Nec Corporation

Kabushiki Kaisha Toshiba

Sanyo Electric Co., Ltd.

Toshiba Corporation

Tatsunori Ide

Yutaka Kashihara

Yutaka Yamanaka

Akihito Ogawa

Shuichi Ohkubo

Hideki Takahashi

Shigeru Shimonou

Masato Fuma

Tsuyoshi Yamamoto

Mitsuya Okada

Katsuki Hattori

Kazuo Watabe

Yuji Nagai

Taku Kato

Chosaku Noda

Atsushi Ishihara

Morio Nakatani

Toshiaki Iwanaga

Eiji Kariyada

Shuichi Okubo

Yoshitaka Kawanishi

Masaaki Matsumaru

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

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 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

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 information recording medium is provided that records and reproduces information by means of laser beams irradiated from the side of the light transmission layer. The optical information recording medium provides a large capacity and a high degree of reliability and is inexpensive. At least a reflective film and a light transmission layer are formed, in the presented order, on the information recording surface of the support substrate. Information is recorded and/or reproduced by using the laser beam irradiated from the side of the light transmission layer. The reflective film, which is made of an alloy containing Ni and Cr as main components, has a thickness of 20 nm or more to 80 nm or less.

Optical information recording medium

An optical storage medium includes a substrate having grooves and lands. A first dielectric layer overlies the substrate. A recording layer overlies the first dielectric layer. A second dielectric layer overlies the recording layer, and a light transmitting layer overlying the second dielectric layer. Each of the grooves is larger in width than adjacent two of the lands.

Optical storage medium with improved substrate structure to provide uniform signal quality

In an optical data recording media provided with a recording layer which changes its optical characteristics by the difference of heat history of heating and cooling by the irradiation of the laser light to a transparent substrate on which tracking channels have been formed. The width of an extruded or concave region formed by the tracking channels on the substrate is narrower than the diameter of the laser beam being used for recording, erasing and reading. Thereby, a problem which is associated with the recording frequency-dependent erasing efficiency in a case where the pulse width modulation method is used as the modulation method, can be solved.

Optical data recording apparatus producing a laser beam having a

An optical information recording medium includes a transparent substrate, a first protection film, a recording film, a second protection film, a dielectric film, and a dielectric reflective film. The first protection film is formed on the transparent substrate. The recording film is formed on the first protection film to record and erase information by causing a reversible phase change between a crystalline state and an amorphous state upon being irradiated with a laser beam, and reproduce recorded information by detecting a change in optical nature accompanying the phase change in the recording film. The second protection film is formed on the recording film to protect the recording film together with the first protection film. The dielectric film is formed on the second protection film and has a refractive index lower than a refractive index of the transparent substrate. The dielectric reflective film is formed on the dielectric film and has a refractive index higher than the refractive index of the transparent substrate.

A phase change type optical disk includes a transparent substrate, a recording layer, a first transparent protection layer, a reflective layer, and a transparent interference layer. The recording layer is formed above the transparent substrate to cause a reversible phase change between a crystalline state and an amorphous state. The recording layer causes a phase change upon being irradiated with a laser beam, thereby recording, reproducing, and erasing information. The first transparent protection layer is formed on the recording layer to protect the recording layer. The reflective layer is formed above the recording layer to reflect light transmitted through the recording layer and causes the reflected light to be incident on the recording layer. The transparent interference layer is formed between the first protection layer and the reflective layer to cause light beams reflected by the reflective layer to optically interfere with each other. Light transmitted through the recording layer is multiple-reflected between the reflective layer and an interface between the interference layer and the first protection layer.

Re-writable phase change type optical disk with suppressed recording

An optical information-recording medium includes a substrate, and a lower protective layer, a recording layer, an upper protective layer, and a reflective layer, formed on the substrate. The recording layer exhibits different optical properties dependent on different thermal histories of a rise and a fall in temperature caused by irradiation of a laser beam on the substrate. The optical information-recording medium has a layer structure constructed such that reflectivity of the optical information-recording medium and the phase of light reflected therefrom vary with the change in the optical properties of the recording layer, with absorptivity of light of the recording layer being larger when the recording layer is in a crystalline state than when the recording layer is in an amorphous state, and at the same time, reflectivity exhibited when the recording layer in the crystalline state being 10% or higher. The reflective layer has a thickness set such that a value of reflectivity of the reflective layer exhibited in the form of a single layer is 90% or more of a value of reflectivity of a bulk form of a substance of the reflective layer, or to a value of 40 nm or larger.

Optical information-recording medium

An information recording medium includes a recording thin film formed on a substrate. The recording thin film consists of a material containing cobalt, antimony, and tellurium as main components, and an energy beam is irradiated on the recording thin film to change optical characteristics of the recording thin film, thereby recording information.

Information recording medium

The optical data recording media is provided on a substrate with a recording layer changing its optical characteristic dependent upon difference in the heat history, or processes of temperature elevation due to laser beam irradiation and the following cooling. The media is composed of layered structure not only varying its own reflectance or transmittance as an integrated media, but also changing the optical phase of the reflected light or transmitted light, when the optical characteristic of the recording layer is changed. In the method of recording, erasing and reproducing data using this optical data recording media, when the variations of the reflectance is to be detected, recording and erasing are effected after temporarily setting the recording layer in a state having a higher reflectance. On the other hand, when the variations of the transmittance is to be detected, recording and erasing are effected after temporarily setting the recording layer in a state having a higher transmittance. The substrate has such guide grooves that the width of either the convex portion between the guide grooves or the concave portion of the guide grooves is smaller than the diameter of the laser beam spot for reproduction.

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Tokyo, Japan

Tatsunori Ide