JP5201590B2 - Fluorescent lamp - Google Patents

Description

  The present invention relates to a fluorescent lamp that can suppress abnormal heating of an electrode portion that occurs at the end of the life of the fluorescent lamp.

  When the fluorescent lamp is lit, a high frequency current of several tens of kHz is input to the filament through the lead wire. The lighting circuit is generally provided with a detection mechanism that stops oscillation at the end of the life of the fluorescent lamp. However, the detection mechanism does not work for some reason, and a large electric power is input to the filament, and the electrode part may be abnormally heated.

  In order to prevent abnormal heating of the electrode part, in Patent Document 1, an insulator is provided on the flare stem so as to cover the top of the flare stem between the pair of lead wire sealing parts, and leads are provided in the holes of the insulator. A method of inserting each wire and fixing it so as to move somewhat with respect to the lead wire is disclosed. As a result, a conductive material is deposited on the stem and the insulator to form a conductive path, and abnormal current heating due to current flowing through the conductive path can be prevented.

  Further, in Patent Document 2, a glass member as a rod-shaped shielding member is substantially parallel to the central axis of the filament in each of a pair of lead wires made of nickel or the like supported by hermetically penetrating the flare stem. And the method of arrange | positioning so that a predetermined | prescribed clearance gap may arise between glass members is disclosed. This prevents the conductive scattered matter from adhering and accumulating between the stem top and the lead-in line. In addition, a lot of conductive scattered matter adheres and accumulates on the surface of each glass member. However, since each glass member is disposed so that a predetermined gap is formed between the glass members in a pair of lead wires, And the formation of a conductive path by conductive scattered matter is suppressed.

  Further, in Patent Document 3, a pair of inner lead wires, which are electric lead wires made of nickel or the like, are hermetically penetrated and fixed to the flare stem in the axial direction, and a filament that is an electrode at the inner end of the inner lead wire. A method is disclosed in which a glass member, which is a glass member, is fixed substantially in parallel to the filament at an axially intermediate portion of at least one of the inner lead wires. This reduces the amount of electrode material scattered from the filament that accumulates on the top surface of the flare stem.

Japanese Patent Laid-Open No. 11-345596 JP 2004-158207 A JP 2005-302386 A

The cause of abnormal heating that occurs at the end of the life of a fluorescent lamp is that the conductive material deposited on the top of the stem forms a current-carrying circuit and current flows through this current-carrying circuit. It is known that heat is generated by electric discharge from the welded portion with the introduced lead wire. A method for preventing the conductive material from accumulating on the top of the stem has been studied conventionally, but a method for preventing discharge from the weld has not been studied.
The techniques described in Patent Documents 1 to 3 can prevent the conductive path from being formed by the conductive material deposited on the top of the stem by preventing the conductive material from depositing on the top of the stem. However, it is not possible to suppress abnormal heating of the electrode portion due to a discharge generated from the welded portion between the lead wire and the lead wire provided in the stem at the end of the life of the fluorescent lamp, which is the second cause.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fluorescent lamp capable of suppressing abnormal heating of the electrode portion at the end of the life of the fluorescent lamp.

  In order to achieve the above object, a fluorescent lamp according to the present invention includes a filament, a pair of lead wires having one end joined to both ends of the filament, and a pair of conductive members that protrude. At least one of a joint between the other end of the pair of lead wires and the other end of the pair of lead wires and the pair of conductive members is connected to the protruding portion of the pair of conductive members. And an insulating member for sealing.

  ADVANTAGE OF THE INVENTION According to this invention, the abnormal heating of the electrode part in the lifetime end of a fluorescent lamp can be suppressed.

It is an external view which shows the structure of the annular fluorescent lamp which concerns on embodiment of this invention. It is a figure which shows the electrode part of an annular fluorescent lamp. It is a figure which shows the state by which the glass member is each attached to the welding part which joined the lead wire and the lead wire with which the stem was equipped, and the welding part is covered with the glass member. It is a figure which shows the state by which the glass member was mounted | worn in the welding part. It is a figure which shows the state by which a pair of glass member was mounted | worn by the welding part.

[First embodiment]
Hereinafter, a fluorescent lamp 10 according to a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the fluorescent lamp 10 includes a base 1 made of resin or the like, a base pin 2, and an annular fluorescent tube 3.

