Patents Assigned to Corning Incorporatedc
  • Patent number: 6358873
    Abstract: A glass for tungsten halogen lamp glass envelopes, glass filter lenses, and glass filters consisting essentially in terms of weight percent on the oxide basis, of about 50-62% SiO2, 10-17% Al2O3, 0-6% B2O3, 3.6-10% CaO, 0-7.5% MgO, 0.1-0.3% SrO, 2.4-18% BaO, 0-1% ZnO, 1-8% Nd2O3. The glass exhibits the following physical properties: strain point between about 665° C. to about 750° C., coefficient of thermal expansion to the set point of between about 49-59×10−7/° C., liquidus temperature below 1320° C., viscosity at liquidus temperature greater than 2,000 poises, and transmission at 585 nm of between 5-60% for a 1.2 mm thickness. The lamp color temperature for a tungsten halogen lamp containing a glass envelope, a glass filter lens, or a glass filter prepared from the glass composition is increased from about 3 to 7% above a similar glass with no Nd2O3, and the total visible lumen loss is limited to less than about 10%.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: March 19, 2002
    Assignee: Corning Incorporatedc
    Inventor: Ronald L. Stewart