JPH07141986A - Disassembling-activating method for cathode-ray tube cathode - Google Patents

Abstract

PURPOSE:To perform stable disassembling-activation for a cathode-ray tube cathode. CONSTITUTION:In an aging process of the manufacturing method of a picture tube, a heater is lit and the temperature of a cathode-ray tube cathode is controlled within a range of 700-750 deg. CBN by a time a1 direct after the aging process is started to perform disassembling-activation for a cathode-ray tube cathode. Then the temperature of the cathode-ray tube cathode is controlled within a range of 850-900 deg. CBN by a time a2 to stabilize cathode carbonate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decomposing and activating a cathode ray tube cathode such as a cathode ray tube of a television receiver.

[0002]

2. Description of the Related Art Conventionally, in a general evacuation process in which a picture tube which is a cathode ray tube of a television receiver is evacuated,
Attach a vacuum exhaust system to the tip tube of the stem glass of the picture tube, exhaust the air in the glass bulb, heat the glass bulb in the furnace to adsorb the gas stored in the glass bulb, etc. Furthermore, the electrode (cathode)
Was heated by high frequency (baking) to discharge gas.
And the thermal decomposition (decomposition activity) of the electron emitting material of the cathode
And finally had the tip tube disconnected.

However, in the large-sized picture tube and some of the small-sized picture tubes, the baking and the decomposition activity of the cathode in the exhaust furnace have been abolished in order to simplify the above exhaust process.

In the simplified evacuation process in the method of manufacturing a picture tube, first, a vacuum evacuation system is attached to the tip tube of the stem glass of the picture tube to evacuate the air in the glass bulb, and the glass in the furnace. Heat the valve,
Sufficiently release the gas adsorbed and stored in the glass bulb.

Next, a getter flash process is carried out in which barium as a getter for adsorbing gas is blown over the entire surface of the picture tube to form a barium film. Since the gas is adsorbed by this getter, the degree of vacuum in the picture tube can be further increased. Further, the gas generated when the fluorescent surface is irradiated with the electron beam light can also be adsorbed to the getter.

After that, in order to make the degree of vacuum inside the glass bulb above a certain value, one step from the getter flash step is performed.
The baking process is started after an interval of 0 minutes or more. In this baking process,
A high frequency coil is covered from the grid electrode to the third grid electrode and heated to discharge gas from the electron gun. At the same time, the cathode ray tube cathode (cathode carbonate) is decomposed and the gas (CO ₂ ) released by this decomposition activity is quickly absorbed by the getter. In this way, the method of heating the picture tube with the high-frequency coil placed outside the picture tube and letting out gas from the electron gun (gun parts) inside the picture tube, and at the same time performing decomposition activity of the cathode ray tube cathode It's called outside ganyaki.

The cathode carbonate is barium (B
a), calcium (Ca), and strontium (S
Although the three elements of r) are mixed, the decomposition temperature of barium is the highest among these three elements and is 700 to 720.
° CBN (brightness temperature 700 to 720 ° C).

The above-mentioned ° CBN is a unit showing the brightness temperature of the nickel base metal, and the conversion formula to Celsius (° C) is shown in the following formula (1).

(Y ° C) = 1.14 × (X ° CBN) -134 (1)

Here, the decomposition reaction formula in the decomposition activity of barium (Ba) is shown in the following formulas (2) and (3).

[0011] _{BaCO 3 → BaO + CO 2 ↑} ··· (2) BaO → Ba 2+ + 2e - ··· (3)

The heating temperature by the high frequency coil in this baking process is 720 at the first grid electrode of the electron gun.
The optimum heating temperature is 750 ° C although the temperature is controlled in the range of up to 780 ° C. Gas is released from the electron gun by heating the electron gun at the above-described heating temperature for 3 minutes. At the same time, barium that constitutes the cathode carbonate undergoes a decomposition reaction as shown in equation (2). The elements other than barium constituting the cathode carbonate cause a decomposition reaction similar to that of barium at a heating temperature lower than the heating temperature required for the decomposition reaction of barium.

Thereafter, in order to stabilize the decomposition of the cathode, an interval (interval) of 7 minutes or more is set, and the process proceeds to the aging step. In this aging step, the cathode of the cathode ray tube is heated by turning on the heater in the picture tube to stabilize the electron emission characteristics of the cathode of the cathode ray tube as shown in the above formula (3). As a result, the cathode carbonate is made into a solid solution.

