JP2004049211A - Plant culture apparatus equipped with lighting device and the lighting device used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plant culture apparatus equipped with a lighting device which increases photon flux density inside the culture apparatus and achieves uniformity in the photon flux density and distribution of color (light quality), and to provide the lighting device used for the same. <P>SOLUTION: A flat emission-type light source panel 27 is mounted on an upper part of the culture apparatus 26. The culture apparatus 26 is formed into a box shape in which stanchions 28 are arranged in its four corners and right and left parts of side walls, and further the side walls are composed of a transparent film or plate so that the inside of the apparatus can be observed and bacteria, dusts, etc., are prevented from invading the apparatus. The flat emission-type light source panel 27 has a cold-cathode fluorescent lamp 20, a reflector 24 for reflecting light from the lamp, a light-guiding plate 22, and a reflection sheet 21 and a diffusion sheet 23 which are arranged on both surfaces of the plate, respectively. The diffusion sheet 23 transforms the light which is guided from the light-guiding sheet 22 and then passes through the diffusion sheet 23 into the light composed of beams parallel in the direction vertical to an irradiation surface of the panel, so that the light having approximately uniform intensity and distribution of the color all over the irradiation surface is emitted. <P>COPYRIGHT: (C)2004,JPO

Description

【表２】

【表３】

【表４】

表１は距離設定基準面より１０ｃｍ上の位置で測定した光量子束密度の測定結果、表２は距離設定基準面より８ｃｍ上の位置で測定した光量子束密度の測定結果、表３は距離設定基準面より５ｃｍ上の位置で測定した光量子束密度の測定結果、および、表４は培養支持体上面で測定した光量子束密度の測定結果であり、分割領域Ａ〜Ｉの上部の数値は光量子束密度（単位：μｍｏｌ／ｍ^２　・ｓ）の実測値を、また、下部の数値は青色光と赤色光との比率として青色光の比率、すなわち、青色／（赤色＋青色）（単位：％）を測定した値をそれぞれ示している。
【００６３】
なお、各植物培養装置の光源は培養支持体上面中央部の光量子束密度が５０μｍｏｌ／ｍ^２　・ｓ以下になる条件で点灯し、また、培養に適している色分布（光質）として、青色光と赤色光との比率を２：８とした。
【００６４】
さらに、光源の点灯条件として、冷陰極蛍光ランプ１本の平面発光型光源パネルの場合、入力電圧：７．４ｖ、入力電力：４．１ｗ、ランプ電流：４．９ｍＡｒｍｓであり、一方のＬＥＤ光源の場合、青色ＬＥＤ９個と赤色ＬＥＤ３６個で、入力電圧：１０ｖ、入力電力：３．０ｗである。
【００６５】
表１乃至４に示す測定結果から明らかなように、本発明の植物培養装置では、距離設定基準面からの距離にかかわらず光量子束密度の分布のばらつきが従来の装置に比較して小さい。
【００６６】
すなわち、本発明の植物培養装置では、表１に示すように、培養支持体上面の中央部の分割領域Ｅの光量子束密度を１００％としたときの各分割領域の光量子束密度のばらつきは９２〜９７％であった。また、表４に示すように、光源に最も近い位置においても、光量子束密度のばらつきは９２〜９８％であった。また、色分布（光質）に関しては、本発明の植物培養装置では、距離設定基準面からの距離にかかわらず全ての分割利用域において２０％と一定であった。
【００６７】
したがって、このような本発明の装置によれば、特に、クローン苗の培養に求められる成長の均一性を達成することが可能である。
【００６８】
これに対して、ＬＥＤ素子を用いた従来の植物培養装置では、培養支持体面上の光量子束密度および色分布（光質）のばらつきは少ないが、光量子束密度および色分布（光質）ともに、距離設定基準面からの距離により大きくばらついている状態が表１乃至４に示されている。
【００６９】
このような測定結果から、従来の装置では、光量子束密度のばらつき傾向は苗が生長するに従い、すなわち、光源に近づくほど顕著であり、また、光源面に対して平行な面ではなく、少し角度を変えると、その光質の差がより大きくなるという問題もあることがわかる。
【００７０】
次に、本発明の平面発光型光源パネルを用いた植物培養装置により、シンビジウム苗条の無菌培養を行い、その成長状況を観測した。また、本発明の装置の効果を確認するために、従来の培養棚を用いる植物育成装置およびＬＥＤを光源とする従来の植物育成装置についても同様な観測を行った。表５にこの結果を示す。
【００７１】
なお、この実験に用いた植物育成装置は、光源の赤色光と青色光との構成比を８：２とし、温度２５℃、３０００ｐｐｍの炭酸ガスを使用したインキュベーター内で、光源を１６時間点灯し、８時間休止するという点灯サイクルで栽培を行なった。
【００７２】
表５には、培養棚を用いた従来の植物育成装置であって、管状の蛍光ランプ光源から培養支持体上面までの距離が２５ｃｍの従来例１、同じく管状の蛍光ランプ光源から培養支持体上面までの距離が４０ｃｍの従来例２、ＬＥＤ素子の平面配列を光源とし、この光源から培養支持体上面までの距離が１１ｃｍの従来例３、そして冷陰極蛍光ランプからなる平面発光型光源パネルを光源とし、この光源から培養支持体上面までの距離が１１ｃｍの本発明の実施例１の各装置について、草丈が１０ｍｍ、５０ｍｍ、９０ｍｍに到達した各時点までの日数および地上部生体重量が記載されている。
【００７３】
【表５】

この観測結果から、草丈が１０ｍｍの低い時期の成長スピード、すなわち、栽培日数は従来例も本発明の実施例でも差はないが、草丈が５０ｍｍ〜９０ｍｍと伸びて光源に近づくと、本発明の実施例の栽培日数は従来例に較べて８日から最大２５日も短縮され、本発明の成長スピードは加速度的に早くなっている。
【００７４】
この理由は、図９に示した光量子束密度のグラフからも明らかなように、植物が成長して光源に近づいても、管状の蛍光ランプ光源を用いた従来例１、２における光量子束密度は殆ど変わらないが、ＬＥＤ光源を用いた従来例３あるいは平面発光型光源を用いた本発明の実施例１では光量子束密度は比例的に増加し、したがって、植物は成長すればする程、多くの光量を必要とするので、相乗的に成長するものと考えられる。
【００７５】
ただ、ＬＥＤ光源を用いた従来例３は、本発明の実施例１と較べて、図９の培養支持体からの距離約１１ｃｍにおける光量子束密度の差だけ低い光量子束密度を有しているため、成長スピードもやや低くなっている。この理由の一つは、表１乃至４に示したように培養支持体面およびこれに平行で異なる高さの栽培面での光量子束密度のバラツキが大きく、しかも、色分布、すなわち、赤色光と青色光との比のバラツキが大きく、均質な光となっていないためと推測できる。
【００７６】
表６には表５に示した管状の蛍光ランプ光源を用いた従来例２、ＬＥＤ光源を用いた従来例３および平面発光型光源パネルを用いた本発明の実施例１についての成長速度とスペース効率との関係を示されている。
【００７７】
【表６】

