JP3434544B2 - Color picture tube - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask type color picture tube, and more particularly to a color picture tube having a mask frame of a shadow mask having an electron shielding function. 2. Description of the Related Art Generally, as shown in FIG. 4, a shadow mask type color picture tube has a substantially rectangular panel 2 provided with a skirt portion 1 at a peripheral portion thereof, and a skirt portion 1 of the panel 2. The panel has an envelope composed of a funnel-shaped funnel 3 joined thereto. A phosphor screen 4 made of a three-color phosphor layer is formed on the inner surface of the panel 2, and a substantially rectangular shadow mask 5 is formed inside the phosphor screen 4. Are arranged facing the phosphor screen 4 at a predetermined interval. This shadow mask 5
A mask frame 8 having an L-shaped cross section in which an inner projecting portion 7 is formed at one end of a side wall 6; and a large number of electron beam passage holes formed in a surface facing the phosphor screen 4; And a mask body 9 to which the other end of the side wall 6 is attached. The elastic support 10 attached to the side wall 6 of the mask frame 8 is connected to a stud pin 11 provided on the skirt 1 of the panel 2.
And is supported inside the panel 2. Further, inside the large-diameter portion of the funnel 3, an internal magnetic shield 12 attached to the inner projecting portion 7 of the mask frame 8 is disposed. On the other hand, an electron gun 15 for emitting three electron beams 14B, 14G, 14R is arranged in the neck 13 of the funnel 3. [0003] Then, 3
The electron beams 14B, 14G, and 14R are formed so as to be deflected by a magnetic field generated by a deflecting device 17 mounted on the outside of the funnel 3 to scan the phosphor screen 4 horizontally and vertically to display a color image. I have. Meanwhile, the conventional internal magnetic shield 12 is
As shown in FIG. 5, in order to minimize the collision of the electron beam with the inner surface of the mask frame 8 and the inner surface of the skirt portion of the mask body 9, the mounting portion 19 with the mask frame 8 is greatly extended inward. It is formed in a structure having an electron shielding function of shielding an electron beam directed toward the inner surface of the mask frame 8 and the inner surface of the skirt portion of the mask body 9. However, such an internal magnetic shield 12 is
Since the clip 20 must be inserted into the inside and attached to the mask frame 8, workability is not good. For this purpose, as shown in FIG. 6, a flange portion 22 is provided on the inner magnetic shield 12 so as to protrude outward, and the flange portion 22 is provided on the inner protruding portion 7 of the mask frame 8.
On the other hand, there is an attempt to make the inner overhang 7 of the mask frame 8 larger than the mask frame shown in FIG. 5 so that the inner overhang 7 has an electron shielding function. However, when the amount of overhang of the inner overhanging portion 7 of the mask frame 8 is increased, the weight of the mask frame 8 increases, and when an impact or vibration is applied to the color picture tube, the shadow mask 5 is displaced. However, the electron beam does not land on a predetermined phosphor layer, and color shift is likely to occur. In addition, the cost of the shadow mask 5 is increased. On the other hand, in recent color picture tubes, as one means for reducing the weight, the elastic support is attached to the center of each side of the mask frame to support the shadow mask. A method of mounting and supporting a body is adopted. When the shadow mask is supported at the four corners in this manner, the four corners of the mask frame have greater strength than other parts, so that the plate thickness can be reduced and the weight can be reduced. However, even if the shadow mask is supported by such a method, it is still insufficient against shock and vibration, and it is desired to improve the shock and vibration resistance. As a means for improving the shock resistance and vibration resistance of the shadow mask, there is a method of increasing the strength of the elastic support. However, if the strength of the elastic support is increased, the mask frame is deformed. In order to prevent this deformation, the thickness of the mask frame must be increased, which is against the weight reduction of the shadow mask. [0010] As described above, the conventional internal magnetic shield is designed to minimize the collision of the electron beam with the inner surface of the mask frame and the inner surface of the skirt of the mask body. The mounting portion with the mask frame is greatly extended inward to form a structure having an electron shielding function. However, with this structure, the workability of the work of attaching to the mask frame is not good. [0011] Therefore, a flange portion is provided on the inner magnetic shield so as to protrude outward, and the flange portion is attached to the inner protruding portion of the mask frame. On the other hand, the inner protruding portion of the mask frame is larger than the mask frame. Attempts have been made to make the inner overhanging portion have an electron shielding function. However, if the overhang of the inner overhang of the mask frame is increased in this way,
When the weight of the mask frame increases and impact or vibration is applied to the color picture tube, the shadow mask is displaced,
The electron beam does not land on the predetermined phosphor layer, and color shift is likely to occur. In addition, the cost of the shadow mask will increase. On the other hand, in recent color picture tubes, as one of means for reducing the weight, a method in which an elastic support is attached to four corners of a mask frame and supported is adopted. When supported at the four corners in this way, the four corners of the mask frame
Since the strength is higher than the other parts, the thickness can be reduced and the weight can be reduced. However, even if the shadow mask is supported by such a method, it is
It is not sufficient, and it is desired to improve the shock and vibration resistance. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. Even when a mask frame of a shadow mask is provided with an electron shield function for preventing an electron beam from colliding with its inner surface or the inner surface of a skirt portion of a mask body. Another object of the present invention is to improve the shock resistance and vibration resistance of the shadow mask without increasing the weight of the mask frame, and to reduce the occurrence of color misregistration. Means for Solving the Problems A substantially rectangular mask frame having an inwardly extending portion formed at one end of a side wall and a mask frame having a large number of electron beam passage holes formed inside a substantially rectangular panel. A shadow mask comprising a mask body attached to the other end of the side wall of the mask is disposed, and this shadow mask locks an elastic support attached to a corner of the mask frame to a stud pin provided on the panel. In the color picture tube supported by the above, the length a of the side wall on at least the short side of the mask frame and the length b of the inner protruding portion are formed in a relationship of a <b. As described above, when the length a of the side wall and the length b of the inner protruding portion on at least the short side of the mask frame are formed in a relation of a <b, the shadow mask can be formed without increasing the weight of the mask frame. , The deterioration of the shock resistance and vibration resistance characteristics can be prevented, and the color shift can be suppressed. Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a color picture tube as one embodiment of the present invention. This color picture tube has an envelope composed of a substantially rectangular panel 2 provided with a skirt portion 1 on the periphery and a funnel-shaped funnel 3 joined to the skirt portion 1 of the panel 2. On the inner surface of the panel 2, a phosphor screen 4 composed of a three-color phosphor layer emitting blue, green, and red light is formed, and a substantially rectangular shadow mask 30 facing the phosphor screen 4 at a predetermined interval is formed inside the phosphor screen. Is arranged. The shadow mask 30 has a substantially rectangular L-shaped cross-sectionally formed mask frame 33 having an inner protrusion 32 formed at one end of a side wall 31, and an effective number of electron beam passage holes facing the phosphor screen 4. A skirt portion is formed on the outer periphery of the surface, and the skirt portion is composed of a mask body 34 attached to the inside of the other end of the side wall 31 of the mask frame 33. And mask frame 8
The elastic support 10 attached to the side walls 35 at the four corners of the panel 2 is supported on the inside of the panel 2 by engaging the stud pins 11 provided on the skirt 1 of the panel 2. Further, inside the large-diameter portion of the funnel 3, an internal magnetic shield 36 attached to the inner projection 32 of the mask frame 33 is arranged. This internal magnetic shield 36
Is formed at one end with an outwardly protruding flange portion, which is attached to the inner protruding portion 32 of the mask frame 33 with this flange portion. On the other hand, in the neck 13 of the funnel 3, three electron beams 14B, 14G, 14R
Is provided. Then, 3 emitted from the electron gun 15
The electron beams 14B, 14G, and 14R are formed by a structure in which a color image is displayed by deflecting the electron beams 14B, 14G, and 14R by a magnetic field generated by a deflecting device 17 mounted outside the funnel 3 and scanning the phosphor screen 4 horizontally and vertically. I have. In particular, in this color picture tube, the mask frame 33 is designed to minimize the collision of the electron beam with its inner surface and the inner surface of the skirt portion of the mask body 34 as shown in FIG.
As shown in FIG. 5, the inner overhang 32 is made to extend more inward than the inner overhang of the conventional mask frame shown in FIG.
An overhang at the center of each side so as to provide an electron shield function for shielding the electron beam directed to the inner surface of the mask and the inner surface of the skirt portion of the mask body, and not to impede the incidence of the electron beam on the effective surface of the mask body 34. It is formed in a curved shape with a large amount and a protruding amount reduced as approaching the four corners. Further, in the mask frame 33 of this embodiment, when the length of the side wall of each side is a and the length of the inner protruding portion is b,
As shown in FIG. 2, the length a of the side wall and the length b of the inner protruding portion are formed such that a> b on the long side 38 and a <b on the short side 39. An example of such a mask frame 33 is shown in FIG.
Table 1 shows the center of the long side (on the vertical axis Y) and the center of the short side (horizontal axis X) of an 8 cm, 110 ° deflection color picture tube.
