JP3527112B2 - Color cathode ray tube with built-in split resistors - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube used for a television, a display and the like, and more particularly to a built-in dividing resistor mounted on an electron gun.

[0002]

2. Description of the Related Art Conventionally, when a predetermined voltage is supplied to each electrode of a color cathode ray tube, if it is attempted to supply all the voltages from the outside, it may be difficult due to problems such as arrangement of voltage supply lines. For example, when a voltage is applied to the electrodes of the electron gun, it is necessary to arrange a large number of metal leads in a narrow space, which causes a disadvantage that discharge easily occurs between the metal leads and the electrodes.

Also, the number of stem pins for supplying a voltage to the electron gun is restricted on the set side, and in the latter-stage focusing type color cathode ray tube for focusing between the shadow mask and the fluorescent screen, it is supplied from the anode button. In some cases, it may be difficult to directly supply a desired voltage from the outside, such as when it is necessary to supply a voltage different from the generated anode voltage.

Therefore, a desired voltage is not directly supplied from the outside to such a predetermined electrode, but is divided and supplied by a built-in dividing resistor built in the color cathode ray tube, for example, built-in division in an electron gun. For example, a resistor is installed. FIG. 5 shows this conventional built-in division resistor,
The built-in division resistor is provided with a plurality of electrode portions 3a to 3d on one plate surface of an electrically insulating substrate such as ceramic, and a zigzag-shaped resistor layer 2 pattern containing lead ruthenate connected to these electrode portions. Through holes are provided in the electrically insulating substrate corresponding to the respective electrode parts, and the connection terminals are connected thereto. 7 is a trimming section. Also, the zigzag resistance pattern is coated with an electrically insulating coating to protect it from high voltage.
The built-in division resistor shown in FIG. 5 is such that the final acceleration voltage is supplied to one of the connection terminals and a predetermined division potential is supplied to each electrode of the electron gun from the other connection terminal.

By the way, the built-in division resistor as described above is
A zigzag resistance pattern and a plurality of trimming portions 7 connected to the zigzag resistance pattern are formed on one plate surface of the electrically insulating substrate, and the trimming portion of alumina is formed in the trimming portion so that the resistance division ratio becomes a predetermined value. The resistance value is changed and the resistance division ratio is adjusted by sandblasting a part of the powder using the powder as an abrasive. However, when trimming is performed by sandblasting,
In some cases, the surface of the zigzag pattern near the trimming portion was roughened, or a fine alumina powder adhered to the zigzag resistance pattern, leaving the alumina powder even after cleaning.

[0006]

Generally, in a color cathode ray tube, if the electrode of the electron gun has a sharp projection or the like, an undesired discharge occurs in actual use. Therefore, in the manufacturing process of the color cathode ray tube, For a portion of the electrode of the electron gun, such as a sharp protrusion, which is prone to discharge, a sparking process is applied to apply a high voltage that is 2-3 times higher than the normal final acceleration voltage to cause discharge and melt shaping. We are trying to stabilize it in actual use. By the way, by performing the trimming by the sand blast, the surface of the zigzag pattern portion near the trimming portion is rough, or fine alumina powder is fixed to the zigzag pattern portion, and when it is coated with an electric insulating coating layer, When the sparking process, which is a manufacturing process of color cathode ray tube, is applied, discharge is generated in a zigzag resistance pattern with a rough surface or alumina powder adhered, and the resistance division ratio changes, so the expected focus The problem that performance is not obtained occurs.

As a method for solving this problem, there is a laser trimming method. However, this laser trimming causes a great deal of damage to the trimming portion and the resistor layer and causes a problem in withstand voltage in a color cathode ray tube to which a final accelerating voltage of 20 to 30 kV is applied, resulting in fluctuation of the resistance division ratio and discharge. If the resistance division ratio fluctuates, the focus performance deteriorates, and if discharge occurs in the tube, the cathode, heater and socket substrate may be destroyed or peripheral circuit elements may be adversely affected.

Further, as another method for solving this problem, there is a technique described in Japanese Patent Laid-Open No. 4-174942, for example. This is a method in which the resistance layer is locally heat-treated in the range of 800 to 1200 ° C. by a laser to change the structural state of the resistance layer, and trimming is performed by utilizing the resulting change in resistance value. However, by partially changing the structure of the resistance layer, the resistance value changes mainly on the impact of the sparking process or the part irradiated with the laser during long-term use, and as a result, the resistance division ratio is expected to change. There is a problem that focus performance cannot be obtained.

