KR101408861B1 - Electrowetting display device - Google Patents

Abstract

An electrowetable display device according to the present invention is an electrowetable display panel comprising a lower substrate, an upper substrate, and a fluid disposed between the lower substrate and the upper substrate, wherein the lower substrate comprises a base, A lower electrode, an insulating layer covering the base and the lower electrode, and a partition wall portion disposed on the insulating layer and defining a plurality of pixels, wherein the upper substrate includes a panel portion, And the partition wall portion includes a plurality of partition walls having a predetermined length, width, and height, and an opening portion through which the fluid can flow is formed between the partition walls.

Description

ELECTROWATTING DISPLAY DEVICE [0001]

The present invention relates to an electrowetting display device, and more particularly, to an electrowetting display device having a plurality of barrier ribs formed between a lower substrate and an upper substrate, the barrier ribs having a plurality of barrier ribs, And the fluid can flow through the open portion.

Recently, a variety of e-book products are emerging, among which there are products having a reflection type screen device. Most of the products currently on the market have a disadvantage in that they can only display at low speed and black and white screen by using E-ink. In addition, products using MEMS technology have been introduced, but there is still a limit to the colors that can be expressed.

In order to overcome these problems, recently, a screen device using an electro-wetting method has been developed, and domestic and foreign large enterprises are spurring research into an electro-wet screen device in earnest.

Electro wetting technology refers to the phenomenon that the contact area and the contact angle of the conductive liquid change when a voltage is applied between the conductive liquid and the electrode in contact with the liquid. The basic structure of the screen device using electrowetting is to inject a liquid having a color into each unit cell and then to control the movement of the liquid having conductivity by using electro-wetting, thereby increasing the area of the coloring liquid in each unit cell It is a way of expressing the image through adjustment.

However, such a unit cell is defined as a closed curved surface constituted by a predetermined partition, so that the fluid in each pixel does not flow to the outside but is movable only within the pixel. Accordingly, the uniformity of each pixel is lowered, the uniformity of the optical characteristic is also lowered, and the white area ratio is limited.

Korean Patent Publication No. 10-2011-0074087

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-mentioned problems, and it is an object of the present invention to provide an electrowetting display device having a plurality of barrier ribs formed between a lower substrate and an upper substrate, And an object of the present invention is to provide an electrowetting display device including an opening portion through which the fluid can flow.

In order to achieve the above object, an electrowetting display device according to the present invention comprises:

An electrowetting display panel comprising a lower substrate, an upper substrate, and a fluid disposed between the lower substrate and the upper substrate, wherein the lower substrate comprises a base, a lower electrode formed on the base, Wherein the upper substrate includes a panel portion and an upper electrode formed on a lower portion of the panel portion, and the partition wall portion has a predetermined length A plurality of partition walls having a width and a height, and an opening portion through which the fluid can flow is formed between the respective partition walls.

Preferably, according to an embodiment of the present invention, the pixel has a polygonal shape formed by a number of partition walls formed by aggregation, and each of the openings includes a vertex portion of a polygon forming the pixel, or a portion of each side of the polygon As shown in FIG.

Preferably, according to an embodiment of the present invention, the partition wall portion may include a first partition wall forming a first side of one pixel, and a second partition wall having a predetermined gap with the first partition wall, And a second partition wall extending from the first partition wall and extending from the first partition wall to form a second side of the pixel, the first partition wall having an inner angle with the first side of the pixel, the opening being composed of a gap between the first partition wall and the second partition wall .

Preferably, according to an embodiment of the present invention, the partition wall comprises a hydrophobic material.

Preferably, according to an embodiment of the present invention, the barrier rib includes a conductive material to which a voltage can be applied.

Preferably, according to an embodiment of the present invention, the barrier rib includes a conductive part made of a conductive material so that a voltage can be applied to at least a part of the inside, and a coating part coated on the outside of the conductive part and made of a hydrophobic material .

Preferably, according to an embodiment of the present invention, at least one side of the end portions of the first and second barrier ribs is configured to be parallel to each other.

