A cholesteric liquid crystal display device

Abstract

The utility model relates to display technical field discloses a kind of cholesteric liquid crystal display devices, comprising: first substrate and second substrate are oppositely arranged;Cholesteric liquid crystal layer between first substrate and second substrate;Third electrode, first insulating layer and first electrode consisting of multiple first strip electrode are sequentially laminated and arranged in the side of first substrate facing second substrate;Fourth electrode, second insulating layer and second electrode consisting of multiple second strip electrode are sequentially laminated and arranged in the side of second substrate facing first substrate;The extension direction of first strip electrode and the extension direction of second strip electrode are perpendicular to each other;In the direction perpendicular to first substrate, third electrode covers the gap region between adjacent two first strip electrode, and fourth electrode covers the gap region between adjacent two second strip electrode. Thus it can guarantee that cholesteric liquid crystal in display area is effectively driven, and the picture quality performance of product is improved.

Description

Technical Field

[0001] This utility model relates to the field of display technology, and in particular to a cholesteric liquid crystal display device. Background Technology

[0002] Cholesteric liquid crystal displays (Ch-LCDs) exhibit bistable characteristics, remaining stably in either a planar state or a focal conic state when no voltage is applied. In the planar state, the cholesteric liquid crystal reflects specific wavelengths of light, resulting in a bright pixel; in the focal conic state, it scatters light, which is absorbed by a black backplane, resulting in a dark pixel. For example... Figure 1 As shown, by applying different voltages, cholesteric liquid crystals can be converted between planar, focal conic, and vertical states.

[0003] Traditional passive cholesteric liquid crystal displays (LCMs) consist of a pixel matrix formed by multiple crisscrossing row and column electrodes, resembling a grid. Within the display area, a vertical electric field is formed at the overlap of row and column electrodes to drive the liquid crystals. However, in areas where row and column electrodes do not overlap, or in blank areas without electrodes, an effective vertical electric field cannot be formed, preventing the liquid crystals in these areas from being accurately driven to the desired state. When the display is subjected to external force, the liquid crystals in the pressure area transform into a planar state due to stress. When a black screen needs to be displayed, only the liquid crystals in the overlapping areas can be driven to a focal conic state through the electric field between the electrodes. The liquid crystals in the remaining areas cannot be driven to a focal conic state, resulting in a non-black screen and a decrease in the contrast of the display. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a cholesteric liquid crystal display device that can ensure that all cholesteric liquid crystals in the display area can be effectively driven, thereby improving the image quality of the product.

[0005] To solve the above-mentioned technical problems, this utility model provides a cholesteric phase liquid crystal display device, comprising: A first substrate and a second substrate arranged opposite to each other; A third electrode, a first insulating layer, and a first electrode composed of multiple first strip electrodes are sequentially stacked on the side of the first substrate facing the second substrate. A fourth electrode, a second insulating layer, and a second electrode composed of multiple second strip-shaped electrodes are sequentially stacked on the side of the second substrate facing the first substrate. A cholesteric liquid crystal layer is sandwiched between the first substrate and the second substrate; Wherein, the extension direction of the first strip electrode is perpendicular to the extension direction of the second strip electrode; in a direction perpendicular to the first substrate, the third electrode covers the gap region between two adjacent first strip electrodes, and the fourth electrode covers the gap region between two adjacent second strip electrodes.

[0006] The beneficial effect of this utility model is that the cholesteric liquid crystal display device provided by this utility model has a third electrode, a first insulating layer, and a first electrode composed of multiple first strip-shaped electrodes stacked sequentially on the side of the first substrate facing the second substrate. A fourth electrode, a second insulating layer, and a second electrode composed of multiple second strip-shaped electrodes are stacked sequentially on the side of the second substrate facing the first substrate. The third electrode covers the gap region between two adjacent first strip-shaped electrodes of the first electrode in a direction perpendicular to the first substrate, and the fourth electrode covers the gap region between two adjacent second strip-shaped electrodes of the second electrode in a direction perpendicular to the first substrate. Through this structural arrangement, a vertical electric field covering the entire display area can be formed between the third and fourth electrodes. Not only can the liquid crystal in the overlapping area of ​​the first and second electrodes be effectively driven, but the liquid crystal in the gap regions of the first and second electrodes, as well as the electrode-free blank areas, can also be effectively driven, achieving accurate control of the liquid crystal in all positions within the display area. When pressed by an external force, even if the liquid crystal in all areas becomes planar due to stress effect, by applying voltage through the third and fourth electrodes, the liquid crystal in all areas, including the gap area, can be driven to the focal conic state, thereby ensuring that the black screen can be presented as pure black, significantly improving the contrast and image quality of the display device. Attached Figure Description

