JP3100459B2 - Cathode ray tube device - Google Patents

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 apparatus comprising a cathode ray tube and a deflection yoke mounted on the cathode ray tube. The present invention relates to a cathode ray tube device capable of reducing a radiated high-frequency electric field.

[0002]

2. Description of the Related Art As a related first technique, as described in Japanese Patent Application Laid-Open No. S61-138433, a focusing electrode system constituting an electron gun sealed in a neck portion of a cathode ray tube is disclosed. In some cases, a magnetic core constituting a deflection yoke attached to a cathode ray tube is annularly covered with a nonmagnetic conductive magnetic shield.

As a related second technique in the related art, as disclosed in Japanese Patent Application Laid-Open No. 62-241241, a toroidal winding is provided around a core of a deflection yoke having a circular horizontal deflection coil. In some cases, a turned canceling coil is provided, and the canceling coil is connected to a horizontal deflection coil, thereby generating a magnetic field having a polarity opposite to that of the horizontal deflection magnetic field leaked from the deflection yoke main body generated by the horizontal deflection coil to the outside.

[0004]

Generally, in a cathode ray tube device, 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 cathode ray tube is deflected from the deflection yoke and the deflection high voltage circuit. 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.

[0005] However, of the above related techniques in the related art, the first technique is that a time-varying leakage magnetic field from the outside due to a flyback transformer or the like included in a deflection high voltage circuit is generated in the trajectory of the electron beam. In this case, no consideration is given to reducing 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. Also, since the fluorescent screen side opening of the horizontal deflection coil to which the high voltage pulse voltage is applied is not covered with the shield, the high frequency electric field radiated from the deflection yoke to the outside of the cathode ray tube device should be almost reduced. Is no longer possible.

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

Accordingly, 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, a cathode ray tube apparatus according to the present invention comprises a horizontal deflection coil.
Deflection yoke having a
A high-voltage pulse to the horizontal deflection coil.
Tube to generate horizontal deflection magnetic field by applying voltage
An apparatus wherein said pulse applied to said horizontal deflection coil is
Reverse pulse voltage that generates a pulse voltage of the opposite polarity to the pulse voltage
Generating means and the reverse pulse voltage generated by the reverse pulse voltage generating means.
The pulse voltage of polarity is input, and the horizontal deflection coil is
Cancels the electric field generated when a horizontal deflection magnetic field is generated
Electric field canceling electric field to generate an electric field of the opposite polarity to the electric field
And a cathode , and inside the funnel portion of the cathode ray tube.
Formed inside and serves as a path for the electric field generation
And graphite formed on the outside of the funnel portion.
And grounded exterior graphite,
In the vicinity of the position on the funnel where the exterior graphite should be
In addition, the electric field is canceled in a form separated from the exterior graphite.
Electrodes were placed .

[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 receives 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 high-frequency electric field. Accordingly, the generated electric field acts 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. Therefore, the high-frequency electric field radiated to the outside as a whole of the cathode-ray tube device is reduced. Will be. The electric field canceling electrode serves as a path for generating an electric field.
It is located near the interior graphite via the funnel.
Therefore, it effectively acts to cancel the electric field.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
Before that, a description of a cathode ray tube device that is useful for understanding the present invention
I do. FIG. 1 shows a cathode ray tube useful for understanding the present invention .
Is a side view of an example shown partially broken of the apparatus, FIG. 2 is a circuit diagram illustrating a flyback transformer which is included in the deflection high voltage circuit in FIG. 1, FIG. 3 is a part of the electric field cancellation electrode in FIG. 1 FIG. 3 is a perspective view cut away.

In the drawings, reference numeral 1 denotes a cathode ray tube device, 2
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 electric field canceling electrode 6 is mounted on the funnel 2b of the cathode ray tube 2.

