Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

The Nippon Synthetic Chemical Industry Co., Ltd.

Yuichi Takahashi

Kazuo Momoo

Seiji Nishiwaki

Junichi Asada

Kenji Nagashima

Youichi Saitoh

Hiroaki Matsumiya

Junji Nagaoka

Jun-ichi Asada

Kaoru Inoue

Kousei Sano

Nobuya Matsutani

Mitsuo Shibutani

Toshiya Akagi

Yasushi Kobayashi

Yuichi Kamioka

Koji Shimoyama

Yoshiyuki Miyabata

Noritaka Akagi

Koichi Muramatsu

Yukio Hibino

Shinichi Morimoto

Mitio Ohba

Fumitake Sakai

Kei Ikeda

An optical information processing device writes and reads information on an information recording medium having recording layers. The optical information processing device includes: first and second light sources; a light condensing element that condenses light from the first and second light sources on the medium; a first photodetector that receives light reflected by the medium after being emitted from the first light source and generates a first focusing error signal; a second photodetector that receives light reflected by the medium after being emitted from the second light source and generates a second focusing error signal; and a focusing control circuit that controls the light condensing element by using the first focusing error signal in such a manner that the light from the second light source is condensed on each of the recording layers. The second focusing error signal is used to add a correction to the focusing control circuit.

Optical information processing device

A record playback apparatus of the present disclosure includes a plurality of optical pickups that records information on a recording medium or plays back information from the recording medium; a single transport mechanism that transports the plurality of optical pickups together; and a transport control circuit that drives the single transport mechanism so that, when the single transport mechanism is driven to transport the plurality of optical pickups to respective target positions on the recording medium, absolute value of a maximum value of transport errors of the plurality of optical pickups with respect to the respective target positions becomes substantially equal to absolute value of a minimum value of transport errors of the plurality of optical pickups with respect to the respective target positions.

Record playback apparatus

The first, third, fourth, and seventh photosensors are disposed on one side with respect to the centerline, and the second, fifth, sixth, and eighth photosensors are disposed on another side with respect to the centerline. The first and seventh photosensors are positioned between the third and fourth photosensors in the direction parallel to the centerline. The second and eighth photosensors are positioned between the fifth and sixth photosensors in the direction parallel to the centerline. The first photosensor receives overlapped light of the 0th-order light with the +1st-order diffracted light, the second photosensor receives overlapped light of the 0th-order light with the &#x2212;1st-order diffracted light, each of the third to sixth photosensors receives the 0th-order light, and does not receive the +1st-order diffracted light and the &#x2212;1st-order diffracted light, and each of the seventh and eighth photosensors receives at least the 0th-order light.

Recorder and player apparatus stably keeping track of recording medium

The recording and reproducing apparatus according to the present disclosure includes: a light source; an optical system configured to divide a beam from the light source, and to form a first optical spot and a second optical spot on a recording medium; a recording circuit configured to drive the light source and to modulate a light amount of the light source, and further to record the information on the recording medium by the first optical spot by modulating the light amount of the light source based on information; and an evaluation circuit configured to evaluate the information recorded on the recording medium by reproducing by the second optical spot in a period in which the recording circuit causes the light source to emit the beam at a constant light amount.

Recording and reproducing apparatus

A recording and reproducing apparatus according to the present disclosure includes a first optical pickup configured to record information on either a land track and a groove track, with respect to a recording medium that is able to be recorded in the land track and the groove track, a second optical pickup configured to record information on a track different from a track recorded by the first optical pickup, and a controller configured to cause the first optical pickup to record information if tracks of both sides of a track that the first optical pickup follows are recorded, and to cause the second optical pickup to record information if tracks of both sides of a track that the second optical pickup follows are recorded.

An optical pickup includes a light source; a diffraction elementfor generating a write main beam and a read sub-beam via diffraction; an objective lens; a wavelength plate; a polarization hologram elementhaving a plurality of diffraction regions with different diffraction characteristics, designed so that each diffraction region separates a light beam reflected from the optical storage medium and transmitted through the wavelength plate into a 0order light beam and &#xb1;1order light beams; an actuator; and a photodetectorconfigured to detect a light beam reflected from the optical storage mediumand diffracted by the polarization hologram element. The photodetectorgenerates an RF signal from a detection result concerning a 0order light beam derived from the main beam, generates a focus error signal and a tracking error signal from a detection result concerning one of &#xb1;1order light beams derived from the main beam, and generates a signal indicating that data has been recorded normally from a detection result concerning a 0order light beam derived from the sub-beam.

