# US 11,029,528 B1 · Display alignment using diffraction

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- Number: US 11,029,528 B1
- Document ID: US11029528B1
- Status: Granted
- Kind: B1
- Application number: 16/375,706
- Filed: 2019-04-04
- Granted: 2021-06-08
- Earliest claimed: 2016-09-28
- Assignees: Facebook Technologies, LLC
- Applicants: Facebook Technologies, LLC
- Inventors: Samuel Redmond D'Amico; Evan M. Richards
- Web page: https://patentgrep.com/patent/US11029528B1

## CPC

- G02B 27/4255: {for alignment or positioning purposes (optical displacement encoding scales G01D5/347)}
- G02B 27/017: {Head mounted}
- G02B 27/0179: {Display position adjusting means not related to the information to be displayed}
- G09G 3/20: for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters}
- G09G 3/3208: organic, e.g. using organic light-emitting diodes [OLED]
- G09G 5/36: characterised by the display of a graphic pattern, e.g. using an all-points-addressable [APA] memory
- G09G 5/38: with means for controlling the display position
- G06T 2207/10152: Varying illumination
- G09G 2320/0693: Calibration of display systems
- G09G 2340/0485: Centering horizontally or vertically
- G09G 2340/0492: Change of orientation of the displayed image, e.g. upside-down, mirrored
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- 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)
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL

## Abstract

In systems and methods for adjusting the position of a headset element (e.g., a display and/or other optical element), coherent light (e.g., a laser beam) is transmitted through a display of a headset to produce a diffraction pattern on a detector, which detects the diffraction pattern. The orientation of the headset element is determined based in part on the detected diffraction pattern. Based on the determined orientation and a target orientation, an adjustment to the orientation of the headset element is determined. The position of the headset element is adjusted based on the determined adjustment. This method may be repeated until the headset element is determined to be correctly oriented.

## Claims

### Claim 1

A method comprising:
determining a first orientation of a display based in part on a diffraction pattern detected by a detector, the diffraction pattern generated by transmitting coherent light through the display to produce the diffraction pattern on the detector;
determining an adjustment to the first orientation of the display using the determined first orientation and a target orientation;
generating instructions for adjusting the display to a second orientation based on the determined adjustment; and
transmitting the instructions to a display alignment device.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first orientation of the display includes a plurality of degrees of freedom of the display, the plurality of degrees of freedom including at least a tip and a tilt, the tip corresponding to an amount of rotation about a first axis of the display, and the tilt corresponding to an amount of rotation about a second axis of the display that is orthogonal to the first axis.

### Claim 3 (depends on 2)

The method of claim 2, wherein determining the first orientation of the display comprises:
determining the tilt of the display based on a horizontal spacing between two or more fringes of the detected diffraction pattern; and
determining the tip of the display based on a vertical spacing between two or more fringes of the detected diffraction pattern.

### Claim 4 (depends on 1)

The method of claim 1, further comprising determining a position of the display along an axis perpendicular to a surface of the display based on a scaling of the diffraction pattern.

### Claim 5 (depends on 1)

The method of claim 1, wherein the instructions for adjusting the display to the second orientation comprise instructions for rotating the display with the display alignment device, wherein the display alignment device is coupled to the display.

### Claim 6 (depends on 1)

The method of claim 1, further comprising:
determining a first position of the display based on identified locations of one or more target pixels illuminated by the display in one or more captured images of the one or more target pixels;
determining a second adjustment to the position of the display using the determined first position of the display;
generating second instructions for adjusting the display to a second position based on the determined second adjustment; and
transmitting the second instructions to the display alignment device.

### Claim 7 (depends on 6)

The method of claim 6, wherein the instructions for adjusting the display to the second orientation based on the determined adjustment comprise instructions for adjusting a tip and a tilt of the display, the tip corresponding to an amount of rotation about a first axis of the display, and the tilt corresponding to an amount of rotation about a second axis of the display that is orthogonal to the first axis, and wherein the second instructions for adjusting the display to the second position based on the determined second adjustment comprise instructions for moving of the display in directions parallel to a surface of the display.

