JPH097522A - Knocking method of cathode ray tube and cathode ray tube - Google Patents

Abstract

(57) [Abstract] [Purpose] Discharge between electrodes (mainly between G5 and G4, G3
Discharge sources other than G4, G2 and G3) can be removed without spending time. [Arrangement] An electrode body 9 is applied (provided) to the outer surface of the neck portion 2, and the electrode body 9 and the low-voltage electrodes G1, G2, G of the electron gun are attached.
4, a charge-up voltage that promotes charge-up of the inner surface of the neck portion 2 is applied to knock a discharge source due to the charge-up of the inner surface of the neck portion 2 or the like, that is, a discharge other than the inter-electrode discharge. [Effect] Since the inner surface of the neck portion 2 is forcibly charged up and knocked by the charge-up voltage, it is possible to knock the discharge source of the discharge due to the charge-up without prolonging the knocking time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for knocking a cathode ray tube, and particularly discharges such as stray (dark current), creeping discharge, and electron avalanche caused by charge-up on the inner surface of the neck, that is, other than interelectrode discharge. The present invention relates to a method for knocking a discharge source of the above discharge, for example, burrs, dust, and the like, and a cathode ray tube capable of preventing the occurrence of a discharge other than an interelectrode discharge during use.

[0002]

2. Description of the Related Art A cathode ray tube, which is often used for a television receiver, a display of a computer, or the like, causes discharge or stray in an electron gun. The inside of the cathode ray tube is called a vacuum, but it is not a complete vacuum, and since a high potential difference occurs between the grid electrodes formed with a narrow interval in the electron gun, slight dust, burrs, etc. This is because the presence causes electrolytic concentration, resulting in discharge. If a discharge occurs, it will appear on the screen, and a loud and loud sparking sound will be generated, not only making the viewer uncomfortable, but also anxiety, especially a sign of an accident such as an explosion. May cause anxiety based on such misunderstandings.

Therefore, a knocking step is required for manufacturing the cathode ray tube. This is because dust, burrs, etc., which cause discharge when the cathode ray tube is completed and is actually used by being incorporated in a television receiver or a computer display, is completed by the completion of the cathode ray tube. In order to remove it before incorporating it into a rear television receiver or the like, it is a process of intentionally causing a discharge by applying a voltage so that a potential difference higher than a normal potential difference applied during use is generated between the electrodes. FIG. 4 is an explanatory diagram showing a conventional example of a knocking method for a Trinitron (trademark) type cathode ray tube.

In the drawings, 1 is a funnel, 2 is a neck portion, 3 is a bead glass for supporting an electrode of an electron gun, 4 is an anode, and 5 is a convergence deflector. G1-G
Reference numeral 5 denotes first to fifth grid electrodes of the electron gun. When used, the first electrode G1 is at 0V, the second electrode G2 is, for example, several 100V (300V to 500V), and the third electrode G3 is, for example, 30KV. (In short, the same voltage as the anode voltage),
The fourth electrode G4 is, for example, 8 KV, and the fifth electrode G5 is the third.
The same potential as that of the electrode of, for example, 30 KV is applied. And
Between G5 and G4, between G4 and G3, between G3 and G2 is 2
Even though the potential difference is 0 KV, the interval is, for example, 2
It is as narrow as about mm. Therefore, if there is burrs or dust on the surface of the electrodes, the electric field concentrates there and discharge occurs between the electrodes. 6 is a burr or dust that is the source of the discharge (discharge source),
Reference numeral 7 is a discharge caused by the electric field concentration due to the dust.

In many cases, the discharge source 7 scatters and disappears due to the discharge. Therefore, in the manufacturing stage, knocking is a condition in which discharge is more likely to occur to forcibly generate discharge so that discharge does not occur during use. Knocking is the normal anode voltage applied to the anode (for example, It is performed by using a knocking power source 8 that generates a knocking voltage (for example, 60 KV) higher than 30 KV. Specifically, low voltage electrodes, that is, G4, G2, G
1 to the same potential, and the low voltage electrodes G4, G2, G1
Knocking is performed by applying the knocking voltage between the high voltage electrodes G3 and G5.