Preferably, according to an embodiment of the present invention, at least a part of the end of the partition is formed with a rounded portion having a predetermined curvature

Preferably, according to an embodiment of the present invention, the plurality of pixels include at least one first pixel and a second pixel adjacent to each other, and a fluid passage is formed between the first pixel and the second pixel do.

Preferably, according to an embodiment of the present invention, the fluid passage is partitioned into a space between two partition wall portions adjacent to each other and extending in the same direction.

The electrowetting display device according to the present invention has an opening portion between each partition, and each of the pixels also has an open structure with respect to each other, so that the polar liquid filled in the pixel can flow through the opening portion.

Therefore, when the electric field application and the non-application are alternately performed, the polar liquid and the non-polar liquid flow, but are not captured in the space in the pixel and do not flow in the space within the pixel, Therefore, the reaction rate depending on the application and non-application of the electric field can be improved.

Further, when applying an electric field, each non-polar liquid can be uniformly arranged in each pixel, and accordingly, the optical characteristics of each cell can be made uniform.

Further, the polarizing liquid or the nonpolar liquid may not be trapped in the pixel, and the total white area ratio may become larger as the polar liquid and the nonpolar liquid are moved to the other pixel through the openings when the electric field is applied or not.

1 is a cross-sectional view of an electrowetting display device according to the present invention.
2 is a view showing a lower substrate of an electrowetting display device according to the present invention.
3 is a view showing a unit pixel of the electrowetting display device of the present invention.
4 is a view illustrating a lower substrate of an electrowetting display device according to an embodiment of the present invention.
5 is a view showing the shape of a pixel of an electrowetting display device according to an embodiment of the present invention.
6 is a view showing a unit pixel of an electrowetting display device according to an embodiment of the present invention.
7 is a view showing a unit pixel of an electrowetting display device according to an embodiment of the present invention.
8 is a view illustrating a lower substrate of an electrowetting display device according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" Can be used to easily describe the correlation of components with other components. Spatially relative terms should be understood as terms that include different orientations of components during use or operation in addition to those shown in the drawings. For example, when reversing a member shown in the figures, a member described as "below" or "beneath" of another member may be placed "above" another member. Thus, the exemplary term "below" can include both downward and upward directions. The members can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises, "and / or" comprising ", as used herein, unless the recited element, step, operation and / Or additions.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The thickness and size of each member in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

Further, in the embodiments, the angles and directions mentioned in the process of describing the structure of the present invention are based on those shown in the drawings. In the description of the structure constituting the present invention in the specification, reference points and positional relationship with respect to angles are not explicitly referred to, reference is made to the relevant drawings.

FIG. 1 is a cross-sectional view of an electrowetting display device 1 according to the present invention, and FIG. 2 is a view showing a lower substrate 100 of the electrowetting display device 1 according to the present invention. FIG. 3 is a view showing the unit pixel R of the electrowetting display device 1 of the present invention, and FIG. 4 is a cross-sectional view of the electroless wet display device 1 according to the embodiment of the present invention. And FIG. 5 is a view showing the shape of a pixel R of the electrowetting display device 1 according to an embodiment of the present invention.

1, an electrowetting display device 1 according to the present invention includes a lower substrate 100, a lower substrate 100 opposed to the lower substrate 100, 100). ≪ / RTI >

The lower substrate 100 includes a lower base 110, a lower electrode 120 disposed on the base 110, and an insulating layer 130 disposed on the base 110 and the lower electrode 120. [ . The lower electrode 120 may be formed of a transparent and conductive material such as ITO and IZO. The insulating layer 130 may include a hydrophobic material. For example, the insulating layer 130 may be made of a hydrophobic material, or may be formed of a hydrophobic material But it is not limited thereto.

The upper substrate 300 also includes an upper panel 310 and an upper electrode 320 disposed below the panel 310. The upper electrode 320 and the lower electrode 120 may be formed of a transparent and conductive material such as ITO and IZO. Meanwhile, an insulating layer 130 may be formed on the upper electrode 320.

