Abstract: A microscope condenser of the Abbe type has the optical characteristics of the biconvex singlet followed by the convex-plano singlet improved by making the first surface of the biconvex singlet aspherical. The aspherical surface substantially reduces spherical aberration and coma as well as pupillary aberration of the condenser.

Abstract: A variable speed drive for controlling the movement of the zoom component of a zoom lens system such that the speed of zooming will be proportional to the amount of manual displacement of a control member. The same manually operable control member which controls the speed, the amount and the direction of zooming also controls the position of the focusing component so that focusing as well as selectively varying the speed and amount of zooming can all be effected by a single control member.

Abstract: A light-weight objective which comprises a small number of lens components, i.e., a first positive lens component, a second positive lens component and a third positive cemented lens component and can be manufactured at low cost, and wherein aberrations are favorably corrected at a wavelength of 6328 A.

Abstract: A retrofocus wide angle objective with the backfocal length being at least two times the overall focal length, comprising in optical alignment, a plurality of negative meniscus lenses of forward convexities, a positive lens, a negative meniscus lens of forward convexity, a bi-convex lens, a negative lens, a positive doublet lens and a positive lens, and the first surface counting from the front being configured in a non-spherical form such that the curvature increases with distance from the optical axis. This non-spherical surface compensates for barrel distortion and negative coma which are introduced by the object-side negative meniscus lenses into the lens system.

Abstract: A wide-angle photographic lens system with a short overall length comprising three lens components of four lenses, the surface on the object side of the third lens component being formed as an aspherical surface expressed by the following formulas: ##EQU1##

Abstract: An instrument for responding to backscattered or backreflected radiation from a path through a medium in which a beam of electromagnetic radiation is transmitted along the path, and a receiver system is arranged to receive backscattered radiation returning along the path substantially coaxially with the beam, the receiver system including detection means for the backscattered radiation and equalizing means for producing a substantially equal response regardless of the point of backscatter along the path. The equalizing means comprises a passive radiation transmission structure interposed in the path of return prior to the detection means, the passive structure having a substantially constant acceptance solid-angle for the returning radiation from points over the range of the path whereby radiation reaching the detection means from various points along the path does not vary in intensity due to the different distances of the points from the detection means.

Abstract: A method of and a device for measuring the temperature of the axle bearing of a vehicle, especially of a rail vehicle while moving. The device is mounted adjacent a rail on which the vehicle runs and receives radiation from beneath the axle bearing over a strip-like range thereof of predetermined size. A detector receives the radiation after the radiation has been angularly diverted and develops an electrical signal in conformity with the value of the radiation. A modulator or interrupter ahead of the detector provides for an alternating, or pulsating, signal which is then amplified in an electronic circuit. For comparison purposes, a source of infra red radiation of known value is provided whereby the calibration of the device can be checked.

Abstract: This invention relates to a simplified, and therefore less costly to manufacture, optical system for efficiently forming microimages onto an image plane.

Abstract: Laser detector for gases employs two beams, one at wave length corresponding to an optical absorption resonance of the gas to be detected, 3.39 micron in the preferred methane detector, and another at a similar wave length, but lying outside of the effective absorption curve, with a balance circuit for detection. The embodiments show common beam path, common lasing medium and common power sources for generating the two beams. In one embodiment two resonant cavities share a common discharge tube and output mirror through switching, while in others the resonators are separate but sharing the same gas system or power supply. A suppression cell filled with methane is employed to suppress a dominant transition, to establish lasing at another transition, and adjustable length and adjustable pressure cells are also employed to enable balancing of the system prior to detection.

Abstract: An optical device and method for testing high reflectivity autostigmatic optical elements and systems is disclosed. A thin, partially transmissive optical element, e.g., a pellicle with an optical coating having a transmission factor determined by the nominal reflectivity of the test article, is placed in the measurement leg of a spherical wavefront Fizeau interferometer so that high contrast, two-beam interference fringes can be obtained from a high reflectivity autostigmatic optical element or system.

