HK1216136A1 - Lighting system and plant cultivation apparatus - Google Patents

Abstract

Provided are an illumination device and a plant cultivation apparatus capable of irradiating light, which has been reflected at the surface of a cultivating tray on which plants are cultivated, back toward said cultivating tray with high efficiency. The illumination device (10) comprises: multiple light sources (11); a frame (12) provided with transparent windows for holding multiple light sources (11) and for emitting the light emitted by the multiple light sources (11); and a reflection member installed so as to cover the windows to reflect light from outside the frame (12) and in which multiple holes (13) for respectively emitting the light emitted by each light source (11) are formed.

Description

Illumination system and plant cultivation device

Technical Field

The present invention relates to an illumination system and a plant cultivation apparatus usable for hydroponics, and more particularly, to an illumination system and a hydroponics apparatus equipped with the illumination system, in which light reflected by the surface of a cultivation tray in which plants are cultivated can be reflected again to the cultivation tray.

Background

Hydroponic cultivation rooms are maintained at relatively high temperatures and high humidity. When the lighting system is placed in such an environment, the lighting system is severely deteriorated and the reduction of the lifetime may become a problem. Thus, there has been proposed an illumination system in which a semiconductor light emitting device is provided inside a main body and light is emitted through a transparent window portion of the main body (refer to patent document 1).

Documents of the prior art

Patent document 1: JP 2010-284127.

Disclosure of Invention

Problems to be solved by the invention

The illumination system of the above patent document 1 includes a reflector which surrounds the LED, a reflection surface having a paraboloid is formed on the reflector, and a direction in which light is emitted may be set so that light can be emitted perpendicularly to the transparent cover. Thus, light can be irradiated on the plant with relatively high efficiency.

However, all light emitted from the illumination system cannot be irradiated on the plant, and the light is irradiated on the surface of the cultivation tray or the like. The cultivation tray may be formed of plastic resin such as polyethylene and polyvinyl chloride, or ceramic, and may be selected from materials having white color and luster. This is because the cultivation tray does not absorb heat. In this case, light exposed from the lighting system is reflected on the surface of the cultivation tray, and the reflected light not only returns to the inside of the lighting system but also escapes in the surroundings, etc., causing light waste.

Furthermore, LEDs used as light sources are so expensive that it is desirable to reduce the number of LEDs as little as possible. When the number of LEDs can be reduced, the amount of coolant for cooling the LEDs can be reduced, and the power supplied to the LEDs also becomes low.

Means for solving the problems

The present invention has been made in view of the above problems, and can provide an illumination system including: a plurality of light sources; a main body holding a plurality of light sources, and including a transparent window portion for allowing light emitted from the light sources to escape; and a reflection member disposed so as to cover the window portion so as to reflect light from outside the body, while being formed with a plurality of holes for emitting light emitted from each light source.

Advantageous effects of the invention

According to the present invention, since the window portion is covered with the reflecting member except for a portion where light escapes from the light source, the light reflected from the cultivation tray can be efficiently directed to the plants cultivated at the cultivation tray again, so that it is possible to supply a predetermined amount of light while reducing the number of light sources, and also to reduce not only facility costs but also running costs. Also, since the light source is held inside the main body, the light source can be prevented from deteriorating, so that the life of the light source is extended.

Drawings

Fig. 1 is a diagram illustrating a constitution example of an illumination system according to the present invention;

fig. 2 is a diagram illustrating a relationship between the number of reflections at the reflection sheet and the amount of light returned to the plant when the amount of light emitted from the LED is 100%;

fig. 3 is a view illustrating a configuration example of a plant cultivation apparatus according to the present invention;

fig. 4 is a view illustrating another enlarged configuration example of the plant cultivation apparatus;

fig. 5 is a view illustrating another configuration example of the plant cultivation apparatus according to the present invention;

fig. 6 is a view illustrating a cross section of a lighting system equipped with a water-cooled pipe along its width direction;

fig. 7 is a diagram illustrating a cross-section of the lighting system of fig. 6 along a longitudinal direction thereof;

fig. 8 is a diagram illustrating an enlarged cross-section of an attachment portion of an LED chip of the lighting system of fig. 6;

fig. 9 is a diagram illustrating an exploded plan view of a spacer of the illumination system for explaining a combination thereof;

FIG. 10 is a plan view and a side view of an end cap member of the lighting system of FIG. 6;

fig. 11 is a cross-sectional view of another constitutional example of the lighting system including the water-cooled pipe;

fig. 12 is a view of a cross section of a lighting system including heat dissipation fins in its width direction as an example of the lighting system including a heat exhausting part.

Detailed Description

The present lighting system will be described in detail with reference to fig. 1; however, the present invention should not be limited to the structure depicted in FIG. 1. The illumination system 10 includes: a light source 11; a main body 12 holding a plurality of light sources 11 and including a transparent window portion for allowing light emitted from the light sources 11 to escape; and a reflection sheet 14 serving as a reflection member disposed so as to cover the window portion so as to reflect light from the outside of the main body 12, while being formed with a plurality of holes 13 for escaping light emitted from each light source.

