JP2004200039A - Color picture tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate color unevenness due to a doming phenomenon by substantially eliminating the Poisson distortion that occurs at stretching the flat plate, in the shadow mask of the color picture tube device. <P>SOLUTION: In the shadow mask in which the flat plate 5 is stretched and supported by being impressed with a tensional force in vertical direction, the flat plate 5 is so constructed that a plurality of row plates 11 of stripe shape that are long in vertical direction are arranged in horizontal direction, and the row plates 11 have a bridge 12 at right and left sides in horizontal direction and are linked by the adjacent right and left row plates 12, and when the flat plate 5 is impressed with a tensional force in vertical direction, the length of the flat plate 5 in horizontal direction does not change in substance even if the tensional force in horizontal direction is not impressed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a shadow mask type color picture tube used for a television receiver, a computer display, and the like, and more particularly, to a structure of a striped row plate forming a shadow mask.
[0002]
[Prior art]
FIG. 7 is a schematic sectional view of a general color picture tube.
[0003]
The color picture tube 1 has, on its inner surface, a horizontal direction (a direction perpendicular to the plane of FIG. 7; the x-axis direction or the long side direction of the phosphor screen) and a vertical direction (the vertical direction in FIG. 7; the y-axis direction or the phosphor). An envelope is constituted by a face panel 3 on which a phosphor screen 2 having a flat surface in the short side direction of the screen is formed, and a funnel 4 joined to the rear thereof, and a phosphor screen is provided in the envelope. The funnel 4 includes a metal flat plate 5 and a frame 6 supporting the flat plate 5. The electron gun 8 is provided on a neck 7 of the funnel 4. The electron gun 8 emits three electron beams 9 (in this case, they are seen as overlapping one beam), and the electron beams 9 are deflected by the deflection yoke 10 provided outside the funnel 4 to the flat plate 5. The light reaches the phosphor screen 2 through a plurality of provided electron beam holes.
[0004]
FIG. 8 shows a basic configuration of a conventional stretching type shadow mask in a conventional color picture tube. The shadow mask includes a flat plate 5 and a frame 6. The frame 6 is configured as a rectangular frame body in which a pair of long side frames 6a arranged in parallel and a pair of short side frames 6b holding the long side frames 6a at predetermined intervals are fixed.
[0005]
In the flat plate 5, a plurality of stripe-shaped row plates 11 that are long in the vertical direction are repeatedly arranged in the horizontal direction, and adjacent row plates 11 are connected by bridges 12. The flat plate 5 is stretched and held on the long side frame 6a in a state where a vertical tension Y (indicated by an arrow in FIG. 8) is applied. A portion of the gap of the row plate 11 where the bridge 12 is not provided is an opening, which functions as an electron beam passage hole 13.
[0006]
When the tension Y is applied in the vertical direction, the flat plate 5 shrinks in the horizontal direction to generate a drum-shaped deformation (a so-called Poisson distortion). The phosphor screen 2 predicts a region where the electron beam 9 passing through the electron beam passage hole 13 reaches the phosphor screen 2 in a state where the flat plate 5 is stretched and held on the frame 6 to generate Poisson distortion. The phosphor screens 2 are formed in rows of a plurality of vertical stripes in accordance with the area.
[0007]
In this configuration, 80% or more of the electron beam 9 accelerated to a kinetic energy of several tens keV collides against the flat plate 5 of the shadow mask to which a voltage of several tens kV is applied. At this time, since the kinetic energy is converted into thermal energy, the temperature of the flat plate 5 rises, and the flat plate 5 itself thermally expands. As a result, a large number of electron beam passage holes 13 provided in the flat plate 5 are spatially displaced, so that the electron beam 9 passing through the electron beam passage holes 13 does not properly hit a predetermined phosphor, and color unevenness occurs. This is called a doming phenomenon.
