Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An information processing device for performing calibration of an optical output level control unit for controlling the optical output level of a laser beam which an emission unit emits by multiple channels controlling the current value of current supplied to the emission unit for emitting a laser beam with an optical output level according to the current value, includes a calibration unit for performing calibration processing for each of the multiple channels of the optical output level control unit wherein the emission unit is controlled to emit the laser beam with multiple different optical output levels, the optical output level control unit is controlled to detect the indicating value of the current value corresponding to each optical output level, the relation between the indicating value and the optical output level is obtained, and an indicating value corresponding to a target optical output level is adjusted according to the relation.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A circuit for shifting the level of a signal inputted in the focussing or tracking servocircuit provided with an automatic gain control device in an optical disc apparatus. The circuit comprises a plurality of variable gain amplifiers arranged at a stage prior to detecting a focussing or tracking error and forming the corresponding error signal, inclusive of gain set apparatus for selecting one of a plurality of gains of said gain amplifiers depending on the detected level range of the light quantity reflected from the optical disc.

Abstract: This invention relates to a servo system for positioning and driving a movable member such as a pickup head of an optical reading system, for example. A sinewave signal is generated by a position detector in response to movement of the movable member. A first reference signal is used with the sinewave signal to position the movable member. A second reference signal is used with a modified signal which is generated by differentiating and rectifying the sinewave signal, to drive the movable member.