| 摘要 |
PURPOSE:To enable highly accurate centering in spite of a machine with ordinary accuracy and prevent the lens surface from being scratched by allowing one bell holder of a bell clamp device to be held by a rotary shaft through a spring. CONSTITUTION:A lens 4 is adsorbed by means of vacuum to a fixed shaft side holder 5 and is held temporarily, centering is carried out by the use of an optical axis reading device and, after that, a movable spindle shaft 13 is moved toward the lens 4, which is then pressed by the bell part of a bell holder 10 which is held on the end of the shaft 13 through a coiled spring 12. Thereupon, since the collar 10a of the bell holder 10 is separted from the stepped part of the inside surface of a holder cover 11, and since a proper gap is provided between the outer peripheral surface of the bell holder 10 and the inner peripheral surfaces of the spindle shaft 13 and the holder cover 11, the bell holder 10 is in such a state that it is held only by the coiled spring 12 in the air, thereby it moves following the lens surface, with the whole periphery of the bell part being uniformly brought in close contact with the lens surface. |
