JPH0315877B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an alarm circuit in an editing recording and reproducing device, and in particular, when a PAL color video signal reproduced by an external reproducing device such as a VTR is supplied as a recording signal. In an editing recording and reproducing device that performs electronic editing by splicing recording or insert recording at a desired position on a magnetic tape, an editing system that records the field order of externally input color video signals to be recorded is used. The present invention relates to an alarm circuit that generates an alarm when the field order of a color video signal is recorded in a manner that does not match the field order of the color video signal.

Conventional technology Conventionally, a color video signal reproduced by an external reproduction device such as a VTR is supplied as a recording signal, and continuous recording is performed from a desired position on a recorded magnetic tape, or external input reproduction is performed in a desired section. 2. Description of the Related Art Editing recording and reproducing apparatuses are known that perform electronic editing by insert recording color video signals.
When performing electronic editing using such an editing recording and reproducing device, the vertical synchronizing signal phase must be matched at the joint between the externally input reproduced color video signal to be recorded and the already recorded color video signal on the recorded magnetic tape. , and it is well known that a frame servo circuit is provided which performs recording in a continuous manner in frame units. With this frame servo circuit, in an editing recording and reproducing device for NTSC color video signals, the horizontal synchronization signal phase is H/2 (where H is the horizontal scanning period) for interlaced scanning between odd and even fields. By being shifted, it is possible to prevent the upper part of the playback screen from momentarily shaking at the editing point.

However, even in editing recording and reproducing devices applied to PAL color video signals, since the frame servo circuit described above is conventionally used, there is a probability of about 1/2 of color skipping (so-called color flash).
However, this occurred at the edit point. In other words, the PAL color video signal is a signal obtained by band-sharing multiplexing a luminance signal and a carrier color signal, respectively, and the carrier color signal is a color difference signal (R-Y) and (B-Y) that is a color subcarrier. It is a modulated wave obtained by carrier suppression quadrature two-phase modulation of the frequency sc, and also a color difference signal (R-Y).
It is well known that the phase of the color subcarrier of is inverted for each line (scanning line). Here, as is well known, the color subcarrier frequency sc is expressed as {284-(1/4)} _H +25 [Hz], where _H is the horizontal scanning frequency, and the color subcarrier frequency changes the phase approximately every 1/4H. is reversed, and the second
The phase is reversed every frame due to the 25Hz term.

On the other hand, since PAL color video signals are also interlaced scanned, the phase between the vertical synchronization signal of one field and the vertical synchronization signal of the next field is 1/2H.
It's off. Therefore, from the above, in the case of a PAL color video signal, the phase of the color subcarrier changes in four field cycles.

This will be further explained with reference to FIGS. 1A to 1E. FIGS. 1A to 1E show waveform diagrams near the vertical synchronizing pulse of each field of a PAL color video signal, respectively. In the figures A to E, the arrows indicate the transmission position of the color burst signal, the upward arrow indicates that the color burst signal has a phase of +135° with respect to the R-Y axis, and the downward arrow indicates the color burst signal. Indicates that the signal is at a phase of -135° with respect to the RY axis. Figure 1 A, B, C, D are the first,
The signal waveforms near the start positions of the second, third, and fourth fields are shown.
In the fields, the vertical synchronization signals have the same phase, but the color burst signals have different phases (the same applies between the second field and the fourth field). Also,
The phases of the vertical synchronization signal and the color burst signal are different between the first and third fields and the second and fourth fields.

However, the field following the fourth field is as shown in Figure 1E, and each phase of the vertical synchronization signal and color burst signal of this field is different from that of the vertical synchronization signal and color burst signal of the first field shown in Figure 1A. All coincide with each phase of the burst signal.
Therefore, in the PAL color video signal, the phase of the color subcarrier changes in four field cycles.

However, the above-mentioned conventional frame servo circuit distinguishes between odd-numbered fields and even-numbered fields and records the odd-numbered fields and even-numbered fields so that they are connected alternately. As the signal of the field to be edited and recorded next after the second field, the third field, which is an odd field, or the first field.
The signal from one of the fields was edited and recorded. However, in the above case, the third
There is no problem if you edit and record the signal of the field, but if you edit and record the signal of the first field, when playing back on a monitor receiver, you will notice that the order of the fields at the editing point is not the normal order. The burst phase discriminator in the monitor receiver detects the modulated wave obtained by modulating the carrier wave with the color difference signal (R-Y). There is a time delay between switching and reconnecting the line switch to select and output the signal to be inverted, and during this time a phenomenon occurs in which the colors of the reproduced image become unstable (this is called a color skipping phenomenon). .

