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: A hollow, tubular light conduit including a wall of a transparent polymeric material, and the wall having a structured surface and an opposite, smooth, glossy surface, and at least a portion of the cross-section of the wall lying in a smooth arcuate curve, wherein light striking the inner surface, within an acceptable angular range, is contained by total internal reflection. The structured surface includes a linear array of substantially right angled isosceles prisms arranged side-by-side to form grooves. In addition, the perpendicular sides of the prisms make an angle of approximately 45.degree. with the tangent to the smooth surface. Because of the flexibility of the light conduit and its ability to totally internally reflect light, a manipulated light conduit may be utilized in a variety of ways, for example, as a light fixture whereby some of the light directed into the light conduit is emitted from the light conduit for illumination or for use as a secondary light source.

Abstract: A solar concentrator with wide effective aperture is disclosed, which comprises at least one linear echelon reflector element which is inclined with respect to the direction of incident solar radiation to direct incident solar radiation to a line focus.

Abstract: An automotive lighting element has a lower surface with a plurality of ridges and grooves. Those ridges and grooves are reflectorized so that light emitted by a light source in the lighting element will be reflected back into other portions of the reflector rather than out of the lighting element with a large upward vertical component.

Abstract: A light transmissive film having a smooth surface and a structured surface. The structured surface has a series of triangular prisms running parallel or concentric to one another. A reflector is placed adjacent to the smooth surface so that light entering the film at an angle which is close to parallel to the smooth surface will emerge from the film at a predetermined angle with respect to the incoming beam. A light fixture utilizing the film is also disclosed.

Abstract: A light fixture providing normalized output. An undirected light source is located in an optical cavity having an optical window. A film with a smooth surface and a structured surface is placed in the optical window with the smooth surface facing the interior of the optical cavity. The structured surface has a plurality of triangular prisms thereon.

Abstract: A Fresnel-type reflector having the physical shape of a cone. In a preferred embodiment, the reflector is made by forming a reflective coating on a structured surface of a thin flexible film and forming the film into the shape of a cone. The structures on the surface are designed to cause the reflector to imitate the optical properties of a parabolic reflector when the reflector of the invention is formed into the shape of a cone.

Abstract: Louvered plastic film can be more easily handled and installed by coating at least one surface with a solvent-free monomer composition and exposing the coating to ultraviolet radiation to polymerize the composition.

Abstract: Louvered plastic film can be more easily handled and installed by coating at least one surface with a solvent-free monomer composition and exposing the coating to ultraviolet radiation to polymerize the composition to an adhesive state, preferably a pressure-sensitive adhesive state.

Abstract: A method for manufacturing hollow core optical fibers is disclosed comprising continuously feeding a glass rod of the desired cladding composition into a high temperature furnace with the rod in line contact with the inner surface of the glass tube. The glass transition temperature of the rod is substantially lower than the glass transition temperature of the glass tube. The glass rod composition is uniformly distributed on the glass tube inner wall as it enters the furnace hot zone. The ratio of the rod diameter to the glass tube inner diameter and the drawing temperature determine the coating thickness of the glass cladding on the inner surface of the glass tube. As the coated tube is passed through the furnace hot zone peak, the optical fiber is drawn. The rod and tube feed rate, the drawing temperature of the rod and glass tube and the drawing rate of the coated glass tube are selected to yield a hollow core optical fiber, with preselected interior and exterior diameters.

Abstract: A lens of a transparent material including a structured surface on one side and a smooth surface on the opposite side. The structured surface includes a plurality of three-faceted prisms arranged side by side to form a plurality of ridges and grooves. Each prism has a reflective surface adjacent to a refractive surface and a riser adjacent to the refractive surface. The surfaces are angled with respect to one another so that incident light is transmitted through the lens, whereby the exiting rays may be predisposed to be perpendicular or non-perpendicular. Because of this the lens can be used to disperse, collimate, gather or concentrate the light. Thus, it may be utilized in a variety of ways, for example, in a light fixture, whereby high-angle incident light directed toward either the structured surface or the smooth surface, is transmitted through the lens and is directed in a desired fashion.

Abstract: A zoom lens system having magnification factors in the range of 20 to 47. The lens system of the present invention is particularly useful in micrographic reader/printers.

Abstract: A zoom lens system having magnification factors in the range of 14 to 32. The lens system of the invention is particularly useful in micrographic reader/printers.

Abstract: A zoom lens system which provides magnification factors in the range of 12 to 24. The lens system of the invention is particularly useful in micrographic reader/printers.

Abstract: A zoom lens system having magnification factors in the range of 6.5 to 14. The lens system of the invention is particularly useful in micrographic reader/printers.

Abstract: An optimum start system for determining the optimum start time of a temperature control system within a building so that energy can be conserved by operating the temperature control system at reduced energy levels during periods of non-occupancy of the building and by starting the temperature control system an amount of lead time prior to the beginning of occupancy of said building wherein the amount of lead time is selected to bring space temperature within the building within a comfort range by the start of occupancy, the optimum start system including a space temperature sensor for sensing space temperature within the building, an outdoor air temperature sensor for sensing outdoor air temperature external to the building, and a controller connected to the space temperature sensor, the outdoor air temperature sensor and the temperature control system for determining the lead time as a function of an accuracy factor based upon the accuracy of a prior lead time and as a function of both outdoor air temperatur

Abstract: A temperature compensation system for semiconductor logic gates where the temperature compensation is accomplished by two depletion mode FET's in electrical series relationship is disclosed. One of the FET's is adapted to operate in its triode region of operation and the other in its saturation region of operation.

Abstract: The present invention uses a plurality of basic cells to perform a multiply-accumulate operation. Each basic cell is essentially equivalent to a one bit full adder and two flip-flops. These basic cells are connected in such a way that the processing is said to be pipelined.

Abstract: A floating gate electrically erasable programmable read only memory (E.sup.2 PROM) having polycrystalline silicon gates with a control gate on the poly 1 level and a floating gate on the poly 2 level is disclosed.

Abstract: A radio receiver capable of receiving signals on at least two different frequencies at the same time is described. A hetrodyne frequency is selected midway between the frequencies and an intermediate frequency is selected at a frequency equal to one half of the difference of the frequencies to be received.