Abstract: The invention relates to a device for detachably attaching a lens tube (2) to a lens barrel (1). It is characterized in that the lens barrel inside its forward free edge (5) is provided with peripheral grooves (3) extending in the same plane, the respective bottom of which at the ends (9) of the groove inclined in said plane transforms into the shell surface of the barrel (1), which shell surface tapers conically (6) to the free edge (5) of the barrel. A guide shoulder (4) tapering in wedge-shape thereto is located on the shell surface between two adjacent grooves (3). The tube (2) is provided with radially resilient hooks (11) capable at mounted tube (2) to engage with the grooves (3) of the barrel (1).

Abstract: A Faraday rotator has a non-magnetic garnet substrate with a ferrimagnetic garnet film epitaxially grown on the substrate. A magnet induces a magnetic field in the film for rotating the plane of polarization of a light-beam which strikes an end surface of the film at a predetermined angle. The substrate and film are composed of a material wherein the difference (.DELTA. a=a.sub.s -a.sub.f) between the lattice constant a.sub.s of the substrate and the lattice constant a.sub.f of the film satisfies .vertline..DELTA.a.vertline..ltoreq. 0.001A (angstrom).

Abstract: A process for forming an electrochromic film to be used in an electrochromic device is provided. The process includes a step of introducing a mixture of oxygen gas and inert gas at a predetermined mixing ratio into a reactor in which is provided an electrode having thereon a sheet of tungsten as a target and a counter-electrode holding thereon a substrate under a predetermined total pressure condition and a step of applying a predetermined voltage between said electrodes while maintaining the substrate at a predetermined temperature. The present process allows to provide a WO.sub.3 -sputtered film on the substrate. The present invention also provides an electrochromic display device in which the electrochromic film is operated under control not to reach the color saturation condition, thereby preventing the occurrence of separation of the film and thus ensuring a long-term servicelife.

Abstract: A transmitted-light illuminating device (FIG. 1) for microscopes consists of a condenser (1), an iris-aperture diaphragm (2) and a turret (3). The turret permits interchangeable mounting of auxiliary lenses (4) or diaphragms (5) by means of which large-object fields can be illuminated, if desired; alternatively, the microscope can be used in phase contrast. Condenser, diaphragm and turret are combined into a unit in which the turret is functionally coupled to the iris diaphragm. For this purpose, the index shaft of the turret (3) is eccentrically mounted to the actuating ring (9) of the diaphragm (2), the ring is configurated for detent engagement to retain the newly indexed turret station in axial register with the optical axis of the condenser. Thus, rotation of the turret first drives the actuating ring (9) against its diaphragm stop to thereby open the diaphragm before there is any indexing movement of the turret, from one to its next indexed position.

Abstract: A retro-reflective prism assembly for use with electronic distance measuring instruments in surveying and other civil engineering applications. The unique structure permits tilting and plunging the assembly without requiring a separate tiltable bracket. A novel housing and sealing arrangement positions and seals the prism for limiting shock and preventing water leakage while obviating any need for coating the rear surfaces of the prism. An eccentric tilting knob simplifies angular tilt setting while a convenient transit knob simplifies azimuth adjustment. Vertical sighting holes in the yoke of the assembly provide for convenient plumbing of the assembly. A uniquely configured dust cover is designed for convenient storage on the back of the prism housing during use of the assembly.

Abstract: On the facing surfaces of first and second supporting plates, where at least the first supporting plate is transparent, first and second electrodes, respectively, are provided with at least the first electrodes being transparent. An opaque liquid is present between the supporting plates. Third electrodes which can be moved between the first and second electrodes by electrostatic forces are connected to the second supporting plate. The third electrodes are formed by a display part having a large number of apertures of which the color of the side facing the first supporting plates is contrasted with the color of the liquid. A number of resilient elements is provided below the display part with one end connected to the display part and the other ends connected to pillars which are provided on the second supporting plate.

Abstract: There is disclosed an improved optical device of the type disclosed in application Ser. No. 520,456 and embodying an array of lenses integral with and raised above a crystalline matrix. The improvement comprises an ion-exchanged surface on the lenses wherein the lithium ion from the lens glass is exchanged with a larger monovalent ion, preferably sodium or potassium from a bath, and the contents of such alkali metal ions in the lens are defined by both radial and axial concentration gradients. The device may be heated above the glass strain point to relieve stress and enhance lens power, either simultaneously with or subsequent to the ion exchange.

Abstract: Apparatus for facilitating visual reading of meters, and more particularly for reading of water meters or the like disposed beneath the ground. A center tube assembly is provided comprising a cylindrical center tube and a light guide assembly carried internal of and adjacent to the inner wall of the center tube and selectively positionable relative thereto. Disposed at the proximal and distal ends of the center tube are respective end cap assemblies each carrying a respective lens fixedly mounted therein transverse to the center line of the center tube. Each end cap further includes an outer end spacer portion which spaces the lens surfaces inward along the center line of the tube away from the outermost ridges formed by the spacers. In operation the center tube is aligned vertically over the meter face which is then viewed through the center tube upon activation of the light assembly.

