Abstract: A two element 10X eyepiece has a field of view of about 44.degree. and provides a wide field (20mm) with lenses having curve-diameter ratios considered desirable from a manufacturing view.

Abstract: A variable focus objective lens having a magnification range in the order of 1 : 30 and greater and having two pairs of relatively movable members which objective consists of a front assembly and a rear assembly which includes one of the two pairs of movable members to which consecutive zooming movement is imparted. This is done in order to add a varifocal range to a varifocal range of zooming movement of the movable members of the front assembly, in association with a control mechanism of simple structure incorporated in barrels of the lens mount therefor.

Abstract: Photometer circuitry includes a capacitor discharge means for establishing a time period related to the light absorption properties of a test sample. The time period is used, in conjunction with a frequency generator to drive a digital counter to provide a digital indication of light absorption.

Abstract: A compact retrofocus-type wide-angle photographic lens system with a long back focal length comprising seven lens components and satisfying the following conditions:1. 0.5f < .vertline.f.sub.123 .vertline. < 0.8f, f.sub.123 <02. 0.4f < d.sub.7 + d.sub.9 < 0.8f3. d.sub.9 /d.sub.7 < 0.354. d.sub.8 < 0.2f5. 0.6 < r.sub.5 /r.sub.3 < 1.5For said wide-angle photographic lens system, aberrations are favorably corrected and, moreover, astigmatism in close-up photographing is also corrected quite favorably.

Abstract: An optical objective for the infra-red wave band, comprising front and rear simple positive lens elements each made of Germanium, said elements being axially spaced by a distance S lying between 0.8F and 1.2F, the rear surfaces of said elements being plane or convex to the front with radii of curvature greater than 10F and the front surface of each element being convex to the front with a radius of curvature less than the radius of curvature of its rear surface.

Abstract: A light diffraction technique is set forth for monitoring the behavior of small liquid jets operating in the Rayleigh mode. This monitoring enables measurement of jet parameters, and thereby further enables on-line control of these parameters.

Abstract: Achromat objective lens systems and more particularly an objective lens system having a magnification .beta. on the order of 10 to 30X and designed to operate particularly for the monochromatic light whose wave length is on the order of 6328 A. The lens system consists of three lens components and four lenses. The first and second lens components are positive singlet lenses. The third lens component is a positive doublet lens composed of a negative meniscus lens and a biconvex lens. The lens system is constructed so as to satisfy the following three conditions:______________________________________ 0.9f<d.sub.2 +d.sub.3 +d.sub.4 <1.3f (1) 0.8f<R.sub.6 <1.2f (2) 1.46<n.sub.1d <1.65 1.46<n.sub.2d <1.65 1.46<n.sub.4d <1.65 50<.nu..sub.1d <68 (3) 50<.nu..sub.2d <68 50<.nu..sub.4d <68 .nu..sub.3d <35 ______________________________________Wherein f designates the overall focal length of the system given for a wave length light of 6328 A, R.sub.

Abstract: Apparatus for measuring the frontal power of corneal contact lenses made of a somewhat hydrophilic material and having a predetermined index of refraction in a liquid having itself a predetermined index of refraction. This apparatus comprises a sighting optical system and a measuring optical system spaced from each other and having a common optical axis extending substantially vertically at least in the gap between said two optical systems. It further comprises a small cup disposed in said gap and filled with said liquid, the cup bottom comprising a fluid-tight window centered to said optical axis and means for supporting a contact lens in said liquid in a position centered to said optical axis.

Abstract: A highly sensitive process for measuring fine deformation comprises a stage of illumination with beam to on a periodic structure having diffractive function as well as lacking in diffractive function, a stage of selecting wave of diffraction order having conjugate or nearly conjugate relation among diffracted wave fronts projected from the periodic structure by means of said illumination with beam so as to cause mutual interference, thus, the amount of deformation is measured by the interference fringe formed by said mutual interference when the basic period of periodic structure is displaced or periodic structure is deformed.

Abstract: A discontinuous wide-angle optic for use in a light receiver or transmitter comprises a partial spherical element having a planar boundary surface superposed on the base surface of a pyramidal facet reflector provided with a plurality of inclined facet surfaces, one for each of a plurality of directions of incidence of light passing through the spherical surface of said spherical element. When used in a light receiver, the spherical surface functions as a positive lens to cause entering light rays to converge toward one of the facet surfaces of the reflector for reflection therefrom into an image plane located at a diaphragm formed on a surface of said partial spherical element spaced from its said planar boundary surface.

