JPH04101585A - Recorder - Google Patents

Abstract

PURPOSE:To permit dubbing while preventing picture deterioration and maintaining the continuity of PI processing or PS processing by supplying a low-band converted chroma signal, a switching pulse and a luminance signal and controlling the rotational phase of a drum based on the switching pulse and a synchronizing signal during dubbing. CONSTITUTION:During dubbing, a regenerated RF signal SRF is supplied to a T/C separation circuit 5, and a luminance signal Y0 is separated from a chroma signal C0. The chroma signal passes through an ACC circuit 6 and then is supplied through a path 27 to a recorder 35. The luminance signal Y0 is subjected to various signal processing in a luminance signal regenerative circuit 25 and then supplied through a terminal 31 to the recorder 35. Thus, the picture deterioration is prevented. Furthermore, based on a switching pulse SWP and a vertical synchronizing signal supplied by a reproducing device 1, the rotational phase and the rotational speed of the reproducing device 1 and the recorder 35 are controlled, and thus the continuity of the PI processing and PS processing can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording device, and particularly to a recording device suitable for dubbing.

[Summary of the invention]

This invention provides a chroma signal extracted from a reproduced video signal, subjected to phase shift processing of a carrier signal, and subjected to low frequency conversion, and a switching pulse representing the rotational phase of a drum in a recording device. and the luminance signal extracted from the reproduced video signal is supplied, and during dubbing to record the chroma signal and the luminance signal, based on the switching pulse and the synchronization signal separated from the luminance signal,
By controlling the rotational phase of the drum, deterioration in image quality can be prevented and dubbing can be performed without maintaining the continuity of PI processing or PS processing.

[Conventional technology]

Conventional dubbing has mainly used composite signals.

[Problem to be solved by the invention]

- When dubbing is performed while fishing on a boat, deterioration in image quality is unavoidable. Particularly, when dubbing is performed using a composite signal, signal processing errors occurring in various circuits provided for chroma signal processing are added up by dubbing, which causes image quality deterioration.

For example, the frequency of the chroma signal that has been low-frequency converted is
In frequency conversion that converts to subcarrier frequency by C, A
The response error that occurs in the PC circuit cannot be absorbed within the vertical blanking period described above, and as a result, the response error described above becomes a chroma signal HUE fluctuation that occurs at the top of the monitor screen. There is a problem.

Further, in order to cancel crosstalk between tracks, the chroma signal is subjected to PI processing and passed through a comb filter, but a single line comb filter has the problem of vertical color shift.

Since the characteristics of the bandpass filter placed next to the frequency conversion circuit are narrow bands, the chroma signal band is reduced and the phase characteristics deteriorate, resulting in color blurring and color unevenness. There is a problem with this.

Further, there is a problem in that color level changes, color blurring, etc. occur due to differences in characteristics of burst de-emphasis circuits, de-emphasis circuits, burst emphasis circuits, emphasis circuits, etc. in the recording/reproducing system.

By the way, there is also a method of dubbing using the so-called S terminal, which supplies the video signal in a Y/C separated state.
There is a problem in that the above-mentioned problems cannot be solved except that the signal processing error in the non-correlation part due to Y/C separation on the recording apparatus side can be improved.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a recording apparatus that can prevent image quality deterioration and perform dubbing while maintaining the continuity of PI processing and PS processing.

[Means for Solving the Problems] A recording device according to the present invention records a chroma signal extracted from a reproduced video signal, subjected to phase shift processing of a carrier signal, and subjected to low frequency conversion, and a drum signal. A switching pulse representing the rotational phase of the video signal and a luminance signal extracted from the reproduced video signal are supplied, and during dubbing, a chroma signal and a luminance signal are recorded, based on the switching pulse and a synchronization signal separated from the luminance signal. , the rotational phase of the drum is controlled.

[Effect]

The recording device according to the present invention includes a chroma signal extracted from a reproduced video signal, subjected to phase shift processing of a carrier signal and subjected to low frequency conversion, and a switching pulse representing the rotational phase of the drum. , since the luminance signal extracted from the played video signal is supplied,
You can dub while preventing image quality deterioration.

