JPH06243823A - Discharge tube - Google Patents

Abstract

PURPOSE:To simplify the electrode structure by giving no influence to the electric property of a discharge tube, and to simplify its assembly. CONSTITUTION:A conductive membrane 5 is attached and formed to the inner wall surface of a glass pipe 1A whose one end is sealed, by a spattering or the like, for example, and a cup form metallic electrode 6 is installed to the outer wall surface of the glass pipe 1A, so as to compose an electrode device 4A to be connected electrically and in a high frequency means, and the electrode device 4A is connected to an inner lead wire 3.

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 liquid crystal panel backlight, and in particular, a glass tube is filled with a rare gas and mercury, and a pair of electrode devices are opposed to each other at both ends. The present invention relates to a discharge tube arranged and configured.

[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, and FIG. 2 (b) is an enlarged sectional view of an essential part of the electrode device portion. In FIG. 2 (a),
Reference numeral 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 held at the longitudinal end of the glass tube 1 penetrating the glass tube 1. Inner leads 4 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 distal end portions 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 FIG. 2 (b), 4 ₁ arc discharge electrodes, 4 ₂ the arc discharge electrode 4 made of a cylindrical body of the sintered metal body which emits thermal electrons is provided on the tip portion of the inner lead 3 It is a conical glow discharge electrode which is crimped and fixed to the arc discharge electrode 4 ₁ so as to surround ₁ and is coaxially arranged. The arc discharge electrode 4 ₁ and the glow discharge electrode 4 ₂ constitute an electrode device 4. ing.

In such a structure, the pair of electrode devices 4 arranged to face each other is composed of an arc discharge electrode 4 ₁ and a glow discharge electrode 4 ₂ , which are arranged adjacent to each other, and arc discharge and glow discharge the synergistic effect of obtained by the discharge of the ultra-high luminance is stabilized, the electron emission material discharge tube ultra-high luminance is emitted scattered evaporated from the arc discharge electrode 4 ₁ by ion bombardment with the resulting glow discharge electrode 4 _The long-life discharge tube is obtained because the electron-emitting substance trapped in ₂ can be reused for electron emission.

[0006]

However, in the discharge tube thus constructed, the electrode device 4 is composed of the arc discharge electrode 4 ₁ and the glow discharge electrode 4 _{2 each} having a complicated electrode structure and the inner lead. 3 is fixedly arranged at the tip portion of the glass tube 3, mounted on a stem glass (not shown), and the stem glass structure is assembled by sealing the both ends of the glass tube 1, respectively, and an exhaust pipe (not shown) provided on the stem glass structure. Since the air is exhausted from above to perform the sealing, the manufacturing process is complicated and the productivity cannot be significantly improved.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and the purpose thereof is to simplify the electrode structure without affecting the electrical characteristics of the discharge tube at all. An object of the present invention is to provide a discharge tube capable of simplifying assembly.

[0008]

In order to achieve such an object, the present invention provides a first electrode device in a discharge space in which at least a rare gas and mercury are sealed in a glass tube whose one end is sealed. A second electrode device is disposed so as to face each other, and the first electrode device includes a conductive film formed on an inner wall surface of the glass tube and a metal electrode provided on an outer wall surface of the glass tube, The second electrode device includes an arc discharge electrode that evaporates and emits an electron emitting substance, and a cone-shaped glow discharge electrode that covers the arc discharge electrode and that captures the electron emitting substance that is evaporatively emitted and emitted from the arc discharge electrode. It is what constitutes.

[0009]

According to the present invention, the first electrode device disposed at one end side of the glass tube whose one end is sealed is provided on the conductive film formed on the inner wall surface of the glass tube and on the outer wall surface of the glass tube. Since it is composed of a metal electrode that is formed, one of the electrode structures is simplified and the assembly process is simplified.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an enlarged cross-sectional view of an essential part of an electrode device portion showing a configuration according to an embodiment of a discharge tube according to the present invention, and the same portions as those in the above-mentioned drawings are designated by the same reference numerals. In the figure, a conductive film 5 is formed on the inner wall surface of the glass tube 1A whose one end side is sealed by, for example, sputtering, and a cup-shaped metal electrode 6 is attached to the outer wall surface of the glass tube 1A. The metal electrode 6 and the conductive film 5 are connected in high frequency to form an electrode device 4A. The metal electrode 6 of the electrode device 4A is electrically connected to the inner lead 3.

The conductive film 5 is formed of, for example, an aluminum material to a thickness of 1 to 2 μm by a vapor deposition method, and the metal electrode 6 is formed of an iron or nickel material by a molding method.

In such a structure, assuming that the capacitance between the conductive film 5 and the metal electrode 6 is C (F) and the driving frequency is f (Hz), the impedance Z therebetween is Z = 1 / It becomes 2π · f · C (Ω). Therefore, by increasing the driving frequency f and the capacitance C, the impedance Z becomes smaller and electrical coupling becomes possible.

According to this structure, as shown in FIG. 1, the counter electrode formed in the glass tube 1A so as to face the electrode device 4 is the conductive film 5 formed on the inner wall surface of the glass tube 1A.
Since it is formed by only the inner lead 3, the structure of the electrode is easier than that of the electrode device 4 which requires the inner lead 3 to be sealed with the glass tube 1.

Further, according to this structure, the electrode device 4A and the conductive film 5 form a capacitor having a capacitance of about several tens of pF, which functions as a ballast capacitor. A ballast capacitor of ˜70 pF was connected in series with the discharge tube, but this can be omitted.

In the above-described embodiment, the arc discharge electrode 4 ₁ has been described as a case where a molded structure in which a sintered metal body is molded into a column shape is used, but the present invention is not limited to this. Of course, the same effect as described above can be obtained by using a coil structure formed by forming a tungsten wire into a coil shape.

[0016]

As described above, according to the present invention,
The electrode structure of the electrode device is simplified by configuring the first electrode device facing each other by the conductive film formed on the inner wall surface of the glass tube and the metal electrode provided on the outer wall surface of the glass tube. At the same time, the assembly process is simplified, so that there is an extremely excellent effect that the yield can be improved without affecting the electrical characteristics of the discharge tube at all.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing the structure of a conventional discharge tube.

[Explanation of symbols]

1A Glass tube 2 Fluorescent substance 3 Inner lead 4 Electrode device 4A Electrode device 4 ₁ Arc discharge electrode 4 ₂ Glow discharge electrode 5 Conductive film 6 Metal 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 3-1,36 Noritake Shinmachi, Nishi-ku, Nagoya-shi Noritake Company Limited Company (72) Inventor Sato Fuyu 3-1, 36 Noritake Shin-cho, Nishi-ku, Nagoya Noritake Co., Ltd. Company Limited

Claims (1)

[Claims] 1. A first electrode device and a second electrode device are arranged to face each other in a discharge space in which at least a rare gas and mercury are sealed in a glass tube whose one end is sealed, and the first electrode device. Is composed of a conductive film formed on the inner wall surface of the glass tube, and a metal electrode provided on the outer wall surface of the glass tube, and the second electrode device is an arc discharge electrode that scatters and evaporates and emits an electron emitting substance. And a cone-shaped glow discharge electrode which covers the arc discharge electrode and traps the electron emission material scattered and evaporated and emitted from the arc discharge electrode.