Abstract: A process for the production of a vinyl compound of the formula (1), which process comprises reacting a bifunctional phenylene ether oligomer of the formula (2) with a vinylbenzyl halide in an aprotic polar solvent in the presence of an alkali metal alkoxide and then adding the reaction solution to water or a water/alcohol mixed solution to precipitate a solid

Abstract: An information-recording method and an information-recording medium which make it possible to improve overwrite characteristics in the high speed recording, especially archival overwrite characteristics for overwriting information after retaining the medium in a high temperature environment for a certain period of time, and an information-recording apparatus based on the use of the same are provided. The information-recording method comprises overwriting a random pattern with light beams having a predetermined recording power and a variety of erasing powers; reproducing the random pattern to determine a minimum value Pb1 and a maximum value Pb2 of the erasing power obtained when the pattern, in which a reproduction jitter exceeds a predetermined threshold value, is erased; determining an optimum erasing power Pb from the minimum value Pb1, the maximum value Pb2, and a relational expression represented by Pb=?×Pb1+(1??)×Pb2; and recording the information with the determined optimum erasing power Pb.

Abstract: An phase-change optical disk comprises a substrate, a first protective layer, a first thermostable layer, a recording layer, a second thermostable layer, a second protective layer, an absorptance control layer, and a heat-diffusing layer which are provided in this order from a side on which a laser beam comes thereinto, wherein a recording layer material has composition ratios which are within a range surrounded by composition points of B3 (Bi3, Ge46, Te51), C3 (Bi4, Ge46, Te50), D3 (Bi5, Ge46, Te49), D5 (Bi10, Ge42, Te48), C5 (Bi10, Ge41, Te49), and B5 (Bi7, Ge41, Te52) on a triangular composition diagram. Recrystallization is not caused even when information is recorded on an inner circumferential portion, a reproduced signal is scarcely deteriorated even when rewriting is performed multiple times, and any erasing residue of amorphous matters scarcely appears at an outer circumferential portion.

Abstract: To provide a disk apparatus that can enhance reliability of a head wiring and a driving wiring, a disk apparatus includes a head slider, an arm, a driving unit, a wiring body provided for supplying a head mounted on the head slider with a head current used for signal recording or reproduction with respect to a disk-like recording medium and supplying the driving unit with a driving current used to drive the arm to swing, and a lead-out terminal portion. The wiring body includes a flexure sheet provided in the arm so as to support the head slider, a head wiring provided so as to connect the head slider and the lead-out terminal portion by passing over the flexure sheet thereby to supply the head mounted on the head slider with the head current, and a driving wiring provided along the head wiring in an area ranging from a wiring connecting portion formed on a side of the flexure sheet opposite the head slider to the lead-out terminal portion thereby to supply the driving unit with the driving current.

Abstract: In a state wherein an actuator is located at a shunt position, when an apparatus is subjected to an external shock, the actuator tries to swing due to a rotational moment. An inertia arm generates a rotational moment simultaneously with the actuator. Both the rotational moments competes with each other at an engaging point of the inertia arm side with the actuator side to absorb the external shock. Further the actuator tries to excessively swing exceeding the limit of the original swing range during the operation of the apparatus. In order to prevent this, the inertia arm is used.

Abstract: An information-recording method and an information-recording medium which make it possible to improve overwrite characteristics in the high speed recording, especially archival overwrite characteristics for overwriting information after retaining the medium in a high temperature environment for a certain period of time, and an information-recording apparatus based on the use of the same are provided. The information-recording method comprises overwriting a random pattern with light-beams having a predetermined recording power and a variety of erasing powers; reproducing the random pattern to determine a minimum value Pb1 and a maximum value Pb2 of the erasing power obtained when the pattern, in which a reproduction jitter exceeds a predetermined threshold value, is erased; determining an optimum erasing power Pb from the minimum value Pb1, the maximum value Pb2, and a relational expression represented by Pb=?×Pb1+(1??)×Pb2; and recording the information with the determined optimum erasing power Pb.

