Abstract:
A skylight sunlight redirector is provided with ridges, grooves, and/or prisms that control light transmitted through the redirector as incident sunlight angle changes throughout the day.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates generally to a skylight sunlight redirector and, more particularly, to a light transmitting body with ridges, grooves, and/or prisms to advantageously redirect sunlight into or away from a skylight. 
       BACKGROUND 
       [0002]    Skylights provide effective internal lighting for buildings, maximizing visual comfort and reducing energy usage from artificial lighting. 
         [0003]    A typical skylight includes a rooftop element through which sunlight enters the skylight structure, the sunlight being transmitted through the skylight structure to the interior of the building. For example, a building skylight may also include a channel through roof trusses, the channel being disposed between the rooftop element and the interior opening of the skylight. Alternatively, a tubular skylight may include a rooftop element and a light conducting tube depending downwardly from the rooftop element and terminating at a room interior. 
         [0004]    The sunlight received by a skylight is highly directional. In early morning and late afternoon hours, the incident angle at which sunlight strikes the rooftop element of a skylight is relatively low. Furthermore, at sunrise and sunset, sunlight is attenuated due to its relatively longer passage through the Earth&#39;s atmosphere. Conversely, at mid-day, sunlight&#39;s incident angle upon a skylight rooftop element is relatively high. During the course of a day, the sun&#39;s path through the sky relative to a skylight rooftop element is arcuate relative to the horizon. Furthermore, at mid-day, the sunlight incident angle upon a skylight rooftop element at the Winter solstice is low, while the sunlight incident angle at the Summer solstice is high, with the incident angle varying throughout the year between those two extremes. 
         [0005]    It has been found that the irradiance from sunlight arriving at a skylight from a low incident angle may be further reduced before reaching the interior of a building structure, as the sunlight at a low incident angle tends to be reflected several times within the skylight structure, and thereby lessened, before reaching the interior of the building. Furthermore, it has been found that the irradiance received within a building interior from sunlight arriving at a skylight from a high incident angle may be undesirably strong, causing for example “hot spots” within the building interior, inasmuch as such sunlight arrives at the building interior through the skylight structure with fewer reflections, and thereby with retained brilliance, within the skylight structure. 
         [0006]    In view of the foregoing, it would be advantageous to control the illuminance within a building received from a skylight throughout the day, and during the change of seasons, as the incident angle of sunlight changes. 
       SUMMARY OF THE INVENTION 
       [0007]    A skylight sunlight redirector is provided. As revealed in the following description and the figures herein, this invention discovers an effective technology that advantageously controls the sunlight transmitted through a skylight as the sunlight incident angle changes. 
         [0008]    In accordance with certain aspects of certain embodiments of the present technology, a light transmitting body is provided. The light transmitting body may define a center and a periphery with a plurality of ridges, grooves, and/or prisms disposed within the periphery. The light transmitting body may include a transparent portion that may reside between the center and the periphery and, in some embodiments, that may extend from the center to the periphery. The light transmitting body has a first surface and an opposite second surface. The light transmitting body may define a center axis and, in certain embodiments, the light transmitting body may be symmetrical about that center axis. 
         [0009]    In some embodiments, the light transmitting body may define a cross-section that is at least partially curvilinear. In particular configurations, the light transmitting body may be a dome. In some configurations, the light transmitting body may be a convexity. 
         [0010]    In certain embodiments, the light transmitting body may include an equatorial side and an opposing polar side. The polar side may be non-refractive in some arrangements. In particular configurations, the light transmitting body may be understood to have opposing East and West sides disposed between the equatorial side and the opposing polar side. 
         [0011]    In certain embodiments of the present technology, the light transmitting body may be at least partially transparent. 
         [0012]    In accordance with other certain aspects of certain embodiments of the present technology, the light transmitting body may define a plurality of ridges disposed between its center and its periphery. In certain embodiments, each such ridge may define a length with a first end and an opposing second end, each such ridge disposed in a first arc relative to the center. In particular configurations, each such ridge may be disposed in a second arc relative to the periphery of the light disposing body. Each such ridge may define a cross-section that continually varies along the length of the ridge from the first end to the second end. 
         [0013]    In some embodiments, the ridges defined by the light transmitting body may comprise a first side and, in certain embodiments, a second side, wherein the first side may face the center of the light transmitting body and the second side may face the periphery of the light transmitting body. Such ridges may be disposed on the bottom of the light transmitting body. Alternatively, in other applications of the present technology, such ridges may be disposed on the top of the light transmitting body. 
