JPS6313242A - Resistor incorporated in cathode-ray tube - Google Patents

Abstract

PURPOSE:To minimize change in resistance values of resistor layers before or after a knocking process of a cathode-ray tube, by determining the resistance values of the resistor layers so that those in the second pattern part become smaller than those in the first pattern part and then for.ing definite conductive parts. CONSTITUTION:On an insulating substrate 1, a potential rise gradient in the first pattern part of resistor layers 5', ranging from the first terminal to the first high-potential difference part, is made to be more steep than that in the second pattern part of the resistor layers 5', ranging from the first high-potential difference part to the second terminal 2. Potential difference applied across an insulating film 6 covering the resistor layers 5' is thus decreased. On the insulating substrate 1 besides, the resistor layers are made to extend ranging from the first terminal to the second high-potential difference part or this vicinity, and the conductive parts 20a and 20b function as arrester electrodes so that potential difference applied across the insulating film 6 covering the second high-potential difference part and its peripheral resistor layers 5' is more decreased. Hence, the insulating film is not caused to be deteriorated and broken by the potential applied across it.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Field of industrial application B. Overview of the invention C. Prior art D. Problem to be solved by the invention E. Means for solving the problem F. Effect G. Example G-1 configuration (Figures 1 and 2) G-2 Potential relationship of various parts in a cathode ray tube (FIG. 3) Effects of the invention A Industrial field of application The present invention relates to a built-in resistor that is incorporated together with an electron gun assembly into a tube such as a color cathode ray tube.

B. Summary of the Invention The present invention provides a built-in resistor for a cathode ray tube that is incorporated together with an electron gun assembly in the tube body of the cathode ray tube and supplies a voltage obtained by dividing the anode voltage of the cathode ray tube to the electron gun assembly. A resistor layer having a zigzag pattern and covered with an insulating film is arranged between the low voltage side electrode terminal and the high voltage side electrode terminal on the upper side, and this resistor layer is connected to the low voltage side electrode terminal and the high voltage side electrode terminal. The resistance value per unit length in the direction of connecting the insulating film and the resistor layer is the resistance value per unit length in the direction connecting The second pattern portion between the high potential difference region and the high voltage side electrode terminal is smaller than the first pattern portion,
In addition, a conductor portion that protrudes from the low voltage side electrode terminal without contacting the resistor layer is provided on the insulating substrate, and the conductor portion is connected to the resistor layer from the low voltage side electrode terminal without being covered with an insulating film. Along the first pattern section, a first terminal and a first
By extending to or near a second high potential difference site where the potential difference between the second high potential difference site and the surface of the insulating coating is relatively large in the absence of the conductor portion, When installed in a cathode ray tube and subjected to high voltage application during non-king processing of the cathode ray tube, the insulation of the insulating film at the first high potential difference region and furthermore at the second high potential difference region. This makes it possible to avoid the occurrence of deterioration or destruction, and as a result, it is possible to minimize the change in the resistance value of the resistor layer before and after the knocking treatment of the cathode ray tube.

C. Prior Art Conventionally, in color cathode ray tubes and the like used in color television receivers, in addition to the anode voltage, high voltages are required to be supplied to, for example, convergence electrodes and focus electrodes.

In such a case, it has been proposed to incorporate a voltage dividing resistor as a built-in resistor together with the electron gun structure in the tube, thereby dividing the anode voltage to obtain the respective high voltages. As an example of the conventional built-in resistor used, those shown in FIGS. 4 and 5 are known.

FIG. 4 shows the conventional built-in resistor 7 seen through from above the insulating coating forming the outer surface, and FIG. 5 shows the entire side view of the conventional built-in resistor 7.

