Abstract: A zoom lens system having a wide field angle, a long back focal length, a high zooming ratio, and comprising a small number of lens elements. Said zoom lens system comprises, in the order from the object side, a front lens unit having negative refractive power and a rear lens unit having positive refractive power, and is so adapted as to perform variation of focal length, said front lens unit consisting of a negative meniscus lens element having a convex surface on the object side, a negative lens element and a positive lens element, whereas said rear lens unit comprising, on the extremely image side therein, a positive lens component consisting of a positive lens element having a short radius of curvature on the image side surface thereof and a positive lens element having a short radius of curvature on the object side surface thereof.
Abstract: A device for delivering a collimated beam of electromagnetic energy, such as a laser beam, including a focusing lens which is rotatable about a first axis offset from a focal axis of the lens. Rotation of the lens about the first axis causes a laser beam traveling along the first axis to be deflected to travel along a focus beam axis which intersects the focal axis at a focal point which, in turn, traces a curve on the workpiece. The first axis is parallel to the focal axis and is offset a variable first distance therefrom. The lens is also rotatable about a second axis also offset from and parallel to the focal axis. Rotation of the focusing lens about the second axis alters the first distance between the first axis and the focal axis in order to vary the radius of the curve traced on the workpiece.
Abstract: A telephoto lens system utilizing an inner focusing method, for use in a 35-mm single-lens reflex camera, and despite its lightweight, compact size ensures high performance, and which performs focusing by moving only one lens unit. Performance of the telephoto lens system includes: having a telephoto ratio of no more than 0.7, yet compensating for aberrations when focused upon an object at infinity; adopting an inner focusing method, yet being capable of focusing at the closest distance which is no greater than 7 times the focal length for infinity; and performing near focusing without causing great aberrational variations. The telephoto lens system, in order from the object side, includes: a first lens unit having a positive refractive power; a second lens unit having a weak refractive power; and a third lens unit having a negative refractive power, and which performs focusing for an object at a finite distance by movement of the third lens unit.
Abstract: An apochromatic lens system consisting of four identical glass lens elements and a liquid lens element is disclosed, which has a change in focus of less than one-quarter wavelength over the entire visible spectrum. The glass lens elements and the liquid lens element are made from relatively inexpensive commercially available optical materials.
Abstract: A binoculars has lenses carried by sheet structure defining a box that is foldable between collapsed position and focus adjusting extended positions; the box in adjustable extended position having front and rear walls carrying the lenses; the box in extended position having top and bottom walls each defining fold lines, and also having left and right side walls defining fold lines; the fold lines enabling folding of the box from extended to collapsed position, during which the top and bottom walls move relatively apart and the left and right walls move relatively toward one another; the left and right side walls having fold connection to the top and bottom walls to block light entrance into the box interior in each of the referenced extended positions.
Abstract: An improved optical system suitable for laser processing in semiconductor manufacture. The system is composed of three convex lenses. By suitably selecting the type of each of the lenses, a limited spherical aberration is obtained without compromising the numerical aperture.
August 17, 1989
Date of Patent:
October 23, 1990
Semiconductor Energy Laboratory Co., Ltd.
Abstract: An image-forming lens having a primary surface defined by a spherical surface and located on the side of an object when the lens is used to provide negative magnification, a secondary surface defined by a flat plane and located on the side of an image, the lens having therein a refractive index distribution exhibiting a substantially spherical symmetry with its center located in the vicinity of the highest point of the primary surface located most distantly from the secondary surface when measured perpendicularly from the secondary surface.
Abstract: An optical element of substantial thickness with a spherical convex surface and a spherical concave surface which are concentrically arranged. This optical element, combined with an adequate plus-power effect of the slightly and physiologically accommodating human eye lenses of the normal-sighted observer's eyes, which for the desired distance vision compensate the weakly negative refractive power of the optical element, as a transparent viewing window, is brought into a suitable position near the observer's emmetropic eyes. This combined system presents a real telescope in contrast to the hitherto known concentric lenses.
Abstract: A compact zoom lens system consisting of a small number of lens elements and having a short total length, said zoom lens system comprising a first lens unit having positive refractive power and a second lens unit having negative refractive power which are arranged in the order from the object side, an aperture stop arranged in said first lens unit, at least one lens component arranged after said aperture stop in said first lens unit and at least one graded refractive index lens having refractive index gradient in the direction perpendicular to the optical axis in said first lens unit.
Abstract: A projection lens in which a lens unit which may comprise one or two elements is closely coupled at the object end of the lens to a cathode ray tube. At the image end is a lens unit of overall weak optical power which comprises from the image end a first positive element followed by a closely spaced negative element of substantially higher dispersion. Intermediate the object side lens unit and the image side lens unit is a lens unit of substantial optical power supplying substantially all of the positive optical power of the lens. Closely spaced to this power lens unit on the object side is a negative lens element of high dispersion. This negative lens element may be considered to be part of the power lens unit.
Abstract: Disclosed are a correction lens system used in the process of producing the fluorescent screen of a color picture tube in order to reduce the positional deviation (mislanding) of the landing point of an electron beam projected to form a picture from the position of the corresponding fluorescent substance in the mosaic of the fluorescent screen, and a method of manufacturing the correction lens system. The correction lens system includes a first correction lens provided with a smooth curved surface for correcting the optical path of exposure rays for producing the fluorescent mosaic and a second correction lens provided with a discontinuous curved surface. The optical path of the exposure rays is corrected to the desired optical path by the refraction of the rays through the first and second correction lenses.