[0008]
This doming phenomenon will be described in more detail. The tension Y is applied in the vertical direction when the flat plate 5 is stretched, so that if the tension Y is sufficiently applied, the thermal expansion in the vertical direction can be absorbed. However, even if the flat plate 5 is displaced in the vertical direction, the color of the phosphor is not vertical because the phosphor is a vertical stripe. On the other hand, in the horizontal direction, since a very strong tension cannot be applied due to the structure, thermal expansion cannot be absorbed, and the electron beam passage hole 13 is displaced in the horizontal direction. If so, correction can be made by shifting the frame 6 in the tube axis direction according to a temperature rise by a frame holding mechanism (not shown) having a desired temperature characteristic. Thereby, the relative positional relationship between the electron beam passage hole 13 of the flat plate 5 and the electron beam 9 is equivalent to the flat plate 5 being displaced by expanding or contracting horizontally and vertically. Since the vertical displacement has no relation to the color unevenness, as a result, the same effect as the horizontal movement of the electron beam passage hole 13 can be obtained.
[0009]
In practice, however, not only a simple horizontal translation, but another horizontal displacement component is superimposed. Another horizontal displacement component is a component in which the Poisson's distortion is relaxed and the flat plate 5 expands in the horizontal direction because the vertical tension Y of the flat plate 5 is weakened by thermal expansion. This is different from thermal expansion, which simply translates in the horizontal direction, and acts as a return amount of Poisson distortion in the shape of a drum. Therefore, the amount of displacement in the horizontal direction differs depending on the location. Correction cannot be performed, and color unevenness cannot be avoided. The only way to reduce the non-uniform displacement component in the horizontal direction is to take measures against Poisson distortion in which the deformation amount of the flat plate 5 during stretching is reduced in advance.
[0010]
As an example of the Poisson distortion countermeasure, there is known a means for reducing the number of bridges 12 connecting a plurality of striped row plates 11 in the horizontal direction (for example, see Patent Document 1). When the number of bridges 12 decreases, the Poisson distortion in the horizontal direction of one row plate 11 displaces the adjacent row plates 11 connected by the bridge 12, and the displacement amount is added to the next row plate 11 one after another. Since the phenomenon that is performed can be reduced, the Poisson distortion amount of the entire flat plate 5 can be reduced. However, in this conventional example, if the number of the bridges 12 is simply reduced, a local luminance difference between a place where the bridge 12 is present and a place where the bridge 12 is not present is visually recognized, resulting in screen noise of a fixed pattern. As a countermeasure, a protrusion for shielding an electron beam of substantially the same amount as that in the case where the bridge 12 is provided is provided in a portion where the bridge 12 is eliminated. As described above, the projection having the effect of blocking the electron beam as if a bridge is present without having the function of connecting the row plates 11 is also called a pseudo bridge.
[0011]
[Patent Document 1]
JP 2001-84918 A
[Problems to be solved by the invention]
However, while the above-described countermeasures against Poisson's distortion exert an effect of suppressing the doming phenomenon, it is difficult to accurately manufacture the flat plate 5 and the phosphor screen 2 as designed, and a slight error in the manufacturing causes a luminance difference. However, there is a problem that the image is visually recognized as screen noise.
[0013]
Even if the flat plate 5 and the phosphor screen 2 can be manufactured as designed with high accuracy, if the orbit of the electron beam 9 slightly changes due to some influence, the balance of the electron beam shielding amount between the bridge 12 and the pseudo bridge changes. Then, there is a problem that screen noise occurs again.
[0014]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and enables the Poisson's distortion of the entire flat plate 5 generated when the flat plate 5 is stretched to be controlled at the design stage, thereby making the Poisson's ratio substantially zero. An object of the present invention is to provide a color picture tube in which color unevenness due to the doming phenomenon is eliminated by designing so as to be in a state where Poisson distortion does not substantially occur.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, a color picture tube of the present invention is arranged such that a metal flat plate having a large number of electron beam passage holes facing a phosphor screen is stretched over a frame by applying tension in a vertical direction. In the color picture tube provided with a held shadow mask, the flat plate has a large number of vertically long row plates arranged in a horizontal direction, the adjacent row plates are connected via a bridge, and the flat plate is provided between the adjacent row plates. The electron beam passage holes are formed in a line in the vertical direction, the row plate has a zigzag portion extending in the vertical direction, and the zigzag portion has a vertically erected portion in a vertical direction. A plurality of rows in the direction, and has a shape in which horizontal meandering is repeated between an upper end and a lower end of the row plate (claim 1).
[0016]
According to this configuration, Poisson distortion when the flat plate is stretched and held on the frame can be suppressed, and a doming phenomenon caused by Poisson distortion can be suppressed.
