| 摘要 |
988,411. Reflectors. INFRANOR S.A. Aug. 16, 1961 [Aug. 20, 1960], No. 29532/61. Heading F4R. Means for producing a substantially uniform lighting on a rectangular surface comprises an elongated cylindrical light source, e.g. a discharge tube or an incandescent lamp with a rectilinear filament, arranged at right angles to the optical axis of a reflector system consisting of a cylindrical reflecting cavity, 1, Fig. 2, behind the source 2, the generatrices of which are parallel to the axis of the source, two further cylindrical reflectors 4, 5 on opposite sides of the optical axis, their generatrices also being parallel to the axis of the source and two lateral reflectors 6, 7 disposed near the ends of the source and connected to the lateral edges of the reflectors 4, 5, the cross-sectional form of the reflectors 4, 5 being determined by the formula where α is the angle between any given ray leaving the reflector and the optical axes, J o is the luminous intensity for α=0, αM is half the angle of opening of the beam of the reflector system and # is the angle between the optical axis and a ray falling on the reflector which leaves the reflector at an angle α to the optical axis. For small values of αM the formula reduces approximately to for a reflector and to for the cavity. For providing beams of small divergence, a modified system may be used in which the aperture ab, Fig. 4, of the cavity is greater than the distance cd between the near edges of the reflectors 4, 5, the edges ac and bd being connected by cylindrical non-reflecting elements 8, 9. In addition, the free edges of the reflectors 4, 5 may carry screening extensions 10, 11 to reduce the aperture. In a further modification, secondary reflectors are arranged within the main reflector system to redirect the rays emitted by the source between the rays which impinge on the extreme edge of the reflectors and the direct beam. |