Abstract: A coherent input beam from a laser is fed into a Brillouin-enhanced four wave mixer which generates a phase conjugated seed beam in counterpropagation with the input beam. A brillouin amplifier is provided between the laser and four wave mixer to transfer energy from the input beam to the seed beam and thereby amplify the seed beam to produce a phase conjugated output beam with approximately 50% of the energy of the input beam and narrow bandwidth which is free from random phase jumps associated with the acoustic noise generally required to initiate and sustain stimulated Brillouin scattering. The phase conjugated output beam can be modulated or steered in direction, as desired. Reference beams for the four wave mixer may be derived from the same laser source as the input beam and have energies one or more orders of magnitude smaller than the energy of the input beam.
March 15, 1989
Date of Patent:
September 25, 1990
Hughes Aircraft Company
Davis A. Rockwell, Richard C. Lind, David M. Pepper
Abstract: An apochromat optical system for a photoengraving process comprises a first lens group which includes a first lens having a positive power, a second lens made of Kultz flint glass having a negative power and a third lens in the form of a meniscus having a positive power. The first to third lenses are successively disposed in order starting from the object side. A second lens group includes the substantially same configuration of lenses as in the first lens group. The lenses of the first and second lens groups are approximately symmetrical with respect to the stop. Accordingly, the system has a high aperture ratio and small curvature of a saggital and meridional image field which can reduce an astigmatic difference in a peripheral part of an image.
Abstract: A small-size zoom lens system includes a first lens group, a second lens group, and a third lens group which are successively arranged from an object side to an image side. The first, second, and third lens groups have negative, positive, and negative focal lengths, respectively. The first, second, and third lens groups are movable toward the object side for zooming movement from a wide angle end toward a telephoto end, while varying the distances between the first, second, and third lens groups. The focal length of the ith lens group (i=1, 2, 3), and the focal length fw of the entire zoom lens system at the wide angle end of zooming movement satisfy the following conditions:0.3<.vertline.f.sub.3 .vertline./.vertline.f.sub.1 .vertline.<11.2<.vertline.f.sub.1 .vertline./fw<2.30.9<.vertline.f.sub.3 .vertline./fw<1.
Abstract: A zoom lens system comprising a very small number of lens components, having favorably corrected aberrations, comprising two lens groups having positive refractive power and negative refractive power respectively, and so adapted as to perform variation of focal length by varying the airspace reserved between the two lens groups, said lens group having positive refractive power comprising at least one graded refractive index lens component having the shape of a negative meniscus lens and a refractive power distribution wherein refractive indices are lowered as the lens portions are farther from the optical axis in the direction perpendicular to the optical axis.
Abstract: An objective lens for optical disks comprises a first lens component and a second lens component and, when the distance on an optical axis from an entrance face of the first lens component disposed in a position farthest from an optical disk to the center of gravity of the objective lens is taken as gc, the overall length of the objective lens as .SIGMA. d, and the focal length as f, the following conditions are satisifed and any of surfaces of the lens components is configured as an aspherical surface:g c<.SIGMA.d<0.50.9<.SIGMA.d/f<2.2Thus, the use of the objective lens makes it possible to reduce the load to a driving device for moving the objective lens and to provide the driving device small in size and light in weight.
Abstract: A microscope objective adjustable for different thicknesses of cover-glass includes a second lens (L2 and L3) movable between a first lens (L1) and a third lens (L4) and a fourth lens (L5) movable with the second lens, but in an opposite direction. A ring that accomplishes movements of the second and fourth lenses also resets the focus of the objective. All movements are linear and are arranged to maintain the correction of image error while the objective is adjustable over a wide range of cover-glass thicknesses from 0 to 2 mm.
Abstract: Each individual light emitter of a LED linear array is imaged by a discrete step-index light guide and gradient index microlens device. The light guides consist of high refractive index cores, each surrounded by low refractive index matter. A multiplicity of light guides are deposited in channels formed in a host material, such as a silicon wafer. The host material between adjacent channels functions as an opaque separator to prevent cross-talk between adjacent light guides. Optically bonded to the LED array, the light guides conduct a large portion of the diffuse light emitted to a series of microlenses optically bonded to and in registration with the exit end of each light guide. The microlenses are constructed in a transparent substrate, with each microlens having a spherical or aspherical gradient index profile and short focal length.
Abstract: A first lens, a second lens, means and a third lens means are arranged successively in a direction of travel of a ray. The first lens means each comprising a single lens element power. The second lens means has a predetermined negative refracting power. The third lens means has a predetermined positive refracting power. A fourth lens means consisting of a plurality of lens elements follows the third lens means in the direction of travel of the ray and has a predetermined positive refracting power. At least one surface of the first, second, third, and fourth lens elements is aspherical. The follwoing conditions (1), (2), and (3) are satisfied:4f<f3<20f (1)0.65<(f4/d34)<1.
March 10, 1989
Date of Patent:
August 14, 1990
Matsushita Electric Industrial Co., Ltd.
Abstract: Zoom lenses having sequentially from the front a positive unit facing the long conjugate and consisting of a cemented doublet followed by a single element; a negative unit movable for zooming and consisting of a negative element and a negative doublet concave toward each other; a second negative unit movable for zooming and consisting of a single component including at least one negative element; and a stationary rear unit comprising a petzval-type lens group. The zoom lens has a zoom range greater than 5.times., a total coverage exceeding 48.degree. at some zoom position and an f-number is f-1.48.