Fujitsu Corporation

Nippon Telegraph and Telephone Corporation

Nippon Telegraph & Telephone Co.

Takashi Masaki

Shigenori Yanagi

Toru Ikeda

Manabu Yamamoto

Toru Fujiwara

Shigeru Arai

Shigeyoshi Tanaka

Hideshi Mochizuki

A storage apparatus rotates an optical recording medium at two or more kinds of rotational speeds. The rotational speed is decreased when a read or write margin becomes less than or equal to a first predetermined value or, when a frequency of generation of a servo abnormality of a tracking servo and/or a focus servo is greater than or equal to a first predetermined frequency. On the other hand, the rotational speed is increased when the read or write margin becomes greater than or equal to a second predetermined value or, when the frequency of generation of the servo abnormality of the tracking servo and/or the focus servo is less than or equal to a second predetermined frequency.

Rotation control method and storage apparatus

The present invention provides a low-cost optical recording device that determines an optimum quantity of light for recording and reproducing, and an optimum focus offset value. The present invention also relates to a method of determining such an optimum focus offset value. The optical recording device is equipped with a focus control system for performing a focus control operation to focus light from a light source onto a recording face of an optical recording medium. This optical recording device includes: a focus offset value setting unit for sequentially setting a plurality of offset values for the focus control system; an adder unit for using each focus offset value to adjust the focus control system; a light quantity setting unit for sequentially setting a quantity of recording light emitted from the light source at a plurality of predetermined values; a recording unit for recording information on the optical recording medium; an error rate measuring unit for measuring an error rate in the information reproduced from the optical recording medium; and an optimum focus offset value determining unit for determining an optimum focus offset value based on the measured error rate.

Optical recording device, and method of determining optimum focus offset value for the device

An optical storage device decreases the influence of return light to the laser light source and prevents an increase of power consumption even if high frequency superimposing is performed. The optical storage device applies drive current, to which a high frequency signal is superimposed, to the laser light source, and reads/writes data from/in the storage medium. The high frequency superimposing is set to OFF as a default to save power consumption, and high frequency superimposing is turned ON only when it is judged that servo is unstable, and high frequency superimposing is turned OFF when it is judged that servo is stable.

Optical storage device and emission control method

There is disclosed an information storage apparatus in which even when a remaining power of a battery or a galvanic cell is low, an information recording medium can safely be removed. An MPU, a spindle motor driver, and a spindle motor constitute a decelerator for decelerating rotation of the information recording medium, and as a deceleration mode, a first deceleration mode with a relatively large power consumption and a second deceleration mode with a relatively small power consumption are used. The MPU monitors a voltage of a power supply line via a DSP, decelerates the rotation of the information recording medium in the first deceleration mode when the voltage exceeds a predetermined level, and decelerates the rotation of the information recording medium in the second deceleration mode when the voltage indicates the predetermined level or less.

Information storage apparatus

Method of controlling rotation of optical recording medium at two or more rotational speeds, and storage apparatus employing same method

A tracking control method measures an optimum offset by measuring a light beam irradiation state of a light beam while offsetting a tracking target position of the light beam on a recording medium so that an optimum light beam irradiation state is obtained at the tracking target position, and carries out a tracking control by setting the measured optimum offset.

Tracking control method and storage apparatus

An optical memory apparatus has an offset inserting unit for inserting a predetermined offset to the focus error signal, and a focus servo pull-in determining unit for inserting, when the focus servo control unit executes focus servo pull-in, offset to the focus error signal, detecting level change of the focus error signal and determining success or failure of focus servo pull-in.

Optical memory apparatus and focus servo control method

A division test write processing unit is provided and a test writing process for deciding an optimum light emitting power by executing a test writing on a medium is divided into a plurality of division test writing processes. When an upper command is received, in the division test write processing unit, a division control unit skips to a division executing unit locating at the head of the processes which are not yet executed among a plurality of division executing units and allows the dividing processes of the test writing to be executed for a predetermined time.

