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:
Jan. 07, 1997
Filed:
Jun. 13, 1995
Jakob Maya, Brookline, MA (US);
Jagannathan Ravi, Bedford, MA (US);
Matsushita Electric Works R&D Laboratory, Woburn, MA (US);
Abstract
A fluorescent lamp (2) having at least two phosphor coatings (12) on the surface of the sealed lamp bulb, typically an inner surface. There is variable driving means which preferentially activates one phosphor and not the other phosphors, at one arrangement or setting or configuration of the driving means, while at another setting the driving means activates in addition a different or several different phosphors. Each phosphors may be a blend of phosphors and the phosphors and/or blends may be overcoated upon one another forming multiple layers or all mixed together and applied as a one layer coating on the lamp surface. The inventive lamp uses standard fabricating techniques and materials, but allows the user to change the color temperature of the lamp by controlling parameters of the electrical driving signal, that is the, spectrum and quantity of light emitted are changed in response to the changed driving signal such that the user can arrange the light output to be more or less blue or red or to balance the longer wavelengths perceived against the shorter wavelengths perceived.