JP2929648B2 - Arc tube manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a small arc tube in which a fluorescent screen glass plate and a stem are respectively sealed at both open ends of a glass tube, and electrodes are disposed inside. And a method for producing the same.

[Prior Art] A disc-shaped glass plate having a fluorescent surface formed on its inner surface and a disc-shaped stem in which electrode wires are sealed are sealed at both open ends of a cylindrical glass tube to emit light. When manufacturing a tube, the method of locally heating and sealing the joint with a carbon heater or the like has a feature that the sealing conditions are easily controlled and that little heat is applied to portions other than the sealing portion. .

[Problem to be Solved by the Invention] However, in such a manufacturing method, when one opening end of a glass tube is sealed with a phosphor screen glass plate and then the other opening end is vacuum-sealed with a stem, a heated portion is not provided. Even after joining and the inside of the glass tube becomes airtight, the portion far from the heater is heated by heat conduction, and the adsorbed gas mainly composed of moisture is released therefrom. As a result, there is a problem that the pressure inside the tube increases, and the softened heated portion expands.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing an arc tube that can prevent a sealed portion from swelling due to release of an adsorbed gas during vacuum sealing. It is in.

[Means for Solving the Problems] In order to solve the above problems, the present invention includes a glass plate having a fluorescent screen formed on an inner surface and a stem supporting an electrode at both open ends of a cylindrical glass tube. In the manufacture of an arc tube to be sealed and used as a vacuum container, the one end was closed by a fluorescent glass plate while absorbing a gas released during vacuum sealing by a non-evaporable getter provided through the stem. The opening end of the glass tube and the stem are sealed by a local heating method in a vacuum.

Embodiment 1 FIG. 1 shows an embodiment of the present invention, and shows a sealed state between a glass tube and a stem.

First, a transparent conductive film (ITO) 2 is formed on one surface at one opening end of a cylindrical (diameter 15 mm, tube length 20 mm) glass tube 1, and a phosphor screen 3 made of a phosphor is formed thereon. The glass plate 4 having a disk shape (diameter 15 mm, thickness 0.7 mm) is locally heated and sealed with a carbon heater or the like.

Next, the cathode element 6 is attached to the button-type stem 5 having an outer diameter of 15 mm.
And a collector contact electrode 7 and a low-temperature activation type porous zirconium getter (manufactured by Saes Getter; ST172) 8 as a non-evaporable getter are prepared in advance. The getter 8 is provided with a nichrome wire for energizing and heating, and can be heated later through a sealing wire 9.

Then, as shown in FIG. 1, the stem 5 is placed on a carbon heater 10 which has been processed so that the outer peripheral portion of the stem 5 can be heated, and one end of the stem 5 is closed with the fluorescent screen glass plate 4 thereon. The opened glass tube 1 is arranged so that the peripheral edge of the opening end is located at the peripheral portion of the stem 5. Thereafter, vacuum sealing is performed by heating the carbon heater 10 in a vacuum at 760 ° C. for 60 seconds.

According to this manufacturing method, the adsorbed gas that is released is absorbed by the getter 8, so that the sealed portion between the glass tube 1 and the stem 5 is joined without swelling after the heated portion is joined and the inside becomes airtight. .

In addition, after vacuum sealing, the degree of vacuum inside the arc tube can be increased by energizing and heating the getter 8 via the sealing wire 9.

The type of the getter according to the present invention is not particularly limited as long as it is a non-evaporable type, but it is preferable that the getter be activated by heat at the time of vacuum sealing and have a capability of sufficiently absorbing a released gas mainly composed of moisture. .

[Effects of the Invention] According to the method according to the present invention, the absorption gas released during vacuum sealing is absorbed by the non-evaporable getter provided in the tube, so that the inside of the tube is released by the release of the adsorption gas, as in the related art. , And the disadvantage that the heated portion expands can be eliminated. Further, since the getter is activated by using heat at the time of sealing together with the vacuum sealing, a high vacuum can be obtained without performing a getter activating step after sealing.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a cross-sectional view showing a sealed state of a glass tube and a stem. 1 ... glass tube, 2 ... transparent conductive film, 3 ... phosphor screen, 4
... Glass plate, 5 ... Stem, 6 ... Cathode element, 7
…… Electrode for collector contact, 8… Non-evaporable getter, 9…
... Enclosed wire, 10 ... Carbon heater.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 9 / 24,9 / 26,9 / 38 H01J 61 / 26,63 / 02

Claims (1)

(57) [Claims] 1. A method for manufacturing an arc tube, wherein a glass plate having a fluorescent surface formed on an inner surface thereof and a stem supporting an electrode are respectively sealed at both open ends of a cylindrical glass tube to form a vacuum vessel. While the adsorbed gas released during vacuum sealing is absorbed by a non-evaporable getter provided through the stem, the open end of the glass tube whose one end is closed by a fluorescent glass plate and the stem are locally held in a vacuum. A method for producing an arc tube, wherein the arc tube is sealed by a heating method.