Electrophoretic display device and driving method thereof

Abstract

The present invention discloses an electrophoretic display device and a driving method thereof. The electrophoretic display device includes a first element substrate, a second element substrate, a display medium layer, and an isolation structure. The first element substrate includes a first carrier plate and a plurality of pixel electrodes. The pixel electrodes are arrayed on the first carrier plate. The second element substrate includes a second carrier plate and at least one common electrode. The common electrode overlaps the pixel electrodes. The display medium layer and the isolation structure are located between the first carrier plate and the second carrier plate. The display medium layer includes a plurality of charged particles. The isolation structure includes a barrier structure and an isolation electrode. The isolation electrode is formed on the bottom surface of the barrier structure and is adjacent to the display medium layer.

Description

Technical Field

[0001] The present invention relates to an electrophoretic display device and a driving method thereof. Background Art

[0002] In recent years, due to the continuous and vigorous development of various display technologies, after continuous research and development, products such as electrophoretic displays, liquid crystal displays, plasma displays, organic light-emitting diode displays, etc. have gradually been commercialized and applied to display devices of various sizes and areas. With the increasing popularity of portable electronic products, flexible displays (such as electronic paper (e-paper), e-books, etc.) have gradually attracted market attention. Generally, electronic paper and e-books use electrophoretic display technology to achieve the purpose of displaying images. In the prior art, an electrophoretic display uses charged particles in a display medium to reflect external light sources, thereby enabling sub-pixels to display the required gray levels. Summary of the Invention

[0003] The present invention provides an electrophoretic display device that can improve the problem of mutual interference between sub-pixels.

[0004] The present invention provides a driving method for an electrophoretic display device that can improve the problem of mutual interference between sub-pixels.

[0005] At least one embodiment of the present invention provides an electrophoretic display device, including a first element substrate, a second element substrate, a display medium layer, and an isolation structure. The first element substrate includes a first carrier plate and a plurality of pixel electrodes. The pixel electrodes are arranged in an array on the first carrier plate. The second element substrate includes a second carrier plate and at least one common electrode. The common electrode overlaps the pixel electrodes. The display medium layer and the isolation structure are located between the first carrier plate and the second carrier plate. The display medium layer includes a plurality of charged particles. The isolation structure includes a barrier structure and an isolation electrode. The isolation electrode is formed on the bottom surface of the barrier structure and is adjacent to the display medium layer.

[0006] At least one embodiment of the present invention provides a driving method for an electrophoretic display device, including an electrophoretic display device; forming a first voltage difference between one of the pixel electrodes and at least one common electrode; and forming a second voltage difference between one of the pixel electrodes and the isolation electrode to form an electric field on the isolation electrode that repels the charged particles. Brief Description of the Drawings

[0007] Figure 1A is a cross-sectional schematic view of an electrophoretic display device according to an embodiment of the present invention;

[0008] Figure 1B is Figure 1A a top view schematic of the electrophoretic display device;

[0009] Figure 2A It is a schematic cross-sectional view of an electrophoretic display device according to an embodiment of the present invention;

[0010] Figure 2B is Figure 2A a top view schematic diagram of the electrophoretic display device;

[0011] Figure 3A It is a data graph showing the relationship between the NTSC color gamut coverage and the reflectance of the electrophoretic display device according to some embodiments of the present invention;

[0012] Figure 3B It is a data graph showing the relationship between the color volume (L*a*b) and the reflectance of the electrophoretic display device according to some embodiments of the present invention;

[0013] Figures 4A to 4E It is a schematic cross-sectional view of a driving method of an electrophoretic display device according to an embodiment of the present invention;

[0014] Figure 5 It is a micrograph of a barrier structure according to an embodiment of the present invention;

[0015] Figure 6 It is a micrograph of a barrier structure according to an embodiment of the present invention.

