light for growing the plant 2. The lighting devices 10 emit light toward different illumination ranges (which may partially overlap). Each of the lighting devices 10 is connected to a power source (not shown) by a power supply wiring (e.g., a cable), and emits light using power supplied from the power source via the power supply wiring.

[0017] [Lighting equipment] Next, a specific configuration of the lighting device 10 will be described with reference to FIG.

[0018] 2 is a partially cutaway perspective view of lighting device 10 according to the present embodiment. Specifically, it shows a state in which a portion of globe 13 is cut away. As shown in FIG. 2, lighting device 10 is a light bulb-type lamp, and includes light bulb-type housing 11. Lighting device 10 also includes a light source unit 110 and a control unit 130.

[0019] The light bulb-shaped housing 11 houses the light source unit 110 and the control unit 130. As shown in Fig. 2, the light bulb-shaped housing 11 includes a main body housing 12, a globe 13, and a base 14. The main body housing 12, the globe 13, and the base 14 are combined with each other to form an outer housing of the lighting device 10 (light bulb-shaped housing 11).

[0020] The main body housing 12 has a truncated conical cylindrical shape with an opening area that gradually decreases from the globe 13 side to the base 14 side. The control unit 130 is housed inside the main body housing 12. The main body housing 12 is formed, for example, using a metal material and has high thermal conductivity. Therefore, the main body housing 12 also functions as a heat sink that dissipates heat generated by the light source unit 110.

[0021] The globe 13 is a light-transmitting cover that covers the light source units 110. The globe 13 is configured to extract the light emitted from each of the light source units 110 to the outside of the lamp. The globe 13 is a hollow member having an opening, and has a shape in which the top part opposite the opening is closed. The globe 13 is, for example, a hollow rotating body with the lamp axis as its axis, and is configured to have a narrowed opening in a substantially hemispherical shape, but is not limited to this. The edge of the opening of the globe 13 is fixed to the main body housing 12 with an adhesive. The adhesive is, for example, silicone resin or the like.

[0022] The globe 13 may be made of a light-transmitting material such as a glass material, such as silica glass, or a resin material, such as acrylic (PMMA) or polycarbonate (PC). The globe 13 may be subjected to a diffusion treatment for diffusing light. For example, a light diffusion film (light diffusion layer), or a plurality of light diffusion dots or minute irregularities may be formed on the inner or outer surface of the globe 13. Alternatively, the globe 13 may be made of a transparent (clear) material so that the inside can be seen.

[0023] The base 14 is a power receiving unit that receives power from an external power source to make the light source unit 110 emit light. The base 14 is attached to, for example, a socket of a lighting fixture. The base 14 supplies the power received via the socket to the control unit 130 via a lead wire (not shown). In this embodiment, the base 14 is a screw-in type Edison type base (E base), such as E26, E17, or E16. Alternatively, the base 14 may be a plug-in type base.

[0024] The light source unit 110 emits light for growing the plant 2. The light includes red light and far-red light. In this specification, red light refers to the entire wavelength range of 610 nm to 680 nm in the spectral spectrum. Far-red light refers to the entire wavelength range of 685 nm to 780 nm in the spectral spectrum.

[0025] As shown in FIG. 2, the light source unit 110 includes a plurality of red light emitting elements 112, a plurality of far-red light emitting elements 114, and a substrate .

[0026] The red light emitting element 112 is a light emitting element that emits red light. The red light emitting element 112 is, for example, but not limited to, an LED (Light Emitting Diode). The red light emitting element 112 may be a laser element or an organic EL (Electroluminescence) element.

[0027] For example, the red light emitting element 112 emits narrowband light having a peak emission intensity in the range of 610 nm to 680 nm. The "narrowband light" is, for example, light having a half-width of 60 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less, or 10 nm or less. Alternatively, the red light emitting element 112 may emit broad light having an intensity equal to or greater than a predetermined intensity over the entire range of 610 nm to 680 nm. Note that the intensity equal to or greater than a predetermined intensity may be 50% or more, 40% or more, 30% or more, or 20% or more of the maximum intensity.

