Lighting system with actively controllable optics and method

A lighting system and method electrically control optics of light generated by a light source. The light source generates a light defined by a light distribution. An electro-active optical component changes the light distribution responsive to a change in an electric potential applied across the electro-active optical component by an electronic control system.

FIELD

Embodiments of the subject matter disclosed herein relate to lighting systems.

BACKGROUND

Different types of lighting systems include light sources that generate light. The light can be emitted by the lighting systems in a wide variety of shapes and/or directions. In some systems, filters are used to change the appearance or direction in which the light is oriented. For example, optic lenses may be fixed onto lighting systems between the light source and one or more targets or observers of the light. These fixed lenses can refract the light to change the direction and/or appearance of the light. The lenses, however, may not be able to be moved relative to the light source without manually removing or altering the lenses, or without some mechanical system that moves the light source relative to the lens or moves the lens. As a result, the direction and/or appearance of the light emitted by the lighting systems may be fixed without manual intervention with the lighting system or mechanical actuation of the system, both of which add to the complexity and/or cost of lighting systems.

Other types of lighting systems can include lenses or surfaces that change appearance in order to block some or all of the light emitted by a light source. For example, some windows and/or glass doors may include materials that become cloudy or otherwise change appearance to block the transmission of one or more, or all, wavelengths of light from passing through the window and/or door for security or privacy purposes. Some automobiles include windows that may change a tinting color to block one or more wavelengths of light from passing through the window. These types of systems, however, can reduce the amount of energy of the light that passes through between the source of the light and one or more targets or observers of light. As a result, these types of systems may be undesirable for lighting systems that are used to illuminate a room or other area.

BRIEF DESCRIPTION

In one embodiment, a method (e.g., for actively controlling optics of a lighting system) includes generating light comprising a light distribution from a light source and changing the light distribution by changing an electric potential applied across an electro-active optical component by an electronic control system.

In another embodiment, a system (e.g., a lighting system) includes a light source and an electro-active optical component. The light source is configured to generate a light defined by a light distribution. The electro-active optical component is configured to change the light distribution responsive to a change in an electric potential applied to the electro-active optical component.

In another embodiment, another system (e.g., a lighting system) includes a light source and an electro-active optical component. The light source is configured to generate a light defined by a light distribution. The electro-active optical component is configured to change the light distribution responsive to a change in an electric potential applied to the electro-active optical component. The electro-active optical component also is configured to change a direction at which the light distribution is oriented responsive to a change in specularity of the electro-active optical component.

DETAILED DESCRIPTION

Embodiments of inventive subject matter described herein provide for lighting systems and methods that include or use a light source generating light defined by a light distribution. The light distribution can represent a direction in which the light generated by light source is oriented, a shape or throw of the light, or an intensity of the light. One or more optical assemblies, such as diffusing assemblies and/or reflective assemblies, are electrically controlled to change the distribution of the light. These assemblies may apply electric potential between or across conductive layers on opposite sides of a liquid crystal layer. Depending on the application, removal, and/or magnitude of the electric potential, the assemblies may scatter the light by different amounts to change the light distribution. In one aspect, a reflective assembly can include a reflective layer on one side of the liquid crystal layer and a light transmissive and conductive layer on the opposite side of the liquid crystal layer. Application or removal of electric potential and/or the magnitude of electric potential that is applied across the reflective layer and the other conductive layer can change the specularity of the reflecting assembly. The change in specularity also can change the distribution of the light.

The embodiments described herein may change the distribution of the light without blocking one or more wavelengths of the light that is generated in one embodiment. For example, instead of filtering or blocking one or more wavelengths of the light from passing through or propagating through the assemblies, one embodiment of the subject matter described herein may not block or reduce energy of the light propagating through the assemblies by more than a designated amount (for example, may not reduce the energy of the light by more than 10%, 15%, 20%, or the like).

FIG. 1illustrates a perspective view of a lighting system100according to one embodiment. The lighting system includes an external or outer housing102with a light source (not shown inFIG. 1) disposed therein. A lens104may be coupled with the housing102with light generated by the light source inside the housing102propagating through the lens104and on to one or more targets or observers of the lighting system100. For example, light generated by the light source may propagate through the lens104and out of the lighting system100on to floors, walls, ceiling, or other objects around. Alternatively, the lens104is not included in the lighting system100. An electrical connector106is operably connected with the light source in order to connect the light source with a power supply (not shown inFIG. 1) to power the light source. As described herein, the connector106also may supply electric current from the power supply to one or more of the optical assemblies described herein. While the lighting system100is shown as a floodlight, alternatively, the lighting system100may represent another type of light, such as a light bulb, a lamp, a directional lamp, a tube, a troffer, a light fixture (for example, a streetlight) or the like.

FIG. 2illustrates another view of the lighting system100shown inFIG. 1according to one embodiment. The lighting system100includes the light source200disposed within the housing102of the lighting system100. The light source may represent one or more devices that generate light, such as one or more light emitting devices (LEDs). The connector106connects a power supply circuit202of the lighting system100with the power supply220. The power supply circuit202can include or be embodied in a printed circuit board or other type of device that conducts electric current from the power supply220to the power source200via the connector106. The power supply220can represent a source of electric current, such as an outlet, a utility grid, a battery, or the like. The power supply220may be internal to the lighting system100(such as when the power source220is included within or connected with the housing102) or may be external to the lighting system100.

The lighting system100may include one or more optical assemblies, such as one or more diffusing assemblies216and/or one or more reflective assemblies218. In the illustrated embodiment, the lighting system100includes a single diffusing assembly216and a single reflective assembly218. Alternatively, the lighting system100may include multiple assemblies216, multiple assemblies218, no assembly216, and/or no assembly218.

