Coplanar Electrowetting Display Device and Manufacturing Method Thereof

Abstract

The present disclosure provides an electrowetting display device and method capable of significantly reducing manufacturing costs while having high transmittance, comprising a plurality of pixels, wherein each of the plurality of pixels has a lower electrode panel having first and second electrodes formed electrically isolated from each other on the same plane, a transparent cover spaced apart in the upper direction of the lower electrode panel, a color ink disposed on the lower electrode panel that is deformed by an electrowetting phenomenon when voltage is applied to the first and second electrodes, and an oil having immiscibility with respect to the color ink and filling the remaining space excluding the space occupied by the color ink between the lower electrode panel and the transparent cover.

Description

Technology Field

[0001] The present disclosure relates to an electro-wetting display device and method, and more specifically to a co-plane electro-wetting display device and method. Background Technology

[0002] Currently, display devices utilizing various display methods are in use, and an electrowetting display refers to a display that uses the electrowetting phenomenon as one of these diverse display methods.

[0003] Electrowetting is a phenomenon in which surface tension changes when an electric field is applied to the surface of a fluid. An electrowetting display is a display that utilizes the principle in which a liquid droplet is placed on an electrode coated with an insulating film, and the shape of the liquid droplet changes at the contact surface with the coated electrode when a voltage is applied to the electrode. Electrowetting displays are a type of non-emissive display that implements a display by changing the shape of the liquid according to the voltage applied to the electrode, thereby blocking, transmitting, or reflecting incident light. Such electrowetting displays have the advantages of being able to be manufactured at low cost due to their simple cell structure and simple manufacturing process, as well as having significantly lower power consumption compared to other display methods, and are therefore utilized in e-books, transparent displays, and advertising boards. The problem to be solved

[0004] The object of the present disclosure is to provide an electro-wetting display device and method capable of having high transmittance.

[0005] The object of the present disclosure is to provide an electro-wetting display device and method capable of reducing manufacturing costs. means of solving the problem

[0006] According to one embodiment of the present disclosure, an electrowetting display device comprises a plurality of pixels, each of which includes a lower electrode panel having first and second electrodes formed on the same plane and electrically isolated from each other; a transparent cover spaced apart in the upper direction of the lower electrode panel; a color ink disposed on the lower electrode panel and deformed by an electrowetting phenomenon when voltage is applied to the first and second electrodes; and an oil having incompatibility with respect to the color ink and filling the remaining space between the lower electrode panel and the transparent cover, excluding the space occupied by the color ink.

[0007] The first and second electrodes may be formed to be arranged alternately by dividing the lower surface of the pixel into a plurality of regions.

[0008] The first and second electrodes may be formed in a shape in which a plurality of fan shapes extending radially from the center of the lower surface of the pixel are alternately arranged.

[0009] The lower electrode panel may include an insulating film formed between the first and second electrodes and on the upper side, and a hydrophobic film formed on the insulating film.

[0010] The lower electrode panel may further include a substrate on which the first and second electrodes are formed on the upper surface.

[0011] The above color ink may be composed of water containing pigment so that when voltage is not applied to the first and second electrodes, it clumps together due to surface tension with the hydrophobic film formed on the upper surface of the lower electrode panel to form a water droplet shape.

[0012] The color ink can express the color of the pixel by spreading widely on the upper surface of the lower electrode panel by an electrowetting phenomenon according to the voltage difference of the voltage applied to the first and second electrodes.

[0013] The pixel may further include a surfacer formed in the direction of the transparent cover from the outer edge of the pixel area of ​​the lower electrode panel to isolate the color ink placed on the lower electrode panel so that it does not move to an adjacent pixel.

[0014] According to another embodiment of the present disclosure, an electrowetting display method is performed by a processor to manufacture an electrowetting display device comprising a plurality of pixels, comprising the steps of: manufacturing a lower electrode panel having first and second electrodes formed electrically isolated from each other on the same plane; placing a color ink on the lower electrode panel that is deformed by an electrowetting phenomenon when a voltage is applied to the first and second electrodes; placing a transparent cover spaced apart in the upper direction of the lower electrode panel; and filling an oil having incompatibility with respect to the color ink between the lower electrode panel and the transparent cover. Effects of the invention

[0015] The electrowetting display device and method of the present disclosure have two electrodes disposed only on the lower surface of each pixel, so that no electrodes are formed on the upper surface, thereby having high transmittance and significantly reducing manufacturing costs. Brief explanation of the drawing

