WO2003071573A1

WO2003071573A1 - Color cathode ray tube

Info

Publication number: WO2003071573A1
Application number: PCT/JP2003/001621
Authority: WO
Inventors: Takayuki Shimamura
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2002-02-19
Filing date: 2003-02-17
Publication date: 2003-08-28
Also published as: JP2003242900A

Abstract

A color cathode ray tube comprising a panel (4) on which a fluorescent surface (9) is formed, a funnel (8), an electron gun (13), a color selection electrode structure (3) installed to face the fluorescent surface, and a V-shaped support member (11) for fixing the color selection electrode structure to the panel. The support member (11) is elastic, and is fixed at one fixed portion (11b) of the V-shape to the side surface of the color selection electrode structure (3) and locked at the other movable portion (11a) to the panel (4). The apex of the V-shape is positioned shifted toward a tube axis side beyond the side surface, to which the fixed portion is fixed, of the color selection electrode structure (3). This arrangement permits an effective correction of the opening position of a color-selection electrode, to realize a high-precision color cathode ray tube. In addition, bending moment received by the support member is small even if a high-rigidity frame is used to easily flatten the screen.

Description

Description Color cathode ray tube Technical field

The present invention relates to a color cathode ray tube, and more particularly to an improvement of a support member for fixing a color selection electrode assembly to a panel. Background art

The color cathode ray tube has a color selection electrode such as a shadow mask or an aperture grill. The color selection electrode is held by the frame to form a color selection electrode structure, for example, a shadow mask structure. The shadow mask structure is fixed to the inner wall of the panel via a support member. When the color cathode ray tube is operated, the electron beam collides with the shadow mask, and the shadow mask and the frame holding it are thermally expanded. As a result, the aperture of the shadow mask causes a slight displacement toward the periphery of the shadow mask, which causes a color shift on the screen. In order to correct the color shift, a technique is generally used in which the support member has a function of correcting the position of the opening of the shadow mask. As an example of such a supporting member, a spring having a substantially V-shape is described in Japanese Patent Application Laid-Open No. 62-43232.

Fig. 5 shows an enlarged cross-sectional view of the spring part of a conventional color cathode ray tube using this technology. Reference numeral 4 denotes a panel having a fluorescent screen 9 inside. Reference numeral 3 denotes a shadow mask structure, which has a structure in which a shadow mask 2 is held in a frame 10. The shadow mask structure 3 is supported by a panel 4 by a substantially V-shaped spring 1. The spring 1 includes an elastic movable part la and a fixed part 1b. Fixed part lb, frame 10 Is welded to. The distal end of the movable portion 1a forms a locking portion 1c, and the locking portion lc is locked to a panel pin 5 fixed to the panel 4. 2a indicates the periphery of the opening area of the shadow mask 2. 6 is the axis of the color cathode ray tube, and 7 is the electron beam.

When the spring 1 is elastically deformed due to the thermal expansion of the shadow mask structure 3, the angle between the spring 1 and the tube axis 6 changes. Thereby, the shadow mask 2 approaches the phosphor screen 9, and as a result, the position of each opening of the shadow mask 2 according to the half angle of deflection of the electron beam is corrected.

In this structure, when the inclination angle of the movable portion 1a of the spring 1 with respect to the tube axis 6 is α, and the angle between the electron beam 7 passing through the peripheral edge 2a of the opening area of the shadow mask and the tube axis 6 is a,

t a n a> Am / A f X t a n (90 ° —a)

When the relationship is satisfied, the position of the opening of the shadow mask 2 can be effectively corrected by the operation of the spring 1. In the above equation, Am is the coefficient of thermal expansion of the shadow mask 2 and A f is the coefficient of thermal expansion of the frame 10.

Here, if AmZA f ≥ 1, in order to obtain the effect of the above configuration,> (90 ° —α), that is, (α + α)> 90 °

It is necessary to Therefore, when the above configuration is applied to, for example, a 90 ° polarized color cathode ray tube, the angle of inclination of the spring 1 must be 45 ° or more because the angle α is 45 °.

However, in a high-definition color cathode ray tube, since the aperture area of the shadow mask 2 is expanded and the space formed between the panel 4 and the side wall of the frame 10 is reduced, the following problems occur. Occurred. In other words, when the spring 1 having a large inclination angle is used, the stress applied to the vicinity of the vertex of the spring 1 when the mounting and dismounting of the shadow mask structure 3 are repeated in the manufacturing process. Was excessively large, and the spring 1 was sometimes plastically deformed. In particular, when the inclination angle α was set to 45 ° or more, this phenomenon became remarkable, and the mounting accuracy of the shadow mask structure 3 was reduced.