[0007] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram illustrating the transformation of existing cholesteric liquid crystals between planar, focal conic, and vertical states. Figure 2 A cross-sectional view of the electrode structure of a cholesteric liquid crystal display device provided in an embodiment of this utility model; Figure 3 A top view of the electrode structure of a cholesteric liquid crystal display device provided in another embodiment of the present invention; Figure 4 for Figure 3 Cross-sectional view of the electrode structure of a cholesteric phase liquid crystal display device; Figure 5A cross-sectional view of the electrode structure of a cholesteric liquid crystal display device provided in another embodiment of this utility model; Figure 6 A flowchart illustrating the driving method of the cholesteric liquid crystal display device provided in this embodiment of the present invention.

[0009] Wherein, 1 is the first substrate, 2 is the second substrate, 3 is the third electrode, 4 is the fourth electrode, 5 is the first insulating layer, 6 is the second insulating layer, 7 is the first strip electrode, and 8 is the second strip electrode. Detailed Implementation

[0010] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0011] It should be noted that in the description of this utility model, 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. The terms "first," "second," etc., in this utility model are used to distinguish similar objects and are not used to describe a set order or sequence.

[0012] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] An embodiment of this utility model provides a cholesteric liquid crystal display device. The cholesteric liquid crystal display device includes: A first substrate and a second substrate arranged opposite to each other; A third electrode, a first insulating layer, and a first electrode composed of multiple first strip electrodes are sequentially stacked on the side of the first substrate facing the second substrate. A fourth electrode, a second insulating layer, and a second electrode composed of multiple second strip electrodes are sequentially stacked on the side of the second substrate facing the first substrate. A cholesteric liquid crystal layer is sandwiched between the first substrate and the second substrate; The extension direction of the first strip electrode is perpendicular to the extension direction of the second strip electrode; in a direction perpendicular to the first substrate, the third electrode covers the gap region between two adjacent first strip electrodes of the first electrode, and the fourth electrode covers the gap region between two adjacent second strip electrodes of the second electrode.

[0014] In the cholesteric liquid crystal display device provided in this embodiment of the invention, since a third electrode and a fourth electrode are respectively added to the first substrate and the second substrate, and the third electrode and the fourth electrode respectively cover the gap area of ​​the strip electrodes on the same side, the vertical electric field formed between the third electrode and the fourth electrode can cover all positions within the display area, including the overlapping area of ​​the first strip electrode and the second strip electrode, the area with only the first strip electrode or the second strip electrode, and the blank area without any strip electrodes. This ensures that not only the liquid crystal in the overlapping area of ​​the first electrode and the second electrode can be effectively driven, but also the liquid crystal in the gap area of ​​the first electrode, the gap area of ​​the second electrode, and the blank area without electrodes can be effectively driven, achieving accurate control of the liquid crystal in all positions within the display area. Even if the liquid crystal in all areas becomes planar due to stress effect after being pressed by an external force, applying voltage through the third electrode and the fourth electrode can drive all the liquid crystal in the display area to a focal conic state, thereby ensuring that the black screen can be pure black. This solves the problem that the liquid crystal in the gap area and the blank area cannot be driven in the prior art, effectively avoiding light leakage in the black screen and significantly improving the contrast and image quality of the display device. This cholesteric liquid crystal display device can be widely used in electronic paper, e-books, electronic whiteboards, temperature sensor displays, and various low-power static display products.

[0015] It should be noted that, in this embodiment of the invention, within the display area, the widths of the first strip electrodes can be the same or different; the widths of the second strip electrodes can also be the same or different. In practical applications, the widths of each strip electrode can be differentiated according to the design requirements of the display device, such as the aperture ratio and driving voltage. Similarly, the gap width between two adjacent first strip electrodes can be the same or different, and can be specifically set according to the design requirements of the display device, such as the aperture ratio and driving voltage. Likewise, the gap width between two adjacent second strip electrodes can be the same or different.

