JP2850929B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus suitable for multiple azimuth recording / reproducing.

[0002]

2. Description of the Related Art FIG. 5 is a view for explaining a head arrangement in a magnetic recording / reproducing apparatus, FIG. 6 is a view for explaining a step between a video head and an audio head, and FIG. FIG. 8 is a diagram showing a track pattern, and FIG. 8 is a diagram for explaining a superimposed recording state of an audio FM signal and a video signal.

[0003] The head arrangement of a conventional magnetic recording / reproducing apparatus is as follows.
As shown in FIG. 5, two video heads 16 and 17 which are arranged on the drum 15 at intervals of approximately 180 ° and have different azimuth angles, and the video heads 16 and 17
The two audio heads 18 and 19, which are arranged at an angle of α from each other at an angle of about 180 ° and have different azimuth angles, are installed. The rotation direction of the drum 15 is indicated by an arrow A. The azimuth angles with respect to the plane perpendicular to the traveling direction are set to + φ and −φ for the audio heads 18 and 19, respectively, assuming that the video heads 16 and 17 are + θ and −θ, respectively.

[0006] Also, steps T as shown in FIG. 6 are provided at the mounting surfaces of the video heads 16 and 17 and the audio heads 18 and 19 so that the audio head 18 and the video head 16, and the audio head 19 and the video head 17 are provided. Is adjusted to magnetically record substantially the same track on the magnetic tape. The step T is determined according to the angle α and the traveling speed of the magnetic tape.

Thus, the video and audio heads 16 and 18 (the video and audio heads 17 and
The azimuth angles in 19) have the same signs.

According to the head arrangement shown in FIGS. 5 and 6, the order of recording on the same track is as shown in FIGS.
As shown in FIG. 3, an audio FM signal FM-modulated according to an audio signal is first recorded in a deep layer on a magnetic layer 20a of a magnetic tape 20 using an audio head 18, and the audio track 2 is recorded.
1 is formed, and then a video modulation signal obtained by combining a luminance FM signal modulated according to the luminance signal and a low-frequency conversion chroma signal is overwritten and recorded on the audio track 21 using the video head 16. A video track 22 is formed.

[0007] Similarly, the audio FM signal is transmitted to the audio head 1
9 is used to form an audio track 23, and then the video modulation signal is overwritten and recorded on the audio track 23 using the video head 17 to form a video track 24. FIG.
In FIG. 8, 20b is a bass, 25 is an audio track,
26 is a control track.

Thus, the above-described conventional magnetic recording / reproducing apparatus superimposes and records a video signal and an audio signal using the azimuth difference of the head and the difference in recording frequency, and superimposes and records using this azimuth difference. Video and audio signals can be separated and reproduced.

[0009]

By the way, the above-mentioned conventional magnetic recording / reproducing apparatus utilizes the difference in the azimuth angle of the head and the difference in the recording frequency to determine the head traveling direction (FIG. 6).
(1) Since the recording / reproducing head is provided with a recording / reproducing head for superimposing and recording video and audio signals on a magnetic tape oriented in the same direction as the arrow A) shown in FIG. In addition, video and audio signals can be superimposed and recorded according to the difference in recording frequency. However, the orientation of the magnetic tape used is only one direction, and the azimuth angle of the recording / reproducing head and the orientation of the magnetic tape are used. Is not matched with
There is a drawback that video and audio signals cannot be recorded with high efficiency and reproduced with high efficiency.

[0010]

In order to solve the above-mentioned problems, the present invention provides a magnetic recording / reproducing apparatus having the following configuration.

A magnetic recording / reproducing apparatus comprising a recording / reproducing head for recording / reproducing an information signal on / from a magnetic tape comprising magnetic layers having orientation directions different from the head running direction. The recording / reproducing head, which is an azimuth head having an azimuth angle adapted to an orientation angle related to the orientation direction of the magnetic layer, has a first azimuth angle adapted to an orientation angle related to a first orientation direction, and is provided on the magnetic tape. Approximately 2 of the formed signal track pitch
A first recording / reproducing head having a double head width, and a head having a second azimuth angle adapted to an orientation angle related to a second orientation direction and substantially twice a signal track pitch formed on the magnetic tape. A second recording / reproducing head having a width, wherein recording / reproducing is performed such that a traveling locus of the first head and a traveling locus of the second head partially overlap with a substantially signal track pitch. Magnetic recording and reproducing device.

