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:
Sep. 15, 2015
Filed:
Feb. 16, 2011
Tomohiko Ishibashi, Utsunomiya, JP;
Tomohiko Ishibashi, Utsunomiya, JP;
CANON KABUSHIKI KAISHA, , JP;
Abstract
The optical system includes first (positive) and second (negative) lens units arranged in order from an object side to an image side, and an aperture stop disposed further on the image side than the second lens unit. The first lens unit includes at least one first optical element satisfying φGH>0.0, νdGH<39.5 and ndGH>1.70. The optical system satisfies 0.65<|φ|<6.00 and 0.45<|ΣφGH×φ|<4.00. φGH represents a refractive power of the first optical element when light-entrance and light-exit surfaces thereof are in contact with air, νdGH and ndGH respectively represent an Abbe number and a refractive index of a material forming the first optical element for a d-line, φand φrespectively represent the refractive powers of the first lens unit and the second lens unit, and ΣφGH represents a sum total of the refractive power φGH of the at least one first optical element.