JP3396501B2 - Withstand voltage treatment method for cathode ray tube - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a withstand voltage processing method for a cathode ray tube, and more particularly to a cathode ray tube effective for a cathode ray tube in which a capacitor is connected to an electrode of an electron gun. And a withstand voltage processing method. 2. Description of the Related Art In a cathode ray tube, such as a color picture tube, in which a high voltage is applied to the electrode of an electron gun, in order to ensure the reliability of the withstand voltage, in the manufacturing process, after exhausting,
Withstand voltage process is to put a break. As described in JP-B-61-38569, JP-B-61-38571, and JP-B-64-5739, the withstand voltage treatment is applied to a high-voltage electrode of an electron gun through an anode terminal. This is generally performed by applying a high-voltage pulse and grounding or floating a stem pin connected to an electrode other than the high-voltage electrode. However, in recent high-resolution color picture tubes and high-definition color picture tubes, the structure of the electron gun is complicated in order to display high-resolution and high-definition images. There is a problem that sufficient withstand voltage characteristics cannot be obtained even if the treatment is performed. FIG. 3 shows an example of an electron gun having the above-mentioned structure which is complicated. This electron gun is disclosed in Japanese Unexamined Patent Publication No.
An electron gun disclosed in Japanese Patent No. 5444, three cathodes K arranged in a line in a direction perpendicular to the paper surface, three heaters (not shown) for heating the cathodes K separately,
It has first to fifth electrodes G1 to G5, two intermediate electrodes Gm1, Gm2, and a sixth electrode G6 which are sequentially arranged adjacent to the cathode K, and each of these electrodes is a pair of glass insulating support rods ( (Not shown). Further, in this electron gun, a resistor 1 and a capacitor 2 are arranged along the electrodes. The resistor 1 is for supplying a predetermined voltage to each of the intermediate electrodes Gm1 and Gm2, and has one end connected to a sixth electrode G6 to which a high voltage is applied via an anode terminal. The other end is grounded via a stem pin provided on the stem, and terminals 3 and 4 provided on the middle are connected to intermediate electrodes Gm1 and Gm2, respectively. And the sixth electrode G6
Divides the high voltage supplied via the intermediate electrode Gm
1, formed to supply a predetermined medium voltage to Gm2. The capacitive element 2 is connected to an intermediate electrode Gm1 of an AC component of a dynamic voltage applied to the fifth electrode G5 via a capacitance existing between the fifth electrode G5 and the intermediate electrodes Gm1 and Gm2. , Gm2 is prevented, and one end is connected to the intermediate electrode Gm1 and the other end is grounded via a stem pin. In this electron gun, the fifth electrode G5 and the third electrode G5
The electrode G3 is connected inside the tube. When such an electron gun is processed by the above-mentioned conventional general withstand voltage processing method, the capacitive element 2 is connected to the intermediate electrode Gm1 interposed between the fifth electrode G5 and the sixth electrode G6.
Since this is grounded via this capacitive element 2, the sixth electrode
The high-voltage pulse applied to G6 is grounded via the intermediate electrode Gm1, and no discharge occurs between the fifth electrode G5 and the intermediate electrode Gm1 for withstand voltage processing, and the withstand voltage between these electrodes is improved. Therefore, there is a problem that sufficient withstand voltage characteristics cannot be obtained as an electron gun. In order to solve this problem, even if the stem pin connected to the capacitive element 2 is set to, for example, a float, the stem pin is eventually grounded via the adjacent stem pin, and the above problem cannot be solved. [0010] As described above, conventionally,
The withstand voltage treatment of a cathode ray tube is generally performed by applying a high voltage pulse to a high voltage electrode of an electron gun via an anode terminal and grounding or floating a stem pin to which another electrode is connected. However, if this withstand voltage processing method is applied to a cathode ray tube having an electron gun having a complicated structure, such as a high-resolution color picture tube or a high-definition color picture tube, there is a problem that a sufficient withstand voltage effect cannot be obtained. As an electron gun having the above-mentioned complicated structure, for example, first to fifth electrodes, two intermediate electrodes and a sixth electrode are sequentially arranged on a cathode, and are positioned adjacent to the fifth electrode. A capacitor for preventing the induction of an AC component of a dynamic voltage applied to the fifth electrode via a capacitance existing between the intermediate electrode and the fifth electrode is connected to the intermediate electrode. In the electron gun having the grounded structure, even if a high voltage pulse is applied to the sixth electrode, a discharge for withstand voltage processing does not occur between the fifth electrode and the intermediate electrode adjacent thereto, and sufficient discharge is not generated. There is a problem that withstand voltage characteristics cannot be obtained. In order to solve this problem, for example, when a stem pin to which a capacitor is connected is floated,
Eventually, it is grounded via the adjacent stem pin, and the above problem cannot be solved. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has not only a normal cathode ray tube but also, for example, an electrode grounded via a capacitive element for preventing induction of an AC component of a dynamic voltage. An object of the present invention is to provide a withstand voltage processing method capable of obtaining sufficient withstand voltage characteristics even for a cathode ray tube having an electron gun having a complicated structure such as an electron gun. [0014] A focus voltage is applied.
