Cholesteric liquid crystal display panel and method of manufacturing

Abstract

The application discloses a kind of cholesteric liquid crystal display panel and preparation method, applied to cholesteric liquid crystal display technical field, comprising: liquid crystal cell, liquid crystal cell includes first substrate, second substrate and cholesteric liquid crystal layer;The surface of first substrate is close to second substrate and has multiple by first substrate body integrated inwardly recessed rigid sub-pixel accommodating cavity;Multiple rigid sub-pixel accommodating cavity is periodically arranged along first direction;Between adjacent rigid sub-pixel accommodating cavity, by the isolation portion of first substrate body integrated, is separated, and the top of isolation portion is in contact with second substrate;Cholesteric liquid crystal layer includes cholesteric liquid crystal filled in rigid sub-pixel accommodating cavity;Multiple rigid sub-pixel accommodating cavity includes the rigid sub-pixel accommodating cavity corresponding to the sub-pixel of different colors respectively, and the cholesteric liquid crystal corresponding to different color sub-pixel has different pitch.The cholesteric liquid crystal display panel improves the dimensional stability of pixel boundary, thermal stability and long-term reliability.

Description

Technical Field

[0001] This invention relates to the field of cholesteric liquid crystal display technology, and in particular to a cholesteric liquid crystal display panel and a method for preparing a cholesteric liquid crystal display panel. Background Technology

[0002] Cholesteric liquid crystals possess characteristics such as no backlight required, bistable operation, low power consumption, and selective reflection, making them widely used in electronic paper, electronic tags, outdoor low-power displays, and wearable displays. In color display applications, single-layer color cholesteric liquid crystal display structures form different color regions (red, green, and blue) within the same liquid crystal layer, simplifying the process compared to three-layer stacked structures.

[0003] Single-layer color cholesteric liquid crystal display structures typically employ an "added-on" isolation structure. This involves forming photoresist, polyimide, or other polymer isolation walls on the substrate surface through processes such as photolithography, coating, printing, or curing. These isolation walls then define liquid crystal channels or strip-shaped containers of different colors. However, this approach has several drawbacks: First, the polymer materials differ from the glass substrate in their coefficients of thermal expansion, hygroscopicity, and long-term creep characteristics. Under high-temperature, thermal cycling, or long-term driving conditions, boundary drift, deformation, or interface failure may occur, leading to reliability issues such as inter-pixel crosstalk and color drift. Second, this approach relies on precise polymer dikes for staged infusion or multiple sealing processes, resulting in a cumbersome workflow. Furthermore, the precise patterning of the polymer materials places extremely high demands on the process window, making it highly susceptible to color mixing due to liquid crystal overflow, severely restricting mass production yield and cost control. Additionally, as an additional structure, the polymer walls cannot simultaneously and synergistically define the liquid crystal containment space, cell thickness, alignment boundaries, and chiral component diffusion boundaries, failing to meet the requirements of high-performance displays for structural integration and stability.

[0004] This invention provides a cholesteric liquid crystal display panel and its preparation method to solve the problems of interface failure, pixel crosstalk, and insufficient long-term reliability caused by the use of polymer isolation structures in single-layer color cholesteric liquid crystal display panels. Summary of the Invention

[0005] The purpose of this invention is to provide a cholesteric liquid crystal display panel and its preparation method, so as to solve the problems of interface failure, pixel crosstalk and insufficient long-term reliability caused by the use of polymer isolation structure in single-layer color cholesteric liquid crystal display panels.

[0006] To solve the above-mentioned technical problems, the present invention provides a cholesteric liquid crystal display panel, comprising: A liquid crystal cell, the liquid crystal cell comprising a first substrate, a second substrate, and a cholesteric liquid crystal layer; The first substrate is a glass substrate, and the surface of the first substrate near the second substrate has a plurality of inwardly recessed rigid sub-pixel receiving cavities integrally formed from the first substrate body; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; adjacent rigid sub-pixel receiving cavities are separated by an isolation portion integrally formed from the first substrate body, and the top of the isolation portion between adjacent rigid sub-pixel receiving cavities contacts the second substrate; the first direction is parallel to the surface of the first substrate. The cholesteric liquid crystal layer includes cholesteric liquid crystal filling the rigid sub-pixel cavity; The plurality of rigid sub-pixel receiving cavities include rigid sub-pixel receiving cavities corresponding to sub-pixels of different colors, and the cholesteric liquid crystals corresponding to sub-pixels of different colors have different pitches; In a single liquid crystal filling process, the depth, width, and volume of each rigid sub-pixel receiving cavity are consistent.

[0007] Optionally, the rigid sub-pixel receiving cavity is a strip-shaped receiving cavity that extends along the second direction and is periodically arranged along the first direction.

[0008] Optionally, in the plurality of rigid sub-pixel cavities, every three adjacent rigid sub-pixel cavities constitute a pixel unit; The pixel unit includes three rigid sub-pixel cavities corresponding to the red sub-pixel, green sub-pixel, and blue sub-pixel, respectively.

[0009] Optionally, the first substrate includes a display area and a non-display area, the non-display area being disposed around the display area, and the rigid sub-pixel receiving cavity being disposed in the display area; The non-display area is provided with a liquid injection port, which is connected to the rigid sub-pixel receiving cavity.

[0010] Optionally, the liquid crystal cell includes a first electrode layer and a first alignment layer; The first electrode layer is disposed at least on the bottom surface of the rigid sub-pixel receiving cavity; The first alignment layer is disposed at least on the inner surface of the rigid sub-pixel receiving cavity and at least partially covers the first electrode layer.

[0011] Optionally, the liquid crystal cell includes a second electrode layer and a second alignment layer; The second substrate, the second electrode layer, and the second alignment layer are stacked together; The second electrode layer is located between the second substrate and the second alignment layer; The second alignment layer contacts the top of the rigid sub-pixel receiving cavity.

[0012] The present invention also provides a method for preparing a cholesteric phase liquid crystal display panel, for preparing the above-mentioned cholesteric phase liquid crystal display panel, comprising: A first substrate is provided, the first substrate being a glass substrate, and a plurality of inwardly recessed rigid sub-pixel receiving cavities are integrally formed on a predetermined surface of the first substrate; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; the predetermined surface is the surface of the first substrate near a second substrate; adjacent rigid sub-pixel receiving cavities are separated by an isolation portion integrally formed on the body of the first substrate; the first direction is parallel to the surface of the first substrate. A second substrate is provided, and the first substrate and the second substrate are aligned and bonded together to form a liquid crystal cell, wherein the top of the isolation portion is in contact with the second substrate; A liquid crystal mixture is filled into the rigid sub-pixel cavity; the liquid crystal mixture comprises a photocurable reactive monomer and a photoinitiator, or the liquid crystal mixture comprises an oligomer and a photoinitiator; Selective exposure is performed on the liquid crystal mixture within the rigid sub-pixel cavity, and the cholesteric liquid crystals corresponding to sub-pixels of different colors have different pitches, in order to prepare a cholesteric liquid crystal display panel. In a single liquid crystal filling process, the depth, width, and volume of each rigid sub-pixel receiving cavity are consistent.

[0013] Optionally, a first substrate is provided, on which a plurality of inwardly recessed rigid sub-pixel receiving cavities are integrally formed; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; the preset surface is the surface of the first substrate near the second substrate, including: A first substrate is provided, and multiple inwardly recessed rigid sub-pixel cavities are integrally formed on a predetermined surface of the first substrate using photolithography combined with etching, laser direct writing, ultra-precision machining, hot pressing or molding processes; the multiple rigid sub-pixel cavities are periodically arranged along a first direction; the predetermined surface is the surface of the first substrate close to the second substrate.

[0014] Optionally, filling the rigid sub-pixel receiving cavity with a liquid crystal mixture includes: The same liquid crystal mixture is injected into each of the rigid sub-pixel cavities in one go; The liquid crystal mixture also includes a liquid crystal substrate and a chiral dopant.

[0015] Optionally, the liquid crystal mixture within the rigid sub-pixel cavity is selectively exposed, with different colored sub-pixels corresponding to cholesteric liquid crystals having different pitches, including: The liquid crystal mixture within the rigid sub-pixel cavity is selectively exposed using a mask, grayscale mask, digital micromirror device, laser scanning exposure, or projection exposure method. The cholesteric liquid crystals corresponding to sub-pixels of different colors have different pitches.

[0016] The cholesteric liquid crystal display panel provided by the present invention includes: a liquid crystal cell, the liquid crystal cell including a first substrate, a second substrate, and a cholesteric liquid crystal layer; the first substrate is a glass substrate, and the surface of the first substrate near the second substrate has a plurality of inwardly recessed rigid sub-pixel receiving cavities integrally formed from the first substrate body; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; adjacent rigid sub-pixel receiving cavities are separated by an isolation portion integrally formed from the first substrate body, the top of the isolation portion contacting the second substrate; the cholesteric liquid crystal layer includes cholesteric liquid crystal filling the rigid sub-pixel receiving cavities; the plurality of rigid sub-pixel receiving cavities include rigid sub-pixel receiving cavities corresponding to sub-pixels of different colors, and the cholesteric liquid crystal corresponding to sub-pixels of different colors has different pitches; wherein, during a single liquid crystal filling process, the depth, width, and volume of each rigid sub-pixel receiving cavity are consistent.

