JPS6059793B2 - Video recording and playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video recording and reproducing device, particularly a video recording and reproducing machine (
VTR), it distinguishes between NTSC signals, PAI signals, SECAM signals, etc. and outputs different discrimination signals, and also detects that the video recording/playback device is in the playback state, and outputs control signals according to the detection results. The present invention relates to a video recording and reproducing device that outputs.

For example, in a video recording/playback device that can record and play back signals of two or more formats, such as NTSC and PAL formats, depending on the format, a receiver that can process signals of both formats is required. shall be.

For example, in order to obtain both NTSC and PAL signals on a cathode ray tube as a normal screen, vertical width correction, color processing circuit switching, video signal band correction, etc. must be performed manually or automatically depending on the differences between the two systems. It is also necessary to record the running tape speed, drum rotational speed, or video signal in a video recording/playback machine that can record and play back signals of two or more formats, such as NTSC and PAL formats, or both. Due to differences in reproduction methods, it is necessary to correct or switch them depending on the method. In addition, for example, in a system where a video recording/playback device can be connected to a TV receiver, it is necessary to select whether the receiver receives the video signal from the video recording/playback device or the TV video signal from the receiver. It is. In this type of conventional device, when the receiver receives a video signal from a video recording/reproducing device, the receiver manually switches the signal. The present invention provides a video recording and reproducing apparatus that can automatically perform corrections caused by the difference in the above-mentioned systems, and can also automatically select between a television video signal and a video signal from a video recording and reproducing device.

This invention will be explained in detail below using an embodiment of the invention shown in FIG.

In FIG. 1, 1 is a system discriminator, for example, NTSC.
For the PAL and NTSC systems, the focus is on the difference in the period of the horizontal synchronization signal, and the number of synchronization signals within a certain period of time is counted and distinguished. That method is low level (L level)
is output to terminal 2.

Reference numeral 3 denotes a video signal processing device which superimposes the H level or L level outputted by the system discrimination device 1 on the video signal applied to the video signal input terminal 4 and outputs it to the video signal output terminal 5.

Both the system discrimination device 1 and the video signal processing device 3 are included in the video recording/playback device 6. A concrete example of the system discrimination device 1 and the video signal processing device 3 is shown in FIG.

In FIG. 2, the same parts as in FIG. 1 are designated by the same reference numerals.

First, the method discriminator 1 will be explained. In FIG. 2, 7 is a reference oscillator having a tuning fork 7a for the first tape speed and a tuning fork 7b for the tape speed of FIG. A tape control circuit 8 controls a servo system (not shown) based on the oscillation frequency of the reference oscillator 7.

9 is a frequency dividing circuit that divides the oscillation output of the reference oscillator 1; 10
11 is a control signal amplifier that amplifies the control signal recorded on the tape, and 11 is a comparator that compares the frequency of the output signal of the frequency dividing circuit 9 and the frequency of the output signal of the control signal amplifier 10 for discrimination.

In this configuration, when the first tape speed is the PAL recording system and the second tape speed is the NTSC recording system, various characteristics, ie, vertical frequency, control signal frequency, and recording tape speed, are shown in Table 1.

Here, focusing on the control signal recorded on the tape, if a tape recorded at the first tape speed (PAL. system) is played back at the first tape speed of 23.39Wr1n/S, it will take 25 seconds according to the system. Obtain a control signal of .00Hz.

However, when a tape recorded in the P, AL system is reproduced at the second tape speed (N'ISC system) of 33.357 m/s, the control signal becomes as follows.

Next, the second tape speed (NTSC system) 33.35 order/
By playing back the tape recorded at the second tape speed, a control signal of 29.97 Hz is obtained according to the method.

However, when a tape recorded in the NTSC system is played back at the first tape speed (PAL, system), the control signal becomes.

On the other hand, if the oscillation frequency of the reference oscillator 7 is 1867 Hz at the first tape speed and 2663 Hz at the second tape speed, the frequency dividing circuit 9
When the frequency is divided, the frequency obtained from the frequency dividing circuit 9 is 23.04 (Hz) depending on the first and second tape speeds.
), 32.87 (Hz).

This relationship is shown in Table 2. As is clear from Table 2,
If the output frequency of the frequency divider circuit is set as above, the PA
The control signal frequency during playback of a tape recorded in the L method is always higher than the output frequency of the frequency dividing circuit 9 when played back at the first or second tape speed.

Conversely, the control signal frequency when playing back a tape recorded at the second tape speed (NTSC system) is
Alternatively, when playing back at the second tape speed, the frequency will always be lower than the output frequency of the frequency divider circuit 9. Therefore, the comparator 11 determines by which system the reproduced tape is recorded depending on whether the frequency of the reproduced control signal is higher or lower than the frequency of the frequency dividing circuit, and the H level is determined. Alternatively, an L level signal is output to terminal 2.

Next, the video signal processing device 3 will be explained.

In FIG. 2, 12 to 16 are resistors, 17 is a transistor, and 18 is a capacitor. The H level or L level output of the system discriminator 1 is applied from terminal 2 to dividing resistors 15 and 16, and the video signal is applied from terminal 4 to the base of transistor 17 via dividing resistors 12 and 13. As a result, an output in which the output of the system discriminator 1 and the video signal are superimposed is obtained at the terminal 5 as the output of the video recording/reproducing device 6.
given to 0. The receiver 19 detects the H level or L level signal sent superimposed on the video signal from the video recording/reproducing device 6, and performs NTSC operation if it is at the H level; The level is selected to operate in a system other than the NTSC system (PAL system, SECAM system, and other systems), and vertical width correction, color processing circuit switching, video signal band correction, etc. are performed.

Next, a configuration for detecting that the video recording/reproducing device 6 is in a reproducing state and selecting a television video signal and a video signal from the video recording/reproducing device 6 will be explained using FIG.

In FIG. 1, 21 is an audio signal processing device, 22 is a coupling capacitor, and 23 is a switch, which is electrically or mechanically turned on when the playback button of the video recording/playback device 6 is turned on, and turned off when the playback button is turned on. becomes.

24 is a transistor, 25 to 29 are resistors, and 30 is an output terminal of the video recording/reproducing device 6.

31 is an input terminal of the television receiver 19, into which an output signal from the output terminal 30 of the video recording/reproducing device 6 is input.

32 to 39 are resistors, 40, 41 are capacitors, 42, 4
3 is a transistor, 44 is a switch, and 45 is a control device, which controls the position of the switch 44.

46 is a video detection device for outputting a television video signal, 47 is a video processing device, and 48 is a cathode ray tube.

First, when the playback button of the video recording/playback device 6 is turned on, the switch 23 is turned on, the transistor 24 is turned on, and a signal in which a high-level signal is superimposed on the audio signal is generated at the output terminal 30.

On the other hand, when an input on which a high level (H level) signal is superimposed is given to the receiver 19, the transistor 42 is turned on, the control device 45 is operated, and the switch 44 is turned on.
is connected to the terminal a side, and a video signal from the video recording/reproducing device 6 is applied to the cathode ray tube 48. Next, when the playback button of the video recording/playback device 6 is turned off, the switch 23 is turned off.
Transistor 24 is turned off.

Therefore, a signal in which a low level (L level) signal is superimposed on the audio signal is generated at the output terminal 30 and sent to the receiver 19. In the receiver 19, the transistor 42 is turned off, the control device 45 is operated, the switch 44 is connected to the terminal b side, the video signal from the video recording/reproducing device 6 is turned off, and the TV video signal from the video detection device 46 is turned off. is applied to the cathode ray tube 48. Although one embodiment of the present invention has been described so far, the following configuration is also conceivable. As a result of the discrimination in the system discriminator 1, instead of outputting the H level or L level, a different code signal or a different frequency signal may be output.

Similarly, by turning on and off the playback button of the video recording/playback device 6, a different code signal or a different frequency signal may be output instead of outputting the H level or L level.

Furthermore, the discrimination signal of the system discrimination device 1 may be superimposed on an audio signal instead of being superimposed on a video signal, and a signal generated depending on the playback state of the video recording/playback device 6 may be superimposed on the video signal. It may be superimposed on a signal other than the video signal to be transmitted to the receiver 19, and
The receiver 19 is
It may be transmitted to

Furthermore, the discrimination signal of the system discriminator 1 can be divided into two signals by using, for example, signals of different high and low levels, and by using, for example, different code signals or different frequency signals for the signals generated when the video recording/reproducing device 6 is in the reproduction state. A different signal may be superimposed on the video signal, the audio signal, or one of the signals to be transmitted to the receiver 19 and transmitted. As described above, according to the present invention, in a video recording and reproducing machine, the NT
Distinguish at least two or more system signals among SC system signals, PAL system signals, SECAM system signals, and other system signals, output first control signals respectively according to the results of the discrimination, and perform video recording and playback. Since the system detects that the device is in the playback state and outputs the second control signal according to the detection result, for example, in a passive device such as a television receiver, the method can be controlled by detecting the first control signal. In addition to making the selection automatically, by detecting the second control signal, it is possible to automatically select whether to receive the TV video signal or the video signal from the video recording/playback device, and the receiver No special manual operation is required.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram for explaining one embodiment of the present invention,
FIG. 2 is a block diagram for explaining a part of FIG. 1 in detail. In the figure, 1 is a system discrimination device, 3 is a video signal processing device, 4 is a video signal input terminal, 5 is a video signal output terminal, 6 is a video recording and reproducing device (TR), 19 is a television receiver, and 21 is an audio signal 4 is a processing device, 44 is a switch, 45 is a control device, 46 is a video detection device, 47 is a video processing device, 4
8 is a cathode ray tube.

Claims (1)

[Claims] 1 A first broadcast system signal in which a control signal is recorded on the tape at a first tape speed, and a second broadcast system signal in which a control signal is recorded on the tape at a second tape speed different from the first tape speed. A video recording and reproducing device capable of reproducing a broadcasting system signal, wherein the first reference oscillation frequency is
Recorded at the second tape speed that is lower than the frequency of the control signal recorded at the first tape speed obtained when played back at the first tape speed, and which is lower than the frequency of the control signal recorded at the first tape speed obtained when played back at the first tape speed. the second reference oscillation frequency is set higher than the frequency of the control signal recorded at the first tape speed obtained when playing back at the second tape speed, and the second reference oscillation frequency is set higher than the frequency of the control signal recorded at the first tape speed, and a reference oscillation source set higher than the frequency of the control signal recorded at the second tape speed obtained when playing back at the second tape speed; The reference oscillation frequency is compared with the frequency of the control signal recorded on the tape, and when playing at the second tape speed, the second
a discriminator that compares the reference oscillation frequency of the playback control signal with the frequency of the control signal recorded on the tape and determines whether the frequency of the playback control signal is high or low with respect to the reference frequency; a system discrimination means for outputting a first control signal indicating whether the first broadcasting system signal is a second broadcasting system signal; a detecting device for detecting that the first broadcasting system signal is in a playback state; A video recording and reproducing device comprising an output means for outputting a second control signal indicating whether or not the state is the same.