Digital projector for local dimming in a device

Patent metadata

Field	Value
Publication number	US-11422390-B2
Application number	US-202016849859-A
Country	US
Kind code	B2
Filing date	Apr 15, 2020
Priority date	Apr 15, 2020
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A device includes an optical assembly and a digital projector. The optical assembly is configured to receive visible scene light at a backside of the optical assembly and to direct the visible scene light on an optical path toward an eyeward side. The optical assembly includes a dimming layer disposed on the optical path. The dimming layer includes a photochromic material that is configured to darken in response to exposure to a range of light wavelengths. The digital projector is disposed on the eyeward side of the optical assembly and is configured to selectively emit an activation light within the range of light wavelengths to activate a darkening of a region of the dimming layer to dim the visible scene light within the region.

First claim

What is claimed is:

1. A head-mounted device, comprising:
a frame;
a temple arm coupled to the frame;
a digital projector coupled to the temple arm; and
an optical assembly secured within the frame, wherein the optical assembly is configured to receive visible scene light at a backside of the optical assembly and to direct the visible scene light on an optical path toward an eyeward side of the optical assembly, wherein the optical assembly includes:
a dimming layer disposed on the optical path between the eyeward side and the backside, wherein the dimming layer includes a photochromic material that is configured to darken in response to exposure to a range of light wavelengths, and wherein the digital projector is configured to selectively emit an activation light within the range of light wavelengths to activate a darkening of a region of the dimming layer to dim visible scene light within the region.

2. The head-mounted device of claim 1 , wherein the optical assembly further comprises:
a display layer disposed on the optical path between the dimming layer and the eyeward side of the optical assembly, wherein the display layer is configured to direct visible display light toward the eyeward side.

3. The head-mounted device of claim 1 , wherein the activation light comprises non-visible light, ultraviolet light, infrared light, or violet light.

4. The head-mounted device of claim 1 , wherein the optical assembly further comprises:
a backside filter disposed on the optical path between the backside of the optical assembly and the dimming layer, wherein the backside filter is configured to block the range of light wavelengths and to pass the visible scene light.

5. A device, comprising:
a display layer configured to direct visible display light toward an eyeward side of the device to present a virtual graphic, and wherein the display layer is configured to pass visible scene light received at a backside of the device;
a dimming layer disposed between the display layer and the backside, wherein the dimming layer includes a photochromic material that is configured to darken in response to exposure to a range of light wavelengths;
a laser scanner disposed on the eyeward side of the device; and
a computing device configured to control the laser scanner to emit an activation light within the range of light wavelengths to activate a darkening of a region in the dimming layer to dim the visible scene light in response to determining that the visible scene light will interfere with a visibility of the virtual graphic.

6. The device of claim 5 , wherein the computing device is configured to determine that the visible scene light in the region will interfere with the visibility of the virtual graphic by determining a contrast between the visible scene light and the visible display light within the region or by comparing a color of the visible scene light with a color of the visible display light.

7. The device of claim 5 , wherein the computing device is configured to control the laser scanner to vary an amount of the darkening of the region in the dimming layer.

8. The device of claim 5 , wherein the computing device is configured to control the laser scanner to raster scan within the region of the dimming layer to activate the darkening.

9. The device of claim 5 , wherein the computing device is configured to control the laser scanner to direct the activation light to darken a plurality of separate and distinct regions of the dimming layer.

10. A device, comprising:
a display layer configured to direct visible display light toward an eyeward side of the device to present a virtual graphic, and wherein the display layer is configured to pass visible scene light;
a dimming layer including a photochromic material that is configured to darken in response to exposure to a range of light wavelengths; and
a light source; and
a computing device configured to drive the light source to selectively emit an activation light within the range of light wavelengths to activate a darkening of a region in the dimming layer in response to determining that the visible scene light will interfere with a visibility of the virtual graphic, wherein the darkening of the region reduces a brightness of the visible scene light passing through the region.

11. The device of claim 10 , wherein the computing device is configured to determine that the visible scene light in the region will interfere with the visibility of the virtual graphic by determining a contrast between the visible scene light and the visible display light within the region.

12. The device of claim 10 , wherein the computing device is configured to control the light source to vary an amount of the darkening of the region in the dimming layer.

13. The device of claim 10 , wherein the computing device is configured to control the light source to raster scan within the region of the dimming layer to activate the darkening.

14. The device of claim 10 , wherein the computing device is configured to control the light source to direct the activation light to darken a plurality of separate and distinct regions of the dimming layer.

15. The device of claim 10 , wherein the computing device is configured to determine that the visible scene light in the region will interfere with the visibility of the virtual graphic by comparing a color of the visible scene light with a color of the visible display light.

16. The device of claim 10 , wherein the device further comprises:
an eyeward side filter configured to:
pass the activation light to the dimming layer;
block other light within the range of light wavelengths; and
pass the visible scene light.

17. The device of claim 16 , wherein the eyeward side filter is configured to pass the activation light based on an angle of incidence of the activation light upon the eyeward side filter.

18. The device of claim 16 , wherein the eyeward side filter comprises a diffraction grating configured to pass the activation light and to block the other light within the range of light wavelengths.

19. The device of claim 16 , wherein the eyeward side filter comprises a dielectric mirror configured to pass the activation light and to block the other light within the range of light wavelengths.

20. The device of claim 10 , wherein the light source includes a laser.

Assignees

• Meta Platforms Tech Llc

Inventors

• Leibovici Matthieu Charles Raoul
• Sears Jasmine Soria
• Hurni Christophe Antoine
• Matsuda Nathan
• Wei Guohua
• Shi Yu
• Goward John

Classifications

• G02B5/23

  Photochromic filters · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title

• G02B5/30 Primary

  Polarising elements (light-modulating devices with active elements G02F1/00) · CPC title

• G02C7/102 Primary

  Photochromic filters · CPC title

• G02B27/4244

  in wavelength selecting devices (spectrometry G01J) · CPC title