Methods and apparatuses for casting optical polymer films

Patent metadata

Field	Value
Publication number	US-11679533-B2
Application number	US-202117200239-A
Country	US
Kind code	B2
Filing date	Mar 12, 2021
Priority date	Mar 12, 2020
Publication date	Jun 20, 2023
Grant date	Jun 20, 2023

Abstract

In an example method of forming an optical film for an eyepiece, a curable material is dispensed into a space between a first and a second mold surface. A position of the first mold surface relative to the second mold surface is measured using a plurality of sensors. Each sensor measures a respective relative distance along a respective measurement axis between a respective point on a planar portion of the first mold surface and a respective point on a planar portion of the second mold surface. The measurement axes are parallel to each other, and the points define corresponding triangles on the first and second mold surfaces, respectively. The position of the first mold surface is adjusted relative to the second mold surface based on the measured position, and the curable material is cured to form the optical film.

First claim

What is claimed is:

1. A method of forming an optical film for an eyepiece, the method comprising:
dispensing a curable material into a space between a first mold surface and a second mold surface opposite the first mold surface;
measuring, using a plurality of sensors, a position of the first mold surface relative to the second mold surface, wherein measuring the position of the first mold surface relative to the second mold surface comprises:
determining a first relative distance along a first measurement axis between a first point on a planar portion of the first mold surface and a first point on a planar portion of the second mold surface using a first of the sensors;
determining a second relative distance along a second measurement axis between a second point on the planar portion of the first mold surface and a second point on the planar portion of the second mold surface using a second of the sensors; and
determining a third relative distance along a third measurement axis between a third point on the planar portion of the first mold surface and a third point on the planar portion of the second mold surface using a third of the sensors,
wherein the first, second, and third measurement axes are parallel to each other, the first, second, and third points define corresponding triangles on the first and second mold surfaces, respectively, and the space between the first and second mold surfaces is located within the triangles;
determining, based on the first relative distance along a first measurement axis, the second relative distance along a second measurement axis, and the third relative distance along a third measurement axis:
coordinates (x1,y1,z1) of the first point on the planar portion of the first mold surface or the first point on the planar portion of the second mold surface with respect to a Cartesian coordinate system,
coordinates (x2,y2,z2) of the second point on the planar portion of the first mold surface or the second point on the planar portion of the second mold surface with respect to the Cartesian coordinate system,
coordinates (x3,y3,z3) of the third point on the planar portion of the first mold surface or the third point on the planar portion of the second mold surface with respect to the Cartesian coordinate system, and

wherein the one or more adjustments are determined according to a relationship

[

y
⁢
1

-
x

⁢
1

1

y
⁢
2

-
x

⁢
2

1

y
⁢
3

-
x

⁢
3

1

]

[

R
⁢
x

R
⁢
y

Z

]

=

[

z
⁢
1

z
⁢
2

z
⁢
3

]

,

wherein Z corresponds to the translation of at least one of the first mold surface or the second mold surface along an axis of translation,
wherein Rx corresponds to the rotation of at least one of the first mold surface or the second mold surface about a first axis of rotation, and
wherein Ry corresponds to the rotation of at least one of the first mold surface or the second mold surface about a second axis of rotation;

adjusting the position of the first mold surface relative to the second mold surface based on the measured position; and
curing the curable material in the space to form the optical film.

2. The method of claim 1 , wherein the position of the first mold surface relative to the second mold surface is measured prior to curing the curable material.

3. The method of claim 1 , wherein the position of the first mold surface relative to the second mold surface is measured concurrently with curing the curable material.

4. The method of claim 1 , wherein the position of the first mold surface relative to the second mold surface is measured continuously over time, and
wherein the position of the first mold surface relative to the second mold surface is adjusted continuously over time.

5. The method of claim 1 , wherein the position of the first mold surface relative to the second mold surface is adjusted prior to curing the curable material.

6. The method of claim 1 , wherein the position of the first mold surface relative to the second mold surface is adjusted concurrently with curing the curable material.

7. The method of claim 1 , wherein adjusting the position of the first mold surface relative to the second mold surface comprise

Assignees

• Magic Leap Inc

Inventors

• Sevier Jeremy Lee
• Shafran Matthew S
• Sadam Satish
• Patterson Roy Matthew
• Wang Kangkang
• Chang Chieh
• Carden Charles Scott

Classifications

• B29C39/10

  incorporating preformed parts or layers, e.g. casting around inserts or for coating articles {(coating a surface by casting in general B05D1/30, B29C39/126 takes precedence)} · CPC title

• B29C71/04

  by wave energy or particle radiation {, e.g. for curing or vulcanising preformed articles (during moulding, e.g. in a mould B29C35/08)} · CPC title

• B29L2011/0066

  Optical filters · CPC title

• B29C39/44 Primary

  Measuring, controlling or regulating · CPC title

• B29C35/0888 Primary

  using transparant moulds · CPC title