JPH09284803A - Discriminating device of PAL-M system and NTSC system of magnetic tape reproducing device or magnetic tape recording device - Google Patents

Abstract

(57) Abstract: A PAL-M system and NTSC system discrimination device of a magnetic tape reproducing device or a magnetic tape recording device of the present invention surely discriminates a color television system during reproduction or recording in a VTR. The purpose is to A low-pass conversion color signal extracted by a low-pass filter 1 is passed from an NTSC comb filter 2a or a PAL-M comb filter 2b to a frequency conversion circuit 4 from a 4-phase chroma rotation circuit 7. Is mixed with the signal of (1) and is output as a color signal from the bandpass filter 5. The phase detector 10 compares the output of the local oscillator 13 with the output of the bandpass filter 5, and outputs the phase difference to the local oscillator 9. The color killer detection circuit 11 outputs the result of phase detection of the color subcarrier from the reference signal generator 14 and the color burst of the color signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color television signal recording / reproducing apparatus such as a VTR (video tape recorder) for discriminating between the PAL-M system and the NTSC system, or a PA of a magnetic tape recording device.
The present invention relates to an LM type and NTSC type discriminating device.

[0002]

2. Description of the Related Art The color television broadcasting system is the NTSC (National Television) system adopted by Japan, the United States, and the like.
There is a broadcasting system such as a levision system committee (PAL) system and a PAL (Phase Alternation by Line) system mainly used in European countries. NTSC system, PAL
A color television system such as a system is combined with a black-and-white and color common broadcasting system, which is assigned a code from A to N, depending on a difference between a video signal and an audio signal standard and a transmission system thereof, for example, an M / NTSC system. It is prescribed as such.

By the way, with the spread of VTRs in recent years, it has become easy to obtain video tapes of different broadcasting systems, and a device compatible with a plurality of broadcasting systems, for example, a multi-system color television receiver or a video tape recorder is required.

Among the above-mentioned plurality of color television systems, the M / PAL system and the M / NTSC system both have 525 scanning lines and a field frequency of 60 Hz.
In the PAL system, both systems are very similar, except that the phase of the carrier color signal superimposed on the luminance signal with respect to the color burst is deviated from each other by 90 ° between adjacent scanning lines.

Further, in the VHS system VTR, after separating the video signal into a luminance signal and a color signal, the color signal is subjected to low-frequency conversion, and the low-frequency conversion color signal is recorded on a magnetic tape in the M / PAL system. And M / NTSC system PS (Pha
Se shift) phase shift method is different. That is, the VTR compatible with the M / NTSC system sends a low-frequency conversion color signal whose phase is advanced by 90 ° for each horizontal synchronization (hereinafter referred to as 1H) in the channel (hereinafter referred to as CH) 1 of the video head to CH2. The low-pass conversion color signal whose phase is delayed by 90 ° is recorded every 1H. On the other hand, M / PAL
The VTR compatible with the method records the low-pass conversion color signal in which the phase of the low-pass conversion color signal is invariable in CH1 of the video head and is delayed by 90 ° in every 1H in CH2.

Therefore, the conventional M / PAL system and M / NT are used.
In the VHS system VTR corresponding to the SC system, as in the discrimination method disclosed in, for example, Japanese Patent Laid-Open No. 63-220687, only the reproduced color signal from CH2 is used, and M
The / PAL system and the M / NTSC system are discriminated.
That is, M / PAL system or M recorded on a magnetic tape
When reproducing a color television signal of the / NTSC system, the color signal recorded by the head of CH2 is
The head of H2 shifts the phase by 90 degrees for each 1H to reproduce the signal state before recording, extracts the color burst of the reproduced color signal from CH2, and detects the phase for each 1H. The M / PAL system and the M / N system based on the difference in color burst phase
The TSC method is determined.

[0007]

However, in the above-mentioned conventional method of discriminating between the M / PAL system and the M / NTSC system, only the color burst of the color signal reproduced by the head of CH2 is detected and used for the discrimination. The color burst of the color signal reproduced by the head is not used for the discrimination, and the discrimination of the color television system is likely to malfunction due to the state of the magnetic tape (generation of noise due to scratches on the tape), and the discrimination performance is poor.

