JPH03219782A - Synchronous signal separation device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a synchronization signal separation method and apparatus for separating and reproducing a vertical synchronization signal from any composite synchronization signal contained in an analog video signal.

[Conventional technology and its issues]

FIG. 6 shows an example of a conventional synchronization signal separation method and device, and is a block diagram for explaining the synchronization signal separation method and device for digitally separating and reproducing a vertical synchronization signal from a composite synchronization signal without using an integrator. be.

In Fig. 6, any composite synchronization signal S or S'1 included in the analog video signal is input, the rise of the composite synchronization signal Sl or S'1 is used as a trigger, and the synchronization period is longer than the synchronization period t1 of the horizontal synchronization signal. 2 of 1 cycle t of horizontal synchronization signal
A pulse S with a constant pulse width T shorter than 1/2. 2 is a one-shot pulse generator that generates a composite synchronization signal S
, or S'I and the output pulse S8 of the one-shot pulse generator 1 are manually sampled at the trailing edge of the pulse Sll from the one-shot pulse generator 1, and the composite synchronization signal S1 or S'+ is at L level. This is a synchronization signal separator that separates the vertical synchronization signal S2 into an L level when it is at an H level and a GtH level when it is an H level.

FIG. 7 is a timing chart when the pulse S6 is generated at the rising edge of the composite synchronization signal S1 input to the one-shot pulse generator 1 in the synchronization signal separation device of FIG. FIG. 7(a) shows the case where a composite synchronization signal with a cutting pulse is input, and FIG. 7(a) shows the case when a composite synchronization signal without a cutting pulse is input.

That is, when the composite synchronization signal St with cutting pulse P is input to the one-shot pulse generator 1, the pulse S
6 is output. This pulse S and the composite synchronizing signal S are input to the synchronizing signal separator 2, and the vertical synchronizing signal S2 contained in the composite synchronizing signal SI is separated and taken out (see FIG. 7(a)).

Furthermore, when the composite synchronization signal S' without a cutting pulse is input to the one-shot pulse generator 1, the pulse S
, is output. This pulse S8 and the composite synchronization signal S'1
is input to the synchronization signal separator 2, and the vertical synchronization signal S is included in the composite synchronization signal Sl.

is separated and taken out (see Fig. 7 (6)).

In FIG. 7(a), the vertical synchronizing signal S2 is correctly separated and extracted, but in FIG. 7(6), the sampled vertical synchronizing signal S2 is the first horizontal synchronizing signal of the video period of the composite synchronizing signal It does not change until the signal arrives, and the first horizontal synchronization signal is included in the vertical synchronization period t, making it impossible to obtain the vertical synchronization signal S2 at the correct timing.

In the prior art using the digital method as described above, there was a problem in that the vertical synchronization signal S2 could not be separated and reproduced at the correct timing from the composite synchronization signal 3'+ having no cutting pulse.

The object of the present invention is to provide a composite synchronization signal 3' without cutting pulses.
It is also necessary to correctly separate and reproduce the vertical synchronizing signal S2 from the +.

[Means to solve the problem]

In order to solve the above-mentioned problems and achieve the above-mentioned objects, the method of the present invention provides vertical synchronization from a composite synchronization signal S or S'- included in an analog human-powered video signal as shown in FIGS. 1 to 5. When digitally separating and reproducing the vertical synchronizing signal S2 in a synchronizing signal separating device that separates and reproduces the signal S2, the separated vertical synchronizing signal S is fed back to the synchronizing signal separating device, and the synchronizing period ts of the vertical synchronizing signal S is It is characterized in that the vertical synchronization signal S2 is separated from the composite synchronization signal SI or S' by switching the separation timing between the video period and the video period.

In order to solve the same problem and achieve the same objective, the first device of the present invention uses vertical synchronization signal St or S'1 included in the analog input video signal as shown in FIGS. 1 and 3. In a synchronization signal separation device that separates and reproduces the synchronization signal S2, the polarity of the composite synchronization signal S1 or S'1 is inverted during the synchronization period ts of the separated vertical synchronization signal S2, and during the video period, the pulse S, A pulse generator 1 generates a pulse S using the output pulse S of the polarity switch 3 as a trigger, and a composite synchronization signal S1 or S using the output pulse S4 of the pulse generator 1. '1 is sampled and the vertical synchronization signal S
This configuration includes a vertical synchronizing signal separator 2 that separates the vertical synchronizing signal.

