PURPOSE: To converge and obtain the sunshine efficiently by entering light rays into numbers of optical fibers having photodetection ends positions at the focal points of numbers of lenses on the same plane, and rotating the lens surfaces around vertical and horizontal axes.

CONSTITUTION: Numbers of small-diameter lenses 21 of about 4cm in diameter are arranged on a plane P, and opening parts of optical fibers 22 are provided at the focal points of the respective lenses 21 to constitute a light convergence part 20. Numbers of small fibers 22 which are opened at the focal points of the lenses 21 run through a horizontal hollow shagt 40 and a vertical hollow shaft 50 to guide the sunshine to a desired position. The horizontal shaft 40 and vertical shaft 50 are supported rotatably as shown by arrows Y and X respectively by a motor 60, gears 70 and 80, and a bearing 90, and controlled by an unshown device so that the lens plane P faces the sun correctly all the time. Thus, the devide which eliminates the need for a focus adjustment and has superior maintainability is constituted at an actual site.