Variable Transmission Window

• US 20120169950A1
• Filed: 12/29/2011
• Published: 07/05/2012
• Est. Priority Date: 12/30/2010
• Status: Active Grant

• Current Assignee: VG Smartglass, LLC
• Original Assignee: Smartershade, Inc.
• Inventors: Tatzel, Ryan, McLeod, William
• Granted Patent: US 8,508,681 B2
• Time in Patent Office: Days
• US Class Current: 349/18
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: G02B 27/281 used for attenuating light intensity, e.g. comprising rotatable polarising elements
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133631 with a spatial distribution of the retardation value

Abstract

The various embodiments include variable optical transmission devices with uniform or patterned polarizers or wave retarders configured to provide continuous or nearly continuous variations in light transmission based on linear translation. For example, embodiments include a variable transmission window including a first uniform polarizer with a first polarization axis, a second uniform polarizer with a second polarization axis, a first patterned wave retarder positioned between the first and second polarizers and including a first plurality of domains configured to vary in at least one of optic axis, thickness, or birefringence, and a second patterned wave retarder positioned between the first and second polarizers and including a second plurality of domains configured to vary in at least one of optic axis, thickness, or birefringence. The first or second wave retarder is configured to be linearly translatable relative to the other wave retarder.

Claims

1. A variable transmission device, comprising:

a first uniform polarizer with a first polarization axis;

a second uniform polarizer with a second polarization axis;

a first patterned wave retarder positioned between the first and second polarizers and comprising a first plurality of domains configured to vary in at least one of optic axis, thickness, or birefringence; and

a second patterned wave retarder positioned between the first and second polarizers and comprising a second plurality of domains configured to vary in at least one of optic axis, thickness, or birefringence,

wherein the first or second wave retarder is configured to be linearly translatable relative to the other one of the first or second wave retarder.

2. The variable transmission device of claim 1, wherein the first and second plurality of domains are configured to vary in optic axis.

3. The variable transmission device of claim 2, wherein the first and second wave retarders comprise patterned liquid crystal polymer.

4. The variable transmission device of claim 2, wherein the first and second wave retarders comprise stretched polymer films.

5. The variable transmission device of claim 2, wherein the first and second wave retarders comprise printed self-assembling liquid crystals.

6. The variable transmission device of claim 1, wherein the first and second plurality of domains comprise half-wave plates or quarter-wave plates.

7. The variable transmission device of claim 1, wherein the first and second wave retarders comprise patterned liquid crystal polymer or molded liquid crystal polymer configured to vary in thickness.

8. The variable transmission device of claim 1, wherein the first and second plurality of domains

are configured to vary in retardance.

9. The variable transmission device of claim 1, wherein the first and second wave retarders comprise thermally treated liquid crystal polymer, helical liquid crystal polymer, twisted liquid crystal polymer, or cholesteric liquid crystals.

10. The variable transmission device of claim 1, wherein the first polarization axis and second polarization axis are parallel.

11. The variable transmission device of claim 1, wherein the first polarization axis and second polarization axis are not parallel.

12. The variable transmission device of claim 1, wherein the first and second polarizers are one of iodine doped polarizers, wire grid polarizers, coatable polarizers, or reflective polarizers.

13. The variable transmission device of claim 1, wherein the first patterned wave retarder is connected to the first uniform polarizer in a first panel and the second patterned wave retarder is configured to linearly translate with respect to the first patterned wave retarder.

14. The variable transmission device of claim 1, wherein the first patterned wave retarder is connected to the first uniform polarizer in a first panel, the second patterned wave retarder is connected to the second uniform polarizer in a second panel, and the first panel is configured to linearly translate with respect to the second panel.

15. The variable transmission device of claim 1, wherein the first patterned wave retarder is connected to a rotating support.

16. The variable transmission device of claim 1, wherein the device is located between first and second window plates set into a wall.

19. A method of operating the device of claim 1, the method comprising:

moving the first patterned wave retarder with respect to the second patterned wave retarder such that less light is transmitted through the variable optical transmission device; and

moving the first patterned wave retarder with respect to the second patterned wave retarder such that more light is transmitted through the variable optical transmission device.

17. A variable transmission device, comprising:

a first polarizer; and

a second polarizer;

a first patterned wave retarder positioned between the first and second polarizers and comprising a first plurality of domains configured to vary in orientation of optic axis; and

a second patterned wave retarder positioned between the first and second polarizers and comprising a second plurality of domains configured to vary in orientation of optic axis,

wherein the first or second wave retarder is configured to be linearly translatable relative to the other one of the first or second wave retarder.

18. The variable transmission device of claim 17, wherein:

the first polarizer is a uniform linear with a first polarization axis;

the second polarizer is a uniform linear with a second polarization axis;

the first polarization axis and the second polarization axis are not parallel; and

the device is located between first and second window plates set into a wall.

20. A method of making a patterned wave retarder for a variable transmission window, comprising:

providing a substrate containing an alignment layer;

exposing the alignment layer to radiation to generate a patterned alignment layer;

depositing a liquid crystal polymer layer on the patterned alignment layer; and

polymerizing the liquid crystal polymer layer such that the liquid crystal polymer layer adopts a pattern of the patterned alignment layer to form the patterned wave retarder with a variable optic axis.