JPS6165591A - Superimpose device - Google Patents

Abstract

PURPOSE:To superimpose a character signal with color without increasing the number of input terminals by attenuating an image signal in a superimpose division to input to the base of a first Tr, inputting a signal from a color superimpose means to the base of a second Tr, and connecting both emitters of both Trs. CONSTITUTION:To a terminal 40, a color image signal a is inputted, and an input signal (b) of an end 42 becomes 'H' in the same division as a superimpose division (A division). The output signal (c) of an attenuating circuit 41 attenuates the image signal to about a half. The division A of an output signal (d) of a color superimpose circuit 49 is a division for superimposing a character signal. The character signal is inputted from a terminal 46. A division except A is fixed at a voltage shown by B. This voltage is set at a lower voltage than that of the end of the synchronous signal of the signal (a). In the division of A, centering a voltage shown by (c), a color secondary carrier from a terminal 48 is superimposed. Accordingly, a signal outputted to a terminal 47 in the division of A is superimposed by a character signal with color.

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a superimposing device that superimposes colored characters or the like onto a video signal. Conventional configuration and the time between ^n + S In recent years, it has become common practice to display various information by superimposing character) b symbol boxes on television screens, and superimposed Iζ characters A shadow is placed around the letter ``r'' so that the symbol can be seen clearly. First, the conventional superimposing apparatus mentioned above will be explained with reference to the drawings. Figure 1 shows a conventional block diagram that superimposes shadows around IJ characters and notes. 1 is a terminal to which a DC reproduced video signal is input, and 2 is a signal to input a shadow. 3 is an attenuation circuit that attenuates the image at a certain rate when a signal is input to terminal 2.
Reference numeral 4 designates a terminal to which a kill/rafter signal such as a letter or symbol is input, and 5 represents an adder circuit that adds the kill rafter signal and the output of the attenuation circuit 3. 6 is a terminal to which a video signal to which a character signal has been added is output. FIG. 2 shows a specific example of the operation shown in FIG. 1, and a shows an example of superimposed characters and shadows on the screen. b indicates a character signal that superimposes the character on the scanning line indicated by a solid line in a, and C indicates a signal that inputs a shadow. FIG. 3 shows a specific example of the adder circuit 5, in which the signal from the attenuation circuit 3 is input to the input terminal 10 to the base of the transistor 7, and the character signal of FIG. 1 is input to the base terminal of the transistor 8. This corresponds to terminal 4 for input. The emitters of the transistors 7.8 are connected to each other, and a terminal 6 to which a video signal obtained by adding a constant current source 9 and a character signal is output is connected to the connection point. In general, superimposed Ki1! Since the brightness level of the character signal is set much higher than the maximum brightness level of the video signal, the level of the character signal input to terminal 4 is 1". It is sufficient if the DC level of "L" is set higher than the maximum brightness α level of the eigen1'Gfci, and lower than the level at the tip of the eigen (Ha). In the pause circuit, it is not possible to superimpose colored character signals. Figure 4 shows a block diagram of a conventional circuit that superimposes colored character signals. An input terminal for a DC reproduced video signal; 13 is a terminal to which a signal for inputting shadows is input; 12 is an attenuation circuit that attenuates the video signal at a constant rate when a signal is input to the terminal 13; Terminal 15 is a bias circuit into which the color subcarrier that transmits the color signal is input, and it applies the DC bias input from terminal 1G to the signal from terminal 14. In this Figure 4, in order to input the DC bias, A variable resistor 20 is used. , 17 is a switching circuit, which outputs the signal from the attenuation circuit 12 when no character signal is input to the terminal 18, and the character signal is input to the terminal 18. In this case, the signal from the bias circuit 15 is switched to be output.At this time, the terminal 19 is connected to the terminal 1.
The color subcarrier input from 4 is output, and colored characters and symbols are displayed on the screen. FIG. 5 shows a specific circuit of the switching circuit 17 used in FIG. Here, 22.24.26.30 is a transistor, 23.25 is a diode, 28.33 is a constant current source,
