Claims
- 1. A basic lens for a pancratic camera lens having an afocal screen of variable enlargement wherein the basic lens comprises a plurality of lenses including a first biconvex lens nearest the object to be photographed, a second biconvex lens, a first biconcave lens cemented to said second biconvex lens, a second biconcave lens, a third biconvex lens and a positive meniscus all arranged in an aligned relationship as viewed in the direction of the incident light, wherein the positively refracting surfaces (.PHI.21, .PHI.28) of said second biconvex lens cemented to said first biconcave lens and the positive meniscus, said positively refracting surfaces (.PHI.21, .PHI.28) convex to the incident light, the positively refracting surface (.PHI.27) of the third biconvex lens, said positively refracting surface (.PHI.27) convex to the picture, as well as the negatively refracting surface (.PHI.25) of said second biconcave lens, said negatively refracting surface (.PHI.25) concave to the picture, have the following values:
- .PHI.21 + .PHI.27 + .PHI.28 = 3.14, 2
- and
- .PHI.25 = -1.62.
- 2. A basic lens according to claims 1 wherein,
- .PHI.21 = + 0.98
- .PHI.25 = - 1.62
- .PHI.27 = + 1.24
- .PHI.28 = + 0.92
- 3. Lens according to claim 1, characterized by the following data, with r designating the radii of curvature of the lens surfaces, land ddesignating the axial thicknesses and separations, n.sub.d designating the indices of refraction and V.sub.d designating the Abbe numbers, f.sub.min, f.sub.M, fmax being the minimum focal length, the mean focal length and the maximum focal length, respectively, and 2 y being the length of the diagonal of the image frame:
- __________________________________________________________________________Lens Radii Thickness and Separation N.sub.d V.sub.d__________________________________________________________________________ r.sub.1 = +9.929L.sub.1 d.sub.1 = 0.10 1.805 25.4 r.sub.2 = +2.044L.sub.2 d.sub.2 = 0.38 1.606 43.9 r.sub.3 = plan l.sub.1 = 0.01 r.sub.4 = +2.482L.sub.3 d.sub.3 = 0.21 1.620 60.3 r.sub.5 = +7.189 l.sub.2 = 0.01 r.sub.6 = +1.947L.sub.4 d.sub.4 = 0.28 1.691 54.7 r.sub.7 = +8.453 0.038 . . . f.sub.min l.sub.3 = 0.763 . . . f.sub.M 1.097 . . . f.sub.max r.sub.8 = +6.210L.sub.5 d.sub.5 = 0.05 1.691 54.7 r.sub.9 = +0.629 l.sub.4 = 0.21 r.sub.10 = - 1.112 f.sub.II = -0.62L.sub.6 d.sub.6 = 0.05 1.620 60.3 r.sub.11 = +0.888L.sub.7 d.sub.7 = 0.14 1.805 25.4 r.sub.12 = +5.048 1.204 . . . f.sub.min l.sub.5 = 0.368 . . . f.sub.M 0.145 . . . f.sub.max r.sub.13 = -0.782L.sub.8 d.sub.8 = 0.05 1.744 44.8 r.sub.14 = -1.899 0.024 . . . f.sub.min l.sub.6 = 0.135 . . . f.sub.M 0.024 . . . f.sub.max r.sub.15 = planL.sub.9 d.sub.9 = 0.14 1.620 60.3 r.sub.16 = -1.131 l.sub.7 = 0.01 r.sub.17 = +2.659L.sub.10 d.sub.10 = 0.12 1.620 60.3 r.sub.18 = -4.235 l.sub.8 = 0.04 r.sub.p = planP d.sub.p = 0.25 1.517 64.2 r.sub.p ' = plan Diaphragm 0.09 + 0.05 r.sub.19 = +3.948L.sub.11 d.sub.11 = 0.16 1.720 50.4 r.sub.20 = -2.475 l.sub.9 = 0.01 r.sub.21 = +0.676L.sub.12 d.sub.12 = 0.30 .PHI..sub.21 = +0.982 r.sub.22 = + 0.835 1.664 35.8L.sub.13 d.sub.13 = 0.05 r.sub.23 = + 2.399 1.805 25.4 l.sub.10 = 0.07 r.sub.24 = -1.295L.sub.14 d.sub.14 = 0.11 r.sub.25 = +0.522 1.847 23.8 l.sub.11 = 0.19 .PHI..sub.25 = -1.623 r.sub.26 = +2.482L.sub.15 d.sub.15 = 0.17 1.713 53.8 r.sub.27 = -0.576 .PHI..sub.27 = +1.238 l.sub.12 = 0.01 r.sub.28 = +0.700 .PHI..sub.28 = +0.916L.sub.16 d.sub.16 = 0.12 1.641 60.1 r.sub.29 = +1.440f.sub.min = 0.40f.sub.M = 1.00f.sub.max = 1.91Aperture ratio = 1:1.2Image diagonal 2.sub.y = 0.35__________________________________________________________________________
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 9242/74 |
Nov 1974 |
OE |
|
BRIEF STATEMENT OF THE INVENTION
The invention relates to a basic lens for a pancratic camera lens with an afocal screen of variable enlargement, wherein the screen has a primary, positive front component, followed by second and third negative components and finally a fourth, positive component.
In the camera, field present day, well-known lenses, many lenses are well-known which roughly meet the demands made on them. However, they all have some substantial drawback. For example, the lenses shown in U.S. Pat. Nos. 2,029,806; 2,012,822; 2,771,006 and 2,894,431 have extremely short radii of curvature which prevents the use of conventional, low-cost manufacturing techniques. To some extend these drawbacks are somewhat overcome with a lens of the type shown in French Patent No. 1,536,308, but for such a lens, types of glass are used which contain a high percentage of thorium oxide because of their optical position, a fact which calls for strict protective measures in processing which result in high material costs.
In order to avoid such drawbacks, it is suggested that in the case of a basic lens of the type according to the invention, it be constructed from six lenses, of which the first lens, which faces the object to be photographed is biconvex, to be followed by a second biconvex lens cemented with a concavo-concave lens, behind which finally a biconcave lens, a biconvex lens and a positive meniscus, all arranged in alignment and in the direction of the light incidence.
In order to be able to satisfactorily control distortion as they appear, especially on the edge of the image field, it is advantageous to provide a refracting power for the strongest, negatively refracting surface with the most curvature in the basic lens, according to the absolute value, which is greater than one-half the sum of the three strongest, positively refracting surfaces in this basic lens.
A particularly advantageous application of the basic lens under the invention is to use the already aforementioned afocal screen. Such a screen is well-known and is shown in Austrian Patent No. 317,576. In the optical system consisting of this well-known screen and basic lens according to the invention, the action in terms of the F-number, is determined most efficiently by constructing the basic lens according to the invention.
Additional advantages and characteristics of the invention follow from the description shown diagrammatically in the drawing.
US Referenced Citations (2)
| Number |
Name |
Date |
Kind |
|
3891304 |
Muszumanski et al. |
Jun 1975 |
|
|
3937562 |
Muszumanski et al. |
Feb 1976 |
|
Patent Grant
4050788