In addition, with the flattening of the screen, the frame 10 is required to have high rigidity, and accordingly, the weight increases. Therefore, when an external impact is applied to the frame 10, the spring 1 may receive an excessive bending moment and may be plastically deformed. Disclosure of the invention

The present invention provides a support member having a function of correcting a color shift caused by thermal expansion of a color selection electrode assembly, by suppressing attachment / detachment in a manufacturing process and plastic deformation caused by an external impact force. It is intended to improve the application so that it can be easily applied to a color cathode ray tube having a high definition and flat screen. A color cathode ray tube according to the present invention includes a panel on which a fluorescent screen is formed, a funnel joined to the panel, an electron gun provided on the funnel, and a color selection electrode installed facing the fluorescent screen. And a support member having a substantially V shape for fixing the color selection electrode assembly to the panel. The support member has elasticity, and a tip of a fixed portion, which is one of the substantially V-shaped arms, is fixed to a side surface of the color selection electrode assembly, and a tip of a movable portion, which is the other arm, is the arm. Locked to the panel. In order to solve the above-mentioned problem, the substantially V-shaped apex portion of the support member is located on the tube axis side with respect to a side surface of the color selection electrode assembly where the fixing portion is fixed.

According to this configuration, the aperture position of the color selection electrode is effectively corrected, and a highly accurate color cathode ray tube is realized. Furthermore, even when a high-rigidity frame is used, the bending moment received by the support member is small, and the screen can be easily flattened. The substantially V-shaped apex portion may be arranged to face the panel.

A concave portion is formed on a side surface of the color selection electrode assembly, the concave portion being recessed on the tube axis side from a surface on which the fixing portion of the support member is fixed, and a substantially V-shaped apex portion of the support member is formed by the concave portion. In such a configuration, the substantially V-shaped apex portion is shifted toward the tube axis with respect to the side surface of the color selection electrode assembly to which the fixing portion is fixed. it can. Preferably, the fixed part and the movable part of the support member are each bent, and the bend is formed such that the apex side is displaced toward the tube axis side. BRIEF DESCRIPTION OF THE FIGURES

1 is a cross-sectional view of a color cathode ray tube according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an enlarged part of the color cathode ray tube of FIG. 1, and FIG. 3A is a color cathode ray tube of FIG. An enlarged sectional view of a portion of a spring supporting a shadow mask structure in the pipe,

FIG. 3B is an enlarged cross-sectional view of a spring supporting the shadow mask structure in the conventional color cathode ray tube.

FIG. 4A is a perspective view of a shadow mask structure having a curved shadow mask,

FIG. 4B is a perspective view of a shadow mask structure having a tensioned and supported shadow mask,

FIG. 5 is an enlarged sectional view of a part of a conventional color cathode ray tube. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a color cathode ray tube according to the present embodiment. The color cathode ray tube has a flat panel 4 and a funnel 8 joined to the panel 4. A fluorescent screen 9 is formed on the inner surface of panel 4. The shadow mask structure 3 includes a shadow mask 2 having a large number of apertures formed on the surface thereof, and a substantially rectangular frame 10a for holding the shadow mask 2 by applying tension. The frame 10 a is fixed to the panel 4 via a spring 11 and a panel pin 5 at substantially the center of both sides in the longitudinal direction of the panel 4. The neck 13 of the funnel 8 is provided with an electron gun (not shown). The electron beam 7 emitted from the electron gun passes through the aperture of the shadow mask 2 and irradiates the fluorescent screen 9, whereby an image is displayed on the color cathode ray tube. Reference numeral 6 denotes a tube axis, which is perpendicular to the phosphor screen 9 and passes through almost the center of the panel 4.

FIG. 2 shows an enlarged cross-sectional view of a portion where the shadow mask structure 3 is fixed to the panel 4. The case where the electron beam 7 reaches the periphery 2 a of the opening area of the shadow mask 2 is shown. A concave portion 12 is formed on the side surface of the frame 10 a so as not to block the electron beam 7. The shadow mask structure 3 is fixed to the panel 4 via a substantially V-shaped spring 11. The spring 11 has a structure in which one end of two bent plate-like members is welded to form a vertex 14. The direction parallel to the tube axis 6 through the vertex 14 is indicated by 6a. The plate forming one arm forms the movable portion 11a, and the plate forming the other arm forms the fixed portion 11b. The movable portion 11a and the fixed portion 11b are bent at the center in the longitudinal direction. The fixing portion 11b is fixed to the side surface of the frame 10a at the welding point 15 on the tip side of the bent portion. The movable portion 11a is locked to the panel pin 5 at a locking portion 11c that forms a distal end side of the bent portion. The movable part 11a has an inclination angle of α1 with respect to the direction 6a. The fixing part 1 lb forms a corner 3 with the direction 6 a on the side of the vertex part 14 from the bent part. The top portion 14 enters the concave portion 12 and is shifted to the pipe shaft 6 side from the welding point 15.

