Cholesteric liquid crystal display device and method of manufacturing the same
Patent Information
- Application Number
- JP2025093600
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-05-07
- Filing Date
- 2025-06-04
- Publication Date
- 2026-01-07
Smart Images
Figure 2026001705000001_ABST
Abstract
Description
[Technical Field]
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 661,704, filed June 19, 2024, the entire disclosure of which is incorporated herein by reference.
[0002] The present disclosure relates to cholesteric liquid crystal displays and methods of making the same, and more particularly to dual-layer cholesteric liquid crystal displays and methods of making the same. [Background technology]
[0003] The popularity of reflective display structures has been accompanied by higher standards for reflectivity and contrast ratio.
[0004] There are two types of cholesteric liquid crystals (CLCs) with different optical properties: left-handed and right-handed. However, due primarily to cost and complexity considerations, conventional architectures use only one type of liquid crystal, resulting in a light utilization rate of only 50% and a reflectance of only 30 to 40% for terminal three-color RGB modules. For large-area applications or long-distance viewing, a reflectance of over 60 to 80% is required to ensure easy identification from a long distance.
[0005] Therefore, there is a demand for a display device with a driver circuit that uses both left-handed and right-handed liquid crystals to increase reflectance and provide high-quality display colors. Summary of the Invention
[0006] Some embodiments of the present disclosure provide a double-layer cholesteric liquid crystal display device. The double-layer cholesteric liquid crystal display device includes a first liquid crystal layer, a second liquid crystal layer, a substrate, a first circuit pattern layer, a second circuit pattern layer, and a second circuit pattern layer. The second liquid crystal layer is formed above the first liquid crystal layer. One of the first liquid crystal layer and the second liquid crystal layer includes left-handed cholesteric liquid crystal, and the other of the first liquid crystal layer and the second liquid crystal layer includes right-handed cholesteric liquid crystal. A substrate is formed between the first liquid crystal layer and the second liquid crystal layer. The first circuit pattern layer is formed on the lower surface of the substrate to drive the first liquid crystal layer. The second circuit pattern layer is formed on the upper surface of the substrate to drive the second liquid crystal layer. A first driving circuit is electrically connected to the first circuit pattern layer or the second circuit pattern layer to control the double-layer cholesteric liquid crystal display device.
[0007] Some embodiments of the present disclosure provide a double-layer cholesteric liquid crystal display device. The double-layer cholesteric liquid crystal display device includes a first liquid crystal layer, a second liquid crystal layer, a first substrate, a first conductive electrode, a second conductive electrode, and a frame sealer. The first liquid crystal layer extends along a first direction. The second liquid crystal layer is formed above the first liquid crystal layer. One of the first liquid crystal layer and the second liquid crystal layer includes left-handed cholesteric liquid crystal, and the other of the first liquid crystal layer and the second liquid crystal layer includes right-handed cholesteric liquid crystal. The first substrate extends along the first direction and is formed between the first liquid crystal layer and the second liquid crystal layer. The first conductive electrode extends along the first direction and is formed on the lower surface of the first substrate for driving the first liquid crystal layer. The second conductive electrode is formed on the upper surface of the first substrate for driving the second liquid crystal layer. The frame sealer extends along a second direction (Y-axis) perpendicular to the first direction, and the first conductive electrode extends outside the frame sealer such that the frame sealer is surrounded by the first conductive electrode.
[0008] Some embodiments of the present disclosure provide a method for manufacturing a dual-layer cholesteric liquid crystal display device, the method including: forming a first circuit pattern layer on a lower surface of a substrate, forming a second circuit pattern layer on an upper surface of the substrate, forming a first liquid crystal layer below the first circuit pattern layer, the first circuit pattern layer configured to drive the first liquid crystal layer, forming a second liquid crystal layer above the second circuit pattern layer, the second circuit pattern layer configured to drive the second liquid crystal layer, one of the first liquid crystal layer and the second liquid crystal layer including a left-handed cholesteric liquid crystal and the other of the first liquid crystal layer and the second liquid crystal layer including a right-handed cholesteric liquid crystal, and forming a first drive circuit electrically connected to the first circuit pattern layer or the second circuit pattern layer for controlling the dual-layer cholesteric liquid crystal display device.
[0009] Aspects of the present disclosure will be readily understood from the following detailed description when read in conjunction with the accompanying drawings, in which: It should be noted that various features may not be drawn to scale, and in fact the dimensions of various features may be arbitrarily increased or decreased for clarity of illustration. [Brief explanation of the drawings]
[0010] [Figure 1A] 1 is a cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 1B] 1 is a three-dimensional schematic diagram of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 2A] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 2B] FIG. 2 is another three-dimensional schematic diagram of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 2C] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 3A] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 3B]FIG. 2 is another three-dimensional schematic diagram of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 3C] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 4A] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 4B] FIG. 2 is another three-dimensional schematic diagram of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 5A] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 5B] FIG. 2 is another three-dimensional schematic diagram of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 6A] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 6B] FIG. 2 is another three-dimensional schematic diagram of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 7A] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 7B] FIG. 2 is another three-dimensional schematic diagram of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 8A] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 8B] FIG. 2 is another three-dimensional schematic diagram of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 8C] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 9] FIG. 1 is a cross-sectional view of a cholesteric liquid crystal display device having two stacked display modules according to some embodiments of the present disclosure. [Figure 10] FIG. 1 is a cross-sectional view of a cholesteric liquid crystal display device having three stacked display modules according to some embodiments of the present disclosure. [Figure 11] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device with three stacked display modules according to some embodiments of the present disclosure. [Figure 12] 1 is a cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 13A] 1 is a cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 13B] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 14] FIG. 1 shows a flowchart including operations for fabricating a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 15A] 1A-1C illustrate several operations for fabricating a cholesteric liquid crystal display according to some embodiments of the present disclosure. [Figure 15B] 1A-1C illustrate several operations for fabricating a cholesteric liquid crystal display according to some embodiments of the present disclosure. [Figure 15C] 1A-1C illustrate several operations for fabricating a cholesteric liquid crystal display according to some embodiments of the present disclosure. [Figure 16] 1 is a cross-sectional view showing a cholesteric liquid crystal display device according to some embodiments of the present disclosure. [Figure 17] FIG. 1 is a cross-sectional view of a cholesteric liquid crystal display device having three stacked display modules according to some embodiments of the present disclosure. [Figure 18] FIG. 2 is another cross-sectional view of a cholesteric liquid crystal display device with three stacked display modules according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION
[0011] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to be limiting. In this disclosure, a reference in the following description to forming a first feature on or above a second feature can include embodiments in which the first and second features are formed in direct contact, as well as embodiments in which an additional feature may be formed between the first and second features such that the first and second features are not in direct contact. Furthermore, the present disclosure may repeat symbols and / or letters in various examples. This repetition is for simplicity and clarity and does not, in itself, dictate a relationship between the various embodiments and / or configurations described.
