| 摘要 |
An optical system for projection with a projector apparatus intended to project an image on a screen made with negative curvature includes a single, generally concavo-convex lens, both surfaces of which are aspherically corrected, and the front surface of which is oriented towards the plane of the object. The lens is provided with a diaphragm arranged behind the lens at a distance therefrom at least amounting to that of the diaphragm aperture. The display screen preferably has the form of a hyperboloid with splayed-out edges. The optical system is made with a numerical aperture of 0.09 and is intended to afford an enlargement of 6 to 10 times for objects of the format 190 x 250 mm. The optical system is suitably adapted for an overhead projector and has a Gauss focal length of 230 mm. The lens can be made from methyl methacrylate. |
