JPH07282752A - Fluorescent display tube - Google Patents

Abstract

PURPOSE:To reduce a space factor, restrain a temperature rise in a phosphor layer, and emit light with extra-high brightness by arranging a pitch-black coat at least on a surface contacting with the atmospheric pressure side of a metallic board. CONSTITUTION:An insulating layer 1b is formed on a metallic board la being an insulating board 1A constituting a positive electrode board 7A. A display segment 7 composed of a lead-out wiring layer 2 of respective electrode groups, an insulating film 3, a positive electrode layer 4 and a phosphor layer 5 is layered on this insulating layer 1b, and the positive electrode board 7A is constituted. A pitch-black coat 15 is formed on a surface contacting with the atmospheric pressure side of this positive electrode board 7A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube applied to display numbers, characters, figures, graphs and the like of calculators, audio equipment, home appliances, measuring instruments, etc. The present invention relates to an anode substrate structure of a fluorescent display tube.

[0002]

2. Description of the Related Art FIG. 4 is a cross-sectional view of an essential part showing the structure of a conventional fluorescent display tube. In the figure, a lead-out wiring layer 2 for each electrode group described later is selectively formed on the surface of an insulating substrate 1 made of, for example, a plate glass material. Also,
An insulating layer 3 is deposited on the entire surface of the insulating substrate 1 including the lead wiring layer 2. An anode layer 4 formed of a conductive film corresponding to a desired display pattern is provided on the surface of the insulating layer 3, and the anode layer 4 is formed on the corresponding lead wiring layer 2 via the insulating layer 3, respectively. Through hole connected. Further, a phosphor layer 5 is adhered and formed on the surface of the anode layer 4, and the anode layer 4 and the phosphor layer 5 constitute a display segment 6. In this way, the lead-out wiring layer 2, the insulating film 3 of each electrode group are formed on the insulating substrate 1.
And display segment 6 (anode layer 4 and phosphor layer 5)
Are sequentially laminated to form the anode substrate 7.

Further, on the insulating substrate 1, fixed to both ends of the short side of the insulating substrate 1 at a position spaced apart from the display segment 6 composed of the anode 4 and the phosphor layer 5 by a predetermined distance. A pair of filament supports 8 arranged is provided, and a linear filament 9 is stretched and arranged between the pair of filament supports 8, and between the display segment 6 and the filament 9. For each digit, a control electrode 10 is provided in which an electrically independent mesh portion 10a is supported by a frame body 10b.

The anode layer 4, filament support 8 and control electrode 10 disposed on the insulating substrate 1 are electrically connected to one end of a lead pin (not shown) by a conductive paste or welding. And the other end side is led out to the end portion of the insulating substrate 1 as a lead terminal. Further, on the insulating substrate 1, a light-transmitting cover glass 11 is hermetically sealed by a frit glass 12 at a peripheral portion thereof to form an airtight container, and the inside is exhausted by an exhaust pipe (not shown). A vacuum sealed fluorescent display tube is constructed. In addition, on the inner surface of the cover glass 11, a getter film 14 formed by scattering of the Ba getter 13 that adsorbs unnecessary gas in the tube is attached to a region that does not affect the display by the display segment 6, for example, a corner. Has been formed.

In the fluorescent display tube thus constructed, various electrode structures such as the display segment 6, the filament support 8, the filament 9 and the control electrode 10 are mounted on the insulating substrate 1 and then the insulating substrate 1 is formed. The light-transmitting cover glass 11 and the translucent cover glass 11 are sealed by a frit glass 12 to form an airtight container, and thereafter, while heating the airtight container, the air is exhausted from an exhaust pipe (not shown) using a vacuum device, An exhaust process is performed in which 9 is exhausted while being heated at a specified voltage for a predetermined time, and after reaching a predetermined degree of vacuum, the exhaust pipe is chipped off (sealed). After that, the getter 13 arranged in the airtight container is scattered from the outside of the tube by high frequency induction heating, and the getter film 14 is formed on the inner surface of the cover glass 11 by vapor deposition.

