JP2002135620A - Television set and device/method for outputting synchronization signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the problem of the screen of a television set becoming disturbed by a vertical synchronization signal abruptly generated even though a synchronization signal for horizontal synchronization is contained in a video signal. SOLUTION: A synchronization signal output device is provided with a signal processing circuit 50 (synchronization signal output means), which detects the pulse width of the synchronizing signal contained in the inputted video signal and produces a horizontal synchronizing signal and a vertical synchronizing signal according to the detected pulse width, a co-polarity superimposing signal generating means for generating a superimposing signal of the same polarity with that of the synchronizing signal contained in the video signal from this horizontal synchronization signal and a signal superimposing circuit 70 (signal superimposing means) for superimposing this superimposing signal to the video signal. Since the superimposing signal which is produced from the horizontal synchronization signal and has the same polarity as that of the synchronization signal, the video signal is amplified by the component of the synchronization signal for horizontal synchronization. Thus, it is not required to additionally provide an oscillation circuit and a frequency-dividing circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television device, a synchronization signal output device, and a synchronization signal output method.
In particular, a television device that detects a pulse width of a synchronization signal included in an input video signal, creates and outputs a horizontal synchronization signal and a vertical synchronization signal according to the detected pulse width, and a synchronization signal output. The present invention relates to an apparatus and a method for outputting a synchronization signal.

[0002]

2. Description of the Related Art Conventionally, a synchronizing signal output device provided in a television device of this type detects a pulse width of a synchronizing signal included in a video signal or the like input to a video input terminal of the television device, and detects the pulse width. A horizontal synchronizing signal and a vertical synchronizing signal are generated in accordance with the magnitude of the pulse width, and output to a synchronizing circuit for generating a drive signal. As shown in FIG. 7, in the waveform of the input video signal, a pulse P1 of a synchronization signal is inserted in a signal including a color reference signal and the like. Here, the synchronization signal output device determines that the pulse of the synchronization signal is P1 when the voltage of the video signal is smaller than a predetermined threshold level. As shown in the figure, when it is determined that the pulse P1 of the synchronization signal, the horizontal synchronization signal (H
-SYNC) and outputs it to the outside, detects the pulse width during the period of the pulse P1, and when the detected pulse width is larger than the predetermined width, the vertical synchronization signal (V-SYNC)
C) is created and output to the outside.

[0003]

The above-mentioned conventional synchronous signal output device has the following problems. That is, as shown in FIG. 8, when electric noise is mixed before and after the synchronization signal for horizontal synchronization, the pulse width including the electric noise is detected, and it is determined that the detected pulse width is larger than the predetermined width. is there. Then, although the video signal includes a synchronization signal for horizontal synchronization, a vertical synchronization signal is generated as shown in the figure. As a result, the screen of the television device may be disturbed. Further, as disclosed in Japanese Patent Application Laid-Open No. 55-135487, the horizontal scanning period is detected by dividing the oscillation frequency and counting the frequency-divided horizontal synchronization signal that matches the horizontal synchronization frequency. A circuit including an oscillating circuit and a frequency dividing circuit is required, and the structure becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a simple configuration and can reliably determine a synchronization signal from an input video signal and output a horizontal synchronization signal and a vertical synchronization signal. It is an object of the present invention to provide a television apparatus, a synchronization signal output device, and a synchronization signal output method.

[0005]

In order to achieve the above object, according to the present invention, an RGB signal is separated from an input video signal and output, and a pulse of a synchronization signal included in the video signal is output. A signal processing circuit for detecting a width, generating and outputting a horizontal synchronizing signal, and generating and outputting a vertical synchronizing signal when the detected pulse width is larger than a predetermined width; and the RGB output from the signal processing circuit.
A cathode amplifier for amplifying and outputting a signal, a picture tube for displaying a screen based on the RGB signals amplified by the cathode amplifier, a vertical synchronizing signal and a horizontal synchronizing signal output from the signal processing circuit, A synchronous circuit for generating a vertical drive signal and a horizontal drive signal from the vertical drive signal and a horizontal drive signal for obtaining a vertical drive signal and a horizontal drive signal for driving the electron beam of the picture tube. A deflection circuit and a horizontal deflection circuit, a vertical deflection coil and a horizontal deflection coil for driving an electron beam of the picture tube based on the vertical drive current and the horizontal drive current, and a height supplied from the horizontal drive current to the picture tube. Create a voltage and use the same horizontal drive current to correspond to the horizontal synchronization signal. A flyback transformer that creates a feedback signal having a polarity opposite to that of the synchronization signal, a superimposition signal creation circuit that creates a superimposition signal by inverting the polarity of the feedback signal, and the above-described superimposition signal created by the superimposition signal creation circuit. A signal superimposing circuit for superimposing the superimposed signal on the video signal.

