Electrophoretic display device and display panel

Abstract

The invention provides an electrophoretic display device and a display panel, and the electrophoretic display device comprises a first substrate and a second substrate which are oppositely arranged; the pixel retaining wall is arranged between the first substrate and the second substrate, at least one pixel area is defined between the first substrate and the second substrate, white charged particles and black charged particles are distributed in the pixel area, and the proportion of the volume of the white charged particles to the total volume of the particle accumulation area is smaller than or equal to 15%; a first electrode disposed on the first substrate; the second electrode is arranged on the second substrate, and the black charged particles and the white charged particles are configured to be laid on the side of the first substrate or laid on the side of the second substrate or stacked to the pixel retaining wall under the horizontal and vertical electric fields generated by the first electrode and the second electrode; the reflection structure is arranged on the side, away from the first substrate, of the second substrate, and the reflection structure comprises at least one convex body and / or at least one concave body and is configured to reflect transmission light of the pixel area.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to an electrophoretic display device and a display panel. Background Art

[0002] An electrophoretic display device is a device that uses an electric field to control the distribution of black and white charged particles, thereby changing the reflection effect of the charged particles on light to perform display.

[0003] The reflective layer in a general electrophoretic display device is in a planar shape. The planar reflective layer has a relatively low light reflection effect and the display brightness is relatively low. Summary of the invention

[0004] In view of this, an object of the present disclosure is to provide an electrophoretic display device and a display panel to solve or partially solve the above technical problems.

[0005] Based on the above objectives, the present disclosure provides an electrophoretic display device according to a first aspect, including:

[0006] A first substrate and a second substrate arranged opposite to each other;

[0007] A pixel retaining wall is disposed between the first substrate and the second substrate, defining at least one pixel area between the first substrate and the second substrate, wherein white charged particles and black charged particles are distributed in the pixel area, wherein the volume of the white charged particles accounts for less than or equal to 15% of the total volume of the particle accumulation area;

[0008] A first electrode, disposed on the first substrate;

[0009] A second electrode is disposed on the second substrate, wherein the black charged particles and the white charged particles are configured to be laid on the first substrate side or the second substrate side or accumulated at the pixel barrier wall under the horizontal and vertical electric fields generated by the first electrode and the second electrode;

[0010] The reflective structure is arranged on a side of the second substrate away from the first substrate, and the reflective structure includes at least one convex body and / or at least one concave body, and is configured to reflect the transmitted light of the pixel area.

[0011] In some embodiments, the convex body includes at least one of the following:

[0012] A pyramidal convex body, an arched convex body, or a convex body composed of a convex curved surface and an inclined surface.

[0013] In some embodiments, the width of the two ends of the arched convex body is D, the height of the arched convex body is h, and at least one arched convex body satisfies the D / h value of 19 to 21.

[0014] In some embodiments, the slope of the arched convex body is arc-shaped, and the arc angle γ of the arc satisfies 9.5°<γ / 4<10.5°.

[0015] In some embodiments, the area of ​​the arched convex body accounts for greater than or equal to 90% of the area of ​​the second substrate.

[0016] In some embodiments, the concave body includes at least one of the following:

[0017] A concave pyramid body, an arched concave body, or a concave body that is a combination of a concave curved surface and an inclined surface.

[0018] In some embodiments, at least two reflective structures are provided, and a spacing gap is provided between adjacent reflective structures, and the spacing gap is less than or equal to 2.1 um.

[0019] In some embodiments, in the white state, the white charged particles are adsorbed on the first substrate under the driving of a vertical electric field, and the black charged particles are adsorbed on the pixel walls on both sides of the pixel area under the driving of a horizontal electric field.

[0020] In some embodiments, collecting boxes are respectively provided on the pixel retaining walls on both sides of the pixel area, and are configured to accommodate the adsorbed black charged particles.

[0021] Based on the same inventive concept, a second aspect of the present disclosure provides a display panel, including the electrophoretic display device described in the first aspect.