Also, when dubbing a video signal, based on the switching pulse and the synchronization signal separated from the brightness signal,
Since the rotational phases of the drums of both the reproducing device and the recording device are controlled, it is possible to maintain the continuity of the PI processing and the PS processing, and normal color recording and playback can be realized.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. In this embodiment, an 8-inch video tape recorder is used as an example. A description of this embodiment will be given in the following order.

(1) About framing (2) About the reproduction system (3) About the recording system (4) Circuit operation of the reproduction system and recording system in dubbing mode (1) About framing For the sake of simplicity, a description will be given of matching the rotational phases of the drums of both the reproducing device 1 and the recording device 35, that is, framing.

8. Since the VTR format uses PI processing, problems may occur during dubbing unless framing is done. That is, (743KHz±500K
Hz), when dubbing a chroma signal that has been low-frequency converted to a low frequency (Hz), the chroma signal reproduced by the reproduction device 1 is not subjected to any signal processing that would affect the image quality, and the recording device 3
5 side, the chroma signal may be canceled unless framing is done by matching the channel of the magnetic heald 2 on the recycle bag fl side with the channel of the magnetic helad 57 of the recording device 35. .

A case where the framing is correct will be explained with reference to FIG. 6.

Based on the switching pulse 5IAp shown in FIG. 5B and the horizontal synchronization signal HSY, a chroma signal inversion command 5WOT is formed as shown in FIGS. 5F and 6C. This chroma signal inversion command needle OT operates during the period when the switching pulse SWP is at a low level, that is,
If there are two channels, A and B, the high level and low level are repeatedly inverted for each IH while the A channel magnetic head is tracing the magnetic tape.

As shown in FIGS. 6A and 6B, for example, if there are two channels of AlB and the A channel shown in FIG. As shown in FIGS. A and B, the inverted chroma signals CAI to CA5 are supplied to the A channel where the inverted chroma signals are to be recorded, and
Chroma signals CBI to CBS that have not been inverted to the B channel where the chroma signals that have not been inverted are to be recorded.
is supplied.

As a result, the phases of the A channel chroma signals CAI, CA3, and CA5 are inverted in response to the IH period in which the chroma signal inversion command 5WOT shown in FIG. 6C is at a high level, and the phase of the A channel signal is The result will be as shown in Diagram 6. In this case, the crosstalk component is also inverted in the same way as the chroma signal component, and is recorded with the phase indicated by the broken line.

During normal reproduction, the comb filter 13 delays the signals CAI to CA5 and the crosstalk components shown in Figure 6 and the signals CAI to CA5 by IH, and the signals CAL to CA4 and the crosstalk components shown in Figure 6. are formed, and the signal CA 1-CA shown in the sixth diagram
5 and signals CAI to CA4 shown in FIG. 6E are added, the crosstalk component is canceled and only the chroma signal component is doubled as shown in FIG. 6F. will be played.

Next, a case in which no framing is performed will be described with reference to FIG. 7.

If the A channel shown in FIG. 7A is an inverted processing field, and if framing is done, the inverted chroma signal should be recorded in A, as shown in FIGS. 7A and B. Chroma signals CBI-CBS that have not been inverted are supplied to the channels, and chroma signals CAI-CA5 that have been inverted are supplied to the B channel where the chroma signals that have not been inverted are to be recorded.

As a result, the phases of the A channel chroma signals CB2 and C84 are inverted in response to the IH period in which the chroma signal inversion command 5WOT shown in FIG. 7C is at a high level.
The phase of the A channel signal is as shown in Figure 7. In this case, the crosstalk component is also inverted in the same way as the chroma signal component, and is recorded with the phase indicated by the broken line.

During normal reproduction, the comb filter 13 delays the signals CBI to CB5 and crosstalk components shown in Figure 7, and the signals CBI to CB5 shown in Figure 7 with an IH delay. Components are formed, and the signals CBI to CB shown in the seventh figure are formed.
Since S and the signals CB1 to CB4 shown in FIG. 7 are added, the chroma signal component is canceled and the crosstalk component is strengthened. For this reason, during normal playback, there is a risk that colors may disappear due to invert processing.

