Lens element

Patent metadata

Field	Value
Publication number	US-9612445-B2
Application number	US-201314647688-A
Country	US
Kind code	B2
Filing date	Oct 29, 2013
Priority date	Nov 27, 2012
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

The invention provides a switchable lens element comprising an inverse lens structure formed by an isotropic material and an isotropic cover sheet wherein the resulting lens structure comprises an electrically switchable polymer stabilized blue phase LC medium having the same refractive index in its isotropic state. Furthermore, the present invention relates to the use of such a lens element in an electro-optical device i.e. an autostereoscopic display device operable in a 2D mode or a 3D mode, in which a lens arrangement directs the output from different pixels to different spatial positions to enable a stereoscopic image to be viewed and wherein the lens arrangement comprises a plurality of said switchable lens elements.

First claim

The invention claimed is:

1. A lens element comprising a lens structure, and a replica structure
wherein either the lens structure or the replica structure comprises a blue phase LC material comprising one or more compounds of formula I

wherein
L 11 to L 16 are independently of each other H or F,
R 11 is alkyl, which is straight chain or branched, is unsubstituted, mono- or poly-substituted by F, Cl or CN, and in which one or more CH 2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NR 01 —, —SiR 01 R 02 —, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S—, —CY 01 ═CY 02 - or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another,
Y 01 and Y 02 are, independently of each other, F, Cl, or CN, and alternatively one of them may be H,
R 01 and R 02 are, independently of each other, H, or alkyl with 1 to 12 C-atoms,
Z 11 is —COO— or —CF 2 O—and
X 11 denotes halogen, a mono- or polyhalogenated alkyl-, or alkoxy having 1 to 6 C-atoms or a mono-, di- or polyhalogenated alkenyl having 2 to 6 C-atoms.

2. A lens element according to claims 1 , wherein the replica structure comprises the blue phase LC material, and the lens structure comprises an isotropic material having a constant refractive index.

3. A lens element according to claim 1 , wherein the lens structure comprises the blue phase LC material, and the replica structure comprises an isotropic material having a constant refractive index.

4. A lens structure according to claim 1 , wherein the isotropic material and the blue phase material in its isotropic state have the same refractive index.

5. A lens element according to claim 1 , wherein the blue phase material can be electrically switched into its birefringent state by applying an electric field in the lateral direction regarding the main plane of the lens element.

6. A lens element according to claim 1 , wherein the lens element utilizes in-plane switching electrodes.

7. A lens element according to claim 1 , wherein a lens effect is associated with the birefringent state or optical anisotropic blue phase of the LC material.

8. A lens element according to claim 1 , wherein the blue phase LC material comprises one or more mesogenic compounds, one or more chiral compounds.

9. A lens element according to claim 1 ,
wherein
R 11 is ethyl, n-propyl, n-butyl, n-pentyl, or n-hexyl,
Z 11 is CF 2 O—, and
X 11 denotes —CF 3 .

10. A lens element according to claim 1 , wherein said blue phase LC material further comprises one or more compounds of formula II

L 21 to L 24 are independently of each other H or F,
R 21 has one of the meanings as indicated above for R 11 in formula I,

 denotes a diradical group selected from the following groups:
a) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene and 1,4′-bicyclohexylene, in which, in addition, one or more non-adjacent CH 2 groups may be replaced by —O— and/or —S— and in which, in addition, one or more H atoms may be replaced by F,
b) the group consisting of 1,4-phenylene and 1,3-phenylene, in which, in addition, one or two CH groups may be replaced by N and in which, in addition, one or more H atoms may be replaced by F,

Z 21 is —COO—or —CF 2 O—, and
X 21 denotes halogen, CN, mono- or polyhalogenated alkyl-, or alkoxy having 1 to 6 C-atoms or a mono- or polyhalogenated alkenyl having 2 to 6 C-atoms.

11. A lens element according to claim 1 , wherein said blue phase LC material further comprises one or more compounds of formula III

wherein
L 31 to L 33 are independently of one another H or F,
Z 31 is —COO— or —CF 2 O—,
R 31 has one of the meanings as indicated above for R 11 in formula I, and
X 31 denotes halogen, —CN, a mono- or polyhalogenated alkyl-, or alkoxy one or more having 1 to 6 C-atoms or a mono- or polyhalogenated alkenyl having 2 to 6 C-atoms.

12. A lens element according to claim 1 , wherein said blue phase LC material further comprises one more compounds of formula IV

wherein
R 41 has one of the meanings given for R 11 under formula I above,

 and
X 41 denotes F or CF 3 .

13. A lens element according to claim 1 , wherein said blue phase LC material further comprises one more compounds of formula V,

wherein
L 51 to L 53 are independently of each other, H or F
R 51 has one of the meanings as indicated above for R 11 in formula I, and
X 51 denotes F or CF 3 .

14. A lens element according to claim 1 , wherein said blue phase LC material further comprises one more compounds of formula VI,

wherein
R 61 has one of the meanings as indicated above for R 11 in formula I, and

15. A lens element according to claim 1 , wherein said blue phase LC material further comprises one more compounds formula VII

wherein
R 71 is alkyl, which is straight chain or branched, having 1 to 20 C-atoms, is unsubstituted, mono- or poly-substituted by F, Cl or CN, and in which one or more CH 2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NR 01 —, —SiR 01 R 02 —, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, ——CO—S—, —CY 01 ═CY 02 — or —C≡C—in such a manner that O and/or S atoms are not linked directly to one another,
L 71 and L 72 are, independently of each other, H or F,
Y 01 and Y 02 are, independently of each other, F, Cl or CN, and alternatively one of them may be H, and
R 01 and R 02 are, independently of each other, H, or alkyl with 1 to 12 C-atoms.

16. A lens element according to claim 1 , wherein said blue phase LC material further comprises one or more polymerisable compounds.

17. A lens element according to claim 1 , wherein said blue phase LC material further one or more polymerisable compounds of the formula P
P a -(Sp a ) s1 -(A 1 -Z 1 ) n1 -A 2 -Q-A 3 -(Z 4 -A 4 ) n2 -(Sp b ) s2—P b   P

wherein the individual radicals have the following meanings:
P a , P b each, independently of one another, are a polymerisable group,
Sp a , Sp b each, independently of one another, denote a spacer group,
s1, s2 each, independently of one another, denote 0 or 1,
n1, n2 each, independently of one another, denote 0 or 1,
Q 1 denotes —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —(CO)O-, —O(CO)—, —(CH 2 ) 4 —, —CH 2 CH 2 —, —CF 2 —CF 2 —, —CF 2 -CH 2 —, —CH 2 -CF 2 —,

Assignees

• Merck Patent Gmbh

Inventors

• Wittek Michael
• Haensel Helmut

Classifications

• G02F1/0045

  Liquid crystals characterised by their physical properties · CPC title

• C09K2019/0448

  the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate · CPC title

• G02B30/27 Primary

  involving lenticular arrays · CPC title

• H04N13/322

  using varifocal lenses or mirrors · CPC title

• H04N13/356

  having separate monoscopic and stereoscopic modes · CPC title