KR950004851Y1 - B-u type electron gun for crt - Google Patents

Abstract

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Description

G3-type discharge structure of B-U type electron gun for color cathode ray tube

1 is a cross-sectional view of a conventional electron gun structure.

2 is a diagram showing spark generation in a knocking process in a conventional configuration.

3 is a cross-sectional view of an electron gun structure according to the present invention.

4 is a spark generation degree during the knocking process in the present invention.

5 (a) is an explanatory diagram of the potential difference when a charged particle having an amount of charge qo moves the path AB by an electric force. Figure of potential difference when

6 is a reference diagram that looks at the characteristic data of the present invention.

* Explanation of symbols for main parts of the drawings

9, G ₄ : electrode 10, G ₅ : electrode

11, G ₆ : electrode 1a, G ₅ -G ₆ : electrode spacing

2a, G ₄ -G ₅ : electrode spacing

The present invention relates to a discharge structure of the focusing electrode G ₃ system constituting the main electrostatic lens of a BU (Bi-Unipotential Focus) type electron gun, which is particularly adjusted at the time of knocking by appropriately adjusting the inter-electrode spacing at the portion where high voltage is applied. It is to keep the focusing electrode G ₃ -type electrode clean by generating the speaker evenly.

In the conventional electron gun focusing electrode G _three- based discharge structure, as shown in FIG. 1, three cathodes 4a, 4b, and 4c are arranged inline, and high heat is generated by the heaters 5a, 5b, and 5c. And hot electrons are emitted from the cathodes 4a and 4c, which form a beam that is controlled by the G ₁ electrode 6 as it passes through each electrode and is accelerated by the G ₂ electrode 7 to form the main lens. The fluorescent material of the panel piece is emitted through the focusing electrode G ₃ electrode 8, the focusing electrode G ₅ electrode 10, the connecting electrode G ₄ electrode 9, the focusing electrode G ₆ electrode 11, and the shield cup 12. To compose the screen.

The electrodes are fused and fixed at regular intervals by an insulator bead glass, and an intermediate voltage of about 6.5 to 10.5 [KV] is applied to the focusing electrodes G ₃ and G ₅ electrodes, and the accelerating electrodes G ₄ and G ₆ electrodes. Since a high voltage of about 20 to 25 [KV] is applied, a voltage difference is remarkably generated between the accelerating electrodes G ₄ and G ₆ electrodes and the focusing electrodes G ₃ electrodes and G ₄ electrodes.

At this time, the discharge phenomenon can be roughly classified into two types, the first is A-Stray, which is an afterimage appearing on the screen, and the second is non-stray, which is a light emission phenomenon appearing on the neck portion into which an electron gun is inserted. This discharge phenomenon appears as a phenomenon of non-stray when cold electrons generated at the electron gun electrode hit the neck portion and A-stray when hitting the screen.

In particular, the discharge phenomenon is generated in three forms due to the electrode voltage difference.

Firstly, the focusing electrode G ₃ system stray generated by the difference between the anode voltage and the focusing voltage, and secondly, the acceleration electrode G ₂ system stray generated by the voltage difference between the focusing voltage and the accelerating electrode G ₂ system, and G _2. And G ₁ strays generated by the system acceleration voltage and the control voltage difference on the G ₁ electrode side.

The by these symptoms prior art of the first ceramic acceleration voltage of the accelerating electrode G ₄ electrode G is applied to the _six electrodes, since yirwojyeo to form the focusing voltage applied to the focusing electrode G ₃ electrodes and G ₅ electrode G ₃ based Stray is very fragile.

In addition, when foreign matter adheres to the electron gun or the neck portion, there has been a problem because a discharge phenomenon that causes deterioration of operation characteristics is particularly severe.

Therefore, in order to remove such discharge phenomenon, the electron gun needs to be cleaned. However, there is a limit to the operation of the electron gun. Therefore, a clean up operation is performed to clean the electron gun through a process called knocking.

2 shows a voltage application diagram of a general knocking step performed before aging. A high voltage of about 60 to 80 [KV] is placed on the acceleration electrode G ₄ electrode 9 and the G ₆ electrode 11, and other electrodes G are shown. _{1, G 2, G 3,} G 5 electrodes to a ground electrode G _3, G ₄ electrode gap 3 and the electrode G _4, G ₅ the distance between electrodes 2 and the electrode G ₆ electrode and the electrode G ₆ electrode spacing (1 ), A forced spark is generated to remove foreign matters from the gun.

However, in the above conventional configuration, the G _{3 to} G ₄ electrode gap 3, the G _{4 to} G ₅ electrode gap 2, and the G _{6 to} G ₆ electrode gap 1 are configured in almost the same way. And, being, the application of high voltages to G ₄ electrode and G ₆ electrode at the time of knocking G _3, G _5, G _2, the spark phenomenon at the former knocking process G ₁ electrode, because it is the ground G ₅ electrode in G ₆ electrode side, in the G ₄ electrode side G ₃ electrode, G one should occur towards the G ₅ electrode from the _fourth electrode in the electrode spacing structures, such as conventional G _3, G _4, inter-electrode spark 31 and G _4, G ₅ inter-electrode spark ( 21 only occurs, and the spark between the G ₅ and G ₆ electrodes 41 does not occur.

First of all, the G ₄ electrode is composed of a plate electrode, so that the assembly error between the G ₃ electrode and the G ₄ electrode, and the G ₄ electrode and the G ₅ electrode is large, and thus, the G ₅ electrode is relatively high. The smaller part of the gap between the and G ₆ electrodes is inevitably shown, and the forced spark occurs first in this small gap.