If a DC voltage is used as the knocking voltage, the electron gun may be destroyed, so a pulse voltage having a waveform as shown in FIG. 3B is used. The left example is a knocking voltage of a rectangular pulse having a duty ratio of about 0.1 to 0.2 with a cycle of 1 second, and the middle example is a knocking voltage having a half-wave rectified waveform of 60 Hz.
The example on the right is the knocking voltage of a spike-shaped pulse with a narrow pulse width created by using an induction coil or the like. Note that knocking may be performed using one type of knocking voltage, or knocking may be performed by switching and applying a plurality of types of pulses having different waveforms. The knocking time is, for example, several ten minutes to several tens of minutes. Due to such knocking, the first to fifth grid electrodes G1 to G
Of the low-voltage electrodes G4, G2, G1 and the high-voltage electrodes G3, G5 among the five, that is, the discharge sources 7 such as burrs and dust that cause the inter-electrode discharge can be almost completely removed. it can.

[0007]

However, according to the above-described conventional knocking method, it was not possible to completely prevent the discharge at the electron gun portion of the cathode ray tube. This is because in actual use, various discharge phenomena occur in addition to the inter-grid electrode discharge, and discharges other than the inter-grid electrode discharge cannot be prevented by the conventional knocking method.

There are three types of discharges other than the inter-electrode discharge, the first of which is the inner surface of the neck portion 2 due to charge-up of the inner surface, and the low voltage electrodes such as the grid electrodes G1 and G2 in the case of the above-mentioned trinitron cathode ray tube. , G4 causes a stray (dark current), the second is due to an electron avalanche phenomenon due to charge-up of the inner surface of the neck portion 2, and the third is the inner surface of the neck portion 2, a built-in dividing resistor.
This is due to creeping discharge on the surface of an insulator such as bead glass. These discharges are extremely charged because the inner surface of the neck portion 2 is charged up by the potential of the high voltage electrodes, for example, G3 and G5 by using the cathode ray tube, or the surface of the insulator such as the built-in dividing resistor and the bead glass is charged up. This is a phenomenon caused by a high potential.

More specifically, the first one is
Although the electron gun is in a vacuum, it is not a vacuum in a strict sense, and a high potential difference is generated in the electron gun, that is, as shown in FIG. Since the grid electrodes G1, G2, G4 are extremely close to each other, a leakage current due to a high potential difference flows between them. The second one is the inner surface of the neck portion 2 charged up from the grid electrodes G1, G2, G4. When electrons collide due to a high potential difference between the navels, twice the electrons are emitted as secondary electrons from the inner surface of the neck portion 2. Then, two positive charges are formed on the inner surface of the neck portion 2. By repeating such a phenomenon, a phenomenon occurs in which the electrostatic charges move along the inner surface of the neck portion 2 as if an avalanche had occurred.

The third one is a phenomenon in which the same electronic avalanche that occurs along the inner surface of the neck portion 2 occurs on the surface of an insulator such as bead glass or a built-in split resistor. Similar to the case of the inter-electrode discharge, these mainly generate dust, burrs and the like on the electrode surface and the inner surface of the neck portion 2 as the discharge source.
Then, it is difficult to remove such a discharge source other than the inter-electrode discharge by the above-described conventional knocking method.
Because, from the viewpoint of productivity, knocking must be performed within a time of, for example, 10 to 10 minutes.
This is because a knock-up voltage having a waveform as shown in FIG. 3B does not cause a charge-up state that would occur during actual use even if the knocking voltage takes such a time.

Of course, the knocking time is, for example, several hours to
When the time is as long as ten hours or more, the charge-up is relatively close to that in actual use, and the high knocking voltage removes the discharge source that causes the discharge other than the inter-electrode discharge. However, doing so results in a significant loss of productivity and is practically unacceptable. Further, if the knocking voltage is set to direct current and the so-called duty ratio is set to 100%, charge-up can be performed quickly, but if the waveform of the high knocking voltage is set to a direct current waveform or the duty ratio is set to a value close to 100%,
This is also unacceptable as the cathode ray tube will break.

The present invention has been made to solve the above problems, and a novel knocking method capable of removing a discharge source of discharges other than the interelectrode discharge without spending time and an interelectrode discharge. An object of the present invention is to provide a novel cathode ray tube in which no discharge other than discharge occurs.

[0013]

According to the knocking method of claim 1, an electrode body is provided on the outer surface of the neck portion (in two cases, that is, a case where it is provided temporarily, that is, only when knocking is performed, and a case where it is provided permanently. A voltage is applied between the electrode body and the electrode of the electron gun to promote the charge-up of the inner surface of the neck, and the discharge source of the discharge caused by the charge-up of the inner surface of the neck is knocked. Is characterized by.

