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. 17, 2012
Filed:
Apr. 16, 2010
Masaki Tamura, Kanagawa, JP;
Masaki Tamura, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
Provided is a zoom lens including a first lens group, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power, wherein conditional expressions f/fw>2.0, f/fw<−2.0, −2.0≦f/f≦−0.5, and νd−νd>20 are satisfied, where fis a focal length of a single lens having a positive refractive power in the first lens group, fis a focal length of the second lens group, fw is a focal length of the total lens system at a wide angle end, νdis an Abbe number of the lens having a negative refractive power in the second lens group for the d-line, and νdis an Abbe number of the lens having a positive refractive power in the second lens group for the d-line.