JPH10172452A - Color cathode ray tube with shadow mask - Google Patents

Abstract

(57) Abstract: Provided is a color cathode ray tube including a shadow mask in which the mechanical strength of a shadow mask 6 is increased to reduce the occurrence of howling and the like and the purity margin is increased. SOLUTION: The formation position of each electron beam passage hole 14 in the horizontal direction in a shadow mask 6 having a large number of electron beam passage holes 14 in a slightly curved shadow mask hole 6A is determined. It is composed of a cubic expression and a quintic expression of the distance from the vertical center line, and the composition ratio of the cubic expression and the quintic expression is set to be in a range of 1: 9 to 9: 1. Hole pitches p ₁ , p ₂ , p ₃ , ...
.., P _(n-1) , _pn , p _{(n + 1)} ,.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube provided with a shadow mask, and more particularly, to a cubic expression of a distance of each electron beam passage hole in the horizontal direction of the shadow mask from a vertical center line of the shadow mask. And a color cathode ray tube having a shadow mask formed so as to have a hole pitch represented by a quintic formula.

[0002]

2. Description of the Related Art In general, a color cathode ray tube having a shadow mask has a panel portion having a fluorescent film formed on an inner surface of a face plate, a neck portion having an electron gun for generating three electron beams, and a panel portion. It consists of a funnel connecting the neck. A shadow mask having a large number of electron beam passage holes in a perforated portion is arranged inside the panel portion facing the fluorescent film, and a deflection yoke for deflecting three electron beams is mounted outside the funnel portion. Have been.

In the color cathode ray tube having the above-mentioned structure, in operation, three electron beams emitted from an electron gun are deflected in an appropriate direction by a deflection yoke and then passed through corresponding electron beam passage holes in a shadow mask. It also strikes the phosphor layer on the phosphor film of the corresponding color, thereby causing the phosphor film to display the required color image.

By the way, the shadow mask corresponds to the slightly curved shape of the face plate on which the fluorescent film is formed,
The perforated portion having many electron beam passage holes is also formed so as to have a slightly curved surface shape, and the formation position of each electron beam passage hole in the horizontal direction of the shadow mask is at a hole pitch corresponding to the slight curved surface shape. Have been selected to be.

FIG. 5 is an explanatory view showing a state in which the arrangement position of each electron beam passage hole in the horizontal direction of the shadow mask is set. FIG. 6 is a view showing a known state formed by the method shown in FIG. It is a top view which shows the structure of some shadow mask aperture parts in a shadow mask.

In FIG. 5, reference numeral 51 denotes a panel face plate; 52, a hole having a shadow mask; 53, a tube axis of a color cathode ray tube; 54, a deflection center of an electron beam; 55, an electron beam; This is the length between the center 54 and the panel face plate 51.

In FIG. 6, reference numeral 56 denotes a slit-shaped electron beam passage hole, a ₁ , a ₂ , a ₃ , a ₄ ,..., A
_(n-1) , a _n , a _{(n + 1)} , a _{(n + 2)} ,... are the electron beam passage holes 56 arranged in the vertical direction of the shadow mask.
, P ₁ , p ₂ , p ₃ ,………, p
_(n-1) , p _n , p _{(n + 1)} ,... are adjacent axes a ₁ ,
a ₂ , a ₃ , a ₄ , ..., a _(n-1) , a _n , a
The distance between _{(n + 1)} , a _{(n + 2)} ,..., that is, the hole pitch of the electron beam passage holes 56.

As shown in FIG. 5, the panel face plate 51 is usually formed so as to have a slightly curved surface shape.
Also, it is formed to have a slightly curved shape so as to be substantially parallel to the panel portion face plate 51. When the electron beam 55 emitted from the electron gun (not shown) advances along the tube axis 53 and reaches the deflection center 54 of the electron beam, the electron beam 55 is deflected by a magnetic field generated by a deflection yoke (not shown). After its path direction is slightly bent and passes through the corresponding electron beam passage hole 56 of the shadow mask perforated portion 52, the panel face plate 51
Then, it collides with a corresponding phosphor layer (also not shown) on the phosphor film (not shown) formed in the above.