### Claim 8 (depends on 1)

The method of claim 1, wherein diffracted light that radiates from the display and produces the diffraction pattern is refracted by one or more optical elements of a headset including the display before being detected by the detector.

### Claim 9 (depends on 1)

The method of claim 1, wherein diffracted light that radiates from the display and produces the diffraction pattern is directly incident upon the detector without first passing through additional optical elements.

### Claim 10 (depends on 1)

The method of claim 1, further comprising:
identifying a zero order fringe in the diffraction pattern;
identifying a second fringe in the diffraction pattern; and
determining the first orientation of the display based on a distance between the zero order fringe and the second fringe.

### Claim 11

A non-transitory computer-readable storage medium storing executable computer program instructions, wherein the computer program instructions, when executed by a computer processor, cause the computer processor to perform steps comprising:
determining a first orientation of a display based in part on a diffraction pattern detected by a detector, the diffraction pattern generated by transmitting coherent light through the display to produce the diffraction pattern on the detector;
determining an adjustment to the first orientation of the display using the determined first orientation and a target orientation;
generating instructions for adjusting the display to a second orientation based on the determined adjustment; and
transmitting the instructions to a display alignment device.

### Claim 12 (depends on 11)

The non-transitory computer-readable storage medium of claim 11, wherein the first orientation of the display includes a plurality of degrees of freedom of the display, the plurality of degrees of freedom including at least a tip and a tilt, the tip corresponding to an amount of rotation about a first axis of the display, and the tilt corresponding to an amount of rotation about a second axis of the display that is orthogonal to the first axis.

### Claim 13 (depends on 12)

The non-transitory computer-readable storage medium of claim 12, wherein determining the first orientation of the display comprises:
determining the tilt of the display based on a horizontal spacing between two or more fringes of the detected diffraction pattern; and
determining the tip of the display based on a vertical spacing between two or more fringes of the detected diffraction pattern.

### Claim 14 (depends on 11)

The non-transitory computer-readable storage medium of claim 11, further comprising computer program instructions for determining a position of the display along an axis perpendicular to a surface of the display based on a scaling of the diffraction pattern.

### Claim 15 (depends on 13)

The non-transitory computer-readable storage medium of claim 13, wherein the instructions for adjusting the display to the second orientation comprise instructions for rotating the display with the display alignment device, wherein the display alignment device is coupled to the display.

### Claim 16 (depends on 11)

The non-transitory computer-readable storage medium of claim 11, further comprising computer program instructions for:
determining a first position of the display based on identified locations of one or more target pixels illuminated by the display in one or more captured images of the one or more target pixels;
determining a second adjustment to the position of the display using the determined first position of the display;
generating second instructions for adjusting the display to a second position based on the determined second adjustment; and
transmitting the second instructions to the display alignment device.

### Claim 17 (depends on 16)

The non-transitory computer-readable storage medium of claim 16, wherein the instructions for adjusting the display to the second orientation based on the determined adjustment comprise instructions for adjusting a tip and a tilt of the display, the tip corresponding to an amount of rotation about a first axis of the display, and the tilt corresponding to an amount of rotation about a second axis of the display that is orthogonal to the first axis, and wherein the second instructions for adjusting the display to the second position based on the determined second adjustment comprise instructions for moving of the display in directions parallel to a surface of the display.

### Claim 18 (depends on 11)

The non-transitory computer-readable storage medium of claim 11, wherein diffracted light that radiates from the display and produces the diffraction pattern is refracted by one or more optical elements of a headset including the display before being detected by the detector.

### Claim 19 (depends on 11)

The non-transitory computer-readable storage medium of claim 11, wherein diffracted light that radiates from the display and produces the diffraction pattern is directly incident upon the detector without first passing through additional optical elements.

### Claim 20 (depends on 11)

The non-transitory computer-readable storage medium of claim 11, further comprising computer program instructions for:
identifying a zero order fringe in the diffraction pattern;
identifying a second fringe in the diffraction pattern; and
determining the first orientation of the display based on a distance between the zero order fringe and the second fringe.