PROBLEM TO BE SOLVED: To provide a plant growth hydroponic device in which distance between a plant and a lighting device can be automatically adjusted so that proper intensity of the lighting for the plant is given according to a growth state of the plant.SOLUTION: In a plant growth hydroponic device, a projection 2a is formed on an undersurface of a cultivation plate 2. Two kinds of regions having different water levels are formed at a cultivation bed 1. A first region is a cultivation part 5 where water is held to dip a plant root at a high water-level, and a second region is a receiving columnar part 6 where the projection of the cultivation plate is held through water at a low water-level. As total weight of the cultivation plate 2 increase by growth of the plant, the projection 2a of the cultivation plate is submerged into water in the second region and the water-level of the first region is decreased, thereby sinking the cultivation plate 2 into the receiving columnar part 6 according to the growth of the plant so that a distance between a lighting device and the plant is adequately maintained.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】植物育成水耕栽培装置において、植物の成長状態に合わせて植物に適正な照明の強さとなるように、自動的に植物と照明の間の距離を調整できる植物育成水耕栽培装置を提供する。【解決手段】栽培プレート2の下面に突出部2aを形成し、栽培ベッド1に水位が異なる二種類の領域を形成し、第一の領域は高い水位で植物の根が漬かる水を保持する栽培部5であり、第二の領域は低い側の水位の水を介して栽培プレートの突出部を保持する受柱部6とする。植物の成長による栽培プレート2全体の重量増加に伴い、第二の領域の水に栽培プレートの突出部2aが沈水すると共に第一の領域の水位も下がる。これにより、植物の成長に合わせて栽培プレート2が受柱部6に沈み、照明と植物の間の距離を適正に保つことができる。【選択図】図1
