| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to confine the difference between the rim surfaces of a far sight part and a near sight part within a permissible range by forming the rim surface in a direction orthogonal with an optical axis at the peripheral edge on the near sight part, then superposing the rim surface on the near sight part side and the entire part of the peripheral edge on the far sight part on each other and further forming the rim surface in a direction orthogonal with the optical axis. SOLUTION: A diamond sheet is previously adhered to the grinding disk 43 of a polishing machine 40 and while grinding pressure is applied on the grinding disk 43 by an air cylinder device 21, the grinding disk 43 is rotated. The rim part is then formed in the glass die 12 only on the near sight part 12N side of a small radius of curvature. A glass die rotating mechanism 30 is thereafter moved onto the grinder 40 and the whole of the holder 24 is positioned on the grinding disk 43. A lifting shaft 22 is rotated by a motor 25 in this state and an eccentric shaft 23 is eccentrically rotated around a lifting shaft 22. The grinding pressure is applied on the grinding disk 43 by the air cylinder device 21 to rotationally drive the grinding disk. The rim part is then formed on all of the near sight part 12N and the far sight part 12F of the glass die 12. |
