light adjustment device

Abstract

A light adjusting apparatus includes a substrate, a rotating shaft member made of an axial magnet, a light adjusting section rotatably integrated with the rotating shaft member and an electromagnetic drive source rotating the rotating shaft member using a coil core member made of a coil and a magnetic body, the light adjusting apparatus being configured to adjust light by displacing the light adjusting section to a retracted position and an inserted position, and a rotatable range θa is set to have a portion overlapping at least one of a range θn in which a direction of torque acting on the rotating shaft member when no current is flowing through the coil becomes a negative direction and a range θp in which the direction of torque becomes a positive direction, and a range θ1 where θa overlaps θn and a range θ2 where θa overlaps θp have different widths.

Description

technical field [0001] The present invention relates to a light adjusting device which adjusts light by inserting or detaching a light adjusting part on an optical path. Background technique [0002] Imaging devices having an imaging function are widely used in various fields, but there is also a field of compact imaging devices having a relatively small shape among them. Some examples of such small-sized imaging devices include electronic endoscopes including microendoscopes, optical microscopes equipped with imaging functions, and portable devices equipped with imaging functions. [0003] Conventional compact imaging equipment uses fixed focus lenses, fixed aperture stops, fixed characteristic filters, etc. as optical elements such as lenses, diaphragms, and optical filters in order to prioritize miniaturization. [0004] On the other hand, in recent years, such small-sized imaging equipment has also been required to have higher image quality. As the optical elements of t...

AI Technical Summary

Problems solved by technology

[0007] However, there are cases where a sudden shock is applied to an imaging device equipped with a light adjustment device, etc.

In this case, with the configuration described in the aforementioned Japanese Patent Application Laid-Open No. 9-22042, the light adjustment unit as the movable body may move to a position different from the intended position.

In particular, when the light adjustment device is in a non-driven state, that is, when the coil is not in a power-off state where no current flows through the coil, there is no force applied to the permanent magnet and the light adjustment part, so the light adjustment part is prone to unintended actions such as impacts. while moving

In addition, when the designed magnetic force or the like is not generated from the coil, the light adjustment part may stop in the middle of the path to be moved, and may not retract to a predetermined position.

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