In the invention according to claim 1 configured as described above, when a video signal is input to the television device, the signal processing circuit detects detection of the pulse width of the synchronization signal included in the video signal. . Then, a horizontal synchronization signal is created and output, and when the detected pulse width is larger than a predetermined width, a vertical synchronization signal is created and output. Then, the synchronization circuit generates a vertical drive signal and a horizontal drive signal from the vertical synchronization signal and the horizontal synchronization signal. Then, the vertical deflection circuit and the horizontal deflection circuit obtain the vertical drive signal and the horizontal drive signal, and create a vertical drive current and a horizontal drive current for driving the electron beam of the picture tube. The vertical deflection coil and the horizontal deflection coil drive the electron beam of the picture tube based on the vertical drive current and the horizontal drive current. The flyback transformer creates a high voltage to be supplied to the picture tube from the horizontal drive current, and creates a feedback signal corresponding to the horizontal synchronization signal and having the opposite polarity to the synchronization signal from the horizontal drive current. Therefore, the superimposition signal generation circuit generates the superimposition signal by inverting the polarity of the feedback signal.

[0007] The signal superimposing circuit superimposes the superimposed signal on the video signal. Then, a superimposed signal corresponding to the horizontal synchronization signal and having the same polarity as the synchronization signal is superimposed on the video signal, so that a component of the synchronization signal for horizontal synchronization is amplified in the video signal. That is, even if electric noise is mixed in the video signal, the influence of the electric noise is reduced. Therefore, it is possible to reliably determine the synchronization signal from the input video signal and output the horizontal synchronization signal and the vertical synchronization signal,
It is possible to prevent screen disturbance in the television device. In this case, since there is no need to provide a circuit including the above-described oscillation circuit and frequency dividing circuit, a simple configuration is sufficient. In addition, it is also possible to make the device configuration described in claim 7 described later correspond to the television device.

The present invention can be applied to a synchronizing signal output device constituting the television device. Therefore, the invention according to claim 2 detects a pulse width of a synchronization signal included in an input video signal, and creates and outputs a horizontal synchronization signal and a vertical synchronization signal according to the detected pulse width. Synchronizing signal output means for generating a synchronizing signal having the same polarity as the synchronizing signal included in the video signal from the horizontal synchronizing signal output from the synchronizing signal output means; Signal superimposing means for superimposing the superimposed signal created by the signal creating means on the video signal.

According to the second aspect of the present invention, when a video signal is input to the synchronization signal output device, the synchronization signal output means detects the pulse width of the synchronization signal included in the video signal. To detect. Then, a horizontal synchronizing signal and a vertical synchronizing signal are created and output according to the detected pulse width. Then, for example, the synchronization circuit that creates the drive signal can create the horizontal drive signal and the vertical drive signal using the horizontal synchronization signal and the vertical synchronization signal. Then, the same-polarity superimposed signal creating means,
A superimposed signal having the same polarity as the synchronization signal included in the video signal is created from the horizontal synchronization signal. The signal superimposing means superimposes the superimposed signal on the video signal. Then, since a superimposed signal having the same polarity as that of the synchronization signal is superimposed on the video signal, the component of the synchronization signal for horizontal synchronization is amplified in the video signal. That is, even if electric noise is mixed in the video signal, the influence of the electric noise is reduced.
Therefore, it is possible to reliably determine the synchronization signal from the input video signal and output the horizontal synchronization signal and the vertical synchronization signal. In this case, since there is no need to provide a circuit including the above-described oscillation circuit and frequency dividing circuit, a simple configuration is sufficient.

Here, the synchronizing signal included in the video signal to which the present invention can be applied may be a pulse signal having a voltage lower than a predetermined voltage or a pulse signal having an opposite polarity higher than the predetermined voltage. There may be. The synchronization signal is
What is necessary is just to be able to generate the horizontal synchronizing signal and the vertical synchronizing signal according to the magnitude of the pulse width. For example,
As an example of applying the present invention to a video signal having a specification in which a synchronization signal having a pulse width larger than a predetermined width is used for vertical synchronization, the invention according to claim 3 is configured such that the pulse width of the synchronization signal included in the input video signal is changed. A synchronizing signal output means for detecting and generating and outputting a horizontal synchronizing signal, and generating and outputting a vertical synchronizing signal when the detected pulse width is larger than a predetermined width; and the horizontal signal output from the synchronizing signal output means. A same-polarity superimposed signal creating means for creating a superimposed signal having the same polarity as the synchronous signal included in the video signal from the synchronous signal, and superimposing the superimposed signal created by the same-polarity superimposed signal creating means on the video signal And a signal superimposing means. That is, a synchronizing signal output device to which a video signal of the above specification is input is also effective. Of course, contrary to the above specification, even if the synchronization signal has a pulse width smaller than the predetermined width and is a video signal of the specification for vertical synchronization, the component of the synchronization signal for horizontal synchronization is still amplified, It is possible to reduce the influence of electric noise mixed in the video signal.