The diffusing assembly216may be in the shape of a substantially planar disk (e.g., a circular or other shape of the disk with the outer dimensions of the diffusing assembly216being larger in two directions in a common plane than in a direction that is orthogonal to the plane). The reflective assembly218may have a frustoconical shape around the light source200. Alternatively, a different number, arrangement, and/or shape of the diffusing assembly216and/or reflective a summary218may be provided.

In operation, the light source200generates light having a light distribution204. The light distribution204can be defined by a shape and/or direction212in which the light propagates from the lighting system100. The direction of the light can represent an optical axis of the light that indicates a center of the distribution of light emitted by the light source200. Alternatively, the direction of the light distribution represents an axis about which the distribution of the light is symmetric. The shape of the light can represent a throw or an emitted volume or angle of the light. The throw of the light can represent the angles at which the intensity of the emitted light is at least 50% of the maximum intensity of the emitted light.

The diffusing assembly216and/or reflective assembly218may be electrically controlled in order to change the distribution204of the light without moving the light source200or any other component of the lighting assembly100. The light generated by the light source200may initially be generated by the light source200to the shape defined by a throw angle206shown inFIG. 2. The light emanating from the lighting system100may have a distribution with a shape defined by a throw angle208or210. The throw angles206,208,210represent the spread of the light, and can represent volumes that include at least 50% of the maximum intensity of the light.

The light may propagate from the light source200to the diffusing assembly216. The diffusing assembly216may electrically change scattering of the light as the light propagates through the diffusing assembly216, as described below. This scattering can change the distribution of the light, such as by reducing or increasing the throw angle208,210of the light. For example, electrically controlling the diffusing assembly216to reduce the amount of scattering of the light as the light passes through the diffusing assembly216can cause the distribution of the light to have a throw angle210. Electrically controlling the diffusing assembly216to increase the scattering of the light as the light passes through the diffusing assembly216can cause the distribution of the light to have a larger throw angle208.

The reflective assembly218may be electrically controlled in order to change the direction of the light. The light may be initially generated by the light source202and propagate along a direction212. The specularity of the reflective assembly218can be electrically controlled to vary the amount of scattering of the light as the light passes through one or more layers of the reflective assembly218prior to and/or after reflecting off of a reflective surface in the reflective assembly218. Changes in the amount of scattering of the light within the reflective assembly218can change the specularity of the reflective assembly218and, as a result, alter the direction of the light.

FIG. 3illustrates operation of a cross-sectional view of the diffusing assembly216shown inFIG. 2according to one embodiment. The diffusing assembly216includes a diffusing layer316that controls how much light is scattered during passage of the light through the diffusing assembly216. In one embodiment, the diffusing layer316includes a liquid crystal layer. The diffusing assembly316can include a polymer matrix310having liquid crystals312with liquid crystal molecules314disposed therein. The diffusing layer316is disposed between opposite conductive and light transmissive layers306,308.

The layers306,308may be conductive and also may permit light generated by the light source200shown inFIG. 2to propagate through the layers306,308. One example of such layers306,308includes indium tin oxide (ITO) layers. Other types of transmissive and conductive materials, such as other metal oxides or graphene, may be employed as materials for the layers306,308. In the illustrated embodiment, outer dielectric layers302,304are disposed outside of the conductive and light transmissive layers306,308. The layers302,308can be formed from one or more light transmissive dielectric materials, such as polyethylene terephthalate (PET).

The conductive and light transmissive layers306,308may be conductively coupled with the power source220, such as by the power supply circuit202shown inFIG. 2. The power supply circuit202can include one or more switching devices300, such as switches, relays, etc., which can close to supply electric current to the conductive and light transmissive layers306,308. This current can apply an electric potential across or between the layers306,308such that one layer306or308is at a higher potential or voltage than the other layer308or306.

FIG. 4illustrates operation of the cross-sectional view of the diffusing assembly216shown inFIG. 2according to one embodiment.FIG. 4represents how the diffusing layer316behaves when no electric potential is applied across or between the conductive and light transmissive layers306,308(or, when electric potential is applied, but the potential is less than a designated switching voltage of the layer316).FIG. 3represents how the diffusing layer316behaves when the electric potential is applied across or between the conductive and light transmissive layers306,308(or, when the electric potential is applied at a magnitude that at that is at least as great as the switching voltage).

As shown by comparison ofFIGS. 3 and 4, when no electric potential or an electric potential less than the switching voltage is applied between or across the conductive and light transmissive layers306,308, the molecules314in the liquid crystals312of the diffusing layer316are randomly oriented. This random orientation can cause at least some of the light to be scattered or otherwise diffused by the molecules314, as shown inFIG. 4. The arrowheads of the light distribution204represent the direction in which the light propagates through the diffusing layer316. As shown inFIG. 4, some of the light is scattered by the molecules314thereby resulting in the light scattering in various directions during propagation through the diffusing assembly216.

In contrast, when an electric potential is applied across the conductive and light transmissive layers306,308, as shown inFIG. 3, this potential generates electric field across or through the liquid crystal layer316. This electric field can orient the molecules314of the liquid crystals312in the liquid crystal layer316toward or along common or parallel direction. The common orientation of the molecules314causes less light to be scattered by the molecules314relative to no or a lesser electric potential being applied across the conductive and light transmissive layers306,308. Consequently, less light in the light distribution204is scattered during propagation of the light through the diffusing assembly216.

The application of the electric potential across the conductive and light transmissive layers306,308can cause the diffusing layer316to become clearer (or more light transmissive) relative to no electric potential being applied or less electric potential being applied. As a result, less light is scattered and the shape of the distribution of light204can be smaller (relative to more light being scattered). This can reduce the throw angle of the distribution of the light.