         [0014]    In accordance with particular aspects of certain embodiments of the present technology, at least some of the ridges defined by the light transmitting body may comprise a Fresnel lens. 
         [0015]    In accordance with still other aspects of the present technology, a surface of the skylight sun redirector may carry a plurality of grooves. Each such groove may extend from a first end to an opposite second end and, in some configurations, such cross-section may continually vary from the first end to the second end. In particular embodiments, each such groove may define an arc relative to the center axis of the skylight sun redirector, such arc residing in a plane that is not perpendicular to the center axis. In some embodiments, certain of those grooves may be disposed such that each is not parallel to any other such groove. In particular configurations, each groove may have a triangular cross-section. 
         [0016]    In accordance with yet still other certain aspects of certain embodiments of the present technology, the skylight sun redirector may be a convexity. In some embodiments, the convexity may carry a plurality of prisms. Each such prism may extend from a first end to an opposite second end. In particular embodiments, each such prism may define a cross-section that may continually vary from the first end to the second end. In certain embodiments, such prisms may be arcuate relative to the center. 
         [0017]    In accordance with still further aspects of other embodiments of the present technology, at least one of the prisms carried by the convexity may be configured to redirect sunlight that is incident upon the East and/or West side of the convexity away from the center of the convexity. It will be appreciated that, in accordance with such an embodiment, sunlight incident upon the convexity from the East and/or West sides at a first angle from the horizontal may be redirected by the prism such that it is transmitted by the convexity to depart at an angle from the horizontal greater than such first angle. In accordance with yet still further aspects of other embodiments of the present technology, at least one of the prisms may be configured to redirect sunlight that is incident upon the convexity from the equatorial side toward the convexity. It will be appreciated that, in accordance with such an embodiment, sunlight that is incident upon the equatorial side of the convexity at a particular angle from the horizontal may be redirected by the prism such that it departs the prism at an angle from the horizontal less than such second angle. 
         [0018]    In some embodiments of the present technology, a plurality of the prisms may be non-parallel one-to-another. 
         [0019]    In certain configurations, the first ends of the prisms may be disposed on an East side of the convexity and the second ends may be disposed on a West side of the convexity, the prisms extending through an equatorial side of the convexity. 
         [0020]    In particular embodiments, the prisms may be carried on the lower surface of the convexity. 
         [0021]    The foregoing description sets forth broadly certain features of the present invention so that the detailed description below may be better understood and so that the contributions from this invention may be better appreciated. Additional advantages of the invention will be set forth in part in the detailed description below and in part may be obvious from the detailed description or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description as well as the following detailed description are only exemplary and merely explanatory, and are not restrictive of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The details of the present technology, both as to its structure and operation, can be better understood with reference to the accompanying figures. It should be noted that these figures are not necessarily to scale in all instances. 
           [0023]      FIG. 1  is a perspective view of a skylight sunlight redirector in accordance with certain aspects of the present invention, from an upper, East-polar perspective; 
           [0024]      FIG. 2  is a perspective view of a skylight sunlight redirector in accordance with certain aspects of the present invention, from a lower, East-polar perspective; 
           [0025]      FIG. 3A  is a plan view of a skylight sunlight redirector in accordance with certain aspects of the present invention; 
           [0026]      FIG. 3B  is a plan view of a skylight sunlight redirector in accordance with certain aspects of the present invention; 
           [0027]      FIG. 4  is an equatorial elevation view of a skylight sunlight redirectory in accordance with certain aspects of the present invention; 
           [0028]      FIG. 5  is a polar elevation view of a skylight sunlight redirector in accordance with certain aspects of the present invention; 
           [0029]      FIG. 6  is a broken view of a detail of a skylight sunlight redirector in accordance with certain aspects of the present invention; 
           [0030]      FIG. 7  is a partial sectional view, taken along line I-I in  FIG. 3B , of a skylight sunlight redirector in accordance with certain aspects of the present invention; 
           [0031]      FIG. 8  is a partial sectional view, taken along line II-II in  FIG. 3B , of a skylight sunlight redirector in accordance with certain aspects of the present invention; 
           [0032]      FIG. 9  is a plan view of the East side of a skylight sunlight redirector in accordance with certain aspects of the present invention; 
           [0033]      FIG. 10  is an operational illustration of a skylight sunlight redirector in accordance with certain aspects of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Reference will now be made in detail to embodiments of the present technology, one or more examples of which are illustrated in the drawings. Selected combinations of aspects of the disclosed technology correspond to a plurality of different embodiments of the present invention. It should be noted that each of the exemplary embodiments presented and discussed herein should not imply limitations of the present subject matter. Features illustrated or described as part of one embodiment may be used in combination with aspects of another embodiment to yield yet further embodiments. Additionally, certain features may be interchanged with similar devices or features not expressly mentioned, which perform the same or similar function. 
