# US 8,542,428 B2 · Electropheretic display device and method for manufacturing the same

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- Number: US 8,542,428 B2
- Document ID: US8542428B2
- Status: Granted
- Kind: B2
- Application number: 13/184,323
- Filed: 2011-07-15
- Published: 2012-08-30
- Granted: 2013-09-24
- Earliest claimed: 2011-02-28
- Assignees: Samsung Display Co., Ltd.
- Applicants: Ju-Han Bae; Byeong-Jin Lee; Nam-Seok Roh; Myung-Hwan Kim; Sang-Il Kim; Tae-Hyung Hwang; Son-Uk Lee; Yu Jin Kim
- Inventors: Ju-Han Bae; Byeong-Jin Lee; Nam-Seok Roh; Myung-Hwan Kim; Sang-Il Kim; Tae-Hyung Hwang; Son-Uk Lee; Yu Jin Kim
- Web page: https://patentgrep.com/patent/US8542428B2

## CPC

- G02F 1/167: by electrophoresis
- G02F 1/1677: Structural association of cells with optical devices, e.g. reflectors or illuminating devices
- G02F 1/1681: having two or more microcells partitioned by walls, e.g. of microcup type
- 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

An electrophoretic display device according to an exemplary embodiment of the present invention includes: a lower substrate; an upper substrate; a thin film transistor disposed on the lower substrate; a pixel electrode connected to the thin film transistor; an electronic ink layer positioned between the lower substrate and the upper substrate; a plurality of partitions disposed on the upper substrate; a reflecting layer disposed on the partitions; a color filter disposed between the partitions.

## Claims

### Claim 1

An electrophoretic display device, comprising:
a lower substrate;
an upper substrate;
a thin film transistor disposed on the lower substrate;
a pixel electrode connected to the thin film transistor;
an electronic ink layer positioned between the lower substrate and the upper substrate;
a plurality of partitions disposed on the upper substrate;
a reflecting layer disposed on the partitions; and
a color filter disposed between adjacent partitions of the plurality of partitions.

### Claim 2 (depends on 1)

The electrophoretic display device of claim 1, wherein the electronic ink layer includes:
a plurality of spherical microcapsules; and
a supporting layer supporting the plurality of spherical microcapsules,
wherein each of the plurality of spherical microcapsules includes a plurality of white charged particles or a plurality of black charged particles disposed therein.

### Claim 3 (depends on 2)

The electrophoretic display device of claim 2, wherein each of the plurality of spherical microcapsules includes a plurality of white charged particles and a plurality of black charged particles and the white charged particles and the black charged particles are charged with opposite polarities.

### Claim 4 (depends on 2)

The electrophoretic display device of claim 2, wherein the electronic ink layer further includes a common electrode disposed on the microcapsules.

### Claim 5 (depends on 2)

The electrophoretic display device of claim 2, further comprising a groove disposed at the upper substrate between the partitions.

### Claim 6 (depends on 5)

The electrophoretic display device of claim 5, wherein the color filter is positioned at the groove.

### Claim 7 (depends on 1)

The electrophoretic display device of claim 1, wherein the height of each of the plurality of partitions is in the range of 20 to 25 μm.

### Claim 8 (depends on 1)

The electrophoretic display device of claim 1, wherein the reflecting layer is made of a metal having high reflectivity.

### Claim 9 (depends on 1)

The electrophoretic display device of claim 1, wherein each of the plurality of partitions is made of a white photosensitive film.

### Claim 10 (depends on 1)

The electrophoretic display device of claim 1, wherein each of the plurality of partitions is made of a black photosensitive film.

### Claim 11 (depends on 1)

The electrophoretic display device of claim 1, further comprising an adhesive layer disposed on the reflecting layer and the color filter, wherein the adhesive layer is applied as a liquid adhesive and adheres an upper panel comprising the upper substrate, the plurality of partitions, the reflecting layer, and the color filter to the electronic ink layer.

### Claim 12 (depends on 11)

The electrophoretic display device of claim 11, wherein the thickness of the adhesive layer is in the range of 20 to 25 μm.

### Claim 13

A method for manufacturing an electrophoretic display device, comprising:
forming a thin film transistor on a lower substrate;
forming a pixel electrode connected to the thin film transistor;
forming an electronic ink layer on the pixel electrode;
etching an upper substrate to form a groove and a partition;
forming a reflecting layer on the partition; forming a color filter in the groove;
forming an adhesive layer on the reflecting layer and the color filter; and
adhering the adhesive layer to the electronic ink layer.

### Claim 14 (depends on 13)

The method of claim 13, wherein the etching of the upper substrate to form the groove and the partition includes:
forming a metal pattern on the upper substrate;
forming a first photosensitive film on the metal pattern; and
etching the upper substrate by using the first photosensitive film as a mask.