ここで、成長速度は、表５において、シンビジウムの苗が草丈が９０ｍｍに到達する最長日数１１５日を基準として求め、スペース効率は培養容器の高さ１４ｃｍと各光源の厚さ２ｃｍを考慮し、一般的な培養棚間隔４０ｃｍに重ね置きできる個数として計算した。
【００７８】
すなわち、成長速度は、表５における従来例２の栽培日数１１５日に対する栽培日数の比率で、本発明の実施例１の成長速度は（９０／１１５）＝１．２７であり、従来例３の成長速度は（９８／１１５）＝１．１７で表されている。
【００７９】
また、スペース効率は従来例２による培養容器の高さに対する培養容器の高さ（高さ＋光源の厚さ）の比率で表され、本発明の実施例１のスペース効率は（４０ｃｍ／（１４＋２））＝２．４となり、２倍以上のスペース効率となっている。なお、従来例３のスペース効率は（４０ｃｍ／（１４＋２））＝２．４であり、本発明と同一である。
【００８０】
この表６から成長速度およびスペース効率の総合効果は、本発明の装置が最も高いことがわかる。
【００８１】
このように、本発明の植物培養装置に用いられる平面発光型光源パネルは厚さが約６〜２０ｍｍと薄い上に、培養容器と一体化しているので、多段的な配置による高密度栽培が達成でき、省スペース化による高いスペース効率を有する。
【００８２】
なお、上記本発明の植物培養装置は、導光板を介して内部に光を取り入れているため、培養容器の内部温度の上昇が非常に低く抑えられる。例えば、２５℃に設定した培養容器内においては、１℃以下の温度上昇に留まり、導光板のある光源パネル中央の温度も１℃以下の温度上昇であった。このことは、本発明による平面発光型光源パネルは植物が成長して近接しても葉焼けなどの障害が出ない光源であるといえる。
【００８３】
図１２は、本発明を工業的な植物育成に応用した植物培養装置を示す側面図で、車輪４２を取り付けた棚下４３上に多数の培養容器４４が載せられている。これらの培養容器４４の上部には棚天井４５と僅かな隙間をあけて平面発光型光源パネル４６が設置されている。この平面発光型光源パネル４６は、図１、図５、図６あるいは図７に示される照明装置である。
【００８４】
そこで、このような装置において、平面発光型光源パネル４６の真下に培養容器４４を例えば１６時間置き、その後、棚下４３を平面発光型光源パネル４６のない場所に移動させて１６時間休止する。この休止後再び棚下４３を平面発光型光源パネル４６の真下に移動させ１６時間置く。
【００８５】
次に、上記の休止期間中には多数の培養容器４４が載せられた他の棚下４３（図示せず。）を平面発光型光源パネル４６の真下に移動し、１６時間経過後にはこの棚下４３を平面発光型光源パネル４６のない場所に移動させる。このように、培養システムのフローを作成することによって、一枚の平面発光型光源パネル４６を多数の培養容器４４に対して共用することができる。
【００８６】
図１３乃至１６は本発明に使用する平面発光型光源パネルの他の例を示す図である。これらの光源パネルにおいては、いずれも図１および図２に示される拡散シートを備えていない。図１３は、図１に示したエッジ型平面発光型光源パネルから拡散シート２３を除去したもので、その他の構成は図１とほぼ同一であるため、対応する部分には同一符号を付し、詳細な説明は省略する。
【００８７】
図１４乃至１６は、図１３に示す光源パネルにおける冷陰極蛍光ランプ２０を導光板２２の一辺にのみ配置したエッジ型平面発光型光源パネルの概要を示す断面図である。これらの光源パネルにおいてはまた、導光板２２の厚さが冷陰極蛍光ランプ２０から離れるにしたがって薄くなっている。
【００８８】
図１４の光源パネルにおいては、導光板２２の表面に印刷された散乱ドットパターン２２´は、冷陰極蛍光ランプ２０から離れるにしたがって徐々にその面積が大きく、あるいは、ドット間隔が小さくなるように印刷されている。これによって、導光板２２の内部において、ランプ２０の近くで明るく、遠くなるほど輝度が低下する傾向を緩和している。
【００８９】
図１５に示す光源パネルにおいては、導光板２２の表面に散乱ドットパターン２２´の代わりに、光を乱反射するためのＶ溝５１加工が施され、冷陰極蛍光ランプ２０から離れるにしたがって徐々にＶ溝５１の間隔を小さくしている。これによって、導光板２２の内部において、ランプ２０の近くで明るく、遠くなるほど輝度が低下する傾向を緩和している。
【００９０】
図１６に示す光源パネルにおいては、導光板２２の表面に散乱ドットパターン２２´あるいはＶ溝５１を設ける代わりに、光を乱反射するためにサンブラスト加工のような粗面５２加工を施し、冷陰極蛍光ランプ２０から離れるにしたがって徐々に粗面５２を粗くする。これによって、導光板２２の内部において、ランプ２０の近くで明るく、遠くなるほど輝度が低下する傾向を緩和している。
【００９１】
表７および表８は、図１３に示すエッジ型平面発光型光源パネルを用いた本発明の植物培養装置の培養支持体上における光量子束密度の実測値と色分布（光質）との測定数値を図１３に示すエッジ型平面発光型光源パネルを用いた本発明の植物培養装置との対比により示す表である。
【００９２】
すなわち、この測定は、拡散シート２３を除去した光源パネルと拡散シート２３を備えた光源パネルを用いた植物培養装置との比較を行ったものである。なお、この測定は、表１乃至表４に示した測定と同じ測定方法を用いた。
【００９３】
【表７】

