JPS61264642A - Inline type electron gun - Google Patents

Abstract

PURPOSE:To focus the electron beam well and uniformly by making the curvature at the opposite end sections of opening larger and half of the short diameter of said opening. CONSTITUTION:The electron beams 14a, 14b entered into main leanses at the opposite sides are subjected to the focusing force Fs from three directions or the upper and lower sections of the openings 8, 12 and the end section of curved face while the central beam 14b is subjected to the focusing force Fv from two directions or the upper and lower sections of the openings 8, 12. If the curvature rs>phiv/2, Fv may equal to Fs. The electron beams 14a-14c at the opposite sides and in the center are subjected to the focusing forces Fh', Fh'', Fh''' respectively from the partition boards 9a, 9b, 13a, 13b sides thereby when selecting the curvature rs in the recess of partition board in addition to the positional parameters W and L of the partition board, the focusing forces Fs and Fv can be equalized. Consequently, the electron beam can be focused well and uniformly.

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 used in television receivers, data display devices, and the like.

2. Description of the Related Art Conventionally, the raw bottom portion of the main lens of an in-line electron gun has been constructed as shown in FIG. The details are disclosed in Japanese Patent Application Laid-Open No. 59-31544, etc.
Three main lenses 1a, 1b.

The main focusing electrode 2 and the anode 3, which are arranged opposite to each other to generate 1ai, both have a front shape and a side cross-sectional shape as shown in FIGS. 10 and 11, and divide each internal space into three. Partition plate 4&.

4b has arc-shaped recessed portions 5a and 5b on the opening end surface side.

In the in-line electron gun constructed in this way, the openings in the opposing surfaces of the main focusing electrode 2 and the anode 3 are very large, and the curved surfaces at both ends of the electrodes 2.3 and the diaphragm +a
, 4b.

By the action of lens 6b, large diameter main lenses 1a, 1b, and 1c with little spherical aberration can be generated. For this reason, the beam spot generated on the phosphor screen surface can be made smaller in diameter and a clear color image can be reproduced.However, since the cross-sectional shape of both electrodes 2 and 3 is oval, The radius of curvature X of the curved surfaces at both ends of both electrodes 2゜3 is the minor axis φ7
Therefore, the three main lenses 1a, 1b, 1
If you try to generate a in an ideal form, the equivalent aperture of the main lenses 1a and 1c on both sides will inevitably be the center main lens 1.
As a result, the aperture becomes smaller than the equivalent aperture of b, and the focusing effect on both side electron beams and the focusing effect on the center electron beam become different, resulting in a difference in beam spot diameter, and this causes a bad shape in the reproduced image. give.

SUMMARY OF THE INVENTION In view of the problems to be solved by the invention, an object of the present invention is to provide an in-line electron gun capable of producing three main lenses each having a large equivalent aperture and having almost no difference in aperture. It's about doing.

Means for Solving the Problems The present invention has oval openings in opposing surfaces of the companion main focusing electrode and anode forming three main lenses, and an internal space leading to the openings is spaced apart. In an in-line electron gun that is divided into three parts in the longitudinal direction by a plate, the radius of curvature of the curved surfaces at both ends of the aperture is made larger than half the short axis of the aperture.

Effect With this configuration, the equivalent aperture of the main lenses on both sides is
It can be enlarged until it becomes equal to the equivalent aperture of the central main lens,
It becomes possible to focus the three electron beams well and evenly.

Embodiment The main focusing electrode 6 shown in FIG. 1 has a front shape as shown in FIG. 2 and a side cross-sectional shape as shown in FIG. are doing. The internal space communicating with this opening 8 is formed by a metal partition plate 9a.
, 9b in the longitudinal direction into three parts, and the partition plate 9a.
, 9b is a circular concave notch 1o a , 1 with a radius of curvature ra
It has ob f. In addition, the anode 7 is the main focusing electrode e
and three main lenses 11a between both electrodes 6.7.

11b and 11c are generated.

12 is an oblong opening of the anode 7, and 13a and 13b are partition plates.

By the way, the electrode configuration shown here is similar to that shown in Figures 9 to 1.
The difference from the conventional electrode configuration shown in FIG. (centered on), but the length equivalent to half of the short diameter φ7 of each opening 8.12 (indicated by axis a, a) is also a large value (rs>
φv/2). Note that the axis a,
b.

C are parallel to each other, the diaphragms 9a and 13a are located in the middle of the axis malb, and the diaphragms 9b and 13b are on the axis.

It is located between C.

