Display device and method of manufacturing the same

Abstract

This disclosure provides a display device comprising a plurality of selective light reflection modules stacked together and a light absorption layer disposed at the bottom. Each of the plurality of selective light reflection modules includes a display layer and at least one photoalignment layer. The display layer includes a plurality of pixels, and the photoalignment layer is disposed on the display layer. The photoalignment layer of one of the plurality of selective light reflection modules provides an alignment direction for the pixels of that module, and the photoalignment layer of another of the plurality of selective light reflection modules provides a different alignment direction for the pixels of that module. The alignment directions are different from the other alignment direction. This effectively improves the uniformity of reflectivity at different viewing angles.

Description

Technical Field

[0001] This disclosure relates to a display device and a method for manufacturing the same, and more particularly to a display device and a method for manufacturing the same using a photoalignment process. Background Technology

[0002] The photoelectric properties of Cholesteric Liquid Crystal Displays (ChLCDs) are closely related to the alignment technology of the liquid crystals. Contact alignment technologies, such as rubbing alignment, utilize lint to rub the alignment film. After being rubbed, the long chains on the alignment film surface provide regular and directional surface energy, driving the liquid crystal molecules to align regularly along the direction of friction. However, rubbing alignment is a destructive process; the friction between the lint and the alignment film surface easily causes bright and dark spots, scratches, and electrostatic discharge, resulting in poor product quality. Furthermore, another problem with rubbing alignment is that the reflected light from cholesteric liquid crystals has a focusing effect, causing ambient light to be concentrated at the positive viewing angle. Therefore, this can easily lead to uneven reflectivity of cholesteric liquid crystals at different viewing angles in image display.

[0003] Non-contact alignment technologies, such as photo-alignment, involve coating a photosensitive material onto the substrate of a liquid crystal display (LCD) and then irradiating it with ultraviolet light. Upon illumination, the photosensitive material undergoes a change in its molecular structure, forming a specific microstructure or molecular orientation that guides the liquid crystal molecules to align in a particular direction. While photo-alignment reduces the defects of brush alignment, it still suffers from uneven reflectivity at different viewing angles, leading to visual defects in the display image, such as uneven brightness and color distortion. Summary of the Invention

[0004] Therefore, the purpose of this disclosure is to provide a display device and a method for manufacturing the same, which uses a photo-alignment process to precisely control the alignment direction of the photo-alignment layer on the display layer, and the display layers in different selective light reflection modules are respectively assigned different alignment directions, thereby effectively improving the uniformity of reflectivity at different viewing angles, and also expanding the potential of the display device in high-resolution and wide-viewing-angle display applications.

[0005] According to one embodiment of the present disclosure, a display device is provided, comprising a plurality of selective light reflection modules. The plurality of selective light reflection modules are stacked on top of each other, each of the plurality of selective light reflection modules comprising a display layer and at least one photoalignment layer. The display layer comprises a plurality of pixels. The at least one photoalignment layer is disposed on the display layer. The at least one photoalignment layer of one of the plurality of selective light reflection modules provides an alignment direction for at least one of the plurality of pixels of that module, and the at least one photoalignment layer of another of the plurality of selective light reflection modules provides another alignment direction for at least one of the plurality of pixels of that other module. The alignment directions are different from the other alignment direction.

[0006] Other embodiments of the aforementioned implementation are as follows: the number of the aforementioned at least one photoalignment layer is two, namely a first photoalignment layer and a second photoalignment layer. A display layer is disposed between the first photoalignment layer and the second photoalignment layer. Each of the plurality of selective light reflection modules further includes a first transparent substrate and a second transparent substrate. The first photoalignment layer is disposed on the first transparent substrate, and the second photoalignment layer is disposed on the second transparent substrate.

[0007] Other embodiments of the aforementioned implementation are as follows: the aforementioned first photoalignment layer provides a first alignment direction for at least one of the plurality of pixels, the second photoalignment layer provides a second alignment direction for at least one of the plurality of pixels, and the first alignment direction and the second alignment direction differ by 90 degrees.

[0008] Other embodiments of the aforementioned implementation are as follows: the aforementioned alignment direction differs from another alignment direction by 45 degrees.

[0009] Other embodiments of the aforementioned implementation are as follows: an adhesive layer is provided between adjacent stacked selective light reflection modules described above.

[0010] Other embodiments of the aforementioned implementation are as follows: the rotation pitch of the liquid crystal molecules in each of the aforementioned plurality of selective light reflection modules is different.

[0011] Other embodiments of the aforementioned implementation are as follows: the liquid crystal optical rotation properties of adjacent stacked selective light reflection modules are different.

