Nippon Electric Co., Ltd.

Nec Corporation

Asahi Kasei Kabushiki Kaisha

Shimizu Construction Co., Ltd.

Hiroshi Inada

Tadashi Nomura

Shigeru Shimonou

Nobuhisa Miyake

Toshiaki Sato

Ikuo Takahashi

Toru Ishii

Masaaki Shinohata

Akio Watanabe

Masakazu Yamauchi

Hiroshi Kawase

Yasuhiro Hayashi

Tetsushi Kiyokawa

Keizo Morita

Yusuke Ebe

Sekio Nambu

Kiyoaki Nishikawa

A compound having an uretonimine group contains, as a structural unit, a carbodiimide compound derived from at least one of an aliphatic diisocyanate and an aromatic diisocyanate, and also contains an isocyanate compound as a structural unit, wherein the residue obtained by removing an isocyanate group from the isocyanate compound and the residue obtained by removing a carbodiimide group from the carbodiimide compound are different.

Compound, curing agent composition, resin composition, coating composition and resin cured product

A construction having a damping device for damping vibration having steel wire cables 20 having both ends fixed on the sides of the building 10, the steel wire cables 20 are tautly and obliquely provided on the building 10 so that one side and the other side of the steel wire cables 20 cross at only one point in front view. Since the steel wire cables 20 do not exist in the horizontal direction, the length of the steel wire cables 20 is shorter as compared with the prior art. Accordingly, extension of the steel wire cables 20 decreases, the mechanism is simpler, and maintenance is also simplified.

Construction having a damping device

A beam access apparatus for an optical disc system. The apparatus includes a lens position detector for generating a lens position signal indicating a position of the objective lens in a radial direction of the disc with respect to the optical head which is movable relative to the disc. The apparatus is operated in a head access mode in which the optical head is moved in the radial direction of the disc and the objective lens is caused to follow the movement of the optical head such that the objective lens is positioned at a predetermined location with respect to the optical head. The apparatus is also operable in a lens access mode wherein the objective lens is moved in the radial direction and the optical head is caused to follow the objective lens such that the objective lens is located at a predetermined position with respect to the optical head.

Beam access apparatus for optical disc system

A digital servo control system is responsive to a command signal indicative of a command position of a moveable element and to a phase modulated signal corresponding to the angle of rotation of a motor controlling said moveable element to develop a motor drive signal to position the motor. The system provides control during a velocity control mode and a position control mode, the latter occurring after the moveable element is moved to a predetermined small incremental distance from the commanded position. During the velocity control mode the motor is driven in accordance with a reference velocity selected in dependence upon the position error signal. Following a prescribed time after entry into the position control mode, the position error has added thereto an integration signal which increases in the same sense as the position error.

Servo control system operable on digital basis

In a digital servo control system (31) for a carriage of a serial printer or a like movable element, a control signal (125) digitally represents a reference angular velocity for a motor (26) until an instant at which a displacement from a current position of the element to a commanded position decreases to a predetermined value, a positional error during a preselected interval following the instant, and an integrated value (52) of a position error between the current and the commanded positions to suppress limit cycle after the interval. A PWM signal (56-57) is derived from the control signal and position pulses (62 or 63) representative of a variation in the current position. Preferably, small-amplitude limit cycle is forced to occur during the interval with the positional error indicated by a modified signal (182) derived by adding unity to positive and zero position errors.

Servo control system operable on digital basis with limit cycle

A system for controllably driving a motor to place a movable element at a position indicated by a command signal from an external source produces, in response to a phase staggered incremental position signal pair, one and the other of two position pulse sequences at a time depending on an instantaneous angular velocity of the motor. Responsive to the command signal and the position pulses, a mode signal is produced to indicate a position control mode while a position error is within a predetermined range and otherwise a velocity control mode. Likewise, a signal is produced that represents at least one reference angular velocity and the position error during the respective modes. Responsive to the position pulses alone, gate pulses are produced either with two different pulse widths depending on the modes or with a single pulse width. During presence of each gate pulse and dependent on the sense of the instantaneous angular velocity indicated by the position pulses, a digital algebraic adder circuit calculates an algebraic sum of the reference angular velocity or the position error and a reference feedback value, which may either be memorized in the system or supplied from the source and may take two digital values depending on the modes. A digital signal representative of the sums and either the reference angular velocity or the position error during presence and absence, respectively, of the gate pulses is converted to an analog signal, which is smoothed and amplified to provide a motor drive signal.

Position control system comprising a digital algebraic adder circuit

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Tokyo, Japan

Hiroshi Inada