[0016] Symbol Explanation

[0017] 1: Electrophoretic display device

[0018] 10: First element substrate

[0019] 20: Second element substrate

[0020] 30: Isolation structure

[0021] 40: Display medium layer

[0022] 100: First carrier board

[0023] 110: Active element

[0024] 112: Source electrode

[0025] 114: Gate electrode

[0026] 116: Channel layer

[0027] 118: Drain electrode

[0028] 120: First insulating layer

[0029] 130: Second insulating layer

[0030] 140: Pixel electrode

[0031] 150: Third insulating layer

[0032] 200: Second carrier plate

[0033] 210: Color filter element

[0034] 212: Blue filter element

[0035] 214: Green filter element

[0036] 216: Red filter element

[0037] 220: Flat layer

[0038] 230: Convex microstructure

[0039] 240: Common electrode

[0040] 300, 300A, 300B: Barrier structure

[0041] 302: Bottom surface

[0042] 304: Side surface

[0043] 305: Virtual connection

[0044] 310: Isolation electrode

[0045] 400: Charged particle

[0046] A, B: Width

[0047] DT: Virtual trapezoid

[0048] G, H: Thickness

[0049] GP: Gap

[0050] L: Light ray

[0051] SP1: First sub-pixel

[0052] SP2: Second sub-pixel

[0053] SP3: Third sub-pixel

[0054] θ: Included angle Detailed implementation manner

[0055] Figure 1A is a cross-sectional schematic view of an electrophoretic display device according to an embodiment of the present invention. Figure 1B is Figure 1A a top view schematic of the electrophoretic display device.

[0056] Please refer to Figure 1A and Figure 1B, the electrophoretic display device 1 includes a first element substrate 10, a second element substrate 20, a spacer structure 30, and a display medium layer 40.

[0057] The first element substrate 10 includes a first carrier substrate 100 and a plurality of pixel electrodes 140. In this embodiment, the first element substrate 10 further includes a plurality of active elements 110, a first insulating layer 120, a second insulating layer 130, and a third insulating layer 150.

[0058] The material of the first carrier substrate 100 includes glass, quartz, organic polymer, or light-impermeable / reflection material (e.g., conductive material, metal, wafer, ceramic, or other applicable materials) or other applicable materials. If a conductive material or metal is used, an insulating layer (not shown) is covered on the first carrier substrate 100 to avoid short-circuit problems.

[0059] The active elements 110 are arrayed on the first carrier substrate 100. The active elements 110 include a gate 114, a channel layer 116, a source 112, and a drain 118. The gate 114 overlaps the channel layer 116, and a first insulating layer 120 is sandwiched between the gate 114 and the channel layer 116. The source 112 and the drain 118 are located on the first insulating layer 120 and are electrically connected to the channel layer 116.

[0060] In this embodiment, the active element 110 takes a bottom-gate type thin-film transistor as an example, but the present invention is not limited thereto. In other embodiments, the active element 110 can also be a top-gate type thin-film transistor, a double-gate type, or other types of thin-film transistors.

[0061] In some embodiments, the materials of the gate 114, the source 112, and the drain 118, for example, include metals such as chromium, gold, silver, copper, tin, lead, hafnium, tungsten, molybdenum, neodymium, titanium, tantalum, aluminum, zinc, the above alloys, the above metal oxides, the above metal nitrides, or the combination of the above or other conductive materials. In some embodiments, the material of the channel layer 116, for example, includes amorphous silicon, polycrystalline silicon, microcrystalline silicon, single-crystalline silicon, organic semiconductor materials, oxide semiconductor materials (e.g., indium zinc oxide, indium gallium zinc oxide, or other suitable materials, or the combination of the above materials) or other suitable materials or the combination of the above materials.

[0062] The second insulating layer 130 is located on the active elements 110, and the second insulating layer 130 has an opening overlapping the drain 118 of the active elements 110.

[0063] The pixel electrodes 140 are arrayed on the first carrier substrate 100. In this embodiment, the pixel electrodes 140 are located on the second insulating layer 130 and fill the openings of the second insulating layer 130 to be electrically connected to the drain 118 of the active element 110. In this embodiment, each sub-pixel includes a corresponding pixel electrode 140 and a corresponding active element 110. In some embodiments, the pixel electrodes 140 include transparent electrodes (such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium gallium zinc oxide or other transparent conductive materials), reflective electrodes (such as metals) or other conductive materials. The third insulating layer 150 is located on the pixel electrodes 140 and covers the pixel electrodes 140.

[0064] The second element substrate 20 includes a second carrier substrate 200 and at least one common electrode 240. In this embodiment, the second element substrate 20 further includes a color filter element 210, a planarization layer 220, and a plurality of protruding microstructures 230.

[0065] The material of the second carrier substrate 200 includes glass, quartz, organic polymers or other applicable transparent materials.

