JPH0965166A - Deflection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centering adjustable deflection device by simple constitution at a low cost. SOLUTION: The primary coil 82 of a transformer 13, horizontal deflection coils 15R, G and B and a resonance capacitor 11 resonate and a sawtooth-shaped horizontal deflection current is made to flow to the horizontal deflection coils 15R, G and B. In a horizontal size control circuit 80, diode modulation pulses generated by the resonance operation of a capacitor 12 and the primary coil 18 of a diode modulation transformer 1 are impressed through the capacitor 17G to the horizontal deflection coil 15G. When the turn ratio of the transformer 1 is selected to be 1:1, a voltage waveform outputted by a DC superimposed amplifier 2G is canceled for the voltage of a connection point (d) and turned to a DC voltage. Thus, no flow of an AC current to/from the DC superimposed amplifier is present and the output current of the DC superimposed amplifier 2G becomes only DC components. Thus, the flow of the AC current to/from the DC superimposed amplifier is suppressed, power loss is reduced and a circuit scale is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection device for controlling electron beam scanning of a cathode ray tube.

[0002]

2. Description of the Related Art A first conventional technique will be described with reference to FIG. FIG. 9 shows a horizontal deflection circuit and a horizontal centering adjustment circuit. The circuit includes a transistor 8, a damper diode 9, a resonance capacitor 11, a choke transformer 23, an S
Character correction capacitor 14, horizontal deflection coil 15, AC blocking coil 25, DC superposition amplifier 2, level shift circuit 10
Consists of zero. The DC superposition amplifier 2 includes an operational amplifier 87,
Transistor 26, transistor 27, output resistance 2
8. The level shift circuit 100 includes resistors 90 and 92 and a transistor 91.

A sawtooth-shaped horizontal deflection current flows through the horizontal deflection coil 15 due to the switching operation of the transistor 8. Horizontal linearity is corrected by the S-shaped correction capacitor 14. Secondary coils 94, 9 of the choke transformer 23
The output of 5 is rectified by the diodes 96 and 97 to create the voltage sources + B + Vcc and + B-Vcc, and the DC superposition amplifier 2
To supply power. The DC superposition amplifier 2 is controlled by Vdc, and causes a desired DC current to flow through the horizontal deflection coil 14.

A device of this type is disclosed in Japanese Patent Laid-Open No. 4-630.
There are some disclosed in Japanese Patent Laid-Open No. 65, Japanese Patent Application Laid-Open No. 4-183071, and the like.

The second conventional technique will be described with reference to FIG. FIG. 10 is a circuit configuration diagram of the vertical deflection output circuit. Resistors 46, 50, transistors 51, 52, diode 4
The vertical deflection amplifier 42 is composed of 8, 49. Diodes 56, 58, capacitors 75, resistors 59, 60,
The transistor 57 constitutes a pump-up circuit 62 that raises the power supply voltage only during the vertical blanking period. Reference numeral 53 indicates a voltage source + Vcc. Similarly, reference numeral 67 is an AC coupling capacitor, and 63 is a vertical deflection coil.

The vertical deflection amplifier 42 amplifies the input signal a and outputs the output voltage b to output the vertical deflection coil 63.
Vertical deflection current is supplied to. In the figure, the signal waveforms of the input signal a and the output voltage b are shown. In the vertical blanking period, the transistor 57 is turned on and the power supply voltage of the vertical deflection amplifier is raised to 2Vcc. This voltage is the power supply voltage of the vertical deflection amplifier 42. As for the waveform of this voltage, as shown by a waveform c in the figure, the power supply voltage is increased only during the vertical retrace line period, and a low power vertical deflection circuit is realized.

An apparatus of this kind is disclosed in Japanese Patent Laid-Open No. 4-771.
Some of them are disclosed in Japanese Patent No. 78.

As a third conventional technique, Japanese Patent Laid-Open No. 127-127
The electromagnetic focusing device disclosed in Japanese Patent No. 433 will be described. The conventional electromagnetic focusing device includes focus coils horizontally and vertically. The flyback pulse is directly input to the horizontal deflection focus coil. On the other hand, the vertical deflection focus coil is provided with an additional amplifier, and the amplifier generates a current to be input to the vertical deflection focus coil.

