Electronic Devices Having Transparent Crystalline Structures With Antireflection Coatings

Patent metadata

Field	Value
Publication number	US-2018024274-A1
Application number	US-201715617706-A
Country	US
Kind code	A1
Filing date	Jun 8, 2017
Priority date	Jul 25, 2016
Publication date	Jan 25, 2018
Grant date	—

Abstract

A graded index antireflection layer may be formed on a transparent crystalline member such as a sapphire member. The graded index layer may include aluminum oxide and silicon oxide. The graded index layer may extend from a first surface at the transparent member to a second surface. The fraction of aluminum oxide in the graded index layer may be at a maximum at the first surface so that the index of refraction of the graded index layer at the first surface matches the index of refraction of the transparent member and may be at a minimum at the second surface so the index of refraction of the graded index layer is minimized at the second surface. The graded index layer may be annealed to form aluminum oxide nanocrystals in the graded index layer and to form a polycrystalline aluminum oxide adhesion layer at the first surface.

First claim

What is claimed is:

1 . An electronic device, comprising:
a housing; a component in the housing; a transparent crystalline member that overlaps the component, wherein the transparent crystalline member has a first index of refraction; and a graded index antireflection layer on the transparent crystalline member, wherein the graded index antireflection layer has an index of refraction that varies from the first index of refraction at the transparent crystalline outer layer to a second index of refraction that is less than the first index of refraction at an outer surface of the graded index antireflection layer and wherein the graded index antireflection layer includes nanocrystals.

2 . The electronic device defined in claim 1 wherein the nanocrystals comprise aluminum oxide nanocrystals.

3 . The electronic device defined in claim 2 wherein the nanocrystals have diameters of less than 10 nm.

4 . The electronic device defined in claim 2 wherein the graded index antireflection layer comprises a polycrystalline aluminum oxide layer that serves as an adhesion layer for the graded index layer.

5 . The electronic device defined in claim 1 further comprising a layer of plasmonic metal nanoparticles on the graded index antireflection layer.

6 . The electronic device defined in claim 1 further comprising color- adjusting dopant in the graded index antireflection layer.

7 . The electronic device defined in claim 1 wherein the component comprises a camera, wherein the transparent crystalline member comprises a camera window, wherein the transparent crystalline member comprises aluminum oxide, and wherein the graded index antireflection layer has a polycrystalline layer at an interface between the graded index antireflection layer and the transparent crystalline member.

8 . The electronic device defined in claim 1 wherein the component comprises:
a display, wherein the transparent crystalline member comprises a transparent display cover layer that overlaps the display; and
an oleophobic coating on the graded index antireflection layer.

9 . The electronic device defined in claim 8 wherein the graded index antireflection layer has a polycrystalline layer at an interface between the graded index antireflection layer and the transparent crystalline member.

10 . The electronic device defined in claim 9 wherein the oleophobic layer comprises a polymer layer.

11 . The electronic device defined in claim 10 wherein the polymer layer comprises a fluoropolymer layer.

12 . The electronic device defined in claim 11 wherein the transparent crystalline member comprises a sapphire layer.

13 . Apparatus, comprising:
a transparent sapphire member having an index of refraction; an oleophobic coating; and a graded index layer on the transparent sapphire member, wherein the graded index layer extends between the transparent sapphire member and the oleophobic coating, wherein the graded index layer has a first index of refraction at the transparent sapphire member that matches the index of refraction of the transparent sapphire member and has a second index of refraction at the oleophobic coating that is less than the index of refraction of the transparent sapphire member, and wherein the graded index layer has a polycrystalline layer at the transparent sapphire member.

14 . The apparatus defined in claim 13 further comprising aluminum oxide crystal particles in the graded index layer.

15 . The apparatus defined in claim 14 wherein the graded index layer comprises aluminum oxide and silicon oxide.

16 . The apparatus defined in claim 15 wherein the graded index layer has more of the aluminum oxide than the silicon oxide at the transparent sapphire member and has more of the silicon oxide than the aluminum oxide at the oleophobic coating and wherein the oleophobic coating comprises a fluoropolymer.

17 . The apparatus defined in claim 16 further comprising:
an electronic device housing; and
a display in the electronic device housing, wherein the transparent sapphire member covers the display.

18 . The apparatus defined in claim 16 further comprising:
a camera; and
an electronic device housing, wherein the transparent sapphire layer is mounted in the electronic device housing overlapping the camera and serves as a camera window for the camera.

19 . A method, comprising:
depositing a graded index layer of aluminum oxide and silicon oxide on a sapphire member; and annealing the deposited graded index layer to form nanocrystals of aluminum oxide in the graded index layer.

20 . The method defined in claim 19 wherein annealing the deposited graded index layer comprises heating the deposited graded index layer to a temperature of greater than 1100° C. to form a polycrystalline layer of aluminum oxide in the graded index layer at an interface between the graded index layer and the sapphire member.

Assignees

• Apple Inc

Inventors

• Rogers Matthew S
• Matsuyuki Naoto
• Nguyen Que Anh S

Classifications

• G02B1/02

  made of crystals, e.g. rock-salt, semi-conductors (G02B1/08 takes precedence) · CPC title

• G02B1/113 Primary

  using inorganic layer materials only · CPC title

• G02B3/0087

  with index gradient · CPC title

• G02B1/11 Primary

  Anti-reflection coatings · CPC title