Apple Inc.

Other

Hyungryul J Choi

Vikrant Bhakta

Guolin Peng

Scott M DeLapp

Graham Butler Myhre

Cheng Kai Chen

Zhibing Ge

Eric J Hansotte

David A Kalinowski

Se Baek Oh

Byron R Cocilovo

Scott M Delapp

Chaohao Wang

Matthew Emanuel Last

Arthur Yasheng Zhang

Shih-Chyuan Fan Jiang

Paul V Johnson

Paul J Gelsinger-Austin

John Z Zhong

Dinesh C Mathew

Wei Chen

Jun Qi

Christiaan A Ligtenberg

Yuan Chen

Jiaying Wu

David Andrew Doyle

Francesco Aieta

Khadijeh Bayat

Nan Zhu

Hossein Nemati

Tyler G Anderson

Kevin A Keilbach

Nathanael D Parkhill

Se Hyun Ahn

Stanley K Melax

Hyunmin A Song

Clarisse Mazuir

Matheen M Siddiqui

Malcolm J Northcott

Russell Y Webb

Jae Hwang Lee

Phil M Hobson

Enkhamgalan Dorjgotov

Ligang Wang

Zhenbin Ge

David Glen Havskjold

Xianwei Zhao

Qiong Huang

Brian S Lau

Giovanni Carbone

Branko Petljanski

Cameron A Harder

Yifei Wang

Yoshitaka Matsui

Bradley Charles Steele

Victoria C Chan

Jonathan B Pfeiffer

Jonathan C Moisant-Thompson

Christina G Gambacorta

William W Sprague

Edward Allen Valko

Dominic P Cincione

Elijah H Kleeman

Lei Zhao

Jun Xie

Brandon E Clarke

Supriya Goyal

Xiaoyong Fu

Wencong Zhu

Jaebum Chung

Jian Gao

Shigeto Kobori

Zhujun Shi

Yukinori Asakawa

Jose A Dominguez-Caballero

Di Hu

Bradley C Steele

Cihan Yilmaz

An electronic device may have a display system. The display system may include a waveguide, an input coupler, and a surface relief grating (SRG) structure. There are various ways to form a SRG structure. In one example, nanoimprinting may be performed on a low-index resin to form a mold for a subsequent deposition of high-index material. The high-index material conforms to the mold to form ridges for the SRG structure. A reusable mold may be formed with a plurality of ridges on a flexible substrate and coated by an anti-stick coating. The reusable mold may be coated with a high-index material that is attached to a glass substrate and cured to form a wafer-level SRG structure with high-index ridges on a glass substrate. The wafer-level SRG structure is subsequently diced. SRG structures may also be formed that include varying trough thicknesses, varying ridge thicknesses, and/or a sloped substrate.

Methods of forming holographic gratings for optical systems

A display may include a waveguide for providing light to an eye box. The display may include polarization recycling structures having a polarizing beam splitter and a prism. The polarizing beam splitter may transmit a first portion of unpolarized light as first image light having a first polarization and may reflect a second portion of the unpolarized light as second image light having a second polarization. One or more waveplates may be mounted to the prism for transmitting the second image light. Upon transmission by the waveplate(s), the second image light may have the same polarization as the first image light. An input coupler may couple the first and second image light into the waveguide. Providing polarized light to the waveguide may maximize the optical efficiency of the waveguide. The polarization recycling structures may maximize the amount of the image light that is coupled into the waveguide.

Optical systems for providing polarized light to a waveguide

An electronic device may include a waveguide with an input coupler and an output coupler. The input coupler may receive the image light from imaging optics. The input coupler may be an input coupling prism and the imaging optics may include lens elements. World light may be viewable at an eye box through the output coupler. Biasing, compensation, and/or prescription lenses may overlap the output coupler. The input coupling prism, the lens elements in the imaging optics, and/or one or more of the biasing, compensation, and prescription lenses may be formed from gradient index (GRIN) material. The GRIN material may have a gradient refractive index that varies in one or more gradient directions. Use of GRIN materials may minimize the volume required to form the device without sacrificing optical performance. In addition, the GRIN materials may compensate for dispersion and aberrations in the device.

