JP3534241B2 - CRT discharge device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picture tube discharge apparatus, and more particularly to a picture tube discharge apparatus having a so-called spot killer function for discharging charges remaining in a picture tube when a power-off instruction is given .

[0002]

2. Description of the Related Art Conventionally, as a picture tube discharge device of this type,
The one shown in FIG. 6 is known. In the figure, a picture tube discharger 1 includes a cathode amplifier 2 which is a picture amplification circuit for amplifying a picture signal and outputting the picture signal to a picture tube, and a synchronization circuit 3 for producing a vertical drive signal or a horizontal drive signal from the synchronization signal. A deflection circuit 4 for obtaining a drive signal and driving an electron beam of a picture tube, a spot killer circuit 5 for discharging charges remaining in the picture tube, and a control circuit 6 connected to the synchronizing circuit 3 and the spot killer circuit 5. It consists of and.

In the above structure, when a video signal obtained by separating an intermediate frequency signal created from a television broadcast signal is input to the cathode amplifier 2, the cathode amplifier 2 amplifies the video signal and outputs it to a picture tube. Output. When a vertical synchronizing signal or a horizontal synchronizing signal obtained by separating the intermediate frequency signal is input to the synchronizing circuit 3, the synchronizing circuit 3 creates a sawtooth-shaped vertical drive signal or horizontal drive signal from these synchronizing signals. . When the deflection circuit 4 receives these drive signals, it drives the electron beam of the picture tube. Then, in the picture tube, an electron beam corresponding to the amplified video signal from the cathode amplifier 2 is driven and emitted, and an image appears. When the power is off,
The control circuit 6 performs a power-off process in which the spot killer circuit 5 is operated while operating the synchronization circuit 3 for a predetermined time. Then, the deflection circuit 4 emits the electron beam generated from the charges remaining in the picture tube while being driven in the vertical direction. Therefore, the collision point of the electron beam is not fixed and the electric charge is not concentrated at the collision point, so that the picture tube is not burned.

The above-mentioned conventional picture tube discharge device has the following problems. That is, the power-off process may be performed even if the power is not turned off due to a malfunction such as the mixing of electrical noise, and a sawtooth-shaped drive signal is output from the synchronous circuit even though power is continuously supplied to the cathode amplifier. It may not be done. In this case, although the spot killer circuit operates, the power supply of the cathode amplifier is not stopped, so the collision point of the electron beam is fixed, while the electron beam of the picture tube continues to be output, and the electric charge is concentrated at the collision point. As a result, the picture tube will burn. Further, in the one disclosed in Japanese Patent Laid-Open No. 53-69522, the stop of the vertical deflection operation is detected to control the output of the electron beam, and the power supply of the cathode amplifier cannot be stopped. Besides this,
Even with the ones disclosed in Japanese Patent Laid-Open Nos. 3-178787 and 3-6367, the power supply to the cathode amplifier cannot be stopped.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a picture tube discharge device capable of stopping the power supply to the image amplification circuit even when a malfunction occurs and preventing the picture tube from being burned. To do.

[0006]

In order to achieve the above object, the invention according to claim 1 is a picture tube discharge device for discharging a picture tube according to a picture signal and a synchronizing signal. A video amplifier circuit that amplifies and outputs to a picture tube, and a sawtooth wave that is high level when operating
Drive signal generated from the above sync signal
Output from the signal output end, and when the
Signal output terminal to a low level, a synchronizing circuit that obtains this drive signal, a deflection circuit that drives the electron beam of the picture tube, a spot killer circuit that discharges the electric charge remaining in the picture tube, and a power-on Create the above synchronization circuit
When the power-off is instructed, a control circuit that operates the spot killer circuit while operating the synchronous circuit for a predetermined time when the power-off is instructed, and power can be supplied for a predetermined time after the power-off is instructed It has a time constant circuit such, the dry
When the signal output terminal goes low ,
A conducting circuit is provided which allows a current to flow from the power input terminal to the drive signal output terminal.

In the invention according to claim 1 configured as described above, when the synchronizing circuit creates a drive signal from the synchronizing signal and outputs it from the drive signal output end when the power is turned on , the deflection circuit obtains the drive signal. Then, the electron beam of the picture tube is driven. On the other hand, since the video amplifier circuit amplifies the video signal and outputs it to the picture tube, an electron beam corresponding to the video signal is driven and emitted in the picture tube,
The image will appear.

