Endoscope with observation section and simple optical system

摘要

The endoscope tube (22) coupled to the eyepiece (21) and opt. a TV adaptor (21a) contains a distal aspherical lens (25) with negative magnification and an internal aspherical lens (28) with positive magnification, and two glass rods (27, 30).The eyepiece incorporates a field lens (31), an image-inverting straight prism (33), a composite element (34) and a single lens (35), correcting chromatic aberration in the intermediate image plane (32) at 200 to 600mm from the distal end of the tube. The end faces of the rods are plane-parallel.