[0066] The color filter element 210 is located between the first carrier substrate 100 and the second carrier substrate 200. In this embodiment, the color filter element 210 is formed on the second carrier substrate 200, but the present invention is not limited thereto. In other embodiments, other insulating layers, protective layers and / or buffer layers are further sandwiched between the color filter element 210 and the second carrier substrate 200. In this embodiment, the color filter element 210 includes a blue filter element 212, a green filter element 214, and a red filter element 216. The blue filter element 212, the green filter element 214, and the red filter element 216 are separated from each other.

[0067] The planarization layer 220 is located on the color filter element 210. The planarization layer 220 covers the color filter element 210. A plurality of protruding microstructures 230 are formed on the planarization layer 220, and the protruding microstructures 230 protrude toward the display medium layer 40. In this embodiment, the plurality of protruding microstructures 230 are arrayed on the planarization layer 220. In some embodiments, the protruding microstructures 230 include photoresist materials, and the method of forming the protruding microstructures 230 includes more than one lithography process. For example, the protruding microstructures 230 are formed by three lithography processes, and about one-third of the number of protruding microstructures 230 are formed each time. Therefore, the protruding microstructures 230 formed by each lithography process can have a relatively large spacing from each other, thereby improving the manufacturing yield. The planarization layer 220 and the protruding microstructures 230 include transparent materials. For example, the planarization layer 220 and the protruding microstructures 230 include resins, photoresist materials or other transparent materials.

[0068] The common electrode 240 is formed on the convex microstructure 230. In this embodiment, the common electrode 240 is directly formed on the convex microstructure 230, but the present invention is not limited thereto. In other embodiments, a buffer layer is included between the common electrode 240 and the convex microstructure 230. The common electrode 240 has a surface that undulates corresponding to the convex microstructure 230. The common electrode 240 is, for example, conformal to the convex microstructure 230. The common electrode 240 overlaps the pixel electrode 140. In some embodiments, the common electrode 240 includes a transparent electrode, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium gallium zinc oxide, or other conductive materials.

[0069] The display medium layer 40 is located between the first carrier plate 100 and the second carrier plate 200. The display medium layer 40 includes a plurality of charged particles 400. The charged particles 400 are, for example, particles with negative or positive charges, and the charged particles 400 include light-absorbing materials. In the absence of an applied electric field, the charged particles 400 are dispersed in the electrophoretic solution of the display medium layer 40.

[0070] The isolation structure 30 is located between the first carrier plate 100 and the second carrier plate 200. In this embodiment, the isolation structure 30 is located between the convex microstructure 230 and the third insulating layer 150. The isolation structure 30 includes a barrier structure 300 and an isolation electrode 310.

[0071] The barrier structure 300 is directly formed on the convex microstructure 230 and / or the common electrode 240. The barrier structure 300 includes a reflective material. In some embodiments, the barrier structure 300 includes a photoresist material and reflective particles dispersed in the aforementioned photoresist material (such as porous (or air-containing) silicon dioxide (SiO2), titanium dioxide (TiO2), aluminum oxide (Al2O3), calcium carbonate (CaCO3), barium sulfate (BaSO4), zirconium oxide (ZrO2), metal-coated polymer microparticles, hollow polymer particles, or other particles that can reflect light). In other embodiments, the barrier structure 300 includes a photoresist material and a reflective layer formed on the surface of the aforementioned photoresist material. In some embodiments, the method of forming the barrier structure 300 includes a photolithography process.

[0072] The partial display medium layer 40 is located between the bottom surface 302 of the barrier structure 300 and the first element substrate 10. In this embodiment, an angle θ less than 90 degrees is included between the side surface 304 and the bottom surface 302 of the barrier structure 300. Therefore, the line width of the barrier structure 300 increases as it approaches the first element substrate 10, thereby reducing the probability of interference between charged particles 400 of different sub-pixels. Specifically, since the line width of the barrier structure 300 is wider near the first element substrate 10, the length of the gap between the barrier structure 300 and the third insulating layer 150 is longer, making it less likely for the charged particles 400 to pass through the gap between the barrier structure 300 and the third insulating layer 150, thereby avoiding the problem of uneven brightness caused by different numbers of charged particles 400 in different sub-pixels. In some embodiments, the angle θ includes an acute angle or a rounded corner.

[0073] In Figure 1A the embodiment of, in the cross-sectional structure of the electrophoretic display device 1, the virtual trapezoid DT includes the bottom surface 302 of the barrier structure 300, the side surface 304 of the barrier structure 300, the virtual connection line 305 extending from the side surface 304 of the barrier structure 300 to the flat layer 220, and the surface of the flat layer 220 between the virtual connection lines 305. The width of the surface of the flat layer 220 between the virtual connection lines 305 is A, the width of the bottom surface 302 of the barrier structure 300 is B, and the height of the virtual trapezoid DT is H, where A + 2H × cot(80°) ≤ B ≤ A + 2H × cot(10°). In some embodiments, the maximum thickness of the barrier structure 300 is H, and the maximum thickness of the display medium layer 40 is G, where 0.55G ≤ H ≤ 0.95G. In some embodiments, the width B is greater than the width A, where the width B is, for example, from 1 micron to 500 microns, and the width A is, for example, from 0.67 micron to 100 microns. In some embodiments, the thickness H is, for example, from 0.95 micron to 35.2 microns.

[0074] In Figure 1A the cross-sectional view of, the common electrode 240 includes a plurality of parts separated by the barrier structure 300. However, in some embodiments, a part of the common electrode 240 extends between the barrier structure 300 and the convex microstructure 230 (not shown in the drawings), connecting the plurality of parts of the common electrode 240 to each other.

[0075] The isolation electrode 310 is formed on the bottom surface 302 of the barrier structure 300 and is adjacent to the display medium layer 40. In this embodiment, the isolation electrode 310 is in direct contact with the display medium layer 40, but the present invention is not limited thereto. In this embodiment, the width of the isolation electrode 310 is less than or equal to the bottom surface 302 of the barrier structure 300. In other words, the isolation electrode 310 completely covers or partially covers the bottom surface 302 of the barrier structure 300. In some embodiments, the isolation electrode 310 includes a transparent electrode (such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium gallium zinc oxide, or other transparent conductive materials), a reflective electrode (such as a metal), or other conductive materials. The isolation electrode 310, the common electrode 240, and the pixel electrode 140 are separated from each other. Therefore, different voltages can be applied to the isolation electrode 310, the common electrode 240, and the pixel electrode 140 to form an electric field between the isolation electrode 310 and the common electrode 240, between the isolation electrode 310 and the pixel electrode 140, and between the pixel electrode 140 and the common electrode 240.

[0076] Please also refer to Figure 1A and Figure 1B , in Figure 1B the top view pattern of, the isolation structure 30 is reticular. In this embodiment, both the barrier structure 300 of the isolation structure 30 and the isolation electrode 310 are reticular. The vertical projection of the isolation structure 30 on the second carrier plate 200 overlaps with the gap GP of the vertical projection of the color filter element 210 on the second carrier plate 200. In other words, the vertical projection of the isolation structure 30 on the second carrier plate 200 is located between the vertical projections of the blue color filter element 212, the green color filter element 214, and the red color filter element 216 on the second carrier plate 200.

[0077] The vertical projection of the isolation structure 30 on the second carrier plate 200 is less than or equal to the gap GP of the vertical projection of the color filter element 210 on the second carrier plate 200. In this embodiment, the vertical projection of the isolation structure 30 on the second carrier plate 200 is less than the gap GP of the vertical projection of the color filter element 210 on the second carrier plate 200. Therefore, when viewing the electrophoretic display device 1 from the front (looking down from top to bottom in Figure 1A ), part of the common electrode 240 and the raised microstructure 230 are located between the color filter element 210 and the isolation structure 30, thereby increasing the white light reflected by the electrophoretic display device 1 to improve the reflectivity and brightness of the electrophoretic display device 1.

[0078] Figure 2A is a cross-sectional schematic diagram of an electrophoretic display device according to an embodiment of the present invention. Figure 2B is Figure 2A the top view schematic diagram of the electrophoretic display device of.

[0079] It must be noted here thatFigure 2A and Figure 2B The embodiments of Figure 1A and Figure 1B adopt the element numbers and partial contents of the embodiments of

[0080] Figure 2A and Figure 2B The main difference between the electrophoretic display device 2 of Figure 1A and Figure 1B the electrophoretic display device 1 of

[0081] In this embodiment, when viewing the electrophoretic display device 2 from the front (when looking down from top to bottom in Figure 2A ), there is no common electrode 240 and protruding microstructure 230 between the color filter element 210 and the isolation structure 30, thereby reducing the white light reflected by the electrophoretic display device 2 to improve the color volume of the electrophoretic display device 2.

[0082] Figure 3A is a data graph showing the relationship between the NTSC gamut coverage rate and the reflectance of an electrophoretic display device according to some embodiments of the present invention. Figure 3B is a data graph showing the relationship between the color volume (L*a*b*) and the reflectance of an electrophoretic display device according to some embodiments of the present invention. Figure 3A and Figure 3B The structure of the electrophoretic display device of Figure 1A and Figure 1B the electrophoretic display device 1 of Figure 2A and Figure 2B the electrophoretic display device 2 of

[0083] In Figure 3A and Figure 3B , by changing the width of the isolation structure and / or the width of the gap of the color filter element to adjust the reflectance of the electrophoretic display device. In some embodiments, the larger the width of the isolation structure and the width of the gap of the color filter element, the higher the reflectance of the electrophoretic display device; the smaller the width of the isolation structure and the width of the gap of the color filter element, the lower the reflectance of the electrophoretic display device.

[0084] From Figure 3A and Figure 3B the data, it can be known that the NTSC gamut coverage rate and the color volume (L*a*b*) of the electrophoretic display device will increase as the reflectance of the electrophoretic display device decreases.

[0085] Figures 4A to 4E It is a cross-sectional schematic diagram of a driving method for an electrophoretic display device according to an embodiment of the present invention. It should be noted here that Figures 4A to 4E The embodiments of Figure 1A and Figure 1B adopt the component numbers and partial contents of the embodiments of

[0086] For which, the same or similar component numbers are used to represent the same or similar components, and the description of the same technical content is omitted. For the description of the omitted part, reference can be made to the foregoing embodiments, which will not be elaborated here.

[0086] Please refer to Figure 4A to form a first voltage difference between at least one of the pixel electrodes 140 and the common electrode 240, so as to form an electric field that attracts charged particles on at least one of the pixel electrodes 140. A second voltage difference is formed between at least one of the pixel electrodes 140 and the isolation electrode 310, so as to form an electric field on the isolation electrode 310 that repels the charged particles 400.

[0087] In some embodiments, the charged particles 400 are negatively charged. A first voltage is applied to the pixel electrodes 140 of the first sub-pixel SP1, the pixel electrodes 140 of the second sub-pixel SP2, and the pixel electrodes 140 of the third sub-pixel SP3, a second voltage is applied to the common electrode 240, and a third voltage is applied to the isolation electrode 310, where the third voltage is less than the second voltage, the second voltage is less than the first voltage, and the first voltage, the second voltage, and the third voltage are all less than +30 volts and greater than -30 volts.

[0088] In some embodiments, the charged particles 400 are positively charged. A first voltage is applied to the pixel electrodes 140 of the first sub-pixel SP1, the pixel electrodes 140 of the second sub-pixel SP2, and the pixel electrodes 140 of the third sub-pixel SP3, a second voltage is applied to the common electrode 240, and a third voltage is applied to the isolation electrode 310, where the third voltage is greater than the second voltage, the second voltage is greater than the first voltage, and the first voltage, the second voltage, and the third voltage are all less than +30 volts and greater than -30 volts.

[0089] In the present embodiment, the refractive index of the convex microstructure 230 (for example, greater than or equal to 1.52 and less than or equal to 2.4) is higher than the refractive index of the electrophoretic liquid of the display medium layer 40 (for example, greater than or equal to 1 and less than or equal to 1.52).

[0090] In some embodiments, when the refractive index of the common electrode 240 is greater than or equal to the refractive index of the convex microstructure 230, total internal reflection of the external light L occurs at the interface between the display medium layer 40 and the common electrode 240.

[0091] In some embodiments, when the refractive index of the common electrode 240 is between the refractive index of the convex microstructure 230 and the refractive index of the electrophoretic liquid of the display medium layer 40, total internal reflection occurs at the interfaces between the convex microstructure 230 and the common electrode 240 and between the display medium layer 40 and the common electrode 240.

[0092] In some embodiments, when the refractive index of the common electrode 240 is lower than or equal to the refractive index of the electrophoretic liquid of the display medium layer 40, total internal reflection occurs at the interface between the convex microstructure 230 and the common electrode 240.

[0093] Part of the external light L passes through the blue filter element 212, the green filter element 214, and / or the red filter element 216 to generate the color to be displayed. Figure 4A In [reference], the external light L passes through the blue filter element 212, the green filter element 214, and the red filter element 216, and causes the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 to generate blue light, green light, and red light, respectively. Figure 4A In [reference], part of the external light L does not pass through the color filter element 210 and is reflected at the interface between the display medium layer 40 and the common electrode or on the surface of the isolation structure 30. If the external light L is white light, the light reflected by the isolation structure 30 is white light.

[0094] Please refer to Figure 4B , a third voltage difference is formed between at least one of the pixel electrodes 140 and the common electrode 240 to form an electric field that repels charged particles on at least one of the pixel electrodes 140. A fourth voltage difference is formed between at least one of the pixel electrodes 140 and the isolation electrode 310 to form an electric field that repels charged particles 400 on the isolation electrode 310.

[0095] In some embodiments, the charged particles 400 are negatively charged. A fourth voltage is applied to the pixel electrodes 140 of the first sub-pixel SP1, the pixel electrodes 140 of the second sub-pixel SP2, and the pixel electrodes 140 of the third sub-pixel SP3, a second voltage is applied to the common electrode 240, and a third voltage is applied to the isolation electrode 310, where the third voltage is less than the fourth voltage, the fourth voltage is less than the second voltage, and the second voltage, the third voltage, and the fourth voltage are all less than +30 volts and greater than -30 volts.

[0096] In some embodiments, the charged particle 400 is positively charged. A fourth voltage is applied to the pixel electrodes 140 of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3. A second voltage is applied to the common electrode 240, and a third voltage is applied to the isolation electrode 310, where the third voltage is greater than the fourth voltage, the fourth voltage is greater than the second voltage, and the second voltage, the third voltage, and the fourth voltage are all less than +30 volts and greater than -30 volts.

[0097] In Figure 4B , the charged particle 400 is attracted to the interface between the display medium layer 40 and the common electrode and absorbs external light L, causing the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 to present a dark state.

[0098] Please refer to Figure 4C , a first voltage is applied to the pixel electrode 140 of the third sub-pixel SP3, and a fourth voltage is applied to the pixel electrodes 140 of the first sub-pixel SP1 and the second sub-pixel SP2. A second voltage is applied to the common electrode 240, and a third voltage is applied to the isolation electrode 310.

[0099] In this embodiment, an electric field that attracts the charged particle 400 is formed on the pixel electrode 140 of the third sub-pixel SP3, and an electric field that repels the charged particle 400 is formed on the pixel electrodes 140 of the first sub-pixel SP1, the second sub-pixel SP2, and the isolation electrode 310.

[0100] In Figure 4C , the external light L passes through the red filter element 216 and is reflected, causing the third sub-pixel SP3 to generate red light. In Figure 4C , the charged particle 400 is attracted to the interface between the display medium layer 40 and the common electrode of the first sub-pixel SP1 and the second sub-pixel SP2 and absorbs external light L, causing the first sub-pixel SP1 and the second sub-pixel SP2 to present a dark state.

[0101] Please refer to Figure 4D , a first voltage is applied to the pixel electrode 140 of the second sub-pixel SP2, and a fourth voltage is applied to the pixel electrodes 140 of the first sub-pixel SP1 and the third sub-pixel SP3. A second voltage is applied to the common electrode 240, and a third voltage is applied to the isolation electrode 310.

[0102] In this embodiment, an electric field that attracts the charged particle 400 is formed on the pixel electrode 140 of the second sub-pixel SP2, and an electric field that repels the charged particle 400 is formed on the pixel electrodes 140 of the first sub-pixel SP1, the third sub-pixel SP3, and the isolation electrode 310.

[0103] In Figure 4D ,external light L passes through the green filter element 214 and is reflected, causing the second sub-pixel SP2 to generate green light. In Figure 4D ,charged particles 400 are attracted to the interface between the display medium layer 40 of the first sub-pixel SP1 and the third sub-pixel SP3 and the common electrode, and absorb external light L, causing the first sub-pixel SP1 and the third sub-pixel SP3 to present a dark state.

[0104] Please refer to Figure 4E ,a first voltage is applied to the pixel electrode 140 of the first sub-pixel SP1, and a fourth voltage is applied to the pixel electrodes 140 of the second sub-pixel SP2 and the third sub-pixel SP3. A second voltage is applied to the common electrode 240, and a third voltage is applied to the isolation electrode 310.

[0105] In this embodiment, an electric field for attracting charged particles 400 is formed on the pixel electrode 140 of the first sub-pixel SP1, and an electric field for repelling charged particles 400 is formed on the pixel electrodes 140 of the second sub-pixel SP2, the third sub-pixel SP3, and the isolation electrode 310.

[0106] In Figure 4E ,external light L passes through the blue filter element 212 and is reflected, causing the first sub-pixel SP1 to generate blue light. In Figure 4E ,charged particles 400 are attracted to the interface between the display medium layer 40 of the second sub-pixel SP2 and the third sub-pixel SP3 and the common electrode, and absorb external light L, causing the second sub-pixel SP2 and the third sub-pixel SP3 to present a dark state.

[0107] Figure 5 is a micrograph of a barrier structure according to an embodiment of the present invention.

[0108] Please refer to Figure 5 ,the barrier structure 300A is formed by a photolithography process. In this embodiment, the viscosity of the photoresist material for forming the barrier structure 300A is 86 mPa·s, and the solid content (the content of reflective particles) is 65%. In this embodiment, the optical density (OD) of the formed barrier structure 300A is 0.03 / μm, the reflectance (R% for 450 nm wavelength light) is greater than 50% (for example, 83.5%), and the transmittance (TT% for 500 nm wavelength light) is greater than 10% (for example, 20.2%). In some embodiments, the shape of the formed barrier structure 300A is adjusted by adjusting the characteristics (such as viscosity, composition, etc.) of the photoresist material used. In Figure 5 ,the side surface 304 of the barrier structure 300A and the bottom surface 302 of the barrier structure 300A (in Figure 5The angle between the upper surface) is less than 90 degrees. In Figure 5 In, the width B of the bottom surface 302 of the barrier structure 300A and the width A of the top surface (in Figure 5 In is the lower surface) is approximately 20 microns: 14.4 microns. In Figure 5 In, the thickness H of the barrier structure 300A is greater than 15 microns.

[0109] Figure 6 Is a micrograph of a barrier structure according to an embodiment of the present invention.

[0110] Please refer to Figure 6 , The barrier structure 300B is formed by a photolithography process. In this embodiment, the viscosity of the photoresist material for forming the barrier structure 300B is 113 mPa·s, and the solid content (the content of reflective particles) is 65%. In this embodiment, the optical density (OD) of the formed barrier structure 300B is 0.08 / μm, the reflectance (R% for 450 nm wavelength light) is less than 50% (for example, 47.4%), and the transmittance (TT% for 500 nm wavelength light) is less than 10% (for example, 4.2%). In some embodiments, the shape of the formed barrier structure 300B is adjusted by adjusting the properties (such as viscosity, composition, etc.) of the photoresist material used. In Figure 6 In, the side surface 304 of the barrier structure 300B and the bottom surface 302 of the barrier structure 300B (in Figure 6 In is the upper surface) have a rounded corner. In Figure 6 In, the width B of the bottom surface 302 of the barrier structure 300B and the width A of the top surface (in Figure 6 In is the lower surface) is approximately 20 microns: 16.4 microns. In Figure 6 In, the thickness H of the barrier structure 300B is greater than 15 microns.

Claims

1. An electrophoretic display device, comprising: A first element substrate, comprising: A first carrier plate; and A plurality of pixel electrodes, arranged in an array on the first carrier plate; A second element substrate, comprising: A second carrier plate; and At least one common electrode, overlapping the pixel electrodes; A display medium layer, located between the first carrier plate and the second carrier plate, and comprising a plurality of charged particles; and An isolation structure, located between the first carrier plate and the second carrier plate, and the isolation structure comprises: A barrier structure; and An isolation electrode, formed on the bottom surface of the barrier structure and adjacent to the display medium layer, wherein an angle between a side surface of the barrier structure and the bottom surface of the barrier structure is less than 90 degrees.

2. The electrophoretic display device according to claim 1, wherein a part of the display medium layer is located between the bottom surface of the barrier structure and the first element substrate.

