JP2000195438A - Color cathode ray tube device - Google Patents

Abstract

(57) [Summary] A color cathode ray tube device that realizes a flat screen by combining a flat panel and a curved shadow mask,
An object of the present invention is to solve the deterioration of the shaping processability and strength of a shadow mask without impairing the landing tolerance. SOLUTION: In a color cathode ray tube device, a pair of side beams 11B.11R is applied to a deflection yoke 55 by a phosphor screen.
7 Permanent magnets 51a and 51b acting in the under convergence direction are arranged at the periphery, and the deflection coil shall generate a magnetic field acting in the over convergence direction.
The distance qo in the tube axis direction at the center between the mask 2 and the mask 30, the distance q at other positions, the distance Pho at the center of the phosphor screen in the arrangement direction of the center beam, the distance Ph at other positions, the diagonal of the phosphor screen Effective diameter D, Δq = q-qo, ΔPh =
When Ph−Pho, 0.06 × D ≧ Δq−qo ×
(ΔPh / Pho) ≧ 3.0 mm.

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 such as a cathode ray tube for a TV and a cathode ray tube for a monitor, and more particularly to a color cathode ray tube device for realizing a flat screen using a press-molded shadow mask.

[0002]

2. Description of the Related Art In general, as shown in FIG. 18, in a color cathode ray tube device, a display unit 1 has a substantially rectangular panel 2, a funnel 3 connected to the panel 2, and a small end of the funnel 3. And a vacuum envelope consisting of a cylindrical neck 4 connected to the vacuum neck. A deflection yoke 6 is mounted from the funnel 3 side of the neck 4 to the small diameter portion 5 of the funnel 3. On an inner surface of the panel 2, a phosphor screen 7 having a dot-like or stripe-like three-color phosphor layer that emits blue, green, and red light is provided. Further, the opposing surface 8 is spaced from and opposed to the phosphor screen 7.
A shadow mask 10 (color selection mask) in which a large number of electron beam passage holes 9 are formed at a predetermined arrangement pitch is arranged. In the neck 4, three electron beams 11B
, 11G, 11R are provided. The electron beams 11B, 11G, 11R emitted from the electron gun 12 are deflected by the horizontal and vertical deflection magnetic fields generated by the deflection yoke 6, and the phosphor screen 7 is passed through the electron beam passage holes 9 of the shadow mask 10. It is formed in a structure that displays a color image by performing horizontal and vertical scanning.

[0003] At present, such a color cathode ray tube device is
Center beam 11G passing through electron gun 12 on the same horizontal plane
And an in-line type emitting three electron beams 11B, 11G, 11R arranged in a line composed of a pair of side beams 11B, 11R, a horizontal deflection magnetic field generated by the deflection yoke 6 as a pincushion type, and a vertical deflection magnetic field as a barrel type. Due to these horizontal and vertical deflection magnetic fields, 3
A self-convergence in-line type color cathode ray tube in which the three electron beams 11B, 11G, and 11R are concentrated over the entire screen without requiring special correction means by deflecting the electron beams 11B, 11G, and 11R has been widely used. .

In recent years, such a color cathode ray tube device has been
There is a strong demand for screen flatness. When the display unit 1 of the panel 2 is flattened to achieve the flatness of the screen,
It is necessary to make the surface of the shadow mask 10 facing the phosphor screen 7 flat. As a result, the following problem occurs.

In general, a color cathode ray tube apparatus mainly has three electron beams 11B, 1B by a purity convergence magnet formed on a neck 4 side of a deflection yoke 6.
1G and 11R are concentrated at the center of the phosphor screen 7. Such three electron beams 11B, 11G, 11R
Pass through the electron beam passage holes 9 of the shadow mask 10 at a predetermined angle and land on predetermined phosphor layers, respectively. In order to make the landing allowance with respect to the phosphor layer appropriate, it is necessary to appropriately set the distance between the inner surface of the display unit 1 of the panel 2 and the shadow mask 10.

[0008] As shown in FIG. 19, the shadow mask 10 is moved from the position of the purity convergence magnet 13.
The distance between the tubes in the axial direction is L (L at the center of the phosphor screen).
Is defined as Lo), and the distance between the shadow mask 10 and the inner surface of the display unit of the panel 2 in the tube axis direction is q (the fluorescent screen
The distance q in the center between the center beam 11G and the pair of side beams 11B and 11R in the three electron beam arrangement direction is Sg (Sg at the position of the purity convergence magnet is Sgo), and the display unit of the panel 2 Center beam 11G and a pair of side beams 11 on the inner surface
Assuming that the distance between B and 11R is σ and the distance between the landing position of the center beam 11G on the inner surface of the panel 2 in the three electron beam arrangement direction is Ph (Pho at the center of the phosphor screen is Pho), q = Since L × σ / Sgσ = Ph / 3,

The following holds: q = L × Ph / 3Sg

Normally, L and Sg are substantially constant over the entire area of the phosphor screen, and Ph is basically constant. Therefore, when the display portion of the panel 2 is made flat, the shadow mask 10 also needs to be made flat.

However, in general, the shadow mask 10 is manufactured by forming a flat thin plate-shaped shadow mask material having an electron beam passage hole formed into a predetermined curved surface by photoetching. As shown in FIG. 20, the non-porous portion 1 surrounding the electron beam passage hole forming region 15 is formed.
6 is sandwiched and fixed between the die 17 and the blank holder 18 and the punch 19 and the knockout 20 are used to overhang the electron beam passage hole forming region 15. Therefore, when the shadow mask is flattened and the amount of elongation due to overhang is reduced, it is not possible to sufficiently perform plastic deformation, and it is not possible to form a predetermined curved surface due to deterioration in workability. Further, the strength of the molding surface is deteriorated, and the molding surface is easily deformed.