Abstract: To provide a disk drive system provided with an inertial latching mechanism which has high reliability and can be arranged in a thin-model disk drive system. There is provided an inertial arm (7) engaging an actuator (22) when a head arm (25) is in or near a parking position and releasing engagement 3with the actuator (22) when the head arm (25) is in or near a position close to a disk (1) and energizing means for holding a position of the inertial arm (7) in a position where the engagement with the actuator (22) is released. Even if a rotational shock is externally applied when the actuator (22) remains in the parking position, moment of rotation is applied on each of the actuator (22) and inertial arm (7) in the same direction, the actuator (22) and inertial arm (7) mutually restrain their operations at an engaging part, and the oscillation of the actuator (22) to a data area can be avoided.

Abstract: The reproduction durability of an optical recording medium is evaluated highly accurately in a short period of time by providing a method for evaluating the optical recording medium, the method including determining an operating laser power for heating a recording layer to a recording operating temperature; determining a temperature of the recording layer when a laser beam having a predetermined reproducing laser power is radiated during a data reproduction; determining a relationship between the reproducing laser power during the data reproduction and a reproduction durability times at the reproducing laser power; and determining a relationship between the temperature of the recording layer during the data reproduction and the reproduction durability times from the relationship between the reproducing laser power during the data reproduction and the reproduction durability times.

Abstract: A head supporting device with a loading/unloading mechanism and a disk drive unit using the head supporting device. The head supporting device and a voice coil motor (VCM) make up a head actuator of the drive system. The head actuator has i) a support arm rotatable on a bearing, moving in directions along the radius of a recording medium and vertical to the surface of the medium; ii) a magnetically levitating head on a slider facing the medium; and iii) resilient member for applying force to the arm in a direction close to the medium. The VCM has a pair of yokes, a magnet, and a coil. When the head is lead to a head retracting position, the other end of the arm is pulled by the interaction of a magnetic member and the magnet at the resting position and adjacencies. This eases the load on the VCM, contributing to a compact and slim disk drive unit with toughness and rapid data-access.

Abstract: A process for the production of a bifunctional phenylene ether oligomer compound having no amine adduct represented by the formula (1), which process comprises oxidatively polymerizing a bivalent phenol and a monovalent phenol in the presence of a copper-containing catalyst and a tertiary amine, a secondary amine having a secondary alkyl group, a tertiary alkyl group or an aryl group, or a mixture of both, [Chemical Formula 1] wherein R1, R2, R3, R7, R8, R9 and R10 are the same or different and represent a halogen atom, an alkyl group having 6 or less carbon atoms or a phenyl group, R4, R5, R6, R11 and R12 are the same or different and represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms or a phenyl group, and each of m and n is an integer of from 0 to 25, provided that at least one of a and b is not 0.

Abstract: A phase-change optical recording medium capable of performing recording and reproduction at a high speed is provided, in which a reproduced signal output is not only sufficiently large but the phase-change optical recording medium also has excellent repeated rewriting performance. An interface layer 3, which is composed of a Ge—Si—N-based material, is formed on at least a surface of one side of a recording layer 4 of the phase-change optical recording medium 10. Accordingly, even when a phase-change material having a high melting point, for example, a Bi—Ge—Te-based phase-change material is used for the recording layer 4, it is possible to provide the phase-change optical recording medium in which the reproduced signal output is sufficiently large and the repeated rewriting performance is excellent.

Abstract: Recording information is disclosed in which an information recording medium is irradiated with a recording energy beam that is power-modulated into at least a record power level and a record-ready power level lower than the record power level. The information is recorded on the recording medium in the form of length and interval of a mark portion. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion.

