JPH065251A - Discharge tube - Google Patents

Abstract

PURPOSE:To manufacture a discharge tube which can secure a sufficient discharge electrode area and can obtain a high brightness light emission in a compact size by forming the secondary electrode surrounding the first electrode connected to an inner lead, in a conical form, in an electrode device. CONSTITUTION:Inner leads 3 are held by penetrating the ends in the longitudinal direction of a glass tube 1 to form a discharge tube main body in which a phosphor substance 2 is spread on the inner wall surface, and a pair of electrode devices 4A are provided oppositely at the tips of the inner leads 3. This electrode device 4A is composed of the first electrode 41A provided at the tip of the inner lead 3, and the second electrode 42A surrounding the first electrode 41A, and the second electrode 42A is formed in a conical form in apperance. Consequently, a discharge tube having a sufficient discharge property can be obtained, and a long service life is obtained as well as increasing the luminous energy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge tube applied to, for example, a backlight for a liquid crystal panel, and in particular, it is constructed by enclosing a rare gas and mercury in a glass tube and connected to inner leads at both ends. The present invention relates to a discharge tube in which an electrode device composed of a first electrode part and a second electrode part surrounding the outer periphery of the first electrode part is arranged to face each other, and more specifically to an electrode structure of the electrode device. It is a thing.

[0002]

2. Description of the Related Art With recent advances in liquid crystal technology, liquid crystal display panels have come to be widely used in various display devices. Recently, a liquid crystal display device using this liquid crystal display panel has been strongly demanded to be particularly small and lightweight, and in order to satisfy the requirements relating to such a liquid crystal display device, a discharge tube is widely used as a backlight of the liquid crystal display panel. Has been adopted.
Therefore, in order to manufacture a miniaturized liquid crystal display device, it has been particularly required to improve the liquid crystal display panel and miniaturize the backlight. At the same time, in order to improve the display quality, higher brightness and longer life are required.

FIG. 2 is a diagram for explaining the structure of this type of discharge tube. FIG. 2 (a) is a sectional view, FIG. 2 (b) is an enlarged perspective view of the essential parts of the electrode device, and FIG. FIG. Figure 2
In (a), 1 is a transparent glass tube forming the main body of the discharge tube, 2 is a fluorescent substance applied to the inner wall surface of the glass tube 1, and 3 is the glass tube 1 at the longitudinal end of the glass tube 1. Inner leads 4 which are held so as to be penetrated are a pair of electrode devices which are arranged coaxially in the longitudinal direction of the glass tube 1 so as to face each other at the tips of the inner leads 3. The glass tube 1 is filled with a mixed gas of, for example, argon gas and mercury for discharging.

Further, in FIGS. 2B and 2C, 4 ₁
Is a first electrode provided at the tip of the inner lead 3,
4 ₂ is a second electrode of the first electrode 4 ₁ so as to surround the inner leads 3 or the first electrode 4 ₁ caulking fixed like a cylinder disposed coaxially.

In such a structure, the pair of electrode devices 4 arranged to face each other is composed of the first electrode 4 ₁ and the second electrode 4 ₂ , which are arranged adjacent to each other. First
The electrode 4 _{1 of the above} is impregnated or coated on the surface with an emitter material as a thermionic emission substance, and it functions as an arc discharge electrode, and the second electrode 4 ₂ functions as a glow discharge electrode. A stable discharge can be obtained.
Ultra-high-intensity discharge tubes stable thermionic emission material first electrode 4 ₁ with obtained is a spatter evaporated by ion bombardment in the inner surface black glass tube 1 are captured in 4 ₂ of the inner surface the second electrode of the This trapped thermoelectron emitting material is used as an electron emitting material on the second electrode 4 ₂ without being changed to a new _one , and is repeatedly captured by the first electrode 4 ₁ again, so that a long life is obtained. The discharge tube of is obtained. A discharge tube of this type is disclosed in, for example, Japanese Patent Application No. 2-318277.

[0006]

However, the discharge tube constructed in this way is arranged in the glass tube 1 when the diameter of the glass tube 1 is limited to meet the demand for downsizing. The electrode diameter of the electrode device 4 is limited, and the electrode area is reduced. Therefore, the second electrode 4
₂ is set to be equal to or less than the inner diameter of the glass tube 1, and its shape is set to be cylindrical. As a result, the second electrode 4 ₂ is part for emission of electrons E when performing glow discharge has not been utilized only the electrode opening end only,
Therefore, there is a problem that a sufficient discharge current cannot be obtained and the amount of light becomes insufficient, so that high-luminance light emission cannot be obtained.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a discharge tube which is small in size and capable of realizing high-luminance light emission.

