Display panel, preparation method and display device

Abstract

The invention discloses a display panel, a preparation method and a display device, and relates to the technical field of display. The display panel comprises a first substrate and a second substrate which are oppositely arranged; the liquid crystal layer is arranged between the first substrate and the second substrate, the liquid crystal layer comprises a plurality of sub-pixels arranged in an array mode, each sub-pixel comprises at least one cholesteric liquid crystal unit reflecting light of the corresponding color, and each cholesteric liquid crystal unit comprises a single-color cholesteric liquid crystal and a capsule wall wrapping the single-color cholesteric liquid crystal. In every two adjacent sub-pixels, under the condition that the cholesteric liquid crystal unit belonging to one sub-pixel is adjacent to the cholesteric liquid crystal unit belonging to the other sub-pixel, the two cholesteric liquid crystal units are in contact with each other. According to the display panel, self-isolation of the single-color cholesteric liquid crystals can be achieved through the capsule wall, the flowability of the single-color cholesteric liquid crystals reflecting different colors is effectively restrained, and then the problems of cross color and pressure points caused by flowing of the single-color cholesteric liquid crystals are fundamentally solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a display panel, a preparation method and a display device. BACKGROUND

[0002] In the related art, in order to prevent the color mixing and pressure point problems caused by the flow of different color liquid crystals in the liquid crystal layer, it is usually necessary to set a partition wall between different color liquid crystals for physical isolation, but if the upper and lower substrates cannot be closely attached to the partition wall, the liquid crystal will still leak from the interface between the partition wall and the substrate. Therefore, the related art cannot solve the color mixing and pressure point problems caused by the flow of different color liquid crystals. SUMMARY

[0003] The main purpose of the present application is to provide a display panel, which aims to solve the technical problem of how to solve the color mixing and pressure point problems caused by the flow of different color liquid crystals in the related art.

[0004] To achieve the above-mentioned purpose, the present application provides a display panel, which comprises: a first substrate and a second substrate arranged oppositely; a liquid crystal layer arranged between the first substrate and the second substrate, the liquid crystal layer comprising a plurality of sub-pixels arranged in an array, the sub-pixels comprising at least one cholesteric liquid crystal unit reflecting light of a corresponding color, each cholesteric liquid crystal unit comprising a monochromatic cholesteric liquid crystal and a capsule wall wrapping the monochromatic cholesteric liquid crystal, and in the case that the cholesteric liquid crystal units belonging to one of the adjacent two sub-pixels and the cholesteric liquid crystal units belonging to the other are adjacent to each other, the two cholesteric liquid crystal units contact each other.

[0005] Further, the material of the capsule wall is polymethyl methacrylate or polystyrene.

[0006] Further, the cholesteric liquid crystal unit is bonded to the first substrate.

[0007] Further, the cholesteric liquid crystal unit is bonded to the first substrate through a bonding layer, and the material of the bonding layer is an aqueous polyurethane dispersion.

[0008] Further, the first substrate comprises a lower substrate, and the second substrate comprises an upper substrate. The lower substrate and the upper substrate are both hard glass substrates or both flexible substrates.

[0009] Further, the display panel is a reflective single-layer cholesteric liquid crystal electronic paper.

[0010] In addition, to achieve the above-mentioned purpose, the present application also provides a display panel preparation method as described above, which comprises: providing a first substrate having a plurality of sub-pixel regions arranged in an array; in each of the sub-pixel regions, printing a solution containing cholesteric liquid crystal cells reflecting light rays of a corresponding color to form a corresponding sub-pixel, to obtain the first substrate provided with a liquid crystal layer; after aligning and bonding the second substrate and the first substrate provided with the liquid crystal layer and encapsulation, a display panel is obtained.

[0011] Further, before the step of in each of the sub-pixel regions, printing a solution containing cholesteric liquid crystal cells reflecting light rays of a corresponding color to form a corresponding sub-pixel, to obtain the first substrate provided with a liquid crystal layer, the display panel preparation method further comprises: a monochromatic cholesteric liquid crystal and a material of a capsule wall are dissolved in a mixed organic solvent to form an oil phase, and polyvinyl alcohol is dissolved in deionized water as an aqueous phase; after the oil phase is dropped into the aqueous phase under continuous stirring, temperature stirring is performed to make the material of the capsule wall precipitate and wrap the monochromatic cholesteric liquid crystal to form the cholesteric liquid crystal cells; wherein the material of the capsule wall is polymethyl methacrylate or polystyrene.

