JPH0946722A - Color superimposing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform conspicuous superimposing display hardly mixed in background pictures. SOLUTION: This device is provided with a VCO 31 frequency controlled by frequency control signals for generating the color reference clock signals of picture signals generated inside, a chrominance signal separation circuit 21 for sampling the color reference clock signals from color video signals inputted from an outside, a phase comparator 27 for comparing the phases of the color reference clock signals from the VCO 31 and the color reference clock signals sampled by the chrominance signal separation circuit 21 and controlling the frequency control signals based on the result and a color synchronization switching circuit 26 for turning the control operation of the frequency control signals by the phase comparator 27 on/off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color superimposing apparatus incorporated in, for example, a video tape recorder, a video disc player, a television receiver, a video teloper, a karaoke machine or the like.

[0002]

2. Description of the Related Art A conventional color superimposing apparatus has a structure as shown in FIG. That is, this conventional color superimposing apparatus includes a color signal separation circuit 41, a sync separation circuit 42, a pattern generation circuit 43, a video signal generation circuit 44, an analog switch 45,
Phase comparator 46, filter 47, amplifier 48, adder 4
9, voltage controlled oscillator circuit (hereinafter referred to as "VCO") 50,
It was provided with a reference voltage source 51 and a frequency divider 52. The pattern generation circuit 43 and the video signal generation circuit 44 are controlled by the control unit 53.

The signal waveform of each part in such a conventional color superimposing apparatus is almost the same as the signal waveform of each part in the color superimposing apparatus according to the present invention. Therefore, referring to FIG. 4 and FIG. The operation of the conventional color superimposing apparatus will be described. In the conventional color superimposing apparatus, the color signal separation circuit 41 extracts the color signal b from the external input composite video signal a, and the sync separation circuit 42 outputs the input composite video signal a.
A horizontal synchronizing signal g, a vertical synchronizing signal, and a color synchronizing signal c are extracted from the.

On the other hand, the VCO 50 multiplies the frequency of the internal color reference clock signal e by n (n is an integer of 2 or more) based on the control voltage from the reference voltage source 51, which has the same potential as the reference voltage. To occur. This color reference clock signal is divided by n by the frequency divider 52 and output to the phase comparator 46 as the internal color reference clock signal e.

The phase comparator 46 is used for the sync separation circuit 4
2 based on the timing of the color synchronization signal c from the color signal separation circuit 41, the color reference clock component in the color signal b from the color signal separation circuit 41, that is, the external color reference clock signal d, and the internal color reference clock signal e from the frequency divider 52 And the phase difference signal f that changes according to the magnitude of the phase difference is output to the filter 47 only during the period in which the color synchronization signal c from the synchronization separation circuit 42 is effective. Further, the phase difference signal f is in a high impedance state while the color synchronization signal c from the synchronization separation circuit 42 is invalid. The phase difference signal f has its high frequency component removed by the filter 47, is amplified by the amplifier 48, is added to the reference voltage from the reference voltage source 51 by the adder 49, and is output to the VCO 50 as a control voltage. That is, the color reference clock signal from the VCO 50 is controlled so that its frequency is n times the frequency of the external color reference clock signal e. As a result, the internal color reference clock signal e, which has the same frequency as the external color reference clock signal d and is continuously output, and the color reference clock signal having a frequency n times that of the internal color reference clock signal e are obtained.

On the basis of the color reference clock signal from the VCO 50 thus obtained, the video signal generating circuit 44
Generates a video signal j having a predetermined brightness and hue corresponding to each color to be displayed. In addition, the pattern generation circuit 4
3 internally generates a dot clock signal h, which is a reference for generating a dot matrix pattern signal i of a superimposed image, based on the timings of the horizontal sync signal g and the vertical sync signal from the sync separation circuit 42. , A dot matrix pattern signal i such as a character or a graphic is generated and output to the analog switch 45 in synchronization with the dot clock signal h, the horizontal synchronizing signal g, and the vertical synchronizing signal in accordance with a command from the control unit 53. . Then, the analog switch 45 selects either the video signal j from the video signal generation circuit 44 or the input composite video signal a from the outside according to the dot matrix pattern signal i from the pattern generation circuit 43 and outputs it to the outside. Output.

