Minnesota Mining and Manufacturing Company

Thomas I Bradshaw

Bruce D Orensteen

Ronald W Seemann

Eric N Hockert

Lee A Pavelka

Joseph M McGrath

Franklin C Bradshaw

Thomas F Look

David M Burns

John F Dreyer

Stephen W Mohn

Robert V O'Keefe

Edmund J Ring

Jack E Cook

Heinrich Bantli

Gerald R Porter

Craig A Schmidt

Edward S Shinbach

Philip V Palmquist

Frank A Borgeson

Steven E Poss

A line light source includes point light source and a light distribution assembly for transporting light from the point source. A fluorescent colorant is included in the light distribution assembly.

Line light source including fluorescent colorant

A portable system and method for printing variable information indicia on a reflective sign comprises providing a first polymeric sign component having a surface suitable for receiving a printed image. A definition of an image to be printed on the first sign component is provided to a portable computer. Indicia in the form of images is then rapidly transferred to the surface of the first sign component.

Method for manufacturing improved data display retroreflective sheeting

An integrated retroreflective data communication display for visual and electromagnetic communication is described. The display may be configured as an integrated retroreflective electronic license plate, with printed visual information, similar to the information printed on traditional license plates, on retroreflective sheeting. An antenna network is integrated within the license plate for electromagnetic communication and may be connected to external electronic modules. The display may also be configured as an integrated retroreflective electronic road sign, also providing visual and electromagnetic information in a unitary structure.

Integrated retroreflective electronic display

An internally illuminated sign employs retroreflective sheeting with optically transmissive bonds between cover layer and base layer, thereby making the sign suitable for applications where visibility of the sign is required if the internal illumination source fails. A light conduit may be employed to allow the source of internal illumination to be remote from the interior of the sign enclosure. Total internal reflection type sheeting also may be employed to diffuse the internal illumination.

Internally illuminated retroreflective sign

A sheet having a set of axial markings viewable as a contour-dependent, directional image. The image is intact only when the sheet is in substantially a predetermined contour and viewed within a predetermined conical field of view. Also a method for forming such sheets.

Sheet containing contour-dependent directional image and method for

A sheet containing an integrated-directional, half-tone image. Each sheet may contain one or more such images. Also a method for forming such images in microlens sheetings comprising directly a highly collimated light through an interposed half-tone mask.

Microlens sheet containing directional half-tone images and method for

A directional image is created in transparent sheeting comprising a monolayer of microlenses by forming deformations in at least some of the microlenses by irradiation with a laser beam which has a short pulse duration. The directional images may be formed in transparent sheeting which has been applied to a document as an overlay. When viewed under diffuse lighting conditions, the deformations appear as a dark image. The deformations may be formed so that when viewed under retroreflective conditions within a conical field the image is darker than the surrounding background, and when viewed under retroreflective conditions outside the conical field the image is brighter than the surrounding background.

Transparent sheets containing directional images and method for forming

Retroreflective sheeting of the prior art comprises a monolayer of transparent glass microspheres partially embedded in a binder layer and a specularly reflective layer covering the back surfaces of the microspheres. In the prior art, a laser beam directed at an angle to the face of the sheeting forms an image in such sheeting which is directional in that it can be viewed only from that angle. In the invention, such a directional image is provided by tiny ellipsoidal cavities, each opening through a back surface of the microsphere.

Directionally imaged retroreflective sheeting

The novel transparent sheet contains at least one authenticating image, each image being viewable from the front of the sheet, but only across a cone which preferably is less than 90.degree.. The novel sheet may be adhesively bonded over information areas of a document for authenticating purposes. When such an authenticating image is viewable only from an angle appreciably different from angles at which the document is ordinarily viewed, the image is obscure in that users of the document will notice the authenticating image only when confirming the authenticity of the document. Usually each authenticating image is viewable only across a cone of about 10 to 20 degrees.

Transparent sheet containing authenticating image and method of making

Sheeting having images that are viewable within limited angles of viewing from the front of the sheeting are prepared from retroreflective sheeting or from sheeting patterned after retroreflective sheeting, i.e., sheeting having a monolayer of microlenses like the monolayer of microspheres in retroreflective sheeting. A layer of transparent material covers the back surface of the microlenses. Axial markings are disposed behind individual microlenses at the back of the layer of transparent material and the markings are viewable from the front of the sheeting as an image.

Directionally imaged sheeting

Sheeting useful as a projection screen, especially for projection television, comprises a transparent film that is configured on its back surface with a random pattern of generally parallel elongated microscopic recesses or projections, is reflectively coated on that surface, and is configured on its front surface with lenticular light-refracting recesses or projections that spread light entering and leaving that surface. The screen is generally oriented during use so that the elongated recesses or projections in the back surface are arranged vertically. Light projected at the screen enters and is refracted at the front surface, is reflected by the back surface, and is refracted again at the front surface to provide bright images visible with good uniformity to a widely distributed audience.

Sheeting useful as a projection screen

A method of sealing a hole or anchoring a rod therein by rupturing multipart curable resin components placed in the hole. At least one of the components is placed in pressure fragmentable macrocapsules which form flake-like fragments upon rupture. The flake-like fragments serve as static mixers and cause turbulence thus initiating mixing and curing of the components without requiring rotation of the rod or other mixing device.

Reinforcing or sealing solid structures or for anchoring bolts therein

A process for reinforcing or sealing solid structures or for anchoring bolts using macrocapsules which contain at least one part of a multi-part curable polymer system and which fracture under pressure to produce flake-like fragments that aid in mixing the components of the multi-part curable polymer system. The macrocapsules can be conveniently made a part of a sealing cartridge for ease of use.

Method for reinforcing or sealing solid structures or for anchoring

Method of monitoring and indicating the concentration of vapor components at a phase interface comprising sampling vapor at the vapor source phase interface, comparing the vapor concentration in the sample with a standard, and indicating the concentration of the vapor relative to the standard. A monitoring device is disclosed which comprises a sensing means and means for responsively coupling the sensing means to the vapor source phase to be monitored so that a representative vapor sample is presented to the sensing means. The method and device disclosed herein can be advantageously used to monitor volatile components, especially moisture, available to potted plants.

Growing community of inventors

Afton, MN, United States of America

Thomas I Bradshaw