JPH0456042A - Color image receiving tube - Google Patents

Abstract

PURPOSE:To correct mislanding by fixing a plurality of holders to places near the four corners of a mask frame, and composing these holders of one type, in which the high expansion side of a bimetal member is located on the mask frame side, and another type in which the low expansion side of the bimetal member is situated on the mask frame side. CONSTITUTION:A plurality of holders 25 partially consisting of a bimetal member, which are to support an approx. rectangular shadow mask 4 on the inside of an approx. rectangular panel 1, are fixed in positions near the four corners of an approx. rectangular mask frame 6 mounted at the periphery of the shadow mask, wherein four such holders 25 are composed of one type 25a, in which the high expansion side of the bimetal member is located on the mask frame side, and another type 25b in which the low expansion side of the bimetal member is situated on the mask frame side. These two types of holders 25 are selected appropriately and mounted in positions near the four corners of the mask frame 6. which provides possibility of correcting effectively an unbalanced mislanding of electron beam to a three-color fluorescent substance layer caused by bombardment with electron beam.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a shadow mask type color picture tube, and more particularly to a color picture tube with improved means for supporting the shadow mask.

(Prior Art) In general, a shadow mask type color picture tube has an envelope consisting of a rectangular panel and a funnel-shaped funnel integrally joined to the panel. A nearly rectangular shadow mask with an electron beam passage hole is used to sort three electron beams emitted from an electron gun placed inside the neck of the funnel and deflected by a deflection yoke attached to the outside of the funnel. ．． The structure is such that an image is displayed by scanning a phosphor screen consisting of a three-color phosphor layer formed on the inner surface of the panel.

Therefore, in order to display a correct color image on the phosphor screen in such a color picture tube,
The shadow mask and the three-color phosphor layers constituting the phosphor screen must be arranged in a precise matching relationship. On the other hand, the shadow mask is attached and detached multiple times during the process of forming the phosphor screen. Therefore,
Usually, a shadow mask is made of stud pins fixed to the panel so that it can be attached to and removed from the panel and is always correctly attached at the same position, and a nearly rectangular mask frame attached to the periphery of the shadow mask. It is supported by a holder that is fixed and removably engaged with the stud pin.

FIG. 5 shows a support structure of a shadow mask for a conventional panel. This support structure corresponds to the stud pins (3) fixed to the inner surface of the center part of each side of the skirt part (2) formed around the periphery of the rectangular panel (1). A holder () is welded and fixed to each outer surface of a substantially rectangular mask frame (6) attached to the periphery of the mask body (5) in which a large number of electron beam passage holes are formed of the shadow mask (4). 7). Each holder (7) is made of a band-like elastic body, and has a structure in which an engaging part provided at the tip part is removably engaged with the opposing stud pin (3).

By the way, the Nyadou mask (4) is the mask itself (
5) The area occupied by the electron beam passage hole, that is, the aperture ratio is very small. Therefore, most of the electron beams emitted from the electron gun during operation of the color picture tube collide with the shadow mask, and the shadow mask (4
) is heated and expanded.

The heating of the shadow mask (4) due to the collision of the electron beams mainly heats the mask body (5) as shown by the broken line (9) at the beginning of the operation of the color picture tube, and then 10) Make it bulge in the direction. However, the heat is gradually transferred to the mask frame (6) and eventually thermally expands the entire shadow mask (4). As a result, the matching relationship between the shadow mask and the three-color phosphor layers constituting the phosphor screen (10), that is, the trajectory (12) of the electron beam passing through the electron beam passage hole (11) of the shadow mask (4), is determined. As shown by the broken line 13), the landing deviation occurs with respect to the three-color phosphor layer.

Therefore, in order to prevent the landing misalignment of the shadow mask (4) due to thermal expansion, the holder (7a) is made of a bimetallic material, as shown in FIG. There is one that has an engaging part (15) attached thereto that is removably engaged.

