Abstract: A method for fabricating three-dimensional microstructures is presented. The method includes: disposing a substantially planar reflow material between two molds; heating the reflow material while the reflow material is disposed between the two molds; and reflowing the reflow material towards the bottom surface of one of the molds by creating a pressure gradient across the reflow material. At least one of molds includes geometrics features that help to shape the reflow material and thereby form a complex three-dimensional microstructure.

Abstract: Digital cameras, optical lens modules for such digital cameras and methods for assembling lens elements in such lens modules. In various embodiments, the digital cameras comprise an optical lens module including N?3 lens elements Li, each lens element comprising a respective front surface S2i?1 and a respective rear surface S2i. In various embodiments the first lens element toward the object side, L1 and its respective front surfaces S1 have optical and/or mechanical properties, such as a clear aperture, a clear height and a mechanical height that are larger than respective properties of following lens elements and surfaces. This is done to achieve a camera with large aperture stop, given a lens and/or camera height.

Abstract: A method of manufacturing a glass molded product includes the steps of preparing a lower die including a lower die surface and a space forming surface formed to extend downward away from an outer edge end portion of the lower die surface with the outer edge end portion being defined as a starting point, preparing an outer frame including an annularly formed inner circumferential surface, arranging the lower die on an inner side of the outer frame, dropping a prescribed amount of molten glass droplet onto the lower die surface such that a surface of the molten glass droplet connects the outer edge end portion and a portion of the inner circumferential surface located above a position of the outer edge end portion to each other and the molten glass droplet does not wet-spread over the space forming surface, and pressurizing and molding the molten glass droplet.

Abstract: A lens cap for an optical module includes: a barrel of a metal material; and a press lens of glass and held in the barrel. The coefficient of linear expansion of the glass is 6 to 8 ppm/K, and the coefficient of linear expansion of the metal material is at least 10 ppm/K at 150° C. to 800° C. and no more than 8 ppm/K at up to 100° C. or below.

Abstract: To produce a meniscus lens from synthetic quartz glass for use in a microlithography apparatus, which lens has a first optical surface (7) and a second optical surface (8) with the same direction of curvature as the first optical surface (7), SiO2 particles are formed by oxidation or flame hydrolysis of a silicon-containing starting compound and deposited layer by layer on a substrate to form a cylindrical SiO2 blank which contains layers with a surface normal extending in the direction of growth. To allow such layers, which have however the least possible adverse effect on optical or mechanical properties, it is proposed according to the invention that the blank is plastically worked in a hot forming process under the effect of a deforming force to form a preform (6), which has at least the first curved surface (7) and in which the layers are curved in the direction of curvature, and that the meniscus lens is obtained from the preform.

Abstract: A rod lens and methods for producing such a rod lens are disclosed. The rod lens and methods include a sealing glass and holder glass or a metallic holder that are heated so that only the sealing glass melts and forms a spherical cap to define a lens element joined to a light guiding element. A plurality of rod lenses may form an array arrangement.

Abstract: A method of producing an optical element, in which a first and a second die are cooperated with each other so as to press-mold a material in order to produce an optical element including a lens portion, the first die has a circular cross-sectional shape, and the second die defines therein an interior space having a polygonal cross-sectional shape with respect to the direction of die-fastening, the first die is adapted to enter into the interior space of the second die in the direction of die-fastening in the interior space so to press-mold the material in order to form the lens surface while the material is bulged out through gaps between the first die and the second die around the lens surface whereby forming protrusions. An optical element and a mold assembly for an optical element are also provided.

Abstract: An imaging lens SL installed in a single-lens reflex digital camera includes, in order from an object side, a first lens group G1, and a second lens group G2 having positive refractive power. The first lens group G1 includes, in order from the object side, a first lens component L11 having a negative meniscus shape with a convex surface facing the object side, a second lens component L12 having a negative meniscus shape with a convex surface facing the object side, and a third lens component L13. The third lens component L13 includes a double concave lens to the most object side. The imaging lens SL includes at least six lens components or more, thereby providing a sufficiently fast imaging lens having excellent optical performance, which is a large aperture, single-focal-length, wide-angle lens having an aspherical surface.

