Display device

Abstract

The invention provides a display device. The display device comprises a reflective display panel, a light guide plate, a light source, a plurality of micro grooves, a light-transmitting substrate and a first adhesion layer, the reflective display panel has a display surface. The light guide plate is arranged on one side of the display surface of the reflective display panel. The first surface and the second surface are connected with the light incident surface and are opposite to each other. The first surface faces the display surface. The light source is arranged on one side of the incident surface of the light guide plate. The plurality of micro grooves are arranged on the second surface of the light guide plate and are recessed from the second surface. The light-transmitting substrate overlaps the light guide plate and is opposite to the second surface. The first adhesive layer is connected with the light-transmitting substrate and the light guide plate and is not overlapped with the plurality of micro grooves.

Description

Technical Field

[0001] The present invention relates to a display device, and in particular to a display device having a light guide plate. Background Art

[0002] Reflective display devices have a place in the market due to their low energy consumption characteristics. In order to meet the needs of use when the ambient light is insufficient, a solution of providing a front light source on one side of its display surface has been proposed. In order to prevent the light guide plate from being damaged due to operation or unexpected external force, this type of front light source will also provide a protective cover plate on the side of the light guide plate facing away from the reflective display panel, and this cover plate will be attached to the light guide plate via an adhesive layer. However, during the manufacturing process, the adhesive layer is prone to sinking into the microstructure (i.e., dots) on the light guide plate when it contacts the light guide plate, thereby affecting its light extraction efficiency. If a glue material with lower viscosity is selected as the adhesive layer, it is easy for the cover plate to separate from the light guide plate or the bonding condition to be poor after bonding. Summary of the Invention

[0003] The present invention is directed to a display device having a high production yield and a light guide plate with good optical performance.

[0004] According to an embodiment of the present invention, a display device includes a reflective display panel, a light guide plate, a light source, a plurality of micro-grooves, a light-transmitting substrate, and a first adhesive layer. The reflective display panel has a display surface. The light guide plate is arranged on one side of the display surface of the reflective display panel. The light guide plate is provided with a light incident surface and a first surface and a second surface connected to the light incident surface and opposite to each other. The first surface faces the display surface. The light source is arranged on one side of the light incident surface of the light guide plate. A plurality of micro-grooves are arranged on the second surface of the light guide plate and are recessed from the second surface. The light-transmitting substrate is arranged to overlap with the light guide plate and opposite to the second surface. The first adhesive layer connects the light-transmitting substrate and the light guide plate and does not overlap with the plurality of micro-grooves.

[0005] In the display device according to an embodiment of the present invention, the first adhesive layer has a plurality of openings, and orthographic projections of the plurality of micro-grooves on the light-transmitting substrate are located within orthographic projections of the plurality of openings on the light-transmitting substrate.

[0006] In the display device according to the embodiment of the present invention, the orthographic projection profiles of the plurality of openings on the light-transmitting substrate are conformal to the orthographic projection profiles of the plurality of micro-grooves on the light-transmitting substrate.

[0007] In a display device according to an embodiment of the present invention, a plurality of microgrooves have a groove width along any direction parallel to the second surface, a plurality of openings have an opening width along any direction, and a ratio of the opening width to the groove width is greater than or equal to 1 and less than or equal to 1.3.

[0008] In the display device according to the embodiment of the present invention, the percentage of the surface area of ​​the portion of the second surface not covered by the first adhesive layer to the surface area of ​​the second surface is greater than or equal to 2.5% and less than or equal to 15%.

[0009] In a display device according to an embodiment of the present invention, the display device further includes a cover plate and a second adhesive layer. The cover plate is disposed on a side of the light-transmitting substrate facing away from the light guide plate. The second adhesive layer connects the cover plate, the light-transmitting substrate, and the light guide plate.

[0010] In a display device according to an embodiment of the present invention, a composite material sidewall is formed along an edge parallel to the second surface between the light-transmitting substrate and the first adhesive layer. A light guide plate has a plate sidewall along the edge of the second surface. The orthographic projection of the composite material sidewall on the second surface is located within and spaced from the edge of the light guide plate. The second adhesive layer covers the composite material sidewall and a portion of the second surface.

