JPS61116735A - Built-in resistor of cathode ray tube - Google Patents

Abstract

PURPOSE:To suppress a change of resistance value of a resistor layer before and after knocking treatment to the minimum by providing a conductive layer part connected to a terminal on the low pressure side on a high potential difference part on an insulation substrate. CONSTITUTION:A conductive layer part 20 is not connected to a resistor layer 5a' and a U-shaped conductive connection part 22 while being connected to an earthing electrode terminal 4 through a connection part 21. And these partial pressure resistor layer 5' and the conductive layer part 20 are coated with an insulating film 6. When knocking voltage is to be impressed on a high pressure electrode terminal 2, an electric charge amount in the surface part of the insulating film 6 corresponding to the high potential difference part including the largest potential difference position is reduced when the conductive layer part 20 is made to be of earthing potential thus suppressing a rise of surface potential. Thereby, insulation deterioration or damage of an insulating film is prevented to be generated thus being able to suppress a change of resistance value of the resistor layer before and after knocking treatment to the minimum.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a built-in resistor that is incorporated together with an electron gun into a tube such as a color cathode ray tube.

2. Description of the Related 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 cases, it has been proposed to incorporate a resistor for voltage division into the tube together with the electron gun as a built-in resistor, thereby dividing the anode voltage to obtain the respective high voltages. As an example of a conventional built-in resistor, those shown in FIGS. 3 and 4 are known.

FIG. 3 shows the conventional built-in resistor 7 seen through from above the insulating coating forming the outer surface, and FIG. 4 shows a side view of the entire conventional built-in resistor 7. The built-in resistor 7 shown in FIGS. 3 and 4 includes a terminal portion formed by depositing a conductive layer on an insulating substrate 1 such as a ceramic plate,
That is, the high voltage electrode terminal 2 to which the anode voltage of the cathode ray tube is supplied.
．． A convergence electrode terminal (hereinafter referred to as CV electrode terminal) 3 and a ground electrode terminal 4 from which a high voltage for the convergence electrode, that is, a convergence voltage can be obtained, and a ground electrode terminal 4 are provided, and between the CV electrode terminal 3 and the ground electrode terminal 4, , a resistor layer 5a having a zigzag pattern having a required resistance value, a resistor layer 5b having the same required resistance value between the high voltage electrode terminal 2 and the CV electrode terminal 3; A resistor layer 5c for fine adjustment is deposited between the layers 5a and 5b and the CV electrode terminal 3, respectively, to form a voltage dividing resistor layer 5. And in the shaded area in Figure 3,
An insulating coating 6 made of lead glass or the like is applied to cover the voltage dividing resistor layer 5. Note that by removing a portion of the fine adjustment resistor layer 5c during the manufacturing process of the built-in resistor 7, the resistance value of the resistor layers 5a and 5b between each terminal can be adjusted. It is provided.

FIG. 5 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 of the cathode ray tube.
This electron gun assembly 9 includes a first grid electrode G1, a second grid electrode G2 . A third grid electrode G3, a fourth grid electrode G4, and a fifth grid electrode G5 are arranged coaxially in this order.

A convergence means 10 is arranged after the fifth grid electrode G5. Each electrode Gl, G2.
G3. G4 and G5 and convergence means 10
are mechanically connected by a 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. . Further, the convergence means 1° connects the fifth grid electrode G5 via the conductive plate 14.
inner deflection electrode plates 10a that are electrically connected to and face each other;
and 10b, and these inner deflection electrode plates 10a on the outside thereof.
and an outer deflection electrode plate 10c disposed opposite to 10b.
and 10d.

