JPH0362694A - Video signal recorder - Google Patents

Abstract

PURPOSE:To generate a video signal of a different system with simple configuration by applying required processing and recording a color signal and a luminance signal of other system from an encoder converting signals at a subcarrier frequency of one color system, converting the color signal and displaying the result on a monitor with the one system. CONSTITUTION:Three primary color R, G, B signals from a processor 3 are converted into an encoder 4 which is controlled with an output of a subcarrier frequency fsc(M) of the PAL-M system from an oscillator 5 into a color signal C and a luminance signal Y of the pseudo NTSC-M system. The signal C is given to the PAL-M conversion circuit 14 and the signal Y is added by an adder circuit 15 to form a video signal of the PAL-M system and displayed on a monitor 16. On the other hand, the signal Y is added to the color signal C from a low frequency conversion circuit 11 controlled by the subcarrier frequency of the NTSC-M system from an adder circuit 18 via a Y signal processing circuit 6 and an FM modulation circuit 8 and recorded as the video signal of the NTSC-M system. Thus, the video signal of the two systems is formed with simple configuration having only one encoder.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention can be used, for example, in a camera-integrated video tape recorder (camera-integrated VTR) whose recording system is the NTSC system and whose video output system is the PAL-M system. The present invention relates to a suitable video signal recording device.

[Invention (already required)]

The present invention provides a video signal that converts an original signal into a video signal of one color system and supplies it to a receiver, and also converts the original signal into a video signal of another color system and records it on a recording medium. In the signal recording device, an encoder converts the original signal into a video signal of another color system at the subcarrier frequency of the first color system, and a color signal of the other color system is converted into a color signal of the first color system. The output signal of the encoder is recorded on the recording medium, and the output signal of the encoder is supplied to the receiver via the color signal conversion circuit, thereby simplifying the circuit. The configuration allows video signals of different color systems to be generated.

[Conventional technology]

The standard television system is the so-called TV 5tanda.
It is classified into rd and color method. Of these, TVSt
andard refers to the basic format of television signals, including the number of scanning lines and field frequency, including black-and-white television. 625.
A field frequency of 50 Hz, etc.) is adopted. Also, as is well known, there are NTSC, PAL, and SIECAM color systems.
The M system is common as the TV 5 standard, and the TV 5 standard is the PAL system.
The B or G system is common, while the TV
A PAL-M color television signal is also possible, in which the 5 standard is the M system, but the PAL system is used as the color system.

In reality, this PAL-M system is adopted as a standard television system in Brazil and other countries. NT mentioned above
SC-M system, PAL-B, G system.

Table 1 summarizes the specifications of the PAL-M system.

The color subcarrier frequency fsc of the NTSC-M system and the color subcarrier frequency fs of the PAL-M system in Table 1
The calculation formula for c (hereinafter referred to as fsc(M)) is shown below.

f sc = f MX455/2 = 3.57954
5 (Mllz); NTSCM method% formula% In this case, the capture range of the color subcarrier is usually ±3
0011z, it is not possible to use an intermediate frequency for both fsc and fsc(M).

In addition, in the NTSC-M system, the phase of the burst signal is always 180" with respect to the color difference signal B-Y, whereas P
In the AL-M method, the phase of the burst signal is the color difference signal B-Y.
The angle changes from +135° to -135° for each scanning line.

When a camera-integrated VTR is used in a country that has adopted the PAL-M system as the standard television system, the video output for the receiver must of course be in the PAL-M system.

On the other hand, as a VTR, NTSC-M system, PAL-B,
While the video signal recording format of the G format has been standardized worldwide, the recording format of the PAL-M format has not been standardized.
The CM recording format was used instead. Therefore, in countries that have adopted such PAL-M system,
For example, a camera-integrated VTR records video signals on videotape using the NTSC-M system, and in order to obtain video signals for the receiver, the NTSC-M video signals are converted into baseband signals such as color difference signals and three primary color signals. The method used was to convert the signal back into a signal and then separately encode it into the PAL-M format.

[Problem to be solved by the invention]

However, in this method of converting the NTSC-M video signal back to the baseband signal and then separately encoding it to PAL-M, the color encoder needs two
In addition to the need for a decoder for baseband signals, the circuit scale becomes extremely large, making it difficult to fit all the processing circuits into a camera-integrated VTR. Therefore, conventionally, a device for converting an NTSC-M video signal into a PAL-M video signal has been used as an external accessory device.

