Abstract: The inside surface of a cover for a skylight is molded to have a variable prism that directs low-angle light into the skylight tube and that reflects away some high-angle light, to achieve a more constant light output over the course of the day. The prism is established by a series of circular parallel grooves, with grooves nearer the apex of the cover having cross-sections that are different than the cross-sections of grooves nearer the periphery of the cover.

Abstract: The inside surface of a cover for a skylight is molded to have a variable prism that directs low-angle light into the skylight tube and that reflects away some high-angle light, to achieve a more constant light output over the course of the day. The prism is established by a series of circular parallel grooves, with grooves nearer the apex of the cover having cross-sections that are different than the cross-sections of grooves nearer the periphery of the cover.

Abstract: A luminaire is provided which includes a light source, a light guide that receives light radiating from the light source, and a plurality of prisms adjacent the light guide that redirect the light from the light guide substantially perpendicular to a longitudinal axis of the light guide. The prism angles, in one embodiment, are 25°-90°-65°. The fine pitch prism arrays preferably alternate or flip-flop every few millimeters, for example, one to two millimeters to create the visual appearance of bright and dark bands which cause the structure to appear like macro prisms.

Abstract: A luminaire is provided which includes a light source, a light guide that receives light radiating from the light source, and a plurality of prisms adjacent the light guide that redirect the light from the light guide substantially perpendicular to a longitudinal axis of the light guide. The prism angles, in one embodiment, are 25°-90°-65°. The fine pitch prism arrays preferably alternate or flip-flop every few millimeters, for example, one to two millimeters to create the visual appearance of bright and dark bands which cause the structure to appear like macro prisms.

Abstract: A luminaire and method are provided comprising a light source, a plurality of prisms, such as linear prisms, for redirecting light from the light source in a predetermined direction, and a reflector for redirecting light from the light source toward the plurality of prisms. Each of the linear prisms has a longitudinal axis and the light source has a longitudinal axis, wherein the longitudinal axes of the linear prisms are substantially parallel to the longitudinal axis of the light source. Each of the plurality of prisms has an included angle, which can vary as a function of the distance from the light source. The angle can vary stepwise or continuously. In one embodiment, each of the plurality of prisms adjacent the light guide has an included angle in the range of between about 35 and 45 degrees. In another embodiment, the included angle is substantially uniform among the prisms.

Abstract: A luminaire is provided which includes a light source, a light guide that receives light radiating from the light source, and a plurality of prisms adjacent the light guide that redirect the light from the light guide substantially perpendicular to a longitudinal axis of the light guide. The prism angles, in one embodiment, are 25°−90°−65°. The fine pitch prism arrays preferably alternate or flip-flop every few millimeters, for example, one to two millimeters to create the visual appearance of bright and dark bands which cause the structure to appear like macro prisms.

Abstract: A luminaire is provided which includes a light source, a light guide that receives light radiating from the light source, and a plurality of prisms adjacent the light guide that redirect the light from the light guide substantially perpendicular to a longitudinal axis of the light guide. The prism angles, in one embodiment, are 25°-90°-65°. The fine pitch prism arrays preferably alternate or flip-flop every few millimeters, for example, one to two millimeters to create the visual appearance of bright and dark bands which cause the structure to appear like macro prisms.

Abstract: A luminaire and method are provided comprising a light source, a plurality of prisms, such as linear prisms, for redirecting light from the light source in a predetermined direction, and a reflector for redirecting light from the light source toward the plurality of prisms. Each of the linear prisms has a longitudinal axis and the light source has a longitudinal axis, wherein the longitudinal axes of the linear prisms are substantially parallel to the longitudinal axis of the light source. Each of the plurality of prisms has an included angle, which can vary as a function of the distance from the light source. The angle can vary stepwise or continuously. In one embodiment, each of the plurality of prisms adjacent the light guide has an included angle in the range of between about 35 and 45 degrees. In another embodiment, the included angle is substantially uniform among the prisms.

