| 摘要 |
The invention relates to a panoramic projection device for planetaria, having the aim of reducing sources of error and the technical outlay, and of permitting the projection of a panorama by means of a projector. The device comprises an illuminating device for illuminating a slide, it being the case that seen in the direction of the light a lens is arranged after the slide and an annular mirror lens is arranged after said lens. The annular mirror lens has a reflecting hyperboloid surface on the side averted from the lens and a spherical surface on the side facing the lens. The annular mirror lens is bounded at the circumference by a surface in the shape of a spherical zone. The centre of the spherical surface and a focal point of the hyperboloid surface are situated in the plane of the lens on the optical axis. The other focal point of the hyperboloid surface and the centre of the surface in the shape of a spherical zone coincide, and are likewise situated on the optical axis. |