As a result, the external composite video signal a
, And a dot matrix pattern signal i drawn in a predetermined color as the foreground, a superimpose image signal k is output from the analog switch 45 to the outside of the color superimposing device.

[0008]

However, in the above-mentioned conventional color superimposing apparatus, control is always performed so that the external color reference clock signal d and the internal color reference clock signal e are in phase with each other. Superimpose display is performed only with a certain color designated by 53. For example, if the color designated by the control unit 53 is similar to the color of the image input from the outside, it is difficult to visually recognize the superimposed image. There was a problem.

Further, if the display has a constant color, the viewer becomes accustomed to the display, and there is a problem that it is difficult to call the viewer's attention when displaying an important message or the like.

The present invention has been proposed in view of the above points, and provides a color superimposing device capable of performing superimposing display that is difficult to be confused with a background image and is easily noticeable. It is an object.

[0011]

In order to achieve the above object, a color superimposing apparatus according to a first aspect of the present invention provides a color video signal input from the outside with characters and graphics generated internally. In a color superimposing device that outputs image signals in a superimposed manner, the color reference clock signal of the image signal generated internally is
It is configured such that it can be switched between an operation mode in which it is synchronized with a color reference clock signal included in a color video signal input from the outside and an operation mode in which it is not synchronized.

The color superimposing apparatus according to the second aspect of the present invention is a color superimposing apparatus that superimposes an internally generated image signal such as a character or graphic on a color video signal input from the outside and outputs the superimposed image signal. In the pause device, the color reference clock signal generating means for generating the color reference clock signal of the internally generated image signal, which is frequency-controlled by the frequency control signal, and the color reference clock signal from the color video signal input from the outside The extracting means compares the phase of the color reference clock signal from the color reference clock signal generating means with the phase of the color reference clock signal extracted by the extracting means, and compares with the comparing means for controlling the frequency control signal based on the result. The operation mode switching means for turning on / off the control operation of the frequency control signal by the means. Eteiru.

Further, the color superimposing apparatus of the invention described in claim 3 is the color superimposing apparatus according to claim 2, wherein the operation mode switching means has an operation input by a user or control data by a program. Based on the above, the control operation of the frequency control signal by the comparison means is turned on / off.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a block diagram of a main part of a centralized control type karaoke system equipped with a color superimposing device according to the present invention, in which a head end device 1 installed in a center device is connected from a coaxial cable. Terminal device 4 installed in each of the plurality of room systems 3 via the transmission line 2
It is connected to the. Each room system 3 has a terminal device 4
In addition to the above, a video monitor 5, a mixing amplifier 6, a plurality of microphones 7, and a plurality of speakers 8 are installed. As will be described later, the terminal device 4 includes an RF terminal, a video output terminal, and an audio output terminal, and the transmission line 2 is connected to the RF terminal. The video monitor 5 is connected to the video output terminal, and the mixing amplifier 6 is connected to the audio output terminal. A plurality of microphones 7 are connected to the input end of the mixing amplifier 6, and a plurality of speakers 8 are connected to the output end of the mixing amplifier 6.

FIG. 2 is a circuit block diagram of the terminal device 4. The terminal device 4 includes a control unit 11, a CATV tuner unit 12, a data modem unit 13, and a superimposing unit 1.
4, a keypad unit 15, a power supply unit 16, an RF terminal 17, a video output terminal 18, and an audio output terminal 19. The control unit 11 has an input end connected to the keypad unit 15, an output end connected to the CATV tuner unit 12 and the superimpose unit 14, and an input / output end connected to the data modem unit 13. The CATV tuner unit 12
The input terminal is connected to the RF terminal 17, the video output terminal is connected to the superimposing section 14, the audio output terminal is connected to the audio output terminal 19, and the control input terminal is connected to the control section 11. In the data modem unit 13, one input / output terminal is R
It is connected to the F terminal 17, and the other input / output terminal is connected to the control unit 11. The superimposing unit 14 has an input end connected to the CATV tuner unit 12, an output end connected to the video output terminal 18, and a control input end connected to the control unit 11. The keypad unit 15 includes a plurality of key switches (not shown) operated by a user, and an output end thereof is connected to the control unit 11. Power supply unit 16
Supplies power to each circuit of the terminal device 4.

