Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Masaharu Imura

Toshikazu Koudo

Yoshiki Kuno

Tsutomu Kai

Hidefumi Ishibashi

Yasuhisa Mashiko

Kazuhiro Mihara

Takanori Okada

Shuichi Yoshida

Kiyoshi Masaki

Noritaka Akagi

Kazuhiko Kouno

Masanori Harui

Hiromichi Ishibashi

Toshihiko Takahashi

Ryusuke Horibe

Toshiyuki Shimada

Kazutoshi Aida

Takumi Matsuura

Atsushi Hirayama

Masamitsu Mimura

An information recording/reproducing apparatus including an optical pickup unit for generating an RF signal performs signal processing to acquire, at a restart of recording after a halt of recording, a data ID to be used as a reference for specifying a recording restart position in the recording medium based on the RF signal. The signal processing includes reproduced signal generation processing to generate a reproduced signal based on the RF signal, and data ID acquisition determination processing to determine, at the restart of recording after the halt of recording, whether or not the data ID has been properly acquired, based on the reproduced signal. If it is determined in the data ID acquisition determination step that the data ID has not been properly acquired, a reproduction parameter to be used for generating the reproduced signal in the reproduced signal generation step is adjusted.

Integrated circuit, information recording/reproducing apparatus, and signal processing method

The present invention is aimed at providing an optical disc device and a recording condition setting method which can automatically determine an optical recording condition to an optical disc, and the optical disc device comprises an optical pickup which records data on a disc; a data encoder which modulates data to be recorded; a recording timing setting means which sets a timing of recording the data on the disc; a phase error detection means which measures an error amount of a mark recorded on the disc from a position where the mark should be properly located; an error convergence means which calculates error information indicating an optimum position of the mark; a recording timing calculation means which calculates a correction value of the recording timing to be set on the recording timing setting means, based on the error information; and a control means which feedbacks an output of the recording timing calculation means to the recording timing setting means, thereby to optimize the recording timing.

Optical disc device and recording condition setting method

A disk drive apparatus for a disk having helically-formed or concentric circle-like formed tracks includes a spindle motor for controlling a rotation of the disk; a pick-up device for recording or reproducing information on or from the disk; a stepping motor for moving the pick-up device in a radial direction of the disk in accordance with a drive current; a system controller for tracking a rotation speed of the spindle motor and for outputting command signals according to the rotation speed of the spindle motor; and a stepping motor controller for controlling the stepping motor by changing a slope of a rising part and a falling part of a waveform of the drive current of the stepping motor according to the command signals.

Disk drive apparatus

A disk apparatus includes a pick-up for reading/writing signals from/on a disk; a pick-up base provided with the pick-up; a traverse motor for moving the pick-up in a radial direction of said disk; a feed screw rotated by the traverse motor and provided with a thread groove on its periphery; a rack having a fixing portion fixed to the pick-up base and a nut portion engaged with the thread groove; a guiding mechanism for guiding the pick-up movably in a radial direction of the disk; and a cantilever parallel spring for connecting the fixing portion to the nut portion of the rack, displaceably in a radial direction of the feed screw.

Stepping motor controlling method and disk apparatus

An information recording method of recording information, in which laser light is applied to a recording medium while depending on predetermined information said laser light is modulated and the intensity of said light is controlled to form recording mark areas at which reflectivity of said recording medium changes, depending on the intensity of said applied light, wherein before starting data recording, said light is applied to said recording medium at predetermined light intensity, reflection light from said recording mark areas of said recording medium is received, the amount of said reflection light is detected, and a light intensity controlling reference value is calculated on the basis of the amount of said detected light, and during data recording, reflection light from said recording mark areas of said recording medium is received, the amount of said reflection light is detected, and a light intensity controlling detection value is calculated on the basis of the amount of said detected light, corrected light intensity is obtained from the difference between said light controlling intensity reference value and said light intensity controlling detection value, said light intensity controlling reference value is corrected depending on said corrected light intensity, and the intensity of said laser light is controlled so that said corrected light intensity controlling reference value substantially coincides with said light intensity controlling detection value.

Information recording method and information recording apparatus

In a method of the present invention for controlling stepping motor, the stepping motor driving current is increased or reduced at a fixed inclination in proportion to the time to control the stepping motor effectively, and, a stepping motor driving current pattern is changed by &frac14; cycle or more to synchronize the state of excitation between the stepping motor driving means and the stepping motor to control the pick-up very accurately. In addition, the disk apparatus of the present invention, which uses a stepping motor is provided with a pulse rate pattern variable means, a pulse rate change proportion measuring means, and a driving voltage variable means, and when the pulse rate and the pulse rate change proportion are low, the driving voltage amplitude is lowered to reduce surplus torque generation in the stepping motor.