[0012] Further, the step of in each of the sub-pixel regions, printing a solution containing cholesteric liquid crystal cells reflecting light rays of a corresponding color to form a corresponding sub-pixel, to obtain the first substrate provided with a liquid crystal layer, comprises: the solution containing the cholesteric liquid crystal cells reflecting light rays of a corresponding color is inkjet printed by using an inkjet printing process, so that the cholesteric liquid crystal cells and an adhesive layer are printed into the sub-pixel regions; wherein the solution containing the cholesteric liquid crystal cells reflecting light rays of a corresponding color comprises the cholesteric liquid crystal cells, the adhesive layer and an inkjet printing additive, and the adhesive layer is an aqueous polyurethane dispersion; the first substrate printed with the cholesteric liquid crystal cells and the adhesive layer is subjected to a heat curing treatment, so that the cholesteric liquid crystal cells are completely bonded in the sub-pixel regions.

[0013] In addition, to achieve the above object, the present application further provides a display device, which comprises a display panel prepared by the display panel preparation method as described above.

[0014] The one or more technical solutions provided by the present application have at least the following technical effects: The display panel provided in this application includes a first substrate and a second substrate disposed opposite to each other; a liquid crystal layer disposed between the first substrate and the second substrate, the liquid crystal layer including a plurality of sub-pixels arranged in an array, each sub-pixel including at least one cholesteric liquid crystal unit that reflects light of the corresponding color, each cholesteric liquid crystal unit including monochromatic cholesteric liquid crystal and a capsule wall encapsulating the monochromatic cholesteric liquid crystal, and in two adjacent sub-pixels, when the cholesteric liquid crystal unit belonging to one of the sub-pixels is adjacent to the cholesteric liquid crystal unit belonging to the other, the two cholesteric liquid crystal units are in contact with each other. This display panel can achieve self-isolation of the monochromatic cholesteric liquid crystal by utilizing the capsule wall, thereby effectively suppressing the flow of monochromatic cholesteric liquid crystals reflecting different colors, and thus fundamentally solving the problems of color crosstalk and spot pressing caused by the flow of monochromatic cholesteric liquid crystals. This application encapsulates the monochromatic cholesteric liquid crystal of sub-pixels in tiny capsules using a capsule wall to obtain cholesteric liquid crystal units. This achieves self-isolation of the monochromatic cholesteric liquid crystal, effectively suppresses the flow of monochromatic cholesteric liquid crystals reflecting different colors, and fundamentally solves the problems of color crosstalk and spot pressing caused by the flow of monochromatic cholesteric liquid crystals, effectively improving the reliability and stability of the display panel. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the display panel structure in related technologies; Figure 2 This is a schematic diagram of the display panel structure in an embodiment of this application; Figure 3 This is a schematic diagram of the array substrate structure according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the first substrate and the liquid crystal layer in the embodiments of this application; Figure 5 This is a schematic diagram illustrating the basic working principle of the display panel in an embodiment of this application; Figure 6 This is a schematic flowchart of the display panel manufacturing method according to an embodiment of this application; Figure 7 This is a schematic diagram of the display panel structure in an embodiment of this application.

[0017] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] With reference to the drawings and the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of the present application.

[0019] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0020] In addition, if the embodiments of the present application involve descriptions such as “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first”, “second” can explicitly or implicitly include at least one of the features. In addition, “and / or” or “and / or” appearing throughout the text means that the three parallel schemes are included, for example, “A and / or B” includes A scheme, or B scheme, or A and B are satisfied at the same time. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of a person of ordinary skill in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection claimed by the present application.

[0021] In the related art, the demand for color display is usually met by horizontally arrayed or vertically stacked cholesteric liquid crystals, wherein the vertically stacked cholesteric liquid crystals are a structure in which three layers of light-controlled cholesteric liquid crystal films are stacked, i.e., a red single-layer cholesteric liquid crystal, a green single-layer cholesteric liquid crystal, and a blue single-layer cholesteric liquid crystal are stacked; in the scheme of realizing color display by horizontally arrayed red, green, and blue single-layer cholesteric liquid crystals, since the cholesteric liquid crystal has fluidity, the cholesteric liquid crystals between different color regions usually cause color bleeding, and in addition, under an applied pressure, the display panel is prone to pressure point problems. Figure 1As shown, in order to prevent the color mixing and pressure point problems caused by the flow of different color liquid crystals, it is generally necessary to set a large number of isolation walls 01 between different color liquid crystals for physical isolation. However, on the one hand, if the upper and lower substrates cannot be closely attached to the isolation walls 01, the flow of liquid crystals cannot be completely suppressed, and the liquid crystals will still seep from the interface between the isolation walls 01 and the substrates, and the color mixing and pressure point problems caused by the flow of different color liquid crystals cannot be fundamentally solved. On the other hand, since the isolation walls 01 are usually formed by a photolithography process to process polymer materials, the setting of the isolation walls 01 not only increases the preparation process of the display panel, but also increases the manufacturing cost of the display panel.

