JP2599790B2 - Horizontal deflection circuit - Google Patents

Description

The present invention relates to a horizontal deflection circuit used for a display device using a cathode ray tube (CRT) and the like, and particularly to a horizontal deflection current control function to reduce the deflection size. The present invention relates to an improvement of a horizontal deflection circuit which can be variably controlled.

[Conventional technology]

FIG. 11 is a circuit diagram showing a conventional example of such a horizontal deflection circuit.

In the drawing, 1 is a drive pulse input terminal, 2 is a drive transistor, 3 is a drive transformer, 4, 6, and 24 are diodes, 5 is a base resistor, 7 is a drive voltage input terminal, 8 is a horizontal output transistor, and 9 is a horizontal output transistor. Damper diode, 10 is a modulation diode, 11 is a first resonance capacitor, 12 is a second resonance capacitor, 13 is a horizontal deflection coil, 14 is a first scanning capacitor, 15 is a modulation coil, 16 is a second scanning capacitor , 17 is a flyback transformer, 18
Is a high voltage rectifier diode, 19 is a high voltage output terminal, 20 is a power supply voltage input terminal, 21 is a vertical parabolic wave voltage input terminal, 22, 25
Are transistors, 23, 63, 26 are resistors, 27
Is a modulation output transistor, 29 is a DC voltage input terminal, 39 is a modulation voltage output terminal, 100 is a horizontal deflection drive circuit, 101 is a horizontal deflection output circuit, and 103 is a horizontal deflection current control circuit.

In FIG. 11, a horizontal deflection drive circuit 100 includes a drive transistor 2, a drive transformer 3, diodes 4, 6,
The horizontal deflection output circuit 101 is constituted by a base resistor 5.
Are a horizontal output transistor 8, a damper diode 9, a modulation diode 10, a first resonance capacitor 11, a second resonance capacitor 12, a horizontal deflection coil 13, a first scanning capacitor 14, a modulation coil 15, and a second scanning capacitor. 16, a flyback transformer 17, and a high-voltage rectifier diode 18.

The horizontal deflection current control circuit 103 includes transistors 22, 25, resistors 23, 63, 26, a diode 24, and a modulation output transistor 27.

Hereinafter, the operation of the conventional circuit shown in FIG. 11 will be briefly described.

In FIG. 11, a horizontal deflection drive circuit 100 functions to amplify a drive pulse input from a drive pulse input terminal 1 and drive a horizontal output transistor 8. The horizontal deflection output circuit 101 is provided with a horizontal deflection coil 1
A horizontal deflection current IDY is passed through 3 to generate a horizontal deflection magnetic field, and the electron beam scans left and right in a CRT (not shown). The horizontal deflection output circuit 101 is generally called a diode modulation circuit because it is configured using the modulation diode 10, the modulation coil 15, and the like.

This diode modulation circuit has a horizontal deflection current control function. By changing the voltage (modulation voltage Vs) between both ends of the second scanning capacitor 16, the horizontal deflection current IDY is controlled to vary the horizontal deflection size. be able to. Eleventh
The horizontal deflection current control circuit 103 in the figure has a function of controlling the modulation voltage Vs.

More specifically, by changing the DC level of the voltage applied to the voltage input terminal 21, the modulation voltage Vs is controlled to control the magnitude of the horizontal deflection current IDY flowing through the horizontal deflection coil 13, whereby the horizontal deflection size is controlled. Can be varied.

However, a vertical parabolic wave is input to the voltage input terminal 21 so that the transistors 22 and 25 and the modulation output transistor 2
Amplify by 7 or the like, and change the modulation voltage Vs into a parabolic shape with a vertical period (therefore, the horizontal deflection current IDY also changes into a parabolic shape with a vertical period) to correct left and right pincushion distortions on the cathode ray tube surface. Also can be done normally.

As a document which roughly describes a conventional horizontal deflection circuit as described above, there is JP-A-63-50266 (hereinafter sometimes referred to as a first conventional example).

In this first conventional example, when a vertical parabolic wave voltage for correcting left and right pincushion distortion is supplied to a horizontal deflection output circuit, a modulation output transistor (transistor Q2 in the drawing attached to JP-A-63-50266) is connected. The signal is amplified by a linear operation (A class operation) and then supplied to a horizontal deflection output circuit.

However, there is a problem that a loss may be large in the modulation output transistor which performs the linear operation (A class operation). Japanese Patent Application Laid-Open No. 52-89024 (hereinafter sometimes referred to as a second conventional example) A technique has been disclosed in which the modulation output transistor is switched by a pulse width modulation output to reduce the loss.

