JP3163615B2 - Magnetic recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The magnetic recording apparatus of the present invention will be described according to the following items.

A. Industrial application fields B. Summary of the invention C. Prior art D. Problems to be solved by the invention E. Means for solving the problems F. Embodiment [FIGS. 1 to 3] G. Invention The present invention relates to a novel magnetic recording device. Specifically, by improving the magnetic head arranged on the rotating drum,
It is an object of the present invention to provide a novel magnetic recording apparatus capable of performing recording that makes full use of the characteristics of a metal-coated magnetic tape and a metal-deposited magnetic tape having different methods of forming a magnetic material or a magnetic layer.

(B. Summary of the Invention) In the magnetic recording apparatus of the present invention, the gap length of a magnetic head is determined for a metal-coated magnetic tape and a metal-deposited magnetic tape using different methods of forming a magnetic material or a magnetic layer in consideration of the recording characteristics. By determining and providing a plurality of types of magnetic heads having different gap lengths, it is possible to perform recording that makes full use of the characteristics of each magnetic tape.

(C. Prior Art) Conventionally, a magnetic recording device has no dedicated magnetic head, and a magnetic head used in a magnetic recording / reproducing device is arranged on a rotating drum of the device.

The magnetic head used in the magnetic recording device and the magnetic recording / reproducing device is technically limited to reduce the gap length, and if the width is too large, the output during reproduction is reduced. μm (for an 8 _mm VTR) has been validated.

(D. Problems to be Solved by the Invention) By the way, in recent years, various types of magnetic tapes, such as magnetic tapes having different magnetic materials and different magnetic layer forming methods, have been developed and commercialized. The inventor of the present invention has studied the relationship between the characteristics of such various magnetic tapes and the gap length of the magnetic head, and as a result, the following has been clarified.

That is, in the case of a magnetic tape, the optimum head gap length for recording is different from the optimum head gap length for reproduction. In particular, the optimum head gap length for recording is different for various magnetic tapes. Was.

Specifically, for example, the magnetic tape for 8 _mm VTR includes a metal-coated magnetic tape (hereinafter, referred to as “MP tape”) and a metal-deposited magnetic tape (hereinafter, referred to as “ME tape”). The recording characteristics of the two are as follows.

The recording characteristics are defined as the difference between the output and the input when a signal of a certain frequency is recorded by a magnetic head having a different head gap length and is output by a magnetic head of a certain gap length. Are compared.

FIG. 2 is a graph showing the recording characteristics of an MP tape when the carrier frequency is a signal of 5 MHz. The horizontal axis represents the head gap length, and the vertical axis represents the rate of decrease of the output signal level with respect to the input signal level ( dB).

As can be seen from FIG. 2, in the case of the MP tape, the output of the luminance signal (Y output) is almost independent of the head gap length (see FIG. 2 (A)), and the output of the chroma signal (see FIG. 2 (A)). The chroma output) gradually increases as the head gap length becomes wider than 0.35 μm (see FIG. 2B).

FIG. 3 shows an ME in the case where the carrier frequency is 3 MHz (shown by a dotted line), 5 MHz (shown by a dashed line), 7 MHz (shown by a solid line), and 9 MHz (shown by a dashed line). It is a graph which shows each recording characteristic for every frequency of a tape, a horizontal axis shows a head gap length, and a vertical axis shows a rate of reduction of the level of an output signal to the level of an input signal (dB).
It is shown.

As can be seen from FIG. 3, in the case of the ME tape, the output of the luminance signal (Y output) has a head gap length of 0.245 to 0.25 even if there is a level difference between the signals of each carrier frequency.
It shows a peak near μm, and when it is narrower than this, the output sharply decreases, and when it is wider, it tends to gradually decrease (see FIG. 3 (A)), and the output of chroma signal (chroma output)
Have a characteristic that they gradually decrease as the head gap length increases (see FIG. 3B).

Therefore, in a conventional magnetic recording device, since only a single type of magnetic head has a head gap length, when a plurality of types of magnetic tapes having different recording characteristics are used, the There has been a problem that it is not possible to perform optimum recording while making full use of the recording characteristics of the tape.

(E. Means for Solving the Problems) In view of the above, the magnetic recording apparatus of the present invention provides magnetic recording media having different gap lengths which are optimal for metal-coated magnetic tapes and metal-deposited magnetic tapes having different methods of forming a magnetic material or a magnetic layer. It has a plurality of types of heads.

Therefore, according to the magnetic recording apparatus of the present invention, it is possible to perform recording that makes full use of the characteristics of the metal-coated magnetic tape and the metal-deposited magnetic tape using different magnetic materials or magnetic layer forming methods.

(F. Embodiment) [FIGS. 1 to 3] Hereinafter, details of the magnetic recording apparatus of the present invention will be described with reference to the illustrated embodiments.

In the illustrated embodiment, the magnetic recording apparatus of the present invention is applied to a high-band 8 _mm VTR recording-only machine.

A recording-only machine is a device that mainly records video and audio signals on a magnetic tape, and is mainly used when a video software supplier creates a soft tape from a master tape.

Figure 1 shows such a high-band 8 _mm VTR recording-only machine 1
It is a schematic block diagram of the principal part of.

Reference numeral 2 denotes a video signal processing circuit for processing a video signal from a master tape or the like input to the recording-only device 1.

Reference numeral 3 denotes a recording amplifier, which receives a video signal from the video signal processing circuit 2, amplifies the video signal, and sends it to a magnetic head described later.