[0012]
[0023] The following detailed description of the present disclosure provides a number of applicable concepts that can be embodied in a wide variety of specific contexts. The specific embodiments described are merely illustrative and are not intended to limit the scope of the present disclosure.
[0013] Cholesteric liquid crystal displays (Ch-LCDs) are bistable and can maintain their display content without consuming power. They are commonly used in temperature sensor displays, e-books, e-paper, e-whiteboards, and other products.
[0014] FIG. 1A is a cross-sectional view of a cholesteric liquid crystal display device 10A according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 10A includes a display structure 10A1 and a drive circuit 10A2 for driving the display structure. The display structure 10A1 may include a cholesteric liquid crystal display (Ch-LCD). Ch-LCDs are bistable and can maintain display content without consuming power. They are commonly used in temperature sensor displays, e-books, electronic paper, electronic whiteboards, and other products.
[0015] The display structure 10A1 includes three substrates 110, 112, and 114, two liquid crystal layers 120 and 122, four circuit pattern layers 130, 132, 134, and 136, a plurality of sealing materials 160, 162, 164, and 166, and a plurality of conductive balls 170 and 174. The substrates 110, 112, and 114 may include glass. The substrates 110, 112, and 114 may also be stacked semiconductors such as silicon, silicon germanium, silicon-on-insulator, and silicon germanium-on-insulator.
[0016] Liquid crystal layers 120, 122 can comprise cholesteric liquid crystals. In some embodiments, liquid crystal layer 120 is a left-handed cholesteric liquid crystal and liquid crystal layer 122 is a right-handed cholesteric liquid crystal. In some embodiments, liquid crystal layer 120 is a right-handed cholesteric liquid crystal and liquid crystal layer 122 is a left-handed cholesteric liquid crystal. Liquid crystal layer 120 can be configured to reflect a first color of light. Liquid crystal layer 122 can be configured to reflect a second color of light having substantially the same wavelength as liquid crystal layer 120. Liquid crystal layer 122 can be configured to reflect a second color of light having a different wavelength than liquid crystal layer 120.
[0017] The substrate 112 may be disposed between the substrate 110 and the substrate 114. The substrate 112 may be disposed between the liquid crystal layer 120 and the liquid crystal layer 122. The substrate 112 may include an upper surface 112U and a lower surface 112L. A circuit pattern layer 130 may be formed below the substrate 110 to drive the liquid crystal layer 120. The circuit pattern layer 130 may be in direct contact with the substrate 110. The circuit pattern layer 132 may be formed on the upper surface 112U of the substrate 112 to drive the liquid crystal layer 120. The circuit pattern layer 132 may be in direct contact with the substrate 112. The circuit pattern layer 134 may be formed below the substrate 112 to drive the liquid crystal layer 122. The circuit pattern layer 134 may be formed on the lower surface 112L of the substrate 112. The circuit pattern layer 134 may be in direct contact with the substrate 112. A circuit pattern layer 136 may be formed above the substrate 114 to drive the liquid crystal layer 122. The circuit pattern layer 136 may be in direct contact with the substrate 114. The circuit pattern layers 130, 132, 134, 136 may include indium tin oxide (ITO) electrodes. The circuit pattern layers may be or include a conductive material, such as a conductive compound, or a metal or metal alloy.
[0018] Several sealing materials 160, 164 may be formed around the display structure 10A1. The sealing material 160 is disposed between the substrates 110, 112 and accommodates the liquid crystal layer 120. The sealing material 164 is disposed between the substrates 112, 114 and accommodates the liquid crystal layer 122. Furthermore, the sealing materials 160, 164 including conductive balls 170, 174 are formed in corresponding regions that electrically connect two adjacent circuit pattern layers. For example, the conductive ball 170 may be surrounded by the sealing material 160 that electrically connects the circuit pattern layers 130, 132. For example, the conductive ball 174 may be surrounded by the sealing material 164 that electrically connects the circuit pattern layers 134, 136.
[0019] The drive circuit 10A2 includes a flexible printed circuit (FPC) F1 and two chip-on-film (COF) boards C1A and C1B. The COF boards C1A and C1B may include integrated circuits for generating electrical signals to control the display structure 10A1. In some embodiments, the COF boards C1A and C1B and the FPC F1 are electrically connected to the left side of the display structure 10A1. The COF boards C1A and C1B are electrically connected between the FPC F1 and the display structure 10A1. The COF boards C1A and C1B are electrically connected to the circuit pattern layers 132 and 134 to provide drive signals to control the display structure 10A1. The FPC F1 may include a flexible printed circuit board, such as a paper-based copper foil laminate, a composite copper foil laminate, or a polymer-impregnated glass fiber-based copper foil laminate.
[0020] Figure 1B is a three-dimensional schematic diagram of a cholesteric liquid crystal display device 10B according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 10B of Figure 1B is similar to the cholesteric liquid crystal display device 10A of Figure 1A, except for the following differences.
[0021] The cholesteric liquid crystal display device 10B may include four ITO electrodes 130B, 132B, 134B, and 136B. The ITO electrodes 130B, 132B, 134B, and 136B in FIG. 1B may correspond to the circuit pattern layers 130, 132, 134, and 136 in FIG. 1A, respectively. The substrates 110, 112, and 114 and the ITO electrodes 130B, 132B, 134B, and 136B may extend along the X-axis. The conductive balls 170 and 174 may extend along the Z-axis, which is perpendicular to the X-axis.
[0022] In some embodiments, the cholesteric liquid crystal display device 10B further includes a timing controller (TCON) substrate T1 electrically connected to the FPC F1. The TCON substrate T1 may include a flexible printed circuit board, such as a paper-based copper foil laminate, a composite copper foil laminate, or a polymer-impregnated glass fiber-based copper foil laminate. The FPC F1 is electrically connected to two COFs C1A and C1B. The COFs C1A and C1B are bonded to two ITO electrodes 132B and 134B. The COF C1A may be bonded to the ITO electrode 132B. The COF C1B may be bonded to the ITO electrode 134B. The COF C1A is bonded to the upper surface of the substrate 112, and the COF C1B is bonded to the lower surface of the substrate 112. The COF C1A is electrically connected to the ITO electrode 132B on the upper surface of the substrate 112. The COF C1B is electrically connected to the ITO electrode 134B on the lower surface of the substrate 112. COFs C1A and C1B are shown as two rectangular regions along a Y axis perpendicular to the X and Z axes. COFs C1A and C1B may include, but are not limited to, rectangular shapes. COFs C1A and C1B are physically separated from each other. COFs C1A and C1B may be spaced apart from each other on the projection of the X and Y axes. COFs C1A and C1B may partially overlap each other on the projection of the X and Y axes.
