| 摘要 |
The invention relates to an endoscopic lens with a viewing direction that forms an angle of <>0 DEG with the longitudinal endoscope axis. The inventive lens comprises: a lens system that forms an object field in a focal plane which is located in a vertical position with respect to the longitudinal axis, and a prism unit which is arranged in the imaging path after the distal window of the endoscope and in which the beam is reflected onto two limiting surfaces so that said beam is diverted in the prism unit from the desired viewing direction to the longitudinal axis of the endoscope. A thin coating is applied to at least one surface of the prism unit. Said coating has a refractive index which is lower than that of the material which makes up the prism unit. As a result, total reflection against said coating occurs. The invention is characterised in that the coating is arranged on the surface of the prism unit facing the cover glass of the endoscope. |
