JPH0773405A - Magnetic recording / reproducing device - Google Patents

Abstract

(57) [Summary] [Purpose] An object of the present invention is to provide a magnetic recording / reproducing apparatus capable of reducing the number of rotary heads and realizing high-quality reproduction image quality. [Structure] Tape feeding speed is 1/3 compared to the first mode
In a magnetic recording / reproducing apparatus capable of recording or reproducing in three modes of a second mode which is double and a third mode which is 1/6, a track width slightly narrower than twice the track pitch in the second mode. A single head 1 for the first mode, a head 3 for the second mode having a track width substantially equal to the track pitch in the second mode, and a track pitch 2 in the third mode.
It is provided with four double azimuth type heads including the third mode head 2 having a track width slightly narrower than double.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a VTR (Video).
More specifically, the present invention relates to a magnetic recording / reproducing apparatus using a rotary magnetic head such as a Tape Recorder). The present invention relates to a magnetic recording / reproducing apparatus capable of recording or reproducing in three modes.

[0002]

2. Description of the Related Art Conventional magnetic recording / reproducing apparatus of this type, for example, a rotary head in a VHS system VTR has an 11-head configuration shown in FIG. 7 and a 9-head configuration shown in FIG. Is being considered.

The structure of the head shown in FIG. 7 is provided with two sets of four double azimuth type heads, one of which, 4 (5R, 5L) and 6 (6R, 6L), is in the first mode (hereinafter , Standard mode) heads and second mode (hereinafter referred to as triple mode) heads. Generally, the track width is selected to be 58 μm, 46 μm in the standard mode and 26 to 32 μm in the triple mode. . Then, with these 4 heads 5R, 5L, 6R, and 6L, recording / reproduction in the standard mode, compatible reproduction in the triple mode, and special reproduction in both modes are performed.

The other four heads 3 (3R, 3L),
7 (7R, 7L) are just track heads for 3x mode and 3rd mode (hereinafter referred to as 6x mode).
Recording / playback in 3x mode / 6x mode and special playback in 6x mode. Here, the azimuth angle in the 6 × mode head 7 is ± 6 °.

Further, the head 4 (4R, 4L) is Hi
-For Fi audio, commonly used for 3 modes. The head 8 is a rotation erasing head.

Next, regarding the structure of the head shown in FIG.
In comparison with the one shown in FIG. 7, the just-track head for 3 × mode is eliminated and the head for 6 × mode is a single head 7 (7R, 7L).

When recording in the triple mode,
In order to prevent unerased Hi-Fi audio signals from occurring, a double azimuth 4-head triple mode head 6 (6R, 6L) is used, and crosstalk from adjacent tracks does not occur during reproduction. As described above, the 6-times mode head 7 (7R, 7L) is used.

[0008]

However, in the case of the conventional magnetic recording / reproducing apparatus shown in FIG. 7, the number of heads is 11
There is a problem that the cost is increased because the number is large.

Further, in the case of the conventional magnetic recording / reproducing apparatus shown in FIG. 8, the head used for recording in the triple mode and the head used for reproduction are different, and therefore the tape and the head are used during recording and during reproduction. The contact conditions are different, and if there is a so-called head hit that occurs when the head plunges into and out of the tape, it is easily affected. Further, since the 6 × mode head is commonly used as the 3 × mode reproduction head, there is a problem that the output is reduced as compared with the full track reproduction.

Further, in any of the magnetic recording / reproducing apparatuses shown in FIGS. 7 and 8, since the azimuth angle of the 6 × mode head is ± 6 °, a sufficient azimuth loss occurs in the 6 × mode with a narrow track pitch. However, there is a problem in that, due to the influence of crosstalk, edge noise occurs during self-recording reproduction, and inversion phenomenon occurs during compatible reproduction.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a magnetic recording / reproducing apparatus capable of reducing the number of heads and realizing high-quality reproduced image quality. .

[0012]

In order to solve the above problems, in the magnetic recording / reproducing apparatus according to the present invention, the first mode single head having a track width slightly narrower than twice the track pitch in the second mode. A head for the second mode having a track width substantially equal to the track pitch in the second mode, and a third head having a track width slightly narrower than twice the track pitch in the third mode.
Four heads of a double azimuth type composed of mode heads are provided, and the azimuth angle of the third mode head is set within ± 10 ° to ± 20 °.