Further, as shown in FIG. 6, the state of formation and arrangement of a large number of electron beam passing holes 56 in a known shadow mask is such that a relatively small hole pitch p ₁ , p ₂ , p _{3 in} the central portion of the shadow mask. Are formed with relatively large hole pitches p _(n-1) , _pn , and p _{(n + 1) in} the peripheral portion of the shadow mask.

Generally, an electron beam 55 deflected at the center of deflection of the electron beam passes through one of the electron beam passage holes 56 of the hole portion 52 of the shadow mask in a process of scanning the electron beam. If it is deflected so as to pass through the hole (this electron beam passage hole is assumed to be 56 _k ), the panel face plate 51 and the shadow mask perforated portion 5 in the portion _where the beam passage hole 56 _k is arranged.
The distance from 2 to b , The distance between the deflection center 54 and the panel portion face plate 51 of the electron beam d _k, the axis passing through the center of the beam passage hole 56 _k a _k and axis a adjacent thereto
Assuming that the hole pitch between _{(k + 1)} and pk is _pk and A _k is a constant determined by the deflection yoke, the interval b _k is represented by the following equation (1).

B _k = A _k · p _k · d _k (1) Then, when forming the perforated portion 52 of the shadow mask,
Using the formula (1), the distance b _k (where k = 1, 2, 3,..., N−1, n, n +) between the entire surface of the shadow mask perforated portion 52 and the panel portion face plate 51 is used.
1,...) Are obtained, the shadow mask holes 52 having a slight curved surface shape are formed so that the obtained intervals b _k are connected in a smooth state, and the formed shadow mask holes 52 having a curved surface shape are formed. In addition, the hole pitch _pk (where k
= 1, 2, 3,..., N−1, n, n + 1,.
..), The respective electron beam passage holes 56 are formed.

In addition, the radius of curvature (R ₂ ) of the peripheral portion of the shadow mask perforated portion 52 is slightly smaller than the radius of curvature (R ₁ ) of the central portion of the perforated portion 52 of the shadow mask. That is, it is formed so that R ₁ > R ₂ . For this reason, the shadow mask perforated portion 52
A large number of electron beam passage holes 56 are formed such that the respective hole pitches a _k gradually increase from the central portion to the peripheral portion.

As a known shadow mask formed by forming a large number of electron beam passage holes 56 in the shadow mask perforated portion 52 based on such a large number of electron beam passage hole forming means, a horizontal direction of the shadow mask can be used. formation position of each electron beam passage holes, which are formed so as to hole pitch p _k according to cubic equation of the distance from the vertical center line of the shadow mask (hereinafter, the first example of this known ) of those, which are formed so as to hole pitch p _k according to the fifth-order equation of the distance from the vertical center line of the shadow mask (hereinafter, this is called as the second example of the known) such There is.

FIG. 7 is a characteristic diagram showing the relationship between the distance from the vertical center line of the shadow mask and the hole pitch of the first known example and the second known example.

In FIG. 7, the horizontal axis is the distance from the center line, the vertical axis is the hole pitch, the curve is the characteristic of the first known example, and the curve is the characteristic of the second known example. .

As shown in FIG. 7, the curve shows that the hole pitch gradually increases as the distance increases. The curve shows that even when the distance increases, the hole pitch p increases up to a certain distance. To a lesser extent, when the distance exceeds a certain distance, the hole pitch sharply increases.

[0017]

As is apparent from the curve shown in FIG. 7, a known first method for forming a large number of electron beam passage holes 56 in the shadow mask perforated portion 52 is shown.
In the example, even if the distance increases, the degree of increase in the hole pitch is not so large.
Radius of curvature cannot be reduced around it,
For this reason, it is difficult to increase the mechanical strength of the shadow mask, and there is a problem in that vibration applied to the shadow mask causes doming or howling.

