JPH0793695B2 - Horizontal deflection circuit - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal deflection circuit in a display device using a picture tube. An object of the present invention is to provide a horizontal deflection circuit suitable for use when the horizontal deflection frequency is high or when the horizontal deflection frequency takes various values.

(Prior Art) FIG. 8 is a circuit diagram showing an example of a conventional horizontal deflection circuit. This is a prior application by the present applicant: Japanese Patent Application No. 1-29061.
It is based on the issue.

Reference numeral 1 denotes a horizontal oscillation circuit that outputs an oscillation waveform V _OSC synchronized with a horizontal synchronization pulse P supplied from a preceding stage (not shown). 2 is a horizontal excitation circuit, 3 is a horizontal excitation transformer, 4
Is a horizontal output transistor, and 5 is a first base resistor. 6 is a damper diode, 7 is a return resonance capacitor, 8 is a horizontal deflection coil, 9 is an S-time correction capacitor, 10
Is a horizontal output transformer (or flyback transformer)
Is.

The horizontal deflection circuit composed of the components 1 to 10 is (1
(Except for components other than ~ 10), which are often found in ordinary television receivers and the like, and the collector of the horizontal output transistor 4 has a sine half-wave horizontal retrace pulse V due to a well-known principle. _c occurs, and the sawtooth wave current I _y having a horizontal deflection cycle synchronized with the incoming synchronization signal is generated in the horizontal deflection coil 8.
Flows. Since the horizontal deflection coil 8 is attached to the neck of a picture tube not shown here,
As a result, the electron beam of the picture tube is deflected left and right.

If the circuit shown in the figure is a circuit for horizontal deflection only, 10 acts as a horizontal output transformer, and power is supplied to the circuit from the DC power supply + E _B (DC voltage + E _B ) connected to one end of the primary winding 10 _a. To supply. When the circuit shown in the figure serving as a horizontal high-voltage generating circuit, 10 acts as a flyback transformer, to obtain a pulse V _hv obtained by boosting the horizontal retrace pulse V _c in the secondary winding 10 _b side, the pulse V _hv After the rectification to make DC high voltage, it is applied to the anode of the picture tube to operate the picture tube.

If the horizontal deflection frequency is a low frequency around 15.73 KHz, like a normal television receiver, this horizontal deflection circuit composed of the components 1 to 10 is sufficient.

However, in recent years, in display devices used in CAD and the like, the horizontal deflection frequency tends to increase to 84 KHz, 97 KHz, 128 KHz, etc. in accordance with the demand for higher definition of images. In this way, when the horizontal deflection frequency becomes high, in the horizontal deflection circuit composed of the components 1 to 10, the speed at which the horizontal output transistor 4 is cut off is slow, and a large loss occurs.

Therefore, it is necessary to take measures to increase the speed at which the horizontal output transistor 4 is cut off. The monostable multivibrator MM1 (hereinafter, also simply referred to as MM1), the _Ibn extraction circuit 12, and the second base resistor 13 are circuits for increasing the speed at the time of interruption.

MM1 is triggered at the rising edge of the output V _osc of the horizontal oscillation circuit 1 (rectangular wave) (here the positive period) a pulse width set to output a square wave V _dn of. In this MM1, the pulse width of the rectangular wave V _dn can be adjusted by the control DC voltage E _c . I _bn
The extraction circuit 12 is supplied with a rectangular wave V _dn , and the rectangular wave V _dn is supplied.
the _dn pulse period (high level period of the V _dn), the reverse base current (storage carrier) I _bn during storage period from the base of the horizontal output transistor 4, draw through a base resistor 13.

FIG. 9 is an explanatory diagram of the circuit operation of this horizontal deflection circuit.
The output _Vosc of the horizontal oscillation circuit 1 shown in FIG.
_Is a rectangular wave with a pulse width that lasts for a certain time t _osc . The output Vd of the horizontal excitation circuit 2 shown in FIG.
Bottoming at T1. The signal has a substantially rectangular wave shape. this
Rise time T2 of Vd is the time from the previous time T1, it has elapsed and the accumulation time t _s1 of the excitation transistor pulse width tosc and horizontal exciting circuit 2 of V _osc.

Base current of the horizontal output transistor 4 shown in FIG.
Ib flows in the positive direction until time T1, and the flowing direction reverses to the negative direction at time T1, and the current value becomes zero after the accumulation time t _s2 of the horizontal output transistor 4 has elapsed from time T1.