The knocking method according to a second aspect is the knocking method according to the first aspect, which is performed at the same time as knocking between the electrodes of the electron gun. The knocking method according to a third aspect is the knocking method according to the first aspect, which is performed separately from the inter-electrode knocking of the electron gun. The cathode ray tube according to claim 4 is characterized in that an electrode body to be grounded is formed on the outer surface of the neck.

[0015]

According to the knocking method of the first aspect, by applying a voltage to the electrode body provided on the outer surface of the neck portion, the inner surface of the neck portion and the surface of the internal insulator such as the built-in dividing resistor and the glass bead connected to the inner surface of the neck portion are cleaned. It can be charged up and, in turn, can form a charge-up state similar to or higher than that which occurs in actual use without taking time. Therefore, it is possible to remove the discharge source of the discharge other than the inter-electrode discharge caused by the charge-up without increasing the time required for knocking.

According to the knocking method of the second aspect, since the discharge source of the inter-electrode discharge of the electron gun is knocked at the same time, the discharge source of the inter-electrode discharge and the discharge source of the discharge other than the inter-electrode discharge can be simultaneously removed. The discharge sources can be completely removed without increasing the time required for knocking. According to the knocking method of claim 3, the discharge source of the inter-electrode discharge is knocked under the condition most suitable for this knocking, and the discharge source of the discharge other than the inter-electrode discharge is knocked under the most suitable condition for this knocking. You can Therefore, the two types of knocking can be surely performed. According to the cathode ray tube of claim 3, since the grounded electrode body is formed on the inner surface of the neck portion, the inner surface of the neck portion is not likely to be charged up, and the inner surface of the neck portion is further charged up. There is no room for a discharge other than the inter-electrode discharge caused by.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 is an explanatory view showing one embodiment of the knocking method of the present invention. In the drawings, 1 is a funnel, 2
Is a neck portion, 3 is a bead glass for supporting an electrode of an electron gun, 4 is an anode, and 5 is a convergence deflector.
G1 to G5 are first to fifth grid electrodes of the electron gun, and when in use, the first electrode G1 is at 0 V, the second electrode G2 is, for example, several 100 V (300 V to 500 V), and the third electrode G3 is at For example, 30 KV (in short, the same voltage as the anode voltage), the fourth electrode G4 is, for example, 8 KV, and the fifth electrode G5.
Is set to the same potential as the third electrode, for example, 30 KV.

Reference numeral 9 denotes, for example, a ring-shaped electrode plate that is applied to the outer surface of the neck portion 2 (in other words, is temporarily formed), and has a charge-up voltage for charging up the inner surface of the neck portion 2 when knocking. In this example, the anode voltage (for example, 30 KV)
A higher voltage (for example, 30 to 50 KV) is applied as a charge-up voltage between the first grid electrode G1 and the cathode potential. Then, the inner surface of the neck portion 2 is charged up via an electrostatic capacitance (so-called capacitor) having the inner portion of the neck portion 2 and the electrode body 9 made of glass as the dielectric material. . Reference numeral 10 is a charge-up power supply that generates the charge-up voltage. Even if the charge-up voltage is a direct-current voltage, there is no possibility that a trouble such as destruction of the electron gun will occur, so it is not necessary to use a pulse-like voltage, and a direct-current voltage may be used. This is also a DC voltage in this example, because it can be charged up more quickly.

An insulating liquid 11 (for example, an inert liquid such as Fluorinert under the trade name) is contained in the tank 12.
The insulating liquid 11 is for maintaining the insulation between the electrode plate 9 and the stem pin (not shown) at the time of knocking, and knocks the neck portion 2 of the cathode ray tube while being immersed therein. This is because if the above-mentioned high charge-up voltage of several tens of KV is applied between the stem pin having a narrow interval and the electrode plate 9, a trouble such as a short circuit or a discharge is likely to occur, and insulation is required. The insulating liquid may be insulating oil.

For knocking, as described above, the charge-up voltage generated from the charge-up power supply 10 is applied to forcibly charge up the inner surface of the neck portion 2 and, similarly to the conventional knocking method shown in FIG. , The normal anode voltage applied to the anode 4 (for example, 30 KV)
Using a knocking power supply 8 that produces a higher knocking voltage (eg 60 KV), lower voltage electrodes, namely G4, G
2 and G1 are set to the same potential, and the low voltage electrodes G4, G2 and G
1 by applying the knocking voltage between the high voltage electrodes G3 and G5. Knocking time is 1
It is 0 to several tens of minutes. Then, first of all, the discharge source of the inter-electrode discharge can be removed in the same manner as the discharge source of the inter-electrode discharge can be removed by the conventional knocking method.

