KR19990039410A - Shadow Mask Vibration Damping Device with Flat CRT - Google Patents

Abstract

The present invention relates to a vibration damping device for attenuating vibrations in a faster time when a shadow mask vibrates when a shock applied to the outside of a flat CRT is transmitted to a color mask. It is to effectively attenuate the vibration generated during the operation of the CRT.

To this end, the electron gun 7 is enclosed in the neck portion 6a of the funnel 6, and the shadow mask 5 is fixedly fixed to the rail 4 fixed to the inner surface of the panel 1, and the shadow mask In a flat CRT tube having vibration damping means on the surface, the vibration damping means is a plate-shaped damping member 12 having a hole 12a that is the same as or larger than the hole 5a of the shadow mask 5, and the damping member is At least one or more ends are installed on the surface of the shadow mask 5 so that both ends are fixed to the rail 4.

Description

Shadow Mask Vibration Damping Device with Flat CRT

The present invention relates to a flat CRT, and more particularly, when an impact applied to the outside of the CRT is transmitted to a shadow mask, which serves as color screening, when the shadow mask vibrates, the vibration is generated in a shorter time. A vibration damping device for damping.

1 is an exploded perspective view illustrating the structure of a flat CRT, and FIG. 2 is a longitudinal cross-sectional view of the coupled state of FIG. 1, with a flat plate-shaped panel 1 having a flat front surface and a resin paper 2 fixed to the front surface of the panel. Safety glass (3) to maintain the explosion-proof characteristics of the CRT, a rectangular frame-shaped rail (4) fixed to the back of the panel with frit glass, and a fixed force applied to the rail, and the color selection role of the electron beam. A shadow mask 5 having a myriad of slots or dot-shaped small holes 5a formed thereon, a panel having a frit glass fixed thereto, and a funnel 6 having a neck portion 6a integrally formed at a rear side thereof, and the funnel It consists of an electron gun (7) enclosed in the neck portion and emits three electron beams of red, green and blue, and a deflection yoke (not shown) installed to be wrapped around the outer circumferential surface of the neck portion to deflect the electron beam. .

Therefore, when power is applied to the cathode of the electron gun 7 and the electron beam is generated, the generated electron beam is accelerated and focused while passing through the acceleration electrode and the focusing electrode in turn and then deflected by the deflection yoke to the shadow mask 5. The image is reproduced by colliding with the fluorescent surface 11 applied to the inner surface of the panel 1 through the formed holes 5a to emit light.

By the above operation, the electron beam 8 that passes through the hole 5a formed in the shadow mask 5 and collides with the fluorescent surface 11 to emit phosphors is only about 20% of the total electron beams, and the rest is shadowed. The impact on the mask is converted into thermal energy, resulting in a domming phenomenon in which the shadow mask thermally expands.

The shadow mask 5 applied to the flat CRT is made of AK (Aluminum Killed) steel having a thickness of about 0.025 mm, also referred to as a "flat foil tension mask".

As described above, the shadow mask 5 of the thin plate is spot welded to the rail 4 having a rectangular frame shape fixed to the rear surface of the panel 1 in the state where the tensile force is applied.

The reason why the tensile force is applied to the shadow mask 5 is that the shadow mask is very thin in order to prevent the doming phenomenon during expansion by the electron beam during the operation of the CRT.

As such, the shadow mask 5 directly fixed to the rail 4 is located close to the rear surface of the panel 1 and is extremely sensitive to vibration, so even if some energy is transmitted to the shadow mask by an external impact or the like. The vibration lasts for a long time (about 10 minutes), which is called Howling.

When vibration occurs in the shadow mask 5 due to the howling phenomenon, the position of each hole 5a formed in the shadow mask is changed, so that the electron beam passing through the hole 5a formed in the shadow mask 5 is fluorescent surface 11. It does not strike the corresponding phosphor of accurately, it shows a problem that the color purity is lowered by hitting the other adjacent phosphor at the same time.

Therefore, the flat CRT must be provided with means for damping the vibration of the shadow mask 5 by external impact.

