U.S. patent application number 17/369984 was filed with the patent office on 2022-02-24 for electrophoretic display device.
This patent application is currently assigned to E Ink Holdings Inc.. The applicant listed for this patent is E Ink Holdings Inc.. Invention is credited to Hsiao-Lung Cheng, Chi-Mao Hung, I-Shin Lo, Pei-Lin Tien.
Application Number | 20220057688 17/369984 |
Document ID | / |
Family ID | 1000005865704 |
Filed Date | 2022-02-24 |
United States Patent
Application |
20220057688 |
Kind Code |
A1 |
Cheng; Hsiao-Lung ; et
al. |
February 24, 2022 |
ELECTROPHORETIC DISPLAY DEVICE
Abstract
An electrophoretic display device includes a substrate, an
electrophoretic display film, a plurality of second electrodes, and
a plurality of third electrodes. The electrophoretic display film
is disposed on the substrate and includes a display medium layer
and a first electrode. The second electrodes and the third
electrodes are disposed on the substrate and located between the
display medium layer and the substrate. A first voltage received by
each of the second electrodes is controlled by a corresponding
thin-film transistor. The third electrodes and the second
electrodes are alternately disposed in a direction. The first
voltage is different from a second voltage received by the third
electrodes.
Inventors: |
Cheng; Hsiao-Lung; (Hsinchu,
TW) ; Tien; Pei-Lin; (Hsinchu, TW) ; Lo;
I-Shin; (Hsinchu, TW) ; Hung; Chi-Mao;
(Hsinchu, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
E Ink Holdings Inc. |
Hsinchu |
|
TW |
|
|
Assignee: |
E Ink Holdings Inc.
Hsinchu
TW
|
Family ID: |
1000005865704 |
Appl. No.: |
17/369984 |
Filed: |
July 8, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 1/1676 20190101;
G02F 1/167 20130101 |
International
Class: |
G02F 1/1676 20060101
G02F001/1676; G02F 1/167 20060101 G02F001/167 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 20, 2020 |
TW |
109128360 |
Claims
1. An electrophoretic display device, comprising: a substrate; an
electrophoretic display film disposed on the substrate and
comprising a display medium layer and a first electrode; a
plurality of second electrodes separately disposed on the substrate
and located between the display medium layer and the substrate,
wherein a first voltage received by each of the second electrodes
is controlled by a corresponding thin-film transistor; and a
plurality of third electrodes disposed on the substrate and located
between the display medium layer and the substrate, wherein the
third electrodes and the second electrodes are alternately disposed
in a direction, the first voltage is different from a second
voltage received by the third electrodes, and the third electrodes
are a plurality of barrier electrodes which are not controlled by
thin-film transistors under the display medium layer.
2. The electrophoretic display device of claim 1, wherein the first
electrode receives the second voltage.
3. The electrophoretic display device of claim 1, wherein an
extending direction of the second electrodes is parallel to an
extending direction of a data line.
4. The electrophoretic display device of claim 1, wherein a
horizontal spacing between two adjacent second electrodes is
between 6 .mu.m and 45 .mu.m.
5. The electrophoretic display device of claim 1, wherein a
horizontal spacing between each of the third electrodes and two
adjacent second electrodes is the same.
6. The electrophoretic display device of claim 5, wherein a width
of each of the third electrodes is equal to the horizontal
spacing.
7. The electrophoretic display device of claim 1, wherein a
material of the third electrodes is the same as a material of the
second electrodes.
8. The electrophoretic display device of claim 1, wherein the first
electrode is a common electrode, the second electrodes are a
plurality of display electrodes, and materials of any two of the
first electrode, the second electrodes, and the third electrodes
are the same.
9. The electrophoretic display device of claim 1, wherein the
second electrodes are arranged in an array, and a shape of each of
the third electrodes is a strip.
10. The electrophoretic display device of claim 1, wherein the
second electrodes are arranged in an array and the third electrodes
are arranged in a grid shape, and the second electrodes and the
third electrodes are all alternately arranged in the direction and
another direction perpendicular to the direction.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of Taiwan
application serial no. 109128360, filed on Aug. 20, 2020. The
entirety of the above-mentioned patent application is hereby
incorporated by reference herein and made a part of this
specification.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates to a display device, and in particular
to an electrophoretic display device.
Description of Related Art
[0003] In recent years, electrophoretic display devices are widely
used in e-readers (e.g., e-books, e-newspapers) or other electronic
elements (e.g., e-shelf labels (ESL)) due to advantages such as
lightness, thinness, durability, and low power consumption in
accordance with energy conservation and environmental
protection.
