Microsoft Technology Licensing, LLC

Tuomas Vallius

Tapani Levola

Lauri Sainiemi

Jani Tervo

David Douglas Bohn

Dmitry Reshidko

Scott Woltman

R Andrew Wall

William J Cummings

Steven John Robbins

Mikko Juhola

Jani Kari Tapio Tervo

Richard Andrew Wall

Pasi Antero Kostamo

Pietari Tuomisto

Pasi Petteri Pietilae

Pasi Pietila

Pasi Saarikko

Joel Steven Kollin

Joshua Owen Miller

Andrew Maimone

Adrian Travis

Yijing Fu

Yarn Chee Poon

Simo Kaarlo Tammela

Xinye Lou

Gangok Lee

Marco Ilmari Mattila

Tero Ollikainen

Keita Oka

An optical combiner, configured for use in a mixed-reality display system that combines holographic and real-world images, includes an assembly of see-through waveguides that are arranged in a stack to provide full color holographic images from constituent RGB (red, green, and blue) color components received from a holographic image source. Each waveguide&#x2014;one per RGB color component&#x2014;includes an in-coupling DOE (diffractive optical element), an intermediate DOE, and an out-coupling DOE that are disposed on internal surfaces of the stacked waveguides in the optical combiner. Each of the out-coupling DOEs incorporates a diffractive lens functionality to render the out-coupled holographic images at a set depth on the mixed-reality display. In an illustrative non-limiting example, the out-coupling DOE may provide a half diopter of negative lens power to set the optical focus of the holographic images at 1.33 m.

Waveguide assembly with virtual image focus

In an optical display system that includes a waveguide with multiple diffractive optical elements (DOEs), gratings in one or more of the DOEs may have an asymmetric profile in which gratings may be slanted or blazed. Asymmetric gratings in a DOE can provide increased display uniformity in the optical display system by reducing the 'banding' resulting from optical interference that is manifested as dark stripes in the display. Banding may be more pronounced when polymeric materials are used in volume production of the DOEs to minimize system weight, but which have less optimal optical properties compared with other materials such as glass. The asymmetric gratings can further enable the optical system to be more tolerant to variations&#x2014;such as variations in thickness, surface roughness, and grating geometry&#x2014;that may not be readily controlled during manufacturing particularly since such variations are in the submicron range.

Diffractive optical elements with asymmetric profiles

Apparatuses and systems including curved optical waveguides, and methods for use include an output-grating of a curved waveguide that includes a spatially modulated grating period configured to cause, for each beam of light corresponding to an image coupled into a bulk-substrate of the curved waveguide by an input-grating, corresponding rays of light output from different locations of the output-grating to be substantially collimated. Adaptive optics of a display engine compensate for aberrations that vary over a field-of-view associated with light corresponding to the image out-coupled by the output-grating. Further, a curved portion of the curved waveguide is designed to keep internally reflected light below a critical angle to prevent inadvertent out-coupling thereof. Further, curved surfaces of the curved waveguide can include polynomial surfaces to compensate for lateral color errors and distortion.

Display apparatuses, systems and methods including curved waveguides

MicroLED arrays offer a small form factor solution for the HMD image sources since they do not need a separate illumination optics. Features of the present disclosure implement a MicroLED display system that incorporate a plurality of monochrome projectors (e.g., three MicroLED projectors) to generate three monochrome images (e.g., red, blue, and green images) that are separately input into a single waveguide of the HMD and combined to form an image that is displayed to the user. By utilizing a single waveguide that includes a plurality of spatially separated input regions (e.g., a region for inputting blue light, a region for inputting red light, a region for inputting green light), the MicroLED display system of the present disclosure may reduce the form factor of the HMD device because of the reduced number of plates that may be required to combine the three monochrome images.

Micro LED display system

An optical waveguide including an input-coupler, a first intermediate-component, a second intermediate-component and an output-coupler is described herein. The input-coupler couples, into the waveguide, light corresponding to an image associated with an input-pupil and directs the light toward the first intermediate-component. The first intermediate-component performs horizontal or vertical pupil expansion and redirects the light corresponding to the image toward the output-coupler. The second intermediate-component is a diffractive component located between the first-intermediate component and the output-coupler and performs pupil redistribution on a portion of the light corresponding to the image before the portion reaches the output-coupler. The output-coupler performs the other one of horizontal or vertical pupil expansion and couples, out of the waveguide, the light corresponding to the image. Related methods and systems are also described.

Optical device to improve image uniformity

Color management of display device

A light engine comprises a liquid crystal on silicon (LCOS) panel that is operated in combination with illumination and imaging optics to project high-resolution virtual images into a waveguide-based exit pupil expander (EPE) that provides an expanded exit pupil in a near-eye display system. In an illustrative example, the illumination optics comprise a laser that produces illumination light that is reflected by a MEMS (micro-electromechanical system) scanner using raster scanning to post-scan optics including a microlens array (MLA) and one or more collimating or magnifying lenses before impinging on the LCOS panel. The LCOS panel operates in reflection in combination with imaging optics, including one or more of beam-steering mirror and beam splitter, to couple virtual image light from the LCOS panel into the EPE.

