Minnesota Mining and Manufacturing Company

Roger H Appeldorn

Sanford Cobb, Jr

Mark E Gardiner

Timothy L Hoopman

John C Nelson

Robert N Hamlin

Shari J Wilson

Raymond H Anderson

Michael C Lea

Dennis F Vanderwerf

David Jon Lundin

John F Dreyer

Forrest J Rouser

Robert L Erwin

Alan G Hulme-Lowe

Paul A Jaster

Mao J Chern

Robert J Johnson

An optical fiber having a core is disclosed. A notch having first and second sides is formed in the fiber and extends into the core. At least the portion of the interior of the notch adjacent the first side has an index of refraction less than that of the core. Light travelling at a first angle to the fiber axis and striking the first side will be totally internally reflected if the first angle is greater than a predetermined angle. If the first angle is less than the predetermined angle, a portion of the light will enter the notch and emerge through the second surface making a second angle to the first surface, the second angle being greater than the first.

Notched fiber array illumination device

A light extraction overlay for extracting light from a desired location on a light guide includes a substantially optically transparent substrate which has a base surface and a structured surface opposite the base surface. The structured surface includes optical elements which have optically smooth surfaces disposed at an angle relative to the base surface. Preferably, the optical elements are coated with a specularly reflective material. The optical elements may be separated by substantially planar portions of the structured surface. In use, the base surface is optically coupled with a portion of a surface of a light guide such that light may be transmitted from the optical fiber into the substrate. Light rays which strike a planar portion of the structured surface are reflected back into the fiber at an angle which is greater than the critical angle necessary for continued propagation in the light guide and, accordingly, continue to propagate along the optical fiber. Light rays which strike an optical element are reflected into the fiber at an angle less than the critical angle angle necessary for continued propagation in the light guide and, accordingly, are transmitted from the surface of the light guide.

Structured surface light extraction overlay and illumination system

The present invention provides a pole light for directing or delivering light in a desired pattern to a surface proximate to the pole light. The present invention also provides a method for lighting a plurality of desired regions on a surface in a precise and predetermined pattern useful, for example, as a traffic management and guidance system.

Pole light having a programmable footprint

An optical fibre has a light emitting region. In the light emitting region are reflecting surfaces, at least one of which has a cross sectional area less than that of the fibre. Light striking the reflecting surfaces will be reflected out of the fibre.

Illumination devices and optical fibres for use therein

A reusable security package is disclosed that includes a closure mechanism for closing a container and for determining whether the container has been opened.

Reusable security enclosure

An improved greenhouse comprising a plurality of walls, a light-transmitting roof panel; and an optical system located inside the greenhouse is described. The optical system comprises a plurality of rows of elongate spaced optical panels generally adjacent and extending transversely across the light-transmitting roof panel. Each panel comprises a thin backing portion forming first and second concave, opposite sides, a first light reflecting means including light-reflecting surfaces attached to the first side of the backing and a second light reflecting means including light-reflecting surfaces attached to the second side of the backing such that the light-reflecting surfaces face generally oppositely. Also disclosed is an improved method of growing plants utilizing such a greenhouse construction.

Greenhouse construction and improved method of growing plants

A closure for use in joining together container portions to enclose an opening in a container. The closure includes a pair of intermeshable closure members, each having a structured surface. The structured surfaces adhere to each other when brought into contact to secure the container portions together.

Container with intermeshable closure members

The present invention provides a retroreflective material which is efficient at high angles of incidence and which may be individually tailored so as to distribute light retroreflected by the material into a desired pattern or divergence profile. The retroreflective material of the present invention comprises a transparent surface layer having a front side and a back side and an array of cube corner reflective elements, each of the reflecting elements including a rectangular base on the back side of the surface layer, two rectangular faces nearly perpendicular to each other each one being joined to an edge of the rectangular base to form a reflecting element having a triangular cross section, and two triangular faces that are approximately parallel to each other and approximately perpendicular to the rectangular faces, and forming the ends of the reflecting elements; and the triangular and rectangular faces defining a pair of approximate cube corners therebetween, the reflecting elements arranged with their bases adjacent to the surface layer. The terms 'approximately parallel' and 'approximately perpendicular' are used herein to refer to faces which are truly parallel or perpendicular and faces which have small variations from true parallelism or perpendicularity.

High efficiency cube corner retroflective material

An intermeshable article useful for a multitude of purposes such as fastening, closing, coupling and connecting, to name but a few. The article includes a member which has at least one major surface which is a structured surface. The structured surface is made up of a plurality of elements. Each element has at least one side inclined relative to the plane of the member at an angle sufficient to form a taper. Thus, each element may mesh with at least one corresponding element when brought into contact therewith and adhere thereto at least partially because of the frictional force of adherence of the contacting sides. The corresponding element may be the article itself, another similar article or a dissimilar article, such as for example a container having a correspondingly shaped structured surface. In the preferred embodiment, the elements are arranged side by side to form a plurality of linear ridges and grooves whereby the sides of adjacent elements form the sides of each groove.

Intermeshable article

A solar energy concentrator including a thin flexible Fresnel lens for focusing incident solar radiation not normal to the lens onto a target area by refraction. The Fresnel lens is supported or suspended above the target area by a frame and folded along at least one line or region parallel to the refractive prisms of the lens which are generally parallel to the axis of the target area whereby the Fresnel lens opens toward the target area. Thus the Fresnel lens is so positioned so as to allow it to bow and flex under wind loads, gravity and other environmental factors without causing significant deterioration in the efficiency of the system.

Refracting solar energy concentrator and thin flexible Fresnel lens

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.

Tilted panel linear echelon solar collector

Cube-corner retroreflective article having improved divergence profiles. The three lateral reflecting faces of the cube-corner retroreflective elements are formed by three intersecting sets of parallel V-shaped grooves, and at least one of the sets includes, in a repeating pattern, at least two groove side angles that differ from one another. Thereby the array of cube-corner retroreflective elements is divided into repeating sub-arrays that each comprise a plurality of cube-corner retroreflective elements in a plurality of distinctive shapes that retroreflect incident light in distinctively shaped light patterns.

Cube-corner retroreflective articles having tailored divergence profiles

A projection television set is afforded by the use of a stand for the television set which permits the television set to be rotated on a horizontal axis to position the screen downward toward a projection lens having an odd number of mirrors to direct an image toward a remote screen without necessitating any rewiring of the television set.

Television support and picture projector

A display device having a plurality of information symbols for each light source such as an LED chip. The upper surface of each LED chip is divided into several light-emitting areas by a patterned array of electrically isolated, spaced electrodes. The LED chips are mounted to a substrate and can be selectively activated by a beam lead tape, which is also mounted to the substrate. A cover for the display forms thin, reflective light channels, each of which extends laterally from a light-emitting area to one or more optical openings in the cover. The optical openings form the information symbols. The lateral channels direct emissions from the LED chip to the openings via multiple reflection and optical dispersion to uniformly illuminate the openings.

Growing community of inventors

White Bear Lake, MN, United States of America

Roger H Appeldorn