On the other hand, as is apparent from the curves shown in FIG. 7, the second example in which a large number of electron beam passage holes 56 are formed in the perforated portion 52 of the shadow mask has a large distance. In addition, since the degree of the increase in the hole pitch becomes large, the radius of curvature of the shadow mask perforated portion 52 can be considerably reduced in the peripheral portion thereof, and the mechanical strength of the shadow mask can be increased. Since the hole pitch in the intermediate portion between the intermediate portion and the peripheral portion is not so large, there is a problem that the purity of the intermediate portion cannot be increased, and a color shift occurs in a displayed image.

The present invention solves these problems, and an object of the present invention is to increase the mechanical strength of the shadow mask to reduce the occurrence of howling and the like, and to increase the purity margin. A color cathode ray tube provided with:

[0020]

In order to achieve the above object, a color cathode ray tube having a shadow mask according to the present invention is arranged such that the position of each electron beam passage hole in the horizontal direction of the shadow mask is adjusted in the vertical direction of the shadow mask. Means are provided with a hole pitch determined by a cubic formula and a quintic formula of the distance from the center line.

According to the above means, a large number of electron beam passing holes are formed at a hole pitch determined by a cubic expression of a distance from the vertical center line of the shadow mask (the first known example). We are trying to solve the problem, that is,
By making the radius of curvature of the perforated portion of the shadow mask relatively small at the periphery thereof, the mechanical strength of the shadow mask is increased, and at the same time, a large number of electron beam passage holes are located at a distance from the vertical center line of the shadow mask. The problem of the one formed with the hole pitch determined by the fifth-order equation (the second known example) is solved. That is, the hole pitch of the middle part between the central part and the peripheral part of the shadow mask is reduced. It is made relatively large to increase the degree of purity in the middle area and suppress the occurrence of color shift in the displayed image.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the present invention, a color cathode-ray tube having a shadow mask is provided in a horizontal direction in a shadow mask having a large number of electron beam passage holes in a slightly curved hole. The formation position of each electron beam passage hole is defined by a cubic formula and a quintic formula of the distance from the vertical center line of the shadow mask, and the composition ratio of the cubic formula and the quintic formula is determined by: The holes are formed at a pitch between 1: 1 and 9: 1.

According to the embodiment of the present invention, the formation position of each electron beam passage hole in the horizontal direction in the shadow mask is determined by the cubic expression and the quintic expression of the distance from the vertical center line of the shadow mask. And the synthesis ratio is 1 to 9
Since the hole pitch is set so as to fall within the range of 9: 1, a large number of electron beam passing holes are formed at a hole pitch determined by a cubic expression of a distance from the vertical center line of the shadow mask ( To solve the problem of the known first example), that is, to make the radius of curvature of the perforated portion of the shadow mask relatively small in the peripheral region, increase the mechanical strength of the shadow mask, and apply vibration. And a plurality of electron beam passage holes are formed at a hole pitch determined by a fifth-order formula of a distance from a vertical center line of the shadow mask (known second pitch).
In other words, the problem of the example is solved, that is, the hole pitch in the intermediate region between the central region and the peripheral region is made relatively large, the purity margin in the intermediate region is increased, and the occurrence of color misregistration in the displayed image is reduced. I am holding it down.

According to the embodiment of the present invention, by changing the combination ratio of the cubic expression and the quintic expression according to the type and use of the color cathode ray tube, the diagonal dimension of the effective surface, and the like,
It is possible to increase the mechanical strength of the shadow mask and increase the purity margin.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a schematic configuration of an embodiment of a color cathode ray tube having a shadow mask according to the present invention.