[0012] Other embodiments of the aforementioned implementation are as follows: The at least one photoalignment layer of the aforementioned plurality of selective light reflection modules comprises a plurality of alignment units, each of which has a plurality of alignment directions. One of the plurality of alignment directions differs from another of the plurality of alignment directions by 45 degrees.

[0013] Other embodiments of the aforementioned implementation are as follows: the plurality of alignment units described above are arranged in an alternating and spaced manner.

[0014] Other embodiments of the aforementioned implementation are as follows: the aforementioned at least one optical alignment layer further includes an unaligned unit, which is used to separate the plurality of alignment units.

[0015] Other embodiments of the aforementioned implementation are as follows: The aforementioned display device further includes a light absorption layer. The light absorption layer is disposed at the bottommost part of the plurality of selective light reflection modules.

[0016] According to another embodiment of this disclosure, a method for manufacturing a display device is provided, comprising the following steps: forming at least one photoalignment layer on at least one of a first transparent substrate and a second transparent substrate; irradiating the at least one photoalignment layer with alignment light for exposure; assembling the first transparent substrate and the second transparent substrate, and injecting liquid crystal molecules between the first transparent substrate and the second transparent substrate to form a display layer in a selective light reflection module, wherein the display layer includes a plurality of pixels; and stacking a plurality of selective light reflection modules. The at least one photoalignment layer of one of the plurality of selective light reflection modules provides an alignment direction for at least one of the plurality of pixels of that plurality of selective light reflection modules, and the at least one photoalignment layer of the other of the plurality of selective light reflection modules provides another alignment direction for at least one of the plurality of pixels of the other of the plurality of selective light reflection modules. The alignment directions are different from the other alignment direction.

[0017] Other embodiments of the foregoing implementation are as follows: Before irradiating the foregoing at least one photoalignment layer with alignment light for exposure, a patterned photomask is covered on the foregoing at least one photoalignment layer to selectively block the alignment light, so that the foregoing at least one photoalignment layer is divided into a plurality of alignment units after exposure, wherein the plurality of alignment units have different alignment directions.

[0018] Other embodiments of the aforementioned implementation are as follows: the aforementioned alignment direction differs from another alignment direction by 45 degrees.

[0019] Other embodiments of the aforementioned implementation are as follows: The aforementioned step of stacking the plurality of selective light reflection modules includes setting a light absorption layer at the bottom of the plurality of selective light reflection modules. Attached Figure Description

[0020] Figure 1 This is a schematic diagram illustrating a display device in a first embodiment of a first embodiment according to the present disclosure;

[0021] Figure 2A It is a drawing Figure 1A schematic diagram of the alignment direction of the upper liquid crystal cell of the display device;

[0022] Figure 2B It is a drawing Figure 1 A schematic diagram of the alignment direction of the lower liquid crystal cell of the display device;

[0023] Figure 3 This is a schematic diagram illustrating the alignment direction of the first photoalignment layer of the upper liquid crystal cell of the display device in a second embodiment of the first embodiment according to the present disclosure;

[0024] Figure 4 This is a schematic diagram illustrating the alignment direction of the first photoalignment layer of the upper liquid crystal cell of the display device in the third embodiment of the first embodiment according to the present disclosure;

[0025] Figure 5 This is a schematic diagram illustrating the alignment direction of the first photoalignment layer of the upper liquid crystal cell of the display device in the fourth embodiment of the first embodiment according to the present disclosure;

[0026] Figure 6 This is a schematic diagram illustrating the alignment direction of the first photoalignment layer of the upper liquid crystal cell of the display device in the fifth embodiment of the first embodiment according to the present disclosure; and

[0027] Figure 7 This is a flowchart illustrating a method for manufacturing a display device according to a second embodiment of the present disclosure.

[0028] The reference numerals in the attached figures are explained as follows:

[0029] 10, 10a, 10b, 10c, 10d: Display devices

[0030] 100, 200: Selective light reflection module

[0031] 101: Adhesive layer

[0032] 110, 210: First transparent substrate

[0033] 111, 211: First transparent substrate

[0034] 112, 212: First transparent electrode layer

[0035] 120, 220: Second transparent substrate

[0036] 121, 221: Second transparent substrate

[0037] 122, 222: Second transparent electrode layer

[0038] 130, 230: Display layer

[0039] 141, 141a, 141b, 141c, 141d, 241: First photoalignment layer

[0040] 142, 242: Second photoalignment layer

[0041] 20: Manufacturing method of display device

[0042] 300: Light Absorption Layer

[0043] D1, D3: First alignment direction

[0044] D2, D4: Second alignment direction

[0045] S01, S02, S03, S04: Steps

[0046] U1: First Alignment Unit

[0047] U2: Second Alignment Unit

[0048] U3: Third Alignment Unit

[0049] U4: Fourth Alignment Unit

[0050] UN: Non-alignment unit Detailed Implementation

[0051] Several embodiments of this disclosure will be described below with reference to the accompanying drawings. For clarity, many practical details will be set forth in the following description. However, it should be understood that these practical details should not be used to limit the scope of this disclosure. That is, in some embodiments of this disclosure, these practical details are not essential. Furthermore, for the sake of simplicity in the drawings, some conventional structures and elements will be illustrated in a simple schematic manner; and repeated elements may be denoted by the same reference numerals.

[0052] Furthermore, in this document, when a component (or unit or module, etc.) is "connected / linked" to another component, it can mean that the component is directly connected / linked to the other component, or it can mean that the component is indirectly connected / linked to the other component, that is, there is another component between the component and the other component. Only when it is explicitly stated that a component is "directly connected / linked" to another component does it mean that there is no other component between the component and the other component. The terms "first," "second," and "third" are only used to describe different components and do not limit the components themselves; therefore, "first component" can also be referred to as "second component." Moreover, the combinations of components / units / circuits in this document are not combinations generally known, conventional, or customary in this field. Whether a component / unit / circuit itself is customary cannot be used to determine whether its combination is easily performed by someone of ordinary skill in the art.

[0053] Please see Figure 1, Figure 1 This is a schematic diagram illustrating a display device in a first embodiment according to the first embodiment of the present disclosure. For example... Figure 1 As shown, the display device 10 includes a plurality of selective light reflection modules 100 and 200 and a light absorption layer 300. The selective light reflection modules 100 and 200 are stacked on top of each other. Selective light reflection module 100 includes a display layer 130 and at least one photoalignment layer, with the photoalignment layer of the selective light reflection module 100 disposed on the display layer 130. Selective light reflection module 200 includes a display layer 230 and at least one photoalignment layer, with the photoalignment layer of the selective light reflection module 200 disposed on the display layer 230. Each of the display layers 130 and 230 includes a plurality of pixels. The light absorption layer 300 is disposed at the bottom of the selective light reflection modules 100 and 200.

[0054] The photoalignment layer of the selective light reflection module 100 is configured to provide an alignment direction for at least one of the plurality of pixels of the display layer 130. The photoalignment layer of the selective light reflection module 200 is configured to provide another alignment direction for at least one of the plurality of pixels of the display layer 230. The alignment direction provided by the photoalignment layer of the selective light reflection module 100 is different from the other alignment direction provided by the photoalignment layer of the selective light reflection module 200. Therefore, the display device 10 of this disclosure can precisely control the photoalignment layers of the selective light reflection modules 100 and 200 to impart different alignment directions to the display layers 130 and 230, respectively, through a photoalignment process, thereby effectively improving the uniformity of reflectivity at different viewing angles and expanding the potential of the display device 10 in high-resolution and wide-viewing-angle display applications.

[0055] In the first embodiment, the selective light reflection module 100 may have two photoalignment layers, and these two photoalignment layers are a first photoalignment layer 141 and a second photoalignment layer 142, respectively. The display layer 130 is disposed between the first photoalignment layer 141 and the second photoalignment layer 142. Specifically, the selective light reflection module 100 may further include a first transparent substrate 110 and a second transparent substrate 120. The first photoalignment layer 141 is disposed between the first transparent substrate 110 and the display layer 130, while the second photoalignment layer 142 is disposed between the second transparent substrate 120 and the display layer 130.

[0056] The first transparent substrate 110 includes a first transparent base material 111 and a first transparent electrode layer 112. The first transparent electrode layer 112 is disposed between the first transparent base material 111 and the first photoalignment layer 141. In some embodiments, the first transparent base material 111 may be, but is not limited to, a rigid substrate or a flexible substrate. The rigid substrate may be, for example, a glass plate or polymethyl methacrylate (PMMA), i.e., an acrylic sheet. The flexible substrate may be, for example, a substrate made of polyimide (PI) or polyethylene terephthalate (PET). The first transparent electrode layer 112 may be made of a transparent conductive material, such as a transparent conductive oxide (TCO), a conductive polymer, or a metal thin film, for example, indium tin oxide (ITO), indium zinc oxide (IZO), poly-3,4-ethylenedioxythiophene (PEDOT), copper metal mesh film, or silver nanowire.

[0057] The second transparent substrate 120 may include a second transparent substrate 121 and a second transparent electrode layer 122. The second transparent electrode layer 122 is disposed between the second transparent substrate 121 and the second photoalignment layer 142. The material of the second transparent substrate 121 is the same as the material of the first transparent substrate 111, and the material of the second transparent electrode layer 122 is the same as the material of the first transparent electrode layer 112.

[0058] Furthermore, the internal structure of the selective light reflection module 200 is the same as that of the selective light reflection module 100. The selective light reflection module 200 may have two photoalignment layers, which are a first photoalignment layer 241 and a second photoalignment layer 242, respectively. The display layer 230 is disposed between the first photoalignment layer 241 and the second photoalignment layer 242. The selective light reflection module 200 may further include a first transparent substrate 210 and a second transparent substrate 220. The first photoalignment layer 241 is disposed between the first transparent substrate 210 and the display layer 230, while the second photoalignment layer 242 is disposed between the second transparent substrate 220 and the display layer 230.

[0059] The first transparent substrate 210 includes a first transparent substrate 211 and a first transparent electrode layer 212. The first transparent electrode layer 212 is disposed between the first transparent substrate 211 and the first photoalignment layer 241. The second transparent substrate 220 may include a second transparent substrate 221 and a second transparent electrode layer 222. The second transparent electrode layer 222 is disposed between the second transparent substrate 221 and the second photoalignment layer 242. In the first embodiment, the materials of the first transparent substrate 211 and the second transparent substrate 221 are the same as the material of the first transparent substrate 111, and the materials of the first transparent electrode layer 212 and the second transparent electrode layer 222 are the same as the material of the first transparent electrode layer 112.

[0060] In some embodiments, an adhesive layer 101 may be provided between two adjacent selective light reflection modules 100 and 200. The adhesive layer 101 may be made of optical clear adhesive (OCA). Since the thickness of the adhesive layer 101 is only between tens and hundreds of micrometers, it is negligible, thus allowing the selective light reflection modules 100 and 200 to fit tightly together. Additionally, a light absorption layer 300 is configured to absorb light passing through the selective light reflection modules 100 and 200, thereby improving the contrast of the display screen on the display device 10. The light absorption layer 300 may be, but is not limited to, a black photoresist material, a black thin film, or other suitable light-absorbing film layer.

[0061] In some embodiments, selective light reflection modules 100 and 200 can both be cholesteric liquid crystal modules, and display layers 130 and 230 can both be cholesteric liquid crystal layers. The rotational pitch of the liquid crystal molecules within each of the selective light reflection modules 100 and 200 can be different. As mentioned earlier, the internal structures of the selective light reflection modules 100 and 200 are identical, but the difference lies in the different rotational pitches of the cholesteric liquid crystal molecules within the display layers 130 and 230 of the selective light reflection modules 100 and 200. The rotational pitch of the liquid crystal molecules is closely related to the wavelength of the reflected light. Essentially, if the rotational pitch of the liquid crystal molecules is the same as the wavelength of a certain color of light, then when the cholesteric liquid crystal is energized and rotates, it can reflect light of that color. In other words, selective light reflection modules 100 and 200 can reflect different colors of light. In other embodiments, the display device may include three stacked selective light reflection modules, each reflecting red, green, and blue light respectively. In this way, the display device can be used as a Cholesteric Liquid Crystal Display (ChLCD) that displays full color and has high contrast after light mixing control.

[0062] Please refer to the following: Figure 1 , Figure 2A and Figure 2B ,in Figure 2AIt is a drawing Figure 1 A schematic diagram of the alignment direction of the upper liquid crystal cell in the display device. Figure 2B It is a drawing Figure 1 This is a schematic diagram of the alignment direction of the lower liquid crystal cell in the display device. It should be noted that in the display device 10, the first photoalignment layer 141 and the second photoalignment layer 142 in the upper liquid crystal cell, and the first photoalignment layer 241 and the second photoalignment layer 242 in the lower liquid crystal cell, can have different alignment directions after photo-alignment processing; that is, each photoalignment layer corresponds to a different photoalignment angle. The photoalignment process involves irradiating the photoalignment layer with alignment light (e.g., linearly polarized light) to provide an alignment direction to the cholesteric liquid crystal in the display layer. The direction of the alignment light determines the corresponding alignment direction of the photoalignment layer.

[0063] like Figure 2A As shown, the first photoalignment layer 141 in the upper liquid crystal cell provides a first alignment direction D1 (e.g., 90°) for each pixel of the display layer 130 along the solid arrow, while the second photoalignment layer 142 provides a second alignment direction D2 (e.g., 0°) for each pixel of the display layer 130 along the dashed arrow. Figure 2A The angle between the solid and dashed arrows in the diagram is used as a reference, and the first alignment direction D1 and the second alignment direction D2 differ by 90 degrees. For example... Figure 2B As shown, the first photoalignment layer 241 in the lower liquid crystal cell provides a first alignment direction D3 (e.g., 45°) for each pixel of the display layer 230 along the solid arrow, while the second photoalignment layer 242 provides a second alignment direction D4 (e.g., 315° or -45°) for each pixel of the display layer 230 along the dashed arrow. Figure 2B Based on the angle between the solid and dashed arrows, the first alignment direction D3 and the second alignment direction D4 differ by 90 degrees. Furthermore, the first alignment direction D1 of the upper liquid crystal cell and the first alignment direction D3 of the lower liquid crystal cell differ by 45 degrees, and the second alignment direction D2 of the upper liquid crystal cell and the second alignment direction D4 of the lower liquid crystal cell also differ by 45 degrees.

