Eye-tracking with MEMS scanning and optical relay

• US 10,394,034 B2
• Filed: 08/15/2017
• Issued: 08/27/2019
• Est. Priority Date: 08/15/2017
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Reshidko, Dmitry, Nguyen, Ian Anh, Wall, Richard Andrew
• Primary Examiner(s): Bolotin, Dmitriy
• Application Number:
  US15/677,999
• Publication Number:
  US 20190056599A1
• Time in Patent Office: 742 Days
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• 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 26/10 Scanning systems
• 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 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0179 Display position adjusting means not related to the information to be displayed
• CPC Class Codes: G02B 27/126 The splitting element being a prism or prismatic array, including systems based on total internal reflection
• CPC Class Codes: G02B 5/04 Prisms
• CPC Class Codes: G05B 2219/35503 Eye tracking associated with head mounted display to detect eye position
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06V 40/19 Sensors therefor
• CPC Class Codes: G06V 40/197 Matching; Classification

Abstract

An eye-tracking system is provided that includes a light source configured to emit at least infrared (IR) light and a microelectromechanical system (MEMS) scanning mirror configured to direct the IR light. The system further includes a relay including at least one prism, and the relay is configured to receive the IR light directed by the MEMS scanning mirror and redirect the IR light. The system further includes a waveguide through which the IR light redirected by the relay passes to reach an eye, and at least one sensor configured to receive the IR light after being reflected by the eye.

Claims

1. An eye-tracking system, comprising:

a light source configured to emit at least infrared (IR) light;

a microelectromechanical system (MEMS) scanning mirror configured to direct the IR light;

a relay including two prisms, each prism having a respective lens, the relay configured to receive the IR light directed by the MEMS scanning mirror and redirect the IR light; and

at least one sensor configured to receive the IR light after being reflected by an eye.

2. The eye-tracking system of claim 1, wherein one of the prisms of the relay is positioned to direct the IR light obliquely toward the eye through a plate.

3. The eye-tracking system of claim 1, wherein the relay is coupled to a waveguide such that the IR light follows an IR light path that exits the relay, enters the waveguide, propagates within the waveguide, and exits the waveguide via an outcoupling element before reaching the eye.

4. The eye-tracking system of claim 1, further comprising a waveguide through which the IR light redirected by the relay passes to reach the eye, wherein:

the light source is further configured to emit visible light;

the MEMS scanning mirror is further configured to direct the visible light; and

the waveguide is configured to propagate the visible light to be displayed by a diffractive optical element.

5. The eye-tracking system of claim 1, included in a head-mounted display device.

6. The eye-tracking system of claim 1, wherein the at least one sensor is a plurality of single-pixel photodiodes.

7. An eye-tracking system, comprising:

a light source configured to emit at least infrared (IR) light;

a microelectromechanical system (MEMS) scanning mirror configured to direct the IR light;

a relay including two prisms that are beam splitters, the relay configured to receive the IR light directed by the MEMS scanning mirror and redirect the IR light; and

at least one sensor configured to receive the IR light after being reflected by an eye.

8. The eye-tracking system of claim 7, further comprising a waveguide through which the IR light redirected by the relay passes to reach the eye, wherein:

the light source is further configured to emit visible light;

the MEMS scanning mirror is further configured to direct the visible light; and

the waveguide is configured to propagate the visible light to be displayed by a diffractive optical element.

9. An eye-tracking system, comprising:

a light source configured to emit at least infrared (IR) light;

a microelectromechanical system (MEMS) scanning mirror configured to direct the IR light;

a relay including two prisms connected by a gradient index rod, the relay configured to receive the IR light directed by the MEMS scanning mirror and redirect the IR light; and

at least one sensor configured to receive the IR light after being reflected by an eye.

10. The eye-tracking system of claim 9, further comprising a waveguide through which the IR light redirected by the relay passes to reach the eye, wherein:

the light source is further configured to emit visible light;

the MEMS scanning mirror is further configured to direct the visible light; and

the waveguide is configured to propagate the visible light to be displayed by a diffractive optical element.

11. An eye-tracking system, comprising:

a light source configured to emit at least infrared (IR) light;

a microelectromechanical system (MEMS) scanning mirror configured to direct the IR light;

a relay including two prisms connected by a fiber bundle, the relay configured to receive the IR light directed by the MEMS scanning mirror and redirect the IR light; and

at least one sensor configured to receive the IR light after being reflected by an eye.

12. The eye-tracking system of claim 11, further comprising a waveguide through which the IR light redirected by the relay passes to reach the eye, wherein:

the light source is further configured to emit visible light;

the MEMS scanning mirror is further configured to direct the visible light; and

the waveguide is configured to propagate the visible light to be displayed by a diffractive optical element.

13. A method of sensing an eye with an eye-tracking system, the method comprising:

emitting at least infrared (IR) light with a light source;

directing the IR light with a microelectromechanical system (MEMS) scanning mirror;

redirecting the IR light with a relay including two prisms, each prism having a respective lens;

reflecting the IR light on the eye; and

receiving the IR light reflected by the eye with at least one sensor.

14. The method of claim 13, wherein the two prisms are beam splitters.

15. The method of claim 13, wherein the two prisms are connected by a gradient index rod.

16. The method of claim 13, wherein the two prisms are connected by a fiber bundle.

17. The method of claim 13, further comprising positioning one of the prisms of the relay to direct the IR light obliquely toward the eye through a plate.

18. The method of claim 13, further comprising coupling the relay to a waveguide such that the IR light exits the relay, enters the waveguide, propagates within the waveguide, and exits the waveguide via an outcoupling element before reaching the eye.

19. The method of claim 13, wherein the at least one sensor is a plurality of single-pixel photodiodes.