[0012]

FIG. 1 shows a magnetic recording / reproducing apparatus according to the present invention.
4 will be described with reference to FIG. FIG. 1 is a diagram for explaining recording / reproduction of the magnetic recording / reproducing apparatus according to the present invention, FIG. 2 is a block diagram of an embodiment of a video signal processing system which is a main part of the magnetic recording / reproducing apparatus according to the present invention, and FIG. FIG. 4 is a view for explaining a laminated state of magnetic layers of a magnetic tape used in a magnetic recording and reproducing apparatus according to the present invention, and FIG. 4 is a view for explaining an orientation direction of each magnetic layer in a magnetic tape used for a magnetic recording and reproducing apparatus according to the present invention. It is.

As shown in FIGS. 1 and 4, the magnetic recording / reproducing apparatus 30 according to the present invention has an orientation direction C (orientation angle + θ, θ = 45 °) and an orientation direction D (orientation angle) with respect to the head running direction A. −θ), a video head 36 that records and reproduces a video modulation signal on a magnetic tape 1 formed by laminating magnetic layers 3 and 4 having
37. A magnetic recording / reproducing apparatus comprising:
6 has an azimuth angle + θ matching the orientation angle of the magnetic layer 3 in the orientation direction C, and the image head 37 has an azimuth angle −θ matching the orientation angle of the magnetic layer 4 in the orientation direction D.

The head arrangement of the magnetic recording / reproducing apparatus 30 is such that video heads 36 and 37 are arranged on a rotating drum at an interval of about 180 °. The azimuth angles with respect to the plane perpendicular to the traveling direction are set to + θ and −θ, respectively.

The above-described video heads 36 and 37 have a head width approximately twice as large as the signal track pitch p formed on the magnetic tape 1. Here, in the case of the VHS system, the signal track pitch p formed on the magnetic tape 1 is 58 μm in the standard mode and 19 μm in the long-time mode. And
The two video heads 36 and 37 are arranged such that the travel locus of the video head 36 and the travel locus of the video head 37 partially overlap with a substantially signal track pitch p.

With the above-described head arrangement, the recording order of the magnetic recording / reproducing apparatus 30 is as follows. First, a video modulation signal is recorded on the magnetic layer 3 of the magnetic tape 1 using the video head 36, and the video track 41 having a track pitch of 2p is obtained. To form Subsequently, the traveling locus of the image head 36 and the image head 37
The video modulation signal is recorded on the magnetic layer 4 of the magnetic tape 1 by using the video head 37 so that the video track 42 is formed so that the running locus of the magnetic tape 1 partially overlaps with the track loci.

Although not shown in FIG. 1, audio tracks and control tracks shown in FIG. 8 are formed as necessary in portions other than the recording area where the signal tracks 41 and 42 of the magnetic tape 1 are formed.

Thus, the magnetic recording / reproducing apparatus 30 of the present invention
A video head 36 adapted to the orientation angle of the orientation direction C and a video head 37 adapted to the orientation angle of the orientation direction D are provided on the magnetic tape 1 of the magnetic layers 3 and 4 having the orientation directions C and D with respect to the head running direction A. Thus, the video signal can be recorded by aligning the azimuth angle of the head with the orientation angle of the magnetic tape 1, and the recorded video signal can be reproduced using this relationship.

By the way, the above magnetic tape 1 is shown in FIG.
As shown in the figure, 14 to 15 μm (thickness of 10 μm
m), a base material 2 such as a polyester film (polyethylene terephthalate), an undercoat layer (not shown) having a thickness of about 1 μm or less formed on the surface of the base material 2 as necessary, and an aspect ratio of 5 to 7 And ferromagnetic needle-like fine particles such as iron oxide having a length of about 0.5 μm are mixed with a binder (a kind of adhesive mainly composed of an organic polymer such as vinyl acetate, vinyl chloride, and polyurethane) and uniformly dispersed. 4 to 5 μm formed on the surface of the base material 2 as described above.
m, a magnetic layer 4 having a thickness of 4 to 5 μm, which is coated on the surface of the magnetic layer 3 so as to mix and uniformly disperse ferromagnetic fine particles and a binder having the same structure as the magnetic layer 3.
Consists of

On the back surface of the base member 2, a back coding layer (not shown) having a thickness of 0.5 μm and made of conductive and lubricating fine particles such as carbon and a binder is formed.

