LIGHT BULB WITH ADJUSTABLE LIGHT OUTPUT
A light bulb includes a base; a light guide having opposed major surfaces between which light propagates by total internal reflection, a light input edge, and two light output regions of different optical characteristics at least one of which is associated with a corresponding one of the major surfaces; and a light source electrically coupled to the base and located adjacent the light input edge. The light source and the light guide are variably positionable relative to one another to vary a location on the light input edge at which light is input to the light guide such that light is emitted from the light guide selectively apportioned between the light output regions 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 guide.
1 . A light bulb, comprising:
a base configured to mechanically mount the light bulb and receive electrical power;
a light guide comprising opposed major surfaces between which light propagates by total internal reflection, a light input edge, and two light output regions at least one of which is associated with a corresponding one of the major surfaces, each light output region being associated with a different optical characteristic; and
a light source electrically coupled to the base and located adjacent the light input edge to input light into the light guide, the light source and the light guide variably positionable relative to one another to vary a location on the light input edge at which the light is input to the light guide such that the light is emitted from the light guide selectively apportioned between the light output regions 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 guide.
2 . The light bulb of claim 1 , wherein the light bulb further comprises a heat sink thermally coupled to the light source.
3 . The light bulb of claim 1 , wherein the characteristic of the light output from the light bulb that is modified is spectrum.
4 . The light bulb of claim 1 , wherein the characteristic of the light output from the light bulb that is modified is color temperature.
5 . The light bulb of claim 1 , wherein the characteristic of the light output from the light bulb that is modified is light output direction.
6 . The light bulb of claim 1 , wherein the optical characteristics associated with the light output regions differ in an amount of a single optical characteristic.
7 . The light bulb of claim 6 , wherein the optical characteristic is at least one of reflective, diffusive, light redirecting, polarizing, reflective polarizing, intensity reducing, wavelength shifting and color attenuation.
8 . The light bulb of claim 1 , wherein the optical characteristic associated with a first one of the light output regions imposes a first characteristic on the output light, the optical characteristic associated with a second one of the light output regions imposes a different characteristic on the output light, and the optical characteristics are at least one of reflective, diffusive, light redirecting, polarizing, reflective polarizing, intensity reducing, wavelength shifting and color attenuation.
9 . The light bulb of claim 1 , further comprising an optical adjuster comprising a major surface juxtaposed with and conforming to one of the major surfaces of the light guide and wherein the association of optical characteristics with the light output regions is achieved by respective optical adjuster regions of the optical adjuster aligned with the light output regions.
10 . The light bulb of claim 9 , wherein the optical adjuster is a first optical adjuster and the light bulb further comprises a second optical adjuster superposed with the first optical adjuster, the second optical adjuster comprising optical adjuster regions with different optical characteristics to increase the number of light output characteristics of the light bulb based on the optical characteristics of the second optical adjuster and the relative positioning of the light source and the light guide.
11 . The light bulb of claim 9 , wherein the optical adjuster is a first optical adjuster and the light bulb further comprises a second optical adjuster comprising a major surface juxtaposed with and conforming to the other of the major surfaces of the light guide, wherein the second optical adjuster has optical adjuster regions with different optical characteristics.
12 . The light bulb of claim 11 , wherein the first optical adjuster has a transmissive optical adjuster region and a reflective optical adjuster region, and the second optical adjuster has a reflective optical adjuster region aligned with the transmissive optical adjuster region of the first optical adjuster and has a transmissive optical adjuster region aligned with the reflective optical adjuster region of the first optical adjuster.
13 . The light bulb of claim 12 , wherein at least one of the transmissive optical adjuster regions additionally is at least one of diffusive, light redirecting, polarizing, intensity reducing, wavelength shifting and color attenuating.
14 . The light bulb of claim 1 , wherein the light guide further comprises:
first light extracting elements at at least one of the major surfaces of the light guide, the first light extracting elements defining a first one of the light output regions; and
second light extracting elements at at least one of the major surfaces of the light guide, the second light extracting elements defining a second one of the light output regions, the first and second light extracting elements respectively configured to achieve the different optical characteristics associated with the first light output region and the second light output region.
