Abstract: A planetarium has a planet projection system comprising: a rotatable stage positioned concentrically with a precession axis of a fixed star projection globe and performing an X-axis motion; and a sleeve-type planet projector positioned at an eccentric position with respect to an X axis on the rotatable stage and performing a Y-axis motion for allowing a projection direction to vary upward and downward in relation to the rotatable stage. The X-axis and Y-axis motions are controlled on the basis of values calculated by a planet-movement operation unit receiving date and time data, to project the movement of planets.

Abstract: Provision of a projector used for a planetarium which is capable of reducing electrical power consumption and size. The projector comprises a light source 1 constituted by an array of a plurality of light emitting diodes L for emitting illumination light. The emitted illumination light passes through a condenser lens 2 to impinge onto a original projection plate 3 provided with a light-permeable pattern P, and then a transmitted image is projected through a projection lens onto a dome screen.

Abstract: Provision of a projector used for a planetarium which is capable of reducing electrical power consumption and size. The projector comprises a light source 1 constituted by an array of a plurality of light emitting diodes L for emitting illumination light. The emitted illumination light passes through a condenser lens 2 to impinge onto a original projection plate 3 provided with a light-permeable pattern P, and then a transmitted image is projected through a projection lens onto a dome screen.

Abstract: A planetarium has a planet projection system comprising: a rotatable stage positioned concentrically with a precession axis of a fixed star projection globe and performing an X-axis motion; and a sleeve-type planet projector positioned at an eccentric position with respect to an X axis on the rotatable stage and performing a Y-axis motion for allowing a projection direction to vary upward and downward in relation to the rotatable stage. The X-axis and Y-axis motions are controlled on the basis of values calculated by a planet-movement operation unit receiving date and time data, to project the movement of planets.

Abstract: A riveting method comprises:adhesion-bonding a synthetic resin sheet 11 to a surface of a metal sheet 10 having a thickness of not more than 1 mm,adhesion-bonding a metal sheet 12 having a thickness of not more than 1 mm to a surface of the synthetic resin sheet 11,then stacking the metal sheet 12 and a metal plate or metal holding plate 2,forming a rivet hole from the surface of the metal plate or metal holding plate 2 to such a depth as reaching the synthetic resin sheet 11 but not penetrating the metal sheet 10,burying a mandrel-inserting type rivet in which a mandrel penetration aperture is formed from a head and through a shank of the rivet, and a mandrel having a mandrel head protruding out of the shank with the outer diameter of the head being more than the inner diameter of the penetration aperture is disposed through the penetration aperture in the rivet hole, andmoving the head of the mandrel by an operation of drawing the mandrel, thereby diametrically enlarging the top end of the rivet shank.

Abstract: The present invention provides a panel with holding frames, in which the panel and the holding frames can be fitted easily and at a high accuracy and there is no problem concerning appearances. The panel with holding frames is formed by fitting the holding frame to each side portion of a square panel. Each holding frame has a leg portion for connecting to a fixation portion for fitting, a support portion fixed to a rear surface of the panel in contact, and a rim portion for catching a periphery of the panel, and the support portion has a relief portion operating to receive the periphery of the panel into the rim portion smoothly. The respective holding frames are temporarily assembled in a frame-shape, and receiving portions for fitting corner blocks are formed at the support portions of the holding frames to make the respective holding frames in a predetermined fixation state after putting the panel into the temporarily assembled frame.