[0016] The cholesteric liquid crystal display device provided in the embodiments of this utility model will be described in detail below through several implementation methods.

[0017] In the first implementation, such as Figure 2As shown, the first substrate 1 and the second substrate 2 are arranged opposite each other, that is, the inner side surface of the first substrate 1 (the side facing the second substrate 2) and the inner side surface of the second substrate 2 (the side facing the first substrate 1) are opposite each other, and the cholesteric liquid crystal layer is sandwiched between them. The first electrode consists of multiple parallel first strip electrodes 7, and the second electrode consists of multiple parallel second strip electrodes 8. The extension direction of the first strip electrode 7 is defined as the first direction, and the extension direction of the second strip electrode 8 is defined as the second direction. The first direction and the second direction are perpendicular to each other. Within the display area, the position where the projections of the first strip electrode 7 and the second strip electrode 8 intersect in the direction perpendicular to the first substrate is the first region A; the position where only the projection of the first strip electrode 7 is shown and no projection of the second strip electrode 8 is shown is the second region B; the blank position where neither the first strip electrode 7 nor the second strip electrode 8 is shown is the third region C; and the position where only the projection of the second strip electrode 8 is shown and no projection of the first strip electrode 7 is shown is the fourth region D. Specifically, the second region B is the orthogonal projection area of ​​the gap between two adjacent first strip electrodes 7 in the direction perpendicular to the first substrate 1. The third region C is specifically a blank area within the display area where neither the first strip electrode 7 nor the second strip electrode 8 exists. The fourth region D is specifically the orthogonal projection area of ​​the gap between two adjacent second strip electrodes 8 in the direction perpendicular to the first substrate 1.

[0018] like Figure 2 As shown, the third electrode 3 and the fourth electrode 4 are respectively disposed on the lowest layer (i.e., the side closest to the substrate) of the first substrate 1 and the second substrate 2, and the first insulating layer 5 and the second insulating layer 6 respectively cover the third electrode 3 and the fourth electrode 4. The first electrode and the second electrode are respectively disposed on the first insulating layer 5 and the second insulating layer 6. The first insulating layer 5 and the second insulating layer 6 are used to electrically isolate the two layers of electrodes on the same side of the substrate, preventing short circuits between the third electrode 3 and the first electrode, and between the fourth electrode 4 and the second electrode. The third electrode 3 covers the gap area between two adjacent first strip electrodes 7 in a direction perpendicular to the first substrate 1, and the fourth electrode 4 covers the gap area between two adjacent second strip electrodes 8 in a direction perpendicular to the first substrate 1. That is to say, at any position in the display area, there is at least a relative arrangement between the third electrode 3 and the fourth electrode 4, which can form a vertical electric field through the cholesteric liquid crystal layer.

[0019] It is important to note that, such as Figure 2As shown, both the third electrode 3 and the fourth electrode 4 are continuous conductive layers covering the entire surface. Specifically, the third electrode 3 completely covers the display area of ​​the first substrate 1, and the fourth electrode 4 completely covers the display area of ​​the second substrate 2. In this embodiment, because the third electrode 3 and the fourth electrode 4 are continuous conductive layers covering the entire surface, a relative arrangement between the third electrode 3 and the fourth electrode 4 exists at any position in the display area, forming a vertical electric field that penetrates the cholesteric liquid crystal layer. The continuous conductive layer scheme has the simplest structure, requiring no patterning of the third electrode 3 and the fourth electrode 4, resulting in the simplest manufacturing process. Furthermore, it ensures that a vertical electric field can be formed between the third electrode 3 and the fourth electrode 4 at any position within the display area, providing the most reliable coverage. This embodiment is particularly suitable for display products with high process yield requirements or small electrode gap dimensions.

[0020] In the second implementation, such as Figure 3 and Figure 4 As shown, the difference between this embodiment and the first embodiment is that both the third electrode 3 and the fourth electrode 4 are strip electrodes.

[0021] like Figure 3 As shown, the third electrode 3 consists of multiple parallel strip-shaped electrodes, whose extending direction is parallel to the extending direction (i.e., the first direction) of the first strip-shaped electrode 7; the fourth electrode 4 consists of multiple parallel strip-shaped electrodes, whose extending direction is parallel to the extending direction (i.e., the second direction) of the second strip-shaped electrode 8. In a direction perpendicular to the first substrate 1, each third electrode 3 is positioned directly below the gap between two adjacent first strip-shaped electrodes 7, and each fourth electrode 4 is positioned directly below the gap between two adjacent second strip-shaped electrodes 8. That is, the third electrode 3 covers the entire gap area between two adjacent first strip-shaped electrodes 7 in a direction perpendicular to the first substrate 1, and the fourth electrode 4 covers the entire gap area between two adjacent second strip-shaped electrodes 8 in a direction perpendicular to the first substrate 1. At any position in the display area, there is at least a relative arrangement between the third electrode 3 and the fourth electrode 4, which can form a vertical electric field penetrating the cholesteric liquid crystal layer.

[0022] In this embodiment, such as Figure 3 As shown, the width of the third electrode 3 can be greater than or equal to the gap width between two adjacent first strip electrodes 7; the width of the fourth electrode 4 can be greater than or equal to the gap width between two adjacent second strip electrodes 8.

[0023] Specifically, such as Figure 3As shown, the width of the third electrode 3 is set to be greater than or equal to the gap width between the first strip electrodes 7, and the width of the fourth electrode 4 is set to be greater than or equal to the gap width between the second strip electrodes 8. This ensures that the third electrode 3 and the fourth electrode 4 completely cover their respective gap regions in the direction perpendicular to the substrate, avoiding the problem that the edge of the gap region cannot form an effective electric field due to insufficient electrode width, thereby ensuring that the liquid crystal in the gap region can be fully driven. Preferably, the width of the third electrode 3 can be slightly larger than the gap width, and the width of the fourth electrode 4 can be slightly larger than the gap width to overcome the coverage deviation caused by the alignment tolerance.

[0024] In this embodiment, such as Figure 4 As shown, both the first insulating layer 5 and the second insulating layer 6 are continuous insulating layers covering the entire surface. That is, the first insulating layer 5 covers the entire surface of the third electrode 3, and the second insulating layer 6 covers the entire surface of the fourth electrode 4. The continuous insulating layer design eliminates the need for patterning the insulating layer, simplifying the manufacturing process. It also ensures complete electrical isolation between the third electrode 3 and the first electrode, and between the fourth electrode 4 and the second electrode, thereby improving product yield.

[0025] By setting the third electrode 3 and the fourth electrode 4 as strip structures, compared with the continuous conductive layer scheme in the first embodiment above, the amount of conductive material used can be reduced, the manufacturing cost can be reduced, and the absorption and reflection loss of light by the film layer can be reduced, which is beneficial to improving the display brightness.

[0026] In the third implementation, such as Figure 5 As shown, the difference between this embodiment and the second embodiment is that the first insulating layer 5 and the second insulating layer 6 are both strip structures, rather than continuous insulating layers over the entire surface.

[0027] Specifically, such as Figure 5 As shown, the first insulating layer 5 consists of multiple parallel strip-shaped structures, with its extending direction parallel to the extending direction of the first strip-shaped electrode 7; the second insulating layer 6 consists of multiple parallel strip-shaped structures, with its extending direction parallel to the extending direction of the second strip-shaped electrode 8. The first insulating layer 5 is disposed between the third electrode 3 and the first strip-shaped electrode 7, and the second insulating layer 6 is disposed between the fourth electrode 4 and the second strip-shaped electrode 8. In the direction perpendicular to the first substrate 1, each first insulating layer 5 is disposed between the corresponding third electrode 3 and the first strip-shaped electrode 7, and each second insulating layer 6 is disposed between the corresponding fourth electrode 4 and the second strip-shaped electrode 8.

[0028] In this embodiment, the width of the first insulating layer 5 can be greater than or equal to the width of the third electrode 3; the width of the second insulating layer 6 can be greater than or equal to the width of the fourth electrode 4. Setting the width of the first insulating layer 5 to be greater than or equal to the width of the third electrode 3, and the width of the second insulating layer 6 to be greater than or equal to the width of the fourth electrode 4, can ensure that the third electrode 3 and the fourth electrode 4 are completely isolated from the first strip electrode 7 or the second strip electrode 8 on the same side by the insulating layer, thus avoiding short circuits between the third electrode 3 and the first electrode, and between the fourth electrode 4 and the second electrode.

