CN101750732B - Color electrowetting display device - Google Patents

Abstract

The present invention relates to a color electrowetting display device. The electrowetting display comprises a first substrate and a second substrate arranged oppositely, and a polar solution layer and a non-polar solution layer with color are sandwiched between the first substrate and the second substrate. A first transparent electrode layer is arranged on the first substrate, a second transparent electrode layer is arranged on the second substrate, and a hydrophilic isolation structure is arranged on the second substrate to define a plurality of sub-pixels. The color electrowetting display device includes an array of a plurality of pixels, each pixel including a plurality of primary color sub-pixels. Each sub-pixel corresponds to the non-polar solution layers with different colors, the non-polar solution layers with different colors are isolated from each other, and the non-polar solution layers in the adjacent sub-pixels are different in color.

Description

Color electrowetting display device

technical field

The present invention relates to a display device, in particular to a color electrowetting display device.

Background technique

The principle of electrowetting display is to use the phenomenon of electrowetting or electrocapillary. When the fluid is subjected to an electric field, the surface free energy (Free Surface Energy) of the fluid is changed, so that the distribution area of the fluid changes.

U.S. Patent No. 6,967,763 discloses an electrowetting display structure, which utilizes the electrowetting (Electrowetting) affinity of a polar liquid to make the opaque non-polar solution converge towards the area away from the pixel electrode to control the display pixels. bright and dark states.

1A and 1B are schematic cross-sectional views of a conventional electrowetting display in a voltage-off state and a voltage-on state, respectively. Please refer to FIG. 1A , a conventional color electrowetting display 10 includes a substrate 11 , and patterned pixel electrodes 12 are disposed on the substrate 11 . A dielectric layer (with hydrophobic surface properties) 13 is disposed on the patterned pixel electrode 12 . The patterned hydrophilic barrier structure 14 is disposed on the dielectric layer 13 to define each pixel area. An opaque non-polar liquid 15a containing black dye and a transparent polar liquid 16 are disposed in each pixel area. When the operating voltage is off, the opaque non-polar liquid 15a is uniformly distributed in the pixel, and the display state of the pixel is a dark state.

When the operating voltage is turned on, the transparent polar liquid 16 is affected by the electrowetting (Electrowetting) force, and is compatible with the pixel electrode, and makes the opaque non-polar liquid 15b gather away from the pixel electrode 12, thus exposing most of the In the pixel area, the display state of the pixel at this time is a bright state (bright state), as shown in FIG. 1B .

FIG. 2 is a schematic cross-sectional view showing a conventional single-layer color electrowetting display device. In FIG. 2 , a conventional single-layer color electroweather display 50 includes a first substrate 51 and a second substrate 61 disposed opposite to each other. The first substrate 51 includes a patterned electrode 52 corresponding to each sub-pixel area. A reflective layer 53 is disposed on the patterned pixel electrode 52 . An isolation structure 54 is disposed on the reflective layer 53 to define a plurality of sub-pixel arrays. The first fluid 55 containing black dye is disposed in each sub-pixel area on the patterned electrode 52 . A transparent second fluid 56 is filled in the first substrate 51 and the second substrate 61 . A color filter 62 including red 62R, green 62G and blue 62B color units is disposed on the second substrate 61 . Each color unit 62R, 62G, 62B corresponds to a sub-pixel area. A sealing structure 70 seals the first substrate 51 and the second substrate 61 in the peripheral area of the display panel. A common electrode 65 is in contact with the second fluid 56 . The electric field generated by the common electrode 65 and the electrodes 52 of each pixel area is used to change the surface tension of the first fluid 55 to achieve the purpose of imaging. More specifically, the reflection and absorption of the external light source is controlled by the shrinkage and tiling of the black non-polar ink, and the reflected light is used to penetrate the color filter on the upper substrate to produce different color lights and achieve full-color Effect.

