The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1992
Filed:
Nov. 21, 1990
Masahiro Oikawa, Ibaragi, JP;
Tetsuya Yamasaki, Sakura, JP;
Kouji Tanaka, Sakura, JP;
Eiji Okuda, Sakura, JP;
Nippon Sheet Glass Co., Ltd., Osaka, JP;
Abstract
In a plate microlens of the invention, wherein gradient index lenses each having an optical axis along a normal to a surface of a transparent base and a refractive index profile gradually changing along a direction of the optical axis and a direction perpendicular thereto are formed integrally in the transparent base; a ratio d/a (where d is a thickness of the gradient index lens on the optical axis and 2a is a diameter of the gradient index lens on a surface of the transparent base) falls within a range of 0.46 to 0.78. In a method for manufacturing a plate microlens of the invention, of forming integrally in a transparent base, gradient index lenses with a gradient index profile based on a concentration gradient of a substance for increasing the refractive index of the transparent base, by forming a diffusion preventive mask with predetermined apertures on a surface of the transparent base and diffusing the substance into the transparent base through the apertures; a ratio a/rm (where rm is a radius of the apertures and a is a radius of the gradient index lenses to be formed) satisfies a relation 1.75.ltoreq.a/rm.ltoreq.4.5.