JPS6034310B2 - Video special effects equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video special effects device that combines a plurality of television signals in a specific pattern to form one television image.

A conventional video special effects device will be explained with reference to FIG.

Note that various combination patterns can be considered as the composite image synthesized by the video special effects device, but for example, the second
As shown in figure a, it is a point-like image with approximately the left diagonal half being A,
A case will be described in which a composite image is generated in which the diagonal right half is a diagonal line image B, and the images A and B are heavy at the boundary between the two images.

Numerals 11 and 12 in FIG. 1 are fundamental wave generators that generate fundamental wave signals, and one of the fundamental wave generators 11 generates a sawtooth signal with a repeating period of one horizontal scanning period IH as shown in FIG. 3a. Waves et al.

Further, from the other fundamental wave generation wave 12, a mirror tooth wave t2 having a repeating period of one vertical scanning period IV is derived.
This sawtooth wave t2 is coupled to the mixing circuit 13 via the switch SW, and mixed with the sawtooth wave derived from the fundamental wave generator 11 to generate a mixed fundamental wave signal. Therefore, the fundamental wave signal which is the output of the mixing circuit 13 has a form in which both the mirror tooth waves t, t2 are weighted, and the waveform thereof is shown by T in FIG. 2b.

The fundamental wave signal is subjected to, for example, amplitude control in the next-stage control circuit 14, and then applied to the slice circuit 15.
This slice circuit 15 converts the fundamental wave signal T to a level L.as shown in FIG. 2b. and level L2, and by slicing, the slicing circuit 15
From this, a control signal S as shown in FIG. 2c is generated.

The control signal S is coupled to a television signal selection circuit 17 via an adder 16.

This selection circuit 17 provides a television signal that presents a dotted image as indicated by A from the first channel CHI, and a television signal that presents a diagonal image indicated by B from the second channel CH2. 4, the machine axis represents the level of the control signal supplied via the adder 16, and the vertical axis represents the level of the control signal supplied through the adder 16. has a characteristic that as the control signal input increases, the output of the first channel CHI decreases, while the output of the second channel CH2 increases.

As a result, when the television screen is reproduced using the output of the selection circuit 17, an image as shown in FIG. 2a is obtained as described above.

Note that a screen (A + B) in which images A and B are superimposed is obtained at the boundary between image A and image B, but this weight image is based on the slope of the rising edge of the series of control signals. This is due to

Furthermore, when synthesizing television images for broadcasting, the pattern is not limited to the one shown in FIG. 2 a, but also the pattern shown in FIG. Direct contact screens may be required.

In order to obtain such a screen, a control signal as shown in FIG. 2e is generated and applied to the selection circuit 17.

When obtaining a control signal as shown in Fig. 2e, for example, the first
In the circuit configuration shown in the figure, the mixed fundamental wave signal T derived from the mixing circuit 13 is amplified by the control circuit 14 to obtain a steep waveform as indicated by the dotted line To in FIG. It can be obtained by slicing in the same manner as described above in 15.

The operation of the control circuit 14 includes not only controlling the gain of the signal derived from the mixing circuit 13 as described above, but also inverting the polarity or adding direct current depending on the required composite image. It has additional functions such as

Furthermore, in the above explanation, the control signal is obtained after mixing the fundamental waves of both fundamental wave generators 11 and 12 in the mixing circuit 13, but the type of wipe waveform, that is, the type of composite image. Depending on the signal generator 11 or 1
It is also possible to generate a control signal using the second signal.

Therefore, similarly to one of the fundamental wave generators 11, a mixing circuit 131, a control circuit 141, and a slicing circuit 151 are connected to the subsequent stage of the fundamental wave generator 12, respectively.

Further, the fundamental wave signals generated by the fundamental wave generators 11 and 12 can be processed separately, and then combined by the adder 16 to obtain a control signal.

As described above, in the conventional video special effects apparatus, the signals applied to the selection circuit for selecting a plurality of television signals are all obtained by slicing the signals using a slicing circuit. Therefore, if the level of the signal applied to the slice circuit changes, the waveform of the control signal changes, making it impossible to obtain a good composite image.

For example, if the amplitude of the fundamental signal is controlled by a control circuit located before the slice circuit, if the slice level is constant, the position of the rise of the control signal will shift each time the amplitude is controlled, and the boundary of the composite image will become uneven. There were drawbacks to moving it.

