Lens barrel and imaging apparatus

Abstract

The present invention relates to a lens barrel and an imaging apparatus. The lens barrel includes: a variable focal length lens system including at least three movable lens groups; and guiding means for moving the variable focal length lens system forward and backward in an optical axis direction. The variable focal length lens system includes at least first, second and third lens groups having positive, negative and positive refracting power respectively, arranged in this order begin from an object side. When a lens position setting is changed from a wide angle end state to a telescopic end state, at least the first and third lens groups are moved toward the object side such that air separation between the first and second lens groups monotonously increases and air separation between the second and third lens groups monotonously decreases. The guiding means includes a fixed frame, a rotating frame, a rectilinear guiding frame, a first guide frame, and a second guide frame.

Description

technical field [0001] The present invention relates to a lens barrel and an imaging device, and particularly relates to a lens barrel employing a so-called foldable structure. Background technique [0002] As a recording method in a digital camera, there is a known method in which an imaging device composed of a photoelectric conversion element such as a CCD sensor and a CMOS sensor converts the amount of light forming an object image on the surface of the imaging device into an electrical output, This electrical output is then recorded. [0003] With the development of micro-processing technology in recent years, CPUs (Central Processing Units) have operated faster and storage media have increased their storage density, so that a large amount of image data that could not be processed before can now be processed at high speed. [0004] Light-receiving devices have also increased in storage density and shrunk in size. Higher storage densities allow higher spatial frequency...

AI Technical Summary

Problems solved by technology

[0006] The luminous flux directed to the part between adjacent photoelectric conversion elements when there is no microlens array is guided to these photoelectric conversion elements through the microlens array, but the microlens array restricts the position of the exit pupil of the lens system (from the image plane distance to exit pupil)

[0007] The reason is that when the exit pupil position of the lens system is close to the photoelectric conversion elements, that is, when the chief ray reaching each of the photoelectric conversion elements forms a large angle with the optical axis of the lens system, the off-axis light flux directed to the outer periphery of the screen is large. The angle is inclined to the optical axis and thus cannot reach the photoelectric conversion element at the periphery, resulting in insufficient light quantity

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