Abstract: A printing plate material producing concave-convex pattern on the surface with a low laser energy output and having high scratch resistance is provided by formation of a photosensitive layer comprising a nitrocellulose, carbon black or other photoabsorber and a polyurethane elastomer on a support. The nitrocellulose has a nitrogen content of about 11 to 12.5% and a solution viscosity of about 1 to 1/8 second. The polyurethane elastomer is obtainable by allowing a polyester polyol to react with a polyisocyanate and a chain-extending agent. Relative to 100 parts by weight of the polyurethane elastomer, the amount of nitrocellulose is about 5 to 300 parts by weight and that of the photoabsorber is about 0.5 to 50 parts by weight. The photosensitive layer may have a glass transition temperature of not lower than 25.degree. C. The photosensitive layer may further comprise a plasticizer.

Abstract: A stamper for injection-molding a plastic substrate for an optical disk characterized in that a rear surface of the stamper a surface roughness between 0.3 to 2.0 S.

Abstract: A disk drive system with a disk loading/ejection control mechanism, includes a disk insertion detection switch for detecting an insertion of a disk and a first cam member for controlling loading and ejection operations of the disk. The first cam member is rotated by a driver to perform loading and ejection of the disk. A loading/ejection position detection switch detects both loading and ejection positions of the disk. A second cam controls the loading/ejection position detection switch, the second cam being co-operatively operated with the first cam. A controller is responsive to the operation of the disk insertion detection switch to drive the driver, and is responsive to both the leading and trailing edges of an output from the loading/ejection position detection switch, for detecting the disk loading and ejection positions to control the driver.

Abstract: An apparatus for ejecting a cassette containing therein a recording/reproducing medium by the driving force produced by an ejection motor has an ejection switch for commanding the cassette ejection and a cassette switch for detecting the cassette loading condition. When the cassette switch has detected the casette loading condition simultaneous with turning on of the ejection switch and when the ejection switch is kept turned on in excess of a predetermined time period continuously regardless of the cassette switch condition, the cassette ejection controller executes the cassette ejection.

Abstract: A disc unit having a plurality of disc drive mechanisms each driving a disc connected in the daisy chain connection mode. The disc unit has a control circuit for controlling the plurality of disc drive mechanisms commonly. The control circuit is incorporated in one of the plurality of disc drive mechanisms to control it and the remaining disc drive mechanisms. .

Abstract: A deflection yoke is constructed of a truncated conical hollow core, a pair of saddle-shaped horizontal deflection coils disposed inside the core, and a pair of toroidal vertical deflection coils wound on the core or a pair of vertical deflection coils wound in a saddle-like configuration and arranged in the vicinity of the core. A pair of cancellation coils opposing each other on an imaginary axis which passes through a central axis of the core in the direction of vertical deflection are arranged near front end sections of the vertical deflection coils, respectively. A central axis of each of said cancellation coils is inclined at a predetermined angle relative to the central axis of the core. The cancellation coils are connected with the horizontal deflection coils, respectively.

Abstract: A stepping motor drive control apparatus for controlling the drive of a stepping motor having a plurality of phase coils which are respectively excited to switch the phase. A cycle of a step signal which steps the stepping motor is measured. According to the measured cycle of the step signal, a switching time of the phase coil to be excited is variably set, so that damping and noise are prevented when the stepping motor is driven.

Abstract: An intake air throttle device, of a diesel engine, with a throttle valve disposed in an intake air passage. The throttle valve is moved into a full-open, an intermediate, and a full-closed position according to the engine operation.An actuator for the throttle valve is vacuum-operated. A temperature sensitive valve is disposed in a conduit connecting the actuator to the vacuum source, thereby the throttle valve is brought into the full-open position when the engine is cool for preventing white smoke in exhaust gas.