Patent ID: 8390924

Claim:
An endoscope comprising: a first illumination optical system configured to include a polarizing element between a light source and an illuminating window and emit illuminating light in a first linear polarization direction to an object from the illuminating window; a first objective optical system configured to allow return light from the object illuminated by the illuminating light to enter through an objective window provided in a distal end face of an insertion portion; and an image pickup device configured to receive an image formed by the first objective optical system; wherein the first illumination optical system and the first objective optical system are placed in a positional relationship such that on the distal end face, a line segment connecting an optical axis of the first illumination optical system and an optical axis of the first objective optical system is parallel or perpendicular to a polarization direction which results when the illuminating light emitted from the first illumination optical system is projected to the distal end face, and no polarizing element is provided between the object and the image pickup device.