VALVE MADE OF SYNTHETIC SILICA GLASS FOR DISCHARGE LAMP, AND METHOD FOR MANUFACTURING THE SAME

• Main Authors: ORIKASA KATSUHIDE, TANAKA MAKOTO, YOSHIDA YOSHIMASA, SATO TATSUHIRO
• Format: Patent
• Language: English
• Published: 06.01.2011
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY; GLASS; JOINING GLASS TO GLASS OR OTHER MATERIALS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

PROBLEM TO BE SOLVED: To provide a valve made of synthetic silica glass for a discharge lamp, which is excellent in devitrification resistance and heat resistance, maintains service life of the lamp for a long period of time and solves the problem of ultraviolet rays, to provide a method for manufacturing the same, and to provide a discharge lamp device using the valve.SOLUTION: The valve is characterized in that the content of OH group in the valve is 2-50 ppm, the total content of alkali metals in the valve is 0.02-10 ppm, the content of OH group in the region from the inner surface to a depth of 0.1 mm is ≤1 ppm, the total content of alkali metals in the region from the inner surface to a depth of 0.1 mm is ≤0.01 ppm, the oxygen-deficient type defect amount at a wavelength of 250 nm is 0.1-2/cm in terms of absorption coefficient, viscosity at 1,100°C is 10to 10poise, and the internal transmittance of a light beam having a wavelength of 150-250 nm is ≤50%/cm.