# US 8,149,374 B2 · Cholesteric liquid crystal display devices with actuating thin-film driving elements

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- Number: US 8,149,374 B2
- Document ID: US8149374B2
- Status: Granted
- Kind: B2
- Application number: 12/468,001
- Filed: 2009-05-18
- Published: 2010-06-03
- Granted: 2012-04-03
- Earliest claimed: 2008-12-01
- Assignees: Industrial Technology Research Institute
- Inventors: Jen-Chieh Yang; Yuan-Chang Liao
- Web page: https://patentgrep.com/patent/US8149374B2

## CPC

- G02F 1/13718: {based on a change of the texture state of a cholesteric liquid crystal}
- G02F 1/0128: {based on electro-mechanical, magneto-mechanical, elasto-optic effects}
- G02F 1/132: {Thermal activation of liquid crystals exhibiting a thermo-optic effect}
- G02F 1/133394: {Piezoelectric elements associated with the cells}
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

Cholesteric liquid crystal display (Ch-LCD) devices with actuating thin-film driving elements are presented. The Ch-LCD device includes a first substrate and an opposing second substrate. An actuating thin-film structure is disposed on the first substrate. A cholesteric liquid crystal layer is filled between the first substrate and the second substrate. A common electrode is disposed on the second substrate. In operation, the actuating thin-film structure is deformed to drive phase transition of the cholesteric liquid crystal layer.

## Claims

### Claim 1

A cholesteric liquid crystal display (Ch-LCD) device, comprising:
a first substrate and a second substrate opposing to each other;
an actuating thin-film structure disposed on the first substrate;
a cholesteric liquid crystal layer filled between the first substrate and the second substrate; and
a common electrode disposed on the second substrate,
wherein, in operation, the actuating thin-film structure is deformed to drive phase transition of the cholesteric liquid crystal layer.

### Claim 2 (depends on 1)

The Ch-LCD device as claimed in claim 1, further comprising a partition structure interposed between the first substrate and the second substrate, thereby defining a plurality of pixels or sub-pixel regions.

### Claim 3 (depends on 2)

The Ch-LCD device as claimed in claim 2, wherein, in each sub-pixel region, the cholesteric liquid crystal layer has different color to compose a full-color cholesteric liquid crystal display device.

### Claim 4 (depends on 1)

The Ch-LCD device as claimed in claim 1, wherein the actuating thin-film structure comprises a first electrode, a piezoelectric thin film, and a second electrode.

### Claim 5 (depends on 4)

The Ch-LCD device as claimed in claim 4, wherein the piezoelectric thin film comprises zinc oxide (ZnO), aluminum nitride (AlN), barium titanate, lead titanate, or lead zirconate titanate (PZT).

### Claim 6 (depends on 1)

The Ch-LCD device as claimed in claim 1, wherein the first substrate and the second substrate are made of a glass substrate or a flexible substrate.

### Claim 7 (depends on 6)

The Ch-LCD device as claimed in claim 6, wherein the flexible substrate comprises a polycarbonate (PC) substrate, a polyethersulfone (PES) substrate, a polyethylene terephthalate (PET) substrate, a polyimide (PI) substrate, a polyimide (PI) substrate, a polynitrobenzene (PNB) substrate, a polyetheretherketone (PEEK) substrate, a polyethylenenapthalate (PEN) substrate, a polyethyleneimine (PEI), or a poly(ADP-ribose) (PAR) substrate.

### Claim 8 (depends on 1)

The Ch-LCD device as claimed in claim 1, wherein the common electrode is a transparent electrode, comprising indium tin oxide (ITO) or indium zinc oxide (IZO).

### Claim 9 (depends on 1)

The Ch-LCD device as claimed in claim 1, further comprising a first alignment layer disposed on the actuating thin-film structure, and a second alignment layer disposed on the common electrode, wherein both the first and second alignment layers are contacted with the cholesteric liquid crystal layer, providing initial orientation for the cholesteric liquid crystal layer.

### Claim 10 (depends on 1)

The Ch-LCD device as claimed in claim 1, wherein the cholesteric liquid crystal layer comprises a micro-capsulated liquid crystal material or a polymer-stabilized liquid crystal material.

### Claim 11 (depends on 1)

The Ch-LCD device as claimed in claim 1, wherein the actuating thin-film structure comprises an electric field driven actuator, a static driven actuator, an electromagnetic driven actuator, or a thermal deformation driven actuator.

### Claim 12 (depends on 1)

The Ch-LCD device as claimed in claim 1, further comprising an absorption layer disposed underlying the first substrate.

### Claim 13

A cholesteric liquid crystal display (Ch-LCD) device, comprising:
a first substrate and a second substrate opposing to each other;
an auxiliary structure disposed overlying the first substrate between which a cavity is formed creating a diaphragm region;
an actuating thin-film structure disposed on the auxiliary structure;
a cholesteric liquid crystal layer filled between the first substrate and the second substrate; and
a common electrode disposed on the second substrate,
wherein, in operation, the actuating thin-film structure is deformed to drive phase transition of the cholesteric liquid crystal layer, and
wherein a deformation area of the actuating thin-film structure is corresponding to the diaphragm region.

### Claim 14 (depends on 13)

The Ch-LCD device as claimed in claim 13, further comprising a partition structure interposed between the first substrate and the second substrate, thereby defining a plurality of pixels or sub-pixel regions.

### Claim 15 (depends on 14)

The Ch-LCD device as claimed in claim 14, wherein, in each sub-pixel region, the cholesteric liquid crystal layer has different color to compose a full-color cholesteric liquid crystal display device.

