JPS60130023A - Electrode filament - Google Patents

Abstract

PURPOSE:To obtain an electrode filament with high efficiency by depositing and forming an LaB6 coating layer for a thermion emission material on a matrix metal wire using the discharge coating. method. CONSTITUTION:A surface coating layer 2 made of LaB6 is formed on the surface of a tungusten wire 1 at a thickness below 10 microns using the discharge coating method. The discharge coating uses a method in which while a coating material electrode and a metal wire are being made to touch, separated, oscillated or rotated and slided, discharge is generated between both and the coating material is deposited to a matrix metal wire, a method in which a coating material wire is dissolved and scattered by shock discharge and is made to collide against the matrix metal wire, a method in which coating material powder is jetted by shock discharge and is made to collide against the matrix and is deposited and applied, a method in which shock discharge is performed between the coating material electrodes opposed to the matrix, and such. As a result, the coating layer can be formed on the surface of the matrix metal wire as the LaB6 compound without decomposing the coating material LaB6 and the coating layer that is deposited to the matrix and is coupled tightly can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in lamp filaments or discharge lamp electrodes made of heat-resistant metal wires.

Conventional filaments for incandescent light bulbs use heat-resistant metal wire, with a small amount of zirconium oxide added to the surface of the coiled filament, which is usually made of tungsten wire, and oxides mainly containing electron-emitting substances such as barium, strontium, and calcium. Apply something and use it. In addition, bulbs with a vacuum, high-pressure mercury or sodium atmosphere, or a special gas such as argon were used. thus,
Improvements have been made so that high illuminance per unit power, for example, lumens/W, can be obtained. In order to improve this even more significantly, the present invention proposes that when a known heat-resistant metal wire is used and a high electron emission beam is used, a discharge is applied to the surface of the wire.
It is formed by welding a thin coating layer of aB5.

An embodiment of the present invention will be described. 1 and 2 are cross-sectional views of a standard model of a filament for a light bulb according to the present invention.

In the present invention, as the heat-resistant metal, a material having a high melting point, conductivity, and electron emitting property, such as tungsten, tantalum, platinum, or iridium, is used. In the example shown in Fig. 1, when tungsten is used as the core material 1, lanthanum hexaboride (LaBa) is coated on the surface of the tungsten wire 1 with a required diameter to a thickness of 10 microns or less using an electrical discharge coating method. ,
A surface coating layer 2 was formed. In the example shown in Fig. 2, when the core material 1 is used as a heat-resistant material, for example, an iridium plating layer 3 with a thickness of 10 microns is formed on the surface of a tungsten wire 1 having a required diameter. The surface coating layer 2 was formed using lanthanum hexaboride, which has a low diffusion rate of boron, to a thickness of 10 microns or less in the same manner as in the case of FIG. 1 above. In addition to this case, there are also cases in which a tantalum filament is used as the core material 1, an iridium layer 3 is formed on the surface thereof, and a boride coating layer 2 is formed, and a tungsten filament is used as the core material 1 and a platinum coating layer 3 is formed on the surface. A lanthanum hexaboride thin film layer 2 formed by forming the lanthanum hexaboride thin film layer 2 can be used.

Good results were also obtained when a thallium filament, a platinum filament, or a tantalum filament was used as the core material 1 and coated with a rare earth boride. Furthermore, molybdenum, nickel, iron, etc. are also used. next,
The tungsten filament 1 of the present invention is plated with platinum to a thickness of 10 microns, and the top surface is coated with lanthanum hexaboride 2 to make a light bulb wire (N15 in the table), compared to other conventional wires. Comparing the lumen/W with that using
Shown in the table. The luminance efficiency has been significantly improved.

In addition, the discharge coating is made by subjecting the coating material electrode and the metal wire to contact/release vibration or rotational sliding to generate a discharge between them. A method of welding the coating material to the wire, a method of melting and scattering the coating material wire by impact discharge and applying impact coating to the base metal wire, or a method of welding and coating the coating material powder by spraying the coating material powder by impact discharge and causing it to collide with the base metal wire. Alternatively, a method of performing impact discharge between electrodes of the coating material facing the base material is used, and the L of the coating material is
A coating layer can be formed on the surface of the base metal wire without decomposing aBa (LaB6 compound), and a coating layer that is firmly bonded to the base metal by welding can be obtained.
Although the thickness was 1 to 0.8 mm, it is desirable to devise an even thicker coating.

When used as a discharge lamp electrode, the service life was over 6000 H and the color temperature was approximately 2800 H when tested by inserting it into a glass tube coated with fluorescent paint and filled with Ar mercury.
K, high efficiency of 32% (52KHz), 13W,
It was 725O lumens.

In this way, in the present invention, a coating layer of LaB5, which is a thermionic emissive material, is welded to a base metal wire using a discharge coating, so that a highly efficient electrode filament can be obtained, and a good electrode with a long life can be obtained. There is an effect that can be obtained.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of a model according to an embodiment of the present invention. 1... Center filament 2... 6 Lanthanum boride coating layer 3... Covering metal layer Patent applicant Bengami Japax Research Institute Agent Patent attorney Nakanishi - #1lvl Calculation 2 Figure

Claims (1)

[Claims] An electrode filament characterized by forming a thin coating layer made of LaBs, a thermionic emission material, on the surface of a heat-resistant metal wire such as tungsten using electric discharge.