The present invention provides a color cathode ray tube having a built-in dividing resistor that solves the above-mentioned problem that occurs in the conventional trimming for adjusting the resistance value and that does not change the resistance dividing ratio even if the sparking process is performed. The purpose is to do.

[0010]

In order to achieve the above object, a color cathode ray tube having a built-in dividing resistor according to the present invention comprises:
In a color cathode line having a built-in dividing resistor that divides a voltage applied from the outside and supplies it to a predetermined electrode, the built-in resistor includes an electrically insulating substrate, a resistor layer formed on the insulating substrate, and the resistor. A first electrical insulating coating layer having a trimming portion connected to the layer for adjusting a resistance value, an electrode portion, and covering the resistor layer; and the first electrical insulating coating film after the trimming process. Second coated on layer
And an electric insulating coating layer.

As a result, even if trimming is performed to adjust the resistance division ratio to a predetermined value, the surface of the zigzag resistance pattern is not roughened and the alumina powder is prevented from adhering to the normal final acceleration. A color cathode ray tube having a highly reliable built-in dividing resistor can be obtained without changing the resistance dividing ratio even if the sparking process of applying a high voltage of 2 to 3 times the voltage is performed.

In the color cathode ray tube of the present invention described above, the thickness of the first electrically insulating coating layer is preferably in the range of 10 to 20 μm. In the color cathode ray tube of the present invention described above, the thickness of the second electrically insulating coating layer is 1
It is preferably in the range of 00 to 500 μm.

Further, in the color cathode ray tube of the present invention described above, the first electric insulating coating layer and the second electric insulating coating layer contain air bubbles dispersed and mixed, and the average particle diameter of the air bubbles is substantially 5 μm or less. It is preferable that

In the color cathode ray tube of the present invention described above, it is preferable that a third electric insulating coating layer is further provided on the back surface of the surface of the electric insulating substrate on which the resistor layer is formed.

In the above-described color cathode ray tube of the present invention, the thickness of the third electrically insulating coating layer is 10 to 100 μm.
It is preferably in the range of m. Further, in the color cathode ray tube of the present invention described above, the second electric insulation coating layer and the third electric insulation coating layer contain bubbles dispersedly mixed therein, and the bubbles of the second electric insulation coating layer are the third electric insulation coating layer. It is preferable that the number per unit volume is smaller than the number of bubbles contained in the insulating coating layer.

In the above-described color cathode ray tube of the present invention, the built-in resistor is provided along the tube axis on a multi-glass that interconnects the electrodes of the electron gun, and divides the final accelerating voltage to a predetermined value. It is preferable to supply to the electrodes.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 3, the color cathode ray tube according to the embodiment of the present invention has an envelope 9 composed of a panel and a funnel, and a phosphor that emits blue, green, and red is applied to the inner surface of the panel. The phosphor screen 10 is formed. An electron gun 11 is housed inside the neck of the envelope 9 facing the phosphor screen surface 10.

As shown in FIG. 4, three cathodes 12, a control electrode 13, an acceleration electrode 14, which are arranged in parallel in the horizontal direction,
First focusing electrode 15, first auxiliary electrode 16, second auxiliary electrode 1
7, second focusing electrode 18, intermediate electrode 19, final accelerating electrode 2
0, a shield cup 21 and two electrodes of an electron gun, which are mutually connected along the tube axis direction, and a color cathode line having a built-in dividing resistor by a built-in dividing resistor installed on the upper surface of at least one of the multi-glasses. A tube electron gun is constructed. A quadrupole lens such as a rectangular aperture is formed on each of the surfaces of the first auxiliary electrode 16 and the second auxiliary electrode 17 which face each other and the surfaces of the second auxiliary electrode 17 and the second focusing electrode 18 which face each other. Well-known means are provided for this. Further, the intermediate electrode 19 is a cylindrical body or a cylindrical body provided with a separating means for separating the lens electric field into three.

