A cholesteric liquid crystal display device and a method for manufacturing the same

Abstract

This invention relates to the field of cholesteric liquid crystal display technology. The invention discloses a cholesteric liquid crystal display device and its fabrication method. By using a dam structure to divide a single-layer liquid crystal cell into multiple pixel regions, and by injecting liquid crystal material containing a photosensitive chiral agent, selective exposure processing can form multiple cholesteric liquid crystals with different pitches in situ within a single liquid crystal layer, each reflecting different colors of light. This achieves full-color display in a single-layer structure, significantly simplifying the device structure, reducing overall thickness and manufacturing costs, and minimizing light loss due to light penetration through multiple layers. Furthermore, during processing, only two liquid crystal injections are required, along with illumination processing, to obtain three pixel regions reflecting different colors, greatly reducing the number of device processing steps.

Description

Technical Field

[0001] This invention relates to the field of cholesteric liquid crystal display technology, and more particularly to a cholesteric liquid crystal display device and its preparation method. Background Technology

[0002] Electronic paper (E-Paper), also known as digital paper or paper-like display, is an electronic display device that provides a visual experience similar to paper. Electronic paper is categorized into electrophoretic electronic paper, cholesteric liquid crystal electronic paper, and toner electronic paper. Among these, cholesteric liquid crystal electronic paper relies on a twisted cholesteric liquid crystal layer reflecting light of a specific wavelength and on the bistable nature of cholesteric liquid crystals to maintain the image even after power is off.

[0003] Common single-layer cholesteric display device structures include Figure 1 As shown, the display includes upper and lower substrates and a liquid crystal layer between them. Electrodes are provided on the surfaces of both the upper and lower substrates. By applying different pulse voltages to the liquid crystal layer through these two electrodes, two stable states can be achieved: a planar state (P-state) and a focal conic state (FC-state). When the cholesteric liquid crystal layer is in the FC-state, external light entering the display is absorbed by the bottom black ink, displaying black. When the cholesteric liquid crystal layer is in the P-state, it reflects light of the corresponding wavelength, and any remaining light passing through is also completely absorbed by the bottom black ink layer. By adjusting the pitch of the cholesteric liquid crystal used, different colors of light can be reflected.

[0004] Therefore, when full-color display is required, existing technologies typically employ a three-layer liquid crystal cell stacking method, such as... Figure 1 As shown. However, the three-layer liquid crystal cell structure makes the film structure of the display panel more complex and thicker, and also causes some light loss when passing through each film layer, resulting in a lower overall reflectivity of the display panel. Therefore, the display panel based on cholesteric liquid crystal full-color reflective display technology is slightly inferior to other electrophoretic display devices in terms of reflectivity and color saturation, and there is still a big gap compared with the actual paper reading effect. Summary of the Invention

[0005] To address the technical problems existing in the background art, this invention proposes a cholesteric liquid crystal display device and its preparation method.

[0006] The present invention discloses a cholesteric liquid crystal display device, comprising a first substrate and a second substrate disposed opposite to each other, and a liquid crystal layer located between the first substrate and the second substrate, characterized in that: A dam structure is provided between the first substrate and the second substrate, and the dam structure divides the liquid crystal layer into multiple isolated pixel regions. The pixel region includes at least a first pixel region, a second pixel region, and a third pixel region; The first pixel region is filled with a first cholesteric liquid crystal; The second and third pixel regions are initially filled with a second cholesteric liquid crystal, which contains a photosensitive chiral agent. The photosensitive chiral agent in the second cholesteric liquid crystal in the third pixel region changes under the action of light, causing the liquid crystal in the third pixel region to transform into a third cholesteric liquid crystal with a different pitch. The first cholesteric liquid crystal, the second cholesteric liquid crystal, and the third cholesteric liquid crystal have different pitches so as to reflect different colors of light respectively; The device further includes a light-shielding layer disposed at a position corresponding to the second pixel region, used to block light from the second pixel region when the second cholesteric liquid crystal in the third pixel region transforms into the third cholesteric liquid crystal.

[0007] Preferably, the first pixel region, the second pixel region, and the third pixel region are arranged in a matrix within the display area, and multiple first pixel regions, multiple second pixel regions, and multiple third pixel regions form multiple first pixel groups, multiple second pixel groups, and multiple third pixel groups that are alternately arranged in the first direction. Multiple pixel regions in each pixel group are arranged correspondingly in the second direction and are connected to each other.