Conventionally, there is a color cathode ray tube apparatus which completely flattens the outer surface of the display portion of the panel with a TV cathode ray tube, and shapes the surface of the shadow mask facing the phosphor screen into a nearly flat shape to realize a flat screen. . In this color cathode ray tube device, in order to increase the strength of the shadow mask,
Molding is performed by a general method of reducing the radius of curvature of a low-strength portion to give it a round shape and improving the strength of the low-strength portion.

That is, as shown in FIG. 21, as shown by a broken line to a solid line, the vicinity of the center 22 having relatively high strength is flattened, and the vicinity of the peripheral portion 23 having low strength is rounded to increase the strength.

However, even with the above configuration, the strength is insufficient as compared with the conventional cathode ray tube device in which the outer surface of the display section of the panel is rounded. Also, in monitor CRTs that require high resolution, the thickness of the shadow mask needs to be about half that of TV CRTs.
In this monitor cathode ray tube, the strength is further deteriorated.

[0012]

As described above, in the color cathode ray tube device, when the panel is flattened, the shadow mask needs to be flattened, and it is impossible to form a predetermined curved surface due to deterioration of the forming process. In addition, it is easily deformed due to deterioration in strength. Therefore, conventionally, in the cathode ray tube device which completely flattens the outer surface of the display portion of the panel and shapes the surface of the shadow mask facing the phosphor screen into a nearly flat shape to realize a flat screen, the strength of the shadow mask is increased. For this reason, the radius of curvature of the low-strength portion is reduced so as to be rounded, thereby improving the strength of the low-strength portion.

However, even with the above configuration, the strength is insufficient as compared with the conventional cathode ray tube device in which the outer surface of the display section of the panel is rounded. Also, in monitor CRTs that require high resolution, the thickness of the shadow mask needs to be about half that of TV CRTs.
There is a problem that the strength is further deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a landing tolerance in a color cathode ray tube apparatus which realizes a flat screen by combining a flat panel and a shadow mask formed on a curved surface. It is an object of the present invention to solve the problems of shaping processability and strength of a shadow mask without impairing the quality.

[0015]

Means for Solving the Problems (1) A vacuum outside display comprising a panel having a substantially rectangular display portion, a funnel-shaped funnel connected to the panel, and a neck connected to an end of a small diameter portion of the funnel. An enclosure, a substantially rectangular phosphor screen provided on the inner surface of the display unit of the panel, and a color selection mask in which a large number of electron beam passage holes are formed on a surface facing away from the phosphor screen, An electron gun that is provided in the neck and emits three electron beams arranged in a line composed of a center beam and a pair of side beams passing on the same plane;
A deflection yoke having a deflection coil for generating a magnetic field for deflecting the three electron beams in a direction in which the three electron beams are arranged and in a direction orthogonal to the direction in which the three electron beams are arranged, from the funnel side of the neck to the outside of the small diameter portion of the funnel; In the color cathode ray tube device, a permanent magnet that acts in the under convergence direction in at least a part of the peripheral portion of the phosphor screen with respect to the pair of side beams is disposed near the phosphor screen side of the deflection yoke, and the deflection coil is disposed on the pair of side beams. A magnetic field acting in the over-convergence direction which almost cancels the effect of the permanent magnet in the under-convergence direction with respect to the beam is generated, and the distance between the inner surface of the panel display portion and the mask in the tube axis direction at the center of the phosphor screen is set. qo is the distance in the tube axis direction other than the center of the phosphor screen in the The distance in the three electron beam arrangement direction of the center beam at the center of the phosphor screen at the center of the phosphor screen on the inner surface of the display unit is Pho, the distance in the three electron beam arrangement direction other than the center of the phosphor screen is Ph, and the diagonal of the phosphor screen is effective. When the diameter is D, and the dimensional units of q, qo, Ph, and Pho are mm and Δq = q-qo ΔPh = Ph-Pho, 0.06 × D ≧ Δq−qo × (ΔPh / Pho) ≧ 3 .0
mm.

(2) In the color cathode ray tube device of (1), permanent magnets are arranged in the arrangement direction of three electron beams.

(3) In the color cathode ray tube device of (1), the permanent magnet is arranged near the diagonal axis direction of the phosphor screen.

(4) In the color cathode ray tube device of (1), the permanent magnet is arranged along the inner surface of the deflection yoke between the direction orthogonal to the arrangement direction of the three electron beams and the diagonal axis direction of the phosphor screen. did.

(5) In the color cathode ray tube device of (1) to (4), the cross section of the small diameter portion of the funnel and the deflection yoke at the small diameter portion is formed in a substantially rectangular shape.

(6) In the color cathode ray tube device of (1) to (5), the outer surface of the display section of the panel is substantially flat.

[0021]

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

As shown by the solid line in FIG. 21, the shadow mask of the conventional color cathode ray tube device which emits three electron beams arranged in a line composed of a center beam and a pair of side beams passing on the same plane has a relatively high intensity. The strength was improved by flattening the vicinity of the high center and rounding the vicinity of the low strength peripheral part. In such a conventional shadow mask, the intensity near the peripheral portion increases, but the intensity near the center relatively decreases, and the intensity is simply equalized over the entire surface of the shadow mask. Therefore, there is a limit in improving the strength, and the strength cannot be significantly improved.

On the other hand, in the color cathode ray tube device of the present invention, as shown in FIG. By increasing the interval q by Δq, the radius of curvature of the low-intensity portion is reduced, and thereby the three electron beam arrangement directions of the pair of side beams 11B, 11R and the center beam 11G toward the center of the phosphor screen 7 are reduced. The interval Sg1 in the three electron beam arrangement direction between the side beams 11B and 11R toward the peripheral portion and the center beam 11G is set to be smaller than the interval Sg0.

