Abstract: A ceramic hydrodynamic bearing used as a radial or a thrust bearing in a spindle motor for a hard disk driver. The bearing includes a ceramic bearing base having hydrodynamic pressure generating grooves. A sliding surface of the bearing base is irradiated with an energy beam with a high energy density to remove said material, thereby forming hydrodynamic pressure generating groove, and at the same time the grooves are coated with a modification layer that is formed by melting the ceramic material that constitutes said ceramic bearing base with the energy beam and by solidifying said ceramic bearing base.

Abstract: A solution containing nitrate ion and other anions is contacted with a bifunctional styrene-divinylbenzene three-dimensional copolymer for selectively removing the nitrate ion. The copolymer contains phosphonate and amino groups of the following formulas: ##STR1## wherein R.sup.1 and R.sup.2 stand, independently from each other, for a hydrocarbyl group, and ##STR2## wherein R.sup.3 and R.sup.4 stand, independently from each other, for hydrogen or an alkyl group with the proviso that R.sup.3 and R.sup.4 do not represent hydrogen at the same time.

Abstract: An information recording and erasing method and apparatus of an optical memory medium including a substrate, a guard film, and an intermediate layer portion so disposed between said substrate and said guard film as to include at least a recording material layer having a phase changing with temperature and include at least one good conductor layer, comprising the steps of supplying magnetic flux varying relatively to said good conductor layer to generate eddy currents within said good conductor layer, and heating said recording material layer with heat generated in said good conductor due to the eddy current loss to effect information recording and erasing with respect to said recording material layer.

Abstract: An edge connector (1) having metal latching devices (5) to latch and unlatch a circuit board (4) is disclosed. More particularly the latching devices (5) include a latching section (53) for latching the board (4) and an unlatching section (54) for releasing the board (4).

Abstract: A bearing structure suitable for a spindle motor or the like, which enables such a motor to rotate with minimal vibrations. The bearing structure comprises a stator including a support shaft which is disposed on a base, and a rotor which is rotatably disposed around the support shaft. A radial hydrodynamic bearing and a thrust hydrodynamic bearing are disposed between the stator and the rotor. The stator has the support shaft, a thrust plate and a radial cylindrical member which is concentric with the support shaft. The thrust plate is secured to an end surface of the radial cylindrical member. The support shaft extends through the centers of the radial cylindrical member and the thrust plate. The rotor has a radial sleeve. The radial hydrodynamic bearing is formed from the inner peripheral surface of the radial sleeve and the outer peripheral surface of the radial cylindrical member, which face each other and either of which is formed with herringbone-shaped grooves for generating dynamic pressure.

Abstract: An optical modulation method and apparatus uses superconductive oxide material for the optical modulation element. The current, magnetic field, temperature or pressure applied to the superconductive oxide material is varied so as to induce a superconduction-normalconduction transition, and the resulting variation in optical characteristics such as the reflectivity, transmissivity or refractive index of the superconductive oxide material modulate the input light. The method and apparatus are fast in operation and simple in structure. The method and apparatus also detect the variation in the current, magnetic field, temperature or pressure as a change in the reflectivity, transmissivity or refractive index of the superconductive oxide material on the basis of a superconduction-normalconduction transition.

Abstract: A spindle motor which is designed to rotate with minimal vibrations and hence is suitable for a hard disk driver. The spindle motor employs hydrodynamic bearings as radial and thrust bearings. A support shaft is formed in a cylindrical configuration with a center hole, and a rotor has a columnar portion which is inserted into the center hole in the support shaft. A thrust bearing collar is attached to the lower end of the rotor, and a thrust bearing member is secured to a base in opposing relation to the thrust bearing collar. A group of stator coils and a radial bearing member are disposed on either the inner peripheral surface of the center hole in the support shaft or the outer peripheral surface of the support shaft, and a group of rotor magnets and a radial bearing sleeve are disposed on either the outer peripheral surface of the columnar portion or the inner peripheral surface of the rotor in opposing relation to the stator coil group and the radial bearing member.

