PURPOSE: To obtain an optical element with improved releasability leading to its proper automatic drawing, etc., by loading a glass material in between top and bottom forces followed by putting the material to such processes as heating, load application, annealing and shrinkage regulation, etc., and then drawing out.
CONSTITUTION: A glass material and top and bottom forces 13,14 are heated to a desired forming temperature, and the glass material is put to press-forming to a shape of the final optical element to obtain a formed product. The top and bottom forces and the formed product are then annealed to a temperature enough to retain both the dimension and shape of the formed product followed by cooling the bottom force to provide a specified temperature difference between the top force 13 or the upper surface of the product being in contact therewith and the bottom force 14 or the lower surface of the product being in contact therewith, thus ensuring the shrinkage of the lower surface to be greater than that of the upper surface. Thence, both the top and bottom forces 13, 14 are opened to take out the glass formed product, thus obtaining the objective optical element.
TOMITA MASAYUKI
SHIGYO ISAMU
YOSHIMURA FUMITAKA
| JP46053365A | ||||
| JPS51101014A | 1976-09-07 |