Abstract: This invention relates to a short focal length, large aperture, high resolution optical system for efficiently transmitting a microfiche image to a viewing surface at an unusually high magnification ratio with an extraordinarily high degree of correction over a prescribed field.

Abstract: A wide angle lens of moderate aperture, similar in general to the lens of Glatzel et al. U.S. Pat. No. 3,833,290, but differing from it and from other similar lenses in the refractive power distribution as between two dispersing components near the front of the lens, and the refractive power distribution as between two air lenses, one formed between the two dispersive components just mentioned and the other formed between the second dispersing component and a next following condensing component. By designing the lens to have the power distribution at these points between certain stated limits, greatly increased performance is achieved, with reduction of specific aberrations of higher order, and with sharpness of distant real points brought extremely close to the ideal Rayleigh limit.

Abstract: A zoom lens comprising a convergent lens group as a focusing lens, a movable divergent lens group as a variator lens, a compensator lens group and a relay lens group being positioned in said order from an object side, wherein the interval between the principal point of said convergent lens group and the principal point of said divergent lens group is 70% to 130% of the absolute value of the focal distance taken by said divergent lens group when the focal distance of the total system is the minimum.

Abstract: A microscope illuminator having three lenses with the center lens having an axially-symmetrical aspheric rear surface provides good lateral color correction for illuminated fields to 20mm. when used with a condenser having good color correction.

Abstract: A system for detecting the brightness of an area which is to be photographed. A plurality of series circuits respectively include a plurality of photosensitive devices for respectively receiving light from different parts of the area while remaining substantially static with respect thereto so that when the area is illuminated unevenly a pair of the photosensitive devices will respectively receive light of maximum and minimum brightness. The plurality of series circuits respectively include also a plurality of series-connected elements respectively connected in series with the plurality of photosensitive devices for respectively providing therewith a plurality of photo-responsive divided voltages. The plurality of series circuits are connected in parallel with each other and with a power source.

Abstract: The zoom objective is of the type in which the provision for focusing is made at the front component consisting of only one element comprising a simple planoconvex component of forward convexity movable for focusing, and comprises further a variator of negative power consisting of a doublet component having a positive meniscus element in front of a double-concave element, a compensator of positive power consisting of a doublet component having a negative element in front of a double-convex element followed by a positive simple meniscus component of forward convexity, and a relay system. Because of the incapability of concentrating aberration correction especially with respect to chromatic aberrations in the front component for focusing, the present invention gives rise to the possibility of achieving a high standard of correction of various aberrations by use of the variator and particularly the compensator throughout the zooming range.

Abstract: A macro-photography varifocal lens assembly is provided for attachment to a camera body. The lens assembly can include a first lens group of negative refractive power and a second lens group of positive refractive power further supplemented by a master or auxiliary lens group of positive refractive power. One of the first and second lens groups are mounted for relative movement to vary the overall focal length of the lens assembly as the lens group moves across a predetermined range of movement. The image plane of the refracted image is continuously shifted from an initial predetermined position at one end of the range of movement towards the object and then away from the object to return to the initial predetermined position at the other end of the range of movement. This relative movement or shift of the image plane towards the object being sufficient to focus an image of an object in a macro-photography range.

Abstract: A compact wide-angle photographic lens system for which the total focal length of the front lens group is made a negative value and for which low-dispersion glass is used for the positive first lens component and high-dispersion glass is used for the negative second lens component in said front lens group in order to favorably correct various aberration, especially chromatic aberration.

Abstract: A method and devices for sensing changes in separation of a first member relative to a second member, as well as variables causing such changes is disclosed. Electromagnetic waves diffracted by means included in said first member interact with waves from means included in said second member to form a characteristic interference pattern. Measured changes in this pattern allow determination of changes in separation.

Abstract: A wide angle objective lens comprising from front to rear a double-plano filter, a negative meniscus lens element, a second negative meniscus lens element, a cemented doublet consisting of a biconvex lens element and a biconcave lens element, a second cemented doublet consisting of a biconcave lens element and a positive meniscus lens element, a third cemented doublet consisting of two plano-convex lens elements, a negative meniscus lens element and a double-plano protective cover plate.