JPS5827486A - Video signal reproducer - Google Patents

Abstract

PURPOSE:To improve the quality of a reproduced picture, by decreasing a vertical oscillation at variable speed reproduction, through the forming of a spurious synchronizing signal which can almost represent the phase of a reproduced vertical locked signal in response to each variable speed reproduction mode and the insertion of the signal to a reproduction signal. CONSTITUTION:A pair of A and B heads, 2 and 3, with almost 180 deg.C interval with different azimuth angle are provided for a rotating drum and an auxiliary head 4 is provided in the vicinity the head 3. An output from heads 2-4 is fed to changeover switch circuits 7 and 8 via amplifiers 5, 6 and 11, where a head output during reproduction scanning is selected, and the selected reproduction signal is processed at a video processing circuit 14 to restore a luminance and a chroma signals. The output of the circuit 14 is applied to a horizontal phase correcting circuit 20 for the correction of discontinuity of the phase when the head output is switched. The output of the circuit 20 is applied to a VD insertion circuit 32 and a spurious vertical synchronizing signal formed at a spurious vertical synchrnozing signal generating circuit 40 is inserted to the output of the circuit 20 to reduce jitter to the vertical direction at variable speed reproduction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video signal reproducing apparatus such as a two-head helical scan WVTR having an auxiliary rotary head.

A rotating two-head VTR that records video signals by forming recording tracks at a predetermined angle with respect to the longitudinal direction of the magnetic chip.There is no guard band between each track to raise the chive record. Perform close recording in the state,
It is known that the azimuths of the two heads and the head B are made to be different from each other in order to minimize the amount of paste p-stoke from adjacent tracks during reproduction. V like this
When performing TR't' slow motion learning reproduction or still reproduction, the angle of the head scanning locus with respect to the recording track changes, and depending on the phase relationship between the track and the head, it may appear that the head has crossed tracks with different recording azimuths. (
For example, reproduction scanning is performed in a position II) across which the B track iA head crosses. ^ When crossing the Azomas track t-, the playback output drops significantly and band noise occurs on the playback screen.

For this reason, a method has been proposed in which the tape is stopped so that the tape is controlled so that the phase of the track and the head scanning locus match without crossing tracks with different azimuths when starting still playback. Furthermore, in this system, during slow playback, the above-described noiseless still and the tape's intermittent feed are combined to obtain a slow-moving image at an arbitrary speed without band noise.

In this case, the start of tape movement is synchronized with the rotation of the head, and during the period of head movement, approximate standard-speed playback is performed with the recording track and head scanning locus having the same inclination. This prevents band noise from appearing. The amount of tape movement may be 17 mm, and the time required for this movement, the period of Kamiyu Noiseless Stell (an integral multiple of the frame), and the time t is equivalent to the amount of tape movement (17 mm). 1/30 m) divided by t is the square ratio.

In such a VTR, the A head is located at substantially the same position as the B head.
A device with an azimuth 12) A' head having the same azimuth as the head has been proposed. In this case, in still playback, the tape stop position is controlled so that the human head scans the center of the All racks, and a so-called field still is performed in which the human head and the two heads alternately scan the racks. In streak playback, this field still and the approximate standard speed playback during intermittent movement of the tape as described above are performed alternately at an arbitrary time rate. In this standard speed playback,
The human head and the head may be used alternately, or the FiA head and the B head may be used alternately.

With a VTR having such an auxiliary head, it is possible to obtain a slow playback screen with no noise bands and a still ratio of extremely high image quality.

By the way, in a VTR equipped with an auxiliary head as described above, a pseudo A vertical synchronization signal is inserted into the playback signal. However, since the KFi tape speed during variable-speed playback changes with respect to the speed during recording, the relative speed between the head and tape changes, and the scanning period (1/60 m) allocated to each head changes. The number of reproduced horizontal synchronization signals varies from the normal 0 tree number (262.5 in the NT8C) within the same period. Therefore, the time length of the reproduced signal for one field expands and contracts according to the chil speed, and the reproduction phase changes due to the mechanical angle difference between the B head and the head.
It is difficult to use a pseudo synchronization signal formed at a fixed position in synchronization with the rotation of the head as a substitute for the reproduction horizontal synchronization signal. When using a fixed pseudo synchronization signal, playback 1iii
A so-called V jitter occurs in which the surface vibrates in the -1 direction for each field.

The present invention provides an image signal reproducing device that eliminates ζO flash.

The first WIJ is a schematic plan view of a positive rotation head dot O used in a VTR according to an embodiment of the present invention. A pair of magnetic heads +2)+31 (A head and B head) spaced apart by 0180° are attached to the rotating drum (1). These A head (2) and B head (3) have azimuthal angles f in opposite directions. Near the Maku B head (3) is an auxiliary head (4) that has the same azimuth as the human head (2).
) (head) is located. This A' head (4
) is a head that is used as a substitute for B head (3) during methyl or slow playback, and is 1.25
They are provided in a phase that advances in the drum rotation direction with an angular difference corresponding to H (H is one horizontal section).

11X2 diagram and tl! , Figure 3 shows the magnetic head (2) in Figure 1.
1(3+K). FIG. 2 is a track diagram showing a recording format according to 1(3+K).
IF) C) In the case of O water XfL between indirect
The phase difference between the recording traces of the synchronization signal O is 0.25H, and the track start end O arrangement difference is 0.75H. In addition, Fig. 3 shows the case where the tape speed is in the 6-hour recording mode (3 rin),
The phase difference between the recording traces of horizontal synchronization No. 4 between the 11th adjacent tracks is OH, and the arrangement difference at the track start ends is 0.5H.

FIG. 4 is a schematic diagram of the reproduced signal processing circuit of this gA embodiment ov'rit. [In Figure 4, the outputs of the head (2), B head (3), and head (4) are the amplifier (5) Qυ
Changeover switch circuit (7) (8) [9] via (6)
An appropriate head output during playback scanning is selected here. The selected reproduced signal is sent to the video processing circuit I, where FM demodulation of the brightness f signal and restoration of the frequency band of the chroma signal are performed. The reproduced signal SPB, which has been lengthened to the regular video signal II, is sent to the horizontal phase correction circuit ■, and correction (skinny correction) of the phase discontinuity of the long-lived horizontal synchronization signal at the point in time when the head output is switched is performed. be exposed. This correction has a 0.5H delay in the signal path! I (to) or 0.
This is done by inserting a 25H delay line (2).

The output ij of the horizontal phase correction sub-path (to) is sent to the monitor TV as a corrected video signal SvB via the VD (-1 synchronization signal) insertion circuit (to). In the VD insertion circuit c (2), the pseudo picture direct synchronization signal created by the pseudo direct synchronization signal generation circuit 1 is inserted in place of the unstable playback picture direct synchronization signal, and the playback screen QV jitter is generated due to the distortion. Prevented.

Next, regarding the operation of the block circuit in Fig. 4, Figs.
This will be explained with reference to FIG.

FIG. 5 shows the track B1 and the head scanning trajectory during still playback, and FIG. 6 shows the head switching signal H-8W and the playback signal 8PBffi during still playback. Further, FIG. 7 is a time chart of the reproduced signal. As shown in FIG. 5, during still playback, the tape stop position is controlled so that μ, A track 0 matches the track and the head scanning locus at approximately the center, and the A head (2) and head (4) Field still playback is performed by switching alternately. Since the human head and the A' head do not cross the B track of different azimuth, a reproduced signal 8PB as shown in FIG. 6B is obtained, and no noise band is generated on the reproduced screen. The output of the human head and the head is controlled by the selector switch (61st in power).
It is switched by the head switching signal H-8W of EA.

In the high level section H of the head switching signal, the selector switch (7
) is connected to HillK, and LI is connected in the low level section.
Connected to I. In addition, the grounding switch (IG) attached to the output of the head (4) is turned off (L@) by the control signal q1, which is at a low level during still playback, and the p, B head (3
) is attached to the output of the inverter α.
3, the control signal q1 is turned on (Hal
l).

7th mBC) The solid line is 1 obtained while the head is rotated by hand.
It is assumed that the field (262, 5H) indicates a reproduction value number of 0, and that the A' head is at the same position as the B head. During still playback of a Bll format tape, the tape is stopped, and the head scanning locus has an arrangement difference of 0.75 in the longitudinal direction of the tracks, as shown by the shaded area in Figure 5.
The length of the recording track becomes longer by the length of the H.
Therefore, a signal corresponding to an interval of 0.375 H is reproduced in excess during the head rotation period (1/60 kick) on both sides of the starting end and trailing end of one track. tataB! 17 oats)
C) On the tape, an extra signal is played back during the 0.25H interval.