【表８】

表７は距離設定基準面より８ｃｍ上の位置で測定した光量子束密度の測定結果、表８は培養支持体上面で測定した光量子束密度の測定結果であり、分割領域Ａ〜Ｉの上部の数値は光量子束密度（単位：μｍｏｌ／ｍ^２　・ｓ）の実測値を、また、下部の数値は青色光と赤色光との比率として青色光の比率、すなわち、青色／（赤色＋青色）（単位：％）を測定した値をそれぞれ示している。
【００９４】
分割領域Ａ〜Ｉにおける光量子束密度のばらつきを、光量子束密度の最大値に対する最小値の割合で表すと、距離設定基準面より８ｃｍ上の位置では表７から、拡散シートがある場合には８６％であるのに対して、拡散シートがない場合にも７８％で、表２に示したＬＥＤ光源の場合の５１％に比較して優れた均一性を有していることがわかる。
【００９５】
なお、培養支持体上面での測定値は、表８に示されるように、拡散シートがある場合およびない場合のいずれの場合にも９６％と同じ値を示した。
【００９６】
図１７乃至図１９は本発明の植物培養装置の他の実施形態を示す図である。これらの実施形態においては、平面発光型光源パネルと培養容器が、載置部材により所定の位置関係に配置されている。すなわち、図１７（ａ）および（ｂ）は、斜視図および側面図である。
【００９７】
図１７（ａ）および（ｂ）において、載置部材５３Ａは、金属や硬質合成樹脂等からなる無空棒材、パイプ材や板材を曲折して形成した前記培養容器２６の高さよりやや高い一対のＺ字型の支柱５４，５４と、この支柱５４，５４の各端部間や中間の折曲部間、ここでは中間の折曲部間を接続した２本の補強用の支持梁５５，５５とで構成され、支柱５４，５４および支持梁５５，…で囲まれた略四角形をなす枠状の載置部材５３Ａの空間５０内に、前記培養容器２６が入れられる。
【００９８】
また、平面発光型光源パネル２７を構成するハウジング１９の対向する両側壁には、下側に開口している直線状の溝部５６を有する取付片５７が設けられている。そして、前記載置部材５３Ａを構成するＺ字型の支柱５４，５４の上方の支持梁５８，５８（一方は図示しない。）に、前記ハウジング１９に設けられた取付片５７，５７の溝部５６，５６を嵌込むことにより一体化される。図中、１９ａは内部にインバーターを収容した突状部である。
【００９９】
この植物培養装置は、載置部材５３Ａの上方側に平面発光型光源パネル２７が保持され、この載置部材５３Ａの支柱５４，５４間に前記培養容器２６を配置すれば、前記光源パネル２７と培養容器２６とは対向して前記光源パネル２７からは水平面上で均一の光照射分布が得られることから、前記培養容器２６内において培養支持体や植物等に均等な光照射が行われる。
【０１００】
また、培養容器２６を囲う載置部材５３Ａが枠状であるので、培養容器２６の出し入れおよび培養容器２６内の植物の育成状態等の観察が容易に行える。
【０１０１】
また、前記培養容器２６の高さがＺ字型の支柱５４，５４の高さよりやや低いので、前記平面発光型光源パネル２７の下面との間に隙間が形成される結果、蛍光ランプ２０の点灯時に前記光源パネル２７からの放射熱を逃がし培養容器２６内の温度上昇を阻止できる。
【０１０２】
なお、前記枠状の載置部材５３Ａを構成する一対の支柱５４，５４をＺ字型としたがＺ字型に限らず、口字型や日字型等などであってもよく、また、支持梁５５の本数は、平面発光型光源パネル２７の重量等に対応して適宜本数設ければよい。また、平面発光型光源パネル２７の取付片５７も溝部５６に限らず、ハウジング１９にフックや切込み等の係止手段を設けたりあるいは載置部材５３Ａ側に光源パネル２７の移動阻止手段を設けるようにしても差支えない。さらに、平面発光型光源パネル２７は、支柱５４に限らず支持梁５５に保持させるようにしてもよい。
【０１０３】
図１８（ａ）、（ｂ）および図１９は、本発明の植物培養装置のさらに他の実施形態を示し、図１８（ａ）および（ｂ）は、斜視図および側面図、図１９は平面発光型光源パネルおよび前記培養容器が配設されていない状態の載置部材単体の斜視図である。
【０１０４】
この実施形態においては、載置部材５３Ｂは、透明アクリル等の合成樹脂等からなる板材を前記培養容器２６の高さよりやや高いコ字型に曲折して構成され、このコ字型が形成する空間５０内に前記培養容器２６が入れられる。
【０１０５】
また、平面発光型光源パネル２７は、載置部材５３Ｂの上板５９上に載置され、この上板５９にねじ６０，…止めや、光源パネル２７の側壁の周縁部が上板５９の周縁に嵌合する（図示しない。）ことによって取付けられている。
【０１０６】
この載置部材５３Ｂは、図１９に示すように、上板５９の中央部に孔５８ａが形成されている。このように開口しておくことにより、光源パネル２７による透過光損失の低減がはかれる。
【０１０７】
このような載置部材５３Ｂを設けることにより、図１７に示した実施形態と同様に、前記培養容器２６の高さがコ字型の載置部材５３Ｂの高さよりやや低いので、前記平面発光型光源パネル２７の下面との間に隙間が形成される結果、蛍光ランプ２０の点灯時に前記光源パネル２７からの放射熱を逃がし培養容器２６内の温度上昇を阻止できる。
【０１０８】
そして、この載置部材５３Ｂは、上板５９の中央部に孔５８ａが形成されているため、平面発光型光源パネル２７の直下に配置した前記培養容器２６内において均等な光照射が行われる。また、コ字型の載置部材５３Ｂはその側面の３方が開口しているので、前記培養容器２６の出し入れが容易である。
【０１０９】
なお、この実施形態においては、図１９に示すように載置部材５３Ｂを構成する上板５９の中央部に孔５８ａを形成したが、載置部材５３Ｂに透明度の高い材料を用いる場合には、孔５８ａを形成することなく、平面発光型光源パネル２７の放射光を載置部材５３Ｂを透過して培養容器２６内に照射してもよい。また、前記載置部材５３Ｂをコ字型に形成したが、開口部は２方となるが口字型等であってもよい。
【０１１０】
【発明の効果】
以上説明した本発明によれば、植物培養装置用の照明装置として冷陰極蛍光パネル（装置）あるいはＬＥＤ素子を使用し、且つ、その照射面に拡散シートを設けたので、培養容器内に高い光量子束密度と均一な色分布（光質）を有する照射光を供給することができる。その結果、クローン苗や無菌苗などの成長速度を著しく向上させることができる。
【０１１１】
また、本発明によれば、高さが２０ｃｍ以下の培養容器により、高い光量子束密度と均一な色分布（光質）の照射光を供給できるため、小型軽量でスペース効率の高い植物培養装置が得られる。
【図面の簡単な説明】
【図１】本発明の平面発光型光源パネルの一実施形態を示す斜視図である。
【図２】図１に示す平面発光型光源パネルの分解斜視図である。
【図３】本発明の植物培養装置の一実施形態を示す斜視図である。
【図４】本発明の植物培養装置の他の実施形態を示す斜視図である。
【図５】本発明の平面発光型光源パネルの他の実施形態を示した斜視図である。
【図６】同じく本発明の平面発光型光源パネルの他の実施形態を示した斜視図である。
【図７】同じく本発明の平面発光型光源パネルの他の実施形態を示した斜視図である。
【図８】図７に示した複数個の蛍光ランプへのインバーターからの電力供給回路構成を示す斜視図である。
【図９】図１に示す平面発光型光源パネルにより放射される光量子束密度の測定結果を示すグラフである。
【図１０】図３に示す本発明の植物培養装置内部における光量子束密度の測定結果を、従来のＬＥＤ素子を用いた植物培養装置および管状光源（蛍光ランプ）を用いた培養棚と対比して示したグラフである。
【図１１】植物培養装置内部における光量子束密度を測定する装置の概要を示す平面図である。
【図１２】本発明を工業的な植物育成に応用した植物培養装置を示す側面図である。
【図１３】本発明の平面発光型光源パネルの他の実施形態を示した斜視図である。
【図１４】同じく本発明の平面発光型光源パネルの他の実施形態を示した断面図である。
【図１５】同じく本発明の平面発光型光源パネルの他の実施形態を示した斜視図である。
【図１６】同じく本発明の平面発光型光源パネルの他の実施形態を示した斜視図である。
【図１７】本発明の植物培養装置の他の実施形態を示し、同図（ａ）は斜視図、（ｂ）は側面図である。
【図１８】本発明の植物培養装置の他の実施形態を示し、同図（ａ）は斜視図、（ｂ）は側面図である。
【図１９】図１８に示す植物培養装置における載置部材の斜視図である。
【図２０】従来の培養棚を用いた植物培養装置の概略構成を示す側面図である。
【図２１】従来のＬＥＤ素子を光源として用いた植物培養装置の概略構成を示す斜視図である。
【図２２】従来の培養棚を用いた植物培養装置の使用状況を示す側面図である。
【図２３】従来のＬＥＤ光源を使用した植物培養装置内の照射光分布モデルを示した斜視図である。
【符号の説明】
１，２６，４４　培養容器
２，２９　培地、培養支持体
３，４３　棚下
４，４５　棚天井
５　熱陰極蛍光ランプ
６　ＬＥＤ素子
７　培養支持体
８　無駄な空間
９　白紙
１０　斑点
１７　光量子測定箇所
１８　センサー
１９　ハウジング
２１　反射シート
２２　導光板
２３，３５，４１　拡散シート
２４　リフレクター
２５，３１　インバーター
２８　支柱
３０　凸部
３２　平面発光型光源パネル上面
３３　トップシール
３４　ＬＥＤ素子
３９　冷陰極蛍光ランプ
４０　反射板
４２　車輪[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plant culture device used for plant tissue culture or plant cultivation using an artificial light source, and a lighting device used for the same.
[0002]
[Prior art]
In recent years, as a future food problem, a closed plant growing method that artificially controls the environment without being affected by the environment has attracted attention.
[0003]
In a culture shelf generally used as a conventional artificial plant growing method, a culture medium 2 is stored at the bottom of a culture vessel 1 as shown in FIG. In ordinary plant tissue culture, a plurality of such culture vessels 1 are placed on the lower shelf 3. By irradiating these containers 1 with a generally used tubular hot-cathode fluorescent lamp 5 installed on the shelf ceiling 4, plant tissue culture and plant cultivation in the culture container 1 are performed.
[0004]
On the other hand, it is known that, in such artificial plant growing, the use of cloned seedlings or sterile seedlings increases productivity and significantly improves yield and quality.
[0005]
By the way, in order to produce such cloned seedlings or aseptic seedlings, a culture vessel is required to be impermeable to bacteria and to prevent drying of the culture support.In particular, the culture vessel is micropropagated, that is, It is indispensable for the production by micropropagation of elite solids by tissue culture technology.
[0006]
FIG. 21 is a perspective view showing an outline of a plant culture vessel proposed by Michio Tanaka for such a purpose. As disclosed in Japanese Patent Application Laid-Open No. 9-252651, this container comprises a culture container 1 having a side wall formed of a special resin film which has a light-transmitting property and a gas-permeability but is impervious to moisture, germs and the like. The LED light source 6 provided at the upper end of the container 1 is integrated.
[0007]
The LED light source 6 has a large number of LED elements arranged in a plane in order to obtain a uniform light distribution in the plane of the culture support 7 provided at the bottom of the culture vessel 1. These LED elements include an LED element that emits red light and an LED element that emits blue light, and are dispersedly arranged so that the respective lights are uniformly mixed with each other.
[0008]
Here, the reason for using an LED element that emits blue light and red light is that light necessary for growing a plant is light having a wavelength in which red and blue components are uniformly mixed, and this uniform mixing is performed. In order to obtain different wavelengths, blue and red LEDs are regularly arranged.
[0009]
[Problems to be solved by the invention]
In the above-described plant growing apparatus using the culture shelf, since a tubular hot cathode fluorescent lamp is used as a light source, it is difficult to make the light amount distribution on the light receiving surface uniform. That is, since the distance between the light source and each cultivation point greatly changes on the horizontal plane of the shelf, it is difficult to make the light amount distribution on the light receiving surface uniform using light emitted concentrically from the tubular light source.
[0010]
Further, the hot cathode fluorescent lamp has disadvantages such as a large tube diameter and a short life as compared with the cold cathode fluorescent lamp, and a circuit for heating the hot filament is required, and the lighting circuit is complicated.
[0011]
Therefore, the distance between the fluorescent lamp 4 and the culture vessel 1 needs to be at least 35 to 50 cm in order to reduce the influence of the radiant heat and make the light amount distribution uniform. As a result, not only the whole growing apparatus becomes large, but also the culture vessel 1 cannot be placed on the lower shelf 3 and the space efficiency is poor.
[0012]
Further, in the plant growing apparatus using the above-described culture shelf, when the number of the culture vessels 1 is small, as shown in FIG. Was also irradiated to a useless space 8 where no culture vessel was installed, and there was a problem in terms of energy saving.
[0013]
Next, in the above-described plant culture vessel using the LED as a light source, the above-mentioned problems of space efficiency and radiant heat are improved, but there are the following problems. That is, since the LED is a point light source, the emission angle of the emitted light is small and the directivity is strong, so that a difference in lightness and darkness appears depending on the location in the water surface in the plant culture vessel, and the distribution of the photon flux density also varies. .
[0014]
This means that, as shown in FIG. 23, when the white paper 9 is horizontally arranged between the LED light source 6 and the culture support 7 and the irradiation state is viewed, the spots 10 corresponding to the number of the LEDs 6 are found on the white paper 9. It can be confirmed from the clear appearance.
[0015]
Further, as described above, the wavelength necessary for growing a plant is a wavelength in which red and blue components are uniformly mixed, and in order to obtain this uniformly mixed wavelength, the blue and red LED elements are required. It is difficult to obtain a uniform color distribution (light quality) only by regularly arranging.
[0016]
In other words, simply arranging the blue and red LED elements regularly varies the intensity of each luminescent color depending on the arrangement position, and a technique for adjusting this to make the color distribution (light quality) uniform has been realized. Did not.
[0017]
Therefore, an object of the present invention is to provide a plant culture apparatus provided with a lighting device that has uniform color light distribution (light quality) and photon flux density distribution in a plant culture container and eliminates the influence of radiant heat. It is assumed that.
[0018]
[Means for Solving the Problems]
A plant culture device equipped with the lighting device of the present invention is a plant culture container that forms a culture space by a wall having at least a ceiling surface having optical transparency, a culture support disposed at the bottom of the container, A flat light-emitting device disposed on the ceiling surface of the plant culture vessel, the flat light-emitting device has a flat light guide plate having at least one end surface as a light incident end surface, and a flat plate of the light guide plate. Light control means for emitting light incident from the one end surface formed on the surface from the flat plate surface and controlling at least the entire illuminance of the flat plate surface to be uniform, and disposed on at least one end surface of the light guide plate. A light source is provided, and an illuminance distribution on a horizontal plane by light emitted from the entire ceiling surface of the plant culture vessel is made uniform.
