JP2001266764A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color cathode-ray tube for preventing generation of wrinkling of an iron material as a color selecting electrode material, for elongation, generated due to thermal expansion, immediately after lighting a beam to be absorbed by the distortion at the time of stretching, reducing the displacement of holes, and preventing the occurrence of wrinkling/doming. SOLUTION: A color-selecting electrode 7 has a holed area 14, having a number of rectangular opening holes 13 and a non-holed area 15 formed therearound. A color-selecting electrode structure 9 is formed by the color selecting electrode 7, having the holed area 14 with an apparent vertical elastic coefficient in a long-axial direction 18 which is 0.02-0.4% of the vertical elastic coefficient of the color-selecting electrode material and an apparent vertical elastic coefficient in a short-axis direction 19, which is 80% or lower than that of the vertical elastic coefficient of the color selecting electrode material.

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 used for televisions, computer displays, and the like.

[0002]

2. Description of the Related Art In general, a color cathode ray tube has a color selection electrode for color-selecting an electron beam emitted from an electron gun and a frame for holding the color selection electrode.

[0003] As a type of the color selection electrode structure, a flat plate member having a large number of openings such as rectangles, circles, and ellipses is pressed into a predetermined curved shape, and a press mask (see FIG. 6a), a two-dimensional tension mask stretch-welded to a frame in a state where tension is applied in two-dimensional directions of a long axis and a short axis to a flat plate member having a similar opening (FIG. 6).
b) Also, a one-dimensional tension mask that is stretch-welded to the frame in a state where tension is applied to only one dimension in either the short axis or the long axis direction to a flat plate member having many similar openings (FIG. 6c) ) Or an aperture grill (refer to Japanese Patent Application Laid-Open No. 4-163830) in which tension is applied to a member made of a number of metal strips and stretch-welded to a frame.

In recent color cathode ray tubes, the panel shape has been flattened from a curved surface in that the reflection of external light is small and the appearance is good, but with the flattening, the panel shape between the phosphor screen and the color selection electrode has been increased. The color selection electrodes also need to be planarized for proper spacing.

However, in the case of a press mask, since a curved surface is formed by pressing, the flattening of the shape tends to cause permanent deformation of the color selection electrode due to an impact such as dropping. It is very difficult to achieve planarization. On the other hand, the two-dimensional tension mask applies tension in the two-dimensional direction of the color selection electrode in the short-axis direction and the long-axis direction, so that an appropriate tension balance in each direction so that wrinkles do not occur in the color selection electrode. Difficult.

Further, the aperture grill having a large number of metal strips has a problem that the color selection electrode is likely to vibrate due to an external impact or the like, and the color selection electrode is large in vibration and hard to stop. Furthermore, since it is composed of a plurality of metal strips, the metal strips are liable to be entangled or broken, and it is difficult to handle the color selection electrode during assembly.

[0007] Compared to these, the one-dimensional tension mask has a more advantageous structure with respect to the above-mentioned problems.
It is being adopted as a color selection electrode structure for a color cathode ray tube having a flat panel.

[0008]

Since the one-dimensional tension mask has a bridge portion between the openings in the perforated region of the color selection electrode, the color selection electrode can be moved only in the short axis direction. Even when tension is applied to the steel sheet, a slight strain is generated in the longitudinal direction, and a tensile force is applied. In general, if the force in the long axis direction is too small, there is a problem that wrinkles occur in the color selection electrode.In particular, when an iron material is used as the color selection electrode material, the iron has a large thermal expansion coefficient. Wrinkles are generated, and color misregistration (hereinafter referred to as wrinkle doming), which is caused by displacement of a hole position due to the wrinkles, easily occurs.

As a countermeasure, a low expansion material such as an invar material is used as a color selection electrode material (Japanese Patent Application No. 10-2980).
Although the method of solving the problem of wrinkle doming is conceivable by using such a material, a low expansion material such as invar has a problem that the material cost is higher than that of an iron material.

As a countermeasure in the case of using an iron material, it has been considered to increase the pitch in the short axis direction of the mask. However, if the pitch is too large, the pitch becomes too small as an independent string like an aperture grille. There is a problem that vibration of the color selection electrode is easily generated due to impact from the device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and uses an iron material as a color selection electrode material while keeping the apparent longitudinal elastic coefficient of a hole in a mask within a predetermined range. It is an object of the present invention to provide a color cathode-ray tube having a color selection electrode structure which does not cause wrinkling doming at the start of image display by being determined.

[0012]

In order to solve the above-mentioned problems, a color cathode ray tube according to the present invention is a color cathode ray tube comprising a panel portion and a color selection electrode assembly. Consisting of a perforated area in which an aperture is formed and a non-porous area formed around the perforated area, a force in a predetermined direction, a cross-sectional area of the color selection electrode in the absence of the hole and a strain due to the force in the predetermined direction. Apparent longitudinal elastic modulus divided by the product of the above, when the predetermined direction is the major axis direction of the color selection electrode, 0.02 to 0.4 of the longitudinal elastic coefficient of the color selection electrode material
%, When the predetermined direction is the short axis direction of the color selection electrode, the color selection electrode has a perforated region that is 80% or less of the longitudinal elastic modulus of the color selection electrode material.