Additionally, if the control signal of the magnetic tape being edited is recorded during the recording of the second and fourth fields, or if there is a dropout just before the editing point, the above-mentioned color bleed phenomenon may occur. .

Problems to be solved by the invention However, conventionally, external inputs that should be recorded
The field order of the PAL color video signal is
Whether or not the field order has been recorded in accordance with the previously recorded PAL color video signal on the editing side is determined by monitoring changes in the hue of the color image displayed on the monitor receiver. but,
When the editing recording/playback device is in the playback mode before the editing point, it outputs the PAL color video signal played from the recorded magnetic tape on the side to be edited to the monitor receiver, and switches to the recording mode just before the editing point. If the editing recording/playback device is of a type that starts recording the external input PAL color video signal to be recorded and also switches the output signal to the monitor receiver to this external input PAL color video signal. Since the color skipping phenomenon in the color image (monitor image) of the monitor receiver near the editing point is for a short period of time, the monitor image near the editing point must be watched carefully. For this reason, especially when there are many editing points or when editing tapes are produced in large quantities, editors become very fatigued, and editors often have to look at counters that indicate the start and end points of editing points, or when editing tapes in large quantities. Since operations are sometimes performed, it is not possible to focus only on the monitor image, and the above-mentioned color skipping phenomenon may be overlooked, which has been a hindrance to improving editing efficiency.

Furthermore, if the editing recording and reproducing device does not have the above-mentioned switching function of the output signal to the monitor receiver, after completing the electronic editing, the edited recorded magnetic tape can be played back. It is necessary to monitor whether or not the above-mentioned color skipping phenomenon occurs in the monitor image, resulting in a problem of poor editing efficiency.

Therefore, the present invention provides an editing record that solves the above-mentioned problems by issuing a warning continuously during the recording mode of the editing recording and reproducing device when the field order is not matched in the vicinity of the editing point. The object of the present invention is to provide an alarm circuit in a playback device.

Means for Solving the Problems The present invention provides means for generating a mode signal indicating whether an editing recording and reproducing device is in a recording mode or a reproducing mode, a PAL color video signal to be recorded, and a recorded signal to be edited and recorded. played from a recording medium
First and second flag pulses indicating one predetermined field of each PAL color video signal (hereinafter referred to as "color frame pulses")
and a phase that detects and stores when the phases of the first and second flag pulses do not match at the playback mode immediately before entering the recording mode. mismatch detection means, an alarm element, and means for making the operating mode of the alarm element different from when the phase mismatch detection signal is not output during the recording mode period when the phase mismatch detection signal is output from the phase mismatch detection means. An embodiment of the present invention will be described below with reference to FIG. 2 and the subsequent drawings.

Embodiment FIG. 2 shows a block system diagram of an example of an editing recording/reproducing apparatus equipped with the circuit of the present invention. Although the present invention can be widely applied to conventional editing recording and reproducing devices, the present applicant has filed a patent application dated December 13, 1988 (invention title: “Color frame servo circuit in editing recording and reproducing device”). The present invention will be explained by taking as an example a case in which the present invention is applied to an editing recording and reproducing apparatus equipped with a color frame servo circuit proposed by the authors. In FIG. 2, a PAL color video signal to be recorded, played back by an external VTR, for example, is input to an input terminal 1, and a video recording circuit 2, a phase comparator circuit 3,
The signal is supplied to a control signal generation circuit 4 and a color frame pulse detection circuit 5, which will be described later. When recording external input video signals by electronic editing, switches SW ₁ , SW ₂ and SW ₃ are connected to contact R, respectively. On the other hand, in order to search for an editing point, a recorded magnetic tape (not shown) is played back prior to recording the externally input PAL color video signal.
During this reproduction, the switches SW ₁ , SW ₂ and SW ₃ are each connected to the contact P side.

As a result, the recorded signal on the recorded magnetic tape reproduced by the rotary head 6 is supplied to the video reproduction circuit 7 via the switch SW ₁ , where it is converted into a reproduced color video signal compliant with the PAL system through known signal processing. After that, it is supplied to a color frame pulse detection circuit 8, which will be described later. As will be described later, the color frame pulse detection circuits 5 and 8 are circuits that detect a predetermined field among the first to fourth fields of the PAL color video signal to generate a color frame pulse, and the output color frame pulses are is supplied to the comparison control circuit 9.

