Showing papers on "Angular aperture published in 1970"
Patent•
21 Sep 1970TL;DR: In this article, the first and second alternately excited light sources image an aperture on a portion of the optic disk, which is held approximately constant by having the eye look at a fixation point.
Abstract: A system and method for obtaining a depth profile of the fundus of the eye in which first and second alternately excited light sources image an aperture on a portion of the optic disk. The refractive power of the eye is held approximately constant by having the eye look at a fixation point. A detector is provided for sensing the degree of overlap of the aperture images due to the first and second light sources. In one embodiment the aperture is displaced in a Z-direction with respect to the eye until the images of the aperture completely overlap. The aperture is then successively displaced horizontally in an X-direction and/or vertically in a Y-direction with respect to the eye and in each position the aperture is adjusted in the Z-direction until the first and second images of the aperture completely overlap. The positions of the aperture where the first and second images thereof overlap correspond to the depth of the respective portions of the optic fundus from any arbitrary point at the front of the eye.
19 citations
Patent•
22 Jan 1970TL;DR: In this article, a single lens reflex camera having interchangeable lenses and an apparatus for determining the amount of exposure by measuring the light passing through the fully opened aperture of the lens is presented.
Abstract: A single lens reflex camera having interchangeable lenses and an apparatus for determining the amount of exposure by measuring the light passing through the fully opened aperture of the lens, in which a diaphragm aperture is preset by setting a preset diaphragm aperture setting ring, having a graduated aperture scale of equal spacing, and the starting point of the movement stroke of the ring is set at a fixed position irrespective of the extent of the maximum aperture of an interchangeable lens, and thus the scale for the maximum aperture of the lens comes to the fixed position, which is characterized by an integral coupling member provided on the above-mentioned preset aperture setting ring or to a preset cam engaged with the ring, and at the same time a correction projection, having such a different length as to correct the apparatus referring to the maximum aperture of the interchangeable lens, is provided at the lens so that when the lens is mounted on a camera, the projection makes such correction as compensating for a drop in value in the light measurement with a full-open aperture by a large aperture lens.
18 citations
TL;DR: Using the Sparrow criterion, an expression for the limit of resolution of an annular aperture operating in partially coherent light was derived in this paper, where an expression was derived for the maximum resolution of a partially coherent image.
6 citations
Patent•
01 Oct 1970
TL;DR: A reversed telephoto projection lens of 200x magnification having a numerical aperture of 0.45 and long back focus comprises two groups, a three-element negative group spaced from a seven-element positive group by a factor of substantially 6.5x the focal length of the lens, being intended for use in a system with a plano-parallel cover glass as discussed by the authors.
Abstract: A reversed telephoto projection lens of 200x magnification having a numerical aperture of 0.45 and long back focus comprises two groups, a three-element negative group spaced from a sevenelement positive group by a factor of substantially 6.5x the focal length of the lens, being intended for use in a system with a plano-parallel cover glass.
4 citations
TL;DR: In this article, the near radiation field of a microwave-illuminated aperture is mapped by a perturbation element and processed to yield a microwave hologram, and optical signal processing of the hologram yields an image of the aperture and its associated far-field pattern.
Abstract: The near radiation field of a microwave-illuminated aperture is mapped by a perturbation element and processed to yield a microwave hologram. Optical signal processing of the hologram yields an image of the aperture and its associated far-field pattern.
3 citations
TL;DR: In this paper, the authors applied the floating wire method to determine the useful aperture of a magnetic quadrupole lens, which is a quadratic function of the distance between a particular trajectory and the optical axis in the lens.
2 citations
Patent•
13 Apr 1970
TL;DR: A three lens element objective with a wide picture angle of about 120 DEG and a relative aperture of about 1:8 was presented in this article, where two relatively thick and strongly meniscus-shaped dispersive lens elements were arranged with axial air spaces.
Abstract: A three lens element objective having a wide picture angle of about 120 DEG and a relative aperture of about 1:8 and comprising two relatively thick and strongly meniscus-shaped dispersive lens elements between which is arranged with axial air spaces a relatively thick collective lens element
1 citations
01 Jan 1970
TL;DR: In this paper, the authors describe the first-order (thin-Lens) and third-order considerations of a data system assembly, and the second-order consideration of a system field test.
Abstract: INTRODUCTION 1 THEORETICAL DESIGN ..... 5 A. First-Order Considerations... 6 B. Third-Order Considerations,. 13 EXPERT MEMO'AL PROCEDURE 17 A. Data System Assembly. 18 B. Ini tial Evaluate. ons 23 C. System Calibration. 29 D. System Hield Tests 3 A. System Calibration 32 B. System Field Tests........................ 38 DISCUSSION. ._, kk CONCLUSIONS ^8 REFERENCES 50 APPENDIX A ..... 53 A. First-Order (Thin-Lens) Considerations ........ 53 B. Third-Order Considerations. .............. . 58 APPENDIX B ..... . 66" APPENDIX C 72 APPENDIX 4 .. 77