JPH02273441A - Deflection yoke for cathode ray tube and its cooling method - Google Patents

Abstract

PURPOSE:To sufficiently restrain temperature rise in the deflecting yoke of a cathode ray tube used for high-vision and having a neck diameter of 37.5mm, a deflection of 110 deg. and an aspect ratio of 16: 9 by setting the ratio of inductance to direct current resistance of the horizontal deflecting yoke st a specific value. CONSTITUTION:The ratio L/RDC of inductance L to direct current resistance RDC of a horizontal deflecting yoke is set at a high value in the range of 0.9 to 1.1mH/OMEGA, whereby the resistance RDC is decreased, loss of copper and that of excessive currents are remarkably reduced, and thus temperature rise is restrained sufficiently so as to enhance cooling effect even for a cathode ray tube used for high-vision and having a neck diameter of 37.5mm, a deflection of 110 deg. and an aspect ratio of 16:9.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention suppresses the amount of heat generated within the coil, and easily conducts and dissipates the heat generated inside in large quantities to the outside, reducing the temperature. This invention relates to a deflection coil for cathode ray tubes that suppresses the rise in temperature.

[Conventional technology]

In order to scan the fluorescent surface with an electron beam in a cathode ray tube,
When adopting the electromagnetic deflection method, a deflection yoke equipped with horizontal and vertical deflection coils is installed so as to surround the outside of the cathode ray tube near the connection point between the funnel and the neck tube.

Accelerating the electron beam with a high anode voltage to obtain a bright display, or increasing the deflection angle to shorten the funnel length of a cathode ray tube, requires a strong deflection magnetic field, which requires a large deflection coil. As ampere turns are required, the amount of heat generated inside the deflection coil increases, and measures to suppress the temperature rise of the deflection yoke become important.

For this purpose, for example, Japanese Patent Application Laid-Open No. 63-62138 discloses that a heat sink with low eddy current is disposed inside or near the coil winding, and the heat sink is formed of a litz wire. has been done.

Additionally, the separators used in conventional deflection yokes are made with emphasis on electrical insulation and safety.
Most of them have a structure in which the horizontal deflection coil and the vertical deflection coil are completely separated. In order to reduce the temperature rise by modifying this separator,
Publication No. 8474.5 discloses that an opening is formed in the cone of a separator disposed on the inner surface of the core, and the inner surface of a vertical deflection coil wound around the core is fitted into the space. It is disclosed that the ampere turns of the horizontal deflection coil can be reduced by reducing the inner diameter of the core or by providing a part of the core with a protrusion that protrudes inward and winding the vertical deflection coil around this protrusion. has been done.

Furthermore, in conventional deflection yokes, the transition portion between the horizontal deflection coil and the vertical deflection coil, particularly the transition portion on the electron gun side, is almost completely covered with a separator in most cases.

[Problem to be solved by the invention]

The deflection yoke to which the above-mentioned conventional countermeasure technology was applied is applied to cathode ray tubes with a conventional neck pipe diameter of 32.5 mm at most, a deflection angle of 110 degrees, and an aspect ratio of 4:3. The inductance L and the DC resistance R,o. Even if the ratio L/Roc is set to 0.8 mH/Ω or less and the number of twisted wires used in the horizontal deflection coil is set to 7 or less, the standard value for temperature rise is still fully satisfied. Ta. However, the horizontal deflection coil (L/R
While keeping Dc) at the conventional value, high-definition (hereinafter referred to as H)
Neck diameter 37.5mmφ, 11
A deflection yoke designed to be applied to a cathode ray tube with a 0 degree deflection was measured at its temperature during use, and it was found that the neck diameter became larger and the deflection sensitivity deteriorated, and the aspect ratio became 16=≦]. As a result of the increased size of the rask, the problem of increased temperature clearly arose.

Conventionally, as one of the measures to reduce the temperature of the deflection yoke, an attempt was made to reduce the temperature by sucking heat into a low eddy current heat sink made of Litz wire, as described in the aforementioned Japanese Patent Application Laid-Open No. 63-621.38. Although there is a deflection yoke, the litz wire that makes up the heat sink is still a conductor, so there is a problem in that the eddy current loss generated in the heat sink itself cannot be completely eliminated.

