JPS58152347A - Color picture tube - Google Patents

Abstract

PURPOSE:To compensate an indirect drift, by varying thickness or length in a side wall part so as to uniformize the relative positional deviation caused by thermal expansion in horizontal, vertical and diagonal shafts around a shadow mask. CONSTITUTION:A shadow mask 2 formed in rectangular externals carrying an opening part provided with a lot of apertures is attached to a mask frame 3 and disposed at a specified interval toward a panel 1 having a phosphor screen inside. In addition, to compensate an indirect drift attributable to the relative positional deviation to be produced by thermal expansion between the shadow mask 2 and the panel 1, thickness or length of the shadow mask side wall part is varied by 11a and 11b adjacent to the shaft end at a horizontal shaft H, by 12a and 12b at a vertical shaft V, by 10a-10d at a diagonal shaft D and by 16a-16d at an intermediate shaft S respectively. Therefore, the compensated value of the indirect drift is rendered corresponding to each individual shaft whereby deterioration in color purity can be obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a color picture tube, and particularly to a shadow mask C2 thereof.

Technical aspects and problems of the invention Ordinary color receivers (house pipes have three colors corresponding to red, green, and evening, respectively)
The electron beam from the book is concentrated by using the aperture of the shadow mask, and is redispersed while reaching the panel inner surface (-) which is placed facing the shadow mask at a predetermined distance. and e) each color emitting phosphor (a method in which two phosphors are collided correctly is commonly used. Therefore, the relative position [relationship, i.e. Beam running to high n degree (
It is necessary to hold two. However, when a color picture tube is actually operated, the amount of electron beams that impinge on the part of the opening in the shadow mask other than the aperture is greater than the amount of electron beam that passes through the aperture. The mask is heated and undergoes thermal expansion, resulting in a change in relative position with the panel. This change in positional relationship is caused by a direct beam landing error due to the primary thermal expansion of the shadow mask (hereinafter this effect is referred to as direct drift) and an indirect beam landing error due to secondary thermal expansion (hereinafter this effect is referred to as indirect drift). ). Direct drift can be seen, for example, immediately after the color picture tube starts operating, or during operation (when a locally bright area occurs on two surfaces).
The shadow mask (2) placed opposite to the side wall part (
2a) and is made of a thin iron plate with a rectangular outer shape of about 0.51 m to 0.2 m, and has a rectangular outer shape.
．． It is supported and fixed to a strong mask frame (3) of about 5N, and is further attached to the electron beam incident side of the cross-sectional mask frame (3) (the second is the side wall part (2a) of the shadow mask and the side wall part (3a) of the mask frame). ), etc. A shield plate (5) is provided to prevent reflection and scattering of the electron beam from etc. Therefore, the heat capacity of the mask frame is considerably larger than the heat capacity t of the shadow mask (2. When a locally bright area occurs, the shadow mask undergoes rapid thermal expansion, but the side walls of the shadow mask and the mask frame quickly adapt and do not undergo thermal expansion, resulting in the opening of the shadow mask having an aberration. The electron beam passing through the glaze aperture shifts from (4) to (4)', and the landing position also shifts from lal to (a1/). During operation after a sufficiently long period of time (=
As can be seen, the mask frame (3) as well as the shadow mask also thermally expands in a direction approximately perpendicular to the tube axis (XI).
1 arises. That is, the electron beam U passing through the same aperture of the shadow mask is shifted in the peripheral direction≦2 on the screen. This displacement is generally in the opposite direction to the direct drift. The above transition state is shown in Figure 2, where the horizontal axis shows time (tl is the vertical axis (double), and the negative triad amount is relative (2).
In the figure, the curve (81) and the curve w (9) indicate the improvement of the amount of drift with respect to the operation time of the electron beam (4) near the middle part and the peripheral part of the screen.The direct drift example is immediately after operation. The drift is at position i of lll1 lines (8) and (9)
bl and lb,', and the same position [(cl and (C
It can be seen that the indirect drift begins at 1', and the transition becomes stable at the same point it la+ and (d)'. Countermeasures for the above-mentioned direct drift have been devised, but for indirect drift C2, the mask frame (31) and the frame holder (6) fixed to the panel bin (7) on the side wall of the panel
) is interposed with a bimetal or the like (not shown), and the entire shadow mask structure is displaced along the tube axis (XI). Such a compensation method is , the overall correction of the vertical axis ffl and the diagonal axis fDl is the same.However, the actual indirect drift value (△D) depends on the temperature distribution at the end of each axis and the distance from the center. It is normal for them to be different, and it is impossible for them to show the same (11).In other words, the amount of indirect triad at the end of the above-mentioned axis is generally △pH △D\, ζΔDD
Normally, compensation using bimetals, etc. is not a compensation for each axis individually, but merely sets a compromise value as appropriate. Therefore, indirect drift is caused by drifting at least in one axis. The light intensity is not corrected, resulting in deterioration of color purity.

Purpose of the Invention The present invention has been made in view of the above problem, and it is possible to individually correspond the compensation value of Torimonden drift to the required compensation value of each axis,
The entire area around the screen (the purpose is to prevent deterioration of color purity across the screen).

SUMMARY OF THE INVENTION The present invention provides a shadow mask in which, for example, the thickness or length of the side wall portion of the shadow mask is varied so that the relative positional displacements of the horizontal, vertical, and diagonal axes around the shadow mask are substantially uniform. In this way, each axis is individually associated with indirect drift.