In reality, as shown in No. 1Ii2 (A' head is 1.25 H ahead of B head in phase, A' head output during still playback of Bl mode tape is as shown in Figure 7 C).
As shown in Bit (M), the phase is mechanically advanced by 1.25 H. Therefore, when the head scanning section moves from 81 to 82 in Figure 7, the interval between the end of the reproduction signal O of the A head (262, 5H) and the beginning of the reproduction signal Q of the head is 0.5H. Even if the head is switched from the A head to the head, the interval of the horizontal synchronizing signal (recess H) is maintained at the 1H interval. However, when the next scan moves from 82 to 83, the interval between the end of the reproduction signal O of the head (262nd, 5H) and the start of the reproduction signal of the human head is 2. Because it is DH,
When switching from the A' head to the A head, the reproduction H interval changes (jumps) in pitch by 0.5H.

When this jump (H jump) occurs, the horizontal synchronization system of the monitor TV cannot follow it, and the lIigI! The horizontal phase of the image shifts, resulting in so-called skew. To prevent this, the scanning section S
At 6, as shown in BH (E) of the 7th diagram, the reproduced signal t-DA (D) is electrically carried by 0.5H to maintain continuity of horizontal synchronization.Furthermore, in the next scan Also in section 84, 0, due to the 0.5H delay in S3.
In order to eliminate the shunt f of 5H, a delay of 0.5H is similarly performed.

In the next scan S5, the head output is delayed in the previous field.
Since the signal DA'12) terminal end C262, 5H) and the start end of the output of the A head are 1.5H, continuity of reproduction H is maintained even without delay processing.

In order to perform upper layer delay control *J, a skew detection circuit is provided in FIG. 4 for detecting phase fluctuations of the reproduced horizontal synchronizing signal obtained from the video processing circuit α. This skew detection circuit has, for example, 2 fm (fm @
5pLLE path f
: It may be a circuit that locks with a reproduced horizontal synchronizing signal and obtains a jump detection signal by comparing the phase of the b-divided pulse (horizontal period) output from this PLL circuit and the reproduced horizontal synchronizing signal.

The output D)iiT (L level) of the gap λ-detection circuit 4 is the selector switch c! The delayed signal applied to the changeover switch (c) via the IJ and passed through the horizontal phase correction circuit 4, 5H delay line @ is selected at the L contact of the changeover switch (c). This delay! 81@ may be a glass delay line, so the output of the video processing circuit Q41 is 1. Distribution M change l
After the frequency is converted to about 10MHz band by l1l unit I2υ, there is a delay of 0.5H stc! 3. The amplifier (c) is selected by the selector switch (c) and returned to the original state by the AM restorer Ov.

When there is no skew detection signal DET (H level),
The output of the AM converter 3υ is applied to the AM transformer RWjC3υ from the H contact of the changeover switch (to) without passing through the delay M.

Note that 0, which is provided in parallel with the 0.5H delay line (c),
25 H delay line (foundation) is BII7 OIT's Cheeve [
Used for horizontal phase correction during still playback.

These delays Ii! @(2) is selected based on the chi f7 automatic detection signal Bi[ by the changeover switch @(2) on its input side and output side. This detection signal is generated by a detection circuit (not shown), and is at an H level when in the BL format, and becomes an L level when BI7 is in the correct state.

#I20 diagram is Bl four! A still from Totete, Suzono.
17 shows the playback signal 8PIO phase and skew detection signal DET in each variable speed playback of Ast and Reverse IIIP. During still playback, as shown in FIG. 7C, a playback signal shown at 2011C is obtained from the A head and the A' head. On the other hand, a skinny detection signal DBT as shown in Fig. 20 is obtained, and 0.
5H delay processing (ski gear correction) is performed. That is, as mentioned above, the delay in the 17-ray A section consisting of continuous human head reproduction and second head reproduction is performed every other frame, and a corrected ik image signal without 11' Young as shown in g7aIID is formed. be done.

Each leading portion of the corrected video signal (m direct synchronization signal position) shown in connection 7aD and the rising and falling points of the head switching signal H-8W
The phase relationship between the two is 0. ! 175H delay (A head playback), 0.
In the frame section where skinny correction is performed, there is a delay of 0.875H (head playback) and a lead of 0.575H (head playback). #lI similar ft synchronized with the rising 9 and falling p positions of the head switching signal as shown in FIG. 7G to such a corrected video signal.
If a synchronization signal VD (pseudo-v) is inserted and sent to the Tatami TV, jitter will occur for each field due to fluctuations in the reproduction phase.

Therefore, in the pseudo synchronization signal generation circuit shown in FIG.
Creating. The phase of the pseudo-V required for Bll format Cheves still playback is 2011C) The number in parentheses (H
unit), 0.375H (before), -0,875H
(after), 0.875 HC before), -〇, 575 H (he)
It is necessary to correct...

In the pseudo direct synchronization signal generation circuit shown in Figure 1184, the rising and falling parts of the head switching signal H-8W are processed by a differentiating circuit
Differentiate by 4υ to create the synchronized signal shown in Figure 7q, and give this to four delay circuits (4ω).These delay circuits may be monomulti circuits, each with a value of 0.57
5H, -0,875H,OH.

A delay pulse corresponding to a delay amount of 0.75H is generated. In addition, as the OH of the delay circuit -, the fixed delay time and 6.5 capacity are 0.375 + 3.5 and -0.875 + 3, respectively.
．． 5.0.75 +3.5.

The outputs of these OjI extension fields (6) to (c) are selected by changeover switches to decoys operated by control signals generated in accordance with the variable speed reproduction mode in the changeover control circuit. The output of the selector switch (48 is given to the 0, 5H delay circuit corresponding to the skinny correction described above), and the output of the oH extension circuit and its bypass signal are switched according to the skinny correction. The output of the changeover switch trowel is sent to the VD insertion circuit (2) as a 9H width phase-adjusted pseudo V (VD') through a monomulti 6υ and inserted into the video signal.

In the still playback of BI7 OIT CHEEB, the inverted signal H-8 of the head switching signal given from the switching control circuit is used.
WK, therefore, the changeover switch is not human lPW raw cJrX
Connected to the IIJ-CH contact, a 0.375H delay signal is selected. In the reproducing section of the head, the changeover switch - is connected to the L contact, and the delay signal of -0,875H is selected. The output of the changeover switch is applied to the monomulti 6υ from the H contact of the changeover switch group via the changeover switch connected to the Li2 point in the BI mode. In the next seven frames in which skew detection occurs, a pseudo V is created in which the changeover switch group satisfies the phase indicated by the number in parentheses in the L-20th diagram.

Next, there is a still playback button for the 8-inch 7-ohm
112 will be revealed. In this mode, a signal corresponding to an interval of 0.25H is extra reproduced on both sides of the beginning and end of one track, such as #'i 7th limit E.

Further, the reproduced signal of the head is obtained with a phase mechanically advanced by 1.25H. Therefore, the phase difference of the reproduction signal between the end of a track and the start of the next track is alternately 0.75H or 1.75H for each field. For this reason, the seventh
If 0.25 HO delay processing is performed in the playback section of the head as shown in Figure FC), the 0 phase difference will be alternately KO, 5H, 1 from the end of the track (262nd, 5th H) to the beginning of the next track.
, 5H, the horizontal phase is 111211IaaB, the horizontal phase is 111211IaaB, and the phase of the reproduction signal 8PIO and the delay control signal DD are shown in each variable speed reproduction such as still, slow 17ast, and alternate Δ-s. During still playback, the following playback signal (No. 21110) is obtained as explained in FIG. As a result, a corrected video signal having the phase shown in FIG. 7F is formed.

In FIG. 114, in order to perform the above-mentioned 00.25 HO delay, the switch of the horizontal phase correction (b) path gJ is connected to the switching signal B (L level in Bl mode). , the changeover switch @expanded skinny detection value is not operated, and the changeover switch 0IO is switched by external human input @mx by the delay control signal DD shown in the 11121 decoy, and this delay control signal 01 field is set! 0.25Hj in the 0 low level section (A' head playback section)!嬌m
eto output is selected.

