| 摘要 |
1. A broad-beam axially symmetrical street lamp having three reflectors (1, 2, 3) in the form of surfaces of rotation, which are arranged above one another around the axis of symmetry (A) of the street lamp, which respectively have a lamp opening in the centre and which reflect the light of the lamp (L) away from the axis of symmetry at a high angle, for a lamp which has a translucent bulb and which is so assigned that its longitudinal axis coincides with the axis of symmetry, characterised in that the generatrix for the surfaces of rotation of the three reflectors are sections consisting of confocal parabolas, whose respective focal points (F) lie on the axis of symmetry (A) at the level of the centre point (M) of the heated discharge tube (B) of the lamp (L) and which are determined by the following values (in each case with a tolerance of + or - 10 %) : see diagramm : EP0085145,P4,F1 where f is the focal length, D is the outer diameter of the larger reflector, alpha is the angle of the main axis - measured clock-wise from the axis of symmetry (A) below the focal point (F) - and d is the diameter of the lamp opening, that the outer diameter (a1) of the lowermost reflector (1) ids represented by a1/D = 0,82 + or - 10 %, and that the second reflector (2) has the largest outer diameter (D), whose value is below 300 mm and preferably amounts to 220 mm + or - 10 %. |