The typical value of the potential applied to each electrode during operation is 50 to 150 V for the cathode 12 and the control electrode 1.
3 is 0 V, the acceleration electrode 14 is 300 to 800 V, and the anode voltage (Va) applied to the final acceleration electrode is 25 to 32 k.
V. The intermediate electrode 19 is Va
The divided voltage is applied so as to be about 40 to 70%. The first focusing electrode 15 is connected to the second auxiliary electrode 17, and a voltage divided by a built-in dividing resistor to a reference focus voltage Vfoc of about 20 to 35% of Va is applied. Further, the second focusing electrode 18 is connected to the first auxiliary electrode 16, and a dynamic focus voltage in which a voltage Vdyn that changes in a parabolic shape in synchronization with the deflection of the electron beam is superimposed on the reference focus voltage Vfoc is applied.
The beam spot shape can be corrected by forming a quadrupole lens whose action intensity changes in synchronization with the deflection by means of forming a pole lens.

Next, the electric field lens formed between the electrodes will be described. In the peripheral portion of the phosphor screen surface 10, a diverging lens action in the horizontal direction and a focusing lens action in the vertical direction due to the deflection magnetic field occur. However, as disclosed in Japanese Patent Laid-Open No. 3-93135, a constant division potential Vfoc is obtained. The potential with the dynamic focus voltage Vdyn superimposed on the second
When the voltage is applied to the focusing electrode 18 and the first auxiliary electrode 16, the potential of the second focusing electrode rises, so that the main lens action is weakened, and at the same time, between the second auxiliary electrode 17 and the second focusing electrode 18, and between the first auxiliary electrode 16 and the first auxiliary electrode 16. A quadrupole lens electric field is formed between the second auxiliary electrode 17 and the second auxiliary electrode 17. The quadrupole lens action between the second auxiliary electrode electrode 17 and the second focusing electrode 18 forms a focusing lens action in the horizontal direction and a diverging lens action in the vertical direction, and the quadrupole lens action is formed between the first auxiliary electrode 16 and the second auxiliary electrode 17. The quadrupole lens action that is formed forms a diverging action in the horizontal direction and a focusing action in the vertical direction.

Due to the weakening of the main lens action and the action of the two quadrupole lenses, the horizontal and vertical lens magnifications can be made substantially equal, and a beam spot close to a circle can be generated over the entire phosphor screen surface 10. However, when the beam current increases, the electron beam passing through the main lens electric field of the electron gun distorts the beam spot into a non-circular shape due to the spherical aberration of the main lens, so it is preferable to increase the diameter of the main lens electric field. As a concrete means, three electron beam passage holes on the side of the intermediate electrode of the second focusing electrode 18 and on the side of the intermediate electrode of the final accelerating electrode 20 are provided in the outer cylinder as disclosed in JP-A-4-133247. In a position retracted from the body,
The three main lens electric fields formed between the second focusing electrode 18 and the three electron beam passage holes of the final accelerating electrode 20 are partially overlapped by adjacent ones to generate a large diameter main lens electric field. As disclosed in JP-A-8-22780 and JP-A-9-180646, a second focusing electrode 18 to which a focusing voltage is applied and a final accelerating electrode to which a high voltage (Va) is applied. An intermediate electrode 19 to which a voltage higher than the focusing voltage and lower than the high voltage (Va) is applied is coaxially disposed between the main electrode 20 and the main electrode 20 to make the potential gradient of the main lens electric field in the tube axis direction gentle. This is a method of further reducing the spherical aberration of the lens.

Here, the intermediate electrode 19 and the first focusing electrode 15
A built-in division resistor that supplies a division potential to the second auxiliary electrode 17 will be described. As an example, the built-in division resistor has a length of 62 mm, a width of 6 mm, and a thickness of 1 mm.
When the final accelerating voltage (Va) used was 27 kV, the total resistance value was 1800 MΩ. The reason for this is to suppress the heat generation of the resistance and prevent the resistance division ratio from changing.