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. And a pulse voltage e2 having an opposite polarity to the high voltage pulse voltage e1 applied from the terminal P1 to the horizontal deflection coil 8 of the deflection yoke 3 as a reverse pulse voltage generation function.
At the terminal P2.

As shown in FIG. 2, the flyback transformer 5 is connected in series with a terminal P1 as a horizontal deflection output terminal and a + B power supply, and is connected in series with a diode 5d to obtain a high voltage from a terminal P4. Secondary coil 5b
And an induction coil 5c. 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, a pulse voltage e2 having a polarity opposite to that of the high-voltage pulse voltage e1 applied to the terminal P1 is generated at the terminal P2 of the induction coil 5c.

On the other hand, the electric field canceling electrode 6 is connected to the cathode ray tube 2.
In the funnel section 2b, a pulse voltage e2 of the opposite polarity generated at the terminal P2 is input, and an electric field substantially proportional to the voltage e2 is generated.

The electric field canceling electrode 6 is formed of a metal plate, and as shown in FIG.
The insulating cover 7b is attached to the insertion portion. The surface 7c of the insulating frame 7 is
And 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 attached to the funnel portion 2b of the cathode ray tube 2, and the electric field canceling electrode 6 efficiently transfers the electric field to the fluorescent screen 2a side. Can be radiated. Further, since the electric field canceling electrode 6 can keep 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 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.

As shown in FIG. 4, the pulse voltages e1 and e2
Have the same phase but the opposite polarities. The amplitude of the pulse voltage e1 is a high voltage, usually about 1000V. For this reason, 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 outputs an electric field almost proportional to the pulse voltage e1 of the horizontal deflection output terminal P1 to the outside of the cathode ray tube device 1. Radiate.

On the other hand, since the electric field canceling electrode 6 receives a pulse voltage e2 having a polarity opposite to the pulse voltage e1 applied to the horizontal deflection coil 8, an electric field substantially proportional to the pulse voltage e2 is applied to the cathode ray tube device 1. And the deflection yoke 3 cancels out the high-frequency electric field radiated outside the cathode ray tube device 1, thereby reducing the high-frequency electric field.

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

FIG. 5 is a cathode ray tube apparatus useful for understanding the present invention .
Is a side view showing another example of FIG. 6 is a front view showing, partly in cross section, of the deflection yoke in FIG. In 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 an induction coil 10 having a function of generating a reverse pulse voltage is provided on a deflection yoke 3, and an electric field canceling electrode 6 is mounted on the outer periphery of the deflection yoke 3 on the fluorescent screen side.

Here, the induction coil 10 includes the deflection yoke 3
And is arranged so that the horizontal deflection magnetic field 9 interlinks. One terminal P5 of the induction coil 10 is connected to the low potential side terminal P3 of the horizontal deflection coil 8, and the other 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 mounted on the outer periphery of the deflection yoke 3 on the fluorescent screen side.

In this embodiment , the induction coil 10 generates a pulse voltage e2 of the opposite polarity similar to the voltage waveform shown in FIG. 4 by the horizontal deflection magnetic field 9 which changes rapidly during the horizontal flyback period. Accordingly, 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 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. In this example , there is an advantage that a high-frequency electric field can be reduced by changing only the deflection yoke 3.

The induction coil 10 is formed by printing or etching a coil conductor pattern on a film-like insulator 11 as shown in FIG. Therefore, the thickness of the induction coil 10 can be reduced, and the deflection yoke 3 can be further connected to the funnel 2 of the cathode ray tube 2.
b. In this example ,
Although the induction coil 10 is mounted on the inner surface of the horizontal deflection coil 8, the induction coil 10 may be placed at any place where the horizontal deflection magnetic field 9 is leaking.

FIG. 7 shows a cathode ray useful for understanding the present invention .
It is a side view which shows the cathode ray tube used in a tube apparatus . In this example , an induction coil 10 having a reverse pulse voltage generation function is provided in a cathode ray tube 2 and an electric field canceling electrode 6 is provided.
Is mounted on the outer periphery of the cathode ray tube 2 on the fluorescent screen side.

