JPS59834A - Electron gun for color picture tube - Google Patents

Abstract

PURPOSE:To both increase mechanical accuracy and improve focusing performance of an electron beam, by constituting oppositely faced electrodes for forming a main electron lens as an integrally formed electrode containing three electron beam permeable hole parts and forming an oppositely facing space of the integrally formed electrode to the narrowest in the peripheral part. CONSTITUTION:Each of a cathode G1 is arranged independent corresponding to three electron beams arranged in one row, and the other elecdrode, the first- the fourth grids 62-65 are constructed to an integrally formed electrode with drilled three permeable hole parts for an electron beam. While incident permeable hole parts 72-74 of an electron beam from a triode part are drilled to a bottom part 71 of a bottomed cylindrical supporting member 641 in the third grid 64, and a flange part 75 is provided to an opening hole part, further at least an internal wall of a side wall part 76 is coaxially arranged with an axis of the hole parts 72-74 and formed by an envelope surface of cylinder 721-741 having a common part 77. In this way, a diameter of an electron gun main lens can be enlarged, and a good focusing characteristic in good accuracy can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron gun for a color picture tube, and more particularly to the structure of an electrode forming a main electron lens of an electron gun mounted on a shadow mask type color picture tube and emitting a plurality of electron beams. It is.

A shadow mask type color picture tube accelerates and converges thermoelectrons emitted from multiple electron beam sources of an electron gun installed in the neck, and directs the resulting multiple electron beams onto a phosphor screen via a shadow mask. It is designed to reproduce the color image quality.

Various types of electron guns are known, but all of them are for electron beams, emitted from a cathode), emitted thermionic A2 electron beams, accelerated, and emitted by a main electron lens into fluorescent light. It is designed to converge on the body screen. Generally, an electrostatic lens is used as the main electron lens, and the characteristics of the electrostatic lens are determined by the diameter of the lens, similar to optical lenses.

Generally, the maximum diameter of the main electron lens is determined by the inner diameter of the neck of the picture tube and the structure of the electron gun. For example, Kameko beams arranged in a row are emitted from an electron gun consisting of electrodes each having an independent structure. In the S case, the diameter of the main electron lens is about 80 inches, and when emitted from an electron gun consisting of an integrated electrode, the diameter of the main electron lens is limited to about 28 inches, which is a sufficient diameter for characteristics. I can't take it.

A shadow mask type color picture tube reproduces a color image by focusing eight electron beams onto a phosphor screen and scanning them both horizontally and vertically using a deflection device. . In this case, focusing the three electron beams on the phosphor screen is called convergence, and in general, the smaller the neck diameter, the better the characteristics are obtained, and the electric current required to deflect and scan the electron beams. That is, the electric power in the t@ direction is proportional to the neck diameter, and the smaller the neck diameter, the smaller the force.

As mentioned above, electron beam convergence, convergence, and deflection scanning are interrelated with respect to the neck diameter, and the current situation is that a compromise between the two is generally designed, especially in the case of recent color picture tubes. In order to conserve resources and power, the diameter of the neck is becoming ultra-thin from the conventionally common 29.1ff'11 to 22.51m. Naturally, as the neck diameter becomes smaller, accuracy becomes more difficult because the electron gun is also smaller.

Next, the structure of the shadow mask type collar receiver tube will be explained with reference to FIG.

That is, the shadow mask type color picture tube has red, green, and W colors on its inner surface, respectively, to prevent the electron beam from striking it.

A panel (2) is formed by adhering a phosphor screen (1) in which a phosphor layer that emits light in each color is regularly provided in the form of dots or bands, and a funnel (3) is attached to this panel (2).
) and a stem bin (5) connected via a neck (4) and a stem bin (5).
) an electron gun (8) that emits three electron beams (7) into a high-vacuum envelope consisting of a stem (6) implanted with a stem (6);
These three '1 electron beams (7) are connected to a phosphor screen (
1) Consists of a shadow mask (9) that is projected onto a predetermined phosphor on the top, and a deflection device (4) attached to the outer wall of the funnel (3) to the neck (4). 4 to direct the electron beam (7) to the phosphor screen (1
) horizontal.

