Endscope system

Abstract

An objective of the present invention is to provide a compact endoscope system with which using a depolarization plate having a complex configuration is not required and it is possible to obtain an adequate depolarization effect. Provided is an endoscope system comprising, in order from the object side: an objective optical system OBL; an optical path segmenting unit 120 which segments light fromthe objective optical system in two; and an image capture element 122 which captures the two segmented images. A lambda / 4 wavelength plate 121a which is formed from one birefringent material is positioned in the optical path between the objective optical system OBL and the optical path segmenting unit 120. Said lambda / 4 wavelength plate 121a satisfies the following equations (1) and (2): 10 <= (d / d0) * 0.25 <= 85 (1) and 0.09 <= the absolute value of delta n <= 0.23 (2) where d is the thickness of the lambda / 4 wavelength plate, d0 is the thickness of the lambda / 4 wavelength plate which reacheszero order in a line e, and delta n is the refraction in the line e of the lambda / 4 wavelength plate.

Description

technical field [0001] The present invention relates to an endoscope system. Background technique [0002] It is generally known that in equipment including an imaging element such as an endoscope system, the depth of field becomes narrower as the number of pixels of the imaging element increases. That is, in the imaging device, when the pixel pitch (the vertical and horizontal dimensions of one pixel) is reduced to increase the number of pixels, the allowable circle of confusion is also reduced accordingly, and thus the depth of field of the imaging device is narrowed. [0003] In order to expand the depth of field, for example, a structure has been proposed in which a self-image is divided and imaged, and the obtained images are synthesized through image processing to expand the depth. Here, when the self-image is divided, it is efficient to use an optical path division unit using polarized light. In the optical path division unit using polarized light, it is desirable t...

AI Technical Summary

Problems solved by technology

That is, in an imaging device, when the pixel pitch (the vertical and horizontal dimensions of one pixel) is reduced to increase the number of pixels, the allowable circle of confusion is also reduced accordingly, and thus the depth of field of the imaging device is narrowed.

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