Abstract: A fuel cell comprises at least two cell members, each of which has a flat-plate solid electrolyte having a fuel electrode layer on one surface thereof and an air electrode layer on the other surface thereof, separators, each of which is arranged between the cell members and comprises frame materials and metallic sheets having concave and convex portions and being coupled to the frame materials, a fuel supply path for supplying fuel and an air supply path for supplying air, a fuel discharge path for disharging fuel and an air exhaust path for exhausting air and collector members mounted on the outer sides of the separators of the highest and lowest stages.

Abstract: A spindle motor comprising a stator including a support shaft positioned on a base, a cap-shaped rotor rotatably and concentrically disposed around the support shaft, thrust and radial bearings disposed between the stator and the rotor, a stator coil secured to the stator, and a rotor magnet member secured to the rotor opposing the stator coil. The thrust and radial bearings are hydrodynamic bearings. A movable piece that constitutes a part of the thrust bearing is secured to the lower end of a cylindrical portion of the rotor and extended outwardly or inwardly from the cylindrical portion, or is disposed above the rotor. The stator coil is secured to the outer peripheral portion of the support shaft above or below the radial bearing. The rotor magnet member is securd to the inner peripheral surface or inner top surface of the rotor. Either a radial or axial gap is provided between the stator coil and the rotor magnet member.

Abstract: A liquid separation membrane for pervaporation composed of a polymeric substance having in the main chain a glycosidic skeleton containing cationic groups and/or anionic groups at least some of which form a salt with counter anions and/or counter cations; and a method for pervaporation, which comprises separating a water-organic liquid mixture or an organic liquid-organic liquid mixture by pervaporation using a separation membrane, said membrane being composed of a polymeric substance having in the main chain a glycosidic skeleton containing cationic groups and/or anionic groups at least some of which form a salt with counter anions and/or counter cations and being dried so as to have a water content of not more than 25% by weight.

Abstract: An edge connector (5) for receiving an edge of a circuit board (6) is disclosed. The contacts (2) positioned in the housing (4) of the connector (5) include a resilient stand-up section (25) having a tip (25a) defining a first contact point (A) and a C-shaped section (26) having a tip (26a) defining a second contact point (C) with the circuit board (6) being received between the first and second contact points (A,C).

Abstract: A waveguide path type optical pickup is provided for preventing a returning light from returning back to a light source. A filter for selectively allowing either Te polarized light or TM polarized light to pass through the filter is provided in an optical path from a light source to an optical path deflector. An optical part for changing the polarized state of light is provided in an optical path from the optical path changing part to an information recording medium, thereby prevent a reduction in S/N ratio or reproducing signal.

Abstract: An electrical connector for mounting onto and electrical connection to a circuit board (20) comprises a dielectric housing (1) in which electrical contacts (10) are secured with connection sections (12) extending outwardly from a bottom surface of the housing (1) and electrically connected by soldering or welding to conductive members (22) of a circuit pattern on board (20). A securing tab (8) is affixed to housing (1) and extends along the bottom surface of housing (1) and is soldered or welded to a metal pad (23) in board (20) thereby securing the connector on board (20) and preventing damage to the connections between the connection sections (12) and the conductive members (22) when the housing (1) is warped as a result of temperature variations.

Abstract: A liquid separation membrane for pervaporation composed of a polymeric substance having in the main chain a glycosidic skeleton containing cationic groups and/or anionic groups at least some of which form a salt with counter anions and/or counter cations; and a method for pervaporation, which comprises separating a water-organic liquid mixture or an organic liquid-organic liquid mixture by pervaporation using a separation membrane, said membrane being composed of a polymeric substance having in the main chain a glycosidic skeleton containing cationic groups and/or anionic groups at least some of which form a salt with counter anions and/or counter cations and being dried so as to have a water content of not more than 25% by weight.

