JPS6034306B2 - 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 parallel or in the enlarged direction. Typical examples include circular wipe, diamond wipe, and vertical wipe. , horizontal 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. A conventional circuit system for obtaining a rotational dip will be described below with reference to FIG.

Reference numerals 1 and 2 are horizontal and vertical fundamental wave generation circuits, in which well-known sawtooth waves, triangular waves, etc. 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 generate 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 embedded in the other image according to a predetermined dip pattern.

Here, it is the level adjusters 3 and 4 that can cause the rotation of the wave boundary line on the screen. This relationship will be explained using the waveform in FIG. 2 and the effect on the screen in FIG. 3. In order to make the following explanation easy and accurate, the horizontal and vertical fundamental waves are expressed as WH and Wv, their mixed fundamental wave as WHv, and the gate key signal obtained by slicing it as WK. did. In Figure 2, the horizontal fundamental wave WH and the vertical fundamental wave W
When the waves v are mixed with the same amplitude, the mixed fundamental wave WHv shown by the 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 at 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 W'K is shown in the waveform diagram c.
obtained as follows.

Here, if we look at the phase of the rising part that creates a wipe boundary between key signals WK and W'K, we can see that at the top of the screen, that is, on the left side of the waveform diagram, key signal W'K is to the left of WK, and at the bottom of the screen, key signal W'K is to the left of WK. W'K is to the right of WK and does not move at point P in the center of the screen. Therefore, the boundary line in FIG. 3 rotates around point P as a 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 in the 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 at the slice level Ls is the same as that of FIG. 3, and is represented by a in FIG. 5.

Next, by slicing at the slice level Ls using a waveform b obtained by increasing the horizontal fundamental wave WH and subtracting the vertical fundamental wave Wv, 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 mixed fundamental wave WHv and the slice level Ls.
In the above explanation, it is assumed that the slice level Ls is always at the center of the amplitude of the mixed fundamental wave WHv, as shown in FIG. However, it is generally surprising that such a state is always maintained. Because '1}
The level adjusters 3 and 4 not only change the horizontal and vertical fundamental waves WH and Wv, which are AC components, but also change the DC component.

In order to avoid this, a fundamental wave generation method can be considered in which [21] 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.

'31 Also, from the fundamental wave generation circuits 1 and 2 to the slice circuit 6
It is necessary to use a direct connection method up to the point where it tends to lack stability. '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 between s changes, and for example, the slice level L's changes as shown in b and c of FIG. 4. In the example of Fig. 4, as the waveform changes from a to b and c, the relative relationship of the slice circuit 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 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.

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 9th change, which is originally a desirable change,
In order to obtain the circuit movement of the boundary line shown in the figure, the relationship between the mixed fundamental wave W side and the slice level Ls in FIG. 8 must be maintained accurately, otherwise 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 as another example, as shown in Figure 11, the effect that the shaded area spreads in a fan shape around point P is due to the horizontal fundamental wave WH and vertical fundamental wave Wv. can be created by using triangular waves for both, but if the mutual relationship between the slice point and the mixed fundamental wave WHv cannot be fixed, the peaks will become separated as shown in FIG.

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 described above, it is not sufficient to obtain the rotation center P point approximately, but it must be obtained accurately and reliably, but this has been difficult with conventional devices for the reasons mentioned above.

In order to eliminate the above-mentioned drawbacks, a video special effect signal generating device has been devised that makes it possible to realize a variety of wipe functions by easily, securely, and accurately fixing the center of rotation.

Hereinafter, an example of a conventional video special effect signal generating device will be described in detail with reference to FIGS. 13 to 20.

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 shown in FIG. 13 and the device shown in FIG.
2, a reference level is inserted into a predetermined section, and then level adjustment and mixing are performed.

The predetermined section referred to here is a section inserted in advance to clamp the fundamental wave or its mixed wave before slicing, and usually 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 drive pulse.

Figures 14b and 14c show examples of inserting reference pulses when sawtooth waves are selected as the horizontal and vertical fundamental waves. In each waveform, reference levels LH and Lv are inserted 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 ratio of resistors R2 and R3 is applied to the base, and a DC voltage is applied from the emitter of low impedance 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 TR is connected through the resistor RI.
The original fundamental wave appears outside the second correction. 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.
Note that the reference level insertion circuit shown in FIG. 15 above is an example, and a reference level that has a certain relationship with the original fundamental wave is inserted before performing level control etc. on the original fundamental wave. Any means will do.

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.

Next, the second difference between the device shown in FIG. 13 and the device shown in FIG. 10, keep the clamp level at a constant value, and slice at the same slice level as the constant value, that is, the Clasp level.

Figure 14d shows the relationship between the mixed fundamental wave WHv and the slice level Ls.
Of course, it is a mixture of the horizontal fundamental wave WH and the vertical fundamental wave Wv shown in , including the reference level part, but the reference level part is crushed as described above, and the slurry Z at the same level is As a result of slicing at the chair 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 each waveform at that time, that is, WH
, WHv, and WK are shown by dotted lines in FIGS. 14b to 14d and f.

When increased or decreased 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. No matter how Bell control or mixing is performed, whether the transmission path is direct-coupled, AC-coupled, or even there is variation in DC, the first
The waveform relationship shown in Figure 4d is obtained. This relationship is the second
The relationship between the mixed fundamental wave WHWW′Hv and the slice level Ls shown in the figure is equivalent to the relationship between the mixed fundamental wave WHW'Hv and the slice level Ls shown in FIG. This relationship between slice levels L's essentially does not occur.

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

Further, when we examine the device shown in FIG. 13, we find the following interesting facts.

FIG. 16 represents each waveform shown in FIG. 14 using another method, and is convenient for understanding the waveform processing by the apparatus shown in FIG. 13.

In other words, Figure 16 shows the horizontal and vertical fundamental waves WH and Wv shown in Figures 14b and 14c corresponding to the time axis on the TV screen and displayed on the screen in the respective time axis directions. The relationship between the reference level on the wave and the rotation center of the wipe pattern created by the mixed fundamental wave in which each fundamental wave is combined can be seen at a glance. In this figure, it goes without saying that there are exactly as many reference level cuts in the vertical fundamental wave Wv as there are scanning lines, but they are roughly expressed for convenience of display. As can be seen from Figures 14b and 14c, the rotation center intersection 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 obtained as a point that does not move no matter how the levels of the fundamental waves WH and Wv are controlled.

Therefore, according to the apparatus shown in FIG. 13, by determining the intersection points PH and Pv between each fundamental wave and the reference level, 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 is obtained by employing the apparatus shown in FIG. 13 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 P day 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 corresponding to the timing when these intersection points PH and Pv coincide is fixed at the center of the left side of the screen, and The wipe boundary changes around , so the first
The phenomenon of change in the center of rotation as shown in Figure 0 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.

Further, the fundamental wave may be of another waveform, for example, a parabolic 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 apparatus shown in FIG. 13, a reference level is inserted into each predetermined section of the horizontal and vertical fundamental waves, the mixed fundamental wave is pulse-clamped within the predetermined sections, and the slice at the same clamp level is Since it is sliced at a level, the center of rotation can be fixed easily and reliably, and various rotational effects can be created accurately.

Furthermore, when performing waveform processing such as level control, the DC level may be ignored in the design, increasing the degree of freedom in installation. 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. However, in the above-mentioned video special effect signal generation device, the level control of each of the horizontal and vertical fundamental waves WH and Wv is performed by controlling either the positive or negative waveform of each waveform from zero to the maximum. Wipe control could only be performed by changing two quadrants when viewed from the center of rotation of the wipe pattern on the TV screen.

For example, in the example of FIG. 16 mentioned above, the boundary line rotates upward from the horizontal state to the right, and moves only 90 degrees until it becomes vertical. The present invention was made in view of the above circumstances, and
The horizontal and vertical fundamental waves WH and Wv do not change in level between unidirectional polarities, and by controlling the levels across positive and negative polarities, a video special effect signal generating device is provided that can further diversify the types of wipe effects. This is what we provide.

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

The video special effect signal generating device shown in FIG. 21 differs from the related device described above with reference to FIG. 13 in that polarity inverting circuits 13 and 14 and level controllers 15 and 16 are added. However, since the other parts are the same, the same parts in FIG. 21 as those in FIG.

The polarity inversion circuits 13 and 14 are the reference level insertion circuit 11.
, 12 output signals are introduced, and output signals of positive and negative polarities are derived.

Level control of this world power signal over positive and negative sacrifices is carried out by level controllers 15 and 16, and the signal is guided to the mixer 5. If the polarity of either the horizontal fundamental wave WH or the vertical fundamental wave Wv is reversed with respect to the reference level, a boundary line with an inclination opposite to that of the wipe pattern boundary line shown in FIG. 16 described above is obtained. . For example, as shown in FIGS. 22a to 22e, in contrast to FIGS. 14a to 14e, if the vertical fundamental wave Wv is inverted with respect to the reference level, the resulting wipe boundary line will be upward-leftward.

