JPS6047348A - Color picture tube - Google Patents

Abstract

PURPOSE:To restrain the effect of accumulated charges to the minimum extent by setting a gap etc. between a focusing electrode of an electron gun and an inner wall of a neck corresponding to the focusing electrode in an optimum con- dition. CONSTITUTION:The third grid 31 and the fourth grid 32 which form a main lens within a neck 36 are successively supported and secured in the appropriate positions through a bead glass 35. On a line which represents the shortest distance between an aperture 33 of the focusing electrode and the inner wall of the neck 36 corresponding to the focusing electrode, that is, in the case of an in-line arrangement system, when the gap between the outer most end of the focusing electrode and the inner wall of the neck is (a), and the width between the end of the aperture to the inner wall of the neck and the outer most end of the focusing electrode is (t), on the line B-B which connects the centers of respectives apertures, to each other 1.0<=t/a<=2.0 shall be satisfied. Whereby, the displacement volume of the convergence due to the effect of the accumulated charges in the inner wall of the neck can basically be restrained to the minimum extent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The fifth aspect of the present invention relates to a color picture tube, and in particular to the center and center of a four-gun magnetic pole structure that minimizes convergence deviation.

[Technical background of the invention and its problems]

Generally, color picture tubes are shadow mask type, 3-electron f
-Me type is used. RjJ et al., as shown in FIG.
The neck part aυ of 41 and the funnel-shaped funnel 15 (121) are connected and have a fluorescent surface (1) on the inner surface. Closely facing the fluorescent light on the inner surface of the panel, there are multiple blanking holes (10) installed.'4 sub-guns (14J generates three '4 J' beams, and the Tokyo I.J.
It consists of a group of electrodes that are extremely fast, and each f is]
In the figure, an aperture (not shown) corresponding to each electron beam is provided.

There are many 1U pole configurations for electronic reading depending on the purpose and use of Wakunoshin, but generally there are 1U pole configurations in the three poles and the eastern part of the prefecture.
Sign. 1711 For example, the electron @u (a) in Figure 1 is at the cathode (1
40), the first grid (141) and the second grid (1
1 of 42) is the triode part where the child beam splits and forms its object point, the third grid (143) and the fourth grid (1
It is composed of a quadrupole beam ′ of 44) and a focused quadrupole portion. For example, the third grid (143) is supplied with a medium voltage of 51 (V to 10 KV) from Bedembin (r not shown).
Step 44) includes a magnetic pole (1, 15) called the convergence cup at the tip, a cup spacer (146), an internal conductive magnetic field (121), and an anode terminal (not shown) embedded in the funnel circle. J'i'' ladder shadow mask (te
and the fluorescent surface (201, which is substantially the same level as 151) (a high level of V to 3QKV is applied).

In such a color picture tube, a plurality of quadrupole beams j171, which are started by one electron gun and focused and accelerated, are deflected by a deflection device (18) disposed outside the envelope. Shadow mask with multi-matching +Ntl! holes (colors are sorted according to the rule, and each is radiated onto the corresponding fluorescent surface)
Then a color image appears.

By the way, there is a Q
A static 1d lens is formed corresponding to the quadrupole beam of Yotani, which controls the properties, shape, and focusing state of the magneton beam.]
11 required. However, the dielectric part other than the metal conductor in this part, for example, the neck inner wall part corresponding to the focusing electrode, is exposed to shadow masks (internal conductivity due to secondary electrons from 1ω and other inner parts of the tube) during operation of the tube. 4 charges are accumulated due to the permeation of the -position from the membrane (121).Such accumulation (4 charges) varies depending on location and time, distorts the shape of the static V lens due to the focusing magnetic pole, and as a result This distorts the spot shape on the light surface and causes a shift in the convergence of color images.

On the other hand, the deflection force of the deflection device a is almost proportional to the diameter of the neck aυ, and the neck diameter is 29. A shortened version of the ``l'' rhyme to 22.5 am has also been adopted. However, when the neck diameter is reduced in this manner, the gap between the neck and the inner wall of the neck becomes smaller, and therefore, it becomes more susceptible to the influence of accumulated loads on the inner wall of the neck.