Delayed video* (For the phase relationship between the vertical synchronization signal at the tip of No. 1 O track and the head switching signal,
As shown in Figure 7 PK, advance 0.75H alternately and 0.25H.
Since there will be a delay of H, see Figure 21 DIZ) i! in parentheses. Create K pseudo Vt at the positions indicated by letters (0, 25H and -0, 75H). Since the 41st pseudo synchronous signal generation circuit is not provided with a delay circuit corresponding to 0.25H and -0,75HK, 0.375H and -0,875
HC)jl delay circuit-(43 output is substituted. In this case, the error with respect to the required delay amount is ±0.125 H, and visually no vy footer occurs.

14 (i!i1), the output of the delay circuit m- is alternately selected for each field by the change-over switch, and is further passed through the L contact of the change-over switch, the H contact of the change-over switch, and the mono-multiple output as a pseudo V. Inserted into the video signal.

In the same manner as described above, it is possible to control the skew correction and the occurrence of pseudo (2) in each variable speed playback of 7 backward throw, reverse throw, double speed, and reverse (-1x speed). ! [Figures 8 to 10 show the playback pattern lII during forward slow playback, Figure 8 is a line diagram showing the track and head scanning locus, Figure 9 is a waveform diagram showing the playback signal, and Figure 10 is a diagram showing the track and head scanning locus.
The figure is a time chart showing reproduction phases. In this playback mode, the tape advances in steps at the pitch of every other track, still playback at the position where the tape is scanned (Muhead and Mu'head), and approximate standard playback (Muhead, Bhead) during step forwarding. , A head) are performed alternately. For example, in double-speed slow playback, the following lE
Reproduction is performed in a mode such as l.

Table 1 Playback track M1 → M1 → M1 → B1 → N → Enter → Tomo →
The hatched area in Figure 8 of B2 shows the scanning trajectory of the tape when it is moved step by step, and just like standard speed playback, playback is performed without crossing tracks of different azimuths, and the playback signal as shown in No. 98B is got rel. Since the playback track and the head scanning trajectory almost match, the phase of the playback signal is as shown in Figure 10 BK), and when the tape is moved, the OA head is switched to the B head, and the next OB Pi4 is switched to the A head. In this case, Hy young does not occur.

#g20Figure 1tiB I 7 Oh! The reproduction phase of the forward slew reproduction of Tutotegu is shown, and E and F are skew detection signals. If skew correction is performed in accordance with the skew detection signal in one frame section immediately before the tape step feed 5o, then! As shown in FIG. 20F, there is no need to perform skew correction in the reproduction section from A-+B to A during the next tape movement. In addition, if skew correction is not performed at the 1-frame interval immediately before starting f-f (D step forwarding), the head playback at the time tape movement starts as shown in #g20 q. If skew correction is required in the subsequent B head and A head playback and the first λ head playback of the next still playback, the skew correction with a delay of 0.5 H is continued to improve the pitch continuity of the playback H. is maintained.

Regarding the pseudo V to be inserted, as shown in Figure F in #I20 and GO brackets, it is the same as described above in the still playback section, and OH (when performing skinny correction) in the tape movement section.
or sail 5H (when performing ski gear correction) create a pseudo V at the O position. Therefore, the 411th pseudo V generation circuit (
In 4G, the output of the delay amount 0HC) is selected by the changeover switch Oη, and j! The output of the KeO changeover switch @7) is selected by the changeover switch connected to the HII point side by the /l pulse FR (B interval A section) for 17 frames during tape movement as shown in Figure #I20. be done. When performing 11K skinny correction, the output of this selector switch is delayed by the o and snag circuits, and
The delayed output passes through a monomulti 611t and is derived as a pseudo V.

B Seal 7 Oittegue's forward stealth attack -?
! In the group, H in the tape movement section as shown in Figure 10 BK.
/ Young does not occur. Therefore, as shown in Fig. 21, 0.25
A correction is made.

That is, the tape moving section C117 frame pulse (second
The changeover switch (to) of the fourth prisoner is controlled by the delay control signal DD shown in FIG. will be held.

As shown in FIG. 21F, the position where the pseudo V occurs is in the tape movement section (without OHC correction). Therefore, in the pseudo-V generation circuit shown in FIG. 4, the output of the delay circuit is selected in the 7-frame length FR section when the tape is moving, and this is output through the monomulti α7)\r! It is output as ii-like V.

Next, [11wJ-113 shows the playback pattern lI during reverse low playback, FIG. 11 is a diagram showing the track and head scanning locus, FIG.
FIG. 3 is a time chart showing the reproduction phase.

this? ! In the raw mode, the step feed of the tape of 2 track pitches is performed in the opposite direction to that during recording, as in the 7-word 1-streak playback, and the scanning locus is as shown by the hatching in FIG. In other words, Steg feed #1lIK is
A head (As) rack) → B head (B1) rack)
→ The reproduction O is switched as shown in FIG. 12B, and a reproduction signal 8Pm as shown in FIG. 12B is obtained.

The playback phase is as shown in 15 WABK, and in the vicinity of the switching points of A→B and B→M, the BI7 Omatsu point is 1 between the rear end of the 2-track O and the start of the next track O.
．． 5 HO extra playback section occurs, B rin four! 1. An OHO extra playback section occurs. Approximate standard speed playback is performed in the moving section of the tape, so skinny does not occur even if the phase difference between the end and start of each playback signal is an integral multiple of H, 1 * phase difference K O, 5 HO fraction If there is, skew will occur. Therefore, the Bll format chip is 0.5 at 9 when switching between A-+B and B-+A.
HO skinny occurs, but skinny does not occur with BI7 automatic tape.

Therefore, with reverse through playback of B Seal 7 Ohtiteg, #: tllE20 heart! Alternatively, the skew detection signal DIT shown in J is obtained, and the changeover switch (to) shown in FIG. 4 is controlled based on this to perform skinny correction. In addition, in 3-rin format tape 0 reverse sp-playback, ts2
As shown in Figure 1H, the skinny correction is not performed in the standard playback section when the tape is moved, and in the other still playback sections (0.25HO skinny correction is applied to the delay control signal DD in the A head playback section, as described above). It is done based on

Next, considering the generation of a pseudo V during reverse slow playback, it is first necessary to create a pseudo V at the 0.75 HO, l extension position in the BI7 automatic, as seen from FIG. 13B. Considering 0.5H skew correction, 120 figure IQ
As shown in parentheses, < 1.25 H (at the time of skew correction) or 0.75 H (at the time of no correction) is 9%, and even if the phase of skew correction is opposite to I as shown in Figure J of IK20, 1 A pseudo Vt is formed at a position of .25H or 0.75H.

Next, the number of pseudo V occurrences in Figure 4 W! In the case of Ushi, the output of the 0.75H delay circuit 4 is set to BI by the changeover switch t47).
-REV (8) -FRO section (Bl CHI f, selected at [Section) of reverse through temporary 0 frame pulse PR, and further 0.5H11g depending on the presence or absence of skinny correction
The circuit @O output is selected by the changeover switch.

B Rin Pho again! The pseudo VK level during playback is 0.5H0 as shown in Figure 13B.
If 1 is formed at the pole position, Vy footer will not occur.Skinny correction is not performed, so in #I4 diagram O**V generation circuit-, 0■Delay circuit (Incorporated) O output is set to changeover switch (
017 Reme ΔRus FRO when moving by Chive
BI-RIV(8)-FRO condition (BI7#-Y) (L level in the FR, f pulse section of V-verse 4-), the output of simplified 4 is switched with a delay of 0.5H. @Selected at OL contact.

Next K11114 to Figure 16 are playback conditions a during double speed playback.
1411a) Rack and head scanning trajectory 011
The 11% iss is the waveform diagram of the reproduction signal, and the 16th is the reproduction phase O time chart.

At double speed playback, as shown in $11411, A)? Scan 0+ alternately with the human head and the human head. The reproduced signal becomes as shown in FIG. 15BO, and no noise band appears on the reproduced screen. Due to faster tape speeds,
Since the length of the head scanning trajectory is reduced relative to the track length, the playback phase becomes as shown in B14SvAB, which is 0.3 before and after the section of 180'' rotation of the head.
A video signal for one field can be obtained by reproducing an extra 75H (Bl) or 0.25H (B). Also, the head reproduction signal is obtained with a mechanically advanced phase of 1.25H. It will be done.