[0029] Preferably, the width of the first insulating layer 5 can be greater than the width of the third electrode 3, and the width of the second insulating layer 6 can be greater than the width of the fourth electrode 4, in order to overcome the insulation layer coverage deviation caused by the alignment tolerance and ensure the reliability of electrical isolation.

[0030] In this embodiment, both the third electrode 3 and the fourth electrode 4 are strip electrodes, and their specific arrangement is the same as in the second embodiment, so it will not be described again here.

[0031] The first insulating layer 5 and the second insulating layer 6 are also designed as strip structures. Compared with the continuous insulating layer scheme of the second embodiment, the insulating layer is only retained in the electrode gap area, which can reduce unnecessary film layer stacking in the display area, reduce the influence of multilayer film structure on light reflection and absorption, and help improve the reflectivity and display brightness of the display device.

[0032] In the above-described embodiments, in specific implementations of the cholesteric liquid crystal display device provided in this utility model embodiment, the materials of the first insulating layer 5 and the second insulating layer 6 can both be insulating and transparent materials. The materials of the first electrode, the second electrode, the third electrode 3, and the fourth electrode 4 can all be transparent and conductive materials.

[0033] In practice, the insulating transparent material can be selected from inorganic insulating materials such as silicon oxide (SiO2), silicon nitride (SiNx), or silicon oxynitride (SiON). These materials possess excellent insulation properties and optical transparency, and their thickness can range from 500 Å to 5000 Å. The transparent conductive material can be selected from indium tin oxide, which has high conductivity and good optical transmittance, and its thickness can range from 500 Å to 1800 Å. Using transparent materials ensures that light can pass smoothly through the electrode layer and the insulating layer, guaranteeing that the reflectivity and transmittance of the display device are not affected. Of course, those skilled in the art will understand that the above material selection is only a preferred embodiment of this invention, and other insulating transparent materials and transparent conductive materials with the same or similar properties can also be used in this invention.

[0034] Furthermore, in a specific implementation, in the cholesteric liquid crystal display device provided in the above-mentioned embodiment of the present invention, a support column and a sealing adhesive may be provided between the first substrate 1 and the second substrate 2; the support column can be used to maintain the distance between the first substrate 1 and the second substrate 2; the sealing adhesive is provided around the display area of ​​the display device to seal the cholesteric liquid crystal layer.

[0035] In implementation, a support column is positioned between the first substrate 1 and the second substrate 2 to maintain the thickness of the liquid crystal cell between the two substrates, ensuring a uniform thickness of the cholesteric liquid crystal layer and thus guaranteeing display uniformity. A sealing adhesive is applied around the display area to bond the first substrate 1 and the second substrate 2 together, sealing the cholesteric liquid crystal within the enclosed space between the two substrates to prevent leakage of the liquid crystal material and the ingress of external water and oxygen. Both the support column and the sealing adhesive are conventional structures in the field of cholesteric liquid crystal display devices. Those skilled in the art can determine their specific dimensions, materials, and arrangement according to actual product design requirements; this invention does not impose specific limitations in these aspects.

[0036] Furthermore, in specific implementations, in the cholesteric liquid crystal display device provided in the embodiments of this utility model, alignment layers may also be provided between the first substrate 1 and the cholesteric liquid crystal layer, and between the second substrate 2 and the cholesteric liquid crystal layer. The alignment layers are used to align the cholesteric liquid crystal molecules along a predetermined direction in the initial state. The material of the alignment layer can be polyimide, and the alignment treatment method can be triboelectric alignment or photoalignment. The method of setting the alignment layer and the selection of its material are well-known technologies in the art, and this utility model does not specifically limit them.

[0037] In the above embodiments, the cholesteric liquid crystal display device has been described in detail. Based on the same inventive concept, the present invention also provides embodiments corresponding to the driving method of the cholesteric liquid crystal display device.

[0038] This utility model embodiment also provides a driving method for the above-mentioned cholesteric liquid crystal display device. Figure 6 A flowchart illustrating the driving method for the cholesteric liquid crystal display device provided in this embodiment of the utility model. Figure 6 As shown, the driving method for a cholesteric liquid crystal display device may specifically include the following steps: S601. A first voltage is applied to the first electrode and the third electrode simultaneously, and a second voltage is applied to the second electrode and the fourth electrode simultaneously; the voltage difference between the first voltage and the second voltage is a first voltage difference, which is used to drive the cholesteric liquid crystal in the display area to a vertical state.

