# US 12,603,023 B2 · Light modulation for foveated display

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,603,023 B2
- Document ID: US12603023B2
- Status: Granted
- Kind: B2
- Application number: 18/640,817
- Filed: 2024-04-19
- Published: 2024-10-31
- Granted: 2026-04-14
- Earliest claimed: 2023-04-28
- Assignees: Meta Platforms Technologies, LLC
- Applicants: Meta Platforms Technologies, LLC
- Inventors: Kai-Han Chang; Yu-Jen Wang
- Web page: https://patentgrep.com/patent/US12603023B2

## CPC

- G09G 3/001: {using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background (slide projectors per se G03B23/00 = 42 HP)}
- G02F 1/292: {by controlled diffraction or phased-array beam steering (controlled diffraction for optical switching G02F1/31)}
- G06F 3/013: {Eye tracking input arrangements (G06F3/015 takes precedence)}
- G09G 2340/0407: Resolution change, inclusive of the use of different resolutions for different screen areas
- G09G 2354/00: Aspects of interface with display user
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)

## Abstract

Gaze data of a user is received. A display zone corresponding to the gaze data is identified. The display zone is a portion of a display pixel array. The display light generated by the display zone is modulated to shift an optical path of the display light within the display zone.

## Claims

### Claim 1

A method comprising:
detecting a gaze angle of an eye of a user;
identifying a Field of View (FOV) in a foveated area corresponding to the gaze angle;
associating a corresponding display zone of a display that corresponds with the FOV in the foveated area; and
for the corresponding display zone, modulating display light between a first polarization orientation in a first subframe and a second polarization orientation in a second subframe, wherein a display frame includes the first subframe and the second subframe, and wherein modulating between the first polarization orientation and the second polarization orientation shifts an optical path of the display light in the corresponding display zone between a first direction and a second direction that is nonparallel to the first direction; and
shifting, by an angular correction component, the display light in at least one of the first subframe and the second subframe such that the display light output from the angular correction component is parallel during each of the first subframe and the second subframe.

### Claim 2 (depends on 1)

The method of claim 1, wherein shifting the optical path of the display light between subframes increases a perceived resolution of the corresponding display zone.

### Claim 3 (depends on 1)

The method of claim 1, wherein modulating the display light between the first polarization orientation in the first subframe and the second polarization orientation in the second subframe includes driving a zonal switchable waveplate between a first state and a second state,
wherein the zonal switchable waveplate outputs the first polarization orientation of the display light in the first state and outputs the second polarization orientation of the display light in the second state.

### Claim 4 (depends on 3)

The method of claim 3, wherein the zonal switchable waveplate is disposed between a Pancharatnam-Berry Phase (PBP) grating and the corresponding display zone, wherein the PBP grating is configured to diffract the first polarization orientation at a first diffraction angle corresponding to the first direction, and wherein the PBP grating is configured to diffract the second polarization orientation at a second diffraction angle corresponding to the second direction, the first polarization orientation being opposite-handed of the second polarization orientation.

### Claim 5 (depends on 4)

The method of claim 4, wherein the first diffraction angle is symmetrical to the second diffraction angle.

### Claim 6 (depends on 3)

The method of claim 3, wherein the zonal switchable waveplate is disposed between a polarization volume hologram (PVH) and the corresponding display zone, wherein the PVH is configured to diffract the first polarization orientation to generate the shift in the optical path to the first direction, and wherein the PVH is configured to pass the second polarization orientation in the second direction, wherein the second polarization orientation is opposite-handed of the first polarization orientation.

### Claim 7

A device comprising:
an eye-tracking system configured to detect a gaze angle of an eye of a user;
a display pixel array configured to generate display light;
a pixel dithering optical component configured to modulate the display light; and
processing logic configured to:
receive the gaze angle generated by the eye-tracking system;
identify a Field of View (FOV) in a foveated area corresponding to the gaze angle;
associate a corresponding display zone of the display pixel array that corresponds with the FOV in the foveated area; and
for the corresponding display zone, modulate the display light between a first polarization orientation in a first subframe and a second polarization orientation in a second subframe to shift an optical path of the display light in the corresponding display zone between a first direction and a second direction that is nonparallel to the first direction; and
shift, by an angular correction component, the display light in at least one of the first subframe and the second subframe such that the display light output from the angular correction component is parallel during each of the first subframe and the second subframe.

### Claim 8 (depends on 7)

The device of claim 7, wherein the pixel dithering optical component includes a zonal switchable waveplate, wherein the processing logic is configured to drive a zone of the zonal switchable waveplate between a first state and a second state, wherein the zonal switchable waveplate outputs the first polarization orientation of the display light in the first state and outputs the second polarization orientation of the display light in the second state, the zone of the zonal switchable waveplate receiving the display light from the corresponding display zone.

### Claim 9 (depends on 8)

The device of claim 8, wherein the pixel dithering optical component further includes a Pancharatnam-Berry Phase (PBP) grating, and wherein the PBP grating is configured to diffract the first polarization orientation at a first diffraction angle corresponding to the first direction, and wherein the PBP grating is configured to diffract the second polarization orientation at a second diffraction angle corresponding to the second direction.

### Claim 10 (depends on 9)

The device of claim 9, wherein the PBP grating comprises a first PBP grating and the angular correction component comprises a second PBP grating of the pixel dithering optical component, the second PBP grating configured to angularly correct output light generated by the first PBP grating, wherein the first PBP grating is disposed between the second PBP grating and zonal waveplate.

### Claim 11 (depends on 8)

The device of claim 8, wherein the pixel dithering optical component further includes a polarization volume hologram (PVH), and wherein the PVH is configured to diffract the first polarization orientation to generate the shift in the optical path to the first direction, and wherein the PVH is configured to pass the second polarization orientation in the second direction, wherein the second polarization orientation is opposite-handed of the first polarization orientation.

### Claim 12 (depends on 11)

The device of claim 11, wherein the PVH comprises a first PVH and the angular correction component comprises a second PVH of the pixel dithering optical component, the second PVH configured to angularly correct the first polarization orientation and pass the second polarization orientation.

### Claim 13 (depends on 8)

The device of claim 8, wherein zonal switchable waveplate is a zonal switchable half-waveplate having zones of the zonal switchable half-waveplate overlaying corresponding display zones of the display pixel array.

### Claim 14 (depends on 7)

The device of claim 7, wherein the pixel dithering optical component further includes:
a liquid crystal layer; and
a zonal polarization control layer disposed between the display pixel array and the liquid crystal layer, wherein the display light is in a first linear polarization orientation, and wherein the zonal polarization control layer includes zones overlaying corresponding display zones of the display pixel array, wherein a zone of the zonal polarization control layer is driven to a first state to pass the display light having the first linear polarization orientation, and wherein the zone of the zonal polarization control layer is driven to a second state to change the first linear polarization orientation to a second linear polarization orientation,
and wherein the liquid crystal layer shifts an optical path of the second polarization orientation but not the first polarization orientation.

### Claim 15 (depends on 14)

The device of claim 14, wherein the liquid crystal layer is a polymerized liquid crystal film having liquid crystals disposed in a fixed orientation.

### Claim 16 (depends on 7)

The device of claim 7, wherein the pixel dithering optical component further includes a zonal liquid crystal layer including zones overlaying corresponding display zones of the display pixel array,
wherein a zone of the zonal liquid crystal layer is driven to a first state to pass the display light having a first linear polarization orientation, and wherein the first state of the zonal liquid crystal layer aligns liquid crystal molecules within the zone to have an optics axis that is parallel to the first linear polarization orientation of the display light,
wherein the zone of the zonal liquid crystal layer is driven to a second state to laterally shift an optical path of the display light having the first linear polarization orientation, and wherein the second state of the zonal liquid crystal layer aligns liquid crystal molecules within the zone to have the optics axis that is not perpendicular and not parallel to the first linear polarization orientation of the display light.

### Claim 17

A display comprising:
a display pixel array configured to generate display light;
a pixel dithering optical component configured to modulate the display light; and
processing logic configured to drive the pixel dithering optical component to:
modulate the display light between a first polarization orientation in a first subframe and a second polarization orientation in a second subframe to shift an optical path of the display light emitted by a display zone of the display pixel array between a first direction and a second direction that is nonparallel to the first direction, the display pixel array including a plurality of display zones; and
shift, by an angular correction component, the display light in at least one of the first subframe and the second subframe such that the display light output from the angular correction component is parallel during each of the first subframe and the second subframe.

### Claim 18 (depends on 17)

The display of claim 17, wherein modulating the display light to shift the optical path of the display light provides a perceived doubling of a pixel resolution in the display zone while remaining display zones in the plurality of display zones still have a perceived pixel resolution consistent with a density of pixels in the display pixel array.

### Claim 19 (depends on 17)

The display of claim 17, wherein the processing logic is further configured to:
receive gaze data from an eye-tracking system; and
modulate one or more zones in the pixel dithering optical component in response to the gaze data, wherein modulating the one or more zones of the pixel dithering optical component increases a perceived resolution of the display pixel array in a display zone corresponding to the one or more zones of the pixel dithering optical component that are being modulated.

### Claim 20 (depends on 17)

The display of claim 17, wherein the pixel dithering optical component includes a zonal switchable waveplate having zones, and wherein individual zones of the zonal switchable waveplate are configured to be switched by the processing logic to shift the optical path of the display light.