JPS6070644A - Inline type electron gun - Google Patents

Abstract

PURPOSE:To obtain a high resolution characteristic of the captioned electron gun by providing a region projecting toward an accelerating electrode on a central portion of a focusing electrode and by displacing a common central axis of side beam holes through the focusing electrode from that of side beam holes through a control electrode and the accelerating electrode to the tube axis side. CONSTITUTION:A center beam hole 16a and both side beam holes 16b, 16c through a control electrode 12 respectively corresponding to negative electrodes 11a, 11b, 11c respectively have central axes 18a, 18b, 18c in common with a center beam hole 17a and both side beam holes 17b, 17c through an accelerating electrode 13. The central axis 18 lies on a tube axis 19. A projecting region 14a projecting to the electrode 13 side is formed at the central portion of a focusing electrode 14. A center beam hole 22a and both side beam holes 22b, 22c through the electrode 14 have central axes 24a, 24b, 24c in common with a central beam hole 23a and both side beam holes 23b, 23c through a final accelerating electrode 15. The central axis 24a lies on the tube axis 19. The central axes 24b, 24c are provided displaced to the tube axis 19 side from the central axes 18b, 18c.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an in-line electron gun for a color picture tube.

Conventional configuration and its problems In general, in a color picture tube equipped with an in-line electron gun in which three electron beam emission ports are arranged in a straight line, a center beam 1a and both side beams are used as shown in FIG. 1b, 1c main lenses 2a, 2b,
2c, where it receives a focusing action. And both side beams 1b.

1 G is concentrated at a central point 3 on the phosphor screen surface together with the center beam 1a.
Beam concentration angle 0 between b+10 and center beam 1a
will be granted. 1, the deflection magnetic field is a self-convergence magnetic field, and the center beam 1a and both side beams 1b+1c are configured to concentrate at one point even in areas other than the central point 3 on the phosphor screen surface. The beam concentration angle 0 thus determined affects the beam concentration characteristics over the entire area on the phosphor screen IJ-plane.

To set the beam concentration angle of 0, there is a method of arranging three electron guns at an angle, but with this method, due to assembly errors when integrating three independent electron guns, the beam concentration angle of 0
It is easy to cause variations in the results.

Therefore, an integrated type electron gun as shown in FIG. 2 is usually employed. The integrated type electron gun was manufactured by Special Publication No. 52-4905.
Although it is described in detail in the publication, etc.

Beam hole 5a at the end surface of the focusing electrode 4 on the final acceleration electrode side
, sbν 6C, both side beam holes 6b.

6C's central axes 6b, 60, and the valley central axes 9b, 9Q of both side beam holes 81), 80 of the beam holes 8a, sb, 8c on the end surface on the focusing electrode side of the final acceleration electrode 7.
By making both the main lenses 10b and IC1 eccentric and axially asymmetrical, both side beams are electrostatically deflected by an amount corresponding to a beam concentration angle of 0.

By the way, in such an integral type electron gun, the eccentricity for giving the beam concentration angle θ is determined by the eccentricity between both side beam holes 5b and 60 of the focusing electrode 4 and both side beam holes 8b and 80 of the final accelerating electrode 7. Since freezing depends on the relative positions of the electrodes 4 and 7, very strict machining accuracy is required for both electrodes 4 and 7.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an integrated in-line electron gun that does not require eccentricity of the central axis as described above between both side beam holes of a focusing electrode and both side beam holes of a final acceleration electrode. There is a particular thing.

Structure of the Invention According to the present invention, a protruding region protruding toward the accelerating electrode is provided at the center of the end surface of the focusing electrode on the accelerating electrode side, a center beam hole is provided in the protruding region, and a beam hole is provided on both sides of the focusing electrode avoiding the protruding region. Side beam holes are provided respectively, and the central axis common to the valley Zide beam holes on the mutually opposing end surfaces of the focusing electrode and the final acceleration electrode is set to be smaller than the central axis common to the side beam holes of the control electrode and the accelerating electrode. This will be explained in detail below together with the embodiments shown in the drawings.

Description of the Embodiment In FIG. 3, three cathodes 11 a, 1 l b, 110 . . . are arranged horizontally and in a straight line. The control electrode 12° acceleration electrode 13, the focusing electrode 14 and the final acceleration electrode 15 are:
It constitutes an integrated in-line type electron gun, and the center beam hole 16a and both side beam holes 16b, 160 of the starvation electrode 12 are connected to the center beam hole 17a and both side beam holes 17b, 170 of the accelerating electrode 13, respectively. They have a common central axis 1B&, 18b, 180, and a central axis 18a common to both center beam holes 16a, 17a is on the tube axis 19.

Further, a circular protrusion region 141L with a protrusion length of 1 width W and protruding toward the acceleration electrode 13 side is formed in the center of the end surface of the focusing electrode 14 on the acceleration electrode side, and a center beam hole 20& is formed in the protrusion region 14a. , and both side beam holes 20b+ 200 are provided on both sides avoiding the protruding region 14a. It's 1.

The valley central axes of these beam holes 20J, 20b, and 20C are located on the aforementioned common central axis 1B &, 18b+180, respectively.

On the other hand, the center beam hole 22& and the side beam holes 22b, 22 at the end surface of the focusing electrode 14 on the final acceleration electrode side
(, Id, center beam hole 23 & and side beam hole 23b on the end surface of the final accelerating electrode 15 on the focusing electrode side,
230 and common central axes 24 a, 24 b, respectively.
It has 24C.

The central axis 24a common to both center beam holes 22&+ 232L is on the tube axis 19, but the side beam hole 22bl
Central axis 24 common to 220 2ab and 230 respectively
b, 24QQ, are eccentric to the tube axis side from the aforementioned common central axis 18b, 180.

