JPH09204905A - Discharge display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the life and reduce the manufacturing cost by providing a surface plate having a surface modified layer containing tin on one surface, and installing the surface plate with this surface being opposed to a discharge space side. SOLUTION: Fused glass 22 is poured from a glass fusing furnace 21 and put into a float bath 23. The bath 23 is filled with molten metal tin 23, and the glass poured thereon is laid in the equilibrated state when it has a certain thickness to form a glass plate having a smooth surface. The solidified glass plate is carried on a roller 25 with cooling. Since the float plate glass is carried on the molten tin 24, a surface alteration layer is automatically formed on the glass surface contacting the tin 24. This surface modified layer becomes a thin reformed layer in which the quality of the glass s2 is changed by dissolving the tin 24 or tin oxide into the glass surface. When this float plate glass is used as the surface plate of a discharge display element, the tin of the modified layer works as a protecting film to prevent the blackening of the surface plate. The surface plate is installed with the surface having the surface modified layer being opposed to the discharge space side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge display element, and more particularly to a discharge display element used for a display device of a large screen color display device.

[0002]

2. Description of the Related Art Conventionally, the image display surface of a large-screen color display device has a discharge display element 1 as shown in FIG.
Are arranged in the vertical and horizontal directions to form a display surface, and by appropriately controlling the blinking of the large number of discharge display elements 1, necessary information such as characters and images is displayed.

The discharge display element 1 is a single tube that emits light of a single color or multiple colors. As shown in FIG. 1, four light emitting chambers 6 are provided on a cylindrical glass bulb 4 containing a common cathode 2.
Discharge tube body 5 formed by partitioning a, 6b, 6c and 6d
Are applied to the inner wall surfaces of the light emitting small chambers 6a, 6b, 6c, 6d, for example, green light is applied to the light emitting small chambers 6a and 6c, red is applied to 6b, and blue is applied to 6d. , A common cathode 2 and anodes 7a, 7b for selectively discharging, respectively, at one end of each of the light emitting chambers 6a, 6b, 6c, 6d.
7c and 7d are provided.

Argon and mercury are sealed in the discharge display element 1. Mercury generates ultraviolet rays by the discharge, and the ultraviolet rays excite the phosphor to emit light. Each light emitting chamber 6a, 6b,
Light emitted from 6c and 6d is a translucent face plate 1 which forms a display surface.
0 is radiated to the outside. A full-color image is displayed by arranging a large number of discharge display elements 1 as described above. In the conventional discharge display element 1, a glass plate is used as the face plate 10.

[0005]

When such a discharge display element is used as a light emitting element of a large screen color display device, it is turned on with a high load in order to display with high brightness. When it is lit with a high load, there is a problem that the blackening due to mercury oxide, sodium amalgam, etc. excessively progresses on the inner surface of the glass plate used for the face plate on the discharge space side, resulting in a significant decrease in screen brightness. It was As measures for preventing such blackening, Japanese Patent Laid-Open No. 5-290815 and Japanese Patent Laid-Open No. 6-
As described in Japanese Patent No. 342645, it is effective to form a protective film on the surface of soda glass.
There are also problems such as an increase in manufacturing cost and difficulty in obtaining stable characteristics.

The object of the present invention is to solve such a problem. The decrease in screen brightness of the discharge display element during lighting is small over a long period of time, that is, the life is long, and the manufacturing cost is reduced. Disclosed is a discharge display element capable of performing the above.

[0007]

To achieve the above object, in a discharge display device of the present invention, a discharge tube body having a translucent face plate forming a display surface and one or more of the discharge tube bodies are provided. In a discharge display device having a discharge space, the face plate is a glass having a surface-altered layer containing tin on one side, and the surface having the surface-altered layer is mounted facing the discharge space side. .

The above-mentioned surface-altered layer glass means a state in which tin or an oxide of tin is dissolved in the glass surface or a state in which it is combined with the contained atoms in the glass, and is different from the case where another film is formed. Further, the surface-altered layer glass is preferably soda glass manufactured by a float method using tin as a bath.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are views showing the structure of an embodiment of a discharge display device according to the present invention, wherein FIG. 1A is a front view and FIG.
Shows a sectional view of a portion XX ′ in the front view (a).
In FIG. 1, the discharge display element 1 is a single tube that emits monochromatic or multicolored light, and a rectangular discharge forming a luminous chamber on a cylindrical glass bulb 4 having a common cathode 2 and an auxiliary anode 3 built therein. One end of the tube body 5 is airtightly sealed and combined using, for example, low melting point glass, and the inside of the discharge tube body 5 is divided into four light emitting small chambers (discharge spaces) 6a, 6b, 6c and 6d. The other end of the discharge tube body 5 is assembled with a light-transmissive soda glass face plate 10 forming a display surface, which is hermetically sealed using a low melting point glass. Face plate 10 made of soda glass
Is a glass plate formed by the float method, and the surface of the glass in contact with the molten tin is on the discharge space side (6a, 6a).
It is the structure used for the side facing b).

