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:
Mar. 24, 1998
Filed:
Oct. 11, 1996
Yuko Morita, Hachiohji, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
At least one metal species g is selected from the metal group G consisting of Nb, Ta, Pb, Ti, Tl and Zr. At least one metal species f is selected from the metal group F1 consisting of La, In, Y, Zr and Ta. The metal species g and f are not simultaneously Ta or Zr. The metal species g and f have concentrations distributed in mutually reverse directions. The element exhibits a ratio of dCf/dCg, in which dCf and dCg represent concentration distribution gradients of metal species f and g, respectively, ranging from -4 to -0.2. Alternatively, at least one metal species f may be selected from the metal group F2 consisting of Ga, Sn, Ba, Sr and Ca, while causing the ratio of dCf/dCg to be in the range of from -7 to -0.5. Thus, a gradient index optical element is obtained, which exhibits less refractive index change and large Abbe number change and is hence superior to conventional elements in correction of chromatic aberration.