Device for regulating the passage of energy

Patent metadata

Field	Value
Publication number	US-9535271-B2
Application number	US-201214368829-A
Country	US
Kind code	B2
Filing date	Nov 29, 2012
Priority date	Dec 27, 2011
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

The present invention relates to a device for regulating the passage of energy through a light-transmitting area, comprising a first polarization layer, a second polarization layer and a switching layer which is arranged between the two polarization layers and changes the polarization properties of polarized light as a function of temperature, where the two polarization layers are characterized by a suitable choice of their transmission in the transmission direction and their degree of polarization. The invention furthermore relates to a process for the production of the device according to the invention and to the use of the device for influencing light transmission and/or the passage of energy into an interior as a function of temperature.

First claim

The invention claimed is:

1. Device for regulating the passage of energy through a light-transmitting area, where the device comprises the following layers:
a first polarisation layer,
a second polarisation layer, and
a switching layer, arranged between the two polarisation layers, which changes the polarisation properties of polarised light as a function of temperature,
where the two polarisation layers have, identically or differently, a degree of polarisation P in the range 20-85% and a transmission in the transmission direction T1 in the range 70-100%, determined at a wavelength of 550 nm, and
where one or both of the polarisation layers are formed from a layer comprising a liquid-crystalline medium and one or more dichroic dyes, with the one or more dichroic dyes present in an amount of 0.01 to 5% by weight of said liquid crystalline medium.

2. Device according to claim 1 , wherein the passage of energy takes place into an interior which is selected from interiors of a building, a vehicle or a transport container.

3. Device according to claim 1 , which switches from a switching state having relatively high light transmission to a switching state having relatively low light transmission as a function of temperature.

4. Device according to claim 3 wherein the switching from the switching state having relatively high light transmission to the switching state having relatively low light transmission takes place gradually in a temperature range from 0° C. to 80° C.

5. Device according to claim 1 , wherein the two polarisation layers have, identically or differently, a degree of polarisation P in the range 30%-85% and a transmission in the transmission direction T1 in the range 75%-100%, determined at a wavelength of 550 nm.

6. Device according to claim 1 , wherein the two polarisation layers are linear polarisers whose planes of polarisation are rotated by an angle of 70° to 110° with respect to one another.

7. Device according to claim 1 , wherein both of the polarisation layers are formed from a layer comprising a liquid-crystalline medium and one or more dichroic dyes.

8. Device according to claim 1 , wherein one or both of the polarisation layers are formed from a layer comprising an aligned polymer.

9. Device according to claim 1 , wherein the switching layer comprises a liquid-crystalline medium which changes from a nematic state to an isotropic state during the switching operation with increasing temperature.

10. Device according to claim 1 , wherein the switching layer in the optically anisotropic state rotates the plane of polarisation of linear-polarised light by an angle of 10° or more, and in the isotropic state does not rotate the plane of polarisation of linear-polarised light or only does so to a negligible extent.

11. Device according to claim 1 , which additionally comprises a substrate layer, which is formed from glass, a polymer or ITO.

12. A method which comprises operating a device according to claim 1 for influencing the passage of energy through a light-transmitting area as a function of temperature.

13. A method according to claim 12 , wherein the device switches from a state having relatively high light transmission to a state having relatively low light transmission without application of electrical voltage.

Assignees

• Merck Patent Gmbh

Inventors

• Junge Michael
• Beyer Andreas

Classifications

• G02F1/133528

  Polarisers · CPC title

• G02F1/0136

  for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation (G02F1/0353 takes precedence) · CPC title

• C09K2219/13

  used in the technical field of thermotropic switches · CPC title

• G02F1/0147 Primary

  based on thermo-optic effects (G02F1/132 takes precedence) · CPC title

• G02F1/132

  Thermal activation of liquid crystals exhibiting a thermo-optic effect · CPC title