[0011] In the display device according to an embodiment of the present invention, the first adhesive layer has a plurality of openings, and orthographic projections of the plurality of micro-grooves on the light-transmitting substrate are located within orthographic projections of the plurality of openings on the light-transmitting substrate.

[0012] In the display device according to the embodiment of the present invention, the orthographic projection profiles of the plurality of openings on the light-transmitting substrate are conformal to the orthographic projection profiles of the plurality of micro-grooves on the light-transmitting substrate.

[0013] In the display device according to the embodiment of the present invention, the percentage of the surface area of ​​the second surface not covered by the first adhesive layer and the second adhesive layer to the surface area of ​​the second surface is greater than or equal to 2.5% and less than or equal to 15%.

[0014] Based on the above, in a display device according to one embodiment of the present invention, a light guide plate and a light source are provided on one side of the display surface of a reflective display panel. The light guide plate has a plurality of microgrooves recessed from the surface on the side facing away from the reflective display panel. A light-transmitting substrate is connected to the surface of the light guide plate having the microgrooves via a first adhesive layer. Because the first adhesive layer does not overlap the microgrooves of the light guide plate, this not only increases flexibility in material selection for the first adhesive layer but also prevents the first adhesive layer from sinking into the microgrooves and affecting the light extraction efficiency of the light guide plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic cross-sectional view of a display device according to a first embodiment of the present invention;

[0016] Figure 2 yes Figure 1 A partially enlarged schematic diagram of a display device;

[0017] Figure 3 yes Figure 1 A schematic top view of a display device;

[0018] Figure 4 yes Figure 1 A schematic cross-sectional view of a display device according to another modified embodiment;

[0019] Figure 5 is a schematic cross-sectional view of a display device according to a second embodiment of the present invention;

[0020] Figure 6 yes Figure 5 A schematic top view of a display device;

[0021] Figure 7 is a schematic cross-sectional view of a display device according to a third embodiment of the present invention.

[0022] Description of Reference Numerals

[0023] 10, 10A, 20, 20A: display device;

[0024] 100: reflective display panel;

[0025] 100ds: display surface;

[0026] 150, 241, 241A, 241B, 241C, 242, 242B: adhesive layer;

[0027] 200, 200A, 200B, 200C: light source module;

[0028] 210: light guide plate;

[0029] 210is: light incident side;

[0030] 210s1: first surface;

[0031] 210s2: second surface;

[0032] 220: light source;

[0033] 230, 230B: light-transmitting substrate;

[0034] 241op: open hole;

[0035] 250: cover plate;

[0036] e1, e2: edges;

[0037] MG: microgrooves;

[0038] s2p:partial;

[0039] SW1: composite sidewall;

[0040] SW2: Board side wall;

[0041] Wop: opening width;

[0042] Wr: groove width;

[0043] X, Z: direction. DETAILED DESCRIPTION

[0044] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0045] Figure 1 is a schematic cross-sectional view of a display device according to a first embodiment of the present invention. Figure 2 yes Figure 1 A partially enlarged schematic diagram of a display device. Figure 3 yes Figure 1 A schematic top view of a display device. Figure 4 yes Figure 1 A schematic cross-sectional view of a display device according to another variant embodiment.

[0046] Please refer to Figure 1 and Figure 2 The display device 10 includes a reflective display panel 100 and a light source module 200. The light source module 200 is disposed on one side of the display surface 100ds of the reflective display panel 100. In other words, the display device 10 is a reflective display device having the light source module 200. In this embodiment, the light source module 200 can be bonded to the reflective display panel 100 via an adhesive layer 150. The adhesive layer 150 is made of, for example, an optically clear adhesive (OCA) or an optically clear resin (OCR).

[0047] Specifically, the light source module 200 includes a light guide plate 210, a light source 220, a light-transmitting substrate 230, and an adhesive layer 241. The light guide plate 210 overlaps the display surface 100ds of the reflective display panel 100. The overlapping relationship herein refers to, for example, the overlap of the light guide plate 210 and the display surface 100ds along a normal direction (e.g., direction Z) of the display surface 100ds. Unless otherwise specified, the overlapping relationship between the two components is defined in the same manner, and the overlapping direction will not be further described.

