JPS58225545A - Color picture tube - Google Patents

Abstract

PURPOSE:To effectively prevent contact between eletron beam and internal surface of cone area by providing a thin part having an increasing internal diameter to the funnel part corresponding to the diagonal corners and by extending said thin part viewed from the direction of tube axis, along the diagonal line from the center axis of nearest electron gun to the thin part considered as the origin. CONSTITUTION:Total of four grooves 12 indicated by the hatched areas are provided on the internal surface 6 of cone area of funnel part corresponding to the diagonal corner part of the panel. These grooves 12 form the thin part with the groove and the internal diameter of funnel of this part is locally increased. When viewed from the phosphor screen side, the groove 12 is so formed that for example, the right side groove 12a is extended radially along the diagonal lines including the axis which connects the diagonal effective diameter points 11 determined from a rectangular having the sides of horizontal and vertical effective diameters with the center axis of the electron gun nearest to the groove 12, namely of the right side electron gun 8a considered as the origin. Therefore, if the electron beam is deflected, for example, to the upper right diagonal corner, the groove is extending in almost the same angle as the locus of electron beam which shows the smallest interval to the internal surface 6.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a color picture tube (-) and relates to a funnel structure of an envelope of a color picture tube having two three-electron guns arranged in-line.

Technical Background and Problems of the Invention The configuration of a color picture tube having three electron guns in a general in-line arrangement is shown in FIG. Figure 1 - The envelope of the color picture tube consists of a panel (1) with an inner surface (2) (binary light surface (3)) and this normal wall (1). Funnel-shaped funnel (5) and this funnel (5) 1 2 connected in-line array 3 electron guns (8m), (8b)
and a neck in which (8C) is installed. And the cone area (B) ζ on the electron gun side of the funnel (5)
:) A deflection device (7) is attached which generates a magnetic field for deflecting the Ma'Ako beam. In such a color picture tube, three electron guns (8a
).

Electron beams (9a) emitted from (8b) and (8C)
), (9b) and (9C) are the deflection devices (color-selecting electrodes deflected by force and placed close to and opposite the fluorescence direction (3). Passing through a number of apertures in the shadow mask (4) After that, the fluorescent surface (3) provided on the inner surface (2++''-) of the panel (11) is caused to emit light to reveal a color image.

Here, the effective distribution of the deflection magnetic field generated by the deflection device (7) is longer than the length of the deflection device (force) in the tube axis direction, so the electron beam is The electron beams begin to be deflected from the electron gun region (A). Therefore, the three electron beams (9a), (9b), and (9C) when passing through the cone region (Hl) of the funnel (5)
In Fig. 1, the distance between the electron beam (9a) emitted from the nearest electron gun (8a) is the smallest, and the distance between It is smallest when it is deflected to the diagonal.

However, in recent color picture tubes, the electron gun area (A)
The diameter of the neck was reduced from just under 3011111 to a quarter or more, and along with this, the deflection device (force cone area)
As for B), a low power consumption type that increases the deflection efficiency slightly and reduces the deflection power is now being used. In such a design, the electron gun is divided into a central electron gun (8b) and electron guns (8a) and (8C) on both sides in terms of focus performance.
The distance between the two is designed to be as large as possible, that is, the electron lens is designed to have a large diameter. For this reason funnel (5)
When passing through the cone region (B) of the electron beam, the distance between the closest deflected side mark, for example the electron beam (9a) in FIG. 1, and the inner surface (6) of the cone region is further reduced. In addition, due to various manufacturing variations (discrepancies in the screen position, variations in beam landing, variations in the placement position of the deflection device, etc.), the electron beam may be affected by the cone area (B)
may come into contact with the inner surface (6) of the When the electron beam comes into contact with the inner surface (6), reflection occurs, causing unnecessary light emission from the fluorescent surface and degrading the screen quality. Further, at time I:, the electron beam is partially interrupted, resulting in a so-called neck shadow. This direction is more pronounced in tubes with a wider deflection angle of 100 degrees or more.

As a countermeasure against this, cone area (B) (7) inner surface (6
)'s diagonal 1: Corresponding portion σ) A method of thinning the wall thickness and widening the inner diameter has been proposed. Corn club area 0)
If it is only in one part, the thickness is local: two thin <L? However, there are major problems in terms of manufacturing and strength). Figure 2 (a
l shows an example of the funnel (5) seen from the fluorescent surface side (σ), and the inward direction (6) of the cone area is shown in the second mano (one diagonal direction of the funnel (two directions are indicated by diagonal lines). The groove αQ shown in FIG. Two radial grooves are provided.Since the groove α0)Q) range is set to about 20 degrees from the viewpoint of manufacturing and strength, the width of the groove Q near the neck area (A) is limited. ) na) J becomes narrower. For this reason, the second analogy is
Figure (b) As shown in t-1, if the electron beam is deflected to the upper right diagonal, the electrons from the electron gun (8a) on the right (fl) are the most severe for the reflection and neck shadow ζ. When the beam (9G) passes near the neck region (A) of the force ball cone region (B), it passes through the outer edge of the groove, causing the problem that the groove does not perform any Q) function. There was t.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to provide an in-line array three-electron gun R-ray picture tube that does not cause reflection of electron beams on the inner surface of the funnel cone portion and does not cause smearing.

