Nec Corporation

Kabushiki Kaisha Toshiba

Sanyo Electric Co., Ltd.

Toshiba Corporation

Yutaka Yamanaka

Yutaka Kashihara

Akihito Ogawa

Tatsunori Ide

Chosaku Noda

Hideki Takahashi

Shigeru Shimonou

Hideaki Ohsawa

Ryuichi Katayama

Masato Fuma

Hiroharu Satoh

Kinji Kayanuma

Kazuo Watabe

Shuichi Ohkubo

Tsuyoshi Yamamoto

Toshiaki Iwanaga

Katsuki Hattori

Yutaka Hirose

Yuji Nagai

Taku Kato

Akira Mashimo

Atsushi Ishihara

Masatsugu Ogawa

Kazuhiro Okanoue

Morio Nakatani

Yuzo Ono

Masaaki Matsumaru

Naotoshi Iwazawa

Yasuo Kimura

Hiroharu Sato

Motoaki Shimizu

Takeharu Shibatoko

Daisuke Eto

Masahumi Miura

Yutaka Toshiba Corporation Kashihara

Masaaki Toshiba Corporation Matsumaru

Akihito Toshiba Corporation Ogawa

Chosaku Toshiba Corporation Noda

Akihito Toshiba Corporation IPD Ogawa

Yutaka Toshiba Corporation IPD Kashihara

Hideki Toshiba Corporation IPD Takahashi

An optical disc has a read-only system lead-in area and a recordable data area. Disc boundary information representing a boundary in a radial direction of an area on which capability of recording at a predetermined recording speed is guaranteed is recorded on the system lead-in area while being related to each tuple speed. An optical disc device, upon user's instruction of tuple-speed recording, compares the boundary information related to the instructed tuple speed with a present recording position, performs recording at the instructed tuple speed if the present recording position is on the outside of the boundary, and performs recording at a tuple speed lower than the instructed tuple speed if the present recording position is on the inside of the boundary.

Optical disc for tuple-speed recording and optical disc device for tuple-speed recording

An information readout device includes an equalizer and a maximum likelihood detector. The equalizer includes a second-order Volterra filter, and equalizes a readout signal read out from an information recording medium to a predetermined characteristic to output the equalization signal. The maximum likelihood detector outputs a binary signal through maximum likelihood detection based on the equalization signal. By limiting the number of second-order terms of the second-order Volterra filter to three terms or four terms, a nonlinear component can be effectively corrected.

Information readout device and information readout method

A two-layer recording type optical disk capable of realizing stable recording and reproduction without being affected by another recording layer and an optical disk apparatus for the two-layer recording type optical disk are provided. In layouts of various areas in the optical disk, a position where a border between a recorded part and an unrecorded part is formed on one recording layer is set so that the position is always separated from a position where a border between a recorded part and an unrecorded part is formed on another recording layer by a predetermined clearance amount. Moreover, to a recording layer farther from an incident surface, test recording or data recording is always performed through a recorded part on a closer recording layer.

Two-layer optical disk and recording/reproducing optical disk apparatus of the two-layer optical disk

The length of a format modulation area in an address segment is limited to be 25% of the address-segment length or less, and the position of the format modulation area is selectable two possible positions. Subsequently, where a CLV optical-disk medium is used, wobble modulation areas in adjacent recording tracks do not overlap each other in the radius direction.

Optical disk medium and optical disk apparatus

An optical disc medium () is provided with a data recording area () having the spiral recording track () and a lead-in area () composed of an embossed pit. In the lead-in area (), information indicating a characteristic range of a signal detected by an optical head from a groove track is previously recorded. In accordance with a kind of the optical disc medium (), even when the characteristic range of the signal detected by the optical head from the groove track is different, since the information indicating the characteristic range is previously recorded on the optical recording medium (), tracking operation of the recording track can be performed under conditions within the characteristic range. Therefore, the tracking operation of the recording track () can be accurately performed to any kind of optical disc medium ().

Recording type optical disc medium and optical disc device for the same

In an optical disk recording method of recording data onto a recordable optical disk which includes a data zone where data is recorded and a management data zone where management data indicating the recorded part of the data zone is recorded, an extended management data zone in which the management data is to be recorded is set in the data zone in response to an extension instruction.