As the light source 11, a fluorescent lamp, an LED, or the like can be used. Here, the LED may be desirable as a light source due to its low power consumption. The light source 11 can be formed of, for example, 4 LED chips each independently emitting red light, green light, and blue light. The colors of the 4 LED chips constituting the light source 11 may be selected depending on the specific application. It is possible to arrange 6 light sources 11 composed of 4 LED chips on 1 substrate as shown in fig. 1 (a). The present invention is not limited thereto and the number of LED chips can be not more than 4 or not less than 5. Also, a number of 5 or less or not less than 7 light sources 11 can be arranged on 1 substrate.

Not shown in fig. 1, a light control box for controlling the brightness of the LED chips of each color can be provided. The light control box can control the brightness of each color independently, or alternatively can control the brightness of the LED chips of all colors uniformly.

When emitting light, the light source 11 generates heat. This heat causes thermal damage to the plant due to heat accumulation in the plant. Therefore, the generated heat must be discharged. The lighting system 10 is realized such that the respective light sources 11 are placed on a substrate having a function of a heat sink substrate, and a coolant pipe is connected to the substrate to discharge heat. Inside the coolant pipe, coolant is supplied, and heat conducted to the coolant pipe through the base plate is absorbed by the coolant. The substrate can comprise an aluminum plate or a copper plate, etc. The coolant can include ammonia, isobutane, carbon dioxide, water, and the like. These are exemplarily described, however, other structures such as air supply into the main body 12 can be employed.

Further, around the light source 11, a reflector 15 is provided, and the reflector 15 causes a possibility of emitting light from the light source 11 toward a predetermined direction. The reflector 15 has a reflecting surface whose diameter increases with respect to the distance from the light source 11. The reflective surface can have a parabolic curvature, such as a parabolic antenna. The reflector 15 may be formed of a metal film of aluminum or silver deposited on an acrylic resin or the like in which the opening for the reflection surface is formed.

In the embodiment shown in fig. 1 (a), 6 light sources 11 are arranged on a substrate, and a reflector 15 is placed such that the reflector 15 covers the substrate. 16 substrates each provided with 6 light sources 11 are held in the main body 12.

The main body 12 is a box-like member including a rectangular upper plate 16, 4 side plates 17 continuous with each side of the upper plate 16, and a transparent lower plate 18 for a window portion. A substrate with 6 light sources 11 is disposed so that the substrate is sandwiched by an upper plate 16 and a lower plate 18, and a terminal block 19 is disposed on the upper plate 16, and a light control box for controlling the luminance of the LED chips of each color is connected to the terminal block 19.

The upper plate 16 and the side plates 17 are selected from any material as long as they can provide rigidity to the lighting system 10 so as to prevent deformation. For example, the material may be selected from metals such as aluminum, stainless steel, copper, titanium, and plastic materials such as ABS resin, and the like. Aluminum or an aluminum alloy may be suitable due to its superior light weight and cost, and the surface may preferably be subjected to alumite processing in order to prevent corrosion. The alumite process may be white alumite and/or a colorless coating may be applied thereon from the viewpoint of light reflectivity and efficient use of light.

The lower plate 18 may be selected from any material as long as the lower plate 18 can efficiently pass the light from the light source 11. For example, the material can include glass as well as acrylic, polycarbonate, polyethylene terephthalate, and the like. It may be possible to dispose an antireflection film for preventing light reflection on the side of the lower plate facing the light source 11.

When it is assumed that the light source 11 side of the lower plate 18 is the upper surface, the opposite lower surface is adhered with the reflective sheet 14. The reflection sheet 14 can be adhered by using an adhesive including a main component selected from epoxy resin, silicone resin, urethane resin, and acryl resin. The reflection sheet 14 reflects light entering from the outside of the main body 12. On the other hand, the holes 13 have a rectangular shape and the same area as the substrate, so that light emitted from the respective light sources 11 is allowed to escape to the outside.

The hole 13 in fig. 1 (a) is formed by cutting the reflection sheet 14 because the reflector 15 has a high reflectance and its area is not so large. However, the present invention may not be limited thereto, and each circle can be cut independently so that only each light source 11 and the reflection surface around the light source 11 are exposed.

The lighting system 10 emits light emitted by each light source 11 through the reflector 15 perpendicularly to the lower plate 18 constituting the window portion, and irradiates plants on the window portion. A portion of the illumination light can be used to perform photosynthesis in the plant. The remaining portion of the light is reflected by the surface of the growing tray back to the lighting system 10. Here, since the direction of light from the light source is set by the reflector 15, most of the remaining light can be returned to the lighting system 10 by reflection by the surface of the cultivation tray.

The light returned to the lighting system 10 is reflected again by the reflective sheet 14 adhered to the lower plate 18 to be irradiated on the plant. By repeating the above operations, light can be efficiently used, and a predetermined amount of light can be supplied while reducing the number of light sources. When the number of the light sources 11 is reduced, the power supply to the light sources 11 is reduced, and thus, the running cost can be reduced. Also, the light source 11 is held in the main body 12, so that deterioration of the light source can be prevented to extend the life of the light source.