Further, as shown in FIG. 23, when the level of the horizontal fundamental wave WH is changed from the solid line to the dotted line to the region of the opposite polarity, it also passes the wipe boundary line and changes to the reverse polarity. Similarly, the wipe effect when the horizontal fundamental wave WH is a triangular wave or a parabolic wave is shown in FIGS. 24 and 25. If this is further continued and the horizontal and vertical fundamental waves WH and Wv are controlled in mutually opposite directions, it is easy to rotate the boundary line once, and the situation at this time is shown in FIG.

FIG. 26 shows an example of the horizontal and vertical fundamental waves WH, Wv and a sawtooth wave, and shows a series of operations from a to k. First, in state a, the vertical fundamental wave Wv is initially zero and the horizontal fundamental wave WH is at its maximum value, so that the television screen is vertically divided into two, with image A displayed on the left and image B on the right. Next, the vertical fundamental wave Wv increases, and the horizontal fundamental wave WH
decreases, so the boundary line tilts to the right.

Next, when the state moves to state b, the horizontal fundamental wave WH decreases to zero, and the vertical fundamental wave Wv increases to its maximum value, the screen is horizontally divided into two, with images A on the top and B on the bottom.

Next, the state moves to state c, where the horizontal fundamental wave WH reverses the polarity of a and b, increases from zero in that direction, and becomes the vertical fundamental wave W.
v starts decreasing from the maximum value.

A description of the states d to h will be omitted below, but after the state h, the state returns to the state a again, during which time the boundary line has rotated once. Note that FIG. 27 shows another embodiment in which, compared to the configuration shown in FIG. The difference is that the amplitude is controlled by using the switches 17 and 18, but as can be seen in Fig. 26, the shock that is applied to the dip pattern when the polarity is changed by switches 17 and 18 is that the level of the horizontal fundamental wave WH or the vertical fundamental wave Wv is zero, that is, There is no problem because the polarity is switched only when the output is attenuated to zero by the level controllers 3 and 4.

Furthermore, even if a DC-like fluctuation occurs, it will be absorbed by the aforementioned clamp circuit (10 in FIGS. 13 and 21) and will have no effect. Further, the circuits shown in FIGS. 21 and 27 illustrate the principle, and each waveform process can be performed accurately and smoothly by using other specific circuits, such as a digital control circuit.

As described above, the present invention allows the center of rotation to be fixed easily, reliably, and accurately.
It is possible to provide a video special effect signal generating device that can realize various rotational wipe functions such as one rotation.

[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 diagram is shown to explain the rotational change of the dip 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.
1 and 12 are other examples of the wipe pattern on the TV screen obtained by the operation shown in FIG. 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 generation device under consideration, FIGS. 14a to 14f are the first
Waveform diagram No. 15 shown to explain the operation of the device shown in FIG.
The figure is a circuit diagram showing an example of the reference level insertion circuit of FIG. 13, and FIG. 16 is a diagram shown to explain the relationship between the horizontal and vertical fundamental waves of FIG. 14 and the wipe pattern on the television screen.
17 to 20 are diagrams shown to explain the relationship between the horizontal and vertical fundamental waves and the wipe pattern on the television screen in other operational examples of the device shown in FIG. 13, and FIG. 21 is a diagram showing the image according to the present invention. A configuration explanatory diagram showing one embodiment of the special effect signal generating device, FIGS. 22a to 22e are waveform diagrams shown to explain the operation of the device in FIG. 21, and FIG. 23 is a horizontal diagram of FIG.
Figures 24 to 26 are diagrams shown to explain the relationship between the vertical fundamental wave and the wipe pattern on the TV screen.
A diagram shown to explain the relationship between the horizontal and vertical fundamental waves and the wipe pattern on the television screen in another example of the operation of the device shown in the figure, and FIG. 27 is a configuration explanatory diagram showing a part of another embodiment of the present invention. It is. 1, 2... Fundamental wave generation circuit, 5... Mixing circuit, 6... Slice circuit, 1 1, 12...
...Reference level insertion circuit, 10... Clamp circuit,
13, 14...Polarity inversion circuit, 16, 16...
...Level controller. Figure 1 Figure 3 Figure 5 Figure 6 Figure 7 Figure 2 Figure 4 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Fig. 18 Fig. 19 Fig. 20 Fig. 21 Fig. 22 Fig. 27 Fig. Eagle and Snake Diagram Size N Boat Diagram Heron Boat Diagram Lagoon

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 level control means for controlling increase/decrease across the range, a mixing means for mixing the horizontal fundamental wave signal and the vertical fundamental wave signal whose amplitudes and polarities are controlled by the means to obtain a mixed fundamental signal, and a mixed fundamental wave obtained by the means. It is characterized by comprising key signal generation means for clamping the signal at a predetermined clamp level for a reference level setting section of each fundamental wave signal and then slicing it at the same level as the clamp level to generate a key signal for rotational wipe. Video special effect signal generator.