Reflective display device

Abstract

A reflective display device comprises a first substrate, a second substrate, a third substrate, a common electrode, a plurality of pixel electrodes, an electrophoresis layer, a plurality of electrode patterns and a liquid crystal layer. The first substrate is provided with a first surface and a second surface opposite to the first surface, the second substrate is provided with a third surface facing the first surface, the third substrate is provided with a fourth surface facing the second surface, and the first substrate is arranged between the second substrate and the third substrate. The common electrode is arranged on the second surface, the pixel electrode is arranged on the fourth surface, and the electrophoresis layer is arranged between the common electrode and the pixel electrode. The electrode pattern is arranged on the first surface, and the liquid crystal layer is arranged between the electrode pattern and the second substrate. The reflective display device can improve contrast and color saturation, thereby improving display quality.

Description

Technical Field

[0001] This invention relates to a reflective display device, and more particularly to a reflective display device comprising an electrophoretic layer and a liquid crystal layer. Background Technology

[0002] One type of existing reflective display device uses an electrophoretic display panel to reflect ambient light to display images, achieving low power consumption. However, due to the gaps between the charged particles in the electrophoretic layer, light leakage occurs when displaying black or dark images, resulting in decreased contrast and color saturation, thus affecting display quality. Summary of the Invention

[0003] One embodiment of the present invention provides a reflective display device that can improve contrast and color saturation, thereby improving display quality.

[0004] An embodiment of the present invention provides a reflective display device comprising a first substrate, a second substrate, a third substrate, a common electrode, a plurality of pixel electrodes, an electrophoretic layer, a plurality of electrode patterns, and a liquid crystal layer. The first substrate has a first surface and a second surface opposite to the first surface; the second substrate has a third surface facing the first surface; the third substrate also has a fourth surface facing the second surface; the first substrate is disposed between the second substrate and the third substrate. The common electrode is disposed on the second surface; the pixel electrodes are disposed on the fourth surface; and the electrophoretic layer is disposed between the common electrode and the pixel electrodes. The electrode patterns are disposed on the first surface; and the liquid crystal layer is disposed between the electrode patterns and the second substrate.

[0005] According to one embodiment of the present invention, the second substrate has a fifth surface opposite to the third surface, and the reflective display device further includes a polarizer disposed on the fifth surface.

[0006] According to another embodiment of the present invention, the reflective display device further includes a plurality of color filter layers and a plurality of light-shielding layers disposed on the third surface.

[0007] According to another embodiment of the present invention, the electrophoretic layer comprises a plurality of charged particles, which overlap with the plurality of color filter layers and the plurality of light-shielding layers on the normal of the first substrate.

[0008] According to another embodiment of the present invention, the reflective display device further includes an optical adhesive disposed between the common electrode and the electrophoretic layer, and in contact with the common electrode and the electrophoretic layer to adhere the common electrode and the electrophoretic layer.

[0009] According to another embodiment of the present invention, no polarizer is provided between the liquid crystal layer and the third substrate.

[0010] According to another embodiment of the present invention, the reflective display device further includes a first flexible circuit board and a second flexible circuit board. The first flexible circuit board is disposed on the first substrate and electrically connected to the plurality of electrode patterns, and the second flexible circuit board is disposed on the third substrate and electrically connected to the plurality of pixel electrodes. The first substrate has a first peripheral region, and the third substrate has a second peripheral region. The first peripheral region and the second peripheral region are not covered by the second substrate in the top view direction of the reflective display device and are located on the same side outside the second substrate. The first flexible circuit board is located in the first peripheral region, and the second flexible circuit board is located in the second peripheral region.

[0011] According to another embodiment of the present invention, the width of the first peripheral area is equal to the width of the second peripheral area.

[0012] According to another embodiment of the present invention, the width of the first peripheral area is greater than the width of the second peripheral area.

[0013] According to another embodiment of the present invention, the width of the second peripheral area is greater than the width of the first peripheral area.