The distance between the end of the human head reproduction signal and the beginning of the head reproduction signal im2.0H (Bl) or 1.75H (B
At ll), the interval between the end of the A' head reproduction signal and the human head reproduction signal O#+11 and O is Q, 5H (Bl) or 0.75.
Therefore, in the Bl format, an H jump of KO, 5H occurs when switching from A to BI7.
In automatic mode, when switching from A to λ and from to to AO, both are 0.
25HC) H jump occurs. In this next Bl,
100.5H skinny correction is performed every 17 frames with the skinny detection signal DET shown in 20vAL, and in 9B, 0.25HO skinny correction is performed every 1 field with the delay control signal DD shown in FIG. 20J. will be held. The horizontal phase correction circuit in Figure 4 for these skinny corrections (
7) The O operation is the same as in still playback described above.

The reproduced VO phase is the 161st ili before correction.
As you can see from B, it is 5, and Bl is 10, 375 H and -
It is 1,625H. As pseudo V in BIK, −
Modification of 0,575H and -1,625H K O,
The output of the delay amount lIJ of 375H and -0,875H is used. Since each correction error is +〇, 75H and uniform, there is no O■ register generation when switching from 1 person → A' and to → A. In the 7 frames with skinny correction, 0, due to the delay circuit - Add a delay of 5H to match the phase.

BIo reproduction vo position ma, -0,25H and -1,5H. When the skinny correction amount of 0.25 H is combined with the generation of pseudo V, -0 as shown by the number in parentheses in Figure 21 J.
, 25H (without skew correction) and -1, 25H (with skew correction). These delay amounts are equal to the 4th vAO pseudo-V generation time u (40 Teha, 0.
375H and U-0,875HoiMK circuit-UO ratio output is representative. The correction errors are 0.625 H and 0.375 H, respectively, which can also be expressed as 0.5 H±0.125 H. Therefore, field and OV jitter does not occur visually.

The following figures K117 to 19 are reverse playback (-1x speed) O
Figure 17 shows the track and head scanning locus and OiI diagram, Figure 18 shows the waveform diagram of the Fi reproduction signal,
Figure 19 is a time chart of the reproduction phase.

Reverse playback RIAV (N) is performed by running the tape in the opposite direction at the recording speed. The head scanning trajectory has approximately three lines as shown in Figure 17.
However, as shown in Fig. 18B, by driving the zero level portion of the reproduction signal into the Vf') nkinder interval, a reproduction surface without noise bands can be obtained. 1
As shown in FIG. 19, the phase difference of the reproduced signal for one field is 1.5H at B1.

1 in Bl. Since it is OH, A4B and B→A in Bl
0.5H of skinny tti is generated when switching between O and F.
Also, at 8-rin, X-chuji- does not occur.

Therefore, Bl tsuo! During reverse playback of a cut tape, the skinny detection value number shown in ``20@Nt0'' is displayed.
% skinny correction is performed. Nine B17 Omatsutote! In this case, the creep control signal DD of level ^ shown in Fig. 20 is generated, and no skinny correction is performed.

Reproducing V phase bride, as shown in FIG. 19B, when Bl is 0.
75H delay, 0.5H delay when Bl. Therefore, in Bl playback, the pseudo V occurrence time II in Figure 4 is 00.75
Select the H far extension circuit IaO output as the pseudo V. The next time the skinny correction is performed, an additional tc0.5HO spread circuit 4 is inserted. As a result, the pseudo TO insertion position is K O, 75H or 1.25 as shown in Figure 20 N or O.
This is the H delay position.

In addition, in the 3rd generation reproduction, the same < 0.75 H delay circuit (c) is used as a substitute for Oai force tO, iHml arcO. The correction error is ao, 25H (tightness), and no V jitter occurs.

The following table 2 summarizes the amount of retard arc necessary to generate a pseudo Vt that can represent the regenerated V at each speed regeneration mentioned above.

Table 2 (Unit: H) The following Table 3 summarizes the delay amount t indicating the pseudo vO generation position actually formed in the pseudo V generation circuit 0Q of FIG. #I4.