Different amounts of electric potential can be applied across or between the conductive and light transmissive layers306,308to cause different amounts of light scattering as the light propagates through the liquid crystal layer316. For example, the amount or degree at which the light is scattered or diffused by the diffusing assembly216can be a function of the amount of electric potential applied across the conductive and light transmissive layers306,308. When a first amount electric potential is applied across the conductive and light transmissive layers306,308, less light may be scattered by the diffusing layer316relative to no electric potential being applied across the layers306,308. If a larger, second amount electric potential is applied across the layers306,308, the light may be scattered to a lesser degree or amount by the liquid crystal layer316then when no electric potential or the first electric potential is applied across the layers306,308. When an even larger, third electric potential is applied across the conductive and light transmissive layers306,308, even less light may be scattered or may be scattered to an even lesser degree than when no electric potential is applied across layers306,308, when the second electric potential is applied across layers306,308, or when the first electric potential is applied across layers306,308. As a result, the amount of light scattering caused by the diffusing assembly216may be a function of electric potential applied to the layers306,308, such as by the amount of light scattering being inversely proportional, inversely related, or otherwise related to the electric potential. This can cause the size or shape of the light distribution to be a function of the electric potential, such as the size or shape of the light distribution increasing for smaller electric potentials and the size or shape of the light distribution decreasing for larger electric potentials.

The scattering of the light can provide for controlling the shape of the light distribution204, which can cover from the original beam angle206or208to a full lambertian distribution. While some energy of the light generated by the light source200may be reduced during propagation through the diffusing assembly216, this loss may be less than 10% (or another threshold) of the energy of the light emitted by the light source200. This energy loss can result in a small loss in lumens of the light, such as 4% or less.

In one aspect, the liquid crystal layer316may include one or more additional dopants to alter the light propagating therethrough. For example, in addition to the liquid crystals312in the liquid crystal layer316, one or more inorganic ions (such as neodymium ions) or organic molecules may be added to the polymer matrix310. These additional dopants can provide for color filtering of the light propagating through the liquid crystal layer316and the diffusing assembly216and for warm dimming of the light.

In one embodiment, visible light emitted by the light source200that is below a cut-off absorption wavelength of the diffusing layer316may be absorbed by the diffusing assembly216or one or more of the layers of the diffusing assembly216. This can prevent the visible or ultraviolet light below the cut off absorption wavelength to not propagate through the diffusing assembly216.

The conductive and light transmissive layers316may extend over the entire surface area of the liquid crystal layer316in one embodiment. Alternatively, one or more of the conductive and light transmissive layer306,308may extend over part, but not all, of the surface area on either side of the liquid crystal layer316. The conductive and light transmissive layer316and/or308may be patterned, or formed in the one or more discrete areas or sub-areas, to cause different amounts of light scattering when the electric potential is applied to the layers306,308at a level below the switching voltage or is not applied to the layers306,308. Different patterns and/or shapes formed by the layer306and/or308can result in different changes in the shape of the distribution of the light that emanates from the diffusing assembly214.

FIG. 5illustrates one example of a relationship500between light scattering in the diffusing assembly216and electric potentials applied across the conductive and light transmissive layers306,308in the diffusing assembly216. The relationship500is shown alongside a horizontal axis502representative of different electric potentials applied across or between the conductive and light transmissive layers306,308in the diffusing assembly216and a vertical axis504representative of the light scattering caused by the diffusing assembly216. The amounts of scattering shown along the vertical axis504may represent intensities of the light emanating from the diffusing assembly216, such as full widths of the distribution204of the light at half maximum of intensity, or FWHM.

As the electric potential applied across the conductive and light transmissive layers306,308increases, the amount of light scattering caused by the diffusing assembly216decreases because the diffusing layer316becomes clearer with increasing electric potentials. Conversely, reducing the electric potential applied across the conductive and light transmissive layers306,308increases the amount of scattering caused by the diffusing assembly216. Using the relationship500, the lighting system100or an operator of the lighting system100can vary the electric potential applied across the conductive and light transmissive layers306,308along a continuous range of potentials in order to continuously vary or alter the amount of light scattering. Consequently, the amount or degree of light scattering caused by the diffusing assembly216can be selected by changing the electric potential applied across the conductive and light transmissive layers306,308.

FIG. 6illustrates examples of different shapes of the distribution204of light emanating from the diffusing assembly216at different electric potentials applied across or between the conductive and light transmissive layers306,308. The different shapes include distribution shapes600,602,604,606,608,610,612,614,616, which are shown alongside a horizontal axis618representative of different angles from the direction212(shown inFIG. 2) of the distribution204of light and a vertical axis620representative of relative intensities of the light at the different angles. The location of the vertical axis620along the horizontal axis618can represent the direction212shown inFIG. 2.

The angles represented by the horizontal axis618can represent angles to one or more sides of the direction212in which the light is generated or emanates from the lighting system100, as shown inFIG. 2. For example, the location along the horizontal axis618at a value of 20° can represent an angle that is 20° to the right of the direction212shown inFIG. 2, a location along the horizontal axis618of negative 40° can represent an angle that is 40° to the left of the direction212shown inFIG. 2, and so on.

The different distribution shapes shown inFIG. 6represent different shapes of the distribution204of the light for different electric potentials applied across or between the layers306,308in the diffusing assembly216. At larger amounts of electric potential, less diffusion of the light occurs while, at smaller amounts of electric potential, more diffusion of the light occurs.

FIG. 7illustrates operation of the diffusing assembly216of the lighting system100according to one example. Two lighting systems100are shown inFIG. 7. The lighting systems100each emit light from an upper or light emitting surface700, which can represent the outer surface of the lens104shown inFIGS. 1 and 2. The light emitting surfaces700of the two lighting systems100may be the same distance702from a common plane or surface716. The surface or plane716may represent a floor, wall, or other surface.