Optical systems having gradient index optical structures

A display may include illumination optics, a spatial modulator, and a waveguide. The illumination optics may produce illumination that is modulated by the spatial modulator to produce image light. The waveguide may direct the image light towards an eye box. The illumination optics may include light source sets that produce the illumination. Each set may include a low power light source and a high power light source. In a first state, the high and low power light sources may be active. In a second state, the low power light sources may be active. Control circuitry may adjust between the first and second states based on image data. The second state may be used when virtual objects in the image data are confined to a peripheral region of the field of view of the eye box.

Optical systems having light sources with power saving modes

An electronic device may include a display module that generates light and an optical system that redirects the light towards an eye box. The system may include an input coupler on a waveguide and a lens that directs the light towards the input coupler. The input coupler may include a prism having a reflective surface that reflects the light into the waveguide. The reflective surface may be curved to provide the light with an optical power. The prism may be configured to expand a field of view of the light. A birefringent beam displacer may expand the effective pupil size of the light. The lens may include lens elements that converge the light at a location between the lens elements and the waveguide. A switchable panel may be placed at the location and toggled between first and second orientations to increase the effective resolution of the light.

Optical systems with reflective prism input couplers

A head-mounted device may have a projector that emits light. The light may include visible images produced using image data and optionally infrared light. A waveguide may propagate the light and may have a first output coupler that couples the visible images out of the waveguide and towards an eye box. One or more optical sensors may generate optical sensor data based on the light emitted by the projector. Control circuitry may detect an angle between the waveguide and the projector based on the optical sensor data. The control circuitry may adjust the image data to compensate for changes in the angle over time. The optical sensors may include an optical sensor mounted to the projector and facing the waveguide and/or one or more optical sensors mounted to an optical bridge sensor.

Waveguide angle sensing

An electronic device may include a display with a waveguide and a surface relief grating (SRG) on the waveguide. The SRG may direct image light towards an eye box. An optical blocker may at least partially overlap the SRG. The blocker may include a first optical wedge having a curved surface and a second optical wedge separated from the curved surface by an air gap or a low refractive index material. The curved surface may have a freeform shape that configures the first optical wedge to propagate world light incident upon the blocker within a selected range of incident angles away from the SRG via total internal reflection. The blocker may transmit world light at other incident angles to the eye box through the waveguide. This may allow the blocker to block high incident angle world light from reaching the SRG and producing unsightly rainbow artifacts at the eye box.

Optical systems with artifact blocking structures

An electronic device may include an emissive display panel that emits light. The light may propagate along an optical path extending to an eye box. A waveguide with an input coupler and an output coupler may be interposed on the optical path. An angle-selective transmission filter (ASTF) may be interposed on the optical path and may filter the emitted light as a function of angle to remove high-angle light from the optical path before the light is provided to the output coupler. The ASTF may include diffractive grating structures such as thin-film holograms, volume holograms, or surface relief gratings, louvered mirrors, multi-layer coatings, or a pinhole array. This ASTF may serve to minimize stray light within the display, thereby optimizing the contrast and the modulation transfer function (MTF) of the display.

Optical systems having angle-selective transmission filters

An electronic device may include an optical combiner with a waveguide. The waveguide may have an output coupler that directs high resolution light towards an eye box within a field of view. Peripheral light sources may provide low resolution peripheral light to the eye box about a periphery of the field of view. The peripheral light sources may be mounted to a frame for the waveguide, to an additional substrate mounted to the frame and overlapping the waveguide, in a low resolution projector that projects the peripheral light towards reflective structures in the additional substrate, or in a display module that produces the high resolution light. The optical combiner may overlay real world light with the high resolution light and the low resolution peripheral light.