[0008] Preferably, the first pixel region is connected to a first injection port, and the second pixel region and the third pixel region are connected to a second injection port, with the first injection port and the second injection port located on different sides of the display area.

[0009] Preferably, the light source is ultraviolet light.

[0010] Preferably, the light-shielding layer is a black light-shielding layer, which is disposed on the first substrate and only covers the position corresponding to the second pixel area.

[0011] Preferably, the first substrate is further provided with a light-absorbing layer, and the second substrate is provided with a UV-resistant layer.

[0012] In this invention, the proposed cholesteric liquid crystal display device divides a single-layer liquid crystal cell into multiple pixel regions using a dam structure. By injecting liquid crystal material containing a photosensitive chiral agent and selectively exposing it, multiple cholesteric liquid crystals with different pitches can be formed in situ within a single liquid crystal layer, each reflecting different colors of light. This achieves full-color display in a single-layer structure, significantly simplifying the device structure, reducing overall thickness and manufacturing costs, and minimizing light loss due to light penetration through multiple layers. Furthermore, during processing, only two liquid crystal injections are required, along with illumination treatment, to obtain three pixel regions reflecting different colors, greatly reducing the number of processing steps.

[0013] The present invention also proposes a method for preparing the above-mentioned cholesteric liquid crystal display device, comprising the following steps: The second substrate and the first substrate, which have a dam structure, are bonded together such that the dam structure forms a plurality of isolated pixel regions between them, the pixel regions including at least a first pixel region, a second pixel region and a third pixel region; The first cholesteric liquid crystal is injected into the first pixel region, and the second cholesteric liquid crystal is injected into the second pixel region and the third pixel region, wherein the second cholesteric liquid crystal contains a photosensitive chiral agent; Selective light irradiation is applied to the device after liquid crystal injection, causing a change in the photosensitive chiral agent in the second cholesteric liquid crystal within the third pixel region, forming a third cholesteric liquid crystal, while the second cholesteric liquid crystal within the second pixel region remains unchanged.

[0014] Preferably, it further includes: pre-forming a light-shielding layer on a first substrate, the position of which corresponds to the second pixel region.

[0015] Preferably, the selective light irradiation of the device after liquid crystal filling specifically involves irradiating it with ultraviolet light from the outside of the first substrate.

[0016] Preferably, the first substrate and the second substrate are bonded together by a dam structure through high temperature and pressure.

[0017] In this invention, the method for fabricating a cholesteric liquid crystal display device involves two substrates connected by a dam structure. During the processing, only two liquid crystal injections are required, along with light treatment, to obtain three pixel regions that reflect different colors, greatly reducing the number of device processing steps. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a color cholesteric liquid crystal display device in the prior art.

[0019] Figure 2This is a schematic diagram of one embodiment of a cholesteric liquid crystal display device proposed in this invention.

[0020] Figure 3 This is a schematic diagram of the pixel region distribution of one embodiment of a cholesteric liquid crystal display device proposed in this invention.

[0021] Figure 4 This is a flowchart illustrating one embodiment of the method for preparing a cholesteric liquid crystal display device proposed in this invention.

[0022] Figure 5 This is a schematic diagram of liquid crystal injection in one embodiment of the method for preparing a cholesteric liquid crystal display device proposed in this invention.

[0023] Figure 6 This is a schematic diagram of the illumination process in one embodiment of the method for preparing a cholesteric liquid crystal display device proposed in this invention.

[0024] Figure 7 This is a schematic diagram of another embodiment of the method for preparing a cholesteric liquid crystal display device proposed in this invention.

[0025] Figure label: 101. First substrate; 102. Second substrate; 103. Dike structure; 104. First cholesteric liquid crystal; 105. Second cholesteric liquid crystal; 106. Light-shielding layer; 107. Third cholesteric liquid crystal; 2. Light-absorbing layer; 3. UV-resistant layer; 4. First filling port; 5. Second filling port. Detailed Implementation