[0008]

In order to achieve such an object, the present invention forms the second electrode in a conical shape.

[0009]

Since the second electrode of the present invention is formed in a conical shape, a sufficient discharge electrode area can be secured.
Sufficient discharge characteristics are obtained and the amount of emitted light is increased.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1A and 1B are views for explaining the configuration of an embodiment of a discharge tube according to the present invention. FIG. 1A is a sectional view, FIG. 1B is an enlarged perspective view of a main part of the electrode device, and FIG. It is the cross-sectional view, and the same portions as those in the above-mentioned drawings are denoted by the same reference numerals. In the figure, the electrode device 4A includes an inner lead 3
The second electrode 4 _2A surrounding the first electrode 4 _1A provided at the tip of the is made of aluminum plate material as shown in FIGS. Is formed into a structure.

The second electrode 4 _2A thus formed in a conical shape is inserted into the inner lead 3 having the first electrode 4 _1A formed at the tip thereof, and surrounds the first electrode 4 _1A . The root portion is caulked and fixed, and is arranged at a predetermined position coaxially with the inner lead 3.

According to this structure, the second electrode 4 _2A
Since the surface area of the electrode facing the tube axis on the inner wall surface is enlarged by forming the conical shape, the portion that emits the electrons E during glow discharge has its inner wall in addition to the electrode opening end. Radiation of electrons E from the inclined surface is added, so that a sufficient discharge current is obtained, the amount of light is increased, and high-luminance light emission is obtained.

Further, since the first electrode 4 _1A is included in the second electrode 4 _2A formed in a conical shape, the first electrode 4 _1A has a temperature suitable for emitting thermoelectrons. It can be raised to emit light with high brightness. Further, the conical second electrode 4 _2A is blackened by thermionic emission material which is sputtered by the ion bombardment of the first electrode 4 _{1A and} is scattered and evaporated, or adhered to the inner surface of the glass tube 1 by the electrode member. while preventing, available thermionic emission by the electron emitting materials attached to the inner surface of the second electrode _2A, also, the electron emission substance by causing redeposition the electron emission substance on the surface of the first electrode 4 _1A The regeneration effect can be used and the life can be extended.

In the above-mentioned embodiment, the case where the second electrode _42A is made of an aluminum material has been described, but it may be made of a nickel material, and a mixture of tungsten and nickel may be formed by a die. Alternatively, a sintered body may be used in which the cross section has a saw-tooth shape and the entire shape is a bell shape and is sintered.

[0015]

As described above, according to the present invention,
Since the second electrode is formed in a conical shape, a sufficient discharge electrode area can be secured, so that sufficient discharge characteristics can be obtained,
It has extremely excellent effects such as an increase in the amount of emitted light, a small size, high-luminance light emission, and a long-life discharge tube.

[Brief description of drawings]

FIG. 1A is a sectional view showing a structure according to an embodiment of a discharge tube according to the present invention, FIG. 1B is an enlarged perspective view of an essential part showing a structure of an electrode device, and FIG. 1C is a sectional view thereof.

FIG. 2A is a cross-sectional view showing the configuration of a conventional discharge tube,
(B) is an enlarged perspective view of an essential part showing the configuration of the electrode device, (c)
Is a sectional view thereof.

[Explanation of symbols]

1 Glass Tube 2 Fluorescent Material 3 Inner Lead 4A Electrode Device 4 _1A First Electrode 4 _2A Second Electrode

Front Page Continuation (72) Inventor Ken Kawai 700 Wada, Ueno Town, Ise City, Mie Prefecture, Ise Denshi Kogyo Co., Ltd. (72) Inventor Qi Tsuji, 1-3-1, Noritake Shincho, Nishi-ku, Nagoya Limited (72) Inventor Yoshiyuki Okubo No. 1-36 Noritake Shincho, Nishi-ku, Nagoya-shi Noritake Company Limited Company (72) Inventor Sato Winter No. 36 Noritake Shin-cho, Nishi-ku, Nagoya Noritake Co., Ltd. Company Limited

Claims (1)

[Claims] 1. A discharge comprising a pair of electrode devices arranged opposite to each other in a discharge space and having a first electrode portion connected to an inner lead and a second electrode portion surrounding the outer periphery of the first electrode portion. In the tube, the discharge tube is characterized in that the second electrode portion is formed in a conical shape.