Display panel, display device, and method for manufacturing display panel

Patent metadata

Field	Value
Publication number	US-9507189-B2
Application number	US-201314424575-A
Country	US
Kind code	B2
Filing date	Sep 2, 2013
Priority date	Sep 3, 2012
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

The present invention provides a display panel that exhibits increased light use efficiency and decreased occurrence of display anomalies. The display panel includes substrates; a light modulating layer that contains shape-anisotropic members that rotate according to the direction of an electric field and that controls the transmittance of incident light by changing the area projected onto the substrates by the shape-anisotropic members; and supporting members that support the shape-anisotropic members and are rotatably connected thereto.

First claim

What is claimed is:

1. A display panel, comprising:
a first substrate and a second substrate facing each other;
a light modulating layer between said first substrate and said second substrate having a plurality of shape-anisotropic members that rotate in accordance with a direction of an electric field, said light modulating layer controlling transmittance of incident light by changing an area projected onto a plane parallel to the first substrate and the second substrate by the shape-anisotropic members; and
one or more supporting members provided on the first substrate or the second substrate to support the respective shape-anisotropic members, said supporting member being made of a photocurable resin,
wherein the shape-anisotropic members are rotatably connected to the respective supporting members.

2. The display panel according to claim 1 , wherein an end of each of the shape-anisotropic members is rotatably connected to the respective supporting members.

3. The display panel according to claim 1 , wherein voltages applied to the light modulating layer are switched between an alternating current voltage and a direct current voltage with a frequency of 0 Hz.

4. The display panel according to claim 1 , wherein the voltages applied to the light modulating layer are alternating current voltages.

5. The display panel according to claim 1 , wherein the light modulating layer blocks light when a direct current voltage or a low frequency voltage is applied thereto, and allows light to pass therethrough when a high frequency voltage is applied thereto.

6. The display panel according to claim 1 ,
wherein the light modulating layer includes a polar solvent, a non-polar solvent, and a plurality of shape-anisotropic members that are either hydrophilic or hydrophobic,
wherein one of the first substrate and the second substrate is hydrophilic so that the polar solvent stays in contact therewith,
wherein the other of the first and the second substrate is hydrophobic so that the non-polar solvent stays in contact therewith, and
wherein the area projected onto the plane parallel to the first substrate and second substrate by the shape-anisotropic members is caused to change by altering a magnitude of a voltage applied to the light modulating layer.

7. The display panel according to claim 6 ,
wherein when the shape-anisotropic members are hydrophilic and are aligned such that long axes thereof are parallel to the first and second substrates, the shape-anisotropic members are contained within the polar solvent, and
wherein when the shape-anisotropic members are hydrophobic and are aligned such that the long axes thereof are parallel to the first and second substrates, the shape-anisotropic members are contained within the non-polar solvent.

8. The display panel according to claim 1 , further comprising:
solid electrodes respectively provided on the first substrate and the second substrate;
at least one comb-shaped electrode provided on the solid electrode via an insulating layer on at least one of the first and second substrates; and
a circuit for changing a direction of the electric field applied to the light modulating layer.

9. The display panel according to claim 8 , wherein the circuit for changing the direction of the applied electric field comprises:
a selection circuit that selects, out of the electrodes provided on the first and second substrates, the electrode to which to apply a voltage.

10. The display panel according to claim 9 ,
wherein a plurality of comb-shaped electrodes are provided on at least one of the first substrate and the second substrate, and
wherein the selection circuit selects the electrode to which to apply a voltage such that the voltage is applied either to the respective solid electrodes provided on the first substrate and the second substrate or to the comb-shaped electrodes provided on one of the first substrate and the second substrate.

11. The display panel according to claim 1 ,
wherein the light modulating layer includes a liquid crystal material constituted of liquid crystal molecules,
wherein the first substrate and the second substrate receive an alignment treatment on surfaces thereof that are in contact with the light modulating layer,
wherein the alignment treatment is applied such that, when no voltage is applied to the light modulating layer, the liquid crystal molecules are helically twisted from the first substrate to the second substrate and, when a voltage is applied to the light modulating layer, the liquid crystal molecules are oriented approximately perpendicular to the first substrate and the second substrate, and
wherein the area projected onto the plane parallel to the first substrate and second substrate by the shape-anisotropic members is caused to change by altering a voltage applied to the light modulating layer and thereby causing an orientation of the liquid crystal molecules to change.

12. The display panel according to claim 11 ,
wherein the alignment treatment is applied such that, when no voltage is applied to the light modulating layer, the liquid crystal molecules helically twist from the first substrate to the second substrate, and
wherein a chiral agent is added to the liquid crystal material.

13. The display panel according to claim 12 , wherein the liquid crystal molecules helically twist at 90° to 3600° from the first substrate to the second substrate when no voltage is applied to the light modulating layer.

14. A display device, comprising:
the display panel according to claim 1 ; and
a backlight provided on the same side where the first substrate is located.

15. A method for manufacturing a display panel that has: a first substrate and a second substrate facing each other; and a light modulating layer between said first substrate and said second substrate having a plurality of shape-anisotropic members that rotate in accordance with a direction of an electric field, said light modulating layer controlling transmittance of incident light by changing an area projected onto a plane parallel to the first substrate and the second substrate by the shape-anisotropic members, said method comprising:
injecting, between the first substrate and the second substrate, a photocurable resin material and a medium into which the shape-anisotropic members are mixed;
applying a voltage in between the first substrate and the second substrate after the step of injecting; and
irradiating the display panel with ultraviolet light after the applying a voltage step to cure the photocurable resin material to form supporting members on the first or second substrate that respectively support the shape-anisotropic members such that the respective shape-anisotropic members are rotatably connected to the supporting members.

Assignees

• Sharp Kk

Inventors

• Satoh Eiji
• Tomotoshi Takuma
• Teranishi Tomoko
• Nakahara Takahiro

Classifications

• G02F1/13725

  based on guest-host interaction (G02F1/13762, G02F1/13737, take precedence) · CPC title

• G02B26/0841

  the reflecting element being moved or deformed by electrostatic means · CPC title

• G02F1/167

  by electrophoresis · CPC title

• G02F1/19

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

• G02F1/13306 Primary

  Circuit arrangements or driving methods for the control of single liquid crystal cells (G02F1/132, G02F1/133382 take precedence) · CPC title