LENS FOR ENDOSCOPIC DEVICE, DRIVE FOR FOCUSING AND ENDOSCOPIC SYSTEM Russian patent published in 2017 - IPC G02B13/00 G02B23/24 A61B1/55 

FIELD: physics.

SUBSTANCE: lens for an endoscope comprises a plurality of lenses, an aperture and an optical element disposed near the diaphragm. Lens focal distance is variable in accordance with the movement of the optical element in a direction different from the direction of the optical axis of the plurality of lenses. Depth of field (DOF) of the lens varies in the range of 5 to 100 mm at the far distance, and DOF of the lens varies in the range of 2.5 to 10 mm at the proximal region.

EFFECT: simplifying the lens focusing.

14 cl, 19 dwg, 13 tbl