A color image is reproduced on this phosphor screen (1) by deflection scanning in the vertical direction.

The electron gun (8) installed in such a shadow mask forming force 2-receiver is broadly classified into an independent electrode electron gun and an integrated magnetic pole electron gun, but the integrated type that is commonly used at present is representative. An example of the structure of an electrode electron gun will be explained. As shown in Figure 2, at least 1 grid (1
), second grid ai, two bottomed cylindrical electrode elements (14
+) and (14,), a fourth grid L having a cylindrical shape with a bottom, a convergence electrode housing indicated by a broken line, and horizontal support for the planting pieces provided on each of these electrodes. Electrode support (1) made of glass etc.
7), and the cathodes 01) are each independent corresponding to the 8 electron beams, or other electrodes, that is, the first grid Q
2. Second grid (l4.

The eighth grid μ4) and the fourth grid 09 each have a structure in which three electron beam passage holes are formed in the integrated electrode.

In the electron gun (8) having the above structure, the cathode (Ill,
Grid 01 and 2nd grid 03) are called the octupole part, and form an object point that emits thermionic electrons and enters the main electron lens described later. ] A main electron lens is formed in between to focus the electron beam onto the phosphor screen.

In the electron gun shown in Fig. 2, three electron beam passage holes are formed in the integrated electrode, so they can be assembled after being implanted and fixed to the electrode support housing via implant pieces. The accuracy is superior to that of the independent electrode electron gun, and the center axis spacing θ barrel of the passage hole portion is also constant.

However, for example, the eighth grid I of the electron gun (8) mentioned above has one electrode element (14) as shown in FIGS.
The bottom part 7+1 of 1) has passage holes SI, V3 and UL for the ton r-beam that injects the electron beam from the triode, so there is no problem, but the electrode element (14t
) is a passage hole c+ for a large-diameter electron beam 1 forming a main electron lens in the bottom c(1);6. t:+Isamu and C54)
but%? These ilh, 37M (L jjp
(ii * L (: Q and 64) is almost a perfect circle shape, and the diameter of the passage hole gli (+4.
It can be made sufficiently large depending on the width of Zr. Furthermore, the passage hole part 12,031 and ()a have a central through hole group C.
(The electrostatic lens formed in a and the passage holes Cl on both sides;
9, 'C34) Wall part (821) for preventing mutual interference with the electrostatic lens formed in (aa
t) and (84+), that is, the burring portions are each provided independently.
+-) (142Al is the flange part. The length 31 of this wall part is generally the passage hole part (33, C4: l and C4)
It is considered safe to drink at least 1 hot water of the target diameter. Also, the width of the bridge portions C37) and G31 cannot be made narrower than a certain level due to the construction of the wall portions (821), (88s) and (84t), and the width of the bridge portions C37) and G31 cannot be made narrower than a certain level. 14t
), the thickness of the metal plate that forms /(-), the strength of the burring jig, especially the die, used for ring processing, the wall flu (32
1), (aat) and (a41) jgusaku19) etc., and the bridge (,'ii), C1
) The width of O is made extremely narrow, and the passage hole C3 hot water, +3:l
) and (34) diameter (it is impossible to make one larger. Such an electrode is applied to the electrode for the main electron lens for the v4 utilization 1 neck of the 22.5-meter door, and the wall part (821 )
- If the length I3 duck of (88t) and (34+) is made into 8 or more questions, it is called a passage hole (gong, 0■ and C34), so it is formed by such a passage hole with a small diameter. The principal electron lens had the disadvantage of extremely large spherical aberration. In addition, the electrode element (t4t) is
) is subjected to mechanical distortion, and during the aging process of color picture tubes and the heating process during operation, @polar elements (la,
) It also has the disadvantage of causing self-transformation and also of being susceptible to large amounts of spherical aberration of the principal electron lens.

