JPH07320226A - Magnetic recording device - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording device which performs a two layer recording using a preceding recording head and a succeding recording head and adds new wide bandwidth signals while keeping the reproducing exchangeability of a conventional format machine. CONSTITUTION:A non-recording section 2a, which is constituted by a 6.15mum width nonmagnetic material layer, for example, is provided to make a track depletion section in the central section along the track width direction of a succeding recording head 2. A track recording is performed using the head 2 and a preceding recording head. Thus, the track depletion section corresponding to the section 2a is made to be the portion in which a recording corresponding to the section 2a is made to be the cross talk is minimized between the signals recorded by the preceding recording head and the signals recorded by the succeding recording head and new wide bandwidth signals are added while keeping the reproducing exchangeability of a format machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical scan type magnetic recording apparatus for double-layer recording using a preceding recording head and a following recording head.

[0002]

2. Description of the Related Art As an example of a method for adding a new signal to one recording track while maintaining upward compatibility, there is a double-layer recording system using a preceding recording head and a succeeding recording head. As the two-layer recording method, a VHS (registered trademark) Hi-Fi method or S-VHS (registered trademark) in which a preceding recording head records an FM audio signal or a PCM audio signal with respect to a video signal recorded by a following recording head There are digital audio systems.

FIGS. 5 (a) and 5 (b) are views showing the head gap vicinity portions of the preceding recording head and the following recording head as seen from the tape sliding surface of the magnetic recording tape in such a double-layer recording system. . For example, 20 μ shown in FIG.
A pre-recording head 1b for audio and PCM signals having a recording width of m width and, for example, 58 shown in FIG. 5B.
A trailing recording head 2b for a video signal having a recording width of μm has a magnetic layer on the entire tape sliding surface, and the relative azimuth angle between the leading recording head 1b and the trailing recording head 2b is 36. It is set to °.

[0004]

However, in the two-layer recording method described above, the signal recorded by the preceding recording head 1b is erased to some extent by the succeeding recording head 2b, and in particular, the erasing amount of the high frequency component is large. Become. For this reason,
A deep signal has a problem that a sufficient reproduction level cannot be obtained due to a problem of magnetic saturation of recording and the recording capacity cannot be increased, so that sufficient high frequency recording cannot be performed. For example, in S-VHS digital audio, the pre-recorded audio signal is erased by about 15 dB at the 3 MHz point by the video signal (S-VHS) recorded in the subsequent recording. Then, as the frequency becomes higher, the amount of erasure becomes larger, and recording becomes substantially impossible.

In the VHS, the color signal C having a center frequency of 629 kHz and the frequency deviation of 3.4 M shown in FIG.
In order to improve the sound quality of the FM-modulated video signal of the luminance signal Y of Hz to 4.4 MHz, as shown in (a) or (b) of FIG. 7, L (left) = 1.3 MH
z, R (right) = 1.7 MHz FM-modulated HiFi
When recording an audio signal and a QPSK-modulated PCM signal (audio or data) having a center frequency of 3 MHz or a QPSK-modulated PCM signal (audio signal or data) having a center frequency of 2.6 MHz and 5.2 MHz, FIG. The PCM signal shown in (b) cannot be recorded because the high frequency signal of 5.2 MHz is almost erased by overwriting, and the PCM signal shown in FIG. 7 (a) has its high frequency erased by overwriting. At the time of reproduction, it adversely affected the crosstalk to the video signal.

The present invention has been made in order to solve the above-mentioned problems, and in a magnetic recording apparatus for double-layer recording using a preceding recording head and a following recording head, the reproduction compatibility of a conventional format machine is improved. An object of the present invention is to obtain a magnetic recording device that can add a new broadband signal while maintaining the same.

[0007]

In order to achieve the above-mentioned object, a magnetic recording apparatus according to claim 1 of the present invention uses a two-layer structure using a preceding recording head and a following recording head having different azimuth angles. In a helical scan type magnetic recording apparatus for recording, a non-magnetic layer is formed in a portion corresponding to at least a part of the track width recorded by the preceding recording head in the track width direction near the gap of the following recording head. It is characterized in that a non-recording portion constituted by is provided.