The lighting system100on the left side ofFIG. 7may have an electric potential applied across the layers306,308that is greater than the switching voltage of the diffusing assembly216. The lighting system100on the right side ofFIG. 7may have no electric potential applied across the layers306,308, may have an electric potential applied that is less than the blocking voltage of the diffusing assembly216, or may have an electric potential applied that is less than the lighting system100on the left side ofFIG. 7. The shapes or spread of the distributions204A,204B of the light emitted by the lighting systems100shown inFIG. 7may differ.

Because the diffusing layer316in the diffusing assembly216of the lighting system100on the left side ofFIG. 7may be more clear (due to the larger electric potential), the shape or size of the distribution204A of the light may be tighter or smaller than the shape or size of the distribution204B of the light emitted from the lighting system100on the right side ofFIG. 7. The light in the distributions204A,204B may be cast upon the surface716at different intensities and/or in different shapes. Areas704,710represent areas illuminated by the light in the distributions204A,204B. These areas704,710may be defined by outer dimensions of706,708for the area704and outer dimensions712,714for the area710. As shown inFIG. 7, the spread or size of the distribution204B of the light emitted by the lighting system100having no electric potential or a smaller electric potential applied across or between the layers306,308may be wider or larger than the shape of the distribution204A of the light emitted by the lighting system100(which has a larger or at least some electric potential applied across the layers306,308). This is due to the increased amount of scattering in the light that propagates through the diffusing assembly216in the lighting system100on the right side ofFIG. 7.

FIG. 8illustrates additional examples of changing the shape or size of the distribution204of light emitted by the lighting system100shown inFIG. 1. The same lighting system100casts a distribution204of light toward a surface, such as a floor of a room. When a first amount of electric potential is applied across the conductive and light transmissive layers306,308of the diffusing assembly216in the lighting system100, the distribution204of the light is smaller and, as a result, a smaller illuminated area800is cast on the floor. When this electric potential applied across the layers306,308is decreased, the shape of the distribution204of the light emitted by the lighting system100is larger, as shown by the larger illuminated area802inFIG. 8. When this electric potential is decreased even more, the size of the shape of the distribution204of the light emitted by the lighting system100is even larger, as shown by the largest illuminated area804shown inFIG. 8.

In addition or as an alternate to changing the shape of the distribution204of the light emitted from the lighting system100, the direction212in which the light is emitted from the lighting system100can be changed by changing the electric potential applied to one or more of the assemblies216,218shown inFIG. 2. As described above, the shape or size of the distribution204of light can be altered electrically by changing, applying, or removing electric potential applied across or between conductive layers in the diffusing assembly216. The shape or size of the distribution204of light can be altered without mechanically moving the light source200, lens104, diffusing assembly216, or any other component or part of the lighting system100.

The direction212in which the distribution204of the light is oriented optionally may be changed by electrically changing an amount of electric potential applied to a reflective assembly218of the lighting system100and/or by changing the amount of electric potential applied to the diffusing assembly216.

FIG. 9illustrates operation of the lighting system100by changing a direction212,214in which the distribution204of the light is electrically controlled according to one example. InFIG. 9, the lighting system100may emit light to have the distribution204A toward the surface716to illuminate the area704A on the surface716. The distribution204A of the light is oriented along a first direction212A. In order to laterally shift the distribution204A of light in a different direction212B, an electric potential can be applied to the reflective assembly218to cause the light to have the distribution204B, which is oriented in a different direction212B and that illuminates a different area704B on the surface716. In one aspect, the lighting system100can include multiple, different reflective assemblies218with different potentials applied (or not applied) to the reflective assemblies218in order to alter the direction of the light.

FIG. 10illustrates a cross-section of one embodiment of the reflective assembly218shown inFIG. 2. The reflective assembly can include a diffusing layer1000, which may be similar or identical to the diffusing layer316shown inFIGS. 3 and 4. Alternatively, the diffusing layer1000may differ from the diffusing layer316in that the diffusing layer1000may include a different polymer matrix310, different liquid crystals312, different liquid crystal molecules314, different amounts or densities of the liquid crystals312and/or molecules314, or the like. The diffusing layer1000is disposed between opposite conductive and light transmissive layers306,308, which may be the same as or similar to the layers306,308in the diffusing assembly216. Layers302,304may be the same or similar to the layers302,304in the diffusing assembly216.

One difference between the reflective assembly218and the diffusing assembly216is that the reflective assembly218includes a reflective layer1002. The reflective layer1002reflects the light entering into the reflective assembly218. The reflective layer1002can represent a metallized layer or coating (for example, an aluminum or other metallic coating) on an opposite side of the polymer layer304than the conductive and light transmissive layer308shown inFIG. 10.

In operation, light emitted by the light source200can propagate through the polymer layer302of the reflective assembly218, through the first conductive and light transmissive layer306, through the diffusing layer1000(where the light may or may not be scattered), through the second conductive and light transmissive layer308, through the second polymer layer304, be reflected off of the reflective layer1002, and then propagate back through the polymer layer304, the conductive and light transmissive layer308, the diffusing layer1000(where the light may be scattered), the first conductive and light transmissive layer306, the first polymer layer302, and out of the reflective assembly218.

Applying electric potential across the layers306,308in the reflective assembly218can cause the layer1000scatter or not scatter the light, as described above in connection with the diffusing assembly216. Applying, removing, or changing electric potential applied across the conductive and light transmissive layers306,308of the reflective assembly218can change the specularity of the assembly218. In one aspect, the specularity of the reflective assembly218can be measured as the cosine of an angle made by a direction of light onto or into the reflective assembly218to an angle made by the light that is reflected off of an out of the reflective assembly218.