[0028] The far-red light emitting element 114 is a light emitting element that emits far-red light. The far-red light emitting element 114 is, for example, an LED, but is not limited to this. The far-red light emitting element 114 may be a laser element or an organic EL element.

[0029] For example, the far-red light emitting element 114 emits narrow-band light having a peak emission intensity in the range of 685 nm to 780 nm, or alternatively, the far-red light emitting element 114 may emit broad light having an intensity equal to or greater than a predetermined intensity over the entire range of 685 nm to 780 nm.

[0030] The light source unit 110 may include a filter disposed on the light emission side of the red light emitting element 112, which removes at least one of light less than 610 nm and light greater than 680 nm. The light source unit 110 may also include a filter disposed on the light emission side of the far-red light emitting element 114, which removes at least one of light less than 685 nm and light greater than 780 nm.

[0031] The substrate 116 is a substrate on which the red light emitting elements 112 and the far-red light emitting elements 114 are mounted. The substrate is, for example, a printed wiring board, and includes wiring that electrically connects the multiple red light emitting elements 112 and the far-red light emitting elements 114. The wiring is, for example, a pattern wiring formed using a metal such as copper.

[0032] In this embodiment, the multiple red light emitting elements 112 and the multiple far-red light emitting elements 114 are evenly arranged on one or more circumferences. The one or more circumferences are, for example, multiple circumferences having a common center (i.e., concentric circles), but are not limited to this. In Fig. 2, for example, the multiple red light emitting elements 112 and the multiple far-red light emitting elements 114 are arranged along two imaginary circumferences that form concentric circles.

[0033] An example of an even arrangement on a circumference is an arrangement in which the red light emitting elements 112 and the far-red light emitting elements 114 are arranged in point symmetry or rotation symmetry with the center of the circle as an axis. For example, FIG. 2 shows an example in which the red light emitting elements 112 and the far-red light emitting elements 114 are arranged in four-fold symmetry. This can reduce the bias in the arrangement of the red light emitting elements 112 and the far-red light emitting elements 114 when the substrate 116 is viewed in a plane, and can suppress the bias in the illuminance distribution of the red light and the far-red light. The arrangement of the red light emitting elements 112 and the far-red light emitting elements 114 is not particularly limited. The lighting device 10 may also include an optical element such as a lens that controls light distribution.

[0034] The control unit 130 controls the turning on and off of the light source unit 110. The control unit 130 includes a lighting circuit unit that supplies power from a power source (not shown) to the light source unit 110. The lighting circuit unit is configured, for example, by a substrate and a plurality of circuit elements mounted on the substrate. The plurality of circuit elements include at least one of an integrated circuit (IC) element, a resistor, a diode, a transistor, a transformer, a coil, a capacitor, etc. By electrically connecting the plurality of circuit elements, an AC / DC converter, a boost circuit, a step-down circuit, etc. are configured, and power can be supplied to each of the plurality of red light emitting elements 112 and the plurality of far-red light emitting elements 114.

[0035] The control unit 130 may include a microcontroller for control. The microcontroller includes, for example, a non-volatile memory in which a program is stored, a volatile memory which is a temporary storage area for executing the program, an input / output port, a processor for executing the program, and the like. The control unit 130 may also be a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor in which the connections and settings of circuit cells in an LSI are reconfigurable. At least a part of the functions executed by the control unit 130 may be realized by software or hardware.

[0036] In this embodiment, the control unit 130 simultaneously turns on and off all of the multiple red light emitting elements 112 and the multiple far-red light emitting elements 114. That is, the light emitting time (on time) and the off time of each of the red light emitting elements 112 and the far-red light emitting elements 114 are the same. The plant 2 is irradiated with red light and far-red light simultaneously for the same period. Note that the control unit 130 may independently control the red light emitting elements 112 and the far-red light emitting elements 114.

