Matsushita Electric Industrial Co., Ltd.

Ichiro Arimura

Chojuro Yamamitsu

Hiroshi Taniguchi

Tatsuro Juri

Masazumi Yamada

Chiyoko Matsumi

Akira Iketani

Yoshinori Kitamura

Yukio Kurano

Kunio Sekimoto

Masamitsu Ohtsu

Hiromichi Tanaka

Sadafumi Kitamura

Norio Meki

A plurality of digital signals having total data rates of n bit/s or less are input to a digital recording device recording digital signals having a data rate of n bit/s. The digital signals are subjected to format-conversion for the digital recording device to be recorded therein. Furthermore, signals having a data rate of n/i bit/s or less are subjected to format-conversion to be recorded i times in the digital recording device. In the case where the data rate of the digital signals to be input is n/j bit/s, the digital signals are subjected to format-conversion so that the amount of data capable of being recorded per unit time is decreased by i/j; thus, the digital signals are recorded for a long period of time under the condition that the data recording time is prolonged j times. Furthermore, when input data to be recorded on a magnetic tape at a normal data rate by using a magnetic head mounted on a rotary cylinder is recorded, the recording device of the present invention makes it possible to select a plurality of types of track angles generated by the rotation number of the cylinder, the tape traveling speed, and the like.

Apparatus using a method for recording digital data including a data conversion or format conversion, and apparatus using the method

A plurality of digital signals having total data rates of n bit/s or less are input to a digital recording device recording digital signals having a data rate of n bit/s. The digital signals are subjected to format-conversion for the digital recording device to be recorded therein. Furthermore, signals having a data rate of n/i.sub.1 bit/s or less are subjected to format-conversion to be recorded i.sub.1 times in the digital recording device. In the case where the data rate of the digital signals to be input is n/j bit/s, the digital signals are subjected to format-conversion so that the amount of data capable of being recorded per unit time is decreased by i/j; thus, the digital signals are recorded for a long period of time under the condition that the data recording time is prolonged j times. Furthermore, when input data to be recorded on a magnetic tape at a normal data rate by using a magnetic head mounted on a rotary cylinder is recorded, the recording device of the present invention makes it possible to select a plurality of types of track angles generated by the rotation number of the cylinder, the tape traveling speed, and the like.

Method for recording digital data including a data conversion or format

Digital data recording device having a rotary cylinder

A video signal recording and reproducing apparatus in which the luminance signal of a color video signal is frequency-modulated for recording and a reproduction frequency-modulated signal is frequency-demodulated to produce a reproduction video signal. A high frequency component is separated from the reproduction video signal and applied to a slice circuit comprising nonlinear elements including, for example, diodes connected in parallel with reverse polarities, thus eliminating noise at the low frequency signals included in the high frequency component. The apparatus further comprises a device for subtracting the sliced signal and the reproduced video signal one from the other in such a manner that the two signals are in phase with each other substantially at the desired ratio and in a predetermined frequency band. In this way, noise contained in the edge portion of the reproduction video signal, crosstalk and moire patterns caused at the time of azimuth recording without a guardband are decreased, thus improving the signal-to-noise ratio of the edge portion. If this apparatus is combined with a conventional device for reducing noise at the low frequency portion of the video signal, FM interleaving techniques and nonlinear emphasis, a high-density recording with narrow tracks and short wavelength is made possible, thereby producing a stable reproduced image with high S/N ratio having no undesired components.

Video recording and reproducing apparatus with noise reduction

A magnetic recording and reproducing apparatus, for recording and reproducing the color television signal including VIR signal, of the type having a comb filter which is inserted in the chrominance signal system and includes a delay line for causing a delay equal to one horizontal line scanning period. In this apparatus the VIR signal has no line correlation so that the output of the comb filter becomes a VIR signal the amplitude of which is reduced by 6dB and that the amplitude and/or phase of the chrominance components of VIR signal are caused to vary over a wide range due to the effects of VIT signal. In order that the stable and correct color images may be reproduced even by a color television receiver of the type in which the amplitude and phase of the chrominance components of VIR signal are detected so as to automatically adjust the color saturation and hue, the amplitude of the chrominance components of VIR signal is detected and corrected in a recording system of a magnetic recording and reproducing apparatus; the burst signal and the chrominance components of VIR signal are compared in phase so as to correct the phase of the carrier color signal with the difference signal before the carrier color signal is recorded; and in the playback mode the chrominance components of VIP signal of the carrier color signal free from time axis distortions are replaced with the stable oscillator output.