In view of the above, the present invention provides a video signal recording device in which the color system of the video signal recording system and the color system of the video output system are different, in which video signals of different color systems can be generated with a simple circuit configuration. The purpose is to

[Means to solve the problem]

For example, as shown in FIG. 1, the video signal recording apparatus according to the present invention records the original signal in one color format (for example, PAL-M format).
In addition to converting the original signal into a video signal of a color system and supplying it to the receiver (16), the original signal is converted to a video signal of another color system (for example, NTSC-M system) and recorded on a recording medium (23). In a video signal recording device, the original signal is converted to a subcarrier frequency (for example, fsc (M
)) to convert the video signal of the other color system into a video signal of another color system (for example, including a signal separated into a luminance signal Y and a color signal C), and an encoder (4) that converts the color signal of the other color system into a video signal of the first color system. A color signal conversion circuit (1
4), and records the output signal of the encoder (4) on the recording medium (23), and records the output signal of the encoder (4) on the recording medium (23).
4) is supplied to the receiver (16) via the color signal conversion circuit (14).

[Effect]

According to the present invention, the recording method on the recording medium (23) becomes a pseudo color method (for example, NTSC-M method) with only a difference in subcarrier frequency. Moreover, by further adjusting the frequency for low frequency conversion of the color signal when recording on the recording medium (23), the recorded signal becomes completely the same as that of other color systems.

Furthermore, simply by using the color signal conversion circuit (14), a video signal of one color system (for example, PAL-M system) is generated from a pseudo video signal of another color system. Only one is required, and a decoder for converting video signals of other color systems back to baseband signals can be omitted.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3. In this example, the present invention is applied to a camera-integrated VTR.

FIG. 1 mainly shows the recording section of this example. In this FIG. (4) is an encoder that converts the three primary color signals into the luminance signal Y and color signal C of the M system; (5) is a processor that generates the color signal C, and (5) supplies the subcarrier signal for generating the color signal C to the encoder (4). It is an oscillator that supplies In this example, the frequency of the subcarrier signal supplied by the oscillator (5) is set to fs for the PAL-M system.
c(M) (i.e., 3575611.491(z)), and the encoder (4) uses the NTSC-M method (hereinafter, pseudo-NT
This is called the SC-M method. ) to generate a color signal (including a burst signal) C.

The luminance signal Y is supplied to the input terminal of the Y signal processing circuit (6), which is controlled by a sync chip clamp circuit, etc., and to the recording side fixed contact of the first recording/reproducing switch circuit (7). ) is supplied to one input terminal of the adder circuit (9) via the FM modulation circuit (8). Also,
Reference numeral (10) indicates a connection terminal, and as will be described later, a luminance signal reproduced from the video tape is supplied to the reproduction side fixed contact of the first recording/reproduction changeover switch circuit (7) via this connection terminal (10).

Pseudo NTSC-M generated by the encoder (4)
The color signal C of the system is supplied to the input terminal of the low frequency conversion circuit (11) which is more powerful than the frequency conversion circuit and to the recording side fixed contact of the second recording/reproduction changeover switch circuit (12), and this changeover switch circuit (12) A color signal reproduced from a videotape is supplied to a fixed contact on the reproduction side of the color signal via a connection terminal (13) as described later.

In addition, (14) shows a PAL-M conversion circuit, and this PAL-M conversion circuit
The LM conversion circuit (14) is a circuit that converts the color signal of the pseudo NTSC-M system into the color signal of the PAL-M system.In other words, the movable contact of the second recording/reproduction changeover switch circuit (12) The color signal containing the resulting pseudo-NTSC-M burst signal is supplied to the input terminal of the PAL-M conversion circuit (14), but the pseudo-NTSC-M color signal F and burst signal 8.4 are The phase is fixed with respect to the color difference signal l3-Y as shown in FIG. 2A.The PAL-M conversion circuit (14) changes the phase of the input burst signal B for each horizontal scanning line ±45° and change the phase of the input color signal F to the color difference signal B.
-Y is used as a reference and is inverted every horizontal scanning line.