The conventional VTR is M / PA only when reproducing a magnetic tape on which a color television signal is recorded.
It is possible to distinguish between the L system and the M / NTSC system, and when recording a color television signal, the M /
The PAL system or the M / NTSC system cannot be discriminated.

Therefore, the present invention has been made to solve the above-mentioned conventional problems. All color bursts of color signals reproduced by the heads of CH1 and CH2 in a VTR are used for discrimination, and depending on the state of the magnetic tape. An object of the present invention is to provide a PAL-M type and NTSC type discriminating apparatus of a magnetic tape reproducing apparatus or a magnetic tape recording apparatus capable of reducing malfunctions in color television system discrimination and discriminating the color television system during recording. .

[0010]

In order to solve the above-mentioned problems, P of the magnetic tape reproducing apparatus according to claim 1 of the present invention.
The AL-M system and the NTSC system discriminator are PAL-M
In a magnetic tape reproducing apparatus which reproduces a video signal of a color television signal of an NTSC system or an NTSC system from a magnetic tape in which a luminance signal and a color signal are recorded separately.
NTSC that outputs a chroma rotation signal to restore the phase of the low-pass conversion color signal that has been phase-shifted at every horizontal synchronization for magnetic recording corresponding to the NTSC system
A chroma rotation circuit and a PAL-M chroma rotation that outputs a chroma rotation signal for restoring the phase of the low-pass conversion color signal that is phase-shifted at every horizontal synchronization for magnetic recording corresponding to the PAL-M system. Circuit and low-pass conversion color signal reproduced from magnetic tape, NTSC chroma rotation circuit or PAL
A frequency conversion circuit that mixes the outputs of the M chroma rotation circuit, restores the phase for each horizontal synchronization, converts the low-pass conversion color signal into a color signal, and outputs the color signal;
A first switching means for switching the output of the SC chroma rotation circuit or the PAL-M chroma rotation circuit to connect to the frequency conversion circuit, an NTSC reference signal generator for generating an NTSC color subcarrier, and a PAL-M. System PAL for generating color subcarrier
-M reference signal generator, a discrimination circuit for extracting a color burst portion from the color signal, and outputting the result of phase detection of a color subcarrier of the NTSC system or PAL-M system as a discrimination signal, and an NTSC reference signal generation The output of the PAL-M reference signal generator or the output of the PAL-M
Second switching means connected to the discrimination circuit, and an instruction signal for holding or changing the PAL-M system or NTSC system color signal processing mode based on the discrimination signal, the first switching means and the second switching means. And a color mode control means for outputting to the switching means.

According to a second aspect of the present invention, there is provided a PAL-M system and an NTSC system discriminating device for a magnetic tape reproducing apparatus according to a first aspect of the present invention. In addition to the above-mentioned means, an NTSC comb filter for removing the crosstalk of adjacent tracks from the NTSC low-frequency conversion color signal reproduced from the magnetic tape, and the PAL-M low-frequency conversion color reproduced from the magnetic tape. PAL-M comb filter that removes crosstalk of adjacent tracks from the signal and NTSC comb filter or PAL-M comb filter are switched,
A third switching unit connected to the frequency conversion circuit is provided, and the color mode control unit outputs the instruction signal to the third switching unit based on the determination signal.

According to the third aspect of the present invention, the magnetic tape recording apparatus of the PAL-M type and the NTSC type discriminating apparatus is P
In a magnetic tape recording device for recording a video signal of a color television signal of AL-M system or NTSC system on a magnetic tape by separating it into a luminance signal and a color signal, an NTSC system image input for magnetic recording An NTSC chroma rotation circuit that outputs a phase displacement signal for phase shifting the color signal of each signal every horizontal synchronization, and a color signal of the PAL-M system video signal input for magnetic recording every one horizontal synchronization. PAL-M chroma rotation circuit for outputting a phase displacement signal for phase displacement, and the color signal mixed with the output of the NTSC chroma rotation circuit or the PAL-M chroma rotation circuit to obtain a phase for each horizontal synchronization period. By displacing, the color signal is converted into a low frequency conversion color signal for magnetic recording and reproduction. And the frequency conversion circuit to force, NTS
First switching means for switching the output of the C chroma rotation circuit or PAL-M chroma rotation circuit to connect to the frequency conversion circuit; and an NTSC reference signal generator for generating an NTSC color subcarrier.
PAL-M for generating color subcarrier of PAL-M system
A reference signal generator, a discrimination circuit for extracting a color burst portion from the color signal, and outputting a result of phase detection of a color subcarrier of NTSC system or PAL-M system as a discrimination signal, and an NTSC reference signal generator. The output or the output of the PAL-M reference signal generator is switched to hold or change the second switching means connected to the discrimination circuit and the color signal processing mode of the PAL-M system or the NTSC system based on the discrimination signal. And a color mode control unit for outputting an instruction signal for the above to the first switching unit and the second switching unit.

According to a fourth aspect of the present invention, the magnetic tape reproducing apparatus or the magnetic tape recording apparatus of the PAL-M system and NT are used.
The SC type discriminating apparatus is the magnetic tape reproducing apparatus or the magnetic tape recording apparatus according to any one of claims 1 to 3, wherein the color discriminating apparatus comprises the PAL-M type and NTSC type discriminating apparatus. The mode control means is
A stable counter that counts when the discrimination signal indicates that the color television system of the color signal reproduced from the magnetic tape or the color signal of the input video signal and the color signal processing mode match, and that reproduced from the magnetic tape. Equipped with an unstable counter that counts cases where the color television system of the color signal of the input video signal or the color television system of the input video signal and the color signal processing mode are inconsistent, and after the power is turned on and the color signal processing mode is changed. ,
After waiting for a predetermined time, the discrimination signal is read, the stable counter or the unstable counter is counted up according to the read result, and the PAL-M system or NTS is based on the value of the stable counter or the unstable counter.
It is characterized in that an instruction signal for holding or changing the color signal processing mode of the C method is output.

With the above construction, the PAL-M system and the NTSC of the magnetic tape reproducing apparatus according to claim 1 of the present invention.
The system discriminating apparatus uses an NTSC chroma rotation circuit or a PAL-M chroma rotation circuit,
The phase of the low-frequency conversion color signal reproduced from the magnetic tape is restored and converted into a color signal, and the PAL-M system or the NTSC system is discriminated based on the result of phase detection by the discrimination circuit. It is possible to distinguish between the PAL-M system and the NTSC system using all color signals.

According to a second aspect of the present invention, the magnetic tape reproducing apparatus of the PAL-M type and the NTSC type discriminating apparatus is N type.
Since the crosstalk of adjacent tracks is removed from the low-frequency conversion color signal reproduced from the magnetic tape by the TSC comb filter and the PAL-M comb filter, it is possible to reproduce the color signal which is not affected by the crosstalk.

According to a third aspect of the present invention, in the discriminating apparatus of the PAL-M system and the NTSC system of the magnetic tape recording apparatus, the discriminating circuit extracts the color burst portion from the color signal and the NTSC system or the PAL-M system. Based on the result of phase detection with the color subcarrier of PAL-M system or N
Since the TSC system is discriminated, it is possible to discriminate between the PAL-M system and the NTSC system when recording the input video signal.

According to a fourth aspect of the present invention, the PAL-M system of the magnetic tape reproducing apparatus or the magnetic tape recording apparatus and NT.
The SC type discriminating device reads the discriminating signal after waiting a predetermined time after power-on and after changing the color signal processing mode, counts the read result using a stable counter and an unstable counter, and based on the counted result, PAL. Since the M-type or the NTSC-type is discriminated, it is possible to eliminate the malfunction caused by noise and to make a reliable discrimination.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a circuit block diagram of a reproducing system of a VTR to which a PAL-M type and an NTSC type discriminating apparatus of a magnetic tape reproducing apparatus of the present invention is applied. The VTR of this embodiment has color modes of PAL-M and NTSC.

