KR20010098434A - Spring for cathode ray tube - Google Patents

Abstract

The present invention relates to a spring for a color cathode ray tube, and to provide a spring structure that can compensate for displacement due to thermal expansion of a shadow mask frame due to thermal expansion, thereby reducing degradation of color purity due to mislanding of an electron beam. .

Spring of the present invention for realizing this, the elastic support coupled to form a predetermined angle inclined between the stud pin coupling portion 100, the frame welding portion 101, the stud pin coupling portion 100 and the frame welding portion 101 The chain inclined portion 102 is characterized in that a plurality of metal members A and B having different coefficients of thermal expansion separated in their longitudinal direction perpendicular to the tube axis are joined.

Description

Spring for cathode ray tube {SPRING FOR CATHODE RAY TUBE}

The present invention relates to a spring for supporting a mask frame in a color cathode ray tube, and a spring structure for compensating displacement due to thermal expansion of a shadow mask frame causing mis-landing of an electron beam.

With the recent development of cathode ray tube technology, the color cathode ray tube is gradually becoming larger in size, and the weight of the shadow mask support frame is increasing. However, the weight increase of the shadow mask support frame increases the impact resistance during the drop, which causes excessive impact on the spring and the shadow mask connecting the stud pins of the panel and the shadow mask support frame, thereby dropping the shadow mask support frame and dropping the shadow mask. It acts as a cause of deformation, etc., and also causes a change in the landing of the electron beam due to thermal expansion of the shadow mask, thereby acting as a cause of deterioration of color purity.

Therefore, there should be presented a method that can effectively cushion the impact during the drop test and thermal expansion to reduce the impact resistance and color purity deterioration.

1 is a partial cutaway cross-sectional view schematically showing a general color cathode ray tube.

As shown, the panel (1) formed on the front surface of the cathode ray tube and coated with red, green, blue (R, G, B) light emitting phosphors (2), the rear end of the panel (1) Fused funnel (4), shadow mask (6) in which dot or slot-shaped beam penetration holes are formed for color discrimination, and support frame for supporting the shadow mask (6) to maintain a predetermined distance from the panel (1) (8), connecting the geomagnetic field shield (10) coupled to the support frame (8), the support frame (8) to the stud pin (14) formed in the side wall portion (1a) of the panel (1) Spring 12, the electron gun 18, which is sealed in the neck portion of the funnel (4) to emit the electron beam 16 to the light emitting phosphor 2, so that the electron beam 16 is scanned to the light emitting phosphor 2 A deflection yoke 20 for adjusting the traveling trajectory, and a reinforcing band 22 for preventing the deflation from external impact.

As shown in FIGS. 4A to 4C, the spring 12 includes a stud pin coupling portion 12a having a hole h formed therein for fixing to the stud pin 14 of the side wall portion 1a of the panel 1, Inclined and coupled to the frame welding portion 12b, the stud pin coupling portion 12a and the frame welding portion 12b for welding to the support frame 12, the stud pin coupling portion 12a and the frame welding portion 12b ) And an inclined portion 12c having bent surfaces 12d and 12e inclined at a predetermined angle [theta].

In the cathode ray tube configured as described above, the red, green, and blue electron beams emitted from the electron gun 8 enclosed in the neck of the funnel 4 are beam-transmitted by the shadow mask 6 after their trajectory is adjusted in the deflection yoke 20. The red, green, and blue light emitting phosphors applied to the inner surface of the panel 1 by passing through the balls are sequentially blown horizontally and vertically to reproduce the image.

At this time, only about 30% of the electron beams 16 radiated from the electron gun 18 pass through the beam penetrating holes of the shadow mask 6, and the remaining 70% of the electron beams 16 are free of holes other than the beam penetrating holes of the shadow mask 6. Will be hit.

In this way, a part of the electron beam 16 hit by the shadow mask 6 is reflected, and a part of the electron beam 16 is converted into impact energy and absorbed by the shadow mask 6, and the molecular motion inside the shadow mask 6 is activated to intermolecularly. Friction is induced to generate heat due to friction.

As a result, the temperature of the shadow mask 6 rises, and the volume expands according to the thermal expansion rate of the shadow mask material. In this case, the expansion speed and the expansion amount are different depending on the type of the metal material constituting the shadow mask.