Optical systems with low resolution peripheral displays

An electronic device may include a display module that produces light having an image, a lens that directs the light to a waveguide, and a waveguide that directs the light to an eye box. The lens may produce a foveated image in the light by applying a non-uniform magnification to the image in the light. The non-uniform magnification may vary as a function of angle within a field of view of the lens. This may allow the foveated image to have higher resolution within the central region than in the peripheral region. Performing foveation using the lens maximizes the resolution of images at the eye box without increasing the size of the display module. Control circuitry on the device may apply a pre-distortion to the image that is an inverse of distortion introduced by the lens in producing the foveated image.

Optical systems with lens-based static foveation

An electronic device may have a spatial light modulator. Control circuitry in the electronic device may use the spatial light modulator to generate images. A light source may be used to produce illumination for the spatial light modulator. An optical system may direct the illumination onto the spatial light modulator and may direct corresponding reflected image light towards eye boxes for viewing by a user. Head-mounted support structures may be used to support the spatial light modulator, light source, and optical system. The light source may include light-emitting elements such as light-emitting diodes or lasers. Multiple light-emitting elements may be provided in the light source in a one-dimensional or two-dimensional array. During operation, the control circuitry can individually adjust the light-emitting elements.

Electronic device with multi-element display illumination system

A display having a reflective display panel may provide image light to an eye box. The panel may include mirrors rotatable between first and second angles. The mirrors may take a non-zero time period to transition between the first and second angles. During the non-zero time period, the light source may emit pulses of illumination. The mirrors may reflect the pulses of illumination as offset pupils of image light. The mirrors may be at respective intermediate angles while reflecting each of the pulses of illumination. The mirrors may toggle between the first and second angles at a sufficiently fast rate such that the offset pupils form an effective pupil that is expanded in at least one dimension. If desired, the offset pupils may be used to display virtual objects in different focal planes at the eye box.

Optical systems for leveraging the non-zero transition time of display panel mirrors

A head-mounted device may have projector, a first waveguide, a second waveguide, and an optical bridge sensor coupled between the first and second waveguides. An input coupler may couple light with a calibration pattern into the first waveguide. The calibration pattern may be included in visible or infrared light produced by the projector or may be included in infrared light produced by infrared emitters mounted to the first waveguide. An output coupler may couple the light having the calibration pattern out of the first waveguide. An additional output coupler may be used to couple visible light from the projector out of the waveguide and towards an eye box. An image sensor may generate image sensor data based on the light having the calibration pattern. Control circuitry may process the calibration pattern in the image sensor data to detect deformation or warping of the first waveguide.

Waveguide deformation sensing

An electronic device may provide foveated images at an eye box. The device may have a first display module that produces a low resolution portion of the image and a second display module that produces a high resolution portion of the image. A reflective input coupling prism may be mounted to a waveguide. A steering mirror may overlap the prism. The mirror may receive the high resolution portion through the waveguide and the prism. The mirror may reflect the high resolution portion back into the waveguide and may be adjusted to shift a location of the high resolution portion within the image. For example, the steering mirror may adjust the position of the high resolution portion to align with the gaze direction at the eye box. A reflective surface of the prism may reflect the low resolution portion of the image into the waveguide.

Optical systems with multiple light engines for foveation

An electronic device may include a display system for presenting images close to a user's eyes. The display system may include a display unit that directs light and an optical system that redirects the light from the display unit towards a user's eyes. The optical system may include an input coupler and an output coupler formed on a waveguide. The input coupler may redirect light from the display unit so that it propagates in the waveguide towards the output coupler. The output coupler may redirect the light from the input coupler so that it exits the waveguide towards the user's eyes. A light-redirecting element may be used to redirect edge light that would otherwise be outside of the user's field of view towards the user's eyes.

Optical systems for displays

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San Jose, CA, United States of America

Hyungryul J Choi