[Problems to be solved by the invention]

In the case of using the first conventional example (Japanese Patent Laid-Open No. 63266/1988), there is a problem in that a loss determined by a product of a current and a voltage between the emitter and the collector of the modulation output transistor becomes a problem.

This loss is greater in a high-speed and large-output horizontal deflection circuit having a high horizontal frequency and a large horizontal deflection current. Normally, the loss is suppressed to a predetermined value or less by operating the modulation output transistor at an operating point where the loss is relatively small (the emitter-collector voltage is reduced).

However, the emitter-collector current and the emitter-collector voltage of this modulation output transistor differ depending on the horizontal display size (the amplitude of the horizontal deflection current).
When the horizontal display size is changed (when the horizontal display size is reduced), the loss of the modulation output transistor increases, which causes a problem.

In order to solve this problem, as shown in the second conventional example (Japanese Patent Laid-Open No. 52-89024), the modulation output transistor is switched to perform a vertical parabolic wave correction for correcting left and right pincushion distortion. It is effective to convert the signal into a pulse width modulation signal and supply it to the horizontal deflection output circuit.

However, in this pulse width modulation circuit, the duty ratio is generally set as the minimum pulse width for normal operation.
About 10% (including the operating margin) is required. Therefore,
The modulation voltage (integrated value of the output voltage of the modulation output transistor) supplied to the horizontal deflection output circuit includes the duty ratio of 10
% (A voltage that does not contribute to the horizontal deflection operation).

As a result, the maximum horizontal display size is smaller than when the modulation output transistor is operated linearly.

On the other hand, by increasing the horizontal deflection current by lowering the inductance of the horizontal deflection coil, the maximum horizontal display size can be increased. In this case, a horizontal output transistor (see Japanese Patent Application Laid-Open No. 52-89024). And T in it
The maximum collector current of r1) increases, leading to an increase in loss. This increase in loss becomes more serious and problematic in a high-speed and large-output horizontal deflection circuit having a high horizontal frequency and a large horizontal deflection current.

First, the object of the present invention is to solve the problem when the horizontal display size is changed (when the horizontal display size is reduced) using the first conventional example (Japanese Patent Laid-Open No. 63-50266). Another object of the present invention is to provide a horizontal deflection circuit capable of reducing an increase in loss of a modulation output transistor.
It is an object of the present invention to provide a horizontal deflection circuit which can prevent a decrease in the maximum horizontal display size, which is a problem when the second conventional example (Japanese Patent Application Laid-Open No. 52-89024) is used.

[Means for solving the problem]

In order to achieve the first object, in a horizontal deflection circuit of the type shown in the first conventional example, a collector voltage is applied to the collector of a PNP junction modulation output transistor whose emitter is connected to the horizontal deflection output circuit. The control circuit was connected.

In order to achieve the second object, a negative power supply is connected to the modulation output transistor performing the switching operation, and the minimum voltage of the output voltage of the modulation output transistor is set to the negative voltage supplied from the negative power supply. did.

[Action]

In order to achieve the first object, in the collector voltage control circuit, an emitter is connected to a horizontal deflection output circuit in response to a change in a horizontal display size (horizontal deflection current).
The collector voltage of the P-junction modulation output transistor is changed. As a result, the emitter-collector voltage of the modulation output transistor can be kept within a predetermined value even when the horizontal display size (horizontal deflection current) is changed, and the loss of the modulation output transistor increases due to the difference in the horizontal display size. Can be suppressed.

Further, in order to achieve the second object, the lowest voltage of the output voltage (rectangular wave voltage) of the modulation output transistor is set to a negative voltage by the function of a negative power supply connected to the modulation output transistor performing the switching operation. As a result, the modulation voltage (integrated value of the output voltage of the modulation output transistor) supplied to the horizontal deflection output circuit can be reduced to about 0 V (in the second conventional example, the minimum pulse width is set to a duty ratio of about 10%). It is necessary to secure the modulation voltage, so that the invalid voltage is generated, and the modulation voltage cannot be reduced to nearly 0 V). Therefore, it is possible to prevent a reduction in the maximum horizontal display size due to the invalid voltage (compared with a case where a linear operation modulation output transistor is used), which has conventionally been a problem.

〔Example〕

An invention for achieving the first object is a first invention,
An invention for achieving the second object will be referred to as a second invention, and an embodiment thereof will be described below with reference to the drawings. In each of the drawings, components having the same function are denoted by the same reference numerals.