Scanner-illuminated LCOS projector for head mounted display

In an optical system that includes a coherent light source and an optical waveguide, a pulse width used by the optical waveguide to project image frames on a display is changed on a frame-by-frame basis. By changing the pulse width for each image frame, the locations and characteristics of visible interference patterns on the display are changed for each successive image frame. Changing the interference patterns for each image frame may result in the interference patterns being less detectable to a viewer. The change in pulse width for each image frame may be fixed or dynamic, and may be made in response to interference patterns being detected on the display.

Changing pulse width to reduce visible interference

In an optical near eye display system, a monolithic three-dimensional optical microstructure is formed by a waveguide substrate with at least one DOE having grating regions that integrate the functions of in-coupling of incident light into the waveguide, exit pupil expansion in one or two directions, and out-coupling of light from the waveguide within a single optical element. An in-coupling region of the DOE couples the incident light into the waveguide and to a beam steering and out-coupling region. The beam steering and out-coupling region provides exit pupil expansion and couples light out of the waveguide. The beam steering and out-coupling region of the DOE can be configured with a two-dimensional (2D) grating that is periodic in two directions.

Diffractive optical element with integrated in-coupling, exit pupil expansion, and out-coupling

An apparatus for use in replicating an image associated with an input-pupil to an output-pupil includes a planar optical waveguide including a bulk-substrate, and also including an input-coupler, an intermediate-component and an output-coupler. The input-coupler couples light corresponding to the image into the bulk-substrate and towards the intermediate-component. The intermediate-component performs horizontal or vertical pupil expansion and directs the light corresponding to the image towards the output-coupler. The output-coupler performs the other one of horizontal or vertical pupil expansion and couples light corresponding to the image, which travels from the input-coupler to the output-coupler, out of the waveguide. The apparatus further includes an adjacent planar optical component to provide a more uniform intensity distribution compared to if the adjacent planar optical component were absent.

Waveguide coatings or substrates to improve intensity distributions having adjacent planar optical component separate from an input, output, or intermediate coupler

An apparatus having optical waveguides for providing a large FOV is disclosed. A first light engine projects light into an input diffractive coupler of a first waveguide at a first central angle. An output coupler of the first waveguide projects the light out of the first optical waveguide. A second light engine projects light into an input diffractive coupler of a second waveguide at a second central angle that is greater than the first central angle. An output coupler of the second waveguide projects the light out of the second optical waveguide to intersect with the light projected out of the first optical waveguide. The first waveguide may be used to project a first part of an image into a central portion of a user's vision. The second waveguide may be used to project a second part of the image into a peripheral portion of the user's vision.

Wrapped waveguide with large field of view

A near eye optical display system comprising a waveguide and diffractive optical elements (DOEs) for in-coupling, exit pupil expansion, and out-coupling reduces the transmission of stray light in the system using a doubly-periodic surface relief microstructure that combines a guided-mode resonant filter with Bragg reflectance. Such resonant grating filter may be configured with grooves and/or ridges of different widths that are located on the waveguide that have respective sub-periods that match Bragg reflectance periods for particular wavelengths. The interaction of the sub-periods gives rise to a photonic band gap effect in which the resonant grating's effective refractive index is modulated to increase angular sensitivity and wavelength bandwidth of the resonant grating filter. The sub-periods define an overall period (i.e., a super period) for the resonant grating filter by which incident light is coupled into the waveguide, guided, and then coupled out of the waveguide at the side of incidence.

Reducing stray light transmission in near eye display using resonant grating filter

In a near-eye optical display system comprising a waveguide and diffractive optical elements (DOEs) configured for in-coupling, exit pupil expansion, and out-coupling, a rainbow phenomenon manifested in the display may be removed or reduced using a polarizing filter at the front of the system so that real-world/stray light entering the system has a particular polarization state, for example TM-polarized. The polarizing filter is utilized in conjunction with a downstream out-coupling DOE that includes diffractive grating structures that are configured to enable sensitivity to an opposite polarization state, for example TE-polarized. An imager is configured to produce virtual-world images that also have a TE-polarized state. The polarization-sensitive out-coupling DOE diffracts the TE-polarized imaging beam out of the grating for display while the TM-polarized light from the real world and/or stray light passes through the grating without diffraction and thus cannot contribute to rainbows in the display.

Rainbow removal in near-eye display using polarization-sensitive grating

A near-eye optical display system utilized in augmented reality devices includes a see-through waveguide display having optical elements configured for in-coupling virtual images from an imager, exit pupil expansion, and out-coupling virtual images with expanded pupil to the user's eye. The near-eye optical display system further includes a curved two-sided array of electrically-activated tunable liquid crystal (LC) microlenses that is located between the waveguide and the user's eye. The LC microlenses are distributed in layers on each side of the two-sided array. Each pixel in the waveguide display is mapped to an LC microlens in the array, and multiple nearby pixels may be mapped to the same LC microlens. A region of the waveguide display that the user is gazing upon is detected and the LC microlens that is mapped to that region may be electrically activated to thereby individually shape the wavefront of each pixel in a virtual image.

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Espoo, Finland

Tuomas Vallius