Abstract: A stereo vision optical instrument having eyepieces which are rotatably mounted to the instrument by way of pivot plates includes apparatus coupled between the pivot plates to prevent binding of the eyepieces as they are rotated.
Abstract: A supported thin metal hologram is formed and mounted on a substrate using an adhesive. In a preferred aspect, the hologram is covered with a transparent resin which preferably is identical to the adhesive.
Abstract: A zoom lens system capable of wide-angle viewing for a high zoom ratio has four lens groupss, all of which change the focal length of the overall system while the position of the image plane is held constant. The second lens group comprises a negative lens element having a concave surface of large curvature on the image side, a biconcave negative lens element that is cemented to a positive lens element to provide a cemented surface that has a large curvature and which is convex toward the object, and a negative lens element whose surface on the object side has a large curvature and is concave toward the object.
Abstract: Aberration in an image reflected from a warped surface such as an automobile windshield is corrected by providing an image to the windshield which is predistorted to compensate for the aberration. The predistorted image is created and stored in a hologram by a recording technique wherein a first transmission hologram which records the virtual image of an object is illuminated with a conjugate beam. The beam which is transmitted by the first transmission hologram is reflected off the windshield onto a second hologram recording plate, which is also illuminated by a reference beam passed through the windshield. The desired predistorted image is thereby stored in the second hologram recording plate.
Abstract: The natural resonant frequency (and phase) of a resonant mechanical system (having an spring structure that includes a material whose elastic properties change with temperature, e.g., by at least 0.05% per .degree.C.) is tuned to a desired value by changing the temperature of at least part of the spring structure. A two-dimensional image is generated on a surface by tunign a resonant driver (having such a temperature sensitive element) to a natural resonant frequency in coordination with modulation of a beam that is raster scanned on the surface by the resonant driver.
Abstract: Such system can include, in the first plane, a first optical device for producing converging radiation from incident, substantially parallel radiation passing through the first optical device and, in a second plane, substantially parallel to the first plane, a second optical device for receiving, as incident radiation, converging radiation from the first optical device and for recollimating or reducing the degree of convergence of this incident, converging radiation as it passes through the second optical device.
Abstract: A lock ring prevents inadvertent rotation of a rotatable focusing eyepiece for an optical instrument. The ring is disposed on the device and is fixed against rotation. A face is provided on the ring which is adapted to frictionally engage the eyepiece to prevent inadvertent rotation thereof. The ring is movable or deformable to disengage the face from the eyepiece for focusing.
Abstract: An f..theta. lens system which incorporates the advantages of a telecentric optical system and which is also achromatized so as to permit its use with a multi-mode laser. The lens system includes, in order from the light source side, of a first lens unit composed of one or two lens elements and which has a negative refractive power with a concave surface directed toward the light source side, a second lens unit composed of a positive meniscus lens having a convex surface directed toward the image side, a third lens unit composed of two positive lens elements and one negative lens element and which has a positive refractive power, and a fourth lens unit composed of two plano-convex lens elements and which is spaced a long distance from the third lens unit so as to be located at a position close to the image plane.
Abstract: Highly durable, light-polarizing film having neutral gray as well as high polarizing coefficient is provided. The film comprises a uniaxially stretched base polymer film of, for example, polyvinyl alcohol or derivatives thereof and at least two dichroism dyes adsorbed and orientated therein. The dichroism dyes are, for example, C.I. DIrect Yellow 12, C.I. Direct Black 17 and C.I. Direct Blue 202. The film is usable for display by liquid crystal. A boric-acid treatment is used to improve the polarization properties.
Abstract: An optical collimating apparatus employs a semi-reflective concave mirror and cholesteric liquid crystal element. In one embodiment, the optical collimating apparatus is used as a heads-up display device. Images in the line of sight of an observer substantially pass through a transmitter/combiner, semi-reflective concave mirror, and cholesteric liquid crystal element to an observer. Images generated by an image source are focussed on the transmitter/combiner such that the transmitter/combiner reflects the images into the line of sight of the observer. The generated images are transmitted by the primarily transmissive (convex) side of the semi-reflective concave mirror to the cholesteric liquid crystal element. The cholesteric liquid crystal element reflects the generated images back toward the primarily reflective (concave) side of the semi-refective concave mirror, which in turn reflects the images back toward the cholesteric liquid crystal element, which transmits the generated images to the observer.