FIG. 1 is a diagram showing a first embodiment of the first invention.

In FIG. 1, 1 is a drive pulse input terminal, 2 is a drive transistor, 3 is a drive transformer, 4, 6, and 24 are diodes, 5 is a base resistor, 7 is a drive voltage input terminal,
8 is a horizontal output transistor, 9 is a damper diode, 10
Is a modulation diode, 11 is a first resonance capacitor, 12 is a second resonance capacitor, 13 is a horizontal deflection coil, 14 is a first scanning capacitor, 15 is a modulation coil, 16 is a second scanning capacitor, and 17 is a flywheel. Back transformer, 18 is high voltage rectifier diode, 19 is high voltage output terminal, 20 is power supply voltage input terminal, 21
Is a vertical parabolic wave voltage input terminal, 22, 25, 34 are transistors, 23, 63, 26, 30, 31, 35 are resistors, 27 is a modulation output transistor, 28 and 32 are capacitors, 29 is a DC voltage input terminal, 33
Is a zener diode, 36 is a first switch, 37 is a first one-way switch, 38 is a current output terminal, 39 is a modulation voltage output terminal, 100 is a horizontal deflection drive circuit, 101 is a horizontal deflection output circuit, 102 is a collector voltage control circuit, 103 is a horizontal deflection current control circuit, and 104 is a modulation voltage detection circuit.

In FIG. 1, a horizontal deflection drive circuit 100 includes a drive transistor 2, a drive transformer 3, diodes 4, 6,
The horizontal deflection output circuit 101 is constituted by a base resistor 5.
Are a horizontal output transistor 8, a damper diode 9, a modulation diode 10, a first resonance capacitor 11, a second resonance capacitor 12, a horizontal deflection coil 13, a first scanning capacitor 14, a modulation coil 15, and a second scanning capacitor. 16, a flyback transformer 17, and a high-voltage rectifier diode 18.

The modulation voltage detection circuit 104 includes resistors 30, 31, and 35, a capacitor 32, a Zener diode 33, and a transistor 34. The collector voltage control circuit 102 includes the modulation voltage detection circuit 104 and the first switch 36. The horizontal deflection current control circuit 103 includes a collector voltage control circuit 102, transistors 22, 25, resistors 23, 63, 26, a diode 24, a capacitor 28, and a modulation output. The transistor 27 is configured.

Although FIG. 1 shows the case of the horizontal deflection high voltage integrated type circuit, the basic configuration is the same for the horizontal deflection high voltage separation type, and the operation and effect described below are also the same (however, the flyback transformer 17). Instead of using a choke coil).

 Hereinafter, the operation of the circuit shown in FIG. 1 will be described.

In FIG. 1, a horizontal deflection drive circuit 100 functions to amplify a drive pulse input from a drive pulse input terminal 1 and drive a horizontal output transistor 8. The horizontal deflection output circuit 101 is provided with a horizontal deflection coil 1
A horizontal deflection current IDY is passed through 3 to generate a horizontal deflection magnetic field, and the electron beam scans left and right.

The horizontal deflection output circuit 101 is generally called a diode modulation circuit because it is configured using the modulation diode 10, the modulation coil 15, and the like. This diode modulation circuit has a horizontal deflection current control function, and can control the horizontal deflection current IDY by changing the voltage (modulation voltage Vs) between both ends of the second scanning capacitor 16.

The horizontal deflection current control circuit 103 in FIG. 1 functions to control the modulation voltage Vs.

Specifically, the vertical parabolic wave input from the vertical parabolic wave voltage input terminal 21 is amplified by the transistors 22 and 25, the modulation output transistor 27, and the like, and the modulation voltage Vs is changed into a parabolic shape with a vertical cycle (accordingly, Horizontal deflection current I
DY also changes in a parabolic manner with a vertical cycle), and corrects left and right pincushion distortion.

Further, the collector current control circuit 102 in the horizontal deflection current control circuit 103 controls the collector voltage VC of the modulation output transistor 27, and functions to suppress an increase in loss of the modulation output transistor 27. Next, this collector voltage control circuit
The detailed operation of 102 will be described.

The modulation voltage detection circuit 104 in the collector voltage control circuit 102 detects the modulation voltage Vs (equal to the emitter voltage VE of the modulation output transistor 27) and conducts the first switch means 36 based on the value of the modulation voltage Vs. -Non-conductivity is switched.