[0016] FIG. 1 shows a pixel structure in an electro-wetting display device according to one embodiment. Figure 2 shows a top view of an example of the coplanar electrode of Figure 1. Figure 3 shows the shape change of color ink according to the voltage difference applied to the first and second electrodes of the pixel shown in Figure 1. FIG. 4 illustrates a method for manufacturing an electro-wetting display according to one embodiment. FIG. 5 is a diagram illustrating a computing environment including a computing device according to one embodiment. Specific details for implementing the invention

[0017] Hereinafter, specific embodiments according to the embodiments of the present disclosure will be described with reference to the drawings. The following detailed description is provided to facilitate a comprehensive understanding of the methods, apparatuses, and / or systems described herein. However, this is merely illustrative and the present invention is not limited thereto.

[0018] In describing the embodiments of the present disclosure, detailed descriptions of known technology related to the present invention are omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the embodiments. Furthermore, terms described below are defined with consideration of their functions in the present invention, and these may vary depending on the intentions or practices of the user or operator. Therefore, such definitions should be based on the content throughout this specification. Terms used in the detailed description are intended merely to describe specific embodiments and should not be limiting. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form. In this description, expressions such as “include” or “compose” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts thereof, or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts thereof, or combinations thereof other than those described. Additionally, terms such as “...part,” “...unit,” “module,” and “block” described in the specification refer to a unit that processes at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software.

[0019] FIG. 1 shows a pixel structure in an electro-wetting display device according to one embodiment, and FIG. 2 shows a top view of an example of a co-planar electrode of FIG. 1.

[0020] The electrowetting display device also comprises a plurality of pixels arranged as a type of display, and a cross-sectional view of one pixel is shown in FIG. 1. Referring to FIG. 1, each pixel in the electrowetting display device comprises a lower electrode panel (10), a transparent cover (20), color ink (30), and oil (40).

[0021] A lower electrode panel (10) forming the lower surface of a pixel may include first and second electrodes (11, 12) formed on the lower coplanar, a dielectric layer (13) formed on the first and second electrodes, and a hydrophobic layer (14) formed on the dielectric layer (13).

[0022] The first electrode (11) and the second electrode (12) are formed on the same plane, i.e., on a co-plane, and are formed according to a designated pattern so as to be electrically spaced apart from each other. At this time, the first electrode (11) and the second electrode (12) may be formed to be arranged alternately by dividing the lower surface of the pixel into multiple regions. As an example, FIG. 2 illustrates a case where each of the first electrode (11) and the second electrode (12) has a pattern formed in the shape of multiple fan-shaped segments that extend radially from the center of the lower surface of the pixel. In FIG. 2, (a) shows the pattern of the first electrode (11), (b) shows the pattern of the second electrode (12), and (c) shows the form in which the first electrode (11) and the second electrode (12) of (a) and (b) are formed together.

[0023] As shown in FIG. 2 (a) and (b), a plurality of fan-shaped patterns of the first electrode (11) are formed to be electrically connected to each other so as to receive a first voltage in common, and a plurality of fan-shaped patterns of the second electrode (12) are also configured to be electrically connected to each other so as to receive a second voltage in common. And as shown in (c), the first and second electrodes (11, 12) may be formed to be isolated from each other without being electrically connected. However, FIG. 2 is merely an example, and the shapes of the first electrode (11) and the second electrode (12) are not limited thereto and can be formed in various shapes.

[0024] The first and second electrodes (11, 12) are not shown but can be formed on a substrate (not shown), and as an example, they can be formed by depositing a thin film of tungsten (e.g., 100 nm) on the substrate. Here, the first electrode (11) and the second electrode (12) are formed spaced apart from each other on the same plane, so they can be formed together in a single electrode formation process.

[0025] An insulating film (13) is formed on the upper side and between the first and second electrodes (11, 12). The insulating film (13) prevents the first electrode (11) and the second electrode (12) from being electrically connected to each other, and also prevents the first and second electrodes (11, 12) from coming into direct contact with the color ink (30).

[0026] Since the first electrode (11) and the second electrode (12) are spaced apart from each other and are electrically insulated by an insulating film (13), they can receive different voltages. As the first electrode (11) and the second electrode (12) can receive different voltages, a voltage difference may occur between the first electrode (11) and the second electrode (12), and the shape of the color ink (30) may change due to an electrowetting phenomenon caused by the electric field generated by the voltage difference between the first electrode (11) and the second electrode (12). The insulating film (13) may be formed, for example, by depositing silicon dioxide (SiO2) as a thin film (e.g., 100 nm).

