Apple Inc.

Scott M DeLapp

Hyungryul J Choi

Guolin Peng

Vikrant Bhakta

Se Baek Oh

Bradley Charles Steele

Graham Butler Myhre

Noah Denis Bedard

Francesco Aieta

Kathrin Berkner-Cieslicki

Ting Sun

Kenichi Saito

Byron R Cocilovo

Tyler G Anderson

Christopher Patton

Christopher F Griffo

Enkhamgalan Dorjgotov

Young Cheol Yang

Igor Stamenov

Nan Zhu

Jin Yan

Eric J Hansotte

Kevin A Keilbach

Paul J Gelsinger-Austin

Clas M Oldenbo

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

A head-mounted device may have head-mounted support structures configured to be worn on a head of a user. The head-mounted device may have stereo optical components such as left and right cameras or left and right display systems. The optical components may have respective left and right pointing vectors. Deformation of the support structures may cause the camera pointing vectors and/or the display system pointing vectors to become misaligned. Sensor circuitry such as strain gauge circuitry may measure pointing vector misalignment. Control circuitry may control the cameras and/or the display systems to compensate for measured changes in pointing vector misalignment.

Electronic devices with deformation sensors

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 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

An electronic device may include a display module that produces foveated images having high and low resolution regions. The module may include a reflective display panel that produces first reflected light during first time periods and second reflected light during second time periods. The first reflected light may reflect off of a beam splitter to form the low resolution region of the foveated image. The second reflected light may be transmitted by the beam splitter, de-magnified by a lens, and redirected by an optical steering element to produce the high resolution region at a desired, adjustable, location in the foveated image. The reflective display panel may be replaced by sets of emissive display panels that concurrently display the high and low resolution regions in the foveated image. The sets of emissive display panels may be replaced by front-lit reflective display panels.

Optical systems having multiple light paths for performing foveation

The display may include a display module and a waveguide. The module may produce first light of first wavelengths during first time periods and may produce second light of second wavelengths during second time periods interleaved with the first time periods. Diffractive gratings or a dichroic wedge may redirect the first light into the waveguide at a first angle and may redirect the second light into the waveguide at a second angle separated from the first angle by a separation angle. The separation angle may be equal to half the angle subtended by the projection of a pixel in the module. The first and second time periods may alternate faster than the response of the human eye. This may configure the first and second image light to collectively provide images at an eye box with an increased effective resolution without increasing the space or power consumed by the display module.

Optical systems with resolution-enhancing spectral shifting

An eye tracking system for detecting position and movements of a user's eyes in a head-mounted display (HMD). The eye tracking system includes at least one eye tracking camera, an illumination source that emits infrared light towards the user's eyes, and diffraction gratings located at the eyepieces. The diffraction gratings redirect or reflect at least a portion of infrared light reflected off the user's eyes, while allowing visible light to pass. The cameras capture images of the user's eyes from the infrared light that is redirected or reflected by the diffraction gratings.

Eye tracking system

An electronic device may have a display that provides image light to a waveguide. First and second liquid crystal lenses may be mounted to opposing surfaces of the waveguide. An coupler may couple the image light out of the waveguide through the first lens. The second lens may convey world light to the first lens. Control circuitry may control the first lens to apply a first optical power to the image light and the world light and may control the second lens to apply a second optical power to the world light that cancels out the first optical power. Each lens may include two layers of liquid crystal molecules having antiparallel pretilt angles. The pretilt angles and rubbing directions of the first lens may be antiparallel to corresponding pretilt angles and rubbing directions of the second lens about the waveguide.

Waveguided display system with adjustable lenses

An electronic device may have a display that emits image light, a waveguide, and an input coupler that couples the image light into the waveguide. Beam splitter structures may be embedded within the waveguide. The beam splitter structures may partially reflect the image light multiple times and may serve to generate replicated beams of light that are coupled out of the waveguide by an output coupler. The beam splitter structures may replicate the beams across two dimensions to provide an eye box with uniform-intensity light from the display across its area. The beam splitter structures may include stacked partially reflective beam splitter layers, sandwiched transparent substrate layers having different indices of refraction, a thick volume hologram interposed between substrate layers, or combinations of these or other structures. The reflectivity of the beam splitter structures may vary discretely or continuously across the lateral area of the waveguide.

Waveguided display systems

An electronic device may have a pixel array. A light source may illuminate the pixel array to produce image light. The image light may pass through a multi-element lens and may be coupled into a waveguide using an input coupler such as a prism. An output coupler such as a diffraction grating may couple the image light out of the waveguide and towards a user. The user may view the image light and may observe real-world objects through the waveguide. The waveguide may have locally modified portions that define an aperture stop at a distance from an exit surface of the multi-element lens. The multi-element lens may have first and second achromatic doublets and first and second singlets between the first and second achromatic doublets. The lens elements of the multi-element lens may include lens elements with aspheric surfaces.

Optical systems for electronic devices with displays

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 that couples the light into the waveguide. The input coupler may include a prism on the waveguide and a scanning mirror. The scanning mirror may receive the light through the waveguide and the prism and may reflect the light into the waveguide through the prism while being rotated over a set of orientations. The scanning mirror may fill a relatively large field of view eye box with a corresponding image frame despite the limited field of view of the image light produced by the display module. The orientation of the scanning mirror may be adjusted based on gaze tracking data.

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Sunnyvale, CA, United States of America

Scott M DeLapp