[0017]
Further, the zigzag portion is also provided on a non-hole portion of the flat plate where the electron beam passage hole is not formed (Claim 2). By providing the zigzag portion also in the non-porous portion, that is, the dead space, the Poisson distortion can be reduced even if the dead space is provided in the flat plate 5.
[0018]
The zigzag portion is formed at a horizontal end of the non-porous portion (claim 3). Thereby, the zigzag shape can be easily formed on the row plate.
[0019]
Further, the zigzag portion is formed by a partial difference in plate thickness of the row plate (claim 4). Thereby, it is possible to form the zigzag shape on the row plate at the same time while preventing the zigzag portion from affecting the electron beam passage hole.
[0020]
Further, the bridge connects the valleys of the zigzag portions that are horizontally adjacent to each other (claim 5). With this configuration, the deformation of the zigzag shape when the row plates are stretched can efficiently affect the horizontal stress of the bridge.
[0021]
In addition, the portion that stands upright with respect to the vertical direction has an angle α with respect to the vertical direction, and the row plates are arranged at different pitches in the horizontal direction, and the portion where the pitch is small It is preferable that the relationship of α1 <α2 is satisfied, where α1 is α1 and α2 is α2 in the portion where the pitch is large (claim 6). This is because the Poisson's ratio tends to be in the positive direction (the direction of deformation of the conventional Poisson's distortion) when the horizontal pitch of the row plate increases, while the effect of changing the Poisson's ratio in the negative direction increases as α increases. Because.
[0022]
In addition, the zigzag portion is formed at a horizontal end of the row plate. Thereby, the zigzag shape can be easily formed on the row plate.
[0023]
In addition, the portion that stands upright with respect to the vertical direction forms an angle α with respect to the vertical direction, and the flat plate applies the vertical tension when compared to when no tension is applied. It is deformed so that the angle α becomes small (claim 8). By doing so, the horizontal stress of the bridge can be adjusted.
[0024]
Further, the color picture tube of the present invention has a shadow mask in which a metal flat plate having a large number of electron beam passage holes facing the phosphor screen is stretched and held on a frame by applying tension in the vertical direction. In the color picture tube provided with the flat plate, a large number of vertically long row plates are arranged in a horizontal direction, the adjacent row plates are connected via a bridge, and the electron beam passage holes are vertically positioned between the adjacent row plates. Wherein the flat plates are horizontally displaced in mutually opposite directions in a vertical direction when a vertical tension is applied to the flat plates. 9). According to this configuration, it is not necessary to form the zigzag portion on the row plate.
[0025]
Further, the bridge forms an angle θ smaller than 90 ° with the vertical direction, and the flat plate deforms so that the angle θ increases when a vertical tension is applied (claim 10). This increases the length of the bridge in the horizontal direction, so that the Poisson's ratio can be controlled by compensating for the horizontal shrinkage of the row plate.
[0026]
Further, the row plates have a partial difference in plate thickness, and a portion where the partial difference in the plate thickness is provided differs between the adjacent row plates (claim 11). In this way, when tension is applied in the vertical direction, the thinner part of the sheet extends vertically more than the thicker part, so that there is a difference in the vertical displacement of adjacent row plates. Can be done.
[0027]
Further, the partial difference in the plate thickness is obtained by half etching (claim 12). This makes it possible to easily provide a difference in plate thickness between the row plates and the dead space.
[0028]
Further, the angle θ differs between the bridges adjacent in the horizontal direction or the vertical direction (claim 13). This facilitates optimal control of the Poisson's ratio at each point on the entire flat plate.
[0029]
Preferably, the angle θ is between approximately 30 ° and 60 ° (claim 14). This is because when the angle is in the range, the change in the horizontal direction of the bridge is the largest with respect to the displacement difference between the adjacent row plates.
[0030]
Further, it is preferable that the horizontal length of the flat plate is kept substantially the same length when the vertical tension is applied to the flat plate without applying the horizontal tension (claim 15). According to this configuration, Poisson distortion does not occur even when the flat plate is stretched and held on the frame, so that the doming phenomenon caused by Poisson distortion can be eliminated.