As a countermeasure against such accumulation 'I burden, for example, in Utility Model Publication No. 4.1-2107' Fj Publication &J, '2nd id
(a) and fl))'l As shown, the gap portion Q11 where the main lenses of the third grid 011 and the fourth grid 0, which form the king lens part of the focusing electrode, are formed, The proposal is to have a structure that will sink in the amount of money (goods). same,
Figure A2 (1) l is [υ[
to show that. Although this structure is effective, since the influence of 1λ stock is most affected by the main lens part, it is difficult to provide such a shielding plate Q4 in a tube with a reduced neck diameter due to space considerations. It's very confusing. However, the gap with the inner wall of the neck is very small, making it unreasonable in terms of space, and the shielding plate 241 is too vertical (the fourth grid (2
4, the withstand voltage between the shielding plate f241 and the third grid (21) to which the medium-level voltage is applied becomes a problem.
There are practical problems.

In addition, as another countermeasure, the special public model No. 4'5-34852, C, supports and fixes the valley pole.
There are no proposals to prevent the effects of the 4-load effect of C. 141] A metal wire is connected to the part of the bead glass that corresponds to the part of the focusing electrode to which a low potential is applied. It is effective as a countermeasure against accumulated 4A charge, and even at 36-hours,
In particular, in the case of an electron gun in which the electron beams are arranged in a line, the gap with the inner wall of the neck and the glass area is the largest, so as a countermeasure against magnetic charges, It's not really a valid comment.

[Purpose of the invention]

This explanation has been made in view of the above points, and basically the focusing pole of the D-element gun, which is most susceptible to the influence of accumulated loads, and the gap between the neck inner wall corresponding to the focusing electrode, etc. are optimized. The objective is to minimize the influence of accumulated iK load by setting

[Summary of the invention]

In this method, the opening end on the neck inner wall side of the focusing electrode and the outermost edge of the 4 poles corresponding to the inner wall of the 1st ivy are located on the line where the distance m between the 1314 holes of the focusing electrode and the corresponding neck inner wall is the smallest. The above objective is achieved by setting 1.0≦t/a (, 2, Q), where t is the width of the electrode and a is the gap between the outermost end of the electrode and the inner wall of the neck.

[Implementation sequence of the invention]

About the embodiments of the present invention i+? Enjoy it in detail.

The color picture tube of the present invention is the same as that shown in FIG. 1 except for the mold part of the electron gun, so a description of the overall structure will be omitted.

Figures 3a) and tb) show one example of an electron gun to which the present invention is applied.
” 4 bundles 44! This is a schematic diagram showing the main part near the iIi part. The third grid Gυ and the fourth grid (34) forming the king lens in the neck (G) are supported and fixed in sequence through the peed glass G. In addition, Figure 3 (1)) is M 31
J (a) Shows one fold of OA-A line C. The most important line is the line where the distance between the aperture c3 (to) of the focusing 4 pole and the corresponding neck (g) inner wall is the smallest, or the line 11-13 connecting the centers of the valley holes in the case of the in-line arrangement method in uIJ et al. It is. With this line 13-B-, the gap between the outermost end of the focusing pole and the inner wall of the neck is set to a5, the opening diameter is O, the opening end on the inner wall side of the neck and the outermost end of the focusing pole, etc.; The width between the holes is t, and the gap between the opening end on the inner wall of the neck and the inner wall of the neck is C.

The inventors of the present invention have found that the amount of convergence shift S resulting from the influence of the accumulated r4 load has a correlation with the set values of a, b, C, and .

That is, especially between a, t, and S, 3 ack・−□(1) a, 3/2 1 time a + t = c f2) I( has the proportionality relation.(1 ), the simplest way to reduce the convergence shift S is to increase a and back.Here, the outer diameter of the sheep is, for example, 36.5 am.
, 29.1 aIB, and 22.5 min, and currently smaller ones are the most popular. Further, it is preferable that the aperture ifi b, which is greatly involved in the basic focusing performance of each ``Tun-C'' beam, takes a value as large as possible. In c-), if [is made large, the aperture diameter becomes small, and a becomes small.If a is too small, the degree of margin for insertion of the heart into the neck circle?Neck separation and The pressure resistance characteristic becomes a problem.Therefore, it is difficult to make one or both of a and t sufficiently large.Incidentally, the conventional setting values are a neck outer diameter of 22.5 gates,
Neck minimum inner diameter ζ18. ”/mm, opening diameter/14b
To 2.