Therefore, in order to solve this problem, the switching pulse S
Since the channel during the period when WP is "L", that is, the A channel, and the channel where the inversion occurs between the high and low levels of the chroma signal inversion command or OT, that is, the A channel, are synchronized, dubbing is not possible. In mode, in addition to the luminance signal Y1 and chroma signal CO for dubbing, a switching pulse of 5 tep is supplied from the playback device 1 side to the recording bag [35 side.On the recording device f35 side, a vertical By using the synchronization signal VSY as a reference and matching the polarities of the switching pulse SWP and the vertical synchronization signal VSY, the playback device 1 and the recording device 3
The rotational phases of both drums, that is, the PG phase, can be matched, and a chroma signal with an inverted phase is supplied to the channel on the inversion processing field side.

This makes it possible to take correct framing, and to correctly select a channel in which the chroma signal is reversed.

(2) Reproduction system FIG. 1 shows a block diagram of a reproduction apparatus 1 according to the present invention.

In the configuration shown in FIG. 1, the RF signal SRF reproduced from the magnetic tape 3 by the magnetic head 2 is supplied to the Y/C separation circuit 5 via the amplifier 4.

Further, a rotation detection signal PG from a detection circuit 22 for detecting the rotation of a drum (not shown) is supplied to a flip-flop 23, which outputs a switching pulse SWP. This switching pulse SWP
is supplied to the device 35 side constituted by the terminal 24.

Incidentally, as the above-mentioned detection circuit 22, for example, a monomulti is used.

The Y/C separation circuit 5 separates the reproduced RF signal SRF into a luminance signal YO and a chroma signal CO which has been low frequency converted to, for example, 743 KHz. This chroma signal CO is supplied to the ACC circuit 6, while the luminance signal yo is supplied to the luminance signal reproducing circuit 25.

In the luminance signal reproducing circuit 25, the luminance signal yo is subjected to processing such as dropout compensation, limiter, FM demodulation, de-emphasis, noise suppression, etc., and is made into a luminance signal Y1.
This luminance signal Y1 is supplied to the terminal 28a of the switch circuit 28.

The switch circuit 28 is supplied from a terminal 29, and its connection state is controlled by a control signal generated in response to dubbing mode or normal playback mode. For example, in the dubbing mode, the switch circuit 28 connects the terminals 28a, 28
c is connected, the luminance signal Y1 is taken out from the terminal 31 without being mixed with the chroma signal CI, and is sent to the recording device 3.
5 side. Also, in the normal playback mode, since the terminals 28a and 28b of the switch circuit 28 are connected,
The luminance signal Y1 is supplied to an adder circuit 30.

In the ACC circuit 6, the level of the chroma signal CO is controlled to a predetermined amplitude level, and the chroma signal CO is supplied to the delay circuit 21 and the burst de-emphasis circuit 8.

The delay circuit 21 is for time adjustment of signal processing, and the chroma signal CO delayed for a predetermined time by the delay circuit 21 is taken out from the terminal 26 via the amplifier 7 and sent to the recording device 35 side. Supplied. A path 27 from the above-mentioned ACC circuit 6 to the terminal 26 via the delay circuit 21 and the amplifier 7 is the chroma signal CO which has been reproduced and low frequency converted.
is provided for directly supplying the data from the playback device 1 to the recording device 35 during dubbing mode.

In the burst de-emphasis circuit 8, the chroma signal CO
is attenuated. In other words, since the chroma signal CO is emphasized at a predetermined level, for example (+6 dB), during recording, the chroma signal CO is emphasized at a predetermined level (+6 dB) corresponding to the amount of emphasis during playback.
-6dB), and is attenuated back to the specified level. fI
The attenuated chroma signal CO is supplied to the frequency conversion circuit 9.

In the frequency conversion circuit 9, the above-mentioned low frequency converted chroma signal CO is supplied from the frequency conversion circuit 19 via the carrier invert circuit 10, and the frequency is (4.32MH).
z) with the signal 5T19 to form an output signal, which is passed through the bandpass filter 1.
1.