[0027] The hydrophobic film (14) formed on the insulating film (13) allows the color ink (30) to remain in a droplet shape as shown in FIG. 1 when no voltage is applied to the first and second electrodes (11, 12). That is, when no voltage is applied to the first and second electrodes (11, 12), the color ink (30) forms an obtuse angle at the edge of the contact surface with the hydrophobic film (14), causing it to clump together in a small area. The hydrophobic film (14) can be formed by coating a hydrophobic material on the insulating film (13).

[0028] The transparent cover (20) is positioned at a certain distance from the upper surface of the lower electrode panel (10). The transparent cover (20) prevents the color ink (30) and oil (40) contained between it and the lower electrode panel (10) from leaking out. The transparent cover (20) can be implemented with various transparent materials, such as transparent resin or PDMS (polydimethylsiloxane).

[0029] Color ink (30) and oil (40) are injected and filled between the lower electrode panel (10) and the transparent cover (20). That is, the space between the lower electrode panel (10) and the transparent cover (20) is filled with liquid. Color ink (30) is a liquid that is an element that specifies the color that the corresponding pixel can express and whose shape can change according to the electrowetting phenomenon, and may be composed of, for example, water containing pigment. At this time, the color of the color ink (30) may contain pigments corresponding to each color required by the pixel; for example, in the case of an e-book, white or black pigment may be contained, and in the case of an advertising board or other devices, one of R, G, or B pigments may be contained.

[0030] When a water-based color ink (30) is placed on a hydrophobic film (14) to which no voltage is applied to the first and second electrodes (11, 12), it maintains a rounded shape and occupies only a small area of ​​the total surface area of ​​the hydrophobic film (14), i.e., the area of ​​the pixel. However, when voltage is applied to the first and second electrodes (11, 12) and a voltage difference occurs between the first and second electrodes (11, 12), the color ink (30) changes shape to a widely spread form on the hydrophobic film (14).

[0031] The oil (40) is a liquid that is immiscible with the color ink (30) and fills the remaining space between the lower electrode panel (10) and the transparent cover (20) that is not filled with the color ink (30) without mixing with the color ink (30). Since the oil (40) has a lower density (specific gravity) compared to the water-based color ink (30), the color ink (30) sinks toward the lower electrode panel (10) and remains in contact with the hydrophobic membrane (14). Additionally, the oil (40) prevents the color ink (30), which is a fluid liquid, from moving too easily.

[0032] Meanwhile, a spacer (50) is formed at the edge of the lower electrode panel (10) at each pixel to distinguish it from adjacent pixels. The spacer (50) serves to isolate the color ink (30) located on the hydrophobic film (14) of the lower electrode panel (10) so that it does not move to other adjacent pixels. That is, it isolates the color ink (30) so that it does not go beyond the area of ​​the corresponding pixel, thereby allowing each pixel to maintain a designated color. At this time, the spacer (50) may be formed so as not to reach the transparent cover (20) placed on the top, as shown in FIG. 1. Therefore, the oil (40) can be filled in common across multiple pixels without being limited to the area of ​​each pixel. Although FIG. 1 shows the spacer (50) being formed at the side edge of the lower electrode panel (10) at the pixel, the spacer (50) may also be formed on the lower electrode panel (10). Since the spacer (50) is configured only to isolate the color ink (30) within the pixel area, it may be formed on the upper surface as well as on the side of the lower electrode panel (10).

[0033] Figure 3 shows the shape change of color ink according to the voltage difference applied to the first and second electrodes of the pixel shown in Figure 1.

[0034] Figures 3 (a) to (f) illustrate the shape change of the color ink (30) when the voltage difference between the first electrode (11) and the second electrode (12) increases in increments of 20V from 110V to 210V. As shown in Figure 3, as the voltage difference between the first electrode (11) and the second electrode (12) increases, it can be seen that the color ink (30) spreads widely on the lower electrode panel (10) of the pixel due to the electrowetting phenomenon. That is, the area occupied by the color ink (30) in the pixel gradually increases.

[0035] In this way, in the electrowetting display device, if voltage is not applied to the first and second electrodes (11, 12) at each pixel, the color ink (30) remains clustered in a portion of the hydrophobic film (14). Therefore, the color of the corresponding pixel is not significantly affected by the color ink (30). However, when voltage is applied to the first and second electrodes (11, 12) and the color ink (30) spreads widely on the hydrophobic film (14), the area occupied by the color ink (30) in the pixel expands, and the light incident on and reflected from the corresponding pixel is expressed in a color according to the color ink (30).

[0036] As a result, by applying different voltages to the first and second electrodes (11, 12) of each of the arrayed multiple pixels, the electrowetting display device can output various images.

[0037] In the case of a conventional electrowetting display device, a first electrode is formed on the lower electrode panel (10), and a second electrode is formed on the transparent cover (20). Accordingly, since only one of the two electrodes is formed on the lower electrode panel (10), a separate process for forming the second electrode on the transparent cover (20) had to be added. Consequently, there was a problem of increased manufacturing costs due to the increased number of manufacturing processes. Furthermore, even if the second electrode formed on the transparent cover (20) is formed as a transparent electrode such as Indium Tin Oxide (ITO), the transmittance is lower compared to the case where the second electrode is not formed.

[0038] However, in the above-described embodiment of the co-planar electro-wetting display device, since both the first and second electrodes are formed on the lower electrode panel (10), only the process for the lower electrode panel (10) needs to be performed, thereby reducing manufacturing costs, and additionally, since no additional configuration is formed on the transparent cover (20), a high transmittance can be maintained.

[0039] In the illustrated embodiments, each component may have different functions and capabilities in addition to those described above and may include additional components not described. Additionally, in one embodiment, each component may be implemented using one or more physically separated devices, or by one or more processors or a combination of one or more processors and software, and may not be clearly distinguished in specific operation as in the illustrated examples.

[0040] FIG. 4 illustrates a method for manufacturing an electro-wetting display according to one embodiment.

[0041] Referring to FIG. 4, a method for manufacturing an electro-wetting display according to one embodiment first manufactures a lower electrode panel (10).

[0042] First and second electrodes (11, 12) are formed spaced apart from each other on the same plane (71). Here, the first and second electrodes (11, 12) can be implemented in various patterns and can be formed alternately. For example, as shown in FIG. 2, the first and second electrodes (11, 12) can be formed in a shape in which a plurality of fan shapes extending radially from the center of the pixel bottom surface are alternately arranged. The first and second electrodes (11, 12) can be formed by depositing on a substrate (not shown).

[0043] Then, an insulating film (13) is formed on the first and second electrodes (11, 12) (72). The insulating film (13) can also be formed by deposition in the same way as the first and second electrodes (11, 12), and since the first and second electrodes (11, 12) are formed spaced apart from each other on the same plane, the insulating film (13) is also formed between the first electrode (11) and the second electrode (12) so that the first electrode (11) and the second electrode (12) are electrically isolated from each other. Once the insulating film (13) is formed, a hydrophobic film (14) is formed again on the insulating film (13) (73). The hydrophobic film (14) can be formed by coating a hydrophobic material on the insulating film (13).

[0044] When the hydrophobic film (14) is formed and the lower electrode panel (10) is manufactured, a spacer (50) is formed so that the regions of each pixel are separated from each other (74).

[0045] Color ink (30) of the color assigned to each pixel is placed on the lower electrode panel (10) of each manufactured pixel (81). At this time, the color ink (30) placed on the hydrophobic film (14) of the lower electrode panel (10) comes into contact in the form of a droplet.

[0046] Then, a transparent cover (20) is placed on top of the manufactured lower electrode panel (10) at a certain distance (82). Then, oil (40) is injected between the lower electrode panel (10) and the transparent cover (20) to fill and fill the extra space between the lower electrode panel (10) and the transparent cover (20) (83).

[0047] Although FIG. 4 describes each process as being executed sequentially, this is merely an illustrative description, and a person skilled in the art can modify and adapt it in various ways without departing from the essential characteristics of the embodiment of the present invention, such as changing the order described in FIG. 4, executing one or more processes in parallel, or adding other processes.

[0048] FIG. 5 is a diagram illustrating a computing environment including a computing device according to one embodiment.

[0049] In the illustrated embodiments, each component may have different functions and capabilities in addition to those described below, and may include additional components in addition to those described below. The illustrated computing environment (90) may include a computing device (91) to perform the method of manufacturing the electro-wetting display device illustrated in FIG. 4. In one embodiment, the computing device (91) may be one or more components included in a manufacturing device for manufacturing the electro-wetting display device illustrated in FIG. 1.