As shown in FIG. 4, in the magnetic tape 1 having the above-described configuration, a plurality of magnetic layers 3 and 4 are laminated, and the orientation directions C and D of the magnetic layers 3 and 4 are alternately made different. The magnetic tape 1 is a magnetic tape in which the orientation directions C and D of the adjacent magnetic layers 3 and 4 are orthogonal to each other. Thus, information signals are sequentially and alternately recorded on the magnetic tape 1 by the recording operation of the azimuth head described above. Due to the well-known azimuth effect, it is needless to say that information cannot be recorded on the upper magnetic layer 4 with a head having an azimuth angle of + 45 ° and information cannot be recorded on the lower magnetic layer 3 with a head having an azimuth angle of -45 °. No.

By the way, at the time of the multiplex recording and reproduction described above, +
After recording / reproducing with azimuth head of 45 ° angle,
When recording / reproducing with an azimuth head with an angle of -45 °,
When the magnetic layer 3 oriented at an angle of + 45 ° is recorded / reproduced by an azimuth head at an angle of −45 °, the magnetic particles in the magnetic layer 3 become cos (2 × 45 °) = 0 due to the azimuth effect, The orthogonal azimuth recording by the orthogonal azimuth head becomes possible, and the mutual interference at the time of mutual recording and reproduction is completely eliminated.

Similarly, at the time of the above-mentioned multiple recording and reproduction, -4
After recording / reproducing with an azimuth head of 5 ° angle,
When recording / reproducing with an azimuth head of 45 °, +
When the magnetic layer 3 oriented at an angle of 45 ° is recorded / reproduced with an azimuth head at an angle of -45 °, the magnetic particles in the magnetic layer 3 become cos (2 × 45 °) = 0 due to the azimuth effect, The orthogonal azimuth recording by the orthogonal azimuth head becomes possible, and the mutual interference at the time of mutual recording and reproduction is completely eliminated.

The video signal processing system of the magnetic recording / reproducing apparatus according to the present invention comprises a recording system 50 and a reproducing system 51 as shown in FIG.
Consists of

The configuration of the recording system 50 includes an AGC amplifier 50a for setting the amplitude level of the input video signal to a specified level,
Y / C separation circuits 50b, Y for separating and outputting a luminance signal and a chrominance signal from the video signal supplied from the AGC amplifier 50a
A pre-emphasis circuit 50c for increasing the amplitude of the high frequency of the luminance signal supplied from the / C separation circuit 50b, a DC level of a synchronizing signal part of the luminance signal supplied from the pre-emphasis circuit 50c is fixed, and a high-frequency signal part is fixed. A clipping circuit 50d for clipping the overshoot at a predetermined level, a frequency modulation circuit 50e for FM modulating a carrier frequency with a luminance signal from the clamp / clip circuit 50d, a high-pass filter 50f for removing low-frequency components of the FM modulation signal, ACC circuit 5 for keeping the recording level of the color signal supplied from Y / C separation circuit 50b constant
0g, a frequency conversion circuit 50h for low-frequency conversion of the color signal supplied from the ACC circuit 50g, a low-pass filter 50i for removing high-frequency components of the low-frequency conversion color signal, an FM luminance signal from the high-pass filter 50f and a low-pass filter 50i.
And a recording amplifier 50k for amplifying the video modulation signal.