The band pass filter 11 converts the output signal from the frequency conversion circuit 9 into frequencies around (3,58 MHz), that is, (3,58 MHz±500 KHz).
A chroma signal C1 in the range of is extracted, and this chroma signal C1 is supplied to the de-emphasis circuit 12.

In the de-emphasis circuit 12, de-emphasis is applied to the sideband wave according to the level of the chroma signal C1, and the sideband wave is attenuated to a predetermined level. This chroma signal C1 is supplied to a comb filter 13.

In the comb filter 13, the pre-IH chroma signal CI and the current H chroma signal C1 are combined, so that
Crosstalk components from adjacent tracks are removed to obtain the chroma signal C1 component.

The chroma signal C1 from which crosstalk has been removed is supplied to the adder circuit 30, and the burst signal of the chroma signal C1 is sent to the APC detection circuit 15 and the ACC detection circuit 16.
supplied to

In the APC detection circuit 15, the frequency (3, 5
8MHz) and (8MHz) supplied from the reference signal generation circuit 17.
A phase comparison is made with a reference signal 5T17 (3.58 MHz), and the phase error ERI is supplied to ■C018 as a control voltage.

In VC018, the oscillation frequency of the signal is changed based on the above-mentioned phase error ERI. This signal is supplied to the frequency conversion circuit 19.

In the frequency conversion circuit 19, the reference signal 5T17 (3.58 MHz) supplied from the reference signal generation circuit 17 and
Multiplication with the signal supplied from C018 is performed, and (4,
A signal 5T19 having a frequency of 32 MHz) is formed, and this signal 5T19 is supplied to the carrier invert circuit 10.

The carrier invert circuit 10 performs the following processing.

For crosstalk removal, the video signal is, for example, P
It is recorded using the I (Phase Invert) method.

Therefore, in the carrier invert circuit 10, for example, if the magnetic head has two channels, control is performed to invert the phase of the chroma signal reproduced in one channel for each IH. Therefore, the phase of signal 5T19 corresponding to the chroma signal reproduced in one channel is
Control is performed to invert each time.

Since the signal 5T19 is supplied to the frequency conversion circuit 9, the phase of the chroma signal component and crosstalk component of the output signal from the frequency conversion circuit 9 is inverted every IH. As a result, the phases of the crosstalk components in all H are made to be in phase. Further, since the signal 5T19 whose frequency is (4°32 MHz) is formed by phase comparison between the reference signal 5T17 supplied from the reference signal generation circuit 17 and the burst signal of the chroma signal C1, the chroma signal C.I.
is a signal whose phase is locked to the reference signal 5T17, and the continuity of the chroma signal is maintained.

The above-mentioned ACC detection circuit 16 detects the envelope level of the chroma signal C1, and based on this envelope level, supplies a gain control signal to the ACC circuit 6, and detects the envelope level of the chroma signal C1.
Performs gain control of the C circuit 6.

In the above-mentioned adding circuit 30, as mentioned above, in the normal reproduction mode, the luminance signal Y1 is added to the chroma signal C1 to form a composite signal Scow, and this composite signal 5coIl is taken out from the terminal 14.

(3) Recording System FIG. 2 shows a block diagram of a recording apparatus 35 according to the present invention.

In the configuration shown in FIG. 2, in the dubbing mode, the dubbing chroma signal CO, which has been low frequency converted to 743 KHz, is supplied from the playback device 1 side to the terminal 37a of the switch circuit 37 via the terminal 62, and , a luminance signal Yl for dubbing is supplied from the recycled bag fl side to the terminal 51b of the switch circuit 51 via the terminal 36, and a switching pulse S is supplied via the terminal 64 to the D flip-flop 60.
supplied to

On the other hand, in the normal recording mode, a composite signal Scow supplied from the outside is supplied to the Y/C separation circuit 50 via the terminal 63.