According to the above-described color cathode ray tube, when the color selection electrode is stretched by applying tension in the short axis direction, the amount of distortion generated in the long axis direction increases. Even if iron is used as the material, the amount of elongation caused by thermal expansion immediately after the start of image display is absorbed by the amount of strain during stretching, preventing wrinkles from occurring and minimizing the amount of hole position movement. Can be
Wrinkling doming can be prevented.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings.

FIG. 1 is a partial sectional view of a color cathode ray tube according to a first embodiment of the present invention. As shown in FIG. 1, the color cathode ray tube has a panel 2 having a phosphor screen 1 formed on the inner surface. And the funnel 3 connected behind the panel 2
An electron gun 5 for emitting an electron beam 4 is built in the neck 3a of the funnel 3, and a deflection yoke for deflecting the electron beam 4 is provided on the outer peripheral surface of the funnel 3. 6 is mounted. The panel 2 is coated with phosphor dots of three colors on its inner surface, thereby forming a phosphor screen 1.
A plate-like color selection electrode 7 is arranged substantially in parallel with. The color selection electrode 7 is formed by subjecting a flat plate to an etching process, has a large number of regularly arranged openings, and performs color selection for three electron beams 4 emitted from an electron gun 5. It plays a role and is held by a frame 8 to form a color selection electrode assembly 9. The color selection electrode assembly 9 includes an elastic support 10 attached to the frame 8.
Is locked in the envelope by fitting with the panel pin 11 arranged on the panel 2.

FIG. 2 is a perspective view of the color selection electrode structure according to the first embodiment of the present invention, and FIG. 3 is a top view of the color selection electrode according to the first embodiment of the present invention. As shown in FIG. 2, the color selection electrode assembly 9 is in the short axis direction (the direction of arrow 12).
Is formed by stretching and welding a color selection electrode 7 to which tension is applied to a frame 8. The frame 8 includes a pair of long-side members 8a having an L-shaped cross-section and a pair of short-side members 8b having a U-shaped cross-section of a square member. The front surfaces (surfaces to which the color selection electrodes 7 are welded) of the pair of long side members 8a are curved surfaces protruding toward the phosphor screen with a predetermined radius of curvature. For this reason, the color selection electrode 7 is fixed to the frame 8 in a state of being curved along its long axis. The color selection electrode 7 has a perforated region 14 in which a number of substantially elliptical openings 13 are arranged, and a non-perforated region 15 disposed outside both ends of the perforated region 14 in the major axis direction.

Next, a method of manufacturing the color selection electrode assembly 9 of the color cathode ray tube according to the first embodiment of the present invention will be described. First, the side of the long side member 8a of the frame 8 is
At nine pressing points, a distributed load is applied in the short axis direction (direction of arrow 12) in the elastic range to compress. Then, in this state, the color selection electrode 7 is tensioned by applying a total tension of about 3000 N in the short axis direction (the direction of the arrow 12), and is fixed to the curved surface of the long side member 8a by welding. Thereafter, when the load applied to the long side member 8a is removed, a required distribution of tension is applied to the color selection electrode 7, and the color selection electrode assembly 9 is manufactured. In the first embodiment of the present invention, as one example, a color selection electrode assembly used for a color cathode ray tube for a 25-inch television was manufactured.

The frame 8 is formed by joining a pair of long side members 8a having an L-shaped cross section with an iron material having a thickness of 4.5 mm and a pair of short side members 8b having a square cross section with an iron material having a square of 15 mm. Have been. The color selection electrode has a thickness t = 0.13.
A large number of substantially elliptical holes 13 are provided. These openings 13 have a short axis direction pitch a _v 1
6 = 8.4 mm, major axis direction pitch a _h 17 = 0.78 m
The perforated regions 14 are arranged with a pitch distribution based on m. The aperture diameter is about 0.2 mm in the major axis direction, about 7.0 mm in the minor axis direction, and a vertically long aperture shape with a bridge width of 0.09 mm.

FIG. 4 is a view showing the apparent longitudinal elastic modulus in the short-axis direction in the case where the plate material has openings, for the partial model of the color selection electrode. An expression for obtaining an apparent longitudinal elastic modulus is shown below.

[0020]

(Equation 1) In (Equation 1), E is the apparent longitudinal elastic modulus, P is the force acting in the short-axis direction, which is the predetermined direction, S is the apparent cross-sectional area in the short-axis direction, and ε is the short-axis direction, which is the predetermined direction. This is the distortion. Approximately 200G of longitudinal modulus of color selection electrode material
Pa, the mask AB when a 0.001 mm strain is applied to the color selection electrode as a predetermined strain in the short axis direction.
The force generated in the short axis direction of the part is determined to be about 3N from the simulation by the finite element method. The cross-sectional area of the apparent in the minor axis direction is a _h 0.78 mm × thickness 0.1
3 mm. Therefore, when these results are substituted into the calculation expression of (Equation 1), the following expression is obtained.