[0050] A computing device (91) includes at least one processor (92), a computer-readable storage medium (93), and a communication bus (95). The processor (92) may enable the computing device (91) to operate according to the exemplary embodiment described above. For example, the processor (92) may execute one or more programs (94) stored in the computer-readable storage medium (93). The one or more programs (94) may include one or more computer-executable instructions, and the computer-executable instructions may be configured to enable the computing device (91) to perform operations according to the exemplary embodiment when executed by the processor (92).

[0051] The communication bus (95) interconnects various other components of the computing device (91), including the processor (92) and the computer-readable storage medium (93).

[0052] The computing device (91) may also include one or more input / output interfaces (96) and one or more communication interfaces (97) that provide an interface for one or more input / output devices (98). The input / output interfaces (96) and communication interfaces (97) are connected to a communication bus (95). The input / output devices (98) may be connected to other components of the computing device (91) through the input / output interfaces (96). An exemplary input / output device (98) may include an input device such as a pointing device (such as a mouse or trackpad), a keyboard, a touch input device (such as a touchpad or touchscreen), a voice or sound input device, various types of sensor devices and / or imaging devices, and / or an output device such as a display device, a printer, a speaker and / or a network card. An exemplary input / output device (98) may be included inside the computing device (91) as a component constituting the computing device (91), or it may be connected to the computing device (91) as a separate device distinct from the computing device (91).

[0053] Although the present invention has been described in detail above through representative embodiments, those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

Claims

Claim 1 An electrowetting display device comprising: a lower electrode panel having a plurality of pixels, wherein each of the plurality of pixels has first and second electrodes formed on the same plane and electrically isolated from each other; a transparent cover spaced apart in the upward direction of the lower electrode panel; a color ink disposed on the lower electrode panel and deformed by an electrowetting phenomenon when voltage is applied to the first and second electrodes; and an oil having incompatibility with respect to the color ink and filling the remaining space between the lower electrode panel and the transparent cover excluding the space occupied by the color ink, wherein the first and second electrodes each have a structure in which a plurality of fan-shaped patterns extending radially from the center of the lower surface of the pixel are alternately arranged to interlock with each other, and the color ink is clustered in a droplet shape in the central area of ​​the pixel when voltage is not applied to the first and second electrodes, and then spreads uniformly across the entire pixel area along the radial patterns by an electric field caused by the voltage difference between the first and second electrodes to express color. Claim 2 delete Claim 3 delete Claim 4 The electrowetting display device according to claim 1, wherein the lower electrode panel comprises an insulating film formed between the first and second electrodes and on top, and a hydrophobic film formed on the insulating film. Claim 5 In paragraph 4, the lower electrode panel further comprises an electrowetting display device comprising a substrate on which the first and second electrodes are formed on an upper surface. Claim 6 delete Claim 7 delete Claim 8 The electrowetting display device according to claim 1, further comprising a spacer formed in the direction of the transparent cover from the outer edge of the pixel area of ​​the lower electrode panel to isolate the color ink disposed on the lower electrode panel so as not to move to an adjacent pixel. Claim 9 A method for manufacturing an electrowetting display device comprising a plurality of pixels, performed by a processor, comprising the steps of: manufacturing a lower electrode panel having first and second electrodes formed electrically isolated from each other on the same plane; placing a color ink on the lower electrode panel that is deformed by an electrowetting phenomenon when voltage is applied to the first and second electrodes; placing a transparent cover spaced apart in the upper direction of the lower electrode panel; and filling an oil having incompatibility with respect to the color ink between the lower electrode panel and the transparent cover, wherein the step of manufacturing the lower electrode panel is formed such that the first and second electrodes are each formed in a shape in which a plurality of fan-shaped patterns extending radially from the center of the pixel's lower surface are alternately arranged to interlock with each other, and the color ink is configured to clump together in a droplet shape on the lower electrode panel when voltage is not applied. Claim 10 In claim 9, the step of manufacturing the lower electrode panel comprises forming the first and second electrodes on the same plane, forming an insulating film between and above the first and second electrodes, and forming a hydrophobic film on the insulating film, in a method for manufacturing an electrowetting display. Claim 11 delete Claim 12 delete Claim 13 In claim 10, the step of manufacturing the lower electrode panel is a method for manufacturing an electrowetting display in which the first and second electrodes are formed on the same substrate. Claim 14 delete Claim 15 In claim 9, the step of manufacturing the lower electrode panel further comprises forming a spacer formed in the direction of the transparent cover from the outer edge of the pixel area of ​​the lower electrode panel to isolate the color ink disposed on the lower electrode panel so as not to move to an adjacent pixel.

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