Optical system with switchable diffuser

Abstract

An optical system including a lighting component and a switchable diffuser in optical communication with the lighting component. The optical system may further include a low absorbing optical component. At least one outer surface of the switchable diffuser and/or the low absorbing optical component includes light redirecting structures. When the switchable diffuser is in a first state and the optical system produces a light output, the light redirecting structures are configured to increase the full width at half-maximum (FWHM) of the light output of the optical system in at least one direction by at least 5 degrees relative to that of an otherwise equivalent optical system that does not include the light redirecting structures.

1 . An optical system comprising:
 a lighting component;   a switchable diffuser in optical communication with the lighting component, the switchable diffuser having at least a first state and a second state, the first state characterized by a first haze and the second state characterized by a second haze different from the first haze;   a low absorbing optical component in optical communication with the lighting component and in optical communication with the switchable diffuser,   wherein the low absorbing optical component includes opposing first and second outer surfaces, at least one of the first and second outer surfaces including light redirecting structures,   wherein when the switchable diffuser is in the first state and the optical system produces a light output, the light redirecting structures are configured to increase the full width at half-maximum (FWHM) of the light output of the optical system in at least one direction by at least 5 degrees relative to that of an otherwise equivalent optical system that does not include the light redirecting structures.   
     
     
         2 . An optical system comprising:
 a lighting component;   a switchable diffuser in optical communication with the lighting component, the switchable diffuser having at least a first state and a second state, the first state characterized by a first haze and the second state characterized by a second haze different from the first haze;   wherein the switchable diffuser includes an active layer disposed between a first outer layer and a second outer layer, the first outer layer having a first outer surface opposite the active layer, the second outer layer having a second outer surface opposite the active layer, the second outer layer facing the lighting component, at least one of the first and second outer surfaces including light redirecting structures;   wherein when the switchable diffuser is in the first state and the optical system produces a light output, the light redirecting structures are configured to increase the full width at half-maximum (FWHM) of the light output of the optical system in at least one direction by at least 5 degrees relative to that of an otherwise equivalent optical system that does not include the light redirecting structures.   
     
     
         3 . An optical system comprising:
 a lighting component;   a switchable diffuser in optical communication with the lighting component, the switchable diffuser having at least a first state and a second state, the first state characterized by a first haze and the second state characterized by a second haze different from the first haze;   wherein the switchable diffuser includes an active layer disposed between a first outer layer and a second outer layer, the first outer layer having a first outer surface opposite the active layer, the second outer layer having a second outer surface opposite the active layer,   a low absorbing optical component in optical communication with the lighting component and in optical communication with the switchable diffuser, the low absorbing optical component including opposing third and fourth outer surfaces,   wherein at least one of the first, second, third and fourth outer surfaces includes light redirecting structures,   wherein when the switchable diffuser is in the first state and the optical system produces a light output, the light redirecting structures are configured to increase the full width at half-maximum (FWHM) of the light output of the optical system in at least one direction by at least 5 degrees relative to that of an otherwise equivalent optical system that does not include the light redirecting structures.   
     
     
         4 . The optical system of  claim 1 , wherein an average direction of the light output of the optical system when the switchable diffuser is in the first state is the same as an average direction of a light output of the otherwise equivalent optical system when the switchable diffuser is in the first state. 
     
     
         5 . The optical system of  claim 1 , wherein an average direction of the light output of the optical system when the switchable diffuser is in the first state is different from an average direction of a light output of the otherwise equivalent optical system when the switchable diffuser is in the first state. 
     
     
         6 . The optical system of  claim 1 , wherein the switchable diffuser has a haze less than about 5 percent at all angles of incidence in the range of zero degrees to about 85 degrees when the switchable diffuser is in the first state. 
     
     
         7 . The optical system of  claim 2 , wherein the active layer has a haze less than about 5 percent at all angles of incidence in the range of zero degrees to about 85 degrees when the switchable diffuser is in the first state. 
     
     
         8 . The optical system of  claim 1 , wherein the FWHM of the light output of the optical system is increased in two orthogonal directions relative to that of the otherwise equivalent optical system. 
     
     
         9 . The optical system of  claim 1 , wherein the switchable diffuser includes a plurality of independently addressable regions. 
     
     
         10 . The optical system of  claim 1 , wherein the light redirecting structures include a first set of light redirecting structures in a first region of the low absorbing optical component and a second set of light redirecting structures in a second region of the low absorbing optical component different from the first region of the low absorbing optical component. 
     
     
         11 . The optical system of  claim 2 , wherein the light redirecting structures include a first set of light redirecting structures in a first region of the switchable diffuser and a second set of light redirecting structures in a second region of the switchable diffuser different from the first region of the switchable diffuser. 
     
     
         12 . The optical system of  claim 10 , wherein the first and second set of light redirecting structures have differing distributions of size, shape, spacing or slope. 
     
     
         13 . The optical system of  claim 1 , wherein the light redirecting structures are configured to increase the full width at half-maximum (FWHM) of the light output in at least one direction by at least 10 degrees relative to that of the otherwise equivalent optical system. 
     
     
         14 . The optical system of  claim 1  further comprising an additional diffuser in optical communication with the lighting component. 
     
     
         15 . A lighting system comprising:
 one or more optical systems according to  claim 1 ;   a controller configured to provide a diffuser control signal to one or more of the switchable diffusers of the one or more optical systems; and   one or more sensors,   wherein the controller is configured to receive one or more signals from the one or more sensors.   
     
     
         16 . The optical system of  claim 11 , wherein the first and second set of light redirecting structures have differing distributions of size, shape, spacing or slope. 
     
     
         17 . The optical system of  claim 2 , wherein the switchable diffuser includes a plurality of independently addressable regions. 
     
     
         18 . A lighting system comprising:
 one or more optical systems according to  claim 2 ;   a controller configured to provide a diffuser control signal to one or more of the switchable diffusers of the one or more optical systems; and   one or more sensors,   wherein the controller is configured to receive one or more signals from the one or more sensors.   
     
     
         19 . The optical system of  claim 3 , wherein the switchable diffuser includes a plurality of independently addressable regions. 
     
     
         20 . A lighting system comprising:
 one or more optical systems according to  claim 3 ;   a controller configured to provide a diffuser control signal to one or more of the switchable diffusers of the one or more optical systems; and   one or more sensors,   wherein the controller is configured to receive one or more signals from the one or more sensors.