A built-in resistor 7 as shown in FIGS. 3 and 4 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 group 1. A conductive attachment is connected to the electrode G5 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 in the funnel portion 8b Anode voltage is supplied through the The conductive plate 14 is provided with a conductive spring 16, and when the conductive spring 16 contacts the graphite conductive film 15, the fifth grid electrode G5, the third grid electrode G3, . An anode voltage is supplied to the inner deflection electrode plate 10 a and the fob of the convergence means 10 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 conductive mounted on the piece 17.
through the outer deflection electrode plate 10 of the convergence means lO
c and 10d, and a convergence voltage obtained by dividing the anode voltage by the resistor layers 5a and 5b is connected to the CV electrode terminal 3, and is connected to the outer deflection electrode plate 10C and lOd.
supplied to

Also, the ground electrode terminal 4 of the built-in resistor 7 is connected to the ground electrode terminal pin 9 embedded through the stem 18 at the base of the neck part 8a of the tube body 8, and the resistor is connected directly or externally for adjustment. connected to ground potential point via.

If such a cathode ray tube has, for example, sharp protrusions on various parts of the electron gun assembly 9, undesirable discharge will occur during actual use.

Therefore, in the manufacturing process of cathode ray tubes, parts of the electron gun assembly 9 that are likely to generate electrical discharges, such as sharp protrusions, are melted and shaped by generating electrical discharge in advance, so that they can be melted and shaped before actual use after the finished product. Knocking processing is performed for the purpose of stabilizing the operation of the engine.

In such a knocking treatment process, for example, a high voltage (knocking voltage) that is two to three times higher than that during actual operation of the cathode ray tube is applied to the third grid electrode G3, the fifth grid electrode G5, and the built-in resistor 7. The voltage is applied to the high voltage electrode terminal 2 of the first . Each of the second and fourth grid electrodes G1.
G2 and G4, and the ground electrode terminal 4 of the built-in resistor 7
is considered to be 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, and in particular, the voltage dividing resistor layer 5 is formed on this insulating coating 6. On the low voltage side of the resistor layer 5a,
A larger potential difference will be applied than during actual operation. 6th
In the figure, the horizontal axis shows C, which is the high voltage side, from the ground electrode terminal 4, which is the low voltage side, on the insulating substrate 1 of the built-in resistor 7.
Taking the distance to the V electrode terminal 3 side and plotting the potential V on the vertical axis, the surface potential (curve a) of the insulating coating 6 of the built-in resistor 7 during knocking treatment, the ground electrode terminal 4 and the CV electrode terminal 3 The potential of each part of the resistor layer 5a disposed between the curve b (curve b) and the difference between the two potentials (curve mc) are shown. As is clear from this, the third electrode on the insulating substrate 1 to which a high voltage is applied
10r"1°°"'"*-ro, t"
tjc41F-N 5 a h1''11' The potential difference with the surface of the film 6 becomes maximum, and therefore, the maximum potential difference is applied to the insulating coating 6 at this position (maximum potential difference position). In the vicinity of the third grid electrode G3, a potential exceeding the withstand voltage of the insulating coating 6 is applied, causing insulation deterioration or breakdown of the insulating coating 6, and as a result, the resistor layer 5a is damaged and its resistance value changes significantly. There is a risk.

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, for the built-in resistor 7, increasing the thickness of the insulating coating 6 unnecessarily is disadvantageous in terms of cost. Warping of the entire device 7 occurs, 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, as described in Japanese Patent Application Laid-Open No. 58-102455, in order to deal with the above-mentioned problem, a grounding layer, which is considered to be a low-voltage side, is provided on the surface of an insulating coating covering a resistor layer disposed on an insulating substrate. Built-in resistors have also been proposed with a lightning rod electrode connected to the electrode terminal.

When such a built-in resistor is attached to an electron gun of a cathode ray tube and subjected to knocking processing, the lightning rod electrode provided on the surface of the insulation coating reduces the electrical charge on the surface of the insulation coating, and as a result, Insulation deterioration or breakdown of the insulating coating is prevented, and changes in the resistance value of the resistor layer disposed between the ground electrode terminal and the convergence electrode terminal on the insulating substrate before and after the non-king treatment are suppressed.

