Patents by Inventor Pasi Saarikko

Pasi Saarikko has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10935804
    Abstract: A Pancharatnam Berry Phase (PBP) color corrected structure is presented that comprises a plurality of switchable gratings and a plurality of PBP active elements. Each switchable grating has an inactive mode when reflects light of a specific color channel, of a set of color channels, and transmits light of other color channels in the set of color channels, wherein the specific color channel is different for each of the plurality of switchable gratings, and to have an active mode to transmit light that is inclusive of the set of color channels. The PBP active elements receive light output from at least one of the plurality of switchable gratings. Each of the PBP active elements is configured to adjust light of a different color channel of the set of color channels by a same amount to output light corrected for chromatic aberration for the set of color channels.
    Type: Grant
    Filed: May 12, 2020
    Date of Patent: March 2, 2021
    Assignee: Facebook Technologies, LLC
    Inventors: Lu Lu, Scott Charles McEldowney, Nada O'Brien, Pasi Saarikko
  • Publication number: 20210055553
    Abstract: A waveguide display includes a substrate transparent to visible light and a projector configured to generate display light for an image, where the display light includes display light for a first field of view (FOV) of the image and display light for a second FOV of the image. The waveguide display also includes a first input coupler configured to couple the display light for the first FOV into the substrate, a first set of gratings configured to couple the display light for the first FOV out of the substrate at a first two-dimensional array of locations of the substrate, a second input coupler configured to couple the display light for the second FOV into the substrate, and a second set of gratings configured to couple the display light for the second FOV out of the substrate at a second two-dimensional array of locations of the substrate.
    Type: Application
    Filed: April 3, 2020
    Publication date: February 25, 2021
    Inventors: Wanli Chi, Dominic Meiser, Yang Yang, Wai Sze Tiffany Lam, Pasi Saarikko
  • Publication number: 20210055554
    Abstract: A waveguide display includes a waveguide transparent to visible light, a first volume Bragg grating (VBG) on the waveguide and characterized by a first refractive index modulation, and a second reflection VBG on the waveguide and including a plurality of regions characterized by different respective refractive index modulations. The first reflection VBG is configured to diffract display light in a first wavelength range and a first field of view (FOV) range such that the display light in the first wavelength range and the first FOV range propagates in the waveguide through total internal reflection to the plurality of regions of the second reflection VBG. The plurality of regions of the second reflection VBG are configured to diffract the display light in different respective wavelength ranges within the first wavelength range and the first FOV range.
    Type: Application
    Filed: April 3, 2020
    Publication date: February 25, 2021
    Inventors: Wanli Chi, Dominic Meiser, Yang Yang, Wai Sze Tiffany Lam, Pasi Saarikko, Ningfeng Huang
  • Publication number: 20210055555
    Abstract: A waveguide display includes a waveguide and a grating coupler configured to couple display light into or out of the waveguide. The grating coupler includes at least a first grating layer and a second grating layer arranged in a stack. The first grating layer is characterized by a first thickness and includes a first transmission VBG configured to diffract display light of a first wavelength from a first field of view. The second grating layer is characterized by a second thickness greater than the first thickness and includes a second transmission VBG configured to diffract display light of the first wavelength from a second field of view greater than the first field of view.
    Type: Application
    Filed: April 3, 2020
    Publication date: February 25, 2021
    Inventors: Wanli Chi, Dominic Meiser, Yang Yang, Wai Sze Tiffany Lam, Pasi Saarikko
  • Publication number: 20210055460
    Abstract: A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of tapered slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. The tapered fringes result in the duty cycle of the diffraction grating varying along the thickness direction of the diffraction grating, to facilitate suppressing the portion of the display light out-coupled into the non-blazed diffraction order.
