Optical Element Molding Device

Abstract

An optical element molding device includes upper and lower mold elements and first and second cavity mold elements. Each of the upper and lower mold elements includes a pedestal and a shaft projecting along a common axis from a flange surface of each pedestal. An optical function transferring surface is formed at the tip of each shaft with the tips facing one another along the common axis. The first cavity mold element extends around these tips and the common axis for molding an optical element by heating and pressuring an optical material arranged between the upper and lower mold elements by their relative movement toward one another along the common axis guided by the first cavity mold element. Various surfaces contact one another in order to limit relative movement of the upper and lower mold elements along the common axis during molding and constrain axial inclination of these mold elements.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given below and the accompanying drawings, which are given by way of illustration only and thus are not limitative of the present invention, wherein:

FIG. 1 shows an exploded cross-sectional view of the optical element molding device of Embodiment 1 of the present invention; FIGS. 2A-2B show cross-sectional views of the optical element molding device of FIG. 1 before and during molding heating and pressure being applied, respectively;

FIG. 3 shows a cross-sectional view of the optical element molding device of Embodiment 2 of the present invention;

FIG. 4 shows a cross-sectional view of a modification of the optical element molding device of Embodiment 2 of the present invention;

FIG. 5 shows a cross-sectional view of the optical element molding device of Embodiment 3 of the present invention; and

FIGS. 6A-6B show cross-sections of arrangements of mold elements with errors of axial alignment and axial inclination, respectively, that result in errors in the shape of the optical function surfaces of molded optical elements.

Claims

1. An optical element molding device comprising: an upper mold element;a lower mold element;a first cavity mold element; anda second cavity mold element that includes an upper end surface and a lower end surface; whereineach of said upper mold element and said lower mold element includes a pedestal and a shaft projecting from each pedestal;the shafts of the pedestals extend along a common axis;an optical function transferring surface is formed at the tip of each shaft with the tips facing one another along said common axis;said first cavity mold element extends around said tips and said common axis for molding an optical element by heating and pressuring an optical material arranged between said upper mold element and said lower mold element by said upper mold element and said lower mold element moving relatively toward one another along said common axis guided by said first cavity mold element;each of the pedestals includes a flange surface extending away from said common axis;said second cavity mold element extends around said first cavity mold element but does not contact said first cavity mold element; andat least one of said upper end surface and said lower end surface contacts one of the flange surfaces in order to limit relative movement of said upper mold element and said lower mold element toward one another during molding of an optical element and at the same time constrain axial inclination of said upper mold element and said lower mold element about said common axis.