| 摘要 |
PURPOSE:To prevent a held lens from slanting by providing at least three projection parts which are equal in height in the direction of an optical axis when viewed from the reference surface of the lens fitting surface of a plastic lens frame and supporting a lens by the projection parts. CONSTITUTION:The projection parts which have height sizes alpha, beta, and gamma when viewed from a molding or the reference surface 1 are provided to a die part 8 which is plane at right angles to the optical axis in expansion figures of a metallic mold and a molding, and a rugged lens holding surface is formed on the whole. The height sizes alpha, beta, and gamma are measured and recessed parts with depth sizes alpha', beta', and gamma' are formed at a pitch of 120 deg. by a die 8a at positions corresponding to the projection parts A, B, and C of the molding. Consequently, the height sizes of pedestrials A', B', and C' are (alpha+alpha'), (beta+beta'), and (gamma+gamma') and become equal. The lens is held by the molding 9 without slanting. Further, the surface of the molding 9 may be worked into a reference surface I by the die 8. |