The reflective sheet 14 may preferably have a higher reflectance, and a reflectance of not less than 98% may be employed. In addition, the material of the reflective sheet may use polypropylene as a main raw material because polypropylene is lighter in weight than white PET, has high hydrolysis resistance, and has high weatherability. A reflective sheet made of polypropylene is preferable because the reflectance of light is about 99% higher than that of white PET.

The reflective sheet 14 may be preferably attached to the surface of the cultivation tray and the lower side of the transparent lower plate 18 because light can be properly reflected to the reflective sheet attached to the lower plate 18, thereby utilizing light more efficiently. In addition, some of the light escapes toward the side. Thus, the light reflecting plate may be disposed at the side to prevent the light from escaping toward the side.

In the main body 12, a plurality of light sources 11 are held, and when the humidity in the main body 12 becomes high, deterioration of the light sources 11 becomes severe, causing a reduction in lifetime, it may be preferable to keep the humidity in the main body 12 low. Therefore, a material having hygroscopicity (absorbent) such as a desiccant can be sealed in the main body 12. The absorbent may include activated carbon and silica gel, but is not limited thereto, and any material having hygroscopicity may be used in the present invention. The absorbent can be recovered by heating the absorbent.

Now, it is shown how the result of the simulation of light can be effectively utilized by attaching the reflection sheet 14. Fig. 2 shows the relationship between the number of reflections and the amount of light (%) in the case where the reflection sheet 14 is attached and the case where the reflection sheet 14 is not attached. The case of attaching the reflection sheet 14 was further simulated by two cases, a case where the reflection sheet 14 was attached to both the lower plate 18 and the surface of the cultivation tray (case a) and a case where the reflection sheet 14 was attached only to the lower plate 18 (case B). A simulation of the case without a reflection sheet is performed by assuming that the reflection sheet 14 is not attached at all (case C).

The number of reflections indicates the number of reflections on the reflection sheet 14 attached to the lower plate 18, and the light amount (%) is a percentile of the light amount at each number of reflections when the light amount emitted from the light source 11 is assumed to be 100%. I.e. the sum of the 100% of the amount of light emitted by the light source 11 and the% of the amount of light of the reflected light.

Here, in this simulation, the plant uptake rate was assumed to be 20%; the reflectance of the reflective sheet 14 is 99%; the reflectivity of the surface of the cultivation tray is 80%; the reflectance of the reflector 15 and the like to which the reflection sheet 14 is not attached is 50%. The cultivation tray is a tray made of glossy white vinyl chloride; the body 12 is composed of the following components: an upper plate 16 and a side plate 17 each formed of an aluminum plate; and a lower plate 18 formed of a transparent glass plate.

In case C, as shown by the cross mark in fig. 2, in the case where the number of reflections is 5, the light amount is almost constant at 150%, and an equilibrium state is reached. Since the amount of light emitted from the light source 11 is 100%, the remaining value of about 50% is based on the amount of light of reflected light from the cultivation tray. In fact, there is light escaping to the sides, and it may be considered that the amount of light will be below 150%. The point at which light escapes to the sides may be similar in other cases.

In case B, as shown by the triangular mark in fig. 2, in the case where the number of reflections is 10 times as many as 2 times as in case C, the light amount is almost constant at about 270%, and an equilibrium state is reached. The light amount of the case B is about 270% which is almost 2 times the value of the case C, i.e., 150%. Therefore, by merely attaching the reflection sheet 14 to only the lower plate 18, the light amount of about 2 peyers can be obtained. When it is assumed that the same light amount as in case C is obtained, the number of light sources 11 will be reduced to half of case C.

In case a, when the number of reflections is 14, the equilibrium state is not reached. The light quantity at the number of reflections of 14 was about 450%, which was about 3 times that of case C. This means that by attaching the reflection sheet 14 to the surface of the cultivation tray, the amount of light can be greatly increased, and as a result, the number of light sources 11 necessary to obtain the same amount of light can be significantly reduced. That is, when it is assumed that the desired light amount is the same as in case C, the number of light sources 11 can be reduced down to 1/3.

In the above, the lighting system 10 for hydroponics has been described, and it may be possible to provide the plant-cultivating device 20 including the lighting system 10. The plant cultivation device 20 includes: at least one tank member 21 to which a culture solution is supplied to the tank member 21; cultivation trays 22 placed adjacent to each other on at least one trough 21; and a cultivation shelf 23 on which the at least one trough member 21 is placed obliquely to the longitudinal direction, and the lighting system 10 is attached to the cultivation shelf 23. Further, the plant cultivation apparatus 20 further includes a circulation pump 24 as culture solution supply means for supplying the culture solution into each tank member 21, a culture solution tank 25 as a reservoir of the culture solution, and an air pump 26 as gas supply means for sending air to the culture solution.

