Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: At least one bit of a digital signal including a plurality of bits to be simultaneously recorded on a plurality of tracks of a magnetic tape, is recorded on at least two tracks located at opposite sides with respect to a reference track. The reference track carries a reference signal utilized for producing a synchronous signal with which the plurality of bits are reproduced in synchronization. When reproducing, a.c. signals derived from the two corresponding tracks having the simultaneously recorded bits are added to each other whereby the phase difference of the plurality of bits with respect to the reference signal is compensated while drop out phenomenon is reduced.

Abstract: 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.

Abstract: 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.