[0004] In the existing electrophoretic display device, the
horizontal spacing between two adjacent display electrodes is very
close, wherein the thickness of the display medium layer is, for
example, about 23 microns, and the horizontal spacing between two
adjacent display electrodes is, for example, about 12 microns. At
this time, the vertical electric field between the common electrode
and the display electrode is 1E, and the electric field at the
horizontal spacing between two adjacent display electrodes is 4E.
That is, the conductive particles between the horizontal spacings
are moved horizontally instead of vertically, so that the
electrophoretic display device is prone to blooming effect.
[0005] In order to solve the issue above, currently, the horizontal
spacing between two adjacent display electrodes is increased from
23 micrometers to 56 micrometers, and the electric field at the
horizontal spacing is reduced to 0.82E. In other words, the
electric field at the increased horizontal spacing is very weak.
Therefore, if the electrophoretic display device is applied to a
low-temperature environment, the conductive particles located near
the electric field may not be moved, resulting in the issue of
white lines. Therefore, how to solve the blooming effect of the
electrophoretic display device, while also being applicable to high
and low temperature operating environments, is a technical issue
that requires urgent attention.
SUMMARY OF THE INVENTION
[0006] The invention provides an electrophoretic display device
that may effectively reduce blooming effect, may be applied in a
low temperature environment, and may have a wider temperature
operating range.
[0007] The electrophoretic display device of the invention includes
a substrate, an electrophoretic display film, a plurality of second
electrodes, and a plurality of third electrodes. The
electrophoretic display film is disposed on the substrate and
includes a display medium layer and a first electrode. The second
electrodes are separately disposed on the substrate and located
between the display medium layer and the substrate. A first voltage
received by each of the second electrodes is controlled by a
corresponding thin-film transistor. The third electrodes are
disposed on the substrate and located between the display medium
layer and the substrate. The third electrodes and the second
electrodes are alternately disposed in a direction. The first
voltage is different from a second voltage received by the third
electrodes. The third electrodes are a plurality of barrier
electrodes which are not controlled by thin-film transistors under
the display medium layer.
[0008] In an embodiment of the invention, the first electrode
receives the second voltage.
[0009] In an embodiment of the invention, an extending direction of
the second electrodes is parallel to an extending direction of a
data line.
[0010] In an embodiment of the invention, a horizontal spacing
between two adjacent second electrodes is between 6 .mu.m and 45
.mu.m.
[0011] In an embodiment of the invention, a horizontal spacing
between each of the third electrodes and two adjacent second
electrodes is the same.
[0012] In an embodiment of the invention, a width of each of the
third electrodes is equal to the horizontal spacing.
[0013] In an embodiment of the invention, a material of the third
electrodes is the same as a material of the second electrodes.
[0014] In an embodiment of the invention, the first electrode is a
common electrode, and the second electrodes are a plurality of
display electrodes. Materials of any two of the first electrode,
the second electrodes, and the third electrodes are the same.
[0015] In an embodiment of the invention, the second electrodes are
arranged in an array, and a shape of each of the third electrodes
is a strip.
[0016] In an embodiment of the invention, the second electrodes are
arranged in an array and the third electrodes are arranged in a
grid shape, and the second electrodes and the third electrodes are
all alternately arranged in the direction and another direction
perpendicular to the direction.
[0017] Based on the above, in the design of the electrophoretic
display device of the invention, the third electrodes and the
second electrodes are alternately arranged in the direction, and
the first voltage received by the second electrodes is different
from the second voltage received by the third electrodes. In this
way, the configuration of the third electrodes may block the
horizontal electric field between two adjacent second electrodes,
so as to avoid the generation of blooming effect. In addition,
because the invention adopts the third electrodes instead of
increasing the horizontal spacing between two adjacent second
electrodes, the invention does not generate a weak electric field
area between two adjacent second electrodes. Therefore, the
invention is suitable to be driven at low temperatures. In short,
the electrophoretic display device of the invention may effectively
reduce blooming effect and has high resolution, and may also be
used in a low-temperature environment and may have a wider
temperature operating range.
[0018] In order to make the aforementioned features and advantages
of the disclosure more comprehensible, embodiments accompanied with
figures are described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve to explain the principles of the invention.
[0020] FIG. 1A is a cross-sectional view of an electrophoretic
display device according to an embodiment of the invention.
[0021] FIG. 1B is a top view of second electrodes and third
electrodes of the electrophoretic display device of FIG. 1A.
[0022] FIG. 2 is a top view of second electrodes and third
electrodes according to another embodiment of the invention.
