Method for making a precision molding glass and molding device implementing for the method

A method for making a precision molding glass, comprising the steps of:

• (a) preparing a molding device including a first mold, and a second mold which has an axis common with that of said first mold, said first mold having a first molding surface centered at said axis, a first peripheral surface extending around said axis and connected to said first molding surface, and a first edge formed between said first molding surface and said first peripheral surface, said first peripheral surface having a first distal peripheral portion distal from said first edge, said second mold having a second molding surface opposite to said first molding surface and centered at said axis, a second peripheral surface extending around said axis and connected to said second molding surface, and a second edge formed between said second molding surface and said second peripheral surface, said second peripheral surface having a second distal peripheral portion distal from said second edge;
• (b) mounting a centering unit having a shearing portion around said molding device such that said shearing portion is movable axially between said first and second distal peripheral portions;
• (c) placing a glass material between said first and second molding surfaces;
• (d) heating said glass material to a molding temperature;
• (e) molding said glass material by moving axially said first and second molds toward each other until said glass material is pressed to have a predetermined central thickness and until an excess amount of said glass material is squeezed out of said first and second edges;
• (f) lowering the temperature of said glass material;
• and
• (g) while said glass material is still soft, moving said centering unit from one of said first and second distal peripheral portions to the other one of said first and second distal peripheral portions such that said shearing portion of said centering unit removes said excess amount of said glass material.