The comparison control circuit 9 is a circuit that generates a signal to gradually speed up (or slow down) the capstan motor 14 until the phases of the two input color frame pulses match, and the output signal is sent to the terminal of the switch circuit 10. 10a. This switch circuit 10 is controlled by a coincidence signal taken out from a part of the comparison control circuit 9, and when the phases of the two color frame pulses do not match, it is connected to the terminal 10a side, and when the phases match, it is connected to the terminal 10a side. is switched and connected to terminal 10b. Note that when searching for an edit point, the switch circuit 10 always uses the terminal 10.
Connected to side b. The color frame pulse generation circuits 5, 8, comparison control circuit 9, and switch circuit 10 constitute the color frame servo circuit proposed by the applicant.

On the other hand, the color frame pulse taken out from the color frame pulse detection circuit 8, the reference color frame pulse taken out from a part of the comparison control circuit 9, and the main editing machine generated and outputted from the input terminal 20, for example, from a microcomputer. A mode signal for setting the operating state of the recording or reproducing state to a recording or reproducing state is respectively supplied to a display circuit 11, which will be described later, and which constitutes a main part of the present invention. Here, the mode signal is, for example, at a high level when the editing recording and reproducing device is in the recording mode, and at a low level when it is in the reproducing mode.
It is a value signal.

When searching and registering the editing start point and editing end point on the recorded magnetic tape, and then recording the externally input PAL color video signal by splicing or insert recording, the recorded magnetic tape is once located at the editing point. After being rewound for a certain period of time from the recording position, the tape is made to run forward again from the upstream side of the editing start point and is first reproduced. During this reproduction period, when the phases of the output color frame pulses of the color frame pulse detection circuits 5 and 8 do not match, the output signal of the comparison control circuit 9 is taken out from the switch circuit 10, and the output signal of the comparison control circuit 9 is taken out from the switch circuit 10. They are supplied to the capstan motor 14 through the drive circuits 13, respectively, and are controlled to rotate at a gradual speed increase or deceleration. As a result, the running speed of the recorded magnetic tape gradually increases or decreases.

The rotational speed of the capstan motor 14 is detected by a known frequency generator (FG) 15, and a frequency corresponding to the rotational speed is extracted as a rotational speed detection signal and supplied to the frequency-voltage conversion circuit 16, where it is After being converted to voltage, it is further mixed circuit 1
2. When the phases of the above two color frame pulses match (this matching point is on the upstream side of the tape from the editing start point), the switch circuit 1
0 is switched and connected to the terminal 10b side.

On the other hand, in the above reproduction mode, the control signal reproduced by the control head 17 from the control track of the recorded magnetic tape is transmitted to the switch SW ₂ , the amplifier circuit 18 and the switch SW 2 .
The signals are supplied to the phase comparator circuit 3 through the SW ₃ , where the phase is compared with, for example, a vertical synchronizing signal in the externally input reproduced color video signal from the input terminal 1. Therefore, from the time when the phases of the two color frame pulses match, the output phase error voltage of the phase comparison circuit 3 and the output speed error voltage of the frequency-voltage conversion circuit 16 are mixed in the mixing circuit 12, respectively. ,
It is supplied to the capstan motor 14 through the drive circuit 13 and controls its rotation.

Then, when the tape playback position reaches the editing start point in the above state, the editing recording/playback device automatically enters the recording mode, and switches SW ₁ , SW ₂ and SW ₃ are turned on.
are respectively switched and connected to the contact R side. This results in
External input taken out from video recording circuit 2
A signal obtained by converting the PAL color video signal into a predetermined signal format is supplied to the rotary head 6 through the switch SW ₁ , and begins continuous recording or insert recording on the recorded magnetic tape. At the same time, the control signal generating circuit 4 divides the vertical synchronizing signal in the reproduced color video signal from the input terminal 1 into half and supplies the control signal to the control head 17 through the switch SW ₂ . Accordingly, a control signal is recorded on the control track, for example, at one frame period when recording the first and third fields. Furthermore, FG15
The rotation speed detection signal extracted from the frequency dividing circuit 1
The signal is frequency-divided by 9 to produce a signal with one frame period, and then supplied to the phase comparator circuit 3. The above recording mode continues until the editing end point. In this way,
Electronic editing is performed.

Next, to explain the circuit of the present invention in more detail, FIG. 3 shows a circuit system diagram of an embodiment of the main part of the circuit of the present invention. In the figure, the same components as in FIG. 2 are designated by the same reference numerals. At the start of automatic editing, as mentioned above, input terminal 1 is connected to external input playback.
A PAL color video signal is input, and a PAL color video signal reproduced by an editing recording/reproducing device from a position a certain time before the editing start point of the recorded magnetic tape is input to the input terminal 21. do.
Now, the input terminal 1 receives a PAL color video signal a to be recorded in the field order schematically shown in FIG. Assume that a reproduced PAL color video signal d is input.

The PAL color video signals a and d that have entered the input terminals 1 and 21 are supplied to color frame pulse detection circuits 5 and 8. Here, as is clear from FIGS. 1A to 1E, there are the following two methods for detecting color frame pulses. The first method is to determine and detect the phase difference between color burst signals on any line viewed from the vertical synchronization pulse between odd or even fields. In addition, in the second method, the timing at which the color burst signal first appears immediately after the vertical synchronization pulse is in the order of the third, second, first, and fourth fields, and the timing at which the color burst signal first appears in the field is (For example, when a color burst signal first appears in the 6th H, that field becomes the third field.) The present invention can use either of these two detection methods, but in this embodiment, the color frame pulse generation circuits 5 and 8 adopt the second method, which requires a relatively simple circuit, and the first to An example will be described in which a third field among the fourth fields is discriminated and a color frame pulse is generated when the third field enters.

As a result, the color frame pulse generation circuit 5
A first color frame pulse b as shown in FIG. 4B is taken out from the color frame pulse generation circuit 8, and a second color frame pulse e as shown in FIG. The color frame pulses b are supplied to reference color frame pulse generation circuits 22 in the comparison control circuit 9, respectively. The reference color frame pulse generation circuit 2 delays the color frame pulse b by a period slightly smaller than 4 fields, and generates a pulse c having a constant width wider than the pulse width of the color frame pulse b, as shown in FIG. 4C. , the D-type flip-flop 2 in the display circuit 11 uses this pulse c as a reference color frame pulse.
It is applied to the data input terminal D of No. 3.

On the other hand, the color frame pulse e mentioned above has two inputs.
The signal is supplied to one input terminal of the AND circuit 24, where it is ANDed with a signal obtained by inverting the polarity of the mode signal input from the input terminal 20 by the inverter 25. Therefore, during the period when the editing recording and reproducing device is reproducing the recorded PAL color video signal on the tape upstream side of the editing point of the recorded magnetic tape to be edited and recorded, the AND circuit 24 outputs a color frame. Pass pulse e, then external input playback PAL from input terminal 1 from near the above editing point
When recording of the digital color video signal onto the recorded magnetic tape is started, the output signal of the inverter 24 becomes low level, so that a low level signal is output. The output signal of the AND circuit 24 is applied to the clock input terminal CP of the flip-flop 23.

Flip-flop 23 has a clock input terminal CP
For example, at the rising edge of the input signal, this circuit samples the level of the input reference color frame pulse c at the data input terminal D at that time and outputs the signal obtained from the Q output terminal. During the period _T1 shown, the fields of the input PAL color video signals a and d do not match, so the phases of the color frame pulses b (or c) and e do not match, and the Q output signal of the flip-flop 23 is low. level. On the other hand, when both fields of input PAL color video signals a and b match, and as a result, the phases of color frame pulses b (or c) and e match (period T ₂ described later), the flip-flop The Q output signal of 23 becomes high level. This flipflop 2
The Q output signal of No. 3 is supplied to the 2-input OR circuit 26, where it is logically summed with, for example, a 4 Hz oscillation output signal from the oscillator 27, and then sent to the 2-input AND circuit 2.
is supplied to one input terminal of 8.

Here, the color frame pulse e is supplied as a clock pulse to the clock input terminal of the flip-flop 23 during the reproduction mode of the editing recording/reproducing apparatus as described above, but during the recording mode, the AND circuit 24 closes the gate. '' state and blocks the passage of the color frame pulse e, so no clock pulse is input. Therefore, the flip-flop 23 stores information indicating whether the phases of the color frame pulses b (or c) and e match or do not match immediately before the editing recording and reproducing apparatus switches from the reproduction mode to the recording mode.

The mode signal from the input terminal 20 is supplied to the other input terminal of the AND circuit 28. Therefore, when the editing recording/playback device is in playback mode,
The output signal of the AND circuit 28 becomes low level,
Therefore, no current flows through the light emitting diode 30, and the light emitting diode 30 is turned off. On the other hand, when the editing recording and reproducing device enters the recording mode, the input terminal 20
Since the input mode signal of is high level, AND
The output signal of the OR circuit 26 is taken out as it is to the circuit 28, and is connected to the light emitting diode 3 via the resistor 29.
0.