A low-pass filter (LPF) 1 removes high-frequency components from a signal reproduced from a magnetic tape to extract a low-frequency conversion color signal. This low-frequency conversion color signal is 629 kHz in the NTSC system, where f _H is the horizontal synchronizing frequency.
Z (40f _H ), 631 kHz (4 PAL-M system)
0.125f _H ). The third switch 3 selects the NTSC comb filter 2a or the PAL-M comb filter 2b according to the color mode switching signal. Frequency conversion circuit (CONV) 4 is a 4-phase chroma rotation circuit (4
PHASE CHROMA ROTATION CIRCUIT) The signal from 7 and the output of the comb filter 2 are mixed and output. NTSC here
When the comb filter 2a is selected, the low-pass conversion color signal delayed by 1H is added or subtracted to remove the crosstalk from the adjacent track, and when the PAL-M comb filter 2b is selected, the low frequency delayed by 2H is selected. Cross-talk from adjacent tracks is removed by adding or subtracting the color-converted color signals. The bandpass filter (BPF) 5 extracts a color signal from the output of the frequency conversion circuit 4 and outputs it.

The second switch 12 is responsive to the color mode switching signal to generate an NTSC reference signal generator (NTSC X'tal:
3.579545MHz) 14a and PAL-M reference signal generator (PAL-M
X'tal: 3.575611MHz) 14b Switch to local oscillator
Output to (VCO) 13. Phase detector (PB APC DET) 10
Extracts the color burst from the color signal output from the bandpass filter 5, compares the phase with the color subcarrier output from the local oscillator 13, and compares the phase difference with the local oscillator (2f _L
Output to VCO) 9. The 1/2 times circuit (1/2) 8 divides the output of the local oscillator 9 by 2 and outputs it to the 4-phase chroma rotation circuit 7. The first switch 6 is an NTSC 4-phase chroma rotation circuit according to the color mode switching signal.
(4.204971MHz) 7a and PAL-M 4-phase chroma rotation circuit (4.206937MHz) 7b are switched and output to the frequency conversion circuit 4. The NTSC four-phase chroma rotation circuit 7a generates a signal whose phase is advanced by 90 ° every 1H corresponding to CH1 of the video head, and a signal whose phase is delayed by 90 ° every 1H corresponding to CH2. PAL-M4
The phase chroma rotation circuit 7b is the C of the video head.
In H1, the phase is not changed, and a signal in which the phase is delayed by 90 ° is generated every 1H corresponding to CH2.

Color killer detection circuit (COLOR KILLER DET)
Reference numeral 11 also serves as a color killer circuit and a phase detection circuit, and outputs the result of phase detection of the color subcarrier from the reference signal generator 14 and the color burst of the reproduced color signal according to the set color mode. That is, if the color television systems match (phase detector 10 → local oscillator 9 → 1/2 circuit 8 → 4-phase chroma rotation circuit 7 → first switch 6 → frequency conversion circuit 4 → bandpass filter 5 → phase detection (In the loop of the detector 10), the color burst of the color signal is phase locked to the output of the local oscillator 13 by the phase control of the phase detector 10, and the color killer detection circuit 11 outputs "L" as the color phase discrimination signal.
Is output. Further, if they do not match, the phase control range of the phase detector 10 is exceeded, so the color killer detection circuit 11 outputs “H”. When reproducing from a magnetic tape with the VTR of the present embodiment, the relationship between the color killer detection output and the color mode is shown below by comparing the phase of the color burst of the reproduced color signal with the color subcarrier from the reference signal generator. Shown in the table.

[0022]

[Table 1]

Next, FIG. 2 shows a V to which the discriminating apparatus of the PAL-M system and the NTSC system of the magnetic tape recording apparatus of the present invention is applied.
It is a circuit block diagram of a recording system of TR. The bandpass filter (BPF) 21 extracts a color signal from the input signal and outputs it. The frequency conversion circuit (CONV) 22 uses this color signal and 4-phase chroma rotation circuit (4 PHASE CHROMA ROT
The signal from the ATION CIRCUIT) 25 is mixed and output.
The low-pass filter (LPF) 23 extracts the low-pass conversion color signal from the output of the frequency conversion circuit 22 and outputs it. First
The switch 24 is an NT switch in response to the color mode switching signal.
SC 4-phase chroma rotation circuit 25a and PAL-M
The four-phase chroma rotation circuit 25b is switched and connected to the frequency conversion circuit 22. 1/2 circuit (1/2) 26
Divides the output of the local oscillator (VCO) 27 by two and outputs it to the four-phase chroma rotation circuit 25.