WIPO Application Publication No. WO03/071347 discloses a color electrowetting display structure. For example, FIG. 3 is a schematic cross-sectional view showing a conventional color three-layer electrowetting display device. Please refer to FIG. 3. In the structure of the three-layer color electrowetting color display 100, the upper and lower substrates are separated into multiple sub-pixel structures by an isolation structure 113, and each sub-pixel is filled with a polar solution 106. Corresponding to two different colors of non-polar inks 105W, 105C, 105Y, and 105M, a layer of polar solution is sandwiched between the two non-polar inks, so that the inside of the upper and lower substrates presents three types of ink, polar solution, and ink. layer solution. A color filter 121 is arranged above the upper substrate, and the color filter is complementary to the inks of two different colors inside the upper and lower substrates. During operation, respectively control and apply bias voltages to different electrodes 112, 132-137, and control the incident light 116 to be reflected by the reflective plate 122 or be non-polarized through the contraction and tiling of two non-polar inks of different colors. The inks 105W, 105C, 105Y, and 105M absorb colors of a specific spectrum, and use the reflected light to pass through the color units 121M, 121C, and 121Y of the color filter on the upper plate to produce different colored lights.

However, in the traditional single-layer color structure that uses a color filter and a black non-polar solution (such as ink), the color filter will absorb part of the light source, resulting in a decrease in light utilization efficiency, which in turn reduces the contrast and brightness of the display screen. In addition, the problem of alignment between the color filter and the lower panel will also increase the difficulty and complexity of panel fabrication. On the other hand, the color saturation and colorability of the panel adopting the three-layer structure can be effectively improved, but the panel structure is complicated, the manufacturing process is not easy, and the manufacturing cost is relatively increased.

Contents of the invention

The technical problem to be solved by the present invention is to provide a color electrowetting display device to improve image quality and reduce panel manufacturing cost and difficulty.

In order to achieve the above object, an embodiment of the present invention provides a color electrowetting display device, which includes: a first substrate and a second substrate are arranged oppositely, and a polar solution layer and a non-polar layer with color are interposed therebetween. a liquid solution layer; a first transparent electrode layer is disposed on the first substrate; a second transparent electrode layer is disposed on the second substrate; and a hydrophilic isolation structure is disposed on the second substrate to define multiple sub-pixels; wherein the color electrowetting display device includes an array composed of a plurality of pixels, each pixel includes a plurality of primary color sub-pixels; wherein each sub-pixel corresponds to the non-polar solution layer of a different color, and each of the different colors The non-polar solution layers are isolated from each other; and wherein the non-polar solution layers in adjacent sub-pixels have different colors.

In order to achieve the above object, an embodiment of the present invention further provides a color electrowetting display device, comprising: a first substrate and a second substrate are oppositely arranged, and a polar solution layer and a non-polar solution layer with color are interposed therebetween. a polar solution layer; a first transparent electrode layer disposed on the first substrate; a second transparent electrode layer disposed on the second substrate; and a hydrophilic isolation structure disposed on the second substrate to define A plurality of sub-pixels; wherein the color electrowetting display device includes an array of a plurality of pixels, each pixel includes a black sub-pixel and a plurality of primary color sub-pixels; wherein each sub-pixel corresponds to a different color of the non-polar solution layer , and the non-polar solution layers of different colors are separated from each other; and wherein the non-polar solution layers in adjacent sub-pixels have different colors.

The electrowetting display device of the present invention uses an electric field to change the surface properties of the fluid as a medium for displaying pixels. More specifically, the pixel structure of the colored electrowetting display of the present invention achieves a colored electrowetting display mainly through the morphology of the sub-pixels and the color arrangement in the sub-pixels, thereby improving image quality and reducing panel manufacturing costs and difficulty.

In order to make the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings as follows:

Description of drawings

1A and 1B respectively show the schematic cross-sectional views of the traditional electrowetting display in the voltage-off and voltage-on states;

2 is a schematic cross-sectional view showing a conventional single-layer color electrowetting display device;

3 is a schematic cross-sectional view showing a conventional color three-layer electrowetting display device;

4 is a schematic cross-sectional view showing a single-layer color electrowetting display device according to an embodiment of the present invention;

5A-5C respectively show a schematic diagram of the color conversion of each pixel of a color electrowetting display according to an embodiment of the present invention;

6A-6C respectively show schematic diagrams of the color conversion of each pixel of a color electrowetting display according to another embodiment of the present invention;

7A-7C respectively show schematic diagrams of color conversion of each pixel of a color electrowetting display according to another embodiment of the present invention; and

8A-8C are schematic diagrams showing the color conversion of each pixel of a color electrowetting display according to another embodiment of the present invention.

