3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

Stephen J Willett

Andrew John Ouderkirk

Craig R Schardt

Patrick Rene Destain

Zhisheng Yun

Philip Edwin Watson

Andrew P Bonifas

Jia Hu

David J W Aastuen

Orlin Bruce Knudson

Richard L Rylander

Chaodi Li

William E Phillips, Iii

Michael W O'Keefe

John E Duncan

Tomasz A Pol

Jennifer L Grace

Alexander A Glinski

Charles L Bruzzone

Kim Leong Tan

Xiaohui Cheng

Yarn Chee Poon

Michael F Weber

Gilles J Benoit

Ronald David Jesme

Adam D Haag

Hao Wu

James M Jonza

Simon Magarill

William A Hendrickson

Ernesto M Rodriguez, Jr

Erik A Aho

Cheryl L S Elsbernd

Mohsen Salehi

Hsin Hsin Chou

Stephan J Pankratz

Dale R Lutz

Andrew Bonifas

David P Erickson

Patrick M Campbell

Roy A Auerbach

David J Aastuen

Carol E Hendrickson

Amy J Hite

Gary L Tritle

Cheryl Lee Senger Elsbernd

Kim L Tan

An optical system, including a reflective polarizer, and a display and a mirror disposed on a same side of, and generally facing, the reflective polarizer. The reflective polarizer may transmit at least 80% of incident light having a first polarization state and may reflect at least 80% of incident light having a second polarization state, and the mirror may reflect at least 80% of the incident light for each of the first and second polarization states. The central locations of the display, reflective polarizer, and mirror may define a midplane which includes first, second, and third regions, such that the first region includes portions of the image rays that pass at least once across the region, the second region includes portions of the image rays that pass at least twice across the region, and the third region includes portions of the image rays that pass three times across the region. The first, second, and third regions may have respective areas A, A, and A, such that A/Ais greater than or equal to about 0.20, or 0.22, or 0.24, or 0.26, or 0.28, or 0.30.

Compact heads-up display

A system for use in wirelessly monitoring a pipeline such as a natural gas pipe. The system includes a locator configured to wirelessly transmit power and a subsoil sensor marker located adjacent the pipe and configured to wirelessly communicate with the locator. The sensor marker includes a microcontroller, a memory module, a sensor configured to sense the presence of a gas, and a power module. The power module is configured to harvest a sufficient amount of the power wirelessly transmitted from the locator in order to operate the microcontroller to take a measurement via the sensor, save the measurement in the memory module, and wirelessly transmit the measurement to the locator.

Wireless power transfer and sensing for monitoring pipelines

Projection subsystems are described. More, particularly, projection subsystems that include a light source and a polarizing beam splitter are described. The polarizing beam splitters of the presently described projection subsystems are capable of avoiding performance degradation even after exposure to large doses of incident light.

Projection subsystem

Magneto-Mechanical Resonator Sensor with Mass Distribution Channel Some aspects of the present disclosure feature a sensing device (e.g. for temperature, moisture or detection of substances) comprising a magnetic bias layer, a resonator, a spacer, and an environmental change receptor. The spacer is disposed between the magnetic bias layer and the resonator. At least one of the resonator surfaces has a predefined channel. The environmental change receptor is disposed proximate to the predefined channel. In response to a change in environment, the environmental change receptor distributes along a part of the channel.

Magneto-mechanical resonator sensor with mass distribution channel

Some aspects of the present disclosure feature a sensing device comprising a magnetic bias layer, a resonator, a spacer, and an environmental change receptor. The environmental change receptor is disposed on a surface of the resonator. The mass of the environmental change receptor is changed in response to a change in environment. The resonant frequency of the sensing device shifts in response to the mass change of the environmental change receptor.