In the built-in resistor 7 shown in FIGS. 4 and 5, a terminal portion is formed by depositing an electric shock layer on an insulating substrate 1 such as a ceramic plate. Electrode terminal 2. High voltage for convergence electrodes, i.e.
A convergence electrode terminal (hereinafter referred to as CV electrode terminal) 3 and a ground electrode terminal 4 from which a convergence voltage can be obtained are provided, and a zigzag shape having a required resistance value is provided between the CV electrode terminal 3 and the ground electrode terminal 4. A patterned resistor layer 5a is provided between the high voltage electrode terminal 2 and the CV electrode terminal 3, and a resistor layer 5b having the same required resistance value is further provided between the resistor layers 5a and 5b and the CV electrode terminal 3. A fine adjustment resistor layer 5C is deposited between them, respectively, to form a voltage dividing resistor layer 5. An insulating coating 6 covering the voltage dividing resistor layer 5 is applied to the shaded area in FIG. 4. This insulating coating 6 is formed by drying and firing a fluid material such as lead glass. As shown in FIG. 5, the thickness of the edge portions, such as the portions adjacent to the C2 electrode terminal 3 and the ground electrode terminal 4, is made small. still,
The fine adjustment resistor layer 5c is provided so that the resistance value of the resistor layers 5a and 5b between each terminal can be adjusted by removing a part of it during the manufacturing process of the built-in resistor 7. There is.

FIG. 6 shows a state in which the built-in resistor 7 having such a configuration is incorporated into a color cathode ray tube. Here, an electron gun assembly 9 is disposed within the neck portion a of the tube body 8, and this electron gun assembly 9 has a first grid electrode Gl and a second grid electrode in common for the three cathodes K. G2. Third grid electrode G3. A fourth grid electrode G4 and a fifth grid electrode G5 are sequentially arranged coaxially. A convergence means 10 is arranged after the fifth grid electrode G5. Each electrode Gl, G2, G3.
G4. G5 and the convergence means 10 are mechanically connected by beading glass 11 while maintaining a predetermined positional relationship with each other, and the third grid electrode G3
and the fifth grid electrode G5 are electrically connected by a conductive wire 13. In addition, the convergence means 10
are electrically connected to the fifth grid electrode G5 via the conductive plate 14, and are connected to the opposing inner deflection electrode plates 10a and 1.
0b, and outer deflection electrode plates 10c and 10d arranged on the outside facing these electrode plates 10a and 10b.

A built-in resistor 7 as shown in FIGS. 4 and 5 is attached to such an electron gun assembly 9, and the high voltage electrode terminal 2 of this built-in resistor 7 is connected to the fifth grid electrode G.
5 and the electrically conductive attachment is connected via a piece 12. A graphite conductive film 15 extending to the inner wall of the neck portion 8a is adhered to the inner wall of the funnel portion 8b of the tube body 8, and a high-pressure supply button, that is, an anode button (not shown) provided on the funnel portion 8b. Anode voltage is supplied through. The conductive plate 14 is provided with a conductive spring 16, and when the conductive spring 16 comes into contact with the graphite conductive film 15, the fifth grid electrode G5. Third grid electrode G3. Convergence means 1
An anode voltage is supplied to the inner deflection electrode plates 10a and 10b of 0 and the high voltage electrode terminal 2 of the built-in resistor 7.

The CV electrode terminal 3 of the built-in resistor 7 is connected to the outer deflection electrode plates 10c and 10d of the convergence means 10 through conductive mounting pieces, and the anode voltage is divided by the resistors 1i5a and 5b to the CV electrode terminal. The convergence voltage obtained in step 3 is supplied to the outer deflection electrode plates 10c and 10d. Further, the ground electrode terminal 4 of the built-in resistor 7 is connected to the ground electrode terminal pin 19 which is embedded through the stem 18 at the base of the neck portion 8a of the tube body 8 via a conductive mounting piece, either directly or by adjustment. The external connection is grounded via a resistor.

In such a color cathode ray tube, for example, the electron gun assembly 9
If there are sharp protrusions or the like in each part, undesirable discharge will occur during actual use. Therefore, during the manufacturing process, parts of the electron gun assembly 9 that are likely to generate electrical discharge, such as sharp protrusions, are melted and shaped by generating electrical discharge in advance, so that the parts that are likely to generate electrical discharge during actual use after the finished product is Non-king processing is performed for the purpose of stabilizing the operation. In such a knocking treatment process, for example, the
The tripled high voltage (non-king voltage) is applied to the third grid electrode G3. The voltage is applied to the fifth grid electrode G5 and the high voltage electrode terminal 2 of the built-in resistor 7, and the voltage is applied to the first grid electrode G5. 2nd and 4th
Each of the grid electrodes Gl, G2, and G4 is grounded. During this knocking process, the surface of the insulating coating 6 of the built-in resistor 7, except for a part, is charged to a relatively high potential.
On the low voltage side of the resistor layer 5a forming the resistor layer 5a, a larger potential difference is applied than during actual operation.

