JP3321762B2 - Deflection yoke - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke for deflecting an electron beam of a cathode ray tube (hereinafter referred to as "CRT") used for a television set, a display monitor or the like. The present invention relates to an insulating structure between a neck band and an auxiliary coil having a conductive magnetic core which is arranged on an entrance side and performs a convergence adjusting function.

[0002]

2. Description of the Related Art CRTs used for television sets
In response to the trend toward larger size, wider angle, and higher resolution and higher speed scanning of CRT used for display monitors, it is desired that the performance of deflection yoke be improved more and more. high.

As a corresponding method, recently, an auxiliary coil having a conductive magnetic core is provided on the end face of the molded product bobbin of the deflection yoke on the side of the electron gun, and a current flowing through the vertical or horizontal deflection coil is supplied to the auxiliary coil. A method of diverting parts has been adopted. For these technologies,
It is described in many documents such as JP-A-2-37654, JP-A-3-102744, and JP-A-3-247703.

FIG. 6 shows a state in which a typical deflection yoke having the above-described functions is mounted on a CRT. In the figure, reference numeral 11 denotes a funnel glass of a CRT, 1
2 is a CRT anode button, 13 is a CRT electron gun shield cup, 1 is a pair of horizontal deflection coils (indicated by broken lines in the figure), 2 is a pair of vertical deflection coils, 3 is a molded bobbin, 4 is an auxiliary coil Reference numeral 5 denotes a magnetic core made of a conductive material of the auxiliary coil 4, and reference numeral 6 denotes a metal neckband. Here, the magnetic core 5 of the auxiliary coil 4 is often configured by stacking several thin sheets (thickness of about 0.5 mm) of a conductive silicon steel sheet such as S18. Generally, a plastic bobbin is provided outside the magnetic core 5 and a coil is wound around the bobbin to form the auxiliary coil 4.

[0005]

Conventionally, in this type of deflection yoke, the distance between the magnetic core for the auxiliary coil and the neck band is a basic requirement of the deflection yoke, that is, the dimension of the deflection yoke in the tube axis direction ( The height of the deflection yoke) is required to be as short as possible. Therefore, unless there are other restrictions, the deflection yoke should be designed to be as short as possible within the range of the workability such as attachment of the deflection yoke to the CRT. General. For this reason, the distance between the magnetic core for the auxiliary coil and the neckband is very small, 3 to 5 mm.

However, when the potential of the neckband portion is observed when the switch is turned on for a very short time immediately after the high voltage is supplied to the anode button of the CRT, as shown in FIG. 7, the potential gradually increases with the application of the high voltage. During the time when the anode potential almost reaches the specified voltage, approximately 1
The potential reaches about ３ to １ ／. Assuming that the high voltage is about 30 kV, the potential of the neckband portion becomes 10 kV or more. This is presumably because the neckband is located near the shield cup of the electron gun to which the anode voltage of the CRT is supplied, and is strongly induced by the anode potential and charged to a relatively high potential. On the other hand, the magnetic core for the auxiliary coil having a coil arranged at a position close to the vertical coil and having a part of the current flowing through the vertical coil diverted has a potential relatively close to the ground potential.

[0007] The potential difference between these two parts is a very high potential difference for both the intervals, and sometimes discharge may occur between the two parts. This discharge is a discharge outside the CRT, that is, outside the tube, and the electric potential distribution inside the tube greatly changes instantaneously due to the discharge.

Therefore, when a discharge occurs between the magnetic core of the deflection yoke and the neckband at the time of switching on, in a transient circuit configuration, the potential of components inside the tube such as an electron gun directly connected to the outside of the CRT tube is disturbed. And induces a discharge in the tube of the CRT. When a discharge occurs in the tube of the CRT, a spark noise, which is a noise, is generated as a result, or the instantaneous, but extremely high anode potential causes an X-ray provided in a television set or a display monitor circuit. There is a problem that the protection circuit for prevention automatically operates and stops the driving of the set itself.

