JPS6034308B2 - Video special effect signal generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video special effect signal generation device employed in a video transmission device used in a television broadcasting station, and more particularly to a rotation wipe key signal generation device.

There are many types of key signals for wiping a TV screen, but most of them simply move the wipe boundary line in a parallel or expanding direction. Typical examples include circular wipe, diamond wipe, and vertical wipe. , Fujiwari wipe, corner wipe, etc.

In addition to these wipes, there is a method of rotating the border line around a certain point, but it has not been widely used because it has the disadvantage that the center part cannot be fixed sufficiently on the screen. The rotation method for obtaining the rotating weave of the subordinate will be described below with reference to FIG.

1 and 2 are circuits for generating horizontal and vertical fundamental waves, in which sawtooth waves, triangular waves, etc. having respective periods are generated.

In order to make the content easier to understand, the following explanation will focus on the example of a sawtooth wave, and cases of other waveforms such as a triangular wave will be explained as necessary, but essentially they are all the same. 3 and 4 are bell regulators, which are expressed here as variable resistors for convenience, but of course other circuit systems may be used.

5 is a mixing circuit that mixes and adds horizontal and vertical fundamental waves that have been adjusted by a bell, and this output is sliced at a specific level by a slicing circuit 6 to create a key signal for wiping.

The key signals created in step 6 are two television video signals V^, V
It is added to the selection gate circuit 8 of B, where the screen is switched according to the key signal, and a signal Vo is created in which one image is mixed with the other image according to a predetermined wipe pattern.

Here, it is the level adjusters 3 and 4 that cause the wipe boundary line on the screen to rotate. This relationship will be explained using the waveform in FIG. 2 and the effect on the screen in FIG. 3. Here, in order to make the explanation easier and more accurate in the following explanation, the horizontal and vertical fundamental waves are expressed as WH and Wv, their mixed fundamental wave WHv, and the game key signal obtained by slicing it as WK. . In FIG. 2, when the horizontal fundamental wave WH and the vertical fundamental wave Wv are mixed with the same amplitude, a mixed fundamental wave WHv shown by a solid line in the waveform diagram a is obtained.

Here, the horizontal and vertical time ratios in Figure 2 are exaggerated compared to reality. When this mixed fundamental wave WHv is sliced to the slice level Ls, the waveform shown in FIG. 2b is obtained as the key signal WK.

When the switching circuit 8 is controlled by this b waveform and the signal obtained as the output Vo is expressed on the screen, it becomes as shown in Fig. 3.
, B The two television screens are separated by a boundary line indicated by a solid line. Next, when the level adjusters 3 and 4 increase or decrease the horizontal fundamental wave WH and the vertical fundamental wave Wv in opposite directions, for example, the horizontal fundamental wave WH increases and the vertical fundamental wave Wv
, the mixed fundamental wave W shown by the dotted line in waveform diagram a
Hv' is obtained, and in the same way, the key signal WK' is shown in the waveform diagram c.
obtained as follows.

If we look at the phase of the rising part of the key signals WK and WK' that creates the wipe boundary line, we can see that at the top of the screen, that is, to the left of the waveform diagram, the key signal WK' is to the left of WK, and at the bottom of the screen, the key signal WK' is to the left of WK. ' is to the right of WK, and it does not move at point P in the center of the screen. Therefore, the boundary line in Figure 3 is P
Rotate around the point as indicated by the dotted line. This is the basic principle of rotary wipe. However, the rotation center point P cannot always be stably obtained.

This will be explained with reference to FIGS. 4, 5, and 6.

FIG. 4 shows the mixed fundamental wave WHv of FIG. 2 in another representation, that is, in a state where the waveform is monitored at a vertical period on an oscilloscope.

First, the wipe boundary of the screen by the key signal obtained by slicing the waveform a of FIG. 4 to the slice level Ls is the same as that of FIG. 3, and is represented by a in FIG. 5.

Next, by increasing the horizontal fundamental wave WH and subtracting the vertical fundamental wave Wv, the waveform b is sliced at the slice level Ls.
The boundary line b in FIG. 5 is obtained. Similarly, the boundary line c in FIG. 5 is obtained corresponding to the waveform in FIG. 4c. What needs to be noted here is the relationship between the mixed fundamental wave WHv and the slice level Ls. In the above explanation, the slice level Ls is always at the center of the amplitude of the mixed fundamental wave WHv, as shown in FIG. And so. However, it is generally difficult to maintain such a state all the time. Because, {1}
The level adjusters 3 and 4 not only change the horizontal and horizontal fundamental waves WH and Wv, which are AC components, but also change the DC component.
In order to avoid this, '2) a fundamental wave generation method can be considered in which the DC components of the horizontal fundamental wave WH and the vertical fundamental wave Wv are made zero, but since the DC components are zero, it is difficult to obtain long-term stability. {3} Furthermore, the fundamental wave generation circuits 1 and 2 must be directly connected to the slice circuit 6, and stability is likely to be lacking in this respect as well. (41 It is also possible to use AC coupling without adopting the above direct coupling method and apply a predetermined bias just before the slice circuit 6, but if the rotation is controlled rapidly, transient phenomena will occur and it will take time to settle down.) .