Abstract: A transparent optical film made of a polymeric material has a first smooth surface and a second structured surface for providing a simulated beveled appearance. The structured surface of the film is formed of a plurality of spaced parallel grooves, each groove being formed by a first facet which is substantially perpendicular to the first smooth surface and a second facet which makes an angle between 1 to 60 degrees with the first smooth surface. The film may be affixed to glass, the adhesive applied to the first smooth surface or the second structured surface, to simulate beveled glass. Further, a leaded glass appearance or beveled mirror appearance may be simulated by vapor coating the optical film.

Abstract: A diffractive mirror has a plurality of diffractive zones at least one of which has an optical step having a height equal to j.lambda./2 and at least one of which has an optical step having a height equal to k.lambda./2 where .lambda. is a design wavelength of the mirror and j and k are unequal nonzero integers. Alternatively stated at least one of the optical steps induces a relative phase shift of 2j.pi. at the image point between two light rays emerging from a point source at the object point and striking the lens immediately on opposite sides of the step and at least one of the steps induces a relative phase shift of 2k.pi. at the image point between two light rays emerging from a point source at the object point and striking the lens immediately on opposite sides of that step.

Abstract: A lens according to the invention has diffractive power and two primary foci, where one focus is associated with the first diffractive order and one with the second diffractive order.

Abstract: A multifocal ophthalmic lens includes first and second lens members. Each lens member has a smooth outer surface and an inner surface with an edge about its perimeter. A multifocal diffractive zone plate on at least one of the lens members is characterized by an index of refraction. The lens members are joined at the edges by ultrasonic welding to form a cavity adjacent the diffractive zone plate. The cavity is filled with a liquid medication having an index of refraction which is different than the index of refraction of the diffractive zone plate. A hole through one of the lens members functions as a fluid transport mechanism to permit transfer of the medication between the cavity and eye.

Abstract: An ophthalmic lens exhibiting diffractive power has a plurality of diffractive zones and smooth surfaces. The zones are arranged such that R.sub.0.sup.2 does not equal R.sub.1.sup.2 -R.sub.0.sup.2 where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.

Abstract: A multifocal ophthalmic lens has diffractive power produced by a plurality of concentric zones. The zones have radii that meet the conditionR.sub.0.sup.2 is not equal to R.sub.1.sup.2 -R.sub.0.sup.2where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.

Abstract: A multifocal ophthalmic lens has diffractive power produced by a plurality of concentric zones. The zones have radii that meet the condition R.sub.0.sup.2 <R.sub.1.sup.2 -R.sub.0.sup.2 where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.

Abstract: A diffractive lens has a plurality of diffractive zones at least one of which has an optical step having an optical height equal to j.lambda. and at least one of which has an optical step having an optical height equal to k.lambda. where .lambda. is a design wavelength of the lens and j and k are unequal nonzero integers. Alternatively stated at least one of the optical steps induces a relative phase shift of 2j.pi. at the back conjugate point between two light rays emerging from a point source at the front conjugate point and striking the lens immediately on opposite sides of the step and at least one of the steps induces a relative phase shift of 2k.pi. at the back conjugate point between two light rays emerging from a point source at the front conjugate point and striking the lens immediately on opposite sides of that step.

Abstract: A multifocal ophthalmic lens has a plurality of concentric diffractive zones with adjacent zones separated by steps having predetermined heights. Each step has an outer corner and each outer corner has a radius of curvature equal to at least one half the height of the step associated therewith.

Abstract: An improvement in the system for educational and entertainment purposes in which the user is afforded an opportunity to select a correct answer for a question from among a plurality of possible answers is disclosed. The improvement includes a composite laminated card of insulated material with a plurality of arranged electrically conductive paths between sets of contacts, one set being for a hand held indicator probe and the other set for contact with a finger. The indicator probe has a conductive probe tip for contact with the card and the conductive contact with the user's hand holding the probe. The visual indicator in the probe indicates the presence of a continuity path extending from the probe through the card through the user's finger in contact with the finger contact, through the user's body and again to the probe. Very low voltage and currents are employed to implement the probe for use with body resistance.