| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens system that reduces the size of the entire lens system and simplifies a focusing mechanism by properly setting the arrangement of focusing groups, and to provide optical equipment and a manufacturing method for a lens system. SOLUTION: The lens system includes, in order from an object side along an optical axis, at least a first lens group G1 having positive refractive power, and second to fourth lens groups G2 to G4. The first lens group G1 has a front lens group G1a and a rear lens group G1b disposed on the image side of the front lens group G1a, with an air spacing, and moves the rear lens group G1b in the direction of the optical axis to adjust a focal point. The fourth lens group G4 includes, in order from the object side, a negative lens and positive lens (joined negative lens L41), a negative lens L42, and an aperture stop S. In zooming from a wide-angle end to a telephoto end, the fourth lens group G4 is fixed with respect to an image surface I in the direction of the optical axis. COPYRIGHT: (C)2011,JPO&INPIT |