The synchronizing signal output means only needs to be able to generate and output a horizontal synchronizing signal and a vertical synchronizing signal in accordance with the pulse width of the synchronizing signal. It may be created and output, or may be created with a reverse polarity to create and output a horizontal synchronization signal. The invention according to claim 4 is an example of a configuration in which the synchronization signal output means creates and outputs a horizontal synchronization signal having a polarity opposite to that of the synchronization signal. In the synchronization signal output device, the synchronization signal output means creates the horizontal synchronization signal having a polarity opposite to that of the synchronization signal included in the video signal, and the same polarity superimposed signal creation means outputs the synchronization signal from the synchronization signal output means. The configuration is such that the polarity of the output horizontal synchronizing signal is inverted to generate the superimposed signal.

According to the fourth aspect of the present invention, the same polarity superimposed signal generating means inverts the polarity of the horizontal synchronizing signal output from the synchronizing signal output means to generate the superimposed signal. The signal has the same polarity as the synchronization signal included in the video signal. That is, since the components of the synchronization signal for horizontal synchronization are amplified in the video signal, the influence of the electric noise mixed into the video signal is reduced, and the synchronization signal can be determined reliably. When the synchronization signal output means creates and outputs a horizontal synchronization signal having the same polarity as the synchronization signal, the same polarity superimposed signal creation means does not invert the polarity of the horizontal synchronization signal output from the synchronization signal output means. What is necessary is just to create a superposition signal.

As described above, the same-polarity superimposed signal generating means includes:
It is sufficient that a superimposed signal having the same polarity as the synchronization signal included in the video signal can be created from the horizontal synchronization signal output from the synchronization signal output unit. As an example of the specific configuration,
According to a fifth aspect of the present invention, in the synchronous signal output device according to any one of the second to fourth aspects, the same-polarity superimposed signal creating means includes the horizontal synchronous signal output from the synchronous signal output means. A horizontal drive signal generating means for generating a horizontal drive signal from the control signal, a feedback signal generating means for obtaining the horizontal drive signal and generating a feedback signal corresponding to the horizontal synchronization signal, and generating the superimposed signal from the feedback signal. And a superimposed signal generating means.

In the invention according to claim 5 configured as described above, when the horizontal drive signal generation means generates a horizontal drive signal from the horizontal synchronization signal output from the synchronization signal output means, the feedback signal generation means outputs the horizontal drive signal. The signal is obtained and a feedback signal corresponding to the horizontal synchronization signal is created. Then, the superimposed signal creating means,
A superimposed signal is created from this feedback signal. That is, even if the horizontal drive signal generated by the horizontal drive signal generation unit is used, the influence of the electric noise mixed into the video signal can be reduced, and the synchronization signal can be reliably determined.

Further, as an example of a specific configuration of the feedback signal generating means, the invention according to claim 6 is as follows.
6. The synchronizing signal output device according to claim 5, wherein the feedback signal generating means generates a horizontal drive current for driving an electron beam of a picture tube in a substantially horizontal direction from the horizontal drive signal; A flyback transformer for generating a high voltage to be supplied to the picture tube from the drive current and for generating a feedback signal corresponding to the horizontal synchronization signal from the horizontal drive current is provided.

In the invention according to claim 6, the horizontal deflection circuit obtains a horizontal drive signal and generates a horizontal drive current for driving the electron beam of the picture tube in a substantially horizontal direction. Then, the flyback transformer creates a high voltage to be supplied to the picture tube from the horizontal drive current. At the same time, the flyback transformer creates a feedback signal corresponding to the horizontal synchronization signal from the horizontal drive current. That is, it is suitable when the present synchronizing signal output device is provided in a television device having a horizontal deflection circuit or a flyback transformer.

The signal superimposing means only needs to be able to superimpose the superimposed signal created by the same polarity superimposed signal creating means on the video signal. As an example of the specific configuration, claim 7
In the synchronous signal output device according to any one of claims 2 to 6, the signal superimposing means connects a first capacitor and a first resistor circuit in series, and A first series connection circuit having one end connected to a signal line of a video signal to be connected, a second capacitor and a second resistance circuit connected in series, and the superimposed signal generated by the same polarity superimposed signal generating means. A second series connection circuit having one end connected to the signal line of the first series connection circuit, the other end of the first series connection circuit and the other end of the second series connection circuit are connected, and a signal from this connection portion The output is input to the synchronization signal output means. In the invention according to claim 7 configured as described above, the signal line of the video signal input to the synchronization signal output means is connected to the connection unit via the first series circuit, and the signal line of the superimposed signal is It is connected to the connection unit via a second series circuit. Then, the superimposition signal is superimposed on the video signal at this connection portion, and is input to the synchronization signal output means. That is, the signal superimposing means is simply configured.

