JP2006050988A - Light source for plant cultivation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source for plant cultivation capable of irradiating light to the whole of each plant and effectively performing photosynthesis, shape formation, sterilization and insect killing indispensable to growth and cultivation of plants. <P>SOLUTION: This light source 2 for plant cultivation has a red color LED 23, a blue color LED 24 and a purple color LED 25 loaded in the recessed part 21 of a nonconductive insulating substrate 22 to hardly produce nonuniformity of light irradiation. Photocatalyst thin films 28 activating photocatalyst by ultraviolet rays are each set on the light-emitting sides of the three LEDs 23, 24 and 25. Photosynthesis and shape formation are effectively performed with the red color LED 23 and the blue color LED 24. The purple color LED 25 and the photocatalyst thin films 28 enable extinction of bacteria, suppression of bacteria reproduction, sterilization, deodorization and insect killing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light source for plant cultivation used for plant growth and cultivation, and in particular, can irradiate light to the whole individual plant, and is essential for photosynthesis, morphogenesis, sterilization, insecticide, etc. It is related with the light source for plant cultivation which can perform effectively.

  Flower trees, flowers, vegetables, fruits and the like are generally grown and cultivated outdoors, but can also be artificially performed using a greenhouse, a greenhouse, or the like. In this case, what is important is to appropriately control the environmental conditions such as the amount of light, the amount of water, the temperature, and the humidity in a room such as a greenhouse or a greenhouse, among which light is particularly important.

  When growing or cultivating plants in a greenhouse or a greenhouse, artificial light is used instead of sunlight. Conventionally, light sources such as incandescent bulbs and fluorescent lamps have been used as the artificial light, but these light sources require a large amount of power. The temperature in the atmosphere may be increased more than necessary due to the heat generated by the light source.

  There is a light emitting diode (LED) as a light source with low power consumption, and a plant cultivation method using this LED as a light source is known (for example, see Patent Document 1).

This plant cultivation method includes an LED that emits ultraviolet light with a wavelength of 250 nm to 375 nm, an LED that emits blue light with a wavelength of 410 nm to 460 nm, an LED that emits yellow light with a wavelength of 550 nm to 585 nm, and a red light with a wavelength of 600 nm to 750 nm. The LED that emits light is used as a light source to promote plant growth and to reduce pests on plants.
JP 2001-28947 A ([0012], [0020], FIG. 7, FIG. 8)

  However, according to the conventional plant cultivation method, since a light source consisting of one LED for each color is used, the irradiation area is different for each color, and the plant can only be partially irradiated with light. There may be unevenness.

  Therefore, an object of the present invention is to irradiate the whole individual plant with light, and to effectively perform light synthesis, morphogenesis, sterilization, insecticide, etc. essential for plant growth and cultivation. The purpose is to provide.

  To achieve the above object, the present invention provides a base having a recess, a purple LED that is disposed on the bottom surface of the recess of the base, and emits purple light including ultraviolet light, and a specific wavelength other than the purple light. Provided is a light source for plant cultivation characterized by comprising a visible light LED that emits visible light.

  According to the light source for plant cultivation of the present invention, since the irradiation area becomes constant by mounting the purple LED and the visible light LED on the common base, it is possible to irradiate the whole individual plant with light. Photosynthesis, morphogenesis, etc., which are indispensable for growing and cultivating rice, can be performed effectively.

  Moreover, disinfection and insecticide can be effectively performed by providing the photocatalyst which exhibits a catalytic action by ultraviolet light from the purple LED so as to cover the purple LED and the visible light LED.

  FIG. 1 shows a plant cultivation system according to an embodiment of the present invention. This plant cultivation system 1 has a shelf 11 a in the middle, a greenhouse 11 in which a flower pot 14 is installed on the bottom surface and the shelf 11 a, and a plurality of plant cultivation light sources 2 installed on two ceiling surfaces in the greenhouse 11. And a control device 12 that controls on / off of the voltage supplied to the plant cultivation light source 2 and a power supply device that is connected to a commercial power source such as 100 V and supplies a DC voltage to the control device 12 and the plant cultivation light source 2 13. Here, one light source 2 for plant cultivation is assigned to one flower pot 14, but a plurality may be assigned.

  The control device 12 includes, for example, a CPU, a memory, an interface circuit, a power transistor, and the like, and is configured to control light emission according to a program in which a predetermined energization mode is set in advance.

  The power supply device 13 includes a transformer that steps down 100V, a rectifier circuit, a voltage stabilization circuit, and the like, and generates a predetermined DC voltage.

  FIG. 2 shows a detailed configuration of the light source for plant cultivation according to the embodiment of the present invention. In the figure, (a) is a plan view and (b) is a cross-sectional view taken along line AA of (a). The plant cultivation light source 2 is extended in a substantially S-shape on both sides of the insulating substrate 22, the red LED 23, the blue LED 24, and the purple LED 25 mounted on the mounting surface on the insulating substrate 22. In addition, six leads 26 as a pair of terminals connected to the respective anodes and cathodes of the LEDs 23 to 25, a recess 21 that is formed on the insulating substrate 22 and reflects light emitted from the LEDs 23 to 25 upward, and a recess 21 A light-transmitting sealing resin portion 27 filled to fill the inside, and a photocatalyst thin film 28 fixed to the upper edge of the recess 21 so as to cover the sealing resin portion 27. .

  The insulating substrate 22 is made by resin molding or the like with a lead 26 built therein, and a concave portion 21 for mounting the LEDs 23 to 25 is formed in the center portion so as to have an inclined surface, and the LED 23 to the bottom surface thereof is formed. 25 is mounted. If necessary, a light reflecting surface can be provided on the inner surface of the recess 21.

  The LEDs 23 to 25 have the same shape, are arranged one by one at each triangular point, and are mounted on the bottom surface of the recess 21 so that the LEDs 23 to 25 are equally spaced from each other. In addition, it is not limited to triangular arrangement | positioning, For example, it is also possible to arrange | position three LED on a straight line. The LEDs 23 to 25 are connected to one of the anode and the cathode in common so that the LEDs 23 to 25 can be individually driven, and one wire is routed to the control device 12, and the other is wired to the control device 12 for each LED. To line.

  The lead 26 is manufactured by punching a conductive metal material such as copper or copper alloy, and the end portion on the LED side has a J-shape as shown in FIG. Bending process such as L-shape is applied.

  The sealing resin portion 27 is formed by filling the concave portion 21 with a translucent resin material to a height that is substantially flush with the upper surface of the insulating substrate 22. The sealing resin portion 27 may not be provided, and a transparent glass or plastic plate material may be provided on the lower surface of the photocatalytic thin film 28.

The thin film for photocatalyst 28 is a thin film using fine particles made of an optical semiconductor such as titanium dioxide (TiO ₂ ) having optical semiconductivity. The action of the photocatalyst increases as the particle diameter of the titanium dioxide fine particles decreases. The photocatalytic thin film 28 is formed by applying a colloid of titanium dioxide on the surface of the sealing resin portion 27, or PVD (Physical Vapor Deposition) or CVD (Chemical Vapor Deposition). ) Or the like.

  The light source 2 for plant cultivation shall be arrange | positioned just above the flower pot 14, for example, when the diameter of the upper part of the flower pot 14 is 70-120 mm, it is 150-200 mm high from the position of the plant planted in the flower pot 14. Install in the same place.

  FIG. 3 shows the luminance characteristics of the plant cultivation light source 2. The light source 2 for plant cultivation has the maximum luminance with respect to the vertical plane (0 °), the luminance decreases as the angle increases with respect to the left-right direction, and the wide-angle orientation becomes 0 at ± 90 °. It has the characteristics, and the entire upper opening of the flower pot 14 is irradiated.

  FIG. 4 shows the relationship between the wavelength of each LED 23 to 25 and the luminance of the plant cultivation light source 2. The red LED 23 has an emission wavelength of about 640 to 670 nm, the blue LED 24 has an emission wavelength of about 450 to 480 nm, and the purple LED 25 has an emission wavelength of about 360 to 410 nm. Since the purple LED 25 does not include a wavelength harmful to the human body of 320 nm or less, it is safe even if the human body enters the light emission range of the plant cultivation light source 2.

(Operation of plant cultivation system)
FIG. 5 shows drive waveforms of the LEDs 23 to 25 of the plant cultivation light source 2 by the control device 12. The operation of the present embodiment will be described below with reference to this drive waveform and FIGS. When the power supply device 13 is turned on, a DC voltage is applied to the control device 12. The control device 12 controls energization of the LEDs 23 to 25 of the plant cultivation light source 2 so as to obtain a drive waveform as shown in FIG. Here, rectangular waveforms are repeatedly generated at different on timings, and the LEDs 23 to 25 are driven. In the drawing, the ON time of the purple LED 25 is set longer than that of the other color LEDs in order to obtain a sufficient sterilizing and insecticidal effect.

