JPS58161481A - Video tape recorder - Google Patents

Abstract

PURPOSE:To obtain a reproduced picture with high quality, by providing a head device comprising two incorporated heads on a rotary drum and operating the two heads selectively at reproduction. CONSTITUTION:Two gaps g1, g2 are provided for a head A to form two heads a1, a2 substantially. In tracing a tape with the head A, the head a1 traces a track Ta1 and the head a2 traces a track Ta2. In recording, the tracing is done with the head a1 only and signals are recorded at each one filed. In reproduction, both heads a1, a2 are operated at all times. Then, the head a2 reproduces the track Ta2 at the same time when the head a1 reproduces the track Ta1. Then, the two tracks are reproduced at the same time simultaneously and two reproducing signals PB,D.PB having the time interval of one field are obtained at the same time. A Y signal separated from the signal PB is demodulated at a demodulation circuit 7 and a D.Y signal separated from the signal D.PB is demodulated at a demodulation circuit 8 and they are applied to an adder 9. When the correlation of field exists between the FM-Y signal and the FM-D.Y signal, the Y signal with reduced noise is obtained from the adder 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a helical scan fiVTR capable of obtaining high-quality images.

In order to obtain a high-quality playback image with a conventional VTi (for example, by using the playback video notes and the playback video signal that is delayed by 1 field in the field memory and reproduced by 7), it is necessary to obtain an apparently twice as much tii+myjo@. Completed.

A possible method for this information would be to double scan the 1m plane using j&-. However, this method uses a field memory and has the disadvantage that the circuit becomes complicated and the cost increases. High-quality playback with an i-rate circuit
The purpose of this invention is to provide a VTR capable of obtaining h-images. Hereinafter, the present invention will be described in detail in nine embodiments in which the present invention is applied to a well-known low-frequency curved helical scan VTR.

The original conventional example is to provide one head 8 on the rotating drum (2) around which the tape (1) is wound, as shown in Figure #11, and to attach two caps g1bg2 to this head as shown in Figure 2. This is the case when it is set. Therefore.

The head person consists essentially of two heads, a head a1 with a cap g, and a head a2 with a gap g2.

When tracing tape (1) with this head person.

As in the case of two stripes, the head a1 traces the track Tal, and the head part traces the track Ta2.

It is assumed that the caps g1, g2 have an azimuth angle of i-.

FIG. 6 shows the head operation during recording, so in this case, the operation of head a2 indicated by the dotted line is stopped, and the head J11 is
traces the tracks TJi1 to 'I'aa . . . and records signals one field at a time.

FIG. 4 shows head operation during reproduction, in which the inner side of the head 11b''2 is always operated.

Therefore, in the frame A of the same figure, head a1 is reproducing track +14, and at the same time head 12 is reproducing track 1+. Next, in Figure B, the head 11 reproduces the track Tax and at the same time the head town reproduces the track Tai. Therefore, during playback, two tracks are always played back at the same time, and two six-track signals PB, D, and FB are obtained at the same time with a time interval of one field. These playback g
It is possible to obtain p% 10,000 grade-gI by treating the grains according to the various methods described below in No. I.

In Figures 5 to 10! This is a second example.

Actual implementation? Two heads, B, are provided on the drum (2) at an interval of about 180°, and the broom 6 is shown in FIG.

Two gears with different azimuth angles
Two heads 11 having a, sg
b2 with two heads b1. It is composed of b2. In this case, the azimuth angles of the heads a1 and b2 are equal, and the azimuth angles of the heads a2 and b1 are equal. FIG. 7 shows the operation of each head during recording.

Head a2 and head b2 shown by dotted lines stop operating.

Only head 11 and head b1 are operated.