[0014] The beneficial effect of one embodiment of the present invention is at least that by disposing the liquid crystal layer on the electrophoretic layer, light leakage caused by the gaps between charged particles in the electrophoretic layer can be absorbed, thereby improving contrast and color saturation, and thus improving display quality. Attached Figure Description

[0015] To gain a more complete understanding of the embodiments and their advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein:

[0016] Figure 1 This is a cross-sectional schematic diagram of a reflective display device according to an embodiment of the present invention;

[0017] Figures 2A to 2D for Figure 1 Cross-sectional schematic diagrams of a reflective display device at different technological stages;

[0018] Figure 3 and Figure 4 This is a cross-sectional schematic diagram of a reflective display device according to other embodiments of the present invention;

[0019] Figures 5A to 5C This is a cross-sectional schematic diagram of a reflective display device according to other embodiments of the present invention;

[0020] Figures 6A to 6C This is a cross-sectional schematic diagram of a reflective display device according to other embodiments of the present invention. Detailed Implementation

[0021] The embodiments of the present invention are discussed in detail below. However, it will be understood that the embodiments provide many applicable concepts that can be implemented in a wide variety of specific contexts. The discussed and disclosed embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0022] To clearly illustrate the technical features of the present invention, the dimensions of the components in the accompanying drawings are enlarged proportionally, and the number of some components is reduced. Therefore, the description and explanation of the embodiments of the present invention are not limited to the number of components in the drawings or the dimensions and shapes presented by the components, but should cover dimensions, shapes, and deviations from both caused by actual manufacturing processes and / or tolerances. For example, a flat surface shown in the drawings may have rough and / or non-linear characteristics, and an acute angle shown in the drawings may be a rounded corner. Therefore, the components presented in the drawings are primarily for illustration and are not intended to precisely depict the actual shape of the components, nor are they intended to limit the scope of protection of the claims of the present invention.

[0023] The spatial relative terms used in this invention, such as "below," "under," "above," and "above," are for the convenience of describing the relative relationship between one element or feature and another, as illustrated in the figures. The true meaning of these spatial relative terms includes other orientations. For example, when the illustration is rotated 180 degrees vertically, the relationship between one element and another may change from "below" or "under" to "above" or "above." Furthermore, the spatial relative descriptions used in this invention should be interpreted in the same way.

[0024] It should be understood that although the present invention may use terms such as "first," "second," and "third" to describe various elements or features, these elements or features should not be limited by these terms. These terms are primarily used to distinguish one element from another, or one feature from another. Furthermore, the term "or" as used in the present invention may, as appropriate, include any combination of one or more of the associated listed items.

[0025] Although this invention uses a series of operations or steps to illustrate the manufacturing method, the order in which these operations or steps are shown should not be construed as a limitation of the invention. For example, some operations or steps may be performed in a different order and / or simultaneously with other steps. Furthermore, each operation or step described herein may comprise several sub-steps or actions.

[0026] Furthermore, the present invention can be implemented or applied through other different specific embodiments, and the details of the present invention can also be combined, modified and changed in various embodiments based on different viewpoints and applications without departing from the concept of the present invention.

[0027] Figure 1This is a cross-sectional schematic diagram of a reflective display device 100A according to an embodiment of the present invention. The reflective display device 100A includes a first substrate 102, a second substrate 104, a third substrate 106, a common electrode 108, a plurality of pixel electrodes 110, an electrophoretic layer 112, a plurality of electrode patterns 114, and a liquid crystal layer 116. In various embodiments, the reflective display device 100A may be a total reflective type or a transmissive-transmissive-reflective type display device.

[0028] The first substrate 102 has a first surface S1 and a second surface S2 facing each other, the second substrate 104 has a third surface S3, and the third substrate 106 has a fourth surface S4, wherein the third surface S3 faces the first surface S1, the fourth surface S4 faces the second surface S2, and the first substrate 102 is disposed between the second substrate 104 and the third substrate 106.

[0029] A common electrode 108 is disposed on the second surface S2, a pixel electrode 110 is disposed on the fourth surface S4, and an electrophoretic layer 112 is disposed between the common electrode 108 and the pixel electrode 110. An electrode pattern 114 is disposed on the first surface S1, and a liquid crystal layer 116 is disposed between the electrode pattern 114 and the second substrate 104.

[0030] By depositing the liquid crystal layer 116 on the electrophoretic layer 112, light leakage caused by the gaps between charged particles in the electrophoretic layer 112 can be absorbed, thereby improving contrast and color saturation, and thus improving display quality. In addition, by having the first substrate 102 simultaneously serve as the lower substrate sandwiching the liquid crystal layer 116 with the second substrate 104 and the upper substrate sandwiching the electrophoretic layer 112 with the third substrate 106, the overall thickness of the reflective display device 100A can be reduced, and the light absorption rate can be decreased, thereby increasing brightness.

[0031] In detail, the electrophoretic layer 112 is used to display an image pattern, and the liquid crystal layer 116 is used to adjust the brightness of the aforementioned image pattern. In some embodiments, the liquid crystal layer 116 may have only two tortuous states corresponding to different grayscale values, one of which has a grayscale value of 0, corresponding to the black or dark portion of the aforementioned image pattern, and the other has a grayscale value of one to 255, corresponding to the white or bright portion of the aforementioned image pattern, thereby improving the contrast and color saturation of the reflective display device 100A.