Incidentally, the thermal expansion of the shadow mask (4) due to the collision of electron beams is generally greatest in the four corner regions, and these regions are not necessarily symmetrical with respect to the central axis of the shadow mask (4). Therefore, as shown in Fig. 8, the color image reception is such that the landing of the three electron beams (13B), (13G), (13R) on the three color phosphor layers (12B), (12G), (12R) is unbalanced. There is a tube.

If such an unbalanced shift occurs, for example, (12Ba), (13Ba) and (12B
c).

(13Bc) As shown in phosphor layer (12B)
For regions where the landing position of the electron beam (13B) is shifted inward in the radial direction, the landing position of the electron beam (13B) is moved inward by the arrow (14a) using a holder (7a) made of a bimetallic member having the same configuration.

(14c) direction to correct the landing deviation. However, (12Bb).

As shown in (13Bb), (12Bd), and (13Bd), for regions where the landing position of the electron beam (13B) is shifted outward in the radial direction with respect to the phosphor layer (12B), a bimetallic material of the same configuration is used. With the holder (7a) made of a single member, it is not possible to perform correction at the same time, and landing deviation remains, resulting in color misregistration.

(Problems to be Solved by the Invention) As mentioned above, the shadow mask of a color picture tube generally consists of a plurality of stud pins fixed to the skirt portion of a rectangular panel and a substantially rectangular mask frame of the shadow mask. It is attached to the inside of the panel by a plurality of holders that are welded and fixed to the stud pins and removably locked to the stud pins, and is particularly effective against the three-color phosphor layer caused by thermal expansion of the shadow mask due to the collision of electron beams. A color picture tube is known in which a plurality of holders are all made of bimetallic members of the same structure in order to prevent landing deviation of the electron beam. However, even if the holder is made of bimetallic material as described above, the thermal expansion of the shadow mask due to the collision of the electron beam will
Since the shadow mask is not necessarily symmetrical with respect to the central axis, the landing of the electron beam on the three-color phosphor layer is unbalanced. Therefore, with a holder made of bimetal members of the same configuration, for example, although it is possible to correct the area where the landing position of the electron beam on the three-color phosphor layer is shifted inward in the radiation direction, the landing position of the electron beam on the three-color phosphor layer may be corrected. Areas whose positions are shifted outward in the radial direction cannot be corrected at the same time, and landing shifts remain, resulting in color shift.

This invention was made in order to solve the above-mentioned problem, and the unbalanced landing shift of the electron beam on the three-color phosphor layer that occurs when the shadow mask causes asymmetric thermal expansion due to the collision of the electron beam. The purpose of the present invention is to configure a color picture tube so as to be able to effectively correct the color picture tube.

[Structure of the Invention] (Means for Solving the Problems) A substantially rectangular shadow mask having a substantially rectangular mask frame attached to its periphery has a skirt portion on the inside of a substantially rectangular panel having a skirt portion on its periphery. A color image receiver supported by a plurality of stud pins fixed to the inner surface of the mask frame and a plurality of holders fixed to the mask frame and latched to the stud pins, a part of each of the holders being constituted by a bimetallic member. In the tube, the plurality of holders are fixed near the four corners of the mask frame, and the holder has the high expansion side of the bimetal member facing the mask frame, and the low expansion side of the bimetal member facing the mask frame. It consists of a holder on the side.

(Function) As mentioned above, when two types of holders with different placements of bimetal members relative to the mask frame are used, the thermal expansion due to the collision of the electron beam is not symmetrical, so the landing of the electron beam on the three-color phosphor layer is uneven. Even if a shift in balance occurs, we will respond to the shift in imbalance,
By properly using two types of holders, the unbalanced shift can be effectively corrected and color shift can be prevented.

