Light-modulating panel and light modulator

Patent metadata

Field	Value
Publication number	US-9291812-B2
Application number	US-201314386201-A
Country	US
Kind code	B2
Filing date	Mar 19, 2013
Priority date	Mar 19, 2012
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

This light modulation panel is provided with: a first substrate having comb electrodes disposed on a uniformly planar electrode with an insulating layer therebetween; a second substrate disposed opposite to the first substrate and provided with a uniformly planar electrode; a light modulation layer obtained by dispersing anisometric members in a medium; and formed between the substrates; and a circuit for changing the direction in which an electric field is applied, which changes the direction of an electric field applied to the light modulation layer.

First claim

What is claimed is:

1. A light modulation panel, comprising: a pair of substrates disposed opposite to each other; and a light modulation layer sandwiched between the pair of substrates,
wherein the light modulation layer includes a medium and a plurality of anisometric members such that an area of the anisometric members projected through the anisometric members in a direction normal to the substrates changes, by rotation or deformation of the anisometric members, in response to a direction of an electric field,
wherein each of the pair of substrates includes a uniformly planar electrode,
wherein at least one of the pair of substrates is provided with at least one comb electrode over the uniformly planar electrode across an insulating layer, and
wherein the light modulation panel further comprises a circuit that changes the direction of the electric field applied to the light modulation layer.

2. The light modulation panel according to claim 1 , wherein the circuit that changes the direction of the applied electric field includes a selection circuit that selects electrodes, among the electrodes provided on the pair of substrates, to which voltage is to be applied.

3. The light modulation panel according to claim 2 ,
wherein a plurality of the comb electrodes are provided on at least one of the pair of substrates, and
wherein the selection circuit selects electrodes to which voltage is applied such that voltage is applied between one set of electrodes that includes either the uniformly planar electrodes provided on the pair of substrates, or the comb electrodes provided on the same substrate among the pair of substrates.

4. The light modulation panel according to claim 3 ,
wherein the anisometric members have a charge,
wherein the selection circuit selects electrodes to which alternating current voltage is applied such that the alternating current voltage is applied between one set of electrodes that includes either the uniformly planar electrodes provided on the pair of substrates, or the comb electrodes provided on the same substrate as each other among the pair of substrates,
wherein the light modulation panel further comprises a direct current voltage application unit that applies a direct current voltage between the uniformly planar electrodes provided on the pair of substrates such that a direct current voltage of a polarity opposite to the charge in the anisometric members is applied to the uniformly planar electrode on one of the pair of substrates to which the anisometric members stick when the anisometric members are oriented in a direction parallel to surfaces of the pair of substrates, and
wherein the anisometric members stick to either one of the pair of substrates when the anisometric members are oriented in the direction parallel to the surfaces of the pair of substrates.

5. The light modulation panel according to claim 2 , wherein the selection circuit selects electrodes to which voltage is applied such that voltage is applied to one set of electrodes that includes either the uniformly planar electrodes provided on the pair of substrates, or between the comb electrode and the uniformly planar electrode provided on the same substrate as each other among the pair of substrates.

6. The light modulation panel according to claim 1 ,
wherein a plurality of the comb electrodes are provided on at least one of the pair of substrates,
wherein either an electric field formed between one set of electrodes that includes either the uniformly planar electrodes provided respectively on the pair of substrates or the comb electrodes provided on the same substrate as each other among the pair of substrates is constantly applied to the light modulation layer during driving of the light modulation layer, and
wherein the circuit that changes the direction of the applied electric field includes a voltage application circuit that, when the direction of the electric field applied to the light modulation layer is to change, selectively applies a voltage to form an electric field between another set of electrodes stronger than the electric field formed between the one set of electrodes.

7. The light modulation panel according to claim 1 , wherein said light modulation panel is a display panel.

8. The light modulation panel according to claim 7 , wherein the anisometric members are made of a reflective material.

9. The light modulation panel according to claim 8 , wherein a thickness of the light modulation layer is set so as to be less than a length of long axes of the anisometric members, and such that, when the anisometric members are oriented at an incline at a maximum angle with respect to the pair of substrates, light reflected by the anisometric members does not directly travel towards a display surface side.

10. The light modulation panel according to claim 8 , wherein a colored layer is formed on a substrate, among the pair of substrates, disposed opposite to the display surface side.

11. The light modulation panel according to claim 9 , wherein the pair of substrates are transparent substrates, and see-through display is performed by orienting the anisometric members in a direction perpendicular to the surfaces of the pair of substrates.

12. The light modulation panel according to claim 8 , wherein the pair of substrates respectively include the comb electrodes over the uniformly planar electrodes across the insulating layers.

13. The light modulation panel according to claim 8 , wherein the anisometric members are colored.

14. The light modulation panel according to claim 1 ,
wherein the light modulation layer functions as a color filter, and
wherein the plurality of anisometric members are made of a transparent resin, and include at least red anisometric members, green anisometric members, and blue anisometric members.

15. The light modulation panel according to claim 1 , wherein the anisometric members are oriented in a direction perpendicular to surfaces of the pair of substrates when a voltage is applied between the uniformly planar electrodes provided on the pair of substrates, and the anisometric members are oriented in a direction parallel to the surfaces of the pair of substrates when a voltage is applied between electrodes provided on the same substrate among the pair of substrates.

16. The light modulation panel according to claim 1 , wherein the anisometric members are oriented in a direction parallel surfaces of the pair of substrates when a voltage is applied between the uniformly planar electrodes provided on the pair of substrates, and the anisometric members are oriented in a direction perpendicular to the surfaces of the pair of substrates when a voltage is applied between electrodes provided on the same substrate among the pair of substrates.

17. The light modulation panel according to claim 16 , wherein the anisometric members are made only of metal.

18. The light modulation panel according to claim 1 , wherein a portion of each of the anisometric members is fixed to a surface of at least one of the pair of substrates facing another of the substrates.

19. A light modulation device, comprising the light modulation panel according to claim 1 .

Assignees

• Sharp Kk

Inventors

• Satoh Eiji
• Nakamura Kohzoh
• Watanabe Hisashi
• Nakahara Takahiro

Classifications

• G02F1/1337

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

• G02F1/134363

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

• G02F1/0316

  Electrodes · CPC title

• G02B26/007 Primary

  the movable or deformable optical element controlling the colour, i.e. a spectral characteristic, of the light · CPC title

• G02F1/172 Primary

  based on a suspension of orientable dipolar particles, e.g. suspended particles displays · CPC title