Sony Corporation

Sony Coproration

Akio Terada

Toru Nagara

Kimihiro Saito

Yuichi Suzuki

Norio Tanaka

Tadaaki Nomoto

Takashi Nagatomo

Masamichi Kondo

A recording device includes a light irradiation portion which irradiates an optical recording medium with laser light emitted from a light source via a field lens, a light emission drive portion which drives and causes the light source to emit light, a front monitor which receives the laser light emitted from the light source, a light receiving portion which receives reflected light which is obtained from the optical recording medium in response to the laser light irradiation, a focus servo control portion which controls a focus servo of the field lens on the basis of a light receiving signal by the light receiving portion, a surface jump controller which controls the focus servo control portion so as to perform a focus jump operation to a surface of the optical recording medium, and a surface APC corrector which performs a process as an auto power control (APC) correction process.

Recording device and APC correction method

An information processing device includes: a writing and erasing means for writing and erasing predetermined information to and from a predetermined recording area of a writable optical disc serving as a recording medium; an estimation information writing means for writing estimation information to the recording area to and from which the information is written and erased by the writing and erasing means; and an estimation means for reading the estimation information written to the recording area by the estimation information writing means and estimating a reproduced signal of the read estimation information.

Information processing device and method and program

An optical disk device capable of increasing access speed and an image pickup device having such an optical disk device. In a region at the inside of an optical disk where the rotational speed of the spindle motor reaches its limit, a CAV mode is used for access, while in a region at the outside of the optical disk where a frequency band of an RF signal processor reaches its limit, a CLV mode is used for access. High-speed access to a maximum extent in a range of performance limits of the spindle motor and the RF signal processor is achieved. A retry feature retries failed access attempts to the optical disk when access failure is determined and a controller judges whether or not a defect of the optical disk has caused the access failure. The controller further judges if the predetermined cause of the access failure repeatedly occurs in a predetermined nearby range on the optical disk.

Optical disk device and method of control of an optical disk utilizing retry feature

A laser light power controlling method is provided which comprises the steps of irradiating onto an optical disc a laser light generated by a laser source driven under a data write signal; detecting a reflected portion of the laser light irradiated onto the optical disc; and detecting an undershoot of a detection signal of the reflected laser light and controlling the power of the laser light in accordance with the amount of the detected undershoot. Also, a method for writing data into an optical disc is provided which comprises the steps of irradiating onto an optical disc a laser light generated by a laser source driven under a data write signal; detecting a reflected portion of the laser light irradiated onto the optical disc; and detecting an undershoot of a detection signal of the reflected laser light and discriminating the level of the undershoot with reference to a predetermined threshold. Further, an optical disc recording apparatus is provided which comprises means of irradiating a laser light onto an optical disc correspondingly to a data write signal; a photodetector to detect a reflected portion of the laser light irradiated onto the optical disc; and an undershoot detector to detect an undershoot of a detection signal of the laser light detected by the photodetector; the power of the laser light being controlled in accordance with the amount of the detected undershoot. The optical disc may be a phase-change based one.

Method for controlling laser light power, method for data recording into optical disc, and optical disc recording apparatus

The present invention relates to an information recording/reproducing apparatus that radiates a laser beam to an information recording medium for recording and/or reproducing information, comprising: a laser beam generating means for generating a laser beam that records information to or reproduces information from the information recording medium; a timing control means for controlling information recording timing so that a recording area on a track of the information recording medium is followed by another recording area in a partially overlapping manner; and a laser beam intensity control means for controlling an intensity of the laser beam generated by the laser beam generating means so that a first area with information recorded, a second area with information erased, and a third area with information neither recorded nor erased are formed in the recording area in which information is at least recorded in an overlapping manner.

Information recording/reproducing apparatus and method

The present invention is directed to apparatus. Upon actuation, a system controller controls a digital-to-analog converter to derive a pulse-shaped wave sweep signal. This sweep signal is supplied through an adder and a driver to a focusing actuator, and the focusing actuator drives an objective lens of an optical pickup in response to the sweep signal. According to the focusing servo apparatus of the invention, the focusing servo can be locked in smoothly.

Focusing servo apparatus for an optical disc

An optical disc such as a magnetooptic disc has information storage tracks each associated with a plurality of pairs of wobble pits arranged therealong. A light beam emitted from a light beam source such as a semiconductor laser is applied as a convergent light beam through an objective lens to the optical disc. A deviation of the light beam from a focused condition on the optical disc is detected as a focus error. A light beam returning from the optical disc is detected by a light detector. When the light beam returns from the wobble pits in each pair, the light detector produces a detected signal with successive peak values corresponding to the wobble pits, and the peak values are averaged. The objective lens is moved along its optical axis by an actuator based on the sum of a signal representing the focus error and a bias which maximizes the absolute value of the average of the peak values from the light detector.

Apparatus for recording information on and/or reproducing information

A track jump control device by means of which a scanning head for scanning the recording track of the disc-shaped recording medium is moved to a target track position is disclosed. A signal obtained by differentiating a tracking error signal is used as speed data to perform a closed loop track jump control operation to achieve direct landing on the target track positively even under an environment highly susceptive to disturbances. The track jump control making use of the gray code information indicating the recording tracks on the disc-shaped recording medium on the track-by-track basis is switched to the track jump control making use of the differentiated tracking error signal or vice versa to realize direct landing on the target track quickly and positively by a simplified arrangement.

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Kanagawa, Japan

Akio Terada