Pioneer Corporation

Seiro Oshima

Takao Tagiri

Eiji Muramatsu

Masahiro Kato

Toshihiko Takishita

Atsushi Yamaguchi

Shoji Taniguchi

Yoshio Sasaki

Tatsuhiro Yone

Makoto Matsukawa

Toshihiko Maruyama

Kenji Kawai

Masataka Yamaguchi

Hiroshi Nishiwaki

Tomotaka Yabe

Kazuhiro Yamato

An optical deflector capable of making a swing angle of a reflective plate larger is provided. In drive elements, since a size in the Y direction at first positions separated by a first distance from the reflective plate is larger than a size in the Y direction at second positions separated by a second distance from the reflective plate, the second distance being greater than the first distance, it is possible to increase displacement of tips of beam portions at the first positions and to make a swing angle of the reflective plate large by increasing a generated force of the entire beam portions.

Optical deflector

An optical-recording medium is provided with at least a first recording layer for recording information optically; and a second recording layer for recording information optically by a light beam that passes through said first recording layer; wherein the track pitch of a recording track that is formed on said second recording layer is narrower than the track pitch of a recording track that is formed on said first recording layer.

Optical recording medium, information recording apparatus and information reproduction apparatus

A recording layer close to a disc surface is divided into at least two recording areas, a main information recording area DA and an auxiliary information area (BCA) DC. Grooves are formed in the main information recording area DA. Marks M are formed in barcode form representing identifying information in the auxiliary information recording area (BCA) DC. Track grooves Gor prepits are formed in the recording layer of the auxiliary information recording area (BCA) DC and have a depth smaller than that of the groove formed in the main information recording area DA.

Optical disc

An offset amount measuring method is provided with: a recording process for measurement (i) of recording information for measurement, into a recording track in the Llayer, by a predetermined section, from a measurement reference position, and of (ii) recording the information for measurement, into a recording track in the Llayer, by the predetermined section, from or toward a measurement correspondence position, which is associated with the measurement reference position by the pre-format address; a first detecting process of detecting a border of a first recorded area in which the information for measurement is recorded and a first unrecorded area in the first recording track, on the basis of a difference in reflectance between the first recorded area and the first unrecorded area; a second detecting process of detecting a second border position in the recording track in the Llayer, on the basis of a difference in reflectance; and a determining process of determining the offset amount, on the basis of the detected first and second border positions. Moreover, it is also provided with a judging process of judging whether or not the determined offset amount is within tolerance with respect to the first offset amount set in advance for offset countermeasures.

Offset amount measuring method and apparatus

A groove track and a land track are alternately and spirally formed on an information recording medium. On the land track neighboring the groove track, pre-information indicating position information of a track on a disc is formed as a prepit. On the information recording medium, an embossed area is formed so that information about a copyright and for preventing an illegal copy cannot be rewritten. In the embossed area, an embossed configuration including a pit and a space of predetermined depths is formed. The prepit in the embossed area is formed so that the prepit has an optimized configuration according to a pit length and a space length in the embossed area which the prepit neighbors. Consequently, interference between the embossed configuration and the prepit can be prevented even in a case that the prepit is formed in addition to the embossed configuration in the embossed area.

Information recording medium

The present invention provides an optical recording medium, in which levels of wobble signals extracted from a recording area formed snakily, a reproduction exclusive area and an impossible area are maintained constant. On DVD-RW, groove tracks are snakily formed on a groove section on which recording information is recorded, and pit strings where a plurality of phase pits wave are arranged on the impossible area and the reproduction exclusive area which prevent illegal copying. On the respective areas, pit depths (groove depths), duty of the pit strings and wobbling amplitudes are set according to predetermined conditions so that the output levels of the wobble signals extracted based on the wobbling amplitudes can be maintained constant on the respective areas. As a result, synchronous control can be made accurately at the time of recording and reproduction on/from the DVD-RW.

Optical recording medium, optical recording medium producing apparatus and optical recording medium producing method

A rewritable optical recording medium includes a segmented groove area in which the groove track is segmented along a rotating direction of the recording medium by groove non-forming portions to form a plurality of groove portions; and a continuous groove area in which a continuous groove is formed, the continuous groove having a groove width smaller than a groove width in the segmented groove area.

Rewritable optical recording medium and manufacturing method and apparatus therefor

Optical recording medium having a plurality of meandering groove tracks, optical recording medium producing apparatus and optical recording medium producing method

An optical recording medium is provided which comprises: a substrate including concentrically or spirally formed grooves each having a V-shaped cross section; a first dielectric layer formed on the substrate; a phase-change recording layer formed on the first dielectric layer; a second dielectric layer formed on the phase-change recording layer; and a metallic reflecting layer formed on the second dielectric layer. In particular, the optical recording medium is so formed that an objective lens having an aperture number of 0.55-0.70 can be used and a laser beam having a wavelength of 600-700 nm and passing through the objective lens is passed through the substrate and then converged on the recording layer, thereby recording or reproducing information on the recording layer in areas corresponding to the grooves. Specifically, the optical recording medium further comprises a third dielectric layer consisting of a nitride, the third dielectric layer being disposed between the first dielectric layer and the phase-change recording layer. In this way, it is possible to prevent a deterioration possibly caused due to a heat in the boundary between the first dielectric layer and the second dielectric layer, thereby greatly increasing the number of possible times for over-write recording.

Optical recording medium

A recording medium includes pairs of groove tracks and land tracks having periodically formed bent portion provided side by side on a substrate, a plurality of land prepits previously formed on the land tracks and carrying information about the groove tracks, and a recording layer formed on at least the groove tracks and the land tracks. The land prepits have a radius of mean curvature smaller than a radius of mean curvature of sides of the groove tracks in land-prepit absent regions of the land prepits and are defined by curved surfaces continuously extending from the sides of the groove tracks. Those sides of the groove tracks which face the continuous curved surfaces of the land prepits are curved surfaces that stricture the groove tracks. The depth of the land prepit is larger than that of the groove track.

Growing community of inventors

Yamanashi-ken, Japan

Seiro Oshima