[0064] In some embodiments, the liquid crystal molecules of adjacent stacked selective light reflection modules 100 and 200 may have the same rotation pitch, while the optical rotation of the liquid crystals in the selective light reflection modules 100 and 200 may be different. Specifically, one of the selective light reflection modules 100 and 200 may have a left-handed optical rotation, while the other may have a right-handed optical rotation. Left-handed cholesterol liquid crystal molecules can only reflect left-handed circularly polarized light, while right-handed circularly polarized light will pass through. Conversely, right-handed cholesterol liquid crystal molecules can only reflect right-handed circularly polarized light, while left-handed circularly polarized light will pass through. Thus, the display device 10 includes two selective light reflection modules 100 and 200 with the same liquid crystal molecule rotation pitch, and since the upper and lower left-handed and right-handed liquid crystal cells are given different alignment directions and their photoalignment angles are spaced apart at different angular periods, this not only improves reflectivity and contrast but also compensates for reflection intensity at different viewing angles, making the reflectivity nearly uniform.

[0065] Please refer to the following: Figure 1 , Figure 2A , Figure 2B and Figure 3 ,in Figure 3 This is a schematic diagram illustrating the alignment direction of the first photoalignment layer of the upper liquid crystal cell of the display device in a second embodiment according to the first embodiment of this disclosure. It should be noted that... Figure 3 The internal structure configuration of the display device 10a is the same as that of the display device 10a. Figure 1 The display device 10 differs from the display device 10a in that the first photoalignment layer 141a in the upper liquid crystal cell may include multiple alignment units, each of which has multiple alignment directions. One of the multiple alignment directions may differ from another of the multiple alignment directions by 45 degrees.

[0066] Specifically, the plurality of alignment units can be divided into a plurality of first alignment units U1 and a plurality of second alignment units U2. The plurality of first alignment units U1 and the plurality of second alignment units U2 are arranged alternately to form a grid pattern. Each of the first alignment units U1 may have a first alignment direction, which is equivalent to... Figure 2A The first alignment direction D1. Each of the second alignment elements U2 may have a second alignment direction, which is equivalent to the first alignment direction D1. Figure 2B The first alignment direction D3 in the first alignment unit U1 is 45 degrees different from the second alignment direction (e.g., 45°) of the second alignment unit U2.

[0067] In some embodiments, each of the second photoalignment layer in the upper liquid crystal cell of the display device 10a and the first and second photoalignment layers in the lower liquid crystal cell may also include a plurality of first alignment units (not shown) and a plurality of second alignment units (not shown). Please refer to Table 1, which provides examples of the alignment directions of the first and second photoalignment layers in the upper and lower liquid crystal cells of the display device 10a, but the content of this disclosure is not limited thereto.

[0068]

[0069] As shown in Table 1, the first alignment unit of the second photoalignment layer in the upper liquid crystal cell can have the same characteristics as... Figure 2A The second alignment direction D2 (e.g., 0°) in the upper liquid crystal cell. The second alignment unit of the second photoalignment layer in the upper liquid crystal cell may have an equivalent to Figure 2B The second alignment direction D4 (e.g., -45°) is used. Therefore, in the second photoalignment layer of the upper liquid crystal cell, the first alignment direction (e.g., 0°) of the first alignment unit differs from the second alignment direction (e.g., -45°) of the first alignment unit by 45 degrees. The other photoalignment layers follow the same principle and will not be described in detail.

[0070] In the second embodiment, the display device 10a employs photomask blocking and photoalignment technology to precisely control the first alignment unit U1 and the second alignment unit U2 of the first photoalignment layer 141a to impart the first alignment direction and the second alignment direction to the display layer, and so on for the remaining photoalignment layers. This allows the display device 10a to perform photoalignment on a single pixel or multiple pixel basis. For each alignment unit (i.e., the first alignment unit U1 or the second alignment unit U2), by changing the pattern design of the photomask, adjacent alignment units can have different alignment directions, thereby effectively reducing the variation of reflectivity at different viewing angles and improving the viewing angle uniformity of the display device 10a.

