JPS6019323Y2 - color picture tube - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a color picture tube, and particularly includes a shadow mask having an electron beam passage hole and a mask frame in which the skirt of the shadow mask is supported via a support. The present invention relates to a color picture tube including at least one color picture tube.

As is well known, in a color picture tube equipped with a shadow mask, the so-called beam landing must be accurately established between the electron beam passage hole group of the shadow mask and the phosphor layers that emit light in red, green, and blue colors forming the phosphor screen. A specific relative positional relationship is required to achieve this, and unless this relative positional relationship is kept constant during operation of the color picture tube, a reproduced image of good quality cannot be obtained.

However, when operating the color picture tube to perform beam landing, the shadow mask is bombarded by the electron beam emitted from the electron gun, causing thermal expansion called doming, which will be described later. As a result of the disruption of the relative positional relationship, a beam landing error occurs, which impairs color purity and adversely affects the characteristics of the color picture tube.

That is, for example, this can be seen when a fluorescent screen becomes locally bright immediately after the color picture tube starts operating or during operation, and as shown in FIGS. 1 and 2, the fluorescent screen (not shown) A skirt extends in the direction opposite to the fluorescent screen from the end of the effective part 21 of the electron beam passage hole, which is formed opposite to the panel 1 with a predetermined interval A (usually referred to as the q value). A shadow mask 2 consisting of a portion 2° is formed of a thin iron plate, and the vicinity of the open end edge of this skirt portion 2□ is aligned with the tube axis z of the side wall portion 31.
- A mask frame that is supported on the outside in the z' direction via a support part 4 and has an L-shaped cross section with the frame embossed part 3 □ bent at a substantially right angle to the tube axis Z-Z' direction. 3 has a larger heat capacity than the shadow mask 2, so the mask frame 3 does not adapt to the rapid expansion of the shadow mask 2, and only the shadow mask 3 expands into a so-called dome shape, causing the effective parts 2,
moves to the position 21', the skirt portion 2□ moves to the position 2°', and the position of the electron beam passage hole (not shown) formed in the effective part 21 is displaced, causing a beam landing error.

A general method for compensating for this doming phenomenon of the shadow mask 2 is to make the skirt portion 2° as long as possible and provide a support portion 4 near the open end edge of the skirt portion 2.゜' is produced, and the doming phenomenon in the effective portion 2□ is suppressed to a minimum.

However, the method of compensating for such doming phenomenon is shown in Panel 1.
A structure as shown in FIGS. 3 and 4 is used when the predetermined distance A between the shadow masks and the shadow mask is large, that is, a fluorescent screen (not shown) is disposed opposite to the panel 1 with a predetermined distance A formed thereon. The vicinity of the open end edge of the shadow mask 5 consisting of the skirt portion 5° extending in the direction of the fluorescent screen from the end of the effective portion 51 in which the electron beam passage hole is formed is in the direction of the tube axis z-z' of the side wall portion 31. The mask frame 3 is supported on the inside of the mask frame 3 via a support part 4, and the frame embossing part 3° is bent at a substantially right angle to the tube axis z-z' direction, and has an L-shaped cross section. In this case, the above-described doming compensation for the effective portion 5□ of the shadow mask 5 is not performed.

As is clear from the figure, this means that the skirt part 5□ is the side wall part 3.
1, the expansion in the direction perpendicular to the tube axis z-z', that is, in the direction of the end of the effective part 51, is restricted, so the effective part 51 causes doming and moves to the position 5□'. However, the position of the electron beam passage hole (not shown) formed in the effective portion 51 is significantly displaced, resulting in a beam landing error.

The present invention was developed in view of the drawbacks of the conventional color picture tube mentioned above, and has a simple structure, can be assembled using the same manufacturing process as the conventional one, and is a combination of a shadow mask and a mask frame with extremely little doming. An object of the present invention is to provide a color picture tube having a structure.

Next, an embodiment of the present invention will be explained in detail with reference to FIGS. 5 and 6.

That is, there is a substantially rectangular panel 11 on the inner surface of which is adhered a fluorescent screen 15 in which phosphor layers emitting light in red, green, and blue colors are regularly arranged, and a side wall portion 111 of this panel 11.
A neck 18 that houses an electron gun 17 connected to the fluorescent screen 15 via a funnel 16 and an effective part 121 of the electron beam passage hole of the shadow mask 12, which is disposed opposite to the fluorescent screen 15 at a predetermined distance, emit fluorescent light from the end. Screen 15
The vicinity of the open end edge of the skirt portion 12° extending in the direction is supported via the support portion 14 on the inner side of the end edge portion 1311 of the side wall portion 131 in the direction of the tube axis z-z′ force, and this end edge portion 1
From 311, the inclined part 13□ separates from the tube axis z-z'
The frame emponent part 132 is bent in the direction of the side wall part 111 of the panel 11 at a substantially right angle to the tube axis zz' through the L-shaped cross section of the mask frame 13. The support portion 14 is located inside the side wall portion 131.
A predetermined width E is provided between the skirt portions 122 except in the vicinity.

