Abstract: This invention is a novel retroreflective traffic stripe comprising a widely spaced repeating pattern of linear light turning prisms over cube corner retroreflective prisms in a critical optimal configuration. The light turning prisms comprise at least two exposed surfaces, one approximately vertical facing the headlights of oncoming traffic, and another opposing the first and sloped by approximately 45 degrees. The approximately vertical surface efficiently accepts light from the headlights and transmits such light to the sloped surface which totally internally reflects such light downward onto an array of cube corner retroreflective prisms, which totally internally reflect such light in approximately the reverse direction.

Abstract: This invention is a novel retroreflective traffic stripe comprising an exposed top surface containing a widely spaced repeating pattern of linear light-turning prisms and a second repeating pattern of linear prisms between the light-turning prisms, over a bottom surface containing cube corner retroreflective prisms. The two types of top surface prisms are operable under dry and wet weather conditions, respectively. Both types of top surface prisms are configured to use refraction and reflection to redirect light from distant headlights into a downward direction onto the bottom surface of the traffic stripe under dry and wet weather conditions, respectively. Cube corner retroreflective prisms on the bottom surface accept the light and return it in the opposite direction.

Abstract: This invention is a novel retroreflective traffic stripe comprising a widely spaced repeating pattern of linear light turning prisms over cube corner retroreflective prisms in a critical optimal configuration. The light turning prisms comprise at least two exposed surfaces, one approximately vertical facing the headlights of oncoming traffic, and another opposing the first and sloped by approximately 45 degrees. The approximately vertical surface efficiently accepts light from the headlights and transmits such light to the sloped surface which totally internally reflects such light downward onto an array of cube corner retroreflective prisms, which totally internally reflect such light in approximately the reverse direction.

Abstract: A retroreflective traffic stripe comprising an exposed top surface containing a widely spaced repeating pattern of linear light-turning prisms over a bottom surface containing two different types of cube corner retroreflective prisms. The light-turning prisms are configured to use refraction and reflection to redirect light from distant headlights into a downward direction onto the bottom surface of the traffic stripe. Cube corner retroreflective prisms of the first type on the bottom surface have optical axes which are substantially perpendicular to the surfaces of the traffic stripe and are located substantially beneath such light-turning prisms. Cube corner retroreflective prisms of the second type on the bottom surface have optical axes tilted toward the distant headlights by at least 25 degrees and are located substantially between such light-turning prisms. Under dry road conditions, the light-turning prisms and first type of cube corner prisms provide unprecedented levels of retroreflectivity.

Abstract: A retroreflective traffic stripe comprising a widely spaced repeating pattern of linear light-turning prisms over cube-corner retroreflective prisms. The light-turning prisms comprise at least two exposed surfaces: one approximately vertical facing the headlights of an oncoming vehicle, and another opposing the first and sloped by approximately 45 degrees. The approximately vertical surface accepts light from the headlights and transmits such light to the sloped surface which totally internally reflects such light downward onto an array of cube corner retroreflective prisms, which totally internally reflect such light in approximately the reverse direction. Such reflected light once more encounters the sloped face of the light turning prisms which totally internally reflects the light toward the approximately vertical surface, where such light exits and returns toward the headlights and toward the eyes of the driver of the vehicle.

Abstract: This invention includes a flexible Fresnel lens assembly which can be efficiently stowed into a small volume, and then deployed with a mechanism, including structural elements, that provides tensioning at the ends of the lens assembly to position and support the lens assembly in proper position relative to a photovoltaic receiver, onto which the lens assembly focuses sunlight for conversion into electricity. The flexible stretched lens assembly includes a transparent prismatic polymer film, comprising a refractive optical element, attached to flexible cords, fibers, or wires that carry the bulk of the tension load in the stretched lens assembly when it is deployed in its final functional position. This present invention represents a critical and mission-enabling improvement to an earlier stretched lens array invention described in U.S. Pat. No. 6,075,200 (Reference 1).

