JP3468702B2 - Color cathode ray tube - Google Patents

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, and more particularly to a color cathode ray tube having a color selection electrode in which a shadow mask is stretched and held.

[0002]

2. Description of the Related Art In recent color cathode ray tubes, the face panel has been flattened from the viewpoint that external light is not reflected and the appearance is good. With the flattening of the face panel, the shadow mask is also flattening. When the shadow mask becomes flat, only by supporting the shadow mask main body with a frame as in the conventional case, the shadow mask easily vibrates due to external vibration, which adversely affects the display image of the color cathode ray tube. For this reason, a certain amount of tension is applied to the shadow mask so that the shadow mask is stretched and held on the frame.

On the other hand, in the doming phenomenon in which the shadow mask surface is deformed due to thermal expansion due to collision of the electron beam with the shadow mask, the shadow mask surface is flattened, and the electron beam is displaced due to the doming especially near the both ends of the screen. The amount increases. For this reason, the tension applied to the shadow mask in order to absorb the thermal expansion due to the collision of the electron beam in the above-mentioned stretching and holding is usually the maximum practical value close to the elastic limit.

The shadow mask held in a stretched state is called a tension type shadow mask. The tension type shadow mask is an aperture grill type in which a large number of strip elements are stretched in a mask frame, and a substantially rectangular electron beam passage hole in a flat plate. There are a slot type having a large number of holes formed therein and a dot type having a large number of round electron beam passage holes formed on a flat plate.

Further, there are a one-dimensional tension method and a two-dimensional tension method for holding and supporting. The one-dimensional tension method is a method that applies tension only in the vertical direction (vertical direction) of the shadow mask, and the two-dimensional tension method is
It is a method of applying tension in both the vertical and horizontal directions. A one-dimensional tension method is used for the aperture grill type, and one-dimensional tension method or two-dimensional tension method is used for the slot type and dot type.

The color selection electrode composed of the tension type shadow mask and the frame is supported by the panel pin fixed to the inner wall of the panel which is the envelope via the spring member. One of the methods for supporting the color selection electrode on the panel is the corner suspension method. According to this method, the spring elastically deforms in the direction of lifting the shadow mask due to the temperature change, so that the color shift of the shadow mask due to the temperature change can be simply and effectively corrected. In addition, it is possible to reduce the color misregistration particularly in the corner portion that is easily affected by the beam position deviation.

As one example of the corner suspension system, in Japanese Patent Laid-Open No. 6-243793, a spring holder made of bent plate material is welded to four corners of a mask frame, and a spring is attached to the spring holder. Is proposed.

[0008]

However, the one-dimensional tension type shadow mask as described above is applied with the maximum tension for practical use as described above, and in response to this, the mask frame also has a strong and heavy weight. What is used. For this reason, in order to support the color selection electrode using a heavy frame, the spring also needs to have sufficient strength, so that the effective spring constant is increased and the plate pressure is increased. Measures should be taken.

However, in the corner suspension system, since the spring is attached to a narrow corner, the size of the spring is limited and the width of the spring cannot be widened. Therefore, even if the spring is made thicker to increase the strength of the spring, the spring constant according to the thickness cannot be adjusted by the size of the spring, and the elasticity of the spring becomes poor. Therefore, the original function of the spring, such as detachment and correction of color misregistration, cannot be achieved. Therefore, it is difficult to support a heavy mask frame in the corner suspension system of four-point corner support.

Further, in the process before attaching the color selection electrode to the panel, in order to hold the shadow mask stretched,
There is a step of applying a compressive force to the side surface of the mask frame, and in this case, it is necessary to secure a flat surface portion on the upper side surface of the mask frame for applying the compressive force over the entire length in the longitudinal direction. Therefore, it is necessary to separately attach a plate member for attaching the spring member by welding or the like after the stretching step. For example, the above-mentioned JP-A-6-2437.
The method of retrofitting each supporting member as proposed in Japanese Patent No. 93 has problems in cost and productivity.

The present invention solves the above-mentioned conventional problems and provides a color cathode ray tube having a corner suspension system and excellent in productivity in a color selection electrode having a one-dimensional tension type shadow mask. The purpose is to provide.