The present inventors have previously filed an application for a color cathode ray tube device provided with two orbit correcting means 32 and 33 between the cathode K of the electron gun and the phosphor screen 7 as shown in FIG. . The two trajectory correction means 32 and 33 are basically composed of an additional coil and an electrode of an electron gun.

This color cathode ray tube apparatus has a pair of side beams 11 B and 11 directed toward the center of the phosphor screen 7.
R, the forces FR0 and FF0 received from the neck-side trajectory correction means 32 and the phosphor screen-side trajectory correction means 33 are both set to zero, and a pair of side beams 11B and 11R directed to the peripheral portion of the phosphor screen 7. Against
Receiving the force FR1 in the over-convergence direction from the neck-side trajectory correction means 32 and receiving the force Ff1 in the under-convergence direction from the phosphor screen-side trajectory correction means 33;
As a result, the virtual Sg at the cathode K becomes smaller as Sgc0 → Sgc1 at the center → peripheral portion of the phosphor screen 7 and Δ
q is increased.

On the other hand, according to the present invention, a particularly low strength portion of the molded shadow mask 30 is emphasized, and an additional coil is specially provided on the deflection yoke or the configuration of the electron gun is changed. Instead, the problem is solved by a configuration similar to the conventional one.

As described above, basically, the ideal q
Is represented by the equation (1). However, actually, in addition to the purity convergence magnet, a deflection yoke component such as a deflection coil or a magnet may also be used.
Since the side beam receives a force in the direction in which the three electron beams are arranged, it is conceivable that q deviates from the equation (1) at each position of the phosphor screen. In particular, the horizontal and vertical deflection coils generally compensate for the overconvergence at the periphery of the phosphor screen caused by the difference in the path length of the electron beam to the underconvergence with a non-uniform magnetic field. It is thought that it is increasing.

In view of the above, the inventors have analyzed the influence of a general deflection yoke on q and the like by using both simulation and actual measurement evaluation.

Here, the basic configuration of a deflection yoke of a generally used self-convergence in-line type color cathode ray tube device will be described. As shown in FIG. 3, the deflection yoke 35 is composed of a pair of upper and lower horizontal deflection coils. (Not shown), a pair of left and right vertical deflection coils 36a, 36b
A magnetic core 37, a pair of coma-free coils 38 a and 38 b disposed on the neck side of the deflection yoke 35, and a pair of upper and lower NS magnets 39 a and 39 b disposed on the phosphor screen side of the deflection yoke 35. It is configured. As shown in FIG. 4A, the horizontal deflection coil 40
a and 40b form a circuit configuration connected in parallel. Also,
As shown in (b), the vertical deflection coils 36a and 36b
In this example, damping resistors 41a and 41b for bypassing a high-frequency current are added in parallel to a series-connected circuit, and coma-free coils 38a and 38b are connected in series. Sawtooth-shaped currents having a line deflection frequency and a screen deflection frequency are supplied to these circuits, respectively.

When the three electron beams arranged in one row are made to coincide with each other at the center of the phosphor screen by the purity convergence magnet, the path length becomes longer around the phosphor screen, so that an over-convergence state occurs. Therefore, in a self-convergence in-line type color cathode ray tube device that emits three electron beams arranged in a line in the same horizontal plane, the horizontal deflection coils 40a and 40b are used.
As shown in FIG. 5 (a), the coil wire is connected to the horizontal axis (H
(A coil window portion is enlarged) to form a non-uniform pincushion-type horizontal deflection magnetic field 43 and deflect side beams 11B and 11R (11B in the illustrated example).
) Is more strongly deflected to suppress overconvergence. Similarly, the vertical deflection coil 36
a and 36b, as shown in (b), arrange the coil wire from the horizontal axis (reduce the coil window) to form an asymmetric barrel-type vertical deflection magnetic field 44, and form a pair of side beams. The configuration is such that overconvergence is suppressed by opening the deflection directions of 11B and 11R to the left and right. Further, the convergence at the diagonal portions of the phosphor screen is also affected by the horizontal and vertical deflection coils 40a and 40a.
By adjusting the relative positions of b, 36a and 36b in the tube axis direction, the positions can be adjusted.

However, such a deflection yoke 35
The pincushion distortion shown in FIG. 6 is caused by insufficient deflection of the center beam 11G with respect to the side beams 11B and 11R and excessive deflection of the diagonal axis ends with respect to the horizontal and vertical axis (H axis, V axis) ends of the phosphor screen. And a mismatch between the center beam pattern 45G and the side beam patterns 45B and 45R at the peripheral portion.

In order to solve the mismatch between the center beam and the side beam, as shown in FIG. 7A, the pincushion-type horizontal deflection magnetic field 43 is locally changed to a barrel-type magnetic field 46 on the neck side of the deflection yoke. As shown in (b), the barrel-shaped vertical deflection magnetic field 44 may be a pincushion-type magnetic field 47 locally on the neck side of the deflection yoke.

When the horizontal and vertical deflection magnetic fields 43 and 44 are configured as described above, the deflection amount is small and Sg is large on the neck side of the deflection yoke, so that the influence on the distortion characteristics is suppressed and the convergence (between three electron beams) is suppressed. (Equal to the difference in the amount of deflection). Moreover, the amount of deflection of the center beam with respect to the side beam on the neck side of the deflection yoke can be increased by the neck side deflection magnetic fields 46 and 47, and the misconvergence shown in FIG. 6 can be solved. However, in this case, it is difficult for the vertical deflection coil to form a local pincushion magnetic field required on the neck side of the deflection yoke only by the coil distribution. Therefore, usually on the neck side of the deflection yoke,
A coma-free coil is arranged independently of the vertical deflection coil to form a pincushion magnetic field.

