Telecentric image transmitting systems used in endoscopes and periscopes are mostly of symmetrical construction, and therefore, they are free of distortion. However, in order to improve the general barrel distortion of endoscopes and devices similar to endoscopes, it is desirable to have telecentric relay lens systems for unique magnification, which produce distortion, especially pincushion distortion. This paper describes the construction of a telecentric relay lens system for unique magnification which produces distortion and the imaging peculiarities of such systems. A practical embodiment of a 70-degree endoscope uses a chain of 5 image transmitting systems each producing only 1.5% distortion. As the result, the overall distortion of this endoscope is improved from -15% to -7%.

Date Published: 23 August 1996
PDF: 7 pages
Proc. SPIE 2774, Design and Engineering of Optical Systems, (23 August 1996); doi: 10.1117/12.246669

Published in SPIE Proceedings Vol. 2774:
Design and Engineering of Optical Systems
Joseph J. M. Braat, Editor(s)