JPS5972881A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To realize the field steal and fine slow modes, by providing two two- hour exclusive heads, two six-exclusive heads and a special reproducing head and then using one of the two exclusive heads and the special reproducing head in bot two-hour and six-hour modes. CONSTITUTION:The azimuth angles are shown by (+) and (-) for two-hour exclusive heads 11 and 12, six-hour exclusive heads 13 and 14, and a special reproducing head 15 respectively. In a six-hour mode the recording tracks of heads 13 and 14 are set 13W and 14W respectively, and therefore the reproducing tracks of heads 14 and 15 are set at 16 in a field steal mode. Then an oblique line part 17 contributes to a signal. In a 2-hour mode the recording tracks of heads 11 and 12 are set at 11W and 12W respectively, and therefore, the reproducing tracks of heads 14 and 15 are set 18 in a field steal mode. Then an oblique line part 19 contributes to a signal. In a fine slow mode, heads 14 and 15 are used in a steal mode and heads 13 and 14 are used in a transient play mode during which a steal is shifted to the next one. Thus the noiseless reproduction is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention +' relates to a reproducing circuit for a magnetic recording/reproducing apparatus (hereinafter abbreviated as VTR) having a special reproduction function such as field stay fine throw.

[Prior art]

In a helical scan VTR, normal playback is performed using two heads with different azimuth angles. Steil・
Special replays such as fine throws (those that repeat the stay and play state).

When producing live images, it is possible to use two normal heads, but since the still image quality is determined on a frame-by-frame basis, shaking occurs when pictures change rapidly.

There are drawbacks such as a small noise tracking margin. For this reason, recently, devices equipped with one or two separate holes for special reproduction have already been put into practical use.

ing. (For example, “Television Technology, 1980, 128
See page 45 of the month issue. ) In this case, the field position and angle are reproduced (the same field position and direction are reproduced with two fields of view having the same azimuth angle), and the image quality and noise margin are also improved.

FIG. 1 shows a case of three heads in the conventional example, in which two heads with different azimuth angles are mounted on a cylinder 1.
A helide 4° having the same azimuth angle as the head 3 exists near the helide 3 and the helide 2. Figure 1 shows an example of azimuth angle.

It is indicated by θ. Recording and standard playback are done with Helid 2 and Helid 3, and field still.

Same azimuth helid 3. Head 4 is used. .

FIG. 2 shows the case of 4 to the throat in the conventional example.

In the above, Henod 2. The role of head 3 is the same as in Fig. 1, but instead of head 4, the same horse mackerel is used.

To the square... 5. Helid 6 is set facing 180 degrees.

It is placed. In this case, Field Stall &'! ,
Go=)” 5. Perform using Go9 draw.

FIG. 5 shows an example of a truffle pattern. 100° is the tape.

To the O azimuth, the throat record track is 7.1° ■ The record track to the azimuth? If it is 8, the reproduction track during field stall will be 9, and the portion contributing to signal reproduction will be the shaded portion 10. This has a larger margin against noise compared to conventional frame staling.

However, a common drawback of the above-mentioned conventional examples is that the helide used for recording is the head 2.・If there is a 2-hour mode (track pitch 60 μm) and a 6-hour mode (track pitch 20 μm) like current home VTRs (e.g. VH5), it is optimal for each mode. The problem is that it is not possible to select a suitable head track width.

In other words, since the 6-hour long distance is 20 μm, the width of the helide can not be more than 401 μm due to the 1° constraint of adjacent interference (. Therefore, 2 In time mode, there are guard bands where no signal is recorded, and the feel stays.

Even if a throw is possible, a fine throw is impossible.

There is also a so-called "BIKU" that plays at high speed.

In the 2-hour mode, the Cha Search also has a large amount of noise, making it impractical (・.

[Purpose of the invention]

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to
Whether in time mode or 6-hour mode, it provides a means to achieve F3, Yield Stay, and Fine Throw.

[Summary of the invention]

In order to achieve the above object, the present invention provides a field station equipped with two 2-hour dedicated heads, two 6-hour dedicated heads, and one special playback head.

If you want to achieve fine mellow, use one of the 6-hour dedicated heads and one for special playback, as well as the 2-hour and 1.6-hour modes.

It is a feature.　　　　　　　　　　　　　.

[Embodiments of the invention]

The present invention will be explained in detail below based on specific examples.

do.

FIG. 4 shows an embodiment of the present invention, in which a 2-hour dedicated head 11, a 12.6-hour dedicated head 16° 14, and a special reproduction head 15 are present. Helides 11° and 12 face each other at different azimuths at approximately 180', and heads 16° and 14 also face each other at different azimuths at approximately 180°. to+7d11
The positional relationship between the top and bottom 9 and 15 is arbitrary. head 12,
14 and 15 are the same azimuth.