Here, the induction coil 10 is mounted on the deflection yoke mounting portion indicated by a broken line in the funnel portion 2b of the cathode ray tube 2, and is arranged so that the horizontal deflection magnetic field 9 is linked like the above-mentioned example. ing. One terminal P5 of the induction coil 10 is connected to the ground of the cathode ray tube 2, and the other 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 conductive wire with an insulating coating, and is mounted on the outer periphery of the cathode ray tube 2 on the fluorescent screen side.

In this example , the induction coil 10 generates a pulse voltage e2 of the opposite polarity similar to the voltage waveform shown in FIG. 4 by the horizontal deflection magnetic field 9 which changes rapidly during the horizontal flyback period.
Accordingly, 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 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. In this example, there is an advantage that the high-frequency electric field can be reduced by the configuration of only the cathode ray tube 2. In this example, the electric field canceling electrode 6 is insulated.
Since the conductor consists of a covered wire,
Just change the total area of the electric field canceling electrode 6 easily.
It is easy to adjust the strength of the canceling electric field .

Based on the above, in the present invention, the electric field cancellation
The method of attaching the electrode 6 to the cathode ray tube 2 was devised.
That is, by a method such as forming an electrode disconnect a portion of the exterior graphite funnel portion 2b of the cathode ray tube 2 and the ground portion, to form an electric field cancellation electrode 6 directly CRT 2
This is an example.

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

The present embodiment is characterized in that an induction coil 10 having a reverse pulse voltage generating function is provided on the core 12 of the deflection yoke 3. As the electric field canceling electrode 6, any of the electrodes described in each of the above examples may be used.

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

In this embodiment , the induction coil 10 generates a pulse voltage e2 of the opposite polarity similar to the voltage waveform shown in FIG. 4 by the horizontal deflection magnetic field 9 which rapidly changes during the horizontal flyback period. Accordingly, 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 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. In this example , the configuration having only the deflection yoke 3 has an advantage that it is possible to generate a pulse voltage e2 having a reverse polarity required for canceling a high-frequency electric field.

FIG. 9 is a circuit diagram showing a transformer for impedance conversion used in a cathode ray tube device as another reference example of the present invention. In FIG. 1, reference numeral 13 denotes a transformer for impedance conversion.

The present embodiment is characterized in that the transformer 13 for impedance conversion of the horizontal deflection coil 8 has a function of generating an inverse pulse voltage. As the electric field canceling electrode 6, any of the electrodes described in each of the above examples may be used.

Here, the transformer 13 includes a primary coil 13
In addition to a, an induction coil 13b is provided. One end of the induction coil 13b is connected to the low potential side terminal P3 of the horizontal deflection output.
The terminal P2, which is the other end, is connected to the electric field canceling electrode 6
Connected to.

According to this embodiment , the deflection yoke 3 and the cathode ray tube 1
And without changing the deflection high voltage circuit 4
3 and the electric field canceling electrode 6 are provided, and the deflection yoke 3
The high-frequency electric field radiated from the cathode ray tube device 1 to the outside can be canceled.

In the transformer 13, the deflection high voltage circuit 4
The primary coil 13a connected to the terminal P1 of the first embodiment has an intermediate tap P6 and is connected to the horizontal deflection coil 8, so that a part of the winding is also used as a secondary coil. When the turns ratio between the primary coil and the secondary 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 examples , 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 cathode ray tube device 1
The effect of reducing the high frequency electric field radiated to the outside is the same. Therefore, the induction coils 5c, 10 or 13b
Of the two terminals, the potential of the portion connecting the terminal P5 which is not connected to the electric field canceling electrode 6 is not limited to the ground potential but may be a DC potential.