In FIG. 7, the horizontal axis represents the distance ML from the ground electrode terminal 4, which is the low voltage side, to the CV electrode terminal 3, which is the high voltage side, on the insulating substrate 1 of the built-in resistor 7, and the vertical axis represents the distance ML. Taking the voltage ■, the surface potential of the insulating coating 6 of the built-in resistor 7 during knocking treatment (curve a), the earth electrode terminal 4 and CV
The potential of each part of the resistor N 5 a disposed between the electrode terminal 3 (curve b) and the difference between the two potentials (curve C) are shown.

As is clear from this, for example, a position P close to the third grid electrode G3 on the insulating substrate 1 to which a high voltage is applied
The potential difference between the resistor layer 5a and the surface of the insulating coating 6 is maximum at the portion of the resistor layer 5a that has a relatively low potential at this position (maximum potential difference position).
The maximum potential difference is applied to the insulating film 6 at P. Therefore, the position near the third grid electrode G3 is a high potential difference site, and a potential exceeding the withstand voltage of the insulating coating 6 is applied to the high potential difference site, causing insulation deterioration or breakdown of the insulating coating 6, and as a result, the resistance There is a risk that the body layer 5a will be damaged and its resistance value will change significantly.

To solve the problem of the change in resistance value of the resistor layer 5a due to insulation deterioration or breakdown, it is advantageous to increase the thickness of the insulating coating 6 to increase the withstand voltage.

That is, by forming the insulating film 6 to be thick, it is possible to prevent insulation deterioration or breakdown of the insulating film 6 and to suppress changes in the resistance value of the resistor layer 5a. However, increasing the thickness of the insulating coating 6 for the built-in resistor 7 is disadvantageous in terms of cost. 7, and the insulating coating 6 peels off from the insulating substrate 1 or cracks occur due to the thermal cycle of temperature rise during use and temperature fall when not in use, resulting in inconveniences that lead to a decrease in reliability. It turns out.

Therefore, in order to deal with the above-mentioned problems, the applicant of the present application has proposed a built-in resistor for a cathode ray tube as described in Japanese Patent Application Laid-open No. 130033/1983.

An example of the previously proposed built-in resistor has a zigzag pattern between the ground electrode terminal on the low voltage side and the CV electrode terminal on the high voltage side on the insulating substrate, A resistor layer covered with an insulating film changes the meandering pitch of the zigzag pattern between the ground electrode terminal and the high potential difference area, and the zigzag pattern between the high potential difference area and the CV electrode terminal. The resistance value of the resistor layer per unit length in the direction connecting the ground electrode terminal and the CV electrode terminal is set to be smaller than the meandering pitch of the pattern, and the resistance value of the resistor layer per unit length in the direction connecting the earth electrode terminal and the CV electrode terminal is It is made to be larger between the ground electrode terminal and the high potential difference site. In such a built-in resistor, the potential rise gradient of the resistor layer from the ground electrode terminal on the insulating substrate to the high potential difference area is steep, and the potential of the resistor layer is Centering on the part, excluding both ends,
The overall potential difference across the insulating coating is thereby reduced. Therefore, when attached to the electron gun assembly of a color cathode ray tube and used for non-king processing of the color cathode ray tube, care must be taken to prevent insulation deterioration or breakdown of the insulation coating, especially in areas where a large potential difference is applied. This prevents a significant change in the resistance value of the resistor layer before and after the knocking treatment.