One way to eliminate the drawback of not being able to enlarge the through holes f1μCI, C'(31 and H) described above is to create an electrode element opposite to the fourth grid with a structure as shown in Fig. 6 and PJIJ6. What has been done is considered.

In other words, the '11-pole element (14≦) has passage holes (42, +43 and v4) for the electron beam forming the main electron lens formed at the bottom υ, but in order to make the main electron lens larger, Passing hole t=IZ, (43 and (4a diameter 0
9 is formed to be approximately equal to or slightly larger than the center axis interval (41i).

Furthermore, the passage holes (hJ, +4:J and 144) have an electrostatic lens formed in the central passage hole (4 sides) and an electrostatic lens formed in the passage holes t4:1.(44) on both sides. A wall portion (48t) for preventing interference with each other;
(44t) That is, a burring portion is provided. In addition, these wall portions (481) and (441) have passage hole portions (4ri,
(I moat and (9) are not provided at opposite positions because they are almost the same or slightly larger than the distance between the center axes of the electron beams.

However, in the electrode element (141), the passage hole portion (
421, (41 and (44)) are formed as one large hole group, that is, a communicating hole portion, and then the metal plate (47), (421) is fixed by means such as welding to form an independent hole portion.

Therefore, when a thin plate with a thickness Q of about 411111 is press-formed, the passage hole G42. (43 and (44
) There is no bridge portion between the electrode elements, and therefore, the accuracy of the electrode element is significantly degraded compared to one with a bridge portion, and for example, twisting occurs. Also, metal plate (47
), (It cannot be said that 48 is necessarily arranged with high precision, and the accuracy of the 9 combination is a problem.Also, when assembling it as an electron gun, it is said that it is easily distorted by mechanical stress from the assembly jig etc. There were some problems, and the effect of increasing the size of the passage hole could not be fully demonstrated.

The present invention was made in view of the above-mentioned nine drawbacks, and an object of the present invention is to provide an electron gun for a color picture tube that has excellent mechanical precision and is capable of improving the convergence performance of an electron beam. .

Next, an embodiment of an electron gun for a color picture tube according to the present invention will be explained with reference to FIGS. 7 to 10.

That is, as shown in FIG. 7, the color picture tube electron gun (58) includes a cathode (61), a first grid (62), a second grid (68), a bottomed cylindrical support member (64+), and a perforated plate. 8th grid (64) consisting of 1ilii (64t),
The fourth grid (65), which is also made of a perforated plate-like member, implants the implant pieces provided on each of the electrodes except for the Konno-taka-ze〉' sumi electrode (66) and the Konno-sensu electrode (66). It consists of an electrode support (67) made of supporting glass or the like.

The cathodes (61) correspond to the three electron beams arranged in a column and are independent from each other.
64) and the fourth grid (65) each have a structure in which three electron beam passage holes are formed in the integrated electrode.

In the 'L4 subgun (58) having such a structure, the cathode (
61), Ri'g 1 grid (62), 2nd grid (
68) is called the octupole part, and it forms an object point that emits thermomagnetons and enters the main electron lens described later, and the third grid (64)
) and the fourth grid (65), a main electron lens is formed to focus the electron beam onto the phosphor screen. The 'r4 secondary gun shown in Fig. 7 has passage holes for three electron beams formed in the integrated electrode, so after implanting and fixing them to the electrode support (67) through implant pieces, The assembly accuracy of the independent electrode electron gun is superior to that of the independent electrode electron gun, and the passing hole, that is, the center axis spacing of the electron beam (68)
is also constant.

Next, the structure of the eighth grid of the electron gun (58) will be explained with reference to FIGS. 8 to 10. The bottomed cylindrical support member (6
Passing holes (72), (78), and (74) for injecting the electron beam from the octupole are bored in the bottom (71) of the 41), and a flange (75) is provided in the opening. have.

Further, at least the inner wall of the side wall portion (76) has a passage hole portion (72).
).

