Fujitsu Corporation

Ichiro Watanabe

Takayuki Kawabe

Koji Wakio

Hajime Shimizu

Tsutomu Tanaka

Yasuhiro Watanabe

Shoichi Arai

Kazuhiro Takekawa

Yuji Terauchi

Masayoshi Hashima

Keiju Okabayashi

Shinji Kanda

Naoyuki Sawasaki

Yuichi Murase

Fumi Hasegawa

Kazuyuki Mori

Yuji Tochio

Tsugito Maruyama

Yuji Ishii

Tetsuji Yamabana

Arata Ejiri

Masaharu Koyabu

Hideki Okamoto

An object of the invention is to provide a control apparatus and a control method having a simple constitution, which can stably perform switching of optical path in an optical signal exchanger, while suppressing an influence on a control due to the mechanical resonance of tilt mirrors. To this end, the control apparatus of the optical signal exchanger is constituted such that in an optical signal exchanger of three-dimensional type using one set of MEMS mirror arrays, each having a plurality of tilt mirrors arranged on a plane, each tilt mirror having a reflecting surface an angle of which is controllable, when the angle of the MEMS mirror on the optical path is feedback controlled by detecting power of an optical signal output from a specific position, a resonance component removing section that removes a resonance frequency component included in a control signal is shared corresponding to a pair of driving electrodes arranged in a coaxial direction of the MEMS mirror. As a result, the influence on the feedback control by a resonance action of the MEMS mirror can be reduced, while suppressing an increase in circuit size.

Control apparatus and control method of optical signal exchanger

A follow-up control system follows up a head of a storage device to a storage medium. A sine wave signal learning section () which learns sine wave signals according to follow-up error signals which are input to a feedback control system (), and performs time lead compensation corresponding to a delay of the feedback system (), is provided. Since the time lead compensation is used for the sine wave signal learning model which can learn at high-speed, frequency disturbance of high frequency, for which phase lag must be considered, can be a compensation target, and the present invention contributes to the improvement of follow-up accuracy of the storage device.

Head follow-up control method, head follow-up control device and storage device thereof

An information storage device having a uniaxial tracking mechanism as a pickup which can perform a stable track pull-in operation is provided. A deceleration pulse amplitude &#xe1; supplied to a tracking actuator is determined from a linear function &#xe1;=K(V&#x2212;V) of a detected movement velocity of a beam in the vicinity of a target track. The deceleration pulse amplitude is divided into two, and is supplied to the tracking actuator on two different occasions.

Information storage device

In a focus control for following a focus position of light beam to be radiated to an optical disk to an optical disk surface, the technique is for shorten the memory length in the learning controller. The learning controller is provided to a focus feedback control system and updates the memory comprised of N numbers of memory cells with a shorter sample period than a time obtained by dividing the time required for one rotation of the disk by N numbers and outputs the learning results in the memory with the shorter sample period.

Optical disk apparatus and focus control method thereof

An information storage device having a uniaxial tracking mechanism as a pickup which can perform a stable track pull-in operation is provided. A deceleration pulse amplitude &aacute; supplied to a tracking actuator is determined from a linear function &aacute;&equals;K(V&minus;V ) of a detected movement velocity of a beam in the vicinity of a target track. The deceleration pulse amplitude is divided into two, and is supplied to the tracking actuator on two different occasions.

Information storage device having uniaxial tracking mechanism with decelaration control

A disk apparatus has a head, a positional signal detection section that detects a track of a medium, a feedback control section which computes a control signal for moving the head from the location of a positional signal generated by a position signal detector, and a learning control section which generates and stores an unknown function for one disk rotation, which includes a periodic disturbance, in a memory which is comprised of N number of memory cells by a learning algorithm as an approximate function which is approximated by the height of each of several blocks in the medium. The learning control section reads the learning result of the two memory cells at locations which are moved forward for a predetermined amount of time, and interpolates the results so as to generate a periodic disturbance compensation signal.

Disk apparatus and track following control method

A learning control unit is provided between a feedback calculating unit and a driving unit. When a period for one medium rotation period is assumed to be T , an unknown drive current function Irepeat(t) which repeats for a period of time from a start time t&equals;0 for one medium rotation period to an end time t&equals;T is obtained by a learning algorithm as an approximated function I{circumflex over ( )}repeat(t) that is approximately presumed by a set of the heights C of N rectangular functions having interval numbers i&equals;0&tilde; (N&minus;1) whose time widths are obtained by dividing the period for one medium rotation period into N intervals. After the learning, a learning control signal I{circumflex over ( )}repeat is outputted synchronously with the medium rotation and a feed-forward control is performed. The learning control unit can be provided between a position signal detecting unit and a feedback calculating unit and can learn a position function TESrepeat(t) as an approximated function TES{circumflex over ( )}repeat(t) in a similar manner.

Storage apparatus

A track jump control unit adds an FF signal for repetitive disturbance compensation obtained by a learning control which is used in a track-following control and a final value of an FB control low band component just before a track jump to a track jump signal to move a light spot to an adjacent track, thereby driving a carriage. As a track jump signal, a first kick pulse of a predetermined acceleration and a predetermined time, a second kick pulse which continues at a predetermined acceleration until a detection of a track zero-cross point, and a brake pulse of a predetermined acceleration (deceleration) and a predetermined time are used.

Storage apparatus having device for controlling track jump of a positioner

An approximate value calculating unit is provided for a storage apparatus in which a seek control is performed by speed controlling a head. When a square root arithmetic operation is needed in the calculation of a seek speed target value which is used in the seek control, the approximate value calculating unit divides a range of an input value x serving as a target of the square root arithmetic operation into a plurality of intervals, sets a polynomial of degree N to approximately output a square root {square root over ( )}x of the input value x as an approximate function every interval, and calculates the square root approximate value of the input value x by selectively using the approximate function corresponding to the interval to which the input value x belongs. Further, according to the range dividing method of the input value x, it is sufficient that the polynomial of degree N or the approximate function by the reference table is prepared only for the basic range, and there is no need to prepare the approximate function which covers the range before the input value x. Even when the square root approximate value for the input value x belonging to the range out of the basic range is obtained by executing the input scale conversion and output scale conversion, the approximate function prepared for the basic range can be used.

An apparatus has an input hold circuit for sequentially holding digital feedback signals sequentially transmitted at a sampling period, and for sequentially outputting the transmitted feedback signals or held feedback signals at a period which is shorter than the sampling period; a notch filter for applying a filtering processing to the feedback signals outputted from the input hold circuit; and an output hold circuit for sequentially outputting the feedback signals subjected to the filtering processing by said notch filter, while thinning the same, at a period which is same as the sampling period.

Feedback controller, digital filter device, and storage device

A control unit positions a laser beam toward a target track on a medium on the basis of a tracking error signal (TES) Y indicative of a positional deviation amount from a track center as a zero point on the basis of return light from the medium. A position signal correcting unit executes a correcting arithmetic operation using a non-linear function such as a quadratic polynomial, a quadratic monomial equation, or the like to the TES Y and outputs a corrected TES Z obtained by correcting detection sensitivity characteristics to desired characteristics so that a feedback is sufficiently performed when a lead-in control to the track center by the control unit is executed.

Optical storing apparatus

The data, as read out from a trunk database, and the read-out data, as processed, are stored in a public database. A setup unit and an operations support unit manage the stored data of the public database and the attribute data of the stored data by a dictionary. In accordance with a demand of a user, an inquiry unit processes and displays the data on the basis of the data stored in the public database and the attribute data.

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Kawasaki, Japan

Ichiro Watanabe