[0022] From the above description, it can be seen that in the electrophoretic display device and display panel provided by the present disclosure, the first substrate and the second substrate are arranged relative to each other, and at least one pixel area is formed between the first substrate and the second substrate in cooperation with the pixel retaining wall. The horizontal and vertical electric fields generated by the first electrode and the second electrode between the first substrate and the second substrate, the black charged particles and the white charged particles are laid on the first substrate side or the second substrate side or accumulated on the pixel retaining wall under the horizontal and vertical electric fields, so as to avoid the black charged particles blocking the light transmitted into the pixel area; a reflective structure is arranged on the side of the second substrate away from the first substrate, and the reflective structure includes at least one convex body and / or at least one concave body. When the volume proportion of the white charged particles is less than or equal to 15%, the reflective effect of the reflective structure is better, so that the transmitted light can be reflected out, reducing the energy loss of the transmitted light, thereby improving the reflectivity of the electrophoretic display device to the light, and improving the display brightness. In particular, for white display, since all the black charged particles are adsorbed on the second electrode, the reflective structure has a better reflective effect on the light. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present disclosure or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 is a schematic structural diagram of an electrophoretic display device in general technology;

[0025] Figure 2A is a schematic diagram of an electrophoretic display device according to an embodiment of the present disclosure;

[0026] Figure 2B-1 A schematic diagram of the light path reflection of a pyramid convex body according to an embodiment of the present disclosure;

[0027] Figure 2B-2 A schematic diagram of the light path reflection of the arched convex body according to an embodiment of the present disclosure;

[0028] Figure 2B-3 A schematic diagram of a convex body composed of a convex curved surface and an inclined surface according to an embodiment of the present disclosure;

[0029] Figure 2B-4 It is a schematic diagram of a concave pyramid body according to an embodiment of the present disclosure;

[0030] Figure 2B-5 It is a schematic diagram of an arched concave body according to an embodiment of the present disclosure;

[0031] Figure 2B-6 A schematic diagram of a concave body composed of a concave curved surface and an inclined surface according to an embodiment of the present disclosure;

[0032] Figure 2C A schematic diagram of a specific angle of light path reflection of an arched convex body according to an embodiment of the present disclosure;

[0033] Figure 2D is a schematic diagram of a simulation structure of an electrophoretic display device according to an embodiment of the present disclosure;

[0034] Figure 2E A schematic diagram of a simulated positive viewing angle brightness variation curve of different proportions P1 of white charged particles relative to the total volume of the particle accumulation area according to an embodiment of the present disclosure;

[0035] Figure 2F A schematic diagram of the angular spectrum of the arched convex body of the embodiment of the present disclosure being widened away from the geometric optical path;

[0036] Figure 2G Schematic diagram of simulated front viewing angle brightness change curves of different proportions P2 of the arched convex body according to the embodiment of the present disclosure;

[0037] Figure 2H A schematic diagram of a close planar packing of white charged particles or black charged particles according to an embodiment of the present disclosure;

[0038] Fig.2I A schematic diagram of a brightness change curve at a normal viewing angle under different reflection conditions of an embodiment of the present disclosure;

[0039] Figure 2J It is a schematic diagram of the brightness change curves of the arched convex body reflection, Ag smooth reflection plane reflection and white charged particle reflection at a positive viewing angle according to the embodiment of the present disclosure;

[0040] Figure 2K-1 It is a schematic diagram of the black state (L=0) of the electrophoretic display device after removing the white charged particles according to the embodiment of the present disclosure;

[0041] Figure 2K-2 It is a schematic diagram of an intermediate gray scale after removing white charged particles from the electrophoretic display device according to an embodiment of the present disclosure;

[0042] Figure 2K-3 It is a schematic diagram of a white display state (L=255) of the electrophoretic display device according to an embodiment of the present disclosure after removing white charged particles;

[0043] Figure 3 is a schematic diagram of a display panel according to an embodiment of the present disclosure. Description of the drawings:

[0045] 100. Electrophoretic display device;

[0046] 110, a first substrate, 111 a first electrode;

[0047] 120, a second substrate, 121 a second electrode;

[0048] 130. White charged particles;

[0049] 140. Black charged particles;

[0050] 150. Reflective structure, 151. Convex pyramid body, 152. Convex arch body, 153. Convex body composed of convex curved surface and inclined surface, 154. Concave pyramid body, 155. Concave arch body, 156. Concave body composed of concave curved surface and inclined surface;

[0051] 160, gathering box;

[0052] 170, first cover plate;

[0053] 180, second cover plate;

[0054] 190, pixel retaining wall;

[0055] 200. Display panel. DETAILED DESCRIPTION

[0056] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0057] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0058] In the description of the present application, "A and / or B" may include the case of A alone, the case of B alone, or any of the cases of A and B, where A and B are only used for examples and may be any technical feature connected by "and / or" in the present application.