By changing the burst signal and the color signal, as shown in FIG. 2B, the color signal is converted into F and Ft whose phases are alternately inverted with respect to the color difference signal B-Y, and the burst signal is converted into the color difference signal B-Y. Phase alternately ±13 with Y as reference
It is converted into Bpl and Bp2 which are 5°. This means that the pseudo NTSC-M color signal has been converted to a PAL-M color signal. This PAL-M
A luminance signal Y generated at the movable contact of the first recording/reproducing switch circuit (7) is supplied to the other input terminal of the adding circuit (15). is supplied, and P synthesized by this adder circuit (15)
The video signal of the AL-M system is supplied to a monitor (16) compatible with the PAL-M system.

In addition, the color signal C generated by the encoder (4) is
C (automatic phase control) circuit (17), and this APC
The signal whose frequency extracted by the circuit (17) is the subcarrier frequency fsc (M) for the PAL-M system is sent to the mixer (18).
is supplied to one input terminal of the At the same time, the luminance signal Y generated by the encoder (4) is sent to the synchronization separation circuit (1).
9), and the frequency separated by this synchronization separation circuit (19) is the horizontal frequency rH for the NTSC-M system (that is, also for the PAL-M system). (20), and this AFC circuit (20) generates a signal of frequency fcL from the periodic signal. This frequency f is the low-pass conversion color subcarrier frequency, and this frequency rcL is, for example, f
It is set to cL=47.25 f□ (=743 kltz).

This signal of frequency fCL is supplied to the other input terminal of the mixer (18), and the carrier signal for low frequency conversion whose frequency is fsc (M) + f ct generated by this mixer (18) is sent to the low frequency conversion circuit ( 11) is supplied to the converted signal input terminal.

Since the subcarrier frequency of the color signal C supplied to the input terminal of this low frequency conversion circuit (11) is fsc(M),
This low frequency conversion circuit (11) converts the color signal C to a frequency rc.
It is converted into a low-frequency converted color signal having a width of about ±500 kl (z) with L as the center, and this low-frequency converted color signal is sent to an adding circuit (
9) to the other input terminal of the adder '5'1 circuit (
9) supplies a low frequency converted color signal using the FM modulated luminance signal as a bias signal to the recording head (22) via the recording amplifier (21).

To explain the operation when the three primary color signals generated by the processor (3) in the example of FIG. 1 are encoded and recorded on the videotape (23) while being displayed on the monitor (16),
In this case, the movable contact of the first recording/reproducing switch circuit (7) is switched to the recording side fixed contact, and the movable contact of the second recording/reproducing switch circuit (12) is also switched to the recording side fixed contact.

Then, the subcarrier frequency generated by the encoder (4) is fsc(M) compatible with PAL-M.
The M system color signal C is converted into a low frequency converted color signal whose carrier frequency is RCT compatible with NTSC-M in the low frequency conversion circuit (11) and recorded on the video tape (23). NTSC-M format video signals are recorded.

At the same time, the color signal C of the pseudo NTSC-M system is PAL.
-M conversion circuit (4) converts it into a complete PAL-M color signal and supplies it to the adder circuit (15), so the video signal obtained by this adder circuit (15) is a complete PAL-M color signal.
It has been converted to M format. Therefore, this video signal is
It can be displayed on an LM compatible monitor (16).

As described above, according to this example, the encoder (4) sets the color subcarrier frequency to fsc(M) compatible with PAL-M, and modulates it in accordance with the NTSC-M method, thereby creating a pseudo-NTSC signal.
A C-M color signal C is generated, and this color signal C is converted into a low-band conversion color signal with a center frequency of fcL using a carrier signal for low-band conversion with a frequency of fsc(M)+fCL. Therefore, the videotape (23) has a complete NTSC-
There is an advantage that M format video signals can be recorded.

This videotape (23) is an NTSC-M VTR.
If so, you can play it as is.

Furthermore, in this example, a PAL-M conversion circuit (14) is provided, and a complete PAL-M color signal can be generated by simply changing the phase of the burst signal, etc. of the color signal C generated by the encoder (4). NTSC-
After returning the M system video signal to baseband, PAL-
There is no need to convert to the M method, and there is an advantage that the circuit configuration is extremely simple.

