Abstract: The invention is directed to a colored contact lens designed for enhancing a wearer's eye color while giving the wearer's eyes a very natural appearance. A colored contact lens of the invention comprises a colored central zone which includes a colored substantially-circular pattern composed of non-opaque colored dots. Sizes of the dots and/or amounts of space between the dots are varied in a radially-controlled manner so that local colored dot coverage increases in a radial direction from the center to the peripheral edge or a position near the peripheral edge of the substantially-circular pattern.

Abstract: A form of protective eyewear having retractable eyeshields which protect the wearer's eyes from injury from mechanical, chemical or radiation hazards. The eyeshields have an extended position and a retracted position. In one embodiment, a mechanical actuator moves the eyeshields between the extended position and the retracted position. In another embodiment, the shields contain an inflation chamber which moves the eyeshields between the extended position and the retracted position. The eyewear may be in the form of corrective eyeglasses, sunglasses, safety glasses or safety goggles.

Abstract: In order to improve security for holographic labels which are positioned on a substrate base, a bar code symbol with regions of different light reflective properties is holographically recorded on the base. The base may be, for example an information card, such as a credit card, a label, or a container for a product. The bar code symbol can be recorded so that it is visible to the eye in white light (e.g., as a rainbow hologram) or so that it requires an appropriate reference beam for reconstruction. A reading apparatus (e.g., a bar code reader) directs light at the holographic bar code symbol and detects the reflected optical information with a detector such as a CCD array. The reading apparatus can be a stand-alone device or, in the case of a credit card, can be incorporated into a conventional swiper for reading magnetic information on a strip on the card. A non-holographic bar code symbol can also be provided on or near a holographic display element, e.g., a rainbow hologram.

Abstract: Novel apparatuses for readout of multiplexed volume holographic optical elements, based on parallel incoherent/coherent double angularly multiplexed holographic recording and readout principles, provide for hologram readout with high optical throughput efficiency and minimal crosstalk. Such holographic element readout apparatuses have applications in photonic interconnections for neural networks, telecommunications switching and digital computing; optical information processors and optical memories; and optical display systems. Embodiments are included that allow incoherent superposition of reconstructed images and simplified parallel readout of the volume holographic optical elements. The apparatuses can read out holographic elements that are either optically or computer generated and that are based on continuous-volume or stratified-volume holographic media.

Abstract: A mirror angle adjustment structure is provided for an optical system, such as a laser scanning unit. The structure comprises a support projection projected from a mirror support member at a position corresponding to an end along the lengthwise direction of the mirror, an adjustment screw member disposed at the other end of the mirror corresponding to another end across the mirror and passed through and threaded with the mirror support member from the side where the mirror is disposed, and an urging mechanism, such as a leaf spring, for urging the mirror towards the support projection and the adjustment screw member.

Abstract: A diffraction grating of reflective or transmissive lines is formed by a regular matrix of pixels each containing a respective curvilinear portion of one or more of said lines. When the pixels are illuminated, each generates a two-dimensional optical catastrophe image diffraction pattern whereby the total image diffraction pattern of the grating is optically variable but structurally stable. The invention further provides a diffraction grating of reflective or transmissive lines, comprising a multiplicity of diffraction grating regions which are at least partly separated by multiplicity of grating free regions. Each grating free region has a dimension which is at least large enough to be resolved by the human eye, the total grating free areas not exceeding about 20 to 50% of the total area of the grating. The disclosed diffraction grating is useful as a security device for currency or credit cards.

Abstract: In a retro-focus type lens divided into three lens units by the widest air spacing and the next widest air spacing, a first lens unit is disposed on a long conjugate side and has negative refractive power, and includes a negative lens and a lens provided with an aspherical surface, a second lens unit is disposed subsequently to the first lens unit and provided with a positive lens block, and a third lens unit is disposed subsequently to the second lens unit and has positive refractive power, and includes a negative lens and a positive lens.

Abstract: A holographic recording medium is treated to reduce or eliminate unwanted extraneous diffraction in a volume transmission hologram. Surface regions of the medium are desensitized either before or after a holographic recording to reduce the contrast of the holographic fringe pattern along the surfaces, and thereby to eliminate planar phase grating effects. Treatments include applying a burst of gas or vapor to the surface, irradiating the surfaces with highly absorbed incoherent light, thermally treating the recording medium.

Abstract: A display apparatus for blindzone signal indication comprises an exterior rear view mirror housing and an exterior rear view mirror disposed in the exterior rear view mirror housing. The exterior rear view mirror defines a portion from which light is reflected and a portion through which light may be transmitted from inside the rear view mirror housing. A light source mounted within the housing is located at the light transmissive portion of the mirror and a directional filter located at the light transmitting portion of the mirror filters light emitted by the light source so that a signal from the light source may be seen from the interior of the vehicle, but may not be seen by drivers of other vehicles.

Abstract: A display having a diffraction grating pattern includes:(a) a flat substrate; and(b) at least one dot formed on a surface of the flat substrate, the dot being formed by a diffraction grating pattern as an aggregate of a plurality of curves obtained by translating a curve.