For these reasons, it is difficult to maintain stable conditions on a daily basis, even immediately after carefully adjusting the circuit.

As a result, the slice level L for the mixed fundamental wave WHv
The mutual relationship of s changes, and changes to the slice level Ls', for example, as shown in b and c of FIG. 4. In the example of Fig. 4, as the waveform changes from a to b to c, the relative relationship of the slice level to the mixed fundamental wave WHv becomes Ls', and as a result, the rotation boundary line moves as shown in Fig. 6. Rotation is performed unrelated to point P at the center of the screen, and there is no point that is the center of rotation.

Although the case where both the horizontal fundamental wave WH and the vertical fundamental wave Wv are sawtooth waves has been described above, the same can be said about the case of other waveforms.

For example, if you want to obtain the wipe effect as shown in Figure 7, use the vertical fundamental wave Wv, which used a sawtooth wave in the explanation up to now.
A triangular wave can be used for this purpose.

Figures 8, 9, and 1 represent the waveform changes and screen changes in this case in the same way as Figures 4, 5, and 6.
This is figure 0. In this case, the ninth desired change
In order to obtain the rotational movement of the boundary line shown in the figure, unless the relationship between the mixed fundamental wave WHv and the slice level Ls in FIG. 8 is maintained accurately, the center of rotation will shift as shown in FIG. 10. In FIG. 8, the slice level Ls' is shown as an example in which it deviates above Ls, but if it deviates downward, it becomes as shown by the dotted line in FIG. Such defects occur regardless of the fundamental wave, and another example is the 11th wave.
As shown in the figure, the effect of the hatched area spreading fan-like around point P can be created by using triangular waves for both the horizontal fundamental wave WH and the vertical fundamental wave Wv, but the interaction between the slice point and the mixed fundamental wave W side is still If the relationship cannot be fixed, the tips will become separated as shown in Figure 12. These things not only make it impossible to obtain the desired wipe screen, but also result in an unsightly wipe screen where the center of rotation is not determined. This means that it will not be possible to completely switch to a screen. As mentioned above, it is not enough to secure the rotation center point P, but it is necessary to obtain it accurately and reliably.
For the reasons mentioned above, this was difficult with conventional equipment.

The present invention has been made to eliminate the above-mentioned drawbacks, and by fixing the center of rotation easily, reliably, and accurately, it is possible to realize a wide variety of wiping functions, and to move the center of rotation accurately. The purpose of the present invention is to provide a video special effect signal generating device that can generate video special effects.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The video special effect signal generation device shown in FIG. 13 differs from the conventional video special effect signal generation device described above with reference to FIG. The same parts as those in FIG.

Now, the first difference between the device of the present invention and the conventional device is that
Rather than using the fundamental wave generated by the fundamental wave generation circuits 1 and 2 as is, a reference level is inserted into a predetermined section by the reference level insertion circuits 11 and 12, and then the level is adjusted and mixed.

The predetermined period referred to here is a period inserted in advance to clamp the fundamental wave or its mixed wave before slicing, and normally a pulse within the horizontal blanking period is desirable.

Pulse a shown in FIG. 14a is a pulse for creating a predetermined section, and may be a horizontal planking pulse or a horizontal driving pulse.

Figures 14b and 14c show examples of inserting reference levels when sawtooth waves are selected as the horizontal and vertical fundamental waves, and reference levels LH and Lv are inserted into each waveform during the period of pulse a. has been done.

Although any means may be used to insert such a bell into the original fundamental wave, the circuit shown in FIG. 15 can be used, for example. Here, the transistor TRI forms an emitter follower, and the original fundamental wave applied to the input appears at its emitter. On the other hand, the transistor TR3 generates a reference level, and a DC voltage determined by the slider setting position of the variable resistor R4 is applied to the base, and a DC voltage is applied from the low impedance emitter to the emitter of the transistor TR2.

This transistor TR2 forms a switching circuit,
When a positive pulse is applied to the base through the capacitor C, it is turned on for that period, and the collector is connected to the transistor T.
It becomes a constant level determined by the DC voltage supplied from R3 to the emitter. This level is inserted as a reference level and
During other periods, the transistor TR2 is connected through the resistor RI.
The original fundamental wave appears at the collector of . The pulse supplied via capacitor C here is, of course, the inverted polarity of the pulse shown in FIG. 14a. A transistor TR4 forming an output emitter follower is connected to the collector of the transistor TR2, and a signal is supplied to the next stage via the transistor TR4.
The reference level insertion circuit shown in FIG. 15 above is just an example, and before performing level control or other processing on the original fundamental wave, it inserts a quasi-level that has a certain relationship with the original fundamental wave. Any means of insertion may be used.