Stepping motor control method and disk drive apparatus

A disk reproducing device comprising: clock signal extracting means for extracting a regenerative clock signal from a reproduced signal; synchronization detecting means for detecting a synchronizing signal from the reproduced signal; extracted clock signal verification means for verifying that the regenerative clock signal is correctly extracted; signal processing means for performing variable linear velocity reproduction; target reproducing speed setting means for setting a target reproducing speed; reproducing speed verification means for verifying that a reproducing speed reaches the target reproducing speed; and signal processing start command generating means for outputting a signal processing start command referring outputs of said extracted clock signal verification means and said reproducing speed verification means.

Disk reproducing device, a disk reproducing method, a disk rotation control method, and a regenerative clock signal generating device

A virtual RAM read address generating circuit (,) generates a virtual address on the basis of an output signal of a crystal oscillation circuit (,). A phase comparison circuit (,) which performs phase comparison with a write address, and a spindle control circuit (,) which controls rotation of a disk with reference to outputs of a frequency comparison circuit (,) and the phase comparison circuit (,) are disposed. Therefore, a phase error can be fed back to a spindle motor, thereby preventing linear velocity deviation from occurring in a steady state. By using the thus configured reproducing device, the reproduction quality in the case where a disk wherein recording was performed by the CLV system is reproduced by the variable linear velocity reproduction system is ensured, and both high-speed access and low power consumption are realized.

Disk reproducing device a disk reproducing method a disk rotation control method and a regenerative clock signal generating device

In a method of the present invention for controlling stepping motor, the stepping motor driving current is increased or reduced at a fixed inclination in proportion to the time to control the stepping motor effectively, and, a stepping motor driving current pattern is changed by 1/4 cycle or over to synchronize the state of excitation between the stepping motor driving means and the stepping motor to control the pick-up very accurately. In addition, the disk apparatus of the present invention, which uses a stepping motor is provided with a pulse rate pattern variable means, a pulse rate change proportion measuring means, and a driving voltage variable means, and when the pulse rate and the pulse rate change proportion are low, the driving voltage amplitude is lowered to reduce surplus torque generation in the stepping motor.

A virtual RAM read address generating circuit (41) generates a virtual address-on the basis of an output signal of a crystal oscillation circuit (36). A phase comparison circuit (39) which performs phase comparison with a write address, and a spindle control circuit (3) which controls rotation of a disk with reference to outputs of a frequency comparison circuit (38) and the phase comparison circuit (39) are disposed. Therefore, a phase error can be fed back to a spindle motor, thereby preventing linear velocity deviation from occurring in a steady state. By using the thus configured reproducing device, the reproduction quality in the case where a disk wherein recording was performed by the CLV system is reproduced by the variable linear velocity reproduction system is ensured, and both high-speed access and low power consumption are realized.

Disk reproducing device, a disk reproducing method, a disk rotation

Device end method for reproducing data from disk, method for controlling

The optical disk reproducing apparatus of the invention includes: a waveform equalizing section for emphasizing a predetermined range of frequency band of a reproduced signal; a digitizing section for digitizing the reproduced signal which has been emphasized by the wave equalizing section at a predetermined level, so as to convert the emphasized reproduced signal into a digital signal; a period detecting section for detecting and outputting a period of a predetermined pattern included in the digital signal; a phase lock loop section having a free-run period, for controlling the free-run period based on the output of the period detecting section so that the free-run period becomes substantially equal to a period of a clock component of the digital signal, and for outputting a reproduced clock signal by reproducing the clock component of the digital signal; and a synchronizing section for synchronizing the digital signal with the reproduced clock signal so as to output a synchronized signal as reproduced data.

Optical disk reproducing apparatus

An optical storage medium drive apparatus having a light beam source for recording information on an optical storage medium and reading out the recorded information from the storage medium by using a light beam. The apparatus has an optical head in which the light source is included for emitting a light beam, and a light detector for converting reflected light from the storage medium into an electric signal and an optical system for guiding the light beam from the light source to the optical storage medium and a reflected light beam from the optical storage medium to the light detector. The optical system has therein a light reflector for changing the direction of the light beam and which causes retardation of the light. An optical phase compensator is disposed on the optical path between the optical head and the optical storage medium for compensating for retardation of the light beam caused by the reflector.

Growing community of inventors

Osaka, Japan

Masaharu Imura