The Y/C separation circuit 50 separates the chroma signal C1 and the luminance signal Y.
1 is separated, the chroma signal C1 is supplied to the ACC circuit 38, and the luminance signal Yl is supplied to the terminal 51a of the switch circuit 51.
supplied to

The switch circuit 51 is connected to a terminal 5 from a controller (not shown).
The connection state is controlled by a control signal supplied through terminals 51b and 5. In the dubbing mode, terminals 51b and 5
1c is connected, and terminal 51 is connected in normal recording mode.
a and 51c are connected.

In the ACC circuit 38, the level of the chroma signal CI supplied from the Y/C separation circuit 50 is controlled to a predetermined amplitude level, and the emphasis circuit 39 and the detection circuit 4
0.

In the emphasis circuit 39, emphasis is applied to the sideband wave according to the level of the chroma signal C1, and the sideband wave is emphasized to a predetermined level, and then supplied to the burst emphasis circuit 41.

The burst emphasis circuit 41 emphasizes the chroma signal C1. That is, the chroma signal C1 is emphasized to a predetermined level, for example (+6 dB).

The emphasized chroma signal C1 is sent to the frequency conversion circuit 4.
2.

In the frequency conversion circuit 42, a carrier invert circuit 52
A signal 5 with a frequency of (4.32 MHz) supplied from
T44 is multiplied by the chroma signal C1 having a frequency of (3.58 MHz) supplied from the burst emphasis circuit 41 to form an output signal having a frequency of 743 KHz, which is supplied to the terminal 37b of the switch circuit 37. Ru.

In the detection circuit 40, a phase comparison is made between the above-mentioned chroma signal C1 and a (3.58 MHz) signal 5T43 supplied from the crystal oscillation circuit 43, a phase error ER2 is formed, and the signal is supplied to the crystal oscillation circuit 43. Ru.

The crystal oscillation circuit 43 changes the oscillation frequency of the signal based on the above-mentioned phase error ER2.

This signal 5T43 is fed back to the detection circuit 40 as described above, and is also supplied to the frequency conversion circuit 44. This signal 5T43 is locked to the burst signal of the chroma signal.

The luminance signal Y1 that has passed through the switch circuit 51 is supplied to a synchronization signal separation circuit 46 and a luminance signal recording circuit 45.

In the luminance signal recording circuit 45, processing such as clamping, pre-emphasis, white clipping, dark clipping, and FM modulation is performed on the luminance signal Y1. Luminance signal Y1
is supplied to the adder circuit 54.

The synchronization signal separation circuit 46 separates the horizontal synchronization signal H5Y and the vertical synchronization signal VSY from the luminance signal Y1.

The horizontal synchronization signal HSY is supplied to the AFC detection circuit 47,
The vertical synchronizing signal SY is supplied to the D flip-flop 60.

The AFC detection circuit 47, VC04B, and frequency dividing circuit 49 constitute an AFC loop.

The AFC detection circuit 47 compares the above-mentioned horizontal synchronizing signal H5Y with the signal of the horizontal scanning frequency fH supplied from the VC04B via the frequency dividing circuit 49, and supplies a voltage output proportional to the frequency error to the VC048. Ru.

In VC048, the oscillation frequency of signal 5T4B is controlled by a voltage output proportional to the frequency error described above. The frequency of signal 574B is (47,25f H=743 K
Hz), and this signal 5T48 is sent to the frequency divider circuit 49.
and is supplied to the frequency conversion circuit 44. This signal 574
8 is AFC-locked to the luminance signal Yl.

In the frequency dividing circuit 49, the frequency of the above-mentioned signal 5T4B is divided by a predetermined frequency division ratio to generate a horizontal scanning frequency f.
A signal approximately equal to H is formed, and this signal is returned to the AFC detection circuit 47 and subjected to the aforementioned processing.

The frequency conversion circuit 44 is locked to the burst signal supplied from the crystal oscillation circuit 43 (3.58
AFC is locked to the signal 5T43 (MHz) and the luminance signal Y1 supplied from VC04B (47.25f).
A signal 5T44 with a frequency of (4.32 MHz) is formed by multiplication with a signal 5T4B of H=743 KHz>.

This signal 5T44 is supplied to the carrier invert circuit 52.

