GB1379981A - Lenses - Google Patents

Abstract

1379981 Optical objectives OLYMPUS OPTICAL CO Ltd 9 Feb 1972 5934/72 Heading G2J An objective has three parts I, II and III arranged in order from object to image side, the first part having a first component 1 consisting of a cemented triplet, a second meisocus lens component 2, the second part having a third and a fourth component, e.g. 3 and 4, one of which components is a cemented doublet, and the third part having a fifth, sixth and seventh component, the fifth and sixth (5 and 6) components each consisting of cemented doublets, and the seventh 7 being a meiscus lens, the objective satisfying the following conditions:- 0.8 f<|r 3 |<1.2f; 0.6f<r 15 <0.8f; 1.0f<|r 13 |<1.5f;25<|# 9 -# 8 |; where r 3 is the radius of curvaturve of the cemented surfaces of the first lens component at the image side; r 1 5 is the radius of curvature of the air interface of the sixth lens component at the object side; # 8 and # 9 ) are the AbbÚ numbers of the two lens elements of the fifth component, # 8 at the object side, # 9 at the image side; r 13 is the radius of curvature of the cemented surfaces of the fifth lens group; and f is the focal length of the objective. Optical data are given for three examples, in two of which the seventh component is a cemented doublet.