| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a simplified planetarium device which is less expensive and easier to handle than optical planetariums of the conventional technology, can project starry sky that is sharper and more beautiful than a pinhole planetarium, and which can easily recreate a starry sky in a home environment or the like, without having to use using a special dome screen. <P>SOLUTION: A light, outputted from a light source 6, passes through a transmission plate 3, a fixed diaphragm 2, and a wide-angle projection lens 1 via a condenser lens 5, and projects a starry sky on a screen. The transmission plate 3 is a light-blocking circular disc, with a multiplicity of apertures 3a, corresponding to the positions and the brightness of the actual stars, which are supported by the inner ring of the ball bearing 4, of which center is the rotational axis 10 of the circular disc, can rotate about the rotational axis 10 and is driven by a motor 8 via a belt 7. The centers of the projection lens 1, the window of the fixed diaphragm 2, the condenser lens 5, and the light source 6 are all disposed on the optical axis 9, and the centers of the transmission plate 3, a pulley 11, and the ball bearing 4 coincide with the rotational axis 10. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