[Description of main component symbols]

Known part (Figure 1～3)

10～Traditional color electrowetting display;

11 ~ substrate;

12～pixel electrode;

13 ~ dielectric layer;

14～hydrophilic retaining wall structure;

15a, 15b ~ non-polar liquid;

16 ~ transparent polar liquid;

50～Traditional single-layer color electro-wetting display;

51～the first substrate;

52～patterned electrodes;

53～reflective layer;

54～isolation structure;

55～the first fluid;

56 ~ transparent second fluid;

61～second substrate;

62～color filter;

62R, 62G, 62B～red, green, blue color units;

65～common electrode;

70～sealed structure;

100～Three-layer color electrowetting color display;

105W, 105C, 105Y, 105M～ non-polar inks of different colors;

106～polar solution;

108～intermediate layer;

113～isolation structure;

112, 132-137～electrodes;

116 incident light;

121～color filter;

121M, 121C, 121Y～color unit;

122～reflector.

Part of this case (Figure 4-8C)

200～single-layer color electro-wetting display;

210～second substrate (lower substrate);

212～a patterned pixel electrode layer;

214～dielectric layer;

216～hydrophobic material layer;

222～hydrophilic isolation structure;

225C, 225Y, 225M, 225K ~ non-polar solution layer;

226～Transparent polar fluid;

230～the first substrate (upper substrate);

232～common electrode;

240～sealed structure;

320a-320d, 420a-420d, 520, 620～display pixels;

325C, 425C, 525C～cyan sub-pixels;

325Y, 425Y, 525Y～yellow sub-pixels;

325M, 425M, 525M～magenta sub-pixels;

625R～red sub-pixel;

625G～green sub-pixel;

625B～blue sub-pixel;

325K, 425K, 525K, 625K～black sub-pixel;

326, 426, 526, 626～reflector.

Detailed ways

The following examples are illustrated with various embodiments and accompanying drawings as references for the present invention. In the drawings or descriptions in the specification, the same reference numerals are used for similar or identical parts. And in the drawings, the shapes or thicknesses of the embodiments may be enlarged, and marked for simplicity or convenience. In addition, the parts of each component in the drawings will be described separately. It should be noted that the elements not shown or described in the drawings are forms known to those with ordinary knowledge in the technical field. In addition, specific implementation The example is only to disclose the specific method used in the present invention, and it is not intended to limit the present invention.

The electrowetting display device of the embodiment of the present invention uses an electric field to change the surface properties of the fluid as a medium for displaying pixels. More specifically, the embodiments of the present invention provide a pixel structure of a colored electrowetting display, which mainly achieves a colored electrowetting display through the shape of the sub-pixels and the color arrangement in the sub-pixels, thereby improving image quality and Reduce the cost and difficulty of panel fabrication.

FIG. 4 is a schematic cross-sectional view showing a single-layer color electrowetting display device according to an embodiment of the present invention. Referring to FIG. 4 , a single-layer color electroreactive display 200 includes a first substrate (upper substrate) 230 and a second substrate (lower substrate) 210 disposed opposite to each other. The patterned pixel electrode layer 212 on the second substrate 210 corresponds to each sub-pixel area. The pixel electrode layer 212 can be a transparent conductive material, and its material can be indium tin oxide (ITO) or indium zinc oxide (IZO), and its thickness ranges approximately from 0.1 to 1 micron (μm). The structure of the patterned pixel electrode layer 212 may be rectangular, square, triangular, circular, trapezoidal or elliptical. According to another embodiment of the present invention, a reflective layer is selectively disposed on the second substrate 210 , or disposed between the transparent pixel electrode layer 212 and the substrate 210 . The reflective layer can be made of aluminum, titanium dioxide (TiO2) or zirconium dioxide (ZrO2).

A dielectric layer 214 is disposed on the patterned pixel electrode 212 . According to an embodiment of the present invention, the material of the dielectric layer 214 may be parylene, silicon oxide (SiOx), silicon nitride (SiNx), poly(vinyldiene fluoride), titanium dioxide (TiO2) or zirconium dioxide (ZrO2), and its thickness ranges from 0.1 to 1 micron (μm). Alternatively, a hydrophobic material layer 216 is disposed on the dielectric layer 214 to have a hydrophobic surface. The material of the hydrophobic material layer 216 can be a fluorine-containing or carbon-containing hydrophobic polymer, and its thickness ranges approximately from 0.1 to 1 micron (μm).

A hydrophilic isolation structure 222 is disposed on the hydrophobic material layer 216 to define an array of sub-pixel regions. The material of the hydrophilic isolation structure 222 can be a hydrophilic photoresist, and its thickness ranges approximately from 5 to 10 microns (μm).

A non-polar solution layer 225C, 225Y, 225M, 225K with different colors is disposed in each sub-pixel region on the hydrophobic material layer 216 . The material of the non-polar solution layer is decane, dodecane or tetradecane, and its thickness ranges approximately from 1 to 10 micrometers (μm). Alternatively, the nonpolar solution layers 225C, 225Y, 225M, and 225K can be dyes or pigments of various primary colors (such as RGBK (red, green, blue, black) or CYMK (cyan, yellow, magenta, black)). (pigment). A transparent polar fluid 226 is filled between the first substrate 230 and the second substrate 210 . The material of the transparent polar fluid 226 can be water, sodium chloride aqueous solution or potassium chloride aqueous solution, and its thickness ranges approximately from 30 to 250 micrometers (μm). A sealing structure 240 seals the first substrate 230 and the second substrate 210 in the peripheral area of the display panel. A common electrode 232 is in contact with the polar fluid 226 . The common electrode 232 is a transparent conductive material, which can be indium tin oxide (ITO) or indium zinc oxide (IZO), and its thickness ranges approximately from 0.1 to 1 micron (μm). Using the electric field generated by the common electrode 232 and the electrode 212 of each pixel area, the polar fluid 226 is compatible with the surface of the hydrophobic material layer 216, and the non-polar solution layer is pushed away from the pixel electrode 212 to cohere, so as to achieve purpose of imaging. More specifically, the reflection and absorption of external light sources can be controlled through the shrinkage and tiling of non-polar inks, which can drive the display of pixels of different colors to achieve a full-color effect.

According to an embodiment of the present invention, the color electrowetting display device 200 includes an array of a plurality of pixels, and each pixel includes a plurality (for example, four) of primary color sub-pixels. The shape of each sub-pixel area can be rectangle, hexagon, square, circle, triangle, trapezoid or ellipse. In one embodiment, the plurality of primary color sub-pixels are respectively a black sub-pixel, a red sub-pixel, a green sub-pixel and a blue sub-pixel. In another embodiment, the plurality of primary color sub-pixels are respectively a black sub-pixel, a yellow (Y) sub-pixel, a magenta (M) sub-pixel and a cyan (C) sub-pixel. Each sub-pixel corresponds to a non-polar solution layer of a different color, and the non-polar solution layers of different colors are separated from each other. The non-polar solution layers in adjacent sub-pixels are of different colors.

In the structure of a single-layer electrowetting color display, polar solutions and non-polar inks of different colors are filled inside the upper and lower substrates, and the inks of different colors are separated by hydrophilic partition walls on the substrates, so that Inks of different colors are arranged adjacent to each other to form sub-pixel structures. The reflection and absorption of a specific spectrum of incident light can be controlled through the shrinkage and tiling of non-polar inks of different colors, and different color lights can be produced.

5A-5C respectively show schematic diagrams of color conversion of each pixel of a color electrowetting display according to an embodiment of the present invention. Referring to FIG. 5A , the display pixels 320 a - 320 d are arranged in a square array, respectively having cyan sub-pixels 325C, yellow sub-pixels 325Y, magenta sub-pixels 325M and black sub-pixels 325K. When displaying the dark state, the non-polar inks of the subpixels of all colors are tiled. When displaying the bright state, the gap of the pixel electrode can be used to shrink the non-polar ink of each sub-pixel to the same corner, exposing the lower dielectric layer or reflective plate 326, as shown in FIG. 5B. In another embodiment, when the bright state is displayed, the gap of the pixel electrode can be arranged at the common corner of adjacent sub-pixels, so that the non-polar solution in each adjacent sub-pixel faces each adjacent sub-pixel Adjacent corners are cohesive, exposing the underlying dielectric layer or reflector, as shown in Figure 5C.

6A-6C are schematic diagrams showing the color conversion of each pixel of a color electrowetting display according to another embodiment of the present invention. Please refer to FIG. 6A , the display pixels 420 a - 420 d are closely arranged in a hexagonal shape, and respectively have hexagonal cyan sub-pixels 425C, yellow sub-pixels 425Y, magenta sub-pixels 425M, and black sub-pixels 425K. When displaying the dark state, the non-polar inks of the subpixels of all colors are tiled. When displaying the bright state, the gap of the pixel electrode can be used to arrange the same corner of the sub-pixel, so that the non-polar ink of each sub-pixel shrinks to the same corner, exposing the lower dielectric layer or reflective plate 426, as shown in FIG. 6B Show. In another embodiment, when the bright state is displayed, the gap of the pixel electrode can be arranged at the common corner of adjacent sub-pixels, so that the non-polar solution in each adjacent sub-pixel faces each adjacent sub-pixel Adjacent corners are cohesive, exposing the underlying dielectric layer or reflector, as shown in Figure 6C.