Abstract: A high finesse holographic Fabry-Perot etalon and method of making a high finesse holographic Fabry-Perot etalon is disclosed. Particularly, a holographic Fabry-Perot etalon which achieves high finesse despite non-flat interfaces between the etalon media is presented. In a preferred method of fabricating a high finesse Fabry-Perot etalon, single step recording of both holograms simultaneously, with the spacer and substrates in place, is employed which preserves full phase synchronization between the holograms. In spite of imperfections or irregularities of the interface surfaces of the substrates or spacers, the holographic fringes in the holograms remain flat even for slightly different refractive indices between the various media. The position and flatness of the fringes remains similar to perfect Fabry-Perot etalon structure.

Abstract: A light confining cavity collects much of the radiation reflected by a receiver, absorbing it imperfectly, and casts it again on the same receiver or on other receivers by means of an optical system. Only light in a bundle of rays of limited angular spread can escape from this cavity, which allows an entry aperture relatively large. Thus, the irradiance at the entry aperture may be low, and in some cases even lower than the irradiance at the absorber. In this way the requirements for the cavity materials and for the concentrating system feeding light to the cavity can be relaxed. The invention is of special interest in photovoltaic conversion devices because it improves the absorption of the solar cells and achieves higher conversion efficiency for photons of different energies by using solar cells of different materials.

Abstract: An etalon (10) is provided with a coating (12) so as to selectively pass spectral lines of interest. The etalon includes a substrate (14) having a first major surface and a second, opposite major surface. The etalon further includes a coating, preferably a rugate coating (12), formed upon at least one of the major surfaces. The rugate coating has a spatially varying index of refraction profile through a depth thereof. The profile is selected so as to provide the element with a prescribed dispersion characteristic that matches a dispersion characteristic of a source of the radiation signal.

Abstract: A method and apparatus for highly efficient use of higher-order diffraction beam in holography. The thermoplastic hologram (10) is recorded at a recording angle (.theta..sub.R) between two coherent beams (12, 14) equal to a first-order diffraction angle (.theta..sub.1) corresponding to the angle (.theta..sub.2) of the desired higher-order beam (18) set to the angular peak (22) of diffraction efficiency (20) of the material of the hologram. On read-out, the desired higher-order beam is read. By use of the invention, the intensity of a higher-order beam can be tuned and made nearly equal to that of the first-order beam. Thereby, useful non-linear holographic systems, such as an associative memory (FIG. 4), can be practically implemented.

Abstract: A shatter resistant mirror includes a frangible mirror material for reflecting an image which has a coating of an elastic adhesive material which bonds a rigid backing material to the frangible mirror body. In a preferred embodiment of the invention, the adhesive was one of a water-based synthetic polymeric material or a hot melt pressure sensitive adhesive. The rigid support member preferably is a fiberboard material. In some embodiments of the invention, the composite mirror structure includes multiple layers of composite fiberboard material to provide spacing for mounting the mirror in a particular application.

Abstract: An afocal lens assembly which includes a first and second lens group used r testing an infrared detector assembly. The first lens group includes three lens elements and the second lens group includes four lens elements. The output of the lens assembly includes up to a 60 degree collimated field-of-view. The lens elements are infrared transmissive.

Abstract: An item is described which renders a pair of eyeglasses more comfortable to the wearer. The item prevents eyeglasses from falling down on the nose of the wearer and thus promotes easier breathing. Glasses feel lighter to the wearer because the item lifts glasses away from the cheeks. Additionally, The item is adjustable to a position opposite the eyes for better vision.

Abstract: A reticle and a method of fabricating the samer for projecting a fine pattern on an object surface comprises: a. transparent substrate; a first type phase-shifter selectively patterned and deposited on the substrate producing a phase difference between the light passing therethrough and the light passing through the other areas without phase-shifter; and a second type phase-shifter selectively patterned and forming a groove in the substrate producing a phase difference between the light passing therethrough and the light passing through the other areas without phase-shifter. The reticle may include a patterned shield layer which interrupts transmission of light, and the phase difference of the first and second type phase-shifters is many times selected substantially equal to a half wavelength of light. Another type of a reticle comprises: a transparent substrate; a phase-shifter of a first groove; and another phase-shifter of a second deeper groove formed in the first groove.

Abstract: The invention provides an improved standardized blank adapted for making taps for making tapped holes and an improved positive lock tap holder. A standardized tap blank is provided which is standardized as to diameter, overall length, and shank length. Such a blank is adapted to manufacture a wide range of taps of varying thread sizes, both U.S. and British standards, and metric standard. For broadening the range of capacities that the blanks are adapted for, a set is provided including two additional standardized blanks, standardized as to a different diameter shank length and overall length. Each standardized blank is provided with a square end, standardized as to the square sides and overall length. The standardized tap blanks are further provided with an annular groove to for holding balls.

Abstract: An illuminating reflection apparatus including a light source having a light emitting portion, a main mirror for reflecting light emitted from the light source toward an illuminating area, and an auxiliary mirror for reflecting light emitted from the light source toward the main mirror. The light source and the auxiliary mirror are correlated so that light emitted from the light emitting portion and reflected by the auxiliary mirror is returned to the light emitting portion.