[0026] Reference Figure 2 The present invention provides a cholesteric liquid crystal display device, comprising: a first substrate 101 and a second substrate 102 disposed opposite to each other, and a liquid crystal layer located between the first substrate 101 and the second substrate 102, characterized in that: A dam structure 103 is provided between the first substrate 101 and the second substrate 102. The dam structure 103 divides the liquid crystal layer into multiple isolated pixel regions. Specifically, the dam structure is a dam-shaped or wall-shaped isolation structure disposed between the first substrate and the second substrate to physically separate the liquid crystal layer. This structure can be bonded to the first substrate and the second substrate through a high-temperature and high-pressure process, thereby dividing the space between the first substrate and the second substrate into multiple isolated pixel regions and preventing the liquid crystal materials in different pixel regions from mixing or flowing during the filling or use process. The pixel region includes at least a first pixel region A, a second pixel region B, and a third pixel region C; The first pixel region A is filled with a first cholesteric liquid crystal 104; The second pixel region B and the third pixel region C are initially filled with a second cholesteric liquid crystal 105. The second cholesteric liquid crystal 105 contains a photosensitive chiral agent. The photosensitive chiral agent in the second cholesteric liquid crystal 105 in the third pixel region C changes under the action of light, so that the liquid crystal in this region is transformed into a third cholesteric liquid crystal 107 with a different pitch. The first cholesteric liquid crystal 104, the second cholesteric liquid crystal 105, and the third cholesteric liquid crystal 107 have different pitches so as to reflect different colors of light respectively; The device further includes a light-shielding layer 106 disposed at the corresponding position of the second pixel region B, used to block light from the second pixel region when the second cholesteric liquid crystal in the third pixel region C transforms into the third cholesteric liquid crystal.

[0027] The first cholesteric liquid crystal 104 is a cholesteric liquid crystal filled in the first pixel region A and possessing a first specific optical property. The second cholesteric liquid crystal 105 is a cholesteric liquid crystal initially filled in the second pixel region B and the third pixel region C and containing a photosensitive chiral agent. A photosensitive chiral agent is an additive whose chemical or physical properties change when exposed to light under specific conditions. Commonly used photosensitive chiral agents include azobenzene, diarylethylene, and molecular motors. The third cholesteric liquid crystal 107 is a cholesteric liquid crystal with different optical properties formed by the second cholesteric liquid crystal 105 after exposure to light, due to the change in the photosensitive chiral agent. Specifically, the first cholesteric liquid crystal 104 has a first pitch, and the second cholesteric liquid crystal 105 has a second pitch. After specific light exposure, the second cholesteric liquid crystal 105 forms a third cholesteric liquid crystal 107 with a third pitch under the action of the photosensitive chiral agent. By filling pixel regions with cholesteric liquid crystals of different pitches, different colors can be displayed, and finally, color display is achieved through pixel color mixing.

[0028] By dividing the single-layer liquid crystal cell into multiple pixel regions through the cofferdam structure 103 and injecting liquid crystal material containing photosensitive chiral agents, multiple cholesteric liquid crystals with different pitches can be formed in situ within a single liquid crystal layer through selective exposure processing. These liquid crystals reflect different colors of light, thereby realizing full-color display under a single-layer structure. This significantly simplifies the device structure, reduces the overall thickness and manufacturing cost, and also reduces light loss caused by light penetrating multiple film layers.

[0029] To achieve uniform multi-color display across three pixel areas, the specific design method refers to... Figure 3The first pixel region A, the second pixel region B, and the third pixel region C are arranged in a matrix within the display area. Multiple first pixel regions A, multiple second pixel regions B, and multiple third pixel regions C form multiple first pixel groups, multiple second pixel groups, and multiple third pixel groups arranged alternately in the first direction. In a specific design, multiple pixel regions within each pixel group are arranged correspondingly and interconnected in the second direction. This ensures a uniform distribution of the three types of pixels throughout the display area and facilitates communication within the same pixel group. For example, multiple pixel groups are arranged alternately along rows or columns, and multiple pixel regions within each pixel group are arranged alternately and interconnected along columns or rows. The connection between pixel regions can be achieved through dike openings between adjacent pixel regions within the same pixel group.

[0030] To facilitate liquid crystal filling, the first pixel area is connected to a first filling port, and the second pixel area and the third pixel area are connected to a second filling port. The first filling port and the second filling port are located on different sides of the display area.

[0031] In specific configurations, connectivity between pixel regions can be achieved through dike openings between adjacent pixel regions within the same pixel group. An opening is formed on the dike between two adjacent pixel regions within the same pixel group, allowing the pixel regions of the same group to be connected sequentially, thus enabling the infusion of the same pixel group from an infusion port located on one side.