When the power-off is instructed , the time constant circuit supplies electric power for a predetermined time, and the control circuit operates the synchronous circuit for a predetermined time and also operates the spot killer circuit. Then,
A high-level sawtooth drive signal is output from the synchronizing circuit, the electron beam of the picture tube is driven for a predetermined time, and the spot killer circuit discharges the electric charge remaining in the picture tube. Therefore, the remaining charges are emitted as an electron beam while being driven, the charges do not concentrate at the collision point, and the picture tube does not burn. After the lapse of a predetermined time, the drive signal output from the synchronous circuit is stopped,
The drive signal output terminal becomes low level. Then the video
A current flows from the power supply input terminal of the amplifier circuit to the drive signal output terminal that has become a low level, and the remaining power disappears.

On the other hand, due to an erroneous operation such as mixing of electrical noise, the above-described power-off operation may be performed when the power-off is not instructed . At this time, the synchronous circuit and the spot killer circuit operate for a predetermined time, and thereafter, the drive signal from the synchronous circuit is not output and the drive signal output terminal becomes low level. The conduction circuit causes a current to flow from the power input terminal of the video amplifier circuit to the drive signal output terminal which has become a low level. Then, the low-level drive signal output terminal pulls in the voltage level at the power supply input terminal , and the power supply to the video amplifier circuit is stopped. As a result, the power supply to the video amplifier circuit is stopped even when a malfunction occurs due to mixing of electrical noise, etc., and the image sticking of the picture tube is prevented. That is, power off is instructed
In this case, the synchronizing circuit and the spot killer circuit are operated for a predetermined time to discharge the remaining electric charge in the picture tube so as to disperse the electric charge, and the power is supplied to the video amplifier circuit even if a malfunction occurs when the power-off is not instructed. Is stopped. Therefore, the picture tube will not burn even when it malfunctions.

Here, the video amplifier circuit only needs to be able to amplify the video signal and output it to the picture tube, and for example, a general-purpose cathode amplifier can be adopted. The synchronous circuit is at a high level and sawtooth wave when operating.
Drive signal generated from the above sync signal
Output from the signal output end, and when the
It suffices if the output signal output terminal can be set to the low level .
Therefore, for example, a general-purpose synchronizing circuit used in a television device or the like is adopted, or a chroma IC that separates a synchronizing signal from a composite signal of video and audio and creates and outputs a drive signal is adopted. There are various configurations. For the deflection circuit and the spot killer circuit, for example, a general-purpose circuit used in a television device or the like can be adopted.

The control circuit activates the synchronous circuit when the power is turned on.
It suffices to be able to operate the spot killer circuit that discharges the electric charge remaining in the picture tube in a short time while operating the synchronous circuit for a predetermined time when the power-off is instructed . Therefore, for example, it may be configured by a microcomputer having a function of outputting a control signal, or may be a one-chip IC integrated with a synchronizing circuit or the like, and its configuration is various.

The conduction circuit has a time constant circuit capable of supplying electric power for a predetermined time after the power-off is instructed , and
It suffices that a current can flow from the power input terminal of the video amplifier circuit to the drive signal output terminal when the drive signal output terminal becomes low level . Here, as an example of connecting the conduction circuit to the drive signal output terminal, the invention according to claim 2 provides the picture tube discharge device according to claim 1,
The conducting circuit is connected to a vertical drive signal output terminal for outputting a vertical drive signal for vertically driving the electron beam of the picture tube.

In the invention according to claim 2 having the above-mentioned structure, the vertical drive signal output end is at a low level when the operation is performed when the power is off, and a video is output to the vertical drive signal output end at the low level. Power on the amplifier circuit
The voltage level at the power end is pulled. As a result, the power supply to the video amplifier circuit is stopped. Therefore power off
The configuration is suitable for a picture tube discharge device including a spot killer circuit that discharges the electric charge remaining in the picture tube while driving the electron beam of the picture tube in the vertical direction for a predetermined time after the instruction . Of course, the configuration in which the conduction circuit is connected to the vertical drive signal output terminal is only an example, and it may be configured to be connected to the horizontal drive signal output terminal for horizontally driving the electron beam of the picture tube.