In order to solve the same problem and achieve the same purpose, the second device of the present invention is designed to provide a vertical synchronization signal S or 3'+ included in the analog input video signal as shown in FIGS. 4 and 5. A synchronization signal separation device for separating and reproducing the synchronization signal S2 includes a pulse generator 1a that generates a pulse S using the rising edge of the composite synchronizing signal S1 or S' as a trigger, and a pulse generator 1a that generates a pulse S when the composite synchronizing signal S1 or S'1 falls. A pulse generator 1b that generates a pulse S6 as a trigger and a separated vertical synchronization signal S are input, and both of the pulse generators 1
a, 1b output pulse Ss, a signal switcher 4 that switches Ss, and a synchronization signal separator 2 that samples the composite synchronization signal S1 or S2 with the output pulse S of this signal switcher 4 and separates the vertical synchronization signal S2. The structure consists of the following.

[For production]

The method of the present invention feeds back the separated vertical synchronization signal S2 to the synchronization separation device as described above, and switches the timing of separation between the synchronization period t of the vertical synchronization signal S2 and the video period to generate the composite synchronization signal Sl or S. The vertical synchronizing signal S2 is separated and taken out from '1.

In the first device, the separated vertical synchronizing signal S2 is fed back to the polarity switch 3, and during the synchronization period t of the vertical synchronizing signal S separated by the polarity switch 3, the composite synchronizing signal St
or the polarity of 3′1 is reversed, and the synchronization (reversal) period t,
During this period, a pulse S3 in which the polarity of the composite synchronizing signal S1 or S'1 is inverted is outputted from the polarity switch 3. This output pulse S3 is input to the pulse generator 1 as a trigger, which outputs a pulse s4. This output pulse S4 causes the vertical synchronization signal separator 2 to generate a composite synchronization signal S or
'1, and the composite synchronization signal S1 or s'1
Therefore, the vertical synchronizing signal S2 is separated and output.

In the second device, a pulse generator 1a is triggered by the rise and fall of the composite synchronization signal St or S'1;
A pulse Ss - Ss is generated at 1b, and these output pulses Ss = Ss are switched by the signal switcher 4 to which the separated vertical synchronizing signal S2 is fed back, and the output pulse S7 of the signal switcher 4 causes the sync separator 2 to The composite synchronizing signal S1 or S' is sampled, and the vertical synchronizing signal s2 is separated from the composite synchronizing signal S1 or S' and output.

〔Example〕

The present invention will be described in detail below based on the drawings.

FIG. 1 is an explanatory block diagram showing the configuration of an embodiment of the method and apparatus of the present invention, and FIG. 2 is a time chart of input/output signals of the polarity switch in the present invention.

In Fig. 1, 3 is a polarity switch that inverts the polarity of the composite synchronization signal S1 during the synchronization period t of the separated vertical synchronization signal S, and inverts the polarity of the composite synchronization signal SI during the synchronization (inversion) period ts. Output pulse S3. 1 is a one-shot pulse generator that generates a pulse S using the rising edge of the output pulse S3 of the polarity switch 3 as a trigger; 2 is a one-shot pulse S;

A vertical synchronization signal separator that samples the composite synchronization signal S1 at the trailing edge and separates and outputs the vertical synchronization signal S2 as an L level when the composite synchronization signal S1 is L level, and as an H level when it is H level. be.

If the composite synchronization signal S input thereto is in the synchronization period t1 of the separated vertical synchronization signal S2, the polarity switch 3 inverts it, and if it is in the video period, it remains unchanged and sends the pulse S to the one-shot pulse generator 1. , outputs. In the one-shot pulse generator 1, the pulse S from the polarity switch 3,
The rising edge of is the trigger, and the horizontal synchronization signal synchronization period 1+
longer than 1/2 of one cycle t2 of the horizontal synchronization signal
A pulse S4 of a constant pulse width T, which is shorter than the pulse width T, is generated. The synchronization signal separator 2 samples the composite synchronization signal S1 at the trailing edge of the input pulse S4 and extracts the vertical synchronization signal S2.
Separate and output.

FIG. 3(a) is a time chart when a composite synchronizing signal with a cutting pulse is input to the synchronizing signal separation device of FIG. 1. As can be seen from the timing chart shown in FIG. 3(a), the synchronization period ts of the vertical synchronization signal S2
The output pulse S of the polarity switch 3 is inverted only during this period. In other words, at the rising edge of the composite synchronizing signal S, the beginning of the synchronization period ts of the vertical synchronizing signal S is sampled, and at the falling edge of the composite synchronizing signal S, the end of the synchronizing period t of the vertical synchronizing signal S is sampled. . Due to this,
It is possible to obtain the vertical synchronization signal S2 with correct timing.