[0022] The present application provides a solution by encapsulating the monochromatic cholesteric liquid crystal of the sub-pixel in a microcapsule by using the capsule wall to obtain a cholesteric liquid crystal unit 30. Each micro cholesteric liquid crystal unit 30 is an independent reflection unit, thereby realizing self-isolation of the monochromatic cholesteric liquid crystal. This effectively suppresses the flowability of the monochromatic cholesteric liquid crystal reflecting different colors, and fundamentally solves the color mixing and pressure point problems caused by the flow of liquid crystals, and effectively improves the reliability and stability of the display panel.

[0023] Embodiment one of the present application provides a display panel, referring to Figure 2 The display panel includes a first substrate 1, a second substrate 2 and a liquid crystal layer 3.

[0024] The first substrate 1 and the second substrate 2 are arranged opposite to each other, and the liquid crystal layer 3 is arranged between the first substrate 1 and the second substrate 2. The liquid crystal layer 3 includes a plurality of sub-pixels arranged in an array. Each sub-pixel includes a cholesteric liquid crystal unit 30 reflecting light of a corresponding color. Each cholesteric liquid crystal unit 30 includes at least one monochromatic cholesteric liquid crystal 301 and a capsule wall 302 wrapping the at least one monochromatic cholesteric liquid crystal 301. In the case where the cholesteric liquid crystal unit 30 belonging to one of the adjacent two sub-pixels is adjacent to the cholesteric liquid crystal unit 30 belonging to the other sub-pixel, the two cholesteric liquid crystal units 30 contact each other.

[0025] The first substrate 1 is an array substrate, which is used to apply a voltage to control the deflection of the monochromatic cholesteric liquid crystal 301, as Figure 3As shown, the array substrate includes a lower substrate 13 and a thin film transistor (TFT) 11 disposed on the lower substrate 13. Specifically, the TFT 11 includes a gate metal layer 111, a gate insulating layer 112, an active layer 113, source / drain electrode metal layers 114, and a passivation layer 115 stacked together. The lower substrate 13 is a rigid glass substrate. The array substrate also includes a pixel electrode layer 12, which is disposed on the side of the TFT 11 near the liquid crystal layer 3. The source / drain electrode metal layers 114 include a source electrode 114-1 and a drain electrode 114-2. Specifically, the TFT 11 has multiple pixel driving circuits, and the pixel electrode layer 12 has multiple pixel electrodes 121 arranged in an array. Each sub-pixel corresponds to one pixel electrode 121. The pixel electrodes 121 in the pixel electrode layer 12 are connected to the pixel driving circuits. When the display panel is working, the pixel driving circuits are used to charge the corresponding pixel electrodes in response to the scanning signal.

[0026] The second substrate 2 is a counterpart substrate aligned with the array substrate. The second substrate 2 includes an upper substrate 20 and a common electrode layer 21 disposed on the upper substrate 20 near the side of the first substrate 1. The upper substrate 20 is used to isolate the outside world, and the common electrode layer 21 is disposed on its entire surface to form a common electrode. The upper substrate 20 is a rigid glass substrate, and the common electrode layer 21 is made of indium tin oxide (ITO).

[0027] The display panel also includes a planarization layer 4 located between the pixel electrode layer 12 and the liquid crystal layer 3, used to planarize the pixel electrode layer 12. In one example, the planarization layer is an optical cement (OC) layer. To form a high-contrast image, the display panel also includes a light-absorbing layer 5 located on the surface of the first substrate 1 away from the pixel electrode layer 12, used to absorb transmitted light to form a high-contrast image. In one example, the light-absorbing layer 5 is made of black ink. The display panel also includes a support structure, which can be a photo spacer (PS), used to separate the first substrate 1 and the second substrate 2, so that the cholesteric liquid crystal cell 30 has sufficient space between the two substrates.