[0009]

In the conventional horizontal deflection circuit and horizontal centering adjustment circuit, the DC current applying means requires a floating power supply, which complicates the circuit configuration. The AC blocking coil has a large inductance value and its shape tends to be large. In particular, the projection display using a plurality of cathode ray tubes has caused an increase in circuit scale.

Further, an alternating current flows into the direct current applying means, which causes an increase in power loss of the direct current applying means.
Further, when the conventional vertical deflection circuit is applied to a projection type display provided with a plurality of vertical deflection coils, a plurality of vertical deflection output circuits are required, resulting in an increase in circuit scale and an increase in cost.

It is an object of the present invention to provide a small deflecting device for controlling the electron beam scanning of a cathode ray tube and a display device using the same.

[0012]

In order to solve the above problems, the horizontal deflection coil is grounded via a DC superimposition coil, and the horizontal deflection coil is grounded by an AC coupling capacitor (or horizontal size control means output terminal).
To be connected to. Then, a DC current is made to flow from the connection point between the horizontal deflection coil and the AC coupling capacitor.

Further, the transformer secondary coil of the horizontal size control means is connected to the output of the direct current applying means.

Further, one ends of all vertical deflection coils are connected to the vertical deflection output circuit. And the other terminal is
At least one vertical deflection coil is connected to the deflection current detection means (or the ground terminal). The other terminals of the remaining vertical deflection coils are connected to the voltage amplification means.

[0015]

Since the grounded voltage source is used, the voltage source of the DC current applying means can be shared with other circuits, and the circuit configuration can be simplified. Since the transformer secondary coil of the horizontal size control means is connected, the AC current does not flow into the DC current application means, and the power loss in the DC current application means can be suppressed low. Further, since the inductance value of the AC blocking coil can be set small, the shape of the parts can be made small and the circuit scale can be reduced. Furthermore, since a plurality of vertical deflection output means are not required, the cost can be kept low. Therefore, it is possible to provide an inexpensive deflecting device having a simple structure.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a specific circuit configuration diagram of the horizontal deflection circuit and the horizontal centering adjustment circuit, and FIG. 2 is an operation waveform diagram of FIG.

The horizontal deflection circuit and the horizontal centering circuit of this embodiment include a horizontal deflection coil drive circuit 81, a horizontal size control circuit 80, an S-shaped correction capacitor 14, a DC superposition coil 16, red (R) and green. Horizontal deflection coils 15R, 15G and 15B corresponding to (G) and blue (B) respectively,
AC coupling capacitors 17 corresponding to R, G and B respectively
R, 17G, 17B, AC blocking coils 25R, 25G, 25B corresponding to R, G, B, and R, G, B
DC superimposing amplifiers 2R, 2G, 2B corresponding to
And The horizontal deflection coil drive circuit 81 is
It comprises a transistor 8, a primary coil 82 of the flyback transformer 13, a first damper diode 9 and a first resonance capacitor 11. Horizontal size control circuit 80
Is composed of a horizontal size control voltage generating circuit 88, a diode modulation coil 32, a second damper diode 10 and a second resonance capacitor 12.

The operation of FIG. 1 will be described below.

When the transistor 8 performs the switching operation, the primary coil 82 of the flyback transformer 13, the horizontal deflection coils 15R, 15G and 15B, and the resonance capacitor 1 are arranged.
1 and 1 resonate, and a flyback pulse (FIG. 2A) is generated at the connection point a. By this action,
A sawtooth-shaped horizontal deflection current flows through each of the horizontal deflection coils 15R, 15G, and 15B.

The operation of supplying a direct current to the horizontal deflection coil will be described below by taking the horizontal centering adjustment of G as an example. If the capacitance of the AC coupling capacitor 17G is Cac and the capacitance of the S-shaped correction capacitor 14 is Cs, the capacitances of these capacitors are selected so that Cac >> Cs. The horizontal deflection coil 15G is grounded by the DC superposition coil 16. In the horizontal size control circuit 80, the diode modulation pulse (FIG. 2 (2)) is generated at the connection point b due to the resonance action of the second resonance capacitor 12 and the diode modulation coil 32. This diode modulation pulse is applied to the connection point d. However, since the application is performed via the AC coupling capacitor 17G, the voltage waveform actually applied to the connection point d is as shown in FIG.