Magnetic recording and reproducing apparatus for color video signals

A video signal recording and reproducing system in which a video signal to be recorded is passed through preemphasis means and subsequently angular modulated so that it is recorded on a record medium. During playback operation, the video signal is angular demodulated and deemphasized through a deemphasis means. Preemphasis means comprises both a non-linear preemphasis circuit and a fixed preemphasis circuit. The deemphasis means similarly comprises a fixed deemphasis circuit and a non-linear deemphasis circuit. Each of the non-linear circuits is responsive to the amplitude of an input signal thereon.

Recording and reproducing system

A magnetic recording and reproducing system which separates a brightness signal and a carrier color signal from a color television signal, frequency modulates the brightness signal and converts the carrier color signal to a lower frequency, records the modulated brightness signal and the low frequency carrier color signal in different manner for each horizontal scan line such that phases of the carrier are different between adjacent record tracks, and plays back the recorded signal through a comb filter to eliminate crosstalk from adjacent tracks in the carrier color signal. In this system, a horizontal synch. signal is eliminated in response to the detection of dropouts so as to prevent the disturbance of AFC and APC loops by dropouts, which would otherwise create color irregularity, and the horizontal synch. signal free of noise due to dropouts is used to activate the AFC and APC loops.

Drop-out responsive magnetic recording and reproducing system

A steady and inexpensive color killer circuit system for a simplified video tape recorder of the type wherein the luminance signal and chrominance signal of a color television signal are respectively converted into an angular modulation signal and a lower frequency conversion signal for recording these signals in the form of a combined signal and also where a reproduced lower frequency converted chrominance signal is heterodyned with a continuous signal phase locked to the color burst signal in the reproduced chrominance signal to thereby cancel jitter components in the reproduced chrominance signal. The color killer circuit system comprises a single killer detector provided in the reproducing circuit, said killer detector including a switch for coupling the lower frequency converted chrominance signal on the recording side to the reproducing side circuit, a phase shifter for 90-degree phase shifting either one of two inputs, namely the afore-said color burst signal and a continuous signal, to a phase comparator to produce said continuous signal phase locked to the color burst signal, and a synchronous detector for synchronously detecting the color burst signal with the afore-said continuous signal phase locked thereto. The detection output of the killer detector is used to control the color killer circuits.

Color killer circuit system video tape recorder

An equipment for recording and reproducing color television signals or VTR (video tape recorder) is combined with a color television receiver as a single unit in such a way that some of their circuits are used in common with both the VTR and receiver, whereupon the circuit design as well as operation may be greatly simplified. The VTR and receiver are operatively coupled to each other through a switch for selecting a recording or reproducing mode. In recording mode, the video signal, which is received and detected by the receiver, passes through the mode selction switch to the luminance signal processing circuit and the carrier chrominance signal processing circuit in the receiver. The separated luminance and chrominance signals are applied to the input terminal of the VTR so that they may be recorded while one is watching the picture on a picture tube. In the reproduction mode, the luminance and chrominance signals derived from the output of the VTR are added and applied to the input terminal of the processing circuits in the receiver through the mode selection switch so that they are processed in the signal processing circuits to reproduce the picture on the picture tube. In one embodiment of the present invention, the luminance and chrominance signals may be applied to their processing circuits, respectively, in the receiver through another selection switch. An APC type or a ringing type circuit is used for color synchronization. In order to minimize the effects caused by the jitter in the VTR, a feedback loop including the reproduction circuit of the VTR is provided. In the APC (automatic phase control) circuits, the crystal oscillator and/or LC oscillator are used.

Equipment for recording and reproducing color television signal

In a system for cancelling time axis variations introduced into a frequency converted chrominance signal converted into a lower frequency range in the recording and reproduction of a color television signal with a small-size video tape recorder, in which system the cancellation of the time axis variations is effected by using a continuous reference signal obtained through an APC heterodyne system, the center frequency of oscillation of an APC oscillator is made n/m times the subcarrier frequency f.sub.s of the lower frequency converted chrominance signal (m and n being integers and n&gt;m), and the reproduced frequency converted chrominance signal is heterodyned with a signal obtained by heterodyning a continuous signal obtained by dividing the frequency of the output signal of the oscillator by n/m in the presence of a steady reference signal at the same frequency as the standard color sub-carrier frequency to thereby obtain the cancellation of the time axis variations.

System for recording and reproducing a color television signal

A signal processing system for obtaining a continuous signal, phase locked to a signal subjected to timing variations. The continuous signal phase locked to a signal subjected to timing variations is obtained from a variable oscillator, whose oscillation is controlled according to an error signal produced from a phase comparator in accordance with the phase difference between the signal subjected to timing variations and a higher-frequency signal produced from the output of said variable oscillator in the presence of a fixed oscillator.

Growing community of inventors

Kyoto, Japan

Ichiro Arimura