7A-7C respectively show schematic diagrams of color conversion of each pixel of a color electrowetting display according to another embodiment of the present invention. Referring to FIG. 7A , when displaying the dark state, in the display pixel 520 , the non-polar inks of the sub-pixels 525C, 525Y, 525M, and 525K of all colors are tiled. Please refer to FIG. 7B , when it is desired to display a dark red pixel, the cyan sub-pixel 525C is driven to change its ink distribution, so that the overall display pixel 520 presents a dark red color. Please refer to FIG. 7C , when a bright red pixel is to be displayed, the cyan sub-pixel 525C and the black sub-pixel 525K are driven to change the distribution of ink, so that the overall display pixel 520 is bright red.

Table 1 shows how inks of each color are distributed when expressing the color of each pixel when CYMK sub-pixels are used as an electrowetting display structure according to an embodiment of the present invention.

Table I

8A-8C are schematic diagrams showing the color conversion of each pixel of a color electrowetting display according to another embodiment of the present invention. Referring to FIG. 8A , when displaying the dark state, in the display pixel 620 , the non-polar inks of the sub-pixels 625R, 625G, 625B, 625K of all colors are tiled. Please refer to FIG. 8B , when it is desired to display a dark yellow pixel, the blue sub-pixel 625B is driven to change its ink distribution, so that the overall display pixel 620 presents a dark yellow color. Please refer to FIG. 8C , when it is desired to display a bright yellow pixel, the blue sub-pixel 625B and the black sub-pixel 625K are driven to change the distribution of ink, so that the overall display pixel 620 is bright yellow.

Table 2 shows how inks of each color are distributed when the color of each pixel is expressed when RGBK sub-pixels are used as the electrowetting display structure according to an embodiment of the present invention.

Table II

Although the present invention is disclosed above with the embodiment, it is not intended to limit the scope of the present invention. Anyone with ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. Modification, therefore, the protection scope of the present invention should be determined by the scope defined by the appended claims.

Claims (8)

1. a colored electroweting type display device is characterized in that, comprising:

One first substrate and one second substrate subtend are provided with, and insert and put a polar solvent layer and the non-polar solution layer with color therebetween;

One first transparent electrode layer is arranged on this first substrate;

One second transparent electrode layer is arranged on this second substrate; And

One water wettability isolation structure is arranged at this second substrate, to define a plurality of sub-pixels;

Wherein this colored electroweting type display device comprises the array that a plurality of pixel constitutes, and each pixel comprises a plurality of primary color sub-pixel;

This non-polar solution layer of the corresponding different colours of each subpixels wherein, and this non-polar solution layer of variant color is isolated to each other;

Wherein this non-polar solution layer color in the adjacent subpixels is different; And

This second transparent electrode layer is provided with breach; This breach is arranged on the common corner of adjacent subpixels or the same corner of each sub-pixel; When operation, this non-polar solution in each sub-pixel shrinks towards the adjacent corner of this adjacent subpixels or the same corner of each sub-pixel.

2. colored electroweting type display device according to claim 1 is characterized in that, this second transparent electrode layer is a pattern structure, and this pattern structure can be rectangle, square, triangle, circle, trapezoidal or oval.

3. colored electroweting type display device according to claim 1 is characterized in that, comprises that also a dielectric layer is arranged on this second transparent electrode layer.

4. colored electroweting type display device according to claim 3 is characterized in that, comprises that also a hydrophobic material layer is arranged on this dielectric layer.

5. colored electroweting type display device according to claim 3 is characterized in that, the material of this dielectric layer can be Parylene, monox, silicon nitride, gathers difluoroethylene, titania or zirconium dioxide.

6. colored electroweting type display device according to claim 4 is characterized in that, the material of this hydrophobic layer is the hydrophobic polymer of a fluorinated or a carbon containing class.

7. colored electroweting type display device according to claim 1 is characterized in that, the material of this water wettability isolation structure is to be made up of a water wettability photoresistance.

8. colored electroweting type display device according to claim 1 is characterized in that, the material of this polar solvent layer is water, sodium-chloride water solution or potassium chloride solution.

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