Abstract: This invention includes a Fresnel lens assembly positioned relative to an energy receiver, onto which the lens assembly focuses sunlight for collection and conversion. The Fresnel lens assembly includes a thin polymeric film with prisms molded into or attached to the film. This invention also includes an articulating energy receiver which can move closer to or farther away from the lens depending on the longitudinal angle of incidence of the sunlight relative to the lens, to maintain the best focus of sunlight on the energy receiver. The prisms in the present lens are specified to provide acceptable optical performance in the presence of relatively large longitudinal solar incidence angles, relatively smaller lateral solar incidence angles, in combination with the articulating energy receiver. The new lens assembly can further be deployed and supported as a thin flexible stretched membrane with tension maintaining the lens in proper position on orbit.

Abstract: This invention includes a Fresnel lens assembly positioned relative to an energy receiver, onto which the lens assembly focuses sunlight for collection and conversion. The Fresnel lens assembly includes a thin polymeric film with prisms molded into or attached to the film. This invention also includes an articulating energy receiver which can move closer to or farther away from the lens depending on the longitudinal angle of incidence of the sunlight relative to the lens, to maintain the best focus of sunlight on the energy receiver. The prisms in the present lens are specified to provide acceptable optical performance in the presence of relatively large longitudinal solar incidence angles, relatively smaller lateral solar incidence angles, in combination with the articulating energy receiver. The new lens assembly can further be deployed and supported as a thin flexible stretched membrane with tension maintaining the lens in proper position on orbit.

Abstract: This invention includes a flexible Fresnel lens assembly which can be efficiently stowed into a small volume, and then deployed with a mechanism, including structural elements, that provides tensioning at the ends of the lens assembly to position and support the lens assembly in proper position relative to a photovoltaic receiver, onto which the lens assembly focuses sunlight for conversion into electricity. The flexible stretched lens assembly includes a transparent prismatic polymer film, comprising a refractive optical element, attached to flexible cords, fibers, or wires that carry the bulk of the tension load in the stretched lens assembly when it is deployed in its final functional position. This present invention represents a critical and mission-enabling improvement to an earlier stretched lens array invention described in U.S. Pat. No. 6,075,200 (Reference 1).

Abstract: A novel, high-efficiency, extremely light-weight, inflatable refractive solar concentrator for space power is described. It consists of a flexible Fresnel lens, flexible sides, and a back surface, together enclosing a volume of space which can be filled with low pressure gas to deploy the concentrator on orbit. The back surface supports the energy receiver/converter located in the focal region of the Fresnel lens. The back surface can also serve as the waste heat radiator. Prior to deployment, the deflated flexible lens and sides are folded against the back surface to form a flat, low-volume package for efficient launch into space. The inflatable concentrator can be configured to provide either a line focus or a point focus of sunlight. The new inflatable concentrator approach will provide significant advantages over the prior art in two different space power areas: photovoltaic concentrator arrays and high-temperature solar thermal conversion systems.

Abstract: A novel, high-efficiency, extremely light-weight, robust stretched Fresnel lens solar concentrator for space power is described. It consists of a flexible Fresnel lens attached to end supports, wherein said end supports stretch the lens to maintain its proper position and shape on orbit in space. One embodiment of the new concentrator includes means for lens deployment on orbit in space. In this embodiment, prior to deployment, the flexible lens and end supports are folded into a flat, low-volume package for efficient launch into space. Another embodiment of the new concentrator includes non-deployable means of stretching the lens to maintain its proper position and shape in space. Both embodiments of the new concentrator approach will provide significant advantages over the prior art in space photovoltaic concentrator arrays. Photovoltaic concentrator arrays using the new stretched lens will be much lighter and more economical than prior space concentrator arrays.

Abstract: An apparatus designed to direct daylight through an aperture toward a target area in a building or other structure is disclosed. A housing provides a base attachable to the building and a support structure for supporting a reflector above the aperture. According to one embodiment of the invention the reflector is in the shape of an inverted cone. A light diffusing lens structure is disposed in the optical path between the reflector and the target area. In use, light is transmitted through the support structure, reflected from the surface of the reflector, and dispersed about the target area by the light diffusing lens structure.