[0031]
In addition, it is preferable that, when a vertical tension is applied to the flat plate, a horizontal stress at a central portion of the bridge is substantially zero (claim 16). By doing so, a configuration for eliminating Poisson distortion can be realized.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0033]
Each configuration of the color picture tube described with reference to FIGS. 7 and 8 is the same in the present invention, and a description thereof will be omitted.
[0034]
FIG. 1 is a schematic view showing a state before a flat plate 5 of a color picture tube according to the present embodiment is stretched over a frame 6 as viewed from a screen side with a part thereof enlarged.
[0035]
The striped row plate 11 provided on the flat plate 5 has a half-etched portion 14 in which the plate thickness is partially reduced by half-etching, and the thick portion remaining without being etched is formed in a zigzag shape. It has been processed to become. This part will be referred to as a zigzag part 15. The zigzag portion 15 has a shape in which a large number of portions that are set up obliquely to the vertical direction continue in the vertical direction, and have a shape that repeats a horizontal meander between the upper end portion and the lower end portion of the row plate 11.
[0036]
Note that, in FIG. 1, a parallel diagonal line is drawn on the half-etched portion 14, but this is for convenience of description and does not show a cut surface (the same applies to FIGS. 2, 5, and 6).
[0037]
The value smaller than 90 ° among the absolute values of the angle formed by the center line 16 parallel to the vertical direction and the zigzag portion 15 is defined as α. A bridge 12 connecting the adjacent row plates 11 horizontally across the electron beam passage hole 13 is extended to the inside of the row plate as a thick portion of the row plate, and is connected to a valley portion of the zigzag portion 15.
[0038]
Although this pattern slightly changes in size over the entire surface of the flat plate 5, the same pattern is continuously repeated, and the same is applied to the dead space 17 (non-hole portion) provided around the flat plate 5 as a thick portion. Are formed continuously, and the end of the flat plate 5 is terminated with a zigzag pattern as shown in FIG.
[0039]
The horizontal width of the electron beam passage hole 13 is represented by W, the vertical length thereof is represented by H, and the horizontal width of the row plate is represented by S.
[0040]
Next, FIG. 2 shows a slightly exaggerated expression of the deformed state of the flat plate 5 which is stretched and held on the frame 6 by applying a tension Y (see FIG. 7) in the vertical direction.
[0041]
As a result of being stretched vertically, W, H, and S before being stretched change to W ′, H ′, and S ′ on a horizontal axis 18 that passes through the vertical center of the bridge, respectively. At this time, since the row plates 11 of the flat plate 5 are vertically stretched and extend in the vertical direction, the vertical length of the electron beam passage holes 13 also increases. In addition, Poisson distortion is generated due to the vertical extension of the row plate 11, and the horizontal width of the row plate 11 is reduced. That is, W ′> W and S ′ <S.
[0042]
However, the horizontal length (for example, the distance between points A1 and A2 in FIG. 2) of the portion where the bridge 12 crosses the electron beam passage hole 13 does not change. The flat plate 5 shrinks in the horizontal direction by an amount obtained by multiplying the amount of shrinkage by the number of repetitions of the row plate in the horizontal direction. However, in the present invention, the horizontal width of the flat plate 5 is not reduced.
[0043]
This utilizes the fact that the zigzag portion 15 formed in the row plate 11 is deformed in a direction from the zigzag shape to a linear shape as a result of receiving tension in the vertical direction, and the angle α decreases. As a result, the row plate 11 is deformed in a zigzag shape at an angle opposite to that of the zigzag portion 15, and the bridge 12 is pushed to the adjacent row plate 11 side. Assuming that the horizontal displacement of the bridge 12 at this time is ΔW, if ΔW = S−S ′, the positions of A3 and A4 relative to A1 and A2 are before and after the flat plate 5 is stretched. Therefore, the horizontal width of the flat plate 5 does not change. In other words, at this time, it can be said that the stress is almost zero near the center of the bridge in the horizontal direction (in the related art, the tension in the horizontal direction always occurs near the center of the bridge 12 at the time of stretching).
[0044]
On the other hand, the decrease in the horizontal width of the row plate 11 from H to H ′ is an increase in the horizontal width of the electron beam passage hole 13 on the horizontal axis 18 from W to W ′ (W ′ = W + 2ΔW). This does not affect the horizontal width of the flat plate 5.
