| 摘要 |
1281018 Lamps PROJECTEURS CIBIE 30 July 1969 [6 Aug 1968] 38181/69 Heading F4R A lens element for a signalling lamp includes a central portion 10 acting as a converging lens for directing light from a source S into a predetermined angular field and a plurality of dioptric formations e arranged at the border of the central portion, each formation having a substantially square-shaped base and a main face 4 facing away from the body of the lens element. The face 4 is so inclined that a light ray from the source to the centre of the face is deflected into the predetermined field. The face can be contained within a cone having an apex at the source and a cone angle equal to one half of the angle of spread of the field. |
