Abstract: The invention relates to lenses such as aspherical lenses and to a process for their manufacture. According to the invention, the lens is composed of a glass matrix including the constituents below in the following weight proportions:______________________________________ SiO.sub.2 65-85% Al.sub.2 O.sub.3 0-10% B.sub.2 O.sub.3 0-20% Li.sub.2 O + Na.sub.2 O + K.sub.2 O 3-20% CaO + MgO + BaO 1-15% FeO + Fe.sub.2 O.sub.3 0-0.1%, ______________________________________wherein the K.sub.2 O content is equal to or less than 1% and the BaO content is equal to or less than 1%.

Abstract: An optical element is disclosed comprising an upper portion (9) and a lower portion (8) defined in opposite parts with respect to a median line (x--x) passing through the geometric center (C.sub.1, C.sub.2) of the optical element, wherein the factor of luminous transmittance is between 30% and 80% in the lower portion (8) and between 3% and 40% in the upper portion (9). Advantageously, furthermore, the curve of spectral transmittance as a function of the wavelength in the lower portion (8) and at a distance of at least 10 mm from the median line (x--x) is such as to show: a minimum in a wavelength range of from 495 to 510 nm, ii) an increase in spectral transmittance at wavelengths lower than 495 nm and higher than 510 nm, iii) a maximum at a wavelength lower than 440 nm, iv) a reduction in the spectral transmittance as the wavelength decreases starting from said maximum.

Abstract: A polarizing film or composite which can eliminate glare of the light reflected by an object and passing therethrough while maintaining the original color of the object. The polarizing film is color-adjusted so that the color coordinates L, a and b in the UCS color space, where L is the color brightness divided into 0 to 100 sections and in terms of tristimulus values X, Y and Z in the standard colorimetric system CIE, L=100Y.sup.1/2, a=175 (1.02X-Y) Y.sup.1/2, b=70 (Y-0.847Z) y.sup.1/2, will be 22.ltoreq.L.ltoreq.70, -2.0.ltoreq.a.ltoreq.2.0, -2.0.ltoreq.b.ltoreq.2.0, that the light transmittance in the wavelength range of 410-710 nm will be within +30% of its average, and that the light transmittance in the wavelength range of 410-750 nm will be not more than 2% when two of said polarizing films are put one upon the other so that their polarizing axes extend perpendicularly to each other.

Abstract: An optical lens system includes a multi-element lens designed to maximize light collection efficiency and transmission but accepting a sufficiently high level of distortion to forego the system from imaging light patterns at each of a set of wavelengths at which the patterns are being emitted from a planar source simultaneously. The system also illustratively includes a cooled CCD camera with a dewar and filter assembly which is movable along the optic axis of the system to specified positions for selecting a particular wavelength at which an image is in focus so that the light pattern (image) at each different wavelength can be captured at a different time. A CCD camera is used to capture the image and the camera controller includes software to reduce the amount of distortion introduced by the lens.

Abstract: The invention relates to a variable transparency electro-optical device comprising: at least one lens formed by an electro-optical cell (4) comprising a first plate (6) and a second plate (8) each provided with a control electrode (14, 16) and a sealing frame (10) interposed between the two plates to form a sealed volume enclosing an electro-optical material (12), voltage generating means (18) connected to said electrodes to apply a variable voltage to said material in order to automatically or manually vary the transmission of the cell (4) as a function of the ambient light. According to the invention the cell (4) comprises at least one element (6) charged with a photochromic substance having an absorption that varies in reversible manner as a function of the intensity of the light impinging on said cell. The invention has particular applications in devices for protecting the eyes.

Abstract: Disclosed is a method of preparing refractive microlenses in a single step, utilizing laser-induced surface structure formation in semiconductor doped glasses (SDGs). The SDG materials, in conjunction with above-bandgap wavelength laser sources, are used to fabricate lenses that operate with light of below-bandgap wavelengths. In accordance with the teaching of this invention lenses on an approximately 5-500 .mu.m diameter scale are fabricated individually or in arrays by laser irradiation of absorbing glasses. The microlenses have controllable characteristics and can be fabricated to have focal lengths as short as tens of microns. The lenses are generally parabolic or spherical in shape and are highly reproducible.