DESCRIPTION OF THE EMBODIMENTS
[0023] FIG. 1A is a cross-sectional view of an electrophoretic
display device according to an embodiment of the invention. FIG. 1B
is a top view of second electrodes and third electrodes of the
electrophoretic display device of FIG. 1A. Please refer to FIG. 1A
and FIG. 1B at the same time. In the present embodiment, an
electrophoretic display device 100 includes a substrate 110, an
electrophoretic display film 120, a plurality of second electrodes
130a and 130b, and a plurality of third electrodes 140a. The
electrophoretic display film 120 is disposed on the substrate 110
and includes a display medium layer 122 and a first electrode 124.
The second electrodes 130a and 130b are separately disposed on the
substrate 110 and located between the display medium layer 122 and
the substrate 110. An electric field E is formed between the first
electrode 124 and the second electrodes 130a and 130b, and two
adjacent second electrodes 130a and 130b have different polarities
in a direction D1. The third electrodes 140a are disposed on the
substrate 110 and located between the display medium layer 122 and
the substrate 110. The third electrodes 140a and the second
electrodes 130a and 130b are alternately disposed in the direction
D1. A first voltage received by the second electrodes 130a and 130b
is different from a second voltage received by the third electrodes
140a. Each of the third electrodes 140a is used to block a
horizontal electric field E1 between two adjacent second electrodes
130a and 130b. Here, the voltage of each of the second electrodes
130a and 130b is controlled by a corresponding thin-film transistor
(TFT) 150 on the substrate 110, which means that the voltages of
the second electrodes 130a and 130b may be the same or different,
which are controlled by the corresponding TFT 150.
[0024] In detail, the substrate 110 is, for example, an active
device array substrate, such as a TFT array substrate or a
thin-film diode (TFD) array substrate, but is not limited thereto.
The electrophoretic display film 120 further includes a flexible
substrate 126, wherein the flexible substrate 126 is disposed on
the first electrode 124, and the first electrode 124 is located
between the flexible substrate 126 and the display medium layer
122. Here, the display medium layer 122 includes an electrophoretic
fluid 122a and a plurality of charged particles of different colors
distributed in the electrophoretic fluid, such as a plurality of
black charged particles 122b and a plurality of white charged
particles 122c. In an embodiment, the display medium layer 122 is
preferably a display medium layer with a microcup structure, but is
not limited thereto. In another embodiment, the display medium
layer 122 may also be a display medium layer with a microcapsule
structure. In an embodiment, the first electrode 124 receives the
second voltage, which means that the third electrodes 140a and the
first electrode 124 receive the same voltage. In another
embodiment, the first electrode 124 may receive a third voltage,
which means that the second electrodes 130a and 130b, the third
electrodes 140a, and the first electrode 124 respectively receive
different voltages.
[0025] Please refer further to FIG. 1A and FIG. 1B. In the present
embodiment, the first electrode 124 is a common electrode, the
second electrodes 130a and 130b are a plurality of display
electrodes, and the third electrodes 140a are a plurality of
barrier electrodes. The shape of each of the second electrodes 130a
and 130b is, for example, a rectangle, and the second electrodes
130a and 130b are arranged in an array. The shape of each of the
third electrodes 140a is, for example, a strip, and the third
electrodes 140a are arranged along the direction D1. Preferably,
the extending direction of the third electrodes 140a is parallel to
the extending direction of a data line D. Here, the third
electrodes 140a and the second electrodes 130a and 130b are
alternately arranged in the direction D1, but are not limited
thereto.
[0026] As shown in FIG. 1A, there is a horizontal spacing H between
two adjacent second electrodes 130a and 130b, and the horizontal
spacing H is, for example, between 6 .mu.m and 45 .mu.m. The
horizontal spacings H1 and H2 between each of the third electrodes
140a and two adjacent second electrodes 130a and 130b are the same.
That is, the horizontal spacing H2 between the third electrodes
140a and the second electrode 130a is equal to the horizontal
spacing H1 between the third electrodes 140a and the second
electrode 130b. Preferably, the horizontal spacing H is, for
example, 21 microns, and a width W of each of the third electrodes
140a is equal to the horizontal spacings H1 and H2. That is, the
horizontal spacing H1, the horizontal spacing H2, and the width W
of each of the third electrodes 140a are all 7 microns. In other
embodiments, the width W of each of the third electrodes 140a may
also be greater or less than the horizontal spacing H1 and H2,
which still belongs to the scope of the invention. In addition, in
an embodiment, the material of the third electrodes 140a may be the
same as the material of the second electrodes 130a and 130b, which
means that the second electrodes 130a and 130b and the third
electrodes 140a belong to the same layer during the manufacturing
process, and are, for example, transparent conductive materials,
such as indium oxide, tin oxide, indium tin oxide, or indium zinc
oxide, but are not limited thereto. In another embodiment, the
material of the third electrodes 140a is different from the
material of the second electrodes 130a and 130b. The material of
the third electrodes 140a is, for example, metal, such as copper or
aluminum, or other non-transparent conductive materials. In another
embodiment, the material of the third electrodes 140a may be the
same as the material of the first electrode 124. In short, the
materials of any two of the first electrode 124, the second
electrodes 130a and 130b, and the third electrodes 140a are the
same.
