The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 2008
Filed:
Feb. 03, 2003
Hendrik Adrianus Van Sprang, Eindhoven, NL;
Hendrik Adrianus Van Sprang, Eindhoven, NL;
Koninklijke Philips Electronics, Eindhoven, NL;
Abstract
An electric lamp includes a lamp vessel which is transparent to visible light and accommodates a light source. The lamp vessel is covered with a combination of a light-absorbing medium and an optical interference film having layers of alternately layers of silicon dioxide and layers of a material with a comparatively high refractive index (e.g. ZrO) . The reflection R of the interference film changes from 0.60≦R≦0.95 to 0.40≦R≦0.65 with a step ΔR in the range 0.2≦ΔR≦0.45, in a wavelength range 0.95×λ≦λ≦1.2×λ. In operation, the electric lamp emits colored light in the transmission mode and has a substantially color-neutral appearance in the off state.