Wearable heads-up display with integrated eye tracker

• US 10,078,220 B2
• Filed: 05/27/2016
• Issued: 09/18/2018
• Est. Priority Date: 05/28/2015
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Thalmic Labs Inc. (Alphabet Inc.)
• Inventors: Alexander, Stefan, Chapeskie, Jake, Holland, Lloyd Frederick, Mahon, Thomas
• Primary Examiner(s): Ritchie, Darlene M
• Application Number:
  US15/167,472
• Publication Number:
  US 20160349515A1
• Time in Patent Office: 844 Days
• CPC Class Codes: G02B 2027/0107 with optical power
• CPC Class Codes: G02B 2027/0109 comprising details concerning the making of holograms
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 27/0103 comprising holographic elements
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: H04N 9/3129 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 Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

Systems, devices, and methods that integrate eye tracking capability into scanning laser projector (“SLP”)-based wearable heads-up displays are described. At least one narrow waveband laser diode is used in an SLP to define one or more portion(s) of a visible image. At least one corresponding narrow waveband photodetector is aligned to detect reflections of the portion(s) of the image from features of the eye. A holographic optical element (“HOE”) may be used to combine the image and environmental light into the user'"'"'s “field of view.” Three narrow waveband photodetectors each responsive to a respective one of three narrow wavebands output by the RGB laser diodes of an RGB SLP are aligned to detect reflections of a projected RGB image from features of the eye.

Claims

1. A wearable heads-up display with an integrated eye tracker, comprising:

a laser module to provide a laser light output, wherein the laser module comprises a red laser diode to contribute a red laser light to the laser light output, a green laser diode to contribute a green laser light to the laser light output, and a blue laser diode to contribute a blue laser light to the laser light output, and wherein each laser light output provided by the laser module is representative of a respective portion of a displayed image;

a scan mirror aligned with an output of the laser module to receive the laser light output by the laser module and to controllably reflect the laser light output by the laser module;

a wavelength-multiplexed holographical optical element (“

HOE”

) aligned to receive the laser light reflected from the scan mirror and to redirect the laser light towards an eye of a user, wherein the wavelength-multiplexed HOE includes a red hologram that is responsive to red laser light from the red laser diode and unresponsive to both green laser light from the green laser diode and blue laser light from the blue laser diode, a green hologram that is responsive to green laser light from the green laser diode and unresponsive to both red laser light from the red laser diode and blue laser light from the blue laser diode, and a blue hologram that is responsive to blue laser light from the blue laser diode and unresponsive to both red laser light from the red laser diode and green laser light from the green laser diode;

a red photodetector aligned to receive at least a portion of the red laser light reflected from the eye of the user, wherein the red photodetector is responsive to the red laser light from the red laser diode and unresponsive to both the green laser light from the green laser diode and the blue laser light from the blue laser diode;

a green photodetector aligned to receive at least a portion of the green laser light reflected from the eye of the user, wherein the green photodetector is responsive to the green laser light from the green laser diode and unresponsive to both the red laser light from the red laser diode and the blue laser light from the blue laser diode; and

a blue photodetector aligned to receive at least a portion of the blue laser light reflected from the eye of the user, wherein the blue photodetector is responsive to the blue laser light from the blue laser diode and unresponsive to both the red laser light from the red laser diode and the green laser light from the green laser diode.

2. The wearable heads-up display of claim 1 wherein the HOE comprises at least three distinct layers of holographic material, and wherein a first layer of holographic material includes the red hologram, a second layer of holographic material includes the green hologram, and a third layer of holographic material includes the blue hologram.

3. The wearable heads-up display of claim 1 wherein the HOE comprises a single volume of holographic material that includes all three of the red hologram, the green hologram, and the blue hologram.

4. The wearable heads-up display of claim 1 wherein each laser light output provided by the laser module is representative of a respective portion of a same displayed image.

5. The wearable heads-up display of claim 1 wherein the red laser light contributed by the red laser diode is representative of a red portion of the displayed image, the green laser light contributed by the green laser diode is representative of a green portion of the displayed image, and the blue laser light contributed by the blue laser diode is representative of a blue portion of the displayed image.

6. The wearable heads-up display of claim 1, further comprising:

a support frame that has a general shape and appearance of a pair of eyeglasses, wherein the laser module, the scan mirror, the wavelength-multiplexed HOE, the red photodetector, the green photodetector, and the blue photodetector are all carried by the support frame, and wherein the wavelength-multiplexed HOE is substantially transparent to environmental light and positioned in a field of view of the eye of the user when the support frame is worn on a head of the user.

7. The wearable heads-up display of claim 6, wherein the red photodetector, the green photodetector, and the blue photodetector are all carried on a front part of the support frame at a perimeter of the wavelength-multiplexed HOE.

8. The wearable heads-up display of claim 1, wherein each of the holograms is oriented to apply an optical power to the laser light to which the hologram is responsive, and wherein the optical powers applied by the three holograms are the same.

9. The wearable heads-up display of claim 8 wherein each of the holograms is oriented to converge laser light to which the hologram is responsive to a same exit pupil at the eye of the user.

10. The wearable heads-up display of claim 1 wherein the red hologram is oriented to converge red laser light from the red laser diode to a first exit pupil at the eye of the user, the green hologram is oriented to converge green laser light from the green laser diode to the first exit pupil at the eye of the user, and the blue hologram is oriented to converge blue laser light from the blue laser diode to the first exit pupil at the eye of the user.

11. The wearable heads-up display of claim 10 wherein each laser light output provided by the laser module is representative of a respective portion of the displayed image in the first exit pupil at the eye of the user.