(The following margins are continued on the next page.) Table 3 (Unit: H) Note that the delay amount of the Bl format in Tables 2 and 6 does not include the 0-5HOxdF double correction, and the 0 error amount is 0. Includes 25H skinny correction. In addition, FWD(S)/FR indicates the FR pulse interval during forward slow playback (Chive's step movement 11 oi 7 frames (/'').

RIV(8)eFRij River x7ti-GDFRA
It shows the x interval. 9 RPV (N) indicates -1 times speed reproduction tube, and CB indicates high speed reproduction of K21 and Levy. In this cue review mode, correction for pseudo V is not performed.

As mentioned above, according to the delay correction amount in % Table 3 [pseudo V in Figure 4]
Each of the changeover switches and the iron of the generating circuit are controlled. Changeover switch 4 control signal μH-8W terote, A
Hella)'? ! Raw Q' K H side K ml R is done. The control signal of the changeover switch @η is Bll eREV (
S)-FR+REV(N), which is connected to the H contact when it is at H level. The changeover switch -0 control signal is PR+REV(N)+OR, and when this is at L level, it is connected to the KL contact. In addition, the control signal for the changeover switch is Bl-DET
+ Bll eREV (8) ・FR+ CR is connected to the L level and IL contact.

As described above, according to the present invention, the phase t- of the reproduced vertical synchronizing signal corresponds to each variable speed reproduction mode to form a pseudo-1 series synchronizing signal Yt that can represent impaction, and this is inserted into the reproduced signal. Vertical direction for each field of the playback plane in variable speed playback mode.

ram<vy footer), it is faster to obtain a high-quality playback image.

[Brief explanation of the drawing]

111a Embodiment of the present invention o A schematic plan view of the fighting drum O used in the V'l'R, Fig. 2 and #! The 6 causes are recorded by the 1110th rotating magnetic head, respectively. 10-1 diagram of the reproduced signal section m circuit, Figures #I5 to 711 show the playback state during still playback, and No. 511 shows the track and track. A diagram showing the head scanning locus, No. 6m is a reproduction signal 0* shape diagram,
FIG. 7 is a time chart showing the phase of the reproduced signal. 8th to 10th a! g is 7 owards p-reproduction, Figures 11-1311i1. Reverse four-playback, Figures 14 to 16 show 2x speed 77-stroke playback, Hi17 to 191Q enlarged reverse playback, respectively, -η, waveform diagrams, and time charts corresponding to Figures 5 to 711, respectively. It's my turn. Fig. 2011 is a time chart showing the playback phase and cue detection signal for each variable speed playback mode of the B17 automatic tape, and Fig. 21 is the playback phase and gap correction delay control signal in each variable speed playback mode of an 8-inch format tape. This is a time chart. Note that the symbols used in the drawings are (1) -----------synchronized drum (2)---------A head (3J...
・・・・・・・・・・・・B head (4)・・・・・・・・・
・・・－・Auxiliary head (ni head) 翰－・・・－・・・・・・
・・・Horizontal phase correction sub-route (to)－・・・・・・−・−・・・
・0.5Hji line extension (2)・・・・・・・・・・・・・・・・・・
・0.25H extended line (to) - VD insertion enclosure -111... Pseudo synchronous signal generation circuit sister (44 (c) -1...・−・・Delay circuit−beat−・
・・−１・・・・・・Choice switch ４・・・−・・・・・・
--- It is a changeover switch for the Henshima circuit m.

Claims (1)

[Claims] A pair of main rotary heads spaced approximately 180 degrees apart with different y-1 angles, and an auxiliary rotary head provided close to one of the main heads and having the same azimuth as the other main head. In a video signal reproducing device, the tape tube is stopped, high-speed forwarding is performed in steps, and a switch circuit for selecting a head output that does not cross tracks with different recording azimuths when performing variable speed playback different from the recording phase; A horizontal phase correction circuit that delays the output of the switch circuit so as to detect and correct discontinuity in the horizontal pHgJ signal when switching the output, and a regeneration-desired synchronization signal with respect to a reference signal indicating the head rotation phase. A pseudo-direct synchronization signal generation circuit generates multiple types of pseudo-picture direct synchronization values that reproduce position fluctuations for each variable-speed playback mode based on the reference signal; ) An insertion circuit which selects the corresponding PK and inserts it into the output of the horizontal phase correction circuit.