When the user operates the keypad section 15 to input a karaoke request number, the control section 11 requests the headend device 1 to perform a karaoke performance through the data modem section 13, the RF terminal 17 and the transmission line 2. Send control data, including messages. As a result, the headend device 1 receives the control data from the control unit 11 of the terminal device 4, and when the requested song can be played, the headend device 1 transmits the control data including the karaoke performance start message to the terminal device 4, and subsequently. The carrier wave of the designated CATV channel is modulated by the video data and audio data of the requested song and transmitted to the terminal device 4. The RF signal transmitted from the headend device 1 is supplied to the data modem unit 13 and the CATV tuner unit 12 via the transmission line 2 and the RF terminal 17. The control data including the karaoke performance start message is demodulated by the data modem unit 13 and the control unit 1
1, the control unit 11 controls the CATV tuner unit 12 to tune to the designated CATV channel. As a result, the CATV tuner unit 12 demodulates the video signal and audio signal of the requested song from the headend device 1. The video signal demodulated by the CATV tuner unit 12 is output to the video monitor 5 via the superimposing unit 14 and the video output terminal 18.
At this time, the control unit 11 controls the superimposing unit 14 to superimpose characters and the like on the image as needed. The audio signal demodulated by the CATV tuner unit 12 is output to the mixing amplifier 6 via the audio output terminal 19, mixed with the audio signal corresponding to the singer of the microphone 7, that is, the singing voice of the user, and output to the speaker 8. To be done.

FIG. 3 is a circuit block diagram of a superimposing section 14 which is a color superimposing apparatus according to the present invention. The superimposing section 14 includes a color signal separating circuit 21, a sync separating circuit 22 and a pattern. Generation circuit 2
3, video signal generation circuit 24, analog switch 25, color synchronization switching circuit 26, phase comparator 27, filter 28, amplifier 29, adder 30, VCO 31, reference voltage source 32,
And a frequency divider 33.

FIG. 4 is a signal waveform diagram for explaining the color synchronization operation of the superimposing section 14, which shows the CATV tuner section 12 to the color signal separation circuit 21 and the synchronization separation circuit 2.
2 and the input composite video signal a supplied to the analog switch 25, the color signal b supplied from the color signal separation circuit 21 to the phase comparator 27, and the color synchronization supplied from the synchronization separation circuit 22 to the color synchronization switching circuit 26. Signal c, external color reference clock signal d contained in color signal b, internal color reference clock signal e supplied from frequency divider 33 to phase comparator 27, and phase comparator 27 supplied to filter 28. The phase difference signal f is shown.

FIG. 5 is a signal waveform diagram for explaining the image synthesizing operation of the superimposing section 14, which shows the input composite video signal a, the sync separation circuit 22 to the pattern generation circuit 2.
3 and the horizontal synchronizing signal g supplied to the pattern generating circuit 23.
A dot clock signal h generated internally, a dot matrix pattern signal i supplied from the pattern generation circuit 23 to the analog switch 25, and a video signal generation circuit 24.
The video signal j supplied from the analog switch 25 to the analog switch 25 and the superimpose image signal k output from the analog switch 25 are shown.

The operation of the superimposing unit 14 will be described.

First, when the user operates the keypad section 15 to select an operation mode in which the superimpose display color is constant, or the superimpose display color is changed based on the control data from the headend device 1. The case where the operation mode to be constant is selected will be described. The color signal separation circuit 21 separates the color signal b from the input composite video signal a and outputs it to the phase comparator 27. Also, the sync separation circuit 22 separates the horizontal sync signal g and the vertical sync signal signal from the input composite video signal a and outputs them to the pattern generation circuit 23, and also generates the color sync signal c to the color sync switching circuit 26. Output. In the operation mode in which the color of the superimposed display is constant, the color synchronization switching circuit 26 is controlled to the synchronization side by the color synchronization switching signal from the control unit 11, so that the color synchronization switching circuit 26 keeps the color synchronization signal c as it is. Output to the phase comparator 27.