[0028] like Figure 4 As shown, the liquid crystal layer 3 includes a plurality of sub-pixels arranged in an array. Figure 2 As shown, each sub-pixel includes at least one cholesteric liquid crystal unit 30 that reflects light of the corresponding color. Each cholesteric liquid crystal unit 30 includes a monochrome cholesteric liquid crystal 301 and a capsule wall 302 that encloses the monochrome cholesteric liquid crystal 301 for the purpose of achieving color display.

[0029] In one example, the subpixels are arranged in an array of red subpixels (R), green subpixels (G), and blue subpixels (B), respectively. In this case, the cholesteric liquid crystal unit 30 is a cholesteric liquid crystal unit that reflects red light, a cholesteric liquid crystal unit that reflects green light, or a cholesteric liquid crystal unit that reflects blue light, and the monochrome cholesteric liquid crystal 301 is a cholesteric liquid crystal 3011 that reflects red light, a cholesteric liquid crystal 3012 that reflects green light, or a cholesteric liquid crystal 3013 that reflects blue light. For example, each red sub-pixel (R) includes at least one cholesteric liquid crystal unit that reflects red light, the cholesteric liquid crystal unit that reflects red light includes a cholesteric liquid crystal 3011 that reflects red light and a capsule wall 302 that encloses the cholesteric liquid crystal 3011 that reflects red light; each arrayed green sub-pixel (G) includes at least one cholesteric liquid crystal unit that reflects green light, the cholesteric liquid crystal unit that reflects green light includes a cholesteric liquid crystal 3012 that reflects green light and a capsule wall 302 that encloses the cholesteric liquid crystal 3012 that reflects green light; each arrayed blue sub-pixel (B) includes at least one cholesteric liquid crystal unit that reflects blue light, the cholesteric liquid crystal unit that reflects blue light includes a cholesteric liquid crystal 3013 that reflects blue light and a capsule wall 302 that encloses the cholesteric liquid crystal 3013 that reflects blue light.

[0030] like Figure 5 As shown, when ambient light enters from the second substrate 2, it penetrates the common electrode layer 21 and enters the liquid crystal layer 3. The liquid crystal layer 3 is used to reflect and transmit light. The display state of each sub-pixel is precisely controlled by the thin-film transistor 11 below it. Specifically, there is a corresponding thin-film transistor 11 below each sub-pixel. When the gate metal layer 111 in the thin-film transistor 11 receives a scanning signal, the thin-film transistor 11 switches on, and the pixel electrode 121 corresponding to the sub-pixel and the common electrode layer 21 form a pixel capacitor. The monochromatic cholesteric liquid crystal 301 in the sub-pixel is deflected to different degrees under the electric field of the pixel capacitor, thereby reflecting light of different intensities to switch between planar and focal conical states, realizing the reflection and transmission of specific light. After color mixing, a color image is finally displayed. In addition, the bottom light-absorbing layer 6 is used to absorb transmitted light, thereby forming a high-contrast image.

[0031] In this embodiment, the monochromatic cholesteric liquid crystal 301 of the sub-pixel is encapsulated in a microcapsule using the capsule wall 302 to obtain a cholesteric liquid crystal unit 30. Each micro cholesteric liquid crystal unit 30 is an independent reflective unit, thereby achieving self-isolation of the monochromatic cholesteric liquid crystal 301. This effectively suppresses the flow of monochromatic cholesteric liquid crystal 301 reflecting different colors, thus fundamentally solving the color mixing and spot pressing problems caused by the flow of monochromatic cholesteric liquid crystal 301, and effectively improving the reliability and stability of the display panel.

[0032] It should be noted that, since the self-isolation of the monochromatic cholesteric liquid crystal 301 is realized in the embodiment, the isolation wall 01 in the related art is completely abandoned, and thus in the case that the cholesteric liquid crystal cell 30 belonging to one of the two adjacent sub-pixels is adjacent to the cholesteric liquid crystal cell 30 belonging to the other, the two cholesteric liquid crystal cells 30 contact each other.

[0033] The material of the capsule wall 302 can be polymethyl methacrylate or polystyrene.

[0034] Since the use of polystyrene as the material of the capsule wall 302 will cause the transmittance of the cholesteric liquid crystal cell 30 to decrease, in an embodiment, the material of the capsule wall 302 is polymethyl methacrylate. In the embodiment, the materials of the capsule walls 3011, 3012 and 3013 wrapping the red light reflecting cholesteric liquid crystal 3011, the green light reflecting cholesteric liquid crystal 3012 and the blue light reflecting cholesteric liquid crystal are all polymethyl methacrylate.

