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. 22, 1997
Filed:
Feb. 28, 1995
Katsuyuki Ohkubo, Atsugi, JP;
Tomoaki Sugawara, Atsugi, JP;
Hiroyuki Endou, Atsugi, JP;
Hiroshi Ueno, Atsugi, JP;
Akihito Minato, Zama, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A glass material for molding an optical element and including lead and a lead compound is processed chemically and physically and includes a modificative ion component set such that an atomic concentration of the modificative ion component in a range of 600 angstroms from a glass surface layer has a concentration gradient approximated by a curve represented by the following formula (1). ##EQU1## wherein, reference numeral Y designates an atomic concentration of a modificative ion shown by atomic percent. Reference numeral X designates a depth from an uppermost glass surface layer. Each of coefficients A0 to A10 is set to a constant. Symbol 0 designates a power. Reference numeral e(x) designates an error component.