[0019]
Further, a plant culture device equipped with the lighting device of the present invention includes a plant culture container in which at least a ceiling surface forms a light-permeable culture space, a culture support disposed at the bottom of the container, and the plant culture container. A flat light-emitting light source device disposed on the ceiling surface of the container, the flat light-emitting light device includes a light source disposed on the ceiling surface side of the plant culture container, and light from the light source being used for the plant culture. A planar light transmitting member that diffuses and irradiates the culture space of the container, and uniformizes the illuminance distribution on a horizontal plane by light emitted from the entire ceiling surface of the plant culture container. is there.
[0020]
Further, in the plant culturing apparatus equipped with the lighting device of the present invention, the flat light source device includes a light guide plate, a thin-walled cold cathode fluorescent lamp disposed on a peripheral portion of the light guide plate, and a cold cathode. It is characterized by comprising a reflector for reflecting the light emitted from the fluorescent lamp in the direction of the light guide plate, and a reflection sheet provided on the surface of the light guide plate opposite to the light emission surface side.
[0021]
Furthermore, in the plant culture device equipped with the illumination device of the present invention, the flat light source device includes a plurality of thin tubular cold-cathode fluorescent lamps arranged substantially in parallel in a ceiling surface of the plant culture container. And a diffusion sheet arranged on one surface of the cold cathode fluorescent lamp array.
[0022]
Further, in the plant culture device equipped with the lighting device of the present invention, the flat light source device includes a plurality of LED elements arranged in a plane in a ceiling surface of the plant culture container, and the LED elements. And a diffusion sheet arranged on one side of the array.
[0023]
Furthermore, a plant culture device equipped with the lighting device of the present invention includes a plant culture container, a flat light-emitting light source panel for irradiating plant growing light into the plant culture container, and the flat light-emitting light source panel. A mounting member that supports the plant culture container with a gap at the top thereof, and the mounting member has at least a part of a side surface opened, and the plant culture container is connected to the plant culture container through the opened side surface. The flat light-emitting light source panel can be moved to a lower position and taken out from the lower position, and has such a height that the flat light-emitting light source panel is supported above the plant culture vessel with a gap. It is characterized by the following.
[0024]
The illumination device for a plant culture device of the present invention is a light source that irradiates light inside the plant culture container, a light guide plate that guides irradiation light from the light source into the ceiling surface of the plant culture container, and is radiated from the light guide plate. And a diffusion sheet for supplying a substantially uniform illuminance distribution to the inside of the plant culture vessel.
[0025]
Further, in the illumination device for a plant culture device of the present invention, the flat light source device includes a light guide plate, a plurality of LED elements arranged on a peripheral portion of the light guide plate, and light emitted from the LED elements. And a reflecting sheet disposed on one surface of the light guide plate.
[0026]
Further, in the illumination device for a plant culture device of the present invention, the flat light source device includes a plurality of LED elements arranged in a plane on a ceiling surface of the plant culture container, and an arrangement of these LED element arrays. And a diffusion sheet arranged on one surface.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a flat light-emitting light source panel using a cold cathode fluorescent lamp, which is an embodiment of a lighting device for a plant culture device equipped with the lighting device of the present invention, and FIG. 2 is an exploded perspective view thereof.
[0028]
Inside a panel-shaped housing 19, a cold cathode fluorescent lamp 20 in which a thin glass tube having a diameter of 2.6 mm is bent in a U-shape, a reflection sheet 21, and a light guide plate disposed opposite to the cold cathode fluorescent lamp 20 22, an edge-type lighting device including a diffusion sheet 23 for diffusing the transmitted light transmitted through the light guide plate 22 and a reflector 24 is housed.
[0029]
That is, the cold cathode fluorescent lamp 20 is fixed to three sides of the light guide plate 22, and a reflector 24 having a semicircular cross section is provided around the cold cathode fluorescent lamp 20. The reflection sheet 21 is disposed on one surface of the light guide plate 22, and the diffusion sheet 23 is disposed on the opposite surface of the light guide plate 22. The cold cathode fluorescent lamp 20 is accommodated in an opening having a semicircular cross section of the reflector 24, and the light guide plate 22, and the edges of the reflection sheet 21 and the diffusion sheet 23 laminated on both sides thereof are inserted.
[0030]
For the light guide plate 22, for example, an acrylic resin having the best light transmittance is used. On the surface of the light guide plate 22 on the reflection sheet 21 side, a large number of scattering dot patterns 22 'are screen-printed to form a diffused diffuse reflection film. A layer is formed. These scattering dot patterns 22 ′ are obtained by printing ink containing a white pigment or transparent beads that reflect light in a dot shape, and each scattering dot pattern 22 ′ has a large distance from the cold cathode fluorescent lamp 20. The light guide plate 22 is printed such that its area gradually increases toward the center portion or the dot interval decreases. This diffusely reflects the light from the cold cathode fluorescent lamp 20 incident on the inside of the light guide plate 22, and eliminates the tendency that the brightness increases near the lamp 20 and the brightness decreases as the distance increases.
[0031]
As for the light emitted from the cold cathode fluorescent lamp 20, the direct light and the light reflected by the reflector 24 enter from the end face of the light guide plate 22 and are guided into the light guide plate 22. Of the light guided to the light guide plate 22, the light traveling while reflecting inside the light guide plate 22 is reflected by the diffusely diffused film layer composed of the scattering dot pattern 22 ′ on the surface of the light guide plate 22, and is perpendicular to the irradiation surface. The light is converted into parallel light in the same direction, and is emitted as substantially uniform intensity and uniform color light over the entire irradiation surface.
[0032]
This light is further radiated as uniform light on the opposite side of the light guide plate 22 from the reflection sheet 21 by the diffusion sheet 23 fixed to the housing 19. Like the light guide plate 22, the diffusion sheet 23 is made of an acrylic resin having good light transmittance, and a white pigment is mixed in the resin.
[0033]
Such a diffusion sheet 23 is widely used for a liquid crystal display panel. For example, a D series diffusion sheet manufactured by Tsujiden Co., Ltd., model number D-121 can be used. The diffusion sheet 23 forms an irradiation surface from which uniform light is emitted from the entire surface.
[0034]
An inverter 25 for turning on the cold cathode fluorescent lamp 20 is provided on a side surface of the housing 19. Here, the phosphor coated on the inner surface of the bulb of the cold cathode fluorescent lamp 20 emits a blue light and a red light at a ratio of 2: 8 suitable for plant cultivation by adjusting the composition ratio thereof. Let me. The phosphor emits white light including the three primary colors of ordinary light, and a wavelength-selective film is adhered to the irradiation surface 23 of the housing 19 so that the ratio of blue light to red light is 2. : 8 may be generated.
[0035]
In the flat light-emitting light source panel configured as described above, light from the cold cathode fluorescent lamp 20 is reflected by the reflector 24, guided to the light guide plate 22, and emits light from both sides. Of these, the light traveling toward the reflection sheet 21 is reflected by the scattering dot pattern 22 ′ and the reflection sheet 21, and is converted into a parallel light beam in a direction perpendicular to the irradiation surface by passing through the diffusion sheet 23. As a substantially uniform intensity and a uniform color light.
[0036]
Since the flat light-emitting light source panel thus configured uses the thin-tube cold-cathode fluorescent lamp 20 as a light source, if the inverter 25 is removed, the size of the housing 19 becomes, for example, 120 mm × 120 mm and a thickness of 6 mm. It is possible to realize a small and lightweight lighting device for a plant culture device.
[0037]
FIG. 3 is a perspective view showing an embodiment of the plant culturing apparatus of the present invention in which the above-mentioned flat light emitting type light source panel is mounted as a light source. The culture vessel 26 has an opening at the upper ceiling surface, the size of which is 120 mm × 120 mm, which is the same as that of the flat light-emitting light source panel 27, and a height of 140 mm.
[0038]
The culture vessel 26 has a box shape having pillars 28 at four corners and left and right side walls, and the side walls thereof can be observed inside, and in order to avoid invasion of bacteria, dust, and the like, a special transparent film such as described above is used. It is composed of a plate. In addition, a reflective material is applied to the inner surface of the side wall or a reflective sheet is stuck to effectively use light.
