Abstract: The present invention provides a process for preparing an aluminum-titanate-based sintered body comprising the step of firing, at 1250 to 1700° C., a formed product prepared from a raw material mixture containing 100 parts by weight of a mixture of TiO2 and Al2O3 in a weight ratio of TiO2:Al2O3=40:60 to 60:40, and 1 to 15 parts by weight of an alkali feldspar represented by the formula:(NaxK1-x)AlSi3O8 wherein 0?x?1. According to the process of the present invention, it is possible to obtain an aluminum-titanate-based sintered body in which inherent properties of an aluminum titanate, i.e., a low coefficient of thermal expansion and high corrosion resistance are maintained, the mechanical strength thereof is improved, and which can be stably used even under high temperature conditions.

Abstract: The present invention provides a process for preparing a sintered body comprising as a basic component aluminum magnesium titanate represented by the composition formula: MgxAl2(1?x)Ti(1+x)O5 wherein the value of x is 0.1?x<1. The process comprises a step of sintering a formed product from a raw material mixture comprising 100 parts by weight, calculated on an oxide basis, of a mixture comprising a Mg-containing compound, an Al-containing compound and a Ti-containing compound at the same metal component ratio as the metal component ratio of Mg, Al and Ti in the above composition formula, and 1-10 parts by weight of an alkali feldspar represented by the composition formula: (NayK1-y)AlSi3O8 wherein the value of y is 0?y?1.

Abstract: The present invention provides a raw material composition for preparing a sintered body of aluminum titanate, the composition comprising (i) 100 parts by weight of a mixture comprising 40 to 50 mol % of TiO2 and 60 to 50 mol % of Al2O3, (ii) 1 to 10 parts by weight of an alkali feldspar represented by the formula: (NaxK1?x)AlSi3O8 (0?x?1), and (iii) 1 to 10 parts by weight of at least one Mg-containing component selected from the group consisting of a Mg-containing oxide with spinel structure, MgCO3 and MgO, and a process for preparing a sintered body of aluminum titanate comprising sintering a formed product prepared from the raw material composition at 1300 to 1700° C. According to the present invention, a sintered body of aluminum titanate having high mechanical strength and ability to be stably used at high temperatures, as well as its inherent properties of low coefficient of thermal expansion and high corrosion resistance, can be obtained.

Abstract: The present invention relates to an optical component in which a plurality of glass optical elements are integrated thus improving the productivity and providing consistent quality. The optical component of the present invention comprises a plurality of lens parts 1 which is formed from glass material by press molding, a tubular leg part 2 which is formed during the press molding, and which bends at and extends downward from the periphery of the lens part 1, a planar part 3 which bends outwardly and extends horizontally from the tubular leg part 2 providing connection to other lens parts 1, and the cover glass 4 of the image sensor chip 5, which is fixed onto the lower surface of the planar part 3, and/or image sensor chip 5 which is disposed below the lens part 1.

Abstract: The present invention relates to an optical component in which a plurality of glass optical elements are integrated thus improving the productivity and providing consistent quality. The optical component of the present invention comprises a plurality of lens parts 1 which is formed from glass material by press molding, a tubular leg part 2 which is formed during the press molding, and which bends at and extends downward from the periphery of the lens part 1, a planar part 3 which bends outwardly and extends horizontally from the tubular leg part 2 providing connection to other lens parts 1, and the cover glass 4 of the image sensor chip 5, which is fixed onto the lower surface of the planar part 3, and/or image sensor chip 5 which is disposed below the lens part 1.

Abstract: To provide a glass sheet incorporating a plurality of optical elements, which incorporates a plurality of glass optical elements and realizes higher productivity and uniform quality of glass optical elements. The glass sheet incorporating a plurality of optical elements includes a plurality of lens parts formed by molding a glass material, reference surface areas each of which is formed around an outer periphery of each lens part and is horizontal to the lens part, and connection parts each of which extends from one reference surface area and connects one lens part to another lens part, in which the connection part has a margin for facilitating separation of the glass sheet into a plurality of pieces.

Abstract: The present invention provides a process for preparing an aluminum-titanate-based sintered body comprising the step of firing, at 1250 to 1700° C., a formed product prepared from a raw material mixture containing 100 parts by weight of a mixture of TiO2 and Al2O3 in a weight ratio of TiO2:Al2O3=40:60 to 60:40, and 1 to 15 parts by weight of an alkali feldspar represented by the formula:(NaxK1-x)AlSi3O8 wherein 0≦x≦1.

Abstract: The present invention provides a process for preparing a raw material powder for producing a sintered body of aluminum titanate comprising: pulverizing a mixture containing: (1) 100 parts by weight of aluminum titanate crystals pulverized until a maximum grain size of 30 to 50 &mgr;m is attained; and (2) 2 to 6 parts by weight of spinel crystals obtained by heating a mixture containing MgO and Al2O3 at 1250° C. to 1290° a molar ratio of MgO to Al2O3 being 1:0.95 to 1:1.05, said pulverizing being conducted by wet grinding process with a ball mill or cylinder mill.