[0048] The light guide plate 210 has a light incident surface 210is, and a first surface 210s1 and a second surface 210s2 connecting the light incident surface 210is and opposing each other. The first surface 210s1 faces the display surface 100ds of the reflective display panel 100. A light source 220 is disposed on one side of the light incident surface 210is of the light guide plate 210 and is adapted to emit illumination light (not shown) toward the light incident surface 210is of the light guide plate 210. A plurality of microgrooves MG are formed on the second surface 210s2 of the light guide plate 210, and these microgrooves MG are recessed from the second surface 210s2. The aforementioned illumination light enters the light guide plate 210 through the light incident surface 210is and is transmitted laterally therein. After being reflected by the optical surface of the light guide plate 210 that defines these micro-grooves MG, it is emitted from the first surface 210s1 of the light guide plate 210 and illuminates the display surface 100ds of the reflective display panel 100, thereby serving as illumination light for the reflective display panel 100 when the ambient light is insufficient.

[0049] The light-transmitting substrate 230 overlaps the light guide plate 210 and faces the second surface 210s2 of the light guide plate 210. The light-transmitting substrate 230 is made of, for example, polyimide, polycarbonate, polymethyl methacrylate, or other suitable light-transmitting materials. The light-transmitting substrate 230 is connected to the light guide plate 210 via an adhesive layer 241. More specifically, the adhesive layer 241 connects the light-transmitting substrate 230 to the second surface 210s2 of the light guide plate 210. The adhesive layer 241 is made of, for example, optically clear adhesive (OCA) or optically clear resin (OCR).

[0050] It is particularly noteworthy that in this embodiment, to prevent the adhesive layer 241 from sinking into the microgrooves MG during the bonding process between the light-transmitting substrate 230 and the light guide plate 210, thereby affecting the light extraction efficiency of the light guide plate 210, the adhesive layer 241 is disposed so as not to overlap with the multiple microgrooves MG on the light guide plate 210. For example, the adhesive layer 241 may have multiple openings 241op, and these openings 241op respectively overlap with the multiple microgrooves MG on the light guide plate 210. More specifically, the orthographic projections of the microgrooves MG on the light-transmitting substrate 230 are located within the orthographic projections of the multiple openings 241op of the adhesive layer 241 on the light-transmitting substrate 230. In other words, the microgrooves MG completely overlap with the openings 241op.

[0051] In this embodiment, the orthographic projection area of ​​the micro-grooves MG on the light-transmitting substrate 230 may be smaller than the orthographic projection area of ​​the corresponding openings 241op on the light-transmitting substrate 230, but the present invention is not limited thereto. From another perspective, the micro-grooves MG and the openings 241op have a groove width Wr and an opening width Wop, respectively, along any direction parallel to the second surface 210s2 (e.g., direction X). The ratio of the opening width Wop of the opening 241op to the groove width Wr of the micro-grooves MG may be greater than 1, and preferably less than or equal to 1.3.

[0052] However, the present invention is not limited thereto. Figure 4 In another variant embodiment of the display device 10A, the orthographic projection area of ​​the area occupied by the openings 241op of the adhesive layer 241A of the light source module 200A on the light-transmitting substrate 230 can be equal to the orthographic projection area of ​​the area occupied by the corresponding microgrooves MG on the light-transmitting substrate 230. In any direction parallel to the second surface 210s2, the ratio of the opening width of the openings 241op of the adhesive layer 241A to the groove width of the microgrooves MG can be equal to 1. In other words, the plurality of openings 241op of the adhesive layer 241A can respectively align with the plurality of microgrooves MG, but the present invention is not limited thereto.

