Pioneer Corporation

Pioneer Electronic Corporation

Kazuo Takahashi

Kiyoshi Tateishi

Mitsuru Sato

Yoshitsugu Araki

Ichiro Sugai

Takanori Maeda

Ikuya Kikuchi

Junichi Furukawa

Takayuki Nomoto

Hiroshi Nishiwaki

Masaharu Nakano

A guide-layer separated optical recording medium includes a guide layer with a guide track formed therein and a plurality of recording layers, these layers being separately deposited from each other. A layer position information region for indicating position information of each of the recording layers, is formed on the guide track within a different range of the guide layer for each of the recording layers. Each of the recording layers includes a preformat region having a predetermined signal written on a record track along the guide track, and the preformat region on each of the recording layers is provided in a region corresponding to the layer position information region. An optical recording medium drive apparatus and a recording layer access method for the guide-layer separated optical recording medium are also provided. The apparatus and method implement: determining whether a reproduced signal has been obtained, based on the detection level of a reflected beam from the preformat region by a read/write optical system; acquiring position information of one of the plurality of recording layers based on the detection level of a reflected beam from a layer position information region by a servo optical system; and causing a second laser beam to access a desired one of the plurality of recording layers in accordance with the determination result of the reproduced signal and the position information.

Guide-layer separated optical recording medium, optical recording medium drive apparatus, and recording layer access method

Disclosed herein are an optical recording medium driving device and an additional recording method, which performs tracking servo control for moving an objective lens in a direction orthogonal to a tangential direction of a guide track so that a guide tracking error signal is decreased with respect to a guide track of a guide layer separation type recording medium, detects an additional recording start position subsequent to a recorded track if the recorded track is present in a recording layer of the optical recording medium, generates a tracking correction signal according to the reproduction tracking error signal upon tracking servo control of the recorded track just before the additional recording start position, and corrects tracking servo control according to the tracking correction signal upon additional recording start.

Optical disk drive device and additional recording method

An optical pickup is provided for preventing an objective lens from colliding with an optical recording medium at the stage of initial adjustments. The optical pickup device comprises a servo circuit, and a lens driver for driving an objective lens. In the servo circuit, a drive signal generator supplies the lens driver with one of a first focus drive signal for moving the objective lens in a direction closer to an information recording layer, and a second focus drive signal for moving the objective lens in a direction away from the information recording layer. A controller in a timing generator switches a signal supplied to the lens driver from the first focus drive signal to the second focus drive signal when the level changes by a predetermined range or more in a servo signal which is generated during a period in which the first focus drive signal is being supplied to the lens driver.

Optical pickup device and apparatus for reading data from optical storage medium

An apparatus including a first engaging portion for holding an optical pickup, a second engaging portion to be engaged with the first engaging portion, a transfer portion for driving the second engaging portion to transfer the first engaging portion in a radial direction, a calculating portion for calculating a backlash value between the first and second engaging portions in a transfer direction of the first engaging portion, and a driving control unit. The driving control unit controls a driving portion to transfer the optical pickup based on a calculated backlash value.

Optical pickup transfer apparatus

A controller includes a servo-controller for performing nonlinear and linear control of the read/write position according to an error signal to drive an actuator for driving the pickup; a switch for switching the servo-controller from open-mode to closed-mode according to the error signal; and an adjuster for adjusting the gains of the nonlinear and linear control so that the nonlinear control component is larger than the linear control component at the time of switching and the linear control component is larger than the nonlinear control component after the elapse of a predetermined time from the time of switching.

Read/write position controller for optical pickup

An optical disc player executes a focus pull-in operation while avoiding an inconvenience that an objective lens comes into contact with an optical disc, or the like. The objective lens is forcedly moved gradually from a position that is away from the surface of the optical disc and outside a capture range of a focus servo toward the surface of the optical disc. When the objective lens reaches the capture range of the focusing servo loop by the moving operation and a distance between the objective lens and the disc surface is at the minimum distance or is changing in a widening direction, the moving operation of the objective lens is stopped.

Optical disc player with focus pull-in function

A tracking servo apparatus in which reflection light obtained when a laser beam is irradiated onto a recording surface of an optical disc is photoelectrically converted, thereby obtaining a photoelectric conversion signal, a tracking error signal showing a deviation amount of an irradiating position of said laser beam for a track in a disc radial direction on the recording surface is generated by the photoelectric conversion signal, a spherical aberration occurring in an optical system is detected, a level of the tracking error signal is corrected on the basis of the detection result, and the irradiating position of the laser beam is moved in the disc radial direction in accordance with the level-corrected tracking error signal.

Tracking servo apparatus of optical information recording and reproducing apparatus

A recording/reproducing apparatus includes an optical pickup having an objective lens, an actuator for operating the lens, an aberration correction element, and a detector for generating a reading signal; a servo control section; a driver for operating the aberration correction element; a generator for generating a focus disturbance signal and an aberration correction disturbance signal having a period different from that of the focus disturbance signal; and a controller for adjusting the focusing position and the aberration correction amount on the basis of a change in a predetermined characteristic value of the reading signal when the disturbance signals are simultaneously applied.

