Abstract: A contact lens for the correction of astigmatism or presbyopia and for the correction of "high riding" lenses being of lenticular construction. This invention avoids unwanted increase in center thickness of the lens and unwanted prism in the central area. The curved lenticular carrier portion of the lens, the non-visual portion, is constructed with a concentric curve cut which produces a thick lens edge. The lenticular carrier is also provided with a second eccentric curve cut, with respect to the visual axis of the lens, to provide a thickness disparity between the superior and inferior portions of the lens and to provide an offset center of gravity and a desirable rotational positioning of the lens in the eye of a wearer, particularly when the lens is of astigmatic or bifocal type.

Abstract: The present invention relates to a retro-focus type wide angle lens which is compact despite its remarkably large field of view and well compensated for various aberrations.This lens system consists of the first divergent lens group and the second convergent lens group in sequence from the side of the object, whereby the first divergent group consists of a plural number of meniscus lenses convex to the object in such a manner that the distortion is compensated for and a compact lens system is realized by forming the object side surface of the substantially zero first order power lens in the meniscus lenses non spherical. The meniscus lens with non-spherical surface is formed from plastic material, resulting in an inexpensive and light retro-focus type wide angle lens.

Abstract: A photographic objective of continuously variable focal length, having four groups of lens members. The first group is of converging refractive power, the second and third of diverging, and the fourth of converging refractive power. Change in focal length is effected by axial displacement of the second and third groups relative to each other and to the first and fourth groups. The refractive powers of the movable second and third groups are so distributed that the variable air space between the third and fourth groups is larger in the wide angle position than in any other focal length position and is smaller by a factor of 0.3 than the shortest focal length of the objective.

Abstract: A measurement apparatus and method for detecting, resolving and quantifying the distortion caused by a relatively large region of a distorting optically transparent medium. A precisely defined pattern is viewed through the transparent medium to introduce the distortion effects. The altered pattern is photographically recorded in thin film transparency format. A beam of coherent luminous energy projected through the transparency, once focused, produces a Fraunhofer diffraction pattern which is the Fourier transform of the original pattern. Conventional distortion characteristics in the Fourier domain appear in a form more amenable to quantification and analysis. The character and magnitude of the distortion is readily ascertained by comparing the transforms of distorted and undistorted patterns, yielding quantitative data comparable to conventional distortion effects in terms of grid line slop and lens factor.

Abstract: The present invention relates to an objective lens for zooming by varying the distance between the divergent front lens group and the convergent rear lens group consisting of a first sub-group for forming a convergent light beam and a second sub-group between which sub-groups a photographing aperture is provided so as to be independent from them, whereby when the rear lens group is displaced forward for zooming the photographing aperture is displaced backward with reference to the first sub-group.

Abstract: The present invention relates to a photographic lens capable of zooming by independently moving the front lens group and the rear lens group. The front lens group presents a negative meniscus lens, a biconcave lens and a positive lens, while the rear lens group presents two positive lenses, a positive meniscus lens, a biconcave lens and a positive lens. Let the focal length of the front lens group be Fl, the longest focal length of the total system be Ft and the distance between the secondary principal point of the front lens group and the primary principal point of the rear lens group when the focal length is Et, the zoom lens satisfies the following relations.

Abstract: The system has a variator lens and a compensator lens which are mutually displaceable for varying the focal length of the optical system. In the normal zoom range, the focal length is adjustable between a telephoto condition and a wide angle condition, in accordance with the positions of the variator and compensator lenses. The system has macro capability in both a range beyond the extreme telephoto end of the zoom range and also in a range beyond the extreme wide angle end of the zoom range. In at least the macro range at the telephoto end, the slots in the camming sleeve for the variator and compensator lenses lie substantially in planes.

Abstract: In accordance with the present invention, output beams from a plurality of optical amplifiers in an oscillator-amplifier optical configuration are phase matched utilizing a feedback system employing phase error signals generated by optically heterodyning a frequency shifted, two-wavelength reference beam, with a portion of the output from each of the plurality of amplifiers. Electrical signals from detectors responsive to the optical heterodyned signals are processed in control circuits to provide coarse and fine phase error signals to control elements for controlling the optical path difference of the beams of radiation passing through each of the amplifiers for phase matching the beams.

Abstract: An optical system and technique for monitoring a monotonic change in the thickness of a transparent film by means of optical interference, and for eliminating ambiguity in the identification of absolute film thickness. The system is particularly adapted for monitoring the etching of a dielectric film of uncertain initial thickness in microelectronic fabrication. The technique utilizes a white light source directed upon the film. Reflected light, modified by optical interference in the dielectric film, is monitored by photodetectors at two distinct wavelengths. The cyclic patterns of intensity change at the two wavelengths are compared to identify unambiguously the absolute thickness of the film, although the initial uncertainty in film thickness may have corresponded to several cycles of either wavelength pattern alone.

Abstract: An apparatus and method for controlling the resonant frequency of an optical interferometer cavity having a part having a dimension defining the resonant frequency. An electrical conductor adapted for connection to a source of electrical potential is mounted on and mechanically secured to the part of the cavity which has the dimension defining the resonant frequency. The electrical conductor provides a conduction path substantially parallel to the frequency defining dimension of the aforementioned cavity part and has a coefficient of thermal expansion. Mechanical force is transmitted to the aforementioned cavity part as a function of electrothermally induced change in the length of the electrical conductor, thus causing a change in the resonant frequency of the cavity.

