JPH06217156A - Horizontal output circuit - Google Patents

Abstract

PURPOSE:To simplify the horizontal output circuit provided with a switching regulator circuit. CONSTITUTION:A switching regulator circuit 16 is provided at a deflecting output circuit 14 equipped with a horizontal output transistor 1, damper diode 2, resonance capacitor 3, S-shaped correction capacitor 5, choke coil 6 and diode 15. The chopper transistor of this switching regulator circuit 16 is shared with the horizontal output transistor 1, and the smoothing condenser (power source capacitor) of the switching regulator circuit 16 is shared with the S- shaped correction capacitor 5. Since the horizontal output transistor 1 and the S-shaped correction capacitor 5 are shared with the circuit elements of both of the deflecting output circuit 14 and the switching regulator circuit 16, a circuit configuration can be simplified, and a circuit cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal output circuit used in a television receiver or a display device.

[0002]

2. Description of the Related Art As is well known, a horizontal output circuit performs automatic beam scanning by deflection driving of a television receiver or a display device, but recently, deflection driving of a display device is performed by various horizontal deflection frequencies. Is coming. When the horizontal deflection frequency changes when driving the deflection yoke, the deflection current that flows in the deflection yoke changes, which causes a problem that the screen amplitude of the cathode ray tube changes. The deflection current stabilizing means is provided so that the deflection current does not change even when the value changes.

FIG. 4 shows a conventional example of a horizontal output circuit in which a voltage variable circuit is incorporated as a deflection current stabilizing means. This horizontal output circuit comprises a horizontal output transistor 1 functioning as a horizontal output switch element, a damper diode 2 connected in parallel with the transistor 1, a resonance capacitor 3, a deflection yoke 4 and an S-shaped correction capacitor 5 in series. A deflection output circuit is formed by the circuit and the choke coil 6, and a smoothing capacitor (power supply capacitor) 7, a series transistor 9 as a series dropper switch element, and an internal resistance of the series transistor 9 are formed in the deflection output circuit. It is connected to a variable amplification circuit 17. This circuit operates the amplifier circuit 17 by the horizontal deflection frequency f _H , and changes the internal resistance of the series transistor 9 so that the amplitude of the horizontal deflection current becomes constant, thereby changing the output voltage of the driving power source B _+. . That is, when the horizontal deflection frequency changes in the increasing direction, the deflection current changes in the decreasing direction. Therefore, the deflection current is increased by controlling the output voltage of the drive power source B ₊ to increase the horizontal deflection frequency. The deflection current is controlled to be constant by compensating for the decrease due to the frequency change.

However, in this voltage variable type circuit, the internal resistance of the series transistor 9 is varied to drive the drive power source B _+.
The power loss consumed by the series transistor 9 (power loss due to heat) as it controls the output voltage of
There is a problem that becomes large.

In order to reduce such power loss, a circuit in which the voltage variable type circuit is replaced with a switching regulator is shown in FIG. In this circuit, a choke coil 11 is provided in series between the choke coil 6 and the emitter of the chopper transistor 8, and the choke coil 11
And the cathode of the flywheel diode 12 is connected to the connection between the emitter and the emitter of the chopper transistor 8. The circuit shown in FIG. 5 is a pulse control circuit 10
The pulse width of the switch control signal for turning on / off the chopper transistor 8 in accordance with the change in the horizontal deflection frequency is controlled by changing the voltage of the smoothing capacitor (power supply capacitor) 7 (voltage applied to the deflection yoke). Four
It controls the current flowing to the constant.

FIG. 6 shows a simplified circuit configuration of FIG. Like the circuit shown in FIG. 5, the circuit shown in FIG. 6 also controls the ON period of the chopper transistor 8 by controlling the pulse width of the pulse control circuit 10, whereby the deflection can be performed regardless of the change in the horizontal deflection frequency. The deflection current of the yoke 4 is controlled to be constant.

FIG. 7 shows a horizontal output circuit coupled with a flyback transformer 13 to form a deflection / high voltage integrated circuit. In the figure, the deflection yoke 4 and the S-shaped correction capacitor 5 are provided on the secondary side of the flyback transformer 13, and the circuit shown in FIG. 7 is pulse-controlled similarly to the circuits shown in FIGS. 5 and 6. By controlling the pulse width of the circuit 10, the switch control of the chopper transistor 8 is performed and the deflection current flowing in the deflection yoke 4 is controlled to be constant.

[0008]

However, in the horizontal output circuit provided with the switching regulator shown in FIGS. 5 and 6, the horizontal deflection circuit and the switching regulator circuit have separate and independent circuit configurations.
Since the chopper transistor 8 is required in addition to the horizontal output transistor 1 of the deflection output circuit, there is a problem that the circuit configuration becomes complicated and the circuit cost becomes high.

Further, the circuits shown in FIGS. 5 and 7 require a smoothing capacitor (power supply transistor 7) on the switching regulator circuit side, separately from the S-shaped correction capacitor 5 of the deflection output circuit, and similarly the circuit configuration. Becomes complicated and the circuit cost becomes high.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to separately provide a horizontal output switch element on the side of a deflection output circuit and an S-shaped correction capacitor,
Avoid increasing the number of parts by providing switching elements and capacitors on the switching regulator circuit side, and make the horizontal output switching elements and S-shaped correction capacitors on the deflection output circuit side common to the switching elements and capacitors on the switching regulator circuit side. It is an object of the present invention to provide a horizontal output circuit capable of achieving simplification of the circuit configuration.

[0011]

In order to achieve the above object, the present invention is constructed as follows. That is, the present invention provides a deflection output circuit including a horizontal output switch element, a damper diode, a resonance capacitor, a deflection yoke, and an S-shaped correction capacitor, and a chopper switch element and the output of the same switch element. In a horizontal output circuit provided with a switching regulator circuit including a smoothing capacitor and a choke coil, a chopper switch element of the switching regulator circuit is also used as a horizontal output switch element, and the smoothing capacitor is the S-shaped correction capacitor. The horizontal output switch element of the deflection output circuit and the S-shaped correction capacitor are also used as a part of the switching regulator circuit.

[0012]

In the present invention having the above-described structure, the switching regulator circuit includes the chopper switch element, the smoothing capacitor, and the choke coil, but the horizontal output switch element on the deflection output circuit side is also used as the chopper switch element. By using the S-shaped correction capacitor of the deflection output circuit also as the smoothing capacitor (power supply capacitor) of the switching regulator circuit, the deflection output circuit and the switching regulator circuit can share the switch element and the capacitor, and the number of parts can be increased. The simplification of the circuit configuration is achieved in combination with the reduction of

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same circuit parts as those in the conventional example will be designated by the same reference numerals, and the duplicated description will be omitted. FIG. 1 shows an embodiment of the horizontal output circuit according to the present invention. In the horizontal output circuit of this embodiment, a diode 15 is connected between the emitter of the horizontal output transistor 1 functioning as a horizontal output switch element and the anode of the damper diode 2 with the anode side being the emitter side of the horizontal output transistor 1. The cathode side of the damper diode 2 is connected to the collector side of the horizontal output transistor 1. The resonance capacitor 3, the deflection yoke 4, and the S-shaped correction capacitor 5 are arranged in parallel with the damper diode 2.
The deflection output circuit 14 is configured by being connected to the serial circuit of.