Between the lower substrate 100 and the upper substrate 300, a plurality of barrier ribs for separating the plurality of pixels R are disposed. For example, as shown in FIGS. 1 and 2, the lower substrate 100 includes a plurality of barrier ribs 140 formed on an upper portion thereof, and the barrier ribs 140 may be formed of the barrier ribs 140. Here, the barrier ribs 140 are structures protruding on the lower substrate 100, which means individual structures rather than groups of the structures. At this time, the space formed by surrounding the barrier rib 140 may define one pixel R. That is, a predetermined closed space in which several barrier ribs 140 are formed to surround one pixel R defines one pixel R. That is, one pixel R is a space surrounded by several barrier ribs 140. 1 is a diagram showing a lateral cross-sectional structure of the one pixel R. FIG. 2 and 1, the barrier ribs 140 may be formed on the lower substrate 100, but the barrier ribs 140 may be formed under the upper substrate 300, but the present invention is not limited thereto . Each of the pixels R formed by the barrier ribs 140 is filled with the polar and non-polar liquid 210.

As shown in FIG. 2, the barrier ribs 140 are disposed at predetermined intervals, so that the openings 150 are formed between the barrier ribs 140. That is, the barrier ribs have a first barrier rib 140 forming a first side of one pixel R, and a second barrier rib 140 having a predetermined gap from the first barrier rib 140, And a second partition wall (140) extending to form an angle and having an interior angle with a first side of the pixel (R) and forming a second side of the pixel (R), the opening (150) And a gap between the first barrier rib 140 and the second barrier rib 140.

Accordingly, a number of barrier ribs 140 spaced apart from each other by a predetermined distance are formed to form a number of pixels R. As the barrier ribs 140 have a predetermined gap therebetween, A pixel R defined as a unit space formed by the plurality of barrier ribs 140 may be provided on the barrier rib 140. The barrier rib 140 may be a protruded structure, have.

That is, the barrier ribs have a first barrier rib 140 forming a first side of one pixel R, and a second barrier rib 140 having a predetermined gap from the first barrier rib 140, And a second partition wall (140) extending to form an angle and having an interior angle with a first side of the pixel (R) and forming a second side of the pixel (R), the opening (150) And a gap between the first barrier rib 140 and the second barrier rib 140.

The liquid R is filled in the pixel R, and the liquid includes the non-polar liquid 210 and the polar liquid 220. Here, the nonpolar liquid 210 has a lower specific gravity than the polar liquid 220. Thus, preferably, the non-polar liquid 210 is located above the polar liquid 220 within the pixel R. However, the non-polar liquid 210 is interposed between the polar liquid 220 and the insulating layer 130 as the insulating layer 130 is configured to have the hydrophobic property of repelling the polar liquid 220. That is, as the polar liquid 220 repels the insulating layer 130, the non-polar liquid 210 is disposed between the polar liquid 220 and the insulating layer 130. As described above, the insulating layer 130 may include a hydrophobic material. For example, the insulating layer 130 may be made of a hydrophobic material, A material having hydrophobicity may be coated, but the present invention is not limited thereto.

The polar liquid 220 repels the hydrophobic insulating layer 130 in a state where no electric field is applied to the lower electrode 120 and the upper electrode 320 so that the gap between the polar liquid 220 and the insulating layer 130 The nonpolar liquid 210 is disposed. Accordingly, each cell R is shielded by the nonpolar liquid 210, and the color can be recognized, for example, when the nonpolar liquid 210 has a specific color.

When a voltage is applied to the lower electrode 120 and the upper electrode 320, the polar liquid 220 is drawn toward the lower electrode 120. The polar liquid 220 displaces the non-polar liquid 210 from the central portion of the cell R while being displaced to contact the insulating layer 130 having hydrophobicity. The nonpolar liquid 210 is pushed against the edge of the pixel R as the polar liquid 220 pushes the nonpolar liquid 210 and contacts the insulating layer 130. At this time, a portion where the polar liquid 220 contacts the insulating layer 130 can be optically opened as the colored nonpolar liquid 210 is pushed to the edge of each cell R as described above. For example, when a reflective plate capable of reflecting light is disposed under the cell R, external light may be reflected through a portion where the polar liquid 220 contacts the insulating layer 130.

In this case, according to the embodiment of the present invention, the openings 150 are provided between the respective partition walls 140, and each pixel R also has an open structure with respect to each other, The liquid 220 may flow through the opening 150.

Accordingly, when the application and non-application of the electric field is alternately performed, the polar liquid 220 and the non-polar liquid 210 flow and can flow into the adjacent pixel R by the open portion 150, The reaction rate depending on the unauthorized person can be improved.

That is, according to the prior art having a closed barrier structure, the polar liquid 220 and the non-polar liquid 210 are captured in the space in the pixel R and flow in the space in the pixel R, The polar liquid 220 and the nonpolar liquid 210 are not captured in the space in the pixel R but may be introduced into another adjacent pixel R through the opening 150, The reaction speed depending on the application and non-application of the electric field can be improved as compared with the prior art.

In addition, all the pixels R can operate uniformly because the polar liquid 220 in each of the application and non-application of electric fields shifts the non-polar liquid as it contacts or leaves the hydrophobic surface from the center, The optical characteristics of each cell R through the insulating layer 220 and the insulating layer 130 can be made uniform.

The polar liquid 220 or the nonpolar liquid 210 is not trapped in the pixel R and the polar liquid 220 and the nonpolar liquid 210 are applied to the respective openings 150 when the electric field is applied or not. It is possible to increase the overall white area ratio.

At this time, if each partition 140 is excessively large or small, it may be difficult to secure the effect of the flow of the polar liquid 220 or the nonpolar liquid 210 through the opening 150, The size of the display device 1 may become excessively large and the performance may deteriorate. Therefore, as shown in FIG. 3, each of the partitions 140 may have a predetermined width L, a height H, and a width W. Preferably, the width L of each of the partitions 140 may be between 10 μm and 1000 μm, the height H may be between 1 μm and 1000 μm, and the width W may be in the range of 10 μm to 1000 μm, But not limited thereto.

4, the opening 150 may be formed at at least a portion of each side of the pixel R as well as at the corner of the pixel R, No. At this time, each side of each pixel R may be formed of a plurality of barrier ribs 140.

On the other hand, as shown in FIG. 5, the pixel R may have a hexagonal structure as well as a square. In this case, one pixel R is defined as a space surrounded by six partition walls 140, and the opening 150 may be formed at an edge portion of each pixel R, but is not limited thereto.

On the other hand, each partition 140 may include a hydrophobic material. That is, a hydrophobic coating may be formed on the outside of the barrier 140, or the barrier 140 may be made of a hydrophobic material, but the present invention is not limited thereto.

In addition, each of the partitions 140 may include a conductive material. For example, the barrier 140 may include a conductive portion formed of a conductive material and a coating portion formed of a hydrophobic material on the outer side of the conductive portion. Alternatively, the barrier 140 may be formed of a conductive material, A hydrophobic coating may be formed on the outer side of the cap 140, but the present invention is not limited thereto.

The non-polar liquid 210 and the polar liquid 220 (also referred to as a polar liquid) may be supplied through the barrier 140 to the outside of the barrier 140, Can be controlled.

That is, since the outside of the barrier rib 140 has hydrophobicity, the barrier rib 140 pushes the polar liquid 220 to the center of the cell R, but the voltage is applied to the barrier rib 140 through the conductive member The polar liquid 220 may be displaced to a position adjacent to the barrier 140. Accordingly, the optical characteristics of each of the cells R may fluctuate, so that the optical characteristics can be adjusted more easily than in the case of using only the lower electrode 120 disposed at the lower portion.

6 is a view showing the structure of the partition 140 of the electrowetting display device 1 according to another embodiment.

Referring to FIG. 6, a predetermined angle may be formed at the longitudinal end of each partition wall 140 of the electrowetting display device 1 according to the embodiment.

That is, an opening 150 is formed between two adjacent barrier ribs 140 that are adjacent to each other and have a predetermined angle to form adjacent two sides of the pixel R, and each of the barrier ribs 150 forming the opening 150 140 may be formed to have a predetermined angle so that the opening 150 may have a passage structure in which the polar liquid 220 or the non-polar liquid 210 flows easily.

