| 摘要 |
PURPOSE:To enable a detector to be positioned at the focus of a Cassegrain system and achieve easier adjustment by rotating the parabolic mirror and wedge form optical plate integrally in the infrared ray tracking appratus at a fixed ratio to the rotating period of its plane mirror. CONSTITUTION:The optical axis of a parabolic mirror 2' aligns to a rotating axis 6. A wedge form optical plate 8 whose both surfaces are polished mutually to an angle is installed to the parabolic mirror 2' and rotates together with said mirror. The angle alpha of the wedge form optical plate 8 may be expressed by formula [I] where the respective spacings between a plane mirror 3, wedge form optical plate 8 and detector 4 are let to be d1, d2. n is the refractive index of the wedge form optical plate 8. With such constitution, the portion of the parabolic mirror 2' which non- symmetrical to the rotating axis 6 is only the wedge form optical plate 8 and since this is small in the rate of mass occupying in the rotating portion and is close to the rotating axis 6, it hardly disturbs the rotating balance and its adjustment can be slight. In addition, the manufacturing errors of alpha may be compensated irrespective to balance by moving the mounting position forward or backward and may thus be readily adjusted. |