On the other hand, there is generally no solution for the pincushion distortion shown in FIG. 6, and the pair of upper and lower NS magnets 39a and 39b shown in FIG. Only the upper and lower ends 48 and 49 are corrected by the NS magnet. This NS magnet is Sg
Is disposed on the screen side of the deflection yoke, and the generated magnetic field acts uniformly on the three electron beams, so that the distortion characteristics can be easily adjusted while suppressing the influence on the convergence characteristics. That is, since the NS magnet is located at the upper and lower ends of the deflection yoke on the screen side, it acts in a direction to pull up and down three electron beams.
The correction at the diagonal end of the screen far from the S magnet is small, and distortion at the upper and lower ends is eliminated. The distortion at the left and right ends, which is not corrected by the NS magnet, is corrected by modulating the horizontal deflection current in the vertical deflection cycle so as to be smaller at the upper and lower ends and increased at the center.

Here, considering the influence on the Sg due to the non-uniform magnetic field generated by the horizontal deflection coil, the deflection generated by the horizontal deflection coils 40 (40a, 40b) from the purity convergence magnet 13 as shown in FIG. The three electron beams 11B, 11G, 11R deflected by the magnetic field toward the horizontal axis end of the phosphor screen 7 are relatively side beams 1 by the pincushion-type horizontal deflection magnetic field.
The trajectories of 1B and 11R are corrected in the direction away from the center beam 11G. The horizontal deflection coils 40a, 40b
Is located closer to the phosphor screen 7 than the purity convergence magnet 13,
Electron beams 11B, 11G, 1 reaching the horizontal axis end of
The virtual Sg at the 1R purity convergence magnet 13 is 3 g toward the center of the phosphor screen 7.
SgH is smaller than Sg0, which is the Sg of the electron beams 11B, 11G, and 11R. That is, the pincushion-type horizontal deflection magnetic field has the effect of virtually reducing Sg at the horizontal axis end of the phosphor screen 7, and is a factor that increases Δq.

Similarly, the vertical deflection coil is a factor for increasing Δq.

On the other hand, the action of the non-uniform magnetic field generated by the coma-free coil is in the direction of decreasing Δq, but since it is generally arranged at substantially the same position as the purity convergence magnet, the variation of Δq is small.

The NS magnet is a factor for reducing Δq.

Table 1 shows the currently produced 90-degree deflecting color cathode ray tube apparatus (with an outer surface curvature of R1000 to R150).
Δq-q with a curved surface type of 0 and an aspect ratio of 4: 3)
Data of o × ΔPh / Pho design bogie value and Δq calculated by simulation are shown.

Here, the interval in the three electron beam arrangement direction at the center beam landing position on the inner surface of the panel is Ph, the Ph at the center of the phosphor screen is Pho, and Δ
Ph is the difference between these Ph and Pho (ΔPh = Ph
-Pho).

Although Δq in the simulation is calculated under the condition of uniform Ph, in the production pipe, since Ph changes in design at each point on the screen, the purpose is to standardize to the condition of uniform Ph. Instead of Δq, Δq−qo × ΔPh / P
Indicated by ho. From the equation of Equation 1, since q is proportional to Ph,
If Ph is twice Pho at some point, q will also be twice qo. From this, −qo × ΔPh / Pho is a term that compensates for Δq due to a change in Ph when there is a change in Ph.

The adjustment of Δq by the change of Ph is a known technique and has an effect, but causes non-uniform resolution. By the way, qo of the above color cathode ray tube device is about 9m
m and Pho are about 0.45 mm, and ΔPh is about 5% of Pho at the maximum.

As shown in Table 1, it can be seen that Δq is substantially zero at the end of the vertical axis and within 2 mm at the ends of the horizontal and diagonal axes. A good correlation is obtained between the simulation calculated value and the actual design value.

[Table 1] Table 2 shows data of design bogie values of Δq-qo × ΔPh / Pho in a prototype tube of 110 ° deflection and flat screen as another color cathode ray tube device having different screens and different deflection angles.

When the screen and the deflection angle change as described above, the degree of influence on Δq at each point of the screen of the deflection yoke constituent members and the intensity balance of each constituent member change, so that the aspect of Δq is slightly different. However, self-convergence
If it is a deflection yoke of an in-line type color cathode ray tube device, it is generally in the range of -1 to 2 mm.

[Table 2] Table 3 summarizes the effects of the deflection yoke components and the approximate numerical values.

From Table 3, it can be seen that the influence of the deflection yoke on Δq is only about 2 mm at most in the increasing direction.

[Table 3] In a current color cathode ray tube device, when a diagonal effective diameter of a phosphor screen is D, a panel whose curvature radius is flattened to approximately 2 × D or more is mainly used. In a color cathode ray tube apparatus having a panel whose radius of curvature is 2 × D, assuming that the radius of curvature of the shadow mask is substantially equal to the radius of curvature of the panel, the center of the shadow mask (located on the tube axis passing through the center of the phosphor screen) ) In the direction of the tube axis at the end of the diagonal axis is geometrically given by the following equation.

[0046]

ZM = (2 × D) − ｛(2 × D) ² − (D / 2) ² ｝ ^1/2 = 0.06 × D For example, when the effective diagonal diameter D of the phosphor screen is 410 mm , Head ZM is about 25mm, and if D is 460mm, ZM
Is about 28 mm.

Therefore, if a color cathode ray tube device is to be realized by incorporating a shadow mask press-molded into a panel having a flat outer surface, it is necessary to take measures against the above-mentioned head ZM.