FIG. 5D shows the output V _dn of the MM1, and the output V _dn is
_Has a pulse width of time t _dn . The output V _dn is supplied to the I _bn drawer circuit 12, I _bn drawer circuit 12, as shown by (E), and outputs a rectangular wave Vn which corresponds approximately to an inverted output V _dn. Here, the bottoming period of Vn is V
What is drawn slightly longer than the pulse width of _dn shows the delay due to the elements in the I _bn extraction circuit 12. (Ideally, it is desirable that this delay does not exist.) During the bottoming period of Vn, the reverse base current I _bn flows through the base resistor 13 as shown in FIG. And
In order to energize the flow of the current I _bn , a negative power supply (power supply voltage −E) is added as an auxiliary power supply for the I _bn drawing circuit 12.

Here, the base current Ib of the horizontal output transistor 4 shown in FIG. 7C is as shown by the broken line in FIG. 7C in a normal horizontal deflection circuit in which the MM1 and _Ibn extraction circuits 12 are not connected. , At time T2. However, when the rectangular wave Vn is supplied through the base resistor 13, the base current Ib cannot flow out while the rectangular wave Vn is bottoming, and after the time T3 as shown by the solid line. Flow out.

At the same time, at time T3, the collector current Ic of the horizontal output transistor 4 also starts to flow, as shown in FIG. On the other hand, at time T4 when the flow of the reverse base current I _bn ends, the collector current Ic of the horizontal output transistor 4 becomes zero and enters the cutoff state, and as shown in FIG. (Horizontal blanking pulse) Vc is generated. This pulse
Vc is mainly after the pulse width (retrace time) tr determined by the resonance cycle of the retrace resonance capacitor 7 and the horizontal deflection coil 8.
It becomes zero again. From this time T5 when it becomes zero, as shown by the broken line in FIG.
Id starts flowing out, and at time T3, it smoothly connects to the collector current Ic described above.

Then, the current Id of the damper diode and the collector current Ic
When a current that linearly increases during the scanning period t _s is formed by and, the sawtooth wave current Iy flows in the deflection coil 8 together with the current of the retrace resonance capacitor 7, and the horizontal deflection operation is performed.

(Problems to be Solved by the Invention) By the way, assuming that the time when the collector current Ic shown in FIG. 6H passes through the zero level is time T6, the conduction start time T3 of the collector current Ic is the end point of the horizontal blanking period. It must be entered between time T5 and time T6. If this conduction start time T3 comes before the end time T5, the collector current of the horizontal output transistor 4 will flow before the collector voltage Vc has reached zero, causing a large current loss. , Will damage the transistor. On the contrary, even when the conduction start time T3 comes after the time T6, the collector current is temporarily interrupted this time, so that a small pulse occurs and a large current loss also occurs, leading to damage to the transistor.

As a result, the ideal position at the conduction start time T3 is 1 / 4th before the horizontal scanning period t _s when safety is given the highest priority.
It is the place. However, as described above, when the horizontal deflection frequency becomes high, the value of t _s / 4 itself becomes small, and it becomes difficult to match the position at time T3 with the ideal position. For example, if the horizontal deflection frequency is 100 KHz,
The value of t _s / 4 becomes only 2 μ _s . With such a short value, time T3 can be easily changed due to variations in the circuit conditions.
The ideal condition of is shifted. In particular, the storage time t _s1 of the drive transistor in the horizontal drive circuit 2 and the storage time t _s2 of the horizontal output transistor 4 described above change greatly depending on the temperature, and move the position at time T3.

Since the fluctuation of the position at time T3 seriously affects the reliability of the entire horizontal deflection circuit, this fluctuation has been a big problem in designing a high-definition display.

In order to suppress the fluctuation of the position at the time T3, the value of the output pulse width t _dn of the MM1 has to be strictly determined as the horizontal deflection frequency becomes higher. Further, in the case of a device that supports various horizontal deflection frequencies, the value of the pulse width t _dn naturally changes every time the horizontal deflection frequency changes.
Therefore, the value of the pulse width t _dn is adjusted by the control DC voltage Ec.

In this case, the position at time T3 in FIG.
It can be adjusted freely by adjusting the value of _dn , but the position at time T2 remains fixed. The position at time T2 is the 9th
As shown in the figure, there is no problem if it is ahead of the position of time T3, but when the position of time T2 is behind the position of time T3, the conduction start position of the collector current Ic is not at time T3 but at time T2. turn into. Therefore, if the position at time T2 is
If it comes behind the position at time T6, it causes a loss as described above and damages the horizontal output transistor 4. And this damage cannot be solved no matter how much the pulse width t _dn of the output waveform V _dn of MM1 is adjusted.