Next, the structure of the resistor will be described with reference to FIGS. Through holes for terminals to be connected to the electron gun are provided at a plurality of predetermined positions of the electrically insulating substrate 1 made of 96% by weight alumina ceramic. Next, the electrode part 3 is formed on the first surface of the electrically insulating substrate 1 by screen printing so as to surround the through hole with a thick film resistance material containing at least lead ruthenate. Similarly, the resistor layer 2 having a zigzag pattern and the trimming portion 7 connected to the resistor layer 2 are connected to the electrode portion 3 and formed by screen printing. The electrode portion 3, the resistor layer 2 and the trimming portion 7 are preferably 5 to 30% by weight of conductive particles such as lead ruthenate having a pyrochlore type crystal structure, and non-conductive glass particles 65 to 90 formed of lead oxide, silicon oxide or the like. Temperature coefficient of resistance (TC) containing oxides of titanium and manganese in an amount of 5% by weight or less and 5% by weight or less
R) A thick film resistance material composed of a regulator. The thick film resistance material is mixed with 60 to 70 parts by weight of the above inorganic component and 30 to 40 parts by weight of an organic component binder in which a resin such as ethyl cellulose is dissolved in a solvent such as terpineol to impart screen printability. The sheet resistance value of the resistor layer 2 and the trimming portion 7 is, for example, 4 to 5 MΩ /
□ (where □ represents an arbitrary square area), while the sheet resistance value of the electrode part 3 is lower than that of the resistor layer 2 by making the lead ruthenate / glass component ratio lower than that of the resistor layer 2. It was set to 100 kΩ / □.

Next, the manufacturing procedure will be described below. After screen-printing the electrode part 3, 0.5 at 100 to 150 ° C.
Removed organic solvent and dried for ~ 1 hour, peak about 8
Main firing is performed under the conditions of 50 ° C. for 8 to 10 minutes and total firing time of 0.5 to 1 hour, and then the resistor layer 2 is printed, dried, and main-fired similarly to the electrode portion. At this time, the electrode portion and the resistor layer may be fired at the same time, such as electrode printing → electrode drying → resistor layer printing → resistor layer drying → electrode portion and resistor layer firing.

After the resistor layer 2, the trimming portion 7 and the electrode portion 3 are formed on the electrically insulating substrate 1, the first electrically insulating coating layer 4 covers the electrode portion 3 and the vicinity thereof. The first electrically insulating coating layer 4 is, for example, a lead borosilicate glass material such as boron oxide, silicon oxide, lead oxide, or a paste material containing chromium oxide in aluminum oxide, and this paste material is applied by printing. . After drying at 100 to 150 ° C. for 0.5 to 1 hour to remove the organic solvent,
Peak about 600 ° C for 8-10 minutes, total firing time 0.5-1
Main baking is performed under the conditions of time to decompose the binder and vitrify. As a result, the resistor layer 2 having the zigzag pattern is covered with the first electric insulation coating layer 4, so that the trimming portion for adjusting the resistance division ratio is partially sandblasted by using fine alumina powder as an abrasive. Even if it is applied, the surface of the zigzag resistance pattern is not roughened and the alumina powder is not attached.

Next, the surface of the electrically insulating substrate on which the resistor layer is formed and the second electrically insulating coating layer 5 covering the first electrically insulating coating layer except the electrode portion 3 and its vicinity. A third electrical insulation coating layer 6 on the back surface of the first electrical insulation coating layer 4
Similarly, printing, drying and main firing are performed to complete the built-in division resistor. Since the second electric insulation coating layer coated on the first electric insulation coating layer is overcoated except for the electrode portion having the connection terminal and the vicinity thereof, a normal final accelerating voltage of 2 is applied.
Even if the sparking process of applying a high voltage up to 3 times is performed, the zigzag resistance pattern does not cause discharge. As a result, good withstand voltage characteristics can be obtained without changing the resistance division ratio.

Further, by providing a third electrically insulating coating layer on the back surface of the surface on which the resistor layer is formed, the built-in divided resistor is connected to the color cathode line due to the difference in thermal expansion coefficient between the electrically insulating substrate and the electrically insulating coating. It is possible to prevent the built-in resistor from warping due to a heat process or the like in the tube manufacturing process.

The built-in division resistor according to the embodiment of the present invention has the electrode portion 3 before the trimming process for adjusting the resistance division ratio.
Since the first electric insulation coating layer covering except for the vicinity thereof covers the zigzag resistance pattern, even if sand blasting is performed on the trimming portion to remove a part of the fine alumina powder as an abrasive, the zigzag The resistance pattern surface does not become rough and the alumina powder does not adhere. Since the second electric insulation coating layer covering the first electric insulation coating layer is overcoated except for the electrode portion 3 having the connection terminal and the vicinity thereof, it is 2 to 3 times the normal final accelerating voltage. Even if the sparking process of applying a high voltage is performed, discharge does not occur in a zigzag resistance pattern, so that the resistance division ratio does not change and good withstand voltage characteristics can be obtained.

