Hitachi, Ltd.

Sony Corporation

Samsung Electronics Co., Ltd.

Hitachi-lg Data Storage, Inc.

Exabyte Corporation

Nippon Victor Kabushiki Kaisha

Shigeru Yamazaki

Takao Arai

Takaharu Noguchi

Hiroo Okamoto

Nobutaka Amada

Toshio Tsuchiya

Kenmei Masuda

Hideo Nishijima

Masaharu Kobayashi

Hidekazu Takeda

Kenkichi Inada

Akihisa Obata

Kemmei Masuda

Kuniako Hirayama

Hiroaki Ono

Hitoaki Owashi

Seiichi Saito

Hiroyuki Kimura

Takashi Hoshino

Hiroaki Takahashi

Tomiji Tanaka

Mikio Sugiki

Yuji Hatanaka

Harukuni Kobari

Yasunori Kanazawa

Koji Ishioka

Akinari Mouri

Chitoshi Hibino

Toshiyuki Matsuo

Yoshiaki Takano

A digital information recording-reproducing apparatus which records and reproduces a digital information signal transmitted together with an additional information includes a discriminator which discriminates a type of the digital information signal based on the additional information, a recorder which generates control information based on the additional information, adds the control information to the digital information signal, and records the digital information signal having the control information added thereto, a reproducer which reproduces the recorded digital information signal recorded by the recorder, and a controller which controls reproduction based on the control information. When the discriminator discriminates the type of the digital information signal as being a specific type and the digital information signal is recorded by the recorder, the reproducer reproduces the digital information signal.

Digital information recording-reproducing apparatus

A multilayer optical disk apparatus comprises an optical pickup that emits N (N represents an integer of two or more) laser beams of the same wavelength. The optical pickup emits the N laser beams at the same time, focuses the N laser beams on a first recording layer group alternately configured by N recording layers of the multilayer optical disk and performs a recording operation on the N recording layers at the same time. When changing the recording layers the optical pickup focuses the N laser beams on a second recording layer group configured by recording layers adjacent to the respective recording layers configuring the first recording layer group and performs a recording operation on the N recording layers at the same time.

Multilayer optical disk, multilayer optical disk recording apparatus and multilayer optical disk reproducing apparatus

A digital information recording-reproducing apparatus for recording a digital information signal which includes a recording circuit for recording the digital information signal together with control information, and a reproducing circuit for detecting the recorded control information at a time the recorded digital information signal is to be reproduced, and reproducing the recorded digital information signal only if the detected control information satisfies a predetermined condition.

A hologram recording apparatus, a hologram recording method and a hologram recording medium reduce noise components generated by a phase modulation type spatial light modulator, thus permitting improved integrity of data to be achieved. A light beam whose diffraction state has been controlled by a diffraction control element is condensed on a hologram recording medium. With this arrangement, a predetermined diffracted light component is removed from a diffracted light beam emergent from the diffraction control element when recording information, which is based on the diffraction state controlled by the diffraction control element, in a hologram recording medium. Thus, noise components when information is recorded can be reduced.

Hologram recording apparatus, hologram recording method, and hologram recording medium

A recording/reproducing apparatus capable of switching over among a plurality of heads with high precision, wherein the apparatus is provided with: a recording/reproducing unit for recording/reproducing signals onto/from a recording medium with a plurality of heads; a generating unit for generating control data for controlling the recording/reproducing unit; and a transmitting unit for transmitting control data generated by the generating unit to the recording/reproducing unit, wherein priority is given in transmission to data for controlling the switching of the plurality of heads over other data.

Recording/reproducing apparatus

A digital information reproducing apparatus using rotary heads that reproduces digital information signals recorded on a magnetic tape using magneto resistive heads installed on a rotary drum. The apparatus includes, in the fixed side of the apparatus, a magnetic tape checking circuit that checks the type of the magnetic tape; and a control signal generation circuit that generates a control signal for controlling the gain of a reproduction amplifier circuit; and on the rotary drum, a decoder circuit that identifies the control signal transmitted from the control signal generation circuit. The control signal generation circuit generates the control signal based on a checking result given by the magnetic tape checking circuit, and the decoder circuit identifies the transmitted control signal to control the gain of the reproduction amplifier circuit.