Optical storage apparatus

A servo control apparatus of an optical pickup in which an offset and a gain can be adjustable for each servo control apparatus, and influences caused by changes in environmental conditions and changes with time are reduced without a decrease in operational speed, and increase in size and an increase in cost is disclosed. The servo control apparatus includes a nonvolatile memory for storing compensatory values which correspond to differences of servo characteristics of each servo apparatus and which are measured with the assistance of external measurement instruments, and a compensation portion for compensating an optical pick-up servo signal according to the compensatory values stored in the nonvolatile memory.

Optical pickup servo control apparatus with stored compensatory values

When a migration is predicted and judged of continuous recording and regeneration to an adjacent next optimum condition effective area in the course of data sequential processing for recording or regenerating data continuous in a certain optimum condition effective area, a setting control unit performs optimum condition setting processing (erase, recording, regeneration) of the next optimum condition effective area under the control of an optimum condition setting processing unit, to thereby previously determine the optimum emission power and the optimum magnetic field.

Storage apparatus

An objective lens of an optical head is cleaned with a cartridge accommodating a cleaning disk with a brush thereon. The cleaning disk is rotated in apparatus to clean the surface of objective lens provided on the optical head. Simultaneously with causing the rotation of the cleaning disk by driving a spindle motor, the lens is moved toward and away from the disk by driving a lens actuator. Additionally, simultaneous reciprocation of a carriage carrying the optical head toward alternate inner and outer disk peripheries may be caused. Further, the operation of reciprocating the objective lens toward the inner and outer disk peripheries and the operation of moving the lens toward and away from the cleaning disk with the lens actuator may be performed in combination.

Optical disk apparatus with optical head cleaning

A light emission adjustment processing unit of a laser diode sequentially instructs a D/A converter for light emission of a light emission by test powers at predetermined two points, allows the laser diode to emit the light, instructs a D/A converter for subtraction of subtraction currents corresponding to the test powers at two points, and measures each power by an A/D converter for monitoring. From the measurement results, a relation of the instruction values to an arbitrary power in each D/A converter is obtained by a linear approximation and registered into a power table. When deciding an optimum writing power by a test write, a limit power on the lower limit side is detected while gradually decreasing the writing power from a starting power and a predetermined offset is added to the detected limit power, thereby obtaining the optimum writing power.

A disc apparatus has a cartridge loading/unloading mechanism to perform a loading operation for attaching an optical disc enclosed in a cartridge inserted from an outside to a rotary shaft of a spindle motor and an unloading operation for removing the optical disc from the rotary shaft of the spindle motor and for ejecting the cartridge to the outside. The loading operation of the cartridge loading/unloading mechanism is executed by the rotation of one direction of a load motor. The unloading operation of the cartridge loading/unloading mechanism is executed by the rotation in the reverse direction of the load motor. A drive current of the load motor is turned on or off at a short period, thereby adjusting so as to optimize a drive torque. When an exchangeable optical disc is loaded, a motor is activated, an initialization control is executed during the acceleration, and after a motor rotational speed reached a specific speed, the apparatus enables the writing/reading operations to be executed. When a voice coil motor is driven simultaneously with the spindle motor during the initialization adjustment, the drive current of the spindle motor is limited.

Disk apparatus

A disc-apparatus has a cartridge loading/unloading mechanism to perform a loading operation for attaching an optical disc enclosed in a cartridge inserted from an outside to a rotary shaft of a spindle motor and an unloading operation for removing the optical disc from the rotary shaft of the spindle motor and for ejecting the cartridge to the outside. The loading operation of the cartridge loading/unloading mechanism is executed by the rotation of one direction of a load motor. The unloading operation of the cartridge loading/unloading mechanism is executed by the rotation in the reverse direction of the load motor. A drive current of the load motor is turned on or off at a short period, thereby adjusting so as to optimize a drive torque. When an exchangeable optical disc is loaded, a motor is activated, an initialization control is executed during the acceleration, and after a motor rotational speed reached a specific speed, the apparatus enables the writing/reading operations to be executed. When a voice coil motor is driven simultaneously with the spindle motor during the initialization adjustment, the drive current of the spindle motor is limited.

Growing community of inventors

Kawasaki, Japan

Takashi Masaki