[0023] The cholesteric liquid crystal display devices 10A and 10B of the present disclosure include a drive circuit 10A2 that utilizes left-handed cholesteric liquid crystals and right-handed cholesteric liquid crystals. The drive circuit 10A2 can include FPCs, COFs, vias, and / or other electronic elements, and can be provided on one or both sides of the display structure 10A1 as needed. Therefore, the cholesteric liquid crystal display devices 10A and 10B can enhance reflectivity and provide high-quality display colors over a wider viewing angle.
[0024] Figure 2A is a cross-sectional view of a cholesteric liquid crystal display device 20A according to some embodiments of the present disclosure. Figure 2B is another three-dimensional schematic view of a cholesteric liquid crystal display device 20B according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 20A of Figure 2A is similar to the cholesteric liquid crystal display device 10A of Figure 1A, and the cholesteric liquid crystal display device 20B of Figure 2B is similar to the cholesteric liquid crystal display device 10B of Figure 1B, except for the following differences.
[0025] The cholesteric liquid crystal display devices 20A and 20B each include only one COF C2. This reduces the number of COFs compared to the two COFs C1A and C1B of the cholesteric liquid crystal display devices 10A and 10B, thereby reducing the manufacturing cost of the cholesteric liquid crystal display devices 20A and 20B. As shown in FIG. 2A, the COF C2 is disposed above or on the FPC F2. Alternatively, the COF C2 may be disposed below or underneath the FPC F2. As shown in FIG. 2B, the cholesteric liquid crystal display device 20B further includes a TCON substrate T2 electrically connected to the FPC F2. The FPC F2 may be electrically connected to two circuit pattern layers 132 and 134, as shown in FIG. 2A. The FPC F2 may be electrically connected to two ITO electrodes 132B and 134B, as shown in FIG. 2B.
[0026] The FPC F2 may further include two FPC portions F2A and F2B, shown as two rectangular regions along the Y axis, which is perpendicular to the X and Z axes. The FPC F2 is bonded to the two ITO electrodes 132B and 134B via the FPC portions F2A and F2B. The substrate 112 is located between the two FPC portions F2A and F2B. The FPC portions F2A and F2B are physically separated from each other. The FPC portions F2A and F2B may be spaced apart from each other in the projections of the X and Y axes. The FPC portions F2A and F2B may partially overlap each other in the projections of the X and Y axes. The COF C2 and the FPC portions F2A and F2B may be spaced apart from each other in the projections of the X and Y axes. The COF C2 may be taller than the FPC portions F2A and F2B along the Z axis.
[0027] 2C is another cross-sectional view of a cholesteric liquid crystal display device 20C according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 20C of FIG. 2C is similar to the cholesteric liquid crystal display device 20A of FIG. 2A, except for the following differences.
[0028] Two COGs (chip-on-glass) G2A and G2B are disposed on the top and bottom of the substrate 112. The cholesteric liquid crystal display device 20C can include or be implemented by one or more COGs. The COGs G2A and G2B can include integrated circuits for generating electrical signals to control the cholesteric liquid crystal display device 20C. The COGs G2A and G2B are electrically connected to the circuit pattern layers 132 and 134 to provide drive signals and control the cholesteric liquid crystal display device 20C. The COG G2A is flush with the liquid crystal layer 120, and the COG G2B is flush with the liquid crystal layer 122. The COG G2A is electrically connected to the circuit pattern layer 132 or the ITO electrode 132B. The COG G2B is electrically connected to the circuit pattern layer 134 or the ITO electrode 134B. The COGs G2A and G2B are disposed on the substrate 112, rather than on the FPC F2, to improve the reliability of the cholesteric liquid crystal display device 20C.
[0029] FIG. 3A is a cross-sectional view of a cholesteric liquid crystal display device 30A according to some embodiments of the present disclosure. FIG. 3B is another three-dimensional schematic view of a cholesteric liquid crystal display device 30B according to some embodiments of the present disclosure. FIG. 3C is another three-dimensional schematic view of a cholesteric liquid crystal display device 30C according to some embodiments of the present disclosure. Except for the following differences, the cholesteric liquid crystal display device 30A of FIG. 3A is similar to the cholesteric liquid crystal display device 20A of FIG. 2A, the cholesteric liquid crystal display device 30B of FIG. 3B is similar to the cholesteric liquid crystal display device 20B of FIG. 2B, and the cholesteric liquid crystal display device 30C of FIG. 3C is similar to the cholesteric liquid crystal display device 20C of FIG. 2C. In some embodiments, conductive balls 176 and encapsulation material 166 are disposed near the FPC F3B and the COF C3B. The conductive balls 176 may be formed within the encapsulation material 166 to support the FPC F3B and the COF C3B.
[0030] COF C3A is disposed on FPC F3A, and COF C3B is disposed on FPC F3B. As shown in FIGS. 3A and 3B, FPCs F3A, F3B and COFs C3A, C3B are symmetrically disposed or bonded to both sides of display structure 10A1. FPCs F3A, F3B are disposed on both sides of substrate 112. COFs C3A, C3B and FPCs F3A, F3B are disposed on both sides of substrate 112. COF C3A is formed near the left side of substrate 112. COF C3A is electrically connected to circuit pattern layer 132 via FPC F3A. FPC F3A may extend above substrate 112. COF C3B is formed near the right side of substrate 112. COF C3B is electrically connected to circuit pattern layer 134 via FPC F3B. FPC F3B may extend below substrate 112. COF C3A may be on FPC F3A, and COF C3B may be on FPC F3B. COF C3A may be on FPC F3A, and COF C3B may be below FPC F3B. The area of FPC F3A bonded to ITO electrode 132B as shown in Figure 3B is larger than the area of FPC parts F2A and F2B bonded to ITO electrode 132B as shown in Figure 2B, making it easier and more efficient to route and wire the cholesteric liquid crystal display device 30B.
[0031] 3C, COG G3A is disposed between FPC F3A and liquid crystal layer 120. COG G3B is disposed between FPC F3B and liquid crystal layer 122. COGs G3A and G3B are disposed on substrate 112, rather than on FPCs F3A and F3B, to improve the reliability of cholesteric liquid crystal display device 30C.
