JP3297769B2 - Manufacturing method of cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a cathode ray tube, and more particularly, to a method for manufacturing a cathode ray tube characterized by a knocking process.

[0002]

2. Description of the Related Art In recent years, with the increase in the size and performance of cathode ray tubes, the demand for focus characteristics of cathode ray tubes has increased. Therefore, many methods for reducing the spherical aberration in the electron lens of the cathode ray tube have been adopted. One of the conventional techniques is to provide an auxiliary electrode on an electron gun of a cathode ray tube, connect the auxiliary electrode to a built-in resistor for voltage division, and apply a high voltage to one end of the built-in resistor. High voltage that could not be supplied from the part is applied to the auxiliary electrode,
There is a method of expanding the electric field of the electron lens unit.

FIG. 3A is a conceptual diagram of a single main lens type electron gun portion of a cathode ray tube having no built-in resistor for voltage division. FIG. 3C is a conceptual diagram of an electric field expansion type electron gun having a built-in resistance for voltage division. In FIG.
K is a cathode, G1 is a first grid electrode, G2 is a second grid electrode, G3 is a third grid electrode, G4 is a fourth grid electrode, and CV is a convergence electrode. Also, 12
Is an internal resistor for voltage division, and 10 is an auxiliary electrode connected to a part of the internal resistor 12. The built-in resistor 12 for voltage division
It consists of a resistance pattern formed on the insulating substrate 16. Each of the third grid electrode G3, the fourth grid electrode G4, and the auxiliary electrode 10 corresponds to a focus part electrode, and these form a focus part. By providing the auxiliary electrode 10, an extended lens is formed, and the aperture of the electronic lens is increased. The cathode K, the first grid electrode G1, the second grid electrode G2, the third grid electrode G3, and the fourth grid electrode G4 are supported by a bead glass support (not shown).

If a sharp projection or the like exists on each grid electrode or the like constituting an electron lens, abnormal discharge may occur during operation of the cathode ray tube. In order to prevent such abnormal discharge, a knocking process is performed in the process of manufacturing the cathode ray tube. In the knocking process, a discharge is generated in advance in a portion where a discharge is likely to occur, such as a sharp protrusion of each grid electrode, and the protrusion is melted and removed. FIGS. 3B and 3D show the third CRT.
Grid electrode G3, fourth grid electrode G4 and auxiliary electrode 1
An example of a voltage at the time of actual operation of the cathode ray tube and a knocking voltage applied to 0 is shown. Note that the knocking voltage refers to a voltage applied to each electrode during the knocking process.

During operation of the cathode ray tube, a fourth grid electrode G4 is connected through an anode button and an interior carbon (not shown).
Is applied with a high anode voltage. Further, a voltage is applied to the third grid electrode G3 through, for example, a stem portion (not shown). Further, a voltage (for example, 65% of the anode voltage) obtained by dividing the anode voltage applied to the fourth grid electrode G4 by the internal resistor 12 for voltage division is applied to the auxiliary electrode 10.

[0006]

In the cathode ray tube having no built-in voltage dividing resistor shown in FIG.
Since the difference in knocking voltage between the fourth grid electrode G4 and the third grid electrode G3 is as large as 50 kV, the protrusions and the like can be melted and removed by the knocking process.

However, in the cathode ray tube having the built-in voltage dividing resistor 12 shown in FIG. 3C, the knocking voltage difference between the fourth grid electrode G4 and the auxiliary electrode 10 is, for example, only 17.5 kV. Absent. Therefore, even if the knocking process is performed, there is a problem that the projections and the like do not melt and the projections and the like cannot be removed.

Accordingly, an object of the present invention is to provide a method of manufacturing a cathode ray tube having a built-in resistor for voltage division and an electron gun having a focus unit electrode connected to the built-in resistor, which can perform an effective knocking process. Is to do.

[0009]

The object of the present invention is to provide a cathode line including a knocking process between a focus portion electrode connected to a built-in resistor for voltage division and focus portion electrodes provided before and after the focus portion electrode. A method for manufacturing a tube, wherein (a) a focus portion electrode connected to a built-in resistor for voltage division is grounded in advance by a short circuit, and is provided before and after the focus portion electrode and the focus portion electrode. Performing a knocking process with one of the focus unit electrodes, and (b) disconnecting a short circuit.
(C) a step of performing a knocking process between a focus portion electrode connected to a built-in resistor for voltage division and the other of the focus portion electrodes provided before and after the focus portion electrode. This can be achieved by the method for manufacturing a cathode ray tube according to the invention.