### Claim 15 (depends on 14)

The method of claim 14, wherein the forming of the reflecting layer on the partition include
surface-treating an interior of the groove to form a surface treated portion thereof;
forming a second photosensitive film on the surface treated portion of the groove;
forming the reflecting layer on the second photosensitive film and the partition; and
removing the reflecting layer on the second photosensitive film and the second photosensitive film.

### Claim 16 (depends on 13)

The method of claim 13, wherein the electronic ink layer includes:
a plurality of spherical microcapsules; and
a supporting layer supporting the plurality of spherical microcapsules, wherein each of the plurality of spherical microcapsules includes a plurality of white charged particles or a plurality of black charged particles disposed therein.

### Claim 17 (depends on 16)

The method of claim 16, wherein each of the plurality of spherical microcapsules includes a plurality of white charged particles and a plurality of black charged particles and the white charged particles and the black charged particles are charged with opposite polarities.

### Claim 18 (depends on 16)

The method of claim 16, wherein the electronic ink layer further includes a common electrode formed on the plurality of microcapsules.

### Claim 19

An electrophoretic display device, comprising:
a lower substrate;
a thin film transistor disposed on the lower substrate;
a pixel electrode connected to the thin film transistor;
an upper substrate facing the lower substrate and including a plurality of partitions and a plurality of grooves disposed between the partitions; a common electrode disposed on the grooves and the partitions;
a lateral reflector disposed on the common electrode on the partitions;
color filters disposed in the grooves; and a plurality of electrically charged particles disposed on the color filters.

### Claim 20 (depends on 19)

The electrophoretic display device of claim 19, wherein the common electrode includes a plurality of cutouts.

### Claim 21 (depends on 19)

The electrophoretic display device of claim 19, further comprising a first organic layer disposed on the pixel electrode.

### Claim 22 (depends on 21)

The electrophoretic display device of claim 21, further comprising a white reflector disposed on the first organic layer.

### Claim 23 (depends on 22)

The electrophoretic display device of claim 22, wherein the white reflector includes an opening.

### Claim 24 (depends on 19)

The electrophoretic display device of claim 19, wherein the electrically charged particles are black and the device further comprises a white solvent positioned in the grooves.

### Claim 25 (depends on 19)

The electrophoretic display device of claim 19, wherein the electrically charged particles are white and the device further comprises a black solvent positioned in the grooves.

### Claim 26 (depends on 19)

The electrophoretic display device of claim 19, wherein the electrically charged particles include white electrically charged particles and black electrically charged particles, and the device further comprises a transparent solvent positioned in the grooves.

### Claim 27

An electrophoretic display device comprising:
a lower substrate;
an upper substrate;
a thin film transistor disposed on the lower substrate;
a pixel electrode connected to the thin film transistor;
an electronic ink layer positioned on the pixel electrode between the lower substrate and the upper substrate;
a lens positioned on the electronic ink layer; and
a plurality of color filters disposed on the upper substrate.

### Claim 28 (depends on 27)

The electrophoretic display device of claim 27, wherein the electronic ink layer includes:
a plurality of spherical microcapsules; and
a supporting layer supporting the plurality of spherical microcapsules,
wherein each of the plurality of spherical microcapsules includes a plurality of white charged particles or a plurality of black charged particles disposed therein.

### Claim 29 (depends on 27)

The electrophoretic display device of claim 27, wherein the electronic ink layer includes:
a plurality of spherical microcapsules; and
a supporting layer supporting the plurality of spherical microcapsules,
wherein each of the plurality of spherical microcapsules includes a plurality of white charged particles and a plurality of black charged particles and the white charged particles and the black charged particles are charged with opposite polarities.

### Claim 30 (depends on 29)

The electrophoretic display device of claim 29, wherein the electronic ink layer further includes a common electrode disposed on the plurality of spherical microcapsules.

### Claim 31 (depends on 29)

The electrophoretic display device of claim 29, further comprising a piezoelectric member positioned between the supporting layer and the upper substrate.

### Claim 32 (depends on 27)

The electrophoretic display device of claim 27, wherein the plurality of color filters include a first color filter and a second color filter.

### Claim 33 (depends on 32)

The electrophoretic display device of claim 32, further comprising an opening positioned between the first color filter and the second color filter.

### Claim 34 (depends on 27)

The electrophoretic display device of claim 27, wherein each of the plurality of color filters is separated from other color filters of the plurality of color filters.

### Claim 35 (depends on 34)

The electrophoretic display device of claim 34, further comprising a supporting member positioned on the lower substrate.

### Claim 36 (depends on 35)

The electrophoretic display device of claim 35, further comprising a piezoelectric member positioned between the supporting member and the upper substrate.