[0037] [Growing light] Next, characteristics of the light for growing the plant 2 emitted by the above-mentioned lighting device 10 will be described along with specific examples.

[0038] As described above, the light for cultivation contains red light in the range of 610 nm to 680 nm, and far-red light in the range of 685 nm to 780 nm. The red light can suppress dormancy of the plant 2 and promote its growth. On the other hand, the red light suppresses the flower bud differentiation of the plant 2, which causes a problem of delaying flowering and fruit formation, and delaying the harvest time. In contrast, the far-red light can cancel the effect of suppressing flower bud differentiation caused by the red light. Therefore, by containing red light and far-red light at an appropriate irradiance ratio, the light for cultivation can be effectively illuminated in accordance with the input power, and it is possible to achieve both reduced power consumption and improved harvest yield.

[0039] Specifically, the ratio of the irradiance of the far-red light to the red light is 0.94 or more and 2.06 or less. The ratio of the irradiance of the far-red light to the red light is expressed by the irradiance of the far-red light contained in the light for growth irradiated by the lighting device 10 when the irradiance of the red light contained in the light for growth irradiated by the lighting device 10 is set to 1. Hereinafter, the ratio of the irradiance of the far-red light to the red light is referred to as the "FR / R ratio". The FR / R ratio may be greater than 1. That is, the irradiance of the far-red light may be greater than the irradiance of the red light. This allows the yield to be improved at an appropriate harvest time. Alternatively, the FR / R ratio may be 1.1 or more, 1.2 or more, 1.5 or more, or 1.8 or more.

[0040] The irradiance of red light is 0.085 W / m 2 That's all. The irradiance of far-red light is 0.093 W / m 2 Thus, the irradiance of each of the red light and the far-red light is about 0.1 W / m 2 or more, it is particularly useful for the illumination cultivation of strawberries.

[0041] The irradiance of each of the red light and the far-red light is represented by the area in a spectral distribution diagram of the light for growth (the horizontal axis represents the wavelength, and the vertical axis represents the spectral irradiance). Specifically, the irradiance of the red light is the area in the range of 610 nm to 680 nm, which corresponds to the range represented by the diagonal shading in Figures 3 to 5, for example. The irradiance of the far-red light is the area in the range of 685 nm to 780 nm, which corresponds to the range represented by the dot shading in Figures 3 to 5, for example.

[0042] 3 and 4 are spectral distribution diagrams of light irradiated from the lighting devices according to Examples 1 and 2. FIG. 5 is a spectral distribution diagram of light irradiated from the lighting device according to Comparative Example 1. Specifically, FIGS. 3 to 5 show the spectrum of light from lighting devices designed with target values ​​of FR / R ratios of 1.8, 1.0, and 0.5, respectively. The FR / R ratio can be varied by adjusting the ratio in number, type, and / or amount of power supplied of the red light emitting elements 112 and far-red light emitting elements 114 included in the light source unit 110.

[0043] As shown in Fig. 3 and Fig. 4, the light for growth from the lighting devices according to Examples 1 and 2 both have a first peak P1 and a second peak P2 at which the spectral irradiance is a maximum value. The peak wavelength of the first peak P1 (the wavelength at which the spectral irradiance is a maximum value) is 610 nm or more and 680 nm or less. The peak wavelength of the second peak P2 is 685 nm or more and 780 nm or less. In the spectrum of the light for growth according to Examples 1 and 2, a valley of the spectral irradiance exists between the first peak P1 and the second peak P2.

[0044] Specifically, in the light for growth according to Example 1, the peak wavelength of the first peak P1 is 620 nm or more and 660 nm or less, but may be 640 nm or more and 650 nm or less. In the example shown in FIG. 3, the peak wavelength of the first peak P1 is about 645 nm.

