Layer arrangement for the regulation of light transmission

Patent metadata

Field	Value
Publication number	US-9239476-B2
Application number	US-201213982378-A
Country	US
Kind code	B2
Filing date	Jan 4, 2012
Priority date	Jan 28, 2011
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

The present invention relates to a layer arrangement which changes the transmission of light depending on its temperature, where the layer arrangement has a first polarization layer, a switching layer which influences the polarization properties of light depending on the temperature, and a second polarization layer, as well as an additional NIR transmission-preventing layer.

First claim

The invention claimed is:

1. Layer arrangement which changes the transmission of incident light depending on its temperature, where the layer arrangement comprises a first polarisation layer ( 3 a ), a switching layer ( 2 ) which influences the polarisation properties of light depending on the temperature, a second polarisation layer ( 3 b ), at least one NIR transmission-preventing layer ( 4 ) and a glass sheet or acrylic glass sheet as substrate layer ( 5 ), wherein the layers are arranged in the order of the first polarisation layer ( 3 a ), the switching layer ( 2 ), the second polarisation layer ( 3 b ), the at least one NIR transmission-preventing layer ( 4 ) and then the substrate layer ( 5 ) and wherein the switching layer comprises a liquid-crystalline medium which forms a nematic phase in a first temperature range and forms an isotropic phase in a second temperature range.

2. Layer arrangement according to claim 1 , wherein the switching layer of the layer arrangement is a twisted nematic liquid-crystalline layer.

3. Layer arrangement according to claim 1 , wherein the reduction in the transmission in the transparent state by the layer arrangement in the NIR region is greater by a factor of more than 2 than the reduction in the transmission in the VIS region.

4. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) comprises at least one layer comprising a cholesteric liquid-crystal material.

5. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) comprises at least one layer comprising a ceramic material.

6. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) comprises at least one layer comprising a metallic material.

7. Layer arrangement according to claim 6 , wherein the NIR transmission-preventing layer ( 4 ) consists of a sequence of three to five metal-oxide layers and metal layers arranged alternately.

8. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) comprises at least one layer comprising a dye.

9. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) comprises a combination of a layer comprising a metallic material with a layer comprising a dye.

10. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) consists of an NIR-reflective film or foil having a multilayered structure, where the individual layers consist of at least two materials having different refractive index.

11. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) has been applied with the aid of a thin-film process or a printing process.

12. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) has been applied by sputtering or pyrolytic spraying.

13. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer ( 4 ) has been applied by thermal vapour deposition.

14. Layer arrangement according to claim 1 , wherein the reduction in the transmission in the transparent state by the layer arrangement in the NIR region is greater by a factor of more than 2.08 than the reduction in the transmission in the VIS region.

15. Layer arrangement according to claim 1 , wherein the reduction in the transmission in the transparent state by the layer arrangement in the NIR region is greater by a factor of more than 2.2 than the reduction in the transmission in the VIS region.

16. Layer arrangement according to claim 1 , wherein the reduction in the transmission in the transparent state by the layer arrangement in the NIR region is greater by a factor of more than 2.3 than the reduction in the transmission in the VIS region.

17. Layer arrangement according to claim 1 , wherein the NIR transmission-preventing layer with the substrate layer thereon are on the outside of the layer arrangement facing the direction from which the incident light comes.

Assignees

• Junge Michael
• Beyer Andreas
• Merck Patent Gmbh

Inventors

• Junge Michael
• Beyer Andreas

Classifications

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title

• G02B27/281

  used for attenuating light intensity, e.g. comprising rotatable polarising elements · CPC title

• G02F1/1396

  the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell (G02F1/141 takes precedence) · CPC title

• B60J3/06

  using polarising effect · CPC title

• G02F1/132

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