Abstract: A measuring device, particularly for the measurement of force, has a tilt-invariant interferometer attached to a bifurcated deformation body which consists of a base with one or several diaphragms attached thereon. The interference fringes are counted photoelectrically.

Abstract: A trichroic mirror comprising an optical wedge having two multilayer dielectric interference filters, one disposed on a front surface of the wedge and the other disposed on a back surface of the wedge with the back surface being tilted in a given direction and at a given wedge angle with respect to the front surface, and a reflecting element spaced from the back surface and tilted in a direction opposite to the given direction and at an angle equal to the given wedge angle with respect to the front surface. This mirror separates incident radiation into three spectral bands, all of which may be detected by a single detector in time sequence.

Abstract: Method and apparatus for determining eye refraction using corrective lenses comprising projecting the corrective lens by means of an optical system into the pupil of the eye or in a predetermined spaced relation in front of said pupil, e.g., via a splitting mirror; this permits sight testing without the use of test spectacles and impairment of field of vision.

Abstract: A microscope objective comprising a first, second, third fourth and fifth lenses, in which the first lens is a positive lens, the second lens is a positive meniscus lens, the third lens is a negative lens, the fourth lens is a positive meniscus lens and the fifth lens is a positive lens, and satisfying the following conditions for which the number of lenses constituting the lens system is small, working distance is large and resolving power is extremely high.(1) 0.14f<d3<05f(2)0.28f<.vertline.r.sub.2 .vertline.<0.69f0.28f<.vertline.r.sub.8 .vertline.<0.69f(3) 0.5<r.sub.4 /r.sub.3 <2.7(4) 0.4d.sub.4 <d.sub.5 /n.sub.3 +d.sub.6 +d.sub.7 /n.sub.4 <2.5d.sub.4(5) .nu..sub.3 <35, .nu..sub.1 >50, n.sub.1 >1.

Abstract: A binocular having a treadle-like knob which is coupled to optical elements to effect an adjustment such as focusing or varying the magnification of the optical system. The knob is mounted to be moveable in seesaw fashion about an axis which is generally perpendicular to the optical axes of the telescopes which form the binocular. This arrangement is especially useful in relatively small binoculars which may be held in one hand, the knob being driven by the tips of two fingers on the supporting hand.

Abstract: A zoom lens comprising, from front to rear, a first lens group of positive power movable for focusing, second and third lens groups of negative power movable for zooming, and a fourth lens group stationary during focusing and zooming. When zooming is performed from the wide angle to the telephoto setting, the aforesaid second lens group is axially moved in a one-directional manner toward the image plane, while the aforesaid third lens group is axially moved in a reciprocating manner toward the object. With this type zoom lens, a compact structure is realized by positioning the rear principal plane of the aforesaid first lens group as near the image side as possible and the rear principal plane of the aforesaid second lens group as near the object side as possible.

Abstract: An ophthalmic lens is described having a front face which is a surface of revolution and is located entirely in front of the transverse plane tangential to its center. The curve representing the half-meridian of this front face corresponds to the following general formula:x=ay.sup.2 +by.sup..alpha. +cy.sup..gamma.in which the coefficient a is different from zero and negative, at least one of the coefficients b and c is different from zero and positive, .alpha. is a real number which is greater than or equal to 3 and less than 4, and .gamma. is a real number which is greater than or equal to 4.

Abstract: A zoom optical system utilizes a virtual object relay system in order to obtain compact size in a large aperture instrument while minimizing chromatic aberration. The size may further be reduced by employing limited amounts of special optical materials for some of the lens elements.

Abstract: The photographic objective optical system disclosed keeps an exit pupil stationary during focusing, thereby rendering it possible to maintain the angle between a ray of light incident upon the entrance pupil and the systems optical axis constant during focusing. This way variation of the angular field of view during focusing can be avoided.

Abstract: The disclosure is a microscopic lens comprising three component lenses with concave and convex conical sections which refract light rays. Rays emanating from an object pass through five conical surfaces, first being refracted outward and separated to form a ring image, and then being refracted inward and rejoined to form an enlarged image. There is one outward refraction as opposed to three inward refractions, and it is the difference between these refractions that produces magnification of the object.Magnification produced by one conical microscopic lens is small, so a number of lenses are used to form multi-stage microscopes in which magnification increases at an exponential rate. Thus, though the initial stage lens might produce a small magnification of only 4.5.times., two stages will produce a magnification of 20.times., three stages 91.times., four stages 410.times., etc. Eight stages produce a magnification in excess of 100,000.times.