The second is that G ₄ electrode is surrounded by a discharge phenomenon, since the ground when knocking occurs easily, going on to this by reason around a G ₄ electrode force shavings active, in the vicinity of G ₅ electrode and G ₆ electrode gap Occurs finely

Therefore, the entire knocking process aims to clean up the G ₃ and G ₅ electrodes as a whole, but there is a problem that the G ₅ electrodes are not cleaned up.

The present invention has been devised to improve the above problems, which is characterized in that, in particular, configured to explain the gap between the G ₄ , G ₅ electrode which is a portion to which a high voltage is applied larger than the gap between the G ₅ , G ₆ electrode and attached thereto When described in detail by the drawings as follows.

That is, as shown in FIG. 3, the interval 2a between the G ₄ electrode 9 and the G ₅ electrode 10, which is a portion to which a high voltage is applied, is spaced between the G ₅ electrode 10 and the G ₆ electrode 11. It is configured to be wider than (1a) so that the forced spark phenomenon 42 is guided between the G ₆ to G ₅ electrode gaps 1a, and the gap between the G ₄ electrodes 10 and the G ₆ electrodes 11 to obtain an optimal knocking effect. It is 1.5 times or more and 2.5 times or less.

Referring to the forced spark phenomenon of the tank gun configured as described above, first, as shown in FIG. 5, a particle having a certain charge qo is located at a point B (or b) at a point A (or a) along an arbitrary path. Assuming that it is moving by, the force acting on the particle can be divided into the electric force by the power source as shown in Fig. 5 (a) and the external force as shown in Fig. 5 (a) Assuming that there is no energy, the external work done to the particle (W _AB ) ext is the potential difference between point A (or a) and point B (b) V _A -V _B = (W _AB ) ext / qo . Thus, the change in potential V _A- V _B is the same as the work done outside the unit shoulder without changing the kinetic energy of the particle charged from point A to point B, and the work (W _AB ) ext is the electric field (E). Same as the opposite of the work done by W _AB .

In other words, the work done by the force applied should be equal to the change in the kinetic energy of the particle.

However, since there is no change in the kinetic energy, (W _AB ) ext + (W _AB ) _E = 0 or (W _AB ) ext = − (W _AB ) _E.

So the difference in potential V _AB =-(W _AB ) _E / qo, (W _AB ) _E = Since qO E · ds, V _A -V _B = qo Eds = qo E · ds.

Therefore, the electric field strength E is proportional to V _A -V _B and inversely proportional to the distance d.

Therefore, according to the above principle, the spacing 2a between the G ₄ electrode 9 and the G ₅ electrode 10 is 1.5 to 2.5 times larger than the spacing 1a between the G ₅ electrode 10 and the G ₆ electrode 11. The forced spark 12 is generated in the gap 1a between the G ₅ and G ₆ electrodes by widening below to weaken the intensity E of the electric field between the G ₄ and G ₅ electrodes.

As an example, the display of the sixth ceramic represents the interval (Gap) of the X axis and G ₄ electrode and G ₅ electrode, the left Y-axis G ₃ based A-represents the stray poor shows a right Y-axis astigmatism (Astigmatism) .

The astigmatism is a screen resolution characteristic, and usually refers to a horizontal focusing voltage value and a vertical focusing voltage value of an electron beam, which are usually managed within + 300V.

In this case, as the gap between the G ₄ electrode and the G ₅ electrode increases, the G ₃ stray defect rate decreases, and when the value exceeds 2.5 times, the appearance is almost without exception. However, as the distance increases, the astigmatism increases, and the area that is not adjusted even after adjusting the focusing voltage is 2.7 times or more.

Therefore, the G ₃ electrode and the G ₅ electrode spacing should be 2.5 times or less than the gap between the G ₃ electrode and G ₄ electrode or the G ₅ electrode and G ₆ electrode to improve the G ₃ stray.

Therefore, the present invention generates a forced spark 42 at the interval 1a between the G ₅ electrode and the G ₆ electrode of a BU (Bi-Unipotential Focus) type electron gun, thereby achieving a better knocking effect in the G _3- based discharge structure. Will be.

Claims (2)

A triode consisting of a plurality of inline electron beam radiating means for radiating a battery beam, a control electrode and an accelerating electrode (anode electrode) for adjusting the radiation amount and crossover of the electron beam, and a focus for connecting the electron beam to the screen It has a main lens consisting of a focusing electrode and an acceleration electrode forming a lens, the focusing electrode is divided into two, the first focusing electrode and the second focusing electrode, the acceleration electrode is also divided into two first and second acceleration electrodes, In a BU type electron gun in which a first acceleration electrode is disposed between the first focusing electrode and the second focusing electrode, and the second acceleration electrode is disposed on the screen side, the distance between the first acceleration electrode and the second acceleration electrode is different. The G ₃ -type discharge port of the BU type electron gun for color cathode ray tubes, which is configured to be larger than the distance between the first focusing electrode and the first acceleration electrode or the distance between the second focusing electrode and the second acceleration electrode. article. The method of claim 1, wherein the interval between the first acceleration electrode and the second focusing electrode is 1.5 times greater than the interval between the first focusing electrode and the first acceleration electrode or between the second focusing electrode and the second acceleration electrode. than that of the color cathode-ray tubes BU-type electron gun, characterized in that large and configured smaller than 2.5 times G ₃ based discharge structure.