3m Innovative Properties Company

Kenneth Jarefors

Kristina M Magnusson

Britton G Billingsley

Per-Olav Dahlin

Larissa Zuravskaja

Timothy L Wong

Jon A Kirschhoffer

Laurent Froissard

John M Kruse

John M Pilgrim

Christopher M Brown

Joy L Manske

Britton G Billinglsey

Louise L M Madsen

Louise LM Madsen

Britton G Billingsly

Protective headgear with a curved switchable shutter and curved front and rear cover plates and including at least two antireflective layers.

Protective headgear comprising a curved switchable shutter and comprising multiple antireflective layers

A welding helmet having a filter arrangement is disclosed. The welding helmet is provided with a main filter and at least one auxiliary filter separate from and positioned next to the main filter. The at least one auxiliary filter comprises an electro-optic element adapted to attenuate the transmission of optical radiation incident on the auxiliary filter.

Welding helmet having a filter arrangement

Protective headgear including an automatic darkening filter with an array of switchable shutters, and including a shutter control system, at least one workview image acquisition device, and at least one eye position monitoring device, wherein the shutter control system is controllably connected to each switchable shutter of the array of switchable shutters so as to control the switching of each of the switchable shutters, and is receivably connected to the at least one workview image acquisition device and to the at least one eye position monitoring device.

Vision-protective headgear with automatic darkening filter comprising an array of switchable shutters

A curved eye protection shield for welding protection. The eye protection shield has an electrically switchable darkening filter and a protective cover. The darkening filter has eye facing major inner and outer surfaces, and the protective cover has major inner and outer surfaces. The protective cover is provided for arrangement on the inner surface of the darkening filter. The inner and outer surface of the darkening filter are equidistant, whereas the inner and outer surface of the protective cover are non-equidistant. The invention is advantageous in that it provides an eye protection shield having a minimized refractive power.

Curved eye protection shield for welding protection

Curved, arcuately-bonded liquid-crystal cells that include substrates held together by an edge adhesive cured after the substrates were bent into a congruently curved configuration; methods of making such cells; and, switchable shutters and automatic darkening filters that include such cells.

Curved, arcuately-bonded liquid crystal cell and method of making

A welding protector () has a curved eye protection shield () with an electrically switchable light filter. The welding protector further has a magnifying cover () for arrangement on an eye facing inner side of the eye protection shield. The magnifying cover is pre-shaped based on a curve that extends equidistant to the curve the eye protection shield is based on. Further, the magnifying cover has two optical lenses () which in combination only partially cover the eye protection shield.

Welding protector with magnifying cover

A welding helmet () having a filter arrangement is disclosed. The welding helmet is provided with a main filter () and at least one auxiliary filter () separate from and positioned next to the main filter. The at least one auxiliary filter comprises an electro-optic element () adapted to attenuate the transmission of optical radiation incident on the auxiliary filter.

Automatic darkening filters are often provided on a protective headgear, where protection from high intensity light is desired. An automatic darkening filter includes a switchable shutter, a shutter control system, a light sensor, and an imaging acquisition device. The switchable shutter is capable of assuming at least a dark state, a light state and an intermediate state.

Automatic darkening filter apparatus and method

An automatic-darkening filterthat comprises a first polarizer, a second polarizer, a first liquid-crystal cell, and a sensor. The first polarizerhas a first polarization direction, and the second polarizerhas a second polarization direction. The liquid crystal cellis disposed between the first and second polarizersand contains first and second optically-transparent, flexible, glass layersandwith the liquid crystal layerbeing located between these layers. The sensordetects incident light and causes a signal to be sent, which causes molecular rotation within the liquid crystal layer. The inventive automatic-darkening filter is beneficial in that overall product weight can be reduced and the view field can be increased.

Curved automatic-darkening filter

The present invention relates to an automatic welding filter that changes from a light transmission state to a dark transmission state in response to incident welding light and includes a color-tunable filter whose spectral transmittance can be varied to optimize the visual appearance of a welding task. The color-tunable filter comprises at least one low twist liquid crystal cell disposed between polarization filters having substantially parallel polarization directions. The user is able to adjust the color of the automatic welding filter in the dark transmission state, independently of the shade, in response to a user selected color signal which alters the birefringence properties of the low twist liquid crystal cell.

Automatic welding filter with tunable spectral transmission

A protective automatic darkening filter constructionincludes two low twist liquid crystal cellsinterspersed between a series of offset polarizers. The resulting construction provides improved homogeneity in the dark state as viewed by the user over a large viewing angle. By reducing variations in shade, visibility through the filter may be improved.

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Borlänge, Sweden

Kenneth Jarefors