The focusing force acting on the electron beams entering the main lenses 11a, 11b, and 11c is as shown by the arrows in FIGS. 4 and 5. That is, in FIG. 4, the electron beams 14a and 14 (!) that entered the main lenses on both sides receive a focusing force of Fs from three directions by the upper and lower portions of the apertures 8 and 12, and the curved end, and the electron beams in the center are The beam 14b receives a focusing force Irv from two directions by the upper and lower portions of the aperture 8°12.Then, the radius of curvature r is changed to ri as described above.
By setting l>φv/2, it becomes possible to set Fv=Fll. Further, each of the electron beams 14a, 14b, and 14c on both sides and the center is connected to the partition plate 9.
The focusing force received from the a, 9b, 13a, and 13b sides is Fh,
In addition to the values of the positional parameters W and L occupied by the diaphragm, the focusing forces F, , Fv and can be made equivalent.

Therefore, three electron beams 14a, 14b.

14G can receive equal focusing power in the horizontal and vertical directions by each main lens.

Further, the focusing force that the three electron beams 14a, 14b, 14c receive from the diagonal direction by the respective main lenses 11a, 11b, 11c is as shown in FIG.
, 14b, 14a diagonally from the diaphragm side, Fdz * Fd2 is the focusing force that the electron beams on both sides receive from the apertures 8, 1.
Indicates the focusing force received in the diagonal direction from the curved end side of 2'c
h e Fd1+ Fd+ are equal. On the other hand, 'dz and 'dz depend on the diagonal shape of the openings 8 and 12, but since they are set to rs > φv/2, rs = φ
Compared to the conventional model, which is set to v/2, the diagonal space on the curved end side can be made wider.

This electrostatic influence from the diagonal direction can be reduced and made equivalent to the three main lenses 11a.

It becomes possible to make the equal diameters of 11b and 11a relatively large and equal to each other.

In the embodiment shown in FIG. 6, the radius of curvature rB at both ends of the oval opening 14 formed on the opposing surfaces of the main focusing electrode and the anode is
rg ) φv/2, and the intersection of this curved surface and the upper and lower two sides is smoothly connected by a small circular arc with a radius of curvature re.

This has the advantage of reducing wear and tear on the punching die. In this case, in addition to the value of the radius of curvature rll,
radius of curvature r. It is necessary to appropriately select the value of , but the radius of curvature r should be approximately half of the major axis of the oval opening 14 (11 in rg).
! I/2) and the radius of curvature r. The best results were obtained when the diameter was set to about 3/7 of the short axis (3φ7/end).

In another embodiment shown in FIGS. 7 and 8, the internal space of the oval opening 15 formed on the opposing surfaces of the main focusing electrode and the anode is divided into three parts by a partition plate 16 along the opening surface. ing. However, the partition plate 16 has three circular holes 17a, 1
7b and 17ci, and is formed integrally with the electrode body. And in this case too, rs 'Thrs >φv/2
By setting it to , the same effect as described above can be obtained.

Effects of the Invention Since the present invention is configured as described above, the equal apertures of the main lenses on both sides can be expanded to the equal aperture and diameter of the central main lens, and the three electron beams can be focused well and evenly. Get,
Color images can be reproduced at high resolution.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the main parts of an in-line type electron gun embodying the present invention, Fig. 2 is a front view of the main parts, Fig. 3 is a side sectional view of the main parts, and Figs. Figure 6 is a diagram for explaining the focusing force acting on the electron beam in the main lens of the same main part,
Fig. 6 is a front view showing an oval opening of another embodiment of the present invention, Fig. 7 is a front view of the main part of another embodiment of the invention, and Fig. 8 is a side view of the main part. 9 is a cross-sectional view of a portion of a conventional in-line electron gun, FIG. 10 is a front view of the same portion, and FIG. 11 is a side sectional view of the same portion. 6... Main focusing electrode, 7... Anode, 8,
12゜14.16...Opening, 9a, 9b,
13a, 13b. 16... Partition plate, 11a, 11b, 11a... Life... Main lens. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 6? ``i/7a No. 9 Figure 0゛°1 A1,9 .5b 5 Summer Proceedings Amendment August 29, 1985 5 Displays 1985 Patent Application No. 107571, Title of Invention: In-line Electron Gun'' Correct Relationship with the case of a person who does
(584) Matsushita Electronics Co., Ltd. Representative Fuji
Motofu 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd., Floor 2

Claims (1)

[Claims] An in-line type electronic device that has an oval aperture on opposing surfaces of a main focusing electrode and an anode to generate three main lenses, and an internal space leading to this aperture that is divided into three in the longitudinal direction by a partition plate. An in-line electron gun, characterized in that the radius of curvature of the curved surfaces at both ends of the aperture is larger than one half of the minor axis of the aperture.