[0006]

It is generally known that in the fluorescent display tube having such a structure, the luminous efficiency of the phosphor layer 5 generally decreases as the temperature rises. Since the power consumption of the fluorescent display tube is small, the temperature rise is small and it is not a problem. However,
Generally, in a fluorescent display tube having a large power consumption per substrate area such as an ultra-bright emission fluorescent display tube which obtains an emission brightness of 10,000 cd / m ² or more, the anode substrate 7 coated with the phosphor layer 5 is When the temperature is extreme, the temperature rises to about 100 ° C. or higher, and there is a problem that the luminous efficiency of the phosphor layer 5 decreases. Further, if the temperature rise continues for a long time, the phosphor surface of the phosphor layer 5 is decomposed, dissociated, the emission gas is increased, and the like, which further lowers the luminous efficiency and the emission capability of the filament 9. Traditionally,
As a measure against such a problem, a heat sink is attached to the fluorescent display tube. The material of the anode substrate is switched from an insulating substrate (glass substrate) to a metal substrate. Structures such as are proposed. However, with the above means, the temperature rise of the phosphor layer can be sufficiently suppressed, but there is a problem that the space factor becomes worse. Further, the above means has a problem that the ability to suppress the temperature rise cannot be sufficiently obtained.

Therefore, the present invention has been made in order to solve the above-mentioned conventional problems, and an object thereof is to suppress the temperature rise of the phosphor layer with a simple structure without reducing the space factor and to achieve an ultrahigh temperature. An object of the present invention is to provide a fluorescent display tube capable of realizing luminance emission.

[0008]

In order to achieve such an object, the present invention comprises an insulating substrate composed of a metal substrate and an insulating film formed on the metal substrate, and at least the metal substrate is provided. A dark black film is provided on the surface in contact with the atmospheric pressure side.

[0009]

The dark black film in the present invention efficiently releases the heat generated by the anode substrate to the atmospheric pressure and suppresses the temperature rise of the metal substrate and the phosphor layer.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part showing a configuration according to an embodiment of a fluorescent display tube according to the present invention, and the same parts as those in FIG. 1 is different from FIG. 2 in that the insulating substrate 1A constituting the anode substrate 7A is a Ti substrate 1a made of a titanium (Ti) plate material.
An insulating layer 1b made of a low melting point glass material having a film thickness of about 40 μm is laminated on the substrate 1a. This T
The i-substrate 1a is formed by cutting a titanium plate material into a predetermined size, and heating and baking the titanium plate material at a temperature of about 500 to 600 ° C. in the atmosphere to form a thin oxide film (not shown) on the surface, thereby ensuring adhesion with the low melting point glass. Is improving. Further, a low melting point glass is applied by a screen printing method to a thickness of about 40 μm on the entire inner surface of the Ti substrate 1a having an oxide film formed on its surface, and an insulating layer 1b is formed by heating and baking. There is.

The insulating substrate 1A thus formed is
On the insulating layer 1b, the lead wiring layer 2, the insulating film 3 and the display segment 6 (anode layer 4 and phosphor layer 5) of each electrode group are sequentially laminated and formed on the insulating substrate 1A in the same manner as the configuration of FIG. Is configured. A black spray (Aspen S: made by Asahi Paint) is applied by spraying on the back side of the anode substrate 7A to form a black coating film 15 having a thickness of about 10 μm.

In such a structure, since the black coating 15 is formed on the back side of the Ti substrate 1a of the anode substrate 7A, heat generated by thermionic emission from the filament 9 is conducted to the black coating 15 through the Ti substrate 1a. And is diffused into the atmosphere from the surface of the black coating 15. As a result, the temperature rise of the anode substrate 7A can be reduced and the temperature rise of the phosphor layer 5 can be simultaneously reduced.

FIG. 2 shows data obtained by measuring the relationship between the relative brightness and the input power of the conventional fluorescent display tubes and the present embodiment. As is clear from FIG. 2, the Ti substrate 1a according to this embodiment is used and the Ti substrate 1a is used.
It was confirmed that the fluorescent display tube having the black coating film 15 formed on the back side thereof had an improved relative luminance as compared with the conventional fluorescent display tube.

FIG. 3 shows data obtained by measuring the relationship between the relative brightness and the lighting time of the conventional fluorescent display tube and the present embodiment. Also in this case, the conventional fluorescent display tube does not use the insulating substrate 1A (Ti substrate 1a, insulating layer 1b) and the black coating 15 as in the fluorescent display tube of the present embodiment, and the other dimensions, shapes and materials. Etc. are constructed using exactly the same members. As is clear from FIG. 3, it was confirmed that the fluorescent display tube according to the present example has an improved relative luminance as compared with the conventional fluorescent display tube.

