Patent ID: 9676157
Date: 2017-06-13
CPC Classifications: B29D,C03B,G02C

Claim:
1. A manufacturing method for a mold die used in a molding process for obtaining a mold used to form an eyeglass lens having at least first and second reference points and having an area where power continuously changes, wherein, in the molding process, a glass material placed on a molding surface of the mold die is softened by heat to form an upper surface of the glass material by letting a lower surface of the glass material closely contact the molding surface, the manufacturing method comprising: a design data making step of making design data for the molding surface of the mold die based on predetermined prescription information; a molding surface creation step of creating the molding surface in accordance with the design data; an error amount specifying step of specifying error amounts at first and second corresponding points defined on the created molding surface respectively corresponding the first and second reference points, with respect to design values by the design data; a first correction surface defining step of defining a first correction surface based on an error amount specified at the first corresponding point; a second correction surface defining step of defining a second correction surface based on the first correction surface and an error amount specified at the second corresponding point, wherein power of the second correction surface at the first corresponding point is substantially zero; a design data correction step of combining a design surface by the design data, the first correction surface and the second correction surface, and correcting the design data based on combined data after the combining; and a corrected surface creation step of creating the molding surface in accordance with the corrected design data, wherein, in the second correction surface defining step, the second correction surface is defined such that: a power at the second corresponding point is defined as a value obtained by subtracting a power at the second corresponding point on the first correction surface from the error amount at the second corresponding point; and the entire second correction surface is offset so that the power at the first corresponding point becomes substantially zero.