[0032] Reference Figure 4 This embodiment also proposes a method for fabricating the above-mentioned cholesteric liquid crystal display device, comprising the following steps: A first substrate 101 and a second substrate 102 with a dam structure 103 are bonded together, such that the dam structure 103 forms a plurality of isolated pixel regions between the two substrates. The pixel regions include at least a first pixel region A, a second pixel region B, and a third pixel region C. The bonding process is a step of aligning and bonding the first substrate 101 and the second substrate 102 together. Specifically, the first substrate and the second substrate, which have been respectively formed with a dam structure, a light-shielding layer, or other film layer, are precisely aligned and brought into contact with each other. By applying pressure and optional high temperature conditions, the first substrate, the second substrate, and the dam structure located between them are physically or chemically bonded, thereby fixing the two substrates together as one and forming a plurality of sealed and isolated pixel regions separated by the dam structure between them.

[0033] The first cholesteric liquid crystal 104 is injected into the first pixel region A, and the second cholesteric liquid crystal 105 is injected into the second pixel region B and the third pixel region C. The second cholesteric liquid crystal 105 contains a photosensitive chiral agent. Selective light irradiation is applied to the device after liquid crystal injection, causing a change in the photosensitive chiral agent in the second cholesteric liquid crystal 105 in the third pixel region C, forming a third cholesteric liquid crystal 107, while the second cholesteric liquid crystal 105 in the second pixel region B remains unchanged.

[0034] The fabrication method of this embodiment forms a pixel region defined by the dam structure 103 through cell bonding. Specifically, the dam structure can be pre-formed on the first substrate or the second substrate. During the specific processing, the first substrate 101 and the second substrate 102 are bonded together through the dam structure 103 by applying high temperature and pressure. The high temperature and pressure are specifically process conditions performed under the combined effect of increased temperature and applied pressure. By bonding the first substrate 101 and the second substrate 102 together through the dam structure 103 under high temperature and pressure conditions, the high temperature helps soften the material or fuse the interface, while the pressure ensures tight contact at the bonding surfaces, thereby forming a robust and well-sealed pixel isolation structure.

[0035] Then, two initial liquid crystals were injected into the partitions. (Refer to...) Figure 5 To facilitate liquid crystal injection, in the specific design of the cholesteric liquid crystal display device, the first pixel region A is connected to a first injection port 4, and the second pixel region B and the third pixel region C are connected to a second injection port 5. The first injection port 4 and the second injection port 5 are located on different sides of the display area. Different liquid crystal materials can be independently injected into the first pixel region A and the second and third pixel regions C, realizing independent introduction of liquid crystal materials into different areas and avoiding mixing during the injection process. After injection, UV adhesive can be used to seal the injection ports.

[0036] Reference Figure 6 Finally, through selective light irradiation, utilizing the shielding difference of the light-shielding layer 106, only the liquid crystal in the third pixel region C undergoes a light reaction, thereby forming three liquid crystals with different optical properties within a single layer. Through key structural assembly and differentiation processing steps, the fabrication of a single-layer multi-color display device was achieved. During the processing, only two liquid crystal injections are required, along with light irradiation, to obtain three pixel regions reflecting different colors, significantly reducing the number of device processing steps.

[0037] The light-shielding layer 106 is used to shield the liquid crystal in the second pixel region during the photosensitive reaction of the liquid crystal in the third pixel region. Therefore, the light-shielding layer 106 can be pre-formed on the substrate on both sides of the second pixel region.

[0038] In one specific embodiment, during the illumination of the second cholesteric liquid crystal 105 in the third pixel region C, a light-shielding layer 106 is pre-formed on the first substrate 101, the position of which corresponds to the second pixel region B. The light-shielding layer 106 is a black light-shielding layer 106, disposed on the first substrate 101, and only covers the position corresponding to the second pixel region B. During the illumination process, the cholesteric liquid crystal in the second pixel region B is protected from being affected by the light-shielding layer 106 on the substrate. The light is ultraviolet light. Ultraviolet light is selected as the light that triggers the change of the photosensitive chiral agent, and its specific photon energy can effectively trigger the photochemical reaction required by the photosensitive chiral agent in the second cholesteric liquid crystal 105. With the above design, ultraviolet light is irradiated from the outside of the first substrate 101 during illumination. The irradiation direction is matched with the position of the light-shielding layer 106 on the first substrate 101, so that before the ultraviolet light reaches the liquid crystal layer, it must first pass through the first substrate 101 and the area not covered by the light-shielding layer 106, thus naturally achieving targeted irradiation of the third pixel region C. Furthermore, the first substrate 101 is located on the side of the liquid crystal away from the light-incident side; therefore, during the display process, the light-shielding layer 106 is located below the liquid crystal and does not affect the display effect.