32 indicates a constant voltage source. Terminal 21 is a first signal input terminal, into which a video signal is input. Terminal 27 is a second signal input terminal, into which a color subcarrier is input. A terminal 31 is an input terminal for a switching signal, and a kit/rafter signal is input thereto. At this time, the voltage of the constant voltage source 32 is set near a voltage between the voltages of the "H" level and "L" level of the quitractor signal. Now, if the voltage of the terminal 31 is L'', that is, if the voltage of the terminal 31 is lower than the voltage of the constant voltage source 32, the output ☆; (The video signal is output to the first child 29, and the voltage of the terminal 31 is “ H'', that is, if the voltage at the terminal 31 is higher than the voltage at the constant voltage source 32, a color subcarrier is output to the output terminal 29.By the way, as shown in FIG. - The circuit that superimposes signals has two more input terminals than the circuit shown in Figure 1. This is especially true when implementing such a circuit on an integrated circuit. This hinders the improvement of the Toshiba ratio.Furthermore, as shown in Figure 5, the switching circuit used there has the disadvantage of being double 2 (() compared to the circuit in Figure 1. OBJECTS OF THE INVENTION It is an object of the present invention to provide a superimposing device for superimposing colored character signals with a simple configuration and without increasing the number of input terminals. Structure of the Invention The superimposed IF of the present invention includes an attenuating means for attenuating the level of a video signal in a superimposed section, and a superimposed voltage field that is different between a superimposed section and a non-superimposed section. a first transistor which generates the color secondary general transmission wave in the paused section, a first transistor whose base receives the signal from the attenuation means, and a first transistor which receives the signal from the color superimposition means. The color signal is superimposed with a second transistor whose emitter is connected to the emitter of the first transistor, and the signal is input to the base, thereby reducing the number of input/output terminals when integrated. DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 6 shows a superimposing device of the present invention. A terminal 40 is an input terminal for a video signal; For example, a clamped positive polarity video signal is input. 41 is an attenuation circuit, 42 is a terminal to which a signal that is the same as the character signal or wider than that is input, 43 and 44 are transistors, 45
is a resistor, 46 is an input terminal for a character signal, 47 is an output terminal for a superimposed video signal, 48 is an input terminal for a color subcarrier, and 49 is a character signal input terminal for a color subcarrier.
This is a color superimposition circuit that superimposes the signal on the T('' level. As shown below, the superimposed y
・Explain the configuration of the equipment in detail based on its operation. Figure 7a
is a clamped color film signal input to terminal 40, and FIG. 7 is a signal input to terminal 42, which is a superimposed signal. “14 in the same section as between 311g
''. Figure 7C shows the output signal of the attenuation circuit 41, where the level of the video signal is attenuated to about 1 minute.The attenuation amount in the attenuation circuit 41 may be other than the above value. For example, the video signal level may be completely attenuated to 0IRE in the section where the signal is input to the terminal 42. Fig. 7d shows the output signal of the color senjo circuit 49, and the section △ indicates the character - (8 bows). This is the section where .
It is set lower than the voltage at the tip of the synchronization signal of the video signal, which is not shown in FIG. 7a. In the section A, color subcarriers are superimposed around the voltage indicated by C. This voltage C is set equal to the voltage corresponding to the color video signal 901RE shown in FIG. 7a, for example. At this time, the signal output to the terminal 47 becomes as shown in FIG. 7e, and the color subcarrier is 90 [R
E level, and a colored character signal is superimposed in this section. As described above, according to the present invention, a color signal superimposition circuit can be realized with a simple circuit. Note that the terminal 42
If the signal shown in Figure 7 is not input, when the brightness level of the video signal is high, part of the amplitude of the color subcarrier will be clipped, resulting in insufficient color saturation, as shown in Figure 7f. It turns out that it becomes. By the way, in general, to avoid generating character signals,
A logic circuit using a TTL A" C-M OS or the like is used, and it is extremely easy to generate signals as shown in FIGS. As an example, FIG. 8 shows a part of a specific circuit example in which a colored color signal is superimposed using the character signal for superimposing the monochrome signal shown in FIG. 2. Shown in 8th
In the figure, a shadow input signal as shown in FIG. 2C is inputted to a terminal 50. On the other hand, a signal representing a -1-Yaractor signal as shown in FIG. are logically added and output. The terminal 60 is shown in Figure 6.
It is connected to terminal 42 as shown. On the other hand, the color sub-transmission wave is input to the terminal 55. 58 and 57 are PNPI transistors, 9 is a variable resistor, and a signal as shown in FIG. 7d is obtained at the terminal 56. Terminal 56 is connected to terminal 4G in FIG. In this case, it is not only possible to superimpose a colored character signal, but also to input a shadow around the character signal, as shown in FIG. 2a. As described above, according to the present invention, the attenuating means for attenuating the video signal in the superimposed section and the voltage difference between the superimposed section and the non-superimposed section are used. A color signal type bone means for emitting a signal on which a color subcarrier is superimposed in the section, a first transistor into which a signal from the attenuation means is inputted to the base, and a signal from the color signal superimposition means is inputted into the base. - set the transistor S2 whose emitter is connected to the emitter of the first transistor;

By extracting the signal from the connection point between the first and second transistors, it is possible to superimpose colored signals with a simple configuration. Further, the attenuation means and the color number 13 superimposing means are suitable for being constructed with logic ICs such as MOS and TTL, and the circuit including the first and second transistors is suitable for being constructed with bipolar linear ICs. However, when each is configured with a logic IC and a bipolar-linear IC, according to the embodiment of the present invention, the number of terminals for connection between these IGs can be reduced compared to the conventional example. It is. That is, in FIG. 4 shown as a conventional example, the attenuation circuit 12, the bias circuit 15, and the switching circuit 17 are parts suitable for being constructed with a bipolar linear IC. .16.18 is required as the input signal terminal of the IC. On the other hand, in the embodiment of the present invention shown in FIG.
3.44, the resistor 45 is a bipolar linear IC suitable for configuring C), but in this case, the terminal 40.
Only the base terminals of transistors 42 and 1 to 44 are required as input terminals of the IC. In addition, in the embodiment of FIG. 6, the transistor 43
．． The emitters of transistors 43 and 44 are connected in common, and the voltage is taken out from that connection point, as shown in Figure 9.The collectors of transistors 43 and 44 are also connected in common, and a resistor 48 is connected to the connection point of a. ()τ, the signal may be extracted from the connection point of the resistor and −]rek. In this case, the polarity of the signal is reversed and the signal can be amplified in proportion to the ratio of resistors 48 and 45. Also, in the embodiment of the present invention, the polarity of the N + - transistor and the PNPI- transistor can be amplified. It goes without saying that the method of use is not limited to that of the embodiment, and that transistors different from those of the embodiment may be used depending on the polarity of the signal and the like. Effects of the Invention As described above, the superimposing device of the present invention includes an attenuating means for attenuating the level of the video signal in the superimposed section, and a voltage difference between the superimposed section and the non-superimposed section. a color superimposing means for generating a signal on which a color subcarrier is superimposed in the section to be superimposed; a first transistor to which the signal from the attenuation means is input to the base; Since the input transistor is configured with a second transistor whose emitter is connected to the emitter of the first transistor, the signal can be superimposed with a simple configuration by taking out the signal from the emitter or collector. It is possible to do so, and its practical effects are great.

[Brief explanation of the drawing]

Figure 1 shows a conventional black and white signal superimposing device +
Fig. 2 is an explanatory diagram of the operation of Fig. 1, and Fig. 3 is a diagram of the operation of Fig. 1.
4 is a configuration diagram of a conventional color signal superimposing device, FIG. 5 is a circuit diagram of the main part of FIG. 4,
FIG. 6 is a configuration diagram of an embodiment of the present invention, FIG. 7 is a waveform diagram specifically explaining an example of the operation of the present invention, FIG. 8 is a configuration diagram of the main part of FIG. FIG. 3 is a configuration diagram of another embodiment of the invention. 41... Attenuation circuit, 43.44.52.53.57.
58...Transistor, 45.48...Resistor, 49
... Color heavy cloud circuit agent Yoshihiro Morimoto Figure 1 Figure 2 Figure 3 Figure 4 Figure 7 Cause Figure 3 Figure q

Claims (1)

[Claims] 1. Attenuation means for attenuating the level of the video signal in the superimposed section, and a voltage value different between the superimposed section and the non-superimposed section, and a color change in the superimposed section. a color superimposition means for generating a signal on which a subcarrier is superimposed; a first transistor to which the signal from the attenuation means is input to the base; and a signal from the color superimposition means to the base and the emitter of the first transistor A superimposing device consisting of an emitter and a connected second transistor. 2. Connect the collector of the first transistor and the collector of the second transistor to one of the power supplies via the first resistor, and connect the emitter of the first transistor and the emitter of the second transistor to one side of the power supply through the second resistor. 2. The superimposing device according to claim 1, wherein the superimposing device is connected to the other side of the power source via the superimposing device.