JPS63170836A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent a fixed section from being seen from the panel front by making the fixed section between a funnel section and a panel section black or dark. CONSTITUTION:One end of the funnel section 2 of a black matrix type color cathode-ray tube is connected to a neck section 1, and the other end is fixed to a panel 3 by a sealing member 4. A black or dark member, e.g., a preset composition material using PbO as a main component, is used as the member 4. When this member 4 is used, the incident light from the panel 3 to the member 4 is almost absorbed, thus the whole face is seen black from the front of the panel 3, and its appearance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube, and more particularly to a cathode ray tube in which a funnel portion and a panel portion are fixed together by a sealing member.

There are various types of cathode ray tubes that use a sealing glass called frit glass as the sealing member, and use this to secure the funnel part and the panel part. Most have this type of shape.

It is well known that in this type of cathode ray tube, when the panel section is viewed from the front, the sealing member is visible through the thick part of the side wall of the panel section.

To explain this based on the drawings, Figures 1 and 2
The figure is a partially cutaway side view and an enlarged cross-sectional view of its essential parts, showing an example of a black matrix type color picture tube.
In the drawings, in which color selection electrodes and the like are omitted, reference numeral 1 denotes a neck portion, in which an electron gun assembly (not shown) is normally housed. Reference numeral 2 denotes a funnel portion, one end of which is connected to the neck portion 1, and the other end 2a is fixed to the open end 3a of the panel portion 3 with a sealing member 4 such as frit glass. Reference numeral 5 denotes a fluorescent film made of a fluorescent material and a non-luminescent material film such as graphite, and this fluorescent film 5 covers the face portion 3b of the panel portion 3.
is coated on the inner surface of the film, forming an effective surface as a video image surface. Reference numeral 6 denotes an effective out-of-plane coating film, which is composed of a graphite film extending from the phosphor film 5 or a film including a phosphor layer.
A portion of the face portion 3b and a portion of the side wall portion 3c of the panel portion 3 are covered. 7 is the effective surface boundary line,
This shows the boundary line between the fluorescent film 5 and the coating film 6 outside the effective surface. 8 is an inner circumference line of the side wall part 3c of the panel part 3, 9 is an inner circumference line of the side wall part 3c of the panel part 3, 9 is an outer circumference line of the side wall part 3c of the panel part 3, and 10 is a panel pin for color selection electrode retention. , which is embedded in the side wall portion 3c of the panel portion 3. In addition.

In reality, the end surface of the side wall portion 3c of the panel portion 3 is normally slightly sloped or undulating toward the fixed portion over the entire circumference, but for ease of explanation, the end surface of the side wall portion 3c of the panel portion 3 is Assuming that the fixed part has the same diameter, both the inner and outer peripheries are represented by straight lines perpendicular to the fixed surface.

In such a structure, when the face part 3b is viewed from the front of the panel part 3, there is a boundary line 7 between the fluorescent film 5 and the coating film 6 outside the effective surface, the coating film 6 outside the effective surface, and the side wall on the outside of the effective surface. The sealing member 4 and the like can be visually seen through the inner and outer circumferential line 8°9 of the part 3c, the panel pin 10, and the thick part of the side wall part 3c.
It is a common experience to see deposits, processing scratches, etc. on the surface or inner surface of a c.

However, the frit glass that has been conventionally used as a type of sealing member has PbO as its main component, and Zn is also added to this.
It is made of fine powdered glass containing O, BzOa, AQ20B and 5iOz.

When this is heated at a temperature suitable for bonding the panel and funnel parts, the parts exposed to the outside.

It exhibits a brownish color, but on the surface where it is attached to the panel and funnel parts, a relatively bright brownish color pattern appears in a color close to white, making it difficult to use as a color picture tube. The disadvantage is that it spoils the appearance. That is, if we take the above-mentioned black matrix type color picture tube as an example, the coating film 6 outside the effective surface is usually an extension of the graphite film of the fluorescent film 5, so it exhibits a homogeneous black color. A relatively bright brownish color pattern appears in the almost white color of the fixed part, and the mottled pattern causes a marked difference in quality between the two parts, spoils the appearance, and is a problem for color picture tubes. It had the fatal flaw of severely degrading quality. In addition, as mentioned above, the surface of panel pins embedded in the side wall of the panel is oxidized to maintain good adhesion to the glass, and usually takes on a dark color close to black, while the background frit has a relatively bright color. In this case, as mentioned above, the viewer can clearly see the presence of the panel pin in contrast to the embedded part, and exposing internal structures such as the panel pin inevitably spoils the appearance of the cathode ray tube. Furthermore, the outside surface or inside of the side wall of the panel section may be surface-treated by means such as sandblasting or stamped with a symbol using stamp ink by the panel manufacturer or panel user for the purpose of sorting or memorizing. Manufacturer's name, specification classification, lot number, etc. are often written, but this can be seen through the thick part of the panel within a certain visual range from the front of the panel, and this is often due to reflection from the sealing material. This is one of the factors that impairs the appearance.

It goes without saying that the above-mentioned defects in appearance are more noticeable as the light transmittance of the glass material of the panel portion is higher, and are less noticeable as the light transmittance is lower.

The present invention provides an excellent cathode ray tube that can solve the various drawbacks mentioned above by blackening or darkening the portion of the panel portion that is fixed to the funnel portion.

The present invention is achieved by blackening or darkening the sealing member itself, a part or all of the side wall of the panel, or both the sealing member and the side wall. Examples will be described below.

Example l PbO" 70% by weight Zn0 10% by weight BzOa: 10% by weight MnOx: 5% by weight CozOa
: 5% by weight Others : Level of impurities 90% by weight of these compositions and 10% by weight of vehicle are mixed to form a slurry, and this is applied to the panel side end face of the funnel part in the same way as in the production of conventional color picture tubes. Then, a panel section for a black matrix type, which is formed through a prescribed process and has a fluorescent film, color selection electrodes, etc., is placed on this, and in this state, it is heated at the same temperature as before, and the funnel section and panel section are heated. The part was fixed. As a result, the frit glass exhibited almost the same color tone as the graphite film formed as the coating film outside the effective surface. After that, a black matrix type color picture tube was manufactured through the same process as before, including sealing and evacuation.

Example 2 77% by weight of PbO ZnO: 11% by weight BxOa: 11% by weight CuzO: 0.7% by weight S 0.3% by weight 90% by weight of such a composition and 10% by weight of vehicle were mixed to form a slurry, Use this as a sealing member,
As a result of fixing the funnel part and the panel part, the sealing member having the above composition exhibited a chocolate color close to black.

Here, in addition to the above-mentioned MnOz, CoxOa, etc., metal oxides that are ionized in the glass and have a coloring effect may be used as long as at least the panel side of the fixed part exhibits black or dark color after sealing. Of course.

As described above, according to the present invention, at least the panel side of the fixed part of the funnel part of the panel part exhibits black or dark color, so that most of the light incident from the front side of the panel and the end of the panel is absorbed by this part. It appears black from the front of the panel, and it is difficult to recognize the non-uniformity of the frit as mentioned above, and in the case of a black matrix type color picture tube, the color of the coating film outside the effective surface and from it to the outer periphery is almost the same color. This makes it easier to see them as one, improving the appearance. Similarly, the embedded portion of the panel pin becomes the same color, making it difficult to recognize the presence of the panel pin, which has a substantial effect.

Furthermore, the marks on the edge of the panel mentioned above also become harder to see because the reflected light from the fixed parts is reduced.
It has various excellent effects such as the ability to obtain desirable effects.

[Brief explanation of the drawing]

1 and 2 are a partially cutaway side view and an enlarged sectional view of a main part of a cathode ray tube for explaining the present invention. DESCRIPTION OF SYMBOLS 1... Neck part, 2... Funnel part, 3... Panel part, 4... Sealing member, 5... Fluorescent film, 6...
... Coating film outside the effective surface, 7 ... Boundary line, 8 ... Panel inner circumference line, 9 ... Panel outer circumference Fig. 2

Claims (1)

[Claims] 1. In a black matrix type color cathode ray tube comprising a neck part and a funnel part having one end connected to the neck part and the other end fixed to the panel part by a sealing member, the fixed part is made black or dark-colored. A cathode ray tube characterized in that the panel side exhibits black or a dark color.