That is, as shown in Figure 5a, if the first arriving fundamental wave signal is denoted by U and the amplitude-controlled fundamental wave signal is denoted by V, the slice output of each of these fundamental wave signals is as shown in Figure 5b. become that way.

That is, when the slice levels are L and L2, the slice output of the fundamental wave signal U is X, and the slice output of the fundamental wave signal V is Y.

As can be seen from this figure, when the selection circuit is controlled by one slice output It becomes 1.

This difference in the amplitude components of the fundamental wave signals supplied to the slice circuit causes the boundary of the image to be synthesized to move, which has the drawback of making the reproduced image very unsightly. In order to prevent financial damage as mentioned above,
It is conceivable to adjust the slice level in response to the amplitude control of the fundamental wave signal, but it is difficult to accurately follow the amplitude control of the fundamental wave signal and the adjustment of the slice level, and the movement of the boundary as described above is difficult. It was difficult to avoid the phenomenon.

The present invention provides an image bead effect device that solves the above-mentioned drawbacks.

An embodiment of the present invention will be described below with reference to FIG.

Note that, in the following explanation, a case will be explained in which a composite image as shown in FIG. 2a is obtained, as in the case of the explanation of the prior art.

Reference numeral 21 denotes a first fundamental wave generation circuit that generates a fundamental wave that defines the boundary between each pixel A and B of the combined television image, and as shown in FIG. 3a, the repetition period is, for example, one horizontal scanning period. A mirror tooth wave t, having t, is generated.

This sawtooth wave L' is also applied to the pulse addition circuit 22.
23 is a second fundamental wave generating circuit that generates a fundamental wave similar to the fundamental wave generating circuit 21, and as shown in FIG. A wave t2 is generated, and this sawtooth wave t2 is supplied to the pulse addition circuit 24.

On the other hand, 25 is a reference pulse generation circuit, and this generation circuit 25
From this, a reference pulse Ps as shown in FIG. 7a is generated in synchronization with, for example, a horizontal planking pulse P applied from the outside.

This reference pulse Ps is applied to the pulse adding circuit 22,
24 and adds a reference level to a predetermined section of the mirror-toothed waves t, . . . added from the fundamental wave generating circuits 21 and 23. The pulse adding circuits 22 and 24 are
For example, the circuit configuration is as shown in FIG.

That is, the sawtooth wave derived from the fundamental wave generating circuits 21 and 23 is applied from the terminal i to the base of the transistor TRI.

The sawtooth wave is applied from the emitter of the transistor TRI to the collector of the transistor TR2 via the resistor RI. On the other hand, the reference pulse Ps as described above is applied to the base of the transistor TR2, and it is in a conductive state only during the period when this reference pulse Ps is applied.

Therefore, when the transistor TR2 is in a non-conducting state, the sawtooth wave applied to the collector of the transistor TR2 directly passes through the base of the transistor TR4 to the output terminal ○.
It is derived from

On the other hand, when the transistor TR2 is in a conductive state, the reference potential of the resistor RS is taken out from the output terminal ◯ via the base of the transistor TR4.

Therefore, if the reference potential applied to one pulse addition circuit 22 is EH, and the reference potential applied to the other pulse addition circuit 24 is EV, then one pulse addition circuit 2
2, as shown in FIG. 7b, a sawtooth wave whose predetermined section is set to the reference potential EH, for example, is derived. Further, from another pulse adding circuit 24, as shown in FIG. 7c, the position where the reference potential EH is added is the reference potential E
A sawtooth waveform set to V will be derived.

Note that the reference potentials EH and EV added by the pulse adding circuits 22 and 24 are constant, and are each, for example, OV.

On the other hand, the output of the reference pulse generation circuit 25 is applied to a variable resistor VR, the output terminal of the pulse addition circuit 22 is connected to a network of resistors R4 and R5, and the output terminal of the pulse addition circuit 24 is connected to a resistor R6 and R7. It is connected to the sliding contact of the variable resistor VR through.

Therefore, each output b, c of the pulse adding circuits 22, 24
A pulse whose amplitude is varied by a variable resistor VR (see Fig. 7 d. The dotted line and arrow indicate the range of change in pulse amplitude) is added to the mirror tooth wave output shown in Fig. 7 e and f. is obtained. The sawtooth wave e is applied to a mixing circuit 26, in which a switch S
It is mixed with the lock-tooth wave f supplied via W.