Abstract: Parameters of a clad optical fiber are measured by irradiating the fiber with a laser beam to generate a scattering pattern. Measurements are made of fringes and modulations in the scattering pattern and these measurements are translated into such parameters as core and fiber diameter.

Abstract: To facilitate visual and/or electronic determination of the shape of a light-reflecting test object, a source of coherent light such as a laser produces an illuminating beam and a reference beam, the latter beam being combined in an optical system with reflections of the illuminating beam from the test object to form a holographic pattern on a receiving surface. The optical system includes a main objectives and two ancillary objectives, these ancillary objectives focusing the reflected rays of the illuminating beam and the rays of the reference beam upon two substantially coincident points so located on or near the axis of the main objective, in non-conjugate relationship with the receiving surface, as to train upon that surface a defocused composite beam producing a holographic pattern of contour lines. The substantially coincident points also lie in or near the plane of a real or virtual aperture stop, such as a pinhole diaphragm or its image.

Abstract: Microscope objectives having a numerical aperture of substantially 0.25 and a magnification of about 10X provide a substantially flat image field of about 24mm.

Abstract: Large area lens assembly, e.g., for an overhead projector, has glass stage bonded directly to plastic incremental lens to eliminate light-reflective interface and conserve space. Differential thermal expansion problems are overcome by critical selection of materials, dimensions and procedures. A unitary structure with multiple incremental lenses is made possible.

Abstract: A retrofocus wide angle lens system provides an increased field angle with a large aperture ratio. Besides the specific arrangement of the individual lens components in the various embodiments of the present invention, the retrofocus wide angle lens design further satisfies the following conditions: ##EQU1## WHEREIN R IS THE RADII OF CURVATURES FOR THE SUCCESSIVE LENS SURFACES FROM THE OBJECT TO IMAGE SIDE OF THE LENS SYSTEM; N.sub.I and N.sub.II represent the refractive indices of lenses forming a cemented doublet on the image side of the diaphragm; R represents the common radius of curvature of an intermediate surface of the doublet and f represents the overall focal length of the lens system.

Abstract: An optical element comprising a glass substrate on which a plastics material defining an optical surface is moulded. Shrinkage of the plastics material during curing is compensated for by allowing the glass substrate to deform due to the shrinkage, and optically working flat the outer surface of the glass substrate so that when the element is released from mould this outer surface will restore and take up a curvature which is equal to the amount of curvature lost at the moulded optical surface due to the shrinkage.Fig. 1 is best suited for early publication purposes.

Abstract: A zoom lens assembly has a normal-range finder which is operable at all settings of a macro-range finder. The normal-range finder produces relative movement between two lens elements one of which is also positionable by the macro-range finder. This is achieved in one arrangement by controlling the positions of the lens elements with two coaxially arranged tubes which are coupled together for rotational movement but which can be moved axially with respect to one another by the macro-range finder. In another arrangement a single control tube is used to shift the two lens elements in response to adjustment of the normal-range finder but one of the lens elements is also displaceable within the control tube by rotation of a threaded mounting cylinder.

Abstract: A high-resolution Fourier interferometer-spectrophotopolarimeter is provided using (i) a single linear polarizer-analyzer the transmission axis azimuth of which is positioned successively in the three orientations of 0.degree., 45.degree., and 90.degree., in front of a detector; (ii) four flat mirrors, three of which are switchable to either of two positions to direct an incoming beam from an interferometer to the polarizer-analyzer (1) around a sample cell (2) transmitted through a medium in a cell and (3) reflected by medium in the cell; and (iii) four fixed focussing lenses, all located in a sample chamber attached at the exit side of the interferometer.

Abstract: The invention relates to a method of determining the modulation transfer function of a recording support or of an optical system. In the context of the invention, an optical system includes any components with finite apertures which are required for forming an image of an object. A coherent-optically produced scatterer of known noise distribution or with a known spatial frequency spectrum is used for determining the required modulation transfer function. The modulation transfer function can be determined through the density of transparency distributions present on the recording support.

Abstract: An improved system and technique for detecting and stabilizing long term thermal and mechanical drifts in a swept Fabry-Perot interferometer. Under the control of a timing circuit the distance between two interferometer optical surfaces is changed by periodically sweeping a first surface while the second surface is rocked in a positive and negative direction about two orthogonal axes. The light transmitted by the inerferometer is detected to provide a train of uniform pulses of random spacing having a maximum count when the surfaces are substantially parallel. A counter circuit senses the number of pulses during rocking in both the positive and negative direction about each axis and provides each count to a summing circuit for providing a difference output.