If a DC voltage is used as the knocking voltage, the electron gun may be destroyed.
The use of the pulse voltage having the waveform as shown in (B) is no different from the conventional case. Further, as in the conventional case, knocking may be performed using one type of knocking voltage, or knocking may be performed by switching and applying knocking voltages of a plurality of types of pulses having different waveforms.

By this knocking, the discharge source of the discharge other than the inter-electrode discharge can be removed. This is because knocking is performed for a short time of only ten or more minutes, but is forced by applying a high charge-up voltage to the electrode body 9 provided temporarily (or permanently) on the outer surface of the neck portion 2. Since the inner surface of the neck portion 2 is charged up, the inner surface of the neck portion 2 immediately becomes a strong charge-up state which is equal to or higher than the charge-up that occurs when a normal cathode ray tube is used immediately after the application of the charge-up voltage is started. This is because various discharges due to charge-up on the inner surface or the like, that is, discharges other than the inter-electrode discharge also occur, and the discharge source other than the inter-electrode discharge is removed.

FIG. 2 is a transition diagram of the cumulative value of the number of discharges at the time of knocking, where the horizontal axis represents time and the vertical axis represents the cumulative value of discharge frequency. As is clear from this figure, the inter-electrode discharge reaches about 2000 times in a few minutes and is saturated. Saturation means that no discharge has occurred, and it can be said that the discharge source of inter-electrode discharge can be removed. Moreover, since the potential difference between the low-voltage electrode and the high-voltage electrode at this time is extremely higher than that in the normal use condition (for example, about twice), it is certain that the discharge source cannot be a discharge source under normal use conditions. It can be said that the discharge source in normal use can be completely removed because the discharge can be generated and removed.

Further, as is apparent from FIG. 2, the accumulated value of the number of discharges other than the inter-electrode discharge, that is, the number of discharges due to the charge-up of the inner surface of the neck portion 2 increases in a substantially stepwise manner every 1 minute. Is saturated in about 10 minutes, and is completely saturated in about 15 minutes. Discharges other than this electrode-to-electrode discharge hardly occurred during knocking by the conventional knocking method, and therefore the knocking effect hardly occurred, but in this knocking method, knocking occurs while charging up. The knocking effect can also be obtained for discharge sources other than the inter-electrode discharge. Moreover, the charge-up voltage is 50 to 1
Since it is set to a voltage considerably higher than the anode voltage of 00 KV (for example, 30 KV), it is possible to charge up more strongly than normal charge-up, and it is possible to reliably discharge even a thing that cannot be a discharge source under normal use conditions. It can be generated and removed. Therefore, regardless of whether it is the discharge source of the inter-electrode discharge or the discharge source of a discharge other than the inter-electrode discharge, the discharge source that is normally used can be completely removed.

In the present embodiment, the charge-up voltage was set higher than the anode voltage (eg 30 KV). However, it is not always necessary to do so, and a voltage similar to or lower than the anode voltage may be selected as the charge-up voltage. In short, it suffices to be able to form a charge-up that is stronger than, or about the same as, the charge-up that occurs during normal use, or that is relatively close to the charge-up during knocking.
In addition, in the present embodiment, the electrode body 9 has the neck portion 2
Although the outer surface is covered over the entire circumference, only the portion susceptible to charge-up may be selectively contacted for knocking, and the electrode body 9 is not necessarily plate-shaped. It does not have to be present, and a ring-shaped one may be used.

In addition, in this embodiment, the charge-up electrode body 9 for knocking is provided on the knocking device side, and the electrode body 9 is brought into contact with the outer surface of the neck portion 2 at the time of knocking (so-called temporarily. Form) Neck 2
Although the inner surface is charged up, a conductive film is formed on the outer surface of the neck portion 2 of the electron gun, that is, it is formed permanently and used as an electrode body for charging up at the time of knocking. good. Further, in this embodiment, the knocking voltage and the charge-up voltage were applied in the anode grounded circuit configuration, but the stem side grounded circuit configuration in which the stem side is grounded is the opposite, and the knocking voltage and the charge-up voltage are applied. A voltage may be applied. Although the electron gun shown in FIGS. 1 and 3 is a unipotential type electron gun, the knocking method of the present invention can be applied to a bipotential type electron gun as well, and the aperture grill can be colored. The present invention can be applied not only to knocking a cathode ray tube used as a selection electrode, for example, a Trinitron type cathode ray tube, but also to knocking a shadow mask type cathode ray tube.

