JPS6348139B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron gun device, and more particularly to an in-line type electron gun device in which three gunshot beams are emitted in the same plane. This is related to the configuration that concentrates on the content.

In general, an electron gun device for a color picture tube consists of three electron guns each composed of a plurality of grid electrodes.The main lens formed by the electron guns focuses the electron beam, and the electron beam is projected onto the screen. It is something that makes you confront. However, since this type of electron gun device is composed of three electron guns, assembly work is complicated and assembly accuracy is poor. For this purpose, an electron gun device as shown in FIG. 1 has been proposed in recent years. In the same figure, 10a, 10
b and 10c are cathodes (hereinafter referred to as cathodes) arranged at equal intervals on the same plane, and are provided with a heater 10d inside. 1 is the control electrode (hereinafter the first
2 is a shielding electrode (hereinafter referred to as a second grid), and the cathodes 10a, 10 are
Holes 1a, 1b, 1c in the parts corresponding to b, 10c
and 2a, 2b, and 2c. 2nd above
Two box-shaped upper electrodes 3 are located after the grid 2.
A focusing electrode (hereinafter referred to as a third grid) 3 formed by joining the lower electrode 3y and the lower electrode 3y is arranged.
Note that holes 3a, 3 opposite to the holes 2a, 2b, 2c are provided on the second grid 2 side of the lower electrode 3y.
holes 3l, 3m, and 3n for forming main lenses are formed at the bottom of the electrode 3x. 4 is an anode (hereinafter referred to as the fourth grid) having holes 4a, 4b, and 4c at the bottom.
In this case, because it is necessary to have an automatic static convergence characteristic, the central axis S of the holes 4a and 4c through which the side electron beam B passes is the hole 3l and 3n.
It is eccentric to the outside of the central axis T. Reference numeral 5 designates a shield cup disposed at the end of the fourth grid 4, which has a spring support that supplies voltage by press-contacting the internal graphite formed on the inner wall of the neck portion (not shown). Usually, the first grid 1 has 0V, the second grid 2 has 500V, the third grid 3 has 4.5KV, and the fourth grid 4 has 4.5KV.
A voltage that gradually increases to 25KV is applied.

In such a configuration, each cathode 10a,
The side electron beam B emitted from 10b and 10c and the central electron beam (not shown) emitted from the cathode 10b have their beam amounts controlled by the first grid 1, and then are sent to the second to fourth grids 2 to 4. It passes through and hits a luminous surface (not shown). in this case,
Because the main lens formed in this part is decentered due to the positional relationship between the holes 4a, 4c and 3l, 3n, the electron beam B is deflected to the central electron beam side by this lens, so that so-called automatic static focusing is performed on the fluorescent surface. will be carried out.

However, according to the electron gun device having such a configuration, when the focus is adjusted by changing the focus voltage applied to the third grid 3, the deflection angle of the side electron beam changes, and the static concentration on the fluorescent surface changes. It has the disadvantage of being damaged. On the other hand, when adjusting the focus voltage, there are individual differences in whether to focus on the center of the phosphorescent surface or the entire surface, and there are also large variations, so that the focus voltage may be set to different values. Therefore, the magnitude of the static concentration error that occurs is often such that in a 20-inch picture tube, the distance between both beams on the fluorescent surface is about 0.2 mm to 0.4 mm. This phenomenon in which automatic static concentration is disturbed when the focus voltage is changed has become a more important problem in mass production.

Therefore, an object of the present invention is to prevent disturbances in static concentration by making the change in the deflection angle of the side electron beam extremely small even when the focus voltage is changed.

In order to achieve such an object, the present invention constitutes a first focusing means by a focusing electrode and a first electrode in the preceding stage of the focusing electrode, and further includes a focusing electrode and a first electrode in the succeeding stage of the focusing electrode. The two electrodes constitute a second concentration means, and an automatic static concentration mechanism is provided which is synthesized by these first and second concentration means,
This will be explained in detail below using examples.

FIGS. 2a and 2b are a sectional view and a plan view showing an embodiment of an electron gun device according to the present invention, and the same parts as in FIG. 1 are designated by the same reference numerals. In the figure, 11a, 11b, and 11c are protrusions having ring-shaped side walls that protrude toward the second grid 2 side of the lower electrode 3y of the third grid 3 and surround the holes 3a, 3b, and 3c. . The distance between the tip of this protrusion and the second grid 2 is the minimum distance between the two electrodes, and the holes 3a, 3b, and 3c are provided at positions that are set back from the minimum distance between the electrodes. The protrusions 11a, 11b, 11c are perfectly circular, and the central axes V of the protrusions 11a, 11c corresponding to the side electron beams B are eccentric to the outside than the central axes T of the holes 3a, 3c. The central axis V of the central protrusion 11b corresponding to the central electron beam coincides with the central axis T of the hole 3b. FIG. 2b is a plan view showing this eccentric state. That is, the protrusions 11a, 11b, 11
C constitutes a ring-shaped side wall, and the holes 3a, 3b, and 3c are provided in the bottom surface of the ring-shaped side wall.

