JPS61110935A - Manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE:To obtain a cathode-ray tube with excellent high quality by raising a heater voltage than the rated value in the initial stages of raster aging process. CONSTITUTION:After applying a voltage Ef1 which is 1.1 to 1.2 times the rated voltage to the heater 9a-9c, the rated voltage or a voltage Ef2 which is lower than such rated voltage is applied during about 1/3 from the beginning of total period of the raster eging process 104. The first application of a voltage Ef1 which is higher than the rated voltage is necessary to recover the electron radiation capability deteriorated because impurity gas generated in the spot knoking process 103 adheres to the cathodes 10a-10c. The successive application of rated voltage or a voltage Ef2 which is lower than rated voltage is carried out to prevent that the electron radiation capability of cathode is remarkably deteriorated if the oxidation gas and halogen gas enter the inside of color picture tube and to enhance the capability of detecting impurity gas entering the inside of picture tube because the cathode, when it is low in temperature, is easily influenced by the effect of impurity gas. Thereby, a cathode-ray tube having excellent high quality by receiving electron radiation capability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a cathode ray tube, and in particular to a method for manufacturing a cathode ray tube, in which a cathode ray tube activated by an aging process performed after an evacuation/sealing process and a getter flash unit process is used to spot a cathode ray tube. The present invention relates to a raster aging process in which high voltage treatment is performed in the knocking process, and the electron emitting ability of the cathode can be recovered by impurity gas generated during the high voltage treatment and adhered to the cathode surface.

[Technical background of the invention and its problems]

Generally, in a cathode ray tube, the inner surface of the panel is coated with phosphor, a metal back is applied, an assembled electron gun is inserted into the neck, and then an evacuation process is performed while heating to create a vacuum inside the tube. During this evacuation process, the electron gun is heated by high-frequency induction heating to release impurity gas adhering to the electrode surface, and then the inside of the tube is maintained at a high vacuum of about 10 Torr, and the evacuation tube is sealed. .

The sealed cathode ray tube is further subjected to a getter fludge process to maintain a high vacuum inside the tube, and after the getter absorbs the residual gas inside the tube, the oxide cathode is decomposed, activated, and stabilized through an aging process. will be carried out.

A cathode ray tube that has undergone this aging process will be able to stably emit electrons, but if left as is, the baritum in the getter agent will adhere to the control electrode, shield electrode, and focusing electrode during the aging process, and will emit stray electrons. (stray emissions), which is undesirable. In addition, on the electrode side where high voltage is applied, impurity adhesion during electron gun assembly or scratches caused by the assembly jig may induce discharge between the electrodes or cause stray emissions. A spot knocking process is provided,
These causes of stray emissions and inter-electrode discharge are removed to prevent inter-electrode discharge and stray emissions from occurring during operation.

This spot knocking step I: When performing higher voltage treatment, the electrode surface is not necessarily cleaned, and gas is generated due to interelectrode discharge due to spot knocking. Some of the generated gases are adsorbed by the getter and some are adhered to the surface of the cathode, and the gases adhering to the surface of the cathode are a factor in reducing the electron emitting ability of the cathode.

This adhered gas is not chemically bonded, but is physically adhered to the cathode surface, and can be heated by heating the cathode for several minutes to several tens of minutes by energizing the heater at a voltage higher than the rated voltage. The adhered gas is easily released and the electron emission ability is restored.

However, conventionally, in the raster aging process (heat run process) performed after the spot knocking process, the heater voltage was applied at the rated voltage or a voltage slightly lower than the rated voltage, and in this process, some voltage that could not be recovered was generated, and the next There was a problem that caused the electron emission characteristics to be determined to be defective in the characteristic testing process.

The reason for this is that the purpose of the raster aging process is to carry out an addition heat run under the condition that the television set is installed in order to check the high voltage aging (withstand voltage treatment) processing state, and the number of sparks during the initial operation, This test determines whether stray emissions occur and the generated voltage, and also checks whether there is damage to the cathode due to residual gas in the tube, as well as the processing status of withstand pressure. Therefore, in conventional raster aging, activation of the cathode is considered not to be the objective.
Rather, this was because the heater voltage was set at a rating or lower than the rating at which it was easy to check for damage to the cathode.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and
It is an object of the present invention to provide a method for manufacturing a cathode ray tube that can obtain a cathode ray tube of extremely high quality by increasing the heater voltage above the rated value at the beginning of the raster aging process.

[Summary of the invention]

That is, the present invention applies a specified voltage to each electrode of the cathode ray tube, except for the heater, which has completed the evacuation/sealing process, getter flash unit process, aging process, and spot knocking process, and then applies a raster pattern onto the phosphor screen using the deflection yoke. In a method for manufacturing a cathode ray tube that is designed to carry out a raster aging process that causes a raster aging process to be performed, a voltage higher than the rated voltage is applied to the heater for about 1/3 of the time from the beginning of the raster aging process, and then the rated voltage is applied. This is a method of manufacturing a cathode ray tube, characterized by carrying out the following steps.

[Embodiments of the invention]

Next, a method for manufacturing a cathode ray tube according to the present invention will be explained using a color picture tube with reference to FIGS. 1 to 3.