Focus electrode and the high voltage electrode to which the anode voltage is applied.
The voltage between the pole and the anode is divided by a resistor provided in the tube.
Potential, and grounded AC by the capacitive element.
A cathode ray tube having an electron gun having at least one intermediate electrode, wherein an output terminal of a high-voltage pulse source is connected to an anode terminal of the cathode ray tube, and A high voltage pulse is applied to the voltage electrode, the stem pin connected to the focus electrode of the electron gun is grounded, and all the electrodes of the electron gun connected to the stem pins other than the stem pin connected to the focus electrode generate a high voltage pulse. A high-voltage pulse source is connected to all the electrodes connected to the stem pins other than the stem pin to which the focus electrode is connected by connecting to the terminal provided in the middle of the resistor inserted between the output terminal of the source and the ground terminal. A high-voltage pulse lower than the output of is applied. As described above, when each electrode of the electron gun is connected,
The output terminal voltage of the high-voltage pulse generator is V0, and the resistance value of the resistor between the terminal provided between the output terminal of the high-voltage pulse generator and the ground terminal and the ground terminal is defined as V0. Assuming that the resistance value of the resistor between R1 and the output terminal of the high-voltage pulse generation source is R2, V1 = R1.V0 / (R1 + R2) is applied to all the electrodes connected to the stem pins other than the stem pin connected to the focus electrode. ) Can be applied. As a result, for example, even in an electron gun having an electrode grounded via a capacitive element, a high voltage pulse of the voltage V1 is applied to the electrode, and a discharge is generated between the electrode and an adjacent electrode to achieve a desired withstand voltage treatment. Can be performed. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a method for withstanding voltage processing of a color picture tube provided with the electron gun shown in FIG. 3 as an embodiment thereof (see FIG. 3 for the electron gun). The output terminal 11a of the high voltage pulse generator 10 is shaded.
Through the anode terminal 13 of the cathode ray tube 12, the sixth electrode G6 of the electron gun 14
(High voltage electrode). With this connection, resistor 1
, Two intermediate electrodes Gm1, Gm connected to the sixth electrode G6 through
m2 is also sequentially connected to the output terminal 11a of the high voltage pulse generation source 10 via the sixth electrode G6 and the resistor 1. On the other hand, the fifth electrode G5 (focus electrode) of the electron gun 14 is grounded via the stem pin 15a connected to the fifth electrode G5. Further, a terminal 17 provided between the resistors 16a and 16b inserted between the output terminal 11a and the ground terminal 11b of the high-voltage pulse generator 10 is provided.
Are connected in common to the stem pins 15b, 15c, 15d... Other than the stem pin 15a to which the focus electrode is connected. With this connection, the sixth electrode G6, the intermediate electrode Gm2, and the fifth electrode G5
And the intermediate electrode Gm1 via the electrodes K, G1, G2, G4 other than the third electrode G3 connected to the fifth electrode G5 and the capacitive element 2.
Are connected to the terminals 17, respectively. In such a connection, the voltage at the output terminal 11a of the high-voltage pulse source 10 is set to V0, and the resistors 16a and 16b inserted between the output terminal 11a and the ground terminal 11b of the high-voltage pulse source 10 are connected. Terminal 17 and ground terminal 11 provided in the middle
Assuming that the resistance value of the resistor 16a between the focusing electrode and the output terminal 11a of the high voltage pulse generator 10 is R1, the resistance value of the resistor 16b between the output terminal 11a and the output terminal 11a of the high voltage pulse source 10 is R2.
