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:
Jun. 03, 2008
Filed:
Oct. 04, 2005
Teruhide Inoue, Tokyo, JP;
Kunihiro Nomiyama, Tokyo, JP;
Koichi Sakaguchi, Tokyo, JP;
Nippon Sheet Glass Company, Limited, Tokyo, JP;
Abstract
A gradient-index rod lens is provided that is excellent in yield. The gradient-index rod lens has a core/clad structure and is obtained by providing a mother glass rod, which includes a core glass mother composition and a clad glass mother composition, with a refractive index distribution through ion exchange. The clad and the core each contains an alkali metal oxide but are substantially free from lead. The clad and the core each contains an alkali metal oxide and has a basic composition including components other than the alkali metal oxide, but they are different from each other in the basic composition. The clad glass mother composition has a higher thermal expansion coefficient and glass-transition temperature than those of the core glass mother composition. The difference of the thermal expansion coefficient between the clad glass mother composition and the core glass mother composition is larger than 2×10/° C. but smaller than 20×10/° C.