[0039] like Figure 7 As shown, in a further specific design, the first substrate 101 is further provided with a light-absorbing layer 2, and the second substrate 102 is provided with a UV-protective layer 3. During operation, the light-absorbing layer is an additional functional layer used to absorb light, assisting in the absorption of stray light to improve display contrast. The added UV-protective layer 3 can prevent ambient ultraviolet light or processing ultraviolet light from entering from the second substrate 102 side, interfering with the liquid crystal state or affecting device stability. In particular, during the use of the display device, it prevents ultraviolet light in the ambient light from affecting the second cholesteric liquid crystal 105 containing the photosensitive chiral agent.

[0040] In one specific design, a pixel electrode is provided on a first substrate 101, a light-shielding layer 106 is provided on the inner side, and a light-absorbing layer is provided on the outer side. A common electrode is provided on a second substrate 102, and a UV-resistant layer 3 is provided on its outer side.

[0041] In this embodiment, the proposed cholesteric liquid crystal display device divides a single-layer liquid crystal cell into multiple pixel regions using a dam structure. By injecting liquid crystal material containing a photosensitive chiral agent and selectively exposing it, multiple cholesteric liquid crystals with different pitches can be formed in situ within a single liquid crystal layer, each reflecting different colors of light. This achieves full-color display in a single-layer structure, significantly simplifying the device structure, reducing overall thickness and manufacturing costs, and minimizing light loss due to light penetration through multiple layers. Furthermore, during processing, only two liquid crystal injections are required, along with illumination treatment, to obtain three pixel regions reflecting different colors, greatly reducing the number of processing steps.

[0042] The specific embodiments of the cholesteric liquid crystal display device of the present invention will be further described in detail below with reference to the accompanying drawings. For example... Figure 7 As shown, the present invention provides a cholesteric liquid crystal display device, comprising a first substrate 101 and a second substrate 102 disposed opposite to each other. A dam structure 103 is provided between the first substrate 101 and the second substrate 102. The dam structure 103 is bonded to the first substrate 101 and the second substrate 102 by a high-temperature and high-pressure process, thereby dividing the space between the two into a plurality of mutually sealed and isolated pixel regions. These pixel regions include at least a first pixel region A, a second pixel region B, and a third pixel region C, and they are uniformly distributed in a matrix pattern within the display area. The first pixel region A is connected to a first injection port located on one side of the display area, and the second pixel region B and the third pixel region C are jointly connected to a second injection port located on the other side of the display area, so as to achieve independent injection of each region.

[0043] Specifically, the first pixel region A is filled with a first cholesteric liquid crystal 104, which has a first pitch for reflecting, for example, red light. The second pixel region B and the third pixel region C are initially filled with the same second cholesteric liquid crystal 105, which contains a photosensitive chiral agent. On the inner surface of the first substrate 101, corresponding to the position of the second pixel region B, a light-shielding layer 106 is pre-formed, precisely covering only the second pixel region B. Optionally, to further improve optical performance, a light-absorbing layer 2 can be added to the first substrate 101, and a UV-resistant layer 3 can be added to the second substrate 102.

[0044] The fabrication method of the display device in this embodiment includes the following steps: S1, a second substrate 102 having a cofferdam structure 103 and a first substrate 101 having a black light-shielding layer 106.

[0045] S2. The first substrate 101 and the second substrate 102 are precisely aligned, and the two are bonded together by the cofferdam structure 103 through high temperature and pressure, thereby forming a first pixel region A, a second pixel region B and a third pixel region C that are isolated from each other.

[0046] S3. First cholesteric liquid crystal 104 is injected into the first pixel region A through the first injection port 4, and second cholesteric liquid crystal 105 containing a photosensitive chiral agent is injected into the second pixel region B and the third pixel region C through the second injection port 5. The injection ports are then sealed with UV glue.

[0047] S4. Selective light irradiation is applied to the infused device, specifically by irradiating ultraviolet light from the outside of the first substrate 101. Due to the obstruction of the light-shielding layer 106, the ultraviolet light cannot reach the second pixel region B, so the second cholesteric liquid crystal 105 in this region remains unchanged. However, the ultraviolet light can pass through the first substrate 101 and reach the third pixel region C, which is not covered by the light-shielding layer, triggering a photochemical reaction in the photosensitive chiral agent in the second cholesteric liquid crystal 105 in this region, causing a change in its pitch, thereby forming a third cholesteric liquid crystal 107 with a third pitch in situ, used to reflect, for example, blue light. Thus, the first cholesteric liquid crystal 104 in the first pixel region A, the second cholesteric liquid crystal 105 in the second pixel region B, and the newly formed third cholesteric liquid crystal 107 in the third pixel region C each have different pitches, and can reflect three different colors of light within a single-layer structure to achieve full-color display.