         [0035]    A skylight sunlight redirector  20  is provided. Redirector  20  is configured to be positioned at the rooftop element of a skylight; in certain applications, redirector  20  itself may constitute the rooftop element of the skylight. 
         [0036]    Redirector  20  has a center  21  and a periphery  22 . In certain embodiments, redirector  20  may include a transparent zone  23  that allows transmission of sunlight without refraction. Redirector  20  has a first surface  24  and an opposite second surface  20 . A center axis  26  may be understood to extend perpendicularly through redirector  20  in some embodiments. In particular embodiments, redirector  20  may define a cross-section that is at least partially curvilinear. In particular embodiments, redirector  20  may comprise a dome. In certain embodiments, redirector  20  may comprise a convexity. 
         [0037]    Redirector  20  may be further understood to have an equatorial side  27 , an opposing polar side  28 , and an East side  29  and West side  30  disposed between equatorial side  27  and polar side  28 . 
         [0038]    Redirector  20  may define a plurality of ridges, for examples ridges  40   a ,  40   b . Each such ridge, for example  40   a , may have a first end  41  and an opposing second end  42 . In profile, each such ridge, for example  40   a , may have a first side  43  and a second side  44 . Each such ridge, for example  40   a , may reside in a plane  45 . So configured, each such ridge, for example  40   a , may be disposed in a first arc relative to center  21  and may likewise be disposed in a second arc relative to periphery  22 . Each such ridge, for example ridge  40   a , may also define a cross-section that is continually varying from first end  41  to second end  42 . 
         [0039]    Redirector  20  may be understood to carry a plurality of grooves, for examples grooves  50   a ,  50   b . Each such groove, for example groove  50   a , may have a first end  51  and a second end  52 . In certain embodiments, each such groove, for example groove  50   a , may reside in a plane  53  that is not perpendicular to certain axis  26 . 
         [0040]    Redirector  20  may carry a plurality of prisms, for examples prisms  60   a ,  60   b . Each such prism, for example prism  60   a , may have first end  61  and a second end  62 . In certain embodiments, each such prism, for example prism  60   a , may reside in a plane  63  and plane  63  may be oriented such that it is not perpendicular to center axis  26 . 
         [0041]    In certain embodiments for certain applications, a draining profile  70  may be included. In particular embodiments, draining profile  70  may be a raised water draining rib, whereas in other embodiments draining profile  70  may be a depressed water draining channel. Draining profile  70  may allow condensation to drain off of redirector  20 . 
         [0042]      FIG. 1  illustrates one embodiment of the present technology. As depicted in  FIG. 1 , redirector  20  is illustrated as a convexity. Redirector  20  is shown to include a center  21  and a periphery  22 . Likewise, the illustration of  FIG. 1  includes a transparent zone  23 . From the perspective displayed in  FIG. 1 , a first surface  24  is presented. Also illustrated in  FIG. 1  is equatorial side  27 , polar side  28 , East side  29 , and West side  30 . 
         [0043]    A draining profile  70  is also depicted in  FIG. 1 . 
         [0044]    For illustrative purposes, ridges  40   a ,  40   b  are depicted in  FIG. 1 . Each such ridge  40   a ,  40   b  begins at a first end, for example first end  41 , and ends at a second end, for example second end  42 . 
         [0045]    For other illustrative purposes,  FIG. 1  may also be understood to depict a plurality of grooves, for example grooves  50   a ,  50   b . Each such groove begins at a first end, for example first end  51 , and ends at a second end, for example second end  52 . 
         [0046]    For further illustrative purposes,  FIG. 1  may be further understood to depict a plurality of prisms, for example prisms  60   a ,  60   b . Each such prism begins at a first end, for example first end  61 , and ends at a second end, for example second end  62 . 
