JPH05314927A - Cathode ray tube device and deflection yoke used therefor - Google Patents

Abstract

PURPOSE:To reduce a high frequency electric field which is emitted from a deflection yoke and a deflection high voltage circuit to the outside of a cathode ray tube. CONSTITUTION:A deflection high voltage circuit 3 includes a flyback transformer which has reverse pulse voltage producing function. The flyback transformer produces reverse polarity pulse voltage e2 against high pulse voltage e1 applied from a terminal P1 to a horizontal deflection coil 8 in a deflection yoke 3 at a terminal P2. Electric field cancelling electrodes 6 are mounted on the right and left sides of the funnel portion 2b of a cathode ray tube 2, so that the reverse polarity pulse voltage e2 produced at the terminal P2 may be input thereto to generate an electric field almost proportional to the voltage e2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube device comprising a cathode ray tube and a deflection yoke mounted on the cathode ray tube. More specifically, the present invention relates to a cathode ray tube device and a deflection high voltage circuit provided outside the cathode ray tube device. The present invention relates to a cathode ray tube device capable of reducing an emitted high frequency electric field.

[0002]

2. Description of the Related Art As a related first technique, as described in Japanese Patent Laid-Open No. 61-138433, a focusing electrode system constituting an electron gun enclosed in a neck portion of a cathode ray tube is disclosed. There has been a magnetic core forming a deflection yoke attached to a cathode ray tube, which is annularly covered with a non-magnetic conductive magnetic shield.

As a related second related art, as described in JP-A-62-241241, a toroidal winding is formed around a core of a deflection yoke having a paddle-shaped horizontal deflection coil. By providing a cancel coil that is rotated and connecting the cancel coil to the horizontal deflection coil, there has been a device that generates a magnetic field having a polarity opposite to that of the horizontal deflection magnetic field leaked from the deflection yoke body generated by the horizontal deflection coil to the outside.

[0004]

Generally, in a cathode ray tube apparatus, when a high voltage pulse voltage is applied to a horizontal deflection coil of a deflection yoke to generate a horizontal deflection magnetic field, the deflection yoke and the deflection high voltage circuit drive the cathode ray tube. Since a high-frequency electric field is radiated toward the outside of the device, the high-frequency electric field may adversely affect other electric devices arranged around the cathode ray tube device. Therefore, in the cathode ray tube device, it is necessary to reduce such a high frequency electric field radiated to the outside.

However, of the above-mentioned related arts, the first technology is that a leakage magnetic field that changes with time from the outside due to a flyback transformer or the like included in the deflection high voltage circuit is generated in the trajectory of the electron beam. The influence is prevented, and no consideration is given to the reduction of the high-frequency electric field radiated from the deflection yoke and the deflection high voltage circuit to the outside of the cathode ray tube device. Moreover, since the opening on the phosphor screen side of the horizontal deflection coil to which a high voltage pulse voltage is applied is not covered with a shield, the high frequency electric field radiated from the deflection yoke to the outside of the cathode ray tube device should be reduced. No longer possible.

On the other hand, the second technique is to generate a magnetic field for canceling the leakage magnetic field from the deflection yoke by the current flowing through the cancel coil, and the magnetic field is radiated from the deflection yoke and the deflection high voltage circuit to the outside of the cathode ray tube device. It did not reduce the generated high-frequency electric field.

Therefore, an object of the present invention is to provide a cathode ray tube device capable of reducing a high frequency electric field radiated from the deflection yoke and the deflection high voltage circuit to the outside of the cathode ray tube device.

[0008]

In order to achieve the above object, the cathode ray tube apparatus according to the present invention is provided with a reverse pulse voltage generating means and an electric field canceling electrode.

[0009]

The reverse pulse voltage generating means generates a pulse voltage having a polarity opposite to that of the high voltage pulse voltage applied to the horizontal deflection coil. Further, the electric field canceling electrode inputs the pulse voltage generated by the reverse pulse voltage generating means and generates an electric field. At this time, since the input pulse voltage is a pulse voltage having a polarity opposite to that of the high voltage pulse voltage applied to the horizontal deflection coil, the generated electric field is radiated from the deflection yoke and the deflection high voltage circuit to the outside of the cathode ray tube device. The electric field has a polarity opposite to that of the generated high frequency electric field. Therefore, the generated electric field acts so as to cancel the high frequency electric field radiated from the deflection yoke and the deflection high voltage circuit to the outside of the cathode ray tube device, so that the high frequency electric field radiated to the outside as a whole of the cathode ray tube device is reduced. Will be.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway side view of a cathode ray tube device as a first embodiment of the present invention, and FIG. 2 is a circuit diagram showing a flyback transformer included in the deflection high voltage circuit in FIG. 3 is a perspective view showing the electric field canceling electrode in FIG. 1 with a part thereof cut away.