[0045] In addition, in the case of the light for growth according to Example 1, the spectral irradiance at the peak wavelength of the first peak P1 (first peak spectral irradiance) was about 11 mW m -2 nm -1 Approximately 14mW m -2 nm -1 Less than 12mW m -2 nm -1 Approximately 13mW m -2 nm -1 In the example shown in FIG. 3, the first peak spectral irradiance is about 12.7 mW m -2 nm -1 It is.

[0046] In the light for growth according to the first embodiment, the peak wavelength of the second peak P2 is 720 nm or more and 760 nm or less, but may be 740 nm or more and 750 nm or less. In the example shown in FIG. 3, the peak wavelength of the second peak P2 is about 745 nm.

[0047] In addition, in the light for growth according to Example 1, the spectral irradiance at the peak wavelength of the second peak P2 (second peak spectral irradiance) is greater than the first peak spectral irradiance. Specifically, the second peak spectral irradiance is about 16 mW m -2 nm -1 Approximately 20mW m -2 nm -1 Less than 17mW m -2 nm -1 Approximately 18mW m -2 nm -1 In the example shown in FIG. 3, the second peak spectral irradiance is about 17.8 mW m -2 nm -1 It is.

[0048] In the light for growth according to Example 1, the ratio of the second peak spectral irradiance to the first peak spectral irradiance is 1 or more and 2 or less, but may be 1.1 or more and 1.8 or less, or may be 1.3 or more and 1.6 or less. In the example shown in Fig. 3, the ratio of the second peak spectral irradiance to the first peak spectral irradiance is about 1.4.

[0049] The minimum wavelength of the valley between the first peak P1 and the second peak P2 in the light for growth according to the first embodiment (the wavelength at which the spectral irradiance is at its minimum) is 660 nm or more and 700 nm or less, but may be 670 nm or more and 690 nm or less. In the example shown in FIG. 3, the minimum wavelength is about 680 nm.

[0050] In addition, in the case of the light for growth according to Example 1, the spectral irradiance at the minimum wavelength of the valley between the first peak P1 and the second peak P2 (minimum spectral irradiance) is about 1 mW m -2 nm -1 Approximately 4 mW m -2nm -1 Less than 2mW m -2 nm -1 Approximately 3mW m -2 nm -1 In the example shown in FIG. 3, the minimum spectral irradiance is about 2.8 mW m -2 nm -1 It is.

[0051] In the light for growing according to the first embodiment, the ratio of the minimum spectral irradiance to the first peak spectral irradiance is 0.1 or more and 0.5 or less, but may be 0.4 or less, or may be 0.3 or less. In the example shown in FIG. 3, the ratio of the minimum spectral irradiance to the first peak spectral irradiance is about 0.2.

[0052] In addition, the spectral irradiance of the light for growth in Example 1 at a wavelength of 610 nm is approximately 2 mW m -2 nm -1 More than approximately 6mW m -2 nm -1 Less than 3mW m -2 nm -1 Approximately 5mW m -2 nm -1 In the example shown in FIG. 3, the spectral irradiance at a wavelength of 610 nm is approximately 4.3 mW m -2 nm -1 It is.

[0053] In the light for growth according to the first embodiment, the ratio of the spectral irradiance at a wavelength of 610 nm to the first peak spectral irradiance is 0.2 or more and 0.6 or less, but may be 0.5 or less, or may be 0.4 or less. In the example shown in Fig. 3, the ratio of the spectral irradiance at a wavelength of 610 nm to the first peak spectral irradiance is about 0.35.

[0054] In addition, the spectral irradiance of the light for growth in Example 1 at a wavelength of 780 nm is approximately 3 mW m -2 nm -1 Less than 2mW m -2 nm -1In the example shown in FIG. 3, the spectral irradiance at a wavelength of 780 nm is approximately 1.3 mW m -2 nm -1 It is.

