JPH11120959A - Fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp preventing the fall out of an electrode scattered material sticking preventing member fitted to one lead wire as a flare stem internal lead wire short circuit preventing means at the life termination of a high-frequency lighting fluorescent lamp and a short circuit between the internal lead wires caused by the insulation distance deficit or contact with the other internal lead wire. SOLUTION: A pair of internal lead wires 3a, 3b are inserted into a flare stem 2 at the end of an arc tube 1, and a filament 4 is provided inside ends of the internal lead wires 3a, 3b in this fluorescent lamp. A shield member 6 held by a lead wire 5 electrically insulated from the internal lead wires 3a, 3b is provided at an intermediate section between a pair of internal lead wires 3a, 3b sealed to a flare stem 2 as a scattered material sticking preventing member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp in which a short circuit between internal lead wires caused by deposition and deposition of scattered substances due to evaporation of a filament is prevented.

[0002]

2. Description of the Related Art When a fluorescent lamp is operated at a high frequency for a long period of time, a filament material (W), an electron emitting material (BaO or the like) applied to the filament, and internal lead wires (Ni, Fe) holding the filament are scattered. , Adheres and accumulates on the tip surface of the flare stem near the filament. Particularly at the end of the life of the lamp, scattering becomes severe, and these tend to adhere and accumulate on the tip surface of the flare stem.

[0003] Since the above-mentioned deposits are conductive substances, they may be energized when deposited. Therefore, a conductive path is formed between the pair of internal leads insulated by the scattered matter attached and deposited on the front end surface of the flare stem, and there is a case where conduction is made between the internal leads.

In such a case, after the filament is broken, a current flows through a conductive path formed by the attachment and deposition of the scattered substance between the pair of internal leads, generating heat and causing thermal damage to the flare stem or large power loss. There is a problem that causes.
Therefore, Japanese Patent Application Laid-open No.
A fluorescent lamp described in JP-A-338289 is known.

In the fluorescent lamp described in Japanese Patent Application Laid-Open No. 6-338289, a recess is formed at the root of at least one of the pair of internal leads or between the pair of internal leads. Alternatively, an insulator surrounding at least one of the pair of internal lead wires around the sealing portion, or an overhanging member using an insulator in the middle of the internal lead wire and scattered material is applied to the sealing member. Techniques are provided to prevent adhesion.

[0006]

However, in the conventional fluorescent lamp described in Japanese Patent Application Laid-Open No. 6-338289, the overhanging member is provided in the middle of at least one of the pair of internal lead wires. When the internal lead wire melts due to electric discharge at the end of the life, there is a disadvantage that the overhang member also falls off. Further, when the overhanging member is made of metal, there is a problem that the insulation distance between the overhanging member and the other internal lead wire is insufficient, or that the overhanging member on which the scattered substance is deposited is electrically connected to the other internal lead wire due to contact. .

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it has been found that an overhanging member falls off due to melting of an internal lead wire, an insulation distance between the overhanging member and another internal lead wire is insufficient, or a contact is made. It is an object of the present invention to provide a fluorescent lamp which can eliminate the conduction caused by the fluorescent lamp.

[0008]

In order to achieve the above object, a first aspect of the present invention is to penetrate a pair of internal leads through an arc tube sealing end, and provide a filament at an inner end of the internal leads. In the fluorescent lamp, the shielding member is joined to a lead wire provided electrically insulated from these internal leads at an intermediate portion between the internal leads of the sealing member. It is characterized by.

According to a second aspect of the present invention, the shielding member is made of an insulator or a metal.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the embodiments shown in FIGS. FIG. 1 is a sectional view of an end portion of a fluorescent lamp, and FIG. 2 is a perspective view showing the entire compact fluorescent lamp. In the figure, reference numeral 1 denotes an arc tube made of a glass tube having a phosphor coating on the inner surface. The end of the arc tube 1 is closed by a flare stem 2. A pair of internal lead wires 3a and 3b made of nickel, iron, or the like is passed through the flare stem 2 in an airtight manner, and a filament 4 made of tungsten is provided at an end of the internal lead wires 3a and 3b. . The filament 4 is coated with an electron emitting material such as barium oxide.

In the arc tube thus constructed, a pair of internal lead wires 3a, 3b
The inner lead wire 3a,
A shielding member 6 is provided which is electrically insulated from 3b and held by the sealed lead wire 5. The shielding member 6 is made of an insulator or a metal.

According to the present invention, the filament 4 and the electron emitting material or the internal lead wires 3a and 3b applied to the filament 4 evaporate into the scattered material during the lighting and at the end of the life, and are formed on the surface of the flare stem 2 near the lead wire. Even if it is attempted to adhere, the scattered substance adheres and accumulates on the shielding member 6 provided between the filament 4 and the flare stem 2, and the scattered substance adhering and accumulating on the flare stem 2 decreases. This makes it difficult to form a conductive path formed by the deposition of the scattered substance, and can reduce the ratio of short-circuiting between the pair of internal lead wires 3a and 3b.

Even if the internal lead wire 3a falls off due to thermal damage, the adhesion preventing member does not fall off.
Further, even when the shielding member 6 is made of metal and the adhesion preventing member is tilted and the shielding member 6 comes into contact with the internal lead wire 3a,
Since the adhesion preventing member is separated from the internal lead wire 3b, insulation can be maintained between the pair of internal lead wires 3a and 3b.

[0014]

As described above, the present invention provides an anti-adhesion member which is electrically insulated from a pair of internal leads between a pair of internal leads so that the scattered substance evaporated from the filament is deposited. It becomes difficult to form the formed conductive path, and it is possible to prevent a short circuit between the pair of internal lead wires.

Also, the present invention provides a method for removing an adhesion preventing member due to melting of an internal lead wire to which an adhesion preventing member of a pair of internal lead wires is joined, a short insulation distance between the adhesion preventing member and the other internal lead wire, or the like. Short circuit between the internal lead wires due to contact can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an end portion of a fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an entire fluorescent lamp showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Arc tube 2 ... Flare stem 3 ... Internal lead wire 4 ... Filament 5 ... Lead wire 6 ... Shielding member.

Claims (2)

[Claims] 1. A fluorescent lamp in which a pair of internal leads are hermetically penetrated through a sealed end of an arc tube and a filament is provided at ends of the pair of internal leads inside the arc tube. A fluorescent lamp characterized in that an electrode scattering substance adhesion preventing member constituted by joining a shielding member to a lead wire provided electrically insulated from these internal lead wires is provided at an intermediate portion between the wires. 2. The fluorescent lamp according to claim 1, wherein said shielding member is made of an insulator or a metal.