[0032] Figure 4A is a cross-sectional view of a cholesteric liquid crystal display device 40A according to some embodiments of the present disclosure. Figure 4B is another three-dimensional schematic view of a cholesteric liquid crystal display device 40B according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 40A of Figure 4A is similar to the cholesteric liquid crystal display device 30A of Figure 3A, and the cholesteric liquid crystal display device 40B of Figure 4B is similar to the cholesteric liquid crystal display device 30B of Figure 3B, except for the following differences.
[0033] COF C4A is formed between FPC F4A and liquid crystal layer 120. C4A is electrically connected to circuit pattern layer 132. C4A may be at the same height level as conductive balls 170. COF C4B is formed between FPC F4B and liquid crystal layer 122. C4B is electrically connected to circuit pattern layer 134. C4B may be at the same height level as conductive balls 176.
[0034] Figure 5A is a cross-sectional view of a cholesteric liquid crystal display device 50A according to some embodiments of the present disclosure. Figure 5B is another three-dimensional schematic view of a cholesteric liquid crystal display device 50B according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 50A of Figure 5A is similar to the cholesteric liquid crystal display device 40A of Figure 4A, and the cholesteric liquid crystal display device 50B of Figure 5B is similar to the cholesteric liquid crystal display device 40B of Figure 4B, except for the following differences.
[0035] The cholesteric liquid crystal display device 50A includes a conductive structure 510 on the right side of the substrate 112. The conductive structure 510 may be in direct contact with the side surface 112L of the substrate 112. The conductive structure 510 and a portion of the circuit pattern layer 132 may be covered by a COF C5. The COF C5 is formed between the FPC F5 and the conductive balls 172. The COF C5 is electrically connected to the conductive structure 510 and the circuit pattern layer 132. The two circuit pattern layers 132, 134 may be electrically connected via the conductive structure 510. The conductive structure 510 may be or include a conductive material such as a metal or a metal alloy.
[0036] Figure 6A is a cross-sectional view of a cholesteric liquid crystal display device 60A according to some embodiments of the present disclosure. Figure 6B is another three-dimensional schematic view of a cholesteric liquid crystal display device 60B according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 60A of Figure 6A is similar to the cholesteric liquid crystal display device 50A of Figure 5A, and the cholesteric liquid crystal display device 60B of Figure 6B is similar to the cholesteric liquid crystal display device 50B of Figure 5B, except for the following differences.
[0037] The COF C6 is disposed above the FPC F6 on the right side of the substrate 112. The FPC F6 covers the conductive structure 510 and a portion of the circuit pattern layer 132. The COF C6 is electrically connected to the conductive structure 510 and the circuit pattern layer 132. The two circuit pattern layers 132, 134 may be electrically connected via the conductive structure 510. The conductive structure 510 may be or include a conductive material such as a metal or a metal alloy.
[0038] Figure 7A is a cross-sectional view of a cholesteric liquid crystal display device 70A according to some embodiments of the present disclosure. Figure 7B is another three-dimensional schematic view of a cholesteric liquid crystal display device 70B according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 70A of Figure 7A is similar to the cholesteric liquid crystal display device 50A of Figure 5A, and the cholesteric liquid crystal display device 70B of Figure 7B is similar to the cholesteric liquid crystal display device 50B of Figure 5B, except for the following differences.
[0039] The cholesteric liquid crystal display device 70A has a via structure 720 on the right side of the substrate 112. The via structure 720 can penetrate the substrate 112 and the circuit pattern layers 132 and 134. A portion of the circuit pattern layer 132 is covered by the COF C7. The via structure 720 is not covered by the COF C7. The COF C7 is formed between the FPC F7 and the conductive ball 172. The COF C7 is electrically connected to the via structure 720 and the circuit pattern layer 132. The two circuit pattern layers 132 and 134 can be electrically connected through the via structure 720. The via structure 720 can be or include a conductive material such as a metal or a metal alloy.
[0040] Figure 8A is a cross-sectional view of a cholesteric liquid crystal display device 80A according to some embodiments of the present disclosure. Figure 8B is another three-dimensional schematic view of a cholesteric liquid crystal display device 80B according to some embodiments of the present disclosure. Figure 8C is another three-dimensional schematic view of a cholesteric liquid crystal display device 80C according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 80A of Figure 8A is similar to the cholesteric liquid crystal display device 70A of Figure 7A, and the cholesteric liquid crystal display device 80B of Figure 8B is similar to the cholesteric liquid crystal display device 70B of Figure 7B, except for the following differences.
[0041] The COF C8 is disposed above the FPC F8 on the right side of the substrate 112. The FPC F8 covers a portion of the circuit pattern layer 132 but does not cover the via structure 720. The COF C8 is electrically connected to the via structure 720 and the circuit pattern layer 132. The two circuit pattern layers 132, 134 may be electrically connected through the via structure 720. The via structure 720 may be or include a conductive material such as a metal or a metal alloy.
[0042] 8C, the COG G8 is disposed between the FPC F8 and the liquid crystal layer 120. The COG G8 is disposed on the substrate 112 instead of the FPC F8 in order to improve the reliability of the cholesteric liquid crystal display device 80C.
[0043] 9 is a cross-sectional view of a cholesteric liquid crystal display device 90 including two stacked display modules 90A and 90B according to some embodiments of the present disclosure. The cholesteric liquid crystal display device of FIG. 9 includes two display modules 90A and 90B. Each display module 90A and 90B may correspond to or be included in a cholesteric liquid crystal display device of FIGS. 1A to 8C with corresponding drive circuitry.
[0044] In some embodiments, display module 90A can modulate or adjust green light, and display module 90B can modulate or adjust red light. Display module 90A can include, for example, a substrate 910, liquid crystal layers 920 and 922, and a circuit pattern layer 930. The liquid crystal layers 920 and 922 can include right-handed cholesteric liquid crystals and left-handed cholesteric liquid crystals to reflect green light. Display module 90B can include, for example, liquid crystal layers 924 and 926. The liquid crystal layers 924 and 926 can include right-handed cholesteric liquid crystals and left-handed cholesteric liquid crystals to reflect red light.
[0045] Additionally, an OCA (optically clear adhesive) layer 940 is formed between the display modules 90A and 90B. The OCA layer may include a green filtering OCA layer formed between the display modules 90A and 90B. A rear absorption layer 950 is formed below the display module 90B. Note that the colors shown for the display modules 90A and 90B are not limiting. The display modules 90A and 90B can be used to control or modulate any two of red, green, and blue. The type of OCA layer 940 can be selected or used depending on the display modules 90A and 90B.