In general, the shadow mask 6 is welded on all sides by the support frame (8). Therefore, when the shadow mask 6 is expanded as described above, the shadow mask 6 swells in the direction of the light emitting phosphor 2 with respect to the tube axis direction as shown in FIG.

In FIG. 2, reference numeral 6 denotes a position where the shadow mask is fixed before thermal expansion, and 6a denotes a position where the shadow mask after thermal expansion is moved.

In this state, the heat generated in the shadow mask 6 is conducted to the support frame 8 to increase the temperature of the support frame 6, so that the temperature-supported support frame 6 is thermally expanded. As a result, the support frame 6 extends toward the side wall portion 1a of the panel 1, and the swollen shadow mask 6 moves in the opposite direction of the light emitting phosphor 2 with respect to the tube axis direction.

However, when the support frame 6 is larger in volume than the shadow mask 6, the shadow mask 6 is excessively moved in the opposite direction of the light emitting phosphor 2 with respect to the tube axis direction, thereby causing mislanding. . The landing change amount at this time becomes ΔLE as shown in FIG. 3.

In order to reduce the landing change amount ΔLE, a material having a small thermal expansion may be used as the material of the support frame 8. However, since this acts as a factor of increasing the cost of the product, the structure of the spring 12 may be variously varied in the art. By changing, methods for correcting the position of the shadow mask to reduce the amount of landing change ΔLE have been devised.

3 is an enlarged view of a portion A of FIG. 1, in which a hole formed at one end of the spring 12 is inserted into the stud pin 14 formed at the center of the side wall portion 1a of the panel 1. The other end of the spring 12 is welded to the rectangular support frame 8, and is formed around the perforation of the shadow mask 6 (not shown: an area in which a dot or slot shaped beam penetration hole is formed). A skirt (not shown) with the ends folded along is welded to the inner wall of the support frame 8 to be fixed.

In FIG. 3, reference numeral 16a denotes an electron beam shifted by a predetermined interval in the trajectory of the electron beam 16 before thermal expansion, and 8a denotes a support frame shifted by a predetermined interval at the position of the support frame 8 before thermal expansion.

On the other hand, the spring 12 having an oblique bending is deformed in conjunction with the thermal expansion of the support frame 8, the stepped stud pin coupling portion 12a and the frame welding portion 12b occurs.

4A shows the stud pin coupling portion 12a, the frame welding portion 12b and the inclined portion 12c parallel to the longitudinal direction of the spring, that is, the stud pin coupling portion 12a in the width direction of the spring 12; The spring 12 which has the inclination bending when the level | step difference of the frame welding part 12b and the inclination part 12c is zero is shown. Reference numerals 12d and 12e denote bends to be bent according to the deformation, 12f denotes holes coupled to the stud pins, and 12g denotes weld points fixed to the support frame 8 by welding.

4B shows that the frame welded portion 12a and the inclined portion 12c are bent at a right angle (θ = 90 °) along the bent portion 12d, and the inclined portion 12c and the stud pin coupling portion 12a are also bent portions ( The spring 12 in a state of bending at a right angle (θ = 90 °) in a direction opposite to the above with respect to 12e) makes a maximum step.

FIG. 4C shows the spring 12 having the inclined bend when the step corresponding to the intermediate degree of FIGS. 4A and 4B is generated.

As described above, in a spring having an inclination angle in which a step occurs due to thermal expansion, the displacement amount ΔY of the frame welded portion 12a with respect to the center of the hole 12f of the stud pin coupling portion 12a is represented by the following equation (1). .

[Equation 1]

Here, L represents the length of the inclined portion, and θ represents the inclination angle of the inclined portion.

ΔY ′ in FIG. 4C represents the displacement amount of the frame welded portion 12a with respect to the center of the hole 12f of the stud pin coupling portion 12b when a step occurs in the middle.

5 is a view showing the landing change of the electron beam with respect to the displacement of the conventional shadow mask. Here, B1 denotes the initial position of the initial shadow mask, B2 denotes the position of the shadow mask after thermal expansion, B3 denotes the position after the spring correcting action, and reference numerals 16a, 16b, and 16c denote electron beams, respectively. Reference numerals LP1, LP2 and LP3 denote landing points of the electron beams, and reference numerals S1, S2 and S3 denote the passing positions of the electron beams passing through the beam penetration holes of the shadow mask, respectively.