When no electric potential is applied across the layers306,308of the reflective assembly218(or when a potential that is less than the switching voltage of the diffusing layer1000is applied across the conductive and light transmissive layers306,308), light passing into the reflective assembly218is scattered upon first passage through the diffusing layer1000. This scattered light is then reflected off of the reflective layer1002and travels back into the diffusing layer1000, where the light may again be scattered before emanating from the reflective assembly218via the polymer layer302. The scattering of the light by the diffusing layer1000prior to and/or subsequent to reflection of the light off of the reflective layer1002can cause a decrease in the specularity of the reflective assembly218. Conversely, applying an electric potential across the layers306,308can cause less scattering of the light by the diffusing layer1000prior to and/or subsequent to reflection of the light off of the reflective layer1002. This can cause an increase in specularity of the reflective assembly218, as the reflective assembly218becomes more reflective to the light. Changing the clarity or amount of scattering in the diffusing layer1000can vary the specularity and, as a result, the direction at which the light emanates from the reflective layer218.

FIG. 11illustrates an alternative embodiment of the reflective assembly218shown inFIG. 2. In contrast to the embodiment of the reflective assembly218shown inFIG. 10, the reflective assembly218shown inFIG. 11includes a conductive and reflective layer1100between the diffusing layer1000and the second polymer layer304. The reflective assembly218shown inFIG. 11may not include the separate reflective layer1002. Instead, the layer1100operates as both the reflective layer1002and the conductive and light transmissive layer308of the reflective assembly218shown inFIG. 10.

In contrast to the reflective assembly218shown inFIG. 10, light that is reflected by the reflective assembly218does not pass through the second polymer layer304before or after being reflected by the reflective layer1100. The reflective layer1100may be formed from a conductive and reflective layer, such as a metallized layer (for example, formed from aluminum or other reflective conductive material). The potential that is applied in order to change the clarity or scattering of the liquid crystal layer1000may be applied between or across the conductive and light transmissive layer306and the reflective layer1100.

FIG. 12represents a distribution1200of light reflected off of the reflective assembly218according to a first example. The distribution1200represents the spread of the light reflected by the reflective assembly218when the electric potential applied across or between the conductive layers on opposite sides of the diffusing layer1000shown inFIGS. 10 and 11is at or above the switching voltage of the diffusing layer1000. The distribution1200is shown alongside a linear vertical axis1202representative of intensities of the light reflected off of the reflective assembly218and alongside an angular axis1204representative of angles relative to a normal or perpendicular direction to the polymer layer302of the reflective assembly218. The vertical axis1202can represent the direction that is normal or perpendicular to the surface of the first polymer layer302of the reflective assembly218.

The distribution1200of the light can indicate or represent the specularity of the reflective assembly218. As shown inFIG. 12, the distribution1200of the light reflected off of the reflective assembly218is relatively small or tightly constrained due to the highly specular characteristic of the reflective assembly218. The distribution1200of the light may be relatively tight or narrowly constrained due to the diffusing layer1000being relatively clear due to application of electric potential between the conductive layers on opposite sides of diffusing layer1000, as described above in connection with diffusing assembly216.

FIG. 13represents a distribution1300of light reflected off of the reflective assembly218according to a second example. The distribution1300represents the spread of the light reflected by the reflective assembly218when the electric potential applied across or between the conductive layers on opposite sides of the diffusing layer1000shown inFIGS. 10 and 11is not at or above the switching voltage of the diffusing layer1000(or when no electric potential is applied). The distribution1300of the light may be broader or less tightly constrained relative to the distribution1200due to the diffusing layer1000being less clear due to absence of electric potential or a smaller electric potential applied between the conductive layers on opposite sides of diffusing layer1000.

Changing the specularity of the reflective assembly218may change the distribution of the light emanating from the lighting system100. Similar to the amount of scattering in the diffusing assembly216being a function of the magnitude of electric potential applied across or between the conductive layers on opposite sides of a diffusing layer, the specularity of the reflective assembly218also can be a function of the magnitude of electric potential applied across or between the conductive layers on opposite sides of the liquid crystal layer in the reflective assembly218. Changing the specularity of the reflective assembly218may change how the light is reflected inside the lighting assembly100and, consequently, alter the direction in which light emanates from the lighting system100. The specularity of the reflective assembly218may be variable with respect to the different electric potentials applied to the conductive layers on opposite sides of the liquid crystal layer1000, which can allow for many varied different directions or profiles or distributions of the light relative to some known directional lamps or luminaires.

FIG. 14illustrates a circuit diagram of the power supply circuit202shown inFIG. 2according to one embodiment. The power supply circuit202may be operably coupled with the power supply220which is shown as an alternating current input inFIG. 14(“AC Input” inFIG. 14). Alternatively, the power supply220may be another type of or source electric current. The power supply circuit202includes a driver1400which may be conductively coupled with the power supply220in order to receive current, such as alternating current, from the power supply220. The driver1400may be an LED driver that regulates electric power supplied to the light source200. The driver1400may respond to changing demands of the light source200by providing a constant or substantially constant quantity of electric power to the light source200.

The light source200is illustrated inFIG. 14as including a string or series of light emitting diodes1402. The light source200is connected between the driver1400and one or more of the diffusing assembly216and/or the reflective assembly218. The assemblies216,218may each be referred to as an electro-active optical component or may collectively be referred to as an electro-active optical component. For example, the light source200may be connected with the driver1400in parallel with the diffusing assembly216and/or the reflective assembly218. While the diffusing assembly216and/or reflective assembly218are represented by a polymer dispersed liquid crystal (PDLC) device inFIG. 14, alternatively, one or more of the diffusing assembly216and/or reflective assembly218may be formed from a liquid crystal layer other than a PDLC device.