Abstract: Optical qualities of a production lot of base material used in the fabrication of semi-finished lenses may be accurately determined by employing chipper plate samples produced from the base material in accordance with aspects of the present invention. In various implementations of the present invention, the chipper plates samples may be fabricated by subjecting base material to an extended cycle time and temperature profile using a mold having cavities of different thicknesses. The resulting chipper plates provide an improved indication of the color of semi-finished lenses molded from the production lot as well as an improved indication of resin stabilizer defects that may be utilized during a pelletizing process to control and enhance the quality of a production lot. Furthermore, the chipper plates may be provided by suppliers as samples of a production lot to enable customers to base purchasing decisions on a reliable and accurate measure of optical properties.

Abstract: In a bonded optical element, a second optical element is bonded to a first optical element by forming the second optical element by heating and pressing against the first optical element a second optical element material. The first optical element is a concave lens. A bonded face of an intermediate portion between a lens portion and an edge portion of the first optical element is substantially in an R shape in section.

Abstract: A second optical element is bonded to a first optical element by forming the second optical element by pressing a second optical element material against the first optical element under a condition free from restriction to the second optical element material in the direction orthogonal to a direction in which the second optical element material is pressed.

Abstract: Disclosed is a method for producing single microlenses or an arrays of microlenses composed of a glass-type material, in which method a first substrate is provided with a surface containing impressions over which a second substrate composed of a glass-type material is placed at least partially overlapping it and is joined therewith under vacuum conditions. The substrate composite is tempered in such a manner that the second substrate softens and flows into the impressions of the first substrate, thereby structuring the side of the second substrate facing away from the first substrate in order to form at least one microlens surface.

Abstract: Disclosed is a method for producing single microlenses or an arrays of microlenses composed of a glass-type material, in which method a first substrate is provided with a surface containing impressions over which a second substrate composed of a glass-type material is placed at least partially overlapping it and is joined therewith under vacuum conditions. The substrate composite is tempered in such a manner that the second substrate softens and flows into the impressions of the first substrate, thereby structuring the side of the second substrate facing away from the first substrate in order to form at least one microlens surface.

Abstract: A method of manufacturing a microlens substrate having a plurality of microlenses includes the steps of: preparing a substrate having two major surfaces and a plurality of concave portions formed in one of the two major surfaces, each of the concave portions having a shape corresponding to that of each of the microlenses being formed in the one of the two major surfaces of the substrate; preparing a base material substrate formed of glass having a transformation point lower than that of a constituent material constituting the substrate; and pressure-joining the substrate to the base material substrate in a heating state. In the pressure-joining step, the substrate is joined to the base material substrate and the concave portions fill with the glass material of the base material substrate which is melted by the heat.

Abstract: A method for producing an optical lens unit, the optical lens unit including a lens and a metallic lens barrel that holds the lens therein, includes forming the lens barrel so as to be a hollow cylinder and so as to have an inclined surface, formed on the inner wall of the lens barrel, extending from a position adjacent to a first opening to a position adjacent to a second opening and being tilted at a tilting angle ranging from 10° to 20°; and placing a spherical lens base on the inclined surface formed on the inner wall of the lens barrel, heating the lens base in this state such that the lens base is bonded to the inner wall of the lens barrel by pressure, heating the lens base again, and shaping lens surfaces adjacent to the openings of the lens barrel.

Abstract: A cylindrical holder material having a thin deformed portion is located in a press forming die. An optical element material is installed inside the holder material and the holder material and the optical element material are heated to their respective softening temperatures, thereby forming a cylindrical holder from the holder material and an optical element from the optical element material by press forming the holder material and the optical element material that have been heated to their respective softening temperatures. Thus, the optical element is integrated inside the holder and the deformed portion of the holder is deformed towards the outside thereof by a pressing force applied by the optical element.