[0009]

Means for Solving the Problems] deflection yoke according to the present invention comprises a pair of horizontal deflection coils and a pair of vertical deflection coils, and formed molded article bobbin you support both the inlet side of the molded article bobbin And an auxiliary coil having a conductive magnetic core for generating a magnetic field for convergence correction synchronized with the horizontal or vertical deflection coil, and a molded product bobbin attached to the electron gun side of the molded product bobbin and a cathode ray tube in the deflection yoke comprising a metal neckband having a role of fixing the neck glass portion of said magnetic core
Between the end of the neckband and the above neckband
Through an insulator provided or at the end of the core
The part is covered with an insulator by a specific method.

As a method of covering with an insulator , an end of a magnetic core is inserted into a bag-shaped insulator formed on a molded bobbin,
The sheath insulator is attached to the end of the magnetic core, the end of the magnetic core is covered with an insulating resin by dipping, or the end of the magnetic core is covered with a hardening resin.

[0011]

In the deflection yoke according to the present invention, since the end of the magnetic core is covered with an insulating material, the electric insulation between the magnetic core and the neckband is improved, and the discharge between the magnetic core and the neckband is improved. Can be suppressed, and the discharge in the tube of the CRT can be suppressed low.

[0012]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a rear view of a deflection yoke to which the present invention is applied, as viewed from the electron gun side. In the figure, 3 is a molded bobbin, 4 is an auxiliary coil, 5 is a magnetic core, 6 is a neck band, and 7 is integrally formed on the back surface of the molded bobbin 3 as shown in a perspective view in FIG. The ends of the magnetic core 5 are inserted into the four bag-shaped portions 7.

As described above, since the end of the magnetic core 5 is housed in the bag-like portion 7 made of an insulating material, electrical insulation between the magnetic core 5 and the neck band 6 can be ensured, and generation of electric discharge can be prevented. It can be kept low. Since the bag-shaped portion 7 is formed integrally with the molded product bobbin 3, it can be formed simultaneously with casting of the molded product bobbin, and its manufacture is extremely easy.

Embodiment 2 FIG. FIG. 3 shows another embodiment of the present invention. In the drawing, reference numeral 8 denotes a sheath-like insulator covering the end of the magnetic core 5, and the end of the magnetic core 5 is housed in the sheath-like insulator 8. You. The sheath-shaped insulator 8 is made of the same material as the molded bobbin 3 of the deflection yoke, for example, a polypropylene or a noryl-based material.
Alternatively, it is molded with a molding silicone rubber such as KE-5612G made by Shin-Etsu Silicone.

By covering the end of the magnetic core 5 with such a sheath-like insulator 8, the insulation between the magnetic core 5 and the neckband 6 can be ensured, and the occurrence of electric discharge can be suppressed. In addition, as long as the mechanical dimensions of the magnetic core 5 are the same, the magnetic core 5 can be applied to several types of deflection yokes, and has an advantage of versatility.

Embodiment 3 FIG. FIG. 4 shows an embodiment in which a part of FIG. 3 is modified. The end of the magnetic core 5 is molded by dipping with a highly insulating resin such as silicon resin. 9 is a dipping insulating part. Molding by the dipping method in this way eliminates the need for a dedicated mold for a molded product such as the sheath-shaped insulator in the second embodiment, and can easily cope with various types of magnetic cores for insulation. It is possible.

Embodiment 4 FIG. FIG. 5 shows still another embodiment of the present invention, in which an end of the magnetic core 5 is molded with a hardening resin 10 to achieve insulation. As resin,
One-component non-fluid silicon RTV is easy to use. By molding the end of the magnetic core 5 with the resin 10 in this manner, the second embodiment
There is an advantage that there is no need for a dedicated mold for a molded product such as a sheath-like insulator and no need for a separate process such as the dipping method of the third embodiment. Can be performed.

[0018]

As described above, according to the present invention, the end of the magnetic core having the convergence adjusting function is made of an insulator.
Insulation between the magnetic core and the neckband is ensured because it is isolated from the neckband, and even when the potential of the neckband portion suddenly changes, such as when power is supplied to the CRT, the magnetic core is not damaged. Not only has the effect of reducing the occurrence of abnormal noise due to the discharge inside the tube of the CRT and unnecessary operation of the protection circuit for limiting the X-rays of the set, but also has the effect of reducing insulation. The molded product bo
Manufacturing process by molding simultaneously with the bottle
Can be simplified.