Abstract: The invention relates to a device for determining the granulometric composition of a mixture of particles by diffraction of light. The light flux received on the diffraction pattern is measured in a number of diffraction areas (AI,AJ) each of which is in the shape of an angular sector of circular rings which are concentric with the pattern, these integration areas forming two successions in each of which the inner and outer radii form geometrical progressions with common ratio of two, the ratio between the outer radius and the inner radius of an integration area being chosen in the interval between two and the square root of two, the radii within one succession (AJ) being equal to those within the other (AI) multiplied by the square root of two. Application to studying powder mixtures.

Abstract: A zoom lens barrel is constructed such that the axial movement and rotation of a single operation ring relative to a stationary barrel causes zooming and focusing respectively and provides a device for providing constant magnification photography. This is accomplished by a plurality of cam grooves provided on one of the operation ring and the stationary barrel and a guide pin provided on the other of the operation ring and the stationary barrel and releasably engageable with each of the cam grooves. Each of the cam grooves forces the operation ring to rotate upon axial movement of the operation ring through the engagement with the guide pin such that magnification remains constant during focusing. The magnification that remains constant during focusing varies depending on which of the cam grooves the guide pin is engaged with.

Abstract: This invention provides a high speed compact catadioptric, i.e. reflecting-refracting objective system of F/1.2.The lens system comprises, in accordance with the advance of the light rays, a positive lens with a convex surface toward the object, a lens with front and back surface concave toward the object and with a main mirror surfaced on the peripheral portion of said back surface. A counter-mirror is surfaced to the central portion of said positive lens and a field lens is cemented to the central portion of said lens with the main mirror surfaced thereon. Small zonal errors of spherical aberration, economical production and a reduced sensitivity to machining and mounting errors result from employing only two optical members which carry the mirrors and lens elements.

Abstract: Six groups of six lens elements for use in the photographic arts include a front lens group of three groups of three lens elements, and a back lens group of three groups of three lens elements. The front and back lens groups are symmetrically arranged on either side of a diaphragm mounted therebetween. The whole objective is extremely small in size and has little variation in distortion aberration caused by variation in magnification. In addition, both the image field of curvature and the coma aberration are sufficiently corrected for field angles up to 70.degree. or so under unitary magnification.

Abstract: A contact lens concave-convex in form made of a transparent, optically clear hydrophilic material containing micro-photoelectrolysis elements to produce oxygen by the electrolysis of water.

Abstract: A collinear aiming light image viewer device in a common housing through ch an observer may view both a target scene and a superimposed collinear aiming light beam within the viewer. The aiming light source is positioned in an offset area of the common housing to project a narrow IR beam off a partially reflective mirror along a portion of the optical axis of the image viewer onto a scene wherein the scene and IR beam images are simultaneously viewed through an image intensifier.

Abstract: A wide angle zoom lens system capable of photographing objects from infinity to a close distance while maintaining an excellent image-forming performance employs a first group which is a divergent lens group having a focusing function, and a second group which is a convergent lens group disposed rearwardly of the first group. The first group includes a divergent forward portion and a convergent rearward portion disposed with a predetermined spacing from the forward portion, the forward and rearward portions being movable relative to one another for focusing. The first and second groups are movable relative to each other to effect a magnification change.

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 a similarly shaped fixed prism in the other arm provides optical compensation to avoid aberration problems. The beamsplitter surface is on the fixed wedge-shaped prism, and the two wedge-shaped prisms constitute the only refractive elements in the interferometer arms.

Abstract: A device which measures the mutual coherence function of a laser beam. The device includes: a screen 1 in which openings 3 to 11 are disposed on the path of the beam 2 and allow pencils of light 19, 29 and 34 to pass; an interferometer constituted by an optical plate 13, a dihedron 14 and a mirror 21; a phase modulator 22 disposed on a branch of the interferometer; receivers 23 to 27 which receive the pencils of light 20 and 33 which emerge from the interferometer; and a processing circuit 36. Application to the analysis of a laser beam.

Abstract: A photographic lens system having five lens components in which separation of a cemented lens of the second lens component of the Biometer type lens system has enabled making an aperture ratio of F/2.0, a long back focus and effective correction of various aberrations. The system comprises five lens components and five lens elements comprising a first lens component having a positive meniscus lens, a second lens component having positive meniscus lens, a third lens component having a negative meniscus lens, a fourth lens component having a negative meniscus lens and fifth lens component having a positive meniscus lens.