[0012]

In order to achieve the above object, in the color cathode ray tube of the present invention, a shadow mask is held under tension between a pair of opposing supports, and A color cathode ray tube having a color selection electrode in which the support is held by an elastic member between, a color cathode ray tube provided in an envelope having a face panel, wherein the color selection electrode is provided with a weight reducing means, The support is the support
Of both end extending portions extending themselves from the elastic member in the longitudinal direction, a bent portion is formed by bending a lower portion opposite to the shadow mask, and a spring member is directly fixed to the bent portion, The color selection electrode is fixed to the envelope by engaging a spring member and a pin fixed to a corner portion in the envelope.

According to the color cathode ray tube as described above, since the lightening means is provided, even in the tension type shadow mask, the color shift near the corner, which is particularly susceptible to the beam position shift, can be effectively performed. It is possible to adopt a corner suspension method for correction. Further, even in the corner suspension system, it is possible to sufficiently exert the original function of the spring, that is, detachment and correction of color misregistration by utilizing elasticity. Also,
Since the spring member can be directly fixed to the support, it can be easily attached and productivity can be improved. Further, since the flat surface portion is secured over the entire length of the support in the longitudinal direction of the support, a compressive force can be applied over the entire length of the support in the shadow mask stretching step. After the force is released, the tension balance is maintained, and a color selection electrode that does not cause wrinkles or the like on the shadow mask can be obtained.

In the color cathode ray tube, the weight-reducing means is to reduce the tension of the shadow mask by making the shadow mask a slot type or a dot type to reduce the weight of the color selection electrode. Is preferred. The slot-type or dot-type shadow mask easily absorbs vibrations and can suppress the vibrations even if the tension is lowered, so that the weight of the color selection electrode can be reduced.

Further, it is preferable that the weight-reducing means is to form a comb-like portion on the support. According to the color cathode ray tube as described above, it is possible to form the hollow portion of the material of the support, and thus it is possible to reduce the weight.

Further, it is preferable that the support body is formed of a support body and a comb tooth-shaped member fixed to the support body, and the shadow mask is fixed on an upper surface of the comb tooth-shaped member.

Further, it is preferable that the weight-reducing means is to reduce the tension of the shadow mask by using a material of the shadow mask as a material having a small thermal expansion coefficient to reduce the weight of the color selection electrode. By using a material with a small coefficient of thermal expansion for the shadow mask,
Even if the tension is reduced, the thermal expansion of the shadow mask during the operation of the color cathode ray tube can be suppressed, and the weight of the color selection electrode can be reduced.

Further, it is preferable that the material of the shadow mask contains nickel and iron. Since such a material has a small coefficient of thermal expansion, it is possible to suppress the thermal expansion of the shadow mask during the operation of the color cathode ray tube even if the tension is lowered, and thus the weight of the color selection electrode can be reduced.

In the color cathode ray tube, the angle formed by the horizontal portion of the support and the bent portion is preferably 135 ° or more inside the support.
By setting the angle as described above, it is possible to prevent the positional displacement in the horizontal direction when an impact or the like is applied, so that the color displacement of the color cathode ray tube having the striped fluorescent screen surface can be suppressed especially.

Preferably, the front shape of the face panel is substantially rectangular, and the central axis of the pin is displaced toward the major axis of the face panel with respect to the diagonal line of the face panel. According to the color cathode ray tube as described above, the spatial margin is expanded on the long side of the face panel with respect to the central axis of the pin. Therefore, the spring can be easily attached and detached. Further, the spring strength can be secured by increasing the width of the spring member to adjust the spring constant of the spring.

The shape of the support preferably has a substantially L-shaped section. Further, it is preferable that the shape of the support has a substantially triangular section. With the shape as described above, the strength can be maintained even if the plate thickness of the support is thinner, so that the weight of the color selection electrode can be further reduced.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows a sectional view of a color cathode ray tube according to an embodiment of the present invention. The color cathode ray tube 1 is built in a glass envelope 2 having a face panel 2a, a glass funnel 3 connected to the rear of the envelope 2 and a neck portion 3a of the funnel 3, and the electron beam A And an electron gun 4 for firing.