The power supply circuit202can include a control device1404that is used to control the amount of current supplied to the diffusing assembly216and/or the reflective assembly218. In one aspect, the control device1404can represent a potentiometer or other device having a resistance that can be changed. The control device1404and the diffusing assembly216and/or the reflective assembly218may be connected in series with each other and in parallel with the light source200. In operation, the control device1404may change the resistance provided by the control device1404to change how much electric potential is supplied to the conductive layers on opposite sides of the diffusing layers in the diffusing assembly216and/or the reflective assembly218. As described above, changing the electric potential can change the distribution of light that emanates from the lighting system100. In one embodiment, multiple control devices1404may be provided, with one control device1404controlling the electric potential applied to the conductive layers on opposite sides of the diffusing layer in the diffusing assembly216and another control device1402controlling the electric potential supplied to the conductive layers on opposite sides of the diffusing layer in the reflective assembly218. As a result, these control devices1404can independently control how the diffusing assembly216changes the distribution204of the light and how the reflective assembly218controls the distribution204of light. Alternatively, a single control device1404may control the electric potential supplied to both the diffusing assembly216and the reflective assembly218.

The power supply circuit202diverts at least some of the electric current away from the light source200and conducts this diverted current to the diffusing assembly216and/or reflective assembly218, while the light source200continues to receive sufficient electric current to continue generating the light. For example, the power supply circuit202may tap off of the power supply to the light source200while the light source200is generating light in order to apply the electric potentials to the diffusing assembly216and/or reflective assembly218to make either or both assemblies216,218more clear as described above.

The switching voltages for different types of liquid crystal layers may differ. For example, for liquid crystal layers formed from PDLC, the switching voltage may be between twenty and one hundred volts. For liquid crystal layers formed from polymer network liquid crystal (PNLC) or twisted nematics (TN), the switching voltage can be between three and five volts. Alternatively, the liquid crystal layers316,1000and one or more of the diffusing assembly216and/or reflective assembly218may have different or other switching voltages.

FIG. 15illustrates another embodiment of the power supply circuit202. The power supply circuit202shown inFIG. 15includes a rectifier1500that receives alternating current from the power supply220. The rectifier1500converts the alternating current into a direct current that is supplied to a driver1502, such as an LED driver or the driver1400shown inFIG. 14. As described above in connection withFIG. 14, the light source200may represent plural light devices1402, such as LEDs, connected in series with each other in parallel with the driver. A control device1504also may be connected with the LED driver1502in parallel with the light source200. The control device1504may represent the control device1404shown inFIG. 14. The control device1504may divert some of the current supplied by the driver1502from the light source200to one or more of the diffusing assembly216and/or the reflective assembly218, as described above. This can allow for the light source200to generate light concurrently with the electric potential being applied to either or both assemblies216,218to change the scattering of light by either or both assemblies216,218.

FIG. 16illustrates another embodiment of the power supply circuit202shown inFIG. 1. The power supply circuit202shown inFIG. 16includes the rectifier1500connected with the power supply220. The power supply220may supply alternating current to the rectifier1500, which is modified into a direct current. The rectifier1500supplies this direct current to the driver1502, which supplies the current to the light source200to power the light source to generate the light. In contrast to the power supply circuit202shown inFIG. 15, the control device1504and the power supply circuit202shown inFIG. 16is not connected with the driver1502in parallel with the light source200. Instead, the control device1504and the assemblies216,218shown inFIG. 16are connected in series with each other in a branch of the circuit202that does not include the driver1502or the light source200.

FIG. 17illustrates a control system1700for the lighting system100according to one embodiment. The control system1700includes a communication assembly1702that is connected with the assemblies216,218and/or the light source200, such as via the power supply circuit202. In the illustrated embodiment, the communication assembly1702also is connected with the power supply220. In another embodiment, however, the communication assembly1702may not be connected with the power supply220the supplies power to light source204/or the assemblies216,218.

The communication assembly1702represents hardware circuitry that includes and/or is connected with transceiving hardware or receiving hardware that can wirelessly communicate with one or more remote control devices1704,1706. For example, the communication assembly1702may include one or more antennas, Bluetooth receivers, demodulators, network adapters, or the like, that can receive a wireless signals1708from one or more of the remote control devices1704,1706. The wireless signal1708can direct the power supply circuit202of the lighting system100to supply amount of current or electric potential to one or more of the assemblies216,218. In response to receiving the wireless signal1708, the communication assembly1702can direct the power supply circuit202to supply the appropriate or requested current to one or more of the assemblies216,218so that the appropriate assembly216,218applies, removes, or changes the electric potential applied across or between the conductive layers and opposite sides of liquid crystal layer to change the distribution of light emanating from the lighting system100.

The remote control devices1704,1706can represent one or more electronic devices capable of communicating the wireless signal1708to the communication assembly1702. In the illustrated embodiment, the remote controlled by1704represents a mobile phone or tablet computer capable of sending the wireless signal1708. The remote control device1706shown inFIG. 17is illustrated as a remote control having buttons or other devices for generating and sending the wireless signal1708to the communication assembly1702. Optionally, the lighting system100may include a switch or other input device, or may be connected with the switch or other input device. The switch or input device may be actuated by an operator to cause the power supply circuit202to apply, remove, or change the electric potential supplied to one or more of the assemblies216,218.

FIG. 18illustrates another embodiment of the diffusing assembly216shown inFIG. 2and the lighting system100. The diffusing assembly216may include the liquid crystal layer316and/or the conductive layers306,308extending over the entire surface area of the diffusing assembly216through which light enters and/or exits the diffusing assembly216. Alternatively, the liquid crystal layer316and/or conductive layers306,308may extend over only a portion, but not all, of the surface area through which the light enters and/or exits the diffusing assembly216. InFIG. 18, the diffusing assembly216includes first areas1800and different, non-overlapping second areas1802. The number, size, shapes, and arrangement of the areas1800,1802shown inFIG. 18are provided as one example, and are not limiting on all embodiments of the subject matter described herein.

