JPH01189840A - Color cathode-ray tube - Google Patents

Abstract

PURPOSE:To dissolve the screen color drift due to the external vibration by forming part or all of the shadow mask of a color cathode-ray tube having an electron gun and the shadow mask with a porous metal. CONSTITUTION:A shadow mask 4 is constituted of a mask frame 21 with the thickness of 0.15mm and four mask supporters 23, they are welded and fixed at preset positions respectively, it is fixed to an envelop 7 near a junction between the face section 4 and a funnel section 3. The frame 21 of this mask 4 is formed with an alloy made of Fe-12Cr-3Al which is a vibration-proof alloy and formed in a shape as shown in the figure. A color cathode-ray tube 10 is operated, electron beams E responsible for R, G, B are emitted from an electron gun 1, scanning beams are controlled by the shadow mask 4 and hit a fluorescent film 6. Even when vibration of 160Hz with large effect is forcibly applied to the cathode-ray tube 10, vibration rarely occurs due to the damping action of the mask frame 21, thereby the cathode-ray tube 10 has no color drift, a clear image is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Field of Industrial Application) The present invention relates to improvements in color picture tubes, and in particular to improvements in shadow masks.

Note that the shadow mask related to the present invention includes a mask body,
It shall include a mask frame and a mask support.

(Prior Art) In recent years, color televisions and the like have become larger in size and higher in definition, and users are increasingly becoming more sophisticated.

For example, large screens such as 25-inch to 40-inch screens are required and put into practical use, but there is a particular demand for the development of products with even finer grain and high quality, that is, products with high resolution.

Along with the above, color picture tubes are also required to have high resolution (of course), and they will depend heavily on this characteristic.

In order to improve and maintain the above-mentioned characteristics, the quality of the shadow mask used to control the passage of the electron beam has a particularly large direct effect on the quality of the screen.

Therefore, the quality of this shadow mask is particularly important and is a key point that affects image quality.

By the way, in order to make the shadow mask fully meet the above requirements, it is necessary to (1) form a large number of electron beam passing holes in the shadow mask body (hereinafter referred to as the mask body), and (2) eliminate elements that hinder the effective beam passing through the passing holes. (2) Furthermore, it is necessary to maintain the relative positional relationship of the mask body to the fluorescent surface at a predetermined position during operation.

τ Regarding the factors of ■ to ■ above, ■ and ■ have been technically solved, but for example, if the wall thickness of the mask body is made thinner to 0.1511 to improve ■, the mechanical strength will be lower than the conventional one. It is lower than that of .

If this decreases, the electron beam passing effective surface of the mask body will vibrate even with slight external vibrations, and the relative positional relationship between this effective surface and the fluorescent surface will be disrupted.

this! This will be explained using Figures 4 and 5. #! Figure 4 shows a shadow mask 42, a mask frame 40, a mask body 4
1. The mask support 43 has a structure and is fixed to the side wall of the face portion 45 via the mask support 43.

The shadow mask main body 41 fixed in this way is subjected to a force 2-
When a certain kind of shock is applied to the picture tube 50.

The vibration path is sequentially transmitted to the tube wall of the picture tube, the mask support 43, the mask frame 40, the skirt portion of the mask body 41, and the effective surface of the mask body 41.

This vibration causes the fluorescent surface 46 to vibrate back and forth. This vibration has a great effect on the image quality and appears as a color shift phenomenon in the image. That is, as shown in FIG. 5, in the electron beam EI, the mask body 4 is in a normal state.
1 is the case where there is no vibration, and this is a case where the electron beam hits the designated phosphor due to normal scanning and displays a clear screen with no color shift, but the effective surface of the mask body is not vibrating as shown by the wavy line. When the electron beam swings forward by A, the electron beam becomes E2 and passes through the mask body 410 passage hole. If the passage of the electron beam is erroneous in this way, the electron beam will also strike the phosphor of the phosphor surface 46 in an undesirable manner, resulting in color blurring, which is a so-called so-called blurring that significantly degrades image quality. This is a howling phenomenon. It is necessary to eliminate at least a frequency band of about 20 to 250 Hz, which is particularly sensitive to the human eye.

(Problems to be Solved by the Invention) The present invention is an improvement to eliminate the above-mentioned conventional drawbacks, and is characterized in that the shadow mask is provided with a vibration-proofing means.

[Structure of the invention]

(Means for Solving the Problem) As a vibration isolating means, part or all of the mask frame or mask support may be formed of a vibration isolating metal body, or a porous metal,
Vibration of the mask body is suppressed by using a gold 114m body, a fiber metal body, a thermally sprayed layer, etc.

(Function) When a vibration prevention means is provided on the inner mask frame A of the shadow mask, all vibrations from the outside to the mask body are attenuated, so the mask body becomes a system that is less affected by vibrations. It is possible to maintain the normal position at all times, and the positional relationship with the fluorescent surface is maintained. Therefore, the color shift phenomenon is reduced.
1. Clear images can be obtained by removing most of the particles.

(Example) Example 1 FIG. 1 is a partially cutaway perspective view showing the inside of a color picture tube of the present invention, in which an electron gun 1 is enclosed in a neck part 2,
A shadow mask 4 is disposed and fixed in a funnel portion 3 directly facing a face surface 5 to form a picture tube 10. Note that 6 is a fluorescent film made of R, G, and B that is adhered to the inner wall of the face surface.