For example, as described above, the barrier ribs may include a first barrier rib 140 forming a first side of one pixel R, and a second barrier rib 140 having a predetermined gap from the first barrier rib 140, And a second partition wall (140) extending to form an angle with the first side of the pixel (R) and having an interior angle and being adjacent to the first side of the pixel (R) May include a gap between the first barrier rib 140 and the second barrier rib 140. At least one side of the first and second barrier ribs 140 may be parallel to each other.

At this time, at least one surface of the end portions of the first and second barrier ribs 140 may have a curved shape as shown in FIG. 7, but the present invention is not limited thereto.

8 is a view illustrating a structure of a partition 140 according to another embodiment of the present invention.

Referring to FIG. 8, a fluid passage 160 may be formed between each pixel R.

That is, a fluid passage 160 is formed between one pixel R 1 and at least one other pixel R 2 adjacent to the pixel R 1, and the fluid passage 160 is formed between the barrier 140 and the barrier 140 ). ≪ / RTI > That is, when the fluid passage 160 is formed between the pixel R 1 and the pixel R 2, the pixel R 1 and the pixel R 2 do not share the pixel R forming the side contacting each other. At this time, the fluid passages 160 may be formed as spaces formed between two partition walls 140 which are adjacent to each other and extend in the same direction.

The flow of the nonpolar liquid 210 and the polar liquid 220 is prevented from flowing to the liquid R1 as the fluid passage 160 is formed between one pixel R1 and at least one other pixel R2 adjacent to the pixel R1. The non-polar liquid 210 and the polar liquid 220 can easily flow through the fluid passage 160. In this case, Therefore, the reaction speed according to the above-described electric field application and non-application is improved, and uniform optical characteristics according to the uniform arrangement of the respective non-polar liquids 210 can be achieved when an electric field is applied.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

1: electrowetting display device 100: lower substrate
110: base portion 120: lower electrode
130: insulating layer 140: barrier rib
150: opening part 160: fluid passage
200: Fluid 210: Nonpolar liquid
220: polar liquid 300: upper substrate
310: panel part 320: upper electrode

Claims (10)

An electrowetting display panel comprising a lower substrate, an upper substrate, and a fluid disposed between the lower substrate and the upper substrate,
Wherein the lower substrate comprises:
A lower electrode formed on the base, an insulating layer covering the base and the lower electrode, and a partition wall disposed on the insulating layer and defining a plurality of pixels,
Wherein the upper substrate includes a panel portion and an upper electrode formed below the panel portion,
The partition wall portion includes several partition walls having a predetermined length, width, and height,
Wherein an opening portion through which the fluid can flow is formed between each of the partition walls,
The plurality of pixels comprising at least one first pixel adjacent to the first pixel, and a second pixel,
A fluid passage is formed between the first pixel and the second pixel,
The fluid passage includes:
And a space between two partition walls adjacent to each other and extending in the same direction. The method according to claim 1,
The pixel has a polygonal shape formed by a number of partition walls formed by aggregation,
Wherein the opening is disposed at each of the vertex portions of the polygons forming the pixel, or at least one of the sides of the polygon. The method according to claim 1,
Wherein,
A first barrier rib forming a first side of one pixel and a second barrier rib having a predetermined gap with the first barrier rib and extending to form a predetermined angle with the first barrier rib, And a second bank defining a second side of the pixel,
And the opening portion comprises a gap between the first bank and the second bank. The method according to claim 1,
Wherein the partition wall comprises a hydrophobic material. The method according to claim 1,
Wherein the partition wall comprises a conductive material to which a voltage can be applied. 6. The method of claim 5,
Wherein,
A conductive portion made of a conductive material so that a voltage can be applied to at least a part of the inner side, and
And a coating portion coated on the outer side of the conductive portion and made of a hydrophobic material. The method according to claim 1,
And at least one of the ends of the first and second partition walls is parallel to each other. The method according to claim 1,
The end portion of the partition wall
An electrowetting display panel in which a rounding portion having a predetermined curvature is formed. delete delete

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