One of the areas1800or1802represents the locations in the diffusing assembly216where the liquid crystal layer316and/or the conductive layers306,308are located, while the other areas1802or1800represents the locations in the diffusing assembly216where the liquid crystal layer316and/or the conductive layers306,308are not located. Separating the areas where the liquid crystal layer316and/or layers306,308are located can allow for different distributions1804,1806of the light to emanate from the lighting system100. For example, having only discrete areas of the diffusing assembly216alternate between clear or different levels of scattering the light can allow for various distributions1804,1806of the light to be achieved. In one aspect, changing the scattering of the light in the areas1800or1802(by applying or removing the electric potential across the areas1800or1802) can cause the light to emanate from the lighting system100in the distribution1804while not changing the scattering of the light in the areas1800or1802can cause the light to emanate in the distribution1806.

FIG. 19illustrates another embodiment of the diffusing assembly216shown inFIG. 2and the lighting system100. The diffusing assembly216may be used to change the distribution of the light emanating from the lighting system100by changing the shape of the distribution of light and/or by changing the direction in which the light emanates from the lighting system100. Similar to the diffusing assembly216shown inFIG. 18, the diffusing assembly216shown inFIG. 19may have different areas1900,1902, with one area1900or1902including the liquid crystal layer316and/or the conductive layers306,308and the other area1902or1900not including one or more of the liquid crystal layer316or the conductive layers306,308.

When an electric potential is applied to the area1900or1902having the liquid crystal layer and conductive layers, this area1900or1902may become more clear and cause the lighting system100to generate the light along a distribution1904shown inFIG. 19. Removing or reducing this electric potential across the conductive layers in the area1900or1902having the liquid crystal layer and conductive layers, however, can cause increased scattering of light passing through the area1900or1902, as described above. As a result, the light may be directed to one side and cause the lighting system100to generate a different distribution1906of light. As shown inFIG. 19, this can result in the direction in which the light emanates from the lighting system100to change. The diffusing assembly216therefore can be used to change the shape of the distribution of light (e.g., by causing the light to be cast or thrown over a larger or smaller area depending on the amount of scattering caused by the diffusing assembly216) and/or to change the direction in which the distribution of light is cast (e.g., by directing the light to one side or another of the lighting system). The reflective assembly218may be used to additionally steer (e.g., control) the direction of the distribution of light, or the lighting system100may use the diffusing assembly216without the reflective assembly218to control the direction of the light distribution.

While the lighting systems100illustrated herein include a single diffusing assembly216between the light source200and one or more target objects onto which the light is generated toward (e.g., persons, floors, walls, ceilings, etc.), alternatively, two or more diffusing assemblies216may be between the light source200and the target objects. For example, plural diffusing assemblies216may be stacked or serially aligned with each other such that at least one of the diffusing assemblies216is between the light source200and one or more other diffusing assemblies216. This can allow for additional or alternative control over the distribution of light emanating from the lighting system100.

The lighting systems100described herein can provide for different control over distributions of light emanating from the systems100. The light distributions can be controlled depending on the environment, goals, etc. For example, with respect to a lighting system100that illuminates a crosswalk across a road or other path at an intersection between two or more roads, the lighting system100may generate a distribution of light having a wide shape and direction to illuminate a large portion of the intersection between the roads. Responsive to a person being able to enter the cross walk (e.g., by a traffic signal changing signals, by the person pressing a button, by a motion sensor detecting the person), the lighting system100can change the distribution of light. The distribution of light can be altered by reducing the size of the light distribution and/or changing the direction of the light distribution to focus on the cross walk instead of the entire intersection. As another example, the lighting system100may illuminate an entire office or other room during designated time periods of a day, but then switch to focusing the light distribution on a desk or other location in the room during other designated time periods of the day. The lighting system100may include a timer (e.g., a clock) in the power supply circuit202that can autonomously change the light distribution responsive to changes in time.

FIG. 20illustrates a flowchart of one embodiment of a method2000for electrically controlling optics of a lighting system. The method200may be performed using the systems1700described herein. Alternatively, the method2000may be performed by one or more other lighting systems or other systems. The operations described in connection with the method2000may be used to generate a software program or algorithm for use in controlling one or more lighting systems.

At2002, input is received to change the distribution of light emanating from a lighting system. This input may be received from the remote control device, by actuating a switch or other input device communicatively coupled with the lighting system, by a timer that autonomously changes the distribution of light, or from other input.

At2004, a determination is made as to whether or not the change in the distribution of light is to change a shape of the light distribution. If the shape of light distillation is to change, then flow of the method2000may proceed toward2006. If, on the other hand, the shape of the light distribution is not to change, then flow the method2000can proceed toward2008.

At2006, the amount of scattering of the light and one or more diffusing assemblies of the lighting system is electrically changed. As described above, by applying, removing, or changing electric potential applied across or between conductive layers on opposing sides of a liquid crystal layer, the amount of scattering of the light passing through the diffusing assembly may be controlled or otherwise changed. Changing the amount of scattering in the diffusing assembly can alter the shape of the light distribution in that increased scattering in the diffusing assembly can create a larger distribution or larger shape of the light while reduce scattering can reduce the size of the distribution of the light.

At2008, a determination is made as to whether or not the direction of light distribution is to be changed. If the direction in which the light distribution is oriented is to be changed, then flow of the method2000can proceed toward2010. If, on the other hand, the direction of light distribution is not to be changed, then flow of the method2000may return back toward2002. For example, the method2000may proceed in a loop-wise manner back to2002to receive additional input to change distribution of the light. Alternatively, operation of the method2000may terminate if the direction of the light distribution is not to be changed at2008.