The second switch 31 is an NTSC reference signal generator (NTSC X'tal) according to the color mode switching signal.
32a and PAL-M reference signal generator (PAL-M X'tal) 32
It is switched to b and connected to the local oscillator (VCO) 30. The phase detector (REC APC DET) 28 is a bandpass filter 2
Extract the color burst from the color signal of the output of 1,
The phase is compared with the output of the local oscillator 30, and the phase difference is fed back to the local oscillator 30.

[0025] In addition, a color killer detection circuit (COLOR KILLER
DET) 29 is a color killer circuit and a phase detection circuit,
If the set color mode and the color television system of the input color signal match, "L" is output as the color phase determination signal, and if they do not match, "H" is output. When recording on a magnetic tape with the VTR of the present embodiment, the relationship between the color killer detection output by the phase detection of the color burst of the input color signal and the color subcarrier from the reference signal generator and the color mode is shown in the above table. It is the same as the relationship shown in. In other words, if the input color signal and the color television system of the color mode are the same, the phases match and the detection output becomes "L". If the input color signal and the color television system of the color mode are different, the phase Are not matched, and the detection output becomes "H".

FIG. 3 is a block diagram of a VTR equipped with the reproducing and recording circuits shown in FIGS. 1 and 2, and the color phase discrimination signal of the color signal recording / reproducing circuit 33 and the color mode changeover switch and the color mode control. Circuit 34
Shows the relationship with. The color mode control circuit 34 is composed of a microcomputer or the like, and includes a stable counter 34a for counting "L" of the color phase discrimination signal,
And an unstable counter 34b that counts "H".

Next, the control procedure of the color mode control circuit when reproducing from the magnetic tape in the VTR of the present embodiment will be described with reference to the flowchart of FIG.

First, after the power is turned on, the color mode control circuit 3
4 sets the color mode to M / PAL (ST
1), the stable counter 34a and the unstable counter 34b
Is cleared (ST2). Then, during a stable period (300 ms) of the color signal recording / reproducing circuit 33 of the VTR, the initial setting, that is, the state in which the color mode switching is set to M / PAL is held (ST3).

Next, after the color signal recording / reproducing circuit 33 is stabilized, the color mode control circuit 34 samples and reads the color phase discrimination signal twice every tms (1.9 ms) (ST4). As a result, if they do not match, they are read again, and if they match, the process proceeds to the next step (ST5).

[H] of the color phase discrimination signal,
Confirm "L" (ST6). That is, when the color signal reproduced from the magnetic tape is the M / PAL system, the color phase determination signal becomes "L", the stable counter 34a is counted up, and the unstable counter 34b is cleared (S).
T7). When the color signal is M / NTSC, the color phase discrimination signal becomes "H", the stable counter 34a is cleared, and the unstable counter 34b is counted up (ST8).

The color mode control circuit 34 reads the color phase discrimination signal, keeps counting up the stable counter 34a or the unstable counter 34b, and outputs the stable counter 3
When both 4a and the unstable counter 34b exceed 25 times, they overflow.

When the stability counter 34a overflows (ST9), the initial setting mode is continued (ST1).
0), and the counting operation is continued.

When the unstable counter 34b overflows (ST11), the color mode is reversed and M /
The NTSC mode is set (ST12). Then, the inverted state is held for a period (300 ms) during which the color signal recording / reproducing circuit 33 of the VTR is stable (ST13). That is, the color mode switching is set to M / NTSC. After that, the unstable counter is cleared (ST14) and the counting operation is continued again.

As described above, the color mode control circuit operates the VTR while maintaining the color mode for a certain period of time when the power is turned on and when the color mode is inverted, and then continues or inverts the color mode according to the color phase discrimination signal.

The control procedure of the color mode control circuit when recording the color signal of the input video signal on the magnetic tape is the same as in the case of the above reproduction.

As described above, in the VTR of this embodiment, the PAL-M system and NT are used for both the reproducing circuit and the recording circuit.
Since it is equipped with an SC type discriminating device, P
It is possible to distinguish between the AL-M system and the NTSC system, and in particular, all the color bursts of the color signals reproduced by the CH1 and CH2 heads during reproduction are used for the discrimination, so that the PAL-M system and the NTSC system can be reliably discriminated. .

