Patent ID: 7835087
Filing Date: 2010-11-16
Classification: G02B

Abstract:
1. A method of producing a lens, the method comprising the steps of: shifting a first die relative to a second die; and pressing an optical glass material shaped in a preliminary form between the first die and the second die so as to form a lens having a configuration corresponding to a hollow portion formed by the first die and the second die while shifting the first die relative to the second die, wherein the lens comprises an effective optical surface configured to converge a light flux, the effective optical surface comprising a light entrance side, a light exit side, and an optical axis, wherein the effective optical surface is a convex surface shaped such that when a maximum normal line angle is defined as an angle formed between the optical axis and a normal line at an outermost circumference of the effective optical surface, the maximum normal angle is 60° to 90° and a maximum normal line forming the maximum normal line angle intersects with the optical axis at an intersection located at the light exit side of a point of the maximum normal line on the optical surface, and wherein the preliminary form of the optical glass material is shaped such that a sphere having a same volume of the preliminary form is defined as an equivalent sphere.