| 摘要 |
The invention relates to the maufacture of reflectors of electromagnetic radiation, in which a flat and thin metal foil, for example an annealed copper foil which is clamped along its circumference is deformed plastically by means of a mould which has a convex surface. In the final position the mould with the deformed foil is at some distance from the surface of the matrix. The space between deformed foil and matrix is filled with a liquid synthetic resin, for example a foam-forming polyurethane resin. After complete or partial curing of the synthetic resin the mould is removed and the resulting assembly of deformed foil and synthetic resin layer connected thereto is removed from the matrix. In an interesting embodiment a matrix is used the concave surface of which has recesses so that in the finished reflector the supporting layer is provided with corresponding bosses, such as reinforcement ribs. In a further interesting embodiment a mould is used which has a central annular recess so that in the finished reflector in the optical center thereof a perforated hub is obtained which is of importance for aligning the reflector. |