         [0047]      FIG. 2  illustrates an embodiment of redirector  20  from a different perspective. Illustrated in  FIG. 2  is periphery  22 , a transparent zone  23 , and a portion of second surface  20 . Equatorial side  27 , polar side  28 , East side  29 , and West side  30  are also shown. A draining profile  70  has also been included in the embodiment depicted in  FIG. 2 . 
         [0048]      FIG. 3A  depicts certain features of a particular embodiment of redirector  20 . As illustrated therein, equatorial side  27  is opposed by polar side  28 , and East side  29  and West side  30  are disposed between equatorial side  27  and polar side  28 . Inasmuch as the embodiment depicted in  FIG. 3A  is round in plan view, sides  27 ,  28 ,  29 , and  30  will be appreciated as only generalizations in such an embodiment rather than precisely-dimensioned geometries and are illustrated in  FIG. 3A  only as same. 
         [0049]      FIG. 3A  also depicts center  21 . From the illustration of  FIG. 3A , it may be understood that ridge  40   a , groove  50   a  and/or prism  60   a , as exemplary of other such ridges, grooves, and/or prisms, may be arcuate relative to center  21 . In certain embodiments, ridges  40   a , grooves  50   a , and/or prisms  60   a  may be arcuate centered upon center  21  (not shown). 
         [0050]      FIG. 3A  illustrates redirector  20  from the perspective of depicting second surface  24 . 
         [0051]      FIG. 3B  illustrates the same embodiment of redirector  20  as  FIG. 3A  from a different perspective and is offered for further description of aspects of such embodiment. As depicted therein, periphery  22  surrounds center  21  and transparent zone  23  is included in such embodiment. In certain particular embodiments transparent zone  23  may be non-refractive. 
         [0052]    Equatorial side  27  is also illustrated in  FIG. 3B  and a draining profile  70  has been included in the illustrated embodiment. In use, redirector  20  is installed with equatorial side  27  oriented toward the Earth&#39;s equator; for example, in the Northern hemisphere, equatorial side  27  is oriented toward the South. With embodiments that include draining profile  70 , draining profile  70  may be advantageously used to point more directly toward the Earth&#39;s equator. 
         [0053]    It will also be observed in  FIG. 3B  that the ridges, grooves, and/or prisms, for examples ridges  40   a , grooves  50   a , and prisms  60   a , may comprise arcs of greater than 180 degrees. So configured, the ridges, grooves, and/or prisms, for examples, ridges  40   a , grooves  50   a , and prism  60   a  may capture a more low incident angle sunlight during days near the Summer solstice. Additionally, such increased arc angles also allow a tolerance for slight misalignment upon installation of redirector  20  upon a roof. In certain embodiments, such arcs may be approximately 300 degrees. 
         [0054]      FIG. 4  illustrates an embodiment of redirector  20  in which redirector  20  is a dome.  FIG. 4  represents an elevation view of redirector  20  from equatorial side  27 . The embodiment illustrated in  FIG. 4  is a redirector  20  symmetrical about center axis  26 . 
         [0055]      FIG. 5  illustrates a plan view of the redirector  20  of  FIG. 4  from polar side  28 . 
         [0056]      FIG. 6  shows an embodiment of redirector  20  that includes draining profile  70 . In certain particular embodiments, draining profile  70  may be configured as a raised rib to allow condensation to drain off the dome surface. In other particular embodiments, draining profile  70  may be configured as a depressed channel to promote the drainage of water from the dome surface. In certain embodiments, draining profile  70  may be disposed on first surface  24  but in other embodiments draining profile  70  may be disposed on second surface  25 . 
         [0057]      FIG. 7  shows certain features of a particular embodiment of redirector  20 . As illustrated in  FIG. 7 , redirector  20  may include a cross-section that is at least partially curvilinear.  FIG. 7  also depicts a ridge  40   a  that includes first side  43  and second side  44 . As illustrated in  FIG. 7 , first side  43  faces the center  21  of redirector  20  whereas second side  44  faces the periphery  22  of redirector  20 . 
         [0058]      FIG. 7  also illustrates the inclusion of a groove  50   a . As can be appreciated from  FIG. 7 , groove  50   a  is triangular.  FIG. 7  also may be understood to depict a prism  60   a . In the embodiment of  FIG. 7 , the ridges, grooves, and/or prisms, for examples ridge  40   a , groove  50   a , and prism  60   a , have been configured on the bottom of redirector  20 , but in other embodiments (not shown) they may be disposed on the top of redirector  20 . 
