Short-arc type super-high-voltage discharge lamp

Abstract

Devising an arrangement with relatively high pressure tightness, in a short-arc super-high pressure mercury lamp which is operated with an extremely high mercury vapor pressure, a light emitting part has a pair of opposed electrodes and is filled with at least 0.15 mg / mm3 of mercury; and side tube parts extend from opposite sides of the light emitting part, and in which the electrodes are partially hermetically sealed and are each welded to a respective metal foil, in the areas in which the electrodes are welded to the metal foils, the electrodes are deformed in the direction perpendicular to the metal foils to a degree of deformation that is at most 10%.

Description

technical field [0001] The present invention relates to a short-arc ultra-high pressure discharge lamp having a mercury vapor pressure of 150 atmospheres or higher when lit, and particularly relates to a projection as a DLP (Digital Light Source Processor) or the like using a liquid crystal display device or a DMD (Digital Mirror Device) The short-arc ultra-high pressure discharge lamp used as the light source of the instrument device. Background technique [0002] Projection projectors are required to illuminate images uniformly and with sufficient color rendering on a rectangular screen. Therefore, metal halide lamps in which mercury and metal halides are sealed are used as light sources. In addition, such metal halide lamps have recently been further downsized and made into point light sources, and lamps with an extremely small distance between electrodes have been put into practical use. [0003] Against such a background, lamps having an unprecedentedly high mercury va...

AI Technical Summary

Problems solved by technology

[0011] However, even if the thermal expansion of the electrode rods 6a, 7a is intended to be relieved by such a structure, in fact, cracks remain on the periphery of the electrode rods 6a, 7a and the coil member 10.

[0012] The cracks are small at first, but when the mercury vapor pressure of the light emitting part 10 is about 150 atmospheres, the cracks may also lead to damage of the side pipe part 3.

In addition, in recent years, higher mercury vapor pressures such as 200 atmospheres and further 300 atmospheres have been required. Under such high mercury vapor pressures, the growth of cracks is accelerated during lamp lighting, and as a result, there is damage to the side pipe portion 3. Significantly such a problem occurs

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