| 摘要 |
1,137,788. Optical objectives. L. BERTELE. July 31, 1967 [Aug. 2, 1966], No.35105/67. Heading G2J. A wide angle lens of focal length F, divided into two groups by a diaphragm has in the front group a diverging member L1, which as shown is a sing- let but could be formed by a pair of lens elements spaced apart or cemented together, air-spaced from a diverging meniscus L2 concave to the diaphragm whose inner concave surface is of radius rIV and spaced a distance S I from the adjacent surface of radius r III of a positive element L3 cemented to a concave surface of a negative element L4 adjacent the diaphragm, and a rear group having a negative element L5 adjacent the diaphragm whose concave surface is cemented to a positive element L6 having its other surface of radius r3 and centre of curvature lying on the image side of the surface r III , a diverging element L7 having a surface r 3 1 concave to the diaphragm and spaced from or cemented to the adjacent surface r 3 and air spaced from a rear diverging member L8 which may be a singlet as shown or be formed by a pair of elements spaced apart or cemented together wherein: - and the refractive indices of L4, L5, respectively are less than those of L3, L6. Optical data are provided for five examples. |