Examples of azimuth angles are represented by ■ and O in the figure.

An example of a suitable drag width for VH5, VTR (D case, 2 hour mode, 6 hour mode) is: 9 do 11, 12 ITw = 70 pm 9 do 15
-14 * 15 ITw = 30 μm, 2 hour mode recording and standard playback...

Recording in the 6-hour mode and standard playback are performed using the doors 13 and 14. Helid 1
5 is located near the head 13, and the bottom of the helid 13.

The distance between the magnetic gap and the head 15 is usually 1.
RE~31 m (RB is a length corresponding to one horizontal period on the cylinder circumference, which is approximately 570 μm in the case of VH5).

The key point of this invention is field stay.

When achieving fine slow playback, 2 hours mode)”,
Head 14, throat 1 with the same azimuth for both S time mode
5 is used.

FIGS. 5 and 6 show trarif patterns during field stay reproduction.

In the 6-hour mode shown in FIG.
4 IF', the reproduction track of the head 14 and head 15 becomes 16 during field stall, and the shaded area 17 contributes to the signal.

In the 2-hour mode shown in FIG. 6, the recording track of helide 11 is set to 11F, and the recording track of helide 12 is set to 11F.

If it is 12W, then during field stall, it will be 12W.

The reproduction track of the head 14 and the head 15 is 18, and the shaded area 19 contributes to the signal. 11° That is, the head 14 and head 15 perform the same fee in both the 2-hour mode and the 6-hour mode.

- Lutostilka can be realized. Fires Row.

When doing this, the head is 14 and the total rad is 1 in the stale state.
5. In a transitional play state from one stall to the next, Helid 13. Noiseless reproduction is possible by using the helide 14.

Figure 7 shows an example of the rotary transformer 200 channel arrangement in the 5-head system of the present invention, from the outside: channel 21: 6hr; azimuth head 15 and connection channel 2216hre to azimuth; throat 14 and connection channel 23; fine throw. 9 do 1 to e azimuth
5 and connection channel 24+2ArQ azimuth node 12 and connection channel 2517hr■ to azimuth/l door 11. Important factors in determining this placement are crosstalk and level reduction due to adjacent channels 5hort. To the above 5-1, it is difficult to make good contact with the tape in the above-mentioned node 13, and there is a concern that the output will decrease. Since the helide 15, especially the helium 13, is used for standard reproduction of f and hr, it will be a problem if the output decreases.

In addition, crosstalk is a problem for Henode 13 and He9do 15, which are close to each other, and for 2hr Hevdo 11.
The head L5 and 14 are for 12 and 6 hours. Therefore, it is necessary that these channels are not adjacent or that one of the channels is adjacent to the other.

The second person mode will be described in detail below.

(1) 2hr standard playback Use channels 24 and 25, channel 21. .

22 and 25 are illustrated. The output is + for 2hr playback.

It's so big that there's no problem at all.

(216hr standard playback 11
゜Use channel 7ne/l/21, 22, channel 24
゜25 is sheeted. At this time, Henod 15 sent a signal.

Reproducing and crosstalk with the adjacent head 15.

Since this becomes a problem, the channel 22 of the head 14 is inserted between the channel 23° of the head/I door 15 and the channel 21 of the bottom/groove 13 to prevent zero stroke.

(Sl 2hr, 6hr special playback channels 21, 22, 23 are used, channels 24, 25 are sea-). To adjoining throat 13.15
There is no problem with crosstalk because channels 21 and 23 are separated. Since the channel 24 is shifted, the efficiency of the channel 23 is reduced and the output of the feeder 15 is reduced, but since the feeder 15 is used exclusively for special playback (stay/failure low), this does not pose a practical problem.

Note that the same effect can be obtained even if the channel arrangement shown in FIG. 7 is symmetrically exchanged between the inner and outer channels. .

Figure 8 shows the 9-way switch circuit.
The outputs of the r head node 11, the rotary transformer channel 25, the f and hr head 13, and the rotary lead 1° lance channel 21 are switched by a changeover switch 26, and one is turned on and the other is shorted. Similarly, 9 do 12, low for 2hr.

Output of Talytrans channel 24, for 6hr.

The outputs of the transceiver channel 22 are switched by the switch notch 27, one being on and the other being in the off state. Also, transistor switch 2B
, 29 , 30 , 31 , 32.15 exist.

The operation of this transistor switch will be explained below.