First, as shown in FIG. 7B, one field signal is recorded on the rack bird 1 by the head cap, and then one field signal is recorded on the track Tb1 by the head b1, as shown in FIG. 7B. By repeating this operation 9 times, the head 11 is recorded on the tape (1) as shown in FIG.
Tracks -1 to 'I'ms by head b1 and tracks Tbt to Tbi by head b1 are alternately formed at different azimuth angles. ``cl! The recording condition is exactly the same as the recorded tape vh6 819 Figure shows the operation of each head at this time (4h CI)
in.

☆Head cap h "2* blb b2 is all activated. First, as shown to the same person, p2 is applied to 11% of Hedom's town.
Book tracks Ta1h l1lb are played at the same time 1
Next, two tracks Tb are created according to b1%b of head B.
l*'I'at is played at the same time. In this case, 1
&Totsuku will be traced at the azimuth angle that matches the azimuth angle at the time of recording. By this head operation, it is possible to simultaneously obtain two reproduction signals having a field time interval at Rtn.

Figure 111110 shows an example of a head switching circuit that performs the above operation during playback.

The switch (a) (4) switches the contact point every 19% field based on the PG pulse obtained from the pulse generator provided in the drum (1). and amplifier (5)
) You can get the playback signal PB from the head cap & b2.

The above signal PB from amplifier (6) and p head "2sb1"
A reproduced signal D@PB that is delayed by one field is obtained.
Next, an example of the method No. 100 for tin-salting the signals PH and D@PB obtained in the embodiments 1111 and Ji2 to obtain a high-quality image will be explained.

Figure 11 shows the case where the Y@ signal is separated from the signal PB and subjected to 9 FM. Add the FM 90 Y signal and the signal decoded by the decoder circuit (8) to the addition signal aQ. ◎FM-Y signal and FM-D
, Y signal and field phase tg, add II# unit (
9) You can obtain a Y signal with more reduced noise by adding 0! Instead of (9), a processing circuit using the field phase of the % bridge can be considered, but as shown in Figure 1, in the case of Kakujunwa, 087N can be modified by 3 dBQ degree.

Figure 8112 shows the case where it is applied to a YC minute-comb filter.

In the figure, a chroma signal C is obtained by delaying the signal PB by one field and adding the next signal, the above signal, and PB to an flt calculator αυ.

Further, by adding the ratio signal delayed by 21 fields and the signal PB to the zero calculator α4, the Y signal is obtained.

According to this method, (I No. C
The 8/N of 8/N is changed and the delay of one color is reduced. Figure 13 shows a case in which this is applied to an aperture correction circuit.

In the figure, the Y signal and the signal separated from the signal FB,
It is separated from PB and calculated (transferred) with Y signal (13
In addition, this summed output is added to the subtractor α by adding the signal passed through the -pass filter and the signal passed through the one-field delay path (c), so that the aperture is corrected by j%. It becomes difficult to obtain the Y' flaw signal.

Aperture correction using conventional 2-in phase @ On the μi1+ surface, the edges of 2:iF in and 9 are obtained, but according to the method shown in Fig. 13, it is possible to correct the aperture of 1 line at the edges 9, 1kn, and -1. becomes.

all 4~16Et-1 5th (D implementation 1'1e7Jc
ts This example uses a 2 gear head dom, B! Arrange as shown in Figure I5, but 4! r gap - 1k jiaffi
and gi) Each set of 1 hgbffi is arranged so as to trace the same track as shown in FIG.
The azimuth angles of heads a1 and b2 are equal, and the azimuth angles of heads 12 and bl are equal. t
Heads A and B [known dynaelectric traces are formed during playback.

Figure 1s15 shows the operation of each head during recording, so first stop head a2 as shown in the figure.

A signal of 1 field degree is recorded on tracks Ill, , by head a1. Next, as shown in the figure, the spatula I'bt is stopped and a signal of 1 field degree is recorded on the track 1t1 using the head b1. By repeating this operation.

Similarly to Fig. 8, track T11%%1h TiI4 m
T-... are recorded alternately at different azimuth angles.