In the in-line electron gun configured in this manner, a curved lens electric field 25 as a whole is generated between the accelerating electrode 13 and the focusing electrode 14, as shown in FIG. That is, a strong axially symmetrical prefocus lens electric field 25iL is generated between the center beam aperture 17& of the accelerating electrode 13 and the center beam aperture 20& of the focusing electrode 14, while the side beam apertures 17b, 170 of the accelerating electrode 13 and the focusing electrode 1
Axis-asymmetric prefocus lens electric fields 25 b and 26 C are generated between the side beam holes 20 b and 200 of No. 4 .

For this reason, 3III! il cathode 11 a, 1 l b
, 11C, and the center beam hole 16a and side beam hole 16bν 1 of the control electrode 12.
The three electron beams that passed through 6C are prefocused v
electric field 25 K: Therefore, the prefocus lens electric field on both sides is 2tsb.

25c is axially asymmetrical, so both side beams are slightly deflected toward the tube axis.

In FIG. 6, three prefocus lens parts are shown as equivalent electron sources 26 &, 26 b, 260, and the equivalent electron sources 26k13260 on both sides are separated by ΔX from the common central axis 24b, 24c. Each is eccentric. The center beam 272L then travels straight on the tube axis 19 and passes through the axially symmetrical center main lens 28a on the tube axis 19.
while the two side beams 27b, 270i
The side main lens 28b advances at an angle of dα.
.

Inject into 280.

Center beam 271L and both side beams 27b,
270 is the main lens 28 a + 2 s b +
Both side beams 27b are respectively focused by 2BO and when no deflection magnetic field acts.

270 is on the phosphor screen surface 29, the central axis 24b,
240 by Δx−M. however.

Here, M indicates lens magnification.

Therefore, the amount of deviation (Δx−M) is
If the eccentricity ΔX is set to be equal to the inter-axial distance S between b+ 240 and the tube axis 19 (Δx-M=8),
Center beam 27a and both side beams 27b, 2
70 can be concentrated at a central point on the phosphor screen surface 29.

Prefocus lens electric field on both sides 2sb.

250 and both side beams 27b, 270 are asymmetrical in their respective axes, but if the protruding length and width W of the protruding region 14& are appropriately set to give an appropriate inclination angle σ, the phosphor screen surface 29 The beam spot (bright spot) can be made close to a perfect circle. Moreover, the eccentricity caused between the accelerating electrode and the focusing electrode to which a relatively low voltage is applied.

The amount of eccentricity produced between high voltage electrodes is small compared to the conventional method, and all main lenses are axially symmetrical. Furthermore, since there is no need to provide eccentricity to the beam hole central axis between the opposing end surfaces of the focusing electrode 14 and the final accelerating electrode 16,
The final acceleration electrode side half of the focusing electrode 14 and the final acceleration electrode 1
6 can be formed using the same press mold,
It is possible to reduce convergence defects caused by variations in the shapes of both electrodes 14 and 16. Furthermore, even if the roundness of the beam hole cannot be obtained satisfactorily due to the peculiarities of the press mold, at least the beam focusing can be improved by combining the mutually opposing end surfaces of both electrodes 14 and 16 in an upside-down relationship. Good left-right symmetry can be achieved, and a good beam spot can be obtained.

In another electron gun according to the present invention shown in FIG.
On both sides of 3, a protrusion 3oa protrudes toward the focusing electrode 14 side,
It has 3ob. With this configuration, the necessary prefocus lens electric field 26 can be obtained without increasing the protrusion length of the protrusion region 141L too much.

Effects of the Invention Since the in-line electron gun of the present invention is constructed as described above, it is easy to manufacture, manage, and assemble the relatively complicated focusing electrode and final accelerating electrode, and it is possible to obtain a good beam spot shape and high resolution characteristics. can be obtained.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining the concentration of three electron beams by a conventional in-line electron gun, Fig. 2 is a side sectional view showing the electrode configuration of a part of the same electron gun, and Fig. 3 is a diagram for explaining the concentration of three electron beams by a conventional in-line electron gun. 4 is a side sectional view of the in-line electron gun. FIG. 4 is a diagram for explaining the electric field of the prefocus lens of the electron gun. FIG. 5 is a diagram for explaining the concentration of three electron beams by the electron gun. The figure is a side sectional view of a main part of another embodiment of the present invention. 12... Control electrode% 13... Acceleration electrode %14... Focusing electrode, 14a...
Projection region, 15...Final acceleration electrode, 16t),
160, 17b, 17C. 20b, 200+ 22b, 220.23b, 230・
...Side beam hole. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 Amendment to figure procedure December 20, 1988 Patent Application No. 177366 (1988) 2. Name of the invention In-line electron gun 3. Relationship with the person making the amendment Patent application Address: Kadoma, Taihanfu City Oaza Kadoma 1006 address name (
584) Matsushita Electric Industrial Co., Ltd. Representative Kiyoshi Miyama - 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Column 6 for the detailed description of the invention in the specification subject to the 6th amendment; Contents of the amendment (1) “Circular” in the 8th line of the 6th page of the specification was changed to 5
Correct it to "circular or rectangular".

Claims (1)

[Claims] A protruding region protruding toward the accelerating electrode is provided in the center of the end surface of the focusing electrode on the accelerating electrode side, a center beam hole is provided in the protruding region, and side beam holes are provided on both sides avoiding the protruding region, and The central axis common to each side beam hole on the mutually opposing end surfaces of the focusing electrode and the final accelerating electrode is eccentric to the tube axis side with respect to the central axis common to each side beam hole of the starvation electrode and the accelerating electrode. Features an in-line electron gun.