A deflection yoke 5 for deflecting the electron beam A emitted from the electron gun 5 is mounted on the outer peripheral surface of the funnel 3 of the color cathode ray tube 1. The face panel 2a is coated with phosphor stripes of three colors on its inner surface, thereby forming a phosphor screen surface 2b.

A shadow mask 6 is arranged near the inner surface (phosphor screen surface 2b) of the face panel 2a substantially parallel to the phosphor screen surface 2b and fixed to a mask frame 7. The shadow mask 6 has a large number of through holes that are regularly arranged, and acts as a color selection electrode for the electron beam A emitted from the electron gun 5.

FIG. 2 shows a perspective view of an assembly (color selection electrode) of the shadow mask 6 and the mask frame 7.
The mask frame 7 is a rectangular frame body formed of a long side frame and a short side frame. A pair of left and right elastic members 9 that are short-side frames are fixed by welding to a pair of upper and lower supports 8 that are long-side frames and have an L-shaped cross section.

The shadow mask 6 is a one-dimensional tension type shadow mask, which is fixed to the upper surface of the support 8 of the mask frame 7 by welding, and is in the vertical direction (arrow Y).
Direction), a surface arranged on the phosphor screen side is stretched and held in a cylindrical shape having a convex shape. Also,
The shadow mask 6 shown in this figure is of a slot type, and although only a part is shown in this figure, a large number of electron beam passage holes 10 which are substantially rectangular slot type holes are arranged.

In the tension mask, since tension is applied in order to suppress thermal expansion and vibration, there is a problem that as the tension decreases, a doming phenomenon and color shift due to vibration are likely to occur. If it is lowered, the rigidity of the mask frame can be correspondingly lowered, and the weight of the mask frame can be reduced.

For example, the thermal expansion of the shadow mask can be suppressed by using a shadow mask made of a material having a low coefficient of thermal expansion, and vibrations can be suppressed to a problem-free level by providing some measure against vibration. be able to. By using such means for reducing thermal expansion and vibration, the stress applied to the shadow mask during stretching is reduced to 5 times the yield stress of the plate material of the shadow mask.
It was found that the value could be set as small as 50%.

Here, the low coefficient of thermal expansion means that the coefficient of thermal expansion is lower than that of an iron material generally used as a material for a shadow mask. As such a material, a material containing nickel and iron is preferable, and for example, Invar iron can be used. Specifically, the thermal expansion coefficient of the iron material is about 12.2 × 10 ⁻⁶ (/ ° C.), 36% Ni-
The thermal expansion coefficient of Fe alloy is about 1.5 × 10 ⁻⁶ (/ ° C.).

Further, as the vibration countermeasure means, for example, a slot type or a dot type can be used for the shadow mask. Since the slot-type or dot-type shadow mask easily absorbs vibration, even if the tension is lowered, the vibration can be suppressed to a level at which there is no problem. Further, the vibration preventing means may be separately provided, and for example, a vibration absorbing member such as a plate member brought into contact with the end face of the shadow mask can be used.
In this case, the vibration of the shadow mask is absorbed by the friction caused by the sliding of the end surface of the shadow mask and the vibration absorbing member. Furthermore, by giving a change to the tension distribution, for example, by weakening the tension in the peripheral portion of the shadow mask with respect to the central portion, making it difficult to vibrate in the center and easily vibrate in the periphery,
The maximum amplitude of the shadow mask can be reduced.
Further, the vibration of the shadow mask can be concentrated on the peripheral portion and the vibration absorbing member as described above can be attached to the end surface of the shadow mask to suppress the vibration on the entire surface of the shadow mask.

In this embodiment, the material of the shadow mask 6 is Invar iron and the slot type shadow mask is used.
Since the material of the shadow mask 6 is Invar iron, the coefficient of thermal expansion of the shadow mask 6 can be made lower than that of the conventional iron mask. Further, in a slot-type shadow mask in which a flat plate is provided with a large number of electron beam passage holes, since adjacent ribbon-shaped metals are connected in the lateral direction of the shadow mask by a large number of bridges, an aperture in which long ribbon-shaped metals are arranged is arranged. Vibration is transmitted laterally as compared to the grill type shadow mask. Therefore, the vibration generated in one part is suppressed by the other part which is not vibrating, and by providing the means for suppressing the vibration only in one part, the vibration of the distant place can also be suppressed as a result. .