[0017] As can be seen, this cholesteric liquid crystal display panel utilizes a plurality of inwardly recessed rigid sub-pixel cavities integrally formed from the first substrate body on the surface near the second substrate body. This integrally formed isolation structure replaces the traditional post-processed polymer isolation walls. Because the isolation structure is made of the same material as the substrate body and is integrally formed, it eliminates the boundary drift, deformation, or interface failure problems caused by differences in thermal expansion coefficients, hygroscopicity, and creep characteristics between the polymer material and the glass substrate. This significantly improves the dimensional stability, thermal stability, and long-term reliability of the pixel boundaries, effectively avoiding inter-pixel crosstalk. The rigid sub-pixel cavities integrally formed from the substrate body not only serve as physical isolation structures to divide sub-pixel regions of different colors but also simultaneously stably define the liquid crystal accommodating space, achieving functional integration of the structure.

[0018] The present invention also provides a method for preparing a cholesteric liquid crystal display panel, which has the same beneficial effects as the cholesteric liquid crystal display panel described above, and will not be described in detail here. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A cross-sectional structural schematic diagram of a cholesteric liquid crystal display panel provided in an embodiment of the present invention; Figure 2a A cross-sectional schematic diagram of a rigid sub-pixel receiving cavity with a rectangular cross-section, provided for an embodiment of the present invention; Figure 2b A cross-sectional schematic diagram of a rigid sub-pixel receiving cavity with a trapezoidal cross-section is provided for an embodiment of the present invention; Figure 2c A cross-sectional schematic diagram of a rigid sub-pixel receiving cavity with a V-shaped cross-section is provided for an embodiment of the present invention; Figure 2d A schematic cross-sectional view of a rigid sub-pixel receiving cavity with a U-shaped cross-section is provided for an embodiment of the present invention; Figure 3 A schematic diagram and a partially enlarged view of the planar structure of the first substrate provided in an embodiment of the present invention; Figure 4 A top view of a cholesteric phase liquid crystal display panel provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the lead-out structure of the first electrode layer provided in an embodiment of the present invention; Figure 6 A process flow diagram of a method for preparing a cholesteric liquid crystal display panel provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the selective exposure process in a method for preparing a cholesteric liquid crystal display panel according to an embodiment of the present invention. In the figure: 100. First substrate, 110. Rigid sub-pixel receiving cavity, 111. Red sub-pixel receiving cavity, 112. Green sub-pixel receiving cavity, 113. Blue sub-pixel receiving cavity, 120. Isolation portion, 130. First electrode layer, 131. Electrode lead, 132. Electrical connection portion, 140. First alignment layer, 210. Second substrate, 220. Second electrode layer, 230. Second alignment layer, 300. Cholesteric liquid crystal layer, 310. Liquid crystal mixture, 400. Light-absorbing layer, 500. Sealing structure, 510. Liquid injection port, 511. Exhaust port, 520. Liquid injection manifold, 521. Exhaust manifold, 530. Sealing material. Detailed Implementation

[0021] The core of this invention is to provide a cholesteric liquid crystal display panel. Single-layer color cholesteric liquid crystal display structures typically employ an "added-on" isolation structure, where photoresist, polyimide, or other polymer isolation walls are formed on the substrate surface through processes such as photolithography, coating, printing, or curing. These isolation walls define liquid crystal channels or strip-shaped containers of different colors. However, this approach has the following drawbacks: First, the polymer materials differ from the glass substrate in their coefficients of thermal expansion, hygroscopicity, and long-term creep characteristics. Under high-temperature, thermal cycling, or long-term driving conditions, boundary drift, deformation, or interface failure may occur, leading to reliability issues such as inter-pixel crosstalk and color drift. Second, this approach relies on precise polymer dikes for staged infusion or multiple sealing processes, resulting in a cumbersome process flow. Furthermore, the precise patterning of the polymer materials places extremely high demands on the process window, making it highly susceptible to color mixing due to liquid crystal overflow, severely restricting mass production yield and cost control. In addition, as an additional structure, the polymer walls cannot simultaneously and synergistically define the liquid crystal containment space, cell thickness, alignment boundaries, and chiral component diffusion boundaries, failing to meet the requirements of high-performance displays for structural integration and stability.

[0022] The cholesteric liquid crystal display panel provided in this application includes: a liquid crystal cell, which includes a first substrate, a second substrate, and a cholesteric liquid crystal layer; the surface of the first substrate near the second substrate has a plurality of inwardly recessed rigid sub-pixel receiving cavities integrally formed from the first substrate body; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; the rigid sub-pixel receiving cavities are in contact with the second substrate; the cholesteric liquid crystal layer includes cholesteric liquid crystals filled in the rigid sub-pixel receiving cavities; the plurality of rigid sub-pixel receiving cavities include rigid sub-pixel receiving cavities corresponding to sub-pixels of different colors, and the cholesteric liquid crystals corresponding to sub-pixels of different colors have different pitches.

[0023] This cholesteric liquid crystal display panel features multiple inwardly recessed rigid sub-pixel cavities integrally formed from the first substrate body on the surface near the second substrate. This integrally formed isolation structure replaces the traditional post-processed polymer isolation walls. Because the isolation structure is made of the same material as the substrate body and is integrally formed, it eliminates boundary drift, deformation, or interface failure problems caused by differences in thermal expansion coefficients, hygroscopicity, and creep characteristics between the polymer material and the glass substrate. This significantly improves the dimensional stability, thermal stability, and long-term reliability of the pixel boundaries, effectively avoiding inter-pixel crosstalk. The rigid sub-pixel cavities integrally formed from the substrate body not only physically isolate different color sub-pixel regions but also stably define the liquid crystal accommodating space, achieving functional integration of the structure.

[0024] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The structure of the cholesteric liquid crystal display panel provided by this invention will be described in detail in the following embodiments.

[0026] Example 1

[0027] Please refer to Figures 1 to 4 , Figure 1 A cross-sectional structural schematic diagram of a cholesteric liquid crystal display panel provided in an embodiment of the present invention; Figure 2a A cross-sectional schematic diagram of a rigid sub-pixel receiving cavity with a rectangular cross-section, provided for an embodiment of the present invention; Figure 2b A cross-sectional schematic diagram of a rigid sub-pixel receiving cavity with a trapezoidal cross-section is provided for an embodiment of the present invention; Figure 2c A cross-sectional schematic diagram of a rigid sub-pixel receiving cavity with a V-shaped cross-section is provided for an embodiment of the present invention; Figure 2d A schematic cross-sectional view of a rigid sub-pixel receiving cavity with a U-shaped cross-section is provided for an embodiment of the present invention; Figure 3 A schematic diagram and a partially enlarged view of the planar structure of the first substrate provided in an embodiment of the present invention; Figure 4 A top view of a cholesteric phase liquid crystal display panel provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the lead-out structure of the first electrode layer provided in an embodiment of the present invention.

[0028] See Figure 1 This invention provides a cholesteric liquid crystal display panel, comprising: a liquid crystal cell, the liquid crystal cell including a first substrate 100, a second substrate 210, and a cholesteric liquid crystal layer 300; the surface of the first substrate 100 near the second substrate 210 has a plurality of inwardly recessed rigid sub-pixel receiving cavities 110 integrally formed from the body of the first substrate 100; the plurality of rigid sub-pixel receiving cavities 110 are periodically arranged along a first direction; the rigid sub-pixel receiving cavities 110 are in contact with the second substrate 210; the cholesteric liquid crystal layer 300 includes cholesteric liquid crystal filling the rigid sub-pixel receiving cavities 110; the plurality of rigid sub-pixel receiving cavities 110 include rigid sub-pixel receiving cavities 110 corresponding to sub-pixels of different colors, and the cholesteric liquid crystal corresponding to the sub-pixels of different colors has different pitches.

[0029] The cholesteric liquid crystal display panel provided in this embodiment includes an upper substrate assembly, a liquid crystal cell, a lower substrate assembly, and a functional auxiliary layer. The upper substrate assembly is the encapsulation body of the cholesteric liquid crystal display panel; the lower substrate assembly is the bottom support structure of the cholesteric liquid crystal display panel and the carrier of the cholesteric liquid crystal; the liquid crystal cell is the core functional layer of the cholesteric liquid crystal display panel, including a first substrate 100, a second substrate 210, and a cholesteric liquid crystal layer 300; the functional auxiliary layer includes a light-absorbing layer 400 located on the back side of the cholesteric liquid crystal display panel and a sealing structure 500 located in the peripheral area of ​​the cholesteric liquid crystal display panel.