[0071] Furthermore, the first photoalignment layer 141a in the upper liquid crystal cell of the display device 10a may further include a non-alignment unit UN. The non-alignment unit UN is used to separate the first alignment unit U1 and the second alignment unit U2, and is arranged in a grid-like structure. Specifically, the position of the non-alignment unit UN can be located in the gap area between the electrodes in the first transparent electrode layer 112, and the non-alignment unit UN represents the area on the first photoalignment layer 141a that has not undergone photoalignment processing. In this way, the cholesterol liquid crystal molecules aligned with the non-alignment unit UN are not directly interfered with by the electric field in the switching state. The scattered arrangement of the cholesterol liquid crystal molecules makes them appear darker, so that the cholesterol liquid crystal molecules aligned with the non-alignment unit UN can maintain their original state during the display process and do not change their alignment direction with changes in the electric field, thereby providing more stable optical properties and significantly improving the contrast of the displayed image.

[0072] Please refer to the following: Figure 1 , Figure 4 and Figure 5 ,in Figure 4 This is a schematic diagram illustrating the alignment direction of the first photoalignment layer of the upper liquid crystal cell of the display device in the third embodiment of the first embodiment according to the present disclosure. Figure 5 This is a schematic diagram illustrating the alignment direction of the first photoalignment layer of the upper liquid crystal cell of the display device in the fourth embodiment of the first embodiment according to the present disclosure. It should be noted that... Figure 4 and Figure 5 The internal structure configurations of the display devices 10b and 10c are the same as those in the above-mentioned display devices. Figure 1 The display device 10 in the middle.

[0073] like Figure 4 and Figure 5 As shown, in the first photoalignment layers 141b and 141c of display devices 10b and 10c, a plurality of first alignment units U1 and a plurality of second alignment units U2 are arranged alternately to form a striped pattern. The difference between display device 10b and display device 10c is that the striped pattern of display device 10b is a stripe extending along the longitudinal direction, while the striped pattern of display device 10c is a stripe extending along the transverse direction. However, this disclosure is not limited to the number of first alignment units U1 and second alignment units U2.

[0074] Please refer to the following: Figure 1 , Figure 2A , Figure 2B and Figure 6 ,in Figure 6 This is a schematic diagram illustrating the alignment direction of the first photoalignment layer of the upper liquid crystal cell of the display device in the fifth embodiment of the first embodiment according to this disclosure. It should be noted that... Figure 6 The internal structure configuration of the display device 10d in the middle is the same as that of the display device 10d. Figure 1 The display device 10 differs from the display device 10d in that the first photoalignment layer 141d in the upper liquid crystal cell of the display device 10d may include a plurality of first alignment units U1, a plurality of second alignment units U2, a plurality of third alignment units U3, and a plurality of fourth alignment units U4. One of the plurality of first alignment units U1, one of the plurality of second alignment units U2, one of the plurality of third alignment units U3, and one of the plurality of fourth alignment units U4 are arranged sequentially at intervals to form a grid pattern.

[0075] In detail, each of the first alignment units U1 has a first alignment direction, and it is equivalent to... Figure 2A The first alignment direction D1. Each of the second alignment elements U2 may have a second alignment direction, which is equivalent to the first alignment direction D1. Figure 2BThe first alignment direction D3. Each of the third alignment elements U3 may have a third alignment direction, and it is equivalent to the first alignment direction D3. Figure 2A The second alignment direction D2 in the second alignment direction. Each of the fourth alignment elements U4 may have a fourth alignment direction, and it is equivalent to the fourth alignment direction. Figure 2B The second alignment direction is D4. Therefore, the first alignment direction of the first alignment unit U1 (e.g., 90°), the second alignment direction of the second alignment unit U2 (e.g., 45°), the third alignment direction of the third alignment unit U3 (e.g., 0°), and the fourth alignment direction of the fourth alignment unit U4 (e.g., -45°) are sequentially 45 degrees apart.

[0076] In some embodiments, each of the second photoalignment layer in the upper liquid crystal cell of the display device 10d and the first and second photoalignment layers in the lower liquid crystal cell may also include a plurality of first alignment units (not shown), a plurality of second alignment units (not shown), a plurality of third alignment units (not shown), and a plurality of fourth alignment units (not shown). Please refer to Table 2, which provides examples of the alignment directions of the first and second photoalignment layers in the upper and lower liquid crystal cells of the display device 10d, but the content of this disclosure is not limited thereto.

[0077]

[0078] As shown in Table 2, within the same liquid crystal cell, the alignment directions of the first and second photoalignment layers can differ by 90°. Furthermore, within the same liquid crystal cell and the same photoalignment layer, the alignment directions of different alignment units can sequentially differ by 45°. Because the alignment directions of each alignment unit in each photoalignment layer are different, display device 10d can more effectively reduce the variation in reflectivity at different viewing angles compared to display devices 10, 10a, 10b, and 10c, thereby improving the viewing angle uniformity of display device 10d. In other embodiments, the positions of the first to fourth alignment units can be randomly distributed to avoid overly periodic arrangements that are easily discernible to the human eye or create a moiré pattern effect.