Optical pickup and optical recording and reproducing device

The present invention provides a polyvinyl alcohol-based resin composition having less coloration from melt processing and having high aging stability of the melt viscosity comprising a polyvinyl alcohol-based rein having a structural unit represented by the following formula (1) and having an absorbance of 0.1 to 0.3 of 280 nm in an ultraviolet absorbance spectrum as a 4 mass % aqueous solution, a carboxylic acid and an alkaline (earth) metal salt, wherein when an aqueous solution of the polyvinyl alcohol-based resin composition is prepared so as to have a content of the polyvinyl alcohol-based resin of 4 mass %, the pH of the aqueous solution at 20&#xb0; C. is from 5.5 to 7: 

Polyvinyl alcohol-based resin composition

In one embodiment, an optical pickup includes an optical system which forms multiple light beams based on the light emitted from a light source and which converges a write beam and a read beam, thereby forming a main spot and a sub-spot, respectively, on an optical storage medium. This optical system converges the write and read beams onto the optical storage medium so that the main spot moves through the same region on the optical storage medium ahead of the sub-spot. The optical pickup further includes a detector for sensing the write and read beams reflected from the storage medium. The detector includes a first photodiodethat receives the reflected light from the main spotR on the storage medium and a second photodiodethat receives a portion of the reflected light from the sub-spotR.

Optical pickup and optical read/write apparatus

Disclosed is an improved DRAW technique for writing data on an optical storage medium and reading the data in parallel. In obtaining the optical power of a first light source, writing user data is temporarily suspended to write non-user data with a second light sourceturned OFF.

Optical read/write apparatus

An optical information record/playback device of the present invention includes: a light source; a current driver for supplying current to the light source; an optical system for condensing light from the light source onto a recording medium; a monitoring section for monitoring light emission power of the light source; a current driver control section for controlling output current of the current driver; and an arithmetic/control section for controlling an operation of the current driver control section. Before recording information, the arithmetic/control section sequentially conducts a first test light-emission to cause the light source to emit light by using a closed loop circuit and a second test light-emission to cause the light source to emit light by using an open loop circuit, and compares first and second sampling values, which are respectively obtained by sampling the outputs of the monitoring section during the first and second test light-emissions.

Optical information record/playback device

When performing recording/reproduction of information for a given recording layer of an optical disc having three recording layers, influences of reflected light from other recording layers are reduced or removed, thus making it possible to obtain a more stable RF signal or focus error signal. An optical pickup device includes a light source, a collimator lens, an objective lens, a photodetector, and a light shielding member. Among the recording layers of the optical disc, a first layer and a second layer adjoining each other are disposed in the order of the first layer and second layer from near the objective lens. The light shielding member is disposed at a position satisfying the condition d&#x3e;dto block a part of reflected light from the second layer when light is converged on the first layer, where d is an optical path length from the photodetector to the light shielding member; and dis a distance from the photodetector to a position at which reflected light from the second layer becomes focused between the collimator lens and the photodetector.

Optical pickup device and optical disc device

The present invention provides a chip part manufacturing method comprising a separating process capable of suppressing deformation of chip parts, and also provides chip parts. It comprises a step of forming a plurality of frame-like void portions () in one main surface of substrate () and insulating resin layer () having a spiral void portion () disposed in the region thereof, a step of forming metal layer () in frame-like void portion () and spiral void portion () and on insulating resin layer (), a step of polishing metal layer () at least up to the upper surface of insulating resin layer and forming coil section () in spiral void portion (), and a step of forming a metal layer for connecting chip parts to frame-like void portion (), wherein the metal layer is melted and removed by using an etching agent to separate a plurality of chip parts connected to each other by a frame-like connection.

Chip part manufacturing method and chip parts

An optical pickup device according to the present invention comprises: a first mirror for reflecting a first light beam outputted from a first light source and letting a second light beam outputted from a second light source pass therethrough; a first object lens for converging the first light beam reflected by the first mirror on an information recording surface of a recording medium; a second mirror for reflecting the second light beam passing through the first mirror; a second object lens for converging the second light beam reflected by the second mirror on the information recording surface of the recording medium; and an achromatic lens for correcting an axial chromatic aberration of the second object lens generated by wavelength variation of the second light beam, wherein the achromatic lens is provided in an optical path between the first mirror and the second mirror.

Optical pickup device and lens for optical pickup

A first light ray with a wavelength &#x3bb;1 emanating from the first emission light source passes through the transparent substrate and is condensed by the objective lens on a signal surface of a first optical disk with a substrate thickness t1,

Optical disk device

An optical disk device has an aperture of an objective lens in an incoming path of a beam from a semiconductor laser to an optical disk formed larger than an aperture in a return path from the optical disk or an aperture is varied in recording and in reproduction. This configuration improves recording/reproducing ability since light is focused on an optical disk with high numerical aperture. In addition, since reflected light from the optical disk is detected with low numerical aperture, margins for tilt and defocus are not reduced. Furthermore, since unnecessary signal components contained in the reflected light can be eliminated, a S/N (signal-to-noise ratio) of an information signal also increases. Thus, a high-performance optical disk device can be obtained. Alternatively, by varying the aperture of an objective lens in recording and in reproduction, an optical disk device in which recording density and recording quality are increased without deteriorating reproduction quality can be obtained.

Growing community of inventors

Nara, Japan

Yuichi Takahashi