Patent ID: 8827475

Claim:
A light bulb, comprising: a base for mechanically mounting the light bulb and for receiving electrical power; a light guide; and a light source that directs output light into the light guide, the light source comprising: a light emitting device electrically coupled to the base; and a variable spectrum adjuster in a light path of light emitted by the light emitting device, wherein: the light emitting device and the spectrum adjuster are positionable relative to one another; the spectrum adjuster comprises a color-attenuating region comprising color-attenuating material for attenuating a portion of the spectrum of the light, the color-attenuating material having a continuously varying color-attenuating property based on position in the color-attenuating region; the color-attenuating region has dimensions greater than the cross-sectional dimensions of the light path at the spectrum adjuster; and the spectrum adjuster additionally comprises a non-color-attenuating region, adjacent to the color-attenuating region, the non-color-attenuating region containing no operably-effective amount of a color-attenuating material.