(Means for Solving the Problems) Therefore, in order to solve the above problems, the present invention provides (1) a horizontal oscillation circuit, a horizontal excitation circuit, and an output of the horizontal excitation circuit for excitation via an excitation transformer. Between a horizontal output transistor, a first monostable multivibrator circuit that is triggered by an output waveform of the horizontal oscillation circuit, and whose output pulse width is electrically controllable; and a base of the horizontal output transistor and an auxiliary power supply. And a storage carrier extraction circuit connected to the first monostable multivibrator circuit, the storage carrier extraction circuit is operated by the output pulse of the first monostable multivibrator circuit, and the storage carrier of the base layer when the horizontal output transistor is cut off is removed. In the horizontal deflection circuit configured to draw out, the horizontal oscillation circuit is provided between the horizontal oscillation circuit and the horizontal excitation circuit. A second monostable multivibrator circuit is provided, which is triggered by the output waveform of the circuit, the output pulse width of which is electrically controllable, and which operates the horizontal excitation circuit by the output, and the first and second monostable multivibrator circuits are provided. A horizontal deflection circuit characterized in that the output pulse width of the stable multivibrator circuit is controlled by a common electric signal, and (2) the output of the storage carrier extraction circuit and substantially the first half of the horizontal scanning period. An ethical product circuit that outputs an ethical product pulse that is an ethical product pulse with a rectangular wave pulse having a pulse width of A comparator for obtaining a second DC voltage by comparing the voltage with a predetermined voltage, and using the second DC voltage, the outputs of the first and second monostable multivibrator circuits The horizontal deflection circuit is characterized in that the pulse width is controlled so that the conduction start time of the horizontal output transistor is located at about 1/4 of the front side of the horizontal scanning period, and (3) the predetermined voltage Is a DC voltage that is generated based on a rectangular wave having a pulse width of a horizontal scanning period obtained by shaping a horizontal retrace pulse, and is a DC voltage proportional to a time width of 1/4 of the horizontal scanning period. A horizontal deflection circuit is provided.

(Embodiment) FIG. 1 is a circuit configuration diagram of a first embodiment of the present invention. The same parts as those in the conventional example are designated by the same reference numerals, and a detailed description of those parts will be omitted.

The first embodiment differs from the conventional example shown in FIG.
The monostable multivibrator MM2 (hereinafter sometimes simply referred to as MM2) is provided between the horizontal oscillation circuit 1 and the horizontal excitation circuit 2. The pulse width of the output rectangle of MM2 is controlled by the control DC voltage Ec supplied from the common control terminal c together with the first monostable multivibrator MM1.

FIG. 2 is an operation explanatory diagram of the first embodiment. Same figure (B)
As shown in, the pulse V obtained by the MM2 triggered at the rising edge of the oscillation pulse V _osc from the horizontal oscillation circuit 1
_osc1 is supplied to the next horizontal excitation circuit 2. Then, the time T2 when the output pulse Vd of the horizontal excitation circuit 2 rises is MM
It is determined by the pulse width t _osc1 of the second output pulse V _osc1 .

Therefore, as shown in FIG. 1, when the two monostable multivibrators MM1 and MM2 are controlled in common, the pulse width of the output pulse of MM1 is narrowed and the time of the conduction start time T3 of the collector current Ic of the horizontal output transistor 4 is reduced. Even when the position is moved forward, the position at time T2 moves forward like the position at time T3. Therefore, it is easy to always position the position at time T2 ahead of time T3, and the horizontal output transistor 4 is not damaged.

FIG. 3 shows a specific circuit diagram of the monostable multivibrator with variable output pulse width such as MM1 and MM2 used in the first embodiment. Here, 16 is a monostable multivibrator IC element, and for example, a ready-made IC such as a general-purpose 4528 series or 4538 series is used. Reference numeral 17 is a pulse width determining capacitor, 20 is a pnp transistor, 21 is its emitter resistance, and one end thereof is connected to the DC power supply + E. The portion 22 surrounded by the broken line constitutes a constant current circuit, and the constant current amount I is controlled by the control DC voltage Ec. In this circuit, the terminal voltage Vt of the pulse determining capacitor 17 increases linearly after the trigger, and is inverted when the threshold voltage defined by the IC is reached. Since the slope of the increase of the terminal voltage Vt is determined by the constant current I, the output pulse width is ultimately controlled by the control DC voltage Ec.