[0032] It is worth noting that different film layers may be provided between the common electrode 108 and the second surface S2, between the pixel electrode 110 and the fourth surface S4, and between the electrode pattern 114 and the first surface S1, such as an insulating layer, a conductive layer, or a combination thereof, but not limited thereto. However, no substrate is included between the common electrode 108 and the second surface S2, between the pixel electrode 110 and the fourth surface S4, and between the electrode pattern 114 and the first surface S1.

[0033] In some embodiments, the first substrate 102 and the second substrate 104 may be light-transmitting substrates, while the third substrate 106 may be a light-transmitting substrate or an opaque substrate. The materials of the first substrate 102, the second substrate 104, and the third substrate 106 may include quartz, glass, polymer materials, etc.

[0034] The pixel electrode 110 may include an opaque conductive layer, a transparent conductive layer, or a combination thereof, while the common electrode 108 and the electrode pattern 114 may include a transparent conductive layer. The material of the opaque conductive layer may be, for example, molybdenum, molybdenum nitride, molybdenum niobide, etc., while the material of the transparent conductive layer may be, for example, indium tin oxide, indium zinc oxide, etc.

[0035] Please continue to refer to Figure 1 The reflective display device 100A also includes an optical adhesive 118, which is disposed between the common electrode 108 and the electrophoretic layer 112, and contacts the common electrode 108 and the electrophoretic layer 112 to bond them together. The optical adhesive 118 can be, for example, optical clear adhesive (OCA), optical clear resin (OCR), etc., but is not limited to these.

[0036] In addition, such as Figure 1 As shown, no polarizer is provided between the liquid crystal layer 116 and the third substrate 106. Since the reflective display device 100A does not have a backlight module, there is no need to provide a polarizer below the liquid crystal layer 116, which can reduce the overall thickness of the reflective display device 100A and reduce the light absorption rate, thereby improving the brightness.

[0037] Figures 2A to 2D Based on Figure 1 Cross-sectional schematic diagrams of the 100A reflective display device at different manufacturing stages. First, as shown... Figure 2A As shown, a first substrate 102 is provided, and a plurality of electrode patterns 114 are formed on the first surface S1 of the first substrate 102. A second substrate 104 is disposed on the electrode patterns 114, and a liquid crystal layer 116 is disposed between the electrode patterns 114 and the second substrate 104. Next, as... Figure 2B As shown, a common electrode 108 is formed on a second surface S2 opposite to the first surface S1.

[0038] like Figure 2C As shown, a third substrate 106 is provided, and a pixel electrode 110 is formed on the fourth surface S4 of the third substrate 106. Next, Figure 2D As shown, an electrophoretic layer 112, an optical adhesive 118, and a protective film 120 are sequentially disposed on the pixel electrode 110.

[0039] Finally, the protective film 120 is removed to expose the optical adhesive 118, and the common electrode 108 formed on the second surface S2 of the first substrate 102 is disposed on the optical adhesive 118, so that the optical adhesive 118 adheres to the common electrode 108 and the electrophoretic layer 112, forming a structure as shown in the figure. Figure 1 The reflective display device 100A shown is shown.

[0040] Figure 3 This is a cross-sectional schematic diagram of a reflective display device 100B according to another embodiment of the present invention. Figure 3 Implementation examples and Figure 1 The embodiments share most of the same component structures, materials, processes, and relative positional relationships; therefore, identical technical features will not be repeated here. The difference between the two embodiments is that... Figure 3 The reflective display device 100B also includes a polarizer 122 disposed on the fifth surface S5 of the second substrate 104 opposite to the third surface S3.

[0041] Figure 4 This is a cross-sectional schematic diagram of a reflective display device 100C according to another embodiment of the present invention. Figure 4 Implementation examples and Figure 1 The embodiments share most of the same component structures, materials, processes, and relative positional relationships; therefore, identical technical features will not be repeated here. The difference between the two embodiments is that... Figure 4 The reflective display device 100C further includes a plurality of color filter layers 130 and a plurality of light-shielding layers 132 disposed on the third surface S3 and arranged alternately, and the electrophoretic layer 112 includes a plurality of charged particles P overlapping the color filter layers 130 and the light-shielding layers 132 on the normal line of the first substrate 102.