FIG. 3A is a cross-sectional view around the spring 11. FIG. 3B is a cross-sectional view around the spring 1 in the case of the conventional technology. The members and angles indicated by the respective reference numerals correspond to those indicated by the same reference numerals in FIGS. 2 and 5, respectively. The inclination angle α 1 of the spring 11 in the present embodiment shown in FIG. 3A is set equal to the inclination angle 2 of the conventional spring 1 shown in FIG.

In FIG. 3。, the distance between the fixed portion 11 b of the spring 11 and the locking portion 11 c is X (mm). Let Y (mm) be the offset amount of the spring 11, that is, the distance between the apex 14 of the substantially V-shaped spring 11 and the pipe shaft side from the welding point 15. The thickness of the fixed part 1 1b is t (mm). In the present embodiment, the length Z 1 of the movable portion 11 a is

Z 1 = (X + t + Y) / s i n (1)

Becomes On the other hand, in the prior art shown in FIG. 3B, the length Z 2 of the movable portion 11 a is

Z 2 = X / s i n (2)

It is. Since α 1 = α 2, Ζ1> Ζ2.

Generally, the amount of plastic deformation of the spring 11 when the shadow mask assembly 3 is attached to and detached from the panel 4 is inversely proportional to the length of the movable portion 11a. 11 plastic deformation is small. Therefore, even if the shadow mask structure 3 is repeatedly attached and detached, the accuracy of the attachment position is kept high.

Also, as shown in Fig. 3A, the panel (not shown) of the color cathode ray tube is When an external impact is applied, a force F acts on the spring 11. As a result, the component F y 1 = FX sin (h 1) in the direction perpendicular to the tube axis of the force F acts as a bending stress on the fixed portion 11b. When a similar force F is applied in the prior art, the bending stress F y2 becomes FX sin (2), as shown in FIG. 3B. Since the force F does not depend on the shape of the spring other than the angle α, if 1 = α2, then Fyl = Fy2. On the other hand, in the present embodiment, since the fixed portion 11b is inclined at an angle of / 3 from the pipe axis at the vertex portion 14 side (see FIG. 2), the fixed portion 11b at the vertex portion 14 side of the fixed portion 11b is formed. The cross-sectional secondary moment is (lZcos / 3) ^three times that of the prior art. Therefore, in the present embodiment, the amount of bending of the fixed portion 11b when receiving an external impact of the same magnitude is reduced, so that the mounting position of the shadow mask structure 3 is less likely to shift.

In this embodiment, as shown in FIG. 2, as long as the trajectory of the electron beam 7 emitted from the electron gun is not interrupted, the concave portion 12 provided on the side of the frame 10a must be deepened. Can be. The deeper the concave portion 12 is, the larger the offset amount of the spring 11 can be, and the more effective the correction of the color shift of the screen can be.

This embodiment can be applied to various types of color selection electrode assemblies. For example, as shown in FIG. 4A, a form in which a shadow mask 16 formed into a curved surface is supported by a substantially rectangular frame 10a can be applied. Alternatively, as shown in FIG. 4B, a configuration in which a shadow mask 17 to which tension is applied in the direction of the arrow is supported by a pair of upper and lower frames 18 and an auxiliary frame 19 supporting the same is also applicable. In the embodiment shown in FIG. 4B, a space is formed between the shadow mask 17 and the auxiliary frame 19. Therefore, the spring 11 as shown in FIG. 2 is attached to the side of the auxiliary frame 19, and the substantially V-shaped If the apex portion 14 is arranged, the same operation and effect as those of the above-described embodiment can be obtained. In this case, it is not necessary to provide a recess on the side surface of the frame.

The spring is not limited to the longitudinal side surface of the frame, and may be arranged at any portion such as a corner portion as long as it is stably fixed. The number of springs used can be changed as appropriate according to the size and weight of the shadow mask structure and its mounting position on the panel.

Further, the spring 11 is not limited to a shape in which a plate-like body is bent at two positions as in the present embodiment. As long as it is substantially V-shaped, for example, a shape bent at three or more places may be used, or a shape bent in a bow may be used.