The mixed fundamental wave mixed by this mixing circuit 26 is
It is indicated by To in Figure g. The mixed fundamental wave signal To is transmitted to the control circuit 2
At step 7, processing such as amplification is performed as appropriate, and the signal is supplied to the clamp circuit 28.

This clamp circuit 28 is supplied with a clamp pulse Cp (see FIG. 7i) generated by a clamp pulse generation circuit 29 at a time corresponding to the horizontal blanking period of the television signal, and receives the mixed fundamental wave signal. The mixed fundamental wave signal To is clamped using the reference potential portion of To.

The clamped fundamental wave signal is applied to a slicing circuit 30, and sliced at an upper level L2 and a lower level L approximately centered on the clamp level L.

As a result, the slice circuit 30 outputs both the levels L
, L will be extracted.

Therefore, the output of this slice circuit 30 is as shown in FIG. 7j.

Note that the reference level is omitted in this figure. This signal is used as a control signal for selecting a plurality of television signals.

That is, the control signal obtained as described above is supplied to the selection circuit 32 via the adder 31.

This selection circuit 32 includes channels CHI to A
A television signal exhibiting a dotted image such as B is added from the second channel CH2, and a television signal exhibiting a diagonal line image such as B is added. The selection circuit 32 to which these television signals are added has the same function as the selection circuit described in the prior art, ie, has characteristics as shown in FIG. Note that the selection circuit 3
Regarding No. 2, only its characteristics are shown, but since the specific circuit configuration is a known technology, the detailed circuit configuration will be omitted.

If a control signal (FIG. 7i) is applied to the characteristic selection circuit 32 to select the signals applied from both channels CHI and CH2, and reproduced by a television receiver, for example, the result will be the same as described above. An image as shown in FIG. 2a is obtained.

As explained in the prior art section, if it is desired to obtain a composite image as shown in FIG. 2d, the mixed fundamental wave signal To as shown in FIG. 7g is amplified by, for example, the control circuit 27, and then A control signal as shown in FIG. 7k obtained by slicing may be supplied to the selection circuit 32.

Note that the function of the control circuit 32 is the same as the first one explained in the prior art.
It has the same function as the control circuit 14 shown in the figure, and detailed explanation thereof will be omitted.

Furthermore, in the embodiment of the present invention described above, the control signal is obtained by performing signal processing such as slicing after mixing the two sawtooth waves generated by the two fundamental wave generating circuits 21 and 23. However, depending on the type of television image being composited,
It is also possible to generate a control signal using only one fundamental wave.

Therefore, the mixing circuit 261, the control circuit 271, the clamp circuit 281, the slicing circuit 301, etc. are also connected to the downstream of the fundamental wave generation circuit 23 and the pulse addition circuit 24.
The structure is such that a control signal can be generated. Note that the adder 31 is for separately processing the fundamental waves generated by the fundamental wave generating circuits 21 and 23, and then mixing them with each other to obtain a control signal.

Further, the variable resistor VR includes pulse adding circuits 22, 2.
Although the same pulse as that added in step 4, that is, the output of the reference pulse generation circuit 25, is added, it is not limited to this world pulse, and a pulse generated separately may be used as long as the timing matches this.

Further, the variable resistor VR itself may be a fader operating device (provided on a special effects control console to control the size of the wipe pattern), or the pulse amplitude may be indirectly controlled by the fader operating device. It may be something that is done. Therefore, the size of the wipe area changes as the pulse amplitude changes due to the variable resistor VR. Further, in the above embodiment, the mirror tooth waves e and f were combined to create the mixed fundamental wave g, but instead of this, the saw tooth waves b and c were first combined in the mixing circuit 26 as shown in FIG. 7h. Create a waveform like this, and then apply a pulse (7th pulse) to this waveform from the variable resistor VR.
One with twice the amplitude compared to the pulse in figure d.

) can be added. In this case, the above-mentioned resistors R4 and R
5, R6, and R7 is no longer necessary, and instead, an adding circuit including resistors R8 and R9 may be provided as shown by the dotted line in FIG. Furthermore, although the fundamental wave has been described in the case of a mirror-tooth wave, it goes without saying that a predetermined waveform such as a triangular wave or a parabolic wave may be used depending on the type of the composite image, that is, the wipe waveform.

Note that the reference pulse may be added anywhere as long as it is upstream of the clamp circuit, and any location can be selected depending on the design conditions.