         [0059]    As may be observed in  FIG. 7 , the grooves, for example groove  50   a , have a cross-section that varies along the surface of  FIG. 20 . For illustrative purposes, redirector  20  illustrated in  FIG. 7  has been labeled to include zones A, B, and C; the cross-sections of the grooves, for example groove  50   a , continues to vary in geometry between grooves disposed near periphery  22  and those nearer center  21  (not shown). For example, the representative groove in zone A may have a first side  43  of approximately 3.83 millimeters in length and a second side  44  of approximately 1.62 millimeters in length, with an angle between a first side  43  of one such groove and an opposing second side  44  of an adjacent such groove residing at an angle of about 72 degrees. By comparison, a representative groove from zone B may have a first side  43  about 2.7 millimeters in length and a second side  44  of about 2.0 millimeters in length, with the angle between a first side  43  of one such groove and an opposing second side  44  of an adjacent such groove residing at an angle of about 108 degrees. By further comparison, a representative groove from zone C may have a first side  43  of about 4.0 millimeters in length and a second side  44  of about 3.6 millimeters in length, with an angle between a first side  43  of one groove and a second side  44  of the adjacent groove residing at an angle of about 107 degrees. 
         [0060]    The cross-sections of ridges, grooves, and/or prisms depicted in  FIG. 7 , for example ridges  40   a , grooves  50   a , and prism  60   a , are taken at approximately line I-I in  FIG. 3B , but in certain embodiments of redirector  20  such cross-sections continually vary along the length of such ridges, grooves, and/or prisms, respectively. 
         [0061]      FIG. 7  also illustrates that the ridges, grooves, and/or prisms, for example ridge  40   a , groove  50   a , and prism  60   a , reside in a plane  40 ,  53 , and  63 , respectively. As illustrated in  FIG. 7 , plane  40 ,  53 , and  63  may reside at an acute angle relative to center axis  26  rather than being perpendicular to center axis  26 . 
         [0062]      FIG. 8  illustrates that the ridges, grooves, and/or prisms, for example ridge  40   a , groove  50   a , and prism  60   a , have cross-sections, respectively, that vary along their length. 
         [0063]    The embodiment illustrated in  FIG. 9  illustrates ridges, grooves, and/or prisms, for examples ridge  40   a , groove  50   a , and prism  60   a , not parallel one-to-another. 
         [0064]      FIG. 10  illustrates an operation of redirector  20 . As depicted in  FIG. 10 , morning or evening sunlight from the Sun at position D casts a first incident sunbeam  33  toward redirector  20  at a first incident angle  31  that is relatively low. Mid-day sunlight from the Sun at position E casts a second incident sunbeam  30  toward redirector  20  at a second incident angle  32  that is relatively high. By operation of the ridges, grooves, and/or prisms, for examples ridge  40   a , groove  50   a , and/or prism  60   a , first incident sunbeam  33  is redirected away from center  21 , as illustrated by redirected first sunbeam  34 . Second incident sunbeam  30 , from a mid-day Sun position E, though, is redirected by the ridges, grooves, and/or prisms of redirector  20 , for examples ridge  40   a , groove  50   a , and/or prism  60   a , toward redirector  20 , as depicted by redirected second sunbeam  36 . In one embodiment of redirector  20 , for example, redirector  20  has been configured with ridges, grooves, and/or prisms, for examples ridge  40   a , groove  50   a , and/or prism  60   a , to redirect sunlight with a first incident angle  31  of between zero and fifty-five degrees from the horizontal away from center  21 , as illustrated by redirected first sunbeam  34 , and to redirect incident sunlight with a second incident angle  32  of greater than fifty-five degrees from the horizontal toward redirector  20  as illustrated by redirected second sunbeam  36 . 
         [0065]    The preceding examples, figures, discussion, and explanations consider specific embodiments and configurations. It is to be understood that such specific details are provided for illustrative purposes only and not as limitations to be applied in interpreting the appended claims. It will be further understood that the scope of the present technology further encompasses other embodiments that may become obvious to those skilled in the art. It is intended that the present invention includes such modifications and variations as come within the scope of the appended claims and their equivalence.