Problems to be Solved by the Invention However, in the built-in resistor equipped with a lightning rod electrode as described above, since the lightning rod electrode is provided on the surface of the insulating coating, it is difficult to form the insulating coating by printing. In addition, during the knocking process, the metal material forming the lightning rod electrode evaporates and adheres to the inner wall of the neck of the tube body of the cathode ray tube, and as a result, the metal material adhering to the inner wall of the neck and the neck The disadvantage is that there is a risk of cracking in the neck section due to the difference in coefficient of thermal expansion between the neck section and the neck section.

In view of this, the present invention has a structure in which a resistor layer having a predetermined pattern is formed on an insulating substrate, and this resistor layer is covered with an insulating film, so that it can be used during knocking treatment of a cathode ray tube, etc. It is also possible to effectively reduce the change in the resistance value of the resistor layer at high potential difference areas on the insulating substrate, and as a result, the change in the resistance value of the entire resistor layer before and after non-king treatment can be minimized. Moreover, it is an object of the present invention to provide a built-in resistor for a cathode ray tube that does not increase manufacturing costs or complicate the manufacturing process, and is free from the risk of damaging the neck of the cathode ray tube. shall be.

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 has a plurality of electrode terminals on an insulating substrate and a low voltage side of these electrode terminals. A resistor layer arranged in a predetermined pattern between the first terminal and the second terminal on the high voltage side, and the above-mentioned first resistor layer arranged without contacting this resistor layer. A conductor layer connected to the terminal is formed, and an insulating coating is provided to cover the resistor layer and the conductor layer. The above-mentioned conductor layer portion is such that when there is no conductor layer portion on the insulating substrate, there is a large difference between the surface potential of the insulating coating and the potential of the portion between the first and second terminals. It is assumed that the device is placed at a high potential difference site.

Function: The built-in resistor of the cathode ray tube according to the present invention configured as described above is incorporated in the cathode ray tube together with the electron gun, and when the cathode ray tube is subjected to non-king treatment, for example, the resistor is installed on the high voltage side. A high knocking voltage is supplied to the second terminal, and the first terminal, which is on the low voltage side, is grounded, so that the conductor layer connected to the first terminal is given a ground potential. Therefore, at the position of this conductor layer, that is, when there is no conductor layer on the insulating substrate, there is a large difference between the surface potential of the insulating coating and the potential of the area between the first and second terminals. The increase in the surface potential of the insulating coating at the high potential difference site is suppressed, and the potential difference between the surface of the insulating coating and the insulating substrate at the high potential difference site, that is, the potential difference applied to the insulating coating is reduced. .

Therefore, even under conditions where high voltage is applied during the knocking treatment of cathode ray tubes, insulation deterioration or breakdown of the insulation coating is effectively avoided, and as a result, the resistance value of the resistor layer before and after the knocking treatment is reduced. Changes are kept to a minimum.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows 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. 3 and 4, this example is formed by providing a voltage dividing resistor layer and an insulating film covering this on an insulating substrate. , the state seen through from above the insulating coating forming the outer surface portion is shown. In addition, in FIG. 1, the parts corresponding to the parts shown in FIGS. 3 and 4 are shown in FIGS. 3 and 4.
They are shown with the same reference numerals as those in the figures, and detailed explanation thereof will be omitted.

In the example shown in FIG. 1, the resistor layer 5b and fine adjustment shown in FIG. Resistor layer 5b° and fine adjustment resistor layer 5 similar to resistor layer 5c for
c”, which corresponds to the resistor layer 5a shown in FIG. 3 and arranged between the CV electrode terminal 3 and the earth electrode terminal 4,
A U-shaped conductive connection part 22 interposed in a part of it
A voltage dividing resistor layer 5' is provided, which is formed by resistors N5a' arranged in a zigzag pattern having a constant meandering width. Moreover, between the CV electrode terminal 3 and the earth electrode terminal 4 on the insulating substrate 1,
High voltage electrode terminal 2. CV electrode terminal 3 and earth electrode terminal 4
Similarly, for example, the conductor layer portion 20 formed by firing a ruthenium oxide paste with extremely low resistance,
It is arranged at a position corresponding to the U-shaped conductive connection part 22 interposed in a part of the resistor layer 5a''.

This conductor layer portion 20 does not contact the resistor layer 5 a+ and the U-shaped conductive connection portion 22, but is connected to the ground electrode terminal 4 via the connection portion 21 extending therefrom. The voltage dividing resistor layer 5' and the conductor layer 20 are covered with an insulating film 6 made of, for example, lead glass, as shown by diagonal lines in FIG.

Here, the voltage dividing resistor N5' has a uniform cross-sectional area except for the part of the conductive connection part 22, and is made of a uniform material, for example,
It is formed by firing a high-resistance ruthenium oxide paste, and the respective divided portions are connected to each other by conductive connecting portions 22.

The above-mentioned conductive connection portion 22 and conductor layer portion 20 correspond to the maximum potential difference position P in the built-in resistor 7 shown in FIG. 3, and the example shown in FIG. It is assumed that when the cathode ray tube is assembled into a cathode ray tube such as the one shown in FIG. In this case, the maximum potential difference position P' is the position where the potential difference between the surface potential of the insulating coating 6 and the potential between the earth electrode terminal 4, which is the low voltage side, and the CV electrode terminal 3, which is the high voltage side, is maximum. , and is arranged at a high potential difference site where such potential difference is large.

The example shown in FIG. 1 having such a structure is attached to the electron gun assembly 9 of a cathode ray tube as shown in FIG. When the ground electrode terminal 4 is connected to the conductor layer 20, it is connected to the ground electrode terminal pin 19 and grounded as shown in FIG. 5, and a knocking voltage is applied to the high voltage electrode terminal 2. In this case, by setting the conductive layer portion 20 disposed at a high potential difference site including the maximum potential difference position P'' on the insulating substrate 1 to the ground potential, it corresponds to the high potential difference site including the maximum potential difference position P''. The amount of charge t on the surface portion of the insulating coating 6 is reduced, and an increase in the surface potential at a portion of the insulating coating 6 corresponding to a high potential difference site including the maximum potential difference position P' is suppressed.

A cathode ray tube equipped with an electron gun having the example shown in FIG. 1 is subjected to knocking treatment, the earth electrode terminal 4 is grounded, and the built-in resistor 7 shown in FIG. The surface potential of the insulating coating 6 and the resistor layer 5a when the same knocking voltage as in the case of is supplied
The potential at each part of ' is as shown in FIG.

In the graph of FIG. 2, the distance from the ground electrode terminal 4 on the insulating substrate 1 to the CV electrode terminal 3 side is plotted on the horizontal axis.
The vertical axis represents the potential V. In the graph of FIG. As a result of the reduction in the amount of charge on the surface, the rise in potential at the portion corresponding to the high potential difference site including the maximum potential difference position P' becomes gradual. In addition, the resistor layer 5
The potential of each part of aI is shown by a broken line b', and has a constant potential at a high potential difference site including the maximum potential difference position P° where the conductive connection part 22 is interposed. The difference between the potential of each part of the resistor layer 5a' and the corresponding surface potential of the insulating coating 6, that is, the potential difference applied to the insulating coating 6, is represented by a curve C'', and the height including the maximum potential difference position P'' is At the potential difference site, the increase in the surface potential of the insulating coating 6 is suppressed under the influence of the conductive layer portion 2.0 set to the ground potential, so that the increase in the surface potential of the insulating coating 6 at the maximum potential difference position P in the case of the conventional built-in resistor 7 is suppressed. This will be significantly reduced compared to the potential difference.

In this way, in the example shown in FIG. 1, the increase in the surface potential of the insulating coating 6 at a high potential difference location including the maximum potential difference position P' on the insulating substrate 1 is suppressed, and the insulating coating 6 is Since the potential difference applied thereto can be reduced, insulation deterioration or breakdown of the insulating coating 6 will not occur, and significant changes in the resistor layer 5a' will be prevented.