Abstract: An integral optical device is disclosed that is composed of a photosensitive glass having an optical pattern developed therein by a refractive index change due to formation of colloidal metal particles and/or crystalline microphases nucleated by such particles. In a specific embodiment the pattern is composed of at least one transparent lens system having a radial gradient refractive index distribution of prescribed nature.

Abstract: An apparatus for performing an incoherent optical Fourier transform inclu a source of incoherent light, means for generating and phase modulating a first zone plate, a second zone plate, means for detecting incoherent light processed by the apparatus, and means for filtering the output signal, thereby discriminating between the Fourier transform signal and background constant or bias signals. A method for performing incoherent optical Fourier transform is also disclosed.

Abstract: New methods for making "embedded-lens" retroreflective sheeting, and new forms of such sheeting, are provided. The new methods involve embedding microspheres into a web by continuously presenting a mass of the microspheres against the moving web and heating the web so as to soften at least an exterior stratum of the web, and adding a spacing layer to the microsphere-covered surface of the web. The microspheres are embedded on the average to less than 50 percent of their diameter, which has been found to cause the spacing layer to conform around a greater proportion of the back surface of individual microspheres and thereby position a greater portion of the specularly reflective layer carried on the spacing layer at the approximate focal point for light passed through the microspheres. Use of a preformed spacing layer also contributes to maintaining the spacing layer at a constant thickness around the back surface of the microspheres.

Abstract: The Bragg's angle deviation of volume-phase-gelatin holograms is corrected by increasing the water content of the developed hologram and then reducing the water content of the hologram until the Bragg's angle deviation is zero.

Abstract: A plate lens comprising a transparent base having two flat surfaces and having a plano-convex lens portion which is formed integrally with the transparent base, which has a refractive index greater than that of the transparent base and which has a substantially semicircular or circular section in a direction perpendicular to the flat surfaces of the transparent base. The plate lens has a light-shielding layer on one surface of the transparent base, as needed. The light-shielding layer covers one surface of the transparent base such that a transparent portion may be formed in the vicinity of a position opposing the central point or line of the plano-convex lens portion. The plate lens provides a clear and bright image and is therefore applicable to faceplates for various types of display devices, CRTs and the like. The plate lens may be mass-produced at low cost.

Abstract: The use of a rhomboid-shaped phase grating to derive, from polychromatic input light, plus-one, minus-one and zero diffraction order output beams each of a different independent color.

Abstract: An array of optical frequency-sensitive elements such as diffraction grats or interference filters are arranged in a row, and the optical path of the laser cavity can be directed to include one of these elements. A partitioned optical prism consisting of a triangular portion and one or more paralleogramatic portions are used to direct the path. Between the portions are piezoelectric elements which, when energized, expand to provide an air gap between the portions and to allow total reflection of an optical ray at the surface of the prism next to the gap.

Abstract: An object beam and a reference beam incident on a photosensitive recording material interfere with each other to form a refractive-index strata grating. An energy transfer takes place between the reference beam and the object beam in the presence of a transverse electric field applied to the terminals of the material. A displacement of the interference fringes within the medium permits operation under optimum energy transfer conditions.

Abstract: An infrared objective lens system (15) comprises a primary lens group (13) air spaced from a secondary lens group (14) by means of a support assembly (16). The primary lens group (13) and secondary lens group (14) are aligned on a common optical axis (10) and are arranged to form a real image (9) at an external image surface from infrared radiation entering the system (15) through a pupil .0. in object space (11). Primary lens group (13) is self-compensated for chromatic aberrations, is positively powered and is made of material the refractive index of which is relatively temperature insensitive such as arsenic triselenide and/or zinc selenide. The secondary lens group (14) is positively powered, introduces minimal chromatic aberrations and is formed by a positively powered lens (C) and a negatively powered lens (D). Lens (C) is made of material the refractive index of which is relatively temperature insensitive such as arsenic triselenide.

Abstract: The present invention provides a light scanning apparatus including a semiconductor laser as its light source, a hologram disk having a plurality of equidistant linear gratings of hologram arranged in the form of a circle, which is driven to rotate at constant speed in a predetermined direction, a first optical system for leading the light from the laser to be incident upon one of the gratings, and a second optical system for leading the light diffracted by said one grating to a scanning surface. In one aspect, the second optical system is so structured to maintain the scanning surface to be in conjugate relation in geometric optics with the surface of said one grating thereby allowing to keep the scan line at a desired position even if the oscillation wavelength of the light varies. In another aspect, the incident angle of the light into the one grating is varied in accordance with the oscillation wavelength of the light so as to maintain a constant diffracted angle.

Abstract: An optical processor that can compute the moments of a two-dimensional image in parallel. The image is placed at the plane of a holographic mask which is disposed in the front focal plane of a Fourier-transforming lens and each of the desired moments is found at a respective one of a plurality of photodetectors arrayed in the back focal plane of the lens.

Abstract: A controlled absorption path filter for charge couple device seekers is made using a variable depth fluid. The use of a liquid as an absorber permits the entire aperture area to darken without loss of aperture. Thus the device provides a uniform extinction feature which preserves the system modulation transfer function. The device can be tied to a closed loop system with automatic gain control for feedback. Depending on the nature of absorber in the liquid, the device can also serve as a spectral filter. The device is applicable for visible light to near infrared light.