[0059] The electrophoretic display products currently available on the market are mostly capsule-type structures, and their main device structures are as follows: Figure 1 As shown, it includes a touch substrate, a capsule layer, and an array substrate.

[0060] The touch substrate includes: a cover layer (Glass / polyethylene terephthalate PET), an optical adhesive OCA (Optically Clear Adhesive), a cured film protective layer OC, a routing layer, and an ITO (Indium Tin Oxide) layer.

[0061] The capsule layer includes: black charged particles (black particles), white charged particles (white particles), a solvent (electrophoretic solvent), and a capsule shell; wherein the black particles and the white particles include: TIO2 / C black and an outer coating.

[0062] The array substrate includes: metal electrodes and other array structures.

[0063] Based on the above-mentioned capsule electrophoretic display product structure, in the L255 (white display) state, white charged particles (white particles) are accumulated on the upper layer, but since there must be gaps between the white charged particles, about 50% of the light is transmitted to the lower layer after passing through the white charged particles. Since the black charged particles (black particles) are set in the lower layer, they will absorb the transmitted light and cause this part of the light to be lost, resulting in low display brightness.

[0064] For the box-shaped electrophoretic display product, an electrophoretic solvent is set inside, but the lower plane reflective layer reflects the transmitted light to the side of the box-shaped structure through the mirror surface, which will also cause most of the light energy loss, so that the reflectivity of light in the white display state is still low.

[0065] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0066] The embodiment of the present disclosure provides an electrophoretic display device 100, such as Figure 2A As shown, including:

[0067] The first substrate 110 and the second substrate 120 are arranged opposite to each other; wherein the first substrate 110 and the second substrate 120 can be made of indium tin oxide (ITO).

[0068] The pixel retaining wall 190 is arranged between the first substrate 110 and the second substrate 120, and defines at least one pixel area between the first substrate 110 and the second substrate 120, in which white charged particles 130 and black charged particles 140 are distributed, wherein the volume of the white charged particles 130 accounts for a proportion P1 of the total volume of the particle accumulation area that is less than or equal to 15%.

[0069] The volume of the white charged particles 130 refers to the volume value obtained by multiplying the single volume of each white charged particle 130 by the number of white charged particles 130. The total volume of the particle accumulation area refers to the volume calculated by dividing the white particle accumulation area into at least one rectangular area plus the sum of the volumes calculated by dividing the black particle accumulation area into at least one rectangular area.

[0070] The first electrode 111 is disposed on the first substrate 110 .

[0071] The second electrode 121 is disposed on the second substrate 120 , and the black charged particles 140 and the white charged particles 130 are configured to be laid on the first substrate 110 side or on the second substrate 120 side or accumulated on the pixel blocking wall 190 under the horizontal and vertical electric fields generated by the first electrode 111 and the second electrode 121 .

[0072] The reflective structure 150 is disposed on a side of the second substrate 120 away from the first substrate 110. The reflective structure 150 includes at least one convex body and / or at least one concave body, and is configured to reflect the transmitted light of the pixel area. A reflective layer is distributed on the inner surface of the reflective structure 150, and the reflective layer can be a silver (Ag) reflective layer.

[0073] In a specific implementation, the electrophoretic display device 100 is a box-shaped structure, and in addition to the structure described above, further comprises:

[0074] The first cover plate 170 is disposed on the outside of the first substrate 110; the second cover plate 180 is disposed on the outside of the reflective structure 150; and the electrophoretic solution (e.g., ink solution) is filled inside the pixel area, so that the white charged particles 130 and the black charged particles 140 are distributed in the electrophoretic solution. For example, the size of the electrophoretic display device 100 can be length*width*height=85um*85um*20um (it can also be other sizes, which are not specifically limited here). The volume of the electrophoretic display device 100 is about 600um smaller than the volume of the capsule-type structure. 3 (Specifically determined according to the actual volume difference), according to the particle stability law of fluid mechanics, a smaller volume can provide higher particle (white charged particles 130, black charged particles 140) stability, so the box-shaped electrophoretic display device 100 has a higher bistable characteristic.