Reference numeral 4 denotes a changeover switch for switching between recording of a video signal on an MP tape (hereinafter, referred to as “MP tape mode”) and recording of a video signal on an ME tape (hereinafter, referred to as “ME tape mode”). .

Numeral 5 denotes a tape type discriminating means, which is formed on the tape cassette when a tape cassette (not shown) is mounted on the apparatus 1 to determine whether the magnetic tape on which a signal is recorded is an MP tape or an ME tape. The switch 4 is switched to the MP tape mode or the ME tape mode.

Numerals 6 and 6 denote magnetic heads for the MP tape, which are respectively attached to the peripheral surface of a rotating drum (not shown) at a position shifted by an angle of 180 ° and have a gap length of 0.4 μm or more.

Numerals 7 and 7 denote magnetic heads for the ME tape.
It is attached at a position shifted by an angle of ゜ and a position shifted by 90 ° from the magnetic heads 6 and 6 for the MP tape, and the gap length is set to 0.25 ± 0.05 μm.

When the tape cassette of the MP tape is mounted on the magnetic recording apparatus 1, the tape type discriminating means 5 determines that the mounted tape cassette is the tape cassette of the MP tape, and switches the changeover switch 4 to the MP tape mode. The state shown in the experiment in FIG. 1). Thus, the video signal processed by the video signal processing circuit 2 and amplified by the recording amplifier 3 passes through the changeover switch 4 to the magnetic head 6 for the MP tape,
6 and recorded on an MP tape. At this time, since the gap length of the magnetic heads 6 and 6 for the MP tape is 0.4 μm or more, the recording characteristics of the chroma signal are particularly good (see FIG. 2), and the optimum recording for the MP tape is required. Is done.

Further, when the tape cassette of the ME tape is mounted on the magnetic recording apparatus 1, the tape type discriminating means 5 determines that the mounted tape cassette is the tape cassette of the ME tape,
The changeover switch 4 is switched to the ME tape mode (the state shown by the two-dot chain line in FIG. 1). As a result, the video signal processed by the video signal processing circuit 2 and amplified by the recording amplifier 3 is output to the magnetic heads 7 and 7 for the ME tape via the changeover switch 4 and recorded on the ME tape. .
At this time, since the gap length of the magnetic heads 7, 7 for the ME tape is 0.25 ± 0.05 μm, the recording characteristics of the luminance signal are particularly good (see FIG. 3), and the optimum recording for the ME tape is performed. Done.

(G. Effects of the Invention) As is clear from the above description, the first type of the magnetic recording apparatus of the present invention is a metal-coated magnetic tape and a metal-deposited magnetic tape having different methods of forming a magnetic material or a magnetic layer. A plurality of types of magnetic heads having different gap lengths adapted to the gap dependence of the recording characteristics of the recording head, and that the gap length of the recording head for the metal-coated magnetic tape is larger than the gap length of the recording head for the metal-deposited magnetic tape. A second feature is that in a magnetic recording apparatus for converting a color signal of a video signal into a low-frequency band and superimposing the color signal on a frequency-modulated luminance signal, the metal-coated magnetic layer has a different magnetic material or a different magnetic layer forming method. Multiple magnetic heads with different gap lengths adapted to the gap dependence of the recording characteristics of tape and metal-deposited magnetic tape Characterized in that was.

Therefore, according to the magnetic recording apparatus of the present invention, it is possible to perform recording that makes full use of the characteristics of the metal-coated magnetic tape and the metal-deposited magnetic tape using different magnetic materials or magnetic layer forming methods.

In the above embodiment, the magnetic recording apparatus of the present invention is applied to a high-band 8 _mm VTR, but is not limited to this.
The present invention can also be applied to a magnetic recording apparatus using a metal-coated magnetic tape and a metal-deposited magnetic tape having different recording characteristics, for example, a VHS VTR, a β VTR, or a DAT.

Further, the magnetic recording apparatus of the present invention can be applied to a magnetic recording / reproducing apparatus also having a reproducing function. In this case, the output at the time of reproduction has a gap length of the magnetic head of 0.25 to 0.3 μm regardless of the type of the tape. Since it is understood that there is a good thing, it is preferable to share the head with the shorter head gap length (the magnetic head for the ME tape in the above embodiment).

[Brief description of the drawings]

FIG. 1 shows an embodiment of a magnetic recording apparatus according to the present invention. FIG. 1 is a block circuit diagram of the main part, FIG. 2 is a graph showing the recording characteristics of an MP tape, and FIG. FIG. DESCRIPTION OF SYMBOLS 1 ... magnetic recording device, 6 ... magnetic head (recording head), 7 ... magnetic head (recording head)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 5/00-5/84

Claims (2)

(57) [Claims] A plurality of magnetic heads each having a different gap length adapted to a gap dependence of recording characteristics of a metal-coated magnetic tape and a metal-deposited magnetic tape having different methods of forming a magnetic material or a magnetic layer; Wherein the gap length of the recording head with respect to the magnetic tape is greater than the gap length of the recording head with respect to the metal-deposited magnetic tape. 2. A magnetic recording apparatus for converting a color signal of a video signal into a low-frequency signal and superimposing the color signal on a frequency-modulated luminance signal for recording, comprising: A magnetic recording apparatus comprising a plurality of magnetic heads each having a different gap length adapted to the gap dependence of the recording characteristics of a magnetic tape.