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

FIG. 1 shows a color picture tube which is one embodiment of the present invention. This color picture tube has an outer enclosure consisting of a substantially rectangular panel (1) with a skirt section (2) formed at the periphery and a funnel-shaped funnel (20) integrally joined to this panel (1). On the inner surface of the panel (1) is a phosphor screen (10) consisting of a three-color phosphor layer that emits blue, green, and red light.
is formed, and a substantially rectangular shadow mask (4) is formed inside it, facing and close to this phosphor screen (10).
) is installed. In addition, 3 electron beams (13B), (13G
), (13R) is provided, and three electron beams (22) emitted from this electron gun (22) are provided.
13B), (13G), (131?) into the funnel (2
The fluorescent screen (10) is deflected by a deflection yoke (23) mounted on the outside of the screen (0) to horizontally and vertically scan the phosphor screen (10), thereby displaying a color image.

The shadow mask (4) consists of a mask body (5) in which a large number of electron beam passage holes are formed, and a substantially rectangular mask frame (6) attached to the periphery of the mask body (5).
As shown in FIG. 2, four stud pins (3) are fixed to the inner surface near the four corners of the panel (1), and four stud pins (3) are fixed to the inner surface near the four corners of the mask frame (6). Four holders (25) that lock onto stud pins (3)
) is supported inside the panel (1).

Each of the holders (25) has a two-shaped flexible part (26) made of a bimetallic material made by bonding a high-expansion coefficient metal and a low-expansion coefficient metal, and a flexible part (26) of the flexible part (26). It consists of a stud pin engaging part (27) attached to the end. Moreover, in the color picture tube of this example, (25a),
As shown separately from (25b), two types of holders with different flexible parts (26) are arranged. That is,
As shown in FIG. 3(a), at two predetermined corners among the four corners, the high expansion coefficient metal (28) side of the bimetal member constituting the flexible part (26) is attached to the mask frame (6). ) side, and the low expansion coefficient metal (29) is placed on the skirt (2) of the panel (1).
) side holder (25a) is arranged, and in the remaining two corners, as shown in FIG. The side is the skirt (2) side of the panel (1), and the low expansion coefficient metal (2
Holder (25b) with 9) on the mask frame (6) side
) are located.

By the way, as mentioned above, there are two types of holders (2) with different flexible parts (26) near the four corners of the mask frame (6).
When 5a) and (25b) are arranged, the following effects can be obtained.

That is, as described above, the shadow mask undergoes asymmetrical thermal expansion due to the collision of the electron beam, and due to this thermal expansion, the landing shift of the electron beam with respect to the three-color phosphor layer becomes unbalanced. In this case, even if holders of the same configuration are arranged with respect to the mask frame as in the past, the unbalanced shift cannot be corrected, but as described above, two types of holders (25a), (
25b), one holder (25a) has the high expansion coefficient metal (28) located on the mask frame (6) side.
As shown in FIG. 3(b) in contrast with FIG. 3(a), the high expansion coefficient metal (2) located on the mask frame (6> side)
8> and the low expansion coefficient metal (29) located on the skirt (2) side of the panel (1), the shadow mask (4) is caused by the phosphor screen as shown by the arrow (31). Extrude in the direction. In contrast, high expansion coefficient metals (2
The other holder (25b) where 8) is located on the skirt (2) side of the panel (1) is located on the skirt (2) side of the panel (1), as shown in FIG. (・(2
) Due to the difference in relative elongation between the high expansion coefficient metal (2B) located on the side of the mask frame (6) and the low expansion coefficient metal (29) located on the mask frame (6) side, the shadow mask (4) is
Press down in the opposite direction of the phosphor screen as shown.

As a result, as shown in the MB diagram, a three-color phosphor layer (12B
), (12G), (12R) with electron beam (13B).