[0013]

The magnetic recording / reproducing apparatus according to the present invention uses the first mode single head having a track width slightly narrower than twice the track pitch in the second mode to record / reproduce in the first mode and the second mode. Compatible reproduction is performed, and recording / reproduction in the second mode is performed by the second mode head having a track width substantially equal to the track pitch in the second mode.
The track width is slightly narrower than double, and the azimuth angle is ± 1.
The third mode recording / reproducing can be performed by the third mode head set between 0 ° and ± 20 °.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a magnetic recording / reproducing apparatus of the present invention will be described below with reference to a VHS type VTR with reference to FIGS.

As shown in FIG. 1, the rotary head of the VTR of this embodiment has a track width of about 35 μm, which is slightly narrower than 38 μm, which is twice the track pitch in the triple mode, for the standard mode. The single head 1 (1R, 1L) which it has is provided.

Further, a triple mode head 3 (3R, 3R having a track width of 19 μm used for recording / reproducing in the triple mode).
L), and a double azimuth composed of a 6x mode head 2 (2R, 2L) having a track width of slightly narrower than twice the track pitch in the 6x mode, for example, used for recording / reproduction in the 6x mode. The four heads of the system and the audio heads 4 (4R, 4L) common to the three modes and having a track width slightly wider than the track pitch in the triple mode are provided.

Here, in the above-mentioned conventional example, the track widths of the standard mode head of 58 μm and 46 μm were used, and therefore, in this embodiment, the output deterioration due to the decrease of the track width of the standard mode head occurred. It is worried, but the actual head output has a head inductance of 58μ.
In order to equalize m and 46 μm, by increasing the number of windings of the coil wound around the head core, it is possible to suppress the output deterioration to about 1 dB, and no significant deterioration in S / N is observed.

Further, the R of the single head 1 for standard mode is used.
Since the head track widths of ch and Lch are made equal, the reproduction signal output from each head 1R, 1L becomes equal, and the flicker of the color signal can be reduced.

According to the present embodiment, the non-recorded area in the standard mode is as large as 23 μm per field, and the noise bar becomes thick and color does not appear on the monitor during special reproduction such as video search. As a result, the quality of image quality may be impaired, and the problem that field still cannot be performed in still reproduction or slow reproduction occurs. However, the video signal after the reproduction signal output is FM-demodulated and the low-frequency conversion color signal is 1 field. The above problem can be solved by performing digital circuit processing using a field memory (not shown) for storing.

For example, at the time of video search, by setting the search speed to an even speed, as shown in FIGS. 2 and 3 (when the search speed is set to 4 speed), the Rch head 1R of the standard mode single head 1 is used. Since the relationship of the reproduced signal output with the Lch head 1L is complementary, the missing portion of the signal can be compensated by using the field memory output.

By setting the mounting angle and height of the standard mode single head 1 on the drum for the audio head 4 to a predetermined level, the recording format of the video signal and the audio signal on the tape in the triple mode is satisfied. can do. Therefore, when the linearity of the recording track on the tape is poor in recording with another device and the 19 μm head 3 for the triple mode cannot secure the required on-track amount, the single head 1 for the standard mode with a wide track width is used. By making the selection possible, a required amount of on-track can be secured and compatibility can be maintained.

A 19 μm head 3 for the 3 × mode is used for recording / reproducing in the 3 × mode, but still reproduction or slow reproduction can be realized by using a field memory for the output of the single head 1 for the standard mode. . Also,
For the video search, by using the standard mode single head 1, it is possible to obtain an image with a thin noise bar without using a digital circuit including a field memory.

The 6 × mode head 2 is used for recording / reproducing in the 6 × mode, and for the video search, the digital circuit including the field memory is used by using the 6 × mode head 2. And still playback and slow playback are standard mode, 3
This can be realized by using a field memory as in the double mode.

Further, the crosstalk amount from the adjacent tracks (which can be calculated from the azimuth loss) when the track width of the 6 × mode head is 15 μm and the azimuth angle is ± 6 ° is shown in FIG. As shown in FIG. 4A, the lower edge of the video head is aligned with the lower edge of the recording track, and the lower edge of the video head is further shifted by δ μm from the lower edge of the recording track. (See FIG. 4B).