  As shown in FIG. 2, an electrode portion 30 is provided inside the fluorescent tube 3 of the annular fluorescent lamp 10, and a lighting circuit (not shown) is provided in the main body of the annular fluorescent lamp 10.

  As shown in FIG. 3, the electrode unit 30 includes a stem 20 having a pair of lead wires 21 and 22, a filament 31, a pair of lead wires 32 and 33, glass members 36, 37, 38 and 39, It is composed of

  A pair of lead wires 21 and 22 penetrates the stem 20 and protrudes from the top of the stem 20.

  One end of the introduction wire 22 and one end of the lead wire 32 and one end of the introduction wire 21 and one end of the lead wire 33 are welded.

  The glass members 36, 37, 38, and 39 are each cylindrical, and the glass members 36 and 38 have the same length, and the glass members 37 and 39 have the same length. The glass members 36 and 38 are heated and melted so as to sandwich the welded portion 34, and the glass members 37 and 39 are sealed so as to cover the welded portions 34 and 35, respectively. ing.

  Further, the glass members 36, 37, 38, 39 are arranged substantially parallel to the filament 31, and the glass members 36, 38 and the glass members 37, 39 are separated from each other.

  According to this configuration, since the welds 34 and 35 are sealed with glass having a high dielectric constant, no discharge occurs in the weld. For this reason, the abnormal heating by discharge is suppressed.

  Further, since the glass members 36, 37, 38, 39 are arranged substantially in parallel with the filament 31, the conductive material evaporated and scattered from the filament 31 is deposited on the glass members 36, 37, 38, 39, and the stem. Therefore, it is possible to prevent the electricity from being deposited on 20. Further, since a space is arranged between the glass members 36 and 38 and the glass members 37 and 39, even if a conductive material is deposited on the glass members 36, 37, 38, 39, the lead wires 32 and It is possible to prevent a situation in which the terminal 33 is electrically connected.

[Second Embodiment]
In the first embodiment, the two welded portions 34 and 35 are sealed by the glass members 36 and 38 and the glass members 37 and 39, respectively. However, both ends are not necessarily sealed.

  For example, as shown in FIG. 4, only one weld 34 may be sealed.

  Further, as shown in FIG. 4, a cover may be disposed on the filament so that scattering material from the filament does not accumulate on the top of the stem.

  Moreover, the front-end | tip part of the glass members 41 and 43 and the front-end | tip part of the glass members 42 and 44 may overlap, and may be arrange | positioned so that the top part of the stem 20 may not be exposed seeing from the filament side.

[Third embodiment]
In the first embodiment, the welds 34 and 35 are individually sealed. However, as shown in FIG. 5, they may be sealed with a common glass member.

  In addition, although the said embodiment demonstrated the case where a glass member was a column shape, this glass member is not limited to a column shape, A prismatic shape, a flat plate shape, spherical shape, a rectangular shape, or the middle of a glass member is bent. Various applications and modifications such as are possible.

  Further, the material for sealing the welded portion is not limited to glass, and may be an insulating material having high dielectric constant and heat resistance, such as ceramic.

  Furthermore, the shape of the fluorescent lamp of the present invention may be other than an annular shape such as a straight tube shape or a U-shape.

1 cap 2 cap pin 3 fluorescent tube 10 fluorescent lamp 20 stem 21, 22 lead wire 30 electrode portion 31 filament 32, 33 lead wire 34, 35 lead wire welded portion 36, 37, 38, 39, 41, 42, 43, 44 , 51,52 Glass member

Claims (4)

Filament,
A pair of lead wires joined at one end to both ends of the filament;
A stem having a pair of conductive members arranged so as to protrude, and having the other ends of the pair of lead wires connected to the protruding portions of the pair of conductive members;
An insulating member that seals at least one of the joints between the other end of the pair of lead wires and the pair of conductive members;
A fluorescent lamp characterized by comprising: The insulating member includes two sealing members that respectively cover a pair of the joint portions between the pair of lead wires and the pair of conductive members.
The fluorescent lamp according to claim 1, wherein: The insulating member includes a single sealing member that seals a pair of the joint portions between the pair of lead wires and the pair of conductive members.
The fluorescent lamp according to claim 1, wherein: And a second insulating member disposed on the pair of lead wires.
The fluorescent lamp according to any one of claims 1 to 3, wherein the fluorescent lamp is characterized in that

Images