(13G), (If an unbalanced deviation occurs in the landing of J3R>, (12Ba), (138a)
The high expansion coefficient metal (28) is located on the mask frame (6) side in the region where the electron beam is shifted inward in the radial direction with respect to the phosphor layer, such as (1, 2Bc) and (13Bc). holder (25a) is placed, and (12Bb
), (tanb) and (J2Bd), (1,38d)
The low expansion coefficient metal (29) is placed on the mask frame (6) side (the high expansion coefficient metal (28) is placed on the panel (1) side) in the area where the electron beam is shifted inward in the radial direction with respect to the phosphor layer as shown in FIG. The other holder (25b) located on the skirt (2) side)
), the unbalanced landing shift shown in FIG. 8 can be corrected. In this case, the amount of correction can be appropriately corrected by appropriately selecting the high expansion coefficient metal (28) and the low expansion coefficient metal (29) and adjusting the difference in their thermal expansion coefficients. In addition, there are two types of holders (25) for the shadow mask (4).
The selection of a) and (25b) and their arrangement are achieved by manufacturing a color picture tube in advance using a normal holder that does not use bimetal, and then applying an electron beam to the three-color phosphor layer by colliding the electron beam with the color picture tube. The landing deviation of AFJ is determined in advance, and the determination is made based on the result.

Moreover, generally three color phosphor layers (12B), (12G
).

Electron beam (13B), (13G) for (12R>
, (13R) is the largest at the four corners of the screen, so as with the color picture tube in this example, the holders (25a) and (25b) are attached to the mask frame (
By arranging it near the four corners of 6), it is possible to satisfactorily correct the landing deviation.

[Effects of the Invention] A plurality of holders, each of which is partially made of a bimetallic member and which supports a substantially rectangular shadow mask, are mounted inside a substantially rectangular panel of a substantially rectangular mask frame attached to the periphery of the shadow mask. If it is fixed near the four corners and the four holders are composed of a holder with the high expansion side of the bimetal member facing the mask frame side and a holder with the low expansion side of the bimetal member facing the mask frame side, the second By appropriately selecting different types of holders and arranging them near the four corners of the mask frame, it is possible to effectively correct the unbalanced landing shift of the electron beam on the three-color phosphor layer due to the collision of the electron beam.

Moreover, by arranging the screen near the four corners where the landing deviation on the screen is greatest, the landing deviation can be corrected well, and a color picture tube having good landing characteristics over the entire screen can be constructed.

[Brief explanation of the drawing]

1 to 4 are detailed explanatory diagrams of the present invention, with FIG. 1 showing the configuration of a color picture tube as an embodiment thereof, and FIG. 2 showing support of a shadow mask by a 2tI type holder. Figures 3(a) and 3(b) are diagrams showing the structure of one of the holders, and Figures 4(a) and 4(b) are diagrams showing the structure and operation of the other holder, respectively. Figure 5 is a diagram showing the structure and its operation; Figure 5 is a diagram showing the support structure of a conventional shadow mask; Figure 6 is a diagram showing the support structure of a conventional shadow mask.
The figures are diagrams for explaining the landing deviation of the electron beam on the three-color phosphor layer caused by the thermal expansion of the shadow mask, Figure 7 is a diagram showing the structure of a conventional holder partially made of bimetallic material, and Figure 8 1 is a diagram showing an unbalanced landing shift of an electron beam on a three-color phosphor layer due to collision of the electron beam. 1...Panel, 2...Skirt part, 3...
・Stud pin, 4...Shadow mask, 5...
Mask body, 6...mask frame, IO...
Phosphor screen, 25...Holder 25a...Holder 25b with the high expansion side of the bimetal member facing the mask frame side...Holder 26 with the low expansion side of the bimetal member facing the mask frame side...Flexible part , 27... Stud pin engagement part. Agent Patent Attorney Norihiro Ogo Kao 3 Figure 1 Figure 4 Figure 5a Figure 2 Figure 5

Claims (1)

[Scope of Claims] A plurality of substantially rectangular shadow masks having substantially rectangular mask frames attached to the periphery thereof are fixed to the inner surface of the skirt portion of the panel on the inside of a substantially rectangular panel having a skirt portion on the periphery thereof. in a color picture tube supported by a plurality of stud pins and a plurality of holders fixed to the mask frame and latched to the stud pins, each of the holders being partially made of a bimetallic member; The holder is fixed to the vicinity of the four corners of the mask frame, and is composed of a holder with the high expansion side of the bimetal member facing the mask frame, and a holder with the low expansion side of the bimetal member facing the mask frame. A color picture tube featuring