(1) At the time of recording, Sui Sochi 63 was off, Pi 9 Te 28 and 29 were on.
,switch! +0, 31, and 52 may be either on or off. 2hr, /, hr switching is Sui Note 26,
I'll do it on the 27th. The output current of the recording amplifier 54 is as shown in FIG.
c5 In the example shown, Herad 13. I go to Suibuchi 28.

to GND, and Herad 14. Through switch 29.

flows to GND. At this time, a large amplitude is generated at the collector of the pie 9te 36, so the switch 33 is activated.

There are cases where it turns on. To prevent this, 1° transistors 35 and 56 are provided. α is & 9 o'clock High
k (same as power supply voltage) Signal 1 which is Low at PB, h is Eilh at PB, signal C is Low at Rtc.

Connect to power. In this case, tran when recording.

Both transistors 55 and 56 are turned off, and the base of the transistor switch 53 is kept in an open state, and there is no path for the base current to flow, so even if a large amplitude signal arrives, the base of the transistor switch 53 remains open.
3 does not turn on.

(2) During standard playback (play) First, transistors 35 and 36 are turned on, and switch 3
6 is also turned on. The switches 28 and 29 are turned off, the switch 31 is turned on, and the switch 32 is turned off.

The DC base current of the switch 31 flows to ground via the rotary transformer and the switch 33. switch 30
prevents crosstalk to channel 23 or channel 24 during 2hr playback.

In the t5hr playback, the switch 30 is turned off because the heater 4 connected to the adjacent channel is at a position of approximately 180 degrees with the heater 15 and crosstalk is not a problem. In the example shown in FIG. 8, the output of the helide 13 is applied to the preamplifier 37, and the output of the helide 14 is applied to the preamplifier 38. 2hr*6r regeneration switching is Sui Nochi 26, 27
Let's do it.

(3) During special playback When field stalling occurs for both 2hr playback and 6hr playback, the switch 31 is turned off, the switch 32 is turned on, and playback is performed at the same azimuth points 14 and 15. During a fine throw, in a transitional play state between one stall and the next stall, the switch 31 is turned on and the switch 32 is turned off.

, 11 With this K, noiseless field stay fine throw can be achieved for both 2hr and 6hr playback.

In addition, in the above embodiment, the field stay is performed at two O azimuths, but if the head 15 is installed near the head 14 in ζ 4 and the same azimuth as the head 16 is set.・If you are busy, you can also perform field stay with two ■ azimuth heads (Head / L driver 3°15).

It is. 11
) [Effects of the Invention] As described above, according to the present invention, a 2-hour mo.

- optimal recording and playback of mode, optimal recording and playback of 6-hour mode,
Feel of 2 hour mode and 6 hour mode.

Minimum 1- of Dostil Fine Slow regeneration.

It can be done by number of Nobe/Rido. Even when performing search playback in 2-hour mode or 6-hour mode (for example, forward/reverse 10x speed), the
By using a head with a travuk width wider than the tsuk pitch, reproduction with less noise band is possible than with K, and this is also very effective.

Note that the above-described 2-hour mode and 6-hour mode are added for convenience, and the present invention is similarly applicable to cases where there are two modes or three or more modes with different track positions.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the conventional example in the case of 6 helides, and Figure 2 is an explanatory diagram of the conventional example in the case of 6 helides.
FIG. 3 is an explanatory diagram showing an example of a track pattern for field still playback; FIG. 4 is an explanatory diagram showing an example of a forward arrangement according to an embodiment of the present invention;
Fig. 5 is an explanatory diagram of the track pattern for field stay playback in the 6-hour mode, Fig. 6 is an explanatory diagram of the track pattern for field stay playback in the 2-hour mode, and Fig. 7 is an illustration of the channels of the rotary transformer in the present invention. FIG. 8 is a plan view showing an example of the arrangement, and a circuit diagram showing an example of a circuit for realizing recording/reproduction switching, 2hr/6hr switching, and standard play/special play switching in the present invention. 1... Cylinder, 11, 12... 2 hour dedicated head, 13.14.
・・To 6 hours only -l, 15...For special playback・l
Do. Rod 1 Figure 2 Figure 3 Figure 465- Figure 4

Claims (1)

[Scope of claims] First
．． a second head; a first head; second head. The track width is narrower and they face each other at approximately 18o0. The third one with different azimuth angle. To the fourth throat. In a magnetic recording/reproducing device in which there is at least a fifth head located near the third head and having the same azimuth angle as the fourth head, the first head. The first track on the tape written by the second head, or the sixth. 1 with the 4th head
1. A magnetic storage reproducing apparatus characterized in that a fourth groove and a fifth groove are used when performing field-stay fine-throw reproduction of each track on a tape.