    Type: Application
    Filed: August 23, 2019
    Publication date: February 25, 2021
    Inventors: Hee Yoon Lee, Ningfeng Huang, Pasi Saarikko, Yu Shi, Giuseppe Calafiore, Nihar Ranjan Mohanty
  • Publication number: 20210055552
    Abstract: In a waveguide display, a first projector is configured to generate display light for a first field of view (FOV) of a display image. A first input coupler is configured to couple the display light for the first FOV into a visibly transparent substrate. A first set of gratings is configured to couple the display light for the first FOV out of the substrate at a first two-dimensional array of locations of the substrate. A second projector is configured to generate display light for a second FOV of the display image different from the first FOV. A second input coupler is configured to couple the display light for the second FOV into the substrate. A second set of gratings is configured to couple the display light for the second FOV out of the substrate at a second two-dimensional array of locations of the substrate.
    Type: Application
    Filed: March 6, 2020
    Publication date: February 25, 2021
    Inventors: Wanli Chi, Dominic Meiser, Yang Yang, Wai Sze Tiffany Lam, Pasi Saarikko
  • Publication number: 20210055551
    Abstract: A waveguide display includes a substrate transparent to visible light, a coupler configured to couple display light into the substrate as guided wave in the substrate, and a first VBG and a second VBG coupled to the substrate. The coupler includes a diffractive coupler, a refractive coupler, or a reflective coupler. The first VBG is configured to diffract, at a first region of the first VBG, the display light in the substrate to a first direction, and diffract, at two or more regions of the first VBG along the first direction, the display light from the first region to a second direction towards the second VBG. The second VBG is configured to couple the display light from each of the two or more regions of the first VBG out of the substrate at two or more regions of the second VBG along the second direction.
    Type: Application
    Filed: November 12, 2019
    Publication date: February 25, 2021
    Inventors: Wanli Chi, Dominic Meiser, Yang Yang, Wai Sze Tiffany Lam, Pasi Saarikko
  • Patent number: 10930187
    Abstract: A waveguide display includes a light source, a conditioning lens assembly, a scanning mirror assembly, and a controller. The light source includes a plurality of source elements that are configured to emit image light in accordance with scanning instructions. The conditioning lens assembly transmits conditioned light based in part on the image light. The scanning mirror assembly scans the conditioned image light to particular locations as scanned image light in accordance with scanning instructions. The output waveguide includes an input area and an output area, receives the scanned image light emitted from the scanning mirror assembly at the input area, and outputs the expanded image light from a portion of the output area based in part on a direction of the expanded light output from the scanning mirror assembly. The controller generates the scanning instructions and provides the scanning instructions to the light source and the scanning mirror assembly.
    Type: Grant
    Filed: July 24, 2018
    Date of Patent: February 23, 2021
    Assignee: Facebook Technologies, LLC
    Inventors: Wanli Chi, Pasi Saarikko, Hee Yoon Lee
  • Patent number: 10928635
    Abstract: A headset includes a display assembly. The display assembly has a primary portion and a peripheral portion. The primary portion of the display assembly is configured to emit a first portion of image light, and has a first field of view (FOV). The peripheral portion of the display assembly is configured to emit a second portion of the image light over a second FOV, and the peripheral portion is canted relative to the primary portion. The emitted first portion of image light and the emitted second portion of image light create a composite FOV from the perspective of an eyebox, and a seam between the first FOV and the second FOV is located in a peripheral region of the composite FOV.
    Type: Grant
    Filed: April 9, 2019
    Date of Patent: February 23, 2021
    Assignee: Facebook Technologies, LLC
    Inventors: Nicholas Daniel Trail, Andrew John Ouderkirk, Pasi Saarikko, Sharvil Shailesh Talati, Hee Yoon Lee, Behnam Bastani
  • Patent number: 10914954
    Abstract: A multilayer grating is a diffraction grating that includes a plurality of layers. The plurality of layers arranged to form a 2-dimensional grating, the layers including at least a first patterned layer and a second patterned layer. The first patterned layer includes a plurality of different materials that are arranged in a first pattern such that the first patterned layer has a first index profile. The second patterned layer includes a plurality of different materials that are arranged in a second pattern such that the second patterned layer has a second index profile that is inverted relative to the first index profile. Ambient light incident on the first patterned layer and the second patterned layer creates a first diffracted ray and a second diffracted ray, respectively, and the first diffracted ray and the second diffracted ray destructively interfere with each other based in part on the inverted index profile.