[0039]
Further, a culture support 29 made of a medium or rock wool for cultivation is accommodated at the bottom. A plurality of projections 30,... Are provided at the opening edge of the culture vessel 26, and the above-mentioned flat light-emitting light source panel 27 is placed via the projections 30,. The protrusions 30,... Form a gap between the upper end of the culture vessel 26 and the flat light-emitting light source panel 27, and radiate heat from the flat light-emitting light source panel 27 through this gap to allow the inside of the culture vessel 26 to be released. Prevents radiant heat from entering the system.
[0040]
This gap is not limited to the projections 30 formed on the opening edge around the ceiling of the culture vessel 26, but by providing a projection on the placement side near the lower surface of the flat light source panel 27. Can also be formed. This gap can be formed by providing a concave portion around the ceiling of the culture vessel 26 or the lower surface of the flat light source panel 27, or by providing a convex portion 30,... Or a concave portion on at least one of the two. it can.
[0041]
In this embodiment, the inverter 31 is provided on the upper surface 32 of the flat illuminant light source panel 27. The inverter 31 has a photon flux density of about 50 μmol / m on the culture support 29 at the bottom of the culture vessel 26. ² Dimming is performed by controlling the DC voltage so as to be s. Under these conditions, the power supplied to the fluorescent lamp is 3-4 w and the lamp current is 5 mA.
[0042]
In addition, a top seal 33 may be provided on the culture vessel as shown in FIG. 4 on the upper ceiling surface of the culture vessel 26 as necessary. The top seal 33 is made of a film or a transparent resin sheet that transmits light from a light source but does not pass bacteria, and is selectively provided according to the type of plant to be cultivated. Note that these films and resins may be those that selectively transmit ultraviolet (UV) or infrared (IR).
[0043]
Further, as for the culture container 26, a plastic container or a glass container having a transparent upper surface can be used, and a container surrounded by a high gas transparent film for use in tissue culture of cloned seedlings, that is, bacteria and high gas are permeable. However, a container impermeable to water or a container in which a hole is made in a transparent resin container for gas exchange and a gas-permeable vinyl patch is attached thereto may be used.
[0044]
Next, another embodiment of the illumination device for a plant culture device of the present invention will be described with reference to FIGS.
[0045]
FIG. 5 shows a flat light-emitting light source panel in which a diffusion sheet 35 is arranged on an irradiation surface formed of a two-dimensional array of a plurality of LED elements 34. Directional radiated light from the LED elements 34 is directly diffused by the diffusion sheet 35 to make the photon flux density uniform on the surface of a support (not shown) in the incubator.
[0046]
FIG. 6 shows an edge-type LED light source using a plurality of LED elements 6 instead of the cold cathode fluorescent lamp 20 of the edge-type illumination device shown in FIG. That is, the LED elements 6 are arranged on two opposing sides of the light guide plate 22, and the reflection sheet 21 and the diffusion sheet 23 are arranged on both sides of the light guide plate 22.
[0047]
A reflector 24 having a U-shaped cross section is disposed on two opposing sides of the light guide plate 22 and houses an LED element therein. In such a configuration, light emitted by the LED elements 6 is guided into the plane by the light guide plate 22, and is uniformly distributed in the vertical direction from the surface of the diffusion sheet 23 by the reflection sheet 21 and the diffusion sheet 23. Is irradiated.
[0048]
FIG. 7 is a perspective view of a flat light emitting type light source panel in which a plurality of thin tubular cold cathode fluorescent lamps 39 are arranged in parallel, and a reflection plate 40 and a diffusion sheet 41 are opposed to each other with the arrangement of the cold cathode fluorescent lamps 39 interposed therebetween. FIG. Also in this embodiment, the light is uniformly diffused by the diffusion sheet 41 and irradiated as parallel light beams substantially perpendicular to the irradiation surface.
[0049]
In addition, as the diffusion sheet according to each of the above-described embodiments, for example, using a known lenticular lens, the incident light is converted into a parallel light beam that is substantially perpendicular to the surface of the diffusion sheet and is emitted. This achieves a uniform color distribution (light quality).
[0050]
The above-mentioned cold cathode fluorescent lamp 39 is of a type having electrodes inside, and one inverter is required for each lamp. However, when an external electrode fluorescent lamp (EEFL) is used, the number of lamps is several. Thus, simultaneous driving is possible with one driving inverter (transformer).
[0051]
FIG. 8 is a perspective view showing a circuit configuration in which a plurality of such external electrode fluorescent lamps 39a are arranged in parallel and power is supplied from the inverter 31. Each of the plurality of fluorescent lamps 39a,. External electrodes 42 of a plurality of fluorescent lamps 39a,... Are connected in parallel to lead wires 43, 44 to which the output of the inverter 31 is supplied. With such a configuration, the device is inexpensive and compact.
[0052]
FIG. 9 is a graph showing the measurement results of the photon flux density emitted by the flat light source panel shown in FIG. Here, the photon flux density means a photosynthetic photon flux density (PPF or PPED), and expresses the amount of light per unit area not by energy but by the number of photons or photons as light particles.
[0053]
Plant photosynthesis depends on the number of photons incident on chlorophyll. Generally, one molecule of carbon dioxide (Co ₂ 8) to 10 photons are required in order to consume) in photosynthesis. Therefore, the value indicating the number of photons incident per unit time / unit area in the wavelength range of 400 nm to 700 nm, which is the absorption wavelength range of chlorophyll, is the photon flux density. The unit is μmol / m ² -It is s. Here, 1 mol is 6.02 × 10 ²³ Individual. In terms of energy, from the relation of e = hν (e: energy, h: Planck's constant, ν: frequency), the shorter the wavelength (the higher the frequency), the higher the energy proportionally.
[0054]
In FIG. 9, the ordinate indicates the photon flux density, and the abscissa indicates the distance from the flat light source. Also, the broken lines (a), (b), and (c) in the figure respectively show the photon flux density at a distance of 11 cm from the light source at 100 μmol / m. ² ・ S, 80 μmol / m ² ・ S, 50 μmol / m ² A change when set to s is shown.
[0055]
From this measurement result, the photon flux density emitted by the planar light-emitting type illumination device for a plant culture device of the present invention decreases as the distance from the light source increases, but when the distance from the light source is 20 cm or less, It was found that the distance increased exponentially as the distance became shorter. This indicates that when a plant seedling such as a cloned seedling or a sterile seedling grows and the distance from the luminous body as a light source becomes 20 cm or less, the growth speed increases rapidly.
[0056]
FIG. 10 compares the measurement results of the photon flux density inside the plant culture device of the present invention shown in FIG. 3 with a conventional plant culture device using LED elements and a culture shelf using a tubular light source (fluorescent lamp). FIG. The line graph (a) in the figure is the measurement result in the plant culture device of the present invention, and (b) and (c) are the measurement results for the conventional device.
[0057]
In addition, in the culture device of the present invention and the culture device using LED elements, the distance between the light source device and the culture support is 11 cm, and in the conventional device, the distance between the tubular light source and the culture support is 40 cm. In each case, the photon flux density on the upper surface of the culture support was approximately 50 μmol / m ² -Set to the same value as s.
[0058]
From these measurement results, in the conventional culture device using the plant culture device and the LED element of the present invention, the photon flux density increases in proportion to the distance as the distance from the upper surface of the culture support increases. On the other hand, in the conventional culture shelf, the photon flux density hardly changes even if the distance changes. In addition, it was found that the former of the culture device of the present invention and the culture device using the LED element showed a higher density as a whole.
[0059]
Next, the photon flux density and color distribution (light quality) on the culture support in the plant culture apparatus of the present invention shown in FIG. 3 were measured in comparison with a conventional apparatus using an LED as a light source. FIG. 11 is a plan view showing the outline of the measuring device. That is, in the figure, the upper surface of the culture support in the plant culture apparatus is divided into nine parts, and the sensor 18 is disposed at the center of the photon measurement location 17 for each of the divided areas A to I.
[0060]
The plant culturing apparatus of the present invention used for the measurement uses the apparatus shown in FIG. 3, and as shown in FIG. 3, the gap between the flat light-emitting light source panel 27 and the upper end of the culture vessel 26 is 4 mm. The culture support top surface is set at a position 30 mm from the bottom surface. The upper surface of the culture support is a reference distance setting surface. The conventional plant culture apparatus used for the measurement was the one shown in FIG. 21, and the measuring method used was the same as described above.
[0061]
Tables 1 to 4 are tables showing the measured values of the photon flux density and the measured color distribution (light quality) on the culture support of the plant culture apparatus of the present invention in comparison with the conventional apparatus.
[0062]
[Table 1]