As an example of a concrete configuration of the conduction circuit, the invention according to claim 3 is the picture tube discharge device according to claim 1 or 2, wherein the conduction circuit is the power source. The diode is connected to the input terminal side as the anode and the drive signal output terminal side as the cathode. In the invention according to claim 3 configured as described above, the current flowing through the conduction circuit flows only from the power supply input end on the anode side to the drive signal output end on the cathode side. Then, when the operation at power off is performed and the drive signal output end becomes low level, current flows from the power input end of the video amplifier circuit to the drive signal output end, and the voltage level of this power input end is It is pulled in and the power supply to the video amplifier circuit is stopped. Therefore, it is possible to configure the conduction circuit with a simple circuit.

Further, as an example of a concrete configuration of the time constant circuit provided in the conduction circuit, the invention according to claim 4 is the picture tube discharge device according to any one of claims 1 to 3, The time constant circuit is configured to have a capacitor connected to the power input terminal and the ground.

In the invention according to claim 4 configured as described above, the capacitor stores electric power when the power is turned on. Then, when the power is turned off, electric power is supplied from the capacitor, a drive signal is output from the synchronous circuit, and the electron beam of the picture tube is driven for a predetermined time.
A spot killer circuit releases the charge remaining in the picture tube. After the elapse of a predetermined time, the drive signal output from the synchronizing circuit is stopped and the drive signal output terminal becomes low level.
Then, current flows from the power input terminal to the drive signal output terminal, and the remaining power is lost. It should be noted that the time for supplying electric power when the power is turned off varies depending on the capacitance of the capacitor, and can be adjusted by appropriately varying the capacitance of the capacitor depending on the circuit.

When the power-off operation described above is performed and the voltage level at the drive signal output end of the synchronizing circuit decreases when the power-off is not instructed , the conduction circuit changes from the power input end of the video amplifier circuit to the low level. A current is sent to the drive signal output terminal that becomes. Then, the low-level drive signal output terminal pulls in the voltage level at the power supply input terminal , and the power supply to the video amplifier circuit is stopped. Therefore, the time constant circuit is composed of a simple circuit, and it is possible to prevent the burn-in of the picture tube by stopping the power supply of the video amplifier circuit even in the case of a malfunction caused by mixing of electrical noise.

[0018]

As described above, according to the present invention, it is possible to prevent the burn-in of the picture tube by stopping the power supply to the video amplifier circuit even in the case of a malfunction caused by the mixing of electric noise. According to the second aspect of the present invention, the picture tube discharge including the spot killer circuit for driving the electron beam of the picture tube in the vertical direction for a predetermined time after the power-off is instructed and discharging the electric charge remaining in the picture tube. A picture tube discharger suitable for the apparatus can be provided.
Further, according to the invention of claim 3, the synchronizing circuit is configured by a simple circuit, and the power supply of the video amplifier circuit can be stopped even in the case of malfunction. Further, claim 4
According to the present invention, the time constant circuit is configured by a simple circuit, and the power supply of the video amplifier circuit can be stopped even in the case of malfunction.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION 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 picture tube discharge device according to an embodiment of the present invention is applied. In the figure, IIC
The bus 40 is a microcomputer 1 that is a main control unit that centrally controls internal devices and that constitutes a control circuit of the present invention.
0 and a tuner 20 for receiving television broadcast waves
And a chroma IC 30 that restores and outputs a video signal and an audio signal based on the received television broadcast radio wave. Then, these perform predetermined data communication by serial data communication via the IIC bus 40. Then, the microcomputer 10 controls the entire device by this serial data communication,
The function as a television device is realized.

The tuner 20 is a tuner that employs a so-called voltage synthesizer, and can be controlled via the IIC bus 40. A normal tuner has a tuning voltage (V
0) potentiometer and VHF low band (V
L), VHF high band (VH), and UHF (U) band changeover switch, and by appropriately setting these, a signal corresponding to a desired channel selection frequency is received. The tuner 20 does not include these mechanical configurations, obtains these setting values from the microcomputer 10 via the IIC bus 40, and transmits a television broadcast signal having a reception frequency corresponding to the setting values via an antenna (not shown). To receive. At the same time, from the television broadcast signal to the intermediate frequency signal (IF)
Is generated and output to the chroma IC 30.

