Matsushita Electric Industrial Co., Ltd.

Christopher Scientific Company

Nobuyoshi Kihara

Yasuharu Shimeki

Hiroshi Matsushima

Shiro Tsuji

Misao Kato

Yoshinori Amano

Hiroaki Kotera

Masamitsu Ohtsu

Takafumi Ueno

Masataka Nikaido

Toshihide Hane

Hideshi Taki

Kaoru Sasabe

Masao Takebe

A variable speed digital signal reproducing apparatus, particularly related to low speed reproduction of a digital signals recorded in a recording medium. The apparatus includes a unit for determining whether a reproduction PCM signal is renewed or not. Based on the renewal determination, PCM data of one frame is stored in a memory and the PCM data is read at a frequency rate corresponding to a tape reproducing speed at that time. Furthermore an interpolating device operates on the read PCM data to produce a PCM signal having the same frequency with which the PCM signal was read from the memory means.

Variable speed digital signal reproducing apparatus

In a magnetic recording and reproducing device having at least one rotating magnetic head for recording and reproducing video signal and digital form audio signal in a contiguous manner along each track which is inclined at an angle relative to the direction of travel of a magnetic tape, a discriminator signal is combined to the digital form audio signal. The discrimination signal has a first section carrying a check code and a second section carrying information. During the reproducing mode, the discrimination signal is detected such that the information carried in the second section is made invalid when the check code has a predetermined code pattern, and the information carried in the second section is made valid when the check code has a code pattern other than the predetermined code pattern. Furthermore, the check code is used to indicate the type of information contained in the second section.

Apparatus for recording a discriminative signal

A method is disclosed for processing binary data prior to magnetic recording. The binary data is divided into 4-bit data segments which are converted to 8-bit codes according to a predetermined encoding transfer function describing the relationships between the 4-bit data segments and corresponding 8-bit codes, wherein the bit pattern of each 8-bit code has an intra-code run-length of at least two '0' bits and forms an inter-code run-length of from at least two '0' bits to at most nine '0'bits with an adjacent 8-bit code. The method further includes the step of generating a frame synchronization code and interleaving it with 8-bit codes to form a frame of binary digits. The frame sync code has a bit pattern which is unduplicatable by any combination of 8-bit codes that follow.

Method and apparatus for processing binary data

Source data is organized by a time compression memory (4) into a plurality of successive groups of data words arranged in a pattern of rows and columns with the rows corresponding to respective recording tracks. A plurality of successive groups of parity check words is provided in the same pattern of rows and columns as the data words subsequent to the data word groups. Each parity check word is derived in a parity generator (6) by modulo-2 summations from the data words selected from different data word groups. The data and check words of each row of each respective group are (a) preceded by a synchronization code provided by a sync generator (10) to allow differentiation between data and parity groups, and (b) followed by a cyclic redundancy check, (CRC) code provided by a CRCC generator (9) to allow detection of an error in that data row or check words. The parity check word is used to correct an error specified by the CRC code upon detection of an error.

Method and apparatus for encoding low redundancy check words from source

Signal recording method and apparatus for efficiently correcting a bit error due to dropout occurred in recording an analog data into a digital data and reproducing the digital data is disclosed. The digital signal converted from the analog signal is divided into a plurality of groups to each of which a parity check bit is added. Record pattern is recorded on a record medium by a recording apparatus in accordance with a regular coding such as FM (frequency modulation) or MFM (modified frequency modulation) coding such that more than one bits in a group are not simultaneously influenced by the dropout, e.g. individual bits in a group are spaced from each other by several tracks. On reproducing, the coded digital signal is decoded into the original digital signal and the dropout is detected utilizing the nature of the regularity of the coding. The parity is checked for each of the groups. In this a single error in the group can be corrected and a double error is supplemented by holding a previous value, whereby the error due to the dropout is reduced.

Signal recording method and apparatus

A device for use with a television receiver or the like, in which the time of receiving a telecast and the channel number of the telecast are preset, whereby the telecast of the preset channel can be automatically received at the preset time.

Growing community of inventors

Amagasaki, Japan

Nobuyoshi Kihara