    Type: Grant
    Filed: August 3, 2018
    Date of Patent: February 9, 2021
    Assignee: Facebook Technologies, LLC
    Inventors: Erik Shipton, Giuseppe Calafiore, Pasi Saarikko
  • Patent number: 10914956
    Abstract: A headset includes a first waveguide display and a second waveguide display. The first waveguide display is configured to emit a first portion of image light, the first waveguide display having a first field of view (FOV). The second display assembly is configured to emit a second portion of the image light, and the second display assembly has a second FOV. The first waveguide display and the second display assembly are tiled such that the emitted first portion of image light and the emitted second portion of image light create a tiled FOV from a perspective of an eyebox. And a seam between the first FOV and the second FOV is located in a peripheral region of the tiled FOV.
    Type: Grant
    Filed: March 21, 2019
    Date of Patent: February 9, 2021
    Assignee: Facebook Technologies, LLC
    Inventors: Nicholas Daniel Trail, Andrew John Ouderkirk, Pasi Saarikko, Sharvil Shailesh Talati, Hee Yoon Lee, Behnam Bastani, Hagar Edelstain
  • Patent number: 10914953
    Abstract: A tunable waveguide display includes a source waveguide, a first tunable lens (FTL), an output waveguide, and a second tunable lens (STL). The source waveguide receives light, expands the light in a first dimension, and outputs the expanded light. The FTL adjusts a wavefront of the expanded light to form adjusted light. The output waveguide receives the adjusted light, expands the adjusted light in a second dimension to form image light, and outputs the image light. The STL adjusts a wavefront of the image light. The FTL and the STL control an image plane of the image light.
    Type: Grant
    Filed: June 11, 2018
    Date of Patent: February 9, 2021
    Assignee: Facebook Technologies, LLC
    Inventors: Wai Sze Tiffany Lam, Yijing Fu, Lu Lu, Pasi Saarikko
  • Patent number: 10901205
    Abstract: A head-mounted display (HMD) includes an electronic display configured to emit an image. The HMD also includes an eye tracking module configured to determine a position of an eye of a user of the HMD, and a varifocal block. The varifocal block includes a stacked liquid crystal (LC) structure that has a tunable optical power. The varifocal block is configured to present the image to the user of the HMD at an adjustable focal distance that is determined by the tunable optical power and is based in part on the determined position of the eye.
    Type: Grant
    Filed: August 9, 2017
    Date of Patent: January 26, 2021
    Assignee: Facebook Technologies, LLC
    Inventors: Lu Lu, Pasi Saarikko, Douglas Robert Lanman
  • Patent number: 10877280
    Abstract: A near-eye display includes a light source assembly, a first waveguide, an output waveguide, and a controller. The light source assembly emits image light including light within a first band and a second band. The first waveguide receives the image light, expands the received image light in at least one dimension, and outputs an image light. The output waveguide includes an output area and a plurality of input areas. Each input area receives the image light from the first waveguide. The output waveguide includes a holographic Bragg grating and the output waveguide expands the image light at least along two dimensions to form an expanded image light, and outputs the expanded image light toward an eyebox. The controller controls the scanning of the light source assembly and the first waveguide.
    Type: Grant
    Filed: September 25, 2019
    Date of Patent: December 29, 2020
    Assignee: Facebook Technologies, LLC
    Inventors: Hee Yoon Lee, Wanli Chi, Pasi Saarikko
  • Patent number: 10861415
    Abstract: A wearable display device and a calibration method for the wearable display device are provided. The wearable display device or its component(s) may exhibit optical throughput dependent on beam angle or beam coordinate at the eyebox. The linear or angular dependencies of throughput may be accounted for when generating an image to be displayed, to lessen or offset these dependencies during operation of the wearable display.