FIG. 4 is a circuit diagram of the Ibn extraction circuit 12. Where 2
3 is an input capacitor, 24 is a clamp diode, 25 and 26 are resistors, 27 is an npn transistor, 28 is a pnp transistor, 29
Is an n-channel MOSFET.

When the output pulse V _{dn of the} MM1 is supplied to the clamp diode 24 via the capacitor 23, the pulse V _dn1 with the upper part of the pulse clamped to almost 0 is obtained. This pulse V _dn1 is a resistance
After being divided by 25 and 26, it is supplied to the gate of the FET 29 through the SEPP circuits of the transistors 27 and 28 as substantially the same waveform.

At this time, the source of the FET 29 is connected to the negative power supply -E, and therefore, at the high portion (nearly zero volt) of the pulse V _dn ,
ET29 conducts and its drain produces an inverted pulse Vn. As described above, the reverse base current I _bn of the horizontal output transistor 4 mainly flows during this conduction period.

As described above, the adjustment of the output pulse width of MM1 and MM2 (time T
Adjustment of the position 3) can be performed by the control DC voltage Ec.
In the second embodiment of the present invention shown in FIG. 5, the control DC voltage can be automatically adjusted and the position at time T3 can be automatically set to the best point.

In FIG. 5, the operation of the parts denoted by the same reference numerals as those in FIG. 1 is the same as that of the first embodiment of FIG. 1, and therefore the description thereof is omitted here.

A winding 10c is newly added to the horizontal output transformer 10. From this, a small pulse V _c3 (horizontal retrace pulse) is obtained. _{Reference numeral} 30 is a shaping circuit that shapes and inverts the pulse V _c3 and outputs a rectangular wave V _s having a pulse width of the horizontal scanning period t _s . MM3 is a third monostable multivibrator MM3 that is triggered at the rising edge of the rectangular wave Vs and outputs a rectangular wave _Vhf with a pulse width of approximately ts / 2.

The output rectangular wave Vn of the Ibn extraction circuit 12 is passed through the inverter 22 to _Vn1
After that, the V _n1 and the rectangular wave V _hf are supplied to the AND circuit 33. A rectangular wave (logical product pulse) Va, which is the ethical product of V _n1 and V _hf , obtained by the AND circuit 33 is smoothed by the resistor 34 and the capacitor 35, and its average value voltage (first DC voltage) Ea But,
It is compared with the reference voltage Es in the next operational amplifier 36. And
The output (second DC voltage) Eo of the operational amplifier 36 is MM1 and MM2.
Control the output pulse width of.

This operation will be described with reference to FIG. FIG. 7A shows the base current Ib of the horizontal output transistor 4, and as described above, the output rectangular wave Vn of the Ibn extraction circuit 12 is as shown in FIG. The rising point of the output rectangular wave Vn coincides with the rising point T3 of the current Ib. Furthermore, the output square wave Vn
Is inverted by the inverter 32 to obtain the rectangular wave V _n1 shown in FIG.

On the other hand, the same figure (D) shows a pulse proportional to the collector pulse Vc.
V _c3 (horizontal retrace pulse), and this pulse V _c3 is sliced and inverted by the shaping circuit 30 and is at a high level for almost the horizontal scanning period t _s as shown in FIG. A square wave Vs whose width is the horizontal scanning period t _s ) is obtained. This rectangular wave Vs triggers MM3 at its rising portion, and the MM3 outputs a rectangular wave _Vhf that is at a high level for about half the period ts, as shown in FIG.

Therefore, if the AND circuit 33 _creates the ethical product of V _n1 and V _hf ,
As shown in (G) of the figure, the high level width ta at the end of the horizontal retrace time tr, that is, at time T5, until the start time T3 of the conduction of the base current Ib (collector current Ic) of the horizontal output transistor 4.
A square wave Va with is obtained. This rectangular wave Va is passed through a low-pass filter composed of a resistor 34 and a capacitor 35 to be a DC voltage (average value voltage) Ea. DC voltage Ea is high level width
proportional to the length of ta.

This voltage Ea is compared with the reference voltage Es by the operational amplifier 36. Then, both output pulse widths of MM1 and MM2 are controlled by the output Eo of the operational amplifier 36.