As described above, the tension of the shadow mask can be set as low as possible in this embodiment. The effect of suppressing the vibration is the same in the dot shadow mask. Specifically, 29 type (68 cm)
It was confirmed that, in the color cathode ray tube of No. 3, color shadow due to thermal expansion and vibration can be suppressed by distributing a tension of about 200 kgf to the entire surface of the shadow mask 6 having a plate thickness of 100 μm. Further, by setting the plate thickness of the support 8 to 3 mm,
It was able to withstand such tension.

Here, as a comparative example, in the same 29-inch color cathode ray tube, when an aperture grill type shadow mask made of an iron material having a plate thickness of 100 μm is used,
The tension required in consideration of color shift due to thermal expansion and vibration is 700 to 800 kgf. This is the tension of the conventional one-dimensional tension mask itself. In order to withstand this tension, it is necessary to increase the plate thickness of the support 8 to about 5 mm, and the weight increase of the mask frame 7 cannot be avoided.

In this embodiment, since the support 8 is sufficient to have a plate thickness of 3 mm, the weight of the color selection electrode can be set to about 2 kg, and even the tension mask has almost the same weight as the conventional dome-shaped mask. I was able to Therefore, the corner suspension method could be adopted without being limited by the weight of the mask frame.

Next, the corner suspension system according to this embodiment will be specifically described. FIG. 3 shows a state in which the color selection electrode is attached to the envelope 2. This figure shows
It corresponds to the cross-sectional view taken along the line I-I in FIG. 1. The shadow mask 6 is not shown in order to make the support 8 easier to understand.

As shown in this figure, this mounting is performed by a pin fixed to the corner portion of the envelope 2 in the locking hole 12 (FIG. 2) of the spring member 11 fixed to the corner portion of the color selection electrode. It is carried out by inserting 13 in it.
As shown in FIG. 2, the supporting body 8 extends in the longitudinal direction beyond the pair of elastic members 9. By bending the extending portion, bent portions 8a are formed at both ends of the supporting body 8. ing. The spring member 12 is attached to the bent portion 8a.
Are fixed by welding.

As a result, the spring member 12 can be directly fixed to the support 8 without the interposition of a plate-shaped member or the like, which facilitates mounting. In addition, the bent portion 8 is formed by bending the lower portion of the extending portion of the support body 8.
Since a is formed and the upper portion is used as it is as a frame, a flat surface portion is secured over the entire length in the longitudinal direction of the support body 8 at the upper side surface of the support body 8, and in the process of stretching the shadow mask 6, the support body 8 is formed. It is possible to apply a compressive force over the entire length in the longitudinal direction, and after releasing the compressive force, it is possible to obtain a color selection electrode in which the tension balance is maintained and wrinkles and the like do not occur in the shadow mask 6.

FIG. 4 is an enlarged view of the corner support portion of FIG. Inside the support 8, the angle α formed by the horizontal portion of the support 8 and the bent portion 8a is preferably 135 ° or more. The reason will be described with reference to FIG. FIG. 5 is an enlarged view of the upper right corner support portion. In order to make the explanation easy to understand, the illustration of the support 8 and the bent portion 8 is shown.
Only the spring member 12 and the pin 13 are omitted.

FIG. 5A shows a case where the angle α1 formed by the horizontal portion of the support 8 and the bent portion 8a is smaller than 135 °. Now, consider a case where the spring member 12 is translated in the direction of the central axis 14 of the pin 13 due to an impact,
The amount of movement due to impact is indicated by Δa, and the position of the bent portion 8a after movement is indicated by a two-dot chain line. If the amount of horizontal displacement of the support 8 due to such parallel movement is Δx1 and the amount of vertical displacement is Δy1, the relationship of Δx1> Δy1 is satisfied.
As the angle α1 approaches 135 °, Δx1 decreases and Δy1 increases to approach Δx1 = Δy1.