Specifically, when the modulation output Vs is lower than the predetermined voltage Vsx (when the DC level of the voltage applied to the voltage input terminal 21 is changed, the magnitude of the modulation voltage Vs changes, thereby variably controlling the horizontal deflection size. The first switch means 36 is turned on, and when the voltage is higher than the predetermined voltage Vsx, the first switch means 36 is turned off.

As a result, when the modulation voltage Vs is lower than the predetermined voltage Vsx, the collector voltage VC of the modulation output transistor 27 becomes about 0 V (GND potential), and when the modulation voltage Vs is higher than the predetermined voltage Vsx, the collector voltage of the modulation output transistor 27 VC has a potential determined by a voltage source (not shown) connected to the current output terminal 38.

At this time, the voltage source connected to the current output terminal 38 is used as a power source for a vertical deflection circuit, a video circuit, and the like.
Therefore, the same amount as the current output from the current output terminal 38,
The input current of the voltage source can be reduced, and energy can be effectively used.

With the above operation, it is possible to reduce an increase in loss of the modulation output transistor, which is a problem when the horizontal display size (horizontal deflection size) is changed.

Next, the effects of the embodiment of FIG. 1 will be described with reference to FIGS.

FIG. 2 shows the horizontal deflection current IDY flowing through the horizontal deflection coil 13, the operating current of the modulation output transistor 27 (emitter-collector current IEC) in the circuit shown in FIG.
FIG. 5 is a characteristic diagram showing a relationship between operating voltages (emitter voltage VE and collector voltage VC).

FIG. 3 is a characteristic diagram showing the relationship between the horizontal deflection current IDY flowing through the horizontal deflection coil 13 and the loss PEG of the modulation output transistor 27 in the circuit shown in FIG.

In FIGS. 1, 2 and 3, IDY is the horizontal deflection current, V
E, VC, IEC are the emitter voltage of the modulation output transistor 27,
Collector voltage, emitter-collector current, and PEC are losses of the modulation output transistor 27, and PEC = IEC × (VE−VC)
Can be expressed as

VE, VC, I when IDY = I1 (horizontal display size is small)
EC, PEC are expressed as VE1, VC1, IEC1, P1, and VE, VC, IEC, PEC when IDY = I2 (large horizontal display size) is VE2, VC2, IEC2, P2.
And VE when IDY = IX (IDY is between I1 and I2) is represented as VEX.

As shown in FIG. 2, when increasing IDY, VE
(It was mentioned earlier that it is equal to the modulation voltage Vs)
Is small and the IEC is large. At this time, if the collector of the modulation output transistor 27 is always grounded, as in the case of the prior art, the PAC changes as shown by the solid line in FIG. In other words, when IDY = I1 (small horizontal display size), the loss PEC increases.

On the other hand, in the circuit shown in FIG. 1, IDY = I
At the time of X (when VE = VEX, that is, when Vs = Vsx), the collector voltage VC is connected to the current output terminal 38 by connecting the first switch means 36 (not shown).
The voltage is switched from the potential determined by the voltage source to VC2 (≒ 0 V). Therefore, when IDY> IX, PEC = IEC ×
(VE−VC2), if IDY <IX, then PEC = IEC × (V
E−VC1). As a result, the loss P at IDY <IX
EC becomes as shown by the dashed line in FIG. 3, and IDY =
The loss PEC at the time of I1 is P1 '. Therefore, the loss PEC can be reduced as compared with the case of the related art.

As described above, if the first embodiment of the first invention shown in FIG. 1 is used, the modulation output transistor which causes a problem when the horizontal display size is changed (when the horizontal display size is reduced) is used. The increase in loss at 27 can be reduced.

FIG. 4 is a circuit diagram showing a main part of the second embodiment of the first invention. Here, only the horizontal deflection current control circuit is shown (the horizontal deflection drive circuit and the horizontal deflection output circuit are shown in FIG. 1). And the same.)

In FIG. 4, 40 is a sawtooth voltage input terminal, 42 is a transistor, 47 is a second switch means, 43 is a Zener diode, 44 is a resistor, 45 is an operational amplifier circuit, 46 is a comparator,
48 is a second unidirectional switch means, 50 is a diode, 49
Is a choke coil.

4, a collector voltage control circuit 102 includes an operational amplifier circuit 45, a comparator 46, a second switch 47,
The second unidirectional switch means 48 is constituted by a choke coil 49.

Hereinafter, the operation of the horizontal deflection current control circuit shown in FIG. 4 will be described. In the circuit shown in FIG. 4, after the vertical parabolic wave voltage input from the vertical parabolic wave voltage input terminal 21 is inverted and amplified by the transistor 22, the current is amplified by the transistor 42, and the modulation output is outputted through the diode 24 and the transistor 25. Input to the base of transistor 27.

On the other hand, the collector voltage control circuit 102 in FIG. 4 forms a pulse width modulation circuit, and the modulation output transistor 27
The base-collector voltage is almost constant (this base-collector voltage is determined by the Zener diode 43)
The collector voltage VC is controlled so that

As a result, even if the emitter voltage VE (modulation voltage Vs) of the modulation output transistor 27 changes due to a difference in the horizontal display size, the emitter-collector voltage (VE-VC) can be kept substantially constant. Accordingly, the first type shown in FIG.
Even when the second embodiment of the present invention is used, it is possible to reduce an increase in loss of the modulation output transistor 27 due to a difference in horizontal display size.

Next, a third embodiment of the first invention will be described with reference to FIG. FIG. 5 shows only the horizontal deflection current control circuit according to the third embodiment of the first invention. The horizontal deflection drive circuit and the horizontal deflection output circuit are the same as those in FIG. is there.

5, 51, 55 and 59 are transistors, 52, 53 and 57 are resistors, 54 is a Zener diode, 56 and 58 are diodes, 80 is third switch means, and 81 is third unidirectional switch means. And 106, an emitter-collector voltage detection circuit.

In this embodiment, the transistor 51 and the third switch means 80 are provided with a power MOSF having excellent high-speed switching performance.
Although ET is used, a bipolar transistor or the like may be used.

In FIG. 5, an emitter-collector voltage detection circuit 106 is shown.
Is constituted by transistors 51, 55, 59, resistors 52, 53, 57, a Zener diode 54, and diodes 56, 58. The collector voltage control circuit 102 includes the emitter-collector voltage detection circuit 106, 80, a third one-way switch means 81, and a choke coil 49.

Hereinafter, the operation of the horizontal deflection current control circuit shown in FIG. 5 will be described.

In the circuit shown in FIG. 5, similar to the second embodiment of the first invention shown in FIG.
Even if the emitter voltage VE of the modulation output transistor 27 changes, its emitter-collector voltage (VE-VC)
Is constant (this emitter-collector voltage is determined by the gate-source threshold voltage of the transistor 51).

Specifically, when the emitter-collector voltage (VE-VC) of the modulation output transistor 27 is smaller than a predetermined voltage determined by the gate-source threshold voltage of the transistor 51, the transistor 51 is turned off. Therefore, transistor 55 is non-conductive, transistor
59 becomes conductive, and the third switch means 80 becomes conductive. For this reason, the collector voltage VC decreases.

Conversely, if the emitter-collector voltage (VE-VC) of modulation output transistor 27 is greater than the predetermined voltage, transistor 51 conducts. Therefore, the transistor 55 is turned on, and the transistor 59 and the third switch means 80
Is turned off, the collector voltage VC rises.

By repeating such an operation, the emitter-collector voltage (VE-VC) of the modulation output transistor 27 is kept substantially constant. Therefore, even when the circuit shown in FIG. 5 is used, the same effect as that of the second embodiment of the first invention can be obtained.

Next, an embodiment of the second invention will be described with reference to FIG. FIG. 6 shows only the horizontal deflection current control circuit, and the horizontal deflection drive circuit and the horizontal deflection output circuit are the same as those in FIG. In FIG.
60 is a negative power input terminal, 61 is a resistor, and 62 is a capacitor.

In FIG. 6, an operational amplifier circuit 45, a comparator 46,
The point that the modulation output transistor 27, the diode 41, the resistor 61, and the capacitor 62 form a pulse width modulation circuit, and the modulation output transistor 27 performs a switching operation,
This is different from the first embodiment of the present invention.

Hereinafter, the features of the embodiment of the second invention shown in FIG. 6 will be described in comparison with a case where a conventional pulse width modulation circuit (Japanese Patent Laid-Open No. 52-89024) is used.

In the circuit shown in FIG. 6, the lowest voltage of the output voltage VP (rectangular wave) of the modulation output transistor 27 can be made negative by the operation of the negative power supply (not shown) connected to the negative power supply input terminal 60. . As a result, the modulation voltage Vs supplied to the horizontal deflection output circuit is equal to the second conventional example (Japanese Patent Laid-Open No. 52-8902).
However, even when an invalid voltage determined by the minimum set pulse width (duty of about 10%) generated when using the method described in Japanese Patent Application Laid-Open No. H10-209, the voltage can be reduced to almost 0V. Therefore,
It is possible to prevent a decrease in the maximum horizontal display size, which is a problem when the second conventional example (Japanese Patent Laid-Open No. 52-89024) is used.