[0045]
<Specific examples of the present invention>
FIG. 3 shows a more practical design shape as an example. FIG. 3 is a perspective view of a part of a pattern formed on the flat plate 5 cut out, and a flat plate corresponding to the entire screen is formed using a pattern in which these are continuously repeated.
[0046]
Flat-plate 5, using an iron plate material having a thickness of _{T = 0.15mm, a H = 0.49mm} , a V = 1.157mm, H = 0.995mm, W = 0.125mm, P = 0.1mm, G = 0.05 mm, the Poisson's ratio can be made substantially zero by adjusting the plate thickness t of the half-etched portion 14 to about 0.5 mm and α to about 70 ° to 80 °. The adjustment parameters of the Poisson's ratio are mainly t and α. When t and / or α are reduced, the Poisson's ratio can be moved in a negative direction.
[0047]
However, the size of the pattern is slightly different depending on the position of the flat plate 5. This is mainly corresponding to the angle of incidence on the flat 5 and the phosphor screen 2 of the electron beam 9 is different, for example, the repetition pitch a _H horizontal row plate 11, near the center of the horizontal direction of the flat plate 5 , And is generally designed to gradually increase toward the periphery in the horizontal direction.
[0048]
Correspondingly, always always be in the position of the flat plate 5 throat, in order to keep the horizontal length of the portion where the bridge 12 crosses the electron beam apertures 13 constant, in accordance with the change of a _H, zigzag It is necessary to design the angle α of the portion 15 to change. That is, as a _H increases, may be dealt with by increasing the design values of the absolute value of alpha. The α in part a _H is small [alpha] 1, a large part when the [alpha] 2, an [alpha] 1 <[alpha] 2.
[0049]
With the flat plate 5 having such a design stretched and held on the frame 6, the flat plate 5 is arranged so as to face the inner surface of the face panel 3, and the phosphor screen 2 is arranged so as to correspond to the spatial positional relationship of the electron beam passage holes 13. Are formed in a repeating stripe of phosphors of R (red), G (green) and B (blue), and assembled as a color picture tube.
[0050]
<Operation of the present invention>
Next, the operation of the color picture tube of the present invention during operation will be described.
[0051]
As described in the conventional example, most of the electron beam 9 collides with the flat plate 5 to raise the temperature of the flat plate 5 to cause thermal expansion. At this time, as for the thermal expansion in the vertical direction, as in the conventional example, the row plates 11 can be absorbed if the tension Y is sufficiently applied in the vertical direction. On the other hand, in the horizontal direction, Poisson's distortion is reduced by reducing the vertical tension Y of the row plate 11 due to thermal expansion, and the horizontal width S ′ of the row plate 11 increases (the horizontal width S before stretching). Direction to return to).
[0052]
Here, a major difference between the present invention and the conventional example is that the horizontal width of the flat plate 5 does not change even if S ′ increases. That is, as a result of the vertical tension Y being relaxed by the thermal expansion, the angle α of the zigzag portion 15 increases, so that an action opposite to that at the time of stretching occurs, and the zigzag deformation of the row plate 11 is changed to the original straight line. It changes in the direction to return to the shape. As a result, the action of pulling back the bridge 12 from the adjacent row plate 11 occurs, and ΔW decreases. Since the decrease in ΔW is substantially equal to the increase in the horizontal width S ′ of the row plate 11, the horizontal width of the flat plate 5 does not change.
[0053]
Since the electron beam passage hole does not exist in the dead space of the flat plate 5 and the Poisson's ratio tends to be positive, the horizontal repetition pitch of the zigzag portion 15 formed here is the same as that of the zigzag formed on the row plate 11. It is desirable to take a large value for the portion 15.
[0054]
In addition, it is preferable that the Poisson's ratio be zero even at the horizontal end of the flat plate 5, so that the end of the flat plate 5 is desirably terminated with a zigzag portion (the end portion has a zigzag shape).
[0055]
With the above-described configuration, by designing the Poisson's ratio of the flat plate 5 to be substantially zero (a state in which Poisson distortion is not substantially generated), color unevenness due to the doming phenomenon can be eliminated.
[0056]
<Modification of the present invention>
Although the embodiments of the present invention have been described above, the contents of the present invention are not limited to the specific examples shown here. For example, the following modifications can be considered.
[0057]
(First Modification)
FIG. 4 shows a first modification.
