Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Yoshiharu Kobayashi

Takashi Ishida

Shigeru Furumiya

Hiromichi Ishibashi

Atsushi Nakamura

Junichi Minamino

Nobuo Akahira

Toyoji Gushima

Teruhiro Shiono

Shin-ichi Tanaka

Akira Mutoh

Satoshi Kondo

Mamoru Shoji

Yasumori Hino

Kenji Koishi

Yoshinari Takemura

Yoshihiro Mushika

Ryoji Yamaguchi

Takashi Mihara

Katsuhiko Yoshida

An optical information reproduction device includes a light source () configured to emit reproduction light, a plasmon resonance element () including a resonance section () arranged adjacent to a recording region () of a recording layer (), the resonance section () causing plasmon resonance between the recording region () and the resonance section (), a photodetector () configured to detect reflected light or transmitted light from the plasmon resonance element () on which the reproduction light is irradiated, and a reproduction unit () configured to determine, on the basis of a detection signal from the photodetector (), whether the recording region () is in a recorded state or an unrecorded state, and reproduce information recorded in the recording region ().

Optical information reproduction device, optical information reproduction method, and information recording medium

The present invention contributes to getting a reproduction/recording operation done with stability on an information recording medium by utilizing an absorption edge shifting phenomenon. An apparatusaccording to the present invention includes: a light sourcefor emitting a laser beam; a lensfor condensing the beam onto an information recording medium; and a photodetectorfor detecting light reflected from the medium, of which a recording layer includes a material that absorbs the beam at an increasing absorptance as the absorption edge of a light absorption spectrum shifts, with a rise in temperature, toward a longer wavelength range as a result of a band-to-band transition of electrons. The apparatusof this invention further includes: a wavelength detecting sectionfor detecting at least one of the wavelength of the beam and its variation; a temperature sensing sectionfor sensing at least one of the temperature of the mediumor its ambience and its variation; and a control sectionfor controlling the power of the light sourcebased on the respective outputs of the wavelength detecting sectionand the temperature sensing section

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

The invention provides an optical disk apparatus and an optical disk that are applicable to a multilayer optical disk, and enable tilt detection with a high precision. The optical disk has a transparent planar disk base member, a recording layer formed on the disk base member, and a reflecting layer in a certain positional relation to the recording layer. The optical disk apparatus includes a laser pointerfor irradiating a laser beam onto the recording layer of the optical disk by way of the disk base member to form a focusing spot on the recording layer, a photo-sensor arrayG for receiving a reflected beam from the reflecting layer, and an aberration mode detecting circuitH for detecting tilt of the optical disk by using an output from the photo-sensor arrayG.

Optical disk apparatus for detecting tilt of an optical disk, and an optical disk for tilt detection

An optical disc having marks for dispersed addresses that can be easily detected with high precision. A dispersed address comprises synchronization marks, positive marks, and negative marks. Synchronization marks, positive marks, and negative marks are formed along a groove as partial discontinuities or partial modifications in the wobbled groove.

Optical disc and optical disc address reading apparatus and method

An optical disc drive includes an objective lens for focusing light on an optical disc with five or more stacked data storage layers and a tilt control mechanism for controlling a tilt angle defined between the optical axis of the light and a normal to the storage layers. The drive reads and/or writes data from/on a selected one of the storage layers by focusing the light on the selected layer. The numerical aperture NA of the objective lens is defined so as to fall within the range of 1.3009&#xd7;D&#x2212;2.9315&#xd7;D+2.3133&#xd7;D&#x2212;0.0502 to 1.3009&#xd7;D&#x2212;2.9315&#xd7;D+2.3133&#xd7;D+0.2028, where D is a distance (mm) from a light incident side of the disc to the deepest one of the storage layers, which is located most distant from the light incident side.

Optical disc drive having tilt controlled objective lens and optical disc

A code conversion method and apparatus is provided for scrambling and modulating data. The method and apparatus includes scrambling an input main data unit based on any of plural types of pseudo-random number sequences, and modulating the scrambled main data unit based on any of plural types of modulation data. An output main data unit is produced from the modulated main data unit, and a calculated value representing a difference between a number of 0 bits and a number of 1 bits included in the output main data unit is obtained. Any of the modulation data is then selected dependent upon the calculated value. The method and apparatus further includes determining whether or not a variation of the calculated value has exceeded a predetermined threshold, newly selecting another pseudo-random number sequence used for the step of scrambling if it is determined that the variation of the calculated value has exceeded the predetermined threshold value, and re-scrambling the input main data unit based on the newly selected pseudo-random number sequence.