Next, a modified embodiment of the first embodiment of the first invention will be described with reference to FIG. In FIG. 7, 64 is a power input terminal, 65 is a high voltage stabilizing circuit, 66 and 67 are high voltage dividing resistors, 68 and
70 and 71 are resistors, 69 and 72 are transistors, 73 is an output voltage input terminal of the high-voltage stabilization circuit 65, and 105 is a level shift circuit. The addition of these elements is a feature of the first invention shown in FIG. This is different from the first embodiment.

In the high voltage stabilizing circuit 65 in FIG. 7, the output voltage EB is set so that the high voltage generated at the high voltage output terminal 19 is always constant.
Is controlling. Also, transistors 69 and 72, resistors 68 and 7
Numerals 0, 71, and 23 form a level shift circuit 105. The variation ΔEB of the output voltage EB of the high-voltage stabilization circuit 65 is level-shifted and superimposed on the vertical parabolic wave voltage transmitted through the transistor 22. You.

As a result, the variation ΔEB of the output voltage EB of the high voltage stabilization circuit 65 is superimposed on the modulation voltage Vs. Therefore, regardless of the change in the output voltage EB of the high-voltage stabilization circuit 65, the voltage (EB−Vs) applied to the horizontal deflection coil 13 is kept constant,
The horizontal deflection current IDY flowing through the horizontal deflection coil 13 can also be kept constant.

Such a high voltage stabilizing circuit 65 and the level shift circuit
By the function of 105, even when the beam current (the current output from the high-voltage output terminal 19) changes, it is possible to provide a high-quality image with little change in the high voltage and the screen size.
The operation of the horizontal deflection current control circuit 103 and the effect of the collector voltage control circuit 102 in FIG. 7 are the same as in the first embodiment of the first invention shown in FIG.

FIGS. 8, 9, and 10 show a second embodiment of the first invention, a third embodiment of the first invention, and a modified embodiment of the second embodiment, respectively. (Each figure shows only the horizontal deflection current control circuit, and the other circuits are the same as those in FIG. 7 including the connection of the high-voltage stabilization circuit 65), and the modified embodiment shown in FIG. Similarly to the first embodiment, the point that a level shift circuit 105 is added is different from the embodiments shown in FIGS. 4, 5 and 6. In each modified embodiment, the operation of the horizontal deflection current control circuit and the effect of the collector voltage control circuit are the same as those of the embodiment shown in FIGS. 4, 5, and 6.

〔The invention's effect〕

According to the first aspect, in the conventional circuit in which the modulation output transistor is operated linearly (class A operation), the modulation output transistor causes a problem when the horizontal display size is changed (when the horizontal display size is reduced). Increase in the loss of the battery can be suppressed.

Further, according to the second aspect, it is possible to prevent a reduction in the maximum horizontal display size, which is a problem when using a pulse width modulation type horizontal deflection current control circuit that performs a switching operation of a modulation output transistor.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the first invention according to the present application, FIG. 2 is a characteristic diagram showing a relationship between a horizontal deflection current IDY and an operating current and an operating voltage of a modulation output transistor. FIG. 3 is a characteristic diagram showing the relationship between the horizontal deflection current IDY and the loss PEC of the modulation output transistor, and FIGS. 4 and 5 show the main parts of another embodiment of the first invention according to the present application. FIG. 6 is a circuit diagram showing a main part of one embodiment of the second invention according to the present invention, FIG. 7 is a circuit diagram showing a modified embodiment of the first invention according to the present invention, FIG. FIG. 9 is a circuit diagram showing a main part of another modified embodiment of the first invention according to the present application,
FIG. 10 is a circuit diagram showing a main part of a modified embodiment of the second invention according to the present application, and FIG. 11 is a circuit diagram showing a conventional example of a horizontal deflection circuit. Explanation of reference numerals 1 ... Drive pulse input terminal, 21 ... Vertical parabolic wave voltage input terminal, 27 ... Modulation output transistor, 100 ...
Horizontal deflection drive circuit, 101 Horizontal deflection output circuit, 102
…… collector voltage control circuit, 103 …… horizontal deflection current control circuit, 104 …… modulation voltage detection circuit, 40 …… sawtooth voltage input terminal, 60 …… negative power supply input terminal, 65 …… high voltage stabilization circuit, 105: Level shift circuit, 106: Emitter-collector voltage detection circuit

