KR20040017093A - Tension mask -frame asseambly for color cathode ray tube - Google Patents

Abstract

PURPOSE: A tension mask frame assembly is provided to reduce vibrations of tension mask by winding a wire or mounting a reinforcement member on the support body interconnecting first and second support members. CONSTITUTION: A tension mask frame assembly(100) comprises a frame(120) including a first support member(121) and a second support member(122) spaced apart from each other and a first strength member(123) and a second strength member(124) interposed between the first and second support members so as to support the first and second members; a tension mask(110) mounted to apply tension forces to the first and second support members, wherein the mask has a plurality of electron beam passing holes; a support body(130) having both ends fixed to the ends of the first and second support members in such a manner that the support body prevents a deformation of the tension mask caused due to the difference of thermal expansion between the support body and the first and second strength members and the first and second support members; and a vibration damping member(200) which is wound on the support body or fixes the support body so as to damp vibrations of the support body.

Description

Tension mask -frame asseambly for color cathode ray tube}

The present invention relates to a color cathode ray tube, and more particularly, to a tension mask frame assembly for a color cathode ray tube having an improved structure to attenuate vibration of a tension mask supported on a frame.

A typical color cathode ray tube excites these electron beams from the electron gun by landing on the red, green, and blue phosphors of the fluorescent film formed on the screen surface of the panel through the electron beam passing holes of a mask having a color screening function. To form an image.

In the color cathode ray tube for forming an image as described above, a mask having a color selection function is roughly divided into a dot mask employed in a computer monitor and a slot mask (also called a slit mask) used in a television or the like.

Tension masks, one of the slot masks, are supported to be applied with a tensile force by a frame in consideration of a flat screen surface in order to compensate for image distortion and widen a viewing angle of a screen.

On the other hand, Fig. 1 shows an example of a frame and a mask frame assembly in which a mask is supported so that tensile force is applied by the frame.

Referring to the drawings, the tension mask frame assembly 20 includes a tension mask 22 having a plurality of long slots 21 formed therein, and support members 23 and 23 supporting corresponding edges of the tension mask 22. And rigid members 24 and 24 supporting end portions of the support members 23 and 23, respectively, to apply tension to the tension mask.

The tension mask frame assembly 20 constructed as described above is heated by an electron beam that does not pass through the slot 21, which is an electron beam passing hole, so that the spring supporter 25 made of bimetal is deformed to panel the tension mask frame assembly 20. By moving to the (13) side, the mis-landing of the electron beam due to its thermal expansion is corrected.

The tension mask frame assembly is a blackening and annealing process to remove the stress caused by the welding of the support member, the bars and the tension support member during the manufacturing process, and to blacken the frame composed of the mask, the support bar and the tension support member. It goes through the annealing process. In this process, the mask frame assembly is heated to around 500 ° C. In this process, the mask is plastically deformed or clipped due to the difference between the thermal expansion amount of the frame and the thermal expansion amount of the mask, thereby reducing the tensile force (20% of the tensile force before the annealing process). Decrease). That is, when the mask frame assembly is heated, the thermal capacity of the mask is smaller than the thermal capacity of the frame, and a difference in thermal expansion is generated. The difference in thermal expansion acts as an additional tension on the mask supported by the support bar, thereby masking the blackening and annealing process. Tension is reduced. Such a decrease in the tension of the mask causes a howling phenomenon in use when mounted on the color cathode ray tube, or a drift phenomenon of the electron beam occurs due to thermal deformation of the mask.

In order to solve this problem, a mask frame assembly is disclosed in US Pat. No. 5,111,107 which prevents the amount of expansion of the frame from acting in the direction of the tensile force of the mask. The disclosed mask frame assembly includes a support bar installed to correspond to each other, an elastic support member mounted between the support bars to support the support bar, a mask supported on the support bars, and a surface opposite to the surface corresponding to the mask. It includes a metal member mounted to the elastic support member of the surface and having a coefficient of thermal expansion larger than the elastic support member.

Such a mask frame assembly has a problem that the tensile force is lowered in the mask despite the attachment of the metal member, and the effect also varies depending on the tension distribution.

On the other hand, a color cathode ray tube having a configuration of a mask frame assembly for reducing the tension reduction of the mask during the blackening and annealing process is disclosed in Japanese Laid-Open Patent Publication No. Hei 11-317176.

The disclosed color cathode ray tube is a color cathode ray tube having a pair of supports opposed to each other, and a color-selective electrode in which a grid is suspended in a frame of a pair of elastic support members provided between the supports, wherein the coefficient of thermal expansion of the elastic support is provided. Compared with the grid, the adjustment member having a low thermal expansion coefficient in the low temperature region and a high thermal expansion coefficient in the high temperature region is fixed to a surface on the side opposite to the grid of the elastic support member or has the above-described opposite characteristics. It is fixed to the ball bearing support member on the corresponding side.