Abstract: A glass molding machine includes a shaping die, a temperature controller, a die assembling state, a glass molding stage and a die disassembling stage. The shaping die includes a first, second and body molds. The die assembling stage feeds a glass material to the first mold with the body mold being fitted to the exterior of the first mold. The die assembling stage fits the second mold to the body mold to assemble the shaping die. The glass molding stage heats and molds the glass material. The die disassembling stage removes the second mold from the body mold after the molding, to remove the molded glass product. The temperature controller provides a temperature difference so that a temperature of the body mold is higher than a temperature of the second mold in the die assembling stage and in the die disassembling stage.

Abstract: The invention relates to a method of manufacturing an optical element with a lens barrel, in which an optical raw material is placed on a placement portion projecting toward the center of the lens barrel from the inner peripheral surface thereof, and assuming that a distance between the opposing ends of the projection of the placement portion is L1, the outside diameter of the optical raw material is L2, the inside diameter of the lens barrel portion which is positioned close to and above the placement portion and to which the perimeter of the optical element obtained after forming is joined is L3, and the inside diameter of the smallest opening on the upper end side of the lens barrel is L4, design is performed to satisfy a relation of L1<L2<L3<L4.

Abstract: The invention relates to a method of manufacturing a front-end optical component of an endoscope realizing resistance to humidity. In the method of manufacturing a front-end optical component in which a lens is mounted on the front end of a metallic lens-barrel provided on the front end of the inserting portion of an endoscope, the configuration is made such that a lens raw material is placed on the front-end side in the lens-barrel, the lens raw material is press-formed in a heat-softened state with a pair of upper and lower shaping dies, thereby tightly joining the outer edge of the pressed lens raw material to the inner peripheral surface of the lens-barrel.

Abstract: A metal ring for an optical element that is served to cover a peripheral side surface of a lens and served to fix the lens to a mounting member by means of soldering is provided with a thin-wall sleeve a diameter of which is expanded toward a peripheral direction by means of pressure received from an optical material disposed inside the metal ring to thereby obtain a final peripheral side surface size, a thin-wall portion having an inside periphery near an extension of an inside peripheral surface of the thin-wall sleeve on one of apertures of the thin-wall sleeve, and a holding portion comprising a flange that projects from an edge of the aperture toward the aperture. A metal ring for an optical element, a method for fabrication of the optical element having the metal ring, and an optical element having a metal ring of the invention employ the abovementioned metal ring.

Abstract: A method for making a holder/optical-element assembly includes the steps of positioning a cylindrical holder material in a press-molding die, the holder material having a void part in the inner circumferential surface, positioning an optical-element material inside the holder material, heating the holder material and the optical-element material to their own softening temperatures, press-molding the holder material and the optical-element material to form a cylindrical holder and an optical element, respectively, thereby fixing the optical element to the inside of the holder, allowing a part of the optical element to project outwardly from the outer edge by pressure created during press-molding, and retaining the projected portion in the void part of the holder.

Abstract: Provided are a process for the production of a precision press-molded article having a high transmittance and a method of treating a glass to color or decolor the glass, the process comprising heat-treating a press-molded article containing at least one selected from WO3, Nb2O5 or TiO2 in an oxidizing atmosphere to produce a glass molded article, and the method comprising heat-treating a colored glass containing at least one oxide of WO3 and Nb2O5 in an oxidizing atmosphere to decolor the glass, or heat-treating a glass containing at least one oxide selected from WO3, Nb2O5 or TiO2 in a non-oxidizing atmosphere to color the glass.

