# US 12,007,571 B2 · Suppression of stray light in head worn computing

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

- Number: US 12,007,571 B2
- Document ID: US12007571B2
- Status: Granted
- Kind: B2
- Application number: 18/332,661
- Filed: 2023-06-09
- Published: 2023-10-19
- Granted: 2024-06-11
- Earliest claimed: 2014-01-21
- Assignees: Mentor Acquisition One, LLC
- Applicants: Mentor Acquisition One, LLC
- Inventors: John N. Border
- Web page: https://patentgrep.com/patent/US12007571B2

## CPC

- G02B 27/0172: {characterised by optical features}
- G02B 27/01: Head-up displays
- G02B 27/017: {Head mounted}
- G02B 27/10: Beam splitting or combining systems (polarising systems G02B27/28; mixing and splitting light signals using optical waveguides G02B6/28; {beam shaping, e.g. changing the cross-sectional area, by dividing or superposing multiple light beams G02B27/0905})
- G02B 27/14: operating by reflection only
- G02B 27/283: {used for beam splitting or combining}
- H04N 13/344: with head-mounted left-right displays
- H04N 13/346: using prisms or semi-transparent mirrors
- G02B 27/28: for polarising (used in stereoscopes G02B30/25)
- G02B 2027/0105: {Holograms with particular structures}
- G02B 2027/012: {comprising devices for attenuating parasitic image effects}
- G02B 2027/0174: {holographic}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Aspects of the present invention relate to suppression of stray light in head worn computing.

## Claims

### Claim 1

A method, comprising:
receiving image light;
reflecting a first portion of the image light via an angled partially reflective surface toward an eye of a user of a wearable head device;
receiving environmental light via a combiner;
transmitting, via the combiner, the environmental light toward the angled partially reflective surface;
receiving, at a filter, a second portion of the image light, via the angled partially reflective surface; and
absorbing, via the filter, the second portion of the image light, wherein:
the image light comprises image light of a first wavelength; and
the filter comprises a notch filter, the notch filter configured to selectively absorb the image light of the first wavelength.

### Claim 2 (depends on 1)

The method of claim 1, further comprising transmitting the environmental light toward the eye via the angled partially reflective surface.

### Claim 3 (depends on 2)

The method of claim 2, wherein the environmental light is received at the angled partially reflective surface via the combiner.

### Claim 4 (depends on 1)

The method of claim 1, wherein the filter is oriented substantially vertically with respect to the eye when the wearable head device is worn by the user.

### Claim 5 (depends on 1)

The method of claim 1, wherein:
the first portion of the image light comprises image light of a first wavelength;
the second portion of the image light comprises image light of a second wavelength different from the first wavelength; and
absorbing the second portion of the image light comprises filtering the second wavelength.

### Claim 6 (depends on 1)

The method of claim 1, further comprising:
transmitting, via an optical element, the first portion of the image light and the second portion of the image light in a first direction toward the angled partially reflective surface;
transmitting, via the optical element, a third portion of the image light in a second direction toward a light trap; and
absorbing, via the light trap, the third portion of the image light.

### Claim 7

A wearable head device comprising:
an image source configured to produce image light;
an angled partially reflective surface configured to receive the image light and reflect a first portion of the image light toward an eye of a user of the wearable head device; and
a combiner configured to receive environmental light and transmit the environmental light toward the angled partially reflective surface; and
a filter configured to absorb a second portion of the image light, wherein the second portion of the image light is received via the angled partially reflective surface, wherein:
the image light comprises image light of a first wavelength; and
the filter comprises a notch filter, the notch filter configured to selectively absorb the image light of the first wavelength.

### Claim 8 (depends on 7)

The wearable head device of claim 7, wherein the angled partially reflective surface is further configured to receive the environmental light and transmit the environmental light toward the eye.

### Claim 9 (depends on 8)

The wearable head device of claim 8, further comprising a combiner, wherein the environmental light is received at the angled partially reflective surface via the combiner.

### Claim 10 (depends on 7)

The wearable device of claim 7, wherein the filter is oriented substantially vertically with respect to the eye when the wearable head device is worn by the user.

### Claim 11 (depends on 7)

The wearable device of claim 7, wherein:
the first portion of the image light comprises image light of a first wavelength;
the second portion of the image light comprises image light of a second wavelength different from the first wavelength; and
absorbing the second portion of the image light comprises filtering the second wavelength.

### Claim 12 (depends on 7)

The wearable device of claim 7, further comprising:
a light trap;
an optical element, the optical element configured to transmit a first portion of the image light and the second portion of the image light in a first direction toward the angled partially reflective surface and further transmit a third portion of the image light in a second direction toward the light trap.