Victor Company of Japan, Limited

Makoto Komura

Kazunori Nishikawa

Hiroyuki Sugiyama

Nobuaki Takahashi

Yoshiki Iwasaki

Isao Masuda

Shoji Ueno

Takeshi Shibamoto

Shunichi Shichijo

A digital data transmitting system comprises a first circuit for transmitting digital data related to an information signal data in terms of sectors each having k words with respect to each channel, where k is a natural number. The transmission of the digital data is performed within a predetermined transmission time period once or a plurality of times according to a tolerance of data error rate for an information content of the digital data. The information signal data are among digital data related to a plurality of channels of information signals which are subjected to a digital modulation, and the plurality of channels of information signals are made up of a combination at least including the information signal data among three kinds of information signals. The three kinds of information signals are a non-compressed audio signal, a video signal, and the information signal data other than the non-compressed audio signal and the video signal. The system also comprises a second circuit for adding a code and a synchronizing signal to the digital data which are obtained from the first circuit, and for transmitting the digital data having the first code and the first synchronizing signal added thereto. The first code is at least indicative of a number of times the digital data are repeatedly transmitted within the predetermined transmission time period.

Digital data transmitting system for transmitting digital data a number

A data producing device in a signal reproducing apparatus, comprises a shift register supplied with synchronizing signals and codes which are time-sequentially reproduced from a recording medium, synchronizing signal detectors supplied with the synchronizing signals from the shift register, data transfer circuits provided in parallel with respect to each other and in series with the synchronizing signal detectors, and a control circuit for controlling the data transfer circuits so that a data is selectively read out and produced from a desired data transfer circuit among the plurality of data transfer circuits. The reproduced synchronizing signals and codes are transferred to the shift register and are read out from the shift register in response to a clock pulse having a predetermined frequency. The number of the synchronizing signal detectors is equal to the number of kinds of the synchronizing signals, and the synchronizing signal detectors are provided in parallel with respect to each other. Each of the synchronizing signal detectors detect a specific synchronizing signal. A data in a predetermined code among the codes supplied to the data transfer circuits is transferred to the data transfer circuits, when a synchronizing signal for discriminating the predetermined code is detected in the synchronizing signal detectors and supplied to the data transfer circuits.

Data producing device in a signal reproducing apparatus

A rotary recording medium has information signals recorded on a spiral or concentric tracks formed thereon as variations in geometrical configuration. The tracks comprise a mixture of digital recorded tracks which are recorded with a first modulated signal and analog recorded tracks which are recorded with a second modulated signal. The first modulated signal is a digital signal which has been time-sequentially multiplexed in terms of blocks at a transmission frequency of 44.1 kHz or a frequency extremely close to 44.1 kHz and has then been subjected to a modulation, where each of the blocks are constituted by a synchronizing signal, error correcting codes, and an error detecting code, which are added to a plurality of channels of digital data which are digitally modulated information signals. The second modulated signal is an analog modulated analog information signal at least including a composite video signal. A number of blocks recorded in one track turn of the digital recorded tracks is approximately equal to a product of the transmission frequency and a duration of one revolution of the rotary recording medium.

Rotary recording medium having track turns recorded with digital signal

A rotary recording medium reproducing apparatus comprises a reproducing circuit for picking up and reproducing pre-recorded signals from a rotary recording medium on which digital recorded tracks and analog recorded tracks coexist, a first reproducing circuit for reproducing a composite video signal having a horizontal scanning frequency of a predetermined television system from signals which are reproduced from the analog recorded tracks, among reproduced signals from the reproducing circuit, a second reproducing circuit for demodulating and reproducing original information signals from signals which are reproduced from the digital recorded tracks, among the reproduced signals from the reproducing circuit, an oscillator circuit for generating a signal having a frequency which is a natural number multiple of the horizontal scanning frequency of the predetermined television system, a servo circuit for rotating a motor which rotates the rotary recording medium, in synchronism with the output signal of the oscillator circuit, and a master clock signal generating circuit for supplying to the second reproducing circuit a signal which is obtained by frequency-multiplying the output signal of the oscillator circuit, as a master clock signal.

Rotary recording medium reproducing apparatus for reproducing

A synchronizing signal detecting circuit is used in a digital signal transmitting system which transmits a digital signal in which signals are time-sequentially multiplexed in terms of blocks, where each of the blocks are made up of digital data which are information signals subjected to a digital modulation, a synchronizing signal having a fixed pattern, and an error checking code arranged at a location separated from a location of the synchronizing signal by a predetermined number of bits. The synchronizing signal detecting circuit comprises a counter which is reset when a synchronizing signal detection output which has been discriminated as being correct by use of the error checking code is continuously obtained for N times, where N is a natural number greater than or equal to two.

Synchronizing signal detecting circuit in a digital signal transmitting

A memory circuit write-in system comprises a first circuit for supplying a digital signal including a time base fluctuation component, where one frame of the digital signal is constituted by at least a synchronizing signal and information data and the digital signal has a first repetition frequency with a period of one frame of the digital signal, a memory circuit for writing therein and reading out therefrom the digital signal supplied from the first circuit, and a second circuit for applying a write-in control signal to the memory circuit. The write-in control signal includes no time base fluctuation component and has a second repetition frequency substantially equal to the first repetition frequency, and the memory circuit is controlled by the write-in control signal so that write-in of the digital signal is carried out with a write-in period in a range of two times within the one frame period.

Memory circuit write-in system

In a circuit arrangement for a disk player of the type arranged to reproduce information prerecorded in the form of pits, a variable gain circuit for changing the frequency characteristic of the reproduced signal is provided. The level of the reproduced signal is detected at high and low frequencies so as to produce a control signal the voltage of which varies in accordance with the difference between the level of the high frequency signal component and the level of the low frequency component. The control signal is then applied to the variable gain circuit receiving the reproduced signal so that the frequency characteristic of the reproduced signal will be controlled. Thus, the level of the reproduced signal is boosted at its high frequency range.

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Tokyo, Japan

Makoto Komura