Abstract: A method for molding a chalcogenide glass lens includes providing a mold. A preformed lens of chalcogenide glass is placed within the mold. The lens has a top surface and a bottom surface. An amount of chalcogenide glass is deposited within the mold and on the top surface of the preformed lens. The mold is heated, such that the chalcogenide glass on the top surface of the preformed lens softens, melts, and bonds to the top surface of the preformed lens. A lens surface is formed in the melted chalcogenide glass to form a molded lens which is bonded to the top surface of the preformed lens. The molded lens and preformed lens assembly is then removed from the mold.

Abstract: A lens is fitted into a metal ring that covers the outer peripheral surface of the lens and can be soldered to a fixture member. The side cylindrical part of the metal ring is expanded toward the outer peripheral direction thereof by the pressure of the optical material put inside it, and, thus expanded, it defines the final dimension of the metal ring. One of the two openings formed on both sides of the side cylindrical part of the metal ring is so designed as to have a curving cylindrical part that extends from the side cylindrical part, and this curving cylindrical part is folded toward the optical functional face of the optical device to construct a metal ring-fitted optical device.

Abstract: The invention relates to a method of manufacturing an optical element with a lens barrel, in which an optical raw material is placed on a placement portion projecting toward the center of the lens barrel from the inner peripheral surface thereof, and assuming that a distance between the opposing ends of the projection of the placement portion is L1, the outside diameter of the optical raw material is L2, the inside diameter of the lens barrel portion which is positioned close to and above the placement portion and to which the perimeter of the optical element obtained after forming is joined is L3, and the inside diameter of the smallest opening on the upper end side of the lens barrel is L4, design is performed to satisfy a relation of L1<L2<L3<L4.

Abstract: The invention relates to a method of manufacturing a front-end optical component of an endoscope realizing resistance to humidity. In the method of manufacturing a front-end optical component in which a lens is mounted on the front end of a metallic lens-barrel provided on the front end of the inserting portion of an endoscope, the configuration is made such that a lens raw material is placed on the front-end side in the lens-barrel, the lens raw material is press-formed in a heat-softened state with a pair of upper and lower shaping dies, thereby tightly joining the outer edge of the pressed lens raw material to the inner peripheral surface of the lens-barrel.

Abstract: An optical member having a toric functional surface has a marking which is made by a configuration of a mold used to form the optical member. The marking is formed in the optical member outside an effective area of the functional surface of the optical member. In one embodiment, the optical member is an optical member for a scanning optical system.

Abstract: A metal ring for an optical element that is served to cover a peripheral side surface of a lens and served to fix the lens to a mounting member by means of soldering is provided with a thin-wall sleeve a diameter of which is expanded toward a peripheral direction by means of pressure received from an optical material disposed inside the metal ring to thereby obtain a final peripheral side surface size, a thin-wall portion having an inside periphery near an extension of an inside peripheral surface of the thin-wall sleeve on one of apertures of the thin-wall sleeve, and a holding portion comprising a flange that projects from an edge of the aperture toward the aperture. A metal ring for an optical element, a method for fabrication of the optical element having the metal ring, and an optical element having a metal ring of the invention employ the abovementioned metal ring.

Abstract: A method for fabricating a mold tool for molding optical elements is taught which comprises heating a mold tool blank made from a vitreous material to a temperature above the glass transition temperature of the vitreous material; generating an axial viscosity gradient in the mold tool blank; pressing a punch into an optical quality mold surface of the mold tool blank, the punch including a pressing surface with a predetermined geometry for forming an optical feature; cooling the mold tool blank to a temperature below the glass transition temperature of the material; and removing the punch from the mold tool blank thereby creating the optical feature in the optical quality mold surface. The axial viscosity gradient is achieved by creating an axial thermal gradient.

Abstract: It is an object of this invention to provide a molding apparatus capable of obtaining an optical element of which both an optical functional surface and a lens mounting reference can be molded simultaneously and which has an appropriate lens thickness. In order to achieve this object, the apparatus includes a lower mold having one molding surface on its upper surface, a lower periphery regulating member for fitting on an outer surface of the lower mold to regulate an excess of a glass material swelling outward from the molding surface of the lower mold, an upper mold having the other molding surface on its lower surface, and an upper periphery regulating member for fitting on an outer surface of the upper mold to regulate the excess of the glass material swelling outward from the molding surface of the upper mold.

Abstract: A method for producing a silica glass for photolithography, which comprises the following steps: jetting a starting material gas, an oxygen gas and a hydrogen gas from a burner and depositing and consolidating silica glass powder on a target to form an ingot having a growing direction, where the ingot is grown in such a manner that at least a part of glass synthesis face on the ingot having the silica glass powder deposited and consolidated is a plane substantially perpendicular to the growing direction of the ingot, thereby to obtain the ingot having a portion in which striae are substantially perpendicular to the growing direction of the ingot; and cutting out of the ingot the portion in which the striae are substantially perpendicular to the growing direction of the ingot, thereby to obtain a silica glass having striae which are substantially parallel to each other and are planar.

Abstract: A method of molding a glass element in which a glass material is heated and then press-molded between an upper mold and a lower mold when a temperature of the heated glass material reaches a predetermined temperature. A first cooling of the glass element is performed with the glass element in contact with the pair of molds until a temperature of the glass element is within a range of .+-.20.degree. C. of a glass transition point of the glass material while a pressure applied to the glass element by the upper and lower molds is gradually reduced until the pressure becomes 0 kg/cm.sup.2. Subsequently, a second cooling of the glass element is performed without the upper and lower molds contacting the patterned surface on the glass element. The upper mold has a bottom surface and a sidewall surface with a lowermost end portion of the side wall surface, adjacent the bottom surface, being inclined with respect to a central axis of the upper mold.

Abstract: A lens device which can be used as an objective lens in an optical pickup apparatus includes an objective lens provided along a light path facing a disc and having a predetermined effective diameter, and light controlling means provided along the light path for controlling the light in an intermediate region between near and far axes of an incident light beam, thus providing a simplified and inexpensive device for using discs of differing thickness in a single disc drive, by reducing the spherical aberration effect.

Abstract: Method and apparatus for producing vitreous optical elements by injection molding, which essentially includes the stages of: melting down a glass material into a molten state in a viscosity at or lower than a working point of the glass material; injecting molten glass under pressure into a mold cavity defined between transfer surfaces of relatively movable mold members of a mold assembly unit in communication with a sprue connecting the mold cavity with an injection port on the outer side of the mold assembly unit; and applying a predetermined pressure on the glass material in the mold cavity while cooling the mold assembly unit down to a temperature in the vicinity of yielding point of the glass material.

Abstract: A glass preform, including a core glass adversely affected by interaction with a molding tool, is provided with a thin surface layer of glass components that are inert to the tool and have an index of refraction that matches the core glass. More specifically, the thin layer comprises glass components having respective indexes of refraction above and below the core index of refraction, in an amorphous mixture that matches the core index. According to certain features, the core glass is flint glass including greater than five percent by weight of titania, and the glass components include mixtures of silica or indium and tin oxide applied in a layer having a thickness between one hundred and one thousand angstroms. Other features of the invention provide a method for making the glass preform and a method for molding a precision optical element using the preform.

Abstract: Methods of making gradient property refractive elements such as gradient index lens blanks. The spatial distributions of constituents achieved by subjecting various starting assemblages to various diffusion conditions are predicted. Each such predicted spatial distribution of constituents is converted to a spatial distribution of the graded property. The property distribution which best approximates a desired distribution is selected, to thereby select one starting assemblage and one set of diffusion conditions. That assemblage and set of conditions are used in fabrication of the element.