Before the shadow mask 6 thermally expands, the shadow mask 6 is placed at the position of B1, and the electron beam 16a passes through the position of S1 to strike the light emitting phosphor 2, which is the electron beam 16a at this time. Landing point of is LP1.

In this state, when the shadow mask 6 and the support frame 8 are thermally expanded, the shadow mask 6 is moved to the position of B2 by moving in the opposite direction of the light emitting phosphor 2 with respect to the tube axis, and the electron beam ( 16b) strikes the light emitting phosphor 2 through the position of S2, and the landing point of the electron beam 16b is LP2 at this time.

In this state, when the position of the support frame 8 of the shadow mask is corrected by the elastic action of the spring 12, the shadow mask 6 is moved toward the light emitting phosphor 2 and placed in the position of B3. Therefore, the electron beam 16c passes through the position of S3 to strike the light emitting phosphor 2, and the landing point of the electron beam 16b becomes LP3.

Accordingly, the position of the shadow mask is corrected by the position correction amount [Delta] C so that mislanding as much as the difference of the landing points LP1-LP2 is corrected by the difference of the landing points LP3-LP2.

Since the position correction amount ΔC is determined depending on the bending angle and the number of bending of the spring 12, the thermal expansion amount of the support frame 8, the material of the shadow mask 6, and the like, the value is not constant.

Therefore, in the related art, it is possible to obtain an appropriate size of the spring in consideration of all the above parameters. However, due to the strength of the spring 12 and the workability of the process, it is difficult to apply the optimal size. Therefore, the thermal expansion of the shadow mask frame is difficult. It is not effective to reduce the mislanding of the electron beam.

Therefore, in the prior art as described above, a predetermined bent slope is provided at the connection portion of the spring so that the spring has a structure capable of absorbing a part of the impact amount due to the weight increase of the shadow mask, thereby reducing the external impact. Although it may be large, there is a problem in that color purity deterioration due to the change in landing of the electron beam due to thermal expansion of the shadow mask frame cannot be effectively corrected.

An object of the present invention is to solve the problems of the prior art, to provide a spring structure that can compensate for the displacement of the shadow mask frame due to thermal expansion to reduce the deterioration of color purity due to mis-landing of the electron beam It is.

1 is a partial cutaway cross-sectional view showing a typical color cathode ray tube.

2 is a view showing a thermal expansion state of the shadow mask according to the conventional thermal expansion.

3 is an enlarged view of a portion of FIG. 2;

4A is a plan view showing a state before deformation of a spring having a conventional inclination bending due to thermal expansion;

Figure 4b is a plan view showing a state at the time of maximum deformation of the spring having a conventional inclined bending due to thermal expansion.

Figure 4c is a perspective view showing a state of some deformation of the spring having a conventional inclined bending due to thermal expansion.

5 is a view showing the landing change of the electron beam with respect to the displacement of the conventional shadow mask.

6 is a view showing the structure of a spring according to the first embodiment of the present invention.

7 is a view for explaining the deformation of the spring according to the first embodiment of the present invention.

8 is a view showing the landing change of the electron beam with respect to the displacement of the shadow mask according to an embodiment of the present invention.

9 is a view for explaining the operation of the spring according to the second embodiment of the present invention.

10 is a plan view showing the structure of a spring according to a third embodiment of the present invention.

11 is a plan view showing the structure of a spring according to a fourth embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

1 panel 2 light emitting phosphor

4: funnel 6: shadow mask

8: frame 10: inner shield

12: spring 12a: stud pin coupling

12b: frame welded portion 12c: inclined portion

14: stud pin 16: electron beam

18: electron gun

The spring for the color cathode ray tube of the present invention for achieving the above object is characterized in that a plurality of metal members having different coefficients of thermal expansion in their width direction perpendicular to the tube axis are formed in combination.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, Figure 6 is a view showing the structure of the spring according to the first embodiment of the present invention, reference numeral 101a denotes a welding point welded to the support frame (8).

The spring of the present invention is divided into a stud pin coupling portion 100, an inclined portion 102, which is an elastic support, and a frame welding portion 101, and bent portions 104 and 106 at each boundary portion. In particular, a pair of metal members A and B having different thermal expansion coefficients are joined to each other in the width direction to form a boundary line 108 therebetween.