[0075] In specific implementation, a vertical electric field and a horizontal electric field are applied between the first substrate 110 and the second substrate 120. In the white display state, the white charged particles 130 are adsorbed on the inner surface of the first substrate 110 under the influence of the vertical electric field, and the black charged particles 140 are adsorbed on the pixel baffle 190 under the action of the horizontal electric field, and can also be adsorbed on other positions other than the inner surface of the first substrate 110 that do not affect the transmission of light. In this way, in the white display state, the light is reflected for the first time by the white charged particles 130. Due to the gaps between the white charged particles 130, part of the light will be transmitted into the electrophoretic solution. Since the black charged particles are concentratedly adsorbed, the transmitted light will pass through the second substrate 120 and hit the reflective structure 150, and then be reflected for the second time by the reflective structure 150. The reflective structure 150 is composed of a convex body and / or a concave body, so that the reflective surface of the reflective structure 150 is increased, so that it can have a better reflection effect on the transmitted inclined light and improve the reflection effect.

[0076] The arrangement of the reflective structure 150 is divided into several cases:

[0077] (1) at least one convex body is arranged in a plane between the second substrate 120 and the second cover plate 180;

[0078] (2) at least one concave body is arranged in a plane between the second substrate 120 and the second cover plate 180;

[0079] (3) It is composed of at least one convex body and at least one concave body, and is arranged in a plane between the second substrate 120 and the second cover plate 180.

[0080] The black charged particles 140 are concentrated and adsorbed in a collection box 160 with a horizontal width of 7.5 um (it may also be other sizes, which are not specifically limited here), and the collection box 160 is set in a position in the electrophoresis solution that does not affect the transmission of light.

[0081] Since the reflective structure 150 is a convex and / or concave body with better secondary reflection effect of the transmitted light, it can be used with lower concentration white charged particles 130. However, the specific solubility of the white charged particles 130 that can be used is analyzed by experimental simulation based on the above electrophoretic display device 100.

[0082] In the white display state (L255), the white charged particles 130 are driven by the vertical electric field to the inner surface of the first substrate 110 to accumulate and arrange. In order to facilitate the modeling and analysis of the reflectivity in the white display state, it is assumed in the model that there is such a white charged particle 130 distribution cubic area with a thickness of 1um. Figure 2H In a completely ideal state, the white charged particle 130 (spherical, such as Figure 2H The white circles in the figure are all closely and regularly spread on the inner surface of the entire first substrate 110, and the volume proportion P1 of the white charged particles 130 is 66.7%. In fact, the actual volume proportion P1 should be less than this value, mainly due to the following three reasons: ① The white charged particles 130 are freely arranged in the distribution area; ② The Coulomb repulsion between the white charged particles 130 makes it impossible for the white charged particles 130 to be closely connected; ③ The white charged particles 130 contain an outer layer of coating, and the outer carbon chain of the coating forces that there is always at least one carbon chain length (2nm) between the particles.

[0083] During the simulation analysis, the entire light reflection process is divided into a primary reflection provided by the white charged particles 130 and a secondary reflection provided by the reflective structure 150 . The sum of the reflectivities of the two reflections is the reflectivity of the electrophoretic display device 100 .

[0084] A silver (Ag) smooth plane layer is added as a reflective layer, and an electrophoretic display device without a horizontal electric field (using an Ag smooth reflective plane instead) is used for simulation comparison. The reflection result of the electrophoretic display device 100 of the disclosed solution uses a convex body (for example, an arched convex body 152), and the simulation results are as follows: Fig.2I shown.

[0085] It can be seen from the simulation results that as the volume proportion P1 of the white charged particles 130 increases, the primary reflection (primary reflection of the arched convex body 152) is enhanced, the transmission (primary transmission @20° direction) is weakened, and the secondary reflection (secondary reflection of the arched convex body 152) is weakened; when the volume proportion P1 of the white charged particles 130 is ≤15%, the brightness of the primary reflection is less than the brightness of the secondary reflection, and the secondary reflection plays a dominant role; when the volume proportion P1 of the white charged particles 130 is greater than 15%, the opposite is true.

[0086] Therefore, based on the above simulation results, in some embodiments, the proportion P1 of the white charged particles 130 relative to the total volume of the particle accumulation area is less than or equal to 15%.