Abstract: A method of molding an optical element by pressing glass material uses a cavity composed of a pair of mold members and a side mold member. Either or both of the pair of mold members are rendered slidable along the axial direction of the optical element within the side mold member used during the pressurized molding operation, so that the pair of mold members move in close contact with the contracting glass along the axial direction in the side mold member, during the cooling subsequent to the pressurized molding due to adhesion between the contracting glass and either or both of the pair of mold members. The contraction of the glass during the cooling phase is limited by the adhesive force between the glass and the mold members when at least one of the pair of mold members traverses a gap and reaches a limit of travel; thus tension will be created in the glass.

Abstract: Disclosed is a glass blank used in a producing process for molding an optical element by heating a glass material and press molding the glass material in a mold having optical functional surfaces. Employed is the glass blank having the glass surface coated with a reaction preventive layer and a hydrocarbon layer or with the hydrocarbon layer.

Abstract: For manufacturing a glass article for precision-optical purposes, a preform is provided which is unwrought relating to the desired shape of the glass article to be manufactured and exhibits within the surface areas serving for the formation of optical effective planes a high surface quality. The preform is pressed at a sufficiently high temperature in a mold, the function layers of which, serving for the formation of the optical suitable planes are hard and wear resistant, optionally containing hard nitrides and/or carbides, being mechanically unwrought structureless thin layers coated by cathode sputtering, for example, on a working surface of the basis of the mold. At the beginning of the pressing process, the preform and at least one of the function layers of the mold exhibit a difference in temperature amounting at least to 30 K, but less than a value where inhomogeneities in and/or surface defects on the glass molding may be produced.

Abstract: This invention concerns with a process and apparatus for fabricating microlenses on optical fibers. A pulsed laser beam and an end portion of a fiber are arranged relative to each to another so that the laser beam is incident on the end portion of the fiber at an acute angle .theta. to the longitudinal axis of the fiber. The angle is selected to attain a desired curvature of a lens formed by ablation and heating of the end portion of the fiber by the laser beam. A movement of the fiber and the laser relative each to another results in progressive engagement of the end portion of the fiber with the laser for a preselected distance so as to produce a short taper with a lens at the end thereof. In the preferred embodiment, the fiber rotated about its axis within a passage of the holder which moves the end-portion of the fiber into and through the laser beam resulting in the said lens. The precise repeatability of the lens formation may be controlled by a computer.

Abstract: A method and an apparatus for manufacturing a fluoride glass fiber preform are disclosed which preclude the step of pouring a glass melt into a mold from a crucible, and hence permit the fabrication of a long, homogeneous fluoride glass fiber preform free from foreign substances and air bubbles leading to scattering and which also allow ease in the fabrication of a preform having an elliptic core portion for drawing a polarized wave retaining fiber.

Abstract: For manufacturing a glass article for precision-optical purposes, a preform is provided which is unwrought relating to the desired shape of the glass article to be manufactured and exhibits within the surface areas serving for the formation of optical effective planes a high surface quality. The preform is pressed at a sufficiently high temperature in a mold, the function layers of which, serving for the formation of the optical suitable planes are hard and wear resistant, optionally containing hard nitrides and/or carbides, being mechanically unwrought structureless thin layers coated by cathode sputtering, for example, on a working surface of the basis of the mold. At the beginning of the pressing process, the preform and at least one of the function layers of the mold exhibit a difference in temperature amounting at least to 30 K, but less than a value where inhomogeneities in and/or surface defects on the glass molding may be produced.

Abstract: An aspheric optical test plate assembly is disclosed which permits a qualitative comparison to be made between the surface contour of a known area of an aspheric optical element and the surface contour of an area on the aspheric optical element which should be equivalent to the contour of the known area. The aspheric optical test plate assembly includes an optical test plate in the shape of a segment of a spherical element and means for stressing the element to make its contour approximate the contour of an aspheric surface.

