Hitachi, Ltd.

Other

Hitachi Maxell, Limited

Hitachi-lg Data Storage, Inc.

Hitachi Software Engineering Company, Ltd.

Hitachi Maxwell, Ltd.

Hitachi Video and Information Systems, Inc.

Hisataka Sugiyama

Harukazu Miyamoto

Hiroyuki Minemura

Tetsuya Fushimi

Yoshio Suzuki

Motoyuki Suzuki

Nobuhiro Tokushuku

Takeshi Maeda

Atsushi Saito

Toshimitsu Kaku

Kazuo Shigematsu

Kiyoshi Matsumoto

Motoyasu Terao

Kouichirou Wakabayashi

Takeshi Shimano

Hirofumi Sukeda

Tetsuya Nishida

Norimoto Ichikawa

Shigenori Okamine

Hiroyuki Minamura

Hiroaki Ono

Kimio Tatsuno

Fumiyoshi Kirino

Hiroyuki Tsuchinaga

Wasao Takasugi

Yasuhide Ouchi

Fumio Kugiya

Toru Kawashima

Shigeki Yamazaki

Masanori Matsuzaki

Makoto Itagaki

Shigeru Nakamura

Akira Arimoto

Seiichi Mita

Tsuyoshi Toda

Hideki Saga

Junko Ushiyama

Hiroshi Ide

Keikichi Andoo

Hiroyuki Awano

Masahiko Takahashi

Masahiro Takasago

Tatsuya Ishitobi

Takehiko Sekine

Osamu Komoda

Hiroyuki Hori

Akinori Shiozawa

Toshimichi Shintani

Yosiho Suzuki

Hitoshi Watanabe

Hiroshi Ogasawara

Naoki Satoh

Masaru Ito

Kensuke Ogawa

Takeshi Nakao

Shinichi Arai

Toshinori Sugiyama

Toshimasa Kamisada

Satoshi Kawamura

Takuya Mizokami

Mariko Umeda

Masashi Suenaga

Kozo Masuda

Masataka Ota

Masataka Ohta

Kazuo Isaka

Hisamitsu Tanaka

Fumio Hara

Norio Murase

Shinitsu Kinoshita

Atsushi Saitoh

Horishi Ide

Horoaki Ono

Takahiro Komaki

A distance measurement device includes a light-emitting-unit that emits irradiation light toward an object; a light-receiving unit that receives reflected light from the object; a distance-calculation unit that calculates a distance to the object based on a transmission time of the reflected light received; a posture-adjustment mechanism that adjusts a posture of at least the light-receiving-unit; and a posture-controller that drives the posture-adjustment mechanism. The light-receiving unit is formed of a two-dimensional sensor in which a plurality of pixels are two-dimensionally arrayed, and the distance-calculation unit calculates two-dimensional distance data from received light data in each of the pixels of the two-dimensional sensor. The posture-controller controls the posture of the light-receiving unit via the posture-adjustment mechanism such that a direction of a pixel array of the two-dimensional sensor is inclined by a predetermined angle &#x3b8; with respect to a direction of a ridge of the object to receive the light.

Distance measurement device and distance measurement method

A distance measurement image pickup apparatus has two measurement periods. In a first distance measurement period, short pulsed light (1T) is irradiated, and exposure is performed in a plurality of exposure periods (A, B, and C) in which exposure timings are shifted. In each exposure period, an exposure gate is opened a plurality of times to perform repetitive exposure, and a first non-exposure period is provided from when a last exposure gate is closed until subsequent pulsed light is irradiated. In a second distance measurement period, long pulsed light (4T) is irradiated, and exposure is performed in a plurality of exposure periods (A, B, and C) in which exposure timings are shifted. In each exposure period, exposure is performed by opening the exposure gate only once, and a second non-exposure period is provided from when a last exposure gate is closed until subsequent pulsed light is irradiated.

Distance measurement image pickup apparatus

A recording medium including a plurality of recording layers, including: an optional first recording layer on which a light spot at a diffraction limit is formed; and a second recording layer on which a mark string pattern is formed, said second recording layer being different from said first recording layer, wherein when said mark string pattern is formed on a light receiving plane, while information of said first recording layer is reproduced, assuming that an optical distance between said first and second recording layers is dm, an optical distance d between optional two recording layers among a plurality of said recording layers is different from said dm.

Three-dimensional recording and reproducing apparatus

When the data is reproduced by irradiating a laser beam onto the optical disk, an amount-of-irradiation-beam detection signal is produced according to the amount of the laser beam irradiated onto the optical disk, and the defect on the optical disk is detected on the basis of this amount-of-irradiation-beam detection signal. In addition, when the data is reproduced by irradiating the laser beam onto the optical disk, the amount-of-irradiation-beam detection signal is produced according to the amount of the laser beam irradiated onto the optical disk, an amount-of-reflected-beam detection signal is produced in accordance with the amount of the laser beam reflected from the optical disk, and the defect on the optical disk is detected on the basis of the amount-of-irradiation-beam detection signal and the amount-of-reflected-beam detection signal. Even when the optical disk has a defect, the laser beam is continuously irradiated onto the optical disk.