On the other hand, regarding the panel, the outer surface must be made substantially flat so that the image drawn on the phosphor screen looks flat. Similarly, if the inner surface is made flat, the panel glass is refracted. Will make the screen look concave. Therefore, it is preferable that the thickness of the glass around the phosphor screen be slightly increased and the inner surface be concave. However, if the drop ZP of the diagonal axis end with respect to the center of the phosphor screen on the inner surface of the panel is increased, the flatness of the screen is impaired. As a result of the study, it was found that in the case of a color cathode ray tube having a D of 460 mm, in order to realize a flat screen from the viewpoint of visibility, ZP must be reduced to 12 mm or less.

In this case, in consideration of the influence of the deflection yoke on Δq (about 2 mm), the drop ZM in the tube axis direction at the diagonal axis end with respect to the center of the shadow mask is about 14
mm. It is extremely difficult to press-mold such a shadow mask.

Therefore, in the present invention, the mechanism for increasing Δq described with reference to FIG. 2 is achieved as follows.

As shown in FIG. 10, the three electron beams 11 B and 1 B are directed rightward from the cathode K toward the phosphor screen 7.
Considering the case of deflecting 1G and 11R, in the conventional color cathode ray tube device, as shown in FIG. 10A, three electron beams 11B, 11G and 11R are turned into horizontal deflection coils 40 '(40a' and 40b '). ) The force FHB ',
Assuming that FHG ′ and FHR ′ are FHB ′ << FHG ′ << FHR ′ (the difference between FHB ′ and FHR ′ is large), the three electron beams 11B and 11G around the horizontal portion of the phosphor screen 7 in the horizontal direction.
, 11R.

On the other hand, in the color cathode ray tube device of the present invention, as shown in FIG.
, 11G, 11R are connected to the horizontal deflection coil 40 (40a, 4a).
Ob), the forces FHB, FHG, and FHR are given by FHB ≦ FHG ≦ FMR (the difference between FHB and FHR is small), and a winding distribution that weakens the bincushion-type magnetic field generated by the horizontal deflection coil 40 is provided. 11B and 11R are operated so as to be over-convergence. Further, permanent magnets 51 (51a, 51b) are provided on the phosphor screen 7 of the deflection yoke.
And the forces FMB, FMG, FMR that the three electron beams 11B, 11G, 11R receive by the permanent magnets 51a, 51b.
Is set so that FMB <FMG <FMR so that the side beams 11B and 11R are under-convergence.

This can be easily performed because the degree of freedom of the winding distribution of the deflection coil is large. In addition, the magnetic field of the permanent magnet 51 has three electron beams 11B,
Since the force applied to 11G and 11R is larger as it is closer to the permanent magnet 51, FMB <FMG <FMR, as described above, and the side beams 11B and 11R can be relatively directed in the under-convergence direction. The three electron beams 11B, 11G,
When 11R goes, the magnetic field generated by the deflection coil becomes zero, and the permanent magnet 51 also receives three electron beams 11B and 11G.
, 11R, the permanent magnet 51
Is not affected by the magnetic field.

Therefore, the virtual Sg at the cathode K
Is the center of the phosphor screen 7 → Sgc0 at the peripheral part → Sgc1
, And Δq can be partially increased in the peripheral portion.

That is, the radius of curvature of the low intensity portion of the shadow mask 30 is reduced, and the distance between the inner surface of the panel and the shadow mask 30 in the tube axis direction at the center of the phosphor screen 7 is q 0, except for the center of the phosphor screen 7. And the center beam 1 at the center of the phosphor screen 7
The distance between the 1G three electron beam arrangement directions in the three electron beam arrangement direction is Ph0, the distance between the center beams 11G other than the center of the phosphor screen 7 in the three electron beam arrangement direction is Ph, the effective diagonal diameter of the phosphor screen 7 is D, and their q and qo. , Ph, Pho in mm
When Δq = q−q0 ΔPh = Ph−Pho,

## EQU3 ## 0.06D ≧ Δq−qo × (ΔPh / Pho) ≧
By setting so as to satisfy the relationship of 3.0 mm, both the flatness of the panel and the problems of the strength and moldability of the shadow mask 30 can be achieved.

A method of increasing Δq by the two trajectory correcting means 32 and 33 composed of the additional coil and the electrode of the electron gun described in FIG. 2 and a method of increasing Δq by the winding distribution of the deflection coil and the permanent magnet. It is possible to arbitrarily configure the color cathode ray tube device by combining the above.

In this case, the effect of the two trajectory correction means for gradually increasing Δq from the center of the phosphor screen toward the periphery and the winding distribution of the deflection coil for increasing Δq partially at the periphery of the phosphor screen And the effect of the permanent magnet can be expected, and the degree of freedom for satisfying other characteristics such as convergence and distortion can be increased.

Next, the color cathode ray tube device of this embodiment will be described by way of examples.

[0059]

Embodiment 1 FIG. 11 shows the structure of a color cathode ray tube device according to Embodiment 1 of the present invention.

As shown in FIG. 11A, this color cathode ray tube device has a display panel 1 made of a substantially rectangular glass panel 2, a funnel-shaped glass funnel 53 connected to the panel 2, and a glass funnel 53 connected to the panel. It has a vacuum envelope consisting of a cylindrical neck 4 connected to the small diameter end of the funnel 53. On the inner surface of the display section 1 of the panel 2, a phosphor screen 7 having a dot-like or stripe-like three-color phosphor layer that emits blue, green, and red light is provided. Further, a shadow mask 30 having a curved surface, which is spaced from and opposed to the phosphor screen 7, and on which a plurality of electron beam passage holes are formed at a predetermined arrangement pitch is arranged. On the other hand, a center beam 11G and a pair of side beams 11B, 11B passing on the same horizontal plane in the neck 4
R, three electron beams 11B, 11G, 1
An electron gun 12 for emitting 1R is provided. A deflection yoke 55 is mounted from the funnel 53 side of the neck 4 to the small diameter portion 54 of the funnel 53. The three electron beams 11B emitted from the electron gun 12
, 11G, 11R are deflected by the horizontal and vertical deflection magnetic fields generated by the horizontal and vertical deflection coils of the deflection yoke 55, and horizontally and vertically scan the phosphor screen 7 through the electron beam passage holes of the shadow mask 30. It is formed in a structure for displaying an image.