Magneto-mechanical resonator sensor with pre-disposed mass

Some aspects of the present disclosure feature a system for sensing a change in environment comprising a MMR sensor and a reader. The MMR sensor is configured to be disposed in the environment. The MMR sensor comprises a magnetic bias layer, a resonator, a spacer, and an environmental change receptor. The reader is configured to measure a frequency characteristic of the MMR sensor after the environmental variable changes and the change to the environmental variable is evaluated based on the frequency characteristic.

Systems and methods for magneto-mechanical resonator sensors

The disclosure generally relates to beamsplitters useful in color combiners, and in particular color combiners useful in small size format projectors such as pocket projectors. The disclosed beamsplitters and color combiners include a tilted dichroic reflective polarizer plate having at least two dichroic reflective polarizers tilted at different angles relative to incident light beams, with light collection optics to combine at least two colors of light.

Tilted dichroic polarizing beamsplitter

Titled dichroic polarizing beamsplitter

Projection lens having improved properties such as a high throughput are described. In one embodiment, a projection lens is described comprising in sequential order from a screen side a first lens group, a second lens group of positive refractive power, and a third lens group of positive refractive power. At least one lens group has an aspheric surface. The ratio of the focal length of the projection lens (F) to the focal length of each of the lens groups (F, F, and F) is such that |F/F|&#x3e;5, 0.5&#x3c;|F/F|&#x3c;0.9, and 1&#x3c;F/F&#x3c;8. In another embodiment, a projection lens is described comprising in sequential order from a screen side a first lens group, a second lens group of positive refractive power, and a third lens group of positive refractive power. At least one lens group has an aspheric surface. The ratio of the focal length of the projection lens (F) to the focal length of each of the lens groups (F, F, and F) is such that |F/F|&#x3e;5, 0.5&#x3c;|F/F|&#x3c;2.0, and 1.4&#x3c;F/F&#x3c;8.

Projection lens for projection display systems

Optical elements, color combiners using the optical elements, and image projectors using the color combiners are described. The optical elements can be configured as color combiners that receive different wavelength spectrums of light and produce a combined light output that includes the different wavelength spectrums of light. In one aspect, the received light inputs are unpolarized, and the combined light output is polarized in a desired state. The optical elements are configured to minimize the passage of light which may be damaging to wavelength-sensitive components in the light combiner. Image projectors using the color combiners can include imaging modules that operate by reflecting or transmitting polarized light.

Polarization converting color combiner

Wide-angle projection lens, as well as optical engines and projection display devices comprising such projections lens are described. In one embodiment, a wide-angle projection lens is described comprising in sequential order from a screen side a first lens group of negative refractive power, a second lens group of positive refractive power, a third lens group of positive refractive power; and a fourth lens group of positive refractive power. At least one lens group has an aspheric surface. The ratio of the focal length of the wide-angle projection lens (F) to the focal length of each of the lens groups (F, F, F, and F) is such that |F/F|&#x3e;1.3, F/F&#x3e;2, 1&#x3c;F/F&#x3c;2 and 1.5&#x3c;F/F&#x3c;8.

Wide-angle projection lens for projection display systems

Optical elements, color combiners using the optical elements, and image projectors using the color combiners are described. The optical elements can be configured as color combiners that receive different wavelength spectrums of light and produce a combined light output that includes the different wavelength spectrums of light. The optical elements include a wavelength selective dichroic mirror that reflects a major portion of actinic light that can damage a reflective polarizer within the optical element. The wavelength selective dichroic mirror transmits a major portion of other wavelengths of light. The resulting color combiners using the optical element may have improved durability compared to a color combiner lacking the wavelength selective dichroic mirror. Image projectors using the color combiners can include reflective (including digital micro-mirror) or polarization (including liquid crystal) imaging modules.

High durability color combiner

A projection subsystem includes a light engine that provides a collection lens, a collimator and at least one solid state light emitter. A projection lens assembly receives the image and provides a projection beam having a luminous flux level. The projection subsystem has a portability efficacy.

Optical projection subsystem

Growing community of inventors

Saint Paul, MN, United States of America

Stephen J Willett