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Michitaka Osawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. Within Video Engineering Co., Ltd. (56) References JP-A-52-89024 (JP, A) JP-A-63-50266 (JP, A)

Claims (10)

(57) [Claims] 1. A first terminal comprising a cathode terminal of a damper diode (9), one end of a first resonance capacitor (11), and a series connection of a horizontal deflection coil (13) and a first scanning capacitor (14). One end of the resonance circuit (13, 14) and one end of the input winding of the flyback transformer (17) are connected to the collector terminal of the horizontal output transistor (8), and the anode terminal of the damper diode (9). And the other end of the first resonance capacitor (11) and the other end of the first resonance circuit (13, 14) are commonly connected to a common connection point K, and a cathode terminal of the modulation diode (10) And one end of a second resonance capacitor (12) and one end of a second resonance circuit (15, 16) composed of a modulation coil (15) and a second scanning capacitor (16) connected in series. Connected to the connection point K, the anode of the modulation diode (10) And children, the second
The other end of the resonance capacitor (12) and the other end of the second resonance circuit (15, 16) are all grounded, and the voltage Vs across the second scanning capacitor (16) is applied to the horizontal deflection current. A horizontal deflection circuit in which a horizontal deflection size is variably controlled by controlling a magnitude of a current flowing through the horizontal deflection coil (13) by controlling by a control circuit. A modulation output transistor (27) that amplifies the current control signal when it is input and outputs the amplified voltage as the voltage Vs from its emitter terminal;
A collector voltage control circuit for detecting the voltage Vs and controlling the collector voltage of the modulation output transistor (27) accordingly to reduce the loss of the transistor (27). 2. The horizontal deflection circuit according to claim 1, wherein
A modulation voltage detection circuit (104) for detecting and outputting the voltage Vs, a control terminal connected to an output side of the modulation voltage detection circuit (104), and an output terminal connected to the modulation output transistor ( 27) a first switch means (3) connected to the collector of the modulation voltage detection circuit (104) and turned on and off according to the output of the modulation voltage detection circuit (104).
6) and one end is connected to the collector of the modulation output transistor (27) and the other end is connected to a constant voltage source, and switches when the first switch means (36) is turned off, and outputs the modulation output. A first unidirectional switch means (37) for setting a collector voltage of the transistor (27) to a potential determined by the constant voltage source. 3. The horizontal deflection circuit according to claim 1, wherein
A differential amplifier circuit (45) for detecting the collector voltage of the modulation output transistor (27), comparing the detected voltage with a reference voltage, amplifying the error voltage thereof, and outputting the error voltage;
A comparator (46) that receives the sawtooth voltage and the output of the differential amplifier circuit (45) and compares the two to output a rectangular wave output; and a control terminal connected to the output side of the comparator (46). An output terminal connected to the collector of the modulation output transistor (27) via a choke coil (49), and a second switch means for switching on and off in response to a rectangular wave output from the comparator (46) (47), one end is connected to the output side of the second switch means (47) and the other end is connected to a constant voltage source, and switches when the second switch means (47) is turned off. ,
And a second unidirectional switch means (48) for making the collector voltage of the modulation output transistor (27) equal to the potential determined by the constant voltage source. The base-collector voltage of the modulation output transistor (27) is A horizontal deflection circuit characterized by being controlled substantially constant. 4. The horizontal deflection circuit according to claim 1, wherein
An emitter-collector voltage detection circuit (106) for detecting and outputting an emitter-collector voltage of the modulation output transistor (27), and a control terminal connected to the emitter-collector voltage detection circuit ( 106), the output terminal of which is connected to the collector of the modulation output transistor (27) via a choke coil (49), and becomes conductive when the emitter-collector voltage is lower than a certain predetermined value. When the voltage exceeds the predetermined value, the switch is turned off, and when the switch is turned on, the third switch means (80) for lowering the collector voltage of the modulation output transistor (27) and one end of the third switch means (80). ) Is connected to the output terminal and the other end is connected to a constant voltage source, and switches when the third switch means (80) is non-conductive, thereby switching the modulated output transformer. Third unidirectional switch means (81) for making the collector voltage of the star (27) equal to the potential determined by the constant voltage source. The base-collector voltage of the modulation output transistor (27) is made substantially constant. A horizontal deflection circuit characterized by controlling. 5. A first terminal comprising a cathode terminal of a damper diode (9), one end of a first resonance capacitor (11), and a series connection of a horizontal deflection coil (13) and a first scanning capacitor (14). One end of the resonance circuit (13, 14) and one end of the input winding of the flyback transformer (17) are connected to the collector terminal of the horizontal output transistor (8), and the anode terminal of the damper diode (9). And the other end of the first resonance capacitor (11) and the other end of the first resonance circuit (13, 14) are commonly connected to a common connection point K, and a cathode terminal of the modulation diode (10) And one end of a second resonance capacitor (12) and one end of a second resonance circuit (15, 16) composed of a modulation coil (15) and a second scanning capacitor (16) connected in series. Connected to the connection point K, the anode of the modulation diode (10) And children, the second