In particular, in this color cathode ray tube device,
The outer surface of the display unit 1 of the panel 2 is formed substantially flat, and the inner surface of the display unit 1 is formed as a nearly flat curved surface. The deflection yoke 55 and the small diameter portion 54 of the funnel 53 to which the deflection yaw 55 is attached are formed in a substantially pyramid shape. That is, as shown in a cross section orthogonal to the tube axis (Z axis) viewed from the electron gun side toward the phosphor screen in FIG. 11B, the electron at the small diameter portion where the deflection yoke 55 is mounted is shown. The beam passage area 56 has a substantially rectangular shape, and the small-diameter portion has a substantially rectangular cross-sectional shape surrounding the electron beam passage area 56. Further, the deflection yoke 55 mounted outside the small diameter portion also has a cross-sectional shape along the outer surface of the small diameter portion.

The horizontal deflection magnetic field generated by the horizontal deflection coil of the deflection yoke 55 has a magnetic field distribution in which the pincushion-type magnetic field is weakened on the phosphor screen side, and a pair of side beams directed to the vicinity of the horizontal axis end of the phosphor screen. 11B
, 11R generate a magnetic field that causes overconvergence on the phosphor screen.

Further, a pair of permanent magnets 5 are provided on both sides of the deflection yoke 55 on the horizontal axis (H axis) on the phosphor screen side.
1a and 51b are provided. This pair of permanent magnets 5
1a and 51b generate a magnetic field in which a pair of side beams 11B and 11R directed to the vicinity of the horizontal axis end of the phosphor screen become in an under-convergence direction on the phosphor screen. As a result, the pair of side beams 11B and 11R heading near the horizontal axis end of the phosphor screen is horizontally moved by the over-convergence action of the horizontal deflection coil and the under-convergence action of the pair of permanent magnets 51a and 51b. It becomes almost the same near the shaft end.

With the above configuration, as shown in FIG. 10B, the virtual Sg at the cathode K is changed from Sgc0 to Sgc1 at the center of the phosphor screen 7 and at the peripheral portion in the horizontal axis direction.
Δq can be increased in the peripheral portion in the horizontal axis direction.

Therefore, as shown in FIG. 12, the vertical axis (V axis) end and the diagonal axis (D axis) end drop ZM in the tube axis direction with respect to the center of the surface 58 of the shadow mask 30 facing the phosphor screen. Can be increased as shown by the solid line from the broken line without changing the horizontal axis. That is, by reducing the radius of curvature near the horizontal axis end of the shadow mask 30 and forming a rounded shape, a shadow mask having sufficient strength can be obtained.

That is, as shown in FIG. 13, the magnetic field 60 generated by the pair of permanent magnets is strong near the permanent magnet, but rapidly decreases as the distance from the permanent magnet increases.
In the first embodiment, as described above, since the cross-sectional shape of the deflection yoke is substantially rectangular, the permanent magnet is close to the passage area of the three electron beams. Therefore, the force F which the three electron beams deflected toward the horizontal axis end receives from the permanent magnet
MB, FMG, and FMR have a large difference between FMB and FMR.

On the other hand, as shown in FIG. 14, if permanent magnets 51a and 51b are attached to a deflection yoke 6 having a generally circular cross section, which is generally used in the prior art, the permanent magnets 51a and 51b have three electrons. Beams 11B, 11G, 11
As shown in FIG. 13, the forces received by the three electron beams from the permanent magnets FMB ′ and F
MG ′ and FMR ′ become weaker, and the difference between FMB ′ and FMR ′ becomes smaller.

In the first embodiment, since the difference between the FMB and the FMR acts as a force for correcting the trajectory of the pair of side beams 11B and 11R in the under-convergence direction, the deflection yoke having a circular cross section is obtained. The effect of increasing Δq that cannot be obtained is obtained.

In FIG. 11, the horizontal deflection coil of the deflection yoke 55 is configured so that a pair of side beams 11B and 11R directed to the vicinity of the horizontal axis end of the phosphor screen generate a magnetic field that causes overconvergence on the phosphor screen. A pair of permanent magnets 51a and 51b are provided on both sides of the deflection yoke 55 on the horizontal axis on the phosphor screen side to generate a magnetic field acting on the phosphor screen in the under convergence direction with respect to the pair of side beams 11B and 11R.
FIG. 15 (a cross-sectional view orthogonal to the tube axis as viewed from the electron gun side toward the phosphor screen) shows a horizontal deflection coil with a pair of side beams 11B directed toward a diagonal axis end of the phosphor screen. , 11R to generate a magnetic field that causes overconvergence.
Permanent magnets 51a, 51b, 51c and 51d are provided near the diagonal axis on the side of the phosphor screen so that the magnetic poles are located in a direction perpendicular to the arrangement direction of the three electron beams, and near the diagonal axis end of the phosphor screen. A pair of side beams 11B heading
, 11R to generate a magnetic field acting in the under-convergence direction.

With this configuration, for the same reason as in the first embodiment, the radius of curvature near the diagonal axis end of the shadow mask can be reduced to provide a shadow mask having sufficient strength.

