JPS6251893A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To eliminate adjacent crosstalk to obtain recorded and reproduced pictures of high quality by making the width of heads for luminance signal narrower than that of a luminance signal track and making the width of heads for color signals wider than that of a color signal track. CONSTITUTION:The track pitch of luminance signal tracks 2 and 2' and that of color signal tracks 3 and 3' are 47mu together, and the width of heads 1 and 21' for luminance signal is 50mu, and that of heads 22 and 22; for color signals is 40mu. With respect to the luminance signal, the track width is 47mu by overwriting and a high S/N is attained; and with respect to color signals, a guard having 7mu width is formed because the width of color signal tracks 3 and 3' is 40mu. Thus, crosstalk from adjacent tracks occurs hardly with respect to color signals to record and reproduce signals with a high density and a high picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to magnetic recording and reproducing devices such as video tape recorders.

As a conventional method for obtaining advanced technology and quality, a recording tape is roughly divided into two parts in the width direction, and a luminance signal is recorded and reproduced on one side by a pair of heads having opposite azimuth angles for each field. On the other hand, a method in which color signals are recorded and reproduced for each field using a pair of heads with opposite azimuth angles, and the video track width is made smaller than the width of the head to achieve high-density, high-quality recording. can be considered.

FIG. 3 shows the tape format diagram. Furthermore, the fourth
The figure shows an enlarged view of the luminance track.

The brightness signal heads 16 and 16' are both wider than the track width and form tracks by overwriting. At the time of reproduction, it is possible to hardly reproduce signals of tracks in other fields due to the effect of the azimuth angle provided on the heads 16, 16'.

Note that this also applies to the color signal track and head.

In the above configuration, since the luminance and color signals are originally recorded on separate tracks, each band can be widened and high image quality can be obtained. Furthermore, since the same luminance track 11' is recorded next to the luminance track 11 and the same luminance track 12' is recorded next to the color signal track 12, the signals of each field have a line correlation and are overwritten. Even when playing with a wide head, the effect of adjacent crosstalk is small.

This effect has made it possible to record two hours of high-quality images using consumer cassettes.

FIG. 5 shows the allocation of the luminance signal and two-color signal used in the above configuration. The color difference signal (B
-Y) The carrier frequency of the 7M carrier wave in the frequency allocation is 1.5MHz, and the (RY) signal 2o is 5.5MHz.
8 MH2, and the luminance signal 18 is 4.8 MHz.

Problems to be Solved by the Invention The problems with the above configuration are that the luminance signal, 182 color difference signals (R-Y
) 20 has a high carrier frequency, heads 16 and 16
Satisfactory image quality can be obtained with the azimuth angles set at ', 17 and 17' without being affected by adjacent tracks, but the carrier frequency of the color difference signal (B-Y) 19 is 1.6.
Since the frequency is as low as MHz, there is little azimuth loss, so it cannot be said that there is no problem at all.

Therefore, in order to obtain even higher image quality, (a) increase the tape speed. or (b) Narrow the width of the head. It is also conceivable to provide a guard between the tracks by means such as No. 6 as shown in the pattern of FIG.

However, even in this way ■ S/N deteriorates by the amount of track guard.

(2) In particular, the luminance signal (is/)i deterioration is severe, and as a result, the luminance track has to be widened, making it impossible to achieve high-density recording.

There was a problem.

Means to Solve the Problem The present invention makes the width of the luminance signal head narrower than the width of the luminance signal track, and the width of the chrominance signal head wider than the width of the chrominance signal track, thereby enabling overwriting. It has a structure.

Effect: In the above configuration, a guard is formed in the color signal track, almost eliminating adjacent crosstalk, and high image quality can be obtained. In addition, in the luminance signal track, there is no overwriting, and since the head width is wide, the S/N ratio of the reproduced signal can be high, and on the other hand, adjacent crosstalk can be ignored due to the azimuth between the heads.

Embodiment FIG. 1 shows a tape pattern diagram in an embodiment of the present invention.
FIG. 2 shows an enlarged view showing the relationship between the track and the head. The track pitch (for each luminance color) is 47μ, and the head width for the luminance signal is 60μ. That is, the luminance signal tracks 2 and 2' are recorded by overwriting, and the track width is 4.
It becomes 7μ.

On the other hand, the width of the color signal head 22.22' is 40μ, so the width of the color signal track 3.3' is 40μ (the track pitch remains 47μ). Therefore, a guard of 7μ is formed.

According to the above configuration, a high S/N ratio can be obtained for the luminance signal due to overwriting, and for the color signal, since there is a guard between the color tracks, there is almost no crosstalk from adjacent tracks.

Furthermore, the present invention is effective in the following embodiments.

That is, the tape running speed can be switched between at least two modes: high speed and low speed.
The tape pattern shown in the figure is obtained in high-speed mode (
(tape running speed is high). When the switch is changed to the low speed mode, the widths of the luminance signal head and the chrominance signal head remain unchanged at 60μ and 40μ, so both the luminance signal track and the chrominance signal track are overwritten. In other words, in low-speed mode, there is no guard, especially in the color signal track, and a slight crosstalk occurs during playback.

In other words, in low-speed mode, there will be at least as much crosstalk as in the conventional mode, but long-time recording can be achieved. However, in the high-speed mode, color signal crosstalk does not occur as described above, and high-density, high-quality recording and reproduction is possible.

Effects of the Invention According to the present invention, in high-speed mode, the chrominance signal track is guarded, so there is no influence of crosstalk between adjacent tracks, and a high-quality chrominance signal can be obtained, while the luminance signal track is overwritten, but , a signal with a high S/N ratio can be obtained, and therefore high-density, high-quality recording and reproduction is possible.

[Brief explanation of the drawing]

FIG. 1 is a tape pattern diagram in an embodiment of the present invention;
FIG. 2 is an enlarged view showing the track width and head width, FIG. 3 is a tape pattern diagram of the prior art, FIG. 4 is an enlarged view showing the track width and head width, and FIG. 5 is a frequency pattern showing frequency allocation. FIG. 6 is a diagram of a tape pattern in the prior art. 2.2'... Brightness signal track, 3.3'...
...Color signal track, 21.21'... Head for luminance signal, 22.22'... Head for color signal. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure - 1 Figure 2 tt, tt' = - Z actual r (No. ■ Lapf 14 - - - ta) Muko y Trap 7 f5 - 1 - Co > L Tono L Trapuku a - - 1° times this Taimukai 211+---M(RY)

Claims (1)

[Claims] In a magnetic recording and reproducing apparatus which divides a magnetic tape into approximately two parts in the width direction, records and reproduces a luminance signal and a color signal separately, and has two or more recording tape speeds,
The width of the head for recording and reproducing luminance signals is configured to be larger than the track pitch formed at the fastest of the above arc speeds, while the width of the head for recording and reproducing color signals is configured to be larger than the track pitch formed at the fastest of the above tape speeds. A magnetic recording/reproducing device characterized in that the track pitch is smaller than the track pitch formed at a high speed, and larger than the track pitch formed at other speeds.