Fujitsu Corporation

Hiroshi Tani

Shigenori Yanagi

Toru Ikeda

Tetsuya Tsuji

The present invention aims at providing an inexpensive optical information storing device that produces reduced cross talk. An optical information storing device has a cyclic data output circuitthat outputs cyclic data in which values are repeated every 5 bytes, and an EXOR circuitthat calculates the exclusive-OR (EXOR) of recording data input thereto via a bufferand the cyclic data and inputs the calculation result to an RLL modulation circuitas data to be recorded.

Optical information storing device, data processing circuit and information storage medium

A data assurance method controls an optical head according to the difference between the device temperature and the temperature of inserted removable optical storage media. A rate of temperature change c is calculated from the output of a temperature sensor which detects the device temperature, and then the temperature of the media is estimated. A transition is made to special processing, and a return is made from special processing in a state with a temperature difference to normal processing depending on the rate of temperature change. Consequently a return to normal processing can be made safely and quickly.

Data assurance method for optical storage media and optical storage device

A storage apparatus has a function of jumping to an arbitrary track on a recording medium in response to a track jump request when making access to the recording medium, where the recording medium is divided into a plurality of zones in a radial direction thereof and employing a ZCAV system. The storage apparatus includes a zone recognizing part recognizing a zone to which a present position on the recording medium belongs, and a jumping part jumping to a first zone to which the arbitrary track belongs or to a second zone which is adjacent to the first zone, based on the zone recognized by the zone recognizing part.

Track jump method for ZCAV system and storage apparatus employing ZCAV system

A data read method includes a steps of reading identical data from one region on a recording medium a plurality of times, a step of comparing the data read the plurality of times in units of one or a plurality of bits to obtain comparison results, and generating read data made up of data values having a highest frequency for each unit based on the comparison results, and a step of carrying out an error detecting and correcting process with respect to the read data.

Data read method for remedying low-quality read data and storage apparatus employing such a data read method

A sector mark detecting circuit for detecting a sector mark on an optical storage medium includes a binarizing circuit which binarizes a reading signal of an optical head in accordance with a predetermined detection parameter and is capable of changing the detection parameter. A recognizing circuit is adapted to recognize a sector mark from an output of the binarizing circuit, and a control circuit is adapted to measure an optimal value of the detection parameter of the binarizing circuit and control the detection parameter of the binarizing circuit to the optimal value. A sector mark detection rate is thereby enhanced.

Optical storage device having a sector mark detecting circuit

A light emission fine adjustment processing unit of an optical storage apparatus brings a light beam to a test zone in an on-track state, sequentially instructs testing powers at two points to a light emission current source circuit, allows a laser diode to emit light, simultaneously instructs a subtraction current of the testing powers at two points to a subtraction current source circuit, and adjusts an instruction value so that a measuring power of a monitor power measuring unit is equal to the instructed testing power. An automatic power control holding unit holds an automatic power control unit at the time of the light emission of the laser diode. A test zone confirming unit activates a light emission adjustment process when the present position lies within a range of the test zone, and prevents a breakage of user data when the present position is out of the test zone range. A light emission timing control unit allows the light emission to be performed in only a data field while avoiding an ID field of a sector.

Optical storage apparatus having an automatic laser power control with

A bias current measuring unit measures a drive current which is supplied to a VCM when a carriage is moved to a plurality of measurement positions and held as a bias current to remove a mechanical offset that is applied to the carriage and stores into a storing unit. A bias current operating unit obtains a corresponding bias current Vd with reference to the storing unit on the basis of a carriage position during a seeking operation and adds the bias current Vd to a seek current Vs which is supplied to the VCM, and removes a disturbance component which is caused by a mechanical offset due to a friction between a bearing and a rail, a tension by an FPC, and the like.

Optical storage apparatus

An acceleration .alpha. that is peculiar to a lens actuator is obtained by an acceleration measuring section on the basis of a moving speed when a 1-track jump such that a light beam spot of an optical head is moved to an adjacent track is executed to the lens actuator. A seek control section moves the light beam spot of the optical head to a target track by an acceleration control and a constant speed control of the lens actuator. When the light beam spot reaches a position that is located by a predetermined number of tracks before the target track, the lens actuator is deceleration controlled on the basis of the acceleration measured by the acceleration measurement and the light beam spot is on-tracked to the target track at the end time point of the deceleration control.

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Kawasaki, Japan

Hiroshi Tani