The chroma IC 30 is roughly constructed as shown in FIG. 2 and performs various kinds of signal processing. In the figure, the intermediate frequency signal input to the chroma IC 30 is input to the signal system circuit 31, and the microcomputer 10 outputs the AGCC signal.
The ONTROL signal is input and intermediate frequency amplified by the AGC circuit 32 that performs feedback control. The video signal is subjected to video detection after being subjected to intermediate frequency amplification, subjected to predetermined color demodulation processing based on the detected output, and output as an RGB signal. Further, the audio signal is taken out as a second audio intermediate frequency signal in the process of intermediate frequency amplification, and undergoes FM detection to output the AUDIO signal. After that, the RG output from the signal system circuit 31
The B signal is output to the cathode amplifier 50 that constitutes the video amplifier circuit of the present invention, is appropriately amplified by the cathode amplifier 50, and is supplied to the picture tube 51. On the other hand, the above A
The UDIO signal is similarly output to the external audio amplifier 52, appropriately amplified by the audio amplifier 52, and supplied to the speaker 53.

In the signal system circuit 31, the horizontal and vertical synchronizing signals (SYNC) are separated from the detected output and supplied to the synchronizing circuit 33 in the present invention within the chroma IC 30 and the external microcomputer 10. . In this synchronizing circuit 33, the horizontal circuit from the oscillation circuit arranged in the chroma IC 30 is
The oscillation output corresponding to the vertical synchronizing signal is input, and normally, each oscillation output and the horizontal output from the signal system circuit 31 are input.
A PLL loop is formed with the vertical synchronizing signal. This P
The signal whose phase is locked to the corresponding oscillation output by the LL loop is a sawtooth signal, and is a vertical drive signal (V.DRIVE) and a horizontal drive signal (H.DRIVE).
E) is output to the external vertical deflection circuit 60 and the horizontal deflection circuit 61 which constitute the deflection circuit of the present invention.

The horizontal deflection circuit 61 drives the electron beam in the horizontal direction by generating a predetermined horizontal output signal from the horizontal drive signal and supplying the horizontal output signal to the horizontal deflection coil provided in the picture tube 51. Let The high frequency signal generated in the horizontal deflection circuit 61 is supplied to a high voltage circuit configured by a flyback transformer or the like and supplied to the picture tube 51.
A high voltage is generated for applying to the anode. On the other hand, the vertical deflection circuit 60 generates a vertical output signal from the vertical drive signal and supplies the vertical output signal to the vertical deflection coil provided in the picture tube 51 to drive the electron beam in the vertical direction. As a result, in the picture tube 51, the electron beam corresponding to the video signal is driven and emitted, and an image appears in the picture tube 51.

In the present embodiment, the remote controller transmitter 11 sends a tuning instruction for the tuner 20 and an instruction for turning the power on / off.
It can be done by the operation of. More specifically, when the user pushes down the operation button of the remote control transmitter 11, the infrared remote control signal corresponding to the pushed operation button is transmitted from the remote control transmitter 11. Then, the infrared remote control signal is received by the microcomputer 10 on the main body side via a remote control signal light receiving unit (not shown), and the operation content thereof is detected to perform tuning control of the tuner 20 or control power on / off. Has become.

When the power-off is instructed , the picture tube 5
The spot killer circuit 70 according to the present invention is provided in order to discharge the electric charge remaining in the first anode. Then, when the remote controller transmitter 11 is instructed to turn off the power, the microcomputer 10 performs a process at the time of turning off the power in a predetermined order to shut off the power supply to the internal circuits. At this time, the microcomputer 10 operates the synchronizing circuit 33 for a predetermined time to output a vertical drive signal, and at the same time, outputs a spot killer pulse signal to the spot killer circuit 70 to operate the same, thereby receiving the picture tube 51.
The residual electric charge is discharged. Then, the remaining charges are emitted as an electron beam while being driven, so that the charges do not concentrate at the collision point, and the image sticking of the picture tube is prevented.

Further, the resistor circuit R is connected to the cathode amplifier 50.
Connected to a power supply line 54 that supplies power via 1 .
A conduction circuit 80 including the time constant circuit 81 according to the present invention between the resistance circuit R1 and the vertical drive signal output terminal 34.
Are connected. The current flows from the power input terminal 50a to only one of the vertical drive signal output terminals 34. Further, even when the power-off is instructed , the time constant circuit 81 holds the voltage level of the power supply line 54 for a predetermined time, so that power can be supplied to the spot killer circuit 70 and the like.