It is possible to apply a high voltage pulse of voltage V1 represented by V1 = R1.V0 / (R1 + R2) to the electrodes K, G1, G2, G4, Gm1 connected to the stem pins 15b, 15c, 15d. it can. Therefore, when the high voltage pulse generation source 10 is operated by connecting the electrodes of the electron gun 14 of the cathode ray tube as described above, the intermediate electrode Gm1 connected to the capacitive element 2 is connected to the conventional withstand voltage processing method. Is not grounded as in
And a fifth electrode G5 adjacent to the intermediate electrode Gm1 can also generate a discharge to perform a withstand voltage process. That is, as shown in FIG. 2, the sixth electrode G6
The output terminal of the high-voltage pulse source 20 via the anode terminal 13
In the conventional withstand voltage processing method of connecting the stem pins 15a, 15b, 15c, 15d... To a common ground and connecting the stem pins 15a, 15b, 15c, 15d. Although no discharge occurred between the electrodes, the withstand voltage treatment could not be performed between these electrodes. However, when the treatment was performed by the method of this example, the fifth electrode G5 adjacent to the intermediate electrode Gm1, which could not be conventionally treated, was connected to the fifth electrode G5. During this time, a discharge is generated, and a sufficient withstand voltage process can be performed. In order to check the degree of the withstand voltage processing,
Grounded connected stem pins 15a of the fifth electrode G5, by applying a DC positive high voltage to the anode terminal 13, observation of the unwanted light emission occurring on the phosphor screen, and processed by the conventional withstand voltage processing method cathode line The tube emitted unnecessary light on the phosphor screen at a high anode voltage of about 20 kV, but the cathode ray tube treated by the method of the above embodiment emitted unnecessary light at about 40 kV,
Significant improvement in withstand voltage was observed. The voltage V1 applied to the electrodes K, G1, G2, G4, Gm1 connected to the stem pins 15b, 15c, 15d... Other than the stem pin 15a connected to the focus electrode is a high-voltage pulse source. About 50-80% of the voltage V0 of the output terminal 11a of 10 is good. When the voltage V1 is lower than that, the withstand voltage processing characteristic is degraded. Conversely, when the voltage V1 is higher than that, the connection of the focus electrode is reduced. The discharge occurs between the stem pin 15a and the other stem pins 15b, 15c, 15d,..., And no discharge occurs between the electrodes, so that the withstand voltage processing characteristics deteriorate. As described above, according to the present invention, sufficient withstand voltage processing characteristics can be obtained only by applying the withstand voltage processing method described in the above embodiment, and this withstand voltage processing method is different from the conventional withstand voltage processing method. By using them together, more stable withstand voltage characteristics can be obtained. The output terminal of the high voltage pulse source is connected to the anode terminal of the cathode ray tube, a high voltage pulse is applied to the high voltage electrode of the electron gun, and connected to the focus electrode of the electron gun. The stem pin is grounded, and all the electrodes of the electron gun connected to the stem pin other than the stem pin connected to the focus electrode are provided in the middle of the resistor inserted between the output terminal of the high-voltage pulse generator and the ground terminal. A high voltage pulse lower than the output of the high voltage pulse source, preferably the output of the high voltage pulse source, is applied to all the electrodes connected to the stem pin other than the stem pin to which the focus electrode is connected. The terminal voltage V0 is approximately 50
When a voltage V1 of .about.80% is applied, even in an electron gun having an electrode grounded via a capacitor, for example, an electron gun which cannot be processed by the conventional withstand voltage processing method, a gap between the electrode and an adjacent electrode is required. , A cathode ray tube having good withstand voltage characteristics can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a withstand voltage processing method for a color picture tube according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of a conventional withstand voltage processing method shown for comparison with the withstand voltage processing method of the present invention. FIG. 3 is a diagram showing a configuration of an electron gun for a color picture tube. [Description of Signs] 10 ... High voltage pulse generator 11a ... Output terminal 11b ... Ground terminal 12 ... Cathode tube 13 ... Anode terminal 14 ... Electron gun 15a ... Stem pins 15b, 15c, 15d connected to the focus electrode Other than the focus electrode Stem pins 16a, 16b connected to the electrodes of ... resistance 17 ... terminals

Continuation of the front page (72) Inventor Shigeo Fukuda 7-1, Nisshincho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Electronic Engineering Corporation (56) References JP-A-2-273438 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 9/44

Claims (1)

(57) Claims 1. A focus to which a focus voltage is applied
Electrode, high voltage electrode to which anode voltage is applied, and anode voltage
Is divided by a resistor provided in the tube to supply electric potential.
And at least one AC grounded by a capacitive element
Withstand of a cathode ray tube equipped with an electron gun with two intermediate electrodes
A pressure processing method, wherein an output terminal of a high voltage pulse source is connected to an anode terminal of a cathode ray tube to apply a high voltage pulse to a high voltage electrode of an electron gun of the cathode ray tube; A method of grounding a stem pin connected to an electrode, and connecting all electrodes of the electron gun connected to stem pins other than the stem pin connected to the focus electrode between an output terminal of the high-voltage pulse generator and a ground terminal. A high voltage pulse lower than the output of the high voltage pulse generation source is connected to all the electrodes connected to the stem pins other than the stem pin connected to the focus electrode by connecting to the terminal provided in the middle of the resistor inserted in And a method of withstanding voltage treatment of a cathode ray tube.