[0039] In a possible implementation, in the first stage, a first voltage is applied simultaneously to the first and third electrodes, and a second voltage is applied simultaneously to the second and fourth electrodes. At this time, voltage differences are formed between the first and third electrodes and between the second and fourth electrodes. Since the third electrode covers the gap region between the first strip electrodes, and the fourth electrode covers the gap region between the second strip electrodes, all cholesteric liquid crystals within the display area (including overlapping regions, gap regions, and blank regions) are in a vertical electric field between the third and fourth electrodes. The magnitude of the first voltage difference is sufficient to cause all cholesteric liquid crystals to convert to a vertical state. The range of the first voltage difference can be set between 25V and 45V, and can be adjusted according to the characteristics of the cholesteric liquid crystal material and the thickness of the liquid crystal layer.

[0040] S602, Stop applying the first voltage and the second voltage to allow the cholesteric liquid crystal in the display area to relax from the vertical state to the planar state.

[0041] In a possible implementation, in the second stage, all voltages are stopped. The cholesteric liquid crystal in the vertical state rapidly relaxes to a planar state after the electric field is removed. Since this relaxation process is a natural physical process of liquid crystal molecules returning from a vertical alignment to a planar helical alignment, no additional voltage or control signal is required, and therefore this step does not consume electrical energy. After this step, all cholesteric liquid crystals in the display area are in a planar state, exhibiting a bright state.

[0042] S603. A third voltage is applied to the first electrode and the third electrode simultaneously, and a fourth voltage is applied to the second electrode and the fourth electrode simultaneously; the voltage difference between the third voltage and the fourth voltage is the second voltage difference, which is used to drive the cholesteric liquid crystal in the display area from the planar state to the focal cone state, wherein the second voltage difference is less than the first voltage difference.

[0043] In a possible implementation, in the third stage, a third voltage is applied simultaneously to the first and third electrodes, and a fourth voltage is applied simultaneously to the second and fourth electrodes. Similar to the first stage, since the third and fourth electrodes cover the entire display area, the second voltage difference acts on all cholesteric liquid crystals within the display area. The magnitude of the second voltage difference is sufficient to cause the cholesteric liquid crystals to transition from a planar state to a focal conical state, but because the second voltage difference is less than the first voltage difference, it will not cause the liquid crystals to enter a vertical state. The range of the second voltage difference can be set between 10V and 20V. After this step, all cholesteric liquid crystals within the display area are in a focal conical state, exhibiting a dark state.

[0044] S604. Maintain the third and fourth electrodes at the reference potential, and perform voltage scanning on the first and second electrodes to drive the cholesteric liquid crystal in the overlapping area of ​​the first and second electrodes to display the image.

[0045] In a possible implementation, in the fourth stage, the third and fourth electrodes are maintained at a reference potential, so that they no longer participate in driving. Addressing voltages are applied only to the first and second electrodes for row-by-row or column-by-column scanning. In the overlapping region of the first and second electrodes, the voltage difference between them forms a local vertical electric field, re-driving the cholesteric liquid crystal in these overlapping regions from a focal conic state to a planar state, forming bright pixels; while the liquid crystal in the unscanned overlapping regions, gap regions, and blank regions remains in the focal conic state, presenting a dark state. By controlling the driving state of each overlapping region, the desired display image can be formed on the display area. During this process, the gap regions and blank regions, because the third and fourth electrodes are maintained at the reference potential, are not affected by the scanning voltages of the first and second electrodes and remain in the focal conic state, thus preventing light leakage.

[0046] In the above-described driving method for a cholesteric liquid crystal display device, by executing steps S601 to S604, the liquid crystal in the entire display area is first globally reset and globally converted to a dark state using the third and fourth electrodes. Then, the overlapping area is locally addressed and refreshed using the first and second electrodes, achieving effective control of the entire liquid crystal area and high-quality display image presentation. This method is particularly suitable for screen refresh scenarios after being pressed by external force. After the display device is pressed, causing all liquid crystals to become planar, all liquid crystals can be driven to a focal conic state before normal screen refresh, ensuring that black screens are presented in a pure black state and effectively avoiding the problem of contrast degradation.

