JPH0326618Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a flat cathode ray tube made of three-piece glass.

BACKGROUND ART AND PROBLEMS The present applicant has shown a rear perspective view in FIG.
As shown in the longitudinal cross-sectional view in the figure, a cathode ray tube consisting of a flat glass tube body 1 was provided. This flat glass tube 1 includes a screen panel 3 and a front panel 4 which are opposed to each other and are joined and sealed by fritting so as to form a flat space 2 between them.
A funnel part 5 is joined and sealed to one side of these parts by fritting in the same manner, and this funnel part 5 is
A neck portion 6 is welded to the opening end on the small diameter side. An electron gun 7 is housed within the network portion 6 .

The screen panel 3 and front panel 4 are
The screen panel 3 has main surfaces 3a and 4a facing each other, and side wall surfaces 3b and 4b extending from the side edges excluding the side surfaces joined to the funnel portion 5. The inner surface of the surface 3a of the screen panel 3 has a fluorescent surface 8. is deposited. As the surface 3a reaches the tip side of the tube body 1 so that the fluorescent surface 8 faces the electron gun 7, that is, the side opposite to the side where the electron gun 7 is arranged, It is formed in a curved manner. The electron beam emitted from the electron gun 7 is then directed onto the fluorescent surface 8 by horizontal and vertical electromagnetic deflection means (not shown) arranged on the outer periphery of the tube near the joint between the funnel section 5 and the neck section 6. It is designed to scan horizontally and vertically. The optical image that is excited by the electron beam and emits light is transmitted to the front panel 4 facing the surface 3a of the screen panel 3.
The observation is made from the surface 4a side.

Although not shown, on the inner surface of the surface 3a of the screen panel 3 on which the fluorescent surface 8 is formed, a conductive film made of, for example, an A-deposited film is formed, and the fluorescent surface 8 is formed on this. Ru. Further, a transparent conductive film is formed on the inner surface of the tube body 1, particularly the screen panel 3. Further, a carbon film is formed on the inner surface of the funnel portion 5.

In such a flat cathode ray tube, a portion of the surface 3a of the screen panel 3 excluding the fluorescent surface 8, and side wall surfaces 3b and 4b of the screen panel 3 and front panel 4 are transparent, and the set assembly is easy. Afterwards, you can see through the inside of the set.
It had the disadvantage of being visually unsightly.

Therefore, as shown in FIG. 3, the applicant attached a black conductive tape (carbon + polyester) 9 to the outer surface of the surface 3a of the screen panel 3, and the side wall surfaces of the screen panel 3 and the front panel 4. We considered attaching black insulating tape 10 to 3b and 4b to blind them. in this case,
The reason why the conductive tape 9 is used is that it is also used as an external conductive film. For example, a capacitor is formed between the conductive tape 9 and internal conductive films formed on the inner surfaces of the panels 3 and 4, and this is used as a capacitor in a high voltage rectifier circuit, for example.

However, like this black conductive tape 9
In the case where the insulating tape 10 is provided, if the outer surface of the glass is uneven, the glass and the tape 9,1
Air bubbles enter between the 0 and the light reflection becomes uneven,
There was a drawback that the unevenness was noticeable.

Purpose of the invention In view of this point, the present invention is designed to make the above-mentioned unevenness less noticeable and to obtain a good blinding effect.

Summary of the invention In order to achieve the above object, the present invention uses a flat cathode ray tube made of glass with a three-body structure, and coats at least the image observation area of the front panel with black insulating paint, and coats the inner surface with a phosphor layer. This method is characterized in that a conductive film tape is attached to the outer surface of the coated screen panel, avoiding the frit seal portion.

Therefore, even if the glass surface has irregularities, the black insulating paint is uniformly applied to the glass surface, and light is reflected uniformly, without any unevenness being noticeable, and a good blinding effect can be obtained.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 4 to 6. This figure 4 to 6
In the figure, parts corresponding to those in FIGS. 1 to 3 are designated by the same reference numerals, and detailed explanation thereof will be omitted. still,
The shaded portion is a carbon film formed inside the funnel portion 5.

In this example, as shown in FIGS. 4 to 6, the outer surface of the screen panel 3, the outer surface of the front panel 4, and a part of the outer surface of the funnel section 5, excluding the surface 4a (image observation section) of the front panel 4. An insulating black paint 11 is applied to the surface. Further, a conductive film tape 12 constituting an external conductive film is adhered to the outer surface of the surface 3a of the screen panel 3, avoiding the frit seal portion.

In this case, as the black paint 11, for example, [] Nitto Denko's Nittor 120 Black (trade name), [] Union Kasei Co., Ltd. Unicoat #100 (trade name) is used. Further, in this case, the conductive film tape 12
does not have to be black.

In addition, application of black paint 11 and conductive film tape 1
The second adhesion step is performed, for example, as follows.

First, the outer surface of the surface 4a of the front panel 4 is masked with, for example, adhesive tape.

Next, dip the insulating black paint 11 up to the line A-A' (with the arrow direction facing down).

Next, the applied black paint 11 is dried by normal means such as blowing air or heating.

Next, a conductive film tape 12 is attached to the outer surface of the surface 3a of the screen panel 3.

Finally, the masking on the surface 4a of the front panel 4 is removed.

The reason why an insulating material is used as the black paint 11 is that if a conductive material is brought close to the frit seal part, a part with insufficient withstand voltage will be created between it and the internal conductive film, which may cause discharge. This is because it is not desirable. It is for the same reason that the frit seal portion is avoided when attaching the conductive film tape 12.

According to this example, the insulating black paint 11 applied to a portion of the screen panel 3, front panel 4, and funnel portion 5 is uniformly applied to the glass surface even if the glass surface is uneven. Ru. Therefore, the light is reflected uniformly, and a good blinding effect can be obtained without any unevenness being noticeable.

Further, the conductive film tape 12 does not need to be black, and an inexpensive one can be used.

Effects of the invention According to the invention described above, the black insulating paint applied to at least the image observation area of the front panel is uniformly applied to the glass surface even if the glass surface is uneven, and light reflection is prevented. It is uniform and the unevenness is not noticeable and a good blinding effect can be obtained. In addition, according to the present invention, since a conductive film tape is pasted, by setting it to a ground potential, it is possible to eliminate unstable charges that have accumulated particularly on the fluorescent surface, and to remove the unstable charge accumulated on the fluorescent surface. It is possible to avoid dust from adhering to the image sensor, or to prevent image fluctuation and distortion caused by discharge of accumulated charges.

In addition, the present invention also allows a large-area (large-capacity) capacitor to be formed between the internal conductive film formed on the inner surface of the front panel and screen panel and the above-mentioned conductive film capacitor. can be used, for example, as a capacitor in a high-voltage rectifier circuit.

[Brief explanation of the drawing]

1, 2 and 3 are a perspective view, a vertical sectional view and a perspective view of essential parts, respectively, showing an example of a flat cathode ray tube, and FIGS. 4, 5 and 6 are a perspective view showing an example of a flat cathode ray tube, and FIG. 1 is a side view, a plan view, and a perspective view showing one embodiment. 3 is the screen panel, 4 is the front panel,
5 is a funnel portion, 8 is a fluorescent surface, 11 is an insulating black paint, and 12 is a conductive film tape.

Claims (1)

[Scope of utility model registration request] In a flat cathode ray tube made of three-piece glass, a black insulating paint is applied to at least the front panel except for the image observation area, and a phosphor layer is applied to the inner surface of the screen panel, avoiding the frit seal area. A flat cathode ray tube characterized in that a conductive film tape is attached.