[Table 2]

[Table 3]

[Table 4]

Table 1 shows the measurement results of the photon flux density measured at a position 10 cm above the distance setting reference plane, Table 2 shows the measurement results of the photon flux density measured at a position 8 cm above the distance setting reference plane, and Table 3 shows the distance setting reference. Table 4 shows the measurement results of the photon flux density measured at a position 5 cm above the surface, and Table 4 shows the measurement results of the photon flux density measured on the upper surface of the culture support. (Unit: μmol / m ² · The measured value of s), and the numerical value at the bottom indicates the ratio of blue light to blue light and red light, that is, the measured value of blue / (red + blue) (unit:%), respectively. I have.
[0063]
In addition, the light source of each plant culture device has a photon flux density of 50 μmol / m at the center of the upper surface of the culture support. ² Lights under the condition of s or less, and the ratio of blue light to red light is set to 2: 8 as a color distribution (light quality) suitable for culture.
[0064]
Further, as the lighting conditions of the light source, in the case of a flat light source panel with one cold cathode fluorescent lamp, the input voltage is 7.4 V, the input power is 4.1 W, and the lamp current is 4.9 mArms. In the case of, the input voltage is 10 V and the input power is 3.0 W for 9 blue LEDs and 36 red LEDs.
[0065]
As is clear from the measurement results shown in Tables 1 to 4, in the plant culture device of the present invention, the variation in the distribution of the photon flux density is smaller than that of the conventional device regardless of the distance from the distance setting reference plane.
[0066]
That is, in the plant culture apparatus of the present invention, as shown in Table 1, when the photon flux density of the divided region E at the center of the upper surface of the culture support is 100%, the variation of the photon flux density of each divided region is 92%. ９７97%. Further, as shown in Table 4, even at the position closest to the light source, the variation of the photon flux density was 92 to 98%. Regarding the color distribution (light quality), in the plant culturing apparatus of the present invention, it was constant at 20% in all divided use areas regardless of the distance from the distance setting reference plane.
[0067]
Therefore, according to such an apparatus of the present invention, it is possible to particularly achieve the uniformity of growth required for culturing cloned seedlings.
[0068]
On the other hand, in the conventional plant culture device using the LED element, the variation of the photon flux density and the color distribution (light quality) on the culture support surface is small, but both the photon flux density and the color distribution (light quality) are low. Tables 1 to 4 show states in which the distance largely varies depending on the distance from the distance setting reference plane.
[0069]
From these measurement results, in the conventional apparatus, the tendency of the photon flux density to vary as the seedlings grow, that is, as the seedlings approach the light source, is not parallel to the light source surface, but is slightly inclined. It can be seen that there is also a problem that the difference in the light quality becomes larger when the value is changed.
[0070]
Next, aseptic cultivation of Cymbidium shoots was performed using a plant culturing apparatus using the flat light-emitting light source panel of the present invention, and the growth state was observed. Further, in order to confirm the effects of the device of the present invention, similar observations were made for a conventional plant growing device using a conventional culture shelf and a conventional plant growing device using an LED as a light source. Table 5 shows the results.
[0071]
In the plant growing apparatus used in this experiment, the light source was turned on for 16 hours in an incubator using a 3000 ppm carbon dioxide gas at a temperature of 25 ° C. with a composition ratio of red light and blue light of 8: 2. Cultivation was performed in a lighting cycle of resting for 8 hours.
[0072]
Table 5 shows a conventional plant growing apparatus using a culture shelf, in which the distance from the tubular fluorescent lamp light source to the upper surface of the culture support is 25 cm. Conventional example 2 in which the distance from the light source to the top surface of the culture support is 11 cm, and a planar light source panel including a cold cathode fluorescent lamp is used as a light source. For each device of Example 1 of the present invention in which the distance from the light source to the upper surface of the culture support was 11 cm, the number of days and the above-ground body weight until each time the plant height reached 10 mm, 50 mm, and 90 mm were described. I have.
[0073]
[Table 5]

From this observation result, the growth speed in the low season when the plant height is 10 mm, that is, the cultivation days is not different between the conventional example and the embodiment of the present invention. The cultivation days of the examples are reduced from 8 days to a maximum of 25 days compared to the conventional example, and the growth speed of the present invention is accelerated at an accelerated rate.
[0074]
The reason for this is that, as is clear from the photon flux density graph shown in FIG. 9, even when the plant grows and approaches the light source, the photon flux density in Conventional Examples 1 and 2 using the tubular fluorescent lamp light source is small. Although there is almost no change, in the conventional example 3 using the LED light source or the example 1 of the present invention using the flat light emitting type light source, the photon flux density increases proportionately, so that the more plants grow, the more the plants grow. Since light quantity is required, it is considered that they grow synergistically.
[0075]
However, Conventional Example 3 using an LED light source has a lower photon flux density by the difference of the photon flux density at a distance of about 11 cm from the culture support of FIG. 9 as compared with Example 1 of the present invention. , The growth speed is also slightly lower. One of the reasons for this is that, as shown in Tables 1 to 4, the photon flux density on the culture support surface and on the cultivation surface at different heights parallel thereto is large, and the color distribution, that is, the red light It can be inferred that the variation in the ratio with the blue light is large and the light is not uniform.
[0076]
Table 6 shows the growth rate and space for Conventional Example 2 using the tubular fluorescent lamp light source shown in Table 5, Conventional Example 3 using the LED light source, and Example 1 of the present invention using the flat light source panel. The relationship with efficiency is shown.
[0077]
[Table 6]

Here, in Table 5, the growth rate is determined based on the maximum number of days of 115 days in which the plant height of the Cymbidium reaches 90 mm, and the space efficiency considers the height of the culture vessel of 14 cm and the thickness of each light source of 2 cm, The number was calculated as a number that can be placed on a common culture shelf interval of 40 cm.
[0078]
That is, the growth rate is the ratio of the cultivation days to the 115 cultivation days of Conventional Example 2 in Table 5, and the growth rate of Example 1 of the present invention is (90/115) = 1.27. The growth rate is represented by (98/115) = 1.17.
[0079]
The space efficiency is represented by the ratio of the height of the culture vessel (height + the thickness of the light source) to the height of the culture vessel according to Conventional Example 2, and the space efficiency of Example 1 of the present invention is (40 cm / (14 + 2). )) = 2.4, which is more than twice the space efficiency. The space efficiency of Conventional Example 3 is (40 cm / (14 + 2)) = 2.4, which is the same as that of the present invention.
[0080]
From Table 6, it can be seen that the overall effect of the growth rate and the space efficiency is the highest for the apparatus of the present invention.
[0081]
As described above, since the flat light-emitting light source panel used in the plant culture apparatus of the present invention is as thin as about 6 to 20 mm and is integrated with the culture vessel, high-density cultivation by multi-stage arrangement is achieved. And high space efficiency due to space saving.
[0082]
In the plant cultivation apparatus of the present invention, since light is introduced into the inside through the light guide plate, the rise in the temperature inside the culture vessel can be kept very low. For example, in the culture vessel set at 25 ° C., the temperature rose only 1 ° C. or less, and the temperature at the center of the light source panel with the light guide plate also rose 1 ° C. or less. This means that the flat light source panel according to the present invention is a light source that does not cause obstacles such as burning of leaves even when plants grow close to each other.
[0083]
FIG. 12 is a side view showing a plant culturing apparatus in which the present invention is applied to industrial plant cultivation. A large number of culturing containers 44 are placed on a lower shelf 43 to which wheels 42 are attached. A flat light-emitting light source panel 46 is provided above these culture vessels 44 with a slight gap from the shelf ceiling 45. The flat light source panel 46 is the lighting device shown in FIG. 1, FIG. 5, FIG. 6, or FIG.
[0084]
Therefore, in such an apparatus, the culture vessel 44 is placed immediately below the flat light-emitting light source panel 46 for, for example, 16 hours, and then the lower shelf 43 is moved to a place where the flat light-emitting light source panel 46 is not provided, and is stopped for 16 hours. After this pause, the lower shelf 43 is again moved to just below the flat light source panel 46 and left there for 16 hours.
[0085]
Next, during the above-mentioned rest period, another shelf 43 (not shown) on which a number of culture vessels 44 are placed is moved to a position directly below the flat light-emitting light source panel 46, and after 16 hours, this shelf 43 is moved. Is moved to a place where the flat light source panel 46 is not present. As described above, by creating the flow of the culture system, one flat light-emitting light source panel 46 can be shared by many culture vessels 44.
[0086]
13 to 16 are views showing another example of the flat light source panel used in the present invention. None of these light source panels have the diffusion sheet shown in FIGS. 1 and 2. FIG. 13 is a view obtained by removing the diffusion sheet 23 from the edge-type flat light-emitting light source panel shown in FIG. 1, and the other configuration is almost the same as that of FIG. 1. Detailed description is omitted.
[0087]
FIGS. 14 to 16 are cross-sectional views showing an outline of an edge type planar light emitting type light source panel in which the cold cathode fluorescent lamps 20 in the light source panel shown in FIG. In these light source panels, the thickness of the light guide plate 22 becomes thinner as the distance from the cold cathode fluorescent lamp 20 increases.
[0088]
In the light source panel of FIG. 14, the scattering dot pattern 22 ′ printed on the surface of the light guide plate 22 is printed such that its area gradually increases as the distance from the cold cathode fluorescent lamp 20 increases, or the dot interval decreases. Have been. This alleviates the tendency that the light is bright near the lamp 20 inside the light guide plate 22 and the brightness decreases as the distance increases.
[0089]
In the light source panel shown in FIG. 15, instead of the scattering dot pattern 22 ′, a V-groove 51 is formed on the surface of the light guide plate 22 for irregularly reflecting light. The interval between the grooves 51 is reduced. This alleviates the tendency that the light is bright near the lamp 20 inside the light guide plate 22 and the brightness decreases as the distance increases.
[0090]
In the light source panel shown in FIG. 16, instead of providing the scattering dot pattern 22 ′ or the V-shaped groove 51 on the surface of the light guide plate 22, a rough surface 52 such as sun blasting is applied to diffusely reflect light. The rough surface 52 is gradually roughened as the distance from the fluorescent lamp 20 increases. This alleviates the tendency that the light is bright near the lamp 20 inside the light guide plate 22 and the brightness decreases as the distance increases.
[0091]
Tables 7 and 8 show the measured values of the photon flux density and the measured values of the color distribution (light quality) on the culture support of the plant culture device of the present invention using the edge-type flat light-emitting light source panel shown in FIG. 14 is a table showing a comparison with the plant culture device of the present invention using the edge-type flat light-emitting light source panel shown in FIG. 13.
[0092]
That is, this measurement is a comparison between a light source panel from which the diffusion sheet 23 has been removed and a plant culture apparatus using the light source panel provided with the diffusion sheet 23. In addition, this measurement used the same measurement method as the measurement shown in Table 1 thru / or Table 4.
[0093]
[Table 7]