Cylinders (72+), (78t) and (78t) that are coaxial with the axes of (7B) and (74) and have a common part (77)
741), and the outer wall has a planting piece (8
0) is fixed by means such as welding.

Next, the flange portion (75) of the bottomed cylindrical support member (641)
The perforated plate-like member (64*) that is placed and fixed on the electrode element (14 through holes (43, ...and the wall (4
21)... and the pot metal plate +471, 14)Q are formed, and the conditions that must be met are as follows.

(1) Is the diameter (85) of the passage holes (82), (88), and (84) approximately equal to the distance between the pims (68)?
Be big.

(2) The bridge portions (87) and (88) are integrally formed with the perforated plate-like member (64, and have a height of 90 mm).
be lower than the thickness (89) by a predetermined amount.

(3) Overall mechanical precision and mechanical shock resistance.

Regarding the first I residual, the diameter of the main electron lens should be increased to such an extent that the focusing characteristics of this lens are not deteriorated, and the diameter is determined by the type of the color receptacle.

The structure of a-2 is that the bridge parts (87) and (88) are formed integrally with the perforated plate-like HrH+ phase (64), and the fourth
Since it is formed a predetermined amount lower than the surface facing the grid, the electrostatic lens formed in the central passage hole is formed smoothly in both the hand force direction and short hand force direction (the direction where the bridge part is located). This makes it possible to reduce the asymmetric aberration of the electronic beacon.

That is, in FIG. 1O, the bridge 11S (87).

The (x-x') and (y-y') planes containing (88) are
Predetermined t1 from the outer peripheral wall (800)! : (801) is set lower. For this reason, the valley potential line that forms the silent lens extends in the longitudinal direction (x-x' axis) and the transverse direction (Y
-Y' axis), υ' becomes smooth when it is on the same plane as the plane containing the bridge or the outer circumferential wall, and therefore it is possible to create an electrostatic lens without astigmatism.

This is because when the plane on which the bridge is read and the outer circumferential wall are on the same plane, the shape of the opening becomes oval.
This is due to the fact that the lens also has strong asymmetry, and astigmatism occurs. On the contrary, the bridge part (87),
If (88) is not present at all, an electrostatic lens corresponding to the central hole (82) and both side holes (88).

Astigmatism also occurs due to interference with the electrostatic lens corresponding to (84). In other words, in order to obtain an enlarged static lens with no astigmatism, the plane including the bridge portion must be set lower than the plane of the outer peripheral wall.The third requirement is that Because the bridge part is integrally formed from the beginning instead of fixing the hook plate like the electrode, the mechanical strength and mechanical shock resistance are superior to those shown in Figures 5 and 6. There is.

In other words, the overall shape of the perforated plate-like member (64) is almost the same as the conventional one except that there is no flange group, but the shape of the passage hole is similar to that of the fourth grid. In the vicinity of the opposing surfaces, eight passage holes are formed 4111 and are formed as one communication hole, and the bridge portion (87), (8
8) are eight passage holes independent from each other. This knee-like structure is the same in the case of the fourth grid (65).

In addition to the above-mentioned MiJ, the advantage of this embodiment is that there is almost no distortion even under the mechanical stress of +4t when assembling the electron gun. Thereby, the reference point (reference direction) during assembly can be selected at any point on the perforated plate member (641), so there is no restriction on the assembly method. For example, the reference point during assembly can be set not in the passage hole but also on the outer wall, which facilitates automatic assembly.

Another advantage of this embodiment is that it has excellent resistance to tamping. That is, in general, it is necessary to first remove minute protrusions on the surface of an electron gun in order to prevent a discharge phenomenon occurring between electrodes. To do this, a mechanical polishing process called tampling is applied. At this time, the electrode is subjected to mechanical shock, and the degree of distortion is particularly large in the shape of conventional electrodes without a bridge part or in the shape with attached plate, but in this example, such distortion is #t I hardly accept it.