Abstract: Problem to be solved is that when an information recording medium is repeatedly subjected to recording of information several hundreds times, the atoms in a protective layer are diffused and dissolved into a recording layer to lower a reflectivity greatly and make the medium unendurable to many times of overwriting. This problem can be solved by a medium constituted of interference layer 10, interface layer 12, phase-change type recording layer 14, protective layer 13 having a tin content of from 23.3 atomic % to 32.3 atomic %, and a heat sink layer 8 successively formed on substrate 1, as seen from a light-incidence side. By use of this medium, the dissolution of atoms can be prevented, and overwriting for many times can be achieved.

Abstract: Disclosed are an information recording method and an optical disk unit that maintain a good jitter even when a line velocity is variable in a mark edge system. In the case where an erasing power when erasing a record mark at a linear velocity v1 is Pe1(mW), a recording power when forming the record mark at the linear velocity v1 is Pw1(mW), an erasing power when erasing the record mark at a linear velocity v2 faster than v1 is Pe2(mW), and a power when forming the record mark at the linear velocity v2 is Pw2(mW), a relationship of Pw1/Pe1>Pw2/Pe2 is satisfied.

Abstract: A method for recording information is disclosed in which an information recording medium is irradiated with a recording energy beam power-modulated into at least a record power level and a record-ready power level lower than the record power level. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion. Also, only in the case where the energy beam is modulated by the power lower in power level than the record-ready power level after the last pulse of the energy beam pulse train including at least one pulse for forming a mark portion and the mark portion is followed by a space portion of a predetermined length, the particular radiation energy of low power level is reduced as compared with when the mark portion is followed by a space potion of a different length.

Abstract: A semiconductor substrate processing apparatus is provided with a cleaning process chamber containing a semiconductor substrate for performing a cleaning process on the semiconductor substrate. Connected to the cleaning process chamber is a cleaning liquid feeding pipe for supplying a cleaning liquid to the semiconductor substrate. A gas dissolving unit is provided in the midpoint of the cleaning liquid feeding pipe for dissolving a prescribed gas in ultrapure water. An inert gas or a reducing gas is dissolved as a prescribed gas in ultrapure water. A control unit is provided having a function of supplying the cleaning liquid with the prescribed gas dissolved therein to the semiconductor substrate subjected to the cleaning process before performing a dry process. Therefore, the surface of the semiconductor substrate is free from stains. Moreover, a metal interconnection does not elude.

Abstract: There are provided a vinyl compound which is excellent in heat resistance and electric characteristics and excellent in reactivity by introducing a vinyl group into a terminal of a bifunctional polyphenylene ether oligomer, and a cured product thereof which has a high glass transition temperature, has a low dielectric constant and a low dielectric loss tangent and has the excellent properties of polyphenylene ether.

Abstract: Disclosed is a C/C composite material precursor which gives a C/C composite material by calcination including: carbon fiber, a matrix, and void-forming core which is burnt out or reduces the volume thereof at lower temperatures than temperature of the calcination and forms a void which has openings on the surface of the C/C composite material after calcination. Also disclosed is a method for producing a C/C composite material by calcination of the precursor; and the composite material obtained by the calcination.

Abstract: A disk drive apparatus having a head support device with high impact resistance which ensures L/UL operation and CSS operation. The disk drive apparatus includes a supporting arm rotating about a bearing in a direction perpendicular to a recording face of a recording medium; and a ramp provided at any position between the bearing and a head of the supporting arm. The ramp vertically moves the supporting arm while the supporting arm rotates or linearly moves in a radial direction of the magnetic recording medium.

Abstract: An information-recording method includes the steps of moving a light beam at a selected linear velocity relative to the information-recording medium; controlling the light beam to generate a multi-pulse having at least three power levels of a first power level Ph, a second power level P1 which is lower than the first power level, and a third power level Pm which is intermediate therebetween, the multi-pulse being repeatedly modulated between the first power level Ph and the third power level Pm; adjusting the third power level Pm in response to the selected linear velocity; and recording the information by irradiating the information-recording medium with the controlled light beam. Recording compatibility can be secured for information-recording apparatuses different in recording linear velocity and laser source characteristic.