JPH01101792A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent inversion and pattern noise from taking place in the recording and reproduction in other VTR by providing a comb-line filter responding to a chrominance carrier signal and a switch means supplying an output of the comb-line filter to a chrominance carrier signal output terminal at EE output. CONSTITUTION:When a composite signal is given to an input terminal, that is, switches S1-S5 are thrown to the position of an input signal (a), since an output signal of a band pass filter BPF 40 is given to an input terminal of a REC(EE) of the switch S11, when the EE output is selected by the manual switch S10, the signal is given to a comb-line filter 75. Thus, the output is outputted from an output terminal 80 via switches S5, S8 and a high frequency Y signal component is eliminated from the signal C and the result is outputted. Thus, the Y/C separated output is outputted at the input of the composite signal and recorded/reproduced by other VTR having a wide band mode, then no inversion or noise takes place in the reproduced picture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording/reproducing device, and more particularly to a wideband color under-one type magnetic recording/reproducing device having Y/C separated output terminals and capable of outputting an EE ratio. .

[Prior Art] Recently, in a video tape recorder (VTR) using a color under (low frequency conversion carrier color signal) method as a magnetic recording/reproducing device, a luminance signal (Y signal) and a carrier color signal (C signal) are used.
Luminance signal output terminal and carrier color signal output terminal (hereinafter referred to as Y/C
Devices with separate input/output terminals have appeared.

On the other hand, some VTRs are equipped with an EE ratio output that outputs the input signal as it is without going through the magnetic head when recording or stopping the VTR. In such a VTR, when a composite signal is input, this composite signal is output as is, and a Y signal and a C signal separated from it are output.On the other hand, when a Y signal and a C signal are input, they are output as is and both are output. It is configured to output a composite signal obtained by mixing.

FIG. 3 is a block diagram schematically showing a recording system and a reproducing system of a conventional VTR having such a configuration. The left side of the magnetic tape 48 is the recording system, and the right side is the reproduction system. First, in the recording system, a composite signal input terminal 31, a Y signal input terminal 49, and a C signal input terminal 50 are provided, and when a composite signal is input, switches 81 to S5 are provided.
is switched to the input terminal a side, while in the case of Y/C separated input, the input terminal is switched to the input terminal A side. That is, when inputting a composite signal, the comb filter 32 separates the Y signal, and the bandpass filter (BPF) 2111 separates the C signal.
The signals are separated and these Y and C signals are sent to switch S4.
．． It is configured to be applied to switch S7.88 via S5 and output from Y/C separation output terminal 79.80. Note that Fig. 3 shows a PAL system VTR, and <
If the C signal is separated using a square filter, color fringing occurs, so a BFF is used.

[Problems to be Solved by the Invention] If the output signal from the Y/C output terminal of the VTR configured as described above is connected to another VTR for recording as shown in FIG. 4, the following problems occur. In Fig. 4, the Y/C separated output terminal 7 of the VTR 90 to which the composite signal is input.
9.80 to the other (7) Y/C separation input terminal 94.96 of the VTR 92 is given a Y signal and a C signal. V
Since the TR92 is in the state where the Y/C input is selected, in the case of the variable band type, the wideband mode will be selected. To explain this point, variable band type means
This method changes the cutoff frequency of a high-pass filter (HPF) that separates the reproduced luminance signal depending on whether the signal contains a high-frequency Y signal component. (August 1988)
(Japanese Patent Application No. 1982-208016, filed on May 19, 1983) In this variable band type VTR, when Y/C input is selected,
The wideband mode is selected on the assumption that the C signal applied there does not include the high-frequency Y signal component.

However, when the VTR shown in Fig. 3 is used as the VTR 90 shown in Fig. 4, as shown in Fig. 5, the composite signal (Fig. 5 (a)) and the separated Y signal (Fig. 5 (b)) are C
Since the signal (FIG. 5(C)) is input to the VTR 92, a high frequency Y signal component S is included in the input C signal. will be included. In addition, in Fig. 5, S
is the high frequency Y signal, SY is the high frequency Y signal in the separated Y signal, and f is the frequency of the color subcarrier e.

Therefore, when the VTR92 selects the above-mentioned broadband mode and records in the manner shown in FIG.
Y signal component S included within the signal band.

This presence causes problems, such as an inversion phenomenon occurring at edges in the reproduced image, and an increase in image noise, resulting in a significant deterioration of image quality.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides, when a composite signal is manually generated, a C signal separated by a bandpass filter from the C signal to a comb filter, and the output thereof is converted into an E
It is used as an E output. Note that this comb filter may be newly provided, or may also be used as a comb filter for canceling crosstalk in the reproduction system.