Optical disk, optical disk recording method, and optical disk recording apparatus

An optical disk that has a BCA, from which data can be reproduced even if the BCA has defects. The data format of the BCA comprises a plurality of sub-data units and coupling codes, each coupling two adjacent sub-data units. The sub-data units contain the same data. To reproduce the data, the sub-data units are checked for errors. The data recorded in any sub-data unit that has no errors is reproduced and output to a next stage circuit connected to the optical disk drive.

Optical disk, optical disk drive and method of playing back an optical disk

Data is recorded on an optical disc using a combination of a user data area where user data is recorded, a control data area for reproduction provided on an inner radius side of the user data area, and an outer guard zone provided on an outer radius side of the user data area as a unit of one recording operation. In this configuration, a track pitch TP of the optical disc is greater than or equal to 0.3 &#x3bc;m and smaller than or equal to 0.4 &#x3bc;m, and the width of the outer guard zone along a radius direction of the optical disc is greater than or equal to a value of (100&#xd7;TP) and smaller than or equal to a value of (125&#xd7;TP).

Optical disc recording method and apparatus

An optical disc medium includes a system area and a data area. The system area includes a recording operation test area to which a trial recording operation is carried out to determine an optimal record condition when data is recorded in the data area; a record control data area where data necessary to record user data on the data area is recorded; and a user data lead-in area necessary to reproduce the user data from the optical disc medium. Dummy data are recorded to a portion of the record control data area on a side of the user data lead-in area to prevent a track-out when the data area is accessed.

Optical disc medium, and apparatus and method for recording data on the same

An optical disc medium includes a system area and a data area following the system area. A plurality of sets of an extended record control data area, a bordered area, and a border are possibly set in the data area continuously from the system area, and a first set of the plurality of sets does not include the extended record control data area. A user data is recorded in each of the bordered areas. In each of the plurality of sets other than the first set, a record control data associated with the user data which is recorded in the bordered area of the set is recorded in the extended record control data area.

Optical disc medium having extended record control data areas, optical disc apparatus using the same, and data recording method on the same

An optical disk medium in which a learning area can be expanded, an optical disk information recording method and an optical disk apparatus are provided. A first lead-in area and second lead-in area are provided on the inner side and outer side of a data area. The first lead-in area includes a first learning area, management information recording area and data connection area and the second lead-in area includes a protection area which protects the user data in the inner portion thereof and a second learning area which is provided on the outer side of the protection area and sets an optimum condition for an operation of recording data into the data area. An area in which information indicating the utilization state of the protection area is recorded is prepared in one of the management information recording area and data connection area.

Recording/reproducing method and recording/reproducing apparatus and optical disk

The present invention provides a technique for improving reliability of reading header information. The optical disk is composed of a recording track. The recording track includes a data recording region in which recording pits are formed for recording data, and a header region in which pre-pits are formed for recording header information identifying said data recording region. Said recording pits have a reflectance smaller than that of a space in which said recording pits are not formed. Said recording pits and said pre-pits are formed so that an amplitude (dynamic range) of a level of an optical signal reflected from said header regions is larger than that of an optical signal reflected from said data recording regions.

Optical disc and method for reproducing the same

In order to stably carry out reproduction of information in an optical disc medium () using a PRML (partial-response maximum-likelihood) method for reproducing the signal, the optical disc medium () has not only a data recording area () where data is recorded at high density but also a system information recording area () where information is recorded at low density and binary equalizing/reproducing can be easily made. Information required to circuit setting is recorded in the system information recording area.

Optical disc medium having a system information recording area of low recording density

An optical disk apparatus for suppressing a Digital Sum Value (DSV) and performing Running Optimum Power Control (R-OPC). An encoding/decoding circuit inserts a synchronization information item to a head of only one synchronous frame when data are recorded on an optical disk. First, the encoding/decoding circuit inserts a synchronization information item having a polarity of either a mark or a space on the basis of a DSV. When the polarity of the first synchronization information item is a mark, the polarity of a next synchronization information item is set to a space. When the polarity of the first synchronization information is a space, the polarity of the next synchronization information is set to a mark. A system controller executes R-OPC at a timing when the synchronization information having the polarity of a mark is recorded on the optical disk.

Optical disk and optical disk drive for suppressing a digital sum value and low-frequency components

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Tokyo, Japan

Yutaka Yamanaka