Endoscope

Abstract

An endoscope configured to measure a specimen using a stripe image formed by projecting a light-dark pattern on the specimen, the endoscope including an insertion portion having an elongated shape; an imaging unit provided at a distal portion of the insertion portion and configured to acquire an image of the specimen; a lighting unit configured to illuminate an observation field of view of the imaging unit; and a pattern projector which emits projection light configured to project the light-dark pattern to the specimen and project the light-dark pattern on the specimen. The imaging unit includes an image sensor configured to image the image of the specimen; and an objective optical system configured to form the image of the specimen on the image sensor. The pattern projector includes a pattern generator configured to generate the light-dark pattern; and a projection optical system provided at the distal portion of the insertion portion and configured to emit the projection light to the specimen via the light-dark pattern. A radiation angle of the projection light in the projection optical system is smaller than an angle of view of the objective optical system. The objective optical system is in focus at farther point side than a minimum object distance which is a minimum value of an object distance at which the entire projected light-dark pattern enters an imaging field of view of the image sensor.