3. The electrophoretic display device according to claim 1, wherein a maximum thickness of the barrier structure is H, a maximum thickness of the display medium layer is G, and 0.55G ≤ H ≤ 0.95G.

4. The electrophoretic display device according to claim 1, wherein the second element substrate comprises: A flat layer; And A plurality of convex microstructures, formed on the flat layer, and the convex microstructures protrude towards the display medium layer, wherein the at least one common electrode is formed on the convex microstructures.

5. The electrophoretic display device according to claim 4, wherein in a cross-sectional structure of the electrophoretic display device, a virtual trapezoid comprises the bottom surface of the barrier structure, a side surface of the barrier structure, a virtual connection line extending from the side surface of the barrier structure to the flat layer, and a surface of the flat layer between the virtual connection lines, wherein a width of the surface of the flat layer between the virtual connection lines is A, a width of the bottom surface of the barrier structure is B, a height of the virtual trapezoid is H, and A + 2H × cot(80°) ≤ B ≤ A + 2H × cot(10°).

6. The electrophoretic display device according to claim 4, wherein the barrier structure is directly formed on the convex microstructures and / or the at least one common electrode.

7. The electrophoretic display device according to claim 4, wherein the barrier structure is reticular, and the isolation electrode is reticular.

8. The electrophoretic display device according to claim 1, wherein the second element substrate comprises: A color filter element, located between the first carrier plate and the second carrier plate, wherein a vertical projection of the isolation structure on the second carrier plate overlaps a gap of a vertical projection of the color filter element on the second carrier plate.

9. The electrophoretic display device according to claim 8, wherein the vertical projection of the isolation structure on the second carrier plate is less than or equal to the gap of the vertical projection of the color filter element on the second carrier plate.

10. The electrophoretic display device according to claim 1, wherein the barrier structure comprises a reflective material, and the charged particles comprise a light-absorbing material.

11. A driving method for an electrophoretic display device, comprising: Providing the electrophoretic display device according to claim 1; Forming a first voltage difference between one of the pixel electrodes and the at least one common electrode; And A second voltage difference is formed between one of the pixel electrodes and the isolation electrode, so that an electric field that repels the charged particles is formed on the isolation electrode.

12. The driving method of the electrophoretic display device according to claim 11, wherein a first voltage is applied to one of the pixel electrodes, a second voltage is applied to the at least one common electrode, and a third voltage is applied to the isolation electrode, wherein the third voltage is less than the second voltage, and the second voltage is less than the first voltage, wherein the charged particles are negatively charged, and an electric field that attracts the charged particles is formed on one of the pixel electrodes.

13. The driving method of the electrophoretic display device according to claim 12, further comprising: forming a third voltage difference between another one of the pixel electrodes and the at least one common electrode, wherein a fourth voltage is applied to another one of the pixel electrodes, and the second voltage is applied to the at least one common electrode; and forming a fourth voltage difference between another one of the pixel electrodes and the isolation electrode, so that an electric field that repels the charged particles is formed on the isolation electrode, wherein the third voltage is applied to the isolation electrode, wherein the third voltage is less than the fourth voltage, and the fourth voltage is less than the second voltage, and an electric field that repels the charged particles is formed on another one of the pixel electrodes.

14. The driving method of the electrophoretic display device according to claim 11, wherein a first voltage is applied to one of the pixel electrodes, a second voltage is applied to the at least one common electrode, and a third voltage is applied to the isolation electrode, wherein the third voltage is greater than the second voltage, and the second voltage is greater than the first voltage, wherein the charged particles are positively charged, and an electric field that attracts the charged particles is formed on one of the pixel electrodes.

15. The driving method of the electrophoretic display device according to claim 14, further comprising: forming a third voltage difference between another one of the pixel electrodes and the at least one common electrode, wherein a fourth voltage is applied to another one of the pixel electrodes, and the second voltage is applied to the at least one common electrode; and forming a fourth voltage difference between another one of the pixel electrodes and the isolation electrode, so that an electric field that repels the charged particles is formed on the isolation electrode, wherein the third voltage is applied to the isolation electrode, wherein the third voltage is greater than the fourth voltage, and the fourth voltage is greater than the second voltage, and an electric field that repels the charged particles is formed on another one of the pixel electrodes.

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