[0058]
In the above embodiment, the zigzag portion 15 is formed inside the row plate 11. However, the present invention is not limited to this. For example, as shown in FIG. 4, the end of the row plate 11 itself can be formed in a zigzag shape having an angle α with respect to the vertical direction, such as the end of a dead space.
[0059]
In this case, it is not necessary to provide a partial difference in the thickness of the row plate 11 by etching. However, since the electron beam passage hole 13 also has a zigzag shape, it is limited to a case where a design that does not affect the image quality is possible in consideration of the application and the size.
[0060]
(Second Modification)
FIG. 5 shows a second modification.
[0061]
In the above-described embodiment, the zigzag portion of the row plate pushes the bridge in the horizontal direction toward the adjacent row plate by the tension in the vertical direction, thereby eliminating Poisson distortion of the entire flat plate. The invention is not limited to this. For example, as shown in FIG. 5, the bridge 12 is formed obliquely so that a value smaller than 90 ° among the absolute values of the angle between the bridge 12 and the vertical direction is θ, and the tension in the vertical direction is The adjacent row plates 11 may be displaced in directions different from each other.
[0062]
In this case, in the row plate 11a in which the bridges 12 are formed downward toward the row plate 11 adjacent to the bridge, the plate thickness near the joint between the upper end of the row plate 11a and the dead space of the flat plate is formed thin. It is necessary that the half-etched portion 14 (the half-etched portion 14 shown by oblique lines in the drawing) be used. On the other hand, in the row plate 11b in which the bridge 12 is formed upward toward the row plate 11 adjacent to the bridge, the plate thickness near the joining portion between the lower end of the row plate 11b and the dead space of the flat plate is formed thin. It is necessary that the half-etched portion 14 be used.
[0063]
By doing so, when the tension in the vertical direction is applied, the half-etched portion 14 extends in the vertical direction more than the thick portion of the row plate 11, so that the row plate 11a has a large thickness. The portion is displaced downward with respect to the thick portion of the row plate 11b. As a result, the angle θ of the bridge 12 increases, the bridge 12 rotates in a direction approaching parallel to the horizontal direction, the horizontal length of the bridge 12 effectively increases, and the horizontal width W of the row plate 11 decreases. The amount of contraction ΔW (not shown) due to stretching is canceled.
[0064]
Thus, the horizontal width of the flat plate 5 does not change before and after the stretching, so that Poisson's distortion due to the stretching is absorbed, and the doming phenomenon is improved even during thermal expansion as described in the example of the embodiment. At this time, if the absolute value of the angle θ is designed between 30 ° and 60 °, the effective length of the bridge 12 in the horizontal direction at the time of stretching can be efficiently increased.
[0065]
Further, the bridge 12 may be configured such that the vertical position is shifted by １ ／ pitch for each row.
[0066]
(Third Modification)
FIG. 6 shows a third modification.
[0067]
As shown in FIG. 6, the thin portion of the row plate 11 (the half-etched portion 14 shown by oblique lines in the figure) has a narrow coupling interval between the bridges 12, and the thick portion of the row plate 11 has a bridge. 12 may be formed so as to have a large connection interval, and the thin portions may be arranged at different positions between the adjacent row plates 11.
[0068]
The principle in this case is almost the same as that of the second modification. When the tension is applied in the vertical direction, the half-etched portion 14 extends more than the thick portion of the row plate 11, thereby increasing the absolute value of the angle θ, and the effective length of the bridge 12 in the horizontal direction. Is changed in the direction in which the horizontal width W of the row plate 11 is reduced to cancel the contraction amount ΔW of the horizontal width W of the row plate 11.
[0069]
As for the thermal expansion, similarly to the second modified example, the principle is established by performing a movement reverse to that at the time of stretching.
[0070]
【The invention's effect】
As described above, according to the color picture tube according to the present invention, the horizontal direction displacement of the flat plate of the shadow mask is designed to be substantially zero (a state in which Poisson distortion does not substantially occur). Color unevenness due to the phenomenon can be eliminated.