[0046] 10 is a cross-sectional view of a cholesteric liquid crystal display device 1000 including three stacked display modules 1000A, 1000B, and 1000C according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 1000 of FIG. 10 includes three display modules 1000A, 1000B, and 1000C. Each of the display modules 1000A, 1000B, and 1000C may correspond to or be included in the cholesteric liquid crystal displays of FIGS. 1A-8C with corresponding drive circuits.
[0047] Display module 1000A can modulate or adjust blue light, display module 1000B can modulate or adjust green light, and display module 1000C can modulate or adjust red light. Display module 1000A can include, for example, a substrate 1010, liquid crystal layers 1020 and 1022, and a circuit pattern layer 1030. The liquid crystal layers 1020 and 1022 can include right-handed cholesteric liquid crystals and left-handed cholesteric liquid crystals to reflect blue light. Display module 1000B can include, for example, liquid crystal layers 1024 and 1026. The liquid crystal layers 1024 and 1026 can include right-handed cholesteric liquid crystals and left-handed cholesteric liquid crystals to reflect green light. Display module 1000C can include, for example, liquid crystal layers 1028 and 1029. The liquid crystal layers 1028, 1029 may include right-handed cholesteric liquid crystals and left-handed cholesteric liquid crystals to reflect red light.
[0048] In some embodiments, an OCA layer 1040 is formed between display modules 1000A and 1000B. The OCA layer 1040 may include a blue-filtering OCA layer formed between display modules 1000A and 1000B. An OCA layer 1050 is formed between display modules 1000B and 1000C. The OCA layer 1050 may include blue-filtering and green-filtering OCA layers formed between display modules 1000B and 1000C. A back absorption layer 1060 is formed below display module 1000C. Note that the colors shown for display modules 1000A, 1000B, and 1000C are not intended to be limiting. Display modules 1000A, 1000B, and 1000C can be used to control or modulate any two of red, green, and blue colors. The type of OCA layer 1040, 1050 can be selected or used depending on the display module 1000A, 1000B, 1000C.
[0049] 11 is another cross-sectional view of a cholesteric liquid crystal display device 1100 stacking three display modules 1100A, 1100B, and 1100C according to some embodiments of the present disclosure. Each of the display modules 1100A, 1100B, and 1100C can correspond to or be included in the cholesteric liquid crystal displays of FIGS. 1A-8C with corresponding driving circuitry.
[0050] The display module 1100A may include substrates 1110 and 1112, a liquid crystal layer 1120, polyimide layers 1180 and 1182, and ITO electrodes 1130 and 1132. The substrates 1110 and 1112 may be glass substrates. The liquid crystal layer 1120 may include a blue subpixel layer for modulating blue light. The liquid crystal layer 1120 is surrounded by polyimide layers 1180 and 1182 along the Y axis. The polyimide layers 1180 and 1182 are surrounded by ITO electrodes 1130 and 1132 along the Y axis.
[0051] Display module 1100B may be similar to display module 1100A. Liquid crystal layer 1122 of display module 1100B may include a green subpixel layer for modulating green light. Display module 1100C may be similar to display module 1100A. Liquid crystal layer 1124 of display module 1100C may include a red subpixel layer for modulating red light. Display modules 1100A and 1100B are separated by OCA layer 1150. Display modules 1100B and 1100C are separated by OCA layer 1160. OCA layer 1170 is provided below display module 1100C.
[0052] 12 is a cross-sectional view of a cholesteric liquid crystal display device 1200 according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 1200 includes at least substrates 1210, 1212, 1214, and 1216, liquid crystal layers 1220, 1222, and 1224, alignment layers 1260 and 1262, a transparent conductive electrode 1230, conductive electrodes 1240A, 1240B, 1242A, 1242B, and 1244, frame sealers 1270 and 1272, and support posts 1280, 1281, and 1282.
[0053] Metal 1232 is disposed on substrate 1212, metal 1232 is surrounded by insulating layer 1252, and insulating layer 1252 is covered by conductive electrode 1240A. FPC F12A is disposed above metal 1232, insulating layer 1252, and conductive electrode 1240A and drives cholesteric liquid crystal display device 1200. Metal 1234 is disposed below substrate 1212, metal 1234 is surrounded by insulating layer 1254, and insulating layer 1254 is covered by conductive electrode 1240B. FPC F12B is disposed below metal 1234, insulating layer 1254, and conductive electrode 1240B and drives cholesteric liquid crystal display device 1200. Metal 1236 is disposed on substrate 1216, metal 1236 is surrounded by insulating layer 1256, and insulating layer 1256 is covered by conductive electrode 1244. The FPC F12C is disposed above the metal 1236, the insulating layer 1256, and the conductive electrode 1244 to drive the cholesteric liquid crystal display device 1200. The transparent conductive electrode 1230 can include an ITO electrode. The alignment layers 1260, 1262 can include polyimide films.
[0054] In some embodiments, the substrates 1210, 1214 can be support layers and the substrates 1212, 1216 can be conductive layers electrically connected to the metals 1232, 1234, 1236, so that the cholesteric liquid crystal display device 1200 can include a double-sided conductive layer structure. To reduce the thickness of the cholesteric liquid crystal display device 1200, the use of glass substrates can be reduced.
[0055] In some embodiments, left-handed and right-handed liquid crystals can be filled into the upper and lower liquid crystal cells, respectively. For example, liquid crystal layer 1220 can be made of left-handed liquid crystals, and liquid crystal layer 1224 can be made of right-handed liquid crystals.
[0056] In some embodiments, the liquid crystal layers 1220, 1222, and 1224 can be used to modulate blue, green, and red light, respectively. Thus, the conductive electrodes 1240A and 1240B can comprise yellow conductive electrodes, the conductive electrodes 1242A and 1242B can comprise magenta conductive electrodes, and the conductive electrode 1244 can comprise a black conductive electrode. By utilizing the cholesteric liquid crystal display device 1200, the OCA layers 1150 and 1160 of the cholesteric liquid crystal display device 1100 of FIG. 11 can be replaced with colored films and colored electrodes. Furthermore, the conductive electrode 1244 can comprise a black MoOx layer coated on the substrate 1216 instead of the OCA layer 1170 of FIG. 11. The OCA layer 1170 can be a black absorbing layer. This can improve the reflectivity and contrast of the cholesteric liquid crystal display device 1200 while reducing the number of lamination steps and lowering manufacturing costs.
[0057] 13A is a cross-sectional view of a cholesteric liquid crystal display device 1300A according to some embodiments of the present disclosure. The cholesteric liquid crystal display device 1300A includes at least substrates 1310, 1312, and 1314, liquid crystal layers 1320 and 1322, alignment layers 1360, 1362, 1364, and 1366, a transparent conductive electrode 1330, conductive electrodes 1340A, 1340B, and 1350, a frame sealer 1370, and support posts 1381, 1382, and 1383.
[0058] The liquid crystal layers 1320, 1322 may include left-handed and right-handed liquid crystals. The conductive electrode 1340A is formed on the upper surface 1312U of the substrate 1312 and extends along the X-axis. The conductive electrode 1340B is formed on the lower surface 1312L of the substrate 1312 and extends along the X-axis. The alignment layer 1360 is disposed on the conductive electrode 1340A and extends along the X-axis. The alignment layer 1360 may have a length L136 along the X-axis. The conductive electrode 1340A may have a length L134A along the X-axis. The conductive electrode 1340B may have a length L134B along the X-axis. In some embodiments, the length L134A of the conductive electrode 1340A is longer than the length L136 of the alignment layer 1360, forming a drive circuit including the FPC F13A. The length L134B of the conductive electrode 1340B is longer than the length L136 of the alignment layer 1360, forming another driving circuit including the FPC F13B. The length L134A of the conductive electrode 1340A is approximately the same as the length L134B of the conductive electrode 1340B.
[0059] In some embodiments, the pillars 1381-1383 extend along the Y-axis. The pillars 1381-1383 can protrude from the transparent conductive electrode 1330 below the substrate 1310 toward the substrate 1312. The pillars 1381-1383 can be distributed between two frame sealers at the same height level. The pillars 1381-1383 can have different sizes. Some of the pillars 1381-1383, such as the pillar 1383, can be in direct contact with the alignment layer 1360, which can improve the robustness and reliability of the cholesteric liquid crystal display device 1300A.
[0060] In some embodiments, FPCs F13A and F13B are formed on different sides of the cholesteric liquid crystal display device 1300A. Metal 1332 is disposed on a substrate 1312, surrounded by an insulating layer 1352, which is covered by a conductive electrode 1340A. FPC F13A is disposed above the metal 1332, insulating layer 1352, and conductive electrode 1340A and drives the cholesteric liquid crystal display device 1300A. Metal 1334 is disposed below the substrate 1312, surrounded by an insulating layer 1354, which is covered by a conductive electrode 1340B. FPC F13B is disposed below the metal 1334, insulating layer 1354, and conductive electrode 1340B and drives the cholesteric liquid crystal display device 1300A.
[0061] Figure 13B is another cross-sectional view of a cholesteric liquid crystal display 1300B according to some embodiments of the present disclosure. The cholesteric liquid crystal display 1300B of Figure 13B is similar to the cholesteric liquid crystal display 1300A of Figure 13A, except for the following differences.
[0062] In some embodiments, FPCs F13C and F13D are formed on the same side of cholesteric liquid crystal display device 1300B. Metal 1336 is disposed on substrate 1312, surrounded by insulating layer 1356, which is covered by conductive electrode 1340A. FPC F13C is disposed above metal 1336, insulating layer 1356, and conductive electrode 1340A and drives cholesteric liquid crystal display device 1300B. Metal 1338 is disposed below substrate 1312, surrounded by insulating layer 1358, which is covered by conductive electrode 1340B. FPC F13D is disposed below metal 1338, insulating layer 1358, and conductive electrode 1340B and drives cholesteric liquid crystal display device 1300B.
[0063] FIG. 14 shows a flowchart 1400 including operations for fabricating a cholesteric liquid crystal display, such as the cholesteric liquid crystal display 1300A of FIG. 13A , according to some embodiments of the present disclosure. In operation 1402, a color filter-side polyimide film, such as alignment layer 1364, is formed. In operation 1404, a thin film transistor (TFT)-side polyimide film, such as alignment layer 1360, is formed. In operation 1406, a first sealing step is performed. In operation 1408, a liquid crystal layer 1320, such as a right-handed liquid crystal, is injected. In operation 1410, an assembly step of the liquid crystal layer 1320 and its corresponding alignment layer is performed to form a first assembly structure. In operation 1412, both sides of the first assembly structure are slimmed. In operation 1414, the cholesteric liquid crystal display 1300A is flipped to perform subsequent operations.
[0064] In operation 1416, a polyimide film on the color filter side, such as alignment layer 1366, is formed. In operation 1418, a polyimide film on the TFT side, such as alignment layer 1362, is formed. In operation 1420, a second encapsulation process is performed. In operation 1422, a liquid crystal layer 1322, such as a left-handed liquid crystal, is injected. In operation 1424, an assembly process of the liquid crystal layer 1322 and the corresponding alignment layer is performed to form a second assembly structure. In operation 1426, one-side slimming is performed on the second assembly structure. In operation 1428, both sides of the first and second assembly structures are cut to provide a first display module of a first color. In operation 1430, a first FPC, such as FPC 13A, for the first assembly structure is bonded. In operation 1432, a second FPC, such as FPC 13B, for the second assembly structure is bonded. In operation 1434, a three-layer lamination process is performed such that a first display module of a first color is stacked with two other display modules of two different colors. In some embodiments, a first LCD process can be performed to complete a top R-OC (red open cell) right-handed liquid crystal layer 1320, which can then be aligned with another support layer piece of substrate 1210. A second LCD process can be performed together to complete a bottom R-OC left-handed liquid crystal layer 1322, which can then be aligned with another support layer piece of substrate 1214.
[0065] While the disclosed flowchart 1400 is illustrated and described below as a series of acts or events, it will be understood that the illustrated order of such acts or events is not to be construed in a limiting sense. For example, some acts may occur in a different order and / or concurrently with other acts or events other than those illustrated and / or described herein. Moreover, not all illustrated acts may be required to implement one or more aspects or embodiments of the description herein. Furthermore, one or more acts illustrated herein may be performed in one or more separate acts and / or phases.
[0066] 15A, 15B, and 15C illustrate several steps for fabricating cholesteric liquid crystal displays 1500A, 1500B, and 1500C according to some embodiments of the present disclosure. In some embodiments, the bottom surface of the cholesteric liquid crystal display 1500A can be covered with a protective layer 1570, and a peripheral conductive layer 1580 can be provided on the front surface of the cholesteric liquid crystal display 1500A.
[0067] 15A, metal 1530 is formed below substrate 1510, and metal 1530 is surrounded by insulating layer 1550. Conductive electrode 1560 is formed over insulating layer 1550 and substrate 1510. Protective layer 1570 is formed over conductive electrode 1560. Conductive layer 1580 is formed on substrate 1510. Photoresist 1590 is formed on conductive layer 1580. After stripping, protective layer 1570 and photoresist 1590 can be removed to expose top conductive layer 1580 and bottom conductive electrode 1560.
[0068] 15B, cholesteric liquid crystal display device 1500B can be similar to cholesteric liquid crystal display device 1500A, except that conductive layer 1580 is surrounded by insulating layer 1552, and photoresist 1590 is formed on insulating layer 1552. After stripping, protective layer 1570 and photoresist 1590 can be removed to expose insulating layer 1552 on the top side and conductive electrode 1560 on the bottom side.
[0069] As shown in Figure 15C, the cholesteric liquid crystal display device 1500C can be similar to the cholesteric liquid crystal display device 1500B, except that a conductive electrode 1562 is disposed over the substrate 1510 and the insulating layer 1552, and a photoresist 1592 covers the conductive electrode 1562. After stripping, the protective layer 1570 and the photoresist 1592 can be removed to expose the top-side conductive electrode 1562 and the bottom-side conductive electrode 1560. After a double-sided conductive electrode process as shown in Figure 15C, the double-sided conductive structural layer is completed and aligned with the support layer.
[0070] Figure 16 is a cross-sectional view of a cholesteric liquid crystal display device 1600 according to some embodiments of the present disclosure. Cutting the cholesteric liquid crystal display device 1600 may correspond to operation 1428 of Figure 14. The cholesteric liquid crystal display device 1600 includes three display modules 1600A, 1600B, and 1600C. The display modules 1600A, 1600B, and 1600C may share substrates 1610, 1612, and 1614. The substrates 1610 and 1614 may be support layers, and the substrate 1612 may be a conductive layer.
[0071] In some embodiments, a glass thinning process and a laser fusion glass cutting process are performed to cut a large panel into single panels, as shown in FIG. 16 . Laser beams LS1, LS2, and LS3 can be used to cut and separate display modules 1600A, 1600B, and 1600C. For example, laser beam LS1 separates display modules 1600A and 1600B, and laser beam LS2 separates display modules 1600B and 1600C. A double-sided FPC bonding process can be performed to obtain a semi-finished R-OC panel. Furthermore, a double-sided FPC bonding process can be performed using an LCM (LCD module) process to complete, for example, a semi-finished R-OC panel.
[0072] 17 is a cross-sectional view of a cholesteric liquid crystal display device 1700 including three stacked display modules 1700A, 1700B, and 1700C, according to some embodiments of the present disclosure. Each of the display modules 1700A, 1700B, and 1700C can be similar to the cholesteric liquid crystal display device 1300A of FIG. 13A. For example, the display modules 1700A, 1700B, and 1700C can correspond to B-OC (blue open cell), G-OC (green open cell), and R-OC. A three-layer lamination process can laminate or stack the semi-finished products R-OC, G-OC, and B-OC to provide a final product.
[0073] The display module 1700A may include a B-OC. The display module 1700A may include two FPCs F17A and F17B and three substrates 1710, 1711, and 1712. The FPCs F17A and F17B are provided on both sides of the display module 1700A. The circuit pattern layer 1740A on the substrate 1712 may include a yellow film. The upper structure of the substrate 1711, including but not limited to the corresponding electrodes and polyimide layer, may still be a conductive layer structure. The lower structure of the substrate 1711, including but not limited to the corresponding electrodes and polyimide layer, may be changed from a conductive layer structure to a support layer structure.
[0074] The display module 1700B may include a G-OC. The display module 1700B may include two FPCs F17C and F17D and three substrates 1713, 1714, and 1715. The FPCs F17C and F17D are provided on both sides of the display module 1700B. The circuit pattern layer 1740B below the substrate 1713 may include a yellow film. The circuit pattern layer 1742A on the substrate 1715 may include a magenta film. The upper structure of the substrate 1714, including but not limited to the corresponding electrodes and polyimide layer, may still be a conductive layer structure. The lower structure of the substrate 1714, including but not limited to the corresponding electrodes and polyimide layer, may be changed from a conductive layer structure to a support layer structure.
[0075] The display module 1700C may include an R-OC. The display module 1700C may include two FPCs F17E and F17F and three substrates 1716, 1717, and 1718. The FPCs F17E and F17F are provided on both sides of the display module 1700C. The circuit pattern layer 1742B under the substrate 1716 may include a magenta film. The circuit pattern layer 1744 on the substrate 1718 may include a black film. The upper structure of the substrate 1717, including but not limited to the corresponding electrodes and polyimide layer, may still be a conductive layer structure. The lower structure of the substrate 1717, including but not limited to the corresponding electrodes and polyimide layer, may be changed from a conductive layer structure to a support layer structure.
[0076] FIG. 18 is another cross-sectional view of a cholesteric liquid crystal display device 1800 stacked with three display modules 1800A, 1800B, and 1800C according to some embodiments of the present disclosure. The display module 1800A may include a B-OC. The display module 1800A may include two FPCs F18A and F18B and three substrates 1810, 1811, and 1812. The FPCs F18A and F18B are provided on the same side of the display module 1800A. The circuit pattern layer 1840A on the substrate 1812 may include a yellow film. The upper structure of the substrate 1811, including but not limited to the corresponding electrodes and polyimide layer, may still be a conductive layer structure. The lower structure of the substrate 1811, including but not limited to the corresponding electrodes and polyimide layer, may be changed from a conductive layer structure to a support layer structure.
[0077] The display module 1800B may include a G-OC. The display module 1800B may include two FPCs F18C and F18D and three substrates 1813, 1814, and 1815. The FPCs F18C and F18D are located on the same side of the display module 1800B. The circuit pattern layer 1840B below the substrate 1813 may include a yellow film. The circuit pattern layer 1842A on the substrate 1815 may include a magenta film. The upper structure of the substrate 1814, including but not limited to the corresponding electrodes and polyimide layer, may still be a conductive layer structure. The lower structure of the substrate 1814, including but not limited to the corresponding electrodes and polyimide layer, may be changed from a conductive layer structure to a support layer structure.
[0078] The display module 1800C may include an R-OC. The display module 1800C may include two FPCs F18E and F18F and three substrates 1816, 1817, and 1818. The FPCs F18E and F18F are located on the same side of the display module 1800C. The circuit pattern layer 1842B under the substrate 1816 may include a magenta film. The circuit pattern layer 1844 on the substrate 1818 may include a black film. The upper structure of the substrate 1818, including but not limited to the corresponding electrodes and polyimide layer, may still be a conductive layer structure. The lower structure of the substrate 1818, including but not limited to the corresponding electrodes and polyimide layer, may be changed from a conductive layer structure to a support layer structure.