The other end of the resonance capacitor (12) and the other end of the second resonance circuit (15, 16) are all grounded, and the voltage Vs across the second scanning capacitor (16) is applied to the horizontal deflection current. A horizontal deflection circuit in which a horizontal deflection size is variably controlled by controlling a magnitude of a current flowing through the horizontal deflection coil (13) by being controlled by a control circuit. A modulation output transistor (27) that supplies the voltage Vs from its collector terminal via a choke coil (49), and a collector voltage of the modulation output transistor (27) and a horizontal deflection current control voltage are compared with each other. A differential amplifying circuit (45) for amplifying and outputting a voltage; and a comparator (46) for receiving a sawtooth wave voltage and the output of the differential amplifying circuit (45), comparing the two, and outputting a rectangular wave output. When A base terminal is connected to an output side of the comparator (46), and is turned on in response to a rectangular wave output from the comparator (46);
The modulation output transistor (27) that switches off and supplies a negative potential from the collector terminal as the voltage Vs from a negative power supply connected to the emitter terminal of the modulation output transistor when the transistor is on, and one end of the modulation output transistor (27). And the other end thereof is connected to a constant voltage source, and switches when the modulation output transistor (27) is turned off to switch the voltage Vs supplied from the collector terminal of the modulation output transistor (27). A one-way switch means (41) for adjusting a potential determined by the constant voltage source. 6. The horizontal deflection circuit according to claim 1, wherein:
The input winding of the flyback transformer (17) is connected to the other end of the input winding of the flyback transformer (17) so that the output voltage supplied from the flyback transformer (17) is constant. A high-voltage stabilizing circuit (65) for controlling the power supply voltage supplied to the line, and detecting a voltage fluctuation based on the power supply voltage control of the high-voltage stabilizing circuit (65), and adding this to the horizontal deflection current control signal. A level shift circuit (105) for inputting to the modulation output transistor (27). 7. The horizontal deflection circuit according to claim 2, wherein
The input winding of the flyback transformer (17) is connected to the other end of the input winding of the flyback transformer (17) so that the output voltage supplied from the flyback transformer (17) is constant. A high-voltage stabilizing circuit (65) for controlling the power supply voltage supplied to the line, and detecting a voltage fluctuation based on the power supply voltage control of the high-voltage stabilizing circuit (65), and adding this to the horizontal deflection current control signal. A level shift circuit (105) for inputting to the modulation output transistor (27). 8. The horizontal deflection circuit according to claim 3, wherein:
The input winding of the flyback transformer (17) is connected to the other end of the input winding of the flyback transformer (17) so that the output voltage supplied from the flyback transformer (17) is constant. A high-voltage stabilizing circuit (65) for controlling the power supply voltage supplied to the line, and detecting a voltage fluctuation based on the power supply voltage control of the high-voltage stabilizing circuit (65), and adding this to the horizontal deflection current control signal. A level shift circuit (105) for inputting to the modulation output transistor (27). 9. The horizontal deflection circuit according to claim 4, wherein
The input winding of the flyback transformer (17) is connected to the other end of the input winding of the flyback transformer (17) so that the output voltage supplied from the flyback transformer (17) is constant. A high-voltage stabilizing circuit (65) for controlling the power supply voltage supplied to the line, and detecting a voltage fluctuation based on the power supply voltage control of the high-voltage stabilizing circuit (65), and adding this to the horizontal deflection current control signal. A level shift circuit (105) for inputting to the modulation output transistor (27). 10. The horizontal deflection circuit according to claim 5, wherein the output voltage supplied from the other end of the input side winding of the flyback transformer (17) is constant. A high-voltage stabilization circuit (65) for controlling a power supply voltage supplied to an input side winding of the flyback transformer (17);
A level shift circuit (105) for detecting the voltage fluctuation based on the power supply voltage control and adding the detected voltage fluctuation to the horizontal deflection current control signal and inputting it to the modulation output transistor (27).
And a horizontal deflection circuit, further comprising: