KR20080029068A - Electrophoretic display - Google Patents

Abstract

An electro-phoretic display is provided to move electro-phoretic members easily without the fluid resistance, thereby increasing the display representation speed. Plural pixel electrodes(190) are formed on an insulating substrate. A partition divides the pixel electrodes. A common electrode display panel is formed on the partition and includes a common electrode(220) arranged oppositely to the pixel electrode. An electro-phoretic member(310) is located in the pixel area surrounded by the pixel electrode, the common electrode and the partition. The electro-phoretic member includes also a metal plate electrified by positive and negative charges and a coloring member surrounding the metal plate. The coloring member includes any one of organic insulating material and inorganic insulating material. The coloring material includes a titanium oxide.

Description

Electrophoretic display {ELECTROPHORETIC DISPLAY}

  1 is a layout view illustrating a structure of an electrophoretic display device according to an exemplary embodiment of the present invention;

2 and 3 are cross-sectional views of the electrophoretic display of FIG. 1 taken along the line II-II ', respectively;

4 is a cross-sectional view illustrating three pixel areas of the electrophoretic display of FIG. 1;

5 is a front view of an electrophoretic member of the electrophoretic display device according to the exemplary embodiment of the present invention;

6 is a cross-sectional view illustrating three pixel areas of an electrophoretic display device according to another exemplary embodiment of the present invention; and

7 is a front view of an electrophoretic member of an electrophoretic display according to another exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100, 101: thin film transistor display panel

110: insulation substrate 121: gate line

124: gate electrode 129: end of gate line

140: gate insulating film 151: linear semiconductor layer

161: linear ohmic contact 171: data line

173: source electrode 175: drain electrode

179: end of the data line 180: protective film

181, 182, and 185: contact hole 190: pixel electrode

191 and 192: partition wall 200: common electrode display panel

210: insulating substrate 220: common electrode

230: organic film 300: fluidized medium

310, 311, 312, 313: electrophoretic member

314: metal plate 315, 316, 317, 318: coloring member

319: fluid through hole

The present invention relates to an electrophoretic display device.

Recently, flat panel displays such as liquid crystal displays, organic light emitting diodes (OLEDs), and electrophoretic displays (ELECTROPHORETIC DISPLAYs) have been used in place of existing CRTs.

The electrophoretic display device includes a thin film transistor array panel on which a pixel electrode is formed, a common electrode panel disposed opposite to the thin film transistor array panel and including a common electrode, and an electrophoretic member disposed between the pixel electrode and the common electrode. do.

The electrophoretic member usually includes electrophoretic particles having a positive or negative charge and exhibiting a predetermined color, a dispersion medium in which the electrophoretic particles are dispersed, and a microcapsule containing the electrophoretic particles and the dispersion medium.

The electrophoretic display device displays a desired image in such a manner that the electrophoretic particles rotate or move near the pixel electrode or the common electrode according to the driving voltage applied to the electrophoretic member by the pixel electrode and the common electrode.

However, the conventional electrophoretic display device has a complicated structure of an electrophoretic member, and thus, there is a problem in that the electrophoretic display device is not easily manufactured.

Accordingly, an object of the present invention is to solve the above problems and to provide an electrophoretic display device having a simple structure and easy to manufacture.

An electrophoretic display device according to an exemplary embodiment of the present invention includes a plurality of pixel electrodes formed on an insulating substrate, a common electrode including a partition wall separating the pixel electrodes, and a common electrode formed on the partition wall and disposed to face the pixel electrode. And a plate-shaped electrophoretic member positioned in a pixel area surrounded by the display panel, the pixel electrode, the common electrode, and the partition wall.

The electrophoretic member may include a metal plate positively or negatively charged and a coloring member surrounding the metal plate.

The coloring member may include at least one of an organic insulating material and an inorganic insulating material.

The coloring member may exhibit white color.

The coloring member may include titanium oxide (TiO 2).

The coloring member may represent any one of blue, green, and red colors or any one of yellow, magenta, and cyan colors.

The partition wall may be black.

The liquid crystal may further include a fluid medium filled in the pixel area.

The electrophoretic member may have a fluid passage hole formed therein.

The liquid medium may be black.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Next, an electrophoretic display device and a manufacturing method thereof according to various embodiments of the present invention will be described with reference to the accompanying drawings.

First, an electrophoretic display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6.

1 is a layout view illustrating a structure of an electrophoretic display device according to an exemplary embodiment of the present invention. FIGS. 2 and 3 are cross-sectional views taken along line II-II 'of the electrophoretic display device of FIG. 1, and FIG. 1 is a cross-sectional view illustrating three pixel areas of the electrophoretic display device, and FIG. 5 is a front view of the electrophoretic member of the electrophoretic display device according to an exemplary embodiment of the present invention.

