JPS5957587A - Device for superimposing character and graph signal - Google Patents

Abstract

PURPOSE:To mix picture signals in excellent way, by providing a ratio adjusting circuit to a graph signal superimposing device and making the ratio of colors of the superimposing signal coincident with that of a chrominance signal of a TV picture signal so as to make the color ratio of the TV picture signal of an analog system coincident with that of a digital system video signal. CONSTITUTION:A character/graph signal superimposing device 10 is inserted between a color TV receiver 11 and a driver 12 driving a CRT13. The device 10 consists of a basic circuit 15, which is provided with an amplifier circuit 22 comprising PNP and NPN transistors 16, 17, and the 1st control circuit 23 connected to the base of the TR17 being an output stage of the amplifier circuit 22, and a chrominance signal (R'+G'+B') representing a character or a graph is inputted to the circuit 23. Further, the ratio adjusting circuit 26 is provided between the 2nd control circuit 24 inputting the chrominance signals R', G', B' and an output of the amplifier circuit 22. Then, the ratio of chrominance signals between the TV picture signal of the analog system and the digital system video signal is made coincident with each other so as to mix the picture signals in excellent way.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a text/graphic signal superimposition device, and more specifically, the present invention relates to a text/graphic signal superimposition device, and more specifically, it mixes a chroma demodulated signal, which is an analog signal in a television receiver, and a text/image information signal, which is a digital signal input from the outside. This invention relates to a two-system 1'rj mixing device for analog and digital signals.

Conventionally, as this type of character/figure signal seven superimposition device, there is, for example, Japanese Patent Application No. 57-41932 filed by L. Kide (invention title: “Character/figure is number superimposition device”). .

The above-mentioned character/figure superimposition device V uses at least two transistors to create a demodulated television set on the basis of the transistors in the input stage of the amplification circuit configured to have an increase rate of 1. is generated based on a superimposition video information signal to be superimposed on the television image signal, and among the television image signals,
A cutoff signal for cutting off the part corresponding to the superimposition video information is applied to the base of the transistor in the output stage of the 11J circuit, and the superimposition signal is applied to the output terminal of the transistor in the output stage. The superimposition video information is displayed on the video screen of the television receiver, either together with the television screen or alone, by applying a signal representing the video information for superimposition.

By the way, in the above-mentioned text/graphic signal superimposing device, like other similar text/graphic signal superimposing devices, the image quality and image quality of the text/image information signals displayed on the cathode ray tube (CRT) of a television receiver are affected. In addition, for ease of modification of existing television receivers, the above-mentioned character/image information signal is mixed with a chroma demodulation signal at the input or output side of the cando drive stage of the cathode ray tube of the television receiver. .

As mentioned above, if the character/image information signal is mixed with the chroma demodulation signal at the input or output side of the cathode drive stage of the cathode ray tube of the television receiver, the character/image information signal, which is a digital signal, can be mixed with the chroma demodulation signal. The image information signal is applied to the cathode of the sales line tube by blocking the chroma demodulation signal in the form of a pulse signal having a constant amplitude of 1, and changes the color ratio of the text/image information to the following According to the well-known equation (4), text/image information is displayed on the cathode ray tube in a constant color that is fixed by the pulse signal, without making any special settings.

E y = 0.3 0 ER+0.5 9 EC+0
．． 1 1 EB ... (1) ER-E y=
o. 7 0 ER-0.5 9 EC-0.11 1L
B-12) EB-Ey=-0.30ER-
0.59E(;+0.89EB −+3)EC−
EY=-0.30ER+0.41EG-0.11EB
- (4) So, the above X:! In equations iJ1 to 4, (ER, EB, EGp are primary color signals, and EY is a luminance signal.

However, during the synthesis of the chroma demodulated signal and the text/image information signal obtained as described above, a constant pulse signal is output during the output period of the text/image information signal of the chroma demodulated signal. However, when expanding the system by inputting this composite signal to the encoder again to create a composite video signal in videotape editing, etc., the text/image information signal portion is converted into a composite video signal. There is a problem in that the color ratio is not correct in the signal, and the composite signal of the chroma demodulated signal and the text/image information signal obtained from such a text/graphic signal superimposition device cannot be input to the color encoder. Ta.

The present invention has been made in order to eliminate the above-mentioned problems, and by mixing the chroma demodulation signal, which is an analog signal, and the character/image information signal, which is a digital signal, at a color ratio determined by a televisual system, The purpose of combining the above chroma No. and character/image information signal [to give correct color ratio to No. d, and inputting "-composition 411"! into a color encoder to understand the regular Fushima video signal. There is.

