Integrated eye tracking and laser projection methods with holographic elements of varying optical powers

Patent metadata

Field	Value
Publication number	US-10114222-B2
Application number	US-201715807746-A
Country	US
Kind code	B2
Filing date	Nov 9, 2017
Priority date	May 28, 2015
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

Systems, devices, and methods that integrate eye tracking capability into scanning laser projector (“SLP”)-based wearable heads-up displays are described. An infrared laser diode is added to an RGB SLP and an infrared photodetector is aligned to detect reflections of the infrared light from features of the eye. A holographic optical element (“HOE”) may be used to combine visible light, infrared light, and environmental light into the user's “field of view.” The HOE may be heterogeneous and multiplexed to apply positive optical power to the visible light and zero or negative optical power to the infrared light.

First claim

The invention claimed is:

1. A method of operating a laser projector to project an image to an eye of a user and to track the eye of the user, the method comprising:
outputting visible light by at least a first laser diode of the laser projector, the visible light representative of at least a portion of the image;
outputting infrared light by an infrared laser diode of the laser projector;
controllably and reflectively scanning both the visible light and the infrared light by a scan mirror of the laser projector;
redirecting both the visible light and the infrared light towards the eye of the user by a wavelength-multiplexed HOE, including applying a first positive optical power to the visible light by a first hologram of the wavelength-multiplexed HOE, and applying a second optical power to the infrared light by a second hologram of the wavelength-multiplexed HOE, the second optical power less than the first optical power, to converge the visible light to a first exit pupil with a first diameter and to converge the infrared light to a second exit pupil with a second diameter larger than the first diameter;
detecting a reflection of at least a portion of the infrared light from the eye of the user by an infrared photodetector; and
determining a position of at least one feature of the eye based on the reflection of at least a portion of the infrared light from the eye of the user detected by the infrared photodetector.

2. The method of claim 1 wherein applying a second optical power that is less than the first optical power to the infrared light by the second hologram of the wavelength-multiplexed HOE includes applying a second optical power that is less than or equal to zero to the infrared light by the second hologram of the wavelength-multiplexed HOE.

3. The method of claim 1 wherein determining a position of at least one feature of the eye based on the reflection of the infrared light from the eye of the user detected by the infrared photodetector includes determining the position of at least one feature of the eye based on the reflection of the infrared light from the eye of the user by a processor.

4. The method of claim 1 wherein outputting visible light by at least a first laser diode of the laser projector includes at least one of:
outputting red light by a red laser diode of the laser projector;
outputting green light by a green laser diode of the laser projector; and/or
outputting blue light by a blue laser diode of the laser projector.

Assignees

• Thalmic Labs Inc

Inventors

• Alexander Stefan
• Chapeskie Jake
• Holland Lloyd Frederick
• Mahon Thomas

Classifications

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B27/017

  Head mounted · CPC title

• H04N9/3129

  scanning a light beam on the display screen (scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161) · CPC title

• G02B2027/0174

  holographic · CPC title

• G02B27/0093

  with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking · CPC title