Similar to the carrier invert circuit 10 in the reproduction device 1, the carrier invert circuit 52 performs control to invert the phase of the chroma signal reproduced in one channel for each IH when the magnetic head has two channels, for example. will be held. Therefore, control is performed to invert the phase of the signal 5T44 corresponding to the chroma signal reproduced in one channel for each IH. This reference signal 5T44 is supplied to the frequency conversion circuit 42, and the above-described processing is performed.

In the switch circuit 37, the connection state is controlled based on a control signal supplied via a terminal 59 from a controller (not shown). That is, in the dubbing mode, the terminals 37a and 37C of the switch circuit 37 are connected, and the playback device 1
The chroma signal CO from the side is supplied to a bandpass filter 53. In the dubbing mode, similarly, the terminals 51b and 51c of the switch circuit 51 are connected, and the playback device 1
Luminance signal Y supplied from the side and passed through the luminance signal recording circuit 45
1 is supplied to the adder circuit 54. Further, in the normal recording mode, the terminals 37b and 37c of the switch circuit 37 are connected, and the chroma signal C1 from the frequency conversion circuit 42 is supplied to the bandpass filter 53. Similarly, in the normal recording mode, the switch circuit 51 terminals 51a, 51c
is connected, and the switch circuit 5 is connected from the Y/C separation circuit 50.
1. The luminance signal Y1 that has passed through the luminance signal recording circuit 45 is supplied to the adding circuit 54.

The bandpass filter 53 uses 743 of the chroma signals CO or C1 supplied via the switch circuit 37.
Frequencies in the vicinity of KHz, i.e. (743
The chroma signal that has been low-frequency converted to (KHz±500 KHz) and subjected to AFCO7 is extracted and supplied to the adder circuit 54.

In the adder circuit 54, the FM-modulated luminance signal Yl and one of the above-mentioned chroma signals CO or C1 are added to form an RF signal SRF for recording.

This RF signal SRP is recorded on a magnetic tape 58 by a magnetic head 57 via an amplifier 56.

Further, the vertical synchronizing signal vsy separated from the synchronizing signal separation circuit 15 described above and the switching pulse S-P supplied from the reproducing device 1 via the terminal 64 are supplied to the D flip-flop 60.

The output of the D flip-flop 60 is supplied to the servo circuit 65 as a control signal.

The servo circuit 65 controls the rotational phase and rotational speed of the drum, the feeding speed of the magnetic tape 58, etc. based on the above-mentioned control signals.

(4) Circuit operation of the reproduction device 1 and recording device 35 in dubbing mode Next, the circuit operation in the dubbing mode performed by the recycling bag W1 and the recording device f35 will be explained.

In the dubbing mode, as shown in FIG. 3, the reproducing bag W1 and the recording device 35 are connected, and the reproducing device 1 sends a switching pulse swp, a luminance signal Y1, and a low frequency converted chroma signal to the recording device 35. A signal CO is provided.

The RF signal SRF reproduced from the magnetic tape 3 by the magnetic head 2 of the reproduction device 1 is transmitted to the Y/C through the amplifier 4.
It is supplied to the separation circuit 5. At this time, the rotation of the head (not shown) is detected by the detection circuit 22. Based on the rotation detection signal PG output from the detection circuit 22 , a switching pulse SP is formed in the flip-flop 23 and supplied to the recording device 35 .

The Y/C separation circuit 5 separates the reproduced RF signal SRF into a luminance signal YO and a chroma signal CO.

For example, the chroma signal CO that has been low frequency converted to 743KH2 is supplied to the ACC circuit 6, and the luminance signal YO is supplied to the luminance signal reproducing circuit 25.

The chroma signal CO is controlled to have a predetermined amplitude level by the ACC circuit 6, and then sent to the recording device 3 via a path 27 consisting of a delay circuit 21, an amplifier 7, and a terminal 26.
5.

The luminance signal yo is subjected to the various signal processing described above in the luminance signal reproducing circuit 25 and then sent to the terminal 28 of the switch circuit 28.
supplied to a.

