| 摘要 |
PURPOSE:To achieve V-shaped grinding having a desired curvature in an automatic lens grinder for grinding the end surface of a spectacle lens into a desired configuration by providing the lens grinder with means for grinding the end surface of the lens into a V shape having a desired curvature irrespective of the surface configuration of the lens. CONSTITUTION:An automatic lens grinder includes a head frame 5 having a chucking mechanism for a spectacle lens 6, a horizontal drive pulse motor 19, intermediate grinding stones 25, 26, a rotation angle detector 17, a horizontal displacement detector 20, a radial displacement detector 33 and an arithmetic and control unit 30. First, the head frame 5 is set freely movably, and the center of thickness of the lens 6 corresponding to the rotation angle of the lens 6 is obtained through self alignment of the intermediate grinding stones 25, 26 and the lens 6. Then, correction amount is calculated from the basic curvature and the grinding curvature. Based upon the calculation result, the amount of horizontal movement at grinding of the head frame 5 from the center of thickness corresponding to the rotation angle is obtained, and the motor is driven so as to achieve the amount of horizontal movement. |
