| 摘要 |
PURPOSE:To machine a lens with a labour-saving manner without the center of curvature of the curve of the lens being shifted largely from the optical axis, by measuring the edge thickness of the lens and as well by automatically forming a suitable bevel curve in the lens. CONSTITUTION:If distances aL1, bL1, cL1, dL1 from a horizontal reference position S, and values aL1+aD, bL1+bD, cL1+cD, dL1+dD which are in consideration with the thickness of a spectacle lens, are taken with respect to points (a, b, c, d) corresponding to the rotating angles of the spectacle lens, the developed graph of the lens edge may be obtained by connecting the points (a, b, c, d), in which the inside of a slanted line area that indicates the thickness of the lens edge is an area possible to be formed with a bevel curve. The curve of the surface is specified as a reference, and if a certain rate is specified, the positions Qa, Qb, Qc Qd are obtained by dividing the edge thickness at the points (a, b, c, d) with the specified rate in reference to the surface, and when folded line 100 is obtained in consideration with the inclination of a approximate profile copying line of each adjacent points, this line corresponds to the bevel curve.
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