An AC blocking coil 25G is connected to the connection point d. An AC waveform (FIG. 2 (4)) is slightly generated at the connection point between the AC blocking coil 25G and the DC superimposing amplifier 2G, but the output current of the DC superimposing amplifier 2G can be regarded as almost DC. The current flown from the DC superposition amplifier 2G passes through the horizontal deflection coil 15 and the DC superposition coil 16 and flows into the ground terminal. Therefore, the DC voltage V
Horizontal centering adjustment can be performed by changing dcG and changing the direct current component flowing in the horizontal deflection coil 15. Similarly, horizontal centering adjustment can be performed for R and B as well.

The horizontal size adjustment can be performed by changing the amplitude of the diode modulation pulse according to the horizontal size control signal.

According to the present invention, since the power source of the DC current applying means is a ground type power source, the power source can be shared with other circuits and the circuit configuration can be simplified.

A second embodiment of the present invention will be described with reference to FIGS.

In the second embodiment, the AC blocking coils 25R, 25G and 25B in the first embodiment are constructed by the secondary coils 19R, 19G and 19B of the diode modulation transformer 1. A specific circuit configuration of the horizontal deflection circuit and the horizontal centering adjustment circuit of this embodiment is shown in FIG. 3, and its operation waveform is shown in FIG. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The horizontal size control circuit 80 comprises the primary coil 18 of the diode modulation transformer 1, the second damper diode 10, the second resonance capacitor 12, and the horizontal size control voltage generation circuit 88.

Secondary coil 1 of diode modulation transformer 1
9R, 19G and 19B correspond to R, G and B, respectively, and DC superimposing amplifiers 2R, 2G and 2B, respectively.
B.

The operation of supplying a direct current to the horizontal deflection coil will be described below by taking the horizontal centering adjustment of G as an example.

The capacitance of the AC coupling capacitor 17G is Cac,
If the capacitance 14 of the S-shaped correction capacitor is Cs, Cac >>
These capacitances are selected to be Cs.

In the horizontal size control circuit 80, the second resonance capacitor 12 and the diode modulation transformer primary coil 1 are used.
By the resonance action with the diode modulation pulse (see FIG.
(1)) occurs at the connection point b. This diode modulation pulse is applied to the connection point d. However, since the application is performed via the AC coupling capacitor 17G, the waveform actually applied to the connection point d is as shown in FIG. 4 (2).

The diode modulation transformer 1 is connected to the connection point d.
The secondary coil 19G of is connected. When the winding ratio of the diode modulation transformer 1 is set to 1: 1, the DC superposition amplifier 2
The voltage waveform at the G output terminal is canceled with respect to the voltage at the connection point d to become a DC voltage ((3) in FIG. 4). Therefore,
There is no inflow or outflow of an alternating current to the DC superimposing amplifier 2G, and the output current of the DC superimposing amplifier 2G has only a DC component. The DC current flowing from the DC superposition amplifier 2G is
Passing through the horizontal deflection coil 15 and the DC superposition coil 16,
It flows into the ground terminal. Therefore, the horizontal centering adjustment of G can be performed by changing the DC voltage VdcG.
Similarly, horizontal centering adjustment can be performed for R and B as well.

According to the present invention, the same effect as the first embodiment can be obtained. Further, since no excessive alternating current is passed through the direct current superposition amplifier, power loss can be suppressed. Furthermore, since the inductance value of the AC blocking coil can be reduced, the circuit scale can be reduced.

A third embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 5, the third embodiment is characterized in that the DC superimposing coil 16 in the first embodiment (FIG. 1) is constituted by a secondary coil 72 of a choke transformer 23. A deflection circuit and a horizontal centering circuit. The horizontal size control circuit 8 in the first embodiment
0 is omitted, and all inputs and outputs connected to this are grounded.

In the following description, the same components as those of the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted.

Taking the horizontal centering adjustment of G as an example,
An operation of supplying a direct current to the horizontal deflection coil 15G will be described.

A flyback pulse is generated at the connection point a between the S-shaped correction capacitor 14 and the horizontal deflection coil 15G. On the other hand, a DC current is supplied by the DC superposition amplifier 2G. This direct current passes through the horizontal deflection coil 15 and the secondary coil 72 of the choke transformer 23 and flows into the ground terminal. Therefore, the horizontal centering adjustment of G can be performed by changing the DC voltage VdcG. The same adjustment can be performed for R and B.