Abstract: The contact lens comprises a central optical zone and a peripheral zone for fastening the lens. For centering said lens the peripheral zone comprises two stabilizing bosses which are disposed on the horizontal stabilization axis of the lens. For large palpebral openings it may be preferable to use two pairs of bosses, whereby each pair comprises two bosses, disposed symmetrically to said axis of stabilization. For multifocal corrections it is possible to use a third boss, disposed on the vertical axis of the lens. These stabilizers allow a perfect centering of the lens, hindering its rotation and the use of very thin lenses.
Abstract: An aiming device (diopter) has an easily removable eyepiece with adjustable diaphragm mounted on one end of a housing portion which housing portion has a cavity eccentrically formed therein. A color filter disc and two polarizing filter discs are rotatably disposed in the cavity and provided with circumferential gear structures which are in engagement with internal gear structures formed on operating rings extending around the housing portion and the respective discs to move the discs relative to the viewing axis of the aiming device.
Abstract: A dynamically matched optical filter is formed within a multiple telescope optical imaging system. Entrance and exit pupil geometries, the phases and tilts of multiple imaging paths and system alignments are sensed and controlled to allow wide field of view imaging and the enhancement or suppression of certain spatial frequencies of interest.
March 16, 1988
Date of Patent:
August 15, 1989
The United States of America as represented by the Secretary of the Air Force
Abstract: A thin-film optical interference filter designed and manufactured to have high transmission of blue light and high reflectance of infrared light. The novel feature of this filter rests in the thin-film layer design at the top and bottom of a quarterwave stack and the manufacturing technique by which this thin-film design is deposited. The thin-film layer design suppresses the so called halfwave holes which occur at wide angles of incidence of the incoming light. This desirable effect is achieved by the proper layer thickness and refractive index control in the manufacturing process.
Abstract: A beam steering mirror is mounted in a frame which is centrally supported by a two axis pivot point. Two torque motors are each connected to the frame with parallel diagonally opposed connecting members. The connecting members, when in the form of cables, are pretensioned an amount greater than the dynamic slewing force.
Abstract: An imaging lens system including a distributed index lens which has planar opposite end surfaces and in which the index gradient near the optic axis is substantially zero and the refractive index becomes progressively higher from the optic axis toward the marginal portion, and a plano-convex lens having a planar surface on the side thereof which is adjacent to the distributed index lens and formed of a homogeneous medium.
Abstract: Apparatus and method are disclosed for providing a variable lens and birefringence compensator (10) adapted to be used within the resonator cavity of a repetitively pulsed, variable rate, solid state laser. A cylindrical body of optical material (12) having a temperature dependent index of refraction is thermally coupled to heat exchange means (14) surrounded by potting material (16) and a heat sink (18) which adds heat to or extracts heat from the exterior surface of the cylindrical body in order to establish radially dependent thermal and stress gradients within the body. The heat exchange means is supplied power through leads (20) from the same source (22) which excites the excitation mechanism of the solid state laser. Heat is infused into or extracted from the compensator body at the same rate at which the flashtube stimulates the laser rod (24) within the laser cavity defined by resonator mirrors (26, 28).
Abstract: The present invention is directed to an eye refractometer, one embodiment of which, includes two-aperture stops positioned substantially conjugate with the pupil of the eye to be examined. Further, a two-dimensional light position detecting device is provided for detecting the two-dimensional positions of two light beams passed through the light beam incidence area of the pupil of the eye to be examined, reflected by the fundus of the eye to be examined and passed through the light exit area of the pupil of the eye to be examined. A processor is provided for obtaining the refractive value of the eye from the output of the two-dimensional light position detecting device.
Abstract: An f.theta. lens system is disposed between a rotating polygonal mirror for deflecting a light beam and a surface being scanned, for focusing the light beam deflected by the rotating polygonal mirror on the surface. The f.theta. lens system places the reflecting position of the rotating polygonal mirror and the surface being scanned in conjugate relationship with respect to an auxiliary scanning direction, and has an f.theta. function, the f.theta. lens system comprising two lenses. The surfaces of the first and second lenses are defined as first through fourth surfaces successively from the rotating polygonal mirror toward the surface being scanned, the first surface being a spherical surface, the second surface being a cylindrical surface, the third surface being a cylindrical surface, and the fourth surface being a toric surface. The f.theta. lens system satisfies the conditions: 0.35<R4x/R1x<0.85, and -0.120<(1/R3y)+(1/R4y)<-0.