Abstract: The illuminating light transmitted by the light guide inserted through the elongate inserted section is projected out of the distal end surface of the inserted section. The illuminated objects pass through the respective pupils of the two objective lens systems arranged in parallel within the distal end section of the inserted section and their images are formed on the focal surface. The respective images are transmitted to the rear side by one common relay lens system. The transmitted final images are formed respectively on the image taking surfaces of the image taking devices. The respective images photoelectrically converted by the respective image taking devices are processed to be signals, are displayed in the monitor and are stereo-inspected through shutter spectacles.

Abstract: The illuminating light transmitted by the light guide inserted through the elongate inserted section is projected out of the distal end surface of the inserted section. The illuminated objects pass through the respective pupils of the two objective lens systems arranged in parallel within the distal end section of the inserted section and their images are formed on the focal surface. The respective images are transmitted to the rear side by one common relay lens system. The transmitted final images are formed respectively on the image taking surfaces of the image taking devices. The respective images photoelectrically converted by the respective image taking devices are processed to be signals, are displayed in the monitor and are stereo-inspected through shutter spectacles.

Abstract: The illuminating light transmitted by the light guide inserted through the elongate inserted section is projected out of the distal end surface of the inserted section. The illuminated objects pass through the respective non-superimposed pupils of the two objective lens systems arranged in parallel within the distal end section of the inserted section and their images, which are not equal to each other are formed on the focal surface. The respective images are transmitted to the rear side by one common relay lens system having a single optical axis. The transmitted final images are formed respectively on the image taking surfaces of the image taking devices. The respective images photoelectrically converted by the respective image taking devices are processed to be signals, are displayed in the monitor and are stereo-inspected through shutter spectacles.

Abstract: A stereoscopic endoscope comprises an elongate inserted section, an illuminating light system, an objective optical system at the distal end of the inserted section for forming a plurality of images having parallax between them through a plurality of incident pupils, and a common relay lens system for transmitting the plurality of images to the proximal end of the inserted section. The objective optical system includes a plurality of front lens groups and a rear lens group, wherein the plurality of front lens groups comprise two negative lens units arranged in parallel with each other and the rear lens group comprises a single positive lens group. The two negative lens units are arranged to be substantially symmetrically concentric about an optical axis of the single positive lens group and spaced to be afocal.