Hitachi, Ltd.

Hitachi Consumer Electronics Co., Ltd.

Hitachi-Lg Data Storage, Inc.

Renesas Electronics Corporation

Yutaka Nagai

Toshifumi Takeuchi

Masayuki Hirabayashi

Osamu Kawamae

Koichiro Nishimura

Masafumi Nakamura

Hiroshi Hirayama

Masakazu Ikeda

Hideaki Suzuki

Takao Arai

Shigemitsu Higuchi

Taku Hoshizawa

Takakiyo Yasukawa

Yasuo Mutsuro

Izumi Kimura

Shuichi Sagano

Harukazu Miyamoto

Hiroo Okamoto

Takaharu Noguchi

Yusuke Nakamura

Shigeyuki Itoh

Koichi Watanabe

Akio Fukushima

Yoshinori Ishikawa

Shigeki Inoue

Kenji Akahoshi

Takeyoshi Kataoka

Takehiko Sekine

Shinichi Obata

Hiroshi Tadokoro

Junya Iizuka

Hiroyuki Gunji

Tosifumi Takeuchi

Tomoaki Kudo

Yoshifumi Takeuchi

A method for performing recording on a multilayered optical disk which has three or more recordable or rewritable information recording layers with a first recording layer and a second recording layer located nearer to a light incident surface than the first recording layer, and which respectively has a first test area configured by a plurality of segments in the first recording layer and in the second recording layer, wherein a predetermined radial distance L is defined beforehand. When an arbitrary segment in the second test area is test-recorded, a segment in the first test area, the radial distance of which from the recorded test area in the second test area is within the range of the predetermined radial distance L, is set as a segment in which test recording is not performed.

Multilayered optical disk and its recording method

Obtain an expanded address without altering the bit number of an address which is embedded in a wobble. Generate a virtual bit which is not recorded on a disc, and which is expressed by the disparity from the rules and the presence or absence of information embedded in part or all of the wobble address.

Reproduction and recording method and reproduction and recording device using a virtual bit for address expansion of a recording medium while maintaining a conventional wobble address structure

There are provided an optical disc device and its recording/reproducing method for managing the management information about plural optical discs efficiently. In the present invention, the management information about the plural optical discs is stored in a memory. Moreover, the management information about part or all of the optical discs stored in the memory is recorded in the optical disc.

Optical disc device and optical disc recording/reproducing method

Recording medium, reproduction and recording method, reproduction and recording device

A recording medium, an address generating method, an address detection method and a recording and reproduction apparatus capable of extending the wobble address without any considerable wobble restructuring are disclosed. Virtual bits not recorded in the disc and expressed by the difference of the rule or the presence or absence of the information embedded in a part or the whole of the wobble address are generated. Thus, the extended address can be obtained without changing the number of bits of the address embedded in the wobble.

Recording medium, address generating and detection method, and reproduction and recording apparatus

Where a hybrid disc has different types of media, the light spot moves among recording layers of the different media, after loading the disc into an optical disc apparatus, there is a problem that information on a media type of each recording layer should be recorded in DI etc. of the optical disc. Detailed information on the hybrid disc is stored in DI, by changing a disc layer type identifier or a disc structure in DI such as BCA or PIC on the optical disc.

Optical disc reproducing apparatus for implementing an optical recording and reproducing method for multi-layer optical discs

A technique capable of realizing a power saving in a device for reproducing/recording digital signals by properly controlling a frequency of a clock. The device for reproducing/recording digital signals (device for reproducing an optical disk) includes: a difference comparing circuit for comparing a first parameter (demodulating block counter) updated each time a process for one correcting block is done in a demodulating circuit with a second parameter (error correcting block counter) updated each time a process of one correcting block is done in an error correcting circuit; and a circuit (clock controlling circuit etc.) for switching a frequency of a master clock (MCLK) depending on a comparison result of the difference comparing circuit. Thereby, the frequency of the clock can be switched both of when the demodulation for one correcting block is ended and when the correcting process for one correcting block is ended by using the switched master clock.

Device and method for reproducing digital signal and device and method for recording digital signal

An optical disc apparatus capable of deriving optimum laser beam power even when OPC areas overlap with one another and a method for the apparatus. OPC result is recorded to an optical disc and OPC (area-saving OPC) that reduces an area use quantity by using the OPC result is executed and optimum laser power is determined.

Recording apparatus and recording method

A disk-like recording medium recording/reproducing method or apparatus for performing a data recording operation and a data reproducing operation to the disk-like recording medium alternately. The recording operation is performed at a constant linear velocity, and whether a recording area at an ending point of an n-th recording operation on the medium is continuous to a recording area at a starting point of an (n+1) the recording operation is identified. When a discontinuation of the recording area is identified, the rotational speed at the starting point of the (n+1)th recording operation is changed, during a reproducing operation between the n-th recording operation and the (n+1)th recording operation. When a continuation of the recording area is identified, the rotational speed of the disk-like recording medium at the ending point of the n-th recording operation is held, during a reproducing operation between the n-th recording operation and the (n+1)th recording operation.

Method and apparatus for recording/reproducing digital video signal or audio signal, and optical disk apparatus

In a recording apparatus capable of performing a curing process at high speed by curing a plurality of books at a time during recording and capable of performing recording of a recordable type, when recording is stopped once, the unit of books to be cured at a time is set smaller than that during continuous recording, in order to realize inexpensively both performing a curing process at high speed in hologram recording and realizing recording of a recordable type freely in a book unit. It is therefore possible to terminate recording in the unit of arbitrary books irrespective of the unit of books to be cured, and perform recording of a recordable type without loss.

Optical information recording method and apparatus

Each layer includes a data recording area and a test writing area divided into a plurality of small areas, wherein the small areas of the test writing area are recorded in advance so that other each layer can make a combination of recorded and unrecorded states with respect to the small area, where OPC is carried out, in a layer where OPC is carried out. Moreover, OPC is carried out to each small area, where a combination of recorded/unrecorded states of other each layer differs from each other, to thereby calculate, as the optimum power, an average value of the result of each OPC or a central value of the dispersion thereof.

Multi-layer optical disc, and recording method and apparatus for multi-layer optical disc

A need to effectively record data of various sizes on a large-capacity holographic memory capable of high-speed recording is achieved, for example, by curing a first part of the holographic recording which is able to be multiplex-recorded in one or more units of a predetermined volume, and by not recording/curing a second part which is not able to be multiplex-recorded in a predetermined volume at a timing when the first recording part is cured. Also the above need can be achieved by, another example, by adding dummy data to the second part. Alternatively, the second part can be recorded on another track, in which it is possible to record in different units, e.g. by bit recording in a track that utilizes a DVD recording format. According to the present examples, we can record data of various sizes on the holographic memory effectively while performing large-capacity and high-speed holographic recording.

Optical information recording apparatus and optical information recording method

Growing community of inventors

Yokohama, Japan

Yutaka Nagai