| 摘要 |
PURPOSE:To obtain the lens of high accurate surface in the formation molds consisting of a pair of molds and a trunk mold by constituting the trunk mold of specified construction and making the thermal expansion quantity of the trunk mold larger than that of the parts of the lens and the formation molds. CONSTITUTION:In the formation molds consisting of a pair of molds 3, 4 and trunk molds, the trunk molds is constituted of a main trunk mold 6 and an auxiliary trunk mold 5 which are brought into contact with each other in the shifting direction of the formation molds, and the heat expansion quantity of the main trunk mold 6 and the auxiliary trunk mold 5 in the formation mold shifting direction is made to be larger than that of the thickness of the lens 7 and the received parts of the formation molds 3, 4 shifted in the main trunk mold 6 and in the auxiliary trunk mold 5, and the main trunk mold 6 is made to be positioned in the outer peripheral part of the lens material 8. The lens material 7 is supplied in this formation molds and heated to the transformable temp. and pressed to the end position by press heads 1, 2. The lens 8 is taken out after the cooling is finished. |