Optical disk apparatus and data reproducing method

In a three-dimensional recording and reproducing apparatus having a recording medium including a plurality of recording layers stacked on a substrate and an optical system for converging a light irradiated from the substrate side on each of the plurality of recording layers to three-dimensionally record and reproduce information, the following equation is satisfied:&#x3bb;/4&#x2266;(1/8)(1/&#x2212;1)where A light spot is focused on each layer of the multi-layer structured disc to record and reproduce highly reliable data in a high density.

Because a series of data is recorded continuously, the recording quality of data recorded in course of recording cannot be evaluated. Accordingly, the laser output cannot be controlled properly and there are a deterioration and dispersion of the recording quality. Further, when the recording lasts for a long time, the temperature in the vicinity of laser rises due to the heat from the inside of a disc drive and the recording quality is deteriorated. To solve this, a series of data to be recorded is split and recording is made intermittently in a split data unit. The recording quality is evaluated by reproducing the data recorded nearby before each split data is recorded using a duration and control is performed by reflecting the evaluation result in the laser output so that the recording quality can be maintained satisfactorily over a series of the whole data to be recorded. Further, control is performed so that good recording quality can be maintained even in the recording that lasts for a long time by stopping the function of each part that ought to be operated even at recording or reproduction inside the disc drive in the duration, thereby suppressing a temperature rise.

Intermittent optical disc recording method and optical disc drive splitting data

When user data is recorded on a write-once medium, linking variations can be reduced that are produced as management information for managing the user data is updated by additionally recording on and off, thereby assuring the reliability of the reproduction compatibility of the DVD player. Before the final file of the management information is recorded, dummy data of a plurality of successive blocks are recorded at a time by a single operation, and then the final file is additionally recorded after the dummy data. Therefore, the linking precision can be prevented from being degraded in the linking portions of the management information, and thus the management information can be properly read when the DVD player makes compatible reproduction of the medium.

Information recording method and optical disk apparatus

An optical reproducing apparatus for reproducing information on a medium includes a light source, an optical system for irradiating a light beam generated by the light source on the medium, a detector for detecting a reflected light from the medium; and a reproducer means for reproducing information on the medium by using a signal from the detector. The medium is a substrate having grooves and lands alternately formed thereon in a radial direction, which serve as recording tracks and have prepits.

Optical recording method using land/groove recording

A reproducing apparatus for reproducing information recorded on an optical recording medium including a disk-like substrate, a plurality of tracks extending in a circumferential direction on the substrate and associated with a plurality of grooves, with a plurality of zones provided on the disk-like substrate and extending between a first position and a second position in a radial direction of the substrate. Each zone includes at least two tracks with each track being divided into a plurality of recording units of circular arc shape extending in the circumferential direction. The apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the detector.

Information recording method

A reproducing apparatus for reproducing information recorded on an optical recording medium including a disk-like substrate, a spiral or concentric-shaped groove structure along a track formed on the substrate, and the groove structure being wobbled in a radial direction of the medium. The track is divided into a plurality of recording units in the track direction by at least one radial boundary line formed by a dropout portion, wherein identification information is disposed in the track at a head of each recording unit at the dropout portion. The apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the detector.

A recording method for an optical medium including a disk-like substrate, a spiral or concentric-shaped groove structure along tracks formed on the substrate, each of the tracks being divided into a plurality of units, each of the units including a dropout portion of the groove structure which is a non-groove portion along the track in a circumferential direction of the track, the groove structure being wobbled in a fixed cycle in a radial direction which continues in the circumferential direction along the track. When the wobble is formed in the circumferential direction of the track, the dropout portion is formed so that a phase of the wobble is continued with a phase of the wobble of the groove structure within another unit adjacent to the dropout portion. The method includes providing the optical medium, and recording information by irradiating an optical spot on the medium.

An optical recording method for an optical medium including a disk-like substrate, a spiral or concentric-shaped groove structure along a track formed on the disk-like substrate, the groove structure being wobbled in a radial direction of the optical medium, the track being divided into a plurality of units in the track direction by at least one radial boundary line, at least two adjacent units in the radical direction of the medium comprise one zone, the optical medium including a plurality of zones, and the groove structure included in the adjacent units within at least one zone having substantially a same number of wobbling. The method includes providing the optical medium, and recording information on the optical medium by irradiating an optical spot thereon.

An optical recording apparatus having a light source and an optical system. The medium is a substrate in the form of a substantially circular disk with grooves and lands alternately formed on the substrate in a radial direction. The grooves and lands both serve as recording tracks which are divided into recording units in a circumferential direction. Each recording unit has an address area devoid of the grooves including first and second address information. The first address information is formed on a first boundary between one track and an adjacent track on one side of the one track, and the second address information is formed on a second boundary between the one track and an adjacent track on an other side of the one track with the first address information and the second address information not existing at opposing positions on the boundaries of the one track.

Optical recording apparatus

A reproducing apparatus for reproducing information recorded on an optical recording medium having a disk-like substrate, a spiral or concentric-shaped groove structure along tracks formed on the substrate, and each of the tracks being divided into a plurality of recording units. Each of the recording units includes a dropout portion of the groove structure which is a non-groove portion along the track in a circumferential direction of the track, and the groove structure is wobbled in a fixed cycle in a radial direction, which continues in the circumferential direction along the track. The apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, an optical detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the detector.

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Kodaira, Japan

Hisataka Sugiyama