That is, according to the present invention, in a magnetic recording/reproducing device having a Y/C output terminal, capable of EE output, and configured to separate a carrier color signal from a composite signal in a recording system, the carrier color signal is a responding comb filter, and the output of the comb filter is connected to the Y when outputting EE.
A magnetic recording/reproducing apparatus is provided, characterized in that a switch means is provided for supplying a carrier color signal from a /C output terminal to an output terminal.

[Function] According to the above configuration, the C signal for EE output does not directly output the output of the bandpass filter, but is output after passing through the comb filter, so that the high frequency Y signal included in the C signal Component [S in Figure 5(C). ] is effectively removed and then output. Therefore, when the C signal and the Y signal are applied to another VTR 92 for recording and reproduction as shown in FIG. 4, the above-mentioned problems of inversion and screen noise do not occur.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram schematically showing a preferred embodiment of the present invention. This block diagram shows the magnetic tape 40 as in Figure 4.
The left side of the center is the recording system, and the right side is the playback system.

In the recording system on the left side of FIG.
A composite signal, which is a signal as shown in Figure (a), is input, that is, a signal in which the C signal is multiplexed into the higher band of the Y signal.

This composite signal is supplied to a comb filter 32, which removes the C signal component.
A Y signal as shown in Figure (b) is separated and supplied to one input terminal a of the switch circuit S1. Furthermore, the Y signal output from the switch circuit S1 is passed through a low-pass filter (L
PF) 34, FM via the Buri emphasis circuit 35
The signal is frequency-modulated by the modulator 3B into an FM luminance signal, and is supplied to the mixing circuit 37.

On the other hand, the composite signal input to the input terminal 31 is supplied to one input terminal a of the switch circuit S2. Furthermore, the signal outputted from this switch circuit S2 is passed through a band pass filter (BPF) 40 into a C signal as shown in FIG. ) are separated and ACC (Auto II
latic Chroma Control) circuit 42
The signal is supplied to the frequency converter 43 via.

Next, the C signal from the ACC circuit 42 is frequency-converted to a low frequency range by a frequency converter 43 to become a low-frequency converted color signal, and the LPF
45 to the mixing circuit 37.

The frequency division multiplexed signal output from the mixing circuit 37 is sent to a magnetic head 47 via a recording amplifier 46 to a magnetic tape 48.
recorded above.

Input terminals 49 and 50 each have separate and independent Y
signal and C signal are input, and these Y signal and C signal are respectively input to the switch circuit S1. The other input terminal of S2 is supplied. The switch circuit S1°S is switched in conjunction with the manual switch S9 by turning ON10FF. The input terminals 49, 50 are further connected to two input terminals of the mixing circuit 44, respectively, and the switches S4. It is connected to the input terminal of S5. Also, the output of the comb filter 32 is connected to the input terminal a of the switch S4, and the BPF 4
0 is connected to input terminal a of switch S5. The input terminal 31 is connected to the input terminal a of the switch S3, and the output of the mixing circuit 44 is connected to the input terminal A of the switch S3.

Switch S3. S4. The output terminal of S5 is connected to switch S6.
S7. It is connected to the input terminal REC (EE) side of S8.

The switch S-8 is controlled as follows by a signal from the manual switch S9. That is, when the manual switch S9 is OFF, the signals on the input terminal a side of the switches 81 to S5 are selected, so when the composite signal is applied to the input terminal 31, the switch S9 is kept OFF. Next, when the Y/C separated signal is applied to the input terminals 49 and 50, the switch S9 is turned on, and as a result, the switches 81 to S5 select the signal on the input terminal side.

Therefore, when a composite signal is applied to the input terminal 31, this composite signal is applied to the BPF 40 via the switch S2, and the output signal is sent to the BPF 40 via the switch S2.
1, is applied to the REC (EE) side input terminal of.

Next, in the reproduction system on the right side of FIG.
The signal recorded above is reproduced by the magnetic head 47, and this reproduced signal is supplied to a bypass filter (HPF) 57 via a preamplifier (not shown), where the FM luminance signal is separated. The signal is applied to the limiter 62 via a frequency modulation equalizer circuit (FM equalizer circuit) 58. Next, the output signal of the limiter 62 is sent to the FM demodulator 6.
3 to the original Y signal, which is further supplied to the mixing circuit 68 via the LPFB4.