[0053] Please refer to Figure 2 and Figure 3 In this embodiment, the adhesive layer 241 does not completely cover the second surface 210s2 of the light guide plate 210. Preferably, the percentage of the surface area of ​​the portion s2p of the second surface 210s2 not covered by the adhesive layer 241 relative to the surface area of ​​the second surface 210s2 can be greater than or equal to 2.5 and less than or equal to 15%. For example, in this embodiment, the orthographic projection profile of the plurality of openings 241op of the adhesive layer 241 on the transparent substrate 230 can conform to the orthographic projection profile of the plurality of microgrooves MG on the transparent substrate 230. This ensures a balanced adhesion between the light guide plate 210 and the transparent substrate 230 and the light extraction efficiency of the light guide plate 210.

[0054] It is important to emphasize again that because the adhesive layer 241 of this embodiment, with its multiple openings 241op, does not overlap the multiple micro-grooves MG of the light guide plate 210, during the bonding process between the light-transmitting substrate 230 and the light guide plate 210, the micro-grooves MG are not sunk by material not in the adhesive layer 241, thereby preventing the light-guiding efficiency of the aforementioned illumination light from being affected. Therefore, the light extraction efficiency of the light guide plate 210 is ensured. Furthermore, the material used for the adhesive layer 241 can be made more flexible, such as by using a higher-viscosity adhesive, to prevent the light-transmitting substrate 230 from easily peeling off from the light guide plate 210 after bonding or preventing poor bonding.

[0055] To further enhance the protection of the light guide plate 210, the light source module 200 may further include an adhesive layer 242 and a cover plate 250. The cover plate 250 is disposed on the side of the light-transmitting substrate 230 facing away from the light guide plate 210, and the adhesive layer 242 connects the cover plate 250 and the light-transmitting substrate 230. In other words, the cover plate 250 is bonded to the light-transmitting substrate 230 via the adhesive layer 242. The adhesive layer 242 may be made of, for example, optically clear adhesive (OCA) or optically clear resin (OCR).

[0056] The following will list some other embodiments to illustrate the present disclosure in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the above embodiments and will not be repeated below.

[0057] Figure 5 is a schematic cross-sectional view of a display device according to a second embodiment of the present invention. Figure 6 yes Figure 5 Please refer to the top view of the display device. Figure 5 and Figure 6 , different from Figure 1 In the display device 10 of this embodiment, in the display device 20 of the present embodiment, the adhesive layer 242B of the light source module 200B may further connect the adhesive layer 241B and a portion of the surface 210s2 of the light guide plate 210.

[0058] More specifically, the light-transmitting substrate 230B and the adhesive layer 241B define a composite sidewall SW1 along an edge e1 parallel to the second surface 210s2, and the light guide plate 210 defines a plate sidewall SW2 along an edge e2 of the second surface 210s2. In this embodiment, the orthographic projection of the composite sidewall SW1 on the second surface 210s2 is located within and spaced from the edge e2 of the light guide plate 210. In other words, both the light-transmitting substrate 230B and the adhesive layer 241B are recessed relative to the edge e2 of the light guide plate 210. Consequently, a portion of the second surface 210s2 of the light guide plate 210 is exposed, allowing the adhesive layer 242B connecting the cover plate 250 and the light-transmitting substrate 230B to further cover the composite sidewall SW1 of the light-transmitting substrate 230B and the adhesive layer 241B, as well as the portion of the second surface 210s2. The portion of the second surface 210s2 is located between the composite material side wall SW1 and the plate side wall SW2.

[0059] It is particularly noted that, in this embodiment, the adhesive layer 241B does not have Figure 1The adhesive layer 241 has multiple openings 241op, meaning that the adhesive layer 241B not only connects to the second surface 210s2 of the light guide plate 210 but also overlaps the multiple microgrooves MG. To prevent the adhesive layer 241B from sinking into the microgrooves MG and affecting the light extraction efficiency of the light guide plate 210, a low-viscosity adhesive can be used for the adhesive layer 241B. However, this also reduces the adhesion strength between the transparent substrate 230B and the light guide plate 210. The adhesive layer 242B further covers the composite sidewall SW1 of the transparent substrate 230B and adhesive layer 241B, as well as a portion of the second surface 210s2, thereby further strengthening the connection between the transparent substrate 230B and the light guide plate 210.

