ELECTRONIC ENDOSCOPE WITH ZOOM LENS SYSTEM

摘要

An endoscope having an objective lens, a zoom lens, a solid state imaging device for picking up the image formed by said objective lens and transferred by said zoom lens, and control means for moving the zoom lens and the imaging device so as to assure that for each position occupied by the zoom lens the imaging device is positioned so that the its image-receiving surface is in the focal plane of the zoom lens. The endoscope also comprises first and second motion-transmitting means for moving said zoom lens and said imaging device respectively along the optical axis of said objective lens, whereby the axial spacing between said zoom lens and said objective lens and also the axial spacing between said imaging device and said objective lens may be changed, and manually operable switch means for controlling movement of the zoom lens and the imaging device by said first and second motion transmitting means. The control means also comprises means for sensing the position of said zoom lens and said imaging device along the optical axis of the endoscope, a lookup table containing data as to the spacing required to be maintained between said imaging device and said zoom lens in order for the focal plane of said zoom lens to be located substantially at the image-receiving surface of said imaging device for various positions of said zoom lens system, means for accessing said data, and means for moving said zoom lens system and/or said imaging device in accordance with the accessed data.