[0027] In an embodiment, when a thickness T of the display medium
layer 122 is, for example, 23 microns, and the width W of each of
the third electrodes 140a is, for example, 7 microns, no electric
field is generated between the third electrodes 140a and the first
electrode 124, and the electric field at the horizontal spacings H1
and H2 on the opposite sides of the third electrodes 140a is 3E.
The electric field at the horizontal spacings H1 and H2 is limited
by the third electrodes 140a, so that the horizontal electric field
E1 here may not pass through, thereby suppressing the generation of
blooming effect. In an embodiment, the extending direction of the
third electrodes 140a is parallel to the data line D, and a gate-on
and gate-off timing adjustment technique is added to reduce
blooming phenomenon between gates. Furthermore, the configuration
of the third electrodes 140a also reduces the horizontal electric
field E1 between two adjacent second electrodes 130a and 130b. In
addition, since a weak electric field area is not generated between
two adjacent display electrodes 130a and 130b, the electrophoretic
display device 100 of the present embodiment may be driven at a low
temperature.
[0028] In short, in the design of the electrophoretic display
device 100 of the present embodiment, the third electrodes 140a and
the second electrodes 130a and 130b are alternately arranged in the
direction D1, and the first voltage received by the second
electrodes 130a and 130b is different from the second voltage
received by the third electrodes 140a. In this way, the
configuration of the third electrodes 140a may block the horizontal
electric field E1 between two adjacent second electrodes 130a and
130b, so as to avoid the generation of blooming effect. In
addition, since a weak electric field area is not generated between
two adjacent second electrodes 130a and 130b of the present
embodiment, the electrophoretic display device 100 of the present
embodiment may be driven at a low temperature. Therefore, the
electrophoretic display device 100 of the present embodiment may
effectively reduce blooming effect and has high resolution, and may
also be used in a low-temperature environment and may have a wider
temperature operating range, and may reduce inventory costs and
thereby reduce production costs.
[0029] It should be mentioned here that, the following embodiments
adopt the reference numerals of the embodiments above and a portion
of the content thereof, wherein the same reference numerals are
used to represent the same or similar elements and descriptions of
the same technical content are omitted. The omitted portions are as
described in the embodiments above and are not repeated in the
embodiments below.
[0030] FIG. 2 is a top view of second electrodes and third
electrodes according to another embodiment of the invention.
Referring to FIG. 1B and FIG. 2 at the same time, the arrangement
of the second electrodes 130a and 130b and third electrodes 140b of
the present embodiment is similar to the arrangement of the second
electrodes 130a and 130b and the third electrodes 140a of FIG. 1B,
and the difference between the two is: in the present embodiment,
the second electrodes 130a and 130b are arranged in an array, and
the third electrodes 140b have a strip shape and are arranged in a
grid shape. The second electrodes 130a and 130b and the third
electrodes 140b are alternately arranged in the direction D1 and
another direction D2 perpendicular to the direction D1. In other
words, the configuration of the third electrodes 140b may surround
each of the second electrodes 130a and 130b to more effectively
avoid the generation of blooming effect.
[0031] Based on the above, in the design of the electrophoretic
display device of the invention, the third electrodes and the
second electrodes are alternately arranged in the direction, and
the first voltage received by the second electrodes is different
from the second voltage received by the third electrodes. In this
way, the configuration of the third electrodes may block the
horizontal electric field between two adjacent second electrodes,
so as to avoid the generation of blooming effect. In addition,
because the invention adopts the third electrodes instead of
increasing the horizontal spacing between two adjacent second
electrodes, the invention does not generate a weak electric field
area between two adjacent second electrodes. Therefore, the
invention is suitable to be driven at low temperatures. In short,
the electrophoretic display device of the invention may effectively
reduce blooming effect and has high resolution, and may also be
used in a low-temperature environment and may have a wider
temperature operating range.
[0032] Although the invention has been described with reference to
the above embodiments, it will be apparent to one of ordinary skill
in the art that modifications to the described embodiments may be
made without departing from the spirit of the invention.
Accordingly, the scope of the invention is defined by the attached
claims not by the above detailed descriptions.
* * * * *