In FIG. 1, 1 is a panel portion, 2 is a neck portion, 3 is a funnel portion, 4 is a face plate, 5 is a fluorescent film, 6 is a shadow mask, 6A is a perforated portion of a shadow mask, and 7 is a support frame. , 8 is a deflection yoke, 9 is an electron gun, 10 is a purity adjustment magnet, 11 is a center beam static convergence adjustment magnet,
Reference numeral 12 denotes a side beam static convergence adjusting magnet, and reference numeral 13 denotes an electron beam.

The vacuum envelope (bulb) constituting the color cathode ray tube has a panel section 1 disposed on the front side, an elongated cylindrical neck section 2 containing an electron gun 9 therein, and a panel section 1. And a funnel part 3 having a substantially funnel shape connecting the neck part 2. The panel unit 1 has a face plate 4 on the front surface, and a fluorescent film 5 on the inner surface of the face plate 4.
Is formed. The shadow mask 6 has a perforated portion 6A having many electron beam passage holes (not shown). A support frame 7 is fixedly arranged on the inner peripheral portion of the panel portion 1, and the shadow mask 6 is attached to the support frame 7 such that the perforated portion 6 </ b> A of the shadow mask 6 is opposed to the fluorescent film 5. Funnel 3 and neck 2
The deflection yoke 8 is disposed outside the portion where the deflection yoke is connected. The three electron beams 13 (only one is shown in FIG. 1) projected from the electron gun 9 are deflected in a predetermined direction by the deflection yoke 8 and then pass through the electron beam passage holes of the shadow mask 6. To be projected on the fluorescent film 5, a purity adjusting magnet 10, a center beam static convergence adjusting magnet 11,
Side beam static convergence adjusting magnets 12 are arranged side by side.

In this case, the operation of the color cathode ray tube of the present embodiment, that is, the image display operation is almost the same as the image display operation of the known color cathode ray tube of this kind, and the operation is the same as in the related art. Is well known, and the description of the image display operation in the color cathode ray tube of the present embodiment will be omitted.

Next, FIG. 2 is a plan view showing a partial structure of an example of the shadow mask aperture 6A used in the color cathode ray tube shown in FIG. It is an example in which holes are provided.

In FIG. 2, reference numeral 14 denotes a slit-shaped electron beam passage hole, a ₁ , a ₂ , a ₃ , a ₄ ,..., A
_(n-1) , a _n , a _{(n + 1)} , a _{(n + 2)} ,... are the electron beam passage holes 14 arranged in the vertical direction of the shadow mask.
, P ₁ , p ₂ , p ₃ ,………, p
_(n-1) , p _n , p _{(n + 1)} ,... are adjacent axes a ₁ ,
a ₂ , a ₃ , a ₄ , ..., a _(n-1) , a _n , a
The distance between _{(n + 1)} , a _{(n + 2)} ,..., that is, the hole pitch of the electron beam passage holes 14.

As shown in FIG. 2, the arrangement of the large number of electron beam passage holes 14 in the present embodiment in the hole portion 6A of the shadow mask is such that the hole pitches p ₁ and p are relatively small in the central portion of the shadow mask 6. ₂ and p ₃ , while on the periphery of the shadow mask they are arranged so as to have relatively large hole pitches p _(n-1) , _pn , and p _{(n + 1).} I have. And these hole pitch p
_{1, p 2, p 3,} ...... ..., p (n-1), p n,
p _{(n + 1)} ,... are a combination of a cubic expression and a quintic expression of the distance from the vertical center line (not shown in FIG. 2 ₎ of the shadow mask 6, and A large number of electron beam passage holes 14 are formed and arranged so that the composition ratio with the equation is, for example, one to one.

FIG. 3 is a plan view showing a partial configuration of another example of the perforated portion 6A of the shadow mask used in the color cathode ray tube shown in FIG. It is an example in which a passage hole is provided.