The gutter member 21 may be, for example, a commercially available rain gutter, and may be placed such that the rain gutter member 21 has a gradient of about 1%. Thus, the culture liquid is supplied to the upper side of the tank member 21 by the supply pump 24, and the culture liquid flows to the opposite lower side along the inner surface of the tank member 21. On the opposite side of the groove member 21, a discharge port is provided to discharge an excessive amount of the culture solution, and below the discharge port, a liquid trap is provided. The culture liquid collected in the liquid trap is returned to the culture liquid tank 25. Likewise, the trough member 21 is disposed such that a plurality of trough members are arranged in parallel.

The cultivation tray 22 is placed across the parallel aligned trough members 21 on the trough members 21. The cultivation tray 22 has holes for planting plants at constant intervals, and sponges are put in the holes. On the cultivation tray 22, leaves of the plant grow, and, below the cultivation tray 22, roots of the plant stretch. The roots are accommodated in the trough member 21, and the root caps are immersed in the culture solution flowing along the inner surface of the trough member 21.

Plants absorb cultivation nutrients and water from the root cap and are taken into the body, and leaves grow by absorbing light to perform photosynthesis. In addition to water and oxygen, the broth can include nitrogen, phosphoric acid, potassium, and calcium.

The lighting system 10 is disposed at an upper portion of the cultivation tray 22. The lighting system 10 has a reflector sheet 14 attached at a lower plate where the window part is provided, and preferably, the reflector sheet is attached to the cultivation tray 22. In addition, the sides of the cultivation shelves 23 are shown, so that the sides are open; however, from the viewpoint of effective utilization of light, the side is preferably closed by a reflective plate.

The reflective plate closes the sides of the plants planted in each cultivation tray 22, and includes a reflective surface that prevents light from the lighting system 10 placed above and light reflected from the cultivation tray 22 from escaping to the sides, while reflecting the light again toward the plants.

For example, as shown in fig. 4, a reflection plate 27 may be attached to a surface of the cultivation tray 22 opposite to the reflection surface of the reflection sheet 14, and a reflection plate 28 may be disposed so as to close a side of a plant planted in the cultivation tray 22. The reflection plate 28 may be formed by adhering the reflection sheet 14 to a plate-shaped material such as wood, plastic resin, ceramic, or the like, and the reflection plate 28 may be mounted to the cultivation shelf 23 by fastening means such as bolts and nuts.

The plant-cultivating device 20 may be installed in a room, and may include a circulation fan as an air circulation means for circulating air to maintain a constant temperature in the room. Also, since the humidity in the room becomes high due to the evaporation of the culture solution and the respiration of the plant, the plant cultivation apparatus 20 may include a dehumidifier as a humidity control means for controlling the humidity to be constant. Also, the plant-cultivating device 20 may include a ventilation fan as a ventilation part for discharging indoor air to the outside while drawing in outside air. The plant cultivation apparatus 20 may include a filter or the like as a floating matter removing member for removing fungi and/or dust floating in the air when outside air is sucked.

Likewise, the plant cultivation device 20 may arrange a plurality of cultivation trays 22 placed on the groove member 21 such that the cultivation trays 22 are aligned with respect to an earlier harvest timing, thereby achieving continuous harvesting by transferring the cultivation tray at the harvest time to a harvest site and adding a new cultivation tray on the opposite side.

When aligned in a line as described above, it is desirable to change the number of the light sources 11 depending on the growth of the plant. Since plants require different amounts of light depending on their growth stage. That is, it is desirable to provide a much greater amount of light to plants that grow many leaves and are near the harvest time, and to provide less light to plants that have just germinated and have small leaves. By setting such an appropriate light amount, the number of light sources 11 can be reduced, and as a result, the apparatus cost and the running cost can be reduced accordingly.

For example, the trough member 21 is divided into three regions in its longitudinal direction. As for the area on one side of the cultivation tray on which the still-leafed plants are placed, an illumination system 10 having a smaller number of light sources 11 as shown in fig. 1 (a) may be equipped. As for the area where the center of the cultivation tray on which the slightly-growing plants are planted is placed, an illumination system 10 having a greater number of light sources 11 than the illumination system of fig. 1 (a) as shown in fig. 5 (a) may be equipped.

Also, with respect to an area on the other side of the cultivation tray on which the plants growing many leaves are placed, an illumination system 10 having a much greater number of light sources 11 than the illumination system of fig. 5 (a) as shown in fig. 5 (b) may be equipped. The arrangement of the light sources 11 shown in fig. 5 is illustrated as an example, and any other arrangement may be allowed. In addition, as long as the number of light sources 11 can be increased in the sequence of fig. 1 (a), 5 (a), and 5 (b), the number of light sources 11 may be more or less than the number described in the drawing. Alternatively, instead of increasing or decreasing the number of light sources 11, the number of all light sources 11 is set to be the same, and the amount of light emitted by the individual light sources 11 may be controlled.

The number of the areas divided in the longitudinal direction of the trough member 21 can be not limited thereto, and the number may be 2 or not less than 4. By subdividing the area into not less than 4, fine light amount control can be achieved.