FIG. 3 is a circuit diagram of a main part of a picture tube discharge device according to an embodiment of the present invention. In the figure,
The conduction circuit 80 includes a power input terminal 5 of the cathode amplifier 50.
The diode D1 connected to the power supply line 54 via the resistance circuit R1 as an anode and the vertical drive signal output end 34 as a cathode is provided.
Due to the rectifying action of this diode D1, the current is input to the power supply.
Only one flows from the end 50a to the vertical drive signal output end 34. The time constant circuit 81 is composed of a power source input terminal 50a of the cathode amplifier 50, a capacitor C1 and a resistor circuit R2 connected in parallel to the ground. Here, the capacitor C1 is supplied with power from the power supply line 54 via the resistance circuit R1 when the power is turned on, and supplies the stored power to the external circuit when the power is not supplied from the power supply line 54. Then, Sadamari is the time constant in the capacitance of the capacitor C1 and the resistance value of the resistor circuit R1, the power source
The power supply time is determined when the off instruction is given . That is, the power supply time can be adjusted by changing the electrostatic capacitance of the capacitor C1 and the resistance value of the resistance circuit R1 according to the circuit.

The presence of the above-mentioned conduction circuit 80 enables the power supply.
When the off instruction is given, the electric power stored in the time constant circuit 81 is supplied to the spot killer circuit 70, etc.
Activates the spot killer circuit 70 while operating the synchronizing circuit 33 for a predetermined time. High level from the synchronization circuit 33
A sawtooth-shaped vertical drive signal of (H) is output, the electron beam of the picture tube 51 is driven for a predetermined time, and the spot killer circuit 70 causes the picture tube 51 to discharge the remaining electric charge. After the lapse of a predetermined time, the vertical drive signal output from the synchronizing circuit 33 is stopped, and the vertical drive signal output terminal 34 becomes low level. Then, the diode D1 causes a current to flow from the power supply input end 50a side toward the low level vertical drive signal output end 34, and there is no remaining power.

On the other hand, due to an erroneous operation such as mixing of electrical noise, the above-described processing at the time of turning off the power may be performed even if the instruction to turn off the power is not issued . That is,
The synchronous circuit 33 and the spot killer circuit 70 may operate for a predetermined time, and then the vertical drive signal from the synchronous circuit 33 may not be output. At this time, the vertical drive signal output terminal 34 becomes low level, so that the diode D
1 causes a current to flow from the power supply input end 50a side to the vertical drive signal output end 34 which has become a low level. Then, the power is turned on by the vertical drive signal output terminal 34 which becomes low level.
The voltage level of the power terminal 50a is pulled in, and the power supply to the cathode amplifier 50 is stopped. Therefore, the power supply to the cathode amplifier 50 is stopped even when a malfunction occurs due to mixing of electrical noise, etc., and the image sticking of the picture tube 51 is prevented.

Next, the operation of the picture tube discharge device according to this embodiment will be described with reference to the timing charts of various signal waveforms shown in FIGS. FIG. 4 shows the operation when the power is off. In the initial state, the power is on, and the capacitor C1 is in a state in which electric power is stored. In the figure, operation of the remote control transmitter 11
Ri becomes the power off (timing T1), together with the power supply to the cathode amplifier 50 is cut off, the microcomputer 10
Activates the spot killer circuit 70 while activating the synchronizing circuit 33 of the chroma IC 30 for a predetermined time. The power-off process is performed by supplying the power stored in the capacitor C1 when the power is on, and therefore the power stored in the capacitor C1 gradually decreases (timing T1 to T2). Then, the synchronizing circuit 33 outputs a sawtooth-shaped vertical drive signal of high level (H), and the electric charge remaining in the picture tube 51 is driven and discharged.

After a lapse of a predetermined time, the vertical drive signal output from the synchronizing circuit 33 is stopped and the vertical drive signal output terminal 34 becomes low level (timing T2). Then,
The diode D1 quickly flows a current from the capacitor C1 toward the vertical drive signal output terminal 34 which has become a low level, and the electric power stored in the capacitor C1 disappears (timing T3).

On the other hand, the operation when the power-off operation is performed when the power-off is not instructed is as shown in FIG. In the same figure, when the power-off is not instructed, the synchronous circuit 33 operates to output a vertical drive signal due to a malfunction, and the spot killer circuit 70 operates (timing T11). No vertical drive signal is output, and the vertical drive signal output terminal 34 becomes low level (timing T12
). Then, the diode D1 passes through the resistance circuit R1.
A current flows from the power supply line 54 and the capacitor C1 to the vertical drive signal output terminal 34 that is at a low level. Then, the voltage level of the power supply input terminal 50a is pulled by the vertical drive signal output terminal 34 which has become low level, the stored power in the capacitor C1 is exhausted, and the power supply to the cathode amplifier 50 is stopped (timing T13).
). Therefore, the power supply to the cathode amplifier 50 is stopped even when malfunctioning.

