Anti-vibration zoom lens optics

Abstract

Anti-vibration zoom lens optics of four lens groups where a unit associated with an aperture stop and an anti-vibration unit can be spaced apart from each other without interference between their driving mechanisms. The four groups include a leading, first lens group of positive refractivity, a succeeding second lens group of negative refractivity, a third lens group of positive refractivity, and a trailing, fourth lens group of positive refractivity all arranged in this order from the front end closest to the object to the rearmost. The fourth lens group include three subsets of lens pieces, a leading, first subset, a succeeding, second subset, and a trailing, third subset all arranged in this order from the front end closest to the object to the rearmost, and the second subset of lens pieces are moved perpendicular to the optical axis to compensate for blur in the imaging plane.

Description

technical field [0001] The present invention relates to a vibration-proof zoom lens optical system for a single-lens reflex camera using a film or a solid-state imaging element. Background technique [0002] Conventionally, the following configurations have been proposed as zoom lenses having an anti-vibration function and a zoom ratio of about 4 times. [0003] In a zoom lens with 5 groups of lens elements of positive, negative, positive, positive, and negative, or a zoom lens with 6 groups of lens elements of positive, negative, positive, negative, positive, negative, the A structure that moves the negative second lens group (for example, refer to Patent Document 1). [0004] In a zoom lens with a zoom ratio of 4.1 and five groups of lens elements: positive, negative, negative, positive, and negative, a structure in which a part of the positive fourth lens group is moved for anti-vibration correction (for example, Refer to Patent Document 2). [0005] In a zoom lens hav...

AI Technical Summary

Problems solved by technology

[0009] The technical solutions of Patent Documents 1 and 2 have the following problems: the effective diameter of the lens group that moves for anti-vibration correction is as large as 25mm or more, resulting in an increase in the size of the anti-vibration mechanism, and it is difficult to miniaturize the zoom lens

In addition, there is a problem that the zoom mechanism is complicated because there are five or more zoom lens groups.

[0010] The technical solution in Patent Document 3 has the following problem: starting from the object side, the positive third lens group is divided into a positive 31st lens group, a negative 32nd lens group, and a 33rd lens group, and only the 32nd lens group is The anti-vibration correction is performed by moving in the direction perpendicular to the optical axis, but the position between the diaphragm unit attached to the third lens group and the anti-vibration unit is close, so the parts that drive the diaphragm and the parts of the anti-vibration mechanism interfere with each other, and the lens barrel complex structure

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