Abstract: An apparatus for forming a product by a pressing process, has

Abstract: An optical element has diffractive grooves. Each diffractive groove includes a first surface approximated by a predetermined optical function; a second surface extending in a direction to cross the first surface and being parallel to the optical axis; and a third surface to connect the first surface and the second surface. A width of the third surface in the direction perpendicular to the optical axis is 0.5% to 15% of the sum of a width of the first surface in the direction perpendicular to the optical axis and the width of the third surface in the direction perpendicular to the optical axis.

Abstract: An optical element has diffractive grooves. Each diffractive groove includes a first surface approximated by a predetermined optical function; a second surface extending in a direction to cross the first surface and being parallel to the optical axis; and a third surface to connect the first surface and the second surface. A width of the third surface in the direction perpendicular to the optical axis is 0.5% to 15% of the sum of a width of the first surface in the direction perpendicular to the optical axis and the width of the third surface in the direction perpendicular to the optical axis.

Abstract: A method of producing an optical element forming die to form an optical element by pressing a glass material softened with heat, including a first process of producing a primary processed product having a volume resistance value Z (0<Z≦1 (&OHgr;·cm) by sintering ceramic powders; and a second process of forming the optical element forming die by processing the primary processed product.

Abstract: An optical element for recording and/or reproducing information of an optical information recording medium, includes an optical element body having an incident surface and an opposite surface opposite to the incident surface, A light flux coming from a light source at an outside is introduced to be incident into an inside of the optical element body and is reflected several times in the inside of on the opposite surface; and the incident surface is a referactive surface is convex toward the light source side and the light source side

Abstract: A molding die for molding an optical element, comprises a die base body formed by shaping an amorphous alloy having a super-cooled liquid phase, wherein the composition of the amorphous alloy contains palladium.

Abstract: A molding die for molding an optical element, comprises a die base body formed by shaping an amorphous alloy having a super-cooled liquid phase, and a die face formed by applying a die face forming process onto a part of the die base body and used to form an optical surface of the optical element or a dimensional reference surface.

Abstract: An optical element has diffractive grooves. Each diffractive groove includes a first surface approximated by a predetermined optical function; a second surface extending in a direction to cross the first surface and being parallel to the optical axis; and a third surface to connect the first surface and the second surface. A width of the third surface in the direction perpendicular to the optical axis is 0.5% to 15% of the sum of a width of the first surface in the direction perpendicular to the optical axis and the width of the third surface in the direction perpendicular to the optical axis.

Abstract: A molding die includes a pair of molding die members for forming a molding cavity that molds molded products and a holding member that holds therein the molding die members slidably, wherein a pressure-transfer medium supplied to the clearance between the molding die members and the holding member makes the molding die members to be slid and held in the holding member while the molding die members and the holding member are on the non-contact state.

Abstract: An optical element, comprises a silicon based resin satisfying following three conditional formulas: (1) (number of silicon atoms residing as R1SiO3/2 in the silicon based resin)/(total number of silicon atoms in the silicon based resin)≧0, (2) (number of silicon atoms residing as SiO4/2 in the silicon based resin)/(total number of silicon atoms in the silicon based resin)≧0, (3) {(number of silicon atoms residing as R1SiO3/2 in the silicon based resin)+(number of silicon atoms residing as SiO4/2 in the silicon based resin)}×100/(total number of silicon atoms in the silicon based resin)≧10%, wherein R1 represents a hydrogen atom, a hydroxyl group, an amino group, a halogen atom or an organic group.

Abstract: The invention provides a laser interterometric measuring apparatus for measuring the position of an object. A corner cube prism receives a laser beam from a emitting device, splits the beams into a reference beam and a measuring beam, and let the beams to proceed to a fixed mirror and a movable mirror. The corner cube prism has a coated surface to selectively reflect or pass a beam therethrough in accordance with the polarization condition of the beam. On the coated surface of the corner cube prism are provided a parallelogram prism, a triangle prism disposed next to the parallelogram prism on the coated surface, and a polarizing plate disposed between the parallelogram prism and the triangle prism.

Abstract: The invention provides a laser interferometric measuring apparatus in which there is provided a corner-cube prism which includs a reflecting surface for selectively reflecting or transmitting a beam in accordance with the polarization condition of the beam and a transmitting surface for sending out a beam. A light source, a movable mirror, a fixed mirror, a detector and the corner-cube prism so arranged that the corner-cube prism receives a reference beam and a measuring beam from the light source through the reflecting surface, sends out the reference beam to the fixed mirror and the measuring beam to the movable mirror respectively through the transmitting surface, receives the reflected reference beam from the fixed mirror and the reflected measuring beam from the movable mirror through the transmitting surface and selectively sends out the reflected reference beam and the reflected measuring beam to the detector in accordance with their polarization condition through the reflecting surface.

Abstract: A hologram exposure apparatus for and method of obtaining a hologram using a photoresist for an in-line type interferometer wherein a photoresist substrate is detachably mounted on a substrate rotating device. A concentric pattern of a hologram from a source of light is projected onto the photoresist on the substrate mounted on the substrate rotating device while rotating the substrate and moving a projecting device in a direction at right angles with the rotary shaft of the photoresist substrate.

Abstract: Laser displacement meter for measuring a displacement of an object such as a moving distance, a moving angle, and a moving speed. The meter has a generator circuit for generating a displacement signal; another generator circuit for generating a first signal which corresponds to R sin.theta. value of the displacement signal, and a second signal which corresponds to R cos.theta. value of the displacement signal (R represents an amplitude, .theta. represents a phase of the displacement signal); a memory for storing a displacement value being defined by the first signal and the second signal where .theta. is between 0 and 2.pi.; a circuit for transferring a position signal corresponding to the displacement value from the memory according to the first signal and the second signal; a counter for counting a number, being defined as dividing .theta. by 2.pi., corresponding to the displacement signal and for determining the displacement of the object according to the counted number and the position signal.

Abstract: A laser interferometry length measurer for determining a moving distance of an object. The measurer includes a 45.degree. rotatory polarization plate for dividing a source light beam to a measuring beam and a reference beam; a reflector, which is placed to the object, for reflecting the measuring beam; a prism for composing the reference beam and the reflected measuring beam into a composed source beam; a beam splitter prism for distributing the composed source beam into a plural light beams which have different phases; and a determination unit to determine the moving distance of the object according to those beams.