Electrical discharge lamp envelope
AssigneeSiemens Aktiengesellschaft
InventorsHartmut Schneider, Josef Grabmaier
Life of this patent
Estimating the term…
Abstract
A lamp envelope comprised of silica glass having a SiO.sub.2 --B.sub.2 O.sub.3 glass layer on an inner surface thereof is coated on the free surface of such SiO.sub.2 --B.sub.2 O.sub.3 glass layer with a protective layer comprised of a silica glass having a lower B.sub.2 O.sub.3 amount relative to the B.sub.2 O.sub.3 amount in the SiO.sub.2 --B.sub.2 O.sub.3 glass layer.
Claims5
A method of producing a protective layer on a SiO.sub.2 -B.sub.2 O.sub.3 layer positioned on a silica glass substrate, comprising:
- subjecting said SiO.sub.2 -B.sub.2 O.sub.3 layer to diffusion conditions so that at least some B.sub.2 O.sub.3 at an upper region of said layer is diffused out and the resultant region has a lower B.sub.2 O.sub.3 content relative to the B.sub.2 O.sub.3 content in said layer.
A method of producing a protective layer on a SiO.sub.2 -B.sub.2 O.sub.3 layer positioned on a silica glass substrate, comprising:
- depositing a layer of a material selected from the group consisting of SiO.sub.2 and a SiO.sub.2 -B.sub.2 O.sub.3 mixture onto a free surface of said SiO.sub.2 -B.sub.2 O.sub.3 layer from a suitable gaseous reaction mixture at elevated reaction temperatures so that a pyrolytic decomposition of said reaction mixture takes place and a layer of said material is deposited and bonds onto said free surface of the SiO.sub.2 -B.sub.2 O.sub.3 layer and has a lower B.sub.2 O.sub.3 content relative to the B.sub.2 O.sub.3 content in said SiO.sub.2 -B.sub.2 O.sub.3 layer.
A method of producing a protective layer on a SiO.sub.2 -B.sub.2 O.sub.3 layer positioned on a silica glass substrate, comprising:
- depositing a layer of a material selected from the group consisting of SiO.sub.2 and a SiO.sub.2 -B.sub.2 O.sub.3 mixture onto a free surface of said SiO.sub.2 -B.sub.2 O.sub.3 layer from a suitable reaction mixture at elevated reaction temperatures so that a hydrolytic reaction takes place and said layer is deposited and bonds onto said free surface of the SiO.sub.2 -B.sub.2 O.sub.3 layer and has a lower B.sub.2 O.sub.3 content relative to the B.sub.2 O.sub.3 content in said SiO.sub.2 -B.sub.2 O.sub.3 layer.
Dependencies are inferred from the claim text.