At2010, specularity of one or more reflective assemblies in the lighting system is electrically changed and/or the amount of scattering of the light in one or more diffusing assemblies is electrically changed. As described above, the specularity of the reflective assembly in a lighting system may be altered by changing the amount of scattering in a diffusing layer of the reflective assembly. Light that propagates through this diffusing layer before and/or after reflecting off a reflective surface in the reflective assembly. Applying, changing, or removing electric potential applied to conductive layers on opposite sides of the liquid crystal layer can change amount of scattering in the reflective assembly before and/or after reflection of the light off of the reflective layer and the reflective assembly. These changes in the scattering of the reflective assembly can alter the specularity of the reflective assembly. As a result, the direction in which light emanates from the lighting system may be changed. Optionally, changing the amount of scattering in the diffusing assembly may change the direction in which light emanates from the lighting system, as described above.

In one embodiment, a method (e.g., for actively controlling optics of a lighting system) includes generating light comprising a light distribution from a light source and changing the light distribution by changing an electric potential between conductive and light transmissive layers of a diffusing assembly that includes a liquid crystal layer disposed between the first and second conductive and light transmissive layers.

In one aspect, the light distribution comprises one or more of a shape of the generated light or a direction in which the generated light is oriented.

In one aspect, one or more of shape of the light that is generated or the direction in which the light that is generated is oriented, is changed.

In one aspect, changing the first electric potential changes a scattering of the generated light by the first liquid crystal layer.

In one aspect, the scattering of the generated light by the first liquid crystal layer is changed as a function of the first electric potential between the first and second conductive and light transmissive layers.

In one aspect, changing the light distribution includes changing a shape of the light by changing an amount of diffusion of the light with the first liquid crystal layer as a function of the first electric potential.

In one aspect, changing the light distribution includes changing a direction at which the light is oriented upon exiting the diffusing assembly by changing specularity of a reflective assembly that reflects at least a portion of the light toward the diffusing assembly.

In one aspect, the specularity of the reflective assembly is changed by changing a second electric potential between first and second conductive layers of the reflective assembly that includes a second liquid crystal layer between the first and second conductive layers.

In one aspect, the method also includes diverting at least some of an electric current that is supplied to the light source to power the light source away from the light source and to the first and second conductive and light transmissive layers of the diffusing assembly while the light source continues to generate the light.

In one aspect, the method also includes receiving a control signal from a remote control device to remotely change the light distribution.

In one aspect, changing the light distribution occurs without blocking one or more wavelengths of the light from passing through the diffusing assembly.

In one aspect, changing the light distribution occurs without mechanically moving the light source or the diffusing assembly.

In another embodiment, a system (e.g., a lighting system) includes a light source and a diffusing assembly. The light source is configured to generate a light defined by a light distribution. The diffusing assembly includes a liquid crystal layer disposed between conductive and light transmissive layers. The diffusing assembly is configured to change the light distribution responsive to a change in an electric potential between the conductive and light transmissive layers.

In one aspect, the change in the first electric potential changes a scattering of the light by the first liquid crystal layer.

In one aspect, the scattering is changed as a function of the first electric potential between the first and second conductive and light transmissive layers.

In one aspect, the diffusing assembly is configured to change a shape of the light by changing an amount of diffusion of the light with the first liquid crystal layer as a function of the first electric potential.

In one aspect, the system also includes a reflective assembly comprising a second liquid crystal layer disposed between first and second conductive layers. The reflective assembly is configured to change a direction at which the light distribution is oriented responsive to a change in specularity of the reflective assembly that reflects at least a portion of the light.

In one aspect, the reflective assembly is configured to change the specularity of the reflective assembly responsive to changing a second electric potential between first and second conductive layers of the reflective assembly.

In one aspect, the system also includes a power supply circuit configured to conduct electric current from a power source to the light source to power the light source for generation of the light. The power supply circuit also is configured to divert at least some of the electric current that is supplied to the light source to power the light source to the first and second conductive and light transmissive layers of the diffusing assembly while the light source continues to be powered by the power source and continues to generate the light.

In one aspect, the system also includes a communication assembly configured to receive a control signal from a remote control device to remotely change the first electric potential applied to the first and second conductive and light transmissive layers of the diffusing assembly.

In one aspect, the diffusing assembly is configured to change the light distribution without blocking one or more wavelengths of the light from passing through the diffusing assembly.

In one aspect, the diffusing assembly is configured to change the light distribution without mechanically moving the light source or the diffusing assembly.

In another embodiment, another system (e.g., a lighting system) includes a light source and a diffusing assembly and/or a reflective assembly. The light source is configured to generate a light defined by a light distribution. The diffusing assembly includes a first liquid crystal layer disposed between conductive and light transmissive layers. The diffusing assembly is configured to change the light distribution responsive to a change in an electric potential between the conductive and light transmissive layers. The reflective assembly includes a liquid crystal layer disposed between conductive layers. The reflective assembly is configured to change a direction at which the light distribution is oriented responsive to a change in specularity of the reflective assembly that reflects at least a portion of the light.

In one aspect, the system includes the diffusing assembly and the diffusing assembly is configured to change a shape of the light distribution by changing an amount of diffusion of the light with the first liquid crystal layer as the function of the first electric potential.

In one aspect, the system includes the reflective assembly and the reflective assembly is configured to change the specularity of the reflective assembly responsive to changing a second electric potential between first and second conductive layers of the reflective assembly.

The foregoing description of certain embodiments of the inventive subject matter will be better understood when read in conjunction with the appended drawings. The various embodiments are not limited to the arrangements and instrumentality shown in the drawings. The above description is illustrative and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the inventive subject matter without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the inventive subject matter, they are by no means limiting and are exemplary embodiments. Other embodiments may be apparent to one of ordinary skill in the art upon reviewing the above description. The scope of the inventive subject matter should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. §112(f), unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure. And, as used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the inventive subject matter are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising,” “including,” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.