FIG. 16 shows the head operation during reproduction. During this reproduction, the drum (17) is rotated at twice the speed during recording.

First, as shown in Figure 16, head a2 is stopped and track l1la is reproduced by head a1. This and'#
The idea is that the i-rotation continuation is doubled, and until this t, the head a1
As shown by the dotted line, the ◆L trace is less sloped than the track Tat, and it does not match this track T11.
In the example, the head person and the B person are known as evening.

Perform power tracing. The dynaelectric trace is a method in which the head unit B is attached to a bimorph or the like, and a control voltage is applied to the bimorph so that the locus of the gap between the head unit and B always coincides with the track. By this method, it is possible to make the @ trace of the head town in the 111116 figure m -m to the track 'I'at, and reproduce the signal. - The reproduction of the track Ta1 by this head a1 is performed with the Fm transition straight. Since it is doubled, it will be held at the time of the upper field.

During this time, the signal for one field is reproduced.

Next, as shown in FIG. 16"B, head b2 reproduces the same track Tut. At this time, the operation of own head b1 is stopped. Also in this case, at this tt, head b1
Since the locus does not match the track 'I'at as shown by the dotted line, it is made to work using the dynamo construction trace. Therefore, track 'l-1 is.

Head 511 h bR with the same azimuth angle as during recording
According to
Next, as shown in FIG. 16C, the head 11 is stopped and the track 1) is reproduced using the head a2 in the same manner as described above. Next, as shown in FIG. 0, the head b2 is stopped and the same track Tb1 is reproduced by the head b1. That is, this track Tbt is reproduced twice by the head "2*bj" having the same azimuth angle as during recording.

The reproduced signals obtained twice from the same field as described above are applied to a double-scanning receiver.

Scanned at twice the horizontal and vertical scanning frequency. As a result, it is possible to obtain a high-brightness screen with a larger number of scanning lines than in the past and with reduced surface flicker in the case of the CCIB method, and to obtain a high-density j[, high-quality image.

As mentioned above, the 1811 of this invention has two heads (alb
A head device (A and/or B) in which a2 and/or it blb bz) are integrated is installed on a rotating drum so that the 211 m head can be selectively operated during the 8th grade.

Therefore, according to the present invention, it is possible to simultaneously obtain two reproduction signals having a time interval F4 of % 1 field, or to obtain reproduction signals twice from the same track. By layering these Nyu signals, it is possible to obtain high-quality reconstructed images.

[Brief explanation of drawings]

Figures #11 to 4 show all disaster examples of the present invention.
Figure IIi is a flat Im diagram of the vicinity of the rotating drum, Ki-2en is a diagram showing the relationship between the head and track, Figure 113 is a diagram showing head operation during recording, Figure 114 is a diagram showing head operation during playback, iK5~ 10E shows the second embodiment of the present invention, so Fig. 5 is a plan view of the vicinity of the rotating drum, Fig. 6 is a diagram showing the relationship between the head and the track, and 7wA shows the head operation during recording. #A, Figure 8 shows the recording shape m of the tape, Figure 9 shows the head operation during playback, al11-131
jA is a circuit block diagram showing the path of the Niu Ehibori (9), and Figures 14 to 16 show examples of the contribution of the present invention to 1 [6].
Figure 14 is a diagram showing the relationship between the head and snoring rack, connection 151
1! Gl is a diagram showing the head operation during recording, and FIG. 1116 is a diagram showing the head operation during reproduction. In addition, the symbols used in the drawings are (2)...
・・・・・・・・・・・・ Rotating drums A, B
・・・・・・・・・・・・ Head "1m" 2* b
lb b2... to "))". Agent ±J! l# l Toshiki Sugiura I Figure 12 Figure 13

Claims (1)

[Claims] A VT device characterized in that a head device in which a head 24a is integrated is provided on a rotating drum, and the head 211 is selectively operated during reproduction.