| 摘要 |
A thin film mirror, comprises a mirror shell 605 and a reflective film 601 stretched between forming structures 603 provided on said mirror shell. The shell and film are arranged such that they form a chamber which is capable of being placed under vacuum. The mirror shell has an inner surface which forms an inner wall of the chamber. The mirror shell is a moulded part where its inner surface is a controlled surface, or A surface, in the sense of being the surface formed next to the mould during the moulding process. A male mould with a groove near its edge is used so the shell is made with a protrusion 611 to ensure film tension. The male mould has a profile which is part of a sphere or toroid. |
