Light bulb with adjustable light output

A light bulb, comprising:

• a base configured to mechanically mount the light bulb and receive electrical power;
• a first light guide comprising opposed inner and outer major surfaces between which light propagates by total internal reflection, a light input edge, and a light output region associated with an optical characteristic;
• a second light guide comprising opposed inner and outer major surfaces between which light propagates by total internal reflection, a light input edge, and a light output region associated with an optical characteristic, the inner major surface of the second light guide juxtaposed and conforming to the inner major surface of the first light guide;
• and
• a light source electrically coupled to the base and located adjacent the light input edges, the light source and the light input edges variably positionable relative one another to selectively apportion light between an amount of light input into the first light guide and output from the light output region of the first light guide and an amount of light input into the second light guide and output from the light output region of the second light guide so that a characteristic of the light output from the light bulb is modified based on the optical characteristics associated with the light output regions and the relative positioning of the light source and the light input edges.

A light bulb, comprising:

• a base configured to mechanically mount the light bulb and receive electrical power;
• a housing mechanically coupled to the base;
• a light source electrically coupled to the base and mechanically coupled to the housing;
• and
• a light guide mechanically coupled to the housing so as to be variably positionable relative to the light source, the light guide comprising opposed major surfaces between which light propagates by total internal reflection, a light input edge, and light extracting elements at at least one of the major surfaces, wherein the light guide is positionable between a first position where the light input edge is adjacent the light source such that the light guide is edge lit by the light source and a second position where the light guide is not edge lit by the light source.