| 摘要 |
1,230,344. Optical objectives. WILD HEERBRUGG A.G. and L. BERTELE. April 16, 1969 [April 16, 1968], No.19534/69. Heading G2J. A wide angle lens, of focal length F, comprises diverging outer lens members L 1 and L 9 , and inner lens members L 2 , L 3 and L 4 , and L 5 L 6 L 7 and L 8 separated by a diaphragm B1, the lenses L 3 and L 4 and L 5 and L 6 being cemented at surfaces convex to the diaphragm to form converging portions and spaced from the diverging portions L 2 , and L 7 and L 8 respectively, the spacing 1, between L 1 and L 2 being greater than that, l 2 , between L 2 and L 3 , and that, l 5 , between L 8 and L 9 greater that that, l 4 , between L 6 and L 7 , and the diference between the radii of curvature of the surfaces r 10 and r 11 bounding the space l 4 being at least 1À35 times greater than that between the surfaces r 4 r 5 bounding the space l 2 . The refractive indices of lenses L 3 and L 6 are greater than these of L 4 and L 5 respectively, and the sum of the radii of curvature r 5 and r 10 of the surfaces of L 3 and L 6 remote from the diaphragm is greater than 0À65F., these surfaces being separated by a distance greater than 0À57F., the sum of the air spaces associated with the inner members is between 0À002F. and 0À30F. In another embodment Fig. 2 (not shown) a further diverging lens may be placed adjacent the outer lens member on the image side of the objective, and in a further embodiment Fig. 3 (not shown) the divergent portion of the inner lens member on the image side of the objective may be formed from three elements. The radius of the objective at the image side is smaller, but greater than one quarter, than that at the objective side. Optical data for seven examples is given. |
