Photographing device and control method of rotational angle position of polarized light filter

摘要

A photographing device includes a photographing optical system having an image sensor, a polarizing filter which rotates about an optical axis of the photographing optical system and is positioned in an optical path thereof, a rotation driver which preliminarily rotates the polarizing filter at a predetermined cycle pattern, a detector which detects an object luminance signal of object-emanating light transmitting through the polarizing filter and captured by the image sensor when the polarizing filter preliminarily rotates the polarizing filter at the predetermined cycle pattern, a signal generator which generates a rotation control signal by eliminating any frequency component of a cycle pattern that is different from the predetermined cycle pattern from the object luminance signal, and a controller which controls a rotational angle position of the polarizing filter based on the rotation control signal generated by the signal generator.

主权项

1. A photographing device comprising:
a photographing optical system provided with an image sensor; a polarizing filter that rotates about an optical axis of said photographing optical system and is positioned in an optical path of said photographing optical system; a rotation driver that preliminarily rotates said polarizing filter at a predetermined cycle pattern; a detector that detects an object luminance signal of object-emanating light transmitting through said polarizing filter and captured by said image sensor when said rotation driver preliminarily rotates said polarizing filter at said predetermined cycle pattern; a signal generator that generates a rotation control signal by eliminating any frequency component of cycle pattern that is different from said predetermined cycle pattern from said object luminance signal detected by said detector; and a controller that controls a rotational angle position of said polarizing filter based on said rotation control signal generated by said signal generator, wherein said signal generator generates said rotation control signal, from said object luminance signal detected by said detector, in which any frequency component having a cycle or phase that differs from a cycle or phase of a luminance signal corresponding to a polarized state when said polarizing filter is rotated preliminarily at said predetermined cycle pattern has been eliminated.