That is, in the evacuation/sealing process (Zoo), a color picture tube with panel α9, funnel 0 seconds, and neck device as an envelope is heated while the inside of the tube is evacuated. During evacuation, high-frequency induction heating is used to release the gas adhering to the electrode surface of the electron gun, and after maintaining the inside of the tube at a high vacuum, the evacuation tube is sealed.

In the sealed color picture tube, the inside of the tube is made into a higher vacuum, and the getter is flashed in the getter step (101) in order to further improve the ability to emit electrons from the cathode, and then the heater (9) is flashed in the aging step (102). ”) # (9b
) - (9c): Apply voltage from the heater power supply (1) and connect the cathodes (10a), (10b), (IOC)
Activation is performed.

In this aging step (102), a heater (9a),
(9b).

(9C) as well as control electrode (II), focusing type 1 (1
31, (15), and aging is performed over several tens of minutes to several hours.

, :j') You l:, Lte activates letter Yin t! i (1
0a), (10b).

(I OC) has a spot knocking process (10
3), a withstand voltage treatment is performed so that interelectrode discharge stray emission does not occur even when a high voltage is applied. During this spot knocking process,
Spark discharge occurs between the electric fences because the electric fences are processed by applying a higher voltage than in normal use. A cathode (1 oa) from the gas generated during this spark discharge,
(10b) The (IOC) surface is contaminated with gas.

While still contaminated with such gases, a raster aging process (104) similar to the conventional method is performed, and a characteristic test (104) is performed.
05), the original characteristics cannot be fully exhibited and it is determined to be defective, and the aging process (1
02) etc. must be performed. Therefore, in the present invention, the heater (9a),
(9b), (9C) is the rated voltage Ll to 1.2
After applying the double voltage (Efl), the rated voltage or a voltage lower than the rated voltage (Er2) is applied.

Voltage 1.1 to 1.2 times this rated voltage (13rl)
The application of impurity gas generated by the spot knocking step (103) is applied to the cathode (10a), (10b).
), (10c) in order to recover from the decrease in electron emission ability due to adhesion. Thereafter, the raster aging step (104) is carried out by lowering the rated voltage or a voltage lower than the rated voltage (Er2) because oxidizing gas and halogen gas, especially F and CF, are present in the tube of the color picture tube.
, CF.

If CF, etc. enters the cathode (10
The cathodes (10a), (10a), (10c) are designed to prevent the electron emission ability of (10b), (10c) from being significantly reduced and become defective as a color picture tube, and in the unlikely event that impure gas enters the color picture tube, the cathodes (10a), (10c) are 10b), (106)
Since the lower the temperature, the more likely it is to be damaged by impure gases, this is done to improve the detection ability of these gases. There is no problem with a color picture tube in a normal state where no impurity gas enters.

The following voltages are applied to each electrode during this raster aging step (104).

That is, heaters (9a), (9b), and (9c) are 7.5 ±0.
5 V, (Er2) (FllI5.0 to 63v
, the control electrode αυ has a ground potential (4) and a cathode (10a).
, (10b) and (10c) have a variable power supply (2a)
, (2b), (2c), each cathode current (3a
), (3b), (3c) are 300μA to 40
It is set to 0μA. Shield electrode α3. (14
Niha power supply (5) 400 ±50 V, focused type! (
13, (variable voltage from the variable power source (6), high voltage electrode (anode) αη is connected to the internal conductive film Q1 from the anode terminal connected to the power source (7), via the electric fence contact αe) 29
±IKV is applied. Further, the deflection yoke (8) is supplied with a current of 50% to 120% of the screen size.

The color picture tube that has completed the raster aging process (104) in this way is shipped after passing through the next characteristic inspection process (105).

〔Effect of the invention〕

As described above, according to the manufacturing method of the present invention, it is possible to provide a cathode ray tube of good quality in which the contaminant gas adhering to the cathode surface is effectively released and the electron emission ability is restored.

[Brief explanation of drawings]

1 to 3 are diagrams showing an embodiment of the method for manufacturing a cathode ray tube of the present invention, in which FIG. 1 is a process diagram, and FIG. 2 is a diagram showing changes in heater voltage in the raster aging process;
FIG. 3 is an explanatory diagram showing a color picture tube as an example of a cathode ray tube undergoing an aging process and a power supply group for applying a predetermined voltage to each electrode. 8... Deflection yoke, 9a, 9b, 9c... Heater 10m, 10b, l0C-... Cathode, U-... Control electrode 12.14... Shield electrode, 13.15...
・Focused electric fence 17...High voltage critical condition,

Claims (1)

[Claims] A raster in which a specified voltage is applied to each electrode, including the heater, of a cathode ray tube that has completed the exhaust/sealing process, getter flash process, aging process, and spot knocking process, and a raster is drawn on the phosphor screen by the deflection yoke. In a method for manufacturing a cathode ray tube that performs an aging step, the raster aging step is performed by applying a voltage higher than the rated voltage to the heater for about 1/3 of the time from the beginning, and then applying the rated voltage. A method for manufacturing a cathode ray tube characterized by: