Endoscope system, imaging apparatus, and control method

Abstract

An endoscope system includes an imaging section that includes an optical system and an imaging element, an observation mode setting section that sets an object observation mode, a diaphragm control section that selects a diaphragm state based on the observation mode, and an image processing section that processes an image acquired by the imaging section. The diaphragm control section selecting a first diaphragm state when the observation mode is a first observation mode. The first diaphragm state being a state in which a resolution determined by a diffraction limit based on a diaphragm of the optical system is lower than a resolution determined by the imaging element. The diaphragm control section selecting a second diaphragm state when the observation mode is a second observation mode. The second diaphragm state being a state in which the resolution determined by the diffraction limit based on the diaphragm of the optical system is equal to or higher than the resolution determined by the imaging element.

Description

technical field [0001] The present invention relates to an endoscope system, an imaging device, a control method, and the like. Background technique [0002] In an imaging device such as an endoscope, it is required to realize a pan-focus image for an image captured in a body cavity so as not to hinder a doctor's diagnosis. Therefore, the endoscope achieves such performance by using an optical system with a large aperture value (hereinafter also referred to as F value) to deepen the depth of field. [0003] On the other hand, in recent years, high-pixel imaging elements with several hundreds of thousands of pixels have been gradually used in endoscope systems. When the optical system is fixed, the depth of field is determined according to the size of the allowable circle of confusion, but since the allowable circle of confusion and the pixel pitch are both small in high-pixel imaging elements, the depth of field of the imaging device becomes smaller. In this case, it is co...

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Problems solved by technology

However, under white light illumination, the resolution and the depth of field should be equally important. If the pixel pitch of the imaging element is reduced, even if the F value is increased to converge on the allowable circle of confusion as the practical depth of field, the circle of confusion is due to the The influence does not converge below the allowable circle of confusion, and the resolution originally possessed by the imaging element cannot be obtained.

The method of Japanese Patent Application Laid-Open No. 10-225427 cannot play a role at all under this condition

[0010] By applying the method of Japanese Patent Application Laid-Open No. 8-181909 to a photographed image captured at an F value that cannot ignore the effect of the diffraction, the resolution can be restored to a certain extent, but there will be such a problem: since it does not originally have The energy of the high-frequency component is sufficient, so it will be extremely high-frequency processing, and the noise will increase

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