JPS60227338A - Manufacture of luminous tube for discharge lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an improvement in a method for manufacturing an arc tube of a so-called mail halide lamp, in which a metal I/halogenide is sealed together with mercury and a starting aid gas in the arc tube.

(Prior art and its problems) A so-called metal halide lamp, in which a metal halide is sealed together with mercury and a starting auxiliary gas in an arc tube,
° Compared to high-pressure water complex lamps, they have higher luminous efficiency and better external color rendering, so their range of use is expanding.

Along with this, the variety of lamps has been expanded, and there is an urgent need to commercialize low-wattage two lamps of about 100 W or less as light sources for store lighting and general home lighting.

Various metal halides have been studied and selected for use in the arc tube of low-wattage metal halide lamps, but rare earth metals such as dysprosium iodide and neodymium iodide have been selected for their stable characteristics and high luminous efficiency. It has been found that halides are preferred.

However, rare earth metal halides generally have a low vapor pressure, so if they are used, it is difficult to raise the temperature of the arc tube wall of a low-wattage lamp, and the color temperature of the lamp becomes too high, resulting in a reduction in light emission. A problem arises in that the colors feel extremely unnatural. To solve this problem, conventionally, when manufacturing arc tubes, the outer surface of the light emitting part of the arc tube was frosted to increase the heat retention effect of the wall of the arc tube, but the heat retention effect was insufficient. That was enough. Furthermore, it is extremely difficult to uniformly frost the surface of a small arc tube, and if frosting is applied by means such as sandblasting, the mechanical strength of the arc tube will be significantly reduced, and thermal
The drawback is that it is extremely vulnerable to mechanical shock.

(Objective of the Invention) The present invention has been made in view of the above points, and it is possible to obtain a lamp with appropriate color temperature characteristics without causing a decrease in the luminous efficiency of the lamp or a decrease in the mechanical strength of the arc tube. The object of the present invention is to provide a method for manufacturing an arc tube of a metal halide lamp, which has features such as easy manufacture and stable quality.

(Structure of the Invention) The method for manufacturing an arc tube according to the present invention will be explained below according to the manufacturing steps.

(1) First, an arc tube 1 as shown in FIG. 1 (sl) is prepared by a general manufacturing method. This is done by airtightly sealing a pair of electrodes 3m and 3b and their introduction conductor on both ends of a quartz glass tube 2 with a press seal, and then exhausting the inside through an exhaust pipe 4 provided in the center of the tube 2. Then, a metal halide containing a rare earth metal halide is sealed together with an appropriate amount of mercury and a starting auxiliary gas, and the exhaust pipe 4 is tipped off.

(2) Next, as shown in Figure 1, a transparent glass fiber 5 is prepared in the form of a sheet.

For example, quartz glass fiber is suitable as the glass fiber. In addition, glass fibers shaped into sheets that are soaked in water will not lose their shape when handled.

(2) Next, as shown in FIG. 2, aged glass fibers 5 are wound around the outer surface of the light emitting portion of the arc tube 1.

(2) Finally, as shown in FIG. 3, the surface of the glass fiber 5 wound around the outer surface of the light emitting part of the arc tube 1 is heated and melted using a burner 6 or the like. As a result, only the surface portion of the glass fiber 5 melts and the bulk density of that portion increases, but the portion in contact with the arc tube 1 is hardly molten and the bulk density becomes 11, which is small.

(Effects of the Invention) As is clear from the above description, the present invention provides a method in which light-transmitting glass fiber is wrapped at a desired bulk density around the outer surface of the light-emitting portion of an arc tube filled with a rare earth metal halide. This is a method for manufacturing an arc tube in which only the surface of the glass fiber is heated and melted. Since the light-emitting part of the light-emitting tube is covered with glass fiber, the wall load of the light-emitting tube is designed to be high, and sufficient heat retention effect can be obtained without frosting the light-emitting part, resulting in high luminous efficiency and appropriate color temperature. It will be done. In addition, since the light emitting part of the arc tube is covered with glass fiber, there was a concern that the lamp luminous flux would decrease due to light absorption by the glass fiber. When wrapped at an appropriate bulk density, for example, 0.3 x 1 stroke, good results were obtained in which the increase in luminous efficiency exceeded the light absorption. Assembly is extremely simple, as all you need to do is wrap glass fiber around the arc tube manufactured by this method and heat the surface with a burner or the like. Furthermore, since the surface of the arc tube does not need to be frosted, it has the advantage of being resistant to thermal and mechanical shocks.

(Example) ■ First, we prepared an arc tube with the following specifications.

Inner volume: 0-153 (ellipsoidal spherical shape) External surface area: 3 cm” Filled with water, argon gas, dysprosium iodide, thallium iodide, cesium iodide Rated electrical power crab 40W ■ Next, the following glass fibers were Got ready.

Material: High-purity quartz glass Diameter: 1~5μψ Bulk density: 0.3~/,,1 Area density: 511ql■ Then, the above glass fibers were shaped into a sheet shape, and the width was 201m and the length was 50cm. A piece of paper with the size (2) was cut out, soaked in water, and then wrapped around the surface of the light emitting part of the arc tube. Then, the surface of the glass fiber was heated to about 500° C. with a burner to melt it.

■ When the above arc tube was lit at the rated power, the characteristics were as follows.

All party bundle: 2200tm Luminous efficiency (55 additional A Color temperature: 3700 Average color rendering index Ra: 92

[Brief explanation of drawings]

FIGS. 1 to 3 are explanatory views of the steps of the method for manufacturing an arc tube for a discharge lamp according to the present invention. In the figure, 1... arc tube, 5... translucent glass fiber. Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) Wrapping transparent glass fiber at a desired bulk density around the outer surface of the light-emitting part of the arc tube for a discharge lamp filled with rare earth metal I to halide along with mercury and starting auxiliary gas;
A method for manufacturing an arc tube for a discharge lamp, comprising the step of heating and melting the surface portion of the glass fiber. (2) The method for manufacturing an arc tube for a discharge lamp according to claim 1, characterized in that the arc tube for a discharge lamp is one in which at least dysprosium iodide is sealed. (31) The method for manufacturing an arc tube for a discharge lamp according to claim 1, wherein quartz glass fiber is used as the light-transmitting glass fiber.