As described above, the method of reliably determining the synchronizing signal from the input video signal and outputting the horizontal synchronizing signal and the vertical synchronizing signal is not necessarily limited to a substantial device. Therefore, as one example, the invention according to claim 8 detects a pulse width of a synchronization signal included in an input video signal, and separates a horizontal synchronization signal and a vertical synchronization signal according to the detected pulse width. A synchronizing signal output step of creating and outputting; a synchronizing signal creating step of creating a superimposing signal having the same polarity as the synchronizing signal included in the video signal from the output horizontal synchronizing signal; And a signal superimposing step of superimposing the superimposed signal created in the step on the video signal. That is, the present invention is not necessarily limited to a substantial device and is also effective as a method, and it goes without saying that the device configurations described in claims 3 to 7 can be adapted to the method.

[0019]

As described above, according to the present invention, it is possible to provide a television apparatus capable of preventing screen disturbance with a simple configuration. According to the second aspect of the present invention, with a simple configuration, a synchronization signal output device capable of reliably determining a synchronization signal from an input video signal and outputting a horizontal synchronization signal and a vertical synchronization signal. Can be provided. Further, according to the third aspect of the present invention, with a simple configuration, the synchronization signal is reliably discriminated from the video signal of the specification for using the synchronization signal whose pulse width is larger than the predetermined width for vertical synchronization, and the horizontal synchronization signal and the vertical synchronization signal are determined. A synchronization signal output device capable of outputting a synchronization signal can be provided.

Further, according to the invention of claim 4,
An example of a configuration in which the synchronization signal output means creates and outputs a horizontal synchronization signal having a polarity opposite to that of the synchronization signal can be provided. Further, according to the invention according to claim 5, it is possible to provide an example of a specific configuration of the same polarity superimposed signal generating means. Further, according to the invention according to claim 6, the configuration is suitable when the present synchronization signal output device is provided in a television device having a horizontal deflection circuit and a flyback transformer.

Further, according to the invention according to claim 7,
The signal superimposing means can be simply configured. further,
According to the eighth aspect of the present invention, there is provided a synchronization signal output method capable of reliably determining a synchronization signal from an input video signal and outputting a horizontal synchronization signal and a vertical synchronization signal with a simple configuration. can do.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a television device to which a synchronization signal output device 100 according to an embodiment of the present invention is applied. In FIG. 1, an IIC bus 40 includes a microcomputer 10 as main control means for centrally controlling internal devices, a tuner 20 for receiving television broadcast waves, and a video signal based on the received television broadcast waves. And a one-chip IC 30 for restoring and outputting an audio signal. And
The microcomputer 10 realizes a function as a television device by controlling the entire device by the serial data communication.

The tuner 20 is a tuner employing a so-called voltage synthesizer, and can be controlled via an IIC bus 40. A normal tuner has a tuning voltage (V
0) and a VHF low band (V
L), a VHF high band (VH) and a UHF (U) band changeover switch, and a signal corresponding to a desired tuning frequency is received by appropriately setting these switches. The tuner 20 does not include these mechanical components, obtains these set values from the microcomputer 10 via the IIC bus 40, and transmits a television broadcast signal having a reception frequency corresponding to the set values via the antenna 21. Receive. At the same time, an intermediate frequency signal is generated from the television broadcast signal and input to the one-chip IC 30. A video signal (VIDEO), which is a video signal according to the present invention, input from the video input terminal 22 is also input to the one-chip IC 30 via the signal superposition circuit 70, and an audio signal input from an audio input terminal (not shown) is also input. The data is input to the one-chip IC 30.

The one-chip IC 30 comprises a signal processing circuit 50 as a synchronizing signal output means, a synchronizing circuit 61 as a horizontal drive signal generating means, a superimposed signal generating circuit 62 as a superimposed signal generating means, and the like according to the present invention. I have. Of course,
Signal processing circuit 50, synchronization circuit 61, superimposed signal creation circuit 6
The configuration of 2 by the one-chip IC 30 is merely an example, and may be configured by separate ICs, or by a combination of a plurality of transistors and resistance circuits.

The intermediate frequency signal input to the signal processing circuit 50 of the one-chip IC 30 is amplified by an AGC circuit (not shown). The signal processing circuit 50 performs video detection after the intermediate frequency amplification is performed, performs predetermined color demodulation processing based on the detected output, separates and creates RGB signals, and outputs the RGB signals to the outside. In addition, the signal processing circuit 50 converts the detection output into a horizontal synchronization signal (H-SYNC),
A vertical synchronization signal (V-SYNC) is also created and output to the outside. On the other hand, an audio signal is extracted as a second audio intermediate frequency signal in the process of the intermediate frequency amplification, and an AUDIO signal is created through FM detection and output to the outside. Thereafter, the RGB signals output from the signal processing circuit 50 are output to the cathode amplifier 81,
And is supplied to a picture tube (CRT) 82 as appropriate. Then, the picture tube 82 performs screen display based on the RGB signals amplified by the cathode amplifier 81. on the other hand,
The AUDIO signal is similarly output to an audio amplifier (not shown), and is appropriately amplified by the audio amplifier and supplied to a speaker (not shown).