[0047] Since the embodiments of the driving method section correspond to the embodiments of the cholesteric liquid crystal display device section, please refer to the description of the embodiments of the cholesteric liquid crystal display device section for the embodiments of the driving method section, and will not be repeated here. Furthermore, it has the same beneficial effects as the cholesteric liquid crystal display device mentioned above.

[0048] Furthermore, in a specific implementation, in the driving method of the above-mentioned cholesteric liquid crystal display device, the first pressure difference can be used to make all cholesteric liquid crystals in the display area reach a vertical state, and the second pressure difference can be used to completely convert the cholesteric liquid crystals in the display area from a planar state to a focal conic state. The reference potential can be zero potential.

[0049] In implementation, the first voltage difference is sufficient to completely convert the cholesteric liquid crystal to a vertical state, ensuring that all liquid crystal molecules align along the electric field direction. This allows for complete relaxation to a planar state after the electric field is removed, preventing the formation of multi-domain or mixed states after relaxation due to insufficient driving, which would affect subsequent display effects. The second voltage difference is sufficient to completely convert the planar cholesteric liquid crystal to a focal conic state, ensuring the purity of the dark state in the black screen. The reference potential is set to zero, meaning that the third and fourth electrodes are grounded during the local addressing driving stage. This prevents residual voltage on the third and fourth electrodes from interfering with the addressing electric field between the first and second electrodes, ensuring the accuracy and stability of screen refresh.

[0050] For more detailed information on the working process of each of the above steps, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0051] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0052] The cholesteric liquid crystal display device provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the above embodiments are only intended to help understand the method and core idea of ​​this utility model. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A cholesteric liquid crystal display device, characterized by comprising: include: A first substrate and a second substrate arranged opposite to each other; A third electrode, a first insulating layer, and a first electrode composed of multiple first strip electrodes are sequentially stacked on the side of the first substrate facing the second substrate. A fourth electrode, a second insulating layer, and a second electrode composed of multiple second strip-shaped electrodes are sequentially stacked on the side of the second substrate facing the first substrate. A cholesteric liquid crystal layer is sandwiched between the first substrate and the second substrate; Wherein, the extension direction of the first strip electrode is perpendicular to the extension direction of the second strip electrode; in a direction perpendicular to the first substrate, the third electrode covers the gap region between two adjacent first strip electrodes, and the fourth electrode covers the gap region between two adjacent second strip electrodes.

2. A cholesteric liquid crystal display device according to claim 1, wherein Both the third electrode and the fourth electrode are continuous conductive layers covering the entire surface.

3. The cholesteric liquid crystal display device according to claim 1, wherein Both the third electrode and the fourth electrode are strip-shaped electrodes; The extension direction of the third electrode is parallel to the extension direction of the first strip electrode. The extension direction of the fourth electrode is parallel to the extension direction of the second strip electrode.

4. A cholesteric liquid crystal display device according to claim 3, wherein The width of the third electrode is greater than or equal to the gap width between two adjacent first strip electrodes; The width of the fourth electrode is greater than or equal to the gap width between two adjacent second strip electrodes.

5. The cholesteric liquid crystal display device according to claim 4, characterized in that, Both the first insulating layer and the second insulating layer are continuous insulating layers covering the entire surface.

6. A cholesteric liquid crystal display device according to claim 4, wherein Both the first insulating layer and the second insulating layer are strip-shaped structures; The extension direction of the first insulating layer is parallel to the extension direction of the first strip electrode; The extension direction of the second insulating layer is parallel to the extension direction of the second strip electrode.

7. A cholesteric liquid crystal display device according to claim 6, characterised in that The width of the first insulating layer is greater than or equal to the width of the third electrode; The width of the second insulating layer is greater than or equal to the width of the fourth electrode.

8. The cholesteric liquid crystal display device according to any one of claims 1 to 7, characterized in that, Both the first insulating layer and the second insulating layer are made of insulating transparent materials.

9. The cholesteric liquid crystal display device according to any one of claims 1 to 7, characterized in that, The first electrode, the second electrode, the third electrode, and the fourth electrode are all made of transparent conductive materials.

10. A cholesteric liquid crystal display device according to any one of claims 1 to 7, characterised in that A support pillar and a sealing adhesive are also provided between the first substrate and the second substrate; The support column is used to maintain the distance between the first substrate and the second substrate; The sealing adhesive is disposed around the display area of ​​the display device to seal the cholesteric liquid crystal layer.

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