[0030] In this embodiment, the liquid crystal cell includes a first substrate 100 and a second substrate 210 disposed opposite to each other, and a cholesteric liquid crystal layer 300 encapsulated between the first substrate 100 and the second substrate 210. In addition to the first substrate 100, the second substrate 210, and the cholesteric liquid crystal layer 300, the liquid crystal cell in this embodiment also includes other structures, such as electrode structures and alignment layers. Other structures of the liquid crystal cell can be referred to the following description, and will not be repeated here.

[0031] Cholesteric liquid crystals (CLCs) possess characteristics such as no backlight required, bistable operation, low power consumption, and selective reflectivity, making them suitable for applications such as electronic paper, electronic tags, outdoor low-power displays, and wearable displays. The CLC display panel in this embodiment is based on the selective reflectivity of CLCs. Cholesteric liquid crystals have a helical molecular arrangement structure, and the pitch of this helix determines the wavelength of the selectively reflected light. When the reflected wavelength of the incident light satisfies the Bragg condition, light of a specific wavelength is reflected, while light of other wavelengths is transmitted. The color displayed by the CLC display panel is related to the pitch of the CLC in the Cholesteric liquid crystal layer 300.

[0032] The cholesteric liquid crystal layer 300 in this embodiment is a single-layer cholesteric liquid crystal display layer. The pitch of the cholesteric liquid crystal in the cholesteric liquid crystal layer 300 can be adaptively adjusted according to actual display requirements. This embodiment does not impose specific limitations. It should be noted that the cholesteric liquid crystal layer 300 in this embodiment is formed by selective exposure of a liquid crystal mixture 310 injected in one step. The cholesteric liquid crystal layer 300 is composed of liquid crystal material filled in the rigid sub-pixel receiving cavity 110. The cholesteric liquid crystal corresponding to sub-pixels of different colors has different pitches to achieve selective reflection of light of different wavelengths. The pitch of the cholesteric liquid crystal is related to the selective exposure conditions. The formation of the cholesteric liquid crystal layer 300 can be referred to the following content, which will not be repeated here.

[0033] In one feasible embodiment, to achieve color display, the cholesteric liquid crystals corresponding to the red, green, and blue sub-pixels in the cholesteric liquid crystal display panel are configured with different pitches. Specifically, the selective reflection center wavelengths of the cholesteric liquid crystals corresponding to the red, green, and blue sub-pixels are located in the ranges of 600 nm to 680 nm, 520 nm to 570 nm, and 430 nm to 480 nm, respectively. When ambient white light is incident, each sub-pixel reflects only the light of its corresponding color, thereby forming a color image. The intensity or switching of the reflected light can be controlled by applying an electric field to change the molecular arrangement state of the cholesteric liquid crystal (e.g., switching from a planar state to a focal conic state), thus achieving grayscale display. The unreflected light is absorbed by the light-absorbing layer 400 on the back side of the panel, improving the color purity and contrast of the cholesteric liquid crystal display panel.

[0034] In this embodiment, the first substrate 100 is the core structure of the entire cholesteric liquid crystal display panel. Rigid sub-pixel cavities 110 are integrally formed on the surface of the first substrate 100 near the second substrate 210. These cavities physically isolate sub-pixels of different colors, providing stable and rigid pixel boundaries and fundamentally avoiding crosstalk between pixels. The rigid sub-pixel cavities 110 precisely define the accommodating space and thickness (cell thickness) of the cholesteric liquid crystal within each sub-pixel, helping to ensure that liquid crystal molecules can form a uniform helical structure. Furthermore, the first substrate 100 not only provides a flat bottom surface and sidewalls for the electrode structure and alignment layer, but its non-display area also integrates auxiliary structures such as a liquid injection port 510 communicating with the rigid sub-pixel cavities 110. The high integration of the first substrate 100 is beneficial for the fabrication of the cholesteric liquid crystal display panel.

[0035] In this embodiment, the first substrate 100 is a glass substrate. This embodiment does not impose specific limitations on the material of the glass substrate and can be adapted to meet actual production needs. In one feasible embodiment, the first substrate 100 is a transparent inorganic glass substrate. Specifically, the first substrate 100 is an alkali-free glass substrate or a borosilicate glass substrate. Alkali-free glass does not contain alkali metal oxides and has excellent thermal stability, chemical stability, and electrical insulation. Borosilicate glass, with silicon dioxide and boron oxide as its main components, has a low coefficient of thermal expansion and good thermal shock resistance.

[0036] In this embodiment, the surface of the first substrate 100 near the second substrate 210 has a plurality of inwardly recessed rigid sub-pixel receiving cavities 110 integrally formed from the body of the first substrate 100; the plurality of rigid sub-pixel receiving cavities 110 are periodically arranged along a first direction. That is, the rigid sub-pixel receiving cavities 110 are an array of micro-grooves integrally formed from the body of the first substrate 100, and adjacent grooves are separated by isolation portions 120 integrally formed from the body of the first substrate 100, the grooves constituting the rigid sub-pixel receiving cavities 110. In this embodiment, both the first direction and the second direction are parallel to the surface of the first substrate; the first direction is perpendicular to the second direction.

[0037] The rigid sub-pixel receiving cavity 110 provided in this embodiment is an inwardly recessed microgroove structure integrally formed from the body material of the first substrate 100. The rigid sub-pixel receiving cavity 110 is a rigid microstructure integrally formed from the substrate body, used to define the sub-pixel area and accommodate liquid crystal. The rigid sub-pixel receiving cavity 110 is filled with cholesteric liquid crystal to achieve the display effect of a cholesteric liquid crystal display panel. This embodiment does not impose specific limitations on the specific shape of the rigid sub-pixel receiving cavity 110 or its arrangement on the first substrate 100; adjustments can be made adaptively according to actual display requirements.

[0038] In one specific embodiment of this invention, the first substrate 100 is a glass substrate, and the rigid sub-pixel receiving cavity 110 is a strip-shaped receiving cavity extending along a second direction and periodically arranged along a first direction. Multiple strip-shaped receiving cavities are periodically arranged along the first direction to form a parallel array of grooves, and adjacent strip-shaped receiving cavities are separated by inter-groove glass ridges (i.e., isolation portions 120) formed by the glass substrate body. Specifically, the top of the inter-groove glass ridge contacts or is close to the inner surface of the second substrate 210, thereby forming a stable lateral isolation boundary within the effective display area, effectively preventing crosstalk and electric field interference between adjacent sub-pixels.

[0039] In one specific embodiment of this invention, the first substrate 100 is a glass substrate, and the rigid sub-pixel receiving cavity 110 is a grid-like receiving cavity arranged periodically along a second direction and periodically along a first direction. Multiple grid-like receiving cavities are arranged periodically along the second direction and periodically along the first direction, forming a two-dimensional matrix array of grooves. Adjacent grid-like receiving cavities are separated by inter-groove glass ridges (i.e., isolation portions 120) formed by the glass substrate body. Each grid-like receiving cavity corresponds to an independent sub-pixel. Specifically, the top of the inter-groove glass ridge contacts or is close to the inner surface of the second substrate 210, thereby forming physical isolation between pixels within the effective display area, effectively preventing crosstalk and electric field interference between adjacent sub-pixels, making it suitable for higher resolution display panels.

[0040] In this embodiment, the cross-sectional shape of the rigid sub-pixel receiving cavity 110 is any one of a rectangle, trapezoid, V-shape, U-shape, or a composite shape with rounded corners. In this embodiment, the cross-sectional shape is a section along the first direction. See also Figures 2a to 2d ,in, Figure 2a The cross-sectional shape of the rigid sub-pixel receiving cavity 110 is rectangular. Figure 2b The cross-sectional shape of the rigid sub-pixel receiving cavity 110 is trapezoidal. Figure 2c The cross-sectional shape of the rigid sub-pixel receiving cavity 110 is V-shaped. Figure 2d The cross-sectional shape of the medium-rigid sub-pixel receiving cavity 110 is U-shaped (or a composite shape with rounded corners).

[0041] In this embodiment, the depth h of the rigid sub-pixel receiving cavity 110 is 0.3 micrometers to 50 micrometers, preferably 2 micrometers to 20 micrometers; the opening width w of the rigid sub-pixel receiving cavity 110 is 2 micrometers to 120 micrometers, preferably 5 micrometers to 80 micrometers; and the width t of the isolation wall of the rigid sub-pixel receiving cavity 110 is 0.2 micrometers to 20 micrometers, preferably 1 micrometer to 10 micrometers.

[0042] In this embodiment, the rigid sub-pixel receiving cavity 110 includes rigid sub-pixel receiving cavities 110 corresponding to sub-pixels of different colors. The cholesteric liquid crystals corresponding to the sub-pixels of different colors have different pitches. Different colors refer to the different wavelengths of light selectively reflected by each sub-pixel, thus presenting different colors visually. In this embodiment, the color of the sub-pixels within the rigid sub-pixel receiving cavity 110 is not specifically limited and can be adaptively adjusted according to actual production needs. That is, this embodiment does not limit a specific color combination scheme, and the color corresponding to each sub-pixel can be flexibly configured according to the specific application scenario and target color gamut requirements of the cholesteric liquid crystal display panel.

[0043] In one specific embodiment of this invention, the plurality of rigid sub-pixel receiving cavities 110 include multiple sub-pixel receiving cavities corresponding to red, green, and blue sub-pixels, respectively, namely red sub-pixel receiving cavity 111, green sub-pixel receiving cavity 112, and blue sub-pixel receiving cavity 113; the cholesteric liquid crystals corresponding to the red, green, and blue sub-pixels have different pitches. The selective reflection center wavelength of the cholesteric liquid crystal corresponding to the red sub-pixel is in the range of 600 nm to 680 nm, the selective reflection center wavelength of the cholesteric liquid crystal corresponding to the green sub-pixel is in the range of 520 nm to 570 nm, and the selective reflection center wavelength of the cholesteric liquid crystal corresponding to the blue sub-pixel is in the range of 430 nm to 480 nm.

[0044] In this specific implementation, see Figure 3In the plurality of rigid sub-pixel cavities 110, every three adjacent rigid sub-pixel cavities 110 constitute a pixel unit; the pixel unit includes three rigid sub-pixel cavities 110 corresponding to the red sub-pixel, green sub-pixel, and blue sub-pixel, respectively. This embodiment achieves full-color display by arranging the red, green, and blue sub-pixels adjacently to form a pixel unit and arranging them periodically along a first direction. The three sub-pixels in each pixel unit share one pixel unit, and different pixel units are separated by rigid sub-pixel cavities 110, ensuring the independence of color and the uniformity of display between each pixel unit.

[0045] In another specific embodiment of this invention, the plurality of rigid sub-pixel receiving cavities 110 include receiving cavities corresponding to at least four colors of sub-pixels, with the cholesteric liquid crystals corresponding to the different colored sub-pixels having different pitches. In one feasible embodiment, the plurality of rigid sub-pixel receiving cavities 110 include a plurality of sub-pixel receiving cavities corresponding to red, green, blue, and yellow sub-pixels, with the cholesteric liquid crystals corresponding to the red, green, blue, and yellow sub-pixels having different pitches. In another feasible embodiment, the plurality of rigid sub-pixel receiving cavities 110 include a plurality of sub-pixel receiving cavities corresponding to red, green, blue, and white sub-pixels, with the cholesteric liquid crystals corresponding to the red, green, blue, and white sub-pixels having different pitches.

[0046] In this specific embodiment, every four adjacent rigid sub-pixel cavities 110 constitute a pixel unit, which includes four sub-pixel cavities corresponding to four different colors. Each color's cholesteric liquid crystal has its own different pitch to achieve selective reflection of light of different wavelengths. This cholesteric liquid crystal display panel adds yellow or white sub-pixels to the red, green, and blue three-color base, forming RGBY (red, green, blue, yellow) or RGBW (red, green, blue, white) four-color pixel units; this expands the display color gamut of the cholesteric liquid crystal display panel and increases display brightness under the same power consumption.

[0047] In this embodiment, an isolation structure is formed between adjacent rigid sub-pixel receiving cavities 110 by the body of the first substrate 100. The isolation structure is used to isolate adjacent sub-pixels within the effective display area to prevent crosstalk and electric field interference between different sub-pixels. Adjacent rigid sub-pixel receiving cavities 110 are separated by an isolation portion 120 integrally formed by the body of the first substrate 100. The isolation portion 120 is integrally formed by the body of the first substrate 100 and is formed simultaneously with the rigid sub-pixel receiving cavity 110, without the need for additional isolation material.

[0048] In this embodiment, the rigid sub-pixel receiving cavity 110 is in contact with the second substrate 210; that is, the top of the isolation portion 120 is in contact with or close to the second substrate 210 (or the upper substrate assembly, which includes the second substrate 210), so that adjacent rigid sub-pixel receiving cavities 110 are isolated within the effective display area. Specifically, the top of the isolation portion 120 may be in direct contact with the inner surface of the upper substrate assembly, or may be in contact with or close to an insulating layer, black matrix layer, or sealing auxiliary layer disposed on the inner side of the upper substrate assembly. When the top of the isolation portion 120 is in contact with the upper substrate assembly or a functional layer on the upper substrate assembly, a closed isolation space is formed between adjacent rigid sub-pixel receiving cavities 110, and the liquid crystal material of each sub-pixel is completely separated within its respective receiving cavity, preventing lateral flow. When the top of the isolation portion 120 is close to the upper substrate assembly (i.e., retaining a small gap), the size of this gap should be smaller than the size of the cholesteric liquid crystal molecules. In this embodiment, the rigid sub-pixel accommodating cavity 110 contacts the second substrate 210, so that the adjacent rigid sub-pixel accommodating cavities 110 have stable boundaries within the effective display area, reducing the risk of crosstalk under temperature changes or long-term operation, and further improving the structural stability of the liquid crystal display panel.

[0049] In this embodiment, the first substrate 100 includes a display area and a non-display area, with the non-display area surrounding the display area. A rigid sub-pixel receiving cavity 110 is disposed in the display area. The non-display area is provided with a liquid injection port 510, which communicates with the rigid sub-pixel receiving cavity 110. In this embodiment, the liquid injection port 510 is located at the edge of the non-display area. After the liquid crystal cell is fabricated, the liquid injection port 510 is used to inject the liquid crystal mixture 310 into each receiving cavity. After injection, the liquid injection port 510 is sealed with a sealing material 530 to complete the sealing and encapsulation of the liquid crystal cell.

[0050] The first substrate 100 has a liquid injection manifold 520 at the edge of the display area, which is connected to the liquid injection port 510. The liquid injection manifold 520 connects the ends of all rigid sub-pixel receiving cavities 110, so that the liquid crystal mixture 310 can enter the manifold through the liquid injection port 510 and then be quickly and evenly distributed to each receiving cavity.

[0051] The first substrate 100 has a liquid injection manifold 520, an exhaust manifold 521, and an exhaust port 511 at the edge of the display area. The liquid injection manifold 520 is connected to the liquid injection port 510, and the exhaust manifold 521 is connected to the exhaust port 511. The liquid injection port 510 and the exhaust port 511 are diagonally arranged. See also Figure 4Specifically, the liquid injection manifold 520 is located at the first edge of the display area (as below), connecting the first ends (as below) of all the strip-shaped receiving cavities; the exhaust manifold 521 is located at the second edge of the display area (as above), connecting the second ends (as above) of all the strip-shaped receiving cavities; the first and second sides are arranged opposite to each other. The liquid injection port 510 is located in the non-display area of ​​the first side and connects to the liquid injection manifold 520, and the exhaust port 511 is located in the non-display area of ​​the second side and connects to the exhaust manifold 521, with the liquid injection port 510 and the exhaust port 511 arranged diagonally. Through the above diagonal arrangement, during the vacuum filling process, the liquid crystal mixture 310 enters the liquid injection manifold 520 from the liquid injection port 510, flows along each strip-shaped receiving cavity towards the exhaust manifold 521, and pushes the original air in the receiving cavity to move towards the exhaust manifold 521 and be discharged from the exhaust port 511. This directional flow path from the injection port 510 to the vent port 511 helps ensure that the air in each cavity is completely expelled, allowing the liquid crystal mixture 310 to fill each cavity, effectively reducing the residue of air bubbles and significantly improving the uniformity of crystal filling.

[0052] See Figure 5 The liquid crystal cell of this embodiment includes a first electrode layer 130 and a first alignment layer 140; the first electrode layer 130 is at least disposed on the bottom surface of the rigid sub-pixel cavity 110; the first alignment layer 140 is at least disposed on the inner surface of the rigid sub-pixel cavity 110 and at least partially covers the first electrode layer 130.