[0087] When implementing it, Figure 2J As shown, the overall reflectivity of the electrophoretic display device 100 can be seen that the introduction of the arched convex body 152 and the Ag smooth reflective plane can improve the reflectivity at a positive viewing angle. When the proportion of white charged particles is low P1, the arched convex body 152 has a greater advantage.

[0088] When the white charged particles 130 are completely adsorbed onto the first substrate 110, the reflected energy of the light: the transmitted energy is ≈0.83:1, which is approximately equivalent to the white charged particles 130 volume ratio P1=35% in the simulation model, and the reflectivity (of the light) at the positive viewing angle is 39.33% (the total energy reflectivity of the light is about 45.3%), and the arched convex body 152 is matched with the white charged particles 130 with a volume ratio of P1=15% (relative to the total volume of the particle accumulation area) to achieve this reflectivity value. When the volume ratio P1 of the white charged particles 130 is lower, the reflectivity at the positive viewing angle exceeds the level of the general electrophoretic display device 100. The arched convex body 152 is matched with the white charged particles 130 with a volume ratio of P1=10%, which is about 120% of the reflectivity gain relative to the general electrophoretic display device 100.

[0089] It should be noted that since the size of the Ink particles in the electrophoretic solution is about 200nm, although the light path is affected by diffraction, the impact is relatively small compared to the macroscopic geometric light path. Therefore, when the overall size of the box body of the electrophoretic display device 100 is enlarged / reduced, the volume proportion P1 of the white charged particles 130 will not change accordingly.

[0090] Through the above solution, in conjunction with the structure of the electrophoretic display device 100 disclosed in the present invention, the volume proportion of the corresponding white charged particles 130 can be set to be smaller, and can be specifically selected and configured from a proportion of less than or equal to 15% according to actual conditions. In this way, the display brightness of the existing electrophoretic display device 100 can be achieved or even exceeded by using fewer white charged particles 130, reducing the cost of setting the white charged particles 130.

[0091] In general, the ratio of the white charged particles 130 to the black charged particles 140 is between 4:1 and 7.5:1, preferably 7:1.

[0092] Through the above scheme, the first substrate 110 and the second substrate 120 are arranged opposite to each other, and at least one pixel area is formed between the first substrate 110 and the second substrate 120 in cooperation with the pixel blocking wall 190. The horizontal and vertical electric fields generated by the first electrode 111 and the second electrode 121 between the first substrate 110 and the second substrate 120, the black charged particles 140 and the white charged particles 130 are laid on the side of the first substrate 110 or on the side of the second substrate 120 or accumulated on the pixel blocking wall 190 under the horizontal and vertical electric fields, so as to prevent the black charged particles 140 from blocking the light transmitted into the pixel area; A reflective structure 150 is set on the side 120 away from the first substrate 110, and the reflective structure 150 includes at least one convex body and / or at least one concave body. When the volume proportion of the white charged particles 130 is less than or equal to 15%, the reflective effect of the reflective structure 150 is better, so that the transmitted light can also be reflected, reducing the energy loss of the transmitted light, thereby improving the reflectivity of the electrophoretic display device 100 to light and improving the display brightness. Especially for white display, since all the black charged particles 140 are adsorbed on the pixel blocking wall 190, the reflective structure 150 has a better reflection effect on light.

[0093] In some embodiments, the convex body includes at least one of the following:

[0094] A pyramidal convex body 151, an arched convex body 152, and a convex body 153 composed of a convex curved surface and an inclined surface.

[0095] In specific implementation, ideally, in order to achieve maximum light reflection efficiency, the convex body is preferably a pyramidal convex body 151, and its cross-sectional reflection light path diagram is as follows: Figure 2B-1 As shown, the cross-section of the pyramidal convex body 151 is an isosceles triangle, and the height h of the isosceles triangle = half of the base length * tan10° (10° is calculated based on the refractive index of the electrophoretic solvent. If the refractive index of the electrophoretic solvent changes, the angle will also change, which will be specifically described in the following embodiments).

[0096] In order to prevent the height of the isosceles triangle from affecting the thickness of the box-shaped structure, the pyramid convex body 151 is deformed, such as Figure 2B-2 An arched convex body 152 is inscribed in the pyramidal convex body 151, and the central tangent of the arc surface of the arched convex body 152 coincides with the side of the pyramidal convex body 151. The arched convex body 152 is used as the convex body, so that the secondary reflection effect of the transmitted light can be achieved when the height of the arched convex body 152 is low.

