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. 01, 2014
Filed:
Oct. 18, 2012
Canon Kabushiki Kaisha, Tokyo, JP;
Kaoru Eguchi, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
An optical system includes a first lens unit fixed during a focusing operation and having a positive refractive power, a second lens unit moving in an optical axis direction during the focusing operation and having a negative refractive power, a third lens unit positioned at the image side relative to the second lens unit and having a positive or negative refractive power, the first lens unit is configured by first, second, and third partial lens units, the first partial lens unit is configured by two positive lens components, the second partial lens unit is configured by one cemented lens having a negative combined refractive power, the third partial lens unit is positioned between the second partial lens unit and the second lens unit and has a positive refractive power as a whole, and each lens unit is configured so as to meet an appropriate condition.