Embodiments of the Invention Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings.First, the horizontal axis (H), vertical axis (Vl and diagonal axis I
In order to explain the method of determining the indirect drift compensation value at each axis end of the DI, as a C knee example, the compensation of a color picture tube having indirect drift characteristics as shown in FIG. If possible, try raising the dam.Part 3
factor (two numbers, horizontal axis (H), vertical axis ffl and diagonal axis I
The drift at the DI end is expressed by curves o: ri, u4I and (
15. From Figure 3, at least curve QJ and curve α5
It is necessary to compensate for the contradictory indirect drift lids ΔD13 and ΔD15 of j. Regarding this compensation, No. 41≦2]
＼Right tube axis (Combination state diagram of shadow mask (2) and mask frame (3) seen from X1 direction (explained from 2). The drift mouse is determined by the distance from the center of the shadow mask (2), the strength of the mask frame (3) and the shadow mask, the s&valley cover, heat conduction, deflection angle, etc. Among the elements, the size of the screen and the deflection angle are determined from different viewpoints and cannot be simply changed, so in order to compensate for the X indirect drift, the strength of the mask frame and shadow mask, heat capacity, heat conduction, etc. The following table shows the results of an experiment on the amount of correction for the t-output drift ΔD based on the combination of mask frame and shadow mask ≦2.

1--1 However, the pipe to be measured is a 20-inch 90-degree R5J pipe, the hole and side wall thickness of the shadow mask is 0.15 m, the length of the side wall of the shadow mask is approximately 15 m, and the thickness of the mask frame. was 1.211LI, and the gap between the side wall of the shadow mask and the mask frame was set to approximately 0. From these measurements, Δ
It was confirmed that the direction and value of D differ between the frame C2 and the dimensions, shapes, operating conditions, etc. of each part. That is, the thickness of the shadow mask is 0.1 am to 0.311 J%.
The length of the side wall of the shadow mask is 8+u to 18Iu, the thickness of the mask frame is 0.5m to 12M1, and the fitting gap between part a of the shadow mask side and the mask frame is Ox to 2
A combination of M (2, so the indirect drift ΔD is 14
1i range is about +40 μm to -70 μm (2nd and indirect drift compensation values are confirmed to be light minutes. Therefore, depending on the direction and amount of each indirect drift in the axis, the side wall part of the shadow mask or By adjusting the strength of the mask frame, etc., the heat capacity and heat conduction of each frame are changed to compensate for the indirect drift of the entire screen.

For example, there are two cases showing the indirect drift characteristics of a conventional color picture tube as shown in Fig. 3.
13, near the horizontal axis end (opening 4), (llb) of the shadow mask side wall part, the shadow mask side H is made thinner or the length of the wall part is increased, and the diagonal axis ID
Compensation for △D15 at I is near the end of the diagonal axis (10a)
, (fob), (IOc), (10 (L) and the horizontal axis end is good. The amount of change in this case depends on the applied pipe type (
1, as appropriate. Also, the horizontal axis (Hl and the diagonal axis I
DI and the middle between the vertical axis ffl and the diagonal axis iDl, for example 3
Intermediate axis with 0 degree inclination (near the shaft end of 81 (16a), (
16b), (16c) and Q6a)c, each axis (
Hl, IVI, (Di Tonoha 57th to above changes are fine.

In the above embodiment, the thickness and length of the side wall of the shadow mask are changed and adjusted.
It goes without saying that #1, holes, unevenness, notches, quality, etc. may be changed and adjusted. For example, the material processing conditions may be changed, such as annealing only a portion.In short, the heat capacity and heat conduction may be changed according to the indirect drift compensation value.

Effects of the Invention As described above, after making the direction and amount of indirect drift at each axis end substantially uniform with respect to any one of the horizontal, vertical, and diagonal axes, the entire shadow mask structure is made of bimetallic material. With sleeve compensation, etc., it is possible to secure the landing margin of the electron beam over the entire r[11i direction without compromising compensation on the axis, and to suppress deterioration of color purity. Also, to make the indirect drift at each axis end zero, ζ2v
If I4 is adjusted, there is no need for overall compensation using bimetal etc.0

[Brief explanation of the drawing]

Figure 1 is a partial schematic diagram showing the vicinity of the shadow mask of a conventional color picture tube, Figures 2 and 3 are characteristic diagrams for explaining the changing state of the shadow mask, and Figure 4 is the axis of the shadow mask structure. FIG. 3 is a schematic plan view for explaining a transition at an end. (1)...Panel (2)...Shadow mask f31°・Mask frame (4), Qll...
Electron Beam (7317) Agent Patent Attorney Nori Chika
Yu Yu (and 1 other person) Figure 1 Figure 2

Claims (1)

[Claims] ■) Inner surface (1) A panel having a fluorescent surface (2) A panel having a fluorescent surface (2) An aperture portion having a large number of apertures and a portion extending from the periphery of the aperture, which are arranged facing each other at a predetermined interval. In a color picture tube, the shadow mask has a substantially rectangular outer shape having a horizontal axis, a vertical axis, and a diagonal axis. (2) a shadow mask having means for making relative positional deformation with the panel substantially uniform in the horizontal, vertical, and diagonal axes around the aperture; 2) Means for substantially uniformizing relative positional deformation of the shadow mask with the panel is provided on the side wall near at least two axes of the horizontal axis, vertical axis, and diagonal axis of the shadow mask. characterized by having different thicknesses or lengths