The steps (a) and (b) can be repeated a desired number of times depending on the structure of the electron gun.

[0011]

According to the present invention, first, a knocking process is performed between a focus portion electrode connected to a built-in resistor for voltage division and one of focus portion electrodes provided before and after the focus portion electrode. At this time, the focus unit electrode connected to the internal resistor for voltage division is grounded by the short circuit. Therefore, the potential of the focus portion electrode is substantially 0 V, and the difference in knocking voltage between the focus portion electrode and one focus portion electrode is substantially equal to the voltage applied to one focus portion electrode. That is, a knocking process can be performed by a large knocking voltage difference, and a knocking process having a sufficient effect can be performed.

After the knocking process is completed, the short circuit is cut off, and then the focus unit electrode connected to the built-in resistor for voltage division and the other of the focus unit electrodes provided before and after the focus unit electrode are connected. The knocking process is performed between them. The focus section electrode connected to the built-in resistor
The voltage divided by the internal resistor for voltage division is applied. If the other focus portion electrode is grounded, the divided voltage corresponds to the knocking voltage difference, and a knocking process having a sufficient effect can be performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1A is a conceptual view of a part of an electric field expansion type electron gun having a built-in resistance for voltage division, which is suitable for manufacturing by the method of manufacturing a cathode ray tube according to the present invention. Show. However, FIG. 1A shows a state before a short circuit described later is cut. The electric field expansion type electron gun includes a cathode K, a first grid electrode G1, a second grid electrode G2, a third grid electrode G3, a fourth grid electrode G4, and a convergence electrode CV. Cathode K, first grid electrode G1-
The fourth grid electrode G4 is fixed to a support (not shown) made of bead glass.

This electron gun is provided with an auxiliary electrode 10 and a built-in resistor 12 for voltage division. Built-in resistor for voltage division 1
2 is formed on an insulating substrate 16 made of, for example, alumina, and printed in a zigzag form with a resistance paste in which a conductive material such as ruthenium oxide is mixed into an insulating material such as lead glass, and dried and fired. Can be formed. An anode voltage is applied to one end of the built-in resistor 12. The other end of the built-in resistor 12 is grounded.

The auxiliary electrode 10 is electrically connected to a part of the internal resistor 12 for voltage division. The auxiliary electrode 10 corresponds to a focus unit electrode connected to a built-in resistor for voltage division. The third grid electrode G3 and the fourth grid electrode G4 correspond to focus section electrodes provided before and after the focus section electrode connected to the internal resistor. These form a focus unit.

The focus section electrode (auxiliary electrode 10) connected to the internal resistor for voltage division is grounded by a short circuit 14. The short circuit 14 is also formed on the insulating substrate 16, and, like the built-in resistor 12, for example, a resistance paste in which a conductor material such as ruthenium oxide is mixed into an insulating material such as lead glass is printed, dried, and fired. Can be formed by The auxiliary electrode 10 may be grounded via a part of the internal resistor 12 and the short circuit 14.

During operation of the cathode ray tube, the fourth grid electrode G4 is connected through the anode button and the interior carbon (not shown).
Is applied with a high anode voltage. Further, a voltage is applied to the third grid electrode G3 through, for example, a stem portion (not shown). Further, a voltage (for example, 65% of the anode voltage) obtained by dividing the anode voltage applied to the fourth grid electrode G4 by the internal resistor 12 for voltage division is applied to the auxiliary electrode 10.

Hereinafter, details of the knocking process in the first embodiment will be described.

[First Stage Knocking Process] In the electron gun in the state shown in FIG. 1A, first, a first stage knocking process is performed. That is, the focus portion electrode (auxiliary electrode 10) connected to the internal resistor 12 for voltage division is grounded by the short circuit 14, and the focus portion electrode (auxiliary electrode 10) and the focus portion electrode are provided before and after the focus portion electrode. A knocking process is performed with one of the focus unit electrodes (the fourth grid electrode G4 in the first embodiment).