In the switch circuit 28, the connection state of the terminals is controlled and the terminals 28a and 28c are connected as described above, so the brightness signal Y1 is supplied to the recording device 35 via the switch circuit 28 and the terminal 31.

In the recording device 35, the connection state of the switch circuit 37.51 is controlled by a control signal supplied from a controller (not shown).
1c is in a connected state, and in the switch circuit 37,
Terminals 37a and 37c are in a connected state.

Therefore, the dubbing chroma signal CO supplied via the terminal 62 is supplied to the bandpass filter 53 via the switch circuit 37.

In the band pass filter 53, (743KHz±50
0 KHz) is extracted, and this chroma signal CO is supplied to the adder circuit 54.

Furthermore, the luminance signal Y1 supplied via the terminal 36 is supplied to the luminance signal recording circuit 45 via the switch circuit 51. After the luminance signal recording circuit 45 performs various signal processing as described above, the luminance signal is supplied to the addition circuit 54 .

In the addition circuit 54, the FM-modulated luminance signal Y1 and the above-mentioned chroma signal CO are added to form an RF signal SRF for recording. This RF signal SRF is
6 and recorded on a magnetic tape 58 by a magnetic head 57. - In this dubbing mode, the playback device 1 and the recording device 35
It is necessary to frame the drums by matching the rotational phases of both drums.

To perform framing, it is necessary to form a signal that serves as a servo reference for the drum rotational phase, and to perform a servo control operation based on this signal that serves as the servo reference for the drum rotational phase.

The formation of a signal serving as a servo reference for the drum rotation phase will be described below.

The D flip-flop 60 receives a switching pulse SWP supplied from the synchronizing signal separation circuit 46 and shown in FIG. 4B during a period when the switching pulse SWP supplied from the reproducing device 1 through the terminal 64 and shown in FIG. 4A is at a high level. Vertical synchronization signal S
Sampling is performed at the rising edge of Y.

As a result, a signal Dout serving as a servo reference for the drum rotation phase as shown in FIG.

Based on this servo reference signal Dout, the servo circuit 65 controls the drum rotational phase, drum rotational speed, etc., making it possible to take correct framing and transmitting the chroma signal whose phase has been inverted to the inversion processing field side. will now be supplied to the channel.

Note that there is a gap of 6 between the rising edge of the switching pulse SWP and the rising edge of the vertical synchronizing signal SY.
．． A period of 5H is set, which indicates that the signal Dout serving as a servo reference in the recording device 35 rises at a timing 6.5H has elapsed since the channel switching of the magnetic head 2 in the recycling bag f1. .

FIG. 5 shows the formation of the above-mentioned switching pulse SP to 1i<ATF signal and the switching pulse 5IllP.
Based on (the formation of the chroma signal inversion command 5WOT is shown).

The switching pulse SP shown in FIG. 5B is generated from the rotation detection signal PG shown in FIG. 5A.

Based on the above switching pulse SWP, signals SEI and SR2 for forming the ATF signal are formed as shown in FIGS. 5C and 5D. The signal SEI, which has the same phase and frequency as the switching pulse SWP, is divided by (1/2) to generate the signal S.
E2 is formed.

Depending on the combination of the levels of the above-mentioned signals SEI and SR2, an ATF signal consisting of signals of four types of frequencies f1 to f4, each having a predetermined frequency and shown in FIG. 5E, is formed. Further, FIG. 5F shows a chroma signal inversion command S-○T formed by the switching pulse SP shown in FIG. 5B and the horizontal synchronizing signal H5Y. This chroma signal inversion command 5WOT is such that the high level and low level are inverted every IH while the switching pulse SWP is at a low level, for example.

Accordingly, the framing of the video signal is shown in FIGS. 6G and 6H.