The invention is not limited to the case where a shadow mask is used as a color selection electrode as described in the present embodiment, but the present invention uses a color selection electrode having another structure such as an aperture grill having slit-shaped holes. The same applies to color cathode ray tubes.

Hereinafter, an example of manufacturing a color cathode ray tube will be described. In the example shown below, a color cathode ray tube having a screen size of 34 inches (80 cm), a shadow mask pitch of 0.58 mm, and a thickness of 1.8 mm was manufactured. The frame of the shadow mask structure was 50 mm high and 1.8 mm thick.

(Example based on this embodiment)

As shown in FIG. 3A, a recess 12 having a height of 15 mm, a width of 35 mm, and a depth of 3 mm was provided on the side surface of the corner of the frame 10a. The spring 11 has a movable part 11a including a locking part 11c having a width of 30 mm and a wall thickness of 0.5 mm, and a fixed part 12c having a width of 30 mm and a wall thickness of 1.4. mm. Positioning the top 14 in the recess 12 allows the pipe shaft 6 to be The spring 11 was attached to a part of the corner of the frame 10a. In FIG. 3A, the inclination angles l and i3 were α1 = 45 ° and 3 = 5 °, respectively. The distance X was 30 mm, and the offset amount Y was 2.4 mm.

When the color cathode ray tube was operated in this state, the shift amount of the spot position of the electron beam from the reference value was 5 m at the periphery of the opening area of the shadow mask. When the mounting and dismounting of the shadow mask structure 3 was repeated, the shift amount of the fixed position of the shadow mask structure 3 from the reference value was 10 m, which was suppressed to the allowable value of 20 or less for quality assurance. When a 25 G impact was applied to the panel of the color cathode ray tube, the shift amount of the electron beam was 10 m, which was suppressed to 30 m or less, which is the allowable value for quality assurance. These allowable ranges are values set in consideration of the thermal expansion of the shadow mask, the influence of geomagnetism, and the like.

(Comparative example)

As shown in FIG. 3B, the frame 10 was not provided with a concave portion on the side surface, and the spring 1 used had a fixed portion 1b having a flat plate shape. Further, the distance X in FIG. 3B was set to X = 1 O mm, and the inclination angle 2 was set to α = 45 °.

When the empty cathode ray tube was operated in this state, the shift amount of the spot position of the electron beam from the reference value was 5 m at the periphery of the aperture region, as in the example based on the embodiment. When the mounting and dismounting of the shadow mask structure 3 was repeated, the shift amount of the fixed position of the shadow mask structure 3 from the reference value was 50 m, which exceeded the allowable value of 20 m for quality assurance. In addition, when a 25 G impact was applied to the panel of the color cathode ray tube, the shift amount of the electron beam was 40 m, exceeding the allowable value of 30 xm, which can guarantee the quality. Industrial applicability ADVANTAGE OF THE INVENTION According to this invention, since the inclination angle of a spring can be enlarged and the dimension of a movable part can be lengthened, the correction | amendment of the position of the opening of a color selection electrode is performed effectively, and a high-precision color cathode ray tube is realized. You. Furthermore, even when a high-rigidity frame is used, the bending moment received by the spring due to the impact can be suppressed to a small value, and it is easy to flatten the screen in a high-precision color cathode ray tube.

Claims

The scope of the claims

1. A panel on which a phosphor screen is formed, a funnel joined to the panel, an electron gun provided on the funnel, a color selection electrode assembly disposed opposite to the phosphor screen, and the color A support member having a substantially V-shape for fixing the selection electrode assembly to the panel, wherein the support member has a property, and a distal end portion of a fixing portion, which is one of the substantially V-shaped arms, is provided. In a color cathode ray tube fixed to a side surface of the color selection electrode assembly and having a tip of a movable portion, which is the other arm, locked to the panel,

A color cathode ray tube, wherein a substantially V-shaped apex portion of the support member is shifted toward a tube axis side from a side surface of the color selection electrode assembly where the fixing portion is fixed.

2. The cathode ray tube according to claim 1, wherein the substantially V-shaped apex portion is arranged toward the panel.

3. On the side surface of the color selection electrode assembly, a concave portion is formed which is recessed on the tube axis side from the surface on which the fixing portion of the support member is fixed, and a substantially V-shaped apex portion of the support member is formed. By being arranged at a position where it has entered the concave portion, the substantially V-shaped apex portion is shifted toward the tube axis side from the side surface of the color selection electrode assembly to which the fixing portion is fixed. The color cathode ray tube according to claim 1, wherein

4. The color cathode ray tube according to claim 1, wherein the fixed part and the movable part of the support member are each bent, and the bend is formed such that the apex side is displaced toward the tube axis side.