[0055] In the light for growth according to the first embodiment, the ratio of the spectral irradiance at a wavelength of 780 nm to the second peak spectral irradiance is 0.0 or more and 0.3 or less, but may be 0.2 or less, or may be 0.1 or less. In the example shown in Fig. 3, the ratio of the spectral irradiance at a wavelength of 780 nm to the second peak spectral irradiance is about 0.07.

[0056] 4, in the light for growth according to Example 2, the peak wavelength of the first peak P1 is 620 nm or more and 660 nm or less, but may be 640 nm or more and 650 nm or less. In the example shown in FIG. 4, the peak wavelength of the first peak P1 is about 640 nm.

[0057] In addition, in the case of the light for growth according to Example 2, the spectral irradiance at the peak wavelength of the first peak P1 (first peak spectral irradiance) was about 12 mW m -2 nm -1 Approximately 15mW m -2 nm -1 Less than 13mW m -2 nm -1 Approximately 14mW m -2 nm -1 In the example shown in FIG. 4, the first peak spectral irradiance may be about 13.2 mW m -2 nm -1 It is.

[0058] In the light for growth according to Example 2, the peak wavelength of the second peak P2 is 720 nm or more and 760 nm or less, but may be 740 nm or more and 750 nm or less. In the example shown in FIG. 4, the peak wavelength of the second peak P2 is about 740 nm.

[0059] In addition, in the light for growth according to Example 2, the spectral irradiance at the peak wavelength of the second peak P2 (second peak spectral irradiance) is smaller than the first peak spectral irradiance. Specifically, the second peak spectral irradiance is about 8 mW m -2 nm -1 More than approximately 10mW m -2 nm -1 Less than 9mW m -2 nm -1 Approximately 11mW m -2 nm -1 In the example shown in FIG. 4, the second peak spectral irradiance is about 9.5 mW m -2 nm -1 It is.

[0060] In the light for growth according to Example 2, the ratio of the second peak spectral irradiance to the first peak spectral irradiance is 0.5 or more and 1 or less, but may be 0.6 or more and 0.9 or less, or may be 0.7 or more and 0.8 or less. In the example shown in Fig. 4, the ratio of the second peak spectral irradiance to the first peak spectral irradiance is about 0.72.

[0061] The minimum wavelength of the valley between the first peak P1 and the second peak P2 in the light for growth according to the second embodiment (the wavelength at which the spectral irradiance is at its minimum) is 660 nm or more and 700 nm or less, but may be 670 nm or more and 690 nm or less. In the example shown in FIG. 4, the minimum wavelength is about 685 nm.

[0062] In addition, in the case of the light for growth according to Example 2, the spectral irradiance at the minimum wavelength of the valley between the first peak P1 and the second peak P2 (minimum spectral irradiance) is about 1 mW m -2 nm -1 Approximately 4 mW m -2 nm -1 Less than 2mW m -2 nm -1 Approximately 3mW m -2 nm -1 In the example shown in FIG. 4, the minimum spectral irradiance is about 2.5 mW m -2 nm-1 It is.

[0063] In the light for growing according to the second embodiment, the ratio of the minimum spectral irradiance to the first peak spectral irradiance is 0.1 or more and 0.5 or less, but may be 0.4 or less, or may be 0.3 or less. In the example shown in FIG. 4, the ratio of the minimum spectral irradiance to the first peak spectral irradiance is about 0.19.

[0064] In addition, the spectral irradiance of the light for growth in Example 2 at a wavelength of 610 nm is approximately 2 mW m -2 nm -1 More than approximately 6mW m -2 nm -1 Less than 3mW m -2 nm -1 Approximately 5mW m -2 nm -1 In the example shown in FIG. 4, the spectral irradiance at a wavelength of 610 nm is approximately 4.9 mW m -2 nm -1 It is.

[0065] In the light for growth according to the second embodiment, the ratio of the spectral irradiance at a wavelength of 610 nm to the first peak spectral irradiance is 0.2 or more and 0.6 or less, but may be 0.5 or less, or may be 0.4 or less. In the example shown in FIG. 4, the ratio of the spectral irradiance at a wavelength of 610 nm to the first peak spectral irradiance is about 0.37.

[0066] In addition, the spectral irradiance of the light for growth in Example 2 at a wavelength of 780 nm is approximately 3 mW m -2 nm -1 Less than 2mW m -2 nm -1 It may be less than 1 mW m -2 nm -1 In the example shown in FIG. 4, the spectral irradiance at a wavelength of 780 nm is approximately 0.6 mW m -2 nm -1 It is.

[0067] In the light for growth according to the second embodiment, the ratio of the spectral irradiance at a wavelength of 780 nm to the second peak spectral irradiance is 0.0 or more and 0.3 or less, but may be 0.2 or less, or may be 0.1 or less. In the example shown in Fig. 4, the ratio of the spectral irradiance at a wavelength of 780 nm to the second peak spectral irradiance is about 0.06.

[0068] In addition, both of the light for growth according to Examples 1 and 2 include a third peak having a peak wavelength of 430 nm or more and 490 nm or less, but the third peak may not be included. In addition, the light for growth according to Examples 1 and 2 may not include light with a wavelength component of less than 610 nm. In addition, although several examples of numerical ranges have been given, one of the upper limit value and the lower limit value of the numerical range may not be required. In addition, the upper limit value and the lower limit value of multiple numerical range examples of the same type may be combined.

[0069] Fig. 6 is a diagram showing the irradiance ratio from the lighting devices according to Examples 1 and 2 and Comparative Example 1. Examples 1-1 and 1-2 are two lighting devices designed to irradiate light with the spectrum shown in Fig. 3 (target FR / R ratio value is 1.8). Examples 2-1 and 2-2 are two lighting devices designed to irradiate light with the spectrum shown in Fig. 4 (target FR / R ratio value is 1.0). Comparative Examples 1-1 and 1-2 are two lighting devices designed to irradiate light with the spectrum shown in Fig. 5 (target FR / R ratio value is 0.5).

[0070] Figure 6 shows the results of measuring the irradiance of red light and far-red light contained in the light from each lighting device, and calculating the FR / R ratio based on the measured values. The measurement positions were four locations with horizontal distances of 0.0m, 0.5m, 1.0m, and 1.5m. The horizontal distance is expressed as the distance on the plane from the point directly below the lighting device installed at a position 1.0m above a specified plane (measurement surface), with the point directly below the lighting device set at 0.0m.

[0071] As shown in Fig. 6, the FR / R ratio varies depending on the horizontal plane distance. Here, the FR / R ratio increases as the horizontal plane distance increases, but this is not limited to the above. Depending on the number, arrangement, etc. of the red light emitting elements 112 and the far-red light emitting elements 114, the FR / R ratio may increase as the horizontal plane distance decreases.

[0072] [Light cultivation results] The following describes the results of an experiment on cultivation under electric light using the lighting device 10 according to the present embodiment.

[0073] FIG. 7 is a diagram for explaining the experimental conditions of the electric light cultivation. In FIG. 7, two lighting devices 10A and 10B and a plurality of plants 2 to be cultivated under electric light are shown in a top view. The plants 2 are strawberries. Ten plants 2 (strawberries) are planted in each of the areas 21A, 22A, 21B, and 22B on both sides of the lighting devices 10A and 10B, respectively. Both the areas 21A and 22A are arranged within a circular area 30A that is 1.5 m away from the lighting device 10A on a horizontal plane. Both the areas 21B and 22B are arranged within a circular area 30B that is 1.5 m away from the lighting device 10B on a horizontal plane. The circular area 30A corresponds to an irradiation area where the light for growth is irradiated from the lighting device 10A. The circular area 30B corresponds to an irradiation area where the light for growth is irradiated from the lighting device 10B.

[0074] The lighting device 10A is the lighting device 10 according to Example 1, in which the target value of the FR / R ratio shown in Fig. 3 is 1.8. The lighting device 10B is the lighting device 10 according to Example 2, in which the target value of the FR / R ratio shown in Fig. 4 is 1.0. Furthermore, for the lighting device according to Comparative Example 1, in which the target value of the FR / R ratio shown in Fig. 5 is 0.5, and the incandescent light bulb according to Comparative Example 2, respectively, electric cultivation was carried out under the conditions shown in Fig. 7.

[0075] In the electric light cultivation, each lighting device was turned on for about 2 to 3 hours at night every day from November to February or March. Red light and far-red light were irradiated to the plant 2 at the same time and for the same period. The daily lighting time and the end time of lighting were appropriately adjusted according to the growth of the plant 2 (strawberry). Note that the timing of turning the lights on and off, the lighting time, etc. were the same in each example and each comparative example.

[0076] Fig. 8 is a diagram showing the strawberry harvest volume by month. In Fig. 8, the monthly harvest volume for each lighting device (for each example and comparative example) is shown for each section. In addition, the harvest volume for each section is summed up to show the monthly harvest volume for each lighting device and the total harvest volume from November to March.

[0077] The incandescent light bulb according to Comparative Example 2 is a light bulb generally used in electric cultivation. While incandescent light bulbs can provide a sufficient yield, they have the problem of high power consumption. In contrast, the lighting devices according to Examples 1 and 2 use light emitting elements such as LEDs, and therefore can reduce power consumption. As shown in FIG. 8, the lighting devices according to Examples 1 and 2 can ensure a yield equal to or greater than that achieved when an incandescent light bulb is used. On the other hand, the lighting device according to Comparative Example 1 provides a yield less than that achieved when an incandescent light bulb is used.

[0078] In this way, it is possible to achieve both reduced power consumption and improved yields with the lighting devices according to Examples 1 and 2. Specifically, when the FR / R ratio is 0.94 or more and 2.06 or less, it is possible to achieve both reduced power consumption and improved yields.

[0079] In addition, in current electric cultivation, multiple incandescent light bulbs are used, and the lifespan of all incandescent light bulbs does not necessarily expire at the same time. In general, incandescent light bulbs are replaced with new incandescent light bulbs in order of expiration of their lifespan. As shown in FIG. 8, the yield of the lighting devices according to Examples 1 and 2 is equal to or greater than that of the incandescent light bulb according to Comparative Example 2, so that it is possible to replace the existing incandescent light bulbs with the lighting devices. In this case, the lighting device according to Example 1 or 2 can be used in the same way as the existing incandescent light bulbs. In other words, the timing of turning on and off the light can be the same as that of the incandescent light bulbs.

[0080] As a result, even if the lighting device according to the first or second embodiment is used among many incandescent light bulbs, local variations in yield and harvest time are unlikely to occur, and a stable harvest can be achieved. Compared to replacing all incandescent light bulbs at once, the initial cost can be reduced and the deterioration of workability can be suppressed.

[0081] [summary] As described above, the lighting device according to the first aspect of the present invention is, for example, the lighting device 10 described above, and includes a light source unit 110 that irradiates light for growing the plant 2. The light for growing includes red light in the range of 610 nm to 680 nm and far-red light in the range of 685 nm to 780 nm. The ratio of the irradiance of the far-red light to the red light is 0.94 to 2.06.

[0082] This enables effective cultivation with electric lighting according to the input power, thereby achieving both reduced power consumption and improved harvest yields.

[0083] A lighting device according to a second aspect of the present invention is the lighting device according to the first aspect, wherein the irradiance of the red light is 0.085 W / m 2 The irradiance of far-red light is 0.093 W / m 2 That's all.

[0084] This allows efficient cultivation under electric lighting, particularly when the plant 2 is a strawberry.

