Display panel and display device including hydrophobic and hydrophilic treatment of substrates

Patent metadata

Field	Value
Publication number	US-9726958-B2
Application number	US-201314380765-A
Country	US
Kind code	B2
Filing date	Feb 26, 2013
Priority date	Feb 28, 2012
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

The present invention provides a display panel and a display device which can increase light use efficiency with a simple configuration. An optical modulation layer 30 provided between substrates 10 and 20 contains a polar solvent 31 a , a nonpolar solvent 31 b , and hydrophilic shape-anisotropic members 32 , the hydrophilic substrate 20 makes contact with the polar solvent 31 a , the hydrophobic substrate 10 makes contact with the nonpolar solvent 31 b , a projected area of the shape-anisotropic members 32 onto the substrates 10 and 20 is changed by adjusting a magnitude of a voltage to be applied to the optical modulation layer 30.

First claim

The invention claimed is:

1. A display panel comprising:
a first substrate and a second substrate which face each other, the first substrate being provided on a rear surface side and the second substrate being provided on a display surface side; and
an optical modulation layer that controls a transmittance of incoming light, the optical modulation layer being provided between the first substrate and the second substrate and containing a plurality of shape-anisotropic members, wherein
the optical modulation layer includes a polar solvent and a nonpolar solvent,
the plurality of shape-anisotropic members have a hydrophilic property or a hydrophobic property,
one of the first substrate and the second substrate has a hydrophilic property and makes contact with the polar solvent,
another one of the first substrate and the second substrate has a hydrophobic property and makes contact with the nonpolar solvent,
a projected area of the plurality of shape-anisotropic members onto the first substrate and the second substrate is changed by adjusting a magnitude of a voltage applied to the optical modulation layer,
in a case where the plurality of shape-anisotropic members have the hydrophilic property, a layer thickness of the polar solvent is smaller than a layer thickness of the nonpolar solvent; and
in a case where the plurality of shape-anisotropic members have the hydrophobic property, the layer thickness of the nonpolar solvent is smaller than the layer thickness of the polar solvent.

2. The display panel as set forth in claim 1 , wherein:
in a case where the plurality of shape-anisotropic members have the hydrophilic property and are oriented so that major axes of the respective plurality of shape-anisotropic members are aligned in parallel with the first substrate and the second substrate, the plurality of shape-anisotropic members are contained in the polar solvent; and
in a case where the plurality of shape-anisotropic members have the hydrophobic property and are oriented so that the major axes of the respective plurality of shape-anisotropic members are aligned in parallel with the first substrate and the second substrate, the plurality of shape-anisotropic members are contained in the nonpolar solvent.

3. The display panel as set forth in claim 1 , wherein:
the optical modulation layer allows light to pass through while a voltage is applied to the optical modulation layer, and
the optical modulation layer blocks light while a voltage applied to the optical modulation layer is zero.

4. The display panel as set forth in claim 1 , wherein:
while the voltage is applied to the optical modulation layer, the plurality of shape-anisotropic members are oriented so that the major axes are aligned perpendicular to the first substrate and the second substrate, and
while the voltage applied to the optical modulation layer is zero, the plurality of shape-anisotropic members are oriented so that the major axes are aligned in parallel with the first substrate and the second substrate.

5. The display panel as set forth in claim 1 , wherein the plurality of shape-anisotropic members have chargeability.

6. The display panel as set forth in claim 1 , wherein the projected area is changed by rotating the plurality of shape-anisotropic members in accordance with the magnitude of the voltage to be applied to the optical modulation layer.

7. The display panel as set forth in claim 1 , wherein the projected area is changed by changing shapes of the respective plurality of shape-anisotropic members in accordance with the magnitude of the voltage to be applied to the optical modulation layer.

8. The display panel as set forth in claim 1 , wherein:
the optical modulation layer serves as a color filter; and
the plurality of shape-anisotropic members are made of a transparent resin and include at least a red-colored shape-anisotropic member, a green-colored shape-anisotropic member, and a blue-colored shape-anisotropic member.

9. A display panel comprising:
a first substrate and a second substrate which face each other, the first substrate being provided on a rear surface side and the second substrate being provided on a display surface side; and
an optical modulation layer that controls a transmittance of incoming light, the optical modulation layer being provided between the first substrate and the second substrate and containing a plurality of shape-anisotropic members, wherein
the optical modulation layer includes a polar solvent and a nonpolar solvent,
the plurality of shape-anisotropic members have a hydrophilic property or a hydrophobic property,
one of the first substrate and the second substrate has a hydrophilic property and makes contact with the polar solvent,
another one of the first substrate and the second substrate has a hydrophobic property and makes contact with the nonpolar solvent,
a projected area of the plurality of shape-anisotropic members onto the first substrate and the second substrate is changed by adjusting a magnitude of a voltage applied to the optical modulation layer,
in a case where the plurality of shape-anisotropic members have the hydrophilic property, a layer thickness of the polar solvent is (i) smaller than a layer thickness of the nonpolar solvent and (ii) smaller than a major axis length of each of the plurality of shape-anisotropic members, and
in a case where the plurality of shape-anisotropic members have the hydrophobic property, the layer thickness of the nonpolar solvent is (i) smaller than the layer thickness of the polar solvent and (ii) smaller than the major axis length of each of the plurality of shape-anisotropic members.

10. The display panel as set forth in claim 9 , wherein
in a case where the plurality of shape-anisotropic members have the hydrophilic property and are oriented so that major axes of the respective plurality of shape-anisotropic members are aligned in parallel with the first substrate and the second substrate, the plurality of shape-anisotropic members are contained in the polar solvent; and
in a case where the plurality of shape-anisotropic members have the hydrophobic property and are oriented so that the major axes of the respective plurality of shape-anisotropic members are aligned in parallel with the first substrate and the second substrate, the plurality of shape-anisotropic members are contained in the nonpolar solvent.

11. The display panel as set forth in claim 9 , wherein
the optical modulation layer allows light to pass through while a voltage is applied to the optical modulation layer, and
the optical modulation layer blocks light while a voltage applied to the optical modulation layer is zero.

12. The display panel as set forth in claim 9 , wherein
while the voltage is applied to the optical modulation layer, the plurality of shape-anisotropic members are oriented so that the major axes are aligned perpendicular to the first substrate and the second substrate, and
while the voltage applied to the optical modulation layer is zero, the plurality of shape-anisotropic members are oriented so that the major axes are aligned in parallel with the first substrate and the second substrate.

13. The display panel as set forth in claim 9 , wherein the plurality of shape-anisotropic members have chargeability.

14. The display panel as set forth in claim 9 , wherein the projected area is changed by rotating the plurality of shape-anisotropic members in accordance with the magnitude of the voltage to be applied to the optical modulation layer.

15. The display panel as set forth in claim 9 , wherein the projected area is changed by c

Assignees

• Sharp Kk

Inventors

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

Classifications

• G02B26/023

  comprising movable attenuating elements, e.g. neutral density filters · CPC title

• G02F1/13394

  spacers regularly patterned on the cell subtrate, e.g. walls, pillars (G02F1/133377 takes precedence) · CPC title

• G02B26/026

  based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays (based on orientable dipolar particles G02F1/172; based on electrophoresis G02F1/167) · CPC title

• G02F1/19

  based on variable-reflection or variable-refraction elements not provided for in groups G02F1/015 - G02F1/169 · CPC title

• G02F1/167 Primary

  by electrophoresis · CPC title