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:
Jan. 30, 2018
Filed:
Apr. 08, 2016
Canon Kabushiki Kaisha, Tokyo, JP;
Masatsugu Nakano, Utsunomiya, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
Provided is a zoom lens, including: a negative first lens unit; an aperture stop; and a positive second lens unit, in which the first and second lens units are configured to move so that an interval between the first and second lens units is changed in an optical axis direction, in which the second lens unit includes a positive lens and a negative lens, and in which, when refractive indices of a material with respect to a wavelengths of 400 nm, 1,050 nm and 1,700 nm are respectively represented by Ns, Nm and Nl, and a relative partial dispersion θ of the material is expressed as: θ=(Ns−Nm)/(Ns−Nl), an average value θIR(G)of relative partial dispersions of materials of the positive lens in the second lens unit, and an average value θIR(G)of relative partial dispersions of materials of the negative lens in the second lens unit are appropriately set.