Electronic device with light diffuser

Patent metadata

Field	Value
Publication number	US-10334184-B2
Application number	US-201615268116-A
Country	US
Kind code	B2
Filing date	Sep 16, 2016
Priority date	Sep 16, 2016
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

An electronic device may have an optical system that includes one or more light-based components. The light-based components may include light-emitting components such as light-emitting diodes or lasers and may include light-detecting components such as photodiodes or digital image sensors. The optical system may include a light diffuser. The light diffuser may diffuse light that is being detected by a light-detecting component or may diffuse light that is being emitted by a light-emitting component. Light diffusers in optical systems may be formed from patterned light diffuser layers on transparent substrates. Layers of sealant, thin glass layers, antireflection coatings, and other layers may be incorporated into the light diffusers. The light diffuser layers may operate at visible wavelengths and infrared wavelengths. An infrared light diffuser layer may be formed from a patterned silicon layer such as a patterned layer of hydrogenated amorphous silicon.

First claim

What is claimed is:

1. An optical system through which infrared light passes, comprising:
a cover layer configured to transmit the infrared light;
a substrate layer that is transparent to the infrared light; and
a patterned amorphous silicon light diffusing layer on the substrate layer that is configured to receive the infrared light from the substrate layer and to transmit and diffuse the infrared light through the cover layer.

2. The optical system defined in claim 1 further comprising a sealant layer on the patterned amorphous silicon light diffusing layer.

3. The optical system defined in claim 2 wherein the sealant layer has an index of refraction that is at least 1.0 lower than the index of refraction of the patterned light diffusing layer.

4. The optical system defined in claim 3 further comprising an antireflection coating on the sealant layer.

5. The optical system defined in claim 3 further comprising a glass layer, wherein the sealant layer is interposed between the patterned amorphous silicon light diffuser layer and the glass layer.

6. The optical system defined in claim 5 wherein the glass layer has a thickness of at least 0.05 mm, the infrared light diffuser further comprising an adhesive layer between the glass layer and the sealant layer.

7. The optical system defined in claim 6 further comprising an antireflection coating on the glass layer.

8. The optical system defined in claim 1 wherein the patterned amorphous silicon light diffusing layer comprises one of a pair of patterned amorphous silicon light diffusing layers on opposing first and second surfaces of the substrate layer.

9. The optical system defined in claim 1 wherein the patterned amorphous silicon light diffusing layer has light diffusing elements in an irregular pattern on the substrate layer, wherein the light-diffusing elements have lateral dimensions of 10-50 microns and have a thickness of less than 10 microns.

10. The optical system defined in claim 1 wherein the patterned amorphous silicon light diffusing layer is a patterned layer of hydrogenated amorphous silicon.

11. An electronic device comprising:
a light emitter configured to emit near infrared light;
a substrate that is transparent to the near infrared light from the light emitter;
a silicon layer on the substrate that is configured to pass and diffuse the near infrared light from the light emitter; and
a display having a pixel array and a display cover layer overlapping the pixel array, wherein the display cover layer has a window region configured to pass the diffused near infrared light.

12. The electronic device defined in claim 11 wherein the light emitter comprises an array of light emitting devices.

13. An electronic device, comprising:
a light-emitting component configured to emit infrared light; and
a light diffuser covering the light-emitting component, wherein the light diffuser has a substrate and has a light diffusing silicon layer on the substrate that is configured to transmit and diffuse the emitted infrared light, wherein the light diffusing silicon layer has a planar surface at the substrate and a patterned surface opposite the planar surface, and wherein the patterned surface comprises a pattern of non-planar light scattering elements.

14. The electronic device defined in claim 13 wherein the light diffusing silicon layer comprises amorphous silicon.

15. The electronic device defined in claim 13 wherein the light-emitting component comprises at least one light-emitting device that emits light at 940 nm.

16. The electronic device defined in claim 13 wherein the light-emitting component comprises an array of vertical-cavity surface-emitting lasers.

17. The electronic device defined in claim 16 wherein the array of vertical-cavity surface-emitting lasers is configured to emit light at 940 nm.

18. The electronic device defined in claim 17 further comprising:
an infrared camera; and
a display having a display cover layer, wherein at least some of the emitted light at 940 nm is captured by the infrared camera after reflecting from an external object and passing through a portion of the display cover layer.

19. The electronic device defined in claim 13 wherein the light diffuser further comprises a sealant layer on the light diffusing silicon layer and wherein the sealant layer has an index of refraction that is at least 1.5 lower than the light diffusing silicon layer.

20. The electronic device defined in claim 19 further comprising an antireflection coating on the sealant layer.

21. An optical system through which infrared light passes, comprising:
a cover layer configured to transmit the infrared light;
a substrate layer that is transparent to the infrared light; and
a patterned amorphous silicon light diffusing layer on the substrate layer that is configured to receive the infrared light from the cover layer and to transmit and diffuse the infrared light through the substrate.

Assignees

• Apple Inc

Inventors

• Wang Ligang
• Scepanovic Miodrag
• Mackinnon Neil
• Ge Zhenbin

Classifications

• G02B5/0294 Primary

  adapted to provide an additional optical effect, e.g. anti-reflection or filter · CPC title

• G02B5/0231

  the surface having microprismatic or micropyramidal shape (macroscopic prism arrays G02B5/045) · CPC title

• H04N5/33 Primary

  Transforming infrared radiation (cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20) · CPC title

• H04N23/20

  for generating image signals from infrared radiation only · CPC title