FIG. 3(c) is a time chart when a composite synchronizing signal without a cutting pulse is input to the synchronizing signal separation device of FIG. 1. In this case as well, the vertical synchronizing signal S2 is separated and extracted at the correct timing as shown in FIG. 3(a).

FIG. 4 is an explanatory block diagram showing the configuration of a second embodiment of the method and apparatus of the present invention, in which 1a is a one-shot pulse generator that generates a pulse S triggered by the rise of the composite synchronization signal S, and 1b is a This is a one-shot pulse generator that generates a pulse S6 using the fall of the composite synchronization signal S as a trigger. 4 inputs the vertical synchronization signal S2, and pulses S from the two one-shot pulse generators 1a and 1b.
3. This is a signal switch that switches S6. 2 is a sync signal separator that samples the composite sync signal S1 at the trailing edge of the pulse S7 from the signal switch 4.

This second embodiment uses a signal switcher 4 instead of the polarity switcher 3 of the first embodiment shown in FIG. ing. A one-shot pulse generator 1a that uses the rising edge of the input composite synchronizing signal SI as a trigger to generate a pulse S, and a one-shot pulse generator 1b that generates a pulse S6 using the falling edge of the composite synchronizing signal S1 as a trigger, respectively. Generated pulse S6. S is manually input to the signal switch 4, and during the synchronization period ts of the separated vertical synchronization signal S2, a pulse S6 is triggered by the fall of the composite synchronization signal S1, and during the video period, the rise of the composite synchronization signal S1 is triggered. The pulse S5 is switched by the signal switcher 4, and the sampling timing is changed by the synchronization signal separator 2.

FIG. 5 is a time chart showing the operation of the second embodiment shown in FIG. FIG. 5(a) shows the case where a composite synchronization signal with a cutting pulse is input, and FIG. 5(a) shows the case where a composite synchronization signal without a cutting pulse is input. The pulse interval T of the one-shot pulse is longer than the synchronization period t of the horizontal synchronization signal, and shorter than one-half of one cycle t2 of the horizontal synchronization signal.

In this second embodiment, the input composite synchronizing signal S1 is not inverted and the pulse S3. By switching S, an operation is performed to separate the vertical synchronizing signal S.

The present invention is particularly effective for synchronization signal separation devices such as CRTs, video digitizing devices, and video printers that handle many video signals.

〔Effect of the invention〕

As described above, according to the present invention, in the synchronization signal separation device that separates and reproduces the vertical synchronization signal S2 from the composite synchronization signal S1 or S'1 included in the analog input video signal, the vertical synchronization signal is digitally reproduced. When separating and reproducing S2, the separated vertical synchronizing signal S2 is fed back to the synchronizing signal separation device, and the vertical synchronizing signal S is generated.

This synchronization signal separation method and apparatus is characterized in that the vertical synchronization signal S2 is separated from the composite synchronization signal S or S' by switching the timing of separation between the synchronization period t and the video period. Not only can vertical synchronization signal S2 be correctly separated and reproduced from composite synchronization signal S1 with pulses, but also composite synchronization signal S without incision pulses can be reproduced.
It is also possible to correctly separate and reproduce the vertical synchronizing signal S2 from '1.

[Brief explanation of drawings]

FIG. 1 is an explanatory block diagram showing the configuration of an embodiment of the method and apparatus of the present invention, FIG. 2 is a time chart of the human output signal of the polarity switch in the present invention, and FIG.
Figure 3 is a time chart when a composite synchronization signal with a cutting pulse is input to the synchronization signal separation device shown in the figure.
b) is a time chart when a composite synchronization signal without cutting pulses is manually generated in the synchronization signal separation device of FIG. 1; FIG. 4 is an explanatory block diagram showing the configuration of a second embodiment of the method and apparatus of the present invention; Figure 5(a) shows the case where a composite synchronization signal with cutting pulse is input, and Figure 5(b)
is a time chart showing the operation of the second embodiment shown in FIG. 4 when a composite synchronization signal without cutting pulse is input;
FIG. 6 is an explanatory block diagram showing the configuration of an example of a conventional method and device, FIG. 7(a) shows a case where a composite synchronization signal with a cutting pulse is input, and FIG. 7 is a timing chart showing the operation of the conventional device shown in FIG. 6 when a synchronization signal is input. St, S'+...Composite synchronization signal, S2...
... Vertical synchronization signal, 1, la-1b ... (one shot) pulse generator, 2 ... Synchronization signal separator, 3 ... Polarity switch, t,・・・・・・
・Vertical synchronization (inversion) period, tl...Synchronization period of horizontal synchronization signal, t2...1 cycle of horizontal synchronization signal, T...Constant pulse width, 4... ...Signal switch, S3-S4-Ss-Ss, S7
······pulse.