Furthermore, although the above embodiment has been explained in the case of analog signals, it is of course possible to perform digital processing using digital signals.
This has the advantage that the fundamental wave signal with a reference level added to a predetermined section can be directly extracted, as shown in the figure, and the circuit configuration can be simplified.

According to the above-mentioned video special effects device, a reference level is added to the fundamental wave signal in advance at the front stage of the clamp circuit (any position can be selected depending on the design conditions). , it is possible to perform a clamp operation using this reference level, and even if the fundamental wave signal is amplitude controlled, it is sliced at the preset clamp level to obtain a stable control signal (key signal), and the boundary line of the composite image is is stable and can be expected to perform a good wipe operation without causing unsightly results.
Furthermore, the boundary of the composite image can be moved by changing the reference level given to the fundamental wave, and this reference level is changed by giving a constant reference level and then giving a variable level pulse. That is, by separating the insertion and control of the reference level in this way, there are the following advantages compared to DC control in which the reference level is inserted and the level is controlled in a DC manner at the same time. In DC control, there are large instability factors such as temperature fluctuations, long-term drift, and offset errors in the circuits that transmit and apply control signals, but the circuits that handle AC pulses are designed with AC coupling instead of direct connection. Therefore, the above-mentioned unstable factors are reduced and the overall operational stability is improved.

'o-- Pulse control is also easier to perform accurate level control than DC control.

1) Completely convert the image on the TV screen into another image by changing the size of the wipe pattern area as the center of the wipe pattern moves (so-called "cutting").

) In order to modulate the fader control amount according to the positioner operation amount, pulse control can be performed more easily, accurately, and stably. Pulse control is easier to process and provides more accurate control when creating control signals for complex special effects or when controlling faders by remote control.

In the above embodiment, control was performed by changing the amplitude of a pulse with either positive or negative polarity, but it is also possible to handle pulses with both positive and negative polarities.

That is, for example, as shown in Figure 9a, a reference level is inserted as an intermediate value of the waveform amplitude for the horizontal fundamental wave, and a pulse of variable amplitude varying from positive to negative (see Figure 9b) is inserted into this level. ), the result is a sawtooth wave similar to that shown in FIG. 7b in the previous embodiment. The same applies to vertical fundamental waves and mixed fundamental waves. Furthermore, the 10th
The figure shows an example of varying the amplitude and polarity of the output pulse of the reference pulse generation circuit 25, in which pulses of positive and negative polarity are created by a phase inversion circuit, and this output is taken out by a variable resistor VR. It can be added to the outputs of the pulse adding circuits 22 and 24 at any level over the positive and negative regions. Changing the reference level using pulses that change between positive and negative in this way is particularly effective when controlling the rotation of the wipe pattern.

As described above, the present invention can provide a video special effects device that can stably and easily move the boundary line of a composite image.

[Brief Description of the Drawings] Figure 1 is a circuit configuration diagram of a conventional device, Figures 2 to 5 are diagrams for explaining an embodiment of the present invention, and Figure 6 is an embodiment of the present invention. The circuit configuration diagrams shown in FIGS. 7 to 10 are diagrams for explaining the present invention. 21, 23...Fundamental wave generation circuit, 22, 24...
...Pulse addition circuit, 25...Reference pulse generation circuit, 26,261...Mixing circuit, 2
7,271... Control circuit, 28,281...
... Clamp circuit, 30, 301 ... Slice circuit, 32 ... Selection circuit, VR ... Variable resistor, R4 to R7 ... Addition resistor. Figure 10 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1. Fundamental wave generation means for generating a fundamental wave signal that defines the synthesis boundary of a composite image generated by combining a plurality of television signals, and a constant reference for a predetermined period of time for the fundamental wave signal generated by this means. a reference insertion means for inserting a level; a pulse generation means for generating a pulse corresponding to the predetermined period; a pulse control means for variably controlling the amplitude of the pulse generated by the means; pulse addition means for adding a reference level to the fundamental wave signal into which the reference level has been inserted by the reference insertion means; and pulse clamping of the fundamental wave signal to which pulses have been added in a predetermined section by the means or a composite wave signal thereof in the predetermined section. clamping means for slicing the signal clamped by this means at substantially the same level as the clamp level to generate a key signal for wiping, and selecting a plurality of television signals using the key signal generated by this means. 1. A video special effects device characterized by comprising: means for performing.