D Problems to be Solved by the Invention As described above, resistor layer per unit length in the direction connecting the earth electrode terminal and the CV electrode terminal on the insulating substrate on which the resistor layer having a zigzag pattern is arranged. If the built-in resistor has a resistance value greater between the ground electrode terminal and the high potential difference part than between the high potential difference part and the CV electrode terminal, the electronic resistance of the color cathode ray tube When the color cathode ray tube is attached to a gun and subjected to knocking treatment, the potential rise gradient of the resistor layer from the ground electrode terminal on the insulating substrate to the high potential difference area is said to be steep. The position between the ground electrode terminal and the high potential difference site on the substrate, for example, the first grid electrode G
A situation occurs in which the potential difference between the resistor layer and the surface of the insulating film becomes relatively large at a position near the first or second grid electrode G2, and therefore, the potential difference between the resistor layer and the surface of the insulating film becomes relatively large. If the nearby position is the third
This results in a second high potential difference site different from the high potential difference site near the grid electrode G3. Then, at this second high potential difference site, a potential difference that exceeds the withstand voltage is applied to the insulating coating, causing insulation deterioration or breakdown of the insulating coating, and as a result, the resistor layer is damaged and its resistance value decreases due to knocking. There is a possibility that there will be a significant change between before and after.

Regarding insulation deterioration or breakdown of the insulating coating that may occur at a second high potential difference site relatively close to the ground electrode terminal on such an insulating substrate, for example, there is a method described in JP-A-58-102455. As described above, it is conceivable to provide a lightning rod electrode connected to a ground electrode terminal on the low voltage side on the surface of an insulating film disposed on an insulating substrate and covering a resistor layer. When a built-in resistor equipped with such a lightning rod electrode is installed in the electron gun assembly of a cathode ray tube and non-king processing is performed, the lightning rod electrode provided on the surface of the insulating coating prevents the surface of the insulating coating from being charged. As a result, it is expected that insulation deterioration or breakdown of the insulating film will be prevented, and changes in the resistance value of the resistor layer covered with the insulating film before and after the non-king treatment will be suppressed.

However, when a built-in resistor is used that has a lightning rod electrode on the surface of an insulating coating placed on an insulating substrate and covering a resistor layer as described above, the built-in resistor is attached to the electron gun assembly. The lightning rod electrode provided on the surface of the insulating coating faces the inner wall of the neck of the cathode ray tube while the lightning rod electrode is placed inside the neck of the cathode ray tube. Discharge from the inner wall of the neck to the lightning rod electrode is likely to occur, but such discharge is concentrated from the inner wall of the neck to the edge of the lightning rod electrode, so that the insulating coating below the edge of the lightning rod electrode There is a risk that small holes or microscopic racks may be formed due to electrical discharge to the parts, which may lead to destruction.

In view of this, the present invention provides a zigzag pattern between a first terminal on the low voltage side and a second terminal on the high voltage side among the plurality of electrode terminals provided on an insulating substrate. A resistor layer is formed, and this resistor layer is covered with an insulating film, and is incorporated into a cathode ray tube together with an electron gun assembly, so that high voltage during knocking treatment of the cathode ray tube is When placed under conditions where
Insulation deterioration or breakdown of the insulation coating can be effectively avoided in both the high potential difference area relatively close to the first terminal and the high potential difference area closer to the center of the resistor layer, and as a result, the cathode ray tube We provide a built-in resistor for cathode ray tubes that can minimize changes in the resistance value of the resistor layer before and after knocking treatment, and that does not cause disadvantages in terms of manufacturing costs or reliability. The purpose is to

E. Means for Solving the Problems In order to achieve the above-mentioned object, the built-in resistor of a cathode ray tube according to the present invention is provided with a built-in resistor for a cathode ray tube, which is formed on an insulating substrate and has a low voltage side. A resistor layer having a zigzag pattern is disposed covered with an insulating film between the first terminal and the second terminal on the high voltage side, and the first terminal of this resistor layer is covered with an insulating film. and the second terminal, the resistance value per unit length in the direction connecting the first and second terminals is a first high potential difference site where the potential difference between the first and second terminals and the surface of the insulating coating is large. The second pattern portion of the resistor layer between the first high potential difference portion and the second terminal is smaller than the first pattern portion of the resistor layer between the first high potential difference portion and the first terminal. and a conductor portion protruding from the first terminal without contacting the resistor layer,
The conductor portion is disposed on the insulating substrate and extends from the first terminal along the first pattern portion of the resistor layer to the conductive portion between the first terminal and the first high potential difference portion. It is configured such that it extends to or near a second high potential difference site where the potential difference with the surface of the insulating coating is relatively large when there is no body part, and is not covered with the insulating coating.

F action The built-in resistor of the cathode ray tube according to the present invention configured as described above is set on the high voltage side when it is incorporated into the cathode ray tube together with the electron gun assembly and used for non-king treatment of the cathode ray tube. A high knocking voltage is supplied to the second terminal, and the first terminal, which is on the low voltage side, is grounded,
Thereby, a ground potential is applied to the conductor portion extending from the first terminal. Then, the potential increase gradient of the first pattern portion of the resistor layer from the first terminal to the first high potential difference region on the insulating substrate increases from the first high potential difference region to the second terminal. The potential rise gradient of the second pattern portion of the resistor layer is steeper than that of the second pattern portion of the resistor layer, and as a result,
The potential of the resistor layer is increased as a whole centering on the first high potential difference portion, and the potential difference applied to the insulating film covering the resistor layer is reduced. A conductor portion extending from the first terminal to the second high potential difference site or its vicinity serves as a lightning rod electrode, thereby being located in the vicinity of the conductor portion;
The charging on the surface of the insulating coating on the second high potential difference site and its surroundings is reduced, and the potential difference applied to the insulating coating covering the resistor layer on the second high potential difference site and its surroundings is further reduced. As a result, the potential difference applied to the insulating coating covering the resistor layer does not cause insulation deterioration or breakdown of the insulating coating not only at the first high potential difference site but also at the second high potential difference site, and the cathode ray tube This will prevent a significant change in the resistance value of the resistor layer before and after the knocking treatment. Moreover, since the conductive portion extending from the first terminal to the second high potential difference site or its vicinity is arranged on the insulating substrate without being covered with an insulating film, the neck of the cathode ray tube is Even if discharge occurs from the inner wall of the portion to the conductor portion, the insulating coating will not be destroyed.

G Example G-1 Configuration (FIGS. 1 and 2) FIGS. 1 and 2 show an example of a built-in resistor of a cathode ray tube according to the present invention. Similar to the conventional built-in resistor 7 shown in FIGS. 4 and 5, this example is formed by disposing a voltage dividing resistor layer on an insulating substrate and providing an insulating film to cover this layer. In FIG. 1, the state seen through from above the insulating coating forming the outer surface portion is shown. In addition, in FIGS. 1 and 2, parts corresponding to those shown in FIGS. 4 and 5 are indicated with the same reference numerals as in FIGS. A detailed explanation of is omitted.

In the example shown in FIGS. 1 and 2, a resistive layer 5 for adjustment has a zigzag pattern and is arranged between a CV electrode terminal 3 and a ground electrode terminal 4 on an insulating substrate 1. A resistor layer 5°a with ゛c1 and a resistor layer 5'' disposed between the high voltage electrode terminal 2 and the CV electrode terminal 3.
The voltage dividing resistor layer 5° formed including the resistor layer 52 for adjusting the resistor layers 5a and 5b in the built-in resistor 7 shown in FIGS. 4 and 5 described above is It is provided as a layer corresponding to the voltage dividing resistor layer 5 formed with the fine adjustment resistor layer 5C. Further, on the insulating substrate 1, an insulating coating 6 made of, for example, lead glass is disposed to cover the voltage dividing resistor layer 5''.

For example, the voltage dividing resistor layer 5' has a substantially uniform cross-sectional area,
It is formed as a fired body obtained by firing a uniform resistance material, for example, a high resistance ruthenium oxide paste.

The resistor layer 51a constituting a part of the voltage dividing resistor layer 5° forms a zigzag pattern with a constant meandering width except for the starting end near the ground electrode terminal 4, and on the low voltage side Corresponding to the maximum potential difference position P between a certain ground electrode terminal 4 and the built-in resistor 7 shown in FIGS. Maximum potential difference position P, which is the position where the difference between the surface potential of the insulating coating 6 and the potential of the resistor layer 5''a becomes maximum when assembled and a voltage is applied.
The first pattern portion 5'al, which has a small meandering pitch of the zigzag pattern, is disposed between the maximum potential difference position P'' and the Cv electrode terminal 3 on the high voltage side. The second pattern portion 5'ah is arranged in a zigzag pattern with a large meandering pitch.

In the first pattern portion 5''all, the meandering width of the zigzag pattern is smaller at the starting end portion close to the ground electrode terminal 4 than at other portions.

Since the first pattern portion 5''al and the second pattern portion 5'ah forming the resistor layer 5''a have a zigzag pattern as described above, the insulating substrate 1
The effective length of the first pattern portion 5''al within the unit length between the upper earth electrode terminal 4 and the maximum potential difference position P' is the same as that of the insulating substrate 1 except for the starting end close to the earth electrode terminal 4. It is larger than the effective length of the second pattern portion 5'ah within the unit length between the upper maximum potential difference position P'' and the CV electrode terminal 3, and therefore, between the earth electrode terminal 4 and the maximum potential difference position P'' The resistance value of the resistor layer 51a per unit length is greater than the resistance value of the resistor layer 5+a per unit length between the maximum potential difference position P' and the CV electrode terminal 3. Furthermore, in the area where the starting end of the first pattern portion 5'al close to the ground electrode terminal 4 is arranged, the first pattern portion 5'a7! within the unit length is located within the unit length. The effective length is smaller than the area where other parts of the first pattern portion 5'a1 are arranged, and for example, the effective length between the maximum potential difference position P' and the CV electrode terminal 3
The resistance value per unit length of the resistor layer 51a is about the same as that of the resistor layer 51a.

Further, on the insulating substrate 1, conductive layer portions 20 protruding from both sides of the earth electrode terminal 4 toward the CV electrode terminal 3 side.
a and 20b are provided.

These conductor layer parts 20a and 20b are connected to the high voltage electrode terminal 2.
．． Like the CV electrode terminal 3 and the earth electrode terminal 4, it is obtained by firing a ruthenium oxide paste with extremely low resistance, for example, and is formed integrally with the earth electrode terminal 4. Then, the conductor layer portions 20a and 20
Each of b is formed on the insulating substrate 1 along the starting end of the first pattern portion 5'aA that is close to the earth electrode terminal 4 without contacting the resistor layer 5'a from the earth electrode terminal 4. For example, when the electron gun assembly 9 is incorporated into a color cathode ray tube as shown in FIG. 6 and a voltage is applied, the conductor layer portion 20a between the ground electrode terminal 4 and the maximum potential difference position P'' and extends to or near a high potential difference position Q where the potential difference between the surface of the insulating coating 6 and the first pattern portion 5''al in the resistor layer 5°a is relatively large when there is no 20b. has been done.

Such a high potential difference position Q is located at the second grid electrode G in the electron gun assembly 9 when it is incorporated together with the electron gun assembly 9 in a color cathode ray tube as shown in FIG.
2, and the starting end of the first pattern portion 5'al in the resistor layer 5'a close to the ground electrode terminal 4 extends from the ground electrode terminal 4 to the high potential difference position Q. It is considered a thing. The conductor layer parts 20a and 20b thus arranged on the insulating substrate 1 are
It is assumed that it is exposed on the insulating substrate 1 without being covered with the insulating coating 6.

Potential relationship of each part in the G-2 cathode ray tube (Fig. 3) The built-in resistor shown in Figs. It is attached to the gun assembly 9 in the same manner as the conventional built-in resistor 7, and when a non-king voltage is applied to the high voltage electrode terminal 2 and the earth electrode terminal 4 is grounded during the knocking process of the color cathode ray tube. The surface potential of the insulating film 6 and the potential of each part of the resistor layer 51a are as shown in FIG.

FIG. 3 shows a graph in which the horizontal axis represents the distance from the ground electrode terminal 4 on the insulating substrate 1 to the CVT electrode terminal 3 side, and the vertical axis represents the voltage V. , the potential of each part of the resistor layer 5°a is determined by the first pattern portion arranged between the ground electrode terminal 4 of the resistor layer 5°a and the maximum potential difference position P°, as shown by the curve b'. 5゛a
1, the potential rise gradient from the rear end of the starting end to the maximum potential difference position P° is steep, and the second CV electrode terminal 3 disposed between the maximum potential difference position P
The potential rise gradient from the maximum potential difference position P' to the CV electrode terminal 3 at the pattern portion 5°ah becomes gentle. Therefore, the potential of each part of the resistor layer 5"a is higher than the potential of each part of the resistor layer 5 in the case of the conventional built-in resistor 7, which is shown by the curve in FIG. 7, at the maximum potential difference position P°. As a result, the difference between the surface potential of the insulating coating 6 of the built-in resistor in FIG. 1 and the potential of the resistor layer 5ta, shown by curve a'' in FIG. ,
That is, the potential difference applied to the insulating coating 6 is reduced over the entire insulating coating 6 compared to the case of the conventional built-in resistor 7, and is particularly significantly reduced at the maximum potential difference position P' and its vicinity. That will happen. In the built-in resistor shown in FIG. 1, the resistor is adjusted so that the potential difference applied to the insulating coating 6 is smaller than the withstand voltage limit of the insulating coating 6 at the maximum potential difference position P' where the potential difference is reduced in this way. The effective length of the first patterned portion 5°al and the effective length of the second patterned portion 5°ah of the layer 5″a are selected.

Furthermore, at the starting end of the first pattern portion 5''al of the resistor layer 5°a extending from the ground electrode terminal 4 to the high potential difference position Q, the meandering width of the zigzag pattern is smaller than that at other portions. Therefore, the potential increase gradient is gentler than the potential increase gradient from the rear end of the starting end of the first pattern portion 5°alt to the maximum potential difference position P. 4 to the high potential difference position Q, conductive layer portions 20a and 20b protrude from the grounded earth electrode terminal 4 and are therefore provided with a ground potential near the outside of the insulating coating 6 disposed there. extend from the inner wall of the neck portion of the color cathode ray tube to the conductive layer portions 20a and 20.
Since the state is such that discharge to b is likely to occur, the charge on the surface of the insulating coating 6 is reduced, and the surface potential of the insulating coating 6 is
As shown by the curve a° in FIG. 3, there has been a significant decrease. As a result, the second
An insulating coating 6 covers the resistor layer 5+a at and around the high potential difference position Q corresponding to the grid electrode G.
The potential difference applied thereto is sufficiently reduced, and there is no possibility that the withstand voltage limit of the insulating coating 6 will be exceeded.

Note that the first pattern portion 5'' in the resistor 1i5'a
By making the meandering width of the zigzag pattern smaller than other parts, the starting end of al is designed to prevent discharge from occurring between the conductor layer parts 20a and 20b. It is assumed that sufficient spacing can be obtained. Further, in the range from the ground electrode terminal 4 to the high potential difference position Q, the conductor layer parts 20a and 20b to which the ground potential is applied extend near the outside of the insulating coating 6 disposed there, and play the role of a lightning rod electrode. Therefore, a discharge occurs from the inner wall of the neck portion of the color cathode ray tube to the conductor layer parts 20a and 2ob, but the conductor layer parts 20a and 20b
Since it is arranged without being covered with the insulating film 6 on top,
The insulating coating 6 will not be destroyed due to such discharge.

As described above, in the built-in resistor shown in FIGS. 1 and 2, the same as the conventional built-in resistor 7 can be used in the electron gun assembly 9 of the color cathode ray tube as shown in FIG. In the case where the color cathode ray tube is subjected to knocking treatment, the insulation coating 6 may deteriorate or break at the maximum potential difference position P' on the insulating substrate 1 and also at the high potential difference position Q. As a result, changes in the resistance value of the resistor layer 51a before and after the knocking treatment are suppressed.