In view of this, the present invention includes an amplification circuit configured to have an increase rlj factor of 1 using at least two transistors, and which inputs a television image signal to the base of the transistor in the input stage; A cutoff signal is generated based on the superimposition video information 1d to be superimposed, and cuts off a portion of the television image signal that corresponds to the superimposition video information signal, at the output stage of the increase circuit. a first control circuit that inputs the input to the base of the transistor; and a second control circuit that applies the superimposition video information signal to the output terminal of the transistor in the output stage of the amplification circuit;
Characters and figures (in the word superimposition device, the second control circuit and the amplifier 11] A ratio adjusting circuit for setting the color ratio of one video signal for superimposition is provided between the output terminal of the first transistor in the output stage of the circuit, and the color ratio of the above-mentioned composite simplest color ratio is set to the color of television image No. f8. The six signs are that the proportions are matched.

Hereinafter, the present invention will be specifically explained with reference to the attached figures.

As shown in FIG. 1, the character/graphic signal superimposition device 1O according to the present invention is installed in, for example, a color television receiver (hereinafter referred to as a television receiver) for receiving commercial television broadcasting (word reception). Chroma I in the receiver neck 11
C (not shown) and CPLT13 of the television receiver.
It is designed to be connected in a plug-in manner to the driving device tfM12 that drives the .

The superimposing device +ftlO includes chroma I in the receiving device 11.
3 representing the demodulated color image information of the television broadcast signal received by the television receiver from C.
The three color signals (hereinafter referred to as the red signal, the green signal, and the blue signal) are input to the receiving device 11 (not shown). Horizontal planking signal from the planking signal generation circuit (
Hereinafter, this will be referred to as a BLK signal. ) and, for example, from a well-known teletext receiver (not shown), a borrow (hereinafter referred to as
It is written as a text character signal. ) three color signals, technique signals,
A G signal and a B signal are input.

The superimposing device 10 has the above-mentioned k signal, G circle υ゛, B (
word, (R+G+B) signal, and lζ signal, G signal,
Based on the B signal, the }pivotal turn ll312 is set so that a color image of the television image with text superimposed on it, or a color image of text characters alone, is displayed on the screen of the cR-r13. generates drive signals that control the operation of the

The basic circuit of the superimposing device 10 is shown in FIG.

In FIG. 2, the basic circuit 15 for superimposition shown surrounded by a two-dot chain line consists of a PNP transistor 16 and an NPN transistor 16.
The transistor 17 is connected in an Aiura manner through the resistors 18, 19, 20.21 so that the 11j ratio is 1.
1] NPN of the circuit 22 and the output stage of the increase circuit 22 }
First control circuit 23 connected to the base of transistor 17
, the I signal, the G signal, and the B signal of the text characters are input to the control circuit 24 of the first control circuit 2, and the second control circuit 2.
4 and a ratio adjustment circuit 26 connected between the output terminal 25 of the second addition rIJ circuit 22.

Note that the above increase 1j times 22 is +N P N l at the input stage.
- It is also possible to use a PNP } run transistor in the output stage.

The first control circuit 23 consists of an open collector type inverter 31, and the second control circuit 24 consists of three open collector type inverters 32, 33 and 34.

The inverter 31 of the first control circuit 23 is connected to the text character signal (R+c-4-B') to be superimposed.
) is marked "1", and the technique signal, G signal, and B signal are applied to the inverters 32.3.3 and 34 of the second control circuit 24, respectively.

The ratio adjustment circuit 26 consists of resistors 35, 36 and 37 connected between the outputs of the in/< 32, 33 and 34 and the output terminal 25 of the amplification circuit 22, respectively.

By the way, in the basic circuit 15, if at least one of the color signal I7 signal, G signal, or B signal of the text character signal becomes "H'=level, the first control fI
By the inverter 31 which is the J41 circuit 23, N P
N } The transistor 17 is turned off and the color difference signal, for example (g
-y)la The input to the NPN transistor 17 of the text character portion is aF'Ji, and the level of the output terminal 25 of the amplifying circuit 22 rises toward the power supply 1B.

At this time, the ratio A adjustment circuit 26
Resistance value of 35, 36 and 37 R35' 36
and R3? For example, if you set the ratio of (R-
Y) The signal portion of the text characters of the signal will also be mixed with a signal that matches the above color difference ratio in the television system, thus the invention. R{sri, B believe<
Lr c: The resistors 35, 36 and 37 are set so that the output level of the output element 25 of the intensifying circuit 22 when at least one of the signals reaches the "l4" level satisfies the second equation.
Set the ratio of resistance values R, R and R37 of 35
36 I am doing it.

