Abstract: Apparatus and method employing line-of-sight wave propagation for measurement of various quantities such as velocity and refractivity structure of a transmission medium at selected locations remote from the measuring device.

Abstract: A correction lens disposed between the exposure light source and a glass panel provided with a shadow mask at the exposure step of manufacturing a color television CRT and adaped to compensate for the tendency of the phosphor stripes being formed in a wavy configuration. The correction lens has such a characteristic that, when the light source is observed through the correction lens at the side of the shadow mask, the light source is viewed as displaced in appearance toward the correction lens by a certain constant distance on the optical axis independently of the viewing angle, whereby the image of a linear light source or the linear moving path of a point source of light is made to extend substantially in parallel with the length of the slot of the shadow mask.

Abstract: This disclosure relates to variable focal lens having zooming and compensating groups movable axially in a non-linear relation. A single operating member is rotatable to move the front focusing group without moving the other groups, and movable axially to shift the zooming and compensating groups without moving the focusing group. Axial movement is imparted to the mount for the zooming group, and relative movement of the compensating group is controlled by rotative movement of the zooming group.

Abstract: An optical system for forming an image of an object with extremely small aberrations at unit magnification including a concave mirror and a convex mirror having a smaller radius of curvature than that of the concave mirror and arranged in face-to-face relation to the concave mirror.

Abstract: A miniature and large aperture retrofocus wide-angle photographic lens whose aberration is satisfactorily corrected is composed of five lens groups, A thru E, satisfying the following conditions (I) to (IV):.nu..sub.a,.nu..sub.b >55 (i) ##EQU1##F<d.sub.C.

Abstract: The invention is employed for evaluating particles, such as droplets of aerosol sprays suspended in a gaseous medium. A stream of the particles to be analyzed is flowed into a narrow sample zone across the optical axis of a beam of light. Scattered radiation from the particles is focused on the image plane in which a photosensitive surface is located. Images of particles formed there are reproduced on a fluorescent or phosphorescent display screen of a cathode ray tube. A scale on the screen is employed for measuring the dimensions of the particles. The confinement of the stream of the mixture to about the depth of focus of the objective lens of the camera reduces effects of out-of-focus particles and permits evaluation of individual particles.

Abstract: The invention relates to a new type of soft contact lens from a hydrophilic, swelled copolymer, with high swelling capacity, high permeability for oxygen, comparatively high strength and low modulus of elasticity, said characteristics making the lens suitable for permanent wearing. The lens contains, at swelling equilibrium with water at 20.degree. C, from about 50 to about 95% by weight of water, preferably from about 70 to about 90%, and consists of a multiblock copolymer of acrylonitrile with acrylamide, containing, if desired, a minor amount of other monomer units, not exceeding 20 molar percent. The swelled hydrogel contains two distinct but inseparable phases, one of them being polyacrylonitrile detectable by X-ray analysis, the other being amorphous highly solvated hydrophilic polymer containing predominantly acrylamide units.

Abstract: A soft contact lens for use on the human eye formed from a soft material like silicon or a hydrophilic material. The lens has a generally spherical concave inner surface which conforms to the cornea and a generally convex outer surface. To maintain the correct orientation of the lens when placed on the eye it is provided with a flattened region along a portion of its periphery.

Abstract: A zoom lens comprising, as viewed from the side of a photographing object, a first lens group, which is positive and is provided for focusing, including a positive lens formed by joining a negative lens and a positive lens together and a positive meniscus lens; a second lens group, which is negative and is provided for variation, including a negative lens and another negative lens formed by joining a negative lens and a positive lens together; a third lens group, which is provided for compensation, including a positive lens formed by joining a negative lens and a positive lens together; a fourth lens group which is positive and is provided for image formation; and a fifth lens group which is weakly negative, the third lens group drawing a concave locus toward the object side as the second lens group moves in the direction of an optical axis. The fourth lens group is composed of two positive meniscus lenses closedly adjacent to each other and a biconcave lens disposed apart from these meniscus lenses.

Abstract: A magnifier or loupe of high magnifying power comprising a positive singlet followed by a cemented doublet in the overall form of a meniscus having bi-convex and bi-concave elements. The cemented surfaces, the outer surfaces of the doublet, or both may be made aspheric.

Abstract: An objective lens system particularly adapted for photography with a frontal aperture stop is provided. The lens system includes four lens components including a positive doublet. A diaphragm is provided in front of the first lens component and the lens system satisfies the following relationships;1.84 > N.sub.1 > 1.6 (1) 65 > V.sub.1 > 44 (2)0.7 > d.sub.1 + d.sub.2 /.SIGMA.d > 0.3 (3) 1.5 > .vertline.R.sub.3 .vertline./R.sub.4 > 0.5 (4)0.25 > .vertline.n.sub.3 - n.sub.4 .vertline. > 0.03 (5) 25 > .vertline.V.sub.3 - V.sub.4 .vertline. > 5 (6)0.0005 > n.sub.4 - n.sub.3 /r.sub.6 < 0.0035 (7) 1.0 > R.sub.5 /R.sub.7 > 3.0 (8)wherein, N, is the index of refraction, V is the Abbe number, D are axial distances along the optical axis and R is the radii of curvature. The subnumbers refer to consecutive measurements along the optical axis.

