摘要:
A magnetooptic recording medium having a writing layer and a readout layer on a substrate is used. Data is recorded in the writing layer of the magnetooptic recording medium at a recording density smaller than a diameter of a focal spot of a laser beam. The data recorded in the writing layer of the magnetooptic recording medium at the recording density smaller than the beam diameter is reproduced by setting a reproducing laser power to a proper value. A reproduction laser power calibrating module executes the reproducing operation for calibration of the magnetooptic recording medium, thereby deciding the optimum value of the laser power which is used upon reproduction. For example, the reproduction laser power calibrating module measures a change in reproduction signal while raising the reproducing laser power by using a predetermined minimum reproducing laser power W0 as an initial value and a value obtained by adding a predetermined value Wc to the reproducing laser power (W) when the reproduction signal doesn't change to the optimum reproducing laser power.
摘要:
According to one embodiment, a voltage measuring device that measures an input voltage signal includes a divider, a filter, an adder, and an analog-to-digital converter. The divider divides the input voltage signal into a first signal and a second signal. The filter filters the first signal and attenuates a direct current component of the first signal less than a predetermined frequency component of an alternating current component of the first signal. The adder adds an output signal of the filter to the second signal. The analog-to-digital converter converts an output signal of the adder into a digital signal. The divider adjusts the amplitude of at least one of the first signal and the second signal such that the level of a direct current component of the output signal of the adder is in the input range of the analog-to-digital converter.
摘要:
The present invention provides an information storage apparatus that generates a tracking error signal based on a detection signal, and performs various control operations based on the tracking error signal. When the operation mode is a seek operation mode, the information storage apparatus generates a tracking error signal by holding the peak value of the detection signal. When the operation mode is a tracking operation mode, the information storage apparatus generates a tracking error signal directly from the detection signal. With this information storage apparatus, stable control operations can be performed, regardless of changes of conditions.
摘要:
The present invention provides an information storage apparatus that generates a tracking error signal based on a detection signal, and performs various control operations based on the tracking error signal. When the operation mode is a seek operation mode, the information storage apparatus generates a tracking error signal by holding the peak value of the detection signal. When the operation mode is a tracking operation mode, the information storage apparatus generates a tracking error signal directly from the detection signal. With this information storage apparatus, stable control operations can be performed, regardless of changes of conditions.
摘要:
A method and apparatus for optical recording addresses a problem of edge shift which occurs during the recording. The apparatus includes a rotating mechanism for rotating an optical medium, and an optical head having a light source for recording information on the optical medium. A moving mechanism moves the optical head to a predetermined position on the optical medium, and a recording controlling device controls light source of the optical head in accordance with a recording pulse. The recording controlling device includes a pulse width measuring device for measuring the pulse width of a recording pulse, and fall controlling device effects a recording compensation by advancing a fall of the recording pulse with a lead, such that the lead increases with the measured pulse width. A pulse interval measuring device is provided for measuring a pulse interval preceding the recording pulse, and a rise controlling device effects a recording compensation by delaying a rise of the recording pulse with a delay, such that the delay decreases with the measured pulse interval.
摘要:
A magnetic disk drive includes a switching regulator configured to generate an output voltage, and a magnetic disk control unit that receives the output voltage as a power supply and performs data write and read operations on a magnetic recording medium. The switching regulator includes a voltage conversion part configured to generate a second voltage by switching a first voltage, a smoothing part configured to smooth the second voltage to thus produce an output voltage, a control part configured to control the switching on the basis of a difference between the output voltage and a reference voltage to thus stabilize the output voltage, and a reference voltage changing part configured to change the reference voltage in accordance with an operation mode of the magnetic disk control unit.
摘要:
An optical disk apparatus adapted to a mark edge recording method having a structure such that a data pattern experimentally recorded on an optical disk with one write power is reproduced plural times while changing reproducing conditions (for example, a slice level for binary-coding a reproduced analog signal) and the number of errors is calculated whenever the reproducing process is performed. The thus-structured process is repeated for using a plurality of write powers. An appropriate write power for the optical disk is determined in accordance with the obtained results of the calculations of the number of errors. In a case of a read-only optical disk, a data pattern experimentally and previously recorded on the optical disk is reproduced plural times by changing the reproducing conditions (for example, a slice level for binary-coding a reproduced analog signal), and the number of errors is calculated whenever the reproducing process is performed. In accordance with the obtained results of the calculations of the number of errors, an appropriate reproducing condition for the optical disk is determined.
摘要:
An optical disk apparatus adapted to a mark edge recording method having a structure such that a data pattern experimentally recorded on an optical disk with one write power is reproduced plural times while changing reproducing conditions (for example, a slice level for binary-coding a reproduced analog signal) and the number of errors is calculated whenever the reproducing process is performed. The thus-structured process is repeated for using a plurality of write powers. An appropriate write power for the optical disk is determined in accordance with the obtained results of the calculations of the number of errors. In a case of a read-only optical disk, a data pattern experimentally and previously recorded on the optical disk is reproduced plural times by changing the reproducing conditions (for example, a slice level for binary-coding a reproduced analog signal), and the number of errors is calculated whenever the reproducing process is performed. In accordance with the obtained results of the calculations of the number of errors, an appropriate reproducing condition for the optical disk is determined.
摘要:
An optical disk apparatus adapted to a mark edge recording method having a structure such that a data pattern experimentally recorded on an optical disk with one write power is reproduced plural times while changing reproducing conditions (for example, a slice level for binary-coding a reproduced analog signal) and the number of errors is calculated whenever the reproducing process is performed. The thus-structured process is repeated for using a plurality of write powers. An appropriate write power for the optical disk is determined in accordance with the obtained results of the calculations of the number of errors. In a case of a read-only optical disk, a data pattern experimentally and previously recorded on the optical disk is reproduced plural times by changing the reproducing conditions (for example, a slice level for binary-coding a reproduced analog signal), and the number of errors is calculated whenever the reproducing process is performed. In accordance with the obtained results of the calculations of the number of errors, an appropriate reproducing condition for the optical disk is determined.
摘要:
The present invention provides an information storage apparatus that generates a tracking error signal based on a detection signal, and performs various control operations based on the tracking error signal. When the operation mode is a seek operation mode, the information storage apparatus generates a tracking error signal by holding the peak value of the detection signal. When the operation mode is a tracking operation mode, the information storage apparatus generates a tracking error signal directly from the detection signal. With this information storage apparatus, stable control operations can be performed, regardless of changes of conditions.