FIG. 16 (a cross-sectional view orthogonal to the tube axis viewed from the electron gun toward the phosphor screen) shows a vertical deflection coil formed by a pair of side beams 11B and 11R directed to the vertical axis end of the phosphor screen. The deflection yoke 55 is configured to generate a magnetic field that causes overconvergence.
Permanent magnets 51a, 51a, 51a, 51b, having a magnetic pole inside the vertical axis and the diagonal axis on the phosphor screen side so as to approach the vertical axis and on both sides thereof in a direction orthogonal to the arrangement direction of the three electron beams.
51b, 51c, 51d are provided, and a pair of side beams 11B, 11R heading near the vertical axis end of the phosphor screen.
, A magnetic field acting in an under-convergence direction is generated.

With this configuration, for the same reason as in the first embodiment, the radius of curvature near the vertical axis end of the shadow mask can be reduced, and a shadow mask having sufficient strength can be obtained.

[0073]

[Embodiment 2] Fig. 17 shows a main structure of a color cathode ray tube apparatus according to Embodiment 2 of the present invention.

This color cathode ray tube apparatus is different from the color cathode ray tube apparatus described in the first embodiment in that two orbit correction means 3 comprising an additional coil and constituent electrodes of an electron gun are provided.
2, 33 are provided. The two orbit correction means 32 and 33 are two coils 63a and 63 of the neck-side orbit correction means 32 wound around a pair of U-shaped magnetic cores 62 of a coma-free coil provided on the neck side of the deflection yoke.
b, four coils 64a, 64b, 64c, 64d of the phosphor screen side trajectory correction means 33 wound around a bobbin holding a vertical deflection coil, and these coils 63
a, 63b, 64a, 64b, 64a, 64b, and a current supply circuit (not shown) for supplying a current.

The current supply circuit is connected to a diode rectifier circuit connected to the vertical deflection coil via a coma-free coil connected in series to the vertical deflection coil.
, 63b, 64a, 64b, 64c, 64d are connected to supply zero current when three electron beams scan on the horizontal axis of the phosphor screen, and supply current in the same direction when scanning above and below the phosphor screen. Configuration.

The coil 6 of the neck-side trajectory correcting means 32
3a and 63b are wound so that the magnetic poles formed at the tips of the pair of U-shaped magnetic cores 62 are inverted in the adjacent quadrants by the current from the current supply circuit, and the quadrupole magnetic field components generated thereby are generated. A pair of side beams 11B, 11R at 65
Overconvergence.

On the other hand, the coils 64a, 64b, 64c, 64d of the phosphor screen side trajectory correction means 33
Is wound so that the direction of the magnetic field generated in the adjacent coil by the current from the current supply circuit is reversed, and a pair of side beams 11B are generated by the quadrupole magnetic field component 66 generated thereby.
, 11R under-convergence.

Therefore, when the three electron beams 11B, 11G, 11R are deflected in the direction of the vertical axis of the phosphor screen, the trajectory of the pair of side beams 11B, 11R is corrected by the neck-side trajectory correcting means 32 in the over-convergence direction. The phosphor screen side trajectory correction means 33 corrects the trajectory of the pair of side beams 11B and 11R in the under convergence direction so as to compensate for the trajectory correction in the over convergence direction. As a result, three electron beams 11B, 1B are set in the vertical axis direction of the phosphor screen.
When deflecting 1G and 11R, it acts to reduce Sg and increases Δq from the vertical axis end to the diagonal axis end.

On the other hand, the horizontal deflection coil of the color cathode ray tube apparatus has a pair of horizontal deflection magnetic fields generated by the magnetic field distribution in which the pincushion-type magnetic field is weakened on the phosphor screen side, and is located near the horizontal axis end of the phosphor screen. Side beams 11B and 11R generate a magnetic field that causes overconvergence on the phosphor screen. Further, a pair of permanent magnets provided on both sides of the deflection yoke on the horizontal axis on the phosphor screen side provide a pair of side beams 11B and 11R toward the vicinity of the horizontal axis end of the phosphor screen. Generates a magnetic field that acts in the convergence direction. Thus, when the three electron beams 11B, 11G, 11R are deflected near the horizontal axis end of the phosphor screen, the trajectory of the pair of side beams 11B, 11R is corrected in the overconvergence direction by the magnetic field generated by the horizontal deflection coil, A pair of permanent magnets 51a, 51b
When the three electron beams 11B, 11G, and 11R are deflected near the horizontal axis end of the phosphor screen as a result, they act so as to reduce Sg, and the vicinity of the horizontal axis end is corrected. And Δ
Increase q.

Therefore, by configuring the color cathode ray tube device as described above, Δq can be increased over the entire peripheral portion of the phosphor screen, and the degree of freedom of the curved surface configuration of the shadow mask is increased. Further, other characteristics such as convergence and distortion can be satisfied.

In FIG. 17, the case where the two orbit correcting means are constituted by additional coils has been described. However, the neck-side orbit correcting means may be constituted by the constituent electrodes of the electron gun.

[0082]

According to the above configuration, a color cathode ray tube device realizing a flat screen can be configured by combining a shadow mask having a smaller radius of curvature with respect to the radius of curvature of the inner surface of the panel. Can be.

[0083]

[Brief description of the drawings]

[0084]

FIG. 1 is a diagram for explaining a basic principle of the present invention in a case where a distance between a panel and a shadow mask is increased at a peripheral portion with respect to a center of the shadow mask.

[0085]

FIG. 2 is a diagram for explaining a basic principle of the present invention when two orbit correction means are provided.

[0086]

FIG. 3 is a diagram showing a configuration of a deflection yoke mounted on the color cathode ray tube device.

[0087]

FIG. 4A is a horizontal deflection circuit diagram of the deflection yoke, and FIG. 4B is a vertical deflection circuit diagram.

[0088]

FIG. 5 (a) is a diagram for explaining a magnetic field effect of a horizontal deflection coil of the deflection yoke, and FIG. 5 (b) is a diagram for explaining a magnetic field effect of a vertical deflection coil.