Since the auxiliary electrode 10 is grounded by the short circuit 14, the potential of the auxiliary electrode 10 is almost 0V. A high voltage, for example, 50 kV, is applied to the fourth grid electrode G4 through the anode button and the interior carbon. That is, in the knocking process of the first stage, the difference between the knocking voltages is 50 kV. Therefore, a knocking process can be performed by a large knocking voltage difference,
A knocking process having a sufficient effect can be performed. FIG. 1B shows the value of the knocking voltage in the knocking process of the first stage.

[Step of Cutting Short-Circuit Circuit] Thereafter, as shown in FIG. 1C, the short-circuit circuit 1 is cut using a laser, for example.
Cut 4

[Second Stage Knocking Process] Next, the focus portion electrode (auxiliary electrode 10) connected to the internal resistor for voltage division and the other of the focus portion electrodes provided before and after this auxiliary electrode 10 (embodiment) In No. 1, a knocking process is performed with the third grid electrode G3).

During the knocking process of the second stage, a voltage, for example, 32.5 kV, which is divided by the internal resistor 12 for voltage division, is applied to the auxiliary electrode 10. If the other focus portion electrode (third grid electrode G3) is grounded, the divided voltage corresponds to the difference in knocking voltage,
A knocking process having a sufficient effect can be performed. The value of the knocking voltage in the knocking process of the second stage is shown in FIG.

(Embodiment 2) FIG. 2A shows an electric field expansion type having a built-in resistance for voltage division slightly different from that of Embodiment 1 and suitable for manufacturing by the method of manufacturing a cathode ray tube of the present invention. FIG. 2 shows a conceptual diagram of a part of an electron gun. In Example 2,
The first auxiliary electrode 10A and the second auxiliary electrode 10B are provided between the third grid electrode G3 and the fourth grid electrode G4. Each of the third grid electrode G3, the fourth grid electrode G4, and the first and second auxiliary electrodes 10A and 10B corresponds to a focus part electrode, and these form a focus part.

The first auxiliary electrode 10A is electrically connected to a part of the internal resistor 12, and is grounded by a first short circuit 14A. Second auxiliary electrode 10B
Similarly, is electrically connected to a part of the built-in resistor 12, and is grounded by the second short circuit 14B. FIG. 2A shows these short circuits 14A and 14B.
Shows the state before cutting. The built-in resistor 12 and the first and second short circuits 14A and 14B can have the same structure as in the first embodiment. The first and second auxiliary electrodes 10A,
10B may be grounded via a part of the internal resistor 12 and the first and second short circuits 14A and 14B.

When the first auxiliary electrode 10A is regarded as a focus portion electrode connected to the internal resistor for voltage division, the third grid electrode G3 and the second auxiliary electrode 10B are connected to the focus portion connected to the internal resistor. Electrode (first auxiliary electrode 10
It corresponds to the focus section electrodes provided before and after A).
When the second auxiliary electrode 10B is regarded as a focus electrode connected to the internal resistor for voltage division, the fourth grid electrode G4 and the first auxiliary electrode 10A are connected to the focus electrode connected to the internal resistor. It corresponds to the focus section electrodes provided before and after (the second auxiliary electrode 10B).

During operation of the cathode ray tube, a fourth grid electrode G4 is connected through an anode button and an interior carbon (not shown).
Is applied with a high anode voltage. Further, a voltage is applied to the third grid electrode G3 through, for example, a stem portion (not shown). Further, a voltage obtained by dividing the anode voltage applied to the fourth grid electrode G4 by the internal resistor 12 for voltage division is applied to each of the first and second auxiliary electrodes 10A and 10B.

Hereinafter, details of the knocking processing in the second embodiment will be described.

[First Stage Knocking Process] In the electron gun in the state shown in FIG. 2A, first, a first stage knocking process is performed. That is, the second short circuit 14B
Thus, the focus portion electrode connected to the internal resistor 12 for voltage division (in this first-stage knocking process,
The second auxiliary electrode 10B) is grounded, and the focus portion electrode (the second auxiliary electrode 10B) and one of the focus portion electrodes provided before and after the focus portion electrode (the first stage knocking process). , A knocking process is performed with the fourth grid electrode G4).