[Table 8]

Table 7 shows the measurement results of the photon flux density measured at a position 8 cm above the distance setting reference plane, and Table 8 shows the measurement results of the photon flux density measured on the upper surface of the culture support. Numerical values above the divided areas A to I Is the photon flux density (unit: μmol / m) ² · The measured value of s), and the numerical value at the bottom indicates the ratio of blue light to blue light and red light, that is, the measured value of blue / (red + blue) (unit:%), respectively. I have.
[0094]
When the variation of the photon flux density in the divided areas A to I is represented by the ratio of the minimum value to the maximum value of the photon flux density, at a position 8 cm above the distance setting reference plane, from Table 7, it is found that 86% when there is a diffusion sheet. %, Even when there is no diffusion sheet, it is 78%, indicating that the LED light source has excellent uniformity as compared with 51% in the case of the LED light source shown in Table 2.
[0095]
In addition, as shown in Table 8, the measured value on the upper surface of the culture support showed the same value as 96% in both cases with and without the diffusion sheet.
[0096]
17 to 19 are diagrams showing another embodiment of the plant culturing apparatus of the present invention. In these embodiments, the flat light-emitting light source panel and the culture container are arranged in a predetermined positional relationship by the mounting member. That is, FIGS. 17A and 17B are a perspective view and a side view.
[0097]
17 (a) and 17 (b), a mounting member 53A is a pair of a hollow rod made of metal, hard synthetic resin, or the like, a pair of slightly higher than the height of the culture vessel 26 formed by bending a pipe or plate. , And two reinforcing support beams 55, connected between the ends of the posts 54, 54 and between the intermediate bent portions, here, between the intermediate bent portions. The culture vessel 26 is placed in a space 50 of a substantially rectangular frame-shaped mounting member 53A surrounded by the columns 54, 54 and the supporting beams 55,.
[0098]
On opposite side walls of the housing 19 constituting the flat light source panel 27, there are provided mounting pieces 57 having linear grooves 56 which open downward. The supporting members 58, 58 (one of which is not shown) above the Z-shaped columns 54, which constitute the mounting member 53 </ b> A, have grooves 56 of mounting pieces 57, 57 provided on the housing 19. , 56 are integrated. In the figure, reference numeral 19a denotes a protruding portion in which an inverter is housed.
[0099]
In this plant culturing apparatus, the flat light-emitting light source panel 27 is held above the mounting member 53A, and if the culture vessel 26 is arranged between the columns 54 of the mounting member 53A, the light source panel 27 and Since a uniform light irradiation distribution is obtained on the horizontal plane from the light source panel 27 in opposition to the culture vessel 26, uniform light irradiation is performed on the culture support, plants, and the like in the culture vessel 26.
[0100]
In addition, since the mounting member 53A surrounding the culture container 26 has a frame shape, it is possible to easily put the culture container 26 in and out, and observe the state of growing plants in the culture container 26, and the like.
[0101]
In addition, since the height of the culture vessel 26 is slightly lower than the height of the Z-shaped columns 54, 54, a gap is formed between the culture vessel 26 and the lower surface of the flat light source panel 27. At times, the radiant heat from the light source panel 27 can be released to prevent the temperature inside the culture vessel 26 from rising.
[0102]
In addition, the pair of pillars 54, 54 constituting the frame-shaped mounting member 53A are Z-shaped, but are not limited to the Z-shape, and may be a mouth-letter type, a Japanese-character type, or the like. The number of the support beams 55 may be appropriately set according to the weight of the flat light source panel 27 or the like. Also, the mounting piece 57 of the flat light source panel 27 is not limited to the groove 56, and a locking means such as a hook or a notch may be provided in the housing 19, or a movement preventing means of the light source panel 27 may be provided on the mounting member 53A side. It doesn't matter. Further, the flat light source panel 27 may be held not only by the support columns 54 but also by the support beams 55.
[0103]
FIGS. 18 (a), (b) and 19 show still another embodiment of the plant culturing apparatus of the present invention, wherein FIGS. 18 (a) and (b) are perspective views and side views, and FIG. FIG. 3 is a perspective view of a mounting member alone in a state where a light-emitting light source panel and the culture container are not provided.
[0104]
In this embodiment, the mounting member 53B is formed by bending a plate made of a synthetic resin such as transparent acrylic into a U-shape slightly higher than the height of the culture vessel 26, and the space formed by the U-shape The culture container 26 is placed in the inside of the container 50.
[0105]
The flat light source panel 27 is mounted on an upper plate 59 of the mounting member 53B, and screws 60 are fixed to the upper plate 59. (Not shown).
[0106]
As shown in FIG. 19, the mounting member 53B has a hole 58a formed in the center of the upper plate 59. With such openings, the loss of transmitted light by the light source panel 27 can be reduced.
[0107]
By providing such a mounting member 53B, as in the embodiment shown in FIG. 17, the height of the culture vessel 26 is slightly lower than the height of the U-shaped mounting member 53B. As a result, a gap is formed between the lower surface of the light source panel 27 and the radiant heat from the light source panel 27 when the fluorescent lamp 20 is turned on, thereby preventing the temperature inside the culture vessel 26 from rising.
[0108]
Since the mounting member 53B has the hole 58a formed in the center of the upper plate 59, uniform light irradiation is performed in the culture vessel 26 disposed immediately below the flat light source panel 27. Further, since the U-shaped mounting member 53B is open on three sides, it is easy to put the culture container 26 in and out.
[0109]
In this embodiment, as shown in FIG. 19, the hole 58a is formed in the center of the upper plate 59 constituting the mounting member 53B. However, when a material having high transparency is used for the mounting member 53B, The radiation emitted from the flat light source panel 27 may be transmitted through the mounting member 53B and irradiated into the culture vessel 26 without forming the hole 58a. In addition, although the placing member 53B is formed in a U-shape, the opening is formed in two sides, but may be a U-shape or the like.
[0110]
【The invention's effect】
According to the present invention described above, a cold cathode fluorescent panel (device) or an LED element is used as a lighting device for a plant culture device, and a diffusion sheet is provided on the irradiation surface thereof. Irradiation light having a bundle density and a uniform color distribution (light quality) can be supplied. As a result, the growth rate of clone seedlings, sterile seedlings, and the like can be significantly improved.
[0111]
In addition, according to the present invention, a culture vessel having a height of 20 cm or less can supply irradiation light having a high photon flux density and a uniform color distribution (light quality). can get.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a flat light source panel of the present invention.
FIG. 2 is an exploded perspective view of the flat light emitting panel shown in FIG.
FIG. 3 is a perspective view showing an embodiment of the plant culture device of the present invention.
FIG. 4 is a perspective view showing another embodiment of the plant culture device of the present invention.
FIG. 5 is a perspective view showing another embodiment of the flat light emitting type light source panel of the present invention.
FIG. 6 is a perspective view showing another embodiment of the flat light emitting panel of the present invention.
FIG. 7 is a perspective view showing another embodiment of the flat light source panel of the present invention.
8 is a perspective view showing a configuration of a circuit for supplying power from an inverter to a plurality of fluorescent lamps shown in FIG. 7;
9 is a graph showing a measurement result of a photon flux density emitted by the flat light source panel shown in FIG.
FIG. 10 compares the results of measuring the photon flux density inside the plant culture device of the present invention shown in FIG. 3 with a conventional plant culture device using LED elements and a culture shelf using a tubular light source (fluorescent lamp). It is the graph shown.
FIG. 11 is a plan view showing an outline of an apparatus for measuring a photon flux density inside a plant culture apparatus.
FIG. 12 is a side view showing a plant culturing apparatus in which the present invention is applied to industrial plant cultivation.
FIG. 13 is a perspective view showing another embodiment of the flat light source panel of the present invention.
FIG. 14 is a sectional view showing another embodiment of the flat light source panel of the present invention.
FIG. 15 is a perspective view showing another embodiment of the flat light-emitting light source panel of the present invention.
FIG. 16 is a perspective view showing another embodiment of the flat light source panel of the present invention.
17 shows another embodiment of the plant culturing apparatus of the present invention, wherein FIG. 17 (a) is a perspective view and FIG. 17 (b) is a side view.
18 shows another embodiment of the plant culturing apparatus of the present invention, wherein FIG. 18 (a) is a perspective view and FIG. 18 (b) is a side view.
19 is a perspective view of a mounting member in the plant culture device shown in FIG.
FIG. 20 is a side view showing a schematic configuration of a conventional plant culture apparatus using a culture shelf.
FIG. 21 is a perspective view showing a schematic configuration of a plant culturing apparatus using a conventional LED element as a light source.
FIG. 22 is a side view showing a usage state of a plant culture apparatus using a conventional culture shelf.
FIG. 23 is a perspective view showing an irradiation light distribution model in a plant culture apparatus using a conventional LED light source.
[Explanation of symbols]
1,26,44 Culture vessel
2,29 medium, culture support
3,43 under the shelf
4,45 shelf ceiling
5. Hot cathode fluorescent lamp
6 LED element
7 Culture support
8 Useless Space
9 Blank paper
10 spots
17 Photon measurement points
18 sensors
19 Housing
21 Reflective sheet
22 Light guide plate
23, 35, 41 Diffusion sheet
24 reflector
25,31 inverter
28 props
30 convex
32 Flat panel light source panel top surface
33 Top seal
34 LED element
39 cold cathode fluorescent lamp
40 Reflector
42 wheels