[0048] S5. Black ink is coated on the outer side of the first substrate 101 to form a light-absorbing layer 2.

[0049] By using a dam structure to achieve pixel partitioning within a single cell and employing liquid crystals containing photosensitive chiral agents in conjunction with selective exposure, three different pitch liquid crystals are formed within a single layer in a single step, thus eliminating the need for traditional multilayer stacking architectures. This significantly simplifies the device structure, reduces overall thickness and process complexity, and minimizes light loss caused by light penetrating multiple layers, contributing to improved optical efficiency, color performance, and fabrication efficiency of the display.

[0050] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A cholesteric liquid crystal display device comprising: A first substrate and a second substrate disposed opposite to each other, and a liquid crystal layer located between the first substrate and the second substrate, characterized in that: A dam structure is provided between the first substrate and the second substrate, and the dam structure divides the liquid crystal layer into multiple isolated pixel regions. The pixel region includes at least a first pixel region, a second pixel region, and a third pixel region; The first pixel region is filled with a first cholesteric liquid crystal; The second and third pixel regions are initially filled with a second cholesteric liquid crystal, which contains a photosensitive chiral agent. The photosensitive chiral agent in the second cholesteric liquid crystal in the third pixel region changes under the action of light, causing the liquid crystal in the third pixel region to transform into a third cholesteric liquid crystal with a different pitch. The first cholesteric liquid crystal, the second cholesteric liquid crystal, and the third cholesteric liquid crystal have different pitches so as to reflect different colors of light respectively; The device further includes a light-shielding layer disposed at a position corresponding to the second pixel region, used to block light from the second pixel region when the second cholesteric liquid crystal in the third pixel region transforms into the third cholesteric liquid crystal.

2. A cholesteric liquid crystal display device according to claim 1, characterised in that, The first pixel region, the second pixel region, and the third pixel region are arranged in a matrix within the display area. Multiple first pixel regions, multiple second pixel regions, and multiple third pixel regions form multiple first pixel groups, multiple second pixel groups, and multiple third pixel groups that are alternately arranged in the first direction. Multiple pixel regions in each pixel group are arranged correspondingly in the second direction and are connected to each other.

3. A cholesteric liquid crystal display device according to claim 1 or 2, characterised in that, The first pixel region is connected to a first injection port, and the second pixel region and the third pixel region are connected to a second injection port. The first injection port and the second injection port are located on different sides of the display area.

4. The cholesteric liquid crystal display device according to claim 1, characterized in that, The photosensitive chiral agent is an ultraviolet light photosensitive chiral agent.

5. The cholesteric liquid crystal display device according to claim 1 or 4, characterized in that, The light-shielding layer is a black light-shielding layer, which is disposed on the first substrate and only covers the position corresponding to the second pixel area.

6. The cholesteric liquid crystal display device according to claim 5, characterized in that, The first substrate also has a light-absorbing layer; And / or, a UV-resistant layer is provided on the second substrate.

7. A method for preparing a cholesteric liquid crystal display device according to any one of claims 1-6, characterized in that, Includes the following steps: A first substrate and a second substrate having a dam structure are bonded together, such that the dam structure forms a plurality of mutually isolated pixel regions between the two, the pixel regions including at least a first pixel region, a second pixel region and a third pixel region; The first cholesteric liquid crystal is injected into the first pixel region, and the second cholesteric liquid crystal is injected into the second pixel region and the third pixel region, wherein the second cholesteric liquid crystal contains a photosensitive chiral agent; Selective light irradiation is applied to the device after liquid crystal injection, causing a change in the photosensitive chiral agent in the second cholesteric liquid crystal within the third pixel region, forming a third cholesteric liquid crystal, while the second cholesteric liquid crystal within the second pixel region remains unchanged.

8. The method for preparing the cholesteric liquid crystal display device according to claim 7, characterized in that, Also includes: A light-shielding layer is pre-formed on a first substrate, the position of which corresponds to the second pixel region.

9. The method for preparing a cholesteric liquid crystal display device according to claim 8, characterized in that, The selective light irradiation of the device after liquid crystal filling specifically involves irradiating it with ultraviolet light from the outside of the first substrate.

10. The method for preparing the cholesteric liquid crystal display device according to claim 7, characterized in that, The first substrate and the second substrate are bonded together by a cofferdam structure through high temperature and pressure.

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