The structure of the reproduction system 51 is such that the video modulation signal recorded on the magnetic tape 1 is reproduced by the video heads 36 and 37 and then the video modulation signal supplied from the switch 52 switched to the reproduction side P is reproduced. A reproduction amplifier 51a for amplification, a low-pass filter 51b for separating and outputting a low-frequency conversion color signal from the video modulation signal, an ACC circuit 50c for making the reproduction level of the low-frequency conversion color signal constant, and a low-frequency conversion color signal from the ACC circuit 50c Frequency conversion circuit 50d for re-converting the frequency and outputting a color signal, a band Has filter 51e for compensating for a dropout generated during reproduction, subtractors 51f and 1H
Delay circuit 51g, APC / AFC circuit 51h, VCO5
1i, a high-pass filter 51j that separates and outputs an FM luminance signal from the video modulation signal output from the reproduction amplifier 51a, an equalizer amplifier 51k that compensates for the frequency characteristics of the FM luminance signal, and an FM from the equalizer amplifier 51k.
Limiter circuit 51l for limiting the amplitude of the luminance signal, FM demodulation circuit 51m for demodulating the FM luminance signal from limiter circuit 51l, de-emphasis circuit 51n for reducing the amplitude of the high frequency of the demodulated luminance signal, and de-emphasis circuit 51n And a color signal from the subtracter 51f, and outputs a video signal.
o, an output amplifier 51p for amplifying this video signal.

As described above, at the time of recording, the video modulated signal output from the recording amplifier 50k of the recording system 50 is transmitted to the video head 3 via the switch 52 switched to the recording side R.
The video signal is supplied from the output amplifier 51p of the reproduction system 51 to the above-described recording system.

[0028]

The magnetic recording / reproducing apparatus according to the present invention is a recording / reproducing head for recording / reproducing information signals on / from a magnetic tape comprising magnetic layers having orientation directions oriented in directions different from the head running direction. Wherein the recording / reproducing head is an azimuth head having an azimuth angle adapted to an orientation angle related to the orientation direction of the magnetic layer, and has a first azimuth angle adapted to an orientation angle related to a first orientation direction. A first recording / reproducing head having a head width approximately twice as large as a signal track pitch formed on the magnetic tape, a second azimuth angle adapted to an orientation angle related to a second orientation direction, and the magnetic tape And a second recording / reproducing head having a head width approximately twice as large as the signal track pitch formed by the first head and the traveling locus of the second head. The trajectory of the recording and reproducing heads partially overlaps with the signal track pitch, so the azimuth angle of the recording / reproducing head and the orientation direction of the magnetic tape are matched. And play it with high efficiency,
In addition, there is an effect that an information signal can be recorded with very little deterioration of C / N against so-called track bending, and the recorded information signal can be reproduced with high fidelity.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining recording / reproducing of a magnetic recording / reproducing apparatus according to the present invention.

FIG. 2 is a block diagram of an embodiment of a video signal processing system which is a main part of the magnetic recording / reproducing apparatus according to the present invention.

FIG. 3 is a diagram illustrating a laminated state of magnetic layers of a magnetic tape used in the magnetic recording / reproducing apparatus according to the present invention.

FIG. 4 is a diagram illustrating an orientation direction of each magnetic layer in a magnetic tape used in the magnetic recording / reproducing apparatus according to the present invention.

FIG. 5 is a diagram illustrating a head arrangement in a magnetic recording / reproducing apparatus.

FIG. 6 is a diagram illustrating a step between a video head and an audio head.

FIG. 7 is a diagram showing a track pattern in a standard speed mode in a conventional magnetic recording / reproducing apparatus.

FIG. 8 is a diagram illustrating a superimposed recording state of an audio FM signal and a video signal.

[Explanation of symbols]

 Reference Signs List 1 magnetic tape 2 base material 3, 4 magnetic layer 16, 17, 36, 37 video head 18, 19 audio head 30 magnetic recording / reproducing device A tape longitudinal direction C, D orientation direction p track pitch + θ, -θ orientation angle

Claims (1)

(57) [Claims] 1. A magnetic recording / reproducing apparatus comprising: a recording / reproducing head for recording / reproducing an information signal on / from a magnetic tape formed by laminating magnetic layers having orientation directions different from the head running direction. The recording / reproducing head, which is an azimuth head having an azimuth angle adapted to an orientation angle related to the orientation direction of the magnetic layer, has a first azimuth angle adapted to an orientation angle related to a first orientation direction, and has the magnetic property. A first recording / reproducing head having a head width approximately twice as large as a signal track pitch formed on the tape; a second azimuth angle adapted to an orientation angle related to a second orientation direction; And a second recording / reproducing head having a head width approximately twice as large as a signal track pitch, and a traveling locus of the first head and the second head. A magnetic recording / reproducing apparatus which performs recording / reproducing such that a traveling locus of the data is partially overlapped with a signal track pitch.