Since the color sorting apparatus of the color cathode ray tube constructed as described above is attached to the elastic support member with an adjustment member using a difference in thermal expansion coefficient, the problem as described above cannot be solved fundamentally.

In order to solve the above problems, the present applicant has filed a tension mask frame assembly in the Republic of Korea Patent Application No. 2001-1878.

The tension mask frame assembly includes a pair of first and second support members 31 and 31 spaced apart from each other by a predetermined distance as shown in the figure; First and second rigid members 32 and 32 provided between the first and second support members 31 and 31 to support the first and second support members 31 and 31 and the frame 30. And a tension mask 40 mounted to apply tension to the first and second support members 31 and 31 and having a plurality of electron beam through holes formed therein; It is installed at the end of the first and second support members 31 and 31, and has a structure including a support 50 made of a material having a coefficient of thermal expansion smaller than that of the first and second rigid members 32 and 32. .

However, in the tension mask frame assembly as described above, since the ends of the support 50 are fixed to the first and second support members 31 and 31, the center portion of the support 30 is minutely applied from the outside. It easily vibrates by shock or sound pressure. In particular, since the frame 30 and the tension mask 40 are thermally expanded when the cathode ray tube is driven, the support member 50 is substantially subjected to a tensile force, thereby easily vibrating.

The vibration affects the vibration of the tension mask 40 supported by the first and second support members 31 and 31. In particular, since the tension mask 40 is fixed only to the first and second support members 31 and 31 at its long edges, the short side of the tension mask 40 is in the longitudinal direction (X direction). Since it is free in the upright direction with respect to one side of the tension mask, that is, in the direction perpendicular to the Y direction, that is, it vibrates easily even with a small impact as described above.

On the other hand, a conventional tension mask frame assembly that damps vibration by using a damper action is disclosed in Japanese Patent Laid-Open No. 12-77007, Korean Patent Application No. 2000-6542, Korean Patent Application No. 2000-39985, and the like.

The present invention is to solve the above problems, it is possible to reduce the vibration of the tension mask due to the vibration of the support member to the support members, and further to prevent the mis landing of the electron beam to the fluorescent film to improve the image blur prevention and resolution It is an object of the present invention to provide a tension mask frame assembly of a color cathode ray tube.

1 is a perspective view of a conventional tension mask frame assembly,

Figure 2 is a perspective view showing another example of a conventional tension mask frame assembly,

3 is a partial ablation perspective view of a cathode ray tube equipped with a tension mask frame assembly according to the present invention;

4 is an exploded perspective view of the tension mask frame assembly according to the present invention;

5 is a partially cutaway perspective view showing another example of a tension mask frame assembly according to the present invention;

6 is a partially cutaway perspective view showing another embodiment of a tension mask frame assembly according to the present invention;

7 is a perspective view showing another embodiment of the tension mask frame assembly according to the present invention;

8 is a side view showing another embodiment of a tension mask frame assembly according to the present invention;

9A to 9C and 11A to 11C are graphs showing vibration states of a tension mask in a conventional tension mask frame assembly.

10a to 10c and 12a to 12c is a graph showing a vibration state of the tension mask in the conventional tension mask frame assembly.

In order to achieve the above object, the mask frame assembly of the present invention,

A frame including a pair of first and second support members spaced apart from each other by a predetermined distance, and first and second rigid members installed between the first and second support members to support the first and second support members;

A mask mounted to apply tension to the support members and having a plurality of electron beam through holes formed therein;

An end portion mounted to the first and second supports to prevent creep deformation of the tension mask due to a difference in thermal expansion between the support, the first and second rigid members, and the first and second support members;

It characterized in that it comprises a vibration damping means for attenuating vibration by winding or fixing it to the support.

In the present invention, the vibration damping means is made of a wire wound at a predetermined pitch on the support.

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

Figure 3 shows an embodiment of a color cathode ray tube according to the present invention.

As shown in the drawing, the cathode ray tube includes a panel 52 having a flat screen 51 on which a fluorescent film 51a is formed, a funnel 53 sealed to the panel 52 and having a neck portion 53a, and A deflection yoke 54 mounted to the funnel 53 and an electron gun 55 enclosed in the neck portion 53a are included. In addition, a tension mask frame assembly 100 having a color selection function of an electron beam emitted from the electron gun 55 is installed on an inner surface of the panel 52.

As shown in FIG. 4, the tension mask frame assembly 100 corresponds to a tension mask 110 having a plurality of slots long in the Y direction (tension direction) and an X direction corresponding to a length direction of the tension mask 110. It includes a frame 120 for supporting the long sides to be applied to the tension mask tension.

The tension mask 110 includes a plurality of strips 112 forming a slit 111 spaced apart from each other by a predetermined distance on a thin plate, and a real partitioning the slits 111 by interconnecting the adjacent strips 112. A bridge 113. The adjacent strips 112 may further include dummy bridges 114 extending in opposite directions to partition the slits 111. . The tension mask is not limited to the above-described embodiment and can be any structure as long as it is a structure of a tension mask to which tensile force is applied.

The frame 120 supports both corresponding edges of the tension mask, and includes a pair of first and second support members 121 and 122 spaced apart from each other by a predetermined distance, and the first and second support members 121. Rigid members 123 and 124 supporting the first and second support members 121 and 122 so that tension is applied to the tension mask 110 supported by the 122.

The first and second support members 121 and 122 may include fixing parts 121a and 122a supporting the tension mask and flange parts 121b and 122b extending inwardly from the fixing parts 121a and 122a. It includes.

The first and second rigid members 123 and 124 supporting the first and second support members 121 and 122 are fixed to the first and second support members 121 and 122, respectively. 123b, 124a, and 124b, and connecting portions 123c and 124c for connecting the supports.

The structures of the first and second support members 121 and 122 and the first and second rigid members 123 and 124 are not limited to the above-described embodiments and may be applied to the tension mask 110. Anything is possible.

A support body having both ends coupled to end portions of the rigid members coupled to the flange portions 121b and 122b of the first and second support members 121 and 122 and the first and second support members 121 and 122 ( 130). The shape of the support 130 is not limited to the above-described embodiment, and the tension mask is caused by the difference in the thermal expansion amount between the first and second support members 121 and 122 and the rigid members 123 and 124 during the thermal process. Any structure can be used as long as it can prevent the creep of the tension mask due to the change in the tensile force applied to the tension mask. The support may be formed of a plate bar (flat bar) or an angle bar (angle bar) as shown in FIG. 5, but is not limited thereto. The cross section may be formed of a circular, L-shaped, or polygonal bar.

In addition, the support 130 is provided with vibration sensing means 200 for attenuating the vibration of the support 130. The vibration damping means 200 is formed by winding the wire 201 at a predetermined pitch on the support 130 as shown in FIGS. 4 and 5. The wire 201 wound on the support 130 is preferably installed to be relatively movable without being in close contact with the support 130. The wire 201 wound on the support 130 may be discontinuously wound as shown in FIG. 6, in which case each end of the wire wound about the support is fixed to the support 130 so that the wire is not moved relatively. Preferably. And it is preferable that the wire is wound at least three times on the support. In addition, the material of the wire is preferable to allow the melting point (melting point) 460 degrees or more in consideration of the thermal process.

On the other hand, as shown in Figure 7 the vibration damping means is at least connecting the rigid member 123, 124 and the support 130 to improve the damping effect of the vibration applied to the support 130 from the outside It may be made of one reinforcing member (210). The reinforcing member 210 is made of a plate bar, but is not limited thereto. When two reinforcing members 210 are installed, it is preferable to install the reinforcing members 210 so as to be symmetrical on both sides with respect to the center portion.

The coefficient of thermal expansion of the reinforcing member 210 is smaller because the support 130 must be fixed during operation of the cathode ray tube. On the other hand, when the coefficient of thermal expansion is large, the performance of the support body 130 is reduced. Therefore, the thermal expansion coefficient of the reinforcing member 210 is called the thermal expansion coefficient of the reinforcing member in consideration of the thermal compensation characteristics of the support body 130 during the thermal process Te, the temperature change of the reinforcing member 210 when driving the cathode ray tube △ It is preferable to set so as to satisfy the inequality Te ≤ 0.01 / ΔT when T. The inequality is that when the length of the reinforcing member 210 is referred to as L limit the increase in length due to temperature changes within 1%. The support 130, which is deformed beyond this, may be bent in a vertical direction to limit the performance of the support 130.

Referring to the operation of the tension mask frame assembly for a color cathode ray tube according to the present invention configured as described above are as follows.

In the above-described mask frame assembly 100, the tension mask 110 is mounted on the first and second support members 121 and 122 of the frame 120 to apply a tensile force, and the elastic support members 123 and 124. Since the support 130 is made of a material having a coefficient of thermal expansion smaller than) is mounted to prevent the rigid member from being opened by the amount of thermal expansion of the rigid members 123 and 124 during the thermal process. When the cathode ray tube is driven while the completed tension mask frame assembly is mounted on the cathode ray tube, the tension mask frame assembly is thermally expanded, so that a tensile force is applied to the support 130.

In this way, the support 130 and the tension mask are vibrated by a small impact or a sound pressure of the speaker applied from the outside to which the tensile force is applied, and the wire 201 which is the vibration damping means 200 is wound around the support 130. Therefore, the vibration of the support 130 can be reduced within a short time. That is, the vibration of the support 130 generates a relative movement of the wire, thereby reducing the vibration of the support 130 due to the friction generated at this time. That is, when the support 130 vibrates, the wire 201 also vibrates, and at this time, the elastic energy is rapidly dissipated by the vibration interference of the support 130 and the wire 201, thereby reducing the vibration. In particular, when the support 130 and the rigid member 123, 124 is connected by a reinforcing member it is possible to reduce the vibration of the support by the reinforcing member.

The action as described above will become more apparent through the following experiment of the inventors.

Experiment 1

In this experiment, as described above, the tension mask frame assembly in which the wire 201 is not wound on the support 130 and the tension mask frame assembly according to the present invention, in which the wire is wound on the support, are respectively subjected to vibration to ½ of the tension mask. Vibrations at points, 1/3 and 2/3 were measured to obtain FIGS. 7A-7C and 8A-8C.

Referring to FIGS. 7A and 7C, it can be seen that the tension mask frame assembly in which the wire is not wound around the support has more than 10 seconds of the decay time of the vibration at 1/2 of the tension mask and has an amplitude at 2/3 of the tension mask. It was found that the time to reach this 4 μm takes 5 seconds or more.

However, it can be seen that the tension mask frame assembly in which the wire is wound around the support decreases in amplitude within 4 µm within 5 seconds of the attenuation time of vibration at the half point of the tension mask, and the amplitude at 2/3 of the tension mask. It was found that the time to reach this 4 μm takes within 4 seconds.

In the experiment as described above, it can be seen that in the case of the tension mask frame assembly in which the wire is wound on the support, the vibration attenuation time of which the amplitude is reduced to within 4 μm can obtain an improvement effect of 29 to 70% for each position of the tension mask.

Experiment 2

In this experiment, as described above, the vibration is attenuated after applying the vibration to the tension mask frame assembly having no reinforcing member connecting the support and the rigid member and the tension mask frame assembly having the reinforcing member connecting the support and the rigid member. The states were measured to obtain FIGS. 9A-9C and 10A-10C.

When comparing the vibration state of the conventional tension mask shown in Figure 9a and 9c with the vibration state of the tension mask according to the present invention shown in Figs. 10a to 10c (Figs. 9a and 10a), in the central portion of the tension mask The vibration attenuation time of the tension mask on the side without the reinforcing member was found to be relatively long.

9b and 10, the conventional tension mask can be seen that the amplitude at the 2/6 point of the tension mask is more than 7-8 seconds of the attenuation time of the vibration to 10㎛, the tension mask of the present invention It can be seen that the vibration attenuation time at 2/6 is within 2 seconds. 9C and 10C, the vibration attenuation time at the end of the test mask according to the present invention is shortened.

Through Experiment 2 as described above, the maximum amplitudes at the center, the 2/6 point, and the end of the tension mask were reduced by 25%, 3.5%, and 12.5%, respectively. The time was reduced by 12.5%, 91.7%, and 33.3% at the center, 2/6, and end of the tension mask, respectively.

The tension mask frame assembly of the color cathode ray tube according to the present invention configured as described above reduces the vibration of the support by winding a wire or installing a reinforcing member on the support connecting the first and second support members, and further, the vibration of the tension mask. Image attenuation can be prevented by attenuating.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary and will be understood by those skilled in the art that various modifications and embodiments may be made therefrom. Therefore, the present invention will be defined by the technical spirit of the appended claims the true technical protection scope of the present invention.

Claims (7)

A frame including a pair of first and second support members spaced apart from each other by a predetermined distance, and first and second rigid members installed between the first and second support members to support the first and second support members; A mask mounted to apply tension to the support members and having a plurality of electron beam through holes formed therein; Both ends are fixed to the ends of the first and second support members, respectively, to prevent creep deformation of the tension mask due to the difference in thermal expansion between the support, the first and second rigid members, and the first and second support members. Tension mask frame assembly for a color cathode ray tube, characterized in that it comprises a vibration damping means for reducing the vibration of the support by winding or fixed to the support. The method of claim 1, The vibration damping means is a tension mask frame assembly for a color cathode ray tube, characterized in that made of a wire wound relative to the support. The method of claim 2, Tension mask frame assembly for color cathode ray tube, characterized in that the wire is wound continuously or discontinuously. The method of claim 2, The material of the wire is a melting mask frame assembly for a color cathode ray tube, characterized in that the melting point of more than 460 ℃. The method of claim 1, The vibration damping means is a tension mask frame assembly for a color cathode ray tube, characterized in that consisting of at least one reinforcing member connecting the support and the rigid member. The method of claim 5 Tension mask frame assembly for a color cathode ray tube, characterized in that positioned at the same distance around the center of the support when two or more reinforcing members are installed. The method of claim 5, Tension mask frame assembly for a color cathode ray tube, characterized in that the wire is wound around the support so as to move relative.