[0085] Furthermore, an illumination device according to a third aspect of the present invention is the illumination device according to the first or second aspect, in which the light source unit 110 includes a plurality of red light emitting elements 112 that emit red light and a plurality of far-red light emitting elements 114 that emit far-red light.

[0086] By providing separate light emitting elements for emitting red light and far-red light, the red light and the far-red light can be easily optimized, thereby improving the yield while reducing power consumption.

[0087] An illumination device according to a fourth embodiment of the present invention is the illumination device according to the third embodiment, in which the multiple red light emitting elements 112 and the multiple far-red light emitting elements 114 are evenly arranged on one or more circumferences.

[0088] This makes it possible to suppress bias in the illuminance distribution of red light and far-red light, thereby suppressing the occurrence of variations in harvest yields.

[0089] An illumination device according to a fifth aspect of the present invention is the illumination device according to any one of the first to fourth aspects, and includes a light bulb-type housing 11 that houses a light source unit 110.

[0090] This makes it possible to utilize existing power infrastructure equipment that uses light bulb-type lamps, making it easy to introduce into existing electric cultivation systems.

[0091] A lighting device according to a sixth aspect of the present invention is the lighting device according to any one of the first to fifth aspects, in which the plant 2 is a strawberry or a chrysanthemum.

[0092] As a result, if the plant 2 is a strawberry, the parent plant is cultivated under electric light from around November to around February or March, and if the plant 2 is a chrysanthemum, the parent plant is cultivated under electric light every day throughout the year. This is extremely useful as it is expected to reduce power consumption during long-term cultivation under electric light.

[0093] (others) Although the lighting device according to the present invention has been described based on the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment.

[0094] For example, the light source unit 110 may include one type of light-emitting element (LED) that emits both red light and far-red light, instead of the red light-emitting element 112 and the far-red light-emitting element 114. For example, the light-emitting element that emits light for growth emits broad light having an intensity equal to or greater than a predetermined intensity across the entire range of 610 nm to 780 nm. Alternatively, the light-emitting element that emits light for growth may emit narrow-band light having peaks of emission intensity in the range of 610 nm to 680 nm and in the range of 685 nm to 780 nm, respectively, as light for growth.

[0095] Furthermore, for example, the lighting device 10 does not have to be a bulb-type lamp. The lighting device 10 may be a lighting device fixed to a predetermined structure, such as a ceiling light, a downlight, a spotlight, or a light bar.

[0096] In addition, the present invention also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art may think of, and forms realized by arbitrarily combining the components and functions of each embodiment within the scope that does not deviate from the spirit of the present invention. [Explanation of symbols]

[0097] 2 plants 10, 10A, 10B lighting equipment 11 Light bulb housing 110 Light source section 112 Red light emitting element 114 Far-infrared light emitting element 116 Board 130 Control section

Claims

1. A light source unit is provided for emitting light for growing plants. The light is Red light in the range of 610 nm to 680 nm, and far-red light in the range of 685 nm or more and 780 nm or less, The ratio of the irradiance of the far-red light to the irradiance of the red light is 0.94 or more and 2.06 or less. Lighting equipment.

2. The irradiance of the red light is 0.085 W / m ２ That's all. The irradiance of the far-red light is 0.093 W / m ２ That's all.

10. The lighting device of claim 1.

3. The light source unit includes: A plurality of red light emitting elements that emit the red light; A plurality of far-red light emitting elements that emit the far-red light, 10. The lighting device of claim 1.

4. The plurality of red light emitting elements and the plurality of far-red light emitting elements are evenly arranged on one or more circumferences.

4. The lighting device according to claim 3.

5. A light bulb-shaped housing that houses the light source unit is provided. The lighting device according to any one of claims 1 to 4.

6. The plant is a strawberry or a chrysanthemum. The lighting device according to any one of claims 1 to 4.

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