In FIG. 5, when δ = 0.3 μm,
It can be seen that C / S, which is the ratio of the main signal S to the crosstalk C, is about −7.5 dB at 4.4 MHz which is the carrier band of VHS.

It is possible to match the lower edge of the video head with the lower edge of the recording track in the self-recording reproduction, but in reproducing the recording of another device, δ> 0 due to the difference in linearity of the recording track. Otherwise, it may not be possible to secure the required amount of on-track over the entire area from the start point to the end point of the recording track. Therefore, when δ> 0, the increase in edge noise and the inversion phenomenon are likely to occur, which makes it difficult to secure compatibility. Further, also in the self-recording reproduction, the deterioration of the reproduced image becomes large unless the highly accurate tracking detection is performed.

In order to solve these problems, in the present embodiment, the azimuth angle θ of the 6 × mode head 2 is ±.
It is supposed to be larger than 6 °. Here, even when δ> 0, C / S ≦ = − at both 4.4 MHz and 7 MHz.
The desirable azimuth angle is 20 dB. Therefore, when the azimuth angle θ = ± 45 °, C / S = −∞, but as the azimuth angle θ is increased, the effective wavelength λ
_{Since eff} becomes shorter, gap loss and space loss increase and the reproduction output of the main signal decreases.

Therefore, in the range up to the azimuth angle θ = ± 20 ° at which the reproduction output of the main signal hardly decreases,
Even if δ> 0 at both 4.4 MHz and 7 MHz, C
When the azimuth angle θ at which / S ≦ = −20 dB is obtained from the azimuth loss calculation formula shown in Formula 1, θ = ± 13 °, ±
It becomes 14 °, ± 15 °, ± 19 °, ± 20 °.

[0029]

[Equation 1]

In particular, the crosstalk amount with respect to frequency when the azimuth angle θ = 15 ° is shown in FIG. 6, but there is no great difference in the crosstalk characteristics within the range of the azimuth angle θ described above, and any angle θ may be selected. However, since the azimuth angle θ in W-VHS is 15 °, when considering sharing,
It is desirable to set the azimuth angle θ = 15 °.

In the VTR of this embodiment, the number of heads including the rotation erasing head (not shown) is nine, which is a VTR which does not have the 6x mode function. The number of heads is the same as that of the one having a triple track just-track head, and it is possible to share parts.

[0032]

According to the magnetic recording / reproducing apparatus of the present invention, the number of heads can be reduced and the cost can be reduced, and since the just track head is used in the second mode, a high quality reproduced image is provided. Since the head for the first mode can also be used for the second mode, compatibility can be maintained even with a tape having poor linearity in recording with another device.

Further, since the azimuth angle of the head for the third mode is large, it is possible to reduce crosstalk from the adjacent tracks, and to realize high quality image and good compatibility even in the third mode. You can

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram showing a head configuration in an embodiment of a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 is an explanatory diagram showing a standard mode video search in one embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 3 is an explanatory diagram showing output waveforms in FIG.

FIG. 4 is a schematic explanatory view showing a relationship between a video head and a recording track in an embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 5 is an explanatory diagram for explaining an embodiment of a magnetic recording / reproducing apparatus of the present invention.

FIG. 6 is an explanatory diagram showing the amount of adjacent crosstalk in one embodiment of the magnetic recording / reproducing apparatus of the present invention.

FIG. 7 is a schematic explanatory diagram showing a configuration of a head in a conventional magnetic recording / reproducing apparatus.

FIG. 8 is a schematic explanatory diagram showing a configuration of a head in a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

 1 Single head for standard mode 2 Head for 6x mode 3 Head for 3x mode 4 Head for audio

Claims (2)

[Claims] 1. The tape feed speed is 1 with respect to the first mode.
In a magnetic recording / reproducing apparatus capable of recording or reproducing in three modes of a third mode which is ⅓ times and a third mode which is ⅙ times, the magnetic recording and reproducing apparatus is slightly narrower than twice the track pitch in the second mode. A first mode single head having a track width, a second mode head having a track width substantially equal to the track pitch in the second mode, and a track width slightly narrower than twice the track pitch in the third mode. A magnetic recording / reproducing apparatus provided with four double azimuth type heads each comprising a third mode head. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the azimuth angle of the third mode head is ± 10 ° to ± 20.
A magnetic recording / reproducing apparatus characterized by being set between 0 °.