In addition, as a measure to reduce the temperature of the separator, the above-mentioned Japanese Patent Application Laid-Open No. 184745/1983 discloses that an opening is provided in the cone of the separator, and the inner diameter of the core is reduced by fitting the inner surface of the vertical deflection coil into the cone of the separator. It has been disclosed that a part of the core is provided with a protrusion that protrudes inwardly, and a vertical deflection coil is wound around this part, thereby reducing the ampere turns of the horizontal deflection coil and reducing the temperature. However, no consideration was given to the material of the separator.

The present invention has various aspects regarding the temperature reduction of the deflection yoke.
t, 1-(37.5mmφ for D TV, 1.1.
It is an object of the present invention to provide a deflection yoke for a cathode ray tube which can sufficiently suppress a temperature rise even when applied to a cathode ray tube with a deflection of 0 degrees and an aspect ratio of 1620.

[Means to solve the problem]

In order to achieve the above object, in the present invention, 1-(D
Conventional 0
, the ratio L/Roc of the inductance ■-1 of the Kodaira deflection coil and the DC resistance Roc, which was less than 8 m H/Ω, was reduced to 10 ~30% increase to 0.9~], 1m
It was set to 11/Ω.

In addition, - to reduce the temperature of the deflection yoke for boat fishing,
A thin ceramic heat sink with high thermal conductivity is closely attached to the inner surface of each of the horizontal and vertical deflection coils, and the disk-shaped ceramic heat sink is installed at the transition section between both deflection coils by bending and connecting these heat sinks. The high heat generated in each of the horizontal and vertical deflection coils is thermally conducted and radiated. Furthermore, an opening is made in a part of the separator that is in contact with the horizontal deflection coil, and a material with higher thermal conductivity than the separator is injected into that part, and the horizontal deflection coil is also impregnated to improve thermal conductivity. In addition, the material of the separator itself is made of ceramics with good thermal conductivity, so that the heat generated inside can be easily conducted to the outside and dissipated in large quantities. After doing so, if necessary, a blower blows air into the inside of the holder surrounding the transition portions of both deflection coils to cool the ceramic disc-shaped heat sink provided there.

[Effect]

In the deflection yoke of the present invention for HDTV, L/Roc is increased by 10 to 30% compared to the conventional one, and the number of twisted litz wires for the horizontal deflection coil winding is 8 to 16, thereby increasing the horizontal deflection frequency to 33. The effective resistance RAC of the horizontal deflection coil at 75 kHz or 31.degree.

In addition, we use a ceramic heat sink that does not allow eddy current to flow and has good thermal conductivity.The separator material is also made of ceramic that has good thermal conductivity, and the openings in the separator and the gaps around the deflection coil have high thermal conductivity. filled with the substance of
By impregnating the deflection coil with a material with high thermal conductivity, the thermal conductivity of the entire deflection yoke system can be improved.
It is obvious that the heat generated inside the deflection coil can be conducted to the outside, in large quantities, and dissipated more easily than in the past.

If ventilation openings are provided at the top and bottom of the boulder that surrounds the transition area of both deflection coils, heat radiation will be increased due to the chimney effect, and if cold air is force-fed there from outside using a blower, a large amount of heat can be further dissipated. I can do it.

〔Example〕

FIG. 1 is a partially sectional side view of a deflection yoke according to the first embodiment of the present invention, FIG. 2 is a perspective view of a litz wire used in the horizontal deflection coil of the deflection yoke of the present invention, and FIG. The relationship between (L/Ro.) vs. (L/RAC) and the temperature rise of the deflection yoke when the inductance of the horizontal deflection coil of the deflection yoke of the invention is R90 and the effective high frequency resistance fLRAc is The figure shown in FIG. 4 is a diagram showing the characteristics when the twisting conditions of the wire used in the coil winding are changed. In Figure 4, ■ is a cathode ray tube, 2 is a horizontal deflection coil, 3 is a vertical deflection coil, 4 is a core, 5 is a separator, 17 is a material with high thermal conductivity, and 6 in Figure 2 (a) is a cathode ray tube. In the Litz wire shown in FIG. 2(b), 7 is a wire and 8 is a conductor. From Fig. 3 based on the experimental results, if the setting of (L/Roc) of the horizontal deflection coil is set to 0.9~1,
The temperature increase value ΔT of the deflection yoke can be reduced to 35°C or less. Furthermore, it can be seen that when (1, , , /RDc) is 1°1 or more, the effect of reducing the temperature rise is saturated.

From Fig. 4, (L/RI)C) of 0.9 to 11 is calculated by the number of strands of 8 to 16 wires when the wire diameter of the coil conductor 8 is 0.12 to 0.16 mmφ. It turns out that it can be achieved.