According to such a configuration, the second grid 2 serving as the first electrode disposed in front of the focusing electrode and facing the focusing electrode
and holes 2 on both sides of the lower electrode 3y of the third grid 3.
A decentered lens can be formed between a and 2c and holes 3a and 3c, and the side electron beam B passing through this part
can be deflected and concentrated toward the central electron beam side, and static concentration can be achieved by the so-called first concentration means. In this case, the deflection angle for the side electron beams B on both sides can be adjusted by appropriately setting the height and eccentricity of the protrusions 11a and 11c. In addition, according to this embodiment, as in the conventional case, the third grid 3 and the fourth grid 4, which is a second electrode disposed opposite to the focusing electrode, constitute a second focusing means, and even during this period, automatic static focusing is performed. It is possible to aim for And in this case, the third grid 3 and the fourth grid
The potential difference between the grid 4 and the potential difference between the second grid 2 and the third grid 3 has an inverse relationship with respect to a change in only the focus voltage of the third grid 3. By increasing the voltage of the grid and reducing the potential difference with the fourth grid 4, the potential difference with the second grid 2 can be increased. This is because a larger voltage is applied to the third grid 3 than to the second grid 2, and a larger voltage is applied to the fourth grid 4 than to the third grid 3. Therefore, if the voltage of the third grid 3 is increased and the potential difference between the third grid 3 and the fourth grid 4 is decreased, the deflection angle of the electron beam passing between the third grid 3 and the fourth grid 4 becomes smaller. Since the potential difference between them increases, the deflection angle of the electron beam passing through this portion can be increased. Therefore, the final deflection angle given to the electron beam is
Even if the focus voltage of the third grid 3 changes,
Nothing will change. This also applies when the voltage of the third grid 3 is reduced.

FIGS. 3a and 3b are a sectional view and a plan view of main parts showing another embodiment of the electron gun device according to the present invention,
Components that are the same as those in FIGS. 2a and 2b are designated by the same reference numerals. In the figure, 12a, 12b, 12c protrude toward the third grid 3 side, and holes 2a, 2b, 2c
It is a protrusion with a ring-shaped side wall formed to surround the. These protrusions 12a, 12b, and 12c are also perfectly circular like the protrusions 11a, 11b, and 11c, and the protrusions 12 corresponding to the side electron beams are
The central axis W of a, 12c is the central axis T of the holes 3a, 3c.
The central axis W of the central protrusion 12b corresponding to the central electron beam coincides with the central axis T of the hole 3b. In this case, the main lens generating mechanism is the same as that shown in FIGS. 2a and 2b.

Therefore, even in such a configuration, the protrusion 1
Since decentered lenses can be formed in the portions corresponding to 2a and 12c, automatic static focusing of the electron beam can be performed, producing the same effect as in the case described with reference to FIGS. 2a and 2b.

FIGS. 4a and 4b are a sectional view and a plan view of main parts showing another embodiment of the electron gun device according to the present invention,
Components that are the same as those in FIGS. 2a and 2b are designated by the same reference numerals. 13a, 13b, 13c are recesses with ring-shaped side walls formed in portions corresponding to the holes 3a, 3b, 3c of the third grid 3, and the central axes X of the recesses 3a, 3c corresponding to the side electron beam B are is hole 3
The central axis X of the recess 13b, which is eccentric to the outside of the central axis T of the holes 3a and 3c and corresponds to the central electron beam, coincides with the central axis T of the hole 3b. In this case, the main lens generating mechanism is the same as that shown in FIGS. 2a and 2b.

Even in such a configuration, the recesses 13a and 13
A decentering lens can be formed in a portion corresponding to c, and automatic static focusing of the electron beam B can also be performed in this portion, and the same effect as in the above case can be obtained.

As explained above, according to the present invention, an electron lens is formed between a focusing electrode and a second electrode disposed opposite to each other at a subsequent stage; Among the electron lenses formed between the three electron beams, the electron lens for the side electron beam, that is, the side electron beam located on the side of the central axis of the device itself, is decentered to separate the three electron beams from the first and second electron beams. Since the focusing means is capable of two-stage automatic static focusing, even if the focus voltage of the focusing electrode changes variously, the change in the deflection angle between the focusing electrode and the second electrode in the succeeding stage is controlled by the focusing electrode and the preceding stage. This can be compensated for by changing the deflection angle between the first electrodes, and has the effect of substantially preventing changes in static concentration.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a conventional electron gun device, and FIGS. 2a, b to 4 a, b are sectional views showing an embodiment of an electron gun device according to the present invention. 1 to 4...1st to 4th grid, 5...
...Shield cup, 10a to 10c...Cathode, 10d...Heater, 11a to 11c, 1
2a to 12c...protrusion, 13a to 13c
...Concavity.

Claims (1)

[Claims] 1. In an in-line electron gun device consisting of an assembly of a plurality of electrodes such as a cathode, a control electrode, and a focusing electrode, and emitting three electron beams in the same plane, a second electron gun disposed oppositely before the focusing electrode 1 electrode and a second electrode disposed opposite to the latter stage of the focusing electrode, and each of the first electrode, the second electrode, and the focusing electrode directs two of the three electron beams. comprising first and second concentrating means for concentrating the side electron beam with the remaining center electron beam, and either the first electrode or the focusing electrode has a distance smaller than the minimum electrode spacing between the two electrodes. A hole provided in the other electrode is provided at the retreated position and in a position surrounded by the ring-shaped side wall, and is coaxial with the hole through which the three electron beams pass individually, and An electron gun device characterized in that the center of the hole through which the side electron beam passes through the electrode is eccentric to the center of the ring-shaped side wall surrounding the hole.