Abstract: A system is disclosed for externally locating the geometric center of an internal lens element which requires that an external reference surface be accurately formed so as to lie concentrically with the central axis of the internal lens element. This is a accomplished in a pressing operation by precisely aligning and securing a ring element to a plunger member. Three points are then selected on the outer reference surface which are not only utilized for positioning the internal lens element for grinding an outer surface to a desired thickness, but also are utilized for aligning and affixing an external lens system in geometric alignment with the internal lens.

Abstract: A method of manufacturing lens elements, in which a glass preform heated to the softening temperature and an annular metal holder (3) enclosing the glass preform are arranged between the heated moulding dies (7,9) of a mould and are moulded in a pressing step into a lens element comprising a glass lens (21) and a ring (3) enclosing the glass lens and acting as a fitting. During moulding, the ring 3 forms together with the two dies (7,9) a quasi closed moulding cavity having an annular gap (15). During moulding, the ring (3) is expanded radially and a quantity of glass is pressed.

Abstract: A method of manufacturing biconvex lens elements (21) comprising a biconvex glass lens (23) and a holder (1) consisting of two cylindrical rings (5,7), which are telescopically slidable with respect to each other and have different diameters so that an annular gap (9) is formed. A lens blank is heated together with the holder (1) in the telescopically extended position of the rings (5,7) to the processing temperature of the glass and is arranged between the heated dies (17, 19) of a mould, whereupon the dies (17, 19) are moved towards each other in a pressing stroke, the two rings (5,7) being telescoped into each other, the lens blank in the holder being moulded into a biconvex glass lens (23) and the excess quantity of glass being pressed from the hotter central part of the lens blank into the annular gap (9). The lens element (21) obtained after cooling is characterized by a biconvex glass lens (23), which is FIG. 7.

Abstract: A mold blank for manufacturing eyeglass lenses containing a flat top bifocal segment. A ceramic platform is first constructed containing an optical surface having a recess corresponding to the flat top bifocal segment. A concave-convex glass mold blank polished on both sides is placed on the optical surface and across the recess of the platform and the mold blank together with the platform is placed in a furnace. The furnace is then heated to a preselected temperature at which the mold blank thermally deforms and sags against the optical surface and into the recess. Upon cooling the mold blank can be used to mold plastic eyeglass lenses. A method for making the mold blank is also disclosed.

Abstract: Gradient optical density transmissive light directing devices (24, 26, 28, 30) and fabrication thereof are disclosed herein. Examples of such devices include concentrators, lenses and compound lenses. The present invention teaches a process for the fabrication of glass light transmitting devices having a chosen gradient in index of refraction either bidirectionally (radially and longitudinally relative to an optical axis) or in three dimensions. The present invention further describes the design of several interesting optical devices by particular choices of the gradient in the index of refraction thereof. Such articles have numerous uses in the optics, optical fiber and solar technology industries for the purposes of designing compound lens systems using a single, integral lens, coupling light into fibers and for concentrating and directing light from a source having a significant angular variation to an energy collecting and/or conversion devices such as a photovoltaic cell, to name but a few applications.

Abstract: A method of producing multifocal ophthalmic lenses having a near vision minor lens element adhesively secured to the ocular surface of a major lens is disclosed. The ocular surface of the major lens is finished to provide an ophthalmic prescription lens. This ocular surface may have a spherical, cylindrical, or prismatic curvature, or any combination thereof, and thus generally may have a complex toric curvature. The minor lens has a predetermined "add power", to provide a near vision segment on the major lens, and preferably is flexible, or is made flexible as by heating, so that it can conform to the shape of the toric curve on the ocular surface of the major lens without distortion or change in its add power. An adhesive material is placed on the major lens, and the minor lens is carefully positioned and gently pressed against it so that it conforms to the curvature of the major lens.

Abstract: There is disclosed an improved method of assembling and fusing the segment and major elements of a multifocal lens blank that employs glass spacer members to space the segment from the major element and allow the segment to progressively slump into sealing relationship with the major as fusion temperature is approached. The glass spacer member has a softening point that is lower than that of the major element glass and may approximate that of the segment glass.