On the other hand, the adder 30 initially has the reference voltage source 3
The control voltage having the same potential as the reference voltage from 2 is output to the VCO 31. As a result, the VCO 31 generates a color reference clock signal which is a clock having a constant frequency and outputs it to the video signal generating circuit 24 and the frequency divider 33. As a result, the frequency divider 33 divides the color reference clock signal from the VCO 31 by n to generate the internal color reference clock signal e, and outputs it to the phase comparator 27. As a result, the phase comparator 27 compares the phases of the internal color reference clock signal e from the frequency divider 33 and the external color reference clock signal d in the color signal b from the color signal separation circuit 21, and determines the phase difference. A voltage of a corresponding magnitude is output to the filter 28 as a phase difference signal f only during a period in which the color synchronization signal c input via the color synchronization switching circuit 26 is effective. The phase difference signal f is in a high impedance state while the color synchronization signal c is invalid. The filter 28 removes the high frequency component of the phase difference signal f from the phase comparator 27 and outputs it to the amplifier 29. This is for stabilizing the control system. The amplifier 29 amplifies the phase difference signal f from which the high frequency component has been removed by the filter 28 and adds it to the adder 30.
Output to As a result, the adder 30 adds the phase difference signal f from the amplifier 29 and the reference voltage from the reference voltage source 32, and outputs it as a control voltage to the VCO 31. Therefore, the control voltage input to the VCO 31 changes and VC
The phase of the color reference clock signal output from O31 changes. This change cancels the phase difference between the phase of the external color reference clock signal d in the color signal b output from the color signal separation circuit 21 and the phase of the internal color reference clock signal e output from the frequency divider 33. Work like.

The above operation is repeated, and the internal color reference clock signal e whose frequency and phase match the external color reference clock signal d included in the color signal b in the input composite video signal a inputted from the outside, and its internal color reference clock signal e A color reference clock signal having an n-fold frequency is obtained. Based on this color reference clock signal, the video signal generation circuit 24 generates a video signal j having a color phase and a constant luminance instructed by the color control signal from the control unit 11 and outputs it to the analog switch 25. . In addition, the pattern generation circuit 23 uses the sync separation circuit 22.
On the basis of the timings of the horizontal synchronizing signal g and the vertical synchronizing signal from, the dot clock signal h which is a reference for generating the dot matrix pattern signal i of the superimposed character is internally generated, and this dot clock signal h In synchronization with the horizontal sync signal g and the vertical sync signal,
In accordance with the character code signal from the control unit 11, a dot matrix pattern signal i of the designated character is generated and output to the analog switch 25. The analog switch 25 selects either the video signal j from the video signal generation circuit 24 or the input composite video signal a according to the dot matrix pattern signal i from the pattern generation circuit 23, and outputs the superimposed image signal. Output as k. As a result, the superimpose image signal k from the superimpose unit 14 to the video monitor is displayed with the input composite video signal a as the background and the dot matrix pattern signal i from the pattern generating circuit 23 drawn in a predetermined color as the foreground. 5
Is output to

When the user operates the keypad section 15 to select an operation mode in which the superimposed display color changes inconsistently and becomes a rainbow color, or when the control data from the headend device 1 is selected. On the basis of this, when the operation mode in which the superimposed display color is not fixed and changes to become iridescent is selected, the color synchronization switching circuit 26 is controlled to the asynchronous side by the color synchronization switching signal from the control unit 11. It
Therefore, the color synchronization switching circuit 26 includes the sync separation circuit 22.
The color synchronization signal c from the above is not output to the phase comparator 27. Therefore, the comparison result is not output from the phase comparator 27,
The phase difference signal f remains in a high impedance state, and the control voltage output from the adder 30 also remains constant at the same potential as the reference voltage from the reference voltage source 32. Therefore, the internal color reference clock signal e from the frequency divider 33 has a constant frequency regardless of the external color reference clock signal d. The procedure of the subsequent superimpose operation is the same as in the operation mode in which the superimpose display color is constant,
As a result, the phase of the color signal of the superimposed text portion does not match the external color reference clock signal d of the background image, and the superimposed display color on the screen of the video monitor 5 changes with time or on the scanning line. It changes randomly according to the position and becomes a rainbow color.

As described above, when the user or the headend device 1 switches the operation mode, the superimposed display color changes randomly according to the time and the position on the scanning line to become a rainbow color. It is possible to perform superimpose display that is difficult to be confused and that is easily noticeable. The operation mode is switched on the basis of the control data from the headend device 1 when, for example, a message from the headend device 1 to the user is superimposed, and the content of the operation mode is changed especially by the user. This is the case when you want to pay attention to.