Top), the length a of the side wall at the four corners, the length b of the inner overhang, and their sum (a + b) are shown in comparison with those of the conventional mask frame. The mask frame of the color picture tube was manufactured by press-forming a mild steel plate having a thickness of 0.8 mm. [Table 1] As shown in Table 1, the value of (a + b) at the center of the short side and the long side of the mask frame of this example is formed almost the same as those of the conventional mask frame, and at the four corners, Is formed slightly larger than that of the mask frame. Therefore, when the mask frame is configured in this manner, the electron shield function can be provided with the same weight as the mask frame of the conventional shadow mask in which the elastic support is attached and supported at the four corners. In addition, for example, in the case of the above-mentioned 68 cm, 110 degree deflection color picture tube, as a result of measuring the color purity after applying a shock of 35 G to the tube itself, there is almost no change similarly to the conventional color picture tube, and sufficient shock resistance, A color picture tube maintaining vibration-proof characteristics could be obtained. Regarding the shock and vibration resistance characteristics, in the case of the above-mentioned 68 cm, 110 degree deflection color picture tube (aspect ratio: 5: 4), the side wall length a and the inner overhang length b are
The ratio of a <b is about 40% of the entire circumference of the mask frame. In contrast, the aspect ratio is 16: 9.
For example, in a 66 cm, 105 degree deflection color picture tube, when a> b is set on the long side of the mask frame and a <b is set on the short side, the ratio of a <b is about 35% of the entire circumference of the mask frame. However, also in this case, like the color picture tube of 68 cm and 110 degrees deflection, it was possible to obtain a color picture tube maintaining sufficient shock resistance and vibration resistance characteristics with the same weight as the conventional mask frame. . In other words, when the electron projection function is provided by enlarging the inner projecting portion of the mask frame,
By setting a region of 30% or more around the short side in a relationship of a <b, a color picture tube which does not deteriorate in shock resistance and vibration resistance can be constructed with the same weight as a conventional mask frame. it can. The weight of the mask frame can be reduced by increasing the proportion of the area where a <b.
When the area of a <b is increased, the mechanical strength of the mask frame decreases. If the length a of the side wall is too short with respect to the length b of the inner protruding portion, the mask frame becomes a state close to a flat plate, and the strength is further reduced. Therefore, in order to maintain the strength of the mask frame, a region where a> b is required. Generally, the shape with the best balance in terms of strength is a case where the area of the side wall is equal to the area of the inner protruding portion. As a shape close to this, the long side 38 is set to a> b and the short side 39 is set to a <b. Thereby, the inner projection 32 of the mask frame is greatly extended without lowering the mechanical strength of the mask frame, so that the mask frame has an electron shielding function, and the impact resistance of the shadow mask 30 is improved.
It is possible to prevent the deterioration of the vibration resistance characteristic and to provide a color picture tube in which color misregistration hardly occurs. According to the present invention, a substantially rectangular mask frame having an inwardly extending portion formed at one end of a side wall and a large number of electron beam passage holes are formed inside a substantially rectangular panel. In a color picture tube in which a shadow mask consisting of a mask body attached to an end is disposed, a side wall length a at least at a short side of the mask frame is set.
And the length b of the inner protruding portion is formed in a relationship of a <b, and without increasing the weight of the mask frame, the same weight as that of the conventional mask frame of the shadow mask that supports by attaching elastic supports to the four corners. It is possible to provide a mask frame having an electron shield function, to prevent the shadow mask from deteriorating the shock resistance and vibration resistance characteristics, and to provide a color picture tube which is less likely to cause color misregistration.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a mask frame of a shadow mask of a color picture tube according to an embodiment of the present invention. FIG. 2A is a diagram illustrating a cross-sectional shape at the center of a long side, and FIG. 2B is a diagram illustrating a cross-sectional shape at a center of a short side. FIG. 3 is a diagram showing a configuration of a color picture tube according to an embodiment of the present invention. FIG. 4 is a diagram showing a configuration of a conventional color picture tube. FIG. 5 is a diagram showing a relationship between a mask frame of a conventional color picture tube and an internal magnetic shield. FIG. 6 is a diagram showing an improved structure of a conventional mask frame and an internal magnetic shield. DESCRIPTION OF SYMBOLS 1 ... Skirt 2 ... Panel 4 ... Phosphor screen 10 ... Elastic support 11 ... Stud pins 14B, 14G, 14R ... 3 Electron beam 15 ... Electron gun 17 ... Deflection device 30 ... Shadow mask 31 ... Side wall Reference numeral 32: inner overhang 33: mask frame 34: mask body 36: internal magnetic shield 38: long side 39: short side

Continuation of the front page (56) References JP-A-55-151739 (JP, A) JP-A-2-244542 (JP, A) JP-A-5-211043 (JP, A) JP-A-63-164151 (JP) , U) Actually open 52-79858 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 29/07

Claims (1)

(57) [Claim 1] A substantially rectangular mask frame having an inwardly extending portion formed at one end of a side wall and a large number of electron beam passage holes are formed inside a substantially rectangular panel. A shadow mask comprising a mask main body attached to the other end of the side wall of the mask frame is disposed, and the shadow mask is provided with an elastic support attached to a corner portion of the mask frame on a stud pin provided on the panel. A color picture tube which is supported by being locked by a collar, wherein the mask frame is formed such that at least the side wall length a and the length of the inner protruding portion b on the short side are in a relationship of a <b. Picture tube.