Next, the playback section of the camera-integrated VTR of this example will be explained with reference to FIG. In this FIG. 3, a playback head (24) and a playback amplifier (2
5), the reproduced NTSC-M format video signal is supplied to a low pass filter (LPF) circuit (26) and a high pass filter (HPF) circuit (29).
The F circuit (26) extracts the low frequency converted color signal, and the HPF circuit (29) extracts the FM modulated luminance signal. The low frequency converted color signal is input to the frequency conversion circuit (27) and the subcarrier frequency is changed to fsc (M) for the PAL-M system.
This color signal C is passed through a crosstalk removal circuit (28) to one input terminal of a phase comparator circuit (31) and to the second recording/reproduction switch circuit (1) in FIG.
2) to the connecting terminal (13) leading to the terminal (13). The other input terminal of the phase comparison circuit (31) is supplied with a signal of frequency fsc (M) from the oscillator (32), and the output signal of the phase comparison circuit (31) is input to one input terminal of the addition circuit (33). The output signal of the correction circuit (34) is supplied to the other input terminal of the adder circuit (33).

The output signal of the adder circuit (33) is supplied to the voltage controlled oscillator (VC○) (35) with a free run frequency of nxrcL, and the output signal of this vC○ (35) is supplied to the n frequency divider circuit (35).
6) and the count pulse input terminal of a counter (37), and the count value of this counter (37) is supplied to the input terminal of a correction circuit (34). In addition, the HPF circuit (
29) is supplied to the Y demodulation circuit (30), and the luminance signal Y demodulated by the Y demodulation circuit (30) is connected to the first recording/reproduction switch circuit (7) in FIG. (10), and the horizontal synchronization signal whose frequency obtained by this Y demodulation circuit (30) is the horizontal frequency ft+ of the NTSC-M system (that is, also for the PAL-M system) is controlled by the counter (37). Supply to the terminal. counter (37),
As is well known, the correction circuit (34) and the addition circuit (33)
It has a function to correct the PC circuit so that it locks accurately.

Then, the output signal of the n frequency divider (36), which has a frequency of approximately fcL, is supplied to one input terminal of the mixer (38), and the output signal of the oscillator (32), which has a frequency of fsc(
M) is supplied to the other input terminal of the mixer (38), and the frequency fsc(M)+ obtained by this mixer (3 days) is
The fct signal is supplied to the conversion signal input terminal of the frequency conversion circuit (27). Since the frequency rcL of the output signal of the n frequency divider circuit (36) is the low-pass conversion color subcarrier frequency in the example shown in FIG. C is output.

Then, while the playback unit shown in the example in Figure 3 is operating, the first
In the illustrated example, by switching the movable contacts of the first recording/playback switch circuit (7) and the movable contacts of the second recording/playback switch circuit (12) to fixed contacts on the playback side,
A PAL-M compatible monitor (16) has a videotape (2
3) The reproduced video signal is displayed.

As mentioned above, according to this example, the videotape (23) has NT
Video signals recorded in SC-M format can be easily
Since it is converted to an AL-M format video signal, it can be used on a PAL-M compatible monitor (
16) has the advantage of being able to generate video signals for Furthermore, according to this example, even when loading a videotape recorded on a normal NTSC-M VTR, it is easy to
An AL-M video signal can be generated, and a PAL-M compatible monitor (16) can be used as is.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various configurations may be adopted without departing from the gist of the present invention.

〔Effect of the invention〕

According to the present invention, there is an advantage that video signals of different color schemes can be generated with a simple circuit configuration.

[Brief explanation of drawings]

FIG. 1 shows the constituent countries of a recording circuit according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the example in FIG. 1, and FIG. 3 shows the constituent countries of a reproducing circuit of one embodiment. (4) is an encoder, (5) is an oscillator, (11) is a low frequency conversion circuit, (14> is a PAL-M conversion circuit, (16) is a PAL-M compatible monitor, (23) is an NTSC-M format This is a videotape.

Claims (1)

[Scope of Claims] The original signal is converted into a video signal of one color system and supplied to the receiver side, and the original signal is converted into a video signal of another color system and recorded on a recording medium. an encoder that converts the original signal into a video signal of the other color scheme at a subcarrier frequency of the one color scheme;
a color signal conversion circuit for converting a color signal of the other color system into a color signal of the one color system, the output signal of the encoder is recorded on the recording medium, and the output signal of the encoder is A video signal recording device characterized in that the video signal is supplied to the receiver side via a signal conversion circuit.