[0042] The charged particles P of the electrophoretic layer 112 are moved by the electric field between the common electrode 108 and the pixel electrode 110 and overlap with the color filter layer 130 and the light-shielding layer 132 on the normal line of the first substrate 102 to display an image pattern. The liquid crystal molecules (not shown) in the liquid crystal layer 116 are rotated by the electric field between the electrode patterns 114 to present different gray levels, so as to adjust the brightness of the aforementioned image pattern, thereby enabling the reflective display device 100C to display the screen.

[0043] Figure 5A This is a cross-sectional schematic diagram of a reflective display device 100D according to another embodiment of the present invention. Figure 5A Implementation examples and Figure 1 The embodiments share most of the same component structures, materials, processes, and relative positional relationships; therefore, identical technical features will not be repeated here. The difference between the two embodiments is that... Figure 5AThe reflective display device 100D further includes a first flexible circuit board 140 and a second flexible circuit board 150. The first flexible circuit board 140 is disposed on a first substrate 102 and electrically connected to an electrode pattern 114. The second flexible circuit board 150 is disposed on a third substrate 106 and electrically connected to a pixel electrode 110. The first substrate 102 has a first peripheral region PA1, and the third substrate 106 has a second peripheral region PA2. The first peripheral region PA1 and the second peripheral region PA2 are not covered by the second substrate 104 in the top view direction of the reflective display device 100D and are located on the same side outside the second substrate 104. The first flexible circuit board 140 is located in the first peripheral region PA1, and the second flexible circuit board 150 is located in the second peripheral region PA2.

[0044] Specifically, the second substrate 104 has a first side E1, the first substrate 102 has a second side E2 protruding from the first side E1, and the third substrate 106 has a third side E3 protruding from the first side E1. A first peripheral region PA1 of the first substrate 102 is located between the first side E1 and the second side E2, and a second peripheral region PA2 of the third substrate 106 is located between the first side E1 and the third side E3. A first flexible circuit board 140 is disposed on the first surface S1 and located in the first peripheral region PA1, and a second flexible circuit board 150 is disposed on the fourth surface S4 and located in the second peripheral region PA2.

[0045] like Figure 5A As shown, the width of the first peripheral area PA1 is equal to the width of the second peripheral area PA2, meaning the shortest distance from the first side E1 to the second side E2 is equal to the shortest distance from the first side E1 to the third side E3. In other words, the second side E2 is aligned with the third side E3.

[0046] Figure 5B This is a cross-sectional schematic diagram of a reflective display device 100E according to another embodiment of the present invention. Figure 5B Implementation examples and Figure 5A The embodiments share most of the same component structures, materials, processes, and relative positional relationships; therefore, identical technical features will not be repeated here. The difference between the two embodiments is that... Figure 5B The width of the second peripheral region PA2 of the reflective display device 100E is greater than the width of the first peripheral region PA1. That is, the shortest distance from the first side E1 to the third side E3 is greater than the shortest distance from the first side E1 to the second side E2. In other words, the third side E3 protrudes beyond the second side E2.

[0047] Figure 5C This is a cross-sectional schematic diagram of a reflective display device 100F according to another embodiment of the present invention. Figure 5C Implementation examples and Figure 5AThe embodiments share most of the same component structures, materials, processes, and relative positional relationships; therefore, identical technical features will not be repeated here. The difference between the two embodiments is that... Figure 5C The width of the first peripheral region PA1 of the reflective display device 100F is greater than the width of the second peripheral region PA2. That is, the shortest distance from the first side E1 to the second side E2 is greater than the shortest distance from the first side E1 to the third side E3. In other words, the second side E2 protrudes beyond the third side E3.

[0048] Figure 6A This is a cross-sectional schematic diagram of a reflective display device 100G according to another embodiment of the present invention. Figure 6A Implementation examples and Figure 1 The embodiments share most of the same component structures, materials, processes, and relative positional relationships; therefore, identical technical features will not be repeated here. The difference between the two embodiments is that... Figure 6A The reflective display device 100G further includes a touch electrode 160 and an insulating layer 162, wherein the touch electrode 160 is disposed on the first surface S1 of the first substrate 102, and the insulating layer 162 is disposed between the touch electrode 160 and the electrode pattern 114. In this embodiment, the electrode pattern 114 is disposed on the touch electrode 160, but the present invention is not limited thereto. In other embodiments, the touch electrode 160 may be disposed on the electrode pattern 114, or the electrode pattern 114 may be used directly as the touch electrode.