Further, when the end of the magnetic core is inserted into a bag-shaped portion formed integrally with the molded bobbin, the structure and assembly can be performed very easily. Further, when a sheath-like insulator is attached to the end of a magnetic core to insulate the magnetic core, it can be applied to several types of deflection yokes as long as the mechanical dimensions of the magnetic core are the same. In addition, when the end of the magnetic core is covered with a dipping method using an insulating resin, a mold for molding is not required, and it is possible to easily cope with various types of magnetic cores for insulation. . In addition, the core end molded with a curable resin and insulated has the advantage that it does not require a mold for molding and does not require a separate process like a dipping method. is there.

[Brief description of the drawings]

FIG. 1 is a rear view of a deflection yoke according to a first embodiment.

FIG. 2 is an enlarged perspective view of a main part of FIG.

FIG. 3 is an exploded perspective view showing a main part of a second embodiment.

FIG. 4 is a front view showing a main part of a third embodiment.

FIG. 5 is a rear view of a deflection yoke according to a fourth embodiment.

FIG. 6 is a side view showing a state in which a conventional deflection yoke is mounted on a CRT.

FIG. 7 is a graph showing changes in anode potential and neckband potential after switch-on.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Horizontal deflection coil 2 Vertical deflection coil 3 Molded bobbin 4 Auxiliary coil 5 Magnetic core 6 Neck band 7 Bag-shaped part 8 Sheathed insulator 9 Dipping insulating part 10 Curable resin 11 CRT funnel glass 12 Anode button 13 Electron gun shield cup

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-103925 (JP, A) JP-A-7-38907 (JP, A) JP-A-60-75950 (JP, U) JP-A-6-95050 33347 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 9/28 H01J 29/76

Claims (6)

(57) [Claims] 1. A horizontal deflection coil, a vertical deflection coil,
Has a formed molded article bobbin you support both, an electron beam is disposed on the inlet side of the conductive generating a magnetic field for convergence correction in synchronization with the horizontal or vertical deflection coil core of the molded article bobbin an auxiliary coil, the deflection yoke comprising a metallic neck band attached to the electron gun side of the molded article bobbin for fixing the molded article bobbin neck portion of a cathode ray tube, and the end portion of the magnetic core
Installed integrally with the molded product bobbin between the neckbands
Deflection yoke, characterized in that via the vignetting insulating material. 2. The deflection yoke according to claim 1, wherein an end of the magnetic core is inserted into a bag-shaped insulator provided integrally with the molded bobbin. 3. A horizontal deflection coil, a vertical deflection coil,
A molded bobbin that supports both of them, and this molded bobbin
Horizontal or vertical
Magnetic field for convergence correction synchronized with the direct deflection coil
An auxiliary coil having a conductive core that generates, the
This molded product bobbin is attached to the electron gun side of the molded product bobbin.
Metal neck bar for fixing the bottle to the neck of the cathode ray tube
End of the magnetic core.
Was covered with a sheath insulator different from the above-mentioned molded bobbin.
A deflection yoke. 4. A horizontal deflection coil, a vertical deflection coil,
A molded bobbin that supports both of them, and this molded bobbin
Horizontal or vertical
Magnetic field for convergence correction synchronized with the direct deflection coil
An auxiliary coil having a conductive core that generates, the
This molded product bobbin is attached to the electron gun side of the molded product bobbin.
Metal neck bar for fixing the bottle to the neck of the cathode ray tube
End of the magnetic core.
Was covered with an insulating resin by dipping.
A deflection yoke. 5. A horizontal deflection coil, a vertical deflection coil,
A molded bobbin that supports both of them, and this molded bobbin
Horizontal or vertical
Magnetic field for convergence correction synchronized with the direct deflection coil
An auxiliary coil having a conductive core that generates, the
Mounting et is the electron gun side of the molded article bobbin this molded product volume
Metal neck bar for fixing the bottle to the neck of the cathode ray tube
End of the magnetic core.
Is covered with a curable resin.
Talk. 6. The deflection yoke according to claim 5, wherein a one-component silicone resin is used as the curable resin.