[0053] Specifically, the first electrode layer 130 is disposed on the bottom surface and / or the sidewall surface of the rigid sub-pixel receiving cavity 110, or disposed on the side surface of the first substrate 100 near the second substrate 210 and electrically connected to the cholesteric liquid crystal composite layer 300 within each rigid sub-pixel receiving cavity 110. Furthermore, the liquid crystal cell of this embodiment includes an electrode lead 131 and an electrical connection portion 132. One end of the electrode lead 131 is soldered to the electrical connection portion 132, and the other end is connected to the first electrode layer 130. The electrical connection portion 132 is disposed in the non-display area of ​​the first substrate 100. In this embodiment, the electrical connection portion refers to a part used to achieve electrical connection, and its specific form includes, but is not limited to, connection pads and external connection terminals. In this embodiment, the first electrode layer 130 is a patterned driving electrode layer, and the first electrode layers 130 corresponding to each rigid sub-pixel receiving cavity 110 are electrically isolated from each other. Electrode leads 131 are electrically connected to the first electrode layer 130 and extend from the display area to the non-display area of ​​the first substrate 100. Electrical connection portions 132 are disposed in the non-display area at the edge of the first substrate 100 and are electrically connected to the electrode leads 131, for connecting to a flexible circuit board, a driver chip, or an external test power supply. Thus, each segmented first electrode layer 130 can access pixel driving signals through the corresponding electrode leads 131 and electrical connection portions 132. The driving electrode layer is made of any one of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum-doped zinc oxide (AZO), silver nanowires, or graphene; the electrode lead 131 can be integrally formed with the first electrode layer 130 using the same transparent conductive material, or it can be formed using molybdenum (Mo), aluminum (Al), chromium (Cr), copper (Cu), or a composite metal conductive layer thereof; the electrical connection 132 can be formed using ITO, IZO, Mo, Al, Cr, Cu, Au (gold), or a composite conductive layer thereof.

[0054] The first alignment layer 140 is disposed on the bottom surface, the sidewall surface of the cavity, or a combination thereof (i.e., the inner surface of the rigid sub-pixel cavity 110), preferably covering the liquid crystal contact side of the first electrode layer 130, and is used to provide an alignment effect on the liquid crystal mixture 310 filled in the rigid sub-pixel cavity 110. This embodiment does not impose specific limitations on the material of the first alignment layer 140, and it can be selected according to actual needs. In this embodiment, the material of the first alignment layer 140 is polyimide or a photoalignment material.

[0055] The liquid crystal cell in this embodiment includes a second electrode layer 220 and a second alignment layer 230; a second substrate 210, the second electrode layer 220, and the second alignment layer 230 are stacked; the second electrode layer 220 is located between the second substrate 210 and the second alignment layer 230; the second alignment layer 230 is in contact with the top of the rigid sub-pixel receiving cavity 110. The upper substrate assembly in this embodiment includes a second substrate 210, a second electrode layer 220 disposed inside the second substrate 210, and a second alignment layer 230.

[0056] In one specific embodiment of this invention, the second electrode layer 220 is a common electrode layer that covers the entire display area of ​​the second substrate 210 and is connected to an external common potential. A second alignment layer 230 is coated on the surface of the second electrode layer 220. In this embodiment, the second electrode layer 220 is a common electrode layer. In this embodiment, the first electrode layer 130 is a driving electrode disposed on one side of the first substrate 100, and the second electrode layer 220 is a common electrode layer. Both are located on opposite sides of the cholesteric liquid crystal layer 300, forming a driving electric field along the thickness direction of the liquid crystal cell when a voltage is applied, thereby controlling the alignment state of the cholesteric liquid crystal molecules. The second alignment layer 230 and the first alignment layer 140 together provide orientation anchoring for the cholesteric liquid crystal molecules on both the upper and lower surfaces, which is beneficial for the liquid crystal molecules to form a stable cholesteric helical alignment structure within the rigid sub-pixel cavity 110.

[0057] As another specific implementation of this embodiment, the liquid crystal cell may not have a second electrode layer 220 on one side of the second substrate 210 (i.e., no electrode layer is provided on the second substrate 210). Instead, the first electrode layer 130 and the second electrode layer 220 are both provided on the first substrate 100 and located on the same side of the first substrate 100. The first electrode layer 130 and the second electrode layer 220 are insulated from each other. The first electrode layer 130 is connected to the pixel driving voltage, and the second electrode layer 220 is connected to the common voltage, forming an in-plane electric field or edge electric field driving structure to drive the cholesteric liquid crystal layer 300 in the rigid sub-pixel receiving cavity 110.

[0058] As a feasible specific embodiment, a first electrode layer 130 and a second electrode layer 220 are provided on the bottom surface of the rigid sub-pixel receiving cavity 110. The first electrode layer 130 and the second electrode layer 220 are two sets of comb-shaped electrode structures that are inserted into each other but do not contact each other. The first electrode layer 130 is connected to the pixel driving voltage, and the second electrode layer 220 is connected to the common voltage. After being energized, the electric field is mainly distributed laterally near the bottom surface of the rigid sub-pixel receiving cavity 110 and bends upward into the cholesteric liquid crystal layer to form an in-plane / edge electric field.

[0059] As another feasible specific embodiment, a first electrode layer 130 is provided on the bottom surface of the rigid sub-pixel receiving cavity 110, and a second electrode layer 220 is provided on the isolation portion 120 between adjacent rigid sub-pixel receiving cavities 110. The electric field points from the first electrode layer 130 on the bottom surface of the rigid sub-pixel receiving cavity 110 to the second electrode layer 220 on the isolation portion 120, forming a curved edge electric field that acts on the cholesteric liquid crystal within the rigid sub-pixel receiving cavity 110.

[0060] As another feasible specific embodiment, a first electrode layer 130 is disposed on the bottom surface of the rigid sub-pixel receiving cavity 110, a transparent insulating layer is disposed on the side surface of the first electrode layer 130 facing away from the first substrate 100, and a second electrode layer 220 is disposed on the side surface of the transparent insulating layer facing away from the first substrate 100. The second electrode layer 220 has a slit. After power is applied, the electric field bends from the edge of the upper slit into the liquid crystal layer, forming an edge electric field driving structure.

[0061] The cholesteric liquid crystal display panel provided in this embodiment also includes a light-absorbing layer 400 and a sealing structure 500. The light-absorbing layer 400 is disposed on the back side of the cholesteric liquid crystal display panel. Specifically, the light-absorbing layer 400 is disposed on the surface of the first substrate 100 away from the second substrate 210, and is used to absorb incident light that is not selectively reflected by the cholesteric liquid crystal, thereby improving the color purity and contrast of the reflective display of the cholesteric liquid crystal display panel. In this embodiment, the light-absorbing layer 400 can be a black coating, a black resin layer, a black metal oxide layer, or other low-reflection material layer. The sealing structure 500 is disposed in the non-display area of ​​the cholesteric liquid crystal display panel and is used to bond and seal the upper substrate assembly to the first substrate 100. This embodiment does not impose specific limitations on the material and width of the sealing structure 500, and can be adapted according to actual production needs. In this embodiment, the material of the sealing structure 500 is epoxy sealant or thermosetting sealant, and the width of the sealing structure 500 is 0.5 mm to 1.0 mm.

[0062] The cholesteric liquid crystal display panel provided in this embodiment employs a rigid sub-pixel receiving cavity 110 integrally formed with the first substrate 100 body. Adjacent rigid sub-pixel receiving cavities 110 are separated by an isolation portion 120. The bottom and sidewalls of the rigid sub-pixel receiving cavity 110, together with the isolation portion 120, define the receiving space for cholesteric liquid crystals corresponding to sub-pixels of different colors, enabling the first substrate 100 to simultaneously perform the functions of isolating sub-pixels of different colors and limiting the space for local cell thickness. The isolation portion 120 is in contact with or close to the upper substrate assembly, so that adjacent rigid sub-pixel receiving cavities 110 have stable boundaries within the effective display area. Compared with traditional polymer isolation walls, the rigid sub-pixel receiving cavity 110 has extremely high dimensional stability, thermal stability, and mechanical strength, avoiding pixel crosstalk or display unevenness caused by the expansion and contraction of polymer materials, reducing the risk of crosstalk under temperature changes or long-term operation, and improving the long-term reliability and environmental adaptability of the cholesteric liquid crystal display panel. The cholesteric liquid crystal display panel provided in this embodiment ensures the independence and uniformity of liquid crystal materials for sub-pixels of different colors by setting the injection port 510 and the exhaust port 511 diagonally, and by using the sealing structure of the injection manifold area 520 and the exhaust manifold area 521.

[0063] The cholesteric liquid crystal display panel provided by this invention has multiple inwardly recessed rigid sub-pixel receiving cavities 110 integrally formed from the first substrate 100 body on the surface near the second substrate 210. This integrally formed isolation structure replaces the traditional post-processed polymer isolation wall. Because the isolation structure is made of the same material as the substrate body and is integrally formed, it eliminates the boundary drift, deformation, or interface failure problems caused by differences in thermal expansion coefficients, hygroscopicity, and creep characteristics between the polymer material and the glass substrate. This significantly improves the dimensional stability, thermal stability, and long-term reliability of the pixel boundaries and effectively avoids inter-pixel crosstalk. The rigid sub-pixel receiving cavities 110 integrally formed from the substrate body not only serve as physical isolation structures to divide sub-pixel regions of different colors but also simultaneously stably define the liquid crystal receiving space, achieving functional integration of the structure.