[0097] For example, the surface of the arched convex body 152 is an arc-shaped surface, and the large-angle light hits the arc-shaped surface for reflection. Since the normal line of the reflection surface of the arc-shaped surface is along the arc center direction, the light originally transmitted by the environment that hits the side wall of the box-shaped structure is reflected out, thereby improving the positive viewing angle reflectivity of the light. The reflected light path is as follows: Figure 2B-2 shown.

[0098] The convex body 153 composed of a convex curved surface and an inclined surface may be a convex body composed of half convex curved surface and half inclined surface (e.g. Figure 2B-3 It can also be a convex body with 1 / 4 convex surface and 3 / 4 inclined surface; the ratio of convex surface to inclined surface can be adjusted according to actual needs.

[0099] The convex body of this embodiment is preferably the arched convex body 152 described above according to actual production requirements.

[0100] Through the above scheme, the convex body is used to increase the reflectivity of the reflective structure 150 to light, thereby making it possible to match the white charged particles 130 with a relatively low volume ratio, reduce the cost of setting up the white charged particles 130, and at the same time improve the display brightness of the electrophoretic display device 100.

[0101] In some embodiments, the width of the two ends of the arched convex body 152 is D, the height of the arched convex body 152 is h, and the value of D / h is 19 to 21.

[0102] In specific implementation, in order to achieve accurate beam adjustment, the parameters of the arched convex body 152 are first analyzed through theoretical calculation. Figure 2C The figure shows a dimming schematic diagram of the arched convex body 152. The incident angle of light in the air is α, and the exit angle after entering the electrophoresis solvent (ink solvent) is β, and then it is irradiated on the arched convex body 152 and collimated. The angle between the tangent line at the reflection point and the horizontal direction is θ (corresponding to 1 / 4 of the arc angle γ of the arc, that is, γ / 4=θ). The refractive index of light in the air is n air , the refractive index of light in the ink electrophoresis solvent is n ink .

[0103] According to the laws of refraction and reflection of light, as well as simple mathematical geometric relationships, the following formulas are satisfied between the parameters:

[0104]

[0105]

[0106] It should be noted that since the slope of the arched convex body 152 is an arc, the direction of its normal changes with the position of the arc. The above formulas (1) and (2) are only calculated for the 1 / 4 position of the arc (i.e., the center position of half of the arc structure), that is, the theoretically calculated D / h is only used as a simulation reference value and cannot be used as the final structure determination value. Under the environmental conditions of a certain electrophoretic solvent (such as ink electrophoretic solvent), the optimal D / h must be determined in combination with simulation. The refractive index of common Ink electrophoretic solvents is approximately equal to 1.42. After calculation, θ≈10° (i.e., 9.5° to 10.5°, preferably 10°), and D / h≈22. Based on this, the optical system modeling software (lighttools) was used to simulate and determine D / h. The simulation model structure is as follows: Figure 2D shown.

[0107] The distribution of the brightness of the white charged particles 130 at different volume proportions P1 as a function of D / h is shown in the figure below: Figure 2E As shown, the normal viewing angle is the viewing angle of the human eye.

[0108] The simulation results show that as the height of the arched convex body 152 increases, the brightness at the front viewing angle first increases and then decreases. When the brightness at the front viewing angle reaches the brightest, the D / h of the arched convex body 152 is ≈20, which is the optimal structural parameter (after simulation, D / h values ​​of 19 to 21 can achieve a relatively good light reflection effect). As the concentration of the white charged particles 130 increases, when the proportion of the white charged particles 130 to the total volume of the particle accumulation area P1 is 20% or more, the brightness at the front viewing angle begins to be consistent under different D / h, and the brightness change rate at the front viewing angle is <20%. Therefore, it is believed that when the proportion of the white charged particles 130 to the total volume of the particle accumulation area P1 is 20% or more, the arched convex body 152 no longer plays an effective role.

[0109] In some embodiments, a proportion P2 of the area of ​​the arched convex body 152 relative to the area of ​​the second substrate 120 is greater than or equal to 90%.

[0110] In a specific implementation, since the box-shaped structure contains both white charged particles 130 and black charged particles 140, the black charged particles 140 are accumulated on the inner side of the box-shaped structure in the L255 state, which will affect the light emission. Since the arched convex body 152 is symmetrical, only half of the arched convex body 152 can achieve the target angle deflection for the light coming from the same direction, and the other half of the arched convex body 152 causes a certain degree of angular spectrum broadening, which affects the secondary reflection of the light. The geometric cross-section light path of the arched convex body 152 is as follows: Figure 2FAt the same time, since there is a fixed and irremovable gap between the arched convex bodies 152, the overall proportion of the arched convex bodies 152 also affects the light reflection efficiency. Based on this, the influence of the area proportion P2 of the arched convex bodies 152 relative to the second substrate 120 on the light reflection efficiency (assessed by the front viewing angle brightness) is shown in the simulation results. Figure 2G shown.

[0111] Based on the above simulation results, when the area ratio P2 of the arched convex body 152 relative to the second substrate 120 is greater than or equal to 90%, a higher light reflection effect can be achieved. In this embodiment, the area ratio P2 of the arched convex body 152 relative to the second substrate 120 is further preferably 91%, and the brightness at the front viewing angle reaches an extreme value.

[0112] On this basis, the corresponding size of the arched convex body 152 is selected and set in combination with the condition that the D / h value is 19 to 21. For example, in order to meet the structural parameters of the maximum reflectivity at the normal viewing angle, for a box-shaped structure with a length and width of 85um, the arched convex body 152 is set to D=15um and h=0.765um.

[0113] In some embodiments, the concave body includes at least one of the following:

[0114] Pyramid concave body 154 (such as Figure 2B-4 As shown), the arched concave body 155 (as Figure 2B-5 The concave body 156 (such as Figure 2B-6 shown).

[0115] Through the above scheme, the concave body can also reflect inclined light, so the present application can also be set as the above various concave bodies, or any combination of the above several concave bodies, which is not specifically limited here. Also affected by the process, the pyramid concave body 154 is not easy to manufacture, and the arched concave body 155 is preferably used.

[0116] In some embodiments, at least two reflective structures 150 are provided, and gaps are provided between adjacent reflective structures 150 .

[0117] In specific implementation, the forming of the reflective structure 150 requires the use of a thermal reflow process. Due to the limitations of the thermal reflow process capabilities, adjacent reflective structures 150 (concave bodies and / or convex bodies) are provided with spacing gaps, wherein the smaller the spacing gap, the better, and is generally less than or equal to 2.1um.

[0118] For example, the spacing between adjacent arched convex bodies 152 is ≤2.1um, and according to the actual requirement of the thermal reflow process, Space=1.5um. The thermal reflow process also affects the arched concave bodies 155, and the spacing between adjacent arched concave bodies 155 is ≤2.1um, and according to the actual requirement of the thermal reflow process, Space=1.5um.

[0119] In some embodiments, in the white state, the white charged particles 130 are adsorbed on the first substrate 110 under the vertical electric field driving, and the black charged particles 140 are adsorbed on the pixel retaining walls 190 on both sides of the pixel area under the horizontal electric field driving.

[0120] In specific implementation, when the white state is displayed (L255), a vertical electric field is applied between the first substrate 110 and the second substrate 120 so that the white charged particles 130 are distributed on the first substrate 110, thereby reflecting the light once, but at the same time, part of the light will pass through the white charged particles 130 and enter the electrophoretic solution.

[0121] Under the action of the horizontal electric field, the black charged particles 140 are gathered in the pixel area without affecting the light transmission, so that they will not block the light transmitted into the electrophoretic solution, further ensuring the reflection effect of the reflective structure 150 of each of the above embodiments. The black charged particles 140 are preferably distributed on the pixel blocking walls 190 on both sides of the pixel area.

[0122] In some embodiments, collecting boxes 160 are respectively disposed on the pixel retaining walls 190 on both sides of the pixel area, and are configured to accommodate the adsorbed black charged particles.

