Title:
ズームレンズ
Document Type and Number:
Japanese Patent JP4636812
Kind Code:
B2
Abstract:
A zoom lens system including, in order from an object side to an image side, a first lens unit of positive optical power, and a second lens unit of negative optical power, followed by a lens component having a lens unit, wherein at least one of the first lens unit and the second lens unit moves during zooming. One of the lens units of the zoom lens system includes a layer made of a material that satisfies the following conditions: 11 0.2 Wherein nuIT is an Abbe number of the layer, and thetaIT is a partial dispersion ratio for the g-spectral line and f-spectral line of the layer. The layer has an optical power of a sign opposite to that of the lens unit including the layer.
Inventors:
Hiroyuki Hamano
Hiroshi Saruwatari
Hiroshi Saruwatari
Application Number:
JP2004132608A
Publication Date:
February 23, 2011
Filing Date:
April 28, 2004
Export Citation:
Assignee:
Canon Inc
International Classes:
G02B15/20; G02B1/04; G02B13/18; G02B15/14; G02B15/16
Domestic Patent References:
| JP2001194590A | ||||
| JP2001154093A | ||||
| JP8220439A | ||||
| JP634886A | ||||
| JP2003295059A | ||||
| JP200174901A |
Attorney, Agent or Firm:
Takuma Abe
Sogo Kuroiwa
Sogo Kuroiwa