Next, the specific dimensions of the electrode element (e4t) are shown.
, the width of (88) is 0.31111. Hot water hole (82),
The longitudinal diameter of (8B) and (84) is 7.0. The bridge part (87) is 1.5.
The tone and thickness 89) are the two questions.

Next, a perforated plate member (64
1) is shown in FIG. The same parts as in FIGS. 8 to 10 are designated by the same reference numerals and will not be particularly described.

That is, the perforated plate-like member (64;) has passage holes (82), (
There is a bridge part (s7) between (88) and (84), (ss
) and a first perforated plate-like member (941) having a passage hole (
82), <88), and (84) are formed from a second perforated plate member (941) in communication with each other.

In the electrode shown in FIG. 11, the bridge portion is formed by the first one-hole plate member (941), and the outer peripheral wall is formed by the second member (94).Therefore, the plane including the bridge portion is set lower than the outer peripheral wall by the thickness of the second member (941) (2).

Also, like this, two perforated plate members (941λ・(94t
) are formed separately and integrated, which has the advantage of facilitating machining.

Although the above embodiment mainly describes a pi-potential type electron gun that emits and focuses magneton beams arranged in a row, the present invention is not limited to this and can be applied to other types of electron guns as they are. be able to. Moreover, it is of course possible to use the perforated plate-like member itself as an electrode without placing and fixing the perforated plate-like member on the cylindrical support member.

As mentioned above, the electron gun of the present invention completely solves the mechanical problems caused by enlarging the diameter of the main lens, and has high precision and good convergence characteristics, so its industrial value is extremely high. It is.

[Brief explanation of drawings]

FIG. 1 is a simplified explanatory diagram of a color picture tube, FIG. 2 is a side view showing an example of a conventional electron gun for color picture tubes, FIG. 8 is a plan view of the eighth grid as seen from the fourth grid side, and FIG. is the 8th
FIG. 5 is a cross-sectional view taken along the line 8-. FIG. Figure 6 is the 6th
7 to 10 are views showing an embodiment of the electron gun for a color picture tube according to the present invention, and FIG. 7 is a side view, and FIG. Figure 8 is a plan view of the 8th grid viewed from the 4th grid side, and Figure 9 is a plan view of the 8th grid viewed from the 4th grid side.
10 is an exploded perspective view, and FIG. 11 is an exploded perspective view of a perforated plate member adapted to another embodiment of the present invention. 8.58... Electron gun 12.62... First grid 13.63... Second grid 14.64... Eighth grid 141.141... Bottomed cylindrical electrode elements 87, 88 .8
7.88...Bridge part 47.48...Kin@Saka6'b, 64*'...Perforated plate member 64...Bottomed cylindrical support member Representative Patent attorney Noriyuki Chika (1 other person) No.
1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] l) - A plurality of electrodes including a group of electrodes forming a main electron lens for converging eight electron beams arranged in a row onto a phosphor screen, and supporting these electrodes r- ! In the electron gun for a color picture tube, the opposing electrodes for forming the main electron lens are practically composed of an integrated electrode including eight electron beam passage holes;
The opposing spacing between the opposing surfaces of the integrated electrodes is narrowest at an outer peripheral wall portion that includes the three electron beam passage holes;
and a color picture tube characterized in that the facing interval with a plane obtained by connecting the bridges between the eight electron beam passing holes of the opposing electrodes is formed to be p wider than the facing interval of the outer peripheral wall portion. electron gun. 2) The bridge portion including at least the line connecting the center of the passage hole is missing in the difference between the height of the plane obtained by connecting the bridge and the furrow of the outer peripheral wall on the side of the opposing electrode surface; 2. The electron gun for a color picture tube according to claim 1, wherein the three passage hole portions communicate with each other through the missing portion. 8) The electron beam passage hole in a portion of a plane obtained by connecting the bridges on the opposing electrode surface sides that is far from the opposing surface has a crystalline cylindrical shape. An electron gun for a color picture tube as described in item 2 or item 2.