Digital information reproducing apparatus using rotary magnetic heads

A digital information recording-reproducing apparatus for recording and reproducing a digital information signal which includes a recording circuit for recording the digital information signal together with control information, and a reproducing circuit for detecting the recorded control information at a time the recorded digital information signal is to be reproduced, and reproducing the recorded digital information signal only if the detected control information satisfies a predetermined condition.

According to the invention, techniques for cleaning a rotary magneto-resistive head. Embodiments according to the invention are especially useful in tape drive systems, and the like. Embodiments can provide methods and apparatus for cleaning contaminant from rotary magneto-resistive heads while guarding against damage to the head from excess cleaning, and the like. Specific embodiments can control the rotational speed of a rotary magneto-resistive head in order to facilitate cleaning operations. Embodiments include a cleaning device and a control method, and are suited for use in a magneto-resistive head mounted on a rotary cylinder of a computer tape storage unit, for example, although application of the present invention is not limited to such embodiments.

Method and apparatus for cleaning a magneto-resistive head

High reliability magneto-resistive head cleaning system

A magnetic recording and/or reproducing apparatus has compatibility with a conventional analog signal recording/reproducing VTR and can realize an operation mode in which a digital signal is recorded and/or reproduced. During N-times long time recording, the travel speed of a magnetic recording medium is set to 1/N of that during normal recording to perform recording every N scanning operations of a rotary head and during N-times long time reproduction, the travel speed of the magnetic recording medium is set to 1/N of that during normal recording and the travel of the magnetic recording medium is controlled such that the level of a reproduction signal reproduced every N scanning operations of the rotary head at a predetermined timing is maximized so as to reproduce a reproduction signal at that timing.

Magnetic recording and/or reproducing apparatus

A digital information recording-reproducing apparatus is disclosed, in which a signal temporally compressed to 1/n and transmitted is encoded for recording by a recording encoder. The rotation speed of a rotary drum is set at R.sub.1, and the running speed of a magnetic tape at V.sub.1. The signal encoded is recorded on the magnetic tape by magnetic heads. At the time of reproduction, the rotary drum is driven at a speed m/n times faster than for recording, and the magnetic tape is run at a speed 1/n times faster than for recording. The signal reproduced by the magnetic heads is decoded and restored into the original digital information signal by a reproducing decoder. As a result, there is provided a recording-reproducing apparatus having the function of time-base expansion with a reduced recording time applied to a system for transmitting and recording the software information of video or the like through radio wave or cable.

Apparatus for recording and reproducing temporally compressed digital

A digital information signal transmitting/receiving method and system having a transmitter for transmitting an encrypted digital information signal and a plurality of receivers for receiving the encrypted digital information signal from the transmitter. The transmitter simultaneously distributes a plurality of identification codes associated with the receivers at a time ahead of the digital information signal. The receivers detect whether a particular identification code assigned to the receiver was included within a received plurality of identification codes. When the particular identification code has been detected as having been received the received encrypted digital information signal is decrypted into the original digital information. In order to request that a particular identification code be included so as to allow access to a program, either one of the receivers or the recorders each generate an information request signal. The transmitter is responsive to the information request signals to add to the digital information signal at a time ahead of the digital information signal, identification signals for identifying the receivers or the recorders which generated the information request signals, thereby producing a transmission signal formed of those signals, and to distribute this transmission signal to the receivers. The recorders control the received information signal to be recorded in response to the identification signals received by the receivers.

Digital information signal transmitting/receiving method and system

A PCM signal recording and reproducing apparatus comprises first and second memory circuits, in which PCM signals are read and written using the first memory circuit, while PCM signals stored in the second memory circuit are error-corrected. At the end of writing by the first memory circuit, the first and second memory circuits are interchanged to read the error-corrected PCM signals stored in the second memory circuit. The read-out error-corrected PCM signals are then recorded on another magnetic tape.

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Yokohama, Japan

Shigeru Yamazaki