The stud pin coupling portion 100 of the first metal member A of the pair of metal members is provided with a hole 100a for insertion fixing to the stud pin 14.

The coupled first metal member A forms a low thermal expansion portion having a small thermal expansion coefficient, and the second metal member B can achieve a high thermal expansion portion having a relatively large thermal expansion coefficient.

At this time, the low thermal expansion portion of the first metal member A has a thermal expansion coefficient of about 2 to 4 X 10e ^-6 , and the high thermal expansion portion of the second metal member B has a thermal expansion coefficient of about 10 to 18 X 10e ^-6 . It is preferable to have a ratio, and the ratio of the thermal expansion coefficient of the high thermal expansion portion and the low thermal expansion portion is preferably about 2.5 to 9 times. Here, if the coefficient of thermal expansion is less than 2.5, there is a problem of improvement of characteristics due to the insufficient amount of dominant compensation movement with respect to the outside temperature. If the coefficient of thermal expansion is greater than 9, problems of characteristics during normal last doming due to excessive compensation occur.

In addition, the thickness of the first and second metal members (A, B) is about 0.3 ~ 0.6mm, if the thickness is too thin, there is a problem in machinability, if the thickness is too thick, the bond strength and degassing as the bonding strength increases Will cause problems.

More specifically, the first metal member A used 0.5 t of Invar, which is a low thermal expansion material, and the second metal member B, Sus603 0.5t, which is an aluminum-kilted steel (AK) that is aluminum removed. The thermal expansion coefficient of Sus603, which is high thermal expansion, is 11.5 ± 5 X 10 ^e-6, and Invar, which is low expansion material, is 2.5 ± 5 X 10 ^e-6 , and the coefficient of thermal expansion is about 4.6. Such a design is generally easily available and was selected in consideration of a material suitable for strength and formability.

In addition, it is designed to prevent excessive compensation in consideration of external temperature change and to minimize back compensation due to thermal deformation in normal doming.

In addition, the area ratio of the material was constructed by welding the same area, and the area ratio of the material was designed to be 1: 1 in consideration of the ease of work and the bonding strength, which is an important factor in determining the displacement force.

Referring to the effect of the spring configured as described above are as follows.

In the spring according to the first embodiment of the present invention, when the support frame 8 of the shadow mask is heated and thermally expanded by the impact of the electron beam, as shown in FIG. 6, the first metal member A is formed in both longitudinal directions of the spring. Increases by L1. Then, the second metal member B having a larger coefficient of thermal expansion than the first metal member A is extended by L2 in the longitudinal direction of the spring. Accordingly, it can be seen that there is a difference in length between the two metal members by 2 × (L2-L1).

Due to this difference in length, as shown by the dotted line in FIG. 7, the spring is bent toward the first metal member A having a small coefficient of thermal expansion. At this time, since the hole 100a of the stud pin coupling part 100 is fixed by the stud pin, a larger displacement occurs in the frame welding part 101 side. The displacement amount becomes ΔC1 in the width direction of the spring.

FIG. 8 is a view showing a landing change of an electron beam with respect to a displacement of a shadow mask according to the present invention, and the same reference numerals are used for the same parts as in FIG. 5. Here, reference numeral B1 denotes the initial position of the shadow mask, B2 denotes the position of the shadow mask after thermal expansion, B4 denotes the position of the shadow mask after the spring correcting action, and reference numerals 16a, 16b, and 16c denote electron beams, respectively. , LP1, LP2 and LP4 denote landing points of the electron beams, and reference numerals S1, S2 and S4 denote the passing positions of the electron beams passing through the beam penetrating holes of the shadow mask, respectively.

As described above, when the frame engaging portion 101 is bent due to the difference in the coefficient of thermal expansion of the spring, as shown in Fig. 8, the predetermined value due to the difference in the coefficient of thermal expansion to the position compensation amount? The position compensation amount is added so that the total compensation amount is nΔC. In this case, the landing point of the electron beam is moved from LP2 to LP4, and as a result, it is understood that mis landing as much as (LP2-LP4) is compensated, thereby optimizing the landing state of the electron beam.

Meanwhile, a spring according to the second embodiment of the present invention will be described below.

If the support frame of the shadow mask is heated and thermally expanded by the impact of the electron beam, if the position compensation of the shadow mask is excessive by the spring, the shadow mask is beyond the optimal position B1 shown in FIG. Will be moved to. In this case, since the landing point of the electron beam is shifted in the right direction of LP1, the position of the shadow mask should be compensated in the opposite direction of the light emitting phosphor with respect to the tube axis.

In order to solve this problem, according to the second embodiment of the present invention, the first metal member A of the spring shown in FIG. 6 is provided with aluminum-kilted steel AK, which is steel from which aluminum is removed, thereby providing a high thermal expansion portion having a large thermal expansion coefficient. The second metal member B was formed of Invar, which is an alloy of steel and nickel, to form a low thermal expansion portion having a relatively small thermal expansion coefficient.

In the spring configured as described above, as shown in Fig. 9, due to the difference in thermal expansion coefficient between the metal members, the high expansion portion is bent toward the low expansion portion, which is the opposite direction of the light emitting phosphor with respect to the tube axis, and the displacement amount at this time is the width direction of the spring. Is -ΔC1.

Thus, the landing point shifted in the LP1 direction is compensated in the LP2 direction.

As described above, in the spring having the inclination angle θ and the bent portions 104 and 106, it is understood that the amount of shadow mask displacement with respect to the tube axis can be adjusted by using two metal members having different thermal expansion coefficients. have.

FIG. 10 is a plan view showing the structure of a spring according to a third embodiment of the present invention, showing that three metal members A ', B', and C 'having different thermal expansion coefficients are joined in the lengthwise direction of the spring.

11 is a plan view showing the structure of a spring according to a fourth embodiment of the present invention. As shown in FIG. 11, two metal members A ″ and B ″ having different thermal expansion coefficients are joined in a length direction of the spring, The metal member B ″ is relatively shorter. In this case, the displacement of the spring can be adjusted in the width direction according to the area of the lower metal member B ″.

As described above, it is understood that the spring of the present invention can change the elastic force of the spring by the difference in the thermal expansion coefficient of the joined metal member by joining at least two or more metal members having different thermal expansion coefficients in the width direction in the longitudinal direction. Can be.

Accordingly, the positional shift of the support frame of the shadow mask due to thermal expansion can be corrected, and the deterioration of color purity due to maintaining the optimum electron beam landing state can be prevented.

In addition, there is another effect that can improve the impact resistance properties to prevent deformation of the shadow mask due to external impacts, such as drop impacts.

Claims (8)

A panel having a light emitting phosphor formed on an inner surface thereof, a shadow mask installed at a predetermined interval on the light emitting phosphor of the panel, one end of the spring is coupled to a stud pin disposed inside the panel skirt, and the other end of the spring supports the shadow mask. In the cathode ray tube comprising a spring for installing the shadow mask coupled to the panel in, The spring includes a stud pin coupling part 100 including one end coupled to the stud pin, a frame welding part 101 including the other end coupled to the frame, the stud pin coupling part 100 and the frame welding part 101. Consists of the inclined portion 102 to form a predetermined angle of inclination between, The spring is a color cathode ray tube, characterized in that formed by joining a plurality of metal members having different coefficients of thermal expansion separated in the width direction perpendicular to the tube axis. The method of claim 1, The metal member is provided with a member having a lower coefficient of thermal expansion toward the panel side direction. The method of claim 1, The metal member is provided with a member having a high coefficient of thermal expansion toward the panel side direction. The method of claim 1, The plurality of metal members may include a first metal member made of a material having a thermal expansion coefficient of 2 to 4 X 10e ^-6 and a second metal member having a thermal expansion coefficient of 10 to 18 X 10e ^-6 . Cathode ray tube. The method of claim 4, wherein The color cathode ray tube, characterized in that the ratio of the thermal expansion coefficient (T1) of the first metal member and the thermal expansion coefficient (T2) of the second metal member is 2.5 <T2 / T1 <9. The method of claim 1, A color cathode ray tube, wherein the metal member has a thickness of 0.3 to 0.7 mm. The method of claim 1, The first metal member has a coefficient of thermal expansion of 2.5 ± 5 X 10e ^-6 , the second metal member has a thermal expansion coefficient of 11.5 ± 5 X 10e ^-6 . The method of claim 1, The plurality of metal members, the color cathode ray tube, characterized in that different lengths.