Further, after the power is turned on and after the color mode is inverted, the color signal recording / reproducing circuit waits for a stable period, the discrimination signal is read, the reading result is counted using the stable counter and the unstable counter, and the counted result is obtained. Since the PAL-M system or the NTSC system is discriminated based on this, it is possible to eliminate the malfunction due to noise and to make a reliable discrimination.

[0038]

As described above, the PAL-M system and NTSC of the magnetic tape reproducing apparatus according to claim 1 of the present invention.
The system discriminating apparatus uses an NTSC chroma rotation circuit or a PAL-M chroma rotation circuit,
The phase of the low-frequency conversion color signal reproduced from the magnetic tape is restored and converted into a color signal, and the PAL-M system or the NTSC system is discriminated based on the result of phase detection by the discrimination circuit. It is possible to distinguish between the PAL-M system and the NTSC system using all color signals. As a result, it is possible to reduce malfunctions in color television system discrimination due to the state of the magnetic tape.

According to the second aspect of the present invention, the discriminating apparatus of the PAL-M system and the NTSC system of the magnetic tape reproducing apparatus is N
Since the crosstalk of adjacent tracks is removed from the low-frequency conversion color signal reproduced from the magnetic tape by the TSC comb filter and the PAL-M comb filter, it is possible to reproduce the color signal which is not affected by the crosstalk. As a result, it is possible to obtain a high-quality reproduced video without noise due to crosstalk.

The discriminating apparatus of the PAL-M system and the NTSC system of the magnetic tape recording apparatus according to claim 3 of the present invention extracts the color burst portion from the color signal by the discriminating circuit and then the NTSC system or the PAL-M system. Based on the result of phase detection with the color subcarrier of PAL-M system or N
Since the TSC system is discriminated, it is possible to discriminate between the PAL-M system and the NTSC system when recording the input video signal.

According to a fourth aspect of the present invention, the PAL-M system of the magnetic tape reproducing apparatus or the magnetic tape recording apparatus and NT.
The SC type discriminating device reads the discriminating signal after waiting a predetermined time after power-on and after changing the color signal processing mode, counts the read result using a stable counter and an unstable counter, and based on the counted result, PAL. Since the M-type or the NTSC-type is discriminated, it is possible to eliminate the malfunction caused by noise and to make a reliable discrimination.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a reproduction system of a VTR to which a PAL-M system and an NTSC system discrimination device of a magnetic tape reproduction device of the present invention is applied.

FIG. 2 is a circuit block diagram of a recording system of a VTR to which the PAL-M system and the NTSC system discrimination device of the magnetic tape recording device of the present invention is applied.

FIG. 3 is a block diagram of a VTR equipped with a PAL-M type and NTSC type discriminating device of the magnetic tape reproducing apparatus and the magnetic tape recording apparatus of the present invention.

FIG. 4 is a flowchart showing a control procedure of a color mode control circuit.

[Explanation of symbols]

1 Low pass filter (LPF) 2 Comb type filter 3 3rd switch 4 Frequency conversion circuit (CONV) 5 Band pass filter (BPF) 6 1st switch 7 4 phase chroma rotation circuit (4PHASE CHROMA ROT
ATION CIRCUIT) 8 1/2 circuit (1/2) 9 Local oscillator (2f _L VCO) 10 Phase detector (PB APC DET) 11 Color killer detector circuit (COLOR KILLER DET) 12 Second switch 13 Local oscillator (VCO) ) 14 Reference signal generator

Claims (4)

