Sony Corporation

Hirotaka Miyamoto

Kimihiro Saito

Kunihiko Hayashi

Goro Fujita

Toshihiro Horigome

Jun Nakano

Takeshi Kubo

Tetsuhiro Sakamoto

Takahiro Miura

Takao Kondo

Norihiro Tanabe

Kouichi Yasuda

Jingcheng Yuan

An optical recording medium is provided. The optical recording medium includes a multilayer including an N (N&#x2266;5) number of interfaces capable of reflecting incident light.

Multilayer optical recording medium

An optical disc apparatus can make the focus of an information light beam converged by an objective lens agree with a target track of a target mark layer of an optical disc by appropriately predefining the distance between the focus of a servo light beam and that of the information light beam with regard to the direction of the thickness and a radial direction of the optical disc by means of the optical pickup of the apparatus and then operating for focus control and tracking control of the objective lens so as to make focus of the servo light beam converged by the objective lens agree with a reference track of a reference mark layer.

Optical disc apparatus, position control method and optical pickup

There is provided an optical pickup including: an optical-system having an object-lens illuminating a first light for information recording or reproducing on a recording layer as a target and a second light on an optical-recording medium including a reference plane having a reflection-layer and the recording-layer at a layer position different from that of the reference-plane and on which information recording is performed through mark formation, and a focus-aligned-position-adjusting unit adjusting a focus-aligned position of the first light through the object-lens by changing collimation thereof incident to the object-lens; and a focusing-mechanism driving the object-lens in a focusing direction, wherein, when a depth of focus &#x3bb;/NAdefined by a wavelength &#x3bb; of the first light and a numerical aperture NA of the object lens is set to &#x3b1; and the maximum-surface-blur range is denoted by D, the optical-system is designed so that a use magnification ratio &#x3b2; satisfies |&#x3b2;|&#x2267;&#x221a;(D/&#x3b1;).

Optical pickup, optical drive apparatus, and light illumination method

An optical disc apparatus includes a light separator configured to separate a light beam emitted from a light source into a main beam and a sub-beam, an objective lens configured to, when the light beam is condensed and irradiated to an optical disc having a uniform recording layer in which a track is formed by record marks, irradiate at least part of the sub-beam to an area where the main beam is not irradiated in a radial direction which is defined as a direction of radius of the optical disc, and a signal generating unit configured to generate a mark layer distance signal, representing a distance between a focus of the light beam and a mark layer to which the track belongs, based on a return light beam resulting from at least one of the main beam and the sub-beam, which has been irradiated to the track.

Optical disc apparatus and signal generation method

Disclosed is an optical disc device that is able to increase accuracy in reproducing information from an optical disc. The optical disc devicecalculates a focus error signal SFEand a sum signal SSwhile reciprocating an objective lensin a focus direction until a distance between a focal point FS and a focal point FMbecomes close to the depth d of a target position PG at the time of a pull-in operation, and when a trigger signal STgenerated on the basis of the sum signal SSis at low level, starts focus control on the basis of the focus error signal SFE. Therefore, focus control can start in a state where the focus error signal SFEcurves in an S shape with sufficient amplitude.

Optical disc device and focus control method

An optical recording medium driving apparatus includes an optical pickup which irradiates first and second laser lights from one object lens with respect to an optical recording medium having a bulk layer and a tilt detection surface; a focus control portion that performs the focus control relative to each predetermined position of the optical recording medium in regard to each of the first and second laser lights; a tracking control portion that controls the position of the object lens to perform the tracking control of the first and second laser lights relative to the optical recording medium; and a tilt control portion.

Optical recording medium, optical recording medium driving apparatus, and optical recording medium driving method

An optical disk apparatus appropriately adjusts the optical paths of a reference light beam and information light beam in an optical path forming section of an optical pickup, condenses the reference light beam and information light beam using an objective lens, and performs position control of the objective lens in the focusing and tracking directions so as to focus the reference light beam onto a reference track in a target mark layer, thereby focusing the focal point of the information light beam condensed by the objective lens onto a target track TG in the target mark layer.

Optical disk apparatus, position control method, and optical pickup

An optical disc apparatus includes an objective lens that converges a light beam emitted from a light source and irradiates an optical disc having recording marks formed in a uniform recording layer with it, a detection signal generation section that receives a return light beam from the recording mark and generates a detection signal, a servo control signal generation section that generates a servo control signal representing relative displacement between the recording mark and a focus of the light beam from the detection signal and a servo signal correction section that generates a correction servo control signal by connecting peaks or neighborhoods of the peaks of servo control signals, the peaks being produced according to the recording marks.

Optical disc apparatus and correction servo control signal generation method

A focus control section first performs a reference focus control process in which a reference optical beam is focused on a reference layer of an optical disc according to the result of receiving a reference reflection optical beam, and then switches from the reference focus control process to an information focus control process in which an information optical beam is focused on a mark layer of the optical disc according to the result of receiving an information reflection optical beam.

An optical disk apparatus irradiates first and second lights, which are emitted from an identical light source, on a disk-like volumetric recording medium from both sides thereof with first and second object lenses corresponding to the first and second lights, respectively, such that the lights are focused in an identical focal point position and records a standing wave. The optical disk apparatus includes an aberration adding unit that adds complementary aberrations to the first and second lights made incident on the volumetric recording medium, respectively.

Optical disk apparatus and optical aberration correcting method

An optical disc device that irradiates an optical beam to an optical disc including a recording layer for recording information and a positioning layer provided with a track for identifying a recording position of the information on the recording layer, includes: objective lens that converges a predetermined positioning optical beam to adjust the optical beam to a desired track on the positioning layer and converges an information optical beam that shares an optical axis with the positioning optical beam on the recording layer; moving section that moves the objective lens in a tracking direction which is substantially orthogonal to the track to make a focal point of the positioning optical beam to follow the desired track; a detection section that detects a moving amount of the objective lens to the tracking direction; and correction section that corrects a converging position of the information optical beam in accordance with the moving amount.

Optical disc device and converging position correction method

An optical disc apparatus and a focus position control method can highly accurately record recording marks representing information on or reproduce such recording marks from an optical disc. A blue light beam is irradiated onto the target depth to be irradiated by driving an objective lens to focus a red light beam in a reflection/transmission film formed in the optical disc and displacing a movable lens, which is a focus moving section, of a relay lens. A blue light reflection region is formed as part of the reflection/transmission film and the position of the blue light reflection region where the red light focus and the blue light focus are aligned is defined as reference position. The movable lens is displaced by an arbitrarily selected quantity from the reference position according to the target depth.

Optical disc apparatus, focus position control method and optical disc

An optical pickup includes: an objective lens that collects a first beam and a second beam and emits the first and second beam toward an optical information recording medium on which information can be recorded as a recording mark as a result of being exposed to the first beam; a section that drives the objective lens to focus the second beam on a reflection layer formed on the optical information recording medium, the reflection layer at least partly reflecting the second beam; and a section that changes the convergence state of the first beam to position a focal point of the first beam a distance away from a focal point of the second beam in the direction of depth in order to place the focal point of the first beam at a target depth.

Optical pickup, optical information recording device, optical information recording method, optical information reproduction device, optical information reproduction method and optical information recording medium

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Kanagawa, Japan

Hirotaka Miyamoto