[0079] The present disclosure provides a cholesteric liquid crystal display device that differs from conventional LCD displays because it belongs to the category of reflective displays, also known as electronic paper displays. By utilizing ambient light that strikes the electronic paper display screen and is then refracted into the viewer's eye, similar to the principle of viewing traditional paper or objects in everyday life, the need for a backlight source can be completely eliminated.
[0080] As described above, the present disclosure provides a cholesteric liquid crystal display device with a drive circuit utilizing left-handed cholesteric liquid crystals and right-handed cholesteric liquid crystals. The drive circuit can include FPCs, COFs, vias, and / or other electronic elements, and can be provided on one or both sides of the display structure as needed. Therefore, the cholesteric liquid crystal display device can enhance reflectivity and provide high-quality display colors over a wider viewing angle.
[0081] As used herein, spatially relative terms such as "beneath," "below," "lower," "above," "upper," "higher," "left," "right," and the like may be used herein for ease of description to describe the relationship of one element or feature to another, as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may be oriented in other directions (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be similarly interpreted accordingly. When an element is referred to as being "coupled" or "connected" to another element, it should be understood that it may be directly connected or coupled to the other element, or that intervening elements may be present.
[0082] As used herein, the terms "nearly," "substantially," "substantial," and "about" are used to describe and account for small variations. When used in connection with an event or situation, these terms can refer to the exact occurrence of the event in the situation, as well as to the approximate occurrence of the event or situation. When used herein with respect to a given value or range, the term "about" generally means within ±10%, ±5%, ±1%, or ±0.5% of the given value or range. Ranges can be expressed herein as from one endpoint to another endpoint or between two endpoints. All ranges disclosed herein include endpoints unless otherwise specified. The term "substantially coplanar" can refer to two surfaces that are within micrometers (μm) of each other along the same plane, for example, within 10 μm, 5 μm, 1 μm, or 0.5 μm of each other along the same plane. When referring to numerical values or characteristics that are "substantially" the same, the term can refer to values that are within ±10%, ±5%, ±1%, or ±0.5% of the mean of the value.
[0083] The foregoing is a brief description of some embodiments and detailed features of the present disclosure. The embodiments described in this disclosure may readily be used as a basis for designing or modifying other processes and structures to carry out the same or similar purposes and / or obtain the same or similar advantages as those introduced in the embodiments of the present disclosure. Such equivalent constructions do not depart from the spirit and scope of the present disclosure, and various changes, substitutions, and alterations may be made thereto without departing from the spirit and scope of the present disclosure.
Claims
1. 1. A double layer cholesteric liquid crystal display device comprising: a first liquid crystal layer; a second liquid crystal layer formed above the first liquid crystal layer, wherein one of the first liquid crystal layer and the second liquid crystal layer contains left-handed cholesteric liquid crystal, and the other of the first liquid crystal layer and the second liquid crystal layer contains right-handed cholesteric liquid crystal; a substrate formed between the first liquid crystal layer and the second liquid crystal layer; a first circuit pattern layer formed on the lower surface of the substrate for driving the first liquid crystal layer; a second circuit pattern layer formed on the upper surface of the substrate for driving the second liquid crystal layer; a first driving circuit electrically connected to the first circuit pattern layer or the second circuit pattern layer for controlling the dual-layer cholesteric liquid crystal display device; 1. A double layer cholesteric liquid crystal display device comprising:
2. 2. The dual-layer cholesteric liquid crystal display device of claim 1, wherein the first driving circuit is electrically connected to both the first circuit pattern layer and the second circuit pattern layer.
3. a second driving circuit electrically connected to the first circuit pattern layer or the second circuit pattern layer for controlling the dual-layer cholesteric liquid crystal display device; 10. The dual-layer cholesteric liquid crystal display of claim 1, further comprising:
4. 4. The dual-layer cholesteric liquid crystal display device according to claim 3, wherein the first driving circuit and the second driving circuit are formed on both sides of the substrate, the first driving circuit is electrically connected to the second circuit pattern layer, and the second driving circuit is electrically connected to the first circuit pattern layer.
5. 10. The dual-layer cholesteric liquid crystal display of claim 1, wherein the first driving circuit comprises a flexible printed circuit (FPC) and a first chip.
6. 6. The dual-layer cholesteric liquid crystal display device according to claim 5, wherein the first chip is provided between the FPC and the second circuit pattern layer.
7. 6. The dual-layer cholesteric liquid crystal display device of claim 5, wherein the first chip is formed above the FPC.
8. a second chip disposed on the second circuit pattern layer and formed between the FPC and the second liquid crystal layer; 8. The dual-layer cholesteric liquid crystal display of claim 7, further comprising:
9. 1. A double layer cholesteric liquid crystal display device comprising: a first liquid crystal layer extending along a first direction; a second liquid crystal layer formed above the first liquid crystal layer, wherein one of the first liquid crystal layer and the second liquid crystal layer contains left-handed cholesteric liquid crystal, and the other of the first liquid crystal layer and the second liquid crystal layer contains right-handed cholesteric liquid crystal; a first substrate formed between the first liquid crystal layer and the second liquid crystal layer and extending along the first direction; a first conductive electrode formed on a lower surface of the first substrate and extending along the first direction for driving the first liquid crystal layer; a second conductive electrode formed on the upper surface of the first substrate for driving the second liquid crystal layer; a frame sealer extending along a second direction perpendicular to the first direction, the first conductive electrode extending outside the frame sealer such that the frame sealer is surrounded by the first conductive electrode; 1. A double layer cholesteric liquid crystal display device comprising:
10. a first alignment layer extending along the first direction and formed below the first conductive electrode; a second alignment layer formed above the second conductive electrode; 10. The dual-layer cholesteric liquid crystal display of claim 9, further comprising:
11. 11. The dual-layer cholesteric liquid crystal display of claim 10, wherein the length of the first conductive electrode is greater than the length of the first alignment layer and the length of the second conductive electrode is greater than the length of the second alignment layer.
12. a second substrate extending along the first direction, the second liquid crystal layer being provided between the first substrate and the second substrate; a plurality of support pillars extending along the second direction and protruding from the second substrate toward the first substrate; 11. The dual-layer cholesteric liquid crystal display of claim 10, further comprising:
13. 13. The dual-layer cholesteric liquid crystal display of claim 12, wherein a portion of the pillars is in contact with the second alignment layer.
14. a metal layer formed on the first substrate; a flexible printed circuit (FPC) formed above the metal layer, the second conductive electrode extending between the metal layer and the FPC; 10. The dual-layer cholesteric liquid crystal display of claim 9, further comprising:
15. further comprising an insulating layer surrounding the metal layer and covered by the second conductive electrode; 10. The dual layer cholesteric liquid crystal display of claim 9.