Abstract:
The present invention relates to a method of manufacturing a molded article in the form of an optical element such as a glass lens by heat-softening a glass material such as optical glass and press molding it with high precision in a pressing mold as well as an objective lens for optical picking up. The method of manufacturing comprises press-molding a molding material to make a molded article, measuring an optical property of the molded article, correcting pressing rate of at least one of the pressing molds based on the optical property thus measured, and further press-molding to make a molded article with the corrected pressing rate. A pressing device comprising a pair of pressing molds having molding surfaces processed to prescribed shape, and a means of driving one of the pair of pressing molds at a prescribed rate to press mold a molding material supplied between the pressing molds is disclosed. The device further comprises a means for detecting an optical property, a shape or a number of the molded articles and a means for controlling driving of said means of driving by correcting pressing rate of the molds based on the detected property, shape or number.
Abstract:
The lateral V-shaped groove (2) and the longitudinal V-shaped groove (3), which cross each other, are formed on a surface of the substrate (1). When the optical element (100) is contacted with and supported by four ridges composed of sides (21, 22) of one V-shaped groove and sides (31, 32) of the other V-shaped groove, the optical element is positioned at the three-dimensional support position which is geometrically determined by the four points at which the four ridges and the surface of the optical element come into contact with each other.
Abstract:
A molded article having a highly accurate outer form accuracy, including various optical products, is produced from a preform having a simple form by a press-molding, in which a fine pattern can be highly accurately transferred and no burr is formed. A first mold member having a concave portion with an inner surface made of a molding surface and a second mold member which is to be opposed to the first mold member and has a molding surface are used to press-mold the preform. The preform is shaped in a polyhedral form to permit fitting of the preform in the concave portion of the first mold member.
Abstract:
An optical fiber fixing member having optical fiber engagement grooves 2 and peaks 5 between the engagement grooves 2 is configured as a unitary structure by molding. A preform G is pressed with a mold 21 such that the concavities 25 of the mold 21, which comprises convexities 26 and concavities 25 for the transfer of the engagement grooves 2 and the peaks 5, respectively, are filled with the preform G only partially. The shape of the convexities 26 of the mold 21 is transferred, yielding optical fiber engagement grooves 2 whose surfaces are mold transfer surfaces 6. Because the preform G fills the concavities 25 only partially, the peaks 5 between the optical fiber engagement grooves formed by the filling of the concavities 25 are free rounded surfaces 7 whose shape does not reflect the shape of the concave bottom portions 25a of the mold 21.
Abstract:
In a grindstone for fabricating a mold which has optical fiber engagement portions of an optical fiber guide block used for aligning optical fibers, two main grinding surfaces are provided to form the optical fiber engagement portions contacted with the sides of the optical fibers and a tip end portion which is contiguous to the two main grinding surfaces and which has a contour contained within a predetermined area. The predetermined area has a triangle shape which is defined by two tangent lines along the two main grinding surfaces and a preselected line drawn between two points determined on the two main grinding surfaces. The two points are decided in accordance with a predetermined formula.
Abstract:
A support for a photographic printing paper comprising a substrate and a waterproof resin coating layers provided on the both sides of the substrate, wherein at least the waterproof resin-coating provided on the side of the substrate on which an emulsion for forming an image is coated comprises i) a lowermost waterproof resin coating layer contacting the substrate and ii) at least one upper coating layer containing a waterproof resin capable of melt-extruded at a temperature of from 170.degree. to 290.degree. C. and containing uniformly dispersed titanium dioxide, and a method for manufacturing the support by melt extrusion.
Abstract:
A photochromic composition contains, in a predetermined combination: one or more photochromic compounds represented by General Formula 1; and one or more selected from the group consisting of a photochromic compound represented by General Formula A, a photochromic compound represented by General Formula B, and a photochromic compound represented by General Formula C.
Abstract:
A coating composition for an optical article containing a photochromic compound and two or more (meth)acrylates, the two or more (meth)acrylates containing an alicyclic difunctional (meth)acrylate and a non-cyclic tri- or higher functional (meth)acrylate.
Abstract:
Lens aberration in an objective lens for recording and reproducing optical information, which is composed of a molded aspherical single lens, is inhibited while at the same time good lens productivity is attained. Also attained are excellent optical properties and high production efficiency in a mold processing step and a press molding step conducted to manufacture the lens. To this end there is provided an objective lens 1 having a convex aspherical surface formed at a first surface and a numerical aperture NA which satisfies the condition NA≧0.8. It is preferable to have an aspherical surface also at the second surface. A molding material that was premolded to a prescribed shape and is in a heated and softened state is press molded by using a pair of upper and lower molds having opposing molding surfaces, a molding surface shape is transferred by using a spherical molding material with a radius r and pressing the molding material between a pair of upper and lower molds, and the paraxial curvature radius R of the convex aspherical surface satisfies the following relation r/R≦1.35.
Abstract:
In a method for molding glass products having a fine structure as of an optical fiber holder with a high size precision, a mold used for the molding has the fine structure in a size such that a size difference occurring when the glass product is cooled down to a room temperature where at the end of molding with a pressure a size of the fine structure of the mold for glass product and a size of a fine structure of the glass product formed by transfer of the fine structure of the mold are the same as one another is so adjusted that a size of the fine structure of the completed glass product falls within a permissive size precision range. The mold may has a size satisfying, as a size of a fine structure at a room temperature, a formula [1+(.alpha.g-.alpha.m).times..DELTA.T+.alpha.g'.times..DELTA.T'].times.Sg, wherein Sg denotes a size of a fine structure of thc glass product at the room temperature; .alpha.g denotes a mean thermal expansion coefficient of the glass to be molded in a temperature range from the room temperature to the glass transition temperature of the glass to be molded; .alpha.m denotes a mean thermal expansion coefficient of the mold in a temperature range from the room temperature to the glass transition temperature of thc glass to be molded; .DELTA.T denotes a difference between the room temperature and the glass transition temperature of the glass to be molded; .DELTA.T' denotes a difference between a temperature at which the mold's pressure exerted to the glass product is released and the glass transition temperature, in a case where the mold's pressure exerted to the glass product is released at a temperature higher than the glass transition temperature after pressing the mold with a high pressure; and .alpha.g' is a thermal expansion coefficient of the glass to be molded at a mean temperature of summation of the glass sag temperature and the glass transition temperature.