FIG. 5B shows the case where the angle α2 is 135 °. The amount of parallel movement Δa is the same as in the case of FIG. If the amount of horizontal displacement of the support 8 due to such parallel movement is Δx2 and the amount of vertical displacement is Δy2, then Δx2 = Δy2. As the angle α2 becomes larger than 135 °, the displacement amount Δx2 decreases, and Δ
The relationship is x2 <Δy2.

Therefore, by setting the angle between the horizontal portion of the support 8 and the bent portion 8a to be 135 ° or more,
The displacement in the horizontal direction can be reduced as compared with the case where the angle is smaller than 135 °. Further, as the angle becomes larger than 135 °, the displacement in the horizontal direction can be surely made smaller than the displacement in the vertical direction.

Therefore, among the positional deviations of the color selection electrodes,
In particular, since the positional deviation in the horizontal (left and right) direction can be reduced, the color deviation can be prevented. This is because in the case of the color cathode ray tube having the slot type shadow mask as in the present embodiment, the phosphor layers are arranged in stripes in the vertical (up and down) direction, so that the color selection electrodes are positioned in the vertical direction. This is because the color shift does not occur even if the color shifts, and the color shift is caused by the position shift in the horizontal direction.

Further, as shown in FIG. 6, the central axis 14 of the pin 13 with respect to the diagonal line 15 of the face panel 2a is
It is preferable that the face panel 2a is displaced toward the major axis 16 side (FIG. 3).

In a rectangular panel, pin 1
When the central axis 14 of the face panel 2 is aligned with the diagonal line 15 of the face panel 2a, the space on the long side of the face panel 2a becomes narrower with respect to the central axis 14, and the spring member 12
Is limited in size. Therefore, the spring member 12
Has to be narrow in width, which makes it difficult to attach and detach the spring member 12 and to secure the spring strength.

Therefore, by shifting the central axis 14 of the pin 13 from the diagonal 15 of the face panel 2a toward the major axis 16 of the face panel 2a as in the present embodiment, the central axis 14 of the pin 13 can be adjusted. On the other hand, we have widened the space on the long side of the panel. By doing so, the spring member 12 can be easily attached to and detached from the pin 13, and the spring member 12 can be made larger to adjust the spring constant of the spring member 12 and secure the spring strength. .

FIG. 7 shows a perspective view of a color selection electrode according to another embodiment. The structure shown in this figure differs from that shown in FIG. 2 in the structure of the support. That is, the support body shown in the figure is formed of the support body 17 and the comb-tooth-shaped member 18 fixed to the support body 17, and the comb-tooth-shaped member 1
The shadow mask 6 is fixed to the upper surface of the surface 8. The comb-tooth-shaped member 18 has almost the same length as the support body 17,
The plate member is formed with a notched portion having an opening on the lower side to form comb teeth, thereby achieving weight reduction. Further, as shown in FIG. 7, the weight can be further reduced by forming the hollow portion in the comb teeth.

As described above, by using the comb-tooth-shaped member 18 as a part of the support, the weight of the mask frame can be further reduced, and it is advantageous to fix the color selection electrodes by the corner suspension method. In addition to this, the weight of the mask frame can be reduced by providing the support body with the hollow portion to the extent that the strength thereof is not impaired.

In the above embodiment, the shape of the support is
Although the case of the L-shaped cross section has been described, the present invention is not limited to this, and may include a substantially triangular section in which the hypotenuse 20 is formed, like the support 19 shown in FIG. Such a shape has the effect of improving strength. Further, since the strength can be maintained even if the plate thickness of the mask frame is thinner, the weight of the mask frame can be further reduced.

The case where the shadow mask is of the slot type has been described, but the weight reduction means applicable to each of the dot type and the aperture grill type is provided to the extension portion of the support as in the present invention. The corner suspension method can be applied by using the bent portion.

Although the embodiment in which the shadow mask is held in a cylindrical shape has been described, it may be held in a flat shape.