As shown in FIGS. 2 and M3, the shadow mask 4 is composed of a mask frame 21, a mask frame with a wall thickness of 0.15 m1, and four mask supports 23, each of which is welded and fixed at a predetermined position. , is fixed to the envelope 7 near the joint between the face and the funnel part. The mask 7 layer 421 of this shadow mask 4 is made of anti-vibration alloy F.
It is characterized by having the shape shown in FIG. 2 and made of an alloy consisting of e-12Cr-3AI (Silentalloy trade name).

The color picture tube 1O formed in this manner was operated to emit each R, G, and B electron beam E from the electron gun 1, and the scanning beam was controlled by the shadow mask 4 to strike the phosphor film 6. . When a vibration of 160 Hz, which has a large influence, was forcibly applied to the picture tube lO, it was found that the vibration caused by this vibration hardly occurred due to the damping effect of the mask frame 21. This is proven by the fact that the colors on the screen of a color picture tube are very clear. Note that good results were obtained for this determination when measured according to predetermined standard regulations.

Example 2 The frame 21 of the shadow mask 4 of Example 1 was made of Fe.
It was formed from a composite plate of a -25Cr-2ON1 alloy thin plate of a predetermined width and an iron thin plate. When this was measured by adding vibrations of 25 Hz, there was almost no vibration due to the same damping effect as described above, and almost no howling phenomenon on the color screen was observed.

In addition to the above, twinned Mn-58C is also used as an anti-vibration alloy.
r-2Al, Ni-50(atqb)Ti, Cu-
Zn-Al.

Ferromagnetic type Fe-150r-2No-0,5Ti, rearrangement shop.

Mg-0,52r, composite type Fe-3C-2Si-0,7
It has also been confirmed that the mass frame 21 may be formed by using Mn, AI-39 (at%) Zn, etc. alone or in combination.

Example 3 A large porous metal plate was used as the mask frame of the shadow mask 4. This porous metal plate is made by sintering iron powder with a spherical diameter of lO- into a plate shape with a thickness of about 0.5fi, and this sintered plate is integrated as a sandwich between two iron plates with a thickness of about 0.5111. It is rolled into a composite plate with a thickness of about 1.2111 mm.

A color picture tube was formed by fixing a mask body 22 made of amber metal and having a thickness of 0.15 tjl to the mask frame 21 made of the composite plate. This also had a sufficient vibration damping effect and no howling was observed.

Example 4 The mask frame 21 of the shadow mask 4 is made of a composite made of iron cermet (foamed metal) sandwiched between two iron plates, and the mask body 22 having a thickness of 0.15111 is fixed as above. A color picture tube 10 was made. There was no howling either.

Example-5 The mask frame 21 of the shadow mask 4 is shown in FIG.
As shown in b), thin iron wires are formed into a felt-like mesh body 31. Iron plates 32 and 33 are rolled along both sides of this mesh body 31, and nine pieces are used.
A thick mask body 22 was fixed to form a color picture tube.

No howling occurred either.

Example 6 As the mask frame 21 of the shadow mask 4, a thin iron wire woven into a flat shape and integrated into an iron plate in the same manner as above was used. A mask body similar to that in Example 5 was fixed to this mask frame to form a color picture tube. No howling occurred either.

Example 7 Good results were obtained by using an iron plate coated with iron powder as the mask frame 21 of the shadow mask 4, and fixing the shadow mask main body with a thickness of 0.15 nm to this.

Example 8 Mask support 23 of shadow mask 4 is made of Mn-58C
It was formed using u-2Al (trade name of Ink Cushinito) and fixed to a mask frame 21 with a mask body 22 to make a color picture tube. Similarly to the above, no color shift was found in the image and a clear image was obtained.

The present invention dampens almost all of the added vibrations by using the anti-vibration function of the mask frame 21 to attenuate all the vibrations added to the mask body 22.
Since the electron beam 2 was always maintained in a normal state, the electron beam emitted from the electron gun could be accurately projected onto a predetermined phosphor.

Accordingly, the color picture tube of the present invention is capable of absorbing external vibrations (sound waves).

The color shift on the screen caused by loading (loading) was almost completely eliminated, and clear images with fine wood grains were obtained. This means that vibrations of 20 to 250 H2 that are felt by the human eye are not applied to the mask body.

[Brief explanation of the drawing]

Fig. m1 is a perspective view showing the inside of the color picture tube of the present invention with a part cut away, Fig. 2 is a perspective view of the shadow mask frame of Fig. 1, and Fig. 3 (&2 is a developed view of the shadow mask of Fig. 1). , FIG. 3Cb is a perspective view and a side view of another example of the shadow mask frame shown in FIG. 2, and FIGS. 4 and 5 are sectional views of main parts of a conventional color picture tube and a shadow mask. In the drawings, 4.42... Shadow mask, 21.40... Mask frame, 22.41... Mask body. ] Figure 3 (Phantom Figure 3 Figure 4 Figure 5

Claims (1)

Claims: 1) A color picture tube having an electron gun and a shadow mask, characterized in that part or all of the shadow mask is made of porous metal. 2) The color picture tube according to claim 1, wherein the shadow mask is formed of a sintered body, metal fiber, sprayed metal, or foamed metal. 3) A color picture tube having an electron gun and a shadow mask, in which part or all of the shadow mask is made of anti-vibration metal. 4) The color picture tube according to claim 3, wherein the shadow mask is composed of a composite plate containing anti-vibration metal.