[0041]

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

That is, a book of graphite for an exterior of a cathode ray tube device
Apply a pulse voltage of opposite polarity to the electric field canceling electrode provided near the position on the funnel part that is to come , and reverse polarity to the high frequency electric field radiated from the deflection yoke and deflection high voltage circuit to the outside of the cathode ray tube device by generating the electric field, pole electric field of high frequency emitted to the outside of the cathode-ray tube apparatus
In other words, there is an effect that the noise can be effectively canceled and reduced.

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

[Brief description of the drawings]

FIG. 1 shows a cathode ray tube device which is useful for understanding the present invention .
It is the side view which showed the example partially broken and shown.

FIG. 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 the electric field canceling electrode in FIG. 1 with a part cut away.

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. 5 shows another cathode ray tube device useful for understanding the present invention.
It is a side view which shows the example of.

FIG. 6 is a front view of the deflection yoke in FIG.

FIG. 7 is a side view showing a cathode ray tube used in a cathode ray tube device useful for understanding the present invention.

FIG. 8 is a side view, partially broken away, of a deflection yoke used in a cathode ray tube device as a reference example of the present invention.

FIG. 9 is a circuit diagram showing a transformer for impedance conversion used in a cathode ray tube device as another reference example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cathode tube device, 2 ... Cathode tube, 3 ... Deflection yoke, 4
... High voltage deflection circuit, 5 ... Flyback transformer, 6 ... Electrode 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.

Continued on the front page (72) Inventor Souichi Sakurai 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi Media Research Laboratory, Inc. (72) Koji Kito 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi Media and Media Research Laboratories (72) Inventor Hiroki Oguro 292 Yoshidacho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi Media Media Research Laboratories (72) Inventor Isao Yoshimi 3300 Hayano Mobara-shi, Chiba Sun Co., Ltd. (72) Inventor Masao Ohara 1st Kitano, Makino, Mijosawa City, Iwate Prefecture Hitachi Mizusawa Electronics Corporation (72) Inventor Michitaka Osawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd. (56) References JP-A-4-3155741 (JP, A) JP-A-5-303942 (JP, A) JP-A-5-207404 (JP, A) JP-A-5-244540 ( JP, A) JP-A-5-242821 JP, A) JP flat 3-89437 (JP, A) JP flat 3-64836 (JP, A) (58 ) investigated the field (Int.Cl. ^7, DB name) H01J 29/86 H01J 29/76

Claims (3)

(57) [Claims] A deflection yoke having a horizontal deflection coil ;
A cathode ray tube on which the deflection yoke is mounted, wherein a pulse voltage of a high voltage is applied to the horizontal deflection coil to generate a horizontal deflection magnetic field. A reverse pulse voltage generating means for generating a pulse voltage having a polarity opposite to the voltage, and the pulse voltage having the reverse polarity generated by the reverse pulse voltage generating means is input, and the horizontal deflection coil generates a horizontal deflection magnetic field. to cancel the electric field generated in the electric field cancellation electrode for generating an electric field of the field and opposite polarity, the provided,
And formed inside the funnel portion of the cathode ray tube inside the tube.
Interior graphite that contributes as a path for generating the electric field
And formed outside the tube outside of the funnel portion.
Out of the exterior graphite,
In the vicinity of the location on the funnel to come, the outer graphite
The electric field canceling electrode is arranged in a form separated from
An electric field canceling electrode serves as a path for the electric field generation.
Near the interior graphite through the funnel.
Therefore, it is effective to cancel the electric field.
A cathode ray tube device characterized by the above. 2. The cathode ray tube device according to claim 1, wherein
The reverse pulse voltage generating means has an induction coil.
A flyback transformer, said pulse voltage having the opposite polarity
Pressure is obtained from the induction coil.
Cathode ray tube device. 3. The cathode ray tube device according to claim 1, wherein
The reverse pulse voltage generating means is connected to the deflection yoke.
Located at a position where the horizontal deflection magnetic field interlinks
A cathode ray tube device comprising a coil.