As mentioned above, the fundamental waves WH, W with the reference level inserted
v is controlled and further mixed, but this is exactly the same as before. The second difference between the device of the present invention and the conventional device is that when slicing the waveform-processed mixed fundamental wave WHv, the clamp circuit 13 pulse-clamps the mixed fundamental wave WHv within the predetermined section. , the clamp level is kept at a constant value, and slicing is performed at the same slice level as the constant value, that is, the clamp level.

Figure 14d shows the relationship between the mixed fundamental wave WHv and the slice level Ls. Of course, it is a mixture including the above, but by clamping the reference level part as described above,
As a result of slicing at the same slice level Ls, a key signal WK is obtained as shown in FIG.

What is important here is the case where the horizontal fundamental wave WH and the vertical fundamental wave Wv are respectively increased or decreased, and the respective waveforms at that time, that is, WH, Wv, WHv, WK are shown by dotted lines in FIGS. 14b to 14d and f. When the increase or decrease is made in this way, as can be seen from the figure, the slice is sliced at the same slice level Ls as when no increase or decrease is made as shown by the solid line, and this slice level Ls
Since it is always the same as the reference level section, no matter what kind of bell control or mixing method is used, whether the transmission path is direct connection, AC coupling, or even if there are fluctuations in DC. , is clamped before slicing regardless of this, so that the waveform relationship shown in FIG. 14d is obtained. This relationship is expressed by the mixed fundamental waves WHv and WHv shown in Figure 2.
The relationship between ' and the slice level Ls is equivalent to the relationship between the mixed fundamental wave WHv and the slice level Ls shown in FIG. relationship essentially does not occur.

If the reference pulse is normally inserted within the horizontal retrace period, its presence will be ignored on the final television screen.

Further, when we examine the device of the present invention, we find the following interesting facts.

FIG. 16a represents each waveform shown in FIG. 14 in another way, and is convenient for understanding waveform processing by the apparatus of the present invention.

That is, FIG. 16a shows the horizontal and vertical fundamental waves W, Wv shown in FIGS. 14b and 14c corresponding to the time axis of the television screen and displayed on the screen in the respective time axis directions, The relationship between the reference level of each fundamental wave and the center of rotation of the wipe pattern created by the mixed fundamental wave in which each fundamental wave is mixed can be seen at a glance. In this figure, it goes without saying that in the vertical fundamental wave Wv, the reference level incision is exactly the same as the scanning line, but for convenience of display, it is expressed as a set. As can be seen from Figures 14b and 14c, the rotation center point P on the TV screen corresponds to the timing at which Pv coincides with the point PH where the original fundamental wave and the reference level intersect for each of the horizontal and vertical fundamental waves WH and Wv. is each fundamental wave WH
, Wv is obtained as a point that does not move no matter how the levels are controlled.

Therefore, according to the device of the present invention, if the intersections PH and Pv of each fundamental wave and the reference level are determined, . The rotation center point P of the wipe pattern can be easily determined.

As another example, what happens when the wipe pattern shown in FIG. 7 described above is obtained by employing the present invention will be described. That is, in order to obtain the wipe pattern shown in FIG. 17, the horizontal fundamental wave WH is a sawtooth wave and the vertical fundamental wave Wv is a triangular wave, as is the case with the prior art, but the reference level is set as shown in FIG. The horizontal fundamental wave WH is inserted at the lower end of the sawtooth wave, and the vertical fundamental wave Wv is also inserted at the same level as the tip of the triangular wave. As a result, the intersection points PH and Pv between each fundamental wave and the reference level are at the positions shown in the figure, and the rotation center point on the TV screen that corresponds to the timing when these intersection points PH and Pv coincide is fixed at the center of the left side of the screen. Since the wipe boundary changes in the center, the 10th
The phenomenon of change in the center of rotation as shown in the figure does not occur. Similarly, FIG. 18 shows an example in which a triangular wave is applied to the horizontal fundamental wave WH and a sawtooth wave is applied to the vertical fundamental wave Wv.

Furthermore, other waveforms, such as parabolic waves, may be used as the fundamental wave, and as an example, FIG. 19 shows an example in which a parabolic wave is used as the horizontal fundamental wave WH. At this time, the effect is that the parabolic wipe border, which has a fixed center at the bottom center of the screen, expands to the left and right.

Moreover, as shown in FIG. 20, if each fundamental wave WH and Wv are triangular waves and the reference level is set to the middle level of the waveforms,
Two intersections PH and Pv between each fundamental wave and the slice level are obtained, and a rotation effect about four points P, -P4 on the television screen is obtained.