In the superimposing device 10 according to the present invention, the chroma IC produces color difference signals, that is, (RY) signal, (G-Y) signal, (B
- Y) When there is a demodulation circuit of the type that outputs the signal (d
．． As shown in Figure 3, in addition to 11 (Aiichi~'), (
The basic circuit 15 similar to that in Figure 2 is also connected to the B Y) signal and the Y signal.

Similarly, in FIG. 3, open collector type inverters 41, 42, 43 and 44 receive (R'+d11) from 17, d signal, and B'id signal. This is a logic circuit that cannot be created.

If the text/figure superimposed bag holder is configured as described above, for example, the K signal of the text character signal (d oL/ /<
/l/ (!: Naruto, (”-Y) @-8 increase rl
The N P N transistor of the j circuit 22 is turned off, and the output of the inno{Ichiyo 32 becomes tri '' L=゛ level, and the outputs of the Inno<Ichiyo 33 and 34 become the "It" level, respectively, and the output of the amplification circuit 22 becomes The magnetic potential of the terminal 25 is
The resistance values R35' k36 and k of the resistors 35, 36 and 37 of the ratio adjustment circuit 26 provide a value that satisfies Equation 2.

37 In addition, when (J 1g. The (RY) signal becomes a value that satisfies the formula, and the (RY) signal becomes the text}・
It can be seen that the character signal part is output with the color ratio of the second equation, which is the same as the chroma tone signal.

The (B-Y) signal and the Y signal are also output in exactly the same way as above, and the signal portion of the text character is output with the color ratio of the third equation and the first equation, which are the same as the evening Roma demodulator. .

Therefore, the (R-Y) signal, (B-Y) signal and Y signal output from the character/figure superimposition device shown in FIG. It is possible to obtain a composite video signal in which text characters are superimposed in a ratio.

In the above embodiment, the circuit of the character/figure borrowing superimposition device for three systems of (R-Y), (13-j/) signal, and Y signal is shown for input to the color enhancer. , (G-Y) in a four-person color encoder that does not re-combine, (G-Y) in the same way as above.

However, if the present invention is a demodulation circuit of the type that outputs a receiving device 1l (7 East υ Kuma IC or 3 colors (F3@, that is, a K signal, a G signal, and a B1 correction code) , three basic circuits 15 may be provided corresponding to each color signal.

As is clear from the detailed description above, the present invention
In the conventional character/graphic signal superimposition device, a ratio adjustment circuit is provided to match the color ratio of the video signal for superimposition with the color ratio of the television image signal, so that the digital signal can be added to the television image signal, which is an analog signal system. When the color ratios of the video signal for superimposition match, the output signal of the text/figure signal superimposition system 1β according to the present invention is input to the color encoder to obtain the correct color ratio consisting of two systems of analog and digital signals. You can get a clear composite video signal.

[Brief explanation of the drawing]

i1=; l Figure v: 1 is a block diagram showing the connection position of the character/figure signal superimposition device according to the present invention, and Fig. 2 is a basic circuit diagram of an embodiment of the character/figure signal superimposition device according to the present invention. , FIG. 3 is an overall circuit diagram of an embodiment of the character/graphic signal superimposing device according to the present invention, and FIG. 4 is a waveform diagram of the (RY) signal output from the basic circuit diagram of FIG. 3. DESCRIPTION OF SYMBOLS 10... Character/graphic signal superimposition device, 11... Receiving device, 12... Drive device, 13... CRT, 15...
・Basic circuit, 16...PNP }ransistor, 17.
・・N l) N transistor, 18.19, 20.2
DESCRIPTION OF SYMBOLS 1... Resistor, 22... Increase circuit, 23... First control circuit, 24... Second control circuit, 25... Output terminal, 26... Ratio adjustment circuit 1 . -529-

Claims (1)

[Claims] (1) An amplifier I1] circuit configured to have an amplification factor of 1 using at least two transistors and inputs a television image signal to the base of the transistor in the input stage; A block signal that is generated based on the superimposition video information signal and that cuts off a portion of the television image signal that corresponds to the superimposition video information signal is input to the base of the transistor in the output stage of the amplification circuit. a second control circuit for applying the image information signal for superimposition to the output terminal of the transistor in the output stage of the amplification circuit, In the character/figure signal superimposing device which combines the image signal and the video information signal for superimposition, the above-mentioned second control circuit and the above-mentioned output terminal of the transistor in the output stage of the amplifier circuit are connected to A character/graphic signal superimposition device characterized in that a ratio adjustment circuit for setting the color ratio of the video signal for superimposition is provided between the two, so that the color ratio of the composite signal matches the color ratio of the television image signal. .