The signal processing circuit 50 also receives a video signal which is a voltage signal, and converts the RGB signal, the horizontal synchronizing signal and the vertical synchronizing signal from the video signal in the same manner as in the case of the intermediate frequency signal. Create and output to outside. Here, as shown in FIG. 2, the waveform of the input video signal is such that a pulse P1 of a synchronization signal having an amplitude V1 is inserted into a signal including a color reference signal, a luminance reference signal, and the like. I have. The pulse P1 of the synchronization signal is a pulse signal that becomes smaller than a threshold level of a predetermined voltage. Then, when the voltage of the video signal is smaller than a predetermined threshold level, it is determined to be the pulse P1 of the synchronizing signal, and as shown in the figure, a horizontal synchronizing signal having a voltage of the opposite polarity to the synchronizing signal is generated. . When the pulse width of the detected pulse P1 is larger than the predetermined width, a vertical synchronizing signal, which is a signal having a voltage having a polarity opposite to that of the synchronizing signal, is generated. The created horizontal synchronizing signal and vertical synchronizing signal are output to the synchronizing circuit 61 and also to the microcomputer 10, and are used for controlling the entire television apparatus.

The synchronization circuit 61 receives an oscillation output corresponding to a horizontal / vertical synchronization signal from an oscillation circuit provided in the one-chip IC 30. Normally, each oscillation output and the horizontal output from the signal processing circuit 50 are input.・ PLL with vertical synchronization signal
Constructs a loop. The signal whose phase is locked to the corresponding oscillation output by the PLL loop is a saw-tooth waveform signal as shown in FIG. 2, and includes a horizontal drive signal (H.DRIVE) and a vertical drive signal (V.DRIV).
E) is output to the horizontal deflection circuit 63 and the vertical deflection circuit 64, respectively.

The horizontal deflection circuit 63 generates a predetermined horizontal drive current corresponding to the horizontal drive signal from the horizontal drive signal as shown in FIG. 2 and supplies it to a horizontal deflection coil 66 provided in the picture tube 82. Thus, the electron beam is driven in the horizontal direction. In the timing chart of the horizontal drive current, the vertical axis indicates the current value, and the higher the value, the larger the current value. A high-frequency signal generated by the horizontal deflection circuit 63 is supplied to a flyback transformer (FBT) 65, and a high voltage to be supplied to a picture tube 82 is generated. On the other hand, the vertical deflection circuit 64 generates a vertical drive current from the vertical drive signal and supplies it to the vertical deflection coil 67 provided in the picture tube 82 to drive the electron beam in the vertical direction. As a result, in the picture tube 82, the electron beam corresponding to the video signal is emitted while being driven, and an image appears on the picture tube 82.

The flyback transformer 65 for generating a high voltage to be supplied to the picture tube from the horizontal drive current detects a change in the horizontal drive current and generates a feedback signal which is a voltage signal corresponding to the detected current change. As shown in FIG. 2, the feedback signal is a signal having the same polarity as the horizontal drive signal corresponding to the horizontal drive signal, and has a polarity opposite to that of the synchronization signal included in the video signal. Here, since the horizontal drive signal is a signal corresponding to the horizontal synchronization signal, the feedback signal is also a signal corresponding to the horizontal synchronization signal. Then, the created feedback signal is supplied to the superimposed signal creation circuit 62 in the one-chip IC 30. That is, the horizontal deflection circuit 63 and the flyback transformer 65 that obtain the horizontal drive signal and generate a feedback signal corresponding to the horizontal synchronization signal constitute a feedback signal generation unit according to the present invention.

The superimposition signal generating circuit 62 to which the feedback signal is input from the flyback transformer 65 reduces and inverts the fluctuation range of the voltage of the feedback signal to generate the superimposition signal according to the present invention. Then
As shown in FIG. 2, the superimposed signal corresponds to the synchronization signal for the horizontal synchronization signal included in the video signal and has the same polarity as the synchronization signal for the horizontal synchronization signal. In the timing chart of the superimposition signal, the vertical axis indicates the voltage value, and the higher the value, the larger the voltage value. That is, a synchronizing circuit 61, a horizontal deflection circuit 63, a flyback transformer 65, which generates a superimposed signal having the same polarity as a synchronizing signal included in a video signal such as a video signal from the horizontal synchronizing signal output from the signal processing circuit 50, The signal creation circuit 62 constitutes the same polarity superimposed signal creation means according to the present invention.