Abstract: A diffractive optical element includes an optically functioning part including a diffraction grating and a flange part disposed around the optically functioning part. On an outer circumferential face of the flange part, there are at least three protrusions at respective different locations. The protrusions project outward from the outer circumferential face.

Abstract: An optical lens and method of making the optical lens including a substantially arc-shaped cutting surface on a flange section for easily removing a gate section by cutting. A flange section is located at an outer periphery of an optically functioning section and the substantially arc-shaped cutting surface is located at an outer peripheral portion of the flange section along a circumferential direction of the flange section.

Abstract: A plastic lens which is easy to mold and has favorable optical precision. This plastic lens has a flange at the outer periphery of an optically functioning portion, a part of the peripheral surface of the flange being provided with a gate-positioning projection, and a side face of the gate-positioned projection including a cut-off portion.

Abstract: Provided is a storage case for a diffraction grating, which accommodates the diffraction grating in a constant orientation, so as to improve efficiency in the operation for assembling the diffraction grating. The storage sections each accommodate a diffraction grating Each storage section forms a storage space for accommodating a diffraction grating. The storage space is equipped with a rib for engaging the outer peripheral portion of the diffraction grating.

Abstract: Provided is an optical lens which can reduce and easily adjust astigmatism. The optical lens has a flange at an outer periphery of an optically functioning portion. The flange has smaller-diameter sections recessed inward from its outer peripheral portion. The smaller-diameter sections are located at positions symmetrical to each other about an optical axis of the optically functioning portion.

Abstract: A multifocal lens having a plurality of focal points with focal positions different from each other includes a central optical portion, centered at an optical axis, having a predetermined refractive index. The lens further includes at least one outer optical portion which is an optical member disposed like a ring around an outer periphery of the central optical portion so as to be centered at the optical axis, each having a different refractive index different from the predetermined refractive index and having an optical surface continuous with an optical surface of another optical portion disposed on the center side.

Abstract: An optical lens made of plastic includes an optically functioning part, a flange part and disposed around the optically functioning part. The flange part has an outer circumferential face having a cylindrical surface about a lens optical axis. A gate-removed part is located at the outer circumferential face as an outward-projecting quadratic surface. The gate-removed part is located between a virtual outer circumferential face and a plane passing through a tolerance limit on the lens optical axis side. The virtual outer circumferential face is defined when a residual gate part is cut along a cylindrical surface coaxial with the lens optical axis and having a radius identical to that of the outer circumferential face. The plane is set on the lens optical axis side when the residual gate part is removed by cutting the flange part.

Abstract: A lens includes a center-of-gravity adjusting section in order to prevent the center of gravity of the lens from shifting due to removal of a gate portion formed during molding, thereby providing an optical lens which is easily handled and a method of making the optical lens. An optical lens having a flange at the outer periphery of an optically functioning portion includes a gate-cut section formed by cutting off a part of the flange together with a gate portion, continuously with the flange, and a center-of-axis adjusting section, formed by removing a part of the flange, for positioning the center of gravity in alignment with the optical axis of the optically functioning portion.

Abstract: A plastic lens has a flange provided with a reflecting plane, so that its inclination upon assembling can be detected and adjusted efficiently and accurately. This plastic lens has the flange at an outer periphery of an optically functioning portion. A surface of the flange surrounding the optically functioning portion is a reflecting plane perpendicular to an optical axis of the optically functioning portion.

Abstract: A plastic lens includes an optically functioning section, a flange section disposed at an outer periphery thereof, a reference surface formed at an outer peripheral portion of the flange section and adapted to become a reference for attachment, and a tapered surface formed on at least a part of the outer peripheral portion of the flange section which is located closer to the optically functioning section side than is the reference surface so as to taper down its diameter along the optical axis of the optically functioning section. The tapered surface forms a surface at which a gate for resin injection is located upon manufacture.

Abstract: A molded optical component which is comprised of a lens portion, an annular outer rim integrally formed around the circumference of the lens portion, an annular reference surface formed on the circumference of the outer rim in a predetermined width along one end thereof, and an obliquely cut surface formed across the circumference of the outer rim by stripping a gate stub therefrom. The obliquely cut surface is extended from the other end of the outer rim up to a position falling short of near boundaries of the reference surface.

Abstract: A lens case containing lenses includes a tubular case body and lenses contained in the case body. The case body includes first and second opposed walls having respective inner surfaces, and two protrusions projecting from each of the inner surfaces. The protrusions on the inner surface of the first wall are directly opposite corresponding protrusions on the inner surface of the second wall. Each of the lenses has a central optically functioning part and circumferential peripheral flanges, and the flanges of the lenses abut the protrusions.