In this embodiment, the same effect as in the first embodiment can be obtained. In addition, the DC superposition coil is connected to the choke transformer 23.
The circuit scale can be reduced by using the same secondary coil as the above. The secondary coil of the flyback transformer may be used in common instead of the secondary coil of the choke transformer.

A fourth embodiment of the present invention will be described with reference to FIG.

The present embodiment is a focusing circuit of an electromagnetic focusing device for focusing an electron beam by a magnetic lens. As shown in FIG. 6, the focus circuit of this embodiment includes capacitors 101 and 103, a coil 102, a dynamic focus coil 104, an AC coupling capacitor 107, a DC superposition amplifier 2, and a DC superposition coil 1.
And 06.

The operation will be described below.

In FIG. 6, the inductance value of the DC superposition coil 106 is set to a value sufficiently larger than the inductance values of the coil 102 and the dynamic focus coil 104. Further, the capacity of the AC coupling capacitor 107 is set to a value sufficiently larger than the capacities of the capacitors 101 and 103.

When a flyback pulse is input, an alternating dynamic focus current flows through the dynamic focus coil 104 due to the resonance action of the capacitors 101 and 103, the coil 102, and the dynamic focus coil 104. Dynamic focus coil 1
04 is grounded by the DC superposition coil 106.
Therefore, the output current of the DC superimposing amplifier 2D is the same as that of the dynamic focus coil 104 and the DC superimposing coil 106.
Through to the ground terminal.

In this embodiment, the static focus adjustment can be performed by changing the DC voltage Vdc and operating the DC current of the dynamic focus coil 104.

In the circuit for driving a plurality of dynamic focus coils, the AC coupling capacitors 107 and the DC superposition amplifiers 2D may be provided in the same number as the dynamic focus coils. Further, by applying the vertical cycle signal to the DC voltage Vdc, dynamic focusing in the vertical direction of the screen can also be realized.

As described above, the electromagnetic focusing device of this embodiment has a simple circuit configuration and low power consumption.

A fifth embodiment of the present invention will be described with reference to FIG.

The vertical deflection circuit and the vertical centering circuit of this embodiment include vertical deflection coils 63R, 63G and 63B respectively corresponding to R, G and B, an adder 66G for adding a vertical sawtooth wave and a DC voltage, and a vertical A vertical deflection output circuit 64 for flowing a deflection current and a resistor 65 for detecting a G vertical deflection current.
And voltage amplifiers 74R and 74B.

The operation of this embodiment will be described below.

The vertical deflection output circuit 64 comprises a pump-up circuit 85, a vertical deflection amplifier 86 and a differential amplifier 45. The vertical deflection output circuit 64 supplies a vertical sawtooth current of the same amplitude to all the vertical deflection coils 63R, 63G, 63B.

A resistor 65 is connected to the vertical deflection coil 63G, and the voltage of the resistor 65 is returned to the differential amplifier 45 to form a negative feedback loop. As a result, a current proportional to the output voltage of the adder 66G is supplied to the vertical deflection coil 6
It is designed to flow to 3G. Therefore, by changing the amplitude of the vertical sawtooth wave G of the adder 66G, the vertical sizes of R, G, and B can be collectively changed.

Further, the G vertical centering adjustment can be performed by changing the DC voltage VdcG.

In the vertical deflection coil 63R, the voltage amplifier 7
A DC current flows due to the DC voltage difference between the DC output voltage of 4R and the output voltage of the vertical deflection output circuit 64. In this case, the amplitude of the vertical sawtooth current is the same as that of the vertical deflection coil 63G. Therefore, the DC current component of the vertical deflection coil 63R is adjusted by changing the DC voltage VdcR,
R vertical centering adjustment can be performed independently of G and B. Similarly for B, vertical centering adjustment can be performed independently of R and G.

As described above, the vertical deflection circuit and the vertical centering circuit according to the present embodiment can drive a plurality of vertical deflection coils with one vertical deflection output circuit, so that the circuit configuration can be simplified.

The resistor 65 may be omitted and the vertical deflection coil 63G may be directly installed. In this case, needless to say, the operational amplifier 45 is unnecessary, and the output of the adder 66G is directly input to the vertical deflection amplifier 86.

A sixth embodiment of the present invention will be described with reference to FIG.