[0079] Please refer to the following: Figure 1 , Figure 2A , Figure 2B and Figure 7 ,in Figure 7 This is a flowchart illustrating a method for manufacturing a display device according to a second embodiment of this disclosure. (For example...) Figure 7 As shown, the manufacturing method 20 for the display device includes steps S01, S02, S03, and S04, and can be used to manufacture display devices 10, 10a, 10b, 10c, and 10d. The following will take the manufacturing of a display device 10 having dual liquid crystal cells (i.e., having selective light reflection modules 100 and 200 stacked together) as an example.

[0080] Step S01 involves forming at least one photoalignment layer on at least one of the first transparent substrate 110 and the second transparent substrate 120. In this embodiment, step S01 may include forming a first photoalignment layer 141 and a second photoalignment layer 142 on the first transparent substrate 110 and the second transparent substrate 120, respectively. Before forming the first photoalignment layer 141 and the second photoalignment layer 142, step S01 may further include providing a first transparent substrate 111 and forming a first transparent electrode layer 112 on the first transparent substrate 111, and providing a second transparent substrate 121 and forming a second transparent electrode layer 122 on the second transparent substrate 121. Furthermore, in step S01, the process for forming each electrode layer and each photoalignment layer may be a coating process, a deposition process, or other suitable processes. The deposition process may include, for example, atomic layer deposition (ALD), physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), or other suitable deposition processes.

[0081] Step S02 involves irradiating at least one photoalignment layer with an alignment light source for exposure. In this embodiment, step S02 may include irradiating the first photoalignment layer 141 and the second photoalignment layer 142 with alignment light for exposure, such that after exposure, the first photoalignment layer 141 and the second photoalignment layer 142 respectively possess… Figure 2A The first alignment direction D1 and the second alignment direction D2 in the middle.

[0082] Step S03 involves assembling the first transparent substrate 110 and the second transparent substrate 120, and injecting liquid crystal molecules between the first transparent substrate 110 and the second transparent substrate 120 to form the display layer 130 in the selective light reflection module 100. Thus, the selective light reflection module 100 can be fabricated via steps S01 to S03, and the selective light reflection module 200 is fabricated in the same manner. Furthermore, the first photoalignment layer 241 and the second photoalignment layer 242 in the selective light reflection module 200 can respectively possess [specific properties] after exposure. Figure 2B The first alignment direction D3 and the second alignment direction D4 are respectively provided in the selective light reflection module 100. Therefore, the first photoalignment layer 141 and the second photoalignment layer 142 of the selective light reflection module 100 can provide the first alignment direction D1 and the second alignment direction D2 to each pixel of the display layer 130. Similarly, the first photoalignment layer 241 and the second photoalignment layer 242 of the selective light reflection module 200 can provide the first alignment direction D3 and the second alignment direction D4 to each pixel of the display layer 230.

[0083] Step S04 involves stacking multiple selective light reflection modules 100 and 200, and setting a light absorption layer 300 at the bottom of the multiple selective light reflection modules 100 and 200 to form a display device 10.

[0084] In some embodiments, before performing step S02, the manufacturing method 20 of the display device may further include covering the at least one photoalignment layer with a patterned photomask to selectively block alignment light, so that the at least one photoalignment layer is divided into multiple alignment units after exposure, and the multiple alignment units may have different alignment directions. Specifically, taking the manufacturing of display device 10a as an example, before performing step S02, a designed patterned photomask may be first covered on the first photoalignment layer 141a. The patterned photomask is mainly used to selectively block alignment light, so that only the unblocked areas in the first photoalignment layer 141a can be exposed, thereby dividing the first photoalignment layer 141a into multiple first alignment units U1 and multiple second alignment units U2 (e.g., ...). Figure 3 As shown in the figure, the remaining photoalignment layers follow the same principle and will not be described in detail. Therefore, the manufacturing method 20 of the display device disclosed herein can employ photomask blocking technology to achieve various alignment directions as shown in Tables 1 and 2 above. By changing the pattern design of the photomask, alignment can be performed on a unit basis, with single pixels or multiple pixels, so that adjacent alignment units have different alignment directions. This effectively reduces the variation of reflectivity at different viewing angles, thereby improving viewing angle uniformity.