[0035] Since the transmittance of polymethyl methacrylate is high and it is suitable for the solvent evaporation method to prepare the cholesteric liquid crystal cell 30, the material of the capsule wall 302 in the embodiment is preferably polymethyl methacrylate.

[0036] In an embodiment, the cholesteric liquid crystal cell 30 is bonded to the first substrate 1.

[0037] Specifically, the cholesteric liquid crystal cell 30 is bonded in the corresponding sub-pixel area. For example, the red light reflecting cholesteric liquid crystal cell is bonded in the area of the red sub-pixel (R), the green light reflecting cholesteric liquid crystal cell is bonded in the area of the green sub-pixel (G), and the blue light reflecting cholesteric liquid crystal cell is bonded in the area of the blue sub-pixel (B). In a specific embodiment, the cholesteric liquid crystal cell is bonded to the first substrate 1 through the bonding layer 303, and the material of the bonding layer 303 is water-based polyurethane dispersion.

[0038] In actual application, the display panel can be a reflective single-layer cholesteric liquid crystal electronic paper (Reflective Cholesteric Liquid Crystal Display E-paper). Since the liquid crystal layer 3 adopts the cholesteric liquid crystal with the characteristics of bistability and Bragg reflection selective color, the reflective single-layer cholesteric liquid crystal electronic paper can realize color display, and specifically, the cholesteric liquid crystal is arranged horizontally in RGB.

[0039] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as the above-mentioned first embodiment can be referred to the above description, and the subsequent will not be described in detail. On this basis, the lower substrate 13 and the upper substrate 20 are both flexible substrates, specifically, the lower substrate 13 and the upper substrate 20 are both flexible glass, polyimide or polyethylene terephthalate.

[0040] In the related art, in order to prevent the color mixing and pressure point problems caused by the flow of liquid crystals of different colors and to inhibit the flow of liquid crystals, it is usually necessary to set a plurality of evenly distributed polyimide isolation walls between the liquid crystals of different colors to perform physical isolation, and such rigid structure isolation wall limits the flexible application of the display panel.

[0041] Since the self-isolation of the monochromatic cholesteric liquid crystal 301 is achieved in the present embodiment, it is not necessary to set a large number of isolation walls between the liquid crystals of different colors, and thus the lower substrate 13 and the upper substrate 20 can be replaced with flexible substrates to realize flexible display.

[0042] In addition, in order to achieve the above-mentioned purpose, the present application also provides a display panel preparation method as described above, which will be described in detail below with reference to the accompanying drawings. Figure 6 , Figure 6 The flowchart of the display panel preparation method of the present embodiment is shown in FIG. 10. The display panel preparation method comprises the following steps: Step S10, providing a first substrate 1, the first substrate 1 has a plurality of sub-pixel regions arranged in an array.

[0043] Specifically, in the present embodiment, the gate metal layer 111, the gate insulating layer 112, the active layer 113, the source-drain electrode metal layer 114 and the passivation layer 115 are sequentially prepared on the lower substrate 13 by using the vapor deposition process, coating, exposure, development and etching process to obtain the lower substrate 13 prepared with the thin film transistor 11. In an example, the gate metal layer 111 is prepared on the lower substrate 13 by using the physical vapor deposition (Physical Vapor Deposition, PVD), coating, exposure, development and etching process. In an example, the gate insulating layer 112 is prepared by using the chemical vapor deposition (Chemical Vapor Deposition, CVD) coating, exposure, development and etching process. In an example, the drain electrode metal layer 114 is prepared by using the physical vapor deposition (Physical Vapor Deposition, PVD), coating, exposure, development and etching process. In the present embodiment, the lower substrate 13 is a hard glass substrate.

[0044] The pixel electrode layer 12 is prepared on the lower substrate 13 with thin film transistor 11 by physical vapor deposition (PVD), coating, exposure, development and etching process. The pixel electrode layer 12 is arranged on the thin film transistor 11 close to the liquid crystal layer 3. The pixel electrode layer 12 has a plurality of pixel electrodes 121 arranged in an array. Each sub-pixel corresponds to a pixel electrode 121. Therefore, a plurality of sub-pixel regions arranged in an array are obtained.

[0045] After step S10, the display panel preparation method further comprises: continuing to prepare the flat layer 4 on the lower substrate 13 by coating, exposure, development and etching process. The flat layer 4 is between the pixel electrode layer 12 and the liquid crystal layer 3. The first substrate 1 is obtained.

[0046] In step S20, the solution containing the cholesteric liquid crystal cell 30 reflecting light of corresponding color is printed in each sub-pixel region to form a corresponding sub-pixel. The first substrate 1 provided with the liquid crystal layer is obtained.

[0047] The embodiment is used to accurately print and bond the cholesteric liquid crystal cell 30 in the corresponding sub-pixel region of the first substrate 1. Each sub-pixel region contains one or more cholesteric liquid crystal cells 30. After accurate printing and bonding, the diameter of the cholesteric liquid crystal cell is 10 μm~100 μm.

[0048] In a possible implementation, step S20 can include steps S21~S22: In step S21, the solution containing the cholesteric liquid crystal cell 30 reflecting light of corresponding color is inkjet printed by inkjet printing process. The cholesteric liquid crystal cell 30 and the material of the bonding layer 303 are printed into the sub-pixel region. The solution containing the cholesteric liquid crystal cell 30 reflecting light of corresponding color includes the cholesteric liquid crystal cell 30, the material of the bonding layer 303 and the inkjet printing additive. The material of the bonding layer 303 is water-based polyurethane dispersion. The inkjet printing additive is used to make the single-color cholesteric liquid crystal in the cholesteric liquid crystal cell 30 more uniformly printed into the pixel electrode region. The inkjet printing additive includes co-solvent, dispersant, leveling agent, defoaming agent and deionized water. The co-solvent, dispersant, leveling agent and defoaming agent are not specifically limited.

[0049] Specifically, the materials of the cholesteric liquid crystal unit 30, the adhesive layer 303 and the inkjet printing additive are mixed in precise proportions, then homogenized and filtered to filter the agglomerated cholesteric liquid crystal units, the undispersed additive and other impurities, so as to obtain a solution containing cholesteric liquid crystal units reflecting corresponding color light. This step is repeated three times, and three mixed solutions are prepared, which are respectively a solution of cholesteric liquid crystal units reflecting red light, a solution of cholesteric liquid crystal units reflecting green light and a solution of cholesteric liquid crystal units reflecting blue light.

[0050] The mass ratio is respectively 10-40% of the cholesteric liquid crystal unit, 30-60% of the material of the adhesive layer 303, 2-8% of the cosolvent, 0.2-1% of the dispersing agent, 0.1-0.5% of the leveling agent, 0.1-0.5% of the defoaming agent and 10-30% of the deionized water.

[0051] Specifically, the equipment of the inkjet printing process is an inkjet printer. The inkjet printer can ensure that each nozzle can stably form and eject single and uniform droplets. The three mixed solutions are precisely printed into each corresponding sub-pixel area on the first substrate 1. Each pixel area can contain one or more cholesteric liquid crystal units 30. It should be noted that the cholesteric liquid crystal units 30 in the same pixel area need to reflect light of the same color, thereby forming a corresponding sub-pixel. In an example, as shown in (1) of FIG. 1, a red sub-pixel (R) area contains one cholesteric liquid crystal unit 30 reflecting red light, which corresponds to one pixel electrode 121. In another example, as shown in (2) of FIG. 2, a red sub-pixel (R) area contains two cholesteric liquid crystal units 30 reflecting red light, which correspond to one pixel electrode 121. Figure 7 Figure 7

[0052] Specifically, through the heat curing treatment, on the one hand, each cholesteric liquid crystal unit 30 is completely bonded in the pixel electrode area to achieve the fixation of the cholesteric liquid crystal unit 30, and on the other hand, the cosolvent, the dispersing agent, the leveling agent and the defoaming agent are removed.

[0053] Specifically, through the heat curing treatment, on the one hand, each cholesteric liquid crystal unit 30 is completely bonded in the pixel electrode area to achieve the fixation of the cholesteric liquid crystal unit 30, and on the other hand, the cosolvent, the dispersing agent, the leveling agent and the defoaming agent are removed.

[0054] ​​In order to better realize the fixing and removing effects, the temperature of the heat curing is programmed, specifically, the programmed temperature is divided into three stages, the first stage is a low temperature stage: 25-50 DEG C, the time is 20-40 min; the second stage is a medium temperature stage: 50-80 DEG C, the time is 2-5 min; the third stage is a high temperature stage: 80-110 DEG C, the time is 30-60 min.

[0055] In order to prepare the cholesteric liquid crystal unit 30, in a possible embodiment, in each sub-pixel area, the solution containing the cholesteric liquid crystal unit 30 reflecting light of the corresponding color is printed to form the corresponding sub-pixel, and before the first substrate 1 provided with the liquid crystal layer 3 is prepared, the display panel preparation method further comprises: the materials of the monochromatic cholesteric liquid crystal 301 and the capsule wall 302 are dissolved in the mixed organic solvent to form an oil phase, and the polyvinyl alcohol is dissolved in deionized water as an aqueous phase; under continuous stirring, the oil phase is dropped into the aqueous phase and then heated and stirred, so that the material of the capsule wall 302 is precipitated and wrapped around the monochromatic cholesteric liquid crystal to form the cholesteric liquid crystal unit 30.

[0056] In this embodiment, the preparation process needs to be repeated three times to obtain three cholesteric liquid crystal units of different colors, and the pitches of the three liquid crystal raw materials are different, specifically, the pitch of the cholesteric liquid crystal reflecting red light is greater than that of the cholesteric liquid crystal reflecting green light, and the pitch of the cholesteric liquid crystal reflecting green light is greater than that of the cholesteric liquid crystal reflecting blue light. Specifically, when the raw material of the monochromatic cholesteric liquid crystal 301 is the cholesteric liquid crystal reflecting red light, the cholesteric liquid crystal unit 30 reflecting red light is finally prepared; when the raw material of the monochromatic cholesteric liquid crystal 301 is the cholesteric liquid crystal reflecting green light, the cholesteric liquid crystal unit 30 reflecting green light is finally prepared; and when the raw material of the monochromatic cholesteric liquid crystal 301 is the cholesteric liquid crystal reflecting blue light, the cholesteric liquid crystal unit 30 reflecting blue light is finally prepared.

[0057] Specifically, the mass ratio of the monochromatic cholesteric liquid crystal 301 to the material of the capsule wall 302 is 10:1-15:1, and the solvent ratio of dichloromethane to acetone in the mixed organic solvent is 8:1-10:1, that is, 0.1 g-0.12 g of the mixture of the monochromatic cholesteric liquid crystal and the material of the capsule wall 302 is added per 1 ml of the mixed organic solvent; the stirring speed during continuous stirring is high speed stirring, specifically 1000-2000 r / min; the temperature of the heating and stirring is 30-40 DEG C, and the stirring speed of the heating and stirring is 200-500 r / min, and during the heating and stirring, the material of the capsule wall 302 is induced to precipitate and wrap around the monochromatic cholesteric liquid crystal to form the capsule wall, and the stirring time required for forming the capsule wall is 7-10 h. In this embodiment, the material of the capsule wall 302 is preferably polystyrene.

[0058] Specifically, after the temperature is raised and stirring is performed to form the capsule wall 302, the product is further centrifuged and washed with water to remove excess polyvinyl alcohol, so as to concentrate to obtain the pure cholesteric liquid crystal unit 30.

[0059] S30, after the second substrate 2 and the first substrate 1 provided with the liquid crystal layer 3 are aligned and attached and encapsulated, a display panel is obtained.

[0060] Specifically, the second substrate 2 is obtained at the same time as the first substrate 1, and the step of obtaining the second substrate 2 includes forming a common electrode layer 21 on the upper substrate 20 by physical vapor deposition (PVD), wherein the upper substrate 20 is a hard glass substrate.

[0061] It can be understood that in the embodiment, the monochromatic cholesteric liquid crystal 301 of the sub-pixel is encapsulated in a microcapsule by using the capsule wall to obtain the cholesteric liquid crystal unit 30, and each micro cholesteric liquid crystal unit 3030 is an independent reflection unit, thereby realizing self-isolation of the monochromatic cholesteric liquid crystal 301, thereby abandoning the isolation wall, not only making the display panel have high stability, but also reducing the process of the isolation wall, thereby improving the production efficiency of the display panel and reducing the manufacturing cost of the display panel.

[0062] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as the above-mentioned first embodiment can be referred to the above description, and will not be described in detail. On this basis, in the process of obtaining the first substrate 1 and the second substrate 2, the lower substrate 13 and the upper substrate 20 are replaced by flexible substrates, specifically, the flexible substrate can be flexible glass, polyimide or polyethylene terephthalate.

[0063] Since the process of the isolation wall is reduced in the preparation process of the embodiment, in the process of obtaining the first substrate 1 and the second substrate 2, the lower substrate 13 and the upper substrate 20 can be replaced by flexible substrates to realize flexible display.

