Sony Corporation

Tsuneo Furuya

Katsuya Hori

Shunsuke Furukawa

Yoichiro Sako

Tadao Suzuki

Tadashi Fukami

Yoshizumi Inazawa

Constant P Baggen

Yasuaki Yamagishi

Katsuaki Tsurushima

Marinus J Monen

Yoshimoto Muratsubaki

Fujiyuki Fukamatsu

Shunske Furukawa

A system for transmitting a scramble signal for a sky port scramble system including an organization center for organizing data relating to customers etc. and first and second control units each having a system controller and a scrambler for performing the scramble processing on the basis of the customer data sent from the organization center. In a normal state, the organization center communicates with one of the first and second control units and each of the first and second control units is operated in the same manner. In case of the occurrence of an abnormality or a fault in the communication control unit, only the other control unit is operated and the organization center communicates with the other control unit instead.

Scramble signal transmission system for earth station of communication

Information is transmitted by a digital audio transmission line, which may include recording and playback from a digital audio disc, that includes information other than conventional two-channel audio signals and in which error correction of the data transmitted in either direction between a user and a medium is provided. Information integrity is maintained by a first and second cross-interleave Reed-Solomon code (CIRC), in which a third Reed-Solomon code is overlaid on the CIRC code, whereby a sector is built from user words and protected by a quasi-product code, and then an encoded sector is divided into groups, which are group-wise presented to the CIRC encoder.

Method and apparatus for transmitting digital data

Apparatus for playback from a disc on which main digital data and subsidiary digital data for selectively reproducing of the main digital data have been recorded in multiplex fashion incorporates a write clock generator for generating a write clock synchronized with a reproduced signal from the disc, a read clock generator for generating a read clock having a predetermined period, a buffer memory into which main digital data and subsidiary digital data reproduced from the disc are written and read out in response to the read clock so as to de-interleave the main digital data, and a control unit for seeking a position to be reproduced in the main digital data in response to the subsidiary digital data read out from the buffer memory. The buffer memory into which the subsidiary digital data is written may be a FIFO buffer register which is provided separately from the buffer memory into which the main digital date is written.

Disc playback apparatus for playback of music and digital data

Circuit for operating finite fields

A disc player, for reproducing program information from a disc on which the information is recorded as digital program information data accompanied by digital address data, comprises an optical reader for reading program information data and address data from the disc, such reader being selectively operable in a searching mode and in a playback mode, processing circuitry supplied with program information data to produce program information from the program information data, a detecting means that compares designated address data identifying desired program information with the reproduced address data in the output of the reader and system controlling means for controlling the reader to continue the searching mode until the reproduced address data match the designated address data, at which time the system controlling means operates the reader in its playback mode to read from the disc the program information data identified by the designated address data. Noise-suppressing means substantially prevents the processing circuitry from producing program information from the program information data in the output of the reader operating in the searching mode. The clicking noises and other spurious sounds produced by prior art disc players from the program information data read during the searching mode are thus prevented from occuring before the production of desired program information from the disc.

Disc player with search noise suppression

Information is transmitted by a digital audio transmission line, which may include recording and play back from a digital audio disc, that includes information other than conventional two channel audio signals and error correction of the data transmitted in either direction between a user and a medium is provided. Information integrity is maintained by a first and second cross-interleave Reed-Solomon code (CIRC), in which a third Reed-Solomon code is overlaid on the CIRC code, whereby a sector is built from users words and protected by a quasi-product code, and then an encoded sector is divided into groups, which are group-wise presented to the CIRC encoder.

Apparatus for correcting errors

A digital audio disc system having a main channel in which main data consisting of audio PCM signals and codes for error correction are recorded and a subchannel in which information digital signals other than said main data are recorded is disclosed. The code signals comprising a sync signal which has a prescribed bit pattern, a display position data, a command for a computer, and a display data relating a content of said audio PCM signals are also recorded multi-times on the disc together with said main data so as to enable the error check of said code signals. Both code signals and main data are reproduced and supplied to a display unit so as to indicate the correct display information data on a display screen under control of a microcomputer provided in the playback side. When a pickup device moves on the disc in the radial direction at a speed higher than that in an ordinary playback operation, the display screen of said display unit is cleared or previously reproduced normal display data is held on the screen. When the pickup device does not start the playback of said display data from the display start position, the display data thus reproduced is made invalid until the display data at the display start position is reproduced. In this way, it is possible to prevent indication of abnormal display data.

Digital audio disc system

Apparatus permits the use of a known optical compact audio disc for providing a larger memory capacity so that data other than audio data can be reproduced therefrom while maintaining consistency with respect to signal format and signal processing, such as error correcting methods and recording data formats and the like, by providing write clock signals and read-out clock signals for reading into and out two memories the main digital data signal by using a subdigital data signal that is recorded on the disc along with the main digital data and which is reproduced from the disc at the same time as the main data in order to provide addressing of the main digital data on a more accurate level and with finer resolution, and a control system searches a playback location of the main digital data based upon the subdigital data as read out from the buffer memory, in which subdigital data has been written by the write clock signal.

Disc playback apparatus

A method of error correction comprises error correction coding processing and interleaving and de-interleaving processings for digital subcoding data (as opposed to main data) in subchannels (as opposed to the main channel) to be transmitted. Apparatus is provided comprising means for performing those processings. The method comprises the steps of dividing digital subcoding data in one PACKET into a plurality of PACKs; adding a first redundant code for error detection or error correction to each of the PACKs; and interleaving the digital subcoding data in each of the PACKs and the first redundant code; whereby the interleaved data is transmitted together with frame sync signals and main data. The data in the subchannels is coded and interleaved and then recorded so that the distances between the data are maximized. Therefore, if errors should occur, the interpolation can be properly done, thereby improving the error correcting ability without requiring complicated error correction circuit or large buffer memory such as those required for the data in the main channel.

Method and apparatus for error correction

In apparatus for error correction in which data sequences containing blocks of data, previously arranged on a known time-base, and formed of data words and check words are written into a memory under control of a write address generator, and the data sequences are subsequently read out from the memory under control of a write address generator, so as to generate rearranged data sequences; during writing and reading of the data sequences, error correction is carried out by apparatus that includes an error correction arithmetic circuit for performing the error correction calculation, a pointer addition circuit for adding a pointer to the data words in association with an error state of the blocks, and a memory for memorizing a microprogram having fields to control the error correction arithmetic circuit and pointer addition circuit.

Apparatus for error correction

An optical disc player comprises a rotating member for rotating the optical disc, an optical pickup member for reproducing a digital audio signal including an error correcting code such as the Reed-Solomon Code from the disc, an error correcting decoder for decoding the error correcting code so as to produce a corrected or interpolated digital audio signal and condition flag data indicating the correction of the digital audio signal, and a display for indicating the condition flag data as a stain or contamination condition of the disc.

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Kanagawa, Japan

Tsuneo Furuya