Summary of the Invention The present invention provides a diagonal corner of the panel (two pairs of funnels ζ) with a thin walled portion where the inner diameter is large, and the thin walled portion when viewed from the tube axis direction is set at the central axis of the electron gun closest to the thin walled portion as the origin. It extends diagonally and effectively prevents the electron beam from coming into contact with the inner surface of the cone region.

EXAMPLES OF THE INVENTION Examples of the present invention will be described below. The color picture tube of the present invention is the same as that shown in Fig. 1 except for the vicinity of the 1-channel portion, so a description of the overall structure will be omitted.

FIG. 3 shows an embodiment of the present invention, and is a schematic diagram of the main parts of the funnel inner surface viewed from the fluorescent surface side.

In FIG. 3, grooves a4 indicated by diagonal lines are provided at four locations corresponding to the diagonal corners of the panel. The groove α is formed with a groove C2 so that the groove portion forms a thin walled portion, and the inner diameter of the funnel in this portion becomes locally large. Also, groove <121, when viewed from the fluorescent surface side, for example, in the case of the groove (12a) on the right side, this groove (12a) is the closest electron gun,
It extends radially in the diagonal force direction including an axis connecting the center axis of the electron gun (8a) on the right side of the strike as the origin to the diagonal effective diameter point αυ determined from the rectangle whose sides are the horizontal and vertical effective diameters of the panel. It is set up to do so.

In the case of the left groove (12c), also the left electron gun (8C)
) are provided so as to extend radially in diagonal directions with the central axis as the origin.

Therefore, for example, when the beam is deflected diagonally to the upper right, the direction in which the groove extends is approximately at the same angle as the orbit of the electron beam where the distance between the electron beam and the inner surface (6) is the smallest. That is, the groove (1
3 and the direction of the maximum deflection angle of the electron beam, the risk of the electron beam touching the inner surface of the cone area (two areas) and being reflected or causing a neck shadow is effectively eliminated. In this case, the three electron beams are virtually blocked by one of the apertures of the shadow mask. The problem is with the electron beam, and no problem occurs with the other two electron beams.

FIG. 4 shows another embodiment of the present invention, in which the angle at which the groove a3 extends is more in the horizontal axis direction than in the vertical axis direction with respect to the axis connecting the origin and the diagonal effective diameter point (11). It is a large angle. This is because the panel of a normal color picture tube is substantially rectangular and the horizontal axis is longer, so that it is more effective if the angle in the extending direction of the groove Q31 is regulated.

Figure 4 (bl is the groove (1) including the horizontal axis in Figure 4 (a)
4) is placed in two locations on the left and right.

Effects of the Invention As described above, according to the present invention, it is possible to effectively prevent the electron beam at the maximum deflection angle from contacting and colliding with the inner surface of the funnel cone region C; without changing the outer diameter of the funnel. can.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view showing the configuration of a general color picture tube;
FIG. 2(a) is a schematic front view of the main parts of the inner surface of a conventional funnel viewed from the fluorescent surface side, FIG. 2(b) is a schematic sectional view of FIG. 2(a) viewed from the side, 3N is a schematic front view of the main part showing an embodiment of the present invention, and Fig. 4 (al) and FIG. 4(b) are schematic front views of the main part showing another embodiment of the invention. ( 1)...Panel (2)...ノ(Flannel inner surface (3)...Fluorescent surface (4)...Shadow mask (5)...Funnel (6)
...Inner surface (force...deflection device (8)...electron gun (9)...electron beam (Io, wholesale, θ3
1. (14i...Mizozumi υ...Diagonal effective diameter point agent Patent attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1) A substantially rectangular panel having a fluorescent surface, a funnel-shaped funnel connected to this panel, and this funnel C: three connected electron guns arranged in-line inside. In the color picture tube, the funnel has a thin wall portion having a large inner diameter in the vicinity of the diagonal corresponding to the substantially rectangular panel, and A color picture tube characterized in that the thin-walled portion extends in two diagonal directions with the center axis of the electron gun closest to the thin-walled portion as the origin. 2) The thin-walled portion as seen from the tube axis direction is the thin part ζ:
2. The color picture tube according to claim 1, wherein the color picture tube extends radially in the diagonal direction from the central axis of the nearest electron gun as the origin. 3) The angle of the extending direction of the thin wall portion is MD 2. The color receiver according to claim 1, wherein the color receiver is larger in the horizontal axis direction than the color receiver.