Optical recording/reproducing apparatus

A servo control apparatus is provided to a stable servo control even when delays occur in detecting defects. Based on reflected light of an optical beam from an optical disc, a defect resulting from dark spots, damages, or others on the optical disc is detected. Immediately before the detection, sample data of a control signal are memorized. The sample data are obtained during a predetermined interval of time that corresponds to a detection delay for the defects, which is dependent on a defect detecting device. Using the memorized sample data, a cancel signal is produced for canceling the influence of the control signal, which is owing to a pseudo error signal obtained during the predetermined interval of time. The cancel signal is outputted as the control signal immediately after the detection of the defect.

Servo control apparatus for optical disc driver

The present invention relates to a cartridge and a method that can sweep away dust or the like from a recordation medium housed in the cartridge in a simple way without adversely influencing recording and replaying of the recordation medium. The cartridge includes a shutter opposed to a surface of the recordation medium, a cleaner member, a support for supporting the cleaner member, and a sweeping mechanism actuated upon opening and closing movements of the shutter. The support pivots in a plane substantially in parallel to the surface of the recordation medium when the sweeping mechanism is actuated. When the sweeping mechanism moves forwards, the cleaner member moves without contacting the recordation medium surface. When the sweeping mechanism moves backwards, the cleaner member moves in contact with the recordation medium surface to clean the recordation medium surface.

Cartridge and method of cleaning recordation medium surface

A focus jump moves a focus position of a light beam in a direction perpendicular to the storage medium to the focus position corresponding to a target recording layer so that the light beam is irradiated on the target recording layer. The device includes: a focus position moving unit for moving the focus position of the light beam; a focus error signal detector for detecting a focus error signal based on a variation of a returning light from the storage medium; a feedforward controller for supplying a drive signal to the focus position moving unit to move the focus position of the light beam in an acceleration state in an acceleration control and to move the focus position of the light beam in a deceleration state in a deceleration control; and a position controller for comparing the focus error signal, detected the time of movement of the focus position of the light beam to the target recording layer, with a predetermined target value to generate an error, and for feeding back the drive signal to the focus position moving-unit to reduce the error thereby to control the focus position of the light beam.

Focus jump device for reproducing information from a storage medium

A track jump apparatus for making an actuator jump in order to move a spot position of a laser beam emitted through an objective lens of the actuator from a current position to an object position corresponding to a desired recording track on a recording medium. The track jump apparatus includes: an actuator driving device that moves the actuator in accordance with a driving signal; a tracking error signal detecting device that detects a tracking error signal on the basis of a change of return light from the recording medium caused by a change of the spot position of the laser beam relative to the recording track; a feed-forward control device that applies an acceleration pulse and a deceleration pulse to the actuator driving device; and a position control device that controls a position of the actuator using a feedback of the driving signal so as to reduce a difference between an object value and the tracking error signal detected by the tracking error signal detecting device, when making the actuator jump in order to move the spot position of the laser beam from the current position to the object position. The feed-forward control device sets a constant speed period during which neither of the acceleration pulse and the deceleration pulse is applied to the actuator driving device between an acceleration period during which the acceleration pulse is applied to the actuator driving device and a deceleration period during which the deceleration pulse is applied to the actuator driving device.

Track jump apparatus

The present invention is intended to reliably achieve a locked PLL even with a short VFO field to correctly perform subsequent reproduction of information data. A PLL circuit of the present invention is supplied with a composite signal composed of a repetitive signal including a pulse train of a constant duty ratio and a random signal including a pulse train allowing variations in duty ratio, where the two signals are arranged in time series. The circuit is provided with a VCO for generating an output signal having a frequency according to a control signal, a PFC for comparing the repetitive signal with the output signal in terms of phase and frequency to generate a phase frequency error signal, a PC for comparing the random signal with the output signal to generate a phase error signal, and loop filters for extracting predetermined band components of the phase frequency error signal and the phase error signal to generate the control signal. Since a PLL is formed including the phase frequency comparator, which has a wide dynamic range and operates at a single lock point, during reading a VFO, a reliable drawing operation is achieved even with a short VFO without miss lock.

Phase locked loop circuit

An apparatus for reproducing record information of a multiple-layered optical disc is provided with: an optical pickup having a light source for emitting a reading light, an objective lens for condensing the emitted reading light onto one of the information record layers, a focus actuator for moving the objective lens in a focus direction, and a light-detection device for detecting the reflected reading light and outputting a light detection signal; a focus error generation device for generating a focus error signal; an acceleration/deceleration signal generator for generating and outputting to the focus actuator an acceleration signal to accelerate the objective lens in the focus direction and a deceleration signal to decelerate the objective lens in the focus direction; an inter-layer distance measurement device for measuring an interlayer distance between the information record layers of the multiple-layered optical disc; and a controller for measuring a time duration since the acceleration signal is generated until the focus error signal reaches a predetermined threshold level, and for controlling the acceleration/deceleration signal generator to set a magnitude of the deceleration signal on the basis of the measured inter-layer distance and the measured time duration.

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Tsurugashima, Japan

Kazuo Takahashi