[0064] The specific details of the method for preparing a cholesteric liquid crystal display panel provided by this invention will be described in detail in the following embodiments.

[0065] Example 2

[0066] Please refer to Figures 6 to 7 , Figure 6 A process flow diagram of a method for preparing a cholesteric liquid crystal display panel provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the selective exposure process in a method for preparing a cholesteric liquid crystal display panel according to an embodiment of the present invention.

[0067] See Figure 6In this embodiment of the invention, the method for preparing a cholesteric liquid crystal display panel includes: S101: A first substrate is provided, and a plurality of inwardly recessed rigid sub-pixel receiving cavities are integrally formed on a preset surface of the first substrate; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; the preset surface is the surface of the first substrate close to the second substrate.

[0068] In this step, a first substrate 100 is provided, and multiple rigid sub-pixel cavities 110 are integrally formed on a predetermined surface of the first substrate 100 using microfabrication technology. This step does not impose specific limitations on the microfabrication technology and can be selected according to actual production needs.

[0069] In this embodiment, a first substrate 100 is provided, and a plurality of inwardly recessed rigid sub-pixel cavities 110 are integrally formed on a predetermined surface of the first substrate 100. The plurality of rigid sub-pixel cavities 110 are periodically arranged along a first direction. The predetermined surface is the surface of the first substrate 100 near the second substrate 210. The embodiment includes: providing the first substrate 100, and using photolithography combined with etching, laser direct writing, ultra-precision machining, hot pressing, or molding processes to integrally form a plurality of inwardly recessed rigid sub-pixel cavities 110 on the predetermined surface of the first substrate 100. The plurality of rigid sub-pixel cavities 110 are periodically arranged along a first direction. The predetermined surface is the surface of the first substrate 100 near the second substrate 210. For details regarding photolithography combined with etching, laser direct writing, ultra-precision machining, hot pressing, or molding processes, please refer to relevant content, which will not be repeated here.

[0070] For details regarding the material of the first substrate 100, the structure of the rigid sub-pixel accommodating cavity 110, and its arrangement, please refer to the foregoing content; further details will not be repeated here.

[0071] After step S101 and before step S102, the method for fabricating a cholesteric liquid crystal display panel further includes: fabricating a first electrode layer 130 and a first alignment layer 140 on a first substrate 100 forming a plurality of rigid sub-pixel cavities 110. The first electrode layer 130 is at least disposed on the bottom surface of the rigid sub-pixel cavities 110; the first alignment layer 140 is at least disposed on the inner surface of the rigid sub-pixel cavities 110 and at least partially covers the first electrode layer 130.

[0072] The positions and materials of the first electrode layer 130 and the first alignment layer 140 can be referred to the foregoing description. The fabrication processes of the first electrode layer 130 and the first alignment layer 140 can be referred to related technologies; this embodiment does not impose specific limitations. The formation methods of the electrode leads 131 and the electrical connection portions 132 can be referred to related technologies; this embodiment does not impose specific limitations, as long as the first electrode layer 130 within each rigid sub-pixel accommodating cavity can be electrically connected to the electrical connection portions via the electrode leads 131. Before executing step S102, the method further includes: forming a liquid injection manifold region 520, a liquid injection port 510, an exhaust manifold region 521, and an exhaust port 511 in the non-display area of ​​the first substrate 100. For details regarding the location and materials of the liquid manifold 520, injection port 510, exhaust manifold 521, and exhaust port 511, please refer to the foregoing description. For details regarding the preparation process of the liquid manifold 520, injection port 510, exhaust manifold 521, and exhaust port 511, please refer to relevant technologies. This embodiment does not impose any specific limitations.

[0073] S102: Provide a second substrate, align and bond the first substrate and the second substrate to form a liquid crystal cell, and the rigid sub-pixel receiving cavity is in contact with the second substrate.

[0074] In this embodiment, a second substrate 210 is provided, and a second electrode layer 220 and a second alignment layer 230 are sequentially formed on one side surface of the second substrate 210 to obtain an upper substrate assembly. A sealant is applied to the peripheral area of ​​the non-display area of ​​the first substrate 100 or the upper substrate assembly. The first substrate 100 and the upper substrate assembly are aligned and bonded together, such that the top of the isolation portion 120 of the rigid sub-pixel receiving cavity 110 contacts or is close to the inner surface of the upper substrate assembly (i.e., the surface of the second alignment layer 230). The sealant is cured to form a sealing structure 500, and at least one injection port 510 and one vent port 511 are retained.

[0075] The fabrication process of the second electrode layer 220 and the second alignment layer 230 can be referred to relevant technologies, and this embodiment does not impose specific limitations.

[0076] S103: Fill the rigid sub-pixel cavity with a liquid crystal mixture.

[0077] In this embodiment, filling the rigid sub-pixel accommodating cavity 110 with a liquid crystal mixture 310 includes: injecting the same liquid crystal mixture 310 into each rigid sub-pixel accommodating cavity 110 at once; the liquid crystal mixture 310 includes a liquid crystal substrate, a chiral dopant, a photocurable reactive monomer, and a photoinitiator; or, the liquid crystal mixture 310 includes a liquid crystal substrate, a chiral dopant, an oligomer, and a photoinitiator. As an optional implementation, the liquid crystal mixture 310 includes a liquid crystal substrate, a chiral dopant, a photocurable reactive monomer or oligomer, a photoinitiator, and any one selected from polymerizable chiral dopant, crosslinking agent, stabilizer, or ion control agent; wherein, the polymerizable chiral dopant and the chiral dopant are two different types of materials. The filling process of the liquid crystal mixture 310 can be referred to related technologies, and this embodiment does not impose specific limitations.

[0078] In this embodiment, a prepared liquid crystal mixture 310 (such as a photocurable liquid crystal mixture 310) is injected into the assembled liquid crystal cell in one go using vacuum injection, capillary injection, or drop injection methods. The liquid crystal mixture 310 fills each rigid sub-pixel receiving cavity 110. The liquid crystal mixture 310 includes a liquid crystal substrate, a chiral dopant, a photocurable reactive monomer or oligomer, a photoinitiator, and any one of a polymerizable chiral dopant, a crosslinking agent, a stabilizer, or an ion control agent.

[0079] In this embodiment, the rigid sub-pixel receiving cavity 110 is integrally formed with the first substrate 100, and it has a synergistic effect with the primary injection process. On the one hand, the rigid sub-pixel receiving cavity 110 is integrally formed from the glass substrate body, and the depth, width and volume of each rigid sub-pixel receiving cavity 110 are highly consistent. During the primary injection process, the liquid crystal mixture 310 can be synchronously filled into each rigid sub-pixel receiving cavity 110 at a basically the same rate under the drive of capillary action, avoiding uneven filling caused by differences in the rigid sub-pixel receiving cavities 110. At the same time, adjacent rigid sub-pixel receiving cavities 110 are isolated from each other by the isolation part 120. After the injection is completed, the liquid injection manifold 520 is blocked, and the liquid crystal mixture 310 in each rigid sub-pixel receiving cavity 110 is completely physically separated, providing structural protection for the subsequent formation of cholesteric liquid crystals with different pitches. On the other hand, the isolation section 120 is made of glass, which will not deform under external pressure during vacuum filling and will not swell or dissolve when in contact with the organic solvent in the liquid crystal mixture 310. This avoids the liquid crystal alignment disorder or pixel crosstalk problems caused by the easy deformation of traditional polymer isolation walls, resulting in a wider process window and higher reliability for single-filling. Therefore, the integrally formed rigid sub-pixel receiving cavity 110 works synergistically with the single-filling process to simplify the process and reduce costs while ensuring the uniformity, independence, and stability of the liquid crystal material filling in each sub-pixel receiving cavity, providing a reliable process basis for subsequent selective exposure to form sub-pixels of different colors.

[0080] After performing step S103 and before performing step S104, the method further includes: after injecting the liquid crystal mixture 310, subjecting the rigid sub-pixel receiving cavity 110 containing the liquid crystal mixture 310 to static, heating, or depressurization treatment to remove air bubbles generated during the injection of the liquid crystal mixture 310 and to ensure that the liquid crystal mixture 310 is evenly distributed in each rigid sub-pixel receiving cavity 110.

[0081] S104: Selectively expose the liquid crystal mixture in the rigid sub-pixel cavity, and the cholesteric liquid crystals corresponding to sub-pixels of different colors have different pitches to prepare a cholesteric liquid crystal display panel.

[0082] In this embodiment, the liquid crystal mixture 310 in the rigid sub-pixel cavity 110 is selectively exposed, and the cholesteric liquid crystals corresponding to different colored sub-pixels have different pitches. This includes selective exposure of the liquid crystal mixture 310 in the rigid sub-pixel cavity 110 by means of a mask, grayscale mask, digital micromirror device, laser scanning exposure or projection exposure, and the cholesteric liquid crystals corresponding to different colored sub-pixels have different pitches.

[0083] Specifically, different exposure doses, exposure area ratios, or exposure patterns are applied to the liquid crystal mixture 310 within the rigid sub-pixel accommodating cavity 110 corresponding to different color sub-pixels using photomasks, grayscale masks, digital micromirrors, laser scanning exposure, or projection exposure methods. This causes the photocurable reactive monomers or oligomers in the liquid crystal mixture 310 to undergo polymerization reactions of varying degrees or spatial distributions within the different rigid sub-pixel accommodating cavities 110, forming polymer networks, gel networks, or chiral component fixation regions in situ. Therefore, the cholesteric liquid crystals corresponding to the different color sub-pixels within the rigid sub-pixel accommodating cavity 110 have different pitches.

[0084] In one possible embodiment, see Figure 7 The multiple rigid sub-pixel cavities 110 include multiple sub-pixel cavities corresponding to red, green, and blue sub-pixels, respectively. The cholesteric liquid crystals corresponding to the red, green, and blue sub-pixels have different pitches. Selective exposure is performed on the rigid sub-pixel cavities 110, including those corresponding to red, green, and blue sub-pixels, including: selective exposure using a mask, grayscale mask, digital micromirror device, laser scanning exposure, or projection exposure method; the exposure dose, exposure area ratio, or polymer network density corresponding to the blue sub-pixel is greater than that of the green sub-pixel, and the exposure dose, exposure area ratio, or polymer network density corresponding to the green sub-pixel is greater than that of the red sub-pixel.

[0085] The order of exposure dose / polymer network density is: B (blue subpixel) > G (green subpixel) > R (red subpixel). The resulting cholesteric liquid crystal has a pitch that is: shortest for blue subpixels, intermediate for green subpixels, and longest for red subpixels. A higher polymer network density results in a stronger compression and anchoring effect on the cholesteric liquid crystal's helical structure, leading to a shorter effective pitch and a shorter reflection wavelength; conversely, a lower polymer network density results in a longer effective pitch and a longer reflection wavelength.

[0086] In this embodiment, the selective reflection center wavelength of the cholesteric liquid crystal corresponding to the red sub-pixel is in the range of 600 nm to 680 nm, the selective reflection center wavelength of the cholesteric liquid crystal corresponding to the green sub-pixel is in the range of 520 nm to 570 nm, and the selective reflection center wavelength of the cholesteric liquid crystal corresponding to the blue sub-pixel is in the range of 430 nm to 480 nm.

[0087] After performing step S104, the process also includes: after selective exposure is completed, post-processing of the liquid crystal cell is performed, and then the liquid injection port 510 is sealed to complete the preparation of the display panel.

[0088] Specifically, after selective exposure, the liquid crystal cell undergoes heat treatment, diffusion balancing, and secondary uniform curing or annealing to stabilize the cholesteric liquid crystal layer 300 within each rigid sub-pixel accommodating cavity 110. Subsequently, the injection port 510 and injection manifold 520 are sealed with sealing material 530 to complete the fabrication of the display panel.

[0089] The cholesteric liquid crystal display panel fabrication method provided in this embodiment injects the same liquid crystal mixture 310 into the liquid crystal cell in a single injection, avoiding the cumbersome operation and color mixing risk of multiple injections. After the single injection, selective exposure is used to apply different exposure doses, exposure times, or exposure area ratios to the rigid sub-pixel cavities 110 corresponding to sub-pixels of different colors. This causes the photocurable reactive monomers to undergo different degrees of polymerization reactions in different rigid sub-pixel cavities, forming differentiated polymer network densities in situ. This controls the pitch of the cholesteric liquid crystal, achieving reflective display of red, green, and blue primary colors. Furthermore, the one-time molding of the first substrate 100 replaces the complex process of multiple photolithography and coating to form a polymer dam, also avoiding the cumbersome operation and color mixing risk of multiple injections of different colored liquid crystals. The fabrication method of this embodiment can be achieved through a single injection and a single selective exposure, greatly simplifying the process and improving production efficiency and product yield.

[0090] The preparation method of the cholesteric phase liquid crystal display panel of this application is described below through specific embodiments (specific embodiment 1 and specific embodiment 2). Specific Implementation Example 1

[0092] An alkali-free glass substrate with a thickness of 0.5 mm is provided. Using photolithography and reactive ion etching processes, a rectangular cross-section array of strip-shaped receptacles is formed on the first surface of the alkali-free glass substrate. The depth of each strip-shaped receptacle is 8 micrometers, the opening width of each strip-shaped receptacle is 25 micrometers, and the width of the glass ridge between adjacent strip-shaped receptacles is 5 micrometers. Every three adjacent strip-shaped receptacles serve as the strip-shaped receptacles for red, green, and blue sub-pixels, respectively.

[0093] An ITO transparent driving electrode is deposited as a first electrode layer 130 on the bottom surface of each strip-shaped cavity. The thickness of the first electrode layer 130 is 80 nm to 120 nm, and the sheet resistance is 10 Ω / sq to 20 Ω / sq. The ITO transparent conductive layer is patterned by photolithography etching to electrically isolate the first electrode layers 130 on the bottom surface of each strip-shaped cavity from each other. At the same time, electrode leads 131 and electrical connection portions 132 corresponding to and connected to each first electrode layer 130 are formed on the outer side of the display area (i.e., the non-display area). The electrode leads 131 are used to lead each first electrode layer 130 to the non-display area of ​​the first substrate, and the electrical connection portions 132 are used to electrically connect to a flexible circuit board, a driving chip, or an external test power supply. Subsequently, a polyimide alignment layer 140 is coated on the bottom and inner surfaces of the strip-shaped receiving cavity as the first alignment layer 140. The thickness of the alignment layer is 50 nm to 100 nm, the curing temperature is 180°C, the curing time is 30 min, and a unidirectional friction alignment treatment is performed. An upper glass substrate with an ITO common electrode (i.e., the second electrode layer 220) is provided, the thickness of the second electrode layer 220 being 80 nm. An epoxy frame sealant is used as a sealant to bond the upper glass substrate to the alkali-free glass substrate with the strip-shaped receiving cavity formed thereon. The width of the sealant frame is 0.5 mm to 1.0 mm, and diagonally arranged injection ports 510 and vent ports 511 are retained.

[0094] A photocurable liquid crystal mixture 310 was prepared, and its composition, by weight percentage (wt%), was as follows: 88 wt% of nematic liquid crystal E7 (a cyanobiphenyl-based mixed liquid crystal), 3 wt% of chiral dopant R5011 ((13BR)-5,6-dihydro-5-(trans-4-propylcyclohexyl)-4H-dinaphtho[2,1-F:1',2'-H][1,5]dioxane-nonatetraene), 7 wt% of reactive liquid crystal monomer RM257 (2-methyl-1,4-phenyl 4-(3-acryloyloxypropoxy)benzoic acid), 1.5 wt% of trimethylolpropane triacrylate, and 0.5 wt% of photoinitiator Irgacure 651 (2,2-dimethoxy-2-phenylacetophenone). The liquid crystal mixture 310 is stirred at 50°C for 30 minutes until it becomes uniform and transparent. Then, it is injected into the liquid crystal cell through the injection port 510 using a vacuum injection method to fill each strip-shaped receiving cavity and the flow convergence area.

[0095] After infusion, selective exposure is performed using 365 nm ultraviolet light through a grayscale mask. The exposure dose for the red sub-pixel region is 20 mJ / cm². 2 The exposure dose for the green sub-pixel region is 80 mJ / cm². 2 The exposure dose for the blue sub-pixel region is 160 mJ / cm². 2 After exposure, the polymer network within each strip-shaped cavity is annealed at 50°C for 20 minutes to stabilize its formation. Finally, the injection port 510 and vent port 511 are sealed with UV-cured adhesive to complete the fabrication of the cholesteric liquid crystal display panel.

[0096] After post-processing, the reflection center wavelengths of the red, green, and blue sub-pixels are located at approximately 630 nm, 550 nm, and 460 nm, respectively. Specific Implementation Example 2

[0098] The difference from Specific Embodiment 1 is that the rigid sub-pixel receiving cavity 110 adopts a trapezoidal cross-section. A borosilicate glass substrate with a thickness of 0.4 mm is provided, and a strip-shaped receiving cavity array with a trapezoidal cross-section is formed by a wet etching process. The depth of the strip-shaped receiving cavity is 10 micrometers, the opening width of the strip-shaped receiving cavity is 30 micrometers, the bottom wall width of the strip-shaped receiving cavity is 18 micrometers, and the width of the glass ridge between adjacent strip-shaped receiving cavities at the first surface of the borosilicate glass substrate is 6 micrometers.