As another effect, the first thin film is formed on the substrate.
By coating the electrical insulating coating layer of No. 2, it is possible to prevent the electrical insulating coating layer from shrinking in the surface direction when forming the second electrical insulating coating layer, and in particular, the thickness of the electrical insulating coating layer at the edge portion of the substrate. Since it is easy to maintain, good withstand voltage characteristics can be obtained even if a sparking process is performed.

Here, the first electrically insulating coating layer has a thickness of 10 to 20 μm, which is generally formed by one-time screen printing, and can sufficiently protect the zigzag resistance pattern from sandblasting, while supporting trimming. Since the first electric insulating coating layer is a thin film, the resistance value can be adjusted by scraping off the first electric insulating coating layer by sandblasting. The thickness of the second electric insulation coating layer is 100 μm in order to suppress variation in resistance value (division ratio) in the sparking process.
It is not less than m and prevents the whole from warping due to the difference in the coefficient of thermal expansion with the electrically insulating substrate, and the peeling and damage of the electrically insulating coating can be prevented by the thermal cycle of temperature increase during use and temperature decrease during non-use. The thickness of the second electrically insulating coating layer is preferably in the range of 100 to 500 μm because it is required to be 500 μm or less in order to eliminate it.

Further, generally, increasing the thickness of the electric insulation coating can alleviate the effect of the sparking process, but the cost is high, and as a drawback, there is a difference in the coefficient of thermal expansion from that of the electric insulation substrate, so that the entire internal division resistor is formed. However, there is a problem that the electrical insulation film may be peeled off or damaged due to the thermal cycle of temperature increase during use and temperature decrease during non-use. However, if the range is 100 to 500 μm, , Can solve such problems.

In order to suppress the resistance value (division ratio) variation in the sparking process, the number of bubbles per unit volume mixed and dispersed in the first electric insulating coating layer 4 and the second electric insulating coating layer 5 is small, and Since the smaller size is advantageous, the first
The electric insulating coating layer 4 is formed as thin as 10 to 20 .mu.m, the number of bubbles mixed and dispersed is small, and the size is substantially 5 .mu.m or less. Regarding the second electric insulating coating 5, when the third electric insulating coating 6 on the back surface is fired at the same time,
By facing the second electric insulating coating 5 side to the high-temperature furnace space and the third electric insulating coating 6 side to the belt conveyor side, the second electric insulating coating 5 is mixed and dispersed per unit volume. The number of bubbles is small and the size is substantially 5 μm
It can be made smaller as follows.

Generally, the electrical insulation coating layer that covers the zigzag resistance pattern has a smaller number of bubbles per unit volume dispersed and mixed, and the smaller the particle size of the bubbles, the better the withstand voltage characteristics such as sparking treatment. Be advantageous Therefore, in order to reduce the number of bubbles per unit volume and the particle size, the electric insulation coating layer that covers the resistance pattern is made into two layers, and the zigzag resistance pattern is formed on the first electric insulation before trimming by sandblasting. After coating with the coating layer and trimming, the first electrical insulating coating layer is covered with the second electrical insulating coating layer. In this embodiment, the bubbles dispersed and mixed in the first electric insulating coating layer at this time have a small film thickness, so that the number thereof is small and the particle size can be substantially reduced to 5 μm or less.

On the other hand, the second electrically insulating coating layer faces the multi-glass which connects the electrodes of the electron gun to each other.
It can be formed thinner than in the case of directly facing the electrode of the electron gun, and the thickness of the second electric insulating coating layer can be 100 to 500 μm because the first electric insulating coating layer is separately formed. At this time, the average particle size of the bubbles dispersed and mixed in the second electric insulating coating layer can be reduced to substantially 5 μm or less,
Since the number of bubbles can be reduced, it is advantageous for withstanding voltage characteristics such as sparking treatment.

Further, it is preferable that the bubbles dispersed and mixed in the first and second electric insulating coating layers are contained in the third electric insulating coating layer in a small number per unit volume. In the present embodiment, as a procedure for forming the electric insulating coating layer, a thin first electric insulating coating layer is formed to have a thickness of, for example, about 15 μm, trimming is performed by sandblasting, and then the second electric insulating coating layer is made to have a thickness of, for example, 250 μm. The third electrically insulating coating layer is simultaneously fired to a thickness of 50 μm, for example. At this time, the first surface of the electrically insulating substrate having the first and second electrically insulating coating layers faces the furnace space, while the third surface
The firing is performed so that the second surface of the electrically insulating substrate having the electrically insulating coating layer of 1) faces the belt conveyor side. As a result of the bubbles gathering in the upper layer portion and disappearing to form the electric insulating coating layer, the number of bubbles per unit volume of the bubbles mixed and mixed in the second electric insulating coating layer is contained in the third electric insulating coating layer. The number is reduced, and the effect of protecting the zigzag resistance pattern is enhanced.

Further, it is preferable that the surface resistivity of the second or third electric insulating coating layer is made smaller than that of the electric insulating coating layer composed only of non-conductive glass particles such as lead oxide and silicon oxide. The electrical insulating coating layer covering the resistor layer is an electrical insulator having a large volume resistivity such as glass, and thus has a large surface resistivity. Since the surface resistivity is high, the charging voltage increases when electrons continue to accumulate on the surface of the electric insulation coating layer during actual use or sparking, and when the electric breakdown voltage of the electric insulation coating layer is exceeded, the electric insulation coating layer increases. Is destroyed and the resistance division ratio fluctuates. To prevent this problem, the second
Alternatively, the surface resistivity of the third electrical insulating coating layer may be made smaller than that of the electrical insulating coating layer composed only of non-conductive glass particles such as lead oxide and silicon oxide so that electrons are generated on the surface of the electrical insulating coating layer. It can be discharged from the connection terminal and is not charged.

In this embodiment, during sparking,
The first electrical insulating coating and the second electrical insulating coating were coated except for the vicinity of all the electrode portions 3 so as not to cause destruction around the electrode portions 3. However, in the electrode portions located on the low voltage side, the lead terminals are provided. You may coat other than the part used as. Furthermore, in order to suppress the variation of the resistance value (division ratio), the surface resistivity of the second or third electric insulating coating layer is composed only of non-conductive glass particles such as lead oxide and silicon oxide. It is preferable to intentionally reduce the size so that the surface of the electrically insulating film is not charged up. When electrons are continuously accumulated on the surface of the electric insulation coating layer during actual use or sparking, the charging voltage increases, and when the electric insulation breakdown voltage of the electric insulation coating layer is exceeded, the electric insulation coating layer breaks down and the resistance division ratio increases. In order to prevent this problem, the surface resistivity of the second or third electric insulating coating layer should be made smaller than that of the electric insulating coating layer composed only of non-conductive glass particles such as lead oxide and silicon oxide. Thus, even if electrons are generated on the surface of the electrically insulating coating layer, they can be emitted from the connection terminal. As an example of the conductive material contained in the lead borosilicate glass, tin, antimony and chromium are suitable.

In the present embodiment, the third electrically insulating coating layer is provided on the back surface of the surface of the electrically insulating substrate of the built-in division resistor on which the resistor layer is provided, but the present invention is not limited to this. Not limited to the above, by adjusting the material of the electrically insulating substrate or the material of the electrically insulating coating layer, or by using a substrate which is warped on the opposite side so as to be able to absorb the warp due to the subsequent heat treatment in advance, the third electrically insulating coating film can be obtained. Even if there is no layer, it is possible to prevent the built-in division resistance from warping.

The electron gun of the color cathode ray tube having the built-in division resistance described above is not limited to these. For example, the electron gun shown in FIG. 4 is configured by removing the intermediate electrode and the electrode portion 3b of the built-in dividing resistor for supplying a potential to this electrode, and in FIG. 4, the intermediate electrode 19 is one, but it is configured by a plurality. And the first focusing electrode 1
5 and the second auxiliary electrode 17 are configured by removing the electrode portion 3c of the built-in division resistor for supplying the electric potential, and the electric potential is supplied from an external circuit through the stem. Further, in the electron gun of FIG. 4, two quadrupole lenses are provided. However, this is a single piece, and again
Needless to say, it is possible to use a combination of the above electron guns.