Here, as mentioned above, when the editing recording and reproducing apparatus switches from the playback mode to the recording mode, the flip-flop 23 stores the phase match between the color frame pulses b (or c) and e just before switching to the mode. When the mismatch information is stored and the phases of color frame pulses b (or c) and e match, flip-flop 2
Since the Q output signal of No. 3 is at a high level, the output signal of the OR circuit 26 is also at a high level, and the light emitting diode 30 is turned on during the recording mode. Furthermore, when the phases of color frame pulses b (or c) and e do not match, the Q output signal of the flip-flop 23 is at a low level, so the output signal of the oscillator 27 is taken out at the output terminal of the OR circuit 26. During the recording mode, the light emitting diode 30 is blinked at 4 Hz.

Therefore, the rotation of the capstan motor 14 is controlled by the color frame servo circuit, and during the reproduction mode, both reproduction PAL color video signals a and d are reproduced at time _t1 in FIGS. 4A to 4E. For example, if the fields match in the second field, color frame pulses b and e are not output at this time, but color frame pulses b and e are output at time t ₂ near the start of reproduction of the next third field.
If the phases of e match and the editing recording and reproducing device switches to recording mode during the period T ₂ after time t ₂ , the light emitting diode 30 is turned on, and the editing is recorded in the correct order at the editing point. It is possible to display that what has been done.

On the other hand, if the editing recording/playback device switches from playback mode to record mode within the above period _T1 ,
As described above, the light emitting diode 30 is caused to blink, thereby continuously displaying and issuing a warning during the recording mode that the fields were recorded out of correct order at the editing point. Therefore, the editor can know that the recorded field order near the editing point is not normal even if he is not watching the monitor image.

Application Example Note that the present invention is not limited to the above-described embodiments; for example, the element for generating the alarm may be a lamp, or it is also possible to generate the alarm by sound using a buzzer or the like. Furthermore, if it is assumed that the phase is mismatched when the light is off in the recording mode, and the state when the light is on is normal, the oscillator is not required.

Effects As described above, according to the present invention, if the field order of the externally input color video signal to be recorded does not match the field order of the recorded color video signal on the editing side, the recording will not be possible. Since the alarm is generated during the mode period, there is no need to pay close attention to the monitor image, which greatly reduces editor fatigue when there are many editing points or when creating a large number of editing tapes. In addition, it is possible to easily know where color frame editing is inappropriate without having to play back the editing tape each time, and as a result, the time required for editing confirmation can be significantly shortened, thereby improving editing efficiency. It has features such as the ability to

[Brief explanation of the drawing]

Figures 1A to 1E are waveform diagrams near the vertical synchronizing pulse of each field of the PAL color video signal, respectively.
FIG. 2 is a block system diagram showing an example of an editing recording and reproducing device previously proposed by the applicant, which is equipped with the circuit of the present invention, and FIG. 3 is a circuit system diagram showing an embodiment of the main part of the circuit of the present invention. , and 4 are timing charts for explaining the operation of the block system shown in FIG. 3, respectively. 1... PAL color video signal input terminal to be recorded, 5, 8... Color frame pulse detection circuit, 6... Rotating head, 9... Comparison control circuit, 10... Switch circuit, 11... Display circuit ,
14... Capstan motor, 17... Control head, 20... Mode signal input terminal, 21
...Playback PAL color video signal input terminal, 2
2...Reference color frame pulse generation circuit, 23
...D-type flip-flop, 24, 28...2-input AND circuit, 26...2-input OR circuit, 27...
Oscillator, 30... light emitting diode.

Claims (1)

[Claims] 1. The recorded PAL color video signal is played back from a position a certain period before the recording position of the editing point of the recorded recording medium to be edited and recorded, and the externally input PAL color video signal is reproduced from near the editing point. The editing recording and reproducing device that starts recording on the recorded recording medium includes means for generating a mode signal indicating whether the editing recording and reproducing device is in a recording mode or a reproducing mode, and an external input PAL to be recorded.
a first detection circuit for detecting a first flag pulse indicating a predetermined - field among the first to fourth fields of the system color video signal;
a second detection circuit for detecting a second flag pulse indicating the predetermined - field among the first to fourth fields of the PAL color video signal; a phase mismatch detecting means for detecting and storing a mismatch in phase of the first and second flag pulses at the time of the playback mode immediately before entering the recording mode, and an alarm element; When the output signal of the phase mismatch detection means and the mode signal are respectively supplied and the phase mismatch detection signal is output from the phase mismatch detection means, the operation mode of the alarm element is changed to the phase during the recording mode period. 1. An alarm circuit in an editing recording/reproducing device, comprising means for determining when a mismatch detection signal is not output.