Abstract: A fuel cell comprises a stack of cell members, each cell member including a flat-plate separator, an air electrode, a solid electrolyte and a fuel electrode, spacers arranged along peripheries of the separators among the separators of the stack of cell members, air supply paths for supplying air to the air electrodes, air being sent to the air electrodes through grooves of the flat-plate separators and air supply paths, air exhaust paths for exhausting excessive air, fuel supply paths for sending fuel to the fuel electrodes and fuel discharge paths for discharging excessive fuel. The fuel cell has an oxidation-resistant coating layer on the surface of the separator on the side of the air electrode. The solid electrolyte is made by the use of one selected from the group of Laser Physical Vapor Deposition Method, Plasma Thermal Spraying Method, Electron Beam Vapor Deposition Method and Sputtering Method.

Abstract: An optical head including a substrate, an optical waveguide formed on the substrate, a light source formed on a portion of the substrate, a collimator lens for converting light from the light source into parallel light rays, an objective lens for focusing light from the collimator lens onto a recording medium and for converting reflected light from the recording medium into parallel light rays, a beam splitter for dividing light from the objective lens into two parts to send out one of the parts in a predetermined direction, a coupling lens for focusing light from the beam splitter on a position, and a photodetector for detecting light from the coupling lens, is disclosed, in which the collimator lens, the objective lens, the beam splitter, the coupling lens and the photodetector are integrated on the substrate, and the collimator lens or an objective lens supporting part is made flexible to vary the position of the focus of the collimator lens or objective lens by piezo-electric elements.

Abstract: A testable LSI chip incorporating memory blocks, such as RAM and ROM, and random logic circuitry, and a testing method thereof are disclosed. A front-stage peripheral logic circuit block and rear-stage peripheral logic circuit block connected to the input and output modes of a memory block are provided on their output side and input side, respectively, with the flip-flops in correspondence to the input and output nodes of the memory block. The flip-flops on the output side and flip-flops on the input side are each connected to form a shift register. In testing the front peripheral logic block, the test result is latched in the flip-flops on the output side and then the contents are shifted out for reading. In testing the rear-stage peripheral logic circuit block, a bit pattern for testing is shifted-in and latched in the flip-flops on the input side and then supplied to the rear-stage peripheral logic circuit block under test.

Abstract: An optical head is disclosed, in which a plate-shaped optical wave guide comprises an optical system including a collimator lens, a beam splitter and an objective lens; a laser light source for emitting a laser light in the form of a light beam which is to be impinged on an optical recording medium; and electro-acoustic transducers are disposed between the beam splitter and the objective lens, the transducers being adapted to be driven by the outer electrical signal for producing surface acoustic waves in the optical wave guide, thereby establishing a condensation and rarefaction distribution in refractive index in the optical wave guide which distribution influences the direction of transmission and the degree of focusing of the light beam passing therethrough so that regulation of the tracking and the focal length can be effected without any mechanical movements.

Abstract: A developing replenisher material or a replenisher liquid developer to be supplied to a developer tank of an electrostatic copying machine comprises 1000 parts by weight of a carrier liquid composed mainly of aliphatic hydrocarbon and 200 or 1200 parts by weight of toner particles composed mainly of a binder resin and a pigment. The toner concentration of the replenisher liquid developer is high enough to prevent an overflow from the developer tank, allow many copies to be produced by the copying machine, and prevent a solvent shock. The toner particles, when added to the carrier liquid, can immediately and well be dispersed in the carrier liquid.

Abstract: A light spot determining a first condition that an optical recording medium is cooled after being heated to a temperature exceeding a first temperature and a light spot determining a second condition that the optical recording medium is cooled after being heated to a temperature exceeding a second temperature higher than the room temperature and not exceeding the first temperature higher than the second temperature, namely, the two light spots are radiated onto the optical recording medium and in the same guide track thereof wherein signals are recorded and erased on the optical recording medium by controlling the spot diameter of each light spot and/or the light intensity thereof.