The sixth embodiment differs from the fifth embodiment in that not only the vertical centering but also the vertical size can be adjusted independently for each of R, G and B. Therefore, in this embodiment, as shown in FIG. 8, adders 66R and 66B are newly provided in addition to the configuration of the fifth embodiment.

The vertical sawtooth wave R and the DC voltage VdcR are input to the adder 66R. And after adding both,
The voltage is output to the voltage amplifier 74R. Similarly, the adder 66B adds the vertical sawtooth wave B and the DC voltage VdcB and outputs the added signal to the voltage amplifier 74B.

The same components as those in the fifth embodiment (FIG. 7) are designated by the same reference numerals in FIG. 8 and their description is omitted.

The adjustment operation of the vertical size and vertical centering for each color will be described below.

The G vertical size is adjusted by the amplitude of the vertical sawtooth wave G. Further, the G vertical centering is adjusted by the DC signal VdcG.

At this time, if the amplitudes of the vertical sawtooth wave R and the vertical sawtooth wave B are 0V, the vertical sizes of R, G and B are all the same. However, in the projection display, the optimum vertical size of the raster of each color varies depending on the influence of the concentration angle of the cathode ray tube, the distance from the cathode ray tube to the screen, and the like.

In this embodiment, by changing the amplitude and polarity of the vertical sawtooth wave R and the vertical sawtooth wave B (that is,
By changing the voltage difference applied to the vertical deflection coils 63R and 63B, respectively, the vertical sizes of R and B can be optimally adjusted. For example, in order to increase the B vertical size with respect to G, a vertical sawtooth wave B having a polarity opposite to that of the vertical sawtooth wave G is added to the adder 66B. Then, the voltage amplifier 6
The vertical sawtooth wave output from 6B also has the opposite polarity to the vertical sawtooth wave G.
As a result, the voltage difference applied to the B vertical deflection coil 63B becomes large, and the amplitude of the sawtooth current flowing there becomes large. Therefore, the vertical size of B raster becomes larger than G.

B vertical centering adjustment is performed by applying a DC voltage Vdc
Change B.

Similarly for R, the vertical size and vertical centering can be adjusted.

As described above, according to the present embodiment, the fifth
The same effect as that of the embodiment can be obtained. Further, since the vertical size adjustment can be set independently for each color, the power loss of the convergence circuit can be reduced.

If a display device is constructed using the horizontal deflection circuit, horizontal centering adjustment circuit, electromagnetic focusing device, etc. of each of the above-mentioned embodiments, a low power, small and lightweight display device can be obtained.

[0069]

According to the present invention, the voltage source of the DC current applying means is shared with other circuits, the AC blocking coil and the coil of the horizontal size controlling means are constituted by one transformer, and the DC superimposing coil is the choke transformer. (Alternatively, the secondary coil of the flyback transformer can be used to reduce the scale and simplify the horizontal deflection circuit and the horizontal centering circuit.

Further, since no excess alternating current is passed through the direct current superposition amplifier, power loss can be suppressed. further,
The circuit configurations of the vertical deflection circuit and the vertical centering circuit that drive a plurality of vertical deflection coils can be simplified, and the power loss of the convergence circuit can be effectively reduced. Besides, the present invention can be applied not only to the deflecting device but also to the focusing device.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a first embodiment of the present invention.

FIG. 2 is an operation waveform diagram of the first embodiment.

FIG. 3 is a circuit configuration diagram of a second embodiment of the present invention.

FIG. 4 is an operation waveform diagram of the second embodiment.

FIG. 5 is a circuit configuration diagram of a third embodiment of the present invention.

FIG. 6 is a circuit configuration diagram of a fourth embodiment of the present invention.

FIG. 7 is a block diagram of a fifth embodiment of the present invention.

FIG. 8 is a block diagram of a sixth embodiment of the present invention.

FIG. 9 is a circuit configuration diagram of a first conventional example.

FIG. 10 is a circuit configuration diagram of a second conventional example.