The present invention is not limited to the configuration of the above specific embodiment, and various modifications can be made. For example, in the above embodiment, the color synchronization switching circuit 26 as the selection means is provided on the input side of the phase comparator 27, but it may be provided on the output side of the phase comparator 27.

Further, in the above-mentioned embodiment, the user operates the keypad section 15 to directly switch the operation mode. However, the user operates the keypad section 15 to set a predetermined predetermined value. A configuration may be added in which when the display is instructed, the display is automatically switched to a rainbow display. Of course, the switching control at this time is performed by the control unit 1.
It is executed by 1.

[0029]

As described above, according to the color superimposing apparatus of the invention described in claim 1, the color reference clock signal of the image signal generated internally is included in the color video signal input from the outside. Since it is possible to switch between the operation mode that is synchronized with the color reference clock signal and the operation mode that is not synchronized, the superimpose display color changes randomly according to the time and the position on the scanning line. However, since it is rainbow-colored, it is possible to perform superimpose display that is not easily distracted by the background image and is easily noticeable.

According to the color superimposing apparatus of the invention described in claim 2, the color reference clock signal generation for generating the color reference clock signal of the image signal internally generated by the frequency control by the frequency control signal is performed. Means and
Extraction means for extracting the color reference clock signal from the color video signal input from the outside, and the phase of the color reference clock signal from the color reference clock signal generation means and the color reference clock signal extracted by the extraction means are compared, and The comparison means for controlling the frequency control signal based on the result and the control operation of the frequency control signal by the comparison means are turned on.
Since the operation mode switching means for turning off is provided, by turning off the control operation of the frequency control signal by the comparing means by the operation mode switching means, the synchronization between the external color reference clock signal and the internal color reference clock signal is lost, The superimpose display color changes randomly according to the time and the position on the scanning line to become a rainbow color. Therefore, it is possible to perform superimpose display that is not easily distracted by the background image and is easily noticeable.

Further, according to the color superimposing apparatus of the invention described in claim 3, the operation mode switching means controls the frequency control signal by the comparing means based on the operation input by the user or the control data by the program. By turning on and off, the user or the head-end device can freely change the superimposed display color to a constant color or a rainbow color.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a centralized management type karaoke system including a color superimposing device according to the present invention.

FIG. 2 is a circuit block diagram of a terminal device provided with a color superimposing device according to the present invention.

FIG. 3 is a circuit block diagram of a color superimposing apparatus according to the present invention.

FIG. 4 is a signal waveform diagram for explaining the color synchronization operation of the color superimposing apparatus according to the present invention.

FIG. 5 is a signal waveform diagram of each part for explaining the image combining operation of the color superimposing device according to the present invention.

FIG. 6 is a circuit block diagram of a conventional color superimposing device.

[Explanation of symbols]

 11 Control Unit 21 Color Signal Separation Circuit 22 Sync Separation Circuit 23 Pattern Generation Circuit 24 Video Signal Generation Circuit 25 Analog Switch 26 Color Sync Switching Circuit 27 Phase Comparator 28 Filter 29 Amplifier 30 Adder 31 VCO 32 Reference Voltage Source 33 Divider

Claims (3)

[Claims] 1. A color video signal input from the outside,
In a color superimposing device that superimposes the internally generated image signals such as characters and graphics and outputs them, the color reference clock signal of the internally generated image signal is used as the color reference included in the color video signal input from the outside. A color superimposing device characterized in that it can be switched between an operation mode in which it is synchronized with a clock signal and an operation mode in which it is not synchronized. 2. A color video signal input from the outside,
A color reference clock that generates a color reference clock signal for an internally generated image signal, which is frequency-controlled by a frequency control signal in a color superimposing device that superimposes and outputs image signals such as internally generated characters and graphics. Signal generating means, extracting means for extracting a color reference clock signal from a color video signal input from the outside, color reference clock signal from the color reference clock signal generating means, and color reference clock signal extracted by the extracting means Comparing the phases of, and controlling the frequency control signal based on the comparison result, and an operation mode switching means for turning on and off the control operation of the frequency control signal by the comparing means. A color superimposing device that does. 3. The operation mode switching means is configured to turn on / off the control operation of the frequency control signal by the comparison means based on an operation input by a user or control data by a program. Item 3. The color superimposing apparatus according to Item 2.