Further, in the above-mentioned embodiment, the case where the built-in division resistor is provided on the multi-glass of the electron gun and the voltage applied to each electrode of the electron gun is divided and supplied is described, but the present invention is not limited to this. In a so-called post-focusing type color cathode ray tube that applies a voltage lower than the anode voltage to the shadow mask and focuses the electron beam by the lens effect due to the potential difference between the voltage and the anode voltage, the anode voltage is applied to the shadow mask that is the color selection electrode. It can also be used as a built-in resistor for supplying a lower voltage.

[0041]

As described above, according to the present invention, the surface of the zigzag resistance pattern is roughened and the alumina powder adheres even if trimming is performed to adjust the resistance division ratio to a predetermined value. In addition, since it is possible to prevent reduction in the surface direction with respect to the substrate when forming the second electrical insulating coating layer, it is easy to maintain the thickness of the electrical insulating coating layer at the edge portion of the substrate. , The normal final accelerating voltage of 2
A color cathode ray tube having a highly reliable built-in dividing resistor can be obtained without changing the resistance dividing ratio even if the sparking process of applying a high voltage up to 3 times is applied.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an example of a built-in division resistor of a color cathode ray tube according to the present invention.

FIG. 2 is a cross-sectional view taken along the line II of FIG.

FIG. 3 is an overall view of a color cathode ray tube device according to an embodiment of the present invention.

FIG. 4 is a perspective view of an electron gun to which a built-in division resistor according to an embodiment of the present invention is applied.

FIG. 5 is a plan view showing an example of a conventional built-in dividing resistor.

[Explanation of symbols]

1 Electrically insulating substrate 2 Resistor layer 3a, 3b, 3c, 3d electrode part 4 First electrical insulating coating layer 5 Second electrical insulation coating layer 6 Third electrical insulation coating layer 7 Trimming part 8 connection terminals 9 envelope 10 phosphor screen 11 electron gun 12 cathode 13 Control electrode 14 Accelerating electrode 15 First focusing electrode 16 First auxiliary electrode 17 Second auxiliary electrode 18 Second focusing electrode 19 Intermediate electrode 20 final accelerating electrode 21 shield cup 22 multi-glass 23 External variable resistor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-14524 (JP, A) JP-A-9-320482 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 29/48 H01J 9/14

Claims (8)

(57) [Claims] 1. A color cathode line having a built-in dividing resistor for dividing a voltage applied from the outside and supplying the divided voltage to a predetermined electrode, wherein the built-in resistor is an electrically insulating substrate and a resistor layer formed on the insulating substrate. A first electrically insulating coating layer having a trimming portion connected to the resistor layer for adjusting a resistance value and having an electrode portion, and covering the resistor layer; A color cathode ray tube having a built-in division resistor, comprising: a second electrically insulating coating layer coated on a first electrically insulating coating layer. 2. The thickness of the first electrically insulating coating layer is 10 to 2
The color cathode ray tube having a built-in dividing resistor according to claim 1, wherein the range is 0 μm. 3. The thickness of the second electrically insulating coating layer is 100 to
The color cathode ray tube having a built-in dividing resistor according to claim 1, which has a range of 500 μm. 4. The built-in division according to claim 1, wherein the first electric insulation coating layer and the second electric insulation coating layer contain air bubbles dispersed and mixed, and the average particle diameter of the air bubbles is substantially 5 μm or less. Color cathode ray tube with resistance. 5. The built-in device according to claim 1, further comprising a third electrically insulating coating layer on the back surface of the surface of the electrically insulating substrate on which the resistor layer is formed. A color cathode ray tube having a dividing resistance. 6. The third electrically insulating coating layer has a thickness of 10 to 1
The color cathode ray tube having a built-in dividing resistor according to claim 5, wherein the range is 00 μm. 7. The second electric insulating coating layer and the third electric insulating coating layer contain bubbles dispersedly mixed therein, and the bubbles of the second electric insulating coating layer are contained in the third electric insulating coating layer. The color cathode ray tube having a built-in division resistance according to claim 5, wherein the number per unit volume is smaller than the number of bubbles. 8. The built-in resistor is provided along a tube axis direction on a multi-glass that interconnects electrodes of an electron gun,
8. A color cathode ray tube having a built-in dividing resistor according to claim 1, wherein the final accelerating voltage is divided and supplied to a predetermined electrode.