Furthermore, even if a discharge occurs at a high potential difference site including the maximum potential difference position P' on the insulating substrate 1, the discharge current will easily flow through the conductor layer portion 20, and the probability that the resistor layer 5aI will be affected by the discharge is considered to be extremely low.

In addition, in the above-described example of the built-in resistor of the cathode ray tube according to the present invention, the conductor layer portion 2 connected to the ground electrode terminal 4
0 is formed by firing a low-resistance ruthenium oxide paste, for example, and this conductor layer portion 20 is formed of a resistive material having a resistance value lower than the resistance value of the voltage-dividing resistor layer 5°. In such a case, the maximum potential difference position P on the insulating substrate 1 during non-king processing of the cathode ray tube, etc.
When a discharge occurs in a high potential difference site including ゛, the discharge current flowing through the conductor layer portion 20 can be reduced.

Effects of the Invention As is clear from the above description, the built-in resistor of the cathode ray tube according to the present invention has a first terminal which is installed on the low voltage side when the cathode ray tube is assembled together with the electron gun and is in a voltage application state; A conductor layer connected to the first terminal, which is considered to be a low voltage side, is disposed on an insulating substrate between second terminals, which are considered to be high voltage side, and its position is such that there is no such conductor layer. In some cases, the area is selected as a high potential difference area where the difference between the surface potential of the insulating film covering the resistor layer arranged on the insulating substrate and the potential of the area between the first terminal and the second terminal is large. Therefore, an increase in the surface potential of the insulating coating is suppressed at such a high potential difference site, and as a result, the potential difference applied to the insulating coating is effectively reduced.

Therefore, even under conditions where high voltage is applied during knocking treatment of cathode ray tubes, the potential difference applied to the insulating coating at the high potential difference area will not exceed the withstand voltage of the insulating coating, and insulation deterioration or breakdown of the insulating coating will not occur. This exhibits an excellent property of suppressing to a minimum the change in resistance value of the resistor layer before and after the knocking treatment.

Moreover, since the structure is not such that a metal conductor such as a lightning rod electrode is provided on the surface of the insulating coating, the metal conductor bulges out and adheres to the inner wall of the neck of the tube body of the cathode ray tube, which causes 2 There is no risk of causing an accident in which the neck portion cracks.

Furthermore, since it is easy to form a conductor layer on an insulating substrate, it does not complicate the manufacturing process and has the advantage that it can be manufactured at low cost. There is.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of a built-in resistor of a cathode ray tube according to the present invention, and FIG. 2 is an illustration of potential relationships in various parts when the example shown in FIG. 1 is incorporated into a cathode ray tube. Figures 3 and 4 are plan and side views showing the built-in resistor of a conventional cathode ray tube, and Figure 5 is a cathode ray tube incorporating the built-in resistor shown in Figures 3 and 4. FIG. 6 is a characteristic diagram for explaining the potential relationship at each part of 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'' is a voltage dividing resistor layer, and 5 al is a resistor constituting the voltage dividing resistor layer 5''. 6 is an insulating coating, 9 is an electron gun structure, 20 is a conductive layer portion, and 21 is a connection portion.

Claims (1)

[Claims] A plurality of electrode terminals are arranged on the insulating substrate in a predetermined pattern between a first terminal on the low voltage side and a second terminal on the high voltage side among the electrode terminals. a resistor layer, and the first resistor layer disposed without contacting the resistor layer.
A conductive layer portion connected to the terminal of the insulating substrate is formed, and an insulating coating is provided to cover the resistor layer and the conductive layer portion, and the conductive layer portion is connected to the terminal of the insulating substrate. It is characterized in that it is arranged in a high potential difference region where the difference between the surface potential of the insulating coating and the potential of the region between the first and second terminals is large when the conductor layer portion is not present. Built-in resistor of cathode ray tube.