[Explanation of symbols]

1: Diode modulation transformer, 2: DC superposition amplifier,
8: Transistor, 9: Damper diode, 10: Damper diode, 11: Resonance capacitor, 12: Resonance capacitor, 13: Flyback transformer, 14: S-shaped correction capacitor, 15: Horizontal deflection coil, 16: DC superposition coil, 17 : AC coupling capacitor, 18: Primary coil of diode modulation transformer 1, 19: Secondary coil of diode modulation transformer, 23: Choke transformer, 2
5: AC blocking coil, 32: Diode modulation coil, 4
5: operation amplifier, 63: vertical deflection coil, 64: vertical deflection output circuit, 65: resistor, 66: adder, 72: secondary coil of choke transformer 23, 74: voltage amplifier, 8
0: Horizontal size control circuit, 81: Horizontal deflection coil drive circuit, 85: Pump-up circuit, 86: Vertical deflection amplifier,
101: condenser, 102: coil, 103: condenser, 104: dynamic focus coil, 10
6: DC superposition coil, 107: AC coupling capacitor

Claims (7)

[Claims] A horizontal deflection coil provided in a cathode ray tube;
An S-shaped correction capacitor, a horizontal deflection coil drive means for supplying a horizontal periodic sawtooth current to the horizontal deflection coil, a DC superimposing coil, and a horizontal size control means for controlling the horizontal size,
A direct current applying means for applying a direct current to the horizontal deflection coil; an AC coupling capacitor for adding a horizontal periodic sawtooth current and an output current of the direct current applying means; and an AC blocking coil for blocking an alternating current, The S-shaped correction capacitor, the horizontal deflection coil, and the AC coupling capacitor form a series circuit connected in that order, and the series circuit is connected to the output of the horizontal deflection coil driving means, One end of the deflection coil connected to the S-shaped correction capacitor is grounded through the DC superposition coil, and the other end of the horizontal deflection coil is connected to the output of the DC current applying means through the AC blocking coil. The deflecting device is characterized by being. 2. The horizontal deflection coil driving means is connected between a first parallel circuit composed of a first damper diode and a first resonance capacitor, a horizontal output element, and a power supply and a horizontal output element. A first transformer having a secondary winding, and the horizontal size control means is composed of a second damper diode and a second resonant capacitor and is connected between the first parallel circuit and a ground terminal. A second parallel circuit, a horizontal size control voltage generation means, and a second transformer having a primary winding connected between the second parallel circuit and the horizontal size control voltage generation means. The deflection device according to claim 1, wherein the AC blocking coil is a secondary winding of the second transformer. 3. The deflection device according to claim 2, wherein the winding ratio of the primary winding and the secondary winding of the second transformer is 1: 1. 4. The horizontal deflection coil driving means is connected between a horizontal output element and a power source and the horizontal output element.
A first transformer having a secondary winding and a first parallel circuit including the first damper diode and the first resonant capacitor, wherein the DC superimposing coil is the same as the first transformer. The deflection device according to claim 1, wherein the deflection device is a secondary winding. 5. The deflection device according to claim 4, wherein the winding ratio of the primary winding and the secondary winding of the first transformer is 1: 1. 6. A vertical deflection coil driving means for driving a plurality of vertical deflection coils provided in a plurality of cathode ray tubes, and a voltage amplifying means, wherein the vertical deflection coil driving means vertically applies a vertical deflection current. A vertical deflection amplifier supplied to the deflection coil, and a power supply voltage superimposing means for increasing the power supply voltage supplied to the vertical deflection amplifier only during a vertical retrace line period. At least one of the vertical deflection coils is One terminal is connected to the vertical deflection coil driving means and the other terminal is connected to the ground terminal, and the remaining vertical deflection coils each have one side terminal connected to the vertical deflection coil driving means. And the other terminal connected to the output of the voltage amplifying means. 7. A vertical deflection coil drive means for driving a plurality of vertical deflection coils provided in a plurality of cathode ray tubes, a voltage amplification means, and a deflection current detection means for detecting a current flowing through the vertical deflection coils. The vertical deflection coil driving means comprises a differential amplifier for comparing a vertical deflection current reference waveform and a vertical deflection current feedback signal waveform, a vertical deflection amplifier for supplying a vertical deflection current to the vertical deflection coil, and the vertical deflection amplifier. Power supply voltage superimposing means for increasing the power supply voltage to be supplied only to the vertical retrace line period, and at least one of the vertical deflection coils has one terminal connected to the vertical deflection coil driving means, and The other terminal is connected to the deflection current detecting means, and each of the remaining vertical deflection coils has one terminal connected to the vertical deflection coil driving means. It is, and, it the other terminal is one that is connected to the output of said voltage amplifier means, a deflection device according to claim.