As described above, the illumination system of the present invention can include a component such as a heat dissipation substrate or a coolant pipe for discharging heat generated by the light source 11. Examples of the lighting system including the above-described means for discharging heat may include a lighting system equipped with a water-cooling pipe and a lighting system equipped with a heat-dissipating fin. The detailed constitution of the above illumination system will be explained with reference to fig. 6 to 12. First, a lighting system including a cooling pipe will be described with reference to fig. 6 to 10.

Fig. 6 shows a cross-sectional view of a lighting system comprising a cooling tube along its width direction. Fig. 7 shows a cross-sectional view of the same illumination system along a longitudinal axis perpendicular to the width. The lighting device comprises a cooling panel 30 having a substantially rectangular shape. The cooling panel 30 is composed of a heat dissipation substrate 31 and a hollow portion 32 integrally disposed on an upper surface of the heat dissipation substrate 31 at the center in the width direction thereof.

The cooling panel 30 can be formed by extrusion molding using a metal material having high thermal conductivity, for example, aluminum and/or copper. Inside the hollow portion 32, a water passage pipe 33 made of a metal material having high thermal conductivity such as aluminum or copper is inserted. The water pipe 33 is fixed inside the hollow portion 32 by enlarging the diameter thereof. A cooling fluid, such as water, flows within the flow tube. The cooling fluid may comprise a gas such as air or carbon dioxide or a brine using a main component such as ethylene glycol or propylene glycol, or the like.

The lighting system includes a plurality of LED lighting units 34 attached to the lower surface of the cooling panel 30 and arranged in 2 stacks. Hereinafter, description will be made assuming that the lower surface refers to a surface on a side where the hollow portion 32 does not protrude and the upper surface refers to a surface on the opposite side from the lower portion. The LED light emitting unit 34 includes a plurality of LED chips 35 as the light source 11 and a secondary reflector 36 having a mirror reflector 36a attached so as to surround each LED chip 35. The LED light emitting unit 34 is not limited to 2 stacks, and 1 stack or not less than 3 stacks may be allowed.

The LED chip 35 is directly connected to the lower surface of the cooling panel 30, i.e., the lower surface of the heat dissipation substrate 31. In order to contact the lower surface, a silicone adhesive or a silver paste having high thermal conductivity may be used. The heat dissipation substrate 31 is cooled by discharging heat from the cooling water flowing inside the water flow pipe 33. Then, the heat generated by the LED chip 35 is quickly absorbed by the heat dissipation substrate 31 to suppress the heat generation of the LED chip 35.

As the LED chip 35, an LED chip in which a gallium nitrate-based light emitting portion is formed on a sapphire substrate can be used. According to the present invention, the LED chip 35 having a peak wavelength of 660nm, i.e., red light, may be preferable because the availability of photosynthesis of plants is optimal.

Further, the lighting system includes a spacer 38 at a peripheral edge portion of the cooling panel 30, i.e., a portion near both edges in the width direction and a lower surface of a portion near both edges in the longitudinal direction of the heat dissipating substrate 31, and the spacer 38 is bonded by a primary sealing material 37. The spacer 38 may be made of a metal material such as aluminum or copper having high thermal conductivity by extrusion molding. The primary sealing material 37 may be a bonding sealing tape.

The lighting system further comprises a transparent light-transmitting plate 39, the transparent light-transmitting plate 39 being disposed at the opposing LED chip attachment face to which the LED chips of the cooling panel 30 are attached. The light-transmitting plate 39 is connected to the spacer 38 by the primary sealing material 37 at portions near the peripheral edge, i.e., portions near both edges in the width direction and portions near both edges in the longitudinal direction. The light-transmitting plate 39 may be any type of transparent object having a plate shape, such as a glass plate or a synthetic resin plate selected from polycarbonate resin and the like.

The lighting system has a reflecting sheet 40 as a reflecting member attached to the lower surface of a light-transmitting plate 39 or the like. The reflection sheet 40 may be attached by using an adhesive including a main component such as epoxy resin, silicone resin, urethane resin, acryl resin, or the like as described above. The reflective sheet 40 reflects light entering from the outside to the inside of the illumination system. On the other hand, the reflection sheet 40 includes a hole 41, and the hole 41 is cut out to have substantially the same area as that of the light emission port having the same rectangular shape as the light-transmitting plate 39 and having an enlarged diameter so as to emit the light formed by the secondary reflector 36. The hole 41 can emit the light generated by the LED chip 35 to the outside through the light-transmitting plate 39.

The reflective sheet 40 may have a preferably high reflectance, and a reflective sheet having a reflectance of not less than about 98% can be employed. The material of the reflective sheet may be white PET which is widely used and has a reflectance of about 98%. In addition, the reflective sheet 40 may be a reflective sheet including polypropylene as a main component, which is lighter in weight than white PET and has excellent weatherability while being high in hydrolysis resistance. A reflective sheet made of polypropylene is preferable because the reflectance of light is about 99% higher than that of white PET.

