| 摘要 |
PURPOSE:To constitute a small-sized, lightweight reflecting optical system at low cost by employing a spherical surface mirror which is worked and inspected easily for a primary mirror and an aspherical surface mirror for only a secondary mirror, and using plastic reinforced with fiber for the secondary mirror. CONSTITUTION:The primary mirror 1 is the spherical surface mirror which is worked and inspected easily and only the secondary mirror 2 is the aspherical surface mirror. A light beam incident parallel to an X axis 3 is reflected by the primary mirror at a point B and the secondary mirror at a point C to converge to a point D. The radius of curvature and center of curvature of the secondary mirror 2 are set properly so that the light beam converge to a poing D at any angle BOD, i.e. theta. Then the secondary mirror 2 uses plastic reinforced with carbon fiber which is worked easily and lightweight and aluminum, etc., are vapor-deposited thereupon to constitute the mirror. Thus, the small-sized, lightweight reflecting optical system is obtained and the inexpensive constitution is realized. |
