Single focal length lens system and imaging device having the single focal length lens system

Abstract

A single focal length lens system includes in order from an object side to an image side along an optical axis, a front lens unit, and a rear lens unit which includes an aperture stop. The single focal length lens system does not include any other lens unit on the optical axis, and the rear lens unit includes a focusing lens unit having a negative refractive power. The focusing lens unit is disposed on the image side of the aperture stop, and moves along the optical axis at the time of focusing from an object at infinity to an object at a close distance. The front lens unit does not include a lens which moves in an optical axial direction, and the rear lens unit does not include a lens which moves in the optical axial direction except at the time of focusing.

Description

technical field [0001] The present invention relates to a single focal length lens system and an imaging device with the single focal length lens system. Background technique [0002] In shooting with a telephoto lens or a super telephoto lens (the following settings are set to telephoto lens), the effect of pulling a distant subject or a small subject to the photographer's eyes is obtained. Therefore, the telephoto lens is widely used in various scenes such as shooting of sports scenes, shooting of wild animals such as wild birds, and shooting of celestial bodies. [0003] As a telephoto lens used for photographing such a scene, there are telephoto lenses disclosed in JP-A-2008-145584 and JP-A-11-160617. [0004] In the shooting of the above scene, the mobility of the camera device is particularly important. Here, the mobility refers to, for example, the ease of carrying, the stability when shooting by hand, the high speed of the focusing speed, and the like. In order to...

AI Technical Summary

Problems solved by technology

However, like the telephoto lens of the first embodiment, focusing is mainly performed by the negative lens group constituting the telephoto lens, so it cannot be said that the weight reduction of the optical system and the speed-up of the focusing speed have been sufficiently achieved.

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