The superimposed signal generating circuit 62 outputs the generated superimposed signal to the signal superimposing circuit 70 constituting the signal superimposing means according to the present invention. Signal superimposing circuit 7 to which a superimposed signal is input
0 superimposes a superimposed signal on a video signal input from the outside via the video input terminal 22 and outputs the superimposed signal to the signal processing circuit 50. Then, the signal processing circuit 50 and the synchronization circuit 61
, Horizontal deflection circuit 63, flyback transformer 65
, The superimposed signal generating circuit 62 and the signal superimposing circuit 70 constitute the synchronous signal output device 100 according to the present invention.

As shown in FIG. 3, the signal superposition circuit 70
The first series circuit 71 according to the present invention in which the first capacitor C1 and the first resistor circuit R1 are connected in series, and the present invention in which the second capacitor C2 and the second resistor circuit R2 are connected in series. And a second series circuit 72. FIG. 3 is a schematic circuit diagram showing an outline of the configuration of the synchronization signal output device 100 of the present embodiment. In the figure, a first series circuit 71 has one end on the first resistor circuit R1 side connected to a signal line of a video signal which is an input video signal. The second series circuit 72 has one end on the second capacitor C2 side connected to the signal line of the superimposed signal output from the superimposed signal creation circuit 62. First series circuit 71
The other end of the second series circuit 72 on the second resistor circuit R2 side is connected to the other end of the first capacitor C1 side.
Connected at The connection 73 is connected to the signal processing circuit 5.
0, and the signal output from the connection unit 73 is input to the signal processing circuit 50. That is, the video signal, which is a voltage signal, is superimposed on the superimposition signal, which is also a voltage signal, at the connection unit 73, and is input to the signal processing circuit 50.

The signal processing circuit 50 to which the video signal on which the superimposed signal is superimposed is input detects the pulse width of the synchronizing signal included in the input video signal, and adjusts the pulse width detected as described above. Accordingly, a horizontal synchronizing signal and a vertical synchronizing signal are generated and output to the synchronizing circuit 61. Then, the synchronization circuit 61 creates a horizontal drive signal from the horizontal synchronization signal and outputs it to the horizontal deflection circuit 63. The horizontal deflection circuit 63 drives the electron beam of the picture tube 82 in a substantially horizontal direction from the horizontal drive signal. Create The flyback transformer 65 generates a feedback signal corresponding to the horizontal synchronization signal from the horizontal drive current as described above, and outputs the feedback signal to the superimposition signal generation circuit 62. Then, when the superimposition signal creation circuit 62 creates a superimposition signal from the feedback signal and inputs the superimposition signal to one end of the second serial circuit 72 of the signal superimposition circuit 70, the signal superimposition circuit 70 creates the superimposition signal. The superimposed signal is superimposed on the video signal. As a result, in the video signal which is a video signal, the component of the synchronization signal for horizontal synchronization is amplified.

Next, the operation of the synchronization signal output device 100 according to this embodiment will be described. As shown in FIG. 2, when the voltage of the video signal is smaller than a predetermined threshold level, it is determined to be the pulse P1 of the synchronization signal, and a horizontal synchronization signal having a polarity opposite to that of the synchronization signal is generated. As shown in the figure, when the pulse width of the detected pulse P1 is not larger than the predetermined width, no vertical synchronizing signal is generated.

Then, as described above, when the synchronization circuit 61 creates a horizontal drive signal from the horizontal synchronization signal and the horizontal deflection circuit 63 creates a horizontal drive current from the horizontal drive signal, the flyback transformer 65 outputs the horizontal drive current from the horizontal drive current. As described above, a feedback signal having a polarity opposite to that of the horizontal synchronization signal is generated corresponding to the horizontal synchronization signal. The superimposition signal generation circuit 62 generates a superposition signal by reducing and inverting the fluctuation range of the voltage of the feedback signal, and outputs the superimposed signal to the signal superposition circuit 70. Then, the signal superposition circuit 70
Superimposes the superimposed signal on the video signal and outputs the superimposed signal to the signal processing circuit 50.

Then, the video signal on which the superimposed signal is superimposed is created from the horizontal synchronizing signal and superimposed signal of the same polarity as the synchronizing signal is superimposed, as shown in FIG.
In the video signal, a component of a synchronization signal for horizontal synchronization is amplified. That is, the amplitude of the synchronization signal included in the video signal whose amplitude is set to V1 increases to V2 when the superimposed signal is superimposed. Then, as shown in FIG.
It is possible to lower the threshold level, which is a predetermined voltage for detecting 1.