In FIG. 2, reference numeral 15 denotes a dot-shaped electron beam passage hole, a ₁ , a ₂ , a ₃ , a ₄ , a ₅ ,...
_{..., a (n-1)} , a n, a (n + 1), a (n + 2), a (n + 3),
... Are axes passing through the center of each electron beam passage hole 15 arranged in the vertical direction of the shadow mask, p ₁ , p ₂ ,.
p ₃ , p ₄ ,..., p _(n-1) , _pn , p _{(n + 1)} ,
p _{(n + 2)} ,... Represent adjacent axes a ₁ , a ₂ , a ₃ , a
₄ , a ₅ ,……, a _(n-1) , A _n , a _{(n + 1)} , a
The distance between _{(n + 2)} , a _{(n + 3)} ,..., that is, the hole pitch of the electron beam passage holes 15.

As shown in FIG. 3, the arrangement of the large number of electron beam passage holes 15 in the present embodiment in the hole portion 6A of the shadow mask corresponds to the arrangement of the large number of slot-like electron beam passage holes 14 shown in FIG. It is almost the same as the arrangement state, and is arranged so that the hole pitches p ₁ , p ₂ , p ₃ , and p ₄ are relatively small in the central portion of the shadow mask 6, while in the peripheral portion of the shadow mask. Are arranged to have relatively large hole pitches p _(n-1) , _pn , p _{(n + 1)} , p _{(n + 2)} . The hole pitches p ₁ , p ₂ , p ₃ , p ₄ ,..., P _(n-1) ,
_pn , p _{(n + 1)} , p _{(n + 2)} are the distances 3 from the vertical center line of the shadow mask 6 (not shown in FIG. 3).
A large number of electron beam passage holes 15 are formed and arranged so as to conform to a combination formula of the following expression and a quintic expression, wherein the combination ratio of the cubic expression and the quintic expression is, for example, 1: 1. doing.

In the shadow mask aperture 6A shown in FIGS. 2 and 3, an example has been described in which the synthesis ratio of the cubic expression and the quintic expression is 1: 1. Is not limited to the one-to-one ratio, and the following effects can be achieved if the ratio is in the range of 1: 9 to 9: 1. is there. The combination ratio of the cubic expression and the quintic expression may be appropriately selected within the above range according to the type and use of the color cathode ray tube, the diagonal dimension of the effective surface, and the like.

FIG. 4 is a characteristic diagram showing the relationship between the distance from the vertical center line of the shadow mask and the hole pitch in the shadow mask perforated portion 6A shown in FIGS. 2 and 3. The horizontal axis is the distance from the center line, and the vertical axis is the hole pitch.

In FIG. 4, a hatched portion 16 is a characteristic of a large number of electron beam passage holes 14 and 15 formed with a hole pitch according to the present invention.
If the upper curve 16 _U chose the mixing ratio of the cubic equation and the fifth-order equation to 9: 1, lower curve 16 _D hatched portion 16
Are the respective characteristics when the synthesis ratio of the cubic expression and the quintic expression is selected to be 1: 9. Further, for comparison with those formed with the hole pitch according to the present invention, the dotted line curve 17 shows the characteristics of the known first example, and the dotted line curve 18 shows the characteristics of the known second example. .

As shown in FIG. 4, the hatched portion 1
6 shows that when the distance from the vertical center line of the shadow mask 6 increases, the degree of increase in the hole pitch is indicated by a dotted curve 1.
7 and a dotted line curve 18.

As described above, if the arrangement state of the large number of electron beam passage holes 14 and 15 in the shadow mask aperture 6A is selected as described above, the large number of electron beam passage holes 1 and 15 can be obtained.
4 and 15 are formed with a hole pitch determined by a cubic expression of the distance from the vertical center line of the shadow mask 6 (the first known example), that is, the shadow mask 6 can be solved. The radius of curvature of the perforated portion 6A can be made relatively small in the peripheral region, the mechanical strength of the shadow mask can be increased, the occurrence of howling or the like due to the application of vibration can be suppressed, and the number of electron beam passage holes 14,
15 is formed with a hole pitch determined by a fifth-order formula of the distance from the vertical center line of the shadow mask 6 (the second known example), that is, the problem of the shadow mask 6 can be solved. The hole pitch in the intermediate region between the central region and the peripheral region can be made relatively large, the degree of purity in the intermediate region can be increased, and the occurrence of color shift in the displayed image can be suppressed.