An electrophoretic display device according to an exemplary embodiment of the present invention includes an electrophoretic member positioned in a pixel region A between a thin film transistor array panel 100, a common electrode display panel 200, and both display panels 100 and 200 facing each other. (310, 311, 312).

First, the thin film transistor array panel 100 will be described.

As shown in FIGS. 1 to 4, a plurality of gate lines 121 may be formed on an insulating substrate 110 made of transparent glass or the like. The gate line 121 extends in the horizontal direction, and each gate line 121 includes a plurality of gate electrodes 124 and a wide end portion 129 for connection with another layer or an external circuit. .

The gate line 121 may be formed of aluminum-based metal such as aluminum and aluminum alloy, silver-based metal such as silver and silver alloy, copper-based metal such as copper and copper alloy, molybdenum-based metal such as molybdenum and molybdenum alloy, chromium, titanium, It is preferably made of tantalum. The gate line 121 may include two layers having different physical properties, that is, a lower layer (not shown) and an upper layer (not shown) thereon. The upper layer is made of a metal having a low resistivity, for example, an aluminum-based metal such as aluminum (Al) or an aluminum alloy so as to reduce a signal delay or voltage drop of the gate line 121. In contrast, the lower layer is made of a material having excellent contact properties with other materials, particularly indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum (Mo), molybdenum alloy, chromium (Cr), and the like. An example of the combination of the lower layer and the upper layer is chromium / aluminum-neodymium (Nd) alloy.

The gate line 121 may have a single layer structure or may include three or more layers.

A gate insulating layer 140 made of silicon nitride (SiNx) is formed on the gate line 121.

A plurality of linear semiconductor layers 151 made of hydrogenated amorphous silicon or the like are formed on the gate insulating layer 140. The linear semiconductor layer 151 extends in the vertical direction and includes a plurality of protrusions 154 extending toward the gate electrode 124. Further, the linear semiconductor layer 151 increases in width near the point where the linear semiconductor layer 151 meets the gate line 121 to cover a large area of the gate line 121.

A plurality of linear and island ohmic contacts 161 and 165 formed of a material such as n + hydrogenated amorphous silicon doped with a high concentration of silicide or n-type impurities are formed on the semiconductor layer 151. It is. The linear contact member 161 has a plurality of protrusions 163, and the protrusions 163 and the island contact members 165 are paired and positioned on the protrusions 154 of the semiconductor layer 151.

A plurality of data lines 171 and a plurality of drain electrodes 175 are formed on the ohmic contacts 163 and 165 and the gate insulating layer 140, respectively.

The data line 171 extends in the vertical direction to cross the gate line 121 and transmit a data voltage. Each data line 171 includes a plurality of source electrodes 173 extending toward the gate electrode 124 and bent in a J-shape and a wide end portion 179 for connection with another layer or an external driving circuit. do. The pair of source and drain electrodes 173 and 175 are separated from each other and positioned opposite to the gate electrode 124.

The data line 171 and the drain electrode 175 are preferably made of a refractory metal such as chromium or molybdenum-based metal, tantalum, and titanium, and include a lower layer such as molybdenum (Mo), molybdenum alloy, and chromium (Cr). And an upper layer (not shown) that is an aluminum-based metal disposed thereon.

The gate electrode 124, the source electrode 173, and the drain electrode 175 together with the protrusion 154 of the semiconductor layer 151 form a thin film transistor (TFT), and the channel of the thin film transistor The protrusion 154 is formed between the source electrode 173 and the drain electrode 175.

The ohmic contacts 161 and 165 are present between the semiconductor layer 151 below and the source electrode 173 and the drain electrode 175 thereon, and serve to lower the contact resistance.

The linear semiconductor layer 151 has an exposed portion between the source electrode 173 and the drain electrode 175, and is not covered by the data line 171 and the drain electrode 175, and in most regions, the linear semiconductor layer ( Although the width of the 151 is smaller than the width of the data line 171, as described above, the width of the 151 increases to increase the insulation between the gate line 121 and the data line 171.

On the data line 171, the drain electrode 175, and the exposed semiconductor layer 151, an organic material having excellent planarization characteristics, photosensitivity, and plasma enhanced chemical vapor deposition (PECVD) is formed. A passivation layer 180 made of a low dielectric constant insulating material such as a-Si: C: O, a-Si: O: F, or silicon nitride (SiNx), which is an inorganic material, is formed as a single layer or a plurality of layers. have. For example, when formed of an organic material, in order to prevent the organic material of the passivation layer 180 from contacting the exposed portion of the semiconductor layer 154 between the source electrode 173 and the drain electrode 175, the lower portion of the organic layer An insulating film (not shown) made of silicon nitride (SiNx) or silicon oxide (SiO ₂ ) may be further formed.

The passivation layer 180 includes a plurality of contact holes 181 and 185 that expose the end portion 129 of the gate line 121, the drain electrode 175, and the end portion 179 of the data line 171, respectively. , 182 is formed.

A plurality of pixel electrodes 190 and a plurality of contact assistants 81 and 82 made of ITO or IZO are formed on the passivation layer 180.

The pixel electrode 190 is physically and electrically connected to the drain electrode 175 through the contact hole 185 to receive a data voltage from the drain electrode 175.

The pixel electrode 190 to which the data voltage is applied applies a driving voltage to each of the electrophoretic members 310, 311, and 312 together with the common electrode 220 receiving the common voltage. The electrophoretic members 310, 311, and 312 positioned in the pixel region A by the application of the driving voltage are disposed on the pixel electrode 190 or the common across the fluid medium 300 as shown in FIGS. 3 and 4. Moving to the electrode 220 represents a desired image.

The contact auxiliary members 81 and 82 are connected to the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 through the contact holes 181 and 182, respectively. The contact auxiliary members 81 and 82 compensate for and protect the adhesion between the ends of the gate line 121 and the data line 171 and an external device such as a driving integrated circuit.

The barrier layer 191 including at least one of an organic insulating material and an inorganic insulating material and separating the pixel electrodes 190 is formed on the passivation layer 180. The partition wall 191 surrounds a periphery of the edge of the pixel electrode 190 so that the electrophoretic members 310, 311, and 312 may move together with the pixel electrode 190 and the common electrode 220. A) will be defined.

Next, the common electrode display panel 200 will be described.

The common electrode display panel 200 is disposed to face the thin film transistor array panel 100 and is completely in contact with the partition wall 191 so that the fluid medium 300 filled in the pixel region A does not leak to the outside. The common electrode display panel 200 includes a transparent insulating substrate 210 and a common electrode 220 formed on the insulating substrate 210 to have a uniform thickness.

The common electrode 220 is a transparent electrode made of ITO or IZO and applies a common voltage to each of the electrophoretic members 310, 311, and 312.

In the pixel area A, electrophoretic members 310, 311, and 312 moving between the pixel electrode 190 and the common electrode 220 by crossing the fluid medium 300 and the fluid medium 300 that are black are formed. Is located.

The electrophoretic members 310, 311, and 312 include a first electrophoretic member 310, a second electrophoretic member 311, and a third electrophoretic member 312, alternately in a plurality of pixel regions A. FIG. It is arranged repeatedly.

The first electrophoretic member 310 includes a metal plate 314 having a negative charge and covering the metal plate 314 in the form of a thin film formed by a deposition method or the like, and a red coloring member 315.

The metal plate 314 is made of a generally known metal having a good charge.

The red coloring member 315 covers the metal plate 314 and is an organic insulating film formed by a coating or the like, and exhibits red color. Unlike the present embodiment, the red coloring member 315 may be an inorganic insulating film formed by a method such as vapor deposition.

As shown in FIG. 5, the fluid plate through-holes 319 penetrating in a line perpendicular to the plate surface are formed in the metal plate 314 and the red coloring member 315 of the first electrophoretic member 310, respectively. The fluid medium through-hole 319 is the fluid electrophoretic member 300 when the first electrophoretic member 310 moves to the pixel electrode 190 or the common electrode 220 in response to the application of the driving voltage. It is a space portion passing through 310. The fluid resistance applied to the first electrophoretic member 310 during the process of moving to the pixel electrode 190 or the common electrode 220 by the fluid medium passage hole 319 is reduced to decrease the fluid resistance of the first electrophoretic member 310. The movement is smooth.

In addition, the second electrophoretic member 311 includes a metal plate 314 having a negative charge and a green thin film member 316 covering the metal plate 314.

The green coloring member 316 is also an organic insulating film formed by a coating or the like and shows green. However, the green coloring member 316 may also be an inorganic insulating film formed by a method such as vapor deposition.

In the metal plate 314 and the green coloring member 316 of the second electrophoretic member 311, a fluid medium passage hole 319 penetrating in a line perpendicular to the plate surface is formed, respectively.

In addition, the third electrophoretic member 312 includes a metal plate 314 having a negative charge and covering the metal plate 314, which is a thin film form, and a blue coloring member 317.

The blue coloring member 317 is also an organic insulating film formed by a coating or the like and shows blue. However, the blue coloring member 317 may also be an inorganic insulating film formed by a method such as vapor deposition.

In the metal plate 314 and the blue coloring member 317 of the third electrophoretic member 312, a fluid medium passage hole 319 penetrating in a line perpendicular to the plate surface is formed, respectively.

Unlike the present embodiment, the metal plates 314 of each of the electrophoretic members 310, 311, and 312 may have positive charges having opposite polarities instead of negative charges, and in this case, the driving voltage applied according to the present embodiment The electrophoretic display may be driven in the same manner by applying a driving voltage having the opposite polarity.