H Effects of the Invention As is clear from the above explanation, when the built-in resistor of the cathode ray tube according to the present invention is incorporated together with the electron gun assembly into the tube of the cathode ray tube and a voltage is applied, The potential of the resistor layer arranged in a zigzag pattern between the first terminal on the low voltage side and the second terminal on the high voltage side is transferred from the first terminal to the second terminal on the insulating substrate. The rising slope toward the first high potential difference region formed between the first terminal and the second terminal is made steep;
The potential difference between the surface potential of the insulating coating covering the resistor layer on the insulating substrate and the potential of the resistor layer is significantly reduced, especially at the first high potential difference site, and The second terminal is located relatively close to the first terminal.
In areas with high potential difference and in the vicinity thereof, a conductive part that serves as a lightning rod electrode is arranged on the insulating substrate, reducing the charge on the insulating film covering the resistor layer, and reducing the surface potential of the insulating film and the resistor. Since the potential difference between the layer potential and the potential of the cathode ray tube is sufficiently reduced, when a high voltage is applied during the non-king process of the cathode ray tube, both the first and second high potential difference parts There is no hole that could cause insulation deterioration or breakdown of the insulation coating. In addition, the conductor portion, which plays the role of a lightning rod electrode that reduces the potential difference between the surface potential of the insulating coating and the potential of the resistor layer at the second high potential difference site and its vicinity, has a resistor layer on the insulating substrate. Since it is arranged without being covered by the insulating film covering the resistor layer, even if a discharge occurs against it, there is no risk that the insulating film covering the resistor layer will be damaged by the discharge, thus preventing knocking of the cathode ray tube. Even when a high voltage is applied during processing, it exhibits an excellent property of minimizing changes in the resistance value of the resistor layer.

In addition, in order to prevent insulation deterioration or breakdown of the insulating coating, methods such as increasing the thickness of the insulating coating are not taken, so overall warping and insulation due to the difference in thermal expansion coefficient between the insulating substrate and the insulating coating are not taken. It has the advantage that it does not have the disadvantage of peeling of the coating from the insulating substrate, and can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of a built-in resistor of a cathode ray tube according to the present invention, FIG. 2 is a side view of the example shown in FIG. 1, and FIG.
Figure 4 is a characteristic diagram used to explain the potential relationship in each part when the example shown in Figure 1 is incorporated into a cathode ray tube.
5 and 5 are plan and side views showing the built-in resistor of a conventional cathode ray tube, and FIG. 6 shows the main part of the cathode ray tube in which the built-in resistor shown in FIGS. 4 and 5 is incorporated. The schematic configuration diagram, FIG. 7, is a characteristic diagram used to explain the potential relationship related to the built-in resistor in the cathode ray tube shown in FIG. In the figure, 1 is an insulating substrate, 2 is a high-voltage electrode terminal, 3 is a convergence electrode terminal, 4 is a ground electrode terminal, 5 and 5゛ are voltage-dividing resistor layers, and 5'a is a voltage-dividing resistor layer 5'. 5'al is the first pattern part, 5'ah is the second pattern part.
, 6 is an insulating coating, 9 is an electron gun structure, 20a
and 20b are conductor layer parts. Plan view of the embodiment Fig. 2 1° insulating substrate 5'a = partial voltage resistor fault 3° convergence electrode terminal 6 ゛Insulating laminated layer 4
: Earth electrode terminal 20a, 20b: Conductor layer part Fig. 6

Claims (1)

[Scope of Claims] An insulating substrate, a plurality of electrode terminals formed on the insulating substrate, a first terminal on the low voltage side of the plurality of electrode terminals on the insulating substrate, and a first terminal on the high voltage side. a resistor layer disposed in a zigzag pattern between the first terminal and the second terminal on the insulating substrate;
an insulating coating provided between the first terminal and the resistor layer so as to cover the resistor layer; and a conductor portion provided to protrude from the first terminal without contacting the resistor layer. The resistance value per unit length of the resistor layer in the direction connecting the first terminal and the second terminal is the potential difference between the first and second terminals and the surface of the insulating coating. The first pattern portion of the resistor layer between the first high potential difference region and the first terminal, where the potential difference is to be large, A second pattern portion of the resistor layer between the resistor layers is smaller, and the conductor portion is disposed on the insulating substrate to connect the first terminal to the first pattern portion of the resistor layer. Along the pattern portion, the potential difference between the first terminal and the first high potential difference portion and the surface of the insulating coating is relatively large when the conductor portion is not present. A built-in resistor for a cathode ray tube, characterized in that the built-in resistor extends to or near a second high potential difference site and is not covered by the insulating film.