[Claims] 1. A magnetic tape reproducing apparatus for reproducing a video signal of a PAL-M system or NTSC system color television signal by separating it into a luminance signal and a color signal and recording the same, and is compatible with the NTSC system. NTSC that outputs a chroma rotation signal for restoring the phase of the low-pass conversion color signal that has been phase-shifted at every horizontal synchronization for magnetic recording.
Chroma rotation circuit and PAL that outputs a chroma rotation signal for restoring the phase of the low-pass conversion color signal that has been phase-shifted at every horizontal synchronization for magnetic recording corresponding to the PAL-M system.
-M chroma rotation circuit and low frequency conversion color signal reproduced from magnetic tape, NT
A frequency conversion circuit that mixes the outputs of the SC chroma rotation circuit or the PAL-M chroma rotation circuit, restores the phase for each horizontal synchronization, converts the low-pass conversion color signal into a color signal, and outputs the color signal, and an NTSC chroma A first switching means for switching the output of the rotation circuit or the PAL-M chroma rotation circuit to connect to the frequency conversion circuit, an NTSC reference signal generator for generating an NTSC color subcarrier, and a PAL-M system PAL-M for generating color subcarriers
A reference signal generator and an NT for extracting a color burst part from the color signal
A discriminating circuit that outputs the result of phase detection with the SC or PAL-M type color subcarrier as a discriminating signal, and the output of the NTSC reference signal generator or the PAL-M reference signal generator to switch the discrimination. Second switching means connected to the circuit, and an instruction signal for holding or changing the color signal processing mode of the PAL-M system or the NTSC system based on the discrimination signal, the first switching means and the second switching means. A PAL-M system and NTSC system discriminating apparatus for a magnetic tape reproducing apparatus, comprising: a color mode control means for outputting to the means. 2. An NTSC comb filter for removing crosstalk of adjacent tracks from an NTSC low-pass conversion color signal reproduced from a magnetic tape, and a PAL-M low-pass conversion color signal reproduced from a magnetic tape. PAL excluding crosstalk between adjacent tracks
A third switching means for switching between the -M comb filter and the NTSC comb filter or the PAL-M comb filter for connection to the frequency conversion circuit, wherein the color mode control means is based on the discrimination signal. The P of the magnetic tape reproducing apparatus according to claim 1, wherein the instruction signal is output to the third switching means.
AL-M system and NTSC system discrimination device. 3. A magnetic tape recorder for separating a video signal of a PAL-M or NTSC color television signal into a luminance signal and a color signal and recording them on a magnetic tape, which is input for magnetic recording. NTSC chroma rotation circuit that outputs a phase displacement signal for phase shifting the color signal of the NTSC video signal for each horizontal synchronization, and the color signal of the PAL-M video signal input for magnetic recording And a PAL-M chroma rotation circuit for outputting a phase displacement signal for phase-shifting every horizontal synchronization, and an output of an NTSC chroma rotation circuit or a PAL-M chroma rotation circuit is mixed with the color signal for one horizontal The color signal is phase-shifted at each synchronization cycle to convert the color signal into a low-frequency conversion color for magnetic recording and reproduction. Frequency conversion circuit for converting to and outputting a signal, and first switching means for switching the output of the NTSC chroma rotation circuit or the PAL-M chroma rotation circuit to connect to the frequency conversion circuit, and an NTSC color subcarrier And an NTSC reference signal generator for generating a PAL-M type color subcarrier.
A reference signal generator and an NT for extracting a color burst part from the color signal
A discriminating circuit that outputs the result of phase detection with the SC or PAL-M type color subcarrier as a discriminating signal, and the output of the NTSC reference signal generator or the PAL-M reference signal generator to switch the discrimination. Second switching means connected to the circuit, and an instruction signal for holding or changing the color signal processing mode of the PAL-M system or the NTSC system based on the discrimination signal, the first switching means and the second switching means. A PAL-M type and NTSC type discriminating apparatus for a magnetic tape recording apparatus, comprising: a color mode control means for outputting to the means. 4. The color mode control means, when the discrimination signal indicates that the color television system of the color signal reproduced from the magnetic tape or the color signal of the input video signal matches the color signal processing mode. And a stable counter that counts when the color television system of the color signal reproduced from the magnetic tape or the color signal of the input video signal and the color signal processing mode do not match. After the power is turned on and after the color signal processing mode is changed, the determination signal is read after waiting for a predetermined time, and the stable counter or the unstable counter is counted up according to the read result, and the stable counter or the unstable counter is read. Color signal processing mode of PAL-M system or NTSC system based on the value of the counter. PAL-M system and N of the magnetic tape reproducing apparatus or a magnetic tape recording apparatus according to any one of claims 1 to 3, characterized in that outputs an instruction signal for holding or changing a de
TSC type discrimination device.