[0123] In specific implementation, the number and shape of the gathering boxes 160 can be changed according to actual needs, and are not specifically limited here. For example, the number of the gathering boxes 160 can be 2, 3, 4, 6 or 8, and the shape of the gathering boxes 160 can be rectangular, trapezoidal, circular, elliptical, etc. In this embodiment, it is preferably a rectangle, and the horizontal distribution area width of the rectangle is 7um to 9um, and in this embodiment, it is preferably 7.5um. The length of the vertical distribution area can be set according to the actual aggregation size of the black charged particles 140 to ensure that all the black charged particles 140 can be gathered in the gathering box 160 when the white state is displayed.

[0124] In some embodiments, if the white charged particles 130 are removed, the electrophoretic display device 100 described in the present disclosure may display as follows: Figure 2K-1 , 2K-2 , 2K-3, where Figure 2K-1 The black charged particles 140 are adsorbed on the first substrate 110 in a black display state (L=0); Figure 2K-2 In the grayscale display state, the black charged particles 140 are adsorbed on the first substrate 110. Compared with the black display state, the adsorbed black charged particles 140 are reduced. Specifically, the number of adsorbed black charged particles 140 can be controlled by adjusting the field strength of the vertical electric field according to the actual grayscale situation to achieve display effects of different grayscales. Figure 2K-3 In the white display state (L=255), the black charged particles 140 are gathered in the gathering box 160 and are not distributed on the first substrate 110 .

[0125] Based on the same inventive concept, this embodiment provides a display panel 200, such as Figure 3 As shown, the electrophoretic display device 100 described in any of the above embodiments has the same technical effects as the electrophoretic display device 100 described in the above embodiments, which will not be described in detail here.

[0126] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Based on the concept of the present disclosure, the technical features in the above embodiments or different embodiments may also be combined, and there are many other variations of different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0127] The embodiments of the present disclosure are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

[0128] In the description of the present disclosure, the description with reference to the terms "one embodiment", "another embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. In the present disclosure, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in the present disclosure and the features of different embodiments or examples without contradiction.

Claims

1. An electrophoretic display device, comprising: A first substrate and a second substrate arranged opposite to each other; A pixel retaining wall is disposed between the first substrate and the second substrate, defining at least one pixel area between the first substrate and the second substrate, wherein white charged particles and black charged particles are distributed in the pixel area, wherein the volume of the white charged particles accounts for less than or equal to 15% of the total volume of the particle accumulation area; A first electrode, disposed on the first substrate; A second electrode is disposed on the second substrate, wherein the black charged particles and the white charged particles are configured to be laid on the first substrate side or the second substrate side or accumulated at the pixel barrier wall under the horizontal and vertical electric fields generated by the first electrode and the second electrode; The reflective structure is arranged on a side of the second substrate away from the first substrate, and the reflective structure includes at least one convex body and / or at least one concave body, and is configured to reflect the transmitted light of the pixel area.

2. The electrophoretic display device according to claim 1, wherein: The convex body includes at least one of the following: A pyramidal convex body, an arched convex body, or a convex body composed of a convex curved surface and an inclined surface.

3. The electrophoretic display device according to claim 2, wherein: The width of the two ends of the arched convex body is D, the height of the arched convex body is h, and at least one arched convex body satisfies the D / h value of 19 to 21.

4. The electrophoretic display device according to claim 2, wherein: The slope surface of the arched convex body is arc-shaped, and the arc angle γ of the arc satisfies 9.5°<γ / 4<10.5°.

5. The electrophoretic display device according to claim 2, wherein: The area of ​​the arched convex body accounts for more than or equal to 90% of the area of ​​the second substrate.

6. The electrophoretic display device according to claim 1, wherein: The concave body includes at least one of the following: A concave pyramid body, an arched concave body, or a concave body that is a combination of a concave curved surface and an inclined surface.

7. The electrophoretic display device according to any one of claims 1 to 6, wherein: There are at least two reflective structures, and a spacing gap is provided between adjacent reflective structures, and the spacing gap is less than or equal to 2.1 um.

8. The electrophoretic display device according to claim 1, wherein: In the white state display, the white charged particles are adsorbed on the first substrate under the driving of the vertical electric field, and the black charged particles are adsorbed on the pixel walls on both sides of the pixel area under the driving of the horizontal electric field.

9. The electrophoretic display device according to claim 8, wherein: Aggregation boxes are respectively arranged on the pixel walls at both sides of the pixel area, and are configured to accommodate the adsorbed black charged particles.

10. A display panel comprising the electrophoretic display device according to any one of claims 1 to 9.

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