Claims (6)

[Claims] (1) When digitally separating and reproducing vertical synchronizing signal S_2 in a synchronizing signal separation device that separates and reproduces vertical synchronizing signal S_2 from composite synchronizing signal S_1 or S'_1 included in an analog input video signal, The separated vertical synchronization signal S_2 is fed back to the synchronization signal separation device, and the timing of separation is switched between the synchronization period t_s of the vertical synchronization signal S_2 and the video period, thereby generating the composite synchronization signal S_
1. A synchronization signal separation method characterized in that a vertical synchronization signal S_2 is separated from a vertical synchronization signal S_1 or S'_1. (2) Convert the separated vertical synchronization signal S_2 to the polarity switch (
3), and the polarity switch (3) inverts the polarity of the composite synchronization signal S_1 or S'_1 during the synchronization period t_s of the vertical synchronization signal S_2, leaving it as it is during the video period. Output pulse S_3,
Using this pulse S_3 as a trigger, the pulse generator (1) generates a pulse S_4, and by inputting this pulse S_4 to the synchronization signal separator (2), a composite synchronization signal S_
1 or S'_1 and generates the vertical synchronization signal S_2
2. The synchronization signal separation method according to claim 1, wherein the synchronization signal separation method comprises separating the synchronization signals. (3) In a synchronization signal separation device that separates and reproduces a vertical synchronization signal S_2 from a composite synchronization signal S_1 or S'_1 included in an analog input video signal, when the synchronization period t_s of the separated vertical synchronization signal S_2 A polarity switch (3) that inverts the polarity of the synchronizing signal S_1 or S'_1 and outputs the pulse S_3 as it is during the video period, and the output pulse S of this polarity switch (3).
A pulse generator (1) that generates a pulse S_4 using _3 as a trigger, and an output pulse S_ of this pulse generator (1)
4, a vertical synchronization signal separator (
2) A synchronization signal separation device consisting of: (4) The pulse generator (1) is triggered by the rising edge of the output pulse S_3 of the polarity switch (3), and is longer than the synchronization period t_1 of the horizontal synchronization signal and longer than half of one cycle t_2 of the horizontal synchronization signal. A pulse generator that generates a pulse S_4 with a short constant pulse width T, and a synchronizing signal separator (
2) is a vertical synchronization signal separator that samples the composite synchronization signal S_1 or S'_1 at the trailing edge of the output pulse S_4 of the pulse generator (1) and separates the vertical synchronization signal S_2. Synchronous signal separation device. (5) Rise of composite synchronization signal S_1 or S'_1,
Pulse generators (1a,
1b) generates pulses S_5 and S_6, and returns the separated vertical synchronizing signal S_2 to the signal switch (4) to generate the output pulse S of both pulse generators (1a, 1b).
_5 and S_6 are switched by the signal switcher (4),
2. The synchronizing signal separation method according to claim 1, wherein said output pulse S_7 is input to a synchronizing signal separator (2) to sample the composite synchronizing signal S_1 or S'_1 and separating the vertical synchronizing signal S_2. (6) In a synchronization signal separation device that separates and reproduces a vertical synchronization signal S_2 from a composite synchronization signal S_1 or S'_1 included in an analog input video signal, a pulse is generated using the rising edge of the composite synchronization signal S_1 or S'_1 as a trigger. A pulse generator (1a) that generates the pulse S_5, a pulse generator (1b) that generates the pulse S_6 using the falling edge of the composite synchronization signal S_1 or S'_1 as a trigger, and the separated vertical synchronization signal S_2 are input. A signal switcher (4) that switches output pulses S_5, S_6 of both pulse generators (1a, 1b); and this signal switcher (4)
The output pulse S_7 of the composite synchronization signal S_1 or S'_
A synchronization signal separation device includes a synchronization signal separator (2) that samples a vertical synchronization signal S_2 and separates a vertical synchronization signal S_2.