[0085] In summary, the display device and its manufacturing method disclosed herein have the following advantages: First, they can effectively reduce the variation of reflectivity at different viewing angles to improve viewing angle uniformity and overall reflectivity, and also expand the potential of the display device in high-resolution and wide-viewing-angle display applications. Second, by configuring unaligned units in an arbitrary photoalignment layer, the cholesterol liquid crystal molecules aligned with the unaligned units can maintain their original state during the display process, without changing their alignment orientation with changes in the electric field, thereby providing more stable optical properties and significantly improving the contrast of the displayed image. Third, alignment units with different alignment orientations can be flexibly configured in the photoalignment layer to avoid overly periodic arrangement, which could lead to moiré patterns.

[0086] Although the present disclosure has been described above with reference to embodiments, it is not intended to limit the present disclosure. Any person skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims.

Claims

1. A display device, characterized by comprising: Include: Multiple selective light reflection modules are stacked on top of each other, wherein each of the multiple selective light reflection modules comprises: A display layer containing multiple pixels; and At least one photoalignment layer is disposed on the display layer; Wherein, the at least one photoalignment layer of one of the plurality of selective light reflection modules provides an alignment direction for at least one of the plurality of pixels of the plurality of selective light reflection modules, and the at least one photoalignment layer of the other of the plurality of selective light reflection modules provides another alignment direction for at least one of the plurality of pixels of the other of the plurality of selective light reflection modules; The alignment direction is different from the other alignment direction.

2. The display device as claimed in claim 1, characterized in that, The number of at least two photoalignment layers is two, namely a first photoalignment layer and a second photoalignment layer, and the display layer is disposed between the first photoalignment layer and the second photoalignment layer; and Each of the plurality of selective light reflection modules further includes a first transparent substrate and a second transparent substrate, wherein the first photoalignment layer is disposed on the first transparent substrate and the second photoalignment layer is disposed on the second transparent substrate.

3. The display device of claim 2, wherein, The first photoalignment layer provides a first alignment direction for at least one of the plurality of pixels, and the second photoalignment layer provides a second alignment direction for at least one of the plurality of pixels, wherein the first alignment direction and the second alignment direction differ by 90 degrees.

4. The display device of claim 1, wherein The alignment direction differs from the other alignment direction by 45 degrees.

5. The display device as claimed in claim 1, characterized in that, An adhesive layer is provided between adjacent stacked selective light reflection modules.

6. The display device as claimed in claim 1, characterized in that, The rotational pitch of the liquid crystal molecules in each of the plurality of selective light reflection modules is different.

7. The display device of claim 1, wherein The liquid crystal optical rotation properties of adjacent stacked selective light reflection modules are different.

8. The display device of claim 1, wherein The at least one optical alignment layer of the plurality of selective light reflection modules includes a plurality of alignment units, each of the plurality of alignment units having a plurality of alignment directions, one of the plurality of alignment directions being 45 degrees away from another of the plurality of alignment directions.

9. The display device of claim 8, wherein, The multiple alignment units are arranged alternately and at intervals.

10. The display device of claim 8, wherein, The at least one photoalignment layer further includes an unalignment unit, which is used to separate the plurality of alignment units.

11. The display device of claim 8, wherein, It also includes: A light absorption layer is disposed at the bottom of one of the plurality of selective light reflection modules.

12. A method for manufacturing a display device, comprising: Includes the following steps: At least one photoalignment layer is formed on at least one of a first transparent substrate and a second transparent substrate; An alignment light is irradiated onto the at least one photoalignment layer to perform exposure; The first transparent substrate and the second transparent substrate are assembled, and a liquid crystal molecule is injected between the first transparent substrate and the second transparent substrate to form a display layer in a selective light reflection module, wherein the display layer contains a plurality of pixels; as well as Multiple selective light reflection modules are stacked together; Wherein, the at least one photoalignment layer of one of the plurality of selective light reflection modules provides an alignment direction for at least one of the plurality of pixels of the plurality of selective light reflection modules, and the at least one photoalignment layer of the other of the plurality of selective light reflection modules provides another alignment direction for at least one of the plurality of pixels of the other of the plurality of selective light reflection modules; The alignment direction is different from the other alignment direction.

13. The method for manufacturing a display device as claimed in claim 12, characterized in that, Before irradiating the at least one photoalignment layer with the alignment light for exposure, a patterned photomask is covered on the at least one photoalignment layer to selectively block the alignment light, so that the at least one photoalignment layer is divided into a plurality of alignment units after exposure, wherein the plurality of alignment units have different alignment directions.

14. The method for manufacturing a display device according to claim 12, wherein The alignment direction differs from the other alignment direction by 45 degrees.

15. The method for manufacturing a display device as claimed in claim 13, characterized in that, The step of stacking the plurality of selective light reflection modules includes: A light absorption layer is disposed at the bottom of one of the plurality of selective light reflection modules.

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