JPS6030153B2 - Multiple signal extraction pulse generator - Google Patents

Description

[Detailed Description of the Invention] Vm signal for correcting distortion in the transmission path of luminance signals and chromaticity signals during the direct retrace period of television signals, various test signals, still image signals (facsimile), etc. It has been proposed to insert multiplexed signals.

The present invention relates to a multiplex signal extraction pulse generator that extracts a multiplexed signal from a television signal into which the multiplexed signal is inserted in the vertical retrace period, and is particularly susceptible to noise such as weak electric fields or impulse noise. 0. of the first field and the second field. Hu (day is horizontal period)
This makes it possible to reliably extract this multiplexed signal regardless of field differences.

Currently, as shown in FIGS. 1A and 1E, the VIR signal is inserted into the 1st $th horizontal period (282nd horizontal period in the second field) of the vertical retrace period of the television signal. is proposed. This VIR signal is obtained by inserting a reference signal for correcting transmission distortion at the brightness level of skin color, which has the best color discrimination ability in terms of human visual characteristics. 0, the maximum white level is 100, the amplitude peak-to-peak value of burst signal 1 is 40, and the phase is -(B-Y).3.
The reference color signal 2 has the same amplitude and phase as the burst signal, and is superimposed on the luminance level 70 corresponding to the average skin color luminance level, and the reference color signal 2 is superimposed on the vedestal level with a sine wave of 5 milk MHZ. The level of signal 3 is a brightness level of 50, and the level of reference black signal 4 is a brightness level of 7.5.
It is determined that Here, FIGS. 1A and 1E show signals in the vicinity of the vertical blanking period of the first and second fields of a color television signal, respectively. Previously this VI
To extract the R signal, tell the number of horizontal synchronizing signals, including equalization pulses, from the vertical synchronizing signal, or tell the number of burst signals from the vertical synchronizing signal, and insert this burst signal. A pulse generator has been proposed that detects the horizontal period of the first round and extracts this VIR signal. Also, in devices that count burst signals, malfunctions occur in the case of weak electric fields or when noise such as impulse noise is inserted, and this VIR
There was a drawback in that the signal could not be extracted.

Also, the positions where this VIR signal is inserted are the first field and the second field, which are 0. Because there are differences in fields, this 0. There were various difficulties in generating pulses for extracting this VIR signal due to differences in groups. In view of this point, the present invention is designed to enable accurate extraction of VIR signals even in a relatively weak electric field, even when noise such as impulse noise is inserted, and regardless of field differences. This is what I did.

Hereinafter, one embodiment of the multiple signal extraction pulse generator of the present invention will be described with reference to FIG.

In FIG. 3, reference numeral 5 designates an input terminal to which a color television signal as shown in FIG. 1A and E is supplied. Supplied to circuit 6. This first synchronous separation circuit 6
is constructed like a normal sync separation circuit, and obtains horizontal and vertical sync signals on its output side. The output signal of this first synchronization separation circuit 6 is supplied to an integration circuit 7 constituting a vertical synchronization signal separation circuit, and the vertical synchronization signal obtained from the output of this integration circuit 7 is supplied to a vertical oscillator 8 as a synchronization signal, The vertical synchronizing signal obtained from the output of the vertical oscillator 8 is supplied to a vertical output circuit 9, and the signal obtained from the output of the vertical output circuit 9 causes vertical deflection. Further, the composite synchronization signal obtained at the output of the first synchronization separation circuit 6 is supplied to a differentiator circuit 10' that constitutes a horizontal synchronization signal separation circuit, and the horizontal synchronization signal obtained at the output side of this differentiation circuit 10 is converted into an automatic frequency signal. A control signal obtained at the output side of the automatic frequency control circuit 11 is supplied as a control signal to the horizontal oscillator 12, and the output signal of the horizontal oscillator 12 is supplied to one input terminal of the automatic frequency control circuit 11. The horizontal oscillator 12 is synchronized with the horizontal synchronizing signal obtained from the output of the differentiating circuit 10. In this case, the horizontal synchronizing signal obtained at the output side of the horizontal oscillator 12 is a horizontal signal of a predetermined frequency regardless of whether a weak electric field or impulse noise is inserted into the video signal. The output signal of this horizontal oscillator 12 is supplied to a horizontal output circuit 13, and the signal obtained at the output terminal 13a of this horizontal output circuit 13 creates horizontal flattening. The above-mentioned configuration is the same as the conventional one. In this example, the output signal of the horizontal oscillator 12 is supplied via the waveform shaping circuit 14 to the clock mode of a counting circuit 15 that counts horizontal pulses.