Claims (29)

A plant culture vessel in which at least the ceiling surface forms a culture space having optical transparency, a culture support disposed at the bottom of the vessel, and a planar light-emitting light source device disposed at the top of the plant culture vessel at the ceiling. The flat emission type light source device has a flat light guide plate having at least one end face as a light incident end face, and emits light incident from the one end face formed on the flat face of the light guide plate from the flat face. Light control means for controlling the illuminance of at least the entire flat plate surface to be uniform, and a light source disposed on at least one end surface of the light guide plate, and the light is irradiated from the entire ceiling surface of the plant culture vessel. A plant culturing apparatus equipped with a lighting device, characterized in that the illuminance distribution on a horizontal plane by light is made uniform. The plant cultivation apparatus equipped with the illumination device according to claim 1, wherein a distance between the flat light source device and the culture support is set to about 20 cm or less. The flat emission light source device, a light guide plate, a thin tubular cold cathode fluorescent lamp disposed on the periphery of the light guide plate, and a reflector that reflects the emitted light of the cold cathode fluorescent lamp in the light guide plate direction, The plant cultivation apparatus equipped with the lighting device according to claim 1 or 2, comprising a reflection sheet provided on a side of the light guide plate opposite to a light emission surface. The plant culture device equipped with the lighting device according to claim 3, wherein a light diffusion sheet is arranged on the light emission surface side of the light guide plate. The plant cultivation apparatus equipped with the lighting device according to claim 3 or 4, wherein a scattering dot pattern is printed on a surface of the light guide plate on the reflection sheet side. The plant culture device equipped with the lighting device according to claim 3 or 4, wherein a V-groove cut for scattering light is formed on a surface of the light guide plate on the reflection sheet side. The plant cultivation apparatus equipped with the lighting device according to claim 3 or 4, wherein a blast treatment for scattering light is performed on a surface of the light guide plate on the reflection sheet side. The plant equipped with the lighting device according to claim 1 or 2, wherein the thin-tube cold cathode fluorescent lamp includes a phosphor having a composition that emits red and blue at a ratio of approximately 8 to 2. Culture equipment. A plant culture vessel having at least a ceiling surface forming a culture space having optical transparency, a culture support disposed at the bottom of the vessel, and a planar light-emitting light source device disposed on the ceiling surface of the plant culture vessel. The flat emission type light source device comprises a light source arranged on the ceiling side of the plant culture vessel, and a planar light transmitting member for diffusing and irradiating light from the light source into the culture space of the plant culture vessel. A plant culturing apparatus equipped with a lighting device, characterized in that the illuminance distribution on a horizontal plane by light emitted from the entire ceiling surface of the plant culturing vessel is made uniform. The plant culture device equipped with the lighting device according to claim 9, wherein a distance between the flat light source device and the culture support is set to about 20 cm or less. The flat emission light source device includes a plurality of thin tubular cold cathode fluorescent lamps arranged substantially in parallel in the ceiling surface of the plant culture vessel, and a diffusion sheet disposed on one surface of the cold cathode fluorescent lamp array. A plant cultivation device equipped with the lighting device according to claim 9 or 10. The flat emission light source device is characterized by comprising a plurality of LED elements arranged planarly in the ceiling surface of the plant culture vessel, and a diffusion sheet arranged on one surface of these LED element arrangement. A plant culture device equipped with the lighting device according to claim 9. 13. The plant cultivation apparatus according to claim 11, wherein the diffusion sheet is made of a translucent resin. The plant cultivation apparatus according to claim 11, wherein the thin-tube cold-cathode fluorescent lamp includes a phosphor having a composition that emits red light and blue light at a ratio of about 8: 2. . 13. The lighting device according to claim 12, wherein the plurality of LED elements include an LED element that emits red light and an LED element that emits blue light, and the respective number ratios are approximately 8 to 2. Plant culturing device equipped with the device. The plant cultivation apparatus equipped with the lighting device according to claim 1, wherein a gap for heat radiation is provided between the flat light emitting device and the ceiling portion of the culture vessel. A plant culture container, a flat light-emitting light source panel that irradiates plant growing light into the plant culture container, and a mounting member that supports the flat light-emitting light source panel with a gap above the plant culture container. The mounting member has at least a part of the side surface opened, and the plant culture container moves to the lower position of the flat light source panel and moves from the lower position through the opened side surface. A plant cultivation apparatus equipped with a lighting device, wherein the lighting device is detachable and has a height such that the flat light-emitting light source panel is supported above the plant culture vessel with a gap therebetween. The plant culturing apparatus equipped with the lighting device according to claim 17, wherein the placement member has a side surface formed of a Z-shaped frame. The plant culturing apparatus equipped with the lighting device according to claim 17, wherein the placing member has a side surface formed by a U-shaped frame. A flat light guide plate having at least one end face as a light incident end face, and light incident from the one end face formed on the flat face of the light guide plate is emitted from the flat face, and the illuminance of at least the entire flat face is uniform. A lighting device for a plant culture device, comprising: a flat light source device comprising: a light control unit for controlling the light guide plate to emit light; and a light source disposed on at least one end surface of the light guide plate. 21. The lighting device for a plant culture device according to claim 20, wherein the light control means is a scattered dot pattern printed on one surface of the light guide plate on the reflection sheet side. 21. The lighting device for a plant culture device according to claim 20, wherein a V-groove cut for scattering light is provided on a surface of the light guide plate on the reflection sheet side. The lighting device for a plant culture device according to claim 20, wherein a blast treatment for scattering light is performed on a surface of the light guide plate on the reflection sheet side. A light source for irradiating light inside the plant culture container, a light guide plate for guiding the irradiation light from the light source into the ceiling surface of the plant culture container, and light radiated from the light guide plate is substantially uniform inside the plant culture container. A lighting device for a plant cultivation device, comprising: a flat light source device including a diffusion sheet that supplies a light with an appropriate illuminance distribution. The flat emission light source device is a thin tubular cold cathode fluorescent lamp disposed at the periphery of the light guide plate, a reflector that reflects the emitted light of the cold cathode fluorescent lamp in the light guide plate direction, and a light guide plate. The lighting device for a plant culture device according to claim 24, further comprising a reflection sheet disposed on one surface. The flat emission type light source device includes a plurality of thin tubular cold cathode fluorescent lamps arranged substantially in parallel in a ceiling surface of the plant culture vessel, and a reflection sheet disposed on one surface of the cold cathode fluorescent lamp array. The lighting device for a plant culture device according to claim 24, further comprising: 27. The lighting device for a plant culture device according to claim 25, wherein the cold cathode fluorescent lamp includes a phosphor having a composition that emits red and blue at a ratio of approximately 8: 2. The plant cultivation apparatus according to claim 24, wherein the light source is a plurality of LED elements arranged on a peripheral portion of the light guide plate, and a reflection sheet is arranged on one surface of the light guide plate. Lighting equipment. The flat emission light source device is characterized by comprising a plurality of LED elements arranged planarly in the ceiling surface of the plant culture vessel, and a diffusion sheet arranged on one surface of these LED element arrangement. The lighting device for a plant cultivation device according to claim 24.

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