Abstract: A radiation device for therapeutic use in the human body allows the application of light waves to an affected area of the body. A bulb, preferrably a xenon bulb, produces light which is passed through a lens module having silicon and carbon granules therein. By applying different lenses to the device, a variation in the wavelengths of light and radiation applied to an area is achieved. The device has a pistol-like housing to allow for controlled application of the radiation.

Abstract: A two-wavelength antireflection film includes a substrate and an alternate film. The alternate film consists of alternately laminated layers of a low refractive index material and an intermediate refractive index material, in order from a light entrance side to the surface of the substrate. The low refractive index material is at least a member selected from the group consisting of MgF.sub.2, SiO.sub.2, BaF.sub.2, LiF, SrF.sub.2, AlF.sub.3, NaF, a mixture thereof and a compound thereof. The intermediate refractive index material is at least a member selected from the group consisting of Al.sub.2 O.sub.3, LaF.sub.3, NdF.sub.3, YF.sub.3, a mixture thereof and a compound thereof.

Abstract: Apparatus for obtaining a desired tint, which apparatus uses a light source to provide a gamut of colours. The apparatus comprises wheel and paddle (34,60) which enable a tint to be obtained from such light in such a manner that the hue and saturation of the tint can be varied substantially independently of one another, whilst maintaining a given brightness. The invention extends to a method using such apparatus, and to equipment comprising a set of coloured filters, and also to a method in which a tint created by a combination of filters selected from a set of filters is varied, by removal, addition, or replacement of one or more filters of the combination, to match the selected tint, and finally to the making of lenses using such methods, and the lenses themselves.

Abstract: A novel low-cost solar photovoltaic module using line-focus lenses and photovoltaic receivers incorporating high-performance photovoltaic cells is described. It consists of an array of linear arched Fresnel lenses with a linear photovoltaic cell receiver located along the focal line of each lens. The lens consists of a protective superstrate with molded silicone Fresnel grooves on its inner surface. The photovoltaic cell receiver consists of high efficiency cells interconnected in a string with a solid secondary optical element adhesive bonded to the cells. The entrance aperture of each secondary optical element is rectangular in shape and the optical secondaries are butted up against each other in a line to form a continuous entrance aperture along the focal line. In addition to providing more concentrated sunlight, the solid optical secondaries shield the cells against radiation damage.

Abstract: An extreme wide angle, very large aperture, very compact, solar blind, UV imaging lens system. The lens system has a fused silica polyvinyl alcohol glass color filter, a lens made of fused silica, a lens made of nickel sulfate, a layer of coupling fluid and another lens made of fused silica. Alternatively, sapphire can be used after the color filter instead of the fused silica. An alternative lens is composed of two layers of fused silica, a layer of nickel sulfate, another layer of fused silica, coupling fluid followed by polyvinyl alcohol, a color glass filter and coupling fluid followed by fused silica. In a fourth embodiment, the two layers of fused silica are followed by polyvinyl alcohol, a layer of colored glass filter, fused silica, nickel sulfate, coupling fluid, and fused silica.

Abstract: An electronic image pickup apparatus comprising an imaging optical system for forming images of an object and image pickup device having light receiving surface configured so as to sample the images at discontinuously distributed points. This image pickup apparatus functions to sample the images of the object formed by the imaging optical system while receiving the images on the light receiving surface of the image pickup device and output signals representing light intensities on the object side. Disposed in the imaging optical system is a refracting surface which produces the optical low pass effect and has a shape capable of exhibiting an effect to eliminate moire, for example, due to a fact that it includes a point on which differential coefficients of a function expressing a shape of the refracting surface are discontinuous.