In this case, the number of electron beam passage holes is determined by the cubic expression of the distance from the vertical center line of the shadow mask and 5
When the arrangement state is in accordance with the following formula,
The composite ratio of the following equation and the fifth-order equation is such that for a color cathode ray tube in which the mechanical strength of the shadow mask 6 needs to be increased,
The synthesis ratio of the cubic expression and the quintic expression may be selected to be close to 1: 9. On the other hand, for a color cathode ray tube requiring a higher purity margin, the synthesis ratio of the cubic expression and the quintic expression is sufficient. Should be chosen to be close to 9: 1.

[0042]

As described above, according to the present invention, the formation position of each electron beam passage hole in the horizontal direction in the shadow mask is determined by the cubic expression and the quintic expression of the distance from the vertical center line of the shadow mask. Where the synthesis ratio is 1
Since the hole pitch is set so as to fall within the range of 9 to 9: 1, a large number of electron beam passage holes are formed at the hole pitch determined by the cubic expression of the distance from the vertical center line of the shadow mask. (The first known example) can be solved, that is, the radius of curvature of the perforated portion of the shadow mask is made relatively small in the peripheral region, and the mechanical strength of the shadow mask is increased. In addition to suppressing the occurrence of howling and the like due to the application of vibration, a large number of electron beam passage holes are formed at a hole pitch determined by the fifth-order formula of the distance from the vertical center line of the shadow mask. (The second known example) can be solved. That is, the hole pitch in the intermediate region between the central region and the peripheral region is made relatively large, and the purity in the intermediate region is increased. Enhanced, there is an effect that it is possible to suppress the occurrence of color shift in the displayed image.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of an embodiment of a color cathode ray tube having a shadow mask according to the present invention.

FIG. 2 is a plan view showing a partial configuration of an example of a perforated portion of a shadow mask used in the color cathode ray tube shown in FIG.

FIG. 3 is a plan view showing a partial configuration of another example of a perforated portion of a shadow mask used in the color cathode ray tube shown in FIG. 1;

FIG. 4 is a characteristic diagram showing a relationship between a distance from a vertical center line of the shadow mask and a hole pitch in a hole portion of the shadow mask shown in FIGS. 2 and 3;

FIG. 5 is an explanatory diagram showing a state when an arrangement position of each electron beam passage hole in a horizontal direction of a shadow mask is set.

6 is a plan view showing a configuration of a part of a perforated portion of a shadow mask formed by the technique shown in FIG. 5;

FIG. 7 is a characteristic diagram showing a relationship between a distance from a vertical center line of the shadow mask and a hole pitch in a known shadow mask.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Panel part 2 Neck part 3 Funnel part 4 Face plate 5 Fluorescent film 6 Shadow mask 7 Support frame 8 Deflection yoke 9 Electron gun 10 Purity adjustment magnet 11 Center beam static convergence adjustment magnet 12 Side beam static convergence adjustment magnet 13 Electronics Beam 14 Slot-shaped electron beam passage hole 15 Dot-shaped electron beam passage hole

Claims (1)

[Claims] 1. A horizontal position of each electron beam passage hole in a shadow mask having a large number of electron beam passage holes in a perforated portion formed in a slightly curved shape, from a vertical center line of the shadow mask. Of the distance of
A shadow mask comprising a synthetic formula of the following formula, and formed at a hole pitch such that the synthetic ratio of the cubic formula and the quintic formula is in the range of 1: 9 to 9: 1. A color cathode ray tube comprising: