Wearable heads-up display with integrated eye tracker and different optical power holograms

• US 10,078,219 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:
  US15/167,458
• Publication Number:
  US 20160349514A1
• 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. 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.

Claims

1. A wearable heads-up display (“

WHUD”

) with an integrated eye tracker, comprising;

a laser module including an infrared laser diode to output an infrared light and at least one visible light laser diode to output a visible light;

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

a wavelength-multiplexed holographic optical element (“

HOE”

) aligned to receive both the infrared light and the visible light reflected from the scan mirror and to redirect both the infrared light and the visible light towards an eye of a user, wherein the wavelength-multiplexed HOE includes a first hologram that is responsive to the visible light and unresponsive to the infrared light and a second hologram that is responsive to the infrared light and unresponsive to the visible light, the first hologram to apply a first optical power to the visible light and the second hologram to apply a second optical power to the infrared light, and wherein the first optical power is a positive optical power that is greater than the second optical power and wherein the first hologram is oriented to converge the visible light to a first exit pupil having a first diameter at the eye of the user and the second hologram is oriented to redirect the infrared light to a second exit pupil having a second diameter at the eye of the user, the second diameter larger than the first diameter; and

an infrared detector aligned to receive at least a portion of infrared light reflected from the eye of the user.

2. The WHUD of claim 1 wherein the wavelength-multiplexed HOE comprises at least two distinct layers of holographic material, a first layer of holographic material that includes the first hologram and a second layer of holographic material that includes the second hologram.

3. The WHUD of claim 1 wherein the wavelength-multiplexed HOE comprises a single volume of holographic material that includes both the first hologram and the second hologram.

4. The WHUD of claim 1 wherein the at least one visible light laser diode in the laser module includes at least one visible light laser diode selected from the group consisting of:

a red laser diode, a green laser diode, a blue laser diode, and any combination of a red laser diode, a green laser diode, and/or a blue laser diode.

5. The WHUD of claim 1 wherein the second optical power is less than or equal to zero.

6. The WHUD of claim 1, wherein the infrared detector is aligned to directly receive the at least a portion of infrared light reflected from the eye of the user.

7. The WHUD of claim 1 wherein the second exit pupil encompasses the first exit pupil at the eye of the user.

8. The WHUD of claim 1 wherein:

the at least one visible light laser diode includes a red laser diode, a green laser diode, and a blue laser diode, the first hologram is responsive to red light output by the red laser diode;

the wavelength-multiplexed HOE further includes a third hologram that is responsive to green light output by the green laser diode and a fourth hologram that is responsive to blue light output by the blue laser diode;

the first hologram is oriented to converge the red light to the first exit pupil having the first diameter at the eye of the user;

the third hologram is oriented to converge the green light to the first exit pupil having the first diameter at the eye of the user; and

the fourth first hologram is oriented to converge the blue light to the first exit pupil having the first diameter at the eye of the user.

9. The WHUD 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, and the infrared detector 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 at least one eye of the user when the support frame is worn on a head of the user.

10. The WHUD of claim 9, wherein the infrared photodetector is carried on a part of the support frame at a perimeter of the wavelength-multiplexed HOE.