With such a structure, as shown in FIG. 2, when the input power is increased, the temperature rise is suppressed more than that of the conventional fluorescent display tube, so that the influence of the temperature extinction characteristic of the phosphor layer 5 is exerted. As the input power increases, the ratio of the relative brightness increases. Also, as shown in FIG. 3, immediately after lighting,
The rate of decrease in brightness due to the temperature rise of the phosphor layer 5 was reduced.

In the above-described embodiment, the case where the Ti plate material is used as the metal substrate has been described, but the present invention is not limited to this, and Ti alloy, 426 alloy, 50-50 alloy, 13C
The same effect as described above can be obtained by using any one of r alloy, 18Cr alloy, Fe-Ni-Cr-Mn alloy and the like.

Further, in the above-mentioned embodiment, the case where the coating film by the black spray is used as the dark black coating has been described, but the present invention is not limited to this, and the black spray coating film may be replaced by dark black coating. Color lacquer,
The same effect as described above can be obtained by using any coating film such as dark black paint, dark black pigment or graphite.

[0018]

As described above, according to the present invention,
The insulating substrate that constitutes the anode substrate is composed of a metal substrate and an insulating film formed on the metal substrate. By providing a dark black film on at least the surface of the metal substrate that contacts the atmospheric pressure side, Since the heat generated by the substrate is efficiently radiated into the atmospheric pressure, the temperature rise of the phosphor layer can be reliably suppressed,
An extremely excellent effect of suppressing a decrease in luminous efficiency can be obtained.

Further, according to the present invention, when it is applied to a fluorescent display tube such as an ultra-bright fluorescent display tube in which a temperature rise of a phosphor (room temperature + 10 ° C. or more) occurs, a fluorescent material which simply uses a metal substrate as a substrate. As compared with the display tube, it is possible to obtain extremely excellent effects such as reduction of luminous efficiency (luminance) and reduction of life of constituent members due to temperature rise.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a configuration according to an embodiment of a fluorescent display tube according to the present invention.

FIG. 2 is a characteristic diagram showing a relationship between relative luminance and input power of a fluorescent display tube.

FIG. 3 is a characteristic diagram showing a relationship of relative luminance with respect to a lighting time of a fluorescent display tube.

FIG. 4 is a cross-sectional view of an essential part showing the structure of a conventional fluorescent display tube.

[Explanation of symbols]

1A ... Insulating substrate, 1a ... Ti substrate, 1b ... Insulating film, 2
... Wiring layer, 3 ... Insulating layer, 4 ... Anode layer, 5 ... Phosphor layer, 6
... Display segment, 7A ... Anode substrate, 8 ... Filament support, 9 ... Filament, 10 ... Control electrode, 10a ...
Mesh part, 10b ... Frame body, 11 ... Cover glass, 12
... Frit glass, 13 ... Ba getter, 14 ... Getter film, 15 ... Black coating.

Claims (3)

[Claims] 1. An anode substrate in which a wiring layer and an electrode layer are laminated and formed on an insulating substrate and a display segment formed by coating a phosphor layer on the electrode layer is formed, and the anode substrate is disposed above the display segment. Filamentous cathode, a control electrode disposed between the display segment and the filamentary cathode, and a transparent cover glass that covers the filamentary cathode and the control electrode and is hermetically sealed to the anode substrate. And a vacuum-exhausted vacuum-sealed space formed by the anode substrate and the cover glass, wherein the insulating substrate is a metal substrate, and an insulating film formed on the metal substrate. And a dark black coating provided on at least a surface of the metal substrate which is in contact with the atmospheric pressure side. 2. The metal substrate according to claim 1, wherein the metal substrate is T
i, Ti alloy, 426 alloy, 50-50 alloy, 13Cr
A fluorescent display tube comprising one of an alloy, an 18Cr alloy, and an Fe-Ni-Cr-Mn alloy. 3. The dark black coating according to claim 1,
A fluorescent display tube characterized by using one of dark black lacquer, dark black paint, dark black pigment or graphite.