JPH05135309A - Magnetic recorder - Google Patents

Abstract

PURPOSE:To improve the recording performance of the signal of a low frequency component by modulating a high frequency signal with a low frequency in the case of recording the low frequency signal on a metal vapor deposited tape. CONSTITUTION:A high frequency signal is generated by an oscillator 10 and a control signal with the low frequency of e.g. a rectangular wave is supplied to the other input of a gate circuit 12. Then, since the output signal of the oscillator 10 is turned on-off with the control signal by the gate circuit 12, a high frequency signal is modulated by the control signal. The signal is recorded on the fixed track of the metal vapor deposited tape 11. Then, by envelope-detecting the regenerative signal read through a head 2 with a detecting circuit 13, the rectangular wave same as the input signal is obtained. The recording performance of the high frequency signal is excellent and the output level is high. Then, an obtained amplitude, as well is enlarged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording apparatus for recording main information such as video signals and audio signals on a helical track by a rotary head and recording a control signal on a fixed track by a fixed magnetic head.

[0002]

2. Description of the Related Art Conventionally, in a VTR, a video signal is written on a helical track by a rotary head. Separately from this, a control signal is written on a fixed track by a fixed head in order to obtain position information of the tape. ..

This control signal is a rectangular wave signal having a specific period as shown in FIG.
Recording is performed on the tape 3 by the fixed head 2 via the recording amplifier 1 shown in (b), and the recorded magnetization pattern is reproduced by the fixed head 2 and output via the reproduction amplifier 4.

The reproduced signal is supplied to a necessary device through an electric circuit (not shown), but what is necessary here is not the signal waveform but the position of the pulse, that is, the control signal as shown in FIG. 4 (c). It is the position information of the rising edge and the falling edge of.

By the way, as a video tape, a metal vapor deposition tape capable of recording a video signal at a high density has been developed, and it is beginning to be used in place of a conventional coating type metal tape.

[0006]

However, while the metal vapor deposition tape has a good recording performance for video signals having a relatively high frequency, it has a better recording performance than the coating type metal tape for a control signal using a lower frequency. Unfortunately, there is a problem in that the detection performance of the position information of the control signal becomes problematic because only a low level can be obtained even when reproducing.

The present invention has been made in view of such a situation, and is to improve the recording performance of a control signal while using a metal vapor deposition tape.

[0008]

In order to solve such a problem, the magnetic recording apparatus of the present invention comprises a recording means for modulating a high frequency signal with a low frequency control signal or an index signal for recording. It is characterized by

[0009]

The signal of the low frequency component modulating the signal of the high frequency is treated as the change component information of the signal of the high frequency, and the high frequency signal has good recording performance, so that the change component is also high. It is dominated by the recording performance of the frequency signal, and eventually the recording performance of the low frequency component signal is also improved.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of the present invention, in which an oscillator 10 has a signal corresponding to a wavelength at which the metal vapor deposition tape 11 exhibits the maximum recording performance, for example, a wavelength of 1 to 2 μm.
m signal is being generated. This signal is supplied to one input terminal of the gate circuit 12, but the gate circuit 12 turns on and off the signal supplied to one input terminal according to the level of the control signal supplied to the other input terminal. It has become.

That is, the oscillator 10 generates a high-frequency signal shown in FIG. 2A, and the other input of the gate circuit 12 is supplied with a low-repetition-frequency control signal shown in FIG. 2B. ing. Therefore, the gate circuit 12 turns on / off the output signal of the oscillator 10 according to the control signal, so that a high frequency signal is modulated by the control signal,
It becomes the signal shown in FIG.

The signal shown in FIG. 2 (c) is the recording amplifier 1
And the metal vapor deposition tape 11 via the fixed magnetic head 2
Is recorded on a fixed track. And fixed magnetic head 2
And the reproduction signal read out through the reproduction amplifier 3 and shown in FIG.

By carrying out envelope detection of this reproduction signal by the detection circuit 13, the same rectangular wave as the input signal is obtained as shown in FIG. 2 (e). This rectangular wave signal is an envelope of a high frequency signal, and the high frequency signal has good recording performance and a high output level. Since the amplitude of the obtained envelope waveform corresponds to the peak value of the high frequency signal, the obtained amplitude also becomes large.

Of course, it goes without saying that video signals and audio signals are recorded on the helical track of the metal vapor deposition tape by the rotary magnetic head.

On the other hand, the VTR has a function of cueing in order to quickly find a desired portion of the tape. This is done by recording the index signal and detecting it, but if the frequency of the index signal is made lower than the video signal so as not to adversely affect the video signal, as with the control signal, There is a problem that the reproduction level is lowered.

Therefore, as for the index signal, if a high frequency signal is modulated by a low frequency index signal and the envelope component is detected,
The output signal level of the index signal also becomes high.

FIG. 3 is a diagram showing signals recorded on the tape. Fixed tracks 11a and 11b are provided above and below the tape 11, respectively.
Are arranged, the control signal 11c is recorded on one side, and the index signals 11d and 11e are recorded on the other side. The symbol 1
Reference numeral 1f is a helical track, and video signals and audio signals are recorded, and in order to perform cueing with higher positional accuracy, the index signal 11g may be recorded on the helical track.

With this structure, the fixed track 11
By the index signals 11d and 11e recorded in a, the head can be found in the reproduction (fast forward) direction and the rewind direction.
If necessary, the index signal recorded on the helical track can be used to perform cueing with high positional accuracy. In this case, it is necessary to further provide one system of the circuit configuration shown in FIG. 1, one for the control signal and the other for the index signal.

Although the signal from the oscillator 10 has a shorter wavelength than that of the control signal as described above, the attenuation due to the thickness loss of the metal vapor deposition tape is small and the influence of the spacing loss is small. And the head gap needs to be optimized according to the signal used.

[0020]

As described above, according to the present invention, when a low frequency signal is recorded on a metal vapor deposition tape, a high frequency signal is modulated at a low frequency. Therefore, even a low frequency signal is treated as a high frequency signal. The same recording performance can be ensured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a magnetic recording device to which the present invention is applied.

FIG. 2 is a waveform diagram showing waveforms of various parts in the embodiment of FIG.

FIG. 3 is a diagram showing a signal recorded on a magnetic tape.

FIG. 4 is a block diagram showing an example of a conventional magnetic recording device.

[Explanation of symbols]

 1 Recording Amplifier 2 Fixed Head 3 Tape 4 Reproducing Amplifier 10 Oscillator 11 Metal Vapor Deposition Tape 12 Gate Circuit 13 Detection Circuit

Claims (2)

[Claims] 1. A magnetic recording apparatus for recording main information on a helical track of a metal thin film tape and recording a control signal of a low frequency in a fixed track area, wherein a signal of high frequency is modulated by the control signal of low frequency. A magnetic recording device comprising a recording device for recording as a recording. 2. In a magnetic recording apparatus for recording main information on a helical track of a metal thin film tape and for recording an index signal for indexing at the time of fast forward and rewind in a fixed track area, a high frequency signal is used as the index signal. A magnetic recording apparatus comprising recording means for modulating and recording by.