[0089]

6 is a diagram showing convergence and distortion caused by the action of the magnetic field shown in FIG.

[0090]

7 is a diagram showing a non-uniform magnetic field distribution of a deflection coil necessary for correcting the convergence shown in FIG. 6, and FIG.
7A is a diagram illustrating a horizontal deflection magnetic field distribution, and FIG. 7B is a diagram illustrating a vertical deflection magnetic field distribution.

[0091]

FIG. 8 is a diagram showing convergence and distortion finally reached by the deflection yoke shown in FIG. 3;

[0092]

FIG. 9 is a view for explaining the operation of the horizontal deflection coil of the deflection yoke shown in FIG. 3 relating to the present invention.

[0093]

FIG. 10A is a diagram for explaining the relationship between the orbit of three electron beams and the interval between three electron beams in a conventional color cathode ray tube device, and FIG. 10B is a diagram illustrating the color of the present invention. It is a figure for explaining the relation between the trajectory of three electron beams, and the interval of three electron beams in a cathode ray tube device.

[0094]

FIG. 11A is a diagram showing a color cathode ray tube device according to the first embodiment of the present invention with a part cut away, and FIG. 11B is a diagram showing a configuration of a deflection yoke mounting portion thereof.

[0095]

FIG. 12 is a diagram for explaining a curved shape of a shadow mask of the color cathode ray tube device according to the first embodiment of the present invention.

[0096]

FIG. 13 is a diagram for explaining a force received by three electron beams by a magnetic field generated by a permanent magnet of the color cathode ray tube device according to the first embodiment of the present invention.

[0097]

FIG. 14 is a diagram for explaining the force received by three electron beams by a magnetic field generated by a permanent magnet provided on a deflection yoke having a circular cross section.

[0098]

FIG. 15 is a diagram showing different arrangements of permanent magnets in the color cathode ray tube device according to the first embodiment of the present invention.

[0099]

FIGS. 16 (a) and 16 (b) are diagrams showing other different arrangements of permanent magnets in the color cathode ray tube device according to the first embodiment of the present invention.

[0100]

FIG. 17 is a diagram showing two trajectory correcting means provided in the color cathode ray tube device according to the second embodiment of the present invention.

[0101]

FIG. 18 is a partially cutaway view of a conventional color cathode ray tube device.

[0102]

FIG. 19 is a diagram showing a relationship among a panel, a shadow mask, and three electron beams of a conventional color cathode ray tube device.

[0103]

FIG. 20 is a diagram for explaining press forming of a shadow mask of a conventional color cathode ray tube device.

[0104]

FIG. 21 is a view for explaining means for improving the strength of a conventional shadow mask.

[0105]

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Display part 2 ... Panel 4 ... Neck 7 ... Phosphor screen 11B, 11R ... A pair of side beams 11G ... Center beam 12 ... Electron gun 30 ... Shadow masks 51a, 51b, 51c, 51d ... Permanent magnet 53 ... Funnel 54 ... Small diameter part 55: deflection yoke

Continued on the front page (72) Inventor Hiroaki Ibuki 1-9-2, Hara-cho, Fukaya-shi, Saitama F-term in Fukaya Electronics Factory, Toshiba Corporation (reference) 5C042 AA07 GG07 GG08 GG13 GG23 GG24 GG26

Claims (6)

[Claims] 1. A vacuum envelope comprising a substantially rectangular panel having a display portion, a funnel-shaped funnel connected to the panel, and a neck connected to an end of a small diameter portion of the funnel.
A substantially rectangular phosphor screen provided on the inner surface of the display unit of the panel, a color selection mask having a large number of electron beam passage holes formed on a surface facing away from the phosphor screen, An electron gun that emits three electron beams arranged in a row composed of a center beam and a pair of side beams passing on the same plane, and mounted from the funnel side of the neck to the outside of the small diameter portion of the funnel, A color cathode ray tube device comprising: a deflection yoke having a deflection coil for generating a magnetic field for deflecting the electron beam in the direction in which the three electron beams are arranged and in a direction orthogonal to the direction in which the three electron beams are arranged. At least a part of the peripheral portion of the phosphor screen with respect to the pair of side beams in the under convergence direction. An operating permanent magnet is disposed, and the deflection coil generates a magnetic field acting in an over-convergence direction that substantially cancels the operation of the permanent magnet in an under-convergence direction with respect to the pair of side beams. The distance between the inner surface of the display part of the panel and the mask at the center of the phosphor screen in the tube axis direction is qo, the distance between the inner part of the display screen of the panel and the tube axis is q other than the center of the phosphor screen. Is the distance of the center beam in the three electron beam arrangement direction at the center of Pho, the distance of the three electron beam arrangement directions other than the center of the phosphor screen is Ph, the diagonal effective diameter of the phosphor screen is D, and these q , Qo, Ph, and Pho are expressed in mm, and when Δq = q−qo ΔPh = Ph−Pho, 0.06 × D ≧ Δq−qo × (ΔPh /Pho)≧3.0
mm, a color cathode ray tube device. 2. The color cathode ray tube device according to claim 1, wherein the permanent magnets are arranged in a direction in which the three electron beams are arranged. 3. The color cathode ray tube device according to claim 1, wherein the permanent magnet is disposed near a diagonal axis of the phosphor screen. 4. The permanent magnet is arranged along the inner surface of the deflection yoke between a direction perpendicular to the arrangement direction of the three electron beams and a diagonal axis direction of the phosphor screen. The color cathode ray tube device as described in the above. 5. The color cathode ray tube according to claim 1, wherein a cross section of the small diameter portion of the funnel and the deflection yoke at the small diameter portion is formed in a substantially rectangular shape. apparatus. 6. The color cathode ray tube device according to claim 1, wherein the outer surface of the display section of the panel is substantially flat.