In each of the above figures, 1 is a cathode ray tube device and 2 is a cathode ray tube device.
Is a cathode ray tube, 3 is a deflection yoke, 4 is a deflection high voltage circuit, 5 is a flyback transformer, 6 is an electric field canceling electrode, 7 is an insulating frame, and 8 is a horizontal deflection coil.

The present embodiment is characterized in that the flyback transformer 5 has a function of generating a reverse pulse voltage and that the funnel portion 2b of the cathode ray tube 2 is provided with an electric field canceling electrode 6.

Here, the flyback transformer 5 has terminals P1 and P3 connected to the horizontal deflection coil 8, a terminal P2 connected to the electric field canceling electrode 6, and a high voltage output terminal P4 connected to the anode of the cathode ray tube 2. The high-voltage pulse voltage e2 included in the deflection high-voltage circuit 4 and having a reverse pulse voltage generation function has a reverse polarity to the high-voltage pulse voltage e1 applied to the horizontal deflection coil 8 of the deflection yoke 3 from the terminal P1.
Is generated at the terminal P2.

As shown in FIG. 2, this flyback transformer 5 is connected in series with a primary side coil 5a connected to a terminal P1 which is a horizontal deflection output terminal and a + B power source, and a diode 5d to obtain a high voltage from a terminal P4. Secondary coil 5b
And an induction coil 5c in addition to the basic configuration of. A terminal P5 which is one end of the induction coil 5c is connected to the ground, and a terminal P2 which is the other end is connected to the electric field canceling electrode 6. Therefore, at the terminal P2 of the induction coil 5c, the pulse voltage e2 having the opposite polarity to the high voltage pulse voltage e1 applied to the terminal P1 is generated.

On the other hand, the electric field canceling electrode 6 is used for the cathode ray tube 2
In the funnel portion 2b, which are mounted on both left and right sides, the reverse polarity pulse voltage e2 generated at the terminal P2 is input, and an electric field approximately proportional to the voltage e2 is generated.

The electric field canceling electrode 6 is made of a metal plate and, as shown in FIG. 3, a groove portion 7a formed in the insulating frame 7.
And an insulating cover 7b is attached to the insertion portion. The surface 7c of the insulating frame 7 is a cathode ray tube 2
Is a surface to which the funnel portion 2b is bonded and forms an acute angle with the surface of the electric field canceling electrode 6. Therefore, the electric field canceling electrode 6 can be arranged so as to be substantially parallel to the fluorescent screen 2a when it is mounted on the funnel portion 2b of the cathode ray tube 2, and the electric field canceling electrode 6 can efficiently generate an electric field on the fluorescent screen 2a side. Can be radiated to. Further, since the electric field canceling electrode 6 can maintain a distance from the exterior graphite formed on the funnel portion 2b of the cathode ray tube 2, the stray capacitance can be reduced.

Now, the operation of the electric field canceling electrode 6 will be described in more detail. FIG. 4 is a waveform diagram showing the waveforms of the high-voltage pulse voltage e1 applied to the horizontal deflection coil 8 of the deflection yoke 3 and the reverse-polarity pulse voltage e2 generated by the flyback transformer 5.

As shown in FIG. 4, pulse voltages e1 and e2
Have the same phase as each other, but opposite polarities. The amplitude of the pulse voltage e1 is a high voltage, usually about 1000V. Therefore, the horizontal deflection coil 8 connected to the horizontal deflection output terminal P1 acts as an electrode for radiating a high frequency electric field, and an electric field almost proportional to the pulse voltage e1 of the horizontal deflection output terminal P1 is output to the outside of the cathode ray tube device 1. Radiate.

On the other hand, since the electric field canceling electrode 6 receives the pulse voltage e2 having the opposite polarity to the pulse voltage e1 applied to the horizontal deflection coil 8, an electric field almost proportional to the pulse voltage e2 is applied to the cathode ray tube device 1. Of the high frequency electric field radiated to the outside of the cathode ray tube device 1 by the deflection yoke 3, and the high frequency electric field can be reduced.

When the area of the electric field canceling electrode 6 is increased, even if the pulse voltage e2 applied to the electric field canceling electrode 6 is lowered, the same high frequency electric field reducing effect can be obtained.

FIG. 5 is a side view showing a cathode ray tube device as a second embodiment of the present invention, and FIG. 6 is a front view showing a partially broken view of the deflection yoke in FIG. In each of the above figures, 9 is a horizontal deflection magnetic field, 10 is an induction coil, and 11 is an insulator.

The present embodiment is characterized in that the induction coil 10 having a reverse pulse voltage generating function is provided on the deflection yoke 3, and the electric field canceling electrode 6 is attached to the outer periphery of the deflection yoke 3 on the fluorescent screen side. ..

Here, the induction coil 10 includes the deflection yoke 3
Is mounted on the inner surface of the plate and arranged so that the horizontal deflection magnetic fields 9 interlink. Further, one end P5 of the induction coil 10 is connected to the low potential side terminal P3 of the horizontal deflection coil 8, and the other end terminal P2 is connected to the electric field canceling electrode 6.

On the other hand, the electric field canceling electrode 6 is made of a ring-shaped metal plate, and its periphery is covered with an insulating frame 7. The electric field canceling electrode 6 is attached to the outer circumference of the deflection yoke 3 on the fluorescent screen side.

In the present embodiment, the induction coil 10 generates a pulse voltage e2 having a reverse polarity similar to the voltage waveform shown in FIG. 4 due to the horizontal deflection magnetic field 9 that rapidly changes during the horizontal blanking period. Therefore, the electric field canceling electrode 6 connected to the induction coil 10 radiates an electric field substantially proportional to the pulse voltage e2 to the outside of the cathode ray tube device 1, and the high frequency emitted to the outside of the cathode ray tube device 1 by the deflection yoke 3. And the high frequency electric field can be reduced. The present embodiment has the advantage that the high frequency electric field can be reduced by changing only the deflection yoke 3.

The induction coil 10 is formed by forming a coil conductor pattern on a film-like insulator 11 by printing or etching, as shown in FIG. For this reason, the thickness of the induction coil 10 can be reduced, and the deflection yoke 3 can be more easily connected to the funnel portion 2 of the cathode ray tube 2.
It can be used in close contact with b. Further, in this embodiment, the induction coil 10 is mounted on the inner surface of the horizontal deflection coil 8. However, the induction coil 10 may be placed at any place where the horizontal deflection magnetic field 9 leaks.

FIG. 7 is a side view showing a cathode ray tube used in a cathode ray tube apparatus as a third embodiment of the present invention. This embodiment is characterized in that an induction coil 10 having a reverse pulse voltage generating function is provided in the cathode ray tube 2 and that an electric field canceling electrode 6 is attached to the outer periphery of the cathode ray tube 2 on the fluorescent screen side.

Here, the induction coil 10 is attached to the deflection yoke mounting portion shown by the broken line in the funnel portion 2b of the cathode ray tube 2, and the horizontal deflection magnetic field 9 is interlinked as in the second embodiment. Are arranged as follows. Further, one end P5 of the induction coil 10 is connected to the ground of the cathode ray tube 2, and the other end terminal P2 is connected to the electric field canceling electrode 6. On the other hand, the electric field canceling electrode 6 is composed of a conductive wire with an insulating coating, and is attached to the outer periphery of the cathode ray tube 2 on the fluorescent screen side.

In the present embodiment, the induction coil 10 generates a pulse voltage e2 having a reverse polarity similar to the voltage waveform shown in FIG. 4 due to the horizontal deflection magnetic field 9 that rapidly changes during the horizontal flyback period. Therefore, the electric field canceling electrode 6 connected to the induction coil 10 radiates an electric field substantially proportional to the pulse voltage e2 to the outside of the cathode ray tube device 1, and the high frequency emitted to the outside of the cathode ray tube device 1 by the deflection yoke 3. And the high frequency electric field can be reduced. The present embodiment has an advantage that a high-frequency electric field can be reduced by using only the cathode ray tube 2.

In the present embodiment, the electric field canceling electrode 6
Is composed of a conductive wire with an insulating coating, the total area of the electric field canceling electrode 6 can be easily changed only by changing the conductor length, and the strength of the canceling electric field can be easily adjusted. The method of attaching the electrode 6 to the cathode ray tube 2 is not limited to this embodiment and the above-described first embodiment, but a part of the exterior graphite of the funnel portion 2b of the cathode ray tube 2 is separated from the ground portion to form the electrode. Alternatively, the electric field canceling electrode 6 may be formed directly on the cathode ray tube 2 by a method such as forming.

FIG. 8 is a partially cutaway side view of a deflection yoke used in a cathode ray tube apparatus as a fourth embodiment of the present invention. In the figure, 12 is a core, and 15
Is an insulating tape and 16 is a vertical deflection coil.

The present embodiment is characterized in that the induction coil 10 having a reverse pulse voltage generating function is provided in the core 12 of the deflection yoke 3. The electric field canceling electrode 6 may be any of those described in the above-mentioned embodiments.

Here, the induction coil 10 includes the deflection yoke 3
Is wound around the core 12 in a toroidal shape, arranged so that the horizontal deflection magnetic field 9 is interlinked, and is insulated from the vertical deflection coil 16 by the insulating tape 15. Then, the terminal P5 which is one end of the induction coil 10
Is connected to a low-potential side of the horizontal deflection coil 8 or a terminal having a low-potential in terms of high-frequency pulse such as ground, and is the other terminal P
2 is connected to the electric field canceling electrode 6.

In the present embodiment, the induction coil 10 generates a pulse voltage e2 having a reverse polarity similar to the voltage waveform shown in FIG. 4 due to the horizontal deflection magnetic field 9 that rapidly changes during the horizontal blanking period. Therefore, the electric field canceling electrode 6 connected to the induction coil 10 radiates an electric field substantially proportional to the pulse voltage e2 to the outside of the cathode ray tube device 1, and the high frequency emitted to the outside of the cathode ray tube device 1 by the deflection yoke 3. And the high frequency electric field can be reduced. The present embodiment has an advantage that it is possible to generate the reverse polarity pulse voltage e2 necessary for canceling the high frequency electric field by the configuration of only the deflection yoke 3.

FIG. 9 is a circuit diagram showing a transformer for impedance conversion used in a cathode ray tube apparatus as a fifth embodiment of the present invention. In the figure, 13 is a transformer for impedance conversion.

This embodiment is characterized in that the transformer 13 for impedance conversion of the horizontal deflection coil 8 is provided with a reverse pulse voltage generating function. The electric field canceling electrode 6
As for the above, any of those described in each of the above-described embodiments may be used.

Here, the transformer 13 is the primary coil 13
In addition to a, the induction coil 13b is provided. One end of the induction coil 13b has a low potential side terminal P3 for horizontal deflection output.
And a terminal P2, which is the other end, is connected to the
Connected to.

According to the present embodiment, the deflection yoke 3, the cathode ray tube 1 and the deflection high voltage circuit 4 are not changed, and only the transformer 13 and the electric field canceling electrode 6 are provided. It is possible to cancel the high frequency electric field radiated to the outside.

In the transformer 13, the deflection high voltage circuit 4
The primary side coil 13a connected to the terminal P1 of the above has a part of the winding also used as the secondary side coil by outputting the intermediate tap P6 and connecting to the horizontal deflection coil 8. When the winding ratio of the primary side coil and the secondary side coil of the transformer 13 is 1: 1, the position of the intermediate tap P6 is equal to the position of the terminal P1.

In each of the above-described embodiments, even if the DC voltage is superimposed on the pulse voltage e2 of the opposite polarity which is the output of the induction coil 5c, 10 or 13b, the high frequency radiated to the outside of the cathode ray tube device 1 is high. Has the same effect of reducing the electric field. Therefore, the induction coil 5c, 10 or 1
The potential of the portion of both terminals 3b to which the terminal P5, which is not connected to the electric field canceling electrode 6, is connected is not limited to the ground potential but may be a DC potential.

[0041]

According to the present invention, since it is constructed as described above, the following effects can be obtained.

That is, a reverse polarity pulse voltage is applied to the electric field canceling electrode provided in the cathode ray tube device to generate an electric field having a polarity opposite to the high frequency electric field emitted from the deflection yoke and the deflection high voltage circuit to the outside of the cathode ray tube device. By generating
There is an effect that a high frequency electric field radiated to the outside of the cathode ray tube device can be canceled and reduced.

Furthermore, the relatively simple structure of providing the transformer connected to the horizontal deflection output or the induction coil interlinking with the horizontal deflection magnetic field is necessary for reducing the high frequency electric field radiated to the outside of the cathode ray tube device. There is an effect that a pulse voltage of reverse polarity can be generated.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a cathode ray tube device as a first embodiment of the present invention.

2 is a circuit diagram showing a flyback transformer included in the deflection high voltage circuit in FIG.

FIG. 3 is a perspective view showing a partially cutaway view of the electric field canceling electrode in FIG.

4 is a waveform diagram showing waveforms of a high-voltage pulse voltage e1 applied to the horizontal deflection coil 8 of the deflection yoke 3 and a reverse-polarity pulse voltage e2 generated by the flyback transformer 5. FIG.

FIG. 5 is a side view showing a cathode ray tube device as a second embodiment of the present invention.

FIG. 6 is a front view showing the deflection yoke in FIG. 5 partially broken away.

FIG. 7 is a side view showing a cathode ray tube used in a cathode ray tube device as a third embodiment of the present invention.

FIG. 8 is a side view showing a partially broken view of a deflection yoke used in a cathode ray tube device as a fourth embodiment of the present invention.

FIG. 9 is a circuit diagram showing an impedance conversion transformer used in a cathode ray tube apparatus as a fifth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cathode ray tube device, 2 ... Cathode ray tube, 3 ... Deflection yoke, 4
... Deflection high voltage circuit, 5 ... Flyback transformer, 6 ... Electric field canceling electrode, 7 ... Insulating frame, 8 ... Horizontal deflection coil, 9 ...
Horizontal deflection magnetic field, 10 ... Induction coil, 11 ... Insulator, 12
... core, 13 ... transformer, 15 ... insulating tape, 16 ... vertical deflection coil.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koji Kito, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside Video Media Research Laboratory, Hitachi, Ltd. (72) Hiroki Oguro 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Incorporated company Hitachi, Ltd. Visual Media Research Laboratories (72) Inventor Isao Yoshimi 3300 Hayano, Mobara-shi, Chiba Hitachi Ltd. Mobara factory (72) Inventor Masao Obara 1 Kitano, Masano, Mizusawa-shi, Iwate Hitachi, Ltd. Mizusawa Electronics (72) Inventor, Michitaka Osawa, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa

Claims (10)

[Claims] 1. A deflection yoke having at least a horizontal deflection coil, and a cathode ray tube on which the deflection yoke is mounted, wherein a high-voltage pulse voltage is applied to the horizontal deflection coil to generate a horizontal deflection magnetic field. In a cathode ray tube device, a reverse pulse voltage generating means for generating a pulse voltage having a polarity opposite to that of the pulse voltage applied to the horizontal deflection coil, and the pulse voltage having a reverse polarity generated by the reverse pulse voltage generating means. A cathode ray tube device, which is provided with an electric field canceling electrode that generates an electric field having a polarity opposite to that of the electric field in order to cancel an electric field generated when the horizontal deflection coil generates a horizontal deflection magnetic field. .. 2. The cathode ray tube apparatus according to claim 1, wherein the electric field canceling electrode is attached to the cathode ray tube or a deflection yoke. 3. The cathode ray tube device according to claim 2, wherein the electric field canceling electrode is made of a metal plate and is attached to an outer peripheral portion of the deflection yoke on the phosphor screen side. 4. The cathode ray tube device according to claim 2, wherein the electric field canceling electrode is made of a conductive wire or a metal plate and is attached to a funnel portion of the cathode ray tube. 5. The cathode ray tube apparatus according to claim 1, wherein the reverse pulse voltage generating means comprises a flyback transformer having an induction coil, and the pulse voltage having a reverse polarity is obtained from the induction coil. A cathode ray tube device characterized by the above. 6. The cathode ray tube apparatus according to claim 1, wherein the reverse pulse voltage generating means includes a primary coil connected to a horizontal deflection output of a deflection high voltage circuit, and an induction coil.
A cathode ray tube device, comprising: a transformer provided with, wherein the pulse voltage of opposite polarity is obtained from the induction coil. 7. The cathode ray tube apparatus according to claim 1, wherein the reverse pulse voltage generating means comprises an induction coil arranged at a position where the horizontal deflection magnetic field intersects with the deflection yoke. Cathode ray tube device. 8. A deflection yoke which is used by being attached to a cathode ray tube, has at least a horizontal deflection coil, and generates a horizontal deflection magnetic field by applying a high voltage pulse voltage to the horizontal deflection coil. A deflection yoke, wherein an induction coil is provided at a position intersecting with the horizontal deflection magnetic field, and a pulse voltage having a polarity opposite to that of the pulse voltage applied to the horizontal deflection coil is generated from the induction coil. .. 9. The deflection yoke according to claim 8, wherein
The deflection coil, wherein the induction coil is formed by printing or etching a conductor pattern of the coil on a film-shaped insulator. 10. The deflection yoke according to claim 8, wherein the induction coil is formed by winding a conductor wire around a core in a toroidal shape.