[0099] IZO transparent driving electrodes are sputtered onto the bottom and inner surfaces of the strip-shaped accommodating cavities as first electrode layers 130. The thickness of the first electrode layer 130 is 100 nm, and the sheet resistance is 15 Ω / sq. Subsequently, the IZO transparent conductive layer is patterned using photolithography or laser etching processes to electrically isolate the first electrode layers 130 within each strip-shaped accommodating cavity from each other. Electrode leads 131 and electrical connection portions 132, which are electrically connected to each first electrode layer 130, are formed on the outer side of the display area (i.e., the non-display area). The material of the electrode leads 131 can be integrally formed from the IZO transparent conductive layer and the first electrode layer 130, or it can be formed from Mo, Al, Cr, Cu, or their composite metal conductive layers. The electrical connection portions 132 are disposed in the non-display area at the edge of the borosilicate glass substrate for connection to a flexible circuit board, a driving chip, or an external test power supply, so that each segmented first electrode layer 130 can be respectively connected to pixel driving signals. Subsequently, a first alignment layer 140 with a thickness of 60 nanometers was formed using a photoalignment material, and then irradiated with 300 mJ / cm² polarized ultraviolet light at a wavelength of 313 nanometers. 2 The alignment capability is then formed. The upper substrate is a transparent glass substrate, and a full-surface ITO common electrode is provided on the inner side of the transparent glass substrate as a second electrode layer 220. A second alignment layer 230 can be provided on the side of the second electrode layer 220 facing the liquid crystal layer. The bonding is completed by thermosetting frame adhesive. The frame adhesive curing conditions are 120°C and 40 min. A liquid injection port 510 is provided in the lower left corner and an exhaust port 511 is provided in the upper right corner.

[0100] A photocurable liquid crystal mixture 310 was prepared, comprising, by weight percentage (wt%): 76 wt% nematic liquid crystal SLC1717 (a fluorinated biphenyl mixed liquid crystal), 12.8 wt% chiral dopant S811 ((S)-oct-2-yl-4-((4-(hexoxy)benzoyl)oxy)benzoate), 2.5 wt% polymerizable chiral monomer, 7.8 wt% reactive monomer RM257 (2-methyl-1,4-phenyl 4-(3-acryloyloxypropoxy)benzoate), 0.4 wt% photoinitiator Irgacure 819 (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide), and 0.5 wt% stabilizer BHT (2,6-di-tert-butyl-4-methylphenol). The mixture was stirred at 60°C for 1 hour and filtered through a 0.2-micron filter membrane for later use. The liquid crystal mixture 310 was injected into the liquid crystal cell using a vacuum injection method with a vacuum degree of -0.09 MPa and an injection temperature of 45°C.

[0101] Following infusion, patterned ultraviolet (UV) exposure (i.e., selective exposure) was performed using a digital micromirror system. The exposure wavelength was 405 nm, and the light intensity was 8 mW / cm². 2The red subpixel area was exposed for 5 seconds, the green subpixel area for 15 seconds, and the blue subpixel area for 30 seconds. By varying the exposure times, the photocurable monomers within each strip-shaped cavity exhibited different degrees of polymerization and network densities, thereby adjusting the effective pitch of the cholesteric liquid crystal. After exposure, the mixture was held at 45°C for 30 minutes, then cooled to room temperature, and the injection port 510 and vent port 511 were sealed with UV-sealing adhesive. The resulting cholesteric liquid crystal display panel formed red, green, and blue reflective regions within a single-layer liquid crystal structure, suitable for reflective low-power color displays.

[0102] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section. Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a…" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0103] The cholesteric phase liquid crystal display panel and its preparation method provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A cholesteric liquid crystal display panel, characterized in that, include: A liquid crystal cell, the liquid crystal cell comprising a first substrate, a second substrate, and a cholesteric liquid crystal layer; The first substrate is a glass substrate, and the surface of the first substrate near the second substrate has a plurality of inwardly recessed rigid sub-pixel receiving cavities integrally formed from the first substrate body; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; adjacent rigid sub-pixel receiving cavities are separated by an isolation portion integrally formed from the first substrate body, and the top of the isolation portion between adjacent rigid sub-pixel receiving cavities contacts the second substrate; the first direction is parallel to the surface of the first substrate. The cholesteric liquid crystal layer includes cholesteric liquid crystal filling the rigid sub-pixel cavity; The plurality of rigid sub-pixel receiving cavities include rigid sub-pixel receiving cavities corresponding to sub-pixels of different colors, and the cholesteric liquid crystals corresponding to sub-pixels of different colors have different pitches; In a single liquid crystal filling process, the depth, width, and volume of each rigid sub-pixel receiving cavity are consistent.

2. The cholesteric liquid crystal display panel according to claim 1, characterized in that, The rigid sub-pixel receiving cavity is a strip-shaped receiving cavity that extends along the second direction and is periodically arranged along the first direction.

3. The cholesteric liquid crystal display panel according to claim 1, characterized in that, In the plurality of rigid sub-pixel cavities, every three adjacent rigid sub-pixel cavities constitute a pixel unit; The pixel unit includes three rigid sub-pixel cavities corresponding to the red sub-pixel, green sub-pixel, and blue sub-pixel, respectively.

4. The cholesteric liquid crystal display panel according to claim 1, characterized in that, The first substrate includes a display area and a non-display area, the non-display area being disposed around the display area, and the rigid sub-pixel receiving cavity being disposed in the display area; The non-display area is provided with a liquid injection port, which is connected to the rigid sub-pixel receiving cavity.

5. The cholesteric liquid crystal display panel according to claim 1, characterized in that, The liquid crystal cell includes a first electrode layer and a first alignment layer; The first electrode layer is disposed at least on the bottom surface of the rigid sub-pixel receiving cavity; The first alignment layer is disposed at least on the inner surface of the rigid sub-pixel receiving cavity and at least partially covers the first electrode layer.

6. The cholesteric liquid crystal display panel according to claim 1, characterized in that, The liquid crystal cell includes a second electrode layer and a second alignment layer; The second substrate, the second electrode layer, and the second alignment layer are stacked together; The second electrode layer is located between the second substrate and the second alignment layer; The second alignment layer contacts the top of the rigid sub-pixel receiving cavity.

7. A method for preparing a cholesteric liquid crystal display panel, used to prepare the cholesteric liquid crystal display panel as described in any one of claims 1 to 6, characterized in that, include: A first substrate is provided, the first substrate being a glass substrate, and a plurality of inwardly recessed rigid sub-pixel receiving cavities are integrally formed on a predetermined surface of the first substrate; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; the predetermined surface is the surface of the first substrate close to a second substrate; adjacent rigid sub-pixel receiving cavities are separated by an isolation portion integrally formed on the body of the first substrate. The first direction is parallel to the surface of the first substrate; A second substrate is provided, and the first substrate and the second substrate are aligned and bonded together to form a liquid crystal cell, wherein the top of the isolation portion is in contact with the second substrate; A liquid crystal mixture is filled into the rigid sub-pixel cavity; the liquid crystal mixture comprises a photocurable reactive monomer and a photoinitiator, or the liquid crystal mixture comprises an oligomer and a photoinitiator; Selective exposure is performed on the liquid crystal mixture within the rigid sub-pixel cavity, and the cholesteric liquid crystals corresponding to sub-pixels of different colors have different pitches, in order to prepare a cholesteric liquid crystal display panel. In a single liquid crystal filling process, the depth, width, and volume of each rigid sub-pixel receiving cavity are consistent.

8. The method for preparing a cholesteric liquid crystal display panel according to claim 7, characterized in that, A first substrate is provided, and a plurality of inwardly recessed rigid sub-pixel receiving cavities are integrally formed on a predetermined surface of the first substrate; the plurality of rigid sub-pixel receiving cavities are periodically arranged along a first direction; the predetermined surface is the surface of the first substrate near the second substrate, including: A first substrate is provided, and multiple inwardly recessed rigid sub-pixel cavities are integrally formed on a predetermined surface of the first substrate using photolithography combined with etching, laser direct writing, ultra-precision machining, hot pressing or molding processes; the multiple rigid sub-pixel cavities are periodically arranged along a first direction; the predetermined surface is the surface of the first substrate close to the second substrate.

9. The method for preparing a cholesteric liquid crystal display panel according to claim 7, characterized in that, Filling the rigid sub-pixel cavity with a liquid crystal mixture includes: The same liquid crystal mixture is injected into each of the rigid sub-pixel cavities in one go; The liquid crystal mixture also includes a liquid crystal substrate and a chiral dopant.

10. The method for preparing a cholesteric liquid crystal display panel according to claim 7, characterized in that, Selective exposure is performed on the liquid crystal mixture within the rigid sub-pixel cavity, wherein the cholesteric liquid crystals corresponding to different color sub-pixels have different pitches, including: The liquid crystal mixture within the rigid sub-pixel cavity is selectively exposed using a mask, grayscale mask, digital micromirror device, laser scanning exposure, or projection exposure method. The cholesteric liquid crystals corresponding to sub-pixels of different colors have different pitches.

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