JPH03187124A - Knocking of cathode-ray tube - Google Patents

Abstract

PURPOSE:To improve a knocking effect by impressing prescribed high voltage between a first terminal, in which a heater, a cathode, a first grid and a second grid are all together conductively connected, and a second terminal of the other end of an externally attached resistor, of which one end is conductively connected to a fourth grid and a low voltage side terminal. CONSTITUTION:A leader terminal of a fourth grid 4 is connected to a low voltage side terminal 10 of a divided resistor 9, and an externally attached resistor 15 is connected between the low voltage side terminal 10 of the divided resistor 9 and the minus side of a high voltage generator 16. A terminal 11, to which a heater 7, a cathode 8 as well as respective leader terminals of a first grid 1 and a second grid 2 are commonly connected, are connected to the minus side of the high voltage generator 16. A high voltage side terminal 12 of the divided resistor 9 is grounded while being commonly connected to the plus side of the high voltage generator 16. Thereby, a knocking effect is improved, and overknocking and dielectric breakdown are prevented, so that a pressure-tight characteristic of a cathode-ray tube can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for knocking a cathode ray tube having an electron gun with a built-in dividing resistor.

[Summary of the invention]

The present invention provides a tripotential cathode ray tube having an electron gun with a built-in dividing resistor. I tried to optimize the applied voltage by connecting it to the low voltage side terminal of the dividing resistor. As a result, the knocking effect increased between the second grid and the third grid, as well as between other electrodes and elements.

(Prior Art) In the production of color cathode ray tubes, there is a knocking method for a color cathode ray tube having a tripotential electron gun with a built-in dividing resistor, which is an application of the knocking method for a unipotential electron gun. The circuit diagram is shown in Figure 3. In the figure, the parts surrounded by dotted lines are the dividing resistor 9, the heater 7, the cathode 8, and the first
1 shows an electrical connection diagram for knocking of an electron gun composed of a grid 1, a second grid 2, a third grid 3, a fourth grid 4, a fifth grid 5, and a convergence electrode 6. Let the resistance values of each part of the divided resistor 9 divided into three parts be R, , R, , R, respectively from the high voltage side. 10 is the low voltage side lead-out terminal of the dividing resistor 9;
are heater 7, cathode 8, first grid 1, second grid 2
12 indicates a high voltage side terminal (anode terminal) of the dividing resistor 9.

An external resistor 13 is connected to the low voltage side lead-out terminal 10 of the dividing resistor 9.
The negative side of the high voltage generator 14 is connected to the terminal 11 which is commonly connected to the other terminal, and a high voltage is applied. Let the resistance value of the external resistor 13 be R4. Conventionally, the value of this high voltage is 60KV, and the resistance values of each part of the dividing resistor 9 are R, +Rt = 270MΩ, R3 = 630M
Ω, and the value of the external resistor I3 was R, = 100 MΩ, and knocking occurred.

A conventional knocking method for a cathode ray tube is disclosed in, for example, Japanese Patent Laid-Open No. 138632/1983.

[Problem to be solved by the invention]

Now, in the conventional circuit of FIG. 3, the potential difference between each electrode when high voltage is applied is 43.8 KV between the second grid 2 and the third grid 3, and 60 KV between the fourth grid 4 and the fifth grid 5. , and 43.8 KV between the third grid 3 and the fourth grid 4. In the tri-potential electron gun, the third grid
The voltage of the grid 3 is supplied from the dividing terminals of the dividing resistor 9. Therefore, even during knocking, the voltage from the divided terminals of this dividing resistor 9 is applied, so as mentioned above, the knocking voltage between the second grid 2 and the third grid 3 is as low as 43.8 KV, and sufficient knocking effect is achieved. The output voltage of the high voltage generator I4, which is not at a value that can produce the same voltage, is increased and applied to the anode terminal 12. If the knocking voltage were to be made higher than 60 KV, the potential difference between the fourth grid 4 and the fifth grid 5 would become too large, causing excessive knocking and causing problems.

Further, since a large potential difference occurs between the fourth grid 4 and the dividing resistor 9, dielectric breakdown occurs in a portion of the dividing resistor 9 near the fourth grid 4. Also, when knocking, the 4th
Since the grid 4 and the second grid 2 are connected, no knocking occurs between the lead wires of these electrodes, and in the same way, the lead wires of the fourth grid 4 and the dividing resistor 9 are connected.
Knocking remains between the low-voltage side extraction terminals 10 of , between the lead wire of the fourth grid 4 and the heater 7, and between the lead wire of the fourth grid 4 and the cathode 8. As a result, discharge may occur during actual operation.