In this embodiment, as shown in FIG. 2(a), the number of parallel litz wires 6 is seven, and as shown in FIG. The diameter of the wire was 0.14, and the number of twisted wires was 12.

In this case, L/RDc is 1.0.

FIG. 5 is a perspective view of a deflection yoke according to a second embodiment of the present invention;
The figure shows its configuration. In the figure, reference numerals 91 and 92 are ceramic heat sinks, and other symbols are the same as in the case of FIG. 1. The heat sink made of ceramics has a portion 9 shaped along the inner surfaces of the horizontal deflection coil 2 and the vertical deflection coil 3.
2 and two disc-shaped portions 9 which are bent and connected at both ends, and when incorporated into a deflection yoke, the deflection yoke of the present invention is created as shown in FIG. .

In this embodiment, the case of a wound horizontal deflection coil 2 and a toroidally wound vertical deflection coil 3 has been described, but the same applies regardless of whether the horizontal deflection coil 2 is slit-wound or the vertical deflection coil 3 is hollow-wound. Needless to say, it is effective. In other words, when the horizontal deflection coil 2 is wound with slits, the shape of the ceramic that contacts the inner surface of the coil may be made into a slit shape.

In this embodiment, horizontal deflection coil 2 and vertical deflection coil 3
The heat generated in l is emitted. Therefore, the temperature of the deflection yoke can be reduced.

In addition, in the deflection yoke shown in Fig. 1, the separator 5, which was conventionally made of polypropylene material, is made of a ceramic material with good thermal conductivity, such as boron nitride (BN) or beryllia (Be○), and the separator The gap between both deflection coils is filled with one-component silicone R, TV.
Further heat dissipation effect can be obtained by filling with a material having high thermal conductivity such as Shin-Etsu Silicon KE34.93. In addition, in the deflection yoke, the horizontal deflection coil or the vertical deflection coil is made of a material 17 with high thermal conductivity.
By impregnating it with , the heat dissipation effect of the - layer can be improved.

FIG. 7(a) is a side view of a separator according to a third embodiment of the present invention, and FIG. 7(b) is a sectional view taken along line AA' in FIG. 7(a). In FIG. 7(a), the polypropylene separator 5 has a part on the electron gun side (the part with the highest magnetic flux density) that is in contact with the horizontal deflection coil 2, as shown in the figure.
An opening 11 is provided in the opening 11 . A high thermal conductivity material 17, for example silicone, is injected into this opening]1,
When impregnated, the deflection yoke of the present invention having a cross section as shown in FIG. 7(1)) is completed.

FIG. 8 shows the main part of the fourth embodiment. This embodiment is characterized in that the opening 11 in the third embodiment has a mesh shape. The shape of the opening 10 may be changed in this way, and the heat dissipation effect will be further increased if the contact area between the horizontal deflection coil and the material with high thermal conductivity is made as large as possible. According to this embodiment, the heat generated in the horizontal deflection coil 2 is removed from the opening 11.
Heat is radiated into the air from the gap between the core 4 and the separator 5 through the high thermal conductivity material 17 injected into the deflection yoke, which has the effect of reducing the temperature of the deflection yoke.

FIG. 9(a) is a sectional view of a deflection yoke according to a fifth embodiment of the present invention, and FIG. 9(b) is a cross-sectional view of a deflection yoke according to a fifth embodiment of the present invention. The structure is such that a gap is provided on the electron gun side.

Further, in order to create an air flow, one ventilation portion 14 is provided above and below the transition portion holder 12. According to this embodiment, a gap is provided between the transition part holder 12 on the electron gun side and the transition part 13, and heat is dissipated by the chimney effect of the ventilation opening 14 provided under the first part of the transition part holder 12. It has the effect of increasing

FIG. 10 shows a cooling method for a deflection yoke according to a sixth embodiment of the present invention, in which a transition section 13 on the electron gun side of the deflection yoke sends air through a ventilation pipe 15 to a ventilation opening 14 under a transition section holder 12. It has a structure in which it is cooled by the cold air from the blower 1-6. Since the transition portion 13 of the deflection yoke is very well cooled, the effect of further reducing the temperature rise of the horizontal deflection coil can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, the thermal conductivity inside the deflection yoke can be improved in terms of structure and material. If necessary, the disc-shaped heat radiating plate on the electron gun side can be forcibly cooled by cold air from the blower, which can reduce internal temperature rise. Also, I
-Neck diameter 37.5mmφ for T D TV, 110
In the deflection yoke for horizontal deflection cathode ray tubes, we have revised the stranded wire specifications of the Ritz wire used for winding the horizontal deflection coil (L/
Improves RoJ by 0 to 30% compared to conventional technology, and improves HD TV
The effective resistance RA of the coil in use at high horizontal frequencies of
6 was significantly reduced, making it possible to suppress heat generation in the coil and improve reliability.

[Brief explanation of drawings]

Fig. 1 is a partially sectional side view of a deflection yoke according to the first embodiment of the present invention, Fig. 2(a) is a perspective view showing a coil conductor made of seven parallel Litz wires, and Fig. 2(b) is a perspective view showing one Ritz wire, and Fig. 3 shows the inductance of the horizontal deflection coil of the deflection yoke of the present invention, (L/Roc) when the DC resistance is R90 and the effective high frequency resistance is RAo. Figure 4 shows the relationship between the pair (L/RAC) and the temperature of the deflection yoke, ΔT. Figure 4 shows the characteristics when the stranded wire conditions used for coil winding are changed. The figure is a perspective view of a deflection yoke according to a second embodiment of the present invention, FIG. 6 is a developed view showing the structure of a deflection yoke according to a second embodiment, and FIG. 7(a) is a side view of a separator according to a third embodiment of the present invention. Figure, Figure 7(b)
is a sectional view taken along the line A-A'' in FIG. 7(a), FIG. 8 is a diagram showing the main parts of the fourth embodiment, and FIG. 9(a) is a diagram showing the deflection yoke of the fifth embodiment of the present invention. Cross-sectional view, FIG. 9(b) is similar to FIG. 9(a)
FIG. 10, a plan view seen from the direction of arrow B inside, is the sixth aspect of the present invention.
FIG. 6 is a diagram showing a method of cooling a deflection yoke according to an embodiment. 1...Cathode ray tube, 2...Horizontal deflection coil, 3...Vertical deflection coil, 4...Core, 5...Separator, 6...
Litz wire, 7.Element wire, 8..Conductor, 11..1 opening, 12..Transition part holder, ■3..Transition part, ]4.
・Airflow amount 10 parts, 15...Blower pipe, ]6...Blower, 17...High thermal conductivity material, 91.92・Ceramic heat sink.

Claims (1)

[Claims] 1. In a cathode ray tube deflection yoke with a neck diameter of 37.5 mmφ for high vision and a deflection of 110 degrees, the ratio L/R_ of the inductance L of the horizontal deflection coil and the DC resistance R_D_C.
A deflection yoke for a cathode ray tube, characterized in that D_C is 0.9 to 1.1 mH/Ω. 2. The deflection yoke for a cathode ray tube according to claim 1, wherein the horizontal deflection coil is wound using a Litz wire having strands of 8 to 16 wires. 3. Install a thin ceramic heat sink with good thermal conductivity inside each of the horizontal and vertical deflection coils,
A deflection yoke for a cathode ray tube characterized in that each of these ceramic heat sinks is connected to a ceramic heat sink installed at both deflection coil transition parts. 4. Provide an opening in a part of the separator interposed between the horizontal deflection coil and the vertical deflection coil that contacts the horizontal deflection coil, and inject a substance with better thermal conductivity than the material of the separator into this part, A deflection yoke for a cathode ray tube characterized in that a horizontal deflection coil is further impregnated with this substance. 5. A deflection yoke for a cathode ray tube, characterized in that ventilation openings are provided above and below the transition holder on the electron gun side of the deflection yoke. 6. A method for cooling a deflection yoke for a cathode ray tube, characterized in that cold air is sent into the holder from the ventilation opening of the transition portion holder of the deflection yoke according to claim 5 by a blower. 7. A deflection yoke for a cathode ray tube, characterized in that a space between a horizontal deflection coil and a vertical deflection coil is filled with a material having high thermal conductivity. 8. A separator interposed between the horizontal deflection coil and the vertical deflection coil to electrically insulate them is formed of ceramics with good thermal conductivity, and the gap between the ceramic separator and both deflection coils is A deflection yoke for cathode ray tubes characterized by being filled with a material with high thermal conductivity. 9. The deflection yoke for a cathode ray tube according to claim 7, wherein the horizontal deflection coil or the vertical deflection coil is impregnated with a substance having high thermal conductivity.