Here, as shown in FIG. 5, even if electric noise is mixed before and after the synchronization signal for horizontal synchronization, since the threshold level is lowered, it is possible to detect the pulse width including the electric noise. Disappears. Then, as shown in the figure, a vertical synchronizing signal is not created from a synchronizing signal for horizontal synchronizing. That is, the influence of the electric noise is reduced, and it is possible to reliably determine the synchronization signal from the video signal such as the input video signal and output the horizontal synchronization signal and the vertical synchronization signal. As a result, disturbance of the screen of the television device can be prevented. Further, it is not necessary to provide a circuit including an oscillation circuit and a frequency dividing circuit in order to prevent a screen of the television device from being disturbed by electric noise.

In the present embodiment, the amplitude of the synchronization signal for horizontal synchronization is increased by superimposing the superimposition signal on the video signal input from the video input terminal 22.
To superimpose a superimposed signal having the same polarity as the synchronization signal included in the intermediate frequency signal on the intermediate frequency signal input from 0 to increase the amplitude of the synchronization signal for horizontal synchronization and reduce the influence of mixed electric noise. Is also possible. Further, even if the signal of which pulse width of the pulse P1 of the synchronizing signal is smaller than a predetermined width is a video signal of the vertical synchronizing signal, the component of the synchronizing signal for horizontal synchronizing is amplified. The influence can be reduced.

Further, the present invention can be applied to a case where a video signal having a polarity opposite to that of the above embodiment is input. For example, as shown in FIG. 6, when the synchronizing signal included in the video signal is a pulse signal higher than a predetermined voltage threshold level, the superimposed signal may be a signal having a polarity opposite to that of FIG. Even in this case, since the components of the synchronization signal for horizontal synchronization are amplified in the video signal, the threshold level can be increased, and the effect of electric noise mixed into the video signal can be reduced. As shown in FIG. 6, when the horizontal synchronizing signal has the same polarity as the horizontal synchronizing signal included in the video signal, the superimposed signal to be created may have the same polarity as the horizontal synchronizing signal. .

In the above-described embodiment, the same-polarity superimposed signal generating means according to the present invention includes the synchronizing circuit 61, the horizontal deflection circuit 63, the flyback transformer 65, and the superimposed signal generating circuit 62. However, the configuration may be such that a superimposed signal is created directly from the horizontal synchronization signal output from the signal processing circuit 50. For example, the superimposed signal creation circuit 62
Alternatively, a superimposition signal generation circuit may be provided which directly obtains the horizontal synchronization signal, generates a superimposition signal by reducing and inverting the fluctuation width of the voltage of the horizontal synchronization signal, and outputs the superimposed signal to the signal superimposition circuit 70. Also in this case, the components of the horizontal synchronization signal are amplified in the video signal, and the effect of electric noise mixed into the video signal can be reduced.

As described above, according to the present invention, a video signal is generated from a horizontal synchronizing signal and a superimposed signal having the same polarity as a synchronizing signal included therein is superimposed. Are amplified. In that case, it is not necessary to provide a circuit including an oscillation circuit and a frequency dividing circuit in order to prevent a screen of the television device from being disturbed by electric noise. Therefore, a television device, a synchronization signal output device, and a synchronization signal output method capable of reliably determining a synchronization signal from an input video signal and outputting a horizontal synchronization signal and a vertical synchronization signal with a simple configuration are provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a television device to which a synchronization signal output device according to an embodiment of the present invention is applied.

FIG. 2 is a timing chart showing states of a video signal and other various signals before a superimposition signal is superimposed.

FIG. 3 is a schematic circuit diagram illustrating an outline of a configuration of a synchronization signal output device of the present embodiment.

FIG. 4 is a timing chart showing a state of a video signal after a superimposition signal is superimposed.

FIG. 5 is a timing chart showing states of a video signal, a horizontal synchronizing signal, and a vertical synchronizing signal after superimposing a superimposed signal when electric noise is mixed.

FIG. 6 is a timing chart showing states of a video signal, a horizontal synchronization signal, and a vertical synchronization signal before a superimposition signal is superimposed in a synchronization signal output device according to a modification.

FIG. 7 is a timing chart showing states of a video signal, a horizontal synchronization signal, and a vertical synchronization signal in a synchronization signal output device according to a conventional example.