FIG. 3 shows the relationship between temperature and time in the aging process. At time a immediately after the start of aging, the heating temperature of the cathode of the cathode ray tube is a temperature suitable for performing solid solution treatment of the cathode of the cathode ray tube88.
Set to 0 ° CBN to stabilize the cathode ray tube cathode. After that, the heating temperature of the cathode ray tube cathode is gradually raised, and flushing is performed at time b in FIG.
After this flushing, the heating temperature of the cathode of the cathode ray tube is lowered, and current activation is performed by applying a voltage to the first grid electrode and the second grid electrode of the electron gun to discharge gas from the current holes.

After the aging process is completed, the process proceeds to a knocking process, in order to prevent discharge that occurs in the picture tube when the picture tube is actually used, a spark between electrodes is forcibly generated, The surface is cleaned to further release dust and burrs. And finally,
In the raster aging process, the picture tube is illuminated to perform aging as in the actual case.

[0016]

By the way, in the above baking step, gas is released due to gas discharge from the electron gun and decomposition activity of the cathode ray tube cathode, and this gas deteriorates the vacuum degree in the vicinity of the cathode ray tube cathode. To do. In particular, a picture tube having a size of 20 inches or less has a smaller internal volume than a large picture tube, so that the degree of vacuum is significantly deteriorated.

Here, since the decomposition temperature of the cathode ray tube cathode is higher in an environment where the degree of vacuum is poor, the decomposition temperature of the cathode ray tube cathode is sufficient at the heating temperature set in the baking process. Is not done. Therefore, the cathode ray tube cathode enters the aging step without being decomposed.

Further, in the aging step which is the step subsequent to the baking step, the heating temperature of the cathode ray tube cathode is set to 880 ° CBN which is higher than the heating temperature from the start of aging to the baking step as described above. .
Therefore, the cathode ray tube cathode that has not been decomposed by the baking process is heated at the heating temperature and is rapidly decomposed, and gas (CO ₂ ) is rapidly released or micro sintering occurs. This gas and microsinter contaminate the cathode ray tube cathode in the picture tube,
It is experimentally known that the life of a picture tube is adversely affected.

In the baking step, as described above, heating is performed for 3 minutes at a heating temperature of 720 to 780 ° C. However, the actual manufacture of the picture tube is carried out in a line work. Specifically, in order to secure the heating time of the above 3 minutes, about 15 high-frequency coils are arranged on the line work table for 15 to 15 minutes. By injecting a picture tube in sequence at an interval of 20 seconds and flowing the picture tube, a heating time of 3 minutes required for one picture tube is secured. Here, the high-frequency coil has a heating temperature of 10 ° when the distance from the heating target changes by 1 mm.
A change in C occurs. Therefore, it is very difficult to perform delicate control such that the temperatures of a plurality of high-frequency coils are simultaneously set within an appropriate temperature range during the flow work of actually manufacturing a picture tube.

Further, when the conventional cathode ray tube cathode decomposition activation method is used, the vacuum degree in the picture tube is set to a certain value or more with an interval of 10 minutes between the getter flash step and the baking step. There is. However, in order to leave the picture tube for 10 minutes or more as described above, it is necessary to secure a wide range of storage areas for the picture tube. Also,
In the method of manufacturing a picture tube, it is considered to improve productivity by shortening the interval between steps.

Therefore, in view of the above situation, the present invention provides a cathode ray tube cathode activation method capable of performing stable cathode ray tube cathode decomposition activity and improving the productivity of a picture tube.

[0022]

According to the method for decomposing and activating a cathode ray tube cathode according to the present invention, the luminance is activated by turning on a heater at the start of aging for stabilizing the electron emission characteristics of the cathode ray tube cathode and decomposing and activating the cathode ray tube cathode. The above problems are solved by heating the cathode ray tube cathode at a temperature to activate the decomposition of the cathode ray tube cathode and then heating the cathode ray tube cathode at a brightness temperature at which the cathode ray tube cathode stabilizes.

The cathode ray tube cathode has a brightness temperature of 700 to 750 ° C. when it is decomposed and activated, and the cathode ray tube cathode has a brightness temperature of 850 to 900 ° C. when it is stabilized.

Further, the heating time of the cathode of the cathode ray tube when the cathode of the cathode ray tube is activated for decomposition is 1.5 minutes (1 minute 30 seconds) or more.

Here, in the baking step which is a pre-step of aging, only the gas is discharged by heating the first grid electrode to the third grid electrode of the electron gun with the high frequency coil.