Abstract: A high power objective or lens system of the same general kind as disclosed in Glatzel U.S. Pat. No. 3,915,558, but with a larger aperture and a slightly smaller angular field of view. Rules or conditions are disclosed which, if complied with, will result in a lens with improved image formation. The present lens is particularly suitable for cinematographic purposes.

Abstract: A varifocal forward lens group of a camera objective, with a pair of axially shiftable negative components bracketed by a pair of substantially fixed positive components, has its negative third component more widely separated from its positive fourth component in a wide-angle position of minimum overall focal length than in a telephoto position of maximum overall focal length. The effective diameter of that third component is just large enough to let a bundle of axially incident light rays fully illuminate the fourth component in the wide-angle position, with less than full illumination in the telephoto position. The positive first component is also just large enough to provide full illumination of the effective area of the third component by axial rays in the telephoto position.

Abstract: Method and apparatus for determining the wave number of optical spectrum radiation, particularly for use in controlling lasers. Two parts of a beam provided by a source to be monitored, particularly a laser, are directed to two double-wave interferometers. The differences of the optical path lengths .delta. of the interferometers are assigned a difference of .lambda./4 which corresponds to a phase difference of .pi./2. The two optical output signals emerging from the interferometers are converted into sinusoidal electrical waves in quadrature as a function of the wave number .sigma. = 1/.lambda. of the laser and the period 1/.delta. of the two sinusoidal electrical waves. The electrical waves are processed in suitable circuitry to obtain a modulo value 1/.delta. of the wave number. These steps are repeated for different values of .delta. so as to progressively eliminate uncertainty in the value of the wave number.

Abstract: An objective for a microscope has a meniscus lens of positive power at one nd of the objective. A lens of negative power is located at the other extremity of the objective. Three intermediate doublets of positive power are located between the first two lenses each formed of a convergent lens cemented to a divergent lens. The meniscus lens situated at the front has focal length between 1.5f and 2.5f. The lens of negative power is a doublet formed of a convergent lens and a divergent lens with a focal length between -8f and -15f. The first doublet located close to the lens of negative power has a focal length between 14f and 18f. The second doublet situated immediately before the first doublet has a focal length between 6f and 8f. The third doublet located between the second doublet and the meniscus lens at the front end of the objective has a focal length between 3f and 4f.

Abstract: A contact lens formed from a soft, flexible, hydrophilic, cross-linked polymeric material. The lens has a centrally located optical zone and an outer peripheral portion that has its maximum thickness intermediate the juncture of that portion with the optical zone and the thin edge of the lens.

Abstract: A copying objective lens system of four-component six-element lens configuration comprising a front and rear lens groups arranged symmetrically in respect to the stop positioned at the center, each of said front and rear lens groups comprising a negative cemented doublet lens and positive lens, said copying objective lens system being arranged so that uniform brightness of image can be obtained over the whole field.

Abstract: A wide-angle optical system for a door viewer comprises a concave objective lens of a larger diameter of about 13 to 25 mm which is provided with a convex surface of a large radius of curvature of about 20 to 30 mm at the front surface thereof and with a concave surface of a small radius of curvature of about 4 to 6 mm at the central portion of the rear surface thereof, an intermediate concave lens of a smaller diameter of about 9 to 12 mm which has a concave surface of a small radius of curvature of about 4 to 7 mm provided at the front surface thereof and a convex eyepiece lens of a diameter somewhat smaller than that of the intermediate lens, said eyepiece lens having convex surfaces of a large radius of curvature of about 20 to 30 mm. The intermediate concave lens is positioned so that it contacts at the front surface thereof with the rear surface of the objective lens and so as to align the optical axis thereof with that of the objective lens.

Abstract: Louvered echelon lenses are provided that comprise an optically clear layer having at least one of its large-area surfaces configured as a set of echelon lens elements, and physically attached in optical connection with said layer, an internally louvered layer that comprises an optically clear polymeric matrix and a set of thin optically limiting louvers supported within the matrix in a spaced side-by-side relation.

Abstract: The present lens system is capable of providing not only a zooming function over a relatively wide range, but also macrophotography. The zoom lens system includes a first lens group capable of varying the focal length without a loss of focus and a second lens group forming a master lens group. The second lens group is spatially displaced on the image side of the first lens group and includes a lens component movably mounted on the optical axis of the system that is capable of varying the focal length of the second lens group. The movable lens component in the second lens group has two positions which will provide the same final image plane for the entire zoom lens system, for example, a forward and backward position does not introduce any image plane deviations and permits an extension of the zoom range of the total lens system. The intermediate position of the movable lens component of the second lens group can be utilized for focusing in a macrophotography range.