Abstract: A lens (10) that substantially blocks horizontally polarized light and selectively blocks wavelengths between 300 and 549 nanometers. The selective blocking is controlled by a sharp cut-on filter (14) selected to cut-on at either 450, 500, 515, 530, or 550 nanometers. The specific blocking and cut-on point selected is dependent upon the ultimate usage/environment of the lens (10). If a 450 cut-on filter is selected, wavelengths between 300 and 449 nanometers are blocked before a cut-on occurs at 450 nanometers; similarly, a 550 cut-on filter blocks wavelengths between 300 and 549 nanometers before a cut-on occurs at 550 nanometers. The lens (10) also allows 30 to 40 percent of wavelengths over 625 nanometers to be transmitted. The filter (14)in combination with the polarizer (16) blocks harmful Ultraviolet radiation and blue light.

Abstract: Multilayers of low refractive index amorphous silicon nitride and high refractive index amorphous silicon are interleaved to construct a near-infrared optical filter. For an edge filter, the structure is transparent to near-infrared light and opaque to visible light. For a band-pass filter, the low-pass filter is superimposed with a high-pass filter. Anti-reflection coating can be added to improve the transmittance. These multilayers are deposited with Plasma Enhanced Chemical Vapor Deposition technique.

Abstract: A method and apparatus for smoothing and homogenising the cross-sectional intensity distribution of the output from an excimer laser for improved application of excimer lasers to optical laser surgery to the cornea. The laser beam is focused by means of a cylindrical lens or mirror and then filtered using a narrow gap spatial filter to smooth the intensity distribution by removing high spatial frequencies. The resulting output beam may be collimated by means of a second cylindrical lens or mirror for application to further optical processes.

Abstract: A superachromatic focusing objective lens which focuses wavelengths extending between the ultraviolet and the visible wavelength spectrum and is able to achieve superachromatic correction for three wavelengths within the visible spectrum is disclosed. The present objective lens includes an achromatic lens to assist in the correction spherical and coma aberration, a modified gauss for minimizing spherochromatism, a reversed modified gauss for adding symmetry to aid in the correction of coma, distortion and lateral color aberrations, and a stop located between the modified gauss and the reverse modified gauss. A glass plate is provided for forming a splatter shield to protect the lens from debris, and may be used to define one wall of a vacuum chamber. The elements of the objective lens may be made from various glasses to include calcium fluoride, quartz, and barium fluoride.

Abstract: Selective light-transmitting filters for use with catadioptic area-of-interest display projectors and projection system provide complementary filters for two or more persons. One of the complementary filters permits all radiance at one predetermined, desired wavelength to be transmitted while rejecting or absorbing all others. The complementary filter for a second viewer transmits substantially all radiance at a second predetermined desired wavelength and absorbs or reflects all others, thus permitting each viewer to see only predetermined, desired displays or parts of a display that are projected simultaneously within the system.

Abstract: A device for microscopic sectioning and imaging of an object specimen illuminated with light comprises an objective lens, a diaphragm, and a pixel filter array. The objective lens focuses light from the object specimen to an image focal plane. The diaphragm blocks a portion of the focused light from the objective lens thereby creating a shadow. Each pixel filter in the pixel filter array has an axis and is arranged so as to cooperate with the shadow so that light from an object focal plane and parallel to the pixel filter axes reaches an output image plane.

Abstract: A real image type view finder comprising at least one cemented lenses. Of the lens components constituting the cemented lens, a lens component is made of resin. The lens component may be made of material of high transmittance to ultraviolet rays.

Abstract: An optical system for use in a medical laser apparatus comprising an achromat having optical elements selected to cause two substantially different wavelengths, one visible and one infrared, to focus at a common focal point. The achromat comprises a negative lens and a doublet lens formed of a positive bi-convex lens and a negative meniscus lens. The materials of the two lenses which form the doublet have substantially different dispersions and indices of refraction and are chosen to cause a visible helium neon beam and an infrared carbon dioxide beam to focus at the same point. In the preferred embodiment of the present invention, the negative lens is made of zinc selenide, the bi-convex lens of the doublet is made of potassium chloride, and the negative meniscus is made of zinc selenide. The optical system of the present invention can be mounted in a micromanipulator for use in laser surgery.

Abstract: A ghost image eliminating optical system in a transmission optical system including a plurality of transmission optical elements having boundary reflection surfaces, so that a ghost image can be formed by light reflected by at least two specific boundary reflection surfaces, wherein the specific boundary reflection surfaces are coated with at least two anti-reflection coatings having complementary reflection characteristics to eliminate the ghost image.

Abstract: A filter is provided for blocking a major portion of the light impinging thereon but transmitting three narrow spectral pass bands of light having selected wavelengths. The number of pass bands and the wavelengths included in each pass band are selected in accordance with environmental or military conditions dictating the wavelengths of light that need to be filtered. The transmitted narrow spectral pass bands preferably are spaced approximately equally about the CIE chromaticity diagram. The resulting filter enables exceptional seeing and color differentiation while positively blocking broad ranges of potentially injurious light from passing therethrough.

Abstract: An entrance slit and exit slit of a monochromator is shaped so that the width of the slits becomes smaller from the center towards the ends of their height, where the width is a dimension in the direction of the separation of the light in the monochromator. An example of such shape is rhombic. When the total amount of light emitted from the monochromator and the resolution of the monochromator are set to be the same, the efficiency of light in measuring small samples is increased and the ratio of stray light in the light emitted from the monochromator becomes smaller.

Abstract: An optical system (10) for producing dual fields of view simultaneously. The system (10) includes a first optical system (12) for producing a first field of view image and a second optical system (36) for producing a second field of view image where the angular displacement of the second field of view is different from that of the first field of view. A dichroic beamsplitter (22) is disposed in the present invention so as to reflect light from the first optical system (12). The dichroic beamsplitter (22) is also disposed so as to simultaneously transmit light from the second optical system (36). As a result, the reflected light (20) is primarily composed of light of a first wavelength band and the transmitted light is primarily composed of a second wavelength band. The light from the two different fields of view are then directed to a dual filter (32) which passes the first wavelength band in one portion and passes the second wavelength band in another portion.

Abstract: A color enhancing sun lens comprising a lens having an integrated visible light transmission, with respect to CIE illuminant C, of less than 40% T, wherein the transmission over a 10 nm wide band centered on 480 nm and a second 10 nm wide band centered on 630 nm is at least 1.5 times the integrated visible light transmission of the lens.

Abstract: Provided are optical shaped articles for CRT, such as projection lens and filter used for the CRT's of projection TV's, which comprise a transparent synthetic resin containing a red dyestuff or a combination of a green organic pigment and a yellow dyestuff and having specified spectral transmittance characteristics.

Abstract: In a projection type television apparatus, a first and a second color selecting device are located on an optical light path passing through a cathode ray tube and a series of projection lenses are disposed in front of the cathode ray tube without a color selecting device therein. The first color selecting device has a high refractive factor to light having a wavelength of 570nm or more and the second color selecting device has a high reflection factor or a high absorption factor to light having a wavelength of 520nm or less. With this color selecting device, the range of color reproduction can be much more improved. This thus causes an increased degree of color purity of green light at the central and peripheral areas of the cathode ray tube. Moreover, with this arrangement, it becomes easy to conserve the characteristic of the color selecting devices and to facilitate the manufacturing operation.

Abstract: Light filter apparatus for receiving a light beam having wavelengths in a selected band and for dispersing the light into a plurality of rays, with each ray having a different wavelength for which the intensity peaks. The peak wavelength varies approximately continuously with displacement of spatial position in a chosen direction along the filter's light-receiving plane. In one embodiment, the filter is a modified etalon structure having at least two reflecting surfaces whose separation distance is not constant but increases or decreases monotonically with distance in a chosen direction in a light-receiving plane of the etalon. Each of these two reflecting surfaces may be planar or non-planar but continuous, or may have a step or staircase configuration. This structure may operate using transmitted light or reflected light.

Abstract: Disclosed is an improved color projection TV lens system which provides reduced chromatic aberration and improved chromaticity. These improvements are achieved by incorporating a light absorbing material into at least one lens in the system wherein the lens has a substantially uniform thickness.

Abstract: The present invention is directed to a medium incorporating melanin for radiation protection.