Therefore, if the voltages Ea and Eo change, the output pulse width of MM1 changes first, and the position at time T3 changes. Therefore, if the value of the voltage Ea is about to exceed the value of the reference voltage Es, if the control of the control DC voltage Eo for MM1 moves to move the position at time T3 forward, the entire circuit becomes a negative feedback loop. Has been formed. Therefore, the position at time T3 is determined with a value such that the voltage Ea always matches the voltage Es.

From this, if the value of the reference voltage Es is set so that the position of the time T3, that is, the length of the high level width ta of the rectangular wave Va is just 1/4 of the horizontal scanning period t _s , The negative feedback loop state can be stably maintained. Of course, the output DC pulse width of MM1 is moved by the control DC voltage Eo, and at the same time MM2
Since the output pulse width of is also moved in the same direction, the time T2 shown in FIG. 9 also moves in the same direction as that of the time T3. Therefore, it is possible to avoid the disadvantage that the time T2 is behind the time T3 as in the conventional example, the horizontal output transistor 4 is not damaged, and the reliability of the horizontal output transistor 4 is improved.

In the second embodiment described above, the adjustment of the control DC voltage supplied to MM1 and MM2 is automated. However, the second embodiment
In order to correspond to various values of the horizontal deflection frequency, the value of the reference voltage Es is changed every time the value of the horizontal deflection frequency is changed.
I have to readjust.

Therefore, in the third embodiment shown below (see FIG. 7), even if the value of the horizontal deflection frequency is switched, the position at time T3 is automatically set in the horizontal scanning period in accordance with each horizontal deflection frequency. The value of the reference voltage Es can be automatically set so as to be located at the front 1/4 position of t _s . Since the circuit of the third embodiment is the same as that of the second embodiment until the rectangular waves V _n1 and V _c3 are obtained, the illustration of that part is omitted in FIG. 7.

In FIG. 7, the parts denoted by the same reference numerals as in FIG.
The operation is almost the same as in FIG. The slightly different point is MM3
That is, the value of the output rectangular wave V _hf is not fixed but is controlled by the newly provided operational amplifier 44.

Here, the rectangular wave that has become high level for the horizontal scanning period t _s
Vs is added to MM2 and at the same time resistor 37 and capacitor 3
The voltage becomes E _sc through the low-pass filter by 8 and is divided by the voltage dividing circuit of the resistor groups 39 to 41. At this time, the resistance 41
If the resistance value of is set to Ro, the resistance value of resistor 40 is Ro,
The resistance value of 39 is 2Ro.

The output rectangular wave V _hf of MM3 is smoothed by the resistor 42 and the capacitor 43 to become the voltage E _hf , and the newly provided operational amplifier 44
Is supplied to the inverting terminal of. The non-inverting terminal of the operational amplifier 44 is supplied with half the voltage E _sc of the capacitor 38, that is, E _sc / 2 which is the voltage at the connection point of the resistors 39 and 40. The output of the operational amplifier 44 is supplied to the MM3 as a control voltage to control the pulse width of the output rectangular wave V _hf . Further, a voltage of E _sc / 4 is obtained at the connection point of the resistors 40 and 41, and this voltage is supplied to the inverting terminal of the operational amplifier 36 instead of the voltage Es of FIG.

By doing this, the pulse width of the output rectangular wave V _hf of MM3 becomes
1 / pulse width (high level period) ts of input rectangular wave Vs
Controlled to 2. Further, the voltage at the connection point of the resistors 40 and 41 is proportional to 1/4 of the pulse width ts of the input rectangular wave Vs (if the horizontal deflection frequency is not constant, the duty cycle of the rectangular wave Vs is 1 Proportional to / 4)
Since it becomes a voltage, when it is compared with the average value Ea of the rectangular wave Va by the operational amplifier 36, the pulse width ta of the rectangular wave Va automatically becomes an ideal state of 1/4 of the horizontal scanning period t _s . The ideal state is brought about because the position of the rising time T3 of the output Vn of the MM1 controlled by the operational amplifier 36 is adjusted back and forth as described in FIG.

Of course, the power supplies for the MM1, shaping circuit 30, MM3, AND circuit 33, etc. are all common, for example, + E. Therefore, the voltages of the rectangular waves, V _n1 , V _sc , Va, and V _hf swing between zero and + E, and the resistance value of the resistor 37 is sufficiently smaller than 4Ro.

