Gauss lens with image stabilizing function

A Gauss lens system having a plurality of lens groups positioned along an optical axis from an object side to an image side, the lens system having an image stabilizing function, and comprising:

• a first lens group adjacent the object side, with positive refractive power, the first lens group comprising a negative lens component having a first divergent surface and a convex surface facing the object side and placed closest to the image side;
• a second lens group with positive refractive power on the image side of the first lens group, the second lens group comprising a negative lens component having a second divergent surface and a convex surface facing the image side and placed adjacent to the image side of an aperture stop;
• and
• displacement means for moving the second lens group in a direction substantially perpendicular to the optical axis to prevent vibration, wherein a focal length f2 of the second lens group and a focal length f of the lens system satisfy 0.2<f2/f<4.0;
• wherein a height Hex at which light rays furthest from the optical axis pass through a surface having refractive power closest to the image side of the lens system, a height Hin at which light rays furthest from the optical axis pass through a surface having refractive power closest to the object side, a refractive power .phi.1 of the first divergent surface, and a refractive power .phi.2 of the second divergent surface satisfy 0.2<Hex/Hin<1.0 and 0.6<.phi.1/.phi.2<5.0.

A method for achieving image stabilization in a Gauss lens system having a plurality of lens groups positioned along an optical axis from an object side to an image side, the method comprising:

• providing a first lens group adjacent the object side, with positive refractive power, the first lens group comprising a negative lens component having a first divergent surface and a convex surface facing the object side placed closest to the image side;
• providing a second lens group with positive refractive power on the image side of the first lens group, the second lens group comprising a negative lens component having a second divergent surface and a convex surface facing the image side placed adjacent to the image side of an aperture stop;
• and
• moving the second lens group in a direction substantially perpendicular to the optical axis to prevent vibration, wherein a focal length f2 of the second lens group and a focal length f of the lens system are related such that image stabilization can be achieved;
• wherein a height Hex at which light rays farthest from the optical axis pass through a surface having refractive power closest to the image side of the lens system, a height Hin at which light rays farthest from the optical axis pass through a surface having refractive power closest to the object side, a refractive power .phi.1 of the divergent surface Sd1, and a refractive power .phi.2 of the divergent surface Sd2 satisfy 0.2<Hex/Hin<1.0 and 0.6<.phi.1/.phi.2<5.0.