That is, when the power-off is instructed, the synchronizing circuit 3 is operated as usual by the electric power stored in the capacitor C1.
3 and the spot killer circuit 70 operate to perform processing when the power is turned off, and the image sticking of the picture tube 51 is prevented. Then, the power is turned off due to malfunction such as electric noise mixing.
If the power-off operation is performed when the power supply input terminal 50 is not connected to the vertical drive signal output terminal 34, the diode D1 forming the conduction circuit 80 becomes low level.
retracting the voltage level of a. As a result, the power supply to the cathode amplifier 50 is stopped, and the image sticking of the picture tube 51 is prevented.

As described above, in the present invention, the power is turned off.
Is instructed, the synchronous circuit and the spot killer circuit operate for a predetermined time to discharge the electric charge remaining in the picture tube so as to disperse, and even if the spot killer circuit malfunctions when the power off is not instructed. Stop the power supply to the video amplifier circuit. Therefore, it is possible to provide a picture tube discharge device capable of preventing the picture tube from being burned even when it malfunctions.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a television device to which a picture tube discharge device according to an embodiment of the present invention is applied.

FIG. 2 is a circuit diagram of a main part of a chroma IC.

FIG. 3 is a main part circuit diagram of a picture tube discharge device according to an embodiment of the present invention.

FIG. 4 is a timing chart showing an operation when the power is off.

FIG. 5 is a timing chart showing an operation when the power-off operation is performed when the power-off is not instructed .

FIG. 6 is a circuit diagram of a main part of a picture tube discharge device according to a conventional example.

[Explanation of symbols]

1. Picture tube discharge device 2 ... Cathode amplifier 3 ... Synchronous circuit 4 Deflection circuit 5 ... Spot killer circuit 6 ... Control circuit 10 ... Microcomputer 11 ... Remote control transmitter 20 ... Tuner 30 ... Chroma IC 31 ... Signal system circuit 32 ... AGC circuit 33 ... Synchronous circuit 34 ... Vertical drive signal output end 40 ... IIC bus 50 ... Cathode amplifier 50a ... Power input terminal 51 ... Picture tube 52 ... Audio amplifier 53 ... speaker 54 ... Power line 60 ... Vertical deflection circuit 61 ... Horizontal deflection circuit 70 ... Spot killer circuit 80 ... Continuity circuit 81 ... Time constant circuit R1 ... Resistor circuit D1 ... Diode C1 ... Capacitor R2 ... Resistor circuit

Claims (4)

(57) [Claims] 1. A picture tube discharge device for discharging a picture tube according to a picture signal and a synchronizing signal, the picture amplification circuit amplifying the picture signal and outputting the picture signal to the picture tube . Sawtooth wavy at high level
Create a drive signal from the above sync signal to generate a drive signal
Output from the output end, and when it is not operating, the same drive signal
The synchronizing circuit that makes the signal output terminal low level, the deflection circuit that obtains this drive signal to drive the electron beam of the picture tube, the spot killer circuit that discharges the electric charge remaining in the picture tube, and the above when the power is turned on. Powering the synchronous circuit
Off has When instructed a control circuit for operating the spot killer circuit while operating the predetermined time the synchronous circuit, a time constant circuit capable of supplying a predetermined time power from the power-off is instructed, the drive Signal output end is low
A picture tube discharger comprising: a conduction circuit for flowing a current from the power supply input end of the video amplification circuit to the drive signal output end when the bell is reached. 2. The picture tube discharger according to claim 1, wherein the conduction circuit is connected to a vertical drive signal output terminal for outputting a vertical drive signal for vertically driving the electron beam of the picture tube. A picture tube discharge device characterized in that 3. The picture tube discharge device according to claim 1 or 2, wherein the conduction circuit connects the power supply input end side as an anode and the drive signal output end side as a cathode. CRT discharge device having an integrated diode. 4. The picture tube discharge device according to claim 1, wherein the time constant circuit has a capacitor connected to the power input terminal and the ground. Picture tube discharge device.