Abstract: This invention provides, in a restricted off-axis field optical system having a broad spectral range, which includes refracting elements, the improvement comprising:an optical system constructed and arranged so that the Petzval sum is substantially zero, said refracting elements including elements for balancing the effects of the variation in the Petzval sum due to variation in color by introducing axial chromatic aberration of the opposite sense so that the position of focus at the off-axis field remains substantially constant;according to the invention in one form thereof, the elements for balancing the effects of the variation in the Petzval sum due to variation in color include a symmetrically disposed nearly concentric meniscus element whose convex radius is larger than its concave radius and whose thickness is greater than the difference between its convex and concave radii;further, according to a form of the invention, the system includes at least one convex and one concave mirror, said mirrors being n

Abstract: A high performance telephoto lens having a small telephoto ratio including eight lenses disposed in seven lens groups in front, intermediate and rear groups. The front lens group is composed of, in order, a positive lens having two curved surfaces with the surface of greater absolute value of curvature disposed on the object side, a positive meniscus lens having its convex surface disposed toward the object, a negative biconcave lens having the surface of greater absolute value of curvature disposed toward the image side, a positive meniscus lens having a convex surface directed toward the object. The intermediate lens groups includes two cemented lenses one of which is a negative biconcave lens disposed on the object side and a positive lens disposed on the image side.

Abstract: A Gauss type lens system comprising a first, second, third and fourth lens components, the first lens component being a positive meniscus lens, the second lens component being a cemented doublet consisting of a positive lens and negative lens, the third lens component being a cemented doublet consisting of a negative lens and positive lens, the fourth lens component being a biconvex lens, the Gauss type lens system having the aperture ratio of 1.8 and field angle of 46.degree. and being made low in price by using high refractive-index high dispersion glass materials for many of lenses.

Abstract: A composition which is hydrophobic but possesses excellent wettability comprising a copolymer of a polysiloxane and an ester of glycidyl alcohol and an organic acid. This copolymer is suitable for the manufacture of ocular membranes worn in contact with the eye which present excellent oxygen permeability and which can be worn for extremely long periods of time and then disposed of.A method of preparing the ocular membranes is disclosed, in which the composition is placed between disposable molds and cured therein. The cured, mechanically and optically finished ocular membranes are recovered by the destruction of said molds and without secondary operations.The ocular membrane is a flexible, oxygen-permeable, membrane, adapted to be inserted on the eye and worn thereon continuously for periods of more than one month.

Abstract: To obtain the refractive index of a fluid, each of two beams of light are transmitted at an angle through different ends of a vibrating quartz crystal to phase modulate the beams of light with respect to each other and then transmitted through two different flow cells before being combined at a point of nearly equal optical path length from the source of light, with the resulting interference pattern being transmitted onto a photocell to generate an electrical signal which varies periodically with the modulation of the two beams of light. The signal from the photocell and a signal representing the modulation of the crystal are compared in phase and a third signal indicates the refractive index of the effluent from the chromatographic column generated as a result of this comparison.

Abstract: It comprises a container made at least partly from a transparent material and filled with an index adapting medium. At least one of the walls of the container through which the optical axis of the system extends comprises a piezoelectric multilayer structure for modifying the curvature of the wall in accordance with the voltage applied to the multilayer structure.

Abstract: A lens system including five lenses which are, in order from the object, a first single positive meniscus lens, a second single positive meniscus lens, a third single negative lens, a fourth single meniscus lens and a fifth single positive lens. The overall lens system has an aperture ratio of 1:2.8 and a viewing angle of approximately 24.degree.. A stop diaphragm is disposed at a rear portion of the overall lens system. Operations are well compensated for by providing the various lenses with parameters as specified for the preferred embodiments.

Abstract: The present invention is directed to an inverted telephoto type wide angle lens system having eight lens groups and eight lens elements which fulfill the following conditions:______________________________________ 0.75f < .vertline.f.sub.1,2,3 .vertline. < 1.1f f.sub.1,2,3 < 0 0.89f < f.sub.1,2,3,4,5 < 2.3f 0.5 < d.sub.7 /d.sub.6 < 2.0 1.0 < d.sub.8 /d.sub.10 < 2.4 1.5 < d.sub.7 /d.sub.9 < 5.2 ______________________________________wherein f.sub.1,2,3 represents the total focal length of the first to third single lens elements; f.sub.1,2,3,4,5 represents the total focal length of the first to fifth single lens elements; f represents the focal length of the entire lens system, and d.sub.i represents the i-th axial distance numbered consecutively from the front of the lens system.

Abstract: A refractively scanned interferometer, of the type in which a wedge-shaped prism is moved across one interferometer arm for scanning purposes, in which both the substrate of the beamsplitter and the scanning wedge are optically compensated for by substantially identical elements in the other arm of the interferometer.

Abstract: In an optical system the use of .Iadd.one or .Iaddend.a plurality of air lenses set in an optical medium of higher refractive index than air at a predetermined distance from an object such that various optical aberrations are minimized or eliminated by using aplanatic optical surfaces. Refraction occurs only for a ray going from the higher to the lower refractive index medium. Rays entering the higher refractive index medium from the lower are never refracted since the optical surface is always chosen to have its center .[.or.]. .Iadd.of .Iaddend.radius coincident with the object or image being optically operated on by the lens. The system can be used to magnify the image of an object, the object being most any two-dimensional representation such as a negative or a positive print. The object might alternatively be a light source or an external object whose rays are imaged onto an embedded light sensor so that the functions of the source or sensor respectively can be enhanced by the optical system.