[0064] In addition, in order to achieve the above-mentioned purpose, the present application also provides a display device, which comprises a display panel prepared by the preparation method of the display panel as described above.

[0065] In the embodiment, the display device can include an electronic book, an electronic tag and other devices using the above-mentioned display panel.

[0066] The above-mentioned only some embodiments of the present application, not limited to the protection scope of the present application, any equivalent structural transformation made by the content of the present application specification and drawings, or direct / indirect application in other related technical fields are included in the protection scope of the present application.

Claims

1. A display panel, characterized in that, The display panel includes: The first substrate and the second substrate are arranged opposite to each other; A liquid crystal layer is disposed between the first substrate and the second substrate. The liquid crystal layer includes a plurality of sub-pixels arranged in an array. Each sub-pixel includes at least one cholesteric liquid crystal unit that reflects light of a corresponding color. Each cholesteric liquid crystal unit includes a monochromatic cholesteric liquid crystal and a capsule wall encapsulating the monochromatic cholesteric liquid crystal. In two adjacent sub-pixels, if the cholesteric liquid crystal unit belonging to one of the sub-pixels is adjacent to the cholesteric liquid crystal unit belonging to the other sub-pixel, the two cholesteric liquid crystal units are in contact with each other.

2. The display panel as described in claim 1, characterized in that, The capsule wall is made of polymethyl methacrylate or polystyrene.

3. The display panel as described in claim 1, characterized in that, The cholesteric liquid crystal cell is bonded to the first substrate.

4. The display panel as described in claim 3, characterized in that, The cholesteric liquid crystal unit is bonded to the first substrate by an adhesive layer, the material of which is an aqueous polyurethane dispersion.

5. The display panel as described in any one of claims 1 to 4, characterized in that, The first substrate includes a lower substrate, and the second substrate includes an upper substrate; Both the lower substrate and the upper substrate are either rigid glass substrates or flexible substrates.

6. The display panel as described in claim 5, characterized in that, The display panel is a reflective single-layer cholesteric phase liquid crystal electronic paper.

7. A method for manufacturing a display panel as described in any one of claims 1 to 6, characterized in that, The method for manufacturing the display panel includes: A first substrate is provided, the first substrate having a plurality of sub-pixel regions arranged in an array; In each of the sub-pixel regions, a solution containing cholesteric liquid crystal cells that reflect the corresponding color light is printed to form the corresponding sub-pixel, thereby obtaining the first substrate with a liquid crystal layer. After aligning and bonding the second substrate and the first substrate having the liquid crystal layer, and then encapsulating them, a display panel is obtained.

8. The method for manufacturing a display panel as described in claim 7, characterized in that, Before printing a solution containing cholesteric liquid crystal cells that reflect corresponding color light in each sub-pixel region to form the corresponding sub-pixel and obtaining the first substrate with a liquid crystal layer, the display panel fabrication method further includes: The monochromatic cholesteric liquid crystal and the capsule wall material are dissolved in a mixed organic solvent to form the oil phase, while polyvinyl alcohol is dissolved in deionized water to form the aqueous phase. While continuously stirring, the oil phase is dropped into the aqueous phase and then heated and stirred to cause the material of the capsule wall to precipitate and encapsulate the monochromatic cholesteric liquid crystal, forming the cholesteric liquid crystal unit; wherein, the material of the capsule wall is polymethyl methacrylate or polystyrene.

9. The method for manufacturing a display panel as described in claim 7, characterized in that, In each of the sub-pixel regions, a solution containing cholesteric liquid crystal cells that reflect corresponding color light is printed to form the corresponding sub-pixel, resulting in the first substrate having a liquid crystal layer, comprising: The solution containing cholesteric liquid crystal units that reflect corresponding color light is inkjet printed using an inkjet printing process, so that the cholesteric liquid crystal units and the binder layer are printed into the sub-pixel area; wherein, the solution containing cholesteric liquid crystal units that reflect corresponding color light includes the cholesteric liquid crystal units, the binder layer and inkjet printing additive, and the binder layer is an aqueous polyurethane dispersion. The first substrate, on which the cholesteric liquid crystal unit and the adhesive layer are printed, is subjected to a thermosetting process to completely bond the cholesteric liquid crystal unit to the sub-pixel region.

10. A display device, characterized in that, The display device includes a display panel manufactured by the method of manufacturing a display panel as described in any one of claims 1 to 6.

Images