In this case, since the width of the horizontal pulse obtained at the output side of the horizontal oscillator 12 is wider than the width of the horizontal synchronization signal obtained at the output side of the first sync separation circuit 6, the waveform shaping circuit 14 generates a green signal after this horizontal pulse. is made to coincide with the trailing edge of the horizontal synchronization signal obtained at the output side of the synchronization separation circuit 6. Further, this counter 15 is configured to count the trailing edge of the clock pulse obtained at the output of this waveform shaping circuit 14. Further, in this example, the output signal of the first synchronous separation circuit 6 is supplied to the second synchronous separation circuit 16, which has a relatively large charging time constant and a relatively small discharging time constant. In this case, the charging time constant is set to such an extent that the horizontal synchronizing signal and equalization pulse signal are not obtained on the output side of the second synchronizing separation circuit 16, and the discharging time constant is set so that the horizontal synchronizing signal and the equalizing pulse signal are not obtained on the output side of the second synchronizing separation circuit 16, and the discharging time constant is set so that the horizontal synchronizing signal and equalization pulse signal are not obtained on the output side of the second synchronizing separation circuit 16. The amount of delay shall be substantially negligible.
Specifically, as shown in FIG. 3, the output side of the first synchronous separation circuit 6 is connected to the base of an NPN transistor 16C via a series circuit of a resistor 16a and a capacitor 16b. is grounded through a resistor 16d, the emitter of this transistor 16c is grounded, and the collector of this transistor 6c is connected to the resistor 16.
A power supply terminal Vcc to which a positive DC voltage is supplied via e
and connect this collector to NPN transistor 1
6f, the emitter of this transistor 16f is grounded, the collector of this transistor 16f is connected to the power supply terminal Vcc via a resistor 16g, the collector of this transistor 16f is grounded via a capacitor 16h, and further The collector of this transistor 6f is connected to an NPN transistor 6 constituting an output switching element.
The emitter of this transistor 16i is grounded, the collector of this transistor 6i is connected to the power supply terminal Vcc via a resistor 16i, and an output terminal is derived from the collector of this transistor 16i. . In this case, for example, if a composite synchronizing signal as shown in FIG.
is turned off. Further, the transistor 6C is turned off at the falling edge of the synchronization signal, and the transistor 16f is turned on at this time. Therefore, the transistor 16i on the output side
When the transistor 16f is off, the voltage at the base of the transistor 16f is determined by the charging time constant of the second synchronous separation circuit 16, which is determined by the resistor 16g and capacitor 6h' that form the charging path.
Further, the discharge time constant of the second synchronous circuit 16 is determined by the resistance value when the capacitor 6h and the transistor 16f forming the discharge path are turned on. This second synchronous separation circuit 16 can have a relatively large charging time constant and a relatively small discharging time constant. In this case, the time constant determined by the resistor 16g and the capacitor 16h is a time constant that does not turn on the transistor 6i even when a horizontal synchronizing signal is supplied to the input side. Also, 0.0. It is assumed that the time constant is such that the transistor 16i becomes conductive when the Tanaka pulse is supplied. Therefore, in this example, when a composite synchronization signal as shown in FIGS. 1B and H is supplied to the input side of the second synchronization separation circuit 16, the first
It is possible to obtain pulse signals whose trailing green color substantially coincides with the trailing edge of the pulses forming the vertical synchronizing signal at positions corresponding to the six pulses forming the vertical synchronizing signal as shown in Figures C and G. can. 2. The output signal of the second synchronous separation circuit 16 is supplied to the clear terminal of the counter 15.