As a result, in the dubbing mode, the reproduction device 1 obtains a chroma signal CO that does not pass through the comb filter 13, the APC circuit, the burst de-emphasis circuit 8, the de-emphasis circuit 12, and the bandpass filter 11, and the recording device 35 In this case, since the above-mentioned chroma signal CO is recorded without passing through the emphasis circuit 39 and the burst emphasis circuit 41, it is possible to prevent the occurrence of hue fluctuations in the chroma signal due to response errors in the AP (Jl path). 13, and the emphasis circuit 39 and the de-emphasis circuit 12 can prevent color shift in the vertical direction.
, burst emphasis circuit 41, burst de-emphasis circuit 8, etc. can be prevented from changing the color level and color blurring, and furthermore, the band pass filter 11 can reduce the chroma signal band and prevent deterioration of the phase characteristics. It can prevent bleeding and color unevenness. This makes it possible to prevent image quality deterioration due to dubbing.

Furthermore, the switching pulse s supplied from the reproducing device 1
A playback device based on wp and vertical synchronization signal ■SY! 1
Since the rotational phase and rotational speed of the drum of the recording device [35] are controlled, continuity of PX processing or PS processing can be maintained, and normal color recording and playback can be realized.

According to this embodiment, the switching pulse S is supplied from the reproducing device 1 to the recording device 35, but the reproducing device 1
It is sufficient that the rotational phase of the drum of the recording device 35 can be matched with the rotational phase of the drum of the recording device 35, so it is not limited to the above example.
For example, a PG multiplied signal may be supplied.

In this embodiment, the P■ processing method is used as an example of phase inversion processing, but the present invention is not limited to this, and can be similarly applied to, for example, the PS processing method. .

Furthermore, although this embodiment is explained using an 8-inch video tape recorder as an example, the present invention is not limited to this, and of course can be applied to other video tape recorders.

〔Effect of the invention〕

According to the recording device according to the present invention, when dubbing a video signal, a chroma signal that has been reproduced and low frequency converted and a luminance signal extracted from the reproduced video signal are supplied, so that image quality deteriorates due to dubbing. Furthermore, since the rotational phase of the drums of the playback device and the recording device is controlled based on the switching pulse and synchronization signal supplied from the playback device, the continuity of PI processing or PS processing can be improved. This has the effect of making it possible to maintain normal color recording and playback.

Further, according to the embodiment, in the dubbing mode, a chroma signal that does not pass through a comb filter, an APC circuit, a burst de-emphasis circuit, a de-emphasis circuit, a band-pass filter, etc. is obtained on the playback device side, and the recording device In this case, since the above-mentioned chroma signal is recorded without passing through the emphasis circuit and the burst emphasis circuit, it is possible to prevent the occurrence of hue fluctuations in the chroma signal due to response errors of the APC circuit. It can prevent color shift, and it can prevent color level changes due to differences in characteristics of emphasis circuits, de-emphasis circuits, burst emphasis circuits, burst de-emphasis circuits, etc.
It is possible to prevent the occurrence of color fringing, and furthermore, there is an effect that color fringing and color unevenness can be prevented without reducing the band of the chroma signal due to the bandpass filter or deteriorating the phase characteristics.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a playback device applicable to an embodiment of the present invention, Fig. 2 is a block diagram showing a recording device of an embodiment, and Fig. 3 shows the flow of signals between the playback device and the recording device. FIG. 4 is a timing chart showing how the servo reference signal is formed in the recording device, and FIG. 5 is a timing chart showing how the ATF signal and chroma signal inversion command are formed in the recording device. 6 and 7 are diagrams for explaining the relationship between framing and crosstalk cancellation. Explanation of main symbols in the drawings 1: Reproducing device, 35: Recording device, 60: D flip-flop, 65: Servo circuit, C01CAI to CA5, CBI to CB5: Chroma signal, YO, Yl: Luminance signal, DOUT: Signal, VSY: Vertical synchronization signal, HSY: Horizontal synchronization signal.

Claims (1)

[Scope of Claims] A chroma signal extracted from a reproduced video signal, subjected to carrier signal phase shift processing, and low frequency converted; a switching pulse representing the rotational phase of the drum; and the above-mentioned reproduction. At the time of dubbing, the luminance signal extracted from the video signal is supplied, and the chroma signal and luminance signal are recorded.
A recording apparatus characterized in that the rotational phase of the drum is controlled based on the switching pulse and a synchronization signal separated from the luminance signal.