1. Field of the Invention
The present invention relates to a compact two-group wide-angle zoom lens for a lens shutter camera, which covers a wide angle area by two lens groups.
2. Related Background Art
Recently, as a lens system used for lens shutter cameras, that loaded with a zoom lens has been becoming the mainstream. Since such a zoom lens requires its compactness in the first place, there has been put into practice a two-group zoom lens with a telephoto type of refracting power arrangement, comprising a first lens group with a positive refracting power and a second lens group with a negative refracting power.
Further, there have been known various configurations in which an aspheric surface is used for a lens surface so as to reduce the number of lens sheets, while improving optical performances.
As such art, commonly-assigned Japanese Unexamined Patent Publication No., 9-101454 (Japanese Patent Application No. 7-284551) discloses a technique which can also restrain refractive index from fluctuating upon changes in a plastic lens with respect to temperature.
In the above-mentioned technique, however, since a lens shutter is disposed between the first and second lens groups, which change the distance therebetween upon zooming, it is necessary for these lens groups to secure a considerable amount of distance therebetween when they are moved to the telephoto end. Here, it is thus difficult for the whole lens thickness to be greatly reduced.
USPTO Backgrounds
USPTO Backgrounds