Title:
【発明の名称】屈折率分布型レンズを有したリヤーフォーカス式のズームレンズ
Document Type and Number:
Japanese Patent JP2970083
Kind Code:
B2
Abstract:
PURPOSE:To obtain the rear focus type zoom lens which is reduced in size on the whole and has excellent optical performance over the entire power variation range and the gradient index lens while having a specific power variation ratio by using the gradient index lens and a rear focus type. CONSTITUTION:The zoom lens has four groups, i.e., a 1st group L1 with positive refracting power, a 2nd group L2 with negative refracting power, a 3rd group L3 with positive refracting power, and a 4th group L4 with positive refracting power in order from an object side; and the 2nd group L2 is moved for power variation, the 4th group L4 is moved for the correction of image plane variation due to the power variation, and the 4th group L4 is moved for focusing. At least one of the four lens groups is provided with the gradient index lens.
Inventors:
HORIUCHI AKINAGA
HAMANO HIROYUKI
HAMANO HIROYUKI
Application Number:
JP17439191A
Publication Date:
November 02, 1999
Filing Date:
June 19, 1991
Export Citation:
Assignee:
KYANON KK
International Classes:
G02B9/00; G02B13/18; G02B15/16; G02B15/173; (IPC1-7): G02B15/16; G02B13/18
Domestic Patent References:
| JP333710A | ||||
| JP2287415A | ||||
| JP253017A | ||||
| JP248621A | ||||
| JP248620A | ||||
| JP239011A | ||||
| JP212118A | ||||
| JP6468709A | ||||
| JP63123009A | ||||
| JP6329719A | ||||
| JP6329718A | ||||
| JP58193512A | ||||
| JP255308A | ||||
| JP6381215A | ||||
| JP6224213A | ||||
| JP58160913A | ||||
| JP62247316A | ||||
| JP4104114A | ||||
| JP4343313A | ||||
| JP4317018A | ||||
| JP4310910A | ||||
| JP4296809A | ||||
| JP4242708A | ||||
| JP4242707A | ||||
| JP4171411A | ||||
| JP4153615A | ||||
| JP45609A | ||||
| JP3296706A |
Attorney, Agent or Firm:
Takanashi Yukio