On the other hand, the red colored member 315, the green colored member 316 and the blue colored member 317 are different from the present embodiment, respectively, a yellow colored member representing yellow, a magenta colored member representing magenta, and cyan You may provide with the cyan coloring member which shows (cyan).

Hereinafter, a method of displaying an image of various colors by the electrophoretic display device according to an exemplary embodiment of the present invention will be described with reference to FIGS. 2 to 4.

First, a case in which a positive voltage is applied to the pixel electrode 190 and a negative voltage is applied to the common electrode 220 through the drain electrode 175 of the electrophoretic display device will be described.

In this case, as shown in FIGS. 2 and 4, each of the electrophoretic members 310, 311, and 312 having a negative charge moves to the pixel electrode 190 to which a positive voltage is applied.

Therefore, the external light incident from the outside across the common electrode display panel 200 is absorbed by the fluid medium 300 representing black and displays the black image to the outside.

Next, first, a negative voltage is applied to the pixel electrode 190 and a positive voltage is applied to the common electrode 220 through the drain electrode 175 of the electrophoretic display.

In this case, as shown in FIG. 3, each of the electrophoretic members 310, 311, and 312 having a negative charge moves to the common electrode 220 to which a positive voltage is applied across the fluid medium 300. . Therefore, the external light incident through the common electrode display panel 200 is reflected by each of the electrophoretic members 310, 311, and 312, and the red color indicated by each of the electrophoretic members 310, 311, and 312 for each pixel area A is determined. A white image which is green, blue or a mixture of these colors is displayed.

Electrophoretic display device according to an embodiment of the present invention is simpler than the conventional electrophoretic member of the structure of each electrophoretic member (310, 311, 312) comprising a microcapsule containing the electrophoretic particles and dispersion medium It is easy to manufacture.

Hereinafter, an electrophoretic display device according to another exemplary embodiment of the present invention will be described with reference to FIGS. 6 and 7. 6 is a cross-sectional view illustrating three pixel areas of an electrophoretic display device according to another exemplary embodiment. FIG. 7 is a front view of an electrophoretic member of an electrophoretic display device according to another exemplary embodiment.

In the electrophoretic display device according to another exemplary embodiment of the present invention, the fluid medium 300 is not filled in the pixel region A, and the partition wall 192 of the thin film transistor array panel 101 is black. In addition, an electrophoretic display according to an embodiment of the present invention is provided except that an electrophoretic member 313 including a white coloring member 318 representing white to represent only a black and white image is disposed in each pixel region A. FIG. Same as the device.

Even when there is no black liquid medium 300, as shown in FIG. 6, when the partition wall 192 is black, external light incident on the pixel area A may be absorbed by the partition wall 192. have. Accordingly, since the pixel area A can display a black image and there is no fluid resistance by the fluid medium 300, the electrophoretic members 310, 311, and 312 can be easily moved, and thus the image expression speed of the electrophoretic display device is increased. Can be faster.

In addition, as shown in FIG. 6, the thickness d2 of the barrier rib 192 is thicker than the thickness d1 of the barrier rib 191 of the electrophoretic display device shown in FIGS. 2 to 4. By this, absorption of external light can be further increased.

On the other hand, in the electrophoretic display device according to another exemplary embodiment of the present invention, since the fluid medium 300 is not filled in the pixel area A, as shown in FIG. 7, the fluid passage holes are formed in each of the electrophoretic members 313. 319 may not be formed.

The white coloring member 318 may also be an organic insulating film or an inorganic insulating film, and in the case of an inorganic insulating film, may include a titanium oxide (TiO 2) material.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As mentioned above, according to this invention, the electrophoretic display apparatus which has a simple structure and is easy to manufacture is provided.

Claims (10)

A plurality of pixel electrodes formed on the insulating substrate, Partition walls by separating the pixel electrodes; A common electrode display panel formed on the partition wall and including a common electrode disposed to face the pixel electrode; And a plate-shaped electrophoretic member positioned in the pixel region surrounded by the pixel electrode, the common electrode, and the partition wall. In claim 1, The electrophoretic member, Positive or negatively charged metal plates, and An electrophoretic display device comprising a coloring member surrounding the metal plate. In claim 1, The coloring member includes at least one of an organic insulating material and an inorganic insulating material. In claim 3, The coloring member is white electrophoretic display device. In claim 4, The coloring member includes titanium oxide (TiO 2). In claim 3, The coloring member exhibits any one color of blue, green, and red, or any one of yellow, magenta, and cyan. In claim 1, The partition is black electrophoretic display device. In claim 1, And a fluid medium filled in the pixel area. In claim 8, And the electrophoretic member has a fluid passage hole formed therein. In claim 8, And the liquid medium is black.

Images