The second auxiliary electrode 10B is connected to the second short circuit 1
4B, the second auxiliary electrode 10
The potential of B is almost 0V. A high voltage is applied to the fourth grid electrode G4 through the anode button and the interior carbon. That is, in the knocking process of the first stage,
The knocking voltage is a high voltage applied to the fourth grid electrode G4. Therefore, a knocking process can be performed with a large knocking voltage difference, and a knocking process having a sufficient effect can be performed.

[Second Short Circuit Cutting Step] Thereafter, as shown in FIG. 2B, the second short circuit 14B is cut using, for example, a laser.

[Second-stage knocking process] Next, a focus portion electrode (first auxiliary electrode 10A) connected to the internal resistor for voltage division and one of the focus portion electrodes provided before and after the auxiliary electrode 10 are provided. (In the second-stage knocking process, a knocking process is performed with the second auxiliary electrode 10B).

At the time of the knocking process in the second stage, since the first short circuit 14A has not been cut yet, the focus part electrode (first auxiliary electrode 10A) connected to the internal resistor for voltage division is the first one. It is grounded by the short circuit 14A, and its potential is almost 0V. Also, already the second
Since the short circuit 14B is cut off, a high voltage divided by the internal resistor 12 for voltage division is applied to one focus portion electrode (second auxiliary electrode 10B). Therefore, the high voltage applied to the second auxiliary electrode 10B corresponds to the difference between the knocking voltages, and a knocking process having a sufficient effect can be performed.

[Step of Cutting First Short Circuit] Then, as shown in FIG. 2C, the second short circuit 14B is cut using, for example, a laser.

[Third Stage Knocking Process] Next, the focus portion electrode connected to the internal resistor for voltage division (in this third stage knocking process, the first auxiliary electrode 1
0A) and the other of the focus portion electrodes provided before and after the first auxiliary electrode 10A (the third grid electrode G3 in the third stage knocking process) is knocked.

At the time of the knocking process in the third stage, since the first short circuit 14A has already been cut, a high voltage divided by the internal resistor 12 for voltage division is applied to the first auxiliary electrode 10A. Is done. If the other focus portion electrode (third grid electrode G3) is grounded, a high voltage applied to the first auxiliary electrode 10A corresponds to a difference in knocking voltage, and a knocking process having a sufficient effect can be performed. Can be.

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments. The structure of the electron gun, various numerical values, values of the knocking voltage, and the like described in the embodiments are merely examples, and can be changed as appropriate. Further, a method of applying a voltage to each electrode can be appropriately changed. [First Stage Knocking Process] and Subsequent [Short Circuit Breaking Process] in Embodiment 2
May be repeated as many times as necessary depending on the structure of the electron gun. The manufacturing method or the constituent material of the built-in resistor or the short circuit can be appropriately changed in accordance with desired characteristics, specifications, and design values.

[0039]

According to the method for manufacturing a cathode ray tube of the present invention,
The knocking voltage can be executed with a voltage difference higher than the conventional one, and an effective knocking process can be performed.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an electron gun in each step for explaining one embodiment of a method of manufacturing a cathode ray tube according to the present invention.

FIG. 2 is a conceptual diagram of an electron gun in each step for explaining another embodiment of the method for manufacturing a cathode ray tube according to the present invention.

FIG. 3 is a conceptual diagram of a conventional electron gun of a cathode ray tube.

[Description of Signs] K cathode G1 first grid electrode G2 second grid electrode G3 third grid electrode G4 fourth grid electrode CV convergence electrode 10 auxiliary electrode 10A first auxiliary electrode 10B second auxiliary electrode 12 built-in for partial pressure Resistance 14 Short circuit 14A First short circuit 14B Second short circuit 16 Insulating substrate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 9/44 H01J 29/48

Claims (2)

(57) [Claims] 1. A method for manufacturing a cathode ray tube including a knocking process between a focus portion electrode connected to a built-in resistor for voltage division and a focus portion electrode provided before and after the focus portion electrode, comprising: B) The focus portion electrode connected to the built-in resistor for voltage division is grounded in advance by a short circuit, and the focus portion electrode is connected to one of the focus portion electrodes provided before and after the focus portion electrode. (B) cutting the short circuit, (c) the focus electrode connected to the internal resistor for voltage division, and the focus electrodes provided before and after the focus electrode. A step of performing a knocking process with the other,
A method for manufacturing a cathode ray tube, comprising: 2. The method according to claim 1, wherein the steps (a) and (b) are repeated a desired number of times.