In order to solve this problem, the present invention aims to provide a knocking method that is simple and provides good effects.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a heater, a cathode,
Consists of a first grid, a second grid, a third grid, a fourth grid, a fifth grid, and a dividing resistor;
By adding an external resistor to a cathode ray tube incorporating an electron gun having a lens system in which the grid is connected to the dividing terminal of the dividing resistor and the fifth grid is connected to the high voltage side terminal of the dividing resistor. In the knocking method, the heater, the cathode,
The first grid that connects the first grid and the second grid together
A predetermined high voltage is applied between the second terminal of the external resistor and the second terminal of the other end of the external resistor, one end of which is connected to the fourth grid and the low voltage side terminal of the dividing resistor.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 1 is a block diagram showing the knocking method of the present invention, and FIG. 2 is a circuit diagram of the knocking method of the present invention. Third
The same parts as in the figure are given the same reference numerals, and the explanation will be omitted.

In FIG. 2, the lead terminal of the fourth grid 4 is connected to the low voltage side terminal 10 of the dividing resistor 9. Further, an external resistor 15 is connected between the low voltage side terminal IO of the dividing resistor 9 and the negative side of the high voltage generator 16.

The resistance value of external resistor F515 is assumed to be R1. A terminal 11 to which the heater 7, the cathode 8, and the lead terminals of the first grid 1 and the second grid 2 are commonly connected is connected to the negative side of the high voltage generator. High voltage side terminal 1 of dividing resistor 9
2 is grounded and commonly connected to the positive side of the high voltage generator 16.

Next, the value of the applied high voltage and the circuit constants in the knocking method of the present invention will be explained. In FIG. 2, the overall resistance values R, +R, +R1 of the dividing resistor 9 are 900MΩ,
R+ + Rz = 270MΩ, R, -630MΩ. Also, the resistance value R3 of the external resistor 15 is 200MΩ
It is. 70KV from high voltage generator 16 during knocking
A pulsed high voltage is applied. At this time, the voltage applied to each electrode and terminal is written down to the high voltage side terminal of the dividing resistor 9 (
anode terminal) 12 is Ov, 5th grid 5 is Ov, 3rd
The grid 3 has a voltage of -17 KV, the fourth grid 4, the terminal 10 has a voltage of -57 KV, and the cathode 8, the heater 7, the first grid 1 and the second grid 2 have a voltage of -70 KV. According to the knocking method of this embodiment, a knocking voltage of about 53 KV is applied between the second grid 2 and the third grid 3, and about 57 KV is applied between the fourth grid 4 and the fifth grid 5, and a knocking voltage of about 57 KV is applied between the fourth grid 4 and the fifth grid 5.
Approximately 13K is applied between the lead wire of the heater 7 of the other electrodes, the cathode 8, the first grid I, and the lead wire of the second grid 2.
V is applied. Therefore, the applied voltage at the time of knocking between the second grid and the third grid 3 is 53KV compared to the conventional one.
-44KV=9KV (7) Rise and Natsuta. The voltage applied between the fourth grid 4 and the fifth grid 5 is 57 KV.

〔Effect of the invention〕

As mentioned above, according to the knocking method of the present invention, (1)
The knocking effect between the second and third grids is improved.

(2) The knocking effect between the leader line of the fourth grid and the first and second grids is improved.

(3) Excessive knocking between the fourth and fifth grids can be prevented.

(4) Dielectric breakdown of the portion of the dividing resistor near the fourth grid can be prevented.

(5) The knocking effect between the low-voltage side lead wire of the dividing resistor and the heater, cathode, and their lead wires is improved.

(6) Therefore, the withstand voltage characteristics of the cathode ray tube are improved and reliability is improved.

(7) This technique can be applied to uni-potential cathode ray tubes and pi-potential cathode ray tubes, and it will be more effective if the resistance value of the external resistor is further increased by using an inert liquid or the like.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the knocking method of the present invention, FIG. 2 is a circuit diagram of the knocking method of the present invention, and FIG. 3 is a circuit diagram of the conventional non-king method. 4−−−−−−−−−・−4th grid 9−・−・−・
- Dividing resistor 0 Low voltage side terminal of dividing resistor 5 External resistor 6 High voltage generator

Claims (1)

[Claims] Consisting of a heater, a cathode, a first grid, a second grid, a third grid, a fourth grid, a fifth grid, and a dividing resistor, the third grid is connected to the dividing terminal of the dividing resistor, and the fifth grid is connected to the dividing terminal of the dividing resistor. In a knocking method in which an external resistor is added to a cathode ray tube incorporating an electron gun having a lens system connected to a high-voltage side terminal of a dividing resistor, the heater, the cathode, the first grid, and the second grid are connected to each other. Applying a predetermined high voltage between the first terminals connected together and the second terminal of the other end of the external resistor, one end of which is connected to the fourth grid and the low voltage side terminal of the dividing resistor. A cathode ray tube knocking method characterized by: