Light controlling apparatus and method of fabricating the same

Patent metadata

Field	Value
Publication number	US-10502999-B2
Application number	US-201514837146-A
Country	US
Kind code	B2
Filing date	Aug 27, 2015
Priority date	Aug 29, 2014
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

Provided are a light controlling apparatus and a method of fabricating the same. The light controlling apparatus includes: a first electrode unit and a second electrode unit facing each other; a liquid crystal unit between the first electrode unit and the second electrode unit, the liquid crystal unit including a liquid crystal; a wall having a first polymer being polymerized from a first monomer the first monomer having a higher diffusion speed than a second monomer; and a network having a second polymer being polymerized from the second monomer, the second monomer having a lower diffusion speed than the first monomer.

First claim

What is claimed is:

1. A light controlling apparatus comprising:
a first electrode unit and a second electrode unit facing each other, where the first and second electrode units have a refractive index in a range of 1.6 to 1.8;
a refractive index matching layer;
a liquid crystal unit between the first electrode unit and the second electrode unit, the liquid crystal unit having a refractive index in a range of 1.3 to 1.6 and including:
a liquid crystal;
a wall having a first polymer being polymerized from a first monomer, the first monomer having a higher diffusion speed and a lower polymerization rate than that of a second monomer; and
a network having a second polymer being polymerized from the second monomer, the second monomer having a lower diffusion speed and a higher polymerization rate than that of the first monomer,

wherein the first monomer is UV curable and the second monomer is thermally curable or the second monomer is UV curable at a wavelength range different from that of the first monomer,
wherein the refractive index matching layer is disposed between the first electrode unit and the liquid crystal unit, and between the second electrode unit and the liquid crystal unit, and
wherein the refractive index matching layer has a refractive index in a range of 1.3 to 1.8.

2. The light controlling apparatus according to claim 1 , further comprising a spacer on at least one among the first electrode unit and the second electrode unit.

3. The light controlling apparatus according to claim 1 , wherein each of the first polymer and the second polymer is polymerized from at least one monomer selected from the group consisting of UV-curable monomers, polydimethylsiloxane, RM (reactive mesogen)-based monomers, NOA (Norland Optical Adhesive)-based monomers, bisphenol A dimethacrylate-based monomers, and photo resist.

4. The light controlling apparatus according to claim 1 , wherein if the liquid crystal includes one selected from the group consisting of a negative type liquid crystal and a DFLC (dual frequency liquid crystal), each of the first electrode unit and the second electrode unit comprises a common electrode.

5. The light controlling apparatus according to claim 4 , wherein the light controlling apparatus exhibits a transparent mode with the liquid crystal in a homeotropic state when a voltage is not applied, and wherein the light controlling apparatus exhibits a light shielding mode with the liquid crystal in a random state when a voltage is applied.

6. The light controlling apparatus according to claim 1 , wherein if the liquid crystal includes one selected from the group consisting of a positive type liquid crystal and a DFLC (dual frequency liquid crystal), at least one among the first electrode unit and the second electrode unit includes at least one patterned electrode.

7. The light controlling apparatus according to claim 6 , wherein a horizontal electric field is applied to the patterned electrode.

8. The light controlling apparatus according to claim 7 , wherein the light controlling apparatus exhibits a transparent mode with the liquid crystal in a homeotropic state when a voltage is not applied, and wherein the light controlling apparatus exhibits a light shielding mode with the liquid crystal in a random state when a voltage is applied.

9. The light controlling apparatus according to claim 1 , wherein if the liquid crystal includes one selected from the group consisting of a positive type liquid crystal and a DFLC (dual frequency liquid crystal), at least one among the first electrode unit and the second electrode unit includes at least one patterned electrode and a common electrode.

10. The light controlling apparatus according to claim 9 , wherein a horizontal electric field is applied to the patterned electrode and the common electrode.

11. The light controlling apparatus according to claim 10 , wherein the light controlling apparatus exhibits a transparent mode with the liquid crystal in a homeotropic state when a voltage is not applied, and wherein the light controlling apparatus exhibits a light shielding mode with the liquid crystal in a random state when a voltage is applied.

12. The light controlling apparatus according to claim 1 , further comprising an alignment member in the liquid crystal unit and configured to vertically align the liquid crystal, wherein the light controlling apparatus exhibits a transparent mode when a voltage is not applied.

13. A display device comprising:
a display panel; and
at least one light controlling apparatus according to claim 1 attached to the display panel.

14. The display device according to claim 13 , wherein the display panel is an OLED panel.

15. The display device according to claim 13 , wherein the light controlling apparatus is attached to the front surface of the display panel.

16. The display device according to claim 13 , wherein the light controlling apparatus is attached to the rear surface of the display panel.

17. A method of fabricating a light controlling apparatus, comprising:
laminating a first electrode unit to a second electrode unit, where the first and second electrode units have a refractive index in a range of 1.6 to 1.8;
forming a mixed liquid crystal unit having a refractive index in a range of 1.3 to 1.6 between the first electrode unit and the second electrode unit, the mixed liquid crystal unit having a mixed liquid crystal, and the mixed liquid crystal having a first monomer, a second monomer and a liquid crystal;
positioning a refractive index matching layer on the mixed liquid crystal unit;
positioning a mask having a pattern on the first electrode unit or on the second electrode unit;
forming a wall in a region corresponding to the pattern by polymerizing the first monomer by primary curing of the mixed liquid crystal, the first monomer having a higher diffusion speed and a lower polymerization rate than that of the second monomer; and
forming a network by polymerizing the second monomer by secondary curing of the mixed liquid crystal, the second monomer having a lower diffusion speed and a higher polymerization rate than that of the first monomer,
wherein the primary curing includes UV irradiation and the secondary curing includes thermal treatment or the secondary curing includes UV irradiation at a wavelength range different from that of the primary curing, and
wherein the refractive index matching layer has a refractive index in a range of 1.3 to 1.8.

18. The method of fabricating a light controlling apparatus, according to claim 17 , further comprising disposing a spacer on at least one among the first electrode unit and the second electrode unit.

19. The method of fabricating a light controlling apparatus according to claim 17 , wherein the primary curing includes a wavelength within a range of 360 nm to 380 nm, and the secondary curing includes a wavelength within a range of 330 nm to 360 nm.

20. A mixed liquid crystal in which a liquid crystal, a first monomer and a second monomer are dispersed, comprising:
the first monomer which is configured to be polymerized by initial curing due to a higher diffusion speed and a lower polymerization rate than that of the second monomer so as to form a wall for a light controlling apparatus; and
the second monomer which is configured to be polymerized by subsequent curing due to a lower diffusion speed and a higher polymerization rate than that of the first monomer so as to form a network for the light controlling apparatus,
wherein the first monomer is UV

Assignees

• Lg Display Co Ltd

Inventors

• Kim Kihan
• Ahn Jiyoung
• Lee Moonsun
• Kim Pureum
• Ji Seokwon

Classifications

• G02F1/134363

  for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS] · CPC title

• G02F1/1337

  Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers · CPC title

• C09K19/544

  as dispersing or encapsulating medium around the liquid crystal · CPC title

• G02F1/1334 Primary

  based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals · CPC title

• G02F1/133377

  Cells with plural compartments or having plurality of liquid crystal microcells partitioned by walls, e.g. one microcell per pixel · CPC title