C=177 m1II, a=1. '2 urr
, r and L = 0.57 mm.

Therefore, we focused on the relationship between a and t, and set L/a=x fl)
Equation and (2) When fully deformed, when the interfusion C between the unipolar opening end and the neck inner wall is constant,
From equation (3), convergence shift lft s and t/a
= You can see the relationship.

Figure 4 is a curve showing the relationship between equation (3) and its and t/a.
However, in Fig. 4, the value at t/a = 0.5 is normalized and shown as the reference value. From Fig. 4, the convergence shift is has a minimum value, and ( 3)
From the differential equation d s/d x = 0, the minimum value is t/a
=1.5. In case of 'A', it is easier to set a > t in terms of insertion of 4 sub-guns, neck separation, and 4-pressure margin, but as is clear from Fig. 4, when a is t, The larger it is, that is, the more a>t, the more convergence shift S
is disadvantageous because it increases in terms of acceleration.

By the way, the conventional c=1.77, a=1.2, t=
In the case of 0.57, t/a is approximately 0.48. On the other hand, it is difficult to make the points of each margin described in st + a very small, and from Fig. 4, in the direction of a < t, the change in convergence ratio is is relatively gradual. The limit for t/a is 2.0.

Figure 5 shows the convergence shift amount S when t/a is changed in the same way as Figure 4, and the curve M is c = 1.77.
In the case of mg, the curve N ld c-=2.17a111. Also, the mark O indicates the actual measured value of convergence deviation due to the mounting tube. In the case of Fig. 5, t/ of the Hfl line M is also
All values are normalized and shown using i1α when a = 0.5 as the base value. The actual measurement was made immediately after operating the color picture tube, and after accurately adjusting the convergence at the center of the screen using a minute current during reverse time, the average electron beam current was adjusted to approximately 1m.
The value when the convergence shift is saturated is read as A.

As is clear from Fig. 5, the calculated curves M and Nf
The measured values of i are in relatively good agreement. For example, C21.7
7mm is a4; 0.71mm, when t#toR,
The smallest value of convergence deviation S was superior.

As is clear from the following explanation, the present invention can be applied to any part of the electron gun that corresponds to the Tokyo magnetic pole.

Moreover, it goes without saying that it can be applied not only to in-line type guns but also to delta-type four-piece guns.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a color picture tube in which the convergence shift due to the influence of the accumulated 4A4 load on the inner wall of the neck is minimized.

[Brief explanation of the drawing]

Figure 1 is a cross section showing the schematic structure of a color picture tube: fji I
:J, Fig. 2 fa) is a schematic diagram showing the main parts of the conventional neck part (
υi uii +"4, Fig. 2 (bl is the cross section taken along line A-A of Fig. 2 (al):
3(a) is a schematic sectional view showing the main part of the neck part of the S-no-kome, which explains the present invention in detail, FIG. 3(b) is a 74',
Figures 4 and 5 are cross-sectional views of the A-A line C of al. This is a raw diagram showing the relationship of the ratio t/a between the outermost edge of the sac and the gap a between the inner wall of the wick. (3) 3rd grid, X4 grid C (foundation).
Opening hole (to), bead glass (to), neck proxy valve 1 Presenter Noriyuki Yosuke ((Focus on > 1 person) Fig. 1 Fig. 3

Claims (1)

[Claims] ■) Generation and focusing of a plurality of I+ beams and the above-mentioned valley tunnel-
The color image receiving system is equipped with a group of electrodes with apertures corresponding to the beams in the neck.
On the line where the distance between the hole and the inner wall of the neck is the smallest, the opening end of the focusing electrode on the A/1& side in the neck and the inner wall of the neck. 1.0 < t/a < 2.0, where the width of the electrode acid is 1 and the gap between the outer end of the electrode acid and the inner wall of the neck is a, 1.0 < t/a < 2.0. 2) The t/a is characterized in that t/a = i, 5.
・Total.