FIG. 8 is a timing chart showing states of a video signal, a horizontal synchronization signal, and a vertical synchronization signal when electric noise is mixed in a synchronization signal output device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Microcomputer 20 ... Tuner 21 ... Antenna 22 ... Video input terminal 30 ... One chip IC 40 ... IIC bus 50 ... Signal processing circuit 61 ... Synchronization circuit 62 ... Superimposed signal creation circuit 63 ... Horizontal deflection circuit 64 ... Vertical deflection circuit 65 ... Flyback transformer 66 Horizontal deflection coil 67 Vertical deflection coil 70 Signal superposition circuit 71 First series circuit 72 Second series circuit 73 Connection unit 81 Cathode amplifier 82 Picture tube 100 Synchronous signal output device C1 first capacitor C2 second capacitor R1 first resistor circuit R2 second resistor circuit

Claims (8)

[Claims] 1. A system for separating and outputting an RGB signal from an input video signal, detecting a pulse width of a synchronization signal included in the video signal, creating and outputting a horizontal synchronization signal, and outputting the detected pulse. A signal processing circuit that generates and outputs a vertical synchronization signal when the width is larger than a predetermined width; a cathode amplifier that amplifies and outputs the RGB signal output from the signal processing circuit; A picture tube for displaying a screen based on the RGB signals; a synchronization circuit for creating a vertical drive signal and a horizontal drive signal from the vertical synchronization signal and the horizontal synchronization signal output from the signal processing circuit; Signal and horizontal drive signal,
A vertical deflection circuit and a horizontal deflection circuit for generating a vertical drive current and a horizontal drive current for driving the electron beam of the picture tube; and driving the electron beam of the picture tube based on the vertical drive current and the horizontal drive current. A vertical deflection coil and a horizontal deflection coil, and a high voltage to be supplied to the picture tube is created from the horizontal drive current, and the horizontal drive current corresponds to the horizontal synchronization signal and has a polarity opposite to that of the synchronization signal. A flyback transformer that creates a feedback signal; a superimposition signal creation circuit that inverts the polarity of the feedback signal to create a superimposition signal; and superimposes the superimposition signal created by the superimposition signal creation circuit on the video signal. A television device, comprising: a signal superimposing circuit. 2. A synchronizing signal output means for detecting a pulse width of a synchronizing signal included in an input video signal, and generating and outputting a horizontal synchronizing signal and a vertical synchronizing signal in accordance with the detected pulse width. And a same-polarity superimposed signal creating means for creating a superimposed signal having the same polarity as the synchronous signal included in the video signal from the horizontal synchronous signal output from the synchronous signal output means; A signal superimposing unit for superimposing the created superimposed signal on the video signal. 3. Detecting a pulse width of a synchronization signal included in an input video signal, creating and outputting a horizontal synchronization signal, and creating a vertical synchronization signal when the detected pulse width is larger than a predetermined width. Synchronizing signal output means for outputting; synchronizing signal generating means for generating a synchronizing signal having the same polarity as the synchronizing signal included in the video signal from the horizontal synchronizing signal output from the synchronizing signal output means; A signal superimposing means for superimposing the superimposed signal created by the superimposed signal creating means on the video signal. 4. The synchronization signal output device according to claim 2, wherein the synchronization signal output means outputs the horizontal synchronization signal having a polarity opposite to a polarity of a synchronization signal included in the video signal. The synchronizing signal output device, wherein the same polarity superimposed signal generating means inverts the polarity of the horizontal synchronizing signal output from the synchronizing signal output means to generate the superimposed signal. 5. The synchronizing signal output device according to claim 2, wherein the same polarity superimposed signal generating means performs horizontal drive from the horizontal synchronizing signal output from the synchronizing signal output means. Horizontal drive signal generating means for generating a signal; feedback signal generating means for obtaining the horizontal drive signal and generating a feedback signal corresponding to the horizontal synchronization signal; and superimposing signal generating for generating the superimposed signal from the feedback signal. Means for outputting a synchronizing signal. 6. The synchronization signal output device according to claim 5, wherein the feedback signal generating means generates a horizontal drive current for driving an electron beam of a picture tube in a substantially horizontal direction from the horizontal drive signal. And a flyback transformer that creates a high voltage to be supplied to the picture tube from the horizontal drive current and creates a feedback signal corresponding to the horizontal synchronization signal from the horizontal drive current. Synchronous signal output device. 7. The synchronization signal output device according to claim 2, wherein the signal superimposing means connects a first capacitor and a first resistance circuit in series, and A first series connection circuit having one end connected to a signal line of a video signal to be connected, a second capacitor and a second resistance circuit connected in series, and the superimposed signal generated by the same polarity superimposed signal generating means. A second series connection circuit having one end connected to the signal line of the first series connection circuit, the other end of the first series connection circuit and the other end of the second series connection circuit are connected, and a signal from this connection portion is provided. A synchronizing signal output device for inputting an output to the synchronizing signal output means. 8. A synchronizing signal output step of detecting a pulse width of a synchronizing signal included in an input video signal, and generating and outputting a horizontal synchronizing signal and a vertical synchronizing signal according to the detected pulse width. A same-polarity superimposed signal creating step of creating a superimposed signal having the same polarity as the synchronization signal included in the video signal from the output horizontal synchronization signal; and the superimposed signal created in the same-polarity superimposed signal creating step And a signal superimposing step of superimposing on the video signal.