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. 29, 2010
Filed:
Mar. 20, 2007
Yoshiko Kasuga, Tokyo, JP;
Yasuhiro Fujiwara, Tokyo, JP;
Xuelu Zou, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
The present invention relates to an optical glass having a refractive index (nd) of greater than or equal to 1.65 and an Abbé number (ν (nu)d) of greater than or equal to 50 for use in precision press molding. The glass exhibits that a ratio α (alpha)1/α (alpha)2 is less than 17 when temperature denoting maximum value of differential in amount of elongation of glass relative to temperature differential DELTAT (where DELTAT denotes a constant value of 1° C. or less) over a temperature range from glass transition temperature (Tg) to sag temperature (Ts) is denoted as T1, average coefficient of linear expansion over a range from T1−5° C. to T1+5° C. is denoted as alpha1, and average coefficient of linear expansion over a range from the glass transition temperature (Tg)−160° C. to the glass transition temperature (Tg)−140° C. is denoted as alpha2.