[Brief description of the drawings]
FIG. 1 is a partially enlarged plan view of a flat plate (before stretching) of a shadow mask included in a color picture tube of the present invention. FIG. 2 is a partially enlarged plan view of a flat plate of a shadow mask (after stretching). FIG. 4 is a partially enlarged perspective view of a flat plate of a shadow mask. FIG. 4 is a schematic plan view of a flat plate of a shadow mask according to a first modification of the present invention. FIG. 5 is a flat plate of a shadow mask according to a second modification of the present invention. FIG. 6 is a schematic plan view of a flat plate of a shadow mask according to a third modification of the present invention. FIG. 7 is a side sectional view of a general color picture tube. FIG. 8 is a perspective view of a conventional shadow mask. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Color picture tube 2 Phosphor screen 3 Face panel 4 Funnel 5 Flat plate 6 Frame 7 Neck part 8 Electron gun 9 Electron beam 10 Deflection yoke 11 Row plate 12 Bridge 13 Electron beam passage hole 14 Half etching part 15 Zigzag part 16 Center line 17 Dead space 18 horizontal axis

Claims (16)

In a color picture tube provided with a shadow mask, which is opposed to the phosphor screen and has a large number of electron beam passage holes formed thereon, the tension being applied to the frame in the vertical direction and being held on the frame.
In the flat plate, a number of vertically long row plates are arranged in a horizontal direction, adjacent row plates are connected via a bridge, and the electron beam passage holes are formed between the adjacent row plates in a vertical direction. And
The row plate has a zigzag portion extending in a vertical direction,
The zigzag portion has a shape in which a number of portions that are erected obliquely with respect to the vertical direction are vertically continuous, and have a shape that repeats horizontal meandering between an upper end portion and a lower end portion of the row plate. A color picture tube. 2. The color picture tube according to claim 1, wherein the zigzag portion is also provided on a non-perforated portion on the periphery of the flat plate where the electron beam passage hole is not formed. The color picture tube according to claim 2, wherein the zigzag portion is formed at a horizontal end of the non-porous portion. The color picture tube according to claim 1, wherein the zigzag portion is formed by a partial difference in thickness of the row plates. The color picture tube according to any one of claims 1 to 4, wherein the bridge connects valleys of the zigzag portions that are horizontally adjacent to each other. The part which is erected obliquely with respect to the vertical direction has an angle α with respect to the vertical direction,
When the row plates are arranged at different pitches in the horizontal direction, and the angle α at the small pitch portion is α1, and the angle α at the large pitch portion is α2, α1 <α2. The color picture tube according to claim 1, wherein a relationship is established. The color picture tube according to claim 1, wherein the zigzag portion is formed at a horizontal end of the row plate. The part which is erected obliquely with respect to the vertical direction has an angle α with respect to the vertical direction,
The color picture tube according to any one of claims 1 to 7, wherein the flat plate is deformed such that the angle α is smaller when a vertical tension is applied than when the tension is not applied. In a color picture tube provided with a shadow mask, which is opposed to the phosphor screen and has a large number of electron beam passage holes formed thereon, the tension being applied to the frame in the vertical direction and being held on the frame.
In the flat plate, a number of vertically long row plates are arranged in a horizontal direction, adjacent row plates are connected via a bridge, and the electron beam passage holes are formed between the adjacent row plates in a vertical direction. And
The color picture tube according to claim 1, wherein when the flat plate is applied with a vertical tension, the row plates adjacent in the horizontal direction are vertically displaced in directions opposite to each other. The bridge is at an angle θ less than 90 ° with the vertical,
The color picture tube according to claim 9, wherein the flat plate is deformed such that the angle θ increases when a vertical tension is applied. The collar according to claim 9, wherein the row plates have a partial difference in plate thickness, and a portion where the partial thickness difference is provided is different between adjacent row plates. Picture tube. The color picture tube according to claim 4 or 11, wherein the partial difference in plate thickness is obtained by half etching. The color picture tube according to claim 10, wherein the angle θ is different between the bridges adjacent in the horizontal direction or the vertical direction. 14. The color picture tube according to claim 10, wherein the angle [theta] is approximately between 30 [deg.] And 60 [deg.]. The horizontal length of the flat plate keeps substantially the same length even when the horizontal tension is not applied, when the vertical tension is applied to the flat plate, according to any one of claims 1 to 14. Color picture tube. 16. The color picture tube according to claim 15, wherein when a vertical tension is applied to the flat plate, a horizontal stress at a central portion of the bridge is substantially zero.

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