As described above, according to the device of the present invention, a reference level is inserted into each predetermined section of the horizontal and vertical fundamental waves, and the mixed fundamental wave is pulse-clamped within the predetermined sections, and the slice level is the same as this clamp level. Since the rotation center is easily and reliably fixed by slicing, it is also possible to accurately create various rotation effects.

Further, when performing waveform processing such as level control, the DC level may be ignored in the design, increasing the degree of freedom in design.
Furthermore, even when rapid waveform control is performed, the movement of the center of rotation is hardly visible because it is clamped by horizontal period pulses. Furthermore, the third point in which the device of the present invention differs from the slave device is that the feature shown with reference to FIG. 16a is more actively applied to move the center of rotation.

That is, if the reference level is varied by the variable resistor R4 in FIG. 15, and the reference level inserted into each of the horizontal and vertical fundamental waves WH and Wv is changed as shown by the dotted lines as shown in FIG. 16b, each Intersection point P for each waveform
H', and the intersection point Pv' can be obtained. Therefore, as shown in FIG. 16M, the screen that was originally rotated around point P can now be rotated around point P'. i.e. horizontal,
Changing the reference level inserted into each vertical fundamental wave WH, Wv is equivalent to accurately controlling the position of the center of rotation.

Note that the variable resistors (for WH and Wv) for varying the reference level are connected to a wipe control console (not shown).

) may be directly or indirectly connected to the horizontal and vertical positioner adjusters located in be. When moving the center of rotation as described above using the conventional technology, the slice level must be adjusted in synchronization with the level control using, for example, the fader operator 7 in FIG. It was difficult to control accurately and could not be connected to a positioner controller. As described above, the present invention makes it possible to realize a variety of wipe functions by easily, reliably, and accurately fixing the center of rotation, as well as to accurately move the center of rotation as a video special effect signal. We can provide generators.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing a conventional video special effect signal generation device, FIGS. 2 a to c are waveform diagrams shown to explain the operation of FIG. 1, and FIG. Figures 4a to 4c are waveform diagrams in which the horizontal and vertical waveform ratios of the waveform of Figure 2a are different, and Figures 5 and 6 are waveform diagrams of the The figure is shown to explain the rotational change of the wipe boundary line when the slice level Ls of the waveform shown in the figure is constant and when it changes. Figures illustrating examples; Figures 8a to 8e are diagrams showing the waveform changes of the composite fundamental wave necessary to obtain the rotational changes of the wipe boundary line in Figure 7; Figures 9 and 10 are the waveforms in Figure 8; The first diagram is shown to explain the rotational change of the wipe boundary line when the slice level of is constant and when it changes.
Figures 1 and 12 are other examples of wipe patterns on a television screen obtained by the operation shown in Figure 1, showing cases in which the center of rotation is constant and cases in which the center of rotation changes. A configuration explanatory diagram showing one embodiment of the video special effect signal generating device according to the present invention, FIGS. 14a to 14f are waveform diagrams shown to explain the operation of FIG. 13, and FIG. 15 is the standard of FIG. 13. Circuit diagram showing an example of a level insertion circuit, Fig. 16a
, b are diagrams shown to explain the relationship between the horizontal and vertical fundamental waves in FIG. 14 and the wipe pattern on the TV screen, respectively, and FIGS. 17 to 20 are diagrams showing other operation examples of the device in FIG. 13, respectively. FIG. 3 is a diagram shown to explain the relationship between horizontal and vertical fundamental waves and a wipe pattern on a television screen. 1, 2... Fundamental wave generation circuit, 3, 4...
・Level adjuster, 5...Mixing circuit, 6...
... Slice circuit, 11, 12 ... Reference level insertion circuit, 13 ... Clamp circuit, R4 ...
...Variable resistance. Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 9 Figure 10 Figure 13 Figure 4 Figure 8 Figure 11 Figure 12 Figure 15 Figure 14 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20

Claims (1)

[Claims] 1. In a video special effect signal generation device that generates a key signal for controlling the switching and selection of two types of video signals to generate a rotating wipe pattern on a television screen, horizontal and vertical signals with a predetermined section set to a reference level are used. fundamental wave generating means for respectively generating a horizontal fundamental wave signal and a vertical fundamental wave signal having a period of a control means; a mixing means for mixing the horizontal fundamental wave signal and the vertical fundamental wave signal whose amplitudes are controlled by the means to obtain a mixed fundamental wave signal; key signal generation means for clamping at a predetermined clamp level for a level setting section and then slicing at the same level as the clamp level to generate a rotational wipe key signal; a horizontal fundamental wave signal generated by the fundamental wave generation means; 1. A video special effect signal generating device comprising: reference level variable means for variably setting each reference level of the predetermined section of the vertical fundamental wave signal individually or simultaneously.