As described above, in the third embodiment, the determination of the pulse width ta value of the rectangular wave Va and the reference voltage is automated, that is, the determination of the position at time T3 is completely automated, so that it is not affected by the variation in each part of the circuit. In addition, the position at time T3 can be automatically maintained at the ideal position on the front side 1/4 of the horizontal scanning period t _s . Furthermore, in the third embodiment, the position at time T3 is completely automated, so that even if the horizontal deflection frequency is switched, the position at time T3 is automatically idealized corresponding to each horizontal deflection frequency. Can be set to the target position.

Of course, in the third embodiment, at the same time as adjusting the position at time T3, the position at time T2 described above can be automatically adjusted so as to be always ahead of the position at time T3, so that the horizontal output transistor 4 is damaged. Therefore, the reliability of the horizontal output transistor 4 is improved.

Therefore, the third embodiment is suitable for the horizontal deflection circuit of the high definition display device corresponding to various different values of the horizontal deflection frequency.

(Advantages of the Invention) As described above, the horizontal deflection circuit according to the present invention always stabilizes the horizontal output transistor even when the horizontal deflection frequency is high or the horizontal deflection frequency takes various values. It is possible to operate in the ideal state described above, and it is possible to improve the reliability of the horizontal output transistor.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of the first embodiment, FIG. 2 is an operation explanatory diagram thereof, FIG. 3 is a concrete circuit diagram of a monostable multivibrator, and FIG. 4 is a concrete circuit diagram of an I _bn extracting circuit, FIG. 5 is a circuit configuration diagram of the second embodiment, FIG. 6 is an operation explanatory diagram thereof, FIG. 7 is a circuit configuration diagram of the third embodiment, FIG. 8 is a circuit configuration diagram of a conventional example, and FIG. FIG. DESCRIPTION OF SYMBOLS 1 ... Horizontal oscillation circuit, 2 ... Horizontal excitation circuit, 3 ... Horizontal excitation transformer, 4 ... Horizontal output transistor, 5 ... 1st base resistance, 6 ... Damper diode, 7 ... Return resonance capacitor, 8 ... Horizontal deflection coil, 9 ... S-time correction capacitor, 10
... horizontal output transformer, 12 ... I _bn lead-out circuit, 13 ... second base resistance, 22 ... constant current circuit, 29 ... MOSFET, 30 ... shaping circuit, 33 ... AND circuit, 36,44 ... operational amplifier, MM1 ... first Monostable multivibrator, MM2 ... second monostable multivibrator, MM3 ... third monostable multivibrator.

Claims (3)

[Claims] 1. A horizontal oscillation circuit, a horizontal excitation circuit, a horizontal output transistor excited by an output of the horizontal excitation circuit via an excitation transformer, and an output pulse triggered by an output waveform of the horizontal oscillation circuit. A first monostable multivibrator circuit whose width is electrically controllable; and a storage carrier extraction circuit connected between the base of the horizontal output transistor and an auxiliary power supply, the first monostable multivibrator circuit In the horizontal deflection circuit configured to operate the storage carrier extraction circuit by the output pulse of the circuit to extract the storage carrier of the base layer when the horizontal output transistor cuts off, the horizontal oscillation circuit and the horizontal excitation circuit. During, the output pulse width can be electrically controlled by being triggered by the output waveform of the horizontal oscillation circuit A second monostable multivibrator circuit for operating the horizontal excitation circuit by an output is provided, and output pulse widths of the first and second monostable multivibrator circuits are controlled by a common electric signal. The horizontal deflection circuit is characterized in that 2. An ethical product circuit for outputting an ethical product pulse, which is an ethical product of the output of the accumulated carrier extraction circuit and a rectangular wave pulse having a pulse width of approximately the first half of the horizontal scanning period, and the ethical product pulse. An averaging circuit for averaging the first DC voltage and a comparator for comparing the first DC voltage with a predetermined voltage to obtain a second DC voltage. The output pulse widths of the first and second monostable multivibrator circuits are controlled by using the first and second monostable multivibrator circuits so that the conduction start point of the horizontal output transistor is located at about 1/4 of the front side of the horizontal scanning period. The horizontal deflection circuit according to claim 1, wherein: 3. The predetermined voltage is a direct current proportional to a time width of 1/4 of a horizontal scanning period, which is generated based on a rectangular wave having a pulse width of a horizontal scanning period obtained by shaping a horizontal retrace pulse. The horizontal deflection circuit according to claim 2, wherein the horizontal deflection circuit is a voltage.