Sony Corporation

Other

Minoru Tobita

Goro Fujita

Toshiyuki Nakagawa

Hiroshige Okamura

Tamotsu Yamagami

Shinichi Nakao

Susumu Tosaka

Satoshi Otsuka

Takeshi Funahashi

Yoshikatsu Niwa

Yoichiro Sako

Shigemi Maeda

Kazuhito Kurita

Hideyoshi Horimai

Mikinori Matsuda

Toshiaki Hioki

Tokio Kanada

Akihiro Noda

Yoshiyuki Teraoka

Yoshiro Arikawa

Michio Matsuura

Masato Hattori

Kunio Kawaguchi

Shingo Imanishi

Tetsuhiro Sakamoto

Tomiji Tanaka

Makoto Watanabe

Shiro Morotomi

Tamotsu Ishii

Kazutomo Miyata

Shigeru Yokono

Teruyuki Ota

Toshiya Murakami

Kunihiro Shioura

Atsushi Umezawa

A reproduction apparatus for an optical recording medium that has a convex pit recording layer, in which pits are formed in a convex shape viewed from a laser incidence side, and a concave pit recording layer, in which pits are formed in a concave shape viewed from the laser incidence side, as recording layers in which data is recorded by pit strings, the pits being formed with a depth that is set in a range of &#x3bb;/4.5 to &#x3bb;/6 with respect to a laser wavelength &#x3bb;, including: an optical head section that irradiates laser beams on the recording layers and detects reflected light information to read out information recorded in the recording layers; a tracking error signal generating section that generates a tracking signal; a polarity switching section that switches a polarity of the tracking error signal; and a tracking servo section that performs a tracking servo operation.

Optical recording medium, reproduction apparatus, and tracking servo method

An optical recording medium which has an enhanced appearance or an enhanced design performance while computer data are recorded and a reproduction apparatus and method in which the optical recording medium is used are disclosed. When computer data are recorded on the optical recording medium on which recording data are recorded as interference fringes formed through interference of object light of images with reference light, related information of the recording data is recorded in a state wherein it can be recognized through the visual sense of the user.

Optical recording medium, reproduction apparatus and reproduction method

An optical disc () according to the present invention has a recording area divided into 28 zones of from a zone Zto a zone Z. In a given zone, the number of waves of a wobble is set so as to be equal, that is, the number of waves of the ADIP carrier is set so as to be equal, between optional two neighboring turns of the track or between optional two neighboring tracks. This achieves inphase-outphase matching on an average, for decreasing a WPP signal, so that such an optical disc may be provided in which no low frequency components are superposed on push-pull signals, even though the optical disc is of such a type in which the track pitch is narrower than 1.6 &#x3bc;m, such as 1.25 &#x3bc;m, or in which a mark is detected by DWDD from a groove, as in the case of the next generation MD

Disc-shaped recording medium, method and apparatus for manufacturing same and data recording method

A magneto-optical disk having a small-sized diameter and a large capacity and able to record and reproduce disk discrimination information, and a recording method and a reproducing method of the same, wherein a recording layer including a main recording region in which a first information is recorded, a sub recording region in which a second information including the disk discrimination information is recorded, and a buffer region formed between the main recording region and the sub recording region and in which a third information is recorded is provided on a substrate, the second information is recorded by a mark array formed in stripe shapes in the sub recording region and the buffer region, a plurality of marks constituting the mark array are obtained by changing the magnetization state of the recording layer, and the third information is reproduced by a modulation signal of a reflection ratio along a circumferential direction of the disk.

Magneto-optical disk and recording and/or reproducing method and recording and/or reproducing apparatus using the magneto-optical disk

A recording medium is provided wherein type determination and writing possibility determination is enabled for various types of disks. Opening and closing structure functions to open and close a detection hole of a cartridge. The structure forms a plane substantially horizontal level with a reference plane of the cartridge at a position of a detection hole when the detection hole is in a closed state. The cartridge has at least a first detection hole and a second detection hole formed therein. The second detection hole (H) is opened and closed by the opening and closing structure, and the first detection hole (H) is in an open state at all times.

Cartridge type recording medium, associated apparatus and methodology of disc detection

The present invention pertains to a modulation apparatus and method in which the modulation apparatus is realized with a simple circuit structure and is easily applicable to other systems. A pattern conversion unitconverts data having a basic data length of 2 bits supplied from a DSV control bit determination and insertion unitinto a variable-length code having a basic code length of 3 bits in accordance with a conversion table. A minimum-run-length limitation code detection unitdetects, from a data sequence containing a DSV control bit, the position of minimum runs consecutive from a channel bit string converted by the pattern conversion unit. A consecutive-minimum-run replacement unitreplaces a predetermined portion of the channel bit string supplied from the pattern conversion unitfor a predetermined pattern based on the position information supplied from the minimum-run-length limitation code detection unit, and limits the minimum run length to a predetermined number or less. The present invention is applicable to a modulation apparatus.

Modulation apparatus and method

A disc drive apparatus is provided which determines a recording medium enabling type and recordability for various types of discs. The discs are housed in a cartridge and each cartridge has at least a first and second detection hole formed therein. The second detection hole (H) is variably opened and closed by an opening/closing device, and the first detection hole (H) is in an open state at all times. The disc drive apparatus determines the disc type using a light signal reflected from the loaded recording medium. The disc drive apparatus also determines disc determining parameters (for example, recordability of a disc) based on information received about the disc type and the open/closed state of one or more detection holes formed in the cartridge.

Disc detection device and associated method

An information recording/reproducing apparatus for recording and reproducing information to and from a magneto-optical storage medium that includes a first magnetic layer for recording at least information, a second magnetic layer for regulating a switched connective force, and a third magnetic layer for shifting a magnetic wall of recorded markings for information reproduction. The three layers being stacked on a transparent substrate to make up the storage medium. The information recording/reproducing apparatus includes an optical head and a magnetic head. The optical head has a light source and an objective lens, the light source is configured to emit at least a laser beam with a wavelength of about 780 nm, the objective lens having a numerical aperture of about 0.45 and is configured to focus the laser beam from the light source into a beam spot for emission onto the magneto-optical storage medium. The magnetic head is for applying a recording magnetic field to the magneto-optical storage medium.

Recording and reproducing apparatus for recording and reproducing information to and from a magneto-optical storage medium

An optical disc () according to the present invention has a recording area divided into 28 zones of from a zone Zto a zone Z. In a given zone, the number of waves of a wobble is set so as to be equal, that is, the number of waves of the ADIP carrier is set so as to be equal, between optional two neighboring turns of the track or between optional two neighboring tracks. This achieves inphase-outphase matching on an average, for decreasing a WPP signal, so that such an optical disc may be provided in which no low frequency components are superposed on push-pull signals, even though the optical disc is of such a type in which the track pitch is narrower than 1.6 &#x3bc;m, such as 1.25 &#x3bc;m, or in which a mark is detected by DWDD from a groove, as in the case of the next generation MD2.

Disc-shaped recording medium, manufacturing method and manufacturing device thereof, and data recording method

A modulation apparatus and method for more accurately determining a value of a control bit to be inserted into a data sequence and digital sum value (DSV) control bit generating method in which a data conversion unit supplies modulation-delimiter information including information regarding delimiters of modulation of a data sequence based on a conversion table to a modulation-delimiter detecting unit and supplies to a valid-delimiter detecting unit a DSV-segment-delimiter signal including information regarding a delimiter position of a DSV segment of the data sequence having the DSV control bit. The modulation-delimiter detecting unit detects modulation-delimiter positions based on the modulation-delimiter information supplied thereto and supplies a modulation-delimiter signal to the valid-delimiter detecting unit. The valid-delimiter detecting unit, based on the DSV-segment-delimiter signal supplied thereto, detects a valid-delimiter position for controlling timing for determining a DSV control bit of the relevant DSV segment from the modulation-delimiter positions represented by the modulation-delimiter signal supplied thereto.

Modulation apparatus and method, and DSV-control-bit generating method

The present invention relates to a modulation apparatus and method and a DSV-control-bit generating method for suppressing an increase in circuit size of the modulation apparatus. When an input data stream is supplied to a DSV control bit determination unit, the DSV control bit determination unitdetermines a DSV control bit to be inserted into the input data stream. Upon supplying the input data stream to the DSV control bit determination unit, the input data stream is simultaneously supplied to a delay processor. The input data stream is delayed for a predetermined delay time and supplied to a determined-DSV-control-bit insertion unit. The determined-DSV-control-bit insertion unitinserts the DSV control bit determined by the DSV control bit determination unitinto a predetermined position of the input data stream supplied by the delay means and supplies the input data stream containing the DSV control bit to a modulator. The modulatormodulates the input data stream containing the DSV control bit into a code string in accordance with a predetermined coding rule (for example, 1,7PP modulation).

Modulating apparatus and method, and DSV control bit producing method

Modulation apparatus and method and DSV control bit generation method

An optical disc and an optical disc drive for the optical disc are provided which are suitable for recording data with a high density. The optical disc D uses both lands and grooves as recording tracks. Each of the tracks consists of one address segment and forty five data segments. The address segment is wobbled at one side thereof. Each of the data segments is a DC groove. The address segment records an address information including a sync signal, frame address, track address and CRC, a tilt pattern and a clock mark. The clock mark is adapted to reflect laser beam in one amount before the mark and in another amount after the mark. The tilt pattern has a different track pitch from those in other areas. The data segments record data magneto-optically.

Optical disc and optical drive

Growing community of inventors

Tokyo, Japan

Minoru Tobita