Abstract: The present invention relates to an electric light bulb having a longitudinal axis, a filament disposed at least approximately on said axis, and a glass having an outer peripheral face around the filament that is at least approximately circularly cylindrical about the axis. This outer peripheral face is secured directly to a mirror which it carries, the reflecting surface of the mirror being longitudinal and placed in contact with said outer peripheral face and having a cross-section which is selected and placed relative to the axis in such a manner as to concentrate the light emitted by the filament into a beam of predetermined orientation and flare angle. The invention is particularly applicable to making strip lights.