[0060] Since the components not mentioned in this embodiment are similar to Figure 1 For the display device 10, detailed description can be found in the relevant paragraphs of the aforementioned embodiment, which will not be repeated here.

[0061] Figure 7 is a cross-sectional view of a display device according to a third embodiment of the present invention. Figure 7 The display device 20A of this embodiment is Figure 5 The difference between the display device 20 and the display device 20A is that the adhesive layer is configured differently. Specifically, in this embodiment, the adhesive layer 241C of the light source module 200C of the display device 20A is similar to Figure 1 The adhesive layer 241 may have a plurality of openings 241op. Since the configuration relationship between these openings 241op and the plurality of micro grooves MG on the light guide plate 210 is similar to Figures 1 to 3 For the display device 10, detailed description can be found in the relevant paragraphs of the aforementioned embodiment, which will not be repeated here.

[0062] In particular, because the adhesive layer 241C of this embodiment includes multiple openings 241op and does not overlap the multiple micro-grooves MG of the light guide plate 210, during the bonding process between the light-transmitting substrate 230B and the light guide plate 210, the micro-grooves MG are not sunken by material not in the adhesive layer 241C, thereby preventing the light-guiding effect of the aforementioned illumination light from being affected. Therefore, the light extraction efficiency of the light guide plate 210 is ensured. Furthermore, the material selection for the adhesive layer 241C can be enhanced, such as by using a high-viscosity adhesive, to prevent the light-transmitting substrate 230B from easily peeling off from the light guide plate 210 or preventing poor bonding after bonding.

[0063] On the other hand, since the adhesive layer 242B connecting the cover plate 250 and the transparent substrate 230B further covers the composite side wall SW1 of the transparent substrate 230B and the adhesive layer 241C and a portion of the second surface 210s2, the connection between the transparent substrate 230B and the light guide plate 210 can be further stabilized.

[0064] In summary, in a display device according to one embodiment of the present invention, a light guide plate and a light source are disposed on one side of the display surface of a reflective display panel. The light guide plate has a plurality of microgrooves recessed from its surface on the side facing away from the reflective display panel. A light-transmitting substrate is connected to the surface of the light guide plate having the microgrooves via a first adhesive layer. Because the first adhesive layer does not overlap the microgrooves of the light guide plate, this not only increases flexibility in material selection for the first adhesive layer but also prevents the first adhesive layer from sinking into the microgrooves and affecting the light extraction efficiency of the light guide plate.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A display device, characterized in that: include: A reflective display panel having a display surface; a light guide plate disposed on one side of the display surface of the reflective display panel, the light guide plate comprising a light incident surface, and a first surface and a second surface connected to the light incident surface and opposite to each other, wherein the first surface faces the display surface; a light source, disposed on one side of the light incident surface of the light guide plate; a plurality of micro grooves, disposed on the second surface of the light guide plate and recessed from the second surface; a light-transmitting substrate, overlapping the light guide plate and facing the second surface; as well as The first adhesive layer connects the light-transmitting substrate and the light guide plate and does not overlap the plurality of micro grooves.

2. The display device according to claim 1, wherein The first adhesive layer has a plurality of openings, and the orthographic projections of the plurality of micro grooves on the light-transmitting substrate are located within the orthographic projections of the plurality of openings on the light-transmitting substrate.

3. The display device according to claim 2, wherein: The orthographic projection profiles of the plurality of openings on the light-transmitting substrate are conformal to the orthographic projection profiles of the plurality of micro-grooves on the light-transmitting substrate.

4. The display device according to claim 2, wherein: The plurality of microgrooves have a groove width along any direction parallel to the second surface, the plurality of openings have an opening width along any direction, and a ratio of the opening width to the groove width is greater than or equal to 1 and less than or equal to 1.

3.

5. The display device according to claim 1, wherein A percentage of a surface area of ​​a portion of the second surface not covered by the first adhesive layer to a surface area of ​​the second surface is greater than or equal to 2.5% and less than or equal to 15%.

6. The display device according to claim 1, wherein Also includes: a cover plate, disposed on a side of the light-transmitting substrate facing away from the light guide plate; as well as The second adhesive layer connects