Further, in the above-described embodiment, knocking of the discharge source for inter-electrode discharge and knocking by charging up the inner surface of the neck portion 2 and the like are performed at the same time. However, it is not essential to do so,
For example, first, knocking is performed by applying only a knocking voltage under conditions most suitable for knocking a discharge source of inter-electrode discharge, and then the knocking voltage application conditions are optimal for removing discharge sources of discharges other than inter-electrode discharge. Knocking may be performed by switching to conditions and further applying a charge-up voltage. With this configuration, the knocking time becomes longer than that in the case where the knocking of the discharge source for the inter-electrode discharge and the knocking of the discharge source for the discharge due to the charge-up of the inner surface of the neck portion 2 are performed at the same time. Each type of knocking can be performed under the optimum conditions, resulting in more perfect knocking.

FIG. 2 shows a cathode ray tube in which an electrode body is constantly formed on the outer surface of the neck portion and is grounded. According to such a cathode ray tube, discharge due to charge-up on the inner surface of the neck portion 2, that is, electrode There is no risk of discharge other than inter-discharge. 9 is the electrode body. Because the neck 2
In this case, the electrode body 9 faces the inner surface of the neck portion 2 with the meat portion sandwiched between the electrode body 9 and the inner surface of the neck portion 2, and the neck portion 2 itself serves as a dielectric (so-called capacitor).
Exists, and the electrode body 9 is grounded, the electrode body 9 has the same potential as the cathode when the electron gun is used, so that the inner surface of the neck portion 2 can hardly be charged up, and therefore the neck portion 2 There is no risk of discharge due to charge-up on the inner surface. Therefore, according to such an electron gun, it is not necessary to knock the discharge source due to charge-up. However, the necessity of knocking remains for the inter-electrode discharge.

[0029]

According to the knocking method of the first aspect of the present invention, by applying a voltage to the electrode body provided on the outer surface of the neck, the inner surface of the neck and the surface of the internal insulator such as the built-in dividing resistor and the glass beads connected to the inner surface of the neck are cleaned. It can be charged up and, in turn, can form a strong charge-up state similar to or higher than that which occurs when actually used, without taking time. Therefore, it is possible to remove the discharge source of the discharge other than the inter-electrode discharge caused by the charge-up without increasing the time required for knocking.

According to the knocking method of the second aspect, since the knocking is performed simultaneously with the inter-electrode knocking of the electron gun, the discharge source of the inter-electrode discharge and the discharge source of the discharge other than the inter-electrode discharge can be removed at the same time, and the time required for knocking Both discharge sources can be completely removed without lengthening. According to the knocking method of claim 3, knocking of the discharge source of the inter-electrode discharge is performed under the condition most suitable for the knocking, and knocking of the discharge source of discharge other than the inter-electrode discharge is performed under the most suitable condition for the knocking. be able to. Therefore, the two types of knocking can be surely performed. According to the cathode ray tube of claim 4, since the grounded electrode body is formed on the inner surface of the neck portion 2, the inner surface of the neck portion is not likely to be charged up, and the inner surface of the neck portion is further charged up. There is no room for electric discharges other than the inter-electrode discharge, which is caused by this.

[Brief description of drawings]

FIG. 1 is an explanatory view of one embodiment of a knocking method of the present invention.

FIG. 2 is a transition diagram of a cumulative value of the number of discharges during knocking in the above embodiment.

FIG. 3 is a view showing one embodiment of the electron gun of the present invention.

4A and 4B are diagrams for explaining a conventional example, FIG. 4A shows a cathode ray tube, and FIG. 4B is a waveform diagram showing another example of a knocking voltage.

FIG. 5 is an explanatory diagram of charge-up on the inner surface of the neck portion 2.

[Explanation of symbols]

 2 Neck part 8 Knocking power supply 9 Electrode body 10 Charge-up power supply G1 to G5 Grid electrode (electrode)

Claims (4)

[Claims] 1. An electrode body is provided on the outer surface of the neck portion, and a voltage for promoting charge-up of the inner surface of the neck portion is applied between the electrode body and the electrode of the electron gun to cause charge-up of the inner surface of the neck portion. A knocking method characterized by knocking a discharge source of a discharge other than an inter-electrode discharge 2. The knocking method according to claim 1, wherein the inter-electrode discharge of the electron gun is knocked at the same time as the knocking of the discharge source. 3. The knocking method according to claim 1, which is performed separately from the knocking of the discharge source of the inter-electrode discharge of the electron gun. 4. A cathode ray tube characterized in that an electrode body to be grounded is formed on the outer surface of the neck portion.