[0008]

In the magnetic recording apparatus according to the first aspect of the present invention, in the magnetic recording apparatus of the helical scan system in which two layers are recorded by using the preceding recording head and the following recording head having different azimuth angles, By providing a non-recording portion composed of a non-magnetic layer in the central portion of the row recording head in the track width direction, a track depletion portion corresponding to the non-recording portion is formed as a portion to be recorded only by the preceding recording head. Minimizing mutual crosstalk between signals recorded by the preceding recording head and the following recording head,
A new wideband signal can be added while maintaining the reproduction compatibility of the conventional format machine.

[0009]

The preferred embodiments of the magnetic recording apparatus of the present invention will be described below. FIG. 1 is a view for explaining a recording portion structure of a trailing recording head according to the present embodiment, and is a diagram showing a head gap vicinity portion of the trailing recording head viewed from a tape sliding surface of a magnetic recording tape. In contrast to the conventional trailing recording head shown in FIG. 5 (b) in which the entire tape sliding surface is composed of a magnetic layer, the trailing recording head 2 according to the present embodiment is For example, 6.1 for creating a track depletion portion 4a shown in FIG. 2 described later in the center portion in the track width direction.
A non-recording portion 2a composed of a non-magnetic layer having a width of 5 μm is provided. The succeeding recording head 2 is used together with the preceding recording head 1 similar to the preceding recording head shown in FIG. 5A to record a track pattern as shown in FIG. 2 described later. For example, glass or the like can be used as the nonmagnetic layer. The recording widths of the preceding recording head 1 and the succeeding recording head 2 are the same as those in the conventional example shown in FIG. 5, and have a recording width of 20 μm width and a recording width of 58 μm width. The relative azimuth angle with the head 2 is set to 36 °.

Further, in FIG. 2, the head speed is 5.8 m / s,
FIG. 4 is a schematic diagram of a track pattern according to the present embodiment recorded by a recording head on a magnetic recording tape when the head traveling direction is the arrow direction in the figure. In FIG. 2, the shaded portions indicate the positions of the preceding recording head 1 and the succeeding recording head 2. In FIG. 2, 3 is a track recording portion by the preceding recording head 1 having a recording width of, for example, about 20 μm, and 4 is a recording signal having a recording width of, for example, 58 μm and a video signal having a width of, for example, 6.15 μm at the center portion in the track width direction. 7 shows a track recording section by a trailing recording head 2 having a track depletion section 4a, and the track recording section 3 recorded by the preceding recording head 1 has an audio of frequency allocation shown in FIG. 7A or 7B. A signal and a PCM signal are recorded, and a video signal having the frequency allocation shown in FIG. 6 is recorded in the track recording section 4 which is recorded by the following recording head 2.

When the track pattern shown in FIG. 2 is recorded by using the trailing recording head 2 having the recording portion structure shown in FIG. 1, the trailing recording head 2 uses the frequency allocation video signal shown in FIG. Thus, the preceding recording head 1 can record the audio signal and the PCM signal having the frequency allocation shown in FIG. 7A or 7B.

Here, the depletion portion 4 of the video signal shown in FIG.
The value of 6.15 μm width of a is based on the premise that the signal shown in FIG. 7B is recorded, and when reproducing using a normal head as shown in FIG.
Of the signal recorded in step S6, the 6.15 μm wide portion of the track depletion portion 4a that was not overwritten by the succeeding recording head 2 is not erased by overwriting, so the effective signal track width of the preceding recording head 1 shown in FIG. Although the number is small, a sufficient reproduction output can be obtained, and wideband reproduction without reduction of high frequency components can be performed. Therefore, (a) or (b) of FIG.
In terms of compatibility, the track depletion portion 4a of the video signal having a width of 6.15 μm is located in the center portion in the track width direction, and the width is sufficiently narrow. Even if there is a track bend, it can be traced with a reproducing head having a width of 27 μm, for example.

That is, 6.15 of the track depletion portion 4a of the track recording portion 4 by the trailing recording head 2 shown in FIG.
As shown in FIG. 4 (b), the μm width has a crosstalk from the PCM signal to the video signal of 2 as an effect of azimuth loss under the conditions of a relative azimuth angle of 36 ° and a head speed of 5.8 m / s. It is a value that becomes a dip at 0.6 MHz and 5.2 MHz.

Therefore, if the audio and PCM signals recorded by the preceding recording head 1 are as shown in FIG. 7B,
It has an effect of reducing interference from the PCM signal to the video signal, and the width of 6.15 μm of the track depletion part 4a is a value that can be managed only on the recording side. ,As aforementioned,
Since it is not affected by reproduction tracking, the crosstalk dip frequency can be maintained accurately.

That is, the crosstalk is sufficiently suppressed and the crosstalk amount does not change. Of course, if the audio and PCM signals recorded by the preceding recording head 1 are as shown in FIG. 7A, in order to minimize the crosstalk from the PCM signal to the video signal, the track recording unit shown in FIG. The width of the non-recording portion 2a of the following recording head 2 corresponding to the track depletion portion 4a of No. 4 is 6.32 μm
4A, as a result of the azimuth loss, the crosstalk from the PCM signal to the video signal can be a value that causes a dip at 3 MHz, as shown in FIG. The width of the non-recording portion 2a of the trailing recording head 2 may be set to an optimum value that reduces crosstalk, although it depends on the broadband signal to be added (center frequency of the PCM signal). In the case of an azimuth angle other than °, the optimum value should be certified based on the same idea.

In this embodiment, as shown in FIG. 3, for example, a recording head 20 in which a plurality of magnetic layers 21 are laminated in the track width direction and integrated so as to reduce the eddy current loss is used. By setting the non-recording portion composed of the non-magnetic layer 2a at the center portion in the track width direction of the trailing recording head, the same effect as in the above embodiment can be expected. In the case of such a laminated structure, it is sufficient to replace one of the conventional magnetic layers with a non-magnetic layer, so that it is easy to manufacture and the process control is easy.

In the soft tape making, PCM
When adding a signal, S-VHS recording is unavoidable in the conventional technology. Therefore, it is difficult to distribute and distinguish VHS software and S-VHS software with a PCM signal added. Although it was not possible to input a PCM signal, using this recording device, VH
The PCM signal can be recorded in the S-video signal mode, any conventional level VTR can be reproduced according to the capability of the VTR, and the preceding recording head can record in a wide band, so it can be controlled as business software. The signal can also be recorded. Further, there is an effect that it is possible to reproduce on a consumer machine but not to dubb.

[0018]

As described above, according to the present invention having different azimuth angles, in the helical scan type magnetic recording apparatus for performing two-layer recording using the preceding recording head and the following recording head, By providing a non-recording portion composed of a non-magnetic layer in the track width direction central portion of the row recording head, the track depletion portion corresponding to the non-recording portion is recorded as only the preceding recording head. Crosstalk when reproducing the signal recorded by the following recording head from the signal recorded by the preceding recording head is minimized, and a new wideband signal is added while maintaining the reproduction compatibility of the conventional format machine. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a view for explaining a recording portion structure of a trailing recording head according to an embodiment of the present invention, and an explanatory diagram showing a head gap vicinity portion of the trailing recording head viewed from a tape sliding surface of a magnetic recording tape. Is.

FIG. 2 is a schematic diagram of a track pattern recorded by a recording head on a magnetic recording tape according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a recording head in which a plurality of magnetic layers are laminated and integrated in a track width direction according to another embodiment of the present invention.

FIG. 4 is a characteristic diagram of frequency and azimuth loss based on the setting of the track width of the track depletion portion for explaining the effect of the present invention.

FIG. 5 is an explanatory diagram of a normal recording head.

FIG. 6 is a characteristic diagram of frequency and level of a video signal.

FIG. 7 is a characteristic diagram of frequencies and levels of audio signals and PCM signals.

[Explanation of symbols]

 1 Leading Recording Head 2 Trailing Recording Head 2a Non-Recording Section 3 Track Recording Section Using Leading Recording Head 4 Track Recording Section Using Trailing Recording Head 4a Track Depletion Section

Claims (2)

[Claims] 1. A helical scan type magnetic recording apparatus for double-layer recording using a preceding recording head and a following recording head having different azimuth angles, in the track width direction near the gap of the following recording head. 2. A magnetic recording apparatus, wherein a non-recording portion formed of a non-magnetic layer is provided in a portion corresponding to at least a part of the track width recorded by the preceding recording head. 2. The magnetic recording apparatus according to claim 1, wherein the subsequent recording head has a structure in which a plurality of magnetic layers are laminated, and the nonmagnetic layer is laminated so as to be sandwiched between the magnetic layers.