On the other hand, the reproduction signal output from the preamplifier is LPF
G9, where the low frequency conversion color signal is separated;
This low frequency converted color signal is converted to a high frequency signal by a frequency converter 70 to become the original C signal, and is then supplied to a mixing circuit e8 via a BPF 74 and a comb filter 75. Mixing circuit 6
The signal output from the switch S6 is applied as a composite signal to the input terminal PB side of the switch S6. Comb filter 7
5 is for removing crosstalk and also removing high-frequency luminance signal components in the C signal band.

The output of LPF[i4 and the output of comb filter 75 are further provided to the PB side of switches S-t and Sg.

Note that the switch S3 is on the RFC (EE) side of the switch S6.
The output of is given. The switches 86 to S8 are used when outputting the playback output from the playback system (PB side) and when outputting the input signal to the recording system as is [REC (EE
) side], and the 0 side of manual switch S10
Controlled by N10FF.

In the above configuration, the Y/C separated signal is input to the input terminal 49.5.
0, that is, when the switches S to S5 select the input terminal side, the operation is basically the same as that of the conventional circuit shown in FIG. On the other hand, if the composite signal is given to the input terminal, that is, the switches 81 to S5
When the input terminal a side is selected, the output signal of the BPF40 is given to the RFC (EE) side input terminal of the switch S1□, so when the EE ratio output is selected with the manual switch S10, the comb filter 75. Therefore, the output is outputted from the output terminal 80 via the switch S5 and the switch s8.

In this way, in the present invention, the BPF 4 for separating the C signal in the recording system is used.
Since the output of 0 is not output as is when outputting EE, but is output through the comb filter 75 of the reproduction system, the Y signal and C signal output from the output terminals 79 and 80 for Y/C separated output are The waveforms are shown in FIGS. 2(a) and 2(b). That is, from the C signal to the high frequency Y signal component S shown in FIG. 5(c). is removed and output.

In the above embodiment, the high-frequency Y signal component S in the output C signal of the BPF 40 is processed using the comb filter 75 for canceling crosstalk in the reproduction system. Although the comb filter is removed, the comb filter is not limited to this, and a separately provided comb filter may be used.

[Effects of the Invention] As explained in detail above, in the magnetic recording and reproducing apparatus of the present invention, by passing the signal from the BPF for C signal separation in the recording system through a comb filter, the signals contained in the C signal are separated. This makes it possible to effectively remove the high-frequency Y signal component. Therefore, even if the Y/C separated output is recorded and reproduced by another VTR having an EE ratio output wideband mode when a composite signal is input, no inversion phenomenon or noise will occur in the reproduced image.

Further, in an embodiment in which the comb filter for crosstalk cancellation in the reproduction system is also used, there is no need to separately provide a new comb filter, which is advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing an embodiment of the magnetic recording/reproducing apparatus of the present invention, FIG. 2 is a spectrum diagram of the output Y signal and C signal in the embodiment of FIG. 1, and FIG. 3 is a conventional FIG. 4 is a block diagram showing a magnetic recording and reproducing device. When a VTR having a Y/C separated output is recording or stopped, a Y/C separated signal is supplied from its EE ratio output to another VTR for recording. FIG. 5 is a diagram showing a signal spectrum in the conventional magnetic recording/reproducing apparatus shown in FIG. 3. 31, 49.50... Input terminal 32, 75... Comb filter (comb filter) 34
, 45.64.69...Low pass filter (L P
F) 35...Brief emphasis circuit 36...FM modulator 37.44.68...
Mixing circuits 40, 74...Band pass filter (B P
F) 42...ACC circuit 43.70...
Frequency converter 46...recording amplifier 47...
Magnetic head 48...Magnetic tape 57...Bypass filter (HPF) 58...Frequency modulation equalization circuit (FM equalizer circuit) 62...Limiter 63...FM demodulator 78, 79.80
...Output terminal S1-S1□...Switch inventor
Crane 1) Masahiko Toko - Kenji Shibayama Submitted by Victor Japan Co., Ltd.

Claims (3)

[Claims] (1) A magnetic recording and reproducing device having a luminance signal output terminal and a carrier color signal output terminal, capable of EE output,
In a recording system configured to separate a carrier color signal from a composite signal, a comb filter responsive to the carrier color signal and a switch means for supplying the output of the comb filter to the carrier color signal output terminal at the time of EE output are provided. A magnetic recording/reproducing device characterized in that: (2) The magnetic recording and reproducing apparatus according to claim 1, wherein the comb filter also serves as a comb filter for canceling crosstalk in the reproducing system of the magnetic recording and reproducing apparatus. (3) The comb filter is configured to be responsive to an output signal of a bandpass filter used to separate the carrier color signal from the composite signal. 2. The magnetic recording and reproducing device according to item 2.