15 . The light bulb of claim 14 , wherein the first light extracting elements differ from the second light extracting elements in at least one of size, shape, depth or height, density, orientation, slope angle and index of refraction such that the first light output region outputs light with a different intensity profile than the second light output region.
16 . The light bulb of claim 14 , wherein the first light extracting elements differ from the second light extracting elements in at least one of size, shape, depth or height, density, orientation, slope angle and index of refraction such that the first light output region outputs light with a different light ray angle distribution than the second light output region.
17 . The light bulb of claim 14 , wherein the light extracting elements are light-scattering elements.
18 . The light bulb of claim 14 , wherein the light extracting elements have well-defined shapes.
19 . The light bulb of claim 14 , wherein the light extracting elements are micro-optical elements.
20 . The light bulb of claim 1 , wherein the light source is a solid state light source.
21 . The light bulb of claim 1 , wherein each light output region is associated with the same one of the major surfaces.
22 . The light bulb of claim 1 , wherein each light output region is associated with a respective one of the major surfaces.
23 . The light bulb of claim 1 , wherein one of the light output regions is associated with one of the major surfaces and the other of the light output regions is associated with an edge of the light guide opposite the light input edge.
24 . 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.
25 . The light bulb of claim 24 , wherein each light output region is associated with the respective one of the outer major surfaces.
26 . The light bulb of claim 24 , wherein each light output region is associated with the outer major surface of the other light guide.
27 . The light bulb of claim 24 , wherein one of the light output regions is associated with the respective one of the outer major surfaces and the other of the light output regions is associated with an edge of the respective light guide opposite the respective light input edge.
28 . The light bulb of claim 24 , wherein the light guides have respective light extracting elements.
29 . The light bulb of claim 24 , wherein the relative positioning of the light source and the light input edges determines an amount of the light that exits through the outer major surface of the first light guide and an amount of the light that exits through the outer major surface of the second light guide.
30 . The light bulb of claim 24 , wherein the relative positioning of the light source and the light input edges determines an amount of the light that exits through one or both of the outer major surfaces and an amount of the light that exits through an edge of one of the light guides opposite the corresponding light input edge.
31 . The light bulb of claim 24 , wherein the light source is a solid state light source.
32 . 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.
33 . The light bulb of claim 32 , wherein the light extracting elements are configured to extract light from the light guide with a diffuse light ray angle distribution.
34 . The light bulb of claim 32 , further comprising an optical adjuster mechanically coupled to the housing and variably positionable relative to the light source such that when the light guide is in the second position the optical adjuster is aligned with the light source.
35 . The light bulb of claim 34 , wherein the optical adjuster comprises a lens.
36 . The light bulb of claim 35 , wherein the lens is a collimating lens.
37 . The light bulb of claim 36 , wherein when the light guide is in the second position, the light is emitted with a narrower light ray angle distribution than when the light guide is in the first position.
38 . The light bulb of claim 34 , further comprising an adjustment member mechanically coupled to the housing, wherein the light guide and the optical adjuster are coupled to the adjustment member, and the adjustment member is variably positionable relative to the housing to move the light guide between the first and second positions and move the optical adjuster into alignment with the light source when the light guide is in the second position.
39 . The light bulb of claim 38 , wherein the adjustment member has increased resistance to movement when the light guide is in the first and second positions relative to when the light guide is not in one of the first position or the second position.
40 . The light bulb of claim 38 , wherein the housing comprises cooling air vents through which air flows to dissipate heat generated by the light source and the adjustment member comprises openings that align with the cooling air vents of the housing at least when the light guide is in the first position and the second position.
41 . The light bulb of claim 32 , wherein the light source is a solid state light source.
42 . The light bulb of claim 32 , wherein the base comprises an Edison screw base.