A small hole serving as a discharge path for the common cathode 2 is formed at the bottom of each light emitting chamber of the discharge tube 5, and the light emitting chambers are formed on the inner wall surfaces of each of the light emitting chambers 6a, 6b, 6c and 6d. 6
a, 6c are coated with green, 6b is coated with red, and 6d is coated with a phosphor 9 that emits blue, and the light emitting chambers 6a, 6b, 6c are respectively coated.
The common cathode 2 and the anodes 7a, 7b, 7c and 7d for selectively discharging are provided at the ends of the side plates of 6 and 6d, respectively. 8a and 8b are lead wires connected to the respective electrodes,
Supply power.

Mercury and argon as a starting gas are sealed in the discharge display element 1 in an amount of 500 to 3000 Pa. Mercury generates ultraviolet rays by the discharge, and the ultraviolet rays excite the phosphor to emit light for display. The light emitted from each of the light emitting chambers 6a, 6b, 6c and 6d is transmitted to the outside through the face plate 10 which is a display surface, and a full color image or information is displayed.

FIG. 2 is a diagram showing the outline of the method for producing the soda glass used in the above-mentioned embodiment. This is called a float method, and is a method in which molten glass is poured onto molten metal tin to form a glass plate, and molten glass 22 is poured from a glass melting furnace 21 and placed in a float bath 23. The float bath 23 is filled with molten metal tin 24, and the glass poured over this is in an equilibrium state at a certain thickness, and a glass plate having a smooth surface like a mirror is formed. The solidified glass plate flows over the roller 25 while being cooled. Currently, window glass for buildings and flat glass for automobiles are mostly made by this method,
It is the glass with the lowest manufacturing cost.

Since the float glass sheet flows on the molten tin 24 as described above, a thin altered layer, that is, tin or tin oxide, is melted on the glass surface in contact with the molten tin 24 to change the quality of the glass. A very thin modified layer is automatically formed. When the float plate glass is used for the face plate of the discharge display element, tin in the pre-altered layer acts as a protective film to prevent the face plate from blackening. The surface of the pre-altered layer is, for example,
It can be easily identified because it glows white when irradiated with ultraviolet light of about 365 nm.

FIG. 3 is a characteristic diagram showing the relative luminance maintenance ratio with respect to the lighting time of the discharge display device according to one embodiment of the present invention. In the figure, A is the characteristic of the discharge display element according to the present invention, and B is the characteristic when the modified layer is on the surface side (the side opposite to the light emitting chamber 6) in the float plate glass. The luminance maintenance factor of the discharge display element of characteristic B is halved at 3,000 hours, but in this example, the luminance maintenance factor is 80% or more, and although not shown in the figure, characteristic A is 15,000.
Even with time, there was a maintenance rate of 50% or more, and luminance deterioration could be greatly reduced.

[0015]

As described above, the discharge display device according to the present invention uses the glass plate formed by the float method on the transparent face plate, and discharges the surface-altered layer of the glass plate in contact with molten tin. With the structure used on the space side, the tin film formed on the glass surface acts as a protective film to prevent blackening of the face plate for a long period of time and reduce luminance deterioration. Further, according to the present invention, a special manufacturing process for attaching a protective film for preventing luminance deterioration to a glass plate is not required, and it is not necessary to use a special glass, and the most economical soda glass is used. Therefore, the manufacturing cost of the discharge display element and the display device using a large number of discharge display elements can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a discharge display element according to the present invention.

FIG. 2 is a schematic view showing a method for manufacturing a float plate glass.

FIG. 3 is a characteristic diagram showing a lighting time and a relative luminance maintenance rate of an embodiment of the discharge display device according to the present invention.

[Explanation of symbols]

 1 ... Discharge display element 2 ... Common cathode 3 ... Auxiliary anode 4 ... Glass bulb 5 ... Discharge tube body 6 ... Light emitting chamber 7 ... Display anode 8 ... Lead wire 9 ... Phosphor 10 ... Translucent face plate 22 ... Glass 24 ... Fused tin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Ikuta 888 Fujibashi, Ome-shi, Tokyo Hitachi Heating Co., Ltd. (72) Kanji Kiburi 888 Fujibashi, Ome-shi, Tokyo Hitachi, Ltd. Vessel lighting division

Claims (4)

[Claims] 1. A discharge display element having a translucent face plate forming a display surface and one or more discharge spaces provided in the discharge tube body, wherein one face of the face plate is tin. A discharge display element, comprising a glass having a surface-altered layer containing, and being configured such that the surface having the surface-altered layer faces the discharge space side. 2. The discharge display element according to claim 1, wherein the glass having the surface-altered layer is glass formed by a float method using tin as a bath. 3. The discharge display element according to claim 2, wherein the glass is soda glass. 4. A display device having an image display surface on which a plurality of discharge display elements according to claim 1 or 2 are arranged.