Code conversion method and apparatus, code recording medium, code recording apparatus and code reproducing apparatus

An optical disc medium, including a plurality of sector groups each being made up of multiple contiguous sectors on a track, is provided. In this optical disc medium, the location information of each of those sector groups is divided into a predetermined number of information pieces and distributed to associated sectors on the same track.

Optical disc medium having a plurality of sector groups, a recording method thereof and recorder

An optical recording medium comprises a plurality of identifiers in association with address information, wherein: each identifier is provided on the optical recording medium; and each identifier comprises at least one of: a first pattern provided on the optical recording medium and representing a first code expressed by one bit; a second pattern provided on the optical recording medium and representing a second code expressed by one bit; and a third pattern provided on the optical recording medium and representing a third code expressed by one bit.

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

An optical disc is provided having marks for dispersed addresses that can be easily detected with high precision. A dispersed address includes synchronization marks, positive marks, and negative marks. The synchronization marks, positive marks, and negative marks are formed along a groove as partial discontinuities or partial modifications in the wobbled groove.

Optical disc having positive marks and negative marks in a sector block

Code conversion method and apparatus, code recording medium, code

An information recording apparatus for continuously recording information without losing any information even if the apparatus temporarily falls into a recording-disable state owing to the shock externally applied, etc. is provided. A disability detector for detecting the recording-disable state is provided in the information recording apparatus, thereby interrupting the recording operation and the reading operation from the buffer memory under the recording-disable state, and making a coding rate reduction controller instruct a coder to temporarily reduce the coding rate of the input information. A remaining capacity detector is provided for monitoring the remaining capacity in the buffer memory and instructing the coder to temporarily reduce the coding rate of the input information when the remaining capacity becomes a predetermined value or less. As a result, the reduction in the remaining capacity of the buffer memory under the recording-disable state is prevented. When the overflow of the buffer memory is detected, the information after the generation of the overflow is controlled to be overwritten on a part of the data already written into the buffer memory. The variation history of the case where the recording data amount is varied by the coder because of the variation in the coding rate of the input information or the overwriting operation in the buffer memory is controlled to be recorded on the disk as rate variation management information. By dividing the recording area on a disk-shaped information recording medium into an inner circumference and an outer circumference and recording on the outer circumference after the return from the recording-disable state, the recording transfer rate after the return becomes higher.

Information recording method, information recording apparatus and

An optical disk is divided in a radial direction into an inner area and an outer area each having formed therein spiral or concentric tracks each having a sector which has an address area, an audio signal recording area and a video signal recording area. A specific unit of audio signal and a specific unit of video signal are divided into a plurality of audio blocks and a plurality of video blocks, respectively. Each of the audio blocks and the video blocks are separated into a first group and a second group. The audio blocks and video blocks in the first group are respectively recorded into the audio signal recording area and the video signal recording area in a sector in the inner area, and the audio blocks and video blocks in the second group are respectively recorded into the audio signal recording area and the video signal recording area in a sector in the outer area.

Optical disk and optical recording and reproducing apparatus

In a digital modulator circuit for modulating a fixed-length code into a variable-length code and a digital demodulator for demodulating a variable-length code into a fixed-length code in a parallel data form, pre-modulation and pre-demodulation data is input to a logic circuit in synchronization with a pulse input, while a remainder of the fixed-length or variable-length code digital parallel input data taking place in modulating or demodulating process is fed back as an input to the logic circuit via a flip-flop to modulate or demodulate the data together with pre-modulation or pre-demodulation parallel data input at the next input pulse in a parallel data form. A post-modulation or post-demodulation data as well as a modulation or demodulation bit number output from the logic circuit are input to the buffer circuit to output post-modulation or post-demodulation data of which bits have been all modulated or demodulated.

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Katano, Japan

Yoshiharu Kobayashi