[0049] In some embodiments, the touch electrode 160 may serve as a common electrode for driving the liquid crystal layer 116. The material of the touch electrode 160 may include indium tin oxide, indium zinc oxide, etc. The material of the insulating layer 162 may include a transparent inorganic insulating material (e.g., silicon oxide, silicon nitride, silicon oxynitride, etc.) or an organic insulating material (e.g., polymethyl methacrylate, siloxane, polyimide, epoxy resin, etc.).

[0050] Figure 6B This is a cross-sectional schematic diagram of a reflective display device 100H according to another embodiment of the present invention. Figure 6B Implementation examples and Figure 1 The embodiments share most of the same component structures, materials, processes, and relative positional relationships; therefore, identical technical features will not be repeated here. The difference between the two embodiments is that... Figure 6B The reflective display device 100H further includes a touch electrode 170. The second substrate 104 has a fifth surface S5 opposite to the third surface S3, and the touch electrode 170 is disposed on the fifth surface S5. In some embodiments, the material of the touch electrode 170 may include a light-transmitting conductive material, such as a metal mesh, indium tin oxide, indium zinc oxide, silver nanowires, etc.

[0051] Figure 6CThis is a cross-sectional schematic diagram of a reflective display device 100I according to another embodiment of the present invention. Figure 6C Implementation examples and Figure 1 The embodiments share most of the same component structures, materials, processes, and relative positional relationships; therefore, identical technical features will not be repeated here. The difference between the two embodiments is that... Figure 6C The reflective display device 100I further includes a touch panel 180. The second substrate 104 has a fifth surface S5 opposite to the third surface S3, and the touch panel 180 is disposed on the fifth surface S5. In some embodiments, the touch panel 180 may be a capacitive touch panel, but is not limited thereto.

[0052] In summary, this invention improves contrast and color saturation, thereby enhancing display quality, by placing the liquid crystal layer on top of the electrophoretic layer, which absorbs light leakage caused by the gaps between charged particles in the electrophoretic layer. Furthermore, by sandwiching the liquid crystal layer and the electrophoretic layer between the same substrate and different substrates, the overall thickness of the reflective display device can be reduced, and the light absorption rate can be decreased, thereby increasing brightness.

[0053] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Those skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A reflective display device, characterized in that, include: A first substrate has a first surface and a second surface opposite to the first surface; A second substrate having a third surface facing the first surface; A third substrate has a fourth surface facing the second surface, wherein the first substrate is disposed between the second substrate and the third substrate; A common electrode is disposed on the second surface; Multiple pixel electrodes are disposed on the fourth surface; An electrophoretic layer is disposed between the common electrode and the plurality of pixel electrodes; Multiple electrode patterns are disposed on the first surface; as well as A liquid crystal layer is disposed between the plurality of electrode patterns and the second substrate.

2. The reflective display device as described in claim 1, characterized in that, The second substrate has a fifth surface opposite to the third surface, and the reflective display device further includes a polarizer disposed on the fifth surface.

3. The reflective display device as described in claim 1, characterized in that, Also includes: Multiple color filter layers and multiple light-shielding layers are disposed on the third surface.

4. The reflective display device as described in claim 3, characterized in that, The electrophoretic layer includes multiple charged particles, which overlap with the multiple color filter layers and the multiple light-shielding layers on the normal line of the first substrate.

5. The reflective display device as described in claim 1, characterized in that, Also includes: An optical adhesive is disposed between the common electrode and the electrophoretic layer, and contacts the common electrode and the electrophoretic layer to adhere the common electrode and the electrophoretic layer.

6. The reflective display device as claimed in claim 1, characterized in that, No polarizer is provided between the liquid crystal layer and the third substrate.

7. The reflective display device as claimed in claim 1, characterized in that, Also includes: A first flexible circuit board is disposed on the first substrate and electrically connected to the plurality of electrode patterns; as well as A second flexible circuit board is disposed on the third substrate and electrically connected to the plurality of pixel electrodes. The first substrate has a first peripheral area, the third substrate has a second peripheral area, the first peripheral area and the second peripheral area are not covered by the second substrate in the top view direction of the reflective display device and are located on the same side outside the second substrate, the first flexible circuit board is located in the first peripheral area, and the second flexible circuit board is located in the second peripheral area.

8. The reflective display device as claimed in claim 7, characterized in that, The width of the first peripheral area is equal to the width of the second peripheral area.

9. The reflective display device as claimed in claim 7, characterized in that, The width of the first peripheral area is greater than the width of the second peripheral area.

10. The reflective display device as claimed in claim 7, characterized in that, The width of the second peripheral area is greater than the width of the first peripheral area.

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