[0051]

As described above, according to the color cathode ray tube of the present invention, since the lightening means is provided, even in the tension type shadow mask, the color in the vicinity of the corner which is particularly susceptible to the beam position deviation is increased. A corner suspension method that effectively corrects the deviation can be adopted. Also, even with the corner suspension system,
It is possible to fully exert the original function of the spring, that is, the elasticity is used for the attachment / detachment and the color misregistration is corrected.

Further, since the spring member can be directly fixed to the support, the attachment can be facilitated and the productivity can be improved. Furthermore, since a flat surface portion can be secured over the entire width on the side surface portion of the support, in the step of stretching the shadow mask,
Since compressive force can be applied to the entire width of the support,
After releasing the compressive force, the tension required for the entire shadow mask can be secured.

[Brief description of drawings]

FIG. 1 is a sectional view of a color cathode ray tube according to an embodiment of the present invention.

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

FIG. 3 is a sectional view taken along line I-I of FIG.

FIG. 4 is an enlarged view of the corner portion of FIG.

5A is a diagram showing a displacement of a corner portion according to a comparative example, and FIG. 5B is a diagram showing a displacement of a corner portion according to an embodiment of the present invention.

FIG. 6 is an enlarged view of a corner portion according to another embodiment of the present invention.

FIG. 7 is a perspective view of a color selection electrode according to another embodiment of the present invention.

FIG. 8 is a sectional view of an embodiment of a support according to the present invention.

[Explanation of symbols]

1 color cathode ray tube 2 envelope 2a Face panel 2b phosphor screen surface 3 funnel 4 electron gun 5 deflection yoke 6 shadow mask 7 mask frame 8 support 9 Elastic member 10 Electron beam passage hole 11 Spring member 12 locking holes 13 pin 14 pin center axis 15 Face panel diagonal 16 Long axis of face panel 17 Support body 18 Comb-shaped member

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-167578 (JP, A) JP-A-6-243793 (JP, A) JP-A-7-73817 (JP, A) JP-A-9- 171779 (JP, A) JP 4-126341 (JP, A) JP 4-41653 (JP, A) JP 5-258677 (JP, A) JP 62-20224 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 29/02 H01J 29/07

Claims (10)

(57) [Claims] 1. A face panel including a color selection electrode in which a shadow mask is held between a pair of opposing supports in a state in which tension is applied, and the supports are held by an elastic member between the supports. A color cathode-ray tube provided in an envelope having: the color selection electrode provided with a weight-reducing means, and the support body is provided with the support body in the longitudinal direction.
Of the extension parts at both ends extended from the elastic member , the chassis
A bent portion is formed by bending a lower portion opposite to the dough mask, a spring member is directly fixed to the bent portion, and the spring member and a pin fixed to a corner portion in the envelope are fixed. A color cathode ray tube, wherein the color selection electrode is fixed to the envelope by being engaged with each other. 2. The lightening means is to reduce the tension of the shadow mask by making the shadow mask a slot type or a dot type to reduce the weight of the color selection electrode. Color cathode ray tube. 3. The color cathode ray tube according to claim 1, wherein the weight-reducing means is to form a comb-shaped portion on the support. 4. The support body is formed of a support body and a comb tooth-shaped member fixed to the support body, and the shadow mask is fixed to an upper surface of the comb tooth-shaped member.
The color cathode ray tube described in. 5. The weight reducing means reduces the weight of the color selection electrode by reducing the tension of the shadow mask by using a material of the shadow mask as a material having a small thermal expansion coefficient. The color cathode ray tube described in. 6. The color cathode ray tube according to claim 1, wherein the shadow mask material contains nickel and iron. 7. The color cathode ray tube according to claim 1, wherein an angle formed by the horizontal portion of the support and the bent portion is 135 ° or more inside the support. 8. The front shape of the face panel is substantially rectangular, and the center axis of the pin is displaced toward the major axis of the face panel with respect to the diagonal line of the face panel. The color cathode ray tube according to any one of the above. 9. The color cathode ray tube according to claim 1, wherein the support has a substantially L-shaped section in cross section. 10. The color cathode ray tube according to claim 1, wherein the support has a substantially triangular cross section.