Therefore, in this embodiment, the main body 12 has a configuration in which the light source 11 is enclosed, and includes: a panel 30 to which the light source 11 is attached; spacers 38 connected to the cooling panel 30 by the primary sealing material 37 and disposed circumferentially around the light sources 11; and a light-transmitting plate 39 disposed opposite to the lower surface of the heat dissipation substrate 31 and connected to the spacer 38 by a primary sealing material 37.

Now, the attachment portion of the LED chip 35 will be explained in detail with reference to the cross-sectional view of fig. 8. The LED chip 35 has a configuration in which the generated heat is efficiently conducted to the back surface using a Chip On Board (COB) directly realized on the heat dissipation substrate 31.

The LED light emitting unit 34 is formed as follows: the dielectric layer 50 is laminated on the heat dissipation substrate 31 via an adhesive layer 51. On the dielectric layer 50, a wiring portion 52 including a copper sheet formed in a circuit pattern is laminated to form a circuit board 53. A predetermined number of LED attachment holes 54 having an inverted cone shape are formed at the circuit board 53 at given intervals, and a ring-shaped primary reflector 55 having a white highly reflective surface is disposed on an inner surface of each LED attachment hole 54.

Next, the LED chip 35 is connected to the bottom of each LED attachment hole 54, i.e., on the heat dissipation substrate 31, and a bonding wire 56 is disposed so as to electrically contact the LED chip 35 and the wiring portion 52. The bonding wire 56 is a wire formed of gold, aluminum, copper, or the like. Finally, a transparent sealing resin 57 is filled in the LED attachment hole 54 so as to cover the LED chip 35 and the bonding wire 56. Here, the transparent sealing resin 57 may include acryl resin, epoxy resin, silicon resin, and the like.

The LED light emitting unit 34 thus formed is easy to form, and provides good productivity, since the wiring board 53 can be formed without any processing of the flat surface of the heat dissipation substrate 31. In addition, since any processing for forming the concave surface or the protruding portion is not required for the heat dissipation substrate 31, various known metal plates can be utilized, and the LED chip 35 is also well contacted. In addition, since light can be guided downward, the thickness of the wiring board 53 is preferably set to be thinner than the thickness of the LED chip 35.

Referring again to fig. 7, the LED light emitting unit 34 is fixed to the lower surface of the cooling panel 30, i.e., the lower surface of the heat dissipation substrate 31.

The spacer 38 is composed of 8 members as shown in fig. 9, and is assembled by using the above members. The 8 members are 2 vertical members 38a, 2 cross members 38b, and 4 corner members 38 c. The partition 38 is assembled such that 2 vertical members 38a and 2 horizontal members 38b form a rectangle, and 4 corner members 38c made of synthetic resin connect the rectangles at corner portions. Each corner member 38c includes a 1 st insertion portion into which one side of each of the 2 vertical members 38a is inserted, a 2 nd insertion portion into which one side of each of the 2 lateral members 38b is inserted, and an intermediate connection portion bent about 90 degrees and serving to connect the 1 st insertion portion with the 2 nd insertion portion.

The spacers 38 formed by inserting the vertical members 38a and the horizontal members 38b into the insertion portions are fixed to the upper side together with the cooling panel 30 by the first sealing material 37, and are fixed to the lower side together with the transparent plate 39 by the first sealing material 37. The ventilation through-hole is formed in the inner wall of the partition 38 opposed to the LED light-emitting unit 34 when the partition 38 is disposed in the lighting system. A moisture absorbent such as activated carbon, silica gel, or molecular sieve is filled in the hollow portion inside the separator 38.

Referring again to fig. 6 and 7, the secondary sealing material 60 fills the void space formed between the cooling panel 30 and the light-transmitting plate 39 over the entire periphery of the spacer 38. Chamfered recesses 38d are formed along the length thereof at the upper and lower edge portions at the outer side wall portion of the spacer 38 to fit the inner protrusions 60a at the upper and lower edge portions of the secondary seal material 60.

A frame member 61 having a groove shape for covering to fit is attached to both edges in the width direction of the cooling panel 30 and the light-transmitting plate 39 and the secondary sealing material 60 filled between the cooling panel 30 and the light-transmitting plate 39. The frame member 61 is formed of an upper wall portion 61a, a lower wall portion 61b, and a vertical wall portion 61c connected between the upper wall portion 61a and the lower wall portion 61b, and has a rectangular cross-sectional shape with one edge portion removed. A screwing-in inward ridge portion 61a having a C-shaped cross-sectional shape is formed at the vertical center of the vertical wall portion 61C along the entire length of the frame member 61.

A lower fitting ridge 61e having an arcuate cross section is formed along the entire length of the inner end portion of the upper wall portion 61a of the frame member 61. In response to this, both end portions in the width direction of the heat dissipation substrate 31 of the cooling panel 30 are formed to be thin, and the respective upper surfaces of the thin end portions have fitting concave portions 31a having an arcuate cross section. The cooling panel 30, the light-transmitting plate 39, and the secondary sealing member 60 are fastened to each other by the frame member 61.

In order to secure frame member 61 so as to cover the above components, secondary seal 60 is desirably flexible. In this condition, the screwing ridge portion 61d disposed on the vertical wall portion 61c of the frame member 61 is pressed into the secondary sealing material in a soft condition, so that the secondary sealing material 60 is nipped by the vertical wall portion 61c and the partition 38, deforming the vertical central portion of the secondary sealing material 60. In addition, inward ridges 60a are formed at the vertical both end portions of the secondary seal portion 60, and the inward ridges 60a are fitted to the chamfered recesses 38d of the spacer 38. Then, after curing of the secondary sealing material 60, a much more reliable seal is achieved.

As shown in fig. 7 and fig. 10 (a), (b), the lighting device includes a cover member 62 having a substantially L-shaped cross section. The cover members 62 are disposed to cover the secondary sealing material 60 at both longitudinal ends of the cooling panel 30 and the light-transmitting plate 39. The cover member 62 is composed of a vertical wall portion 62a and a horizontal portion 62b continuous with a lower end of the vertical wall portion 62 a. Portions around both ends of the vertical wall portion 62a are provided with through holes 62c for inserting tapping screws (タッピンね) for movement.

The cover member 62 is placed to cover the secondary sealing material 60 at both ends in the longitudinal direction with the horizontal portion 62b as the outer side. The lid member 62 is attached by inserting a tapping screw into the through hole 62C and then screwing the tapping screw into a screwing inward ridge 61d formed in the frame member 61 so as to have a substantially C-shaped cross section.

Also, when the secondary sealing material 60 is soft, the fixation of the lid member 62 is desirably performed. That is, the cover member 62 and the spacer 38 hold the secondary sealing material 60 under pressure to deform the secondary sealing material 60, and inward ridges 60a are formed at both upper and lower ends. These inward ridges 60a engage the chamfered recesses 38d of the spacer 38, and subsequently, the secondary sealing material 60 is cured, thereby achieving a much more reliable seal.

As the lighting system including the water cooling pipe illustrated in fig. 11, a fitting portion 70 having a C-shaped cross section is integrally formed on the upper surface of the cooling panel 30, and the water flow pipe 33 may be fitted by pressure to be attached to the fitting portion 70.

Although the lighting system shown in fig. 6 or 11 is of a water-cooled type in which the water flow pipe 33 is fixed to the hollow portion 32 or the fitting portion 70 formed integrally with the heat dissipation substrate 31, an air-cooled type system may possibly exhaust heat. Fig. 12 shows a cross-sectional view along the width direction of a lighting system including heat dissipation fins 80 formed integrally with the heat dissipation substrate 31 as an air-cooled system.

In the lighting system including the heat dissipation fins 80, the cooling panel 30 is composed of the flat plate-shaped heat dissipation substrate 31 and the flat plate-shaped fins 80a extending perpendicularly to one side, i.e., the upper surface, of the heat dissipation substrate 31. The fins 80a are arranged with a given interval. When the root refers to a portion in contact with the heat dissipation substrate 31, the fin 80a may be formed to have the same thickness from the top to the root, or to have a thicker thickness from the top to the root, in order to provide a given fin strength. The cooling panel 30 including the fins 80a may be formed by extrusion molding using a metal material such as aluminum or copper having high thermal conductivity.

The air passes through ventilation gaps formed between the fins 80a, and the fins 80a are cooled by contact with the air. Then, the heat dissipation substrate 31 continuous with the fins 80a is cooled. Thus, the heat generated by the LED chip 35 can be absorbed to the heat dissipation substrate 31, and the heat generation of the LED chip 35 can be suppressed.

The above-described fin 80a has been described as having a flat plate shape; however, the fin 80a may have a rod shape. Here, the fins 80a may be formed in an appropriate thickness and length so that the fins 80a are disposed at an appropriate distance and air can be appropriately passed therethrough to suppress heat generation of the LED chip 35.

The lighting system can include a cover 81 covering the fins 80 a. The cover 81 can be prepared to avoid the deposition of dust and/or dirt of the fins 80 a. The cover 81 may be fixed to the cooling panel 30 by screws or the like (not shown). Similarly, the cover 81 may be formed by extrusion molding using aluminum or copper having high thermal conductivity.

The other components may be the same as those of the lighting system exemplarily illustrated in fig. 6-10.

The lighting system including the means for heat removal exemplarily shown in fig. 6 to 12 encloses the LED unit 34 by cooling the panel 30, the spacer 38, the transparent plate 39, and the like, and thus can protect the LED device and the electronic circuit while providing high durability against the use environment under high humidity conditions of the plant cultivation apparatus and the like. In addition, since the reflection sheet 40 is attached, the light reflected by the cultivation surface can be reflected again compositely and efficiently to the plants planted at the cultivation tray. In addition, the above components can exhaust heat to suppress a temperature increase in the cultivation space when light is reflected compositely to the plant.

As a result, deterioration of the light source is prevented, the life of the light source is extended, and the number of light sources is reduced while the size of the cultivation space is reduced by avoiding an additional space between the light source and the plant. In particular, since the durability of the light source can be improved and the cultivation space can be made compact, the economical applicability of the plant factory can be expanded.

In the above, the illumination system and the plant cultivation apparatus including the illumination system of the present invention have been explained by using the above-described embodiments; however, the present invention should not be limited to the above embodiments. May allow changes, such as other embodiments, additions, modifications, and deletions, that may be made by those skilled in the art; however, any embodiments may be included within the scope of the present invention as long as the effects and advantages of the present invention should be obtained.

Description of the symbols

10 … lighting system, 11 … light source, 12 … main body, 13 … holes, 14 … reflective sheet, 15 … reflector, 16 … upper plate, 17 … side plate, 18 … lower plate, 19 … terminal block, 20 … plant cultivation device, 21 … trough member, 22 … cultivation tray, 23 … cultivation shelf, 24 … circulating pump, 25 … cultivation liquid tank, 26 … air pump, 27 … reflective sheet, 28 … reflective sheet, 30 … cooling panel, 31 … heat dissipation substrate, 31a … fitting ridge, 32 … hollow, 33 … water pipe, 34 … LED lighting unit, 35 … LED chip, 36 … secondary reflector, 36a … mirror type reflective portion, 37 … primary sealing material, 38 … separator, 38a … vertical member, 38b … transverse member, 38c … corner member, 38d 3639 chamfered recess, … light-transmitting plate, 40 … reflective sheet, 40 … hole, … wiring layer 3650, … adhesive layer 3651, 53 … circuit board, 54 … LED attachment hole, 55 … primary reflector, 56 … bonding wire, 57 … sealing resin, 58 … screw, 60 … secondary sealing material, 61a … upper wall portion, 61b … lower wall portion, 61c … vertical wall portion, 61d … screwing in with inward ridge portion, 61e … lower mating ridge portion, 62 … cover member, 62a … vertical wall portion, 62b … horizontal portion, 62c … tapping screw insertion through hole, 70 … fitting portion, 80 … heat dissipation fin, 80a … fin, 81 … cover.

Claims (13)

1. An illumination system, comprising:

a plurality of light sources;

a main body holding the plurality of light sources while including a transparent window portion for escaping light emitted from the light sources; and

a reflection member disposed so as to cover the window portion so as to reflect light from the outside of the body, while being formed with a plurality of holes for emitting light emitted from each of the light sources.

2. The illumination system as claimed in claim 1, wherein the reflective member is a reflective sheet, and a reflectance of the reflective sheet is not less than 98%.

3. The lighting system according to claim 1 or 2, wherein a material having hygroscopicity is enclosed in the main body.

4. The lighting system of claim 1, wherein the body comprises: a cooling panel to which the plurality of light sources are attached; a spacer disposed such that the spacer is disposed to surround the plurality of light sources and bonded to the cooling panel by a sealing material; and a light-transmitting plate disposed to face an attachment surface of the plurality of light sources attached to the cooling panel while being connected to the spacer by a sealing material to seal the light sources.

5. The lighting system of claim 4, wherein the cooling panel comprises a hollow portion at a back side of the attachment faces of the plurality of light sources, and is cooled by a cooling fluid flowing in the hollow portion.

6. The lighting system of claim 5, wherein the lighting system further comprises a flow pipe passing through the hollow portion to flow the coolant fluid therein.

7. The lighting system according to claim 4, wherein the cooling panel includes a fitting portion at a back surface of the attachment surfaces of the plurality of light sources, and the water flow pipe is fixed by pressing the water flow pipe into the fitting portion.

8. The lighting system according to claim 4, wherein the cooling panel includes heat dissipation fins, and the heat dissipation fins are arranged at given intervals on the back of the attachment faces of the plurality of light sources.

9. A plant growing apparatus comprising:

at least one trough member;

a cultivation shelf on which at least one trough member is placed obliquely to the longitudinal direction;

a cultivation tray placed adjacent to each other on the at least one trough;

a culture medium supply unit configured to supply a culture medium into each of the tank members; and

a lighting system selected from any one of claims 1 to 8 for illuminating light to plants grown on a plurality of said cultivation trays.

10. The plant cultivation apparatus as claimed in claim 9, wherein the plant cultivation apparatus includes a reflection plate including a reflection surface for reflecting light from the illumination system and light reflected by surfaces of the plurality of cultivation trays, and the reflection plate is disposed so as to close a side of the plurality of cultivation trays on which the plants are planted.

11. A plant growing apparatus according to claim 9 or 10, wherein the growing trays are positioned such that the growing trays are positioned in a sequence in which the plants grow along a longitudinal direction of at least one of the trough members, and the trough members are divided into at least two zones along the longitudinal direction, and the lighting system comprises for the zones at least two lighting systems each comprising a different number of light sources determined depending on the growth of the plants.

12. A plant cultivating device according to any one of claims 9 to 11, further comprising a gas supply means for supplying oxygen to the culture liquid.

13. A plant growing apparatus according to any one of claims 9 to 12, wherein the plant growing apparatus is placed in a room, and further comprises an air circulating means for circulating air in the room, a humidity controlling means for controlling humidity in the room, and a float removing means for removing floats in the room.