| 摘要 |
<p>498,722. Reflectors. ZEISS IKON AKT.- GES. Feb. 24, 1938, No. 5891. Convention date, Feb. 25, 1937. [Class 75 (ii)] A reflector system for illuminating an elongated rectangular field from the centre of a narrow side of the field comprises two main parts of different fundamental optical forms, one of the main parts being arranged behind the light source and illuminating the remotely situated portions of the field and the second main part which illuminates the near field portions being of open ended tubular form and arranged in front of the light source and within the path of the rays from the first part, but with the least possible interception of said rays. Behind the source of light 1, is a reflector comprising an upper paraboloid 2 with axis 3 and a lower paraboloid 7 with axis 8. In front of the source is the tubular reflector comprising an upper part 11 and a lower part 16 which is a paraboloid of short focal length with axis 17. The part 11 has a cross section which gives substantially uniform illumination in the transverse direction of the field. That part of the paraboloid 7 which would be masked by the paraboloid 16 is replaced by a spherical segment 20 adapted to reflect light on to the reflector 11 as shown by the rays 12, 13. In a modified form the paraboloids 2 and 7 have a shorter focal length and the collection angle is 180‹. With this latter form the entire reflector, if of glass, may be made in one piece.</p> |
