Matsushita Electric Industrial Co., Ltd.

Tetsuo Ishiwata

Susumu Yamaguchi

Hiroshi Tanaka

Eiji Yamauchi

Tadashi Yoshino

Hitoshi Komae

Katsuyuki Taguchi

Shuzo Hitotsumachi

Herein disclosed is a method and a system for recording and reproducing digital audio signals which enable simultaneous recording of video signals and audio signals without a synchronous relation, and simultaneous reproducing rerecorded audio signals if a part of channels of the audio signals are rerecorded, since a sample number of the audio signals for each the channel is equal to each other. On rerecording, a modulator 113 demodulates signals and the demodulated signals are separated into audio signals and sample number discriminating signals of the audio signals by a demultiplexor 114. A second counter changes dividing number on the basis of the sample number discriminating signals separated by the demultiplexor 114. A phase comparator 118 compares a phase of a cycle of the second counter 117 and a phase of a video frame cycle. Output signals are limited their band by a low-pass filter 119 and controls an oscillated frequency of a voltage controlled oscillator (VCO) 120. A second switch 106 selects output clock pulses of the VCO so that clock pulses used for A/D conversion are coincided with reproduced clock pulses. A fourth switch 110 selects output signals of a delaying means 115 so that sample number of recorded audio signals and sample number discriminating signals are coincided with reproduced audio signals.

Method and apparatus for reproducing independently recorded

There is provided a signal processing system for recording and reproducing a video signal and a digital audio signal with a rotary-head VTR and, more particularly, a memory control system which generates a block address and a memory write signal so that the sync signal for reproduced digital data is detected reliably and the digital data is stored in the memory circuit correctly.

Sync signal detection system in a memory system for recording and

A phase locked loop is disclosed in which a digital audio signal is recorded in synchronism with a video signal and a sampling frequency of the digital audio signal is reproduced in reproduction mode. A frequency divider of the phase locked loop comprising a phase comparator a low-pass filter, a VCO and a frequency divider unit is switched by the number of the digital audio signal recorded for each vertical sync period (or 1/N thereof) of the video signal, so that a sampling frequency of the digital audio signal having no relationship of integral ratio with a vertical sync frequency Fv of the video signal is reproduced from the same frequency Fv. The reference input to the phase comparator is delayed by a predetermined time in accordance with the number of the digital audio signal, with the result that the sampling frequency reproduced has no period error to the extent that the reference input has no period error.

Sampling frequency reproduction system

A signal processing system for absorbing asynchronism between a video signal and an audio signal which is caused when a PCM audio signal is to be recorded together with the video signal on a helical scan-type tape recorder. When the video signal and the audio signal are recorded on the same track, a recording band width of the audio signal should be narrow. A sample pattern is provided which assures rapid pull-in for both data clock reproduction and carrier reproduction, when the audio signal is modulated by QPSK or when Q-QPSK modulation is used.

Apparatus for recording/reproducing a digital audio signal with a video

A data companding method instantaneously compands the 14-bit digital audio signals to be outputted from a satellite broadcast receiver and so on is realized with the given conversion rule, which has a superior companding characteristics across the whole input range of the 14-bit data with SN being not deteriorated as compared with the 14-10 near-instantaneous companding law at the satellite broadcast transmission. A data compressor and a data expander in accordance with the present invention are realized by the construction of the combination of the coefficient table, a data shifter composed of a pluarlity of 4 to 1 data selectors, and an adder.

Data companding method and data compressor/expander

Memory system for recording and reproducing block unit data

A magnetic recording and reproducing apparatus includes a control device for monitoring a take-up reel, a feed reel, and a capstan motor for rotational speed and direction. By monitoring the take-up reel, feed reel and capstan motor, the control device determines if the apparatus is operating properly. Based on the determinations regarding the proper operation of the apparatus, the control device controls the operation of the capstan motor and the shifting of the idler gear between a first operational state and a second idle state.

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Suita, Japan

Tetsuo Ishiwata