Liquid crystal optical element comprising a resin layer having a surface hardness of b or less
View Patent ↗On substrates 2 a, 2 b of a chiral nematic liquid crystal optical element 1 , transparent electrodes 3 a, 3 b and electrical insulation layers 4 a, 4 b are formed, and further, resin layers 5 a, 5 b hating a pencil hardness of “B” or less are formed on the electrical insulation layers by a spin coating method so as to be in contact with a liquid crystal layer 7 . When the surface hardness of the resin layers is to be measured, a glass substrate on which a resin layer is formed by screen-printing is prepared as a test piece, and the test piece is fitted to a pencil-scratching tester. The surface hardness is measured by scratching the test piece with two kinds of testing pencil selected from testing pencils having 17 grades of density.
1. A chiral nematic liquid crystal optical element, comprising:
a pair of substrates with transparent electrodes;
a liquid crystal layer having a memory property interposed between the substrates;
a first resin layer which is provided on one of the transparent electrodes, said first resin layer having a rubbed vertical alignment surface in contact with the liquid crystal layer; and
a second resin layer which is a resin layer selected from the group consisting of a surface layer which has not been subjected to an alignment treatment by rubbing, a vertical alignment layer or a horizontal alignment layer, said second resin layer being provided between the liquid crystal layer and the other of the transparent electrodes,
wherein said liquid crystal layer exhibits a planar state and a focal conic state; and
wherein the second resin layer has a surface hardness of B or less in a pencil hardness test.
2. The liquid crystal optical element according to claim 1 , wherein the first resin layer is provided only on the substrate on a side opposite to an observing side.
3. The liquid crystal optical element according to claim 1 , wherein said focal conic state produces a scattering of incident light.
4. The liquid crystal optical element according to claim 1 , wherein said planar state produces a selective reflection of incident light.
5. The liquid crystal optical element according to claim 1 , which is a color display.
6. The liquid crystal optical element according to claim 1 , wherein said second resin layer comprises a polyimide which has been baked.
7. The liquid crystal optical element according to claim 1 , further comprising
a first electrically insulating layer which is coated on at least one of the electrodes and a second electrically insulating layer which is coated on the other electrode; and
wherein said first and said second resin layer are coated on said electrically insulating layer.
8. The liquid crystal optical element according to claim 1 , wherein said second resin layer is a surface layer which has not been subjected to an alignment treatment by rubbing.
9. The liquid crystal optical element according to claim 1 , wherein said second resin layer prevents image-sticking.
10. The liquid crystal optical element according to claim 1 , wherein the liquid crystal layer exhibits reflection characteristics as if the liquid crystal layer is a mirror.
11. The liquid crystal optical element according to claim 1 , wherein said rubbed vertical alignment surface does not twist the liquid crystal at 240°.
12. The liquid crystal optical element according to claim 1 , wherein said second resin layer consists of a resin.
13. A chiral nematic liquid crystal optical element, comprising:
a pair of substrates with transparent electrodes;
a liquid crystal layer having a memory property interposed between the substrates;
a metal-oxide layer provided on at least one of the transparent electrodes;
a first resin layer which is provided on one of the transparent electrodes,
said first resin layer having a rubbed vertical alignment surface in contact with the liquid crystal layer; and
a second resin layer which is a resin layer selected from the group consisting of a surface layer which has not been subjected to an alignment treatment by rubbing, a vertical alignment layer or a horizontal alignment layer, said second resin layer being provided between the liquid crystal layer and the other of the transparent electrodes,
wherein said liquid crystal layer exhibits a planar state and a focal conic state; and
wherein the second resin layer has a surface hardness of B or less in terms of a pencil hardness test.
14. The liquid crystal optical element according to claim 13 , wherein the paired transparent electrodes have a drive voltage of 20V or less applied thereacross.
15. The liquid crystal optical element according to claim 13 , wherein said second resin layer comprises a polyimide which has been baked.
16. The liquid crystal optical element according to claim 13 , further comprising
a first electrically insulating layer which is coated on at least one of the electrodes and a second electrically insulating layer which is coated on the other electrode; and
wherein said first and said second resin layer are coated on said electrically insulating layer.
17. The liquid crystal optical element according to claim 13 , wherein said second resin layer is a surface layer which has not been subjected to an alignment treatment by rubbing.
18. The liquid crystal optical element according to claim 13 , wherein said second resin layer prevents image-sticking.
19. The liquid crystal optical element according to claim 13 , wherein the liquid crystal layer exhibits reflection characteristics as if the liquid crystal layer is a mirror.
20. The liquid crystal optical element according to claim 13 , wherein said rubbed vertical alignment surface does not twist the liquid crystal at 240°.
21. The liquid crystal optical element according to claim 5 , wherein said second resin layer consists of a resin.