The anode side of the flywheel diode 12 is connected to the S-shaped correction capacitor 5 side of the series circuit of the deflection yoke 4 and the S-shaped correction capacitor 5, and the choke coil 11 is input to the cathode side of the flywheel diode 12. The ends are connected, and the input end is connected to the driving power source B ₊ . The other end of the choke coil 11 is connected to the deflection yoke 4 side of the series circuit of the deflection yoke 4 and the S-shaped correction capacitor 5, that is, the collector side of the horizontal output transistor 1. This choke coil 11, the deflection yoke 4,
S-shaped correction capacitor 5 and flywheel diode 12
The switching regulator circuit 16 is formed by the horizontal output transistor 1 and the horizontal output transistor 1 of the deflection output circuit 14 in the circuit of this embodiment is clear as compared with the conventional circuit shown in FIG. Is also used as a chopper transistor of the switching regulator circuit 16, and the S-shaped correction capacitor 5 of the deflection output circuit 14 also serves as a smoothing capacitor (power supply capacitor) of the switching regulator circuit 16.

The horizontal output transistor 1 is switching-controlled by a pulse control circuit 10. The pulse control circuit 10 receives a horizontal drive signal having a horizontal deflection frequency f _H , or feedback of this horizontal drive signal and a deflection yoke current. By receiving both the signal and the signal, a switching control signal for the horizontal output transistor 1 as shown in FIG. That is, the pulse control circuit 10
Is to increase the timing of the rising edge of the switching control signal as the horizontal deflection frequency becomes higher, and as the horizontal deflection frequency becomes smaller, the switching control signal in which the rising edge of the switching control signal is delayed is increased by well-known pulse width control signal processing means. produce.

In the present embodiment, the inductance of the choke coil 11 is made sufficiently larger than the inductance of the deflection yoke 4 so that the operating current of the horizontal output transistor 1 becomes sufficiently smaller (smaller) than the deflection current. There is.

This embodiment is constructed as described above,
Next, the deflection current stabilizing operation will be described with reference to the time chart of FIG. When the horizontal output transistor 1 is turned on, a current flows from the drive power source B ₊ through the choke coil 11 to the horizontal output transistor 1 side. Due to this current flow, electromagnetic energy is stored in the choke coil 11.
Further, when the horizontal output transistor 1 is turned on, the electric charge stored in the S-shaped correction capacitor 5 is deflected by the deflection yoke 4.
Through to the horizontal output transistor 1 side. When the horizontal output transistor 1 is turned on, the resonance capacitor 3 is short-circuited by the horizontal output transistor 1 and the diode 15, and the voltage charged in the S-shaped correction capacitor 5 causes the diode 15, the S-shaped correction capacitor 5, and the deflection yoke. The deflection current flows in a loop that sequentially passes through 4 and the horizontal output transistor 1.

When the horizontal output transistor 1 is turned off, the current flowing in the deflection yoke 4 flows to the resonance capacitor 3 side and the collector side of the horizontal output transistor 1, that is, the hot side voltage of the deflection yoke 4 rises. The collector pulse shown in (a) is generated. This collector pulse has a peak when the resonance capacitor 3 is completely charged. After the collector pulse reaches the peak, the charging current flows backward from the resonance capacitor 3 to the deflection yoke 4 side, and the collector voltage decreases to zero. Then, when the charging in the reverse direction starts, the damper diode 2 is turned on, and during this damper period, the damper diode 2 moves to the deflection yoke 4
A current flows to the S-shaped correction capacitor via the.

In this series of circuit operations, for example, when the horizontal deflection frequency is increased, the pulse control circuit 10 causes the switch control signal shown in FIG. That is, since the rising edge shifts to the left side of the figure, the current flowing through the choke coil 11 changes to increase as the ON period of the horizontal output transistor 1 increases, and the peak value of the collector pulse increases accordingly. Changes to. In this way, by changing the peak value of the collector pulse in the direction of increasing, the voltage applied to the deflection yoke 4 also increases,
As a result, the deflection current flowing through the deflection yoke 4 increases, and the decrease in the deflection current due to the increase in the horizontal deflection frequency is compensated for, and the deflection current is controlled to be constant.

Similarly, when the horizontal deflection frequency changes in the lower direction, the current flowing in the choke coil 11 changes in the decreasing direction by controlling the rising of the switch control signal in the latter direction. The increase in the deflection current caused by the change in the peak value of the collector pulse and the voltage applied to the deflection yoke to decrease the deflection current and the change in the horizontal deflection frequency to the lower level causes the switch of the horizontal output transistor 1 to switch. The deflection current is controlled to be constant by offsetting the decrease amount due to the control. As described above, the deflection current is constantly controlled regardless of the change in the horizontal deflection frequency.

In this embodiment, the horizontal output transistor 1 of the deflection output circuit 14 is also used as a chopper transistor of the switching regulator circuit 16, and the S-shaped correction capacitor 5 of the deflection output circuit 14 is used as a switching regulator circuit.
Since it is also used as the 16 smoothing capacitor (power supply capacitor), it can be omitted compared to the case where the chopper transistor on the switching regulator circuit 16 side and the smoothing capacitor are provided separately, and the number of circuit element parts is reduced, The circuit configuration can be simplified, and the circuit cost can be reduced.

The present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted. For example, although the horizontal output switch element is composed of a transistor in the above-mentioned embodiment, it may be composed of another switch element such as a MOS FET.

Further, although the circuit example dedicated to the horizontal output circuit has been described in the present embodiment, a flyback transformer is incorporated in the horizontal output circuit of the present embodiment to form, for example, a deflection / high voltage integrated circuit as shown in FIG. Can also be Also in this case, as is clear from comparison with the deflection / high voltage integrated circuit shown in FIG. 7 of the conventional example, in the circuit of this embodiment, the S-shaped correction capacitor 5 of the deflection output circuit 14 is smoothed by the switching regulator circuit 16. Since it is also used as a capacitor (power supply capacitor), the circuit configuration can be simplified and the circuit cost can be further reduced as compared with the circuit of FIG. 7 in which this smoothing capacitor is configured separately from the S-shaped correction capacitor 5. .

Further, although the horizontal output transistor 1 functioning as a transistor of the switching regulator circuit is connected to the output side of the damper diode 2 and the choke coil 11 in the embodiment, it may be connected to the input side.
Whether connected to the input side or the output side, the operation is the same as a switching regulator circuit.

[0025]

According to the present invention, the horizontal output switching element on the deflection output circuit side is also used as the chopper transistor of the switching regulator circuit, and the S-shaped correction capacitor on the deflection output circuit side is used as the smoothing capacitor (power supply capacitor) of the switching regulator circuit. ), The number of parts of the circuit element is reduced, and the circuit configuration is greatly simplified, and accordingly, the circuit cost can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a horizontal output circuit according to the present invention.

FIG. 2 is a time chart diagram of the circuit of the embodiment.

FIG. 3 is an explanatory diagram of another embodiment of a horizontal output circuit incorporating a flyback transformer.

FIG. 4 is an explanatory diagram of a horizontal output circuit including a conventional voltage-variable horizontal deflection current stabilizing circuit.

FIG. 5 is an explanatory diagram of a conventional horizontal output circuit including a switching regulator circuit.

FIG. 6 is an explanatory diagram showing another conventional example of a horizontal output circuit including a switching regulator circuit.

FIG. 7 is an explanatory diagram showing a conventional example of a horizontal output circuit incorporating a flyback transformer.

[Explanation of symbols]

 1 Horizontal output transistor 4 Deflection yoke 5 S-shaped correction capacitor 10 Pulse control circuit 11 Choke coil 14 Deflection output circuit 16 Switching regulator circuit

Claims (1)

[Claims] 1. A deflection output circuit including a horizontal output switch element, a damper diode, a resonance capacitor, a deflection yoke, and an S-shaped correction capacitor, a switch element for a chopper, and a smoothing element for smoothing the output of the switch element. In a horizontal output circuit provided with a switching regulator circuit including a capacitor and a choke coil, a chopper switch element of the switching regulator circuit is also used as a horizontal output switch element, and the smoothing capacitor is also used as the S-shaped correction capacitor. Thus, the horizontal output switch element of the deflection output circuit and the S-shaped correction capacitor constitute a part of the switching regulator circuit.