Abstract: A nonmagnetic black toner for reversal development comprising a resin binder; and a black colorant comprising a composite oxide of two or more metals, the composite oxide having an oil absorption per unit area of 0.07 ml/m2 or less. The nonmagnetic black toner can be suitably used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Abstract: An IC test system includes a socket having a plurality of contact pins, a positioning member for positioning an IC package for testing, a carriage arm for transferring the IC package positioned by the positioning member to the socket. The socket, positioning member and the carriage arm are fixed to the base of the test system via a common base plate. Vibration caused by the carriage arm is commonly transferred to the socket and the positioning member, whereby a suitable alignment of IC package with respect to the socket can be obtained.

Abstract: A head actuator has two of arms that extend from a bearing assembly, and a relay FPC is fixed to each arm. The relay FPC extends from a head to the proximal end portion of the arm. The relay FPC includes a connecting portion located on the proximal end portion of the corresponding arm and has a first contact each. The connecting portions are opposed to each other across a space and form a female connector. A male connector attached to a main FPC has a projection detachably fitted in the female connector and second contacts provided on the projection and connected to the main FPC. As the projection of the male connector is fitted between the connecting portions of the female connector, the first and second contacts are pressed against each other, whereupon the relay FPC and the main FPC are connected electrically to each other.

Abstract: A recording medium and a recoding medium master, and a method of manufacturing the recording medium which comply with the standard of recording/reproducing characteristic established in the MD standard while enabling precise discrimination of the pit track and groove track and optical detection of the pits by optical pickup and the like are provided. Pits and grooves are arranged on a surface of a disc-shaped substrate so as to form a grooves and the ratio is from 1.00 exclusive to 1.13 inclusive. It is preferable that the track pitch of the grooves is from 1.50 &mgr;m inclusive to 1.70 &mgr;m exclusive. The width of the pits and grooves in the radial direction of the substrate is the same.

Abstract: An optical disc in which two optical discs are laminated together to realize high recording density and improved recording/reproducing characteristics for information signals, and a manufacturing method for the optical disc. When laminating a first disc having a first information recording portion on one surface of a first substrate to a second disc having a second information recording portion on one surface of a second substrate, the direction of warping of the first disc is set so as to be opposite to the direction of warping of the second disc, and the first disc is laminated to the second disc so that the surface of the first substrate having the first information recording surface will face the surface of the second substrate carrying the second information recording portion.

Abstract: The invention provides a developing apparatus which prevents transportation of aggregated toner powder to an image carrier and thereby assures a high print quality by taking a countermeasure to disperse aggregated toner powder when development of an image carrier with developer which includes toner powder and magnetic powder is performed. The developing apparatus includes a developing roller, a developer control member, and an aggregated toner dispersion member disposed in an opposing relationship to the transport magnetic pole of the fixed magnet on the upstream side with respect to the position of the developer control member and having a contact face in the form of a flat face with which the developer held on the outer circumferential face of the developing roller may be contacted under pressure in order to disperse aggregated toner powder in the developer held on the outer circumferential face of the developing roller.

Abstract: A magneto-optical recording medium from which data is read by using a Kerr effect and which is capable of preventing signal imbalance caused from change in birefringence even in a system in which the amplitude of a reproduced signal is small and the spatial frequency of a shortest record signal train of the magneto-optical recording medium is 1.1×NA/&lgr;(line/m) or higher. The photoelastic coefficient of a substrate of the magneto-optical recording medium is 50×10−13 cm2/dyne or smaller. The vertical birefringence of the substrate is 250×10−6 or smaller, the coefficient of water absorption of the same is 0.2 wt % or lower and the thermal coefficient of expansion of the same is 6.5×10−5 cm/cm·° C. or lower.

Abstract: A full color toner for nonmagnetic one-component development usable in a developer device including a developer roller and a blade, the blade serving to regulate a toner layer formed on the developer roller into a uniform thickness and to supply electric charges to toners by triboelectric charging, the full color toner for nonmagnetic one-component development including (a) fine resinous particles including at least a colorant and a binder resin having a polyester resin as a main component; and (b) additives externally applied onto a surface of the fine resinous particles, the additives including inorganic fine particles consisting of positively chargeable, inorganic fine particles and negatively chargeable, inorganic fine particles when subjecting the additives to triboelectric charging with an iron powder.

Abstract: A developing apparatus of an electrophotographic apparatus includes a housing for accommodating a developer, first, second and third developing rollers are rotatably disposed in the housing and arranged opposite to a photoconductor drum for conveying a developer carried on respective surfaces of the developing rollers, and a conveyor roller rotatably disposed in the housing for conveying the developer carried on a surface thereof to one of the developing rollers. First and second screw conveyors are disposed in the housing for conveying the developer in an axial direction opposite to each other. Each of these conveyors has an axial length larger than an axial length of the developing rollers. A partition wall is disposed between the first and second screw conveyors. A toner container for accommodating a toner is mounted on the housing. The toner in the toner container is supplied into the housing and agitators agitate the toner in the housing.