This counter 15 is constructed so that, for example, when counting a horizontal pulse of one stitch, one trigger pulse is obtained as its output. The signal is supplied to the trigger terminal of a monostable multivibrator 7 having a time constant of the IH to be formed, so that a multiple signal extraction pulse is obtained at the output terminal 17a of this monostable multivibrator 17. In the above example, only the discharge path formed by the transistor 16f is turned on and off, but it is obvious that the charging path formed by the resistor 16g may be turned on and off simultaneously and reciprocally. Since the present invention is constructed as described above, when the input terminal 5 is supplied with the first field of the click color television signal as shown in FIG. B
A composite synchronization signal as shown in FIG. 1B is obtained, and this composite synchronization signal as shown in FIG. A clear pulse as shown in FIG. 1C is obtained,
This clears the counter 15 and also clears the counter 15.
A horizontal oscillator 1 as shown in FIG. 1D is connected to the clock terminal of
Since the horizontal pulse obtained at the output side of the second synchronization separation circuit 16 is supplied, this counter 15 counts the falling edge of the pulse after the last clear pulse obtained at the output side of the second synchronous separation circuit 16. When the first charging pulse is counted, a trigger pulse is obtained on the output side of this counter 15, and this is supplied to the monostable multivibrator 7, so the power terminal 17a has a trigger pulse as shown in FIG. 1A. It is possible to obtain a multiplexed signal extraction pulse that can extract the VIR signal inserted in the first slope of the vertical female line period.

In this case, since the falling time constant of the second sync separation circuit 16 is relatively small, the corresponding horizontal pulse can be counted immediately after the vertical sync signal. Further, when the color television signal of the second field as shown in FIG. 1E is coupled to the input terminal 5, a composite sync signal as shown in FIG. At this time, a clear pulse as shown in FIG. 1G is obtained at the output side of the second synchronous separation circuit 16, thereby clearing the counter 15. Further, the clock terminal of this counter 15 is supplied with a horizontal pulse obtained at the output side of the horizontal oscillator 12 as shown in FIG. After counting the first horizontal pulse, a trigger pulse is obtained, which is supplied to the trigger terminal of the monostable multivibrator 17, and inserted into the output side of this monostable multivibrator 7 in the 282nd horizontal period. Multiple signal sampling pulses corresponding to sampling the VIR signals can be obtained. In this case, the trailing edge of the vertical synchronization signal and the next corresponding horizontal pulse are 0. Since there is a difference in the number of fields, it is possible to count without any malfunction. Although not shown, it is obvious that the color television signal applied to the input terminal 5 can be gated using the extraction pulse obtained at the output terminal 17a to extract the multiplexed signal.

As described above, according to the present invention, the first field and the second field are 0. Definitely V regardless of field difference
There are benefits to extracting the IR signal.

Further, in the present invention, the counter 15 counts the horizontal pulses on the output side of the horizontal oscillator 12 controlled by the automatic frequency control circuit 11, which are obtained on the output side of the horizontal oscillator 12. Therefore, even in a weak electric field, there is an advantage that accurate counting can be performed regardless of whether noise such as impulse noise is included in the color television signal. In the above embodiment, the horizontal pulse obtained at the output side of the horizontal oscillator 12 is supplied to the clock terminal of the counter 15 via the waveform shaping circuit 14, but in this case, the waveform shaping circuit 14 is not provided. Of course, it is also possible to count the horizontal blanking signal formed by the output signal of the horizontal oscillator 12 as the clock pulses counted by the counter 15.

Further, the present invention is not limited to the above-described embodiments, and various other configurations may be adopted without departing from the gist of the present invention.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining the present invention, respectively, and FIG. 3 is a configuration diagram showing an embodiment of the multiple signal extraction pulse generator of the present invention. 5 is an input terminal, 6 and 16 are synchronous separation circuits, 11 is an automatic frequency control circuit, 12 is a horizontal oscillator, and 15 is a counter. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A charging path and a discharging path are provided for the capacitor, and the discharging path is turned on and off at the rising and falling portions of the synchronization signal of the television signal, and the charging time constant via the charging path is relatively large, and the discharging path is The time constant of discharge through the capacitor is set relatively small, and the switching element is turned on and off using the voltage obtained in the capacitor, and from the switching element,
A pulse signal whose trailing edge has a substantially negligible delay amount with respect to a vertical synchronization signal is obtained, and a predetermined number of horizontal pulses after the trailing edge of the pulse signal are detected and inserted into the vertical retrace period. A multiple signal extraction pulse generator characterized in that an extraction pulse is obtained at a multiple signal position.