[0021]

(Equation 2) Therefore, the apparent longitudinal elastic modulus in the short axis direction is about 120 GPa, and the apparent longitudinal elastic coefficient in the short axis direction 19 is 60% of the color selection electrode material.

The apparent longitudinal elastic modulus in the major axis direction is calculated to be about 50 MPa by the same calculation method, and the apparent longitudinal elastic modulus in the major axis direction 18 is about 200 GPa of the color selection electrode material. 0.025%.

FIG. 5 shows a short-axis direction pitch a _v 1 at the start of image display by computer simulation.
6 is a result of obtaining a relationship of a moving amount in a long axis direction in a terminal opening 13 on a long axis with respect to No. 6; From this result, it is understood that as the short-axis direction pitch a _v 16 increases, the amount of movement of the opening 13 in the long axis direction decreases. That is, as the apparent longitudinal elastic coefficient in the long axis direction 18 in the perforated region 14 decreases, the doming amount tends to decrease.

In FIG. 5, the movement amount of the terminal hole 13 is reduced by increasing the short-axis direction pitch a _v 16. However, the movement amount is not simply increased. Since the problem of the screen vibration being difficult to stop due to vibration due to external impact or the like occurs in the color selection electrode, the apparent longitudinal elastic modulus in the long axis direction 18 determined by increasing the short axis direction pitch a _v 16 The lower limit is 0.02% of the longitudinal elastic modulus of the color selection electrode material. In this range, the vibration mode of the color selection electrode can be easily stopped as surface vibration without vibrating separately like vibration of an independent string such as an aperture grille. The upper limit of the apparent longitudinal elastic coefficient in the major axis direction 18 is 0.4% of the longitudinal elastic coefficient of the color selection electrode material. In this range, the amount of movement of the terminal hole 13 on the long axis in the long axis direction with respect to the short axis pitch a _v 16 at the start of image display is within the tolerance range of the doming amount, and color shift occurs during image display. do not do.

Further, the apparent longitudinal elastic coefficient in the short axis direction 19 is specified to be 80% or less of the longitudinal elastic coefficient of the color selection electrode material. If it is larger than 80%, the brightness tends to be insufficient due to the small aperture area during image display, and a clear image cannot be obtained.

In a color cathode ray tube using the color selection electrode assembly 9 constituted by the color selection electrodes 7, no wrinkling doming is observed at the start of image display, and excellent color purity is realized even when an iron material is used. A color cathode ray tube was obtained.

[0027]

As described above, according to the present invention,
The apparent longitudinal elastic modulus in the long axis direction in the perforated area of the color selection electrode is 0.02 to 0.02 of the longitudinal elastic coefficient of the color selection electrode material.
0.4%, the apparent longitudinal elastic modulus in the short axis direction is
When the color selection electrode is stretched by applying a tension in the short axis direction by the color selection electrode structure that is 80% or less of the longitudinal elastic coefficient of the color selection electrode material, a large amount of distortion is generated in the long axis direction. Therefore, even when an iron material is used as the color selection electrode material, the amount of elongation generated due to thermal expansion immediately after the start of image display is absorbed by the amount of strain caused by stretching, preventing wrinkles from occurring and moving the hole position. Keep the amount small,
A color cathode ray tube capable of preventing wrinkling doming and achieving excellent color purity by using the color selection electrode can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a color cathode ray tube according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a color selection electrode assembly according to the first embodiment of the present invention.

FIG. 3 is a partial view of a color selection electrode according to the first embodiment of the present invention.

FIG. 4 (a) is an explanatory diagram for obtaining an apparent longitudinal elastic modulus, and FIG. 4 (b) is a partially enlarged view of a color selection electrode.

FIG. 5 is a diagram showing the relationship between the pitch in the short axis direction and the amount of movement in the long axis direction at the terminal opening on the long axis according to the first embodiment of the present invention;

FIG. 6 is a perspective view showing types of conventional color selection electrodes.

[Explanation of symbols]

 2 Panel 7 Color selection electrode 9 Color selection electrode structure 13 Opening 14 Perforated area 15 Non-porous area 18 Long axis direction 19 Short axis direction

Claims (1)

[Claims] 1. A color cathode ray tube comprising a panel and a color selection electrode assembly, wherein the color selection electrode assembly comprises a perforated region having a large number of apertures and a non-perforated region formed around the perforated region. Apparent longitudinal elastic coefficient obtained by dividing the force in the predetermined direction by the product of the cross-sectional area of the color selection electrode in the absence of the aperture and the strain caused by the force in the predetermined direction, 0.02 to 0.4% of the longitudinal elastic modulus of the color selection electrode material when the longitudinal direction of the color selection electrode is set, and the vertical direction of the color selection electrode material when the predetermined direction is set to the short axis direction of the color selection electrode. A color cathode ray tube comprising a perforated region of the color selection electrode having an elastic coefficient of 80% or less.