Abstract: A toner for electrophotography including a binder resin, a colorant, and a reinforcing agent, the toner being characterized in that the reinforcing agent is resin particles comprising a core layer coated with a vinyl polymer having a glass transition temperature of 50.degree. C. or more, the core layer comprising an acrylic acid ester copolymer and/or a methacrylic acid ester copolymer having a glass transition temperature of 0.degree. C. or less, or a diene copolymer having a glass transition temperature of 0.degree. C. or less; a reinforcing agent for toner including the above resin particles; and in a method for forming fixed images by utilizing a nonmagnetic one-component developing method employing a developer device including a developer roller and a blade, the blade serving to regulate a thickness of a toner layer formed on the developer roller and to supply electric charges to the toner, the method for forming fixed images being characterized by the use of the above toner for electrophotography.

Abstract: The positively chargeable toner used for a nonmagnetic one-component developing method includes a toner particle and fine polytetrafluoroethylene particles, the toner particle having (a) a binder resin having a polyester resin having an acid value of 10 mg KOH/g or less; (b) a colorant; and (c) a charge control agent, and the fine polytetrafluoroethylene particles, whose average primary particle size is at least 0.05 .mu.m and less than 0.5 .mu.m, being externally added to the surface of the toner particle. The nonmagnetic one-component developing method includes the step of loading the above positively chargeable toner in a developer device for a nonmagnetic one-component toner.

Abstract: The nonmagnetic one-component toner is usable in a developer device including a developer roller and a blade, the blade serving to regulate a toner layer formed on the developer roller into a uniform thickness and to supply electric charges to the toner by triboelectric charging, and the nonmagnetic one-component toner includes at least a binder resin, a colorant, and an iron compound. Here, the binder resin includes a polyester resin as a main component, and the iron compound has the general formula (I) and is contained in an amount of between 0.1 parts by weight or more and less than 1.0 part by weight, based on 100 parts by weight of the binder resin.

Abstract: An improved method for forming a disc substrate having a bottomed centering hole for rotating and driving the disc. The method includes injecting synthetic resin into a mold cavity formed by a first and second metal molds to form the substrate, and punching at least part of the centering hole by a movable member protruded into the mold cavity to form a through-hole. A stamper containing digital information is held in place inside the mold cavity by its inner circumference by means of a vacuum or a magnet.

Abstract: The present invention relates to an eletrophotographic carrier characterized by that the surface thereof is coated and cured with a partially hydrolyzed sol obtained from at least one alkoxide selected from the group consisting of silicon alkoxides, titanium alkoxides, aluminum alkoxides and zirconium alkoxides, and the production process therefor. Use of the carrier of the present invention mixed with a toner to prepare a developer can always supply a stable image without a coated layer being peeled off during use.

Abstract: A developer stirring device including stirring paths parallel to each other and stirring screws respectively disposed in the stirring paths, in which a delivering element for a developer is provided on one of the stirring screws and a distributing element is provided on the other of the stirring screws so as to allow the developer to circulate through the stirring paths without stagnation, and a developing device for an image forming apparatus using the same.

Abstract: A metal mold device for molding a disc substrate formed by molding a synthetic resin material and having a raised portion on the inner surface of the disc substrate, includes a fixed metal mold and a movable metal mold for defining together a mold cavity for molding the disc substrate. A mold releasing resistance in the form of suitably sized projections or recesses, is provided at a portion of the fixed metal mold or the movable metal mold mating with the outer rim of the disc substrate being molded or at the outer peripheral surface of the raised portion to permit an as-molded disc substrate to be released easily and reliably from a stamper bearing a pattern of pits and lands or pre-grooves and to prevent molding distortions from being produced in the disc substrate being molded.

Abstract: A metal mold device for molding a substrate includes a fixed metal mold, a movable metal mold mounted facing the fixed metal mold for being moved towards and away from the fixed metal mold and for defining a mold cavity between it and the fixed metal mold, a stamper mounted on at least one of the fixed metal mold or the movable metal mold and arranged within the mold cavity, a positioning unit provided on the metal mold on which the stamper is mounted for positioning the loading position of the stamper, and a stamper supporting unit provided on the metal mold on which the stamper is mounted for supporting the stamper by suction. The stamper is positioned by the positioning member and held under suction by the stamper suction unit so that it may be mounted in position on the fixed metal mold or the movable metal mold to permit a disc substrate to be molded highly accurately.

Abstract: A developer composition for an electrostatic charge image, which comprises a toner comprising a binder resin and a coloring agent, and 0.1 to 1.0% by weight of fine polymer particles with a glass transition temperature of 90.degree. C. or higher deposited on the surface of the toner, the binder resin comprising, as a main component, a polyester resin with an OHV/AV value of 1.2 or more wherein OHV and AV represent the hydroxyl value and acid value of the polyester resin, respectively.