[0026]

In the present invention, stable decomposition activity of the cathode ray tube cathode can be achieved by performing the decomposition activity of the cathode ray tube cathode, which was conventionally performed in the baking step, in the aging step.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the relationship between temperature and time in the aging process using the cathode ray tube cathode decomposition activation method according to the present invention, and FIG. 2 shows an image received using the cathode ray tube cathode decomposition activation method according to the present invention. 3 shows a flowchart of a method for manufacturing a tube.

The process sequence of the method for producing a picture tube using the cathode ray tube cathode decomposition activation method according to the present invention is the same as that of the conventional picture tube production method, but the cathode ray tube cathode decomposition activity is In the conventional method for manufacturing a picture tube, the process is performed in the baking step, but in the method for manufacturing a picture tube using the cathode ray tube cathode decomposition activation method according to the present invention, it is performed in the aging step.

First, in the evacuation process of step S1 in FIG. 2, a vacuum evacuation system is attached to the tip tube of the stem glass of the picture tube to evacuate the air in the glass bulb and heat the glass bulb in the furnace. Adsorbed in the glass bulb,
Sufficiently release the stored gas.

Next, in the getter flash step of step S2, barium as a getter is blown over the entire surface of the picture tube to form a barium film, and the getter adsorbs gas to further increase the degree of vacuum in the picture tube. The getter also adsorbs gas generated when the electron beam light is applied to the fluorescent surface. Immediately after the end of the getter flash process, the baking process of step S3 is started.

In this baking step, a high frequency coil is covered from the first grid electrode to the third grid electrode of the electron gun, and the temperature of the first grid electrode is adjusted to 620 to 740 ° C.
The temperature is controlled within the range of 3 to heat for 3 minutes, and only gas is emitted from the electron gun. The temperature in the range of 620 to 740 ° C is a temperature suitable for discharging gas from the electron gun. In this way, in the baking process, since the gas is only discharged from the electron gun, the temperature control range of the electron gun heated in the baking process becomes wider than the temperature control range of the conventional electron gun. The temperature of the high-frequency coil for heating the electron gun can be controlled more easily than before.

Further, in the conventional manufacturing process of the cathode ray tube, the cathode ray tube cathode is decomposed and activated in the baking step. Therefore, in order to make the cathode ray tube cathode decomposition activity stable, the degree of vacuum in the cathode ray tube is set. It has to be a certain value or more, and in order to obtain the degree of vacuum of the certain value or more, an interval of 10 minutes is required when entering the baking step from the getter flash step which is a step before the baking step. However, when the decomposition activation method of the cathode ray tube cathode of the present invention is used, only gas is discharged from the electron gun in the baking step, so immediately after the end of the getter flash step, the baking step is started. I don't mind. However, in actuality, due to the reasons such as the equipment, it takes about 1 time from the getter flash process to the baking process.
There is an interval of minutes.

Immediately after the baking process is completed, the process immediately proceeds to the aging process of step S4. In this aging step, the heater is turned on to heat the cathode of the cathode ray tube, and the decomposition activity of the cathode of the cathode ray tube is performed.

As shown in FIG. 1, the temperature of the cathode ray tube cathode is increased to 7 at time a ₁ immediately after the aging process is started.
Controlled within the range of 0 to 750 ° CBN, but preferably 720 which is the temperature at which the cathode ray tube cathode begins to decompose.
° CBN is good. Decomposition of the cathode ray tube cathode by first heating the first grid electrode in the electron gun and then heating the cathode ray tube cathode at the temperature as described above for a minimum of 1.5 minutes, preferably 5 minutes. The activity is stabilized. Further, it is possible to discharge gas from the lit heater within this time period a ₁ .

Next, at time a ₂ , the heating temperature of the heater is raised to increase the temperature of the cathode ray tube cathode from 850 to 90.
Stabilize the cathode carbonate by heating for 5 minutes with control in the range of 0 ° CBN.

As described above, the temperature of the cathode ray tube cathode during decomposition activation in the aging step using the cathode ray tube cathode decomposition activation method of the present invention is higher than the temperature of the cathode ray tube cathode during decomposition activation in the conventional baking step. Set to a low temperature, 1.5 to 5 from the start of aging
Since the cathode ray tube cathode is slowly decomposed by being heated for a minute, it is possible to completely decompose and activate the cathode ray tube cathode. Further, the temperature at the time of stabilizing the cathode ray tube cathode in the aging step using the decomposition activation method of the cathode ray tube cathode of the present invention is raised to the same temperature as the time of stabilizing the cathode ray tube cathode in the conventional aging step, Stabilization of the tube cathode takes place.

Here, when the conventional method for manufacturing a picture tube is used, the degree of vacuum in the picture tube is changed from the end of the getter flash step to the baking step for decomposing the cathode ray tube. It was necessary to provide an interval of 10 minutes in order to make the value above a certain value. However, in the method for manufacturing a cathode ray tube using the cathode ray tube cathode decomposition activation method according to the present invention, the cathode ray tube cathode decomposition activity is performed in the aging step, and in the actual work of manufacturing the cathode ray tube, a getter is used. Since it takes more than 10 minutes from the end of the flash process to the start of the aging process, it is necessary to secure a wide storage space for leaving the picture tube for 10 minutes as in the case of manufacturing a conventional picture tube. There is no. As a result, it is possible to shorten the interval between steps when manufacturing the picture tube, and improve the productivity in manufacturing the picture tube.

After the aging process is completed, the knocking process of step S5 is proceeded to forcibly perform the inter-electrode spark in order to prevent the discharge generated in the picture tube when the picture tube is actually used. After that, the electrode surface is cleaned to further discharge dust, burrs and the like. Then, finally, in the raster aging process of step S6, the picture tube is illuminated as in the actual case, and aging is performed.

[0039]

As is apparent from the above description, the method of decomposing and activating a cathode ray tube cathode according to the present invention is such that the heater is turned on at the start of aging for stabilizing the electron emission characteristics of the cathode ray tube cathode, and the cathode ray tube is activated. The cathode ray tube cathode is heated at a brightness temperature at which the cathode is decomposed and activated to perform decomposition activity of the cathode ray tube cathode, and then the cathode ray tube cathode is heated at a brightness temperature at which the cathode ray tube cathode is stabilized, where: The luminance temperature of the cathode ray tube cathode when it is decomposed and activated is 700 to 750 ° C., and the luminance temperature of the cathode ray tube cathode when it is stabilized is 850 to 900 ° C.
C, and the heating time of the cathode ray tube cathode when the cathode ray tube cathode is decomposed and activated is 1.5 minutes (1 minute 30
By setting the above time, the stable decomposition activity of the cathode ray tube can be performed regardless of fluctuations in the manufacture of the picture tube and variations in the vacuum degree of the picture tube due to the difference in the volume inside the picture tube.

Further, it is possible to avoid the deterioration of the life of the picture tube due to the rapid decomposition of the cathode of the cathode ray tube in the aging process.

Further, since the interval between the steps from the end of the getter flash step to the start of the aging step is not defined, it is not necessary to set the time for leaving the picture tube, and the productivity of the picture tube is improved. You can

In addition, since only gas is emitted from the electron gun in the baking process, it is not necessary to control the temperature of the high frequency coil controlled in the baking process more strictly than the temperature of the conventional high frequency coil, and the number of steps for managing the process is reduced. Can be reduced.

Note that, as in the case of conventional outside-gun firing, the cathode-ray tube cathode is not disassembled in the exhaust furnace, so the change of the heat pattern can be simplified to automate the input and output of the exhaust gas and to shorten the process time of the process. The characteristics of the conventional out-of-furnace gun firing, such as aging, can be used as they are.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between temperature and time in an aging step using the decomposition activation method for a cathode ray tube according to the present invention.

FIG. 2 is a flow chart of a method of manufacturing a picture tube using the cathode ray tube cathode decomposition activation method according to the present invention.

FIG. 3 is a diagram showing a relationship between temperature and time in a conventional aging process.

Claims (3)

[Claims] 1. A method for decomposing and activating a cathode carbonate of an electron gun of a cathode ray tube by thermally decomposing and activating the cathode carbonate, wherein a heater is turned on at the start of aging for stabilizing electron emission characteristics of the cathode ray tube cathode. , Heating the cathode ray tube cathode at a brightness temperature at which the cathode ray tube cathode activates decomposition to perform decomposition activity on the cathode ray tube cathode, and then heating the cathode ray tube cathode at a brightness temperature at which the cathode ray tube cathode stabilizes. A cathode ray tube cathode decomposition activation method characterized by the above. 2. The brightness temperature of the cathode ray tube cathode during decomposition activation is 700 to 750 ° C., and the brightness temperature of the cathode ray tube cathode during stabilization is 850 to 900 ° C. 1. The method for decomposing and activating a cathode ray tube cathode according to 1. 3. The decomposition activation method for a cathode ray tube cathode according to claim 1, wherein the heating time of the cathode ray tube cathode when the cathode ray tube cathode is activated for decomposition is 1.5 minutes or more.