3 is a rear view illustrating a conventional vibration damping device, and FIG. 4 is an enlarged vertical cross-sectional view of the portion “A” of FIG. 3, in which the shadow mask 5 is not formed with the hole 5a in the Y direction (vertical direction in the drawing). At least one wire 9 is connected in a tensioned state, and then both ends are welded to the rails 4 to suppress vibration of the shadow mask 5.

Therefore, when the CRT is moved from the outside when the shock is applied or the vibration of the speaker sound is transmitted to the shadow mask 5 side fixed to the rail (4) is fixed to be tensioned between the holes (5a) of the shadow mask. Since the wire 9 absorbs and diverges the vibration that has been transmitted, the vibration transmitted to the shadow mask side is further attenuated.

However, this conventional apparatus has the following problems.

First, the diameter of the wire 9 used for vibration damping must be smaller than the gap between the hole 5a and the hole formed in the shadow mask 5 so that the electron beam 8 does not cause interference when passing through the hole 5a. The effective surface of the vibration suppression by the wire is limited, and thus the vibration damping efficiency is lowered.

Second, since the diameter of the wire 9 positioned between the hole 5a and the hole of the shadow mask 5 is relatively small, both ends of the wire cannot be directly welded to the rail 4, so that both ends of the wire are shown in FIGS. As shown in 2, the fixing member 10 is fixed to the separate fixing member 10, and then the fixing member is welded to the rail 4, resulting in a decrease in the work efficiency due to an increase in the number of working hours.

Third, the welding part of the wire 9 is relatively weak, and the wire breaks frequently due to vibration of the shadow mask 5 or external impact.

The present invention has been made in order to solve such a problem in the prior art, and an object thereof is to effectively attenuate the vibration generated during the operation of the CRT without using a wire.

According to an embodiment of the present invention for achieving the above object, an electron gun is enclosed in the neck portion of the funnel, the shadow mask is fixedly fixed to the rail fixed to the inner surface of the panel and the vibration damping means on the surface of the shadow mask In the provided flat CRT, the vibration damping means is a plate-shaped damping member having a hole equal to or larger than that of the shadow mask, and the damping member is at least one flat CRT installed on the surface of the shadow mask so that both ends are fixed to the rail. A shadow mask vibration damping device is provided.

1 is an exploded perspective view for explaining the structure of a flat CRT

Figure 2 is a longitudinal cross-sectional view of the coupled state of FIG.

Figure 3 is a rear view showing a conventional vibration damping device

4 is an enlarged vertical cross-sectional view of portion "A" of FIG.

5 is a rear view showing an embodiment of the present invention.

6A to 6C are enlarged longitudinal cross-sectional views of the portion “B” of FIG. 5.

7 is a rear view showing another embodiment of the present invention.

Explanation of symbols for main parts of the drawings

1: panel 4: rail

5: shadow mask 6: funnel

12 damping member 12a hole

Hereinafter, the present invention will be described in more detail with reference to FIGS. 5 to 7 as an embodiment.

FIG. 5 is a rear view showing an embodiment of the present invention, and FIGS. 6A to 6C are enlarged longitudinal cross-sectional views of a portion “B” of FIG. 5, and FIG. 7 is a rear view showing another embodiment of the present invention, and the present invention is applied. Since the basic configuration of the CRT is the same as in the prior art, detailed description thereof will be omitted and the same reference numerals will be given.

According to the present invention, a vibration damping means fixed to be connected to the surface of the shadow mask 5 to damp vibrations is at least equal to the hole 5a formed in the shadow mask 5, or a plate-shaped damping member having a large hole 12a formed therein. At least one damping member 12 is installed to be connected to the surface of the shadow mask 5 in a state in which the damping member 12 is tensioned in the Y-axis direction (vertical direction in the drawing), and both ends are welded to the rail 4. Fix it.

At this time, the width of the damping member 12 is an area including at least one or more holes 5a in the X-axis direction (horizontal direction on the drawing) of the shadow mask 5.

When the hole 5a formed in the shadow mask 5 on which the damping member 12 is installed is a dot type, a hole 12a is formed in the damping member in a dot type, and in the case of the slot type, the damping member Form a hole with slot type.

The thickness of the damping member 12 installed to be connected to the shadow mask 5 is made thicker than the thickness of the shadow mask 5.

This is to suppress the vibration of the shadow mask that is similar to the vibration shape of the membrane depending on the elastic modulus and strain in the X and Y directions applied to the damping member 12.

In addition, both ends of the damping member 12 welded to the rail 4 are not welded and fixed directly to the effective surface of the shadow mask 5, as shown in Figs. 6A to 6C, and the upper surface 4a and the inclined surface 4b of the rail. ) Or a bent surface 4c.

The reason is to prevent the distortion of the screen by reducing the thermal deformation of the shadow mask 5 due to the heat energy generated during operation of the cathode ray tube.

The damping member 12 installed to be connected to the surface of the shadow mask 5 is positioned on the surface of the shadow mask 5 opposite to the electron gun 7 or on the shadow mask surface opposite to the fluorescent surface 11. It can be fixed or installed on both sides.

When the damping member 12 is installed on both sides of the shadow mask 5, the damping member 12 may be installed at an appropriate position that may cause vibration attenuation even if the positions of the damping members 12 coincide with each other or shift from each other.

The damper member 12 is preferably used in the elastic material while the thermal expansion is small.

This is because the cue, which is the distance between the inner surface of the panel 1 and the shadow mask 5 even though the shadow mask 5 thermally expands due to the collision of the electron beam 8 and loses tension during the operation of the CRT. This is to prevent the change.

As such, when the damping member 12 is stretched in the Y-axis direction and is connected to one side or both sides of the shadow mask 5 by welding to the rail 4, power is applied to the CRT to the CRT. When an external shock is applied or vibration is transmitted to the shadow mask 5 by a speaker sound or the like, and the shadow mask starts to vibrate, the damping member 12 is connected to the surface of the larger area of the shadow mask 5 so that the shadow By changing the vibration mode of the mask or reducing the vibration energy, the howling phenomenon of the shadow mask is removed in a short time.

As described above, in the present invention, unlike the conventional vibration damping means, the shadow of the damping member does not appear at all on the screen, thereby preventing the degradation of the screen characteristics in advance, and of course, adjusting the width of the damping member according to the vibration characteristics of the shadow mask. Therefore, the vibration area of the shadow mask can be minimized.

In addition, the welding operation according to the fixing of the damping member is simplified, thereby maximizing the work efficiency, as well as preventing the damping member from falling off the rail due to vibration.

Claims (13)

An electron gun is enclosed in the neck portion of the funnel, and a shadow mask is fixedly fixed to the rail fixed to the inner surface of the panel, and the vibration damping means is a flat cathode tube provided with vibration damping means on the surface of the shadow mask. A plate-shaped damping member having a hole equal to or larger than a hole, wherein the damping member is a shadow mask vibration damping device of a flat CRT installed on at least one surface of a shadow mask so that both ends thereof are fixed to a rail. The method of claim 1, Shadow mask vibration damping device for flat CRT tubes with dots formed in shadow masks. The method of claim 1, Shadow mask vibration damping device for flat CRT tubes with slots formed in the shadow mask. The method of claim 1, Shadow mask vibration damping device of flat CRT tube with thicker damping member than shadow mask. The method of claim 1, Shadow mask vibration damping device of a flat CRT tube in which both ends of a damping member are welded and fixed to an upper surface of a rail. The method of claim 1, Shadow mask vibration damping device of a flat CRT tube, in which both ends of the damping member are welded to the bent surface of the rail. The method of claim 1, Shadow mask vibration damping device of a flat CRT tube, in which both ends of the damping member are welded to the bent surface of the rail. The method of claim 1, A shadow mask vibration damping device of a flat CRT tube, wherein the damping member is positioned on the shadow mask surface facing the electron gun. The method of claim 1, A shadow mask vibration damping device of a flat cathode ray tube, wherein a damping member is positioned on a shadow mask surface facing a fluorescent surface. The method of claim 1, Shadow mask vibration damping device of a flat CRT fixed to the rail so that the damping members are located on both sides of the shadow mask. The method of claim 10, Shadow mask vibration damping device of a flat CRT located on both sides of the shadow mask so that the damping members coincide with each other. The method of claim 10, Shadow mask vibration damping device of a flat CRT located on both sides of the shadow mask so that the damping members are shifted from each other. The method of claim 1, The damping member is made of an elastic material and is a shadow mask vibration damping device of a flat CRT.