In such a combination structure of the shadow mask 12 and the mask frame 13, when the shadow mask 12 thermally expands, the doming of the effective portion 121 is such that the skirt portion 12□
It will fall to the position of ゜' and be compensated.

In the color picture tube mentioned above, the frame embossed part 1
3□ is bent in the direction of the side wall portion 111 of the panel 11, but the shape is not limited to this, it may be bent to the opposite side, and the shape of the frame 13 is not limited to the side wall portion 131. Shadow mask 1 is placed inside the tube axis Z-Z′ side.
It is only necessary to provide a gap to the extent that the skirt portion 12 □ does not come into contact with the mask frame 13 when it falls down when the mask 2 is domed.

Next, main parts of another embodiment of the present invention will be explained with reference to FIGS. 7 and 8.

In the figure, the same reference numerals as in the previous embodiment indicate the same parts and will not be particularly described.

That is, in this embodiment, the effective portion 2 of the shadow mask 22
An inclined part 22° in which a skirt part 22□ extending in the direction of the fluorescent screen 15 from the end 21 is gradually separated from the end of the effective part 221, and an end substantially parallel to the tube axis z-z' near the support part 14. The mask frame 23 has a side wall portion 231 substantially parallel to the tube axis and a side wall portion 231 substantially parallel to the tube axis z-z'.
It has an L-shaped cross section consisting of a frame embossed part 23 □ bent in the direction of the tube axis z-z' at a substantially right angle to When the shadow mask 22 is domed between
, is provided with an interval of a predetermined width F so that it does not come into contact with the inside of .

In the above-mentioned embodiment, the predetermined widths E and F were set to values that simply compensated for doming in the effective area, but since there is a step in the manufacturing process of color picture tubes that involves heating the shadow mask at a high temperature, in this step If the end of the effective part comes into contact with the mask frame, mechanical strain or permanent deformation will occur in the effective part, which will have an adverse effect on beam landing. Therefore, in the manufacturing process, a predetermined width E, F is prepared in advance in consideration of thermal expansion of the shadow mask. It is necessary to decide.

As mentioned above, the present invention is equipped with a means for compensating shadow mask doming on the inside of the side wall of the mask frame in the tube axis direction, so it is particularly suitable for color image reception of tube types with a relatively wide distance between the fluorescent screen and the shadow mask. It is possible to perform doming compensation for the tube and minimize beam landing errors.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing a conventional general color picture tube. Figure 1 is a cross-sectional view of the main part, Figure 2 is an enlarged explanatory view of the main part, and Figures 3 and 4 are views of the conventional color picture tube. FIG. 3 is a sectional view of the main part, FIG. 4 is an enlarged explanatory view of the main part, and FIGS. 5 and 6 are diagrams showing the color picture tube in which the distance between the fluorescent screen and the shadow mask is relatively wide. FIG. 5 is a simplified sectional view, FIG. 6 is an enlarged explanatory view of main parts, and FIGS. 7 and 8 are views showing other embodiments of the color picture tube of the present invention. FIG. 7 is a sectional view of the main part, and FIG. 8 is an enlarged explanatory view of the main part. 1.11...Panel, 2. 5. 12. 2
2...Shadow mask, 3,13.23...
...Mask frame, 4, 14... Support part,
15... Fluorescent screen.

Claims (3)

[Scope of utility model registration request] (1) A panel has a fluorescent screen adhered to its inner surface in which fluorescent layers that emit light in red, green, and blue colors are regularly arranged, and an electron gun connected to this panel via a funnel is installed. a neck, a shadow mask disposed opposite to the fluorescent screen at a predetermined distance, and a skirt extending from the effective end of the shadow mask toward the fluorescent screen. In a color picture tube comprising at least a mask frame supported on the inside through a support part, the skirt part from the effective end of the shadow mask to the vicinity of the support part;
A color picture tube characterized in that a gap of a predetermined width is provided between the inner sides of the side wall portions of the mask frame in the tube axis direction. (2) Utility model registration claim No. 1, characterized in that the means for providing a predetermined width interval is to provide a sloped portion on the side wall portion of the mask frame or to provide a sloped portion on the skirt portion of the shadow mask. Color picture tube described in section 1) (3) The color picture tube according to claim (1), wherein the frame embossed portion of the mask frame extends toward the side wall of the panel.