### Claim 16 (depends on 13)

The Ch-LCD device as claimed in claim 13, wherein the auxiliary structure is made of a photoresist, a photo curing resin, or a thermal curing resin.

### Claim 17 (depends on 13)

The Ch-LCD device as claimed in claim 13, wherein the actuating thin-film structure comprises a first electrode, a piezoelectric thin film, and a second electrode.

### Claim 18 (depends on 17)

The Ch-LCD device as claimed in claim 17, wherein the piezoelectric thin film comprises zinc oxide (ZnO), aluminum nitride (AlN), barium titanate, lead titanate, or lead zirconate titanate (PZT).

### Claim 19 (depends on 13)

The Ch-LCD device as claimed in claim 13, wherein the first substrate and the second substrate are made of a glass substrate or a flexible substrate.

### Claim 20 (depends on 19)

The Ch-LCD device as claimed in claim 19, wherein the flexible substrate comprises a polycarbonate (PC) substrate, a polyethersulfone (PES) substrate, a polyethylene terephthalate (PET) substrate, a polyimide (PI) substrate, a polyimide (PI) substrate, a polynitrobenzene (PNB) substrate, a polyetheretherketone (PEEK) substrate, a polyethylenenapthalate (PEN) substrate, a polyethyleneimine (PEI), or a poly(ADP-ribose) (PAR) substrate.

### Claim 21 (depends on 13)

The Ch-LCD device as claimed in claim 13, wherein the common electrode is a transparent electrode, comprising indium tin oxide (ITO) or indium zinc oxide (IZO).

### Claim 22 (depends on 13)

The Ch-LCD device as claimed in claim 13, further comprising a first alignment layer disposed on the actuating thin-film structure, and a second alignment layer disposed on the common electrode, wherein both the first and second alignment layers are contacted with the cholesteric liquid crystal layer, providing initial orientation for the cholesteric liquid crystal layer.

### Claim 23 (depends on 13)

The Ch-LCD device as claimed in claim 13, wherein the cholesteric liquid crystal layer comprises a micro-capsulated liquid crystal material or a polymer-stabilized liquid crystal material.

### Claim 24 (depends on 13)

The Ch-LCD device as claimed in claim 13, wherein the actuating thin-film structure comprises an electric field driven actuator, a static driven actuator, an electromagnetic driven actuator, or a thermal deformation driven actuator.

### Claim 25 (depends on 13)

The Ch-LCD device as claimed in claim 13, further comprising an absorption layer disposed underlying the first substrate.

### Claim 26

A cholesteric liquid crystal display (Ch-LCD) device, comprising:
a substrate and an actuating thin-film structure opposing to each other;
a cholesteric liquid crystal layer filled between the substrate and the actuating thin-film structure; and
a common electrode disposed on the substrate,
wherein, in operation, the actuating thin-film structure is deformed to drive phase transition of the cholesteric liquid crystal layer.

### Claim 27 (depends on 26)

The Ch-LCD device as claimed in claim 26, further comprising a partition structure interposed between the substrate and the actuating thin-film structure, thereby defining a plurality of pixels or sub-pixel regions.

### Claim 28 (depends on 27)

The Ch-LCD device as claimed in claim 27, wherein, in each sub-pixel region, the cholesteric liquid crystal layer has different color to compose a full-color cholesteric liquid crystal display device.

### Claim 29 (depends on 26)

The Ch-LCD device as claimed in claim 26, wherein the actuating thin-film structure comprises a first electrode, a piezoelectric thin film, and a second electrode.

### Claim 30 (depends on 29)

The Ch-LCD device as claimed in claim 29, wherein the piezoelectric thin film comprises zinc oxide (ZnO), aluminum nitride (AlN), barium titanate, lead titanate, or lead zirconate titanate (PZT).

### Claim 31 (depends on 26)

The Ch-LCD device as claimed in claim 26, wherein the substrate is made of a glass substrate or a flexible substrate.

### Claim 32 (depends on 31)

The Ch-LCD device as claimed in claim 31, wherein the flexible substrate comprises a polycarbonate (PC) substrate, a polyethersulfone (PES) substrate, a polyethylene terephthalate (PET) substrate, a polyimide (PI) substrate, a polyimide (PI) substrate, a polynitrobenzene (PNB) substrate, a polyetheretherketone (PEEK) substrate, a polyethylenenapthalate (PEN) substrate, a polyethyleneimine (PEI), or a poly(ADP-ribose) (PAR) substrate.

### Claim 33 (depends on 26)

The Ch-LCD device as claimed in claim 26, wherein the common electrode is a transparent electrode, comprising indium tin oxide (ITO) or indium zinc oxide (IZO).

### Claim 34 (depends on 26)

The Ch-LCD device as claimed in claim 26, further comprising a first alignment layer disposed on the actuating thin-film structure, and a second alignment layer disposed on the common electrode, wherein both the first and second alignment layers are contacted with the cholesteric liquid crystal layer, providing initial orientation for the cholesteric liquid crystal layer.

### Claim 35 (depends on 26)

The Ch-LCD device as claimed in claim 26, wherein the cholesteric liquid crystal layer comprises a micro-capsulated liquid crystal material or a polymer-stabilized liquid crystal material.

### Claim 36 (depends on 26)

The Ch-LCD device as claimed in claim 26, wherein the actuating thin-film structure comprises an electric field driven actuator, a static driven actuator, an electromagnetic driven actuator, or a thermal deformation driven actuator.

### Claim 37 (depends on 26)

The Ch-LCD device as claimed in claim 26, further comprising an absorption layer disposed overlying the substrate.