  When the purple LED 25 is turned on, the photocatalytic thin film 28 forms an active surface that is oxidizable by ultraviolet rays on the surface of the photocatalytic thin film 28, and organic compounds and the like are decomposed by the strong oxidation catalytic action. Thereby, microorganisms, such as bacteria, are killed or propagation is suppressed. In addition, insecticidal and deodorizing are also performed.

According to this embodiment, the following effects can be obtained.
(A) Since a plurality of LEDs are mounted in one package, high-density mounting is possible when a plurality of light sources 2 are used.
(B) Even when red and blue are alternately blinked, since the light is emitted from the same package, there is no variation in the size of the irradiation region.
(C) Light sources having the same red, blue, and purple irradiation amounts in the same irradiation region can be produced.
(D) In recent years, since it has become possible to increase the output of LEDs, various light sources from small to large can be easily provided.
(E) Since photosynthesis, morphogenesis, sterilization, etc., essential for plant growth, are effectively performed by light emission of three colors of red, blue, and purple, a light source that is inferior to sunlight can be obtained. .
(F) Since the three-color LEDs are mounted on one substrate, it can be handled as a single item like a light bulb, and can be easily mounted, transported, and distributed. In addition, the use of LEDs makes it possible to extend the life and reduce the power consumption, so that maintenance and management can be facilitated and the running cost can be reduced.
(G) The purple LED 25 can obtain the ultraviolet rays necessary for growing and cultivating plants even in an atmosphere where the ultraviolet rays of sunlight are not easily transmitted and the ultraviolet rays are insufficient, such as in a greenhouse.
(H) By providing the photocatalytic thin film 28, the photocatalysis by the ultraviolet light of the purple LED 25 is performed, and bacteria can be killed, bacterial growth can be suppressed, insecticidal, deodorizing, insecticidal, etc. Is possible.

[Other embodiments]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible within the range which does not change the summary. For example, the energization of the LEDs 23 and 24 is energization control in which the pause time is longer than the energization time, but the energization time width can be arbitrarily set. Moreover, continuous energization may be used.

  Further, the shape of the light source 2 for plant cultivation is not limited to the shape shown in FIG. 2. For example, a socket mounting type using a pin or a plug instead of the lead 26 is used, and soldering is unnecessary. can do. Moreover, you may cover several LED mounted in the bottom face of a recessed part with the resin sealing member which has lens functions, such as a bullet shape.

  In the above embodiment, an insulating substrate is used as a base, but a recess may be provided at the tip of one of the pair of leads, and a plurality of LEDs may be mounted on the bottom surface of the recess.

  Moreover, in the said embodiment, although the case where the plant of the flower pot 14 was raised in the comparatively small-scale greenhouse 11 was taken as an example, this invention is not limited to the flower pot 14, The inside of a greenhouse It may be a field or a nursery.

  Moreover, the wavelength and number of LED used for one light source for plant cultivation are not limited to the said embodiment, It can select arbitrarily according to a use.

It is a connection diagram showing a plant cultivation system according to an embodiment of the present invention. The structure of the light source for plant cultivation which concerns on embodiment of this invention is shown, (a) is a top view, (b) is sectional drawing of the AA of (a). It is a characteristic view which shows the luminance characteristic of the light source for plant cultivation. It is a characteristic view which shows the relationship between the wavelength of each LED of the light source for plant cultivation, and a brightness | luminance. It is a wave form diagram which shows the drive waveform of each LED of the light source for plant cultivation by a control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plant cultivation system 2 Plant light source 11 Greenhouse 11a Shelf 12 Control device 13 Power supply device 14 Flower pot 21 Recess 22 Insulating substrate 23 Red LED
24 Blue LED
25 Purple LED
26 Lead 27 Sealing resin portion 28 Thin film for photocatalyst

Claims (4)

A base having a recess;
A violet LED that is disposed on the bottom surface of the recess of the base and emits violet light including ultraviolet light, and a visible light LED that emits visible light having a specific wavelength other than the violet light is provided. Light source for plant cultivation.   The plant cultivation according to claim 1, wherein the base is provided with a photocatalyst that is provided so as to cover the purple LED and the visible light LED and that exhibits a catalytic action by the ultraviolet light from the purple LED. Light source.   The light source for plant cultivation according to claim 1, wherein the visible light LEDs are a blue LED that emits blue light and a red LED that emits red light.   The light source for plant cultivation according to claim 1, wherein the photocatalyst is a thin film made of titanium dioxide.