    Type: Grant
    Filed: August 14, 2018
    Date of Patent: December 8, 2020
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventors: Yijing Fu, Pasi Saarikko, Hee Yoon Lee, Wanli Chi
  • Patent number: 10845526
    Abstract: A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. A refractive index contrast profile of the diffraction grating along a thickness direction of the diffraction grating is symmetrical, and a refractive index contrast is larger at a middle than at both sides of the refractive index contrast profile, whereby the portion of the display light out-coupled into the non-blazed diffraction order is decreased.
    Type: Grant
    Filed: August 23, 2019
    Date of Patent: November 24, 2020
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventors: Hee Yoon Lee, Ningfeng Huang, Pasi Saarikko, Yu Shi, Giuseppe Calafiore, Nihar Ranjan Mohanty
  • Patent number: 10845596
    Abstract: A waveguide display includes a substrate having two opposite surfaces, and a slanted grating at a first surface of the two opposite surfaces of the substrate. The slanted grating includes a plurality of ridges and is characterized by a grating period in one direction. The plurality of ridges is tilted at a slant angle with respect to a surface normal of the first surface and is characterized by a height. The height of the plurality of ridges, the grating period, and the slant angle are configured to cause destructive interference between ambient light diffracted by the slanted grating. In some embodiments, a difference between the height of the plurality of ridges and an integer multiple of the grating period divided by the tangent of the slant angle is less than a threshold value.
    Type: Grant
    Filed: January 23, 2018
    Date of Patent: November 24, 2020
    Assignee: FACEBOOK TECHNOLOGIES, LLC
    Inventors: Hee Yoon Lee, Ningfeng Huang, Giuseppe Calafiore, Pasi Saarikko
  • Publication number: 20200348514
    Abstract: A waveguide is provided for conveying image light. The waveguide includes an input port for receiving a first beam of image light carrying an image in a wavelength band. A first diffraction grating of the waveguide includes a plurality of volume Bragg gratings (VBGs) configured to expand the first beam along a first axis and to redirect the first beam towards a second diffraction grating of the waveguide. The second diffraction grating includes a plurality of VBGs configured to receive the first beam from the first diffraction grating and to out-couple different portions of the first wavelength band of the first beam along a second axis, thereby expanding the first beam along the second axis for observation of the image by a user.
    Type: Application
    Filed: June 22, 2020
    Publication date: November 5, 2020
    Inventors: Wanli Chi, Hee Yoon Lee, Pasi Saarikko
  • Patent number: 10809537
    Abstract: A waveguide display is used for presenting media to a user. The waveguide display, includes a light source, a projection assembly (PA), a source waveguide (SW), and an output waveguide (OW). The light source emits light, the PA reshapes the wavefront of the light and the SW receives the light from the PA, expands the light in a first dimension and outputs the expanded light. The SW has an adjustable curvature along the first dimension expanding the light with a curved wavefront. The OW receives the expanded light emitted from the SW, expands the expanded light in a second dimension orthogonal to the first dimension to form image light and outputs the image light. The wavefront curvature from the light source, the curvature of the OW along the second dimension and the curvature of the SW control a location of an image plane of the image light.
    Type: Grant
    Filed: June 15, 2018
    Date of Patent: October 20, 2020
    Assignee: Facebook Technologies, LLC
    Inventors: Wai Sze Tiffany Lam, Kyle Justin Curts, Pasi Saarikko
  • Patent number: 10809585
    Abstract: A Pancharatnam Berry Phase (PBP) liquid crystal structure for adjusting or focusing light of a plurality of color channels emitted by a display of a head-mounted display (HMD) comprises a plurality of PBP active elements. Each PBP active element of the structure is configured to act as a half waveplate for light of a corresponding color channel, such that light of the corresponding color channel is adjusted by a predetermined amount. In addition, each PBP active element acts as a one waveplate for light of the remaining color channels, such that light of the remaining color channels passes through the PBP active element substantially unaffected. As such, the PBP structure is able to adjust incident light of the plurality of color channels uniformly in an apochromatic fashion.
    Type: Grant
    Filed: September 5, 2019
    Date of Patent: October 20, 2020
    Assignee: Facebook Technologies, LLC
    Inventors: Lu Lu, Wai Sze Tiffany Lam, Scott Charles McEldowney, Pasi Saarikko