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:
Sep. 03, 1991
Filed:
Mar. 21, 1989
Applicant:
Inventors:
Richard M Ash, Northampton, GB;
Andrew Carter, Northants, GB;
Assignee:
Siemens Plessey Controls Limited, Dorset, GB;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
357 17 ; 357-4 ; 357 16 ; 372 43 ; 372 44 ; 372 45 ;
Abstract
A solid state light source comprising a monolithic light emitter diode structure having a graded bandgap active region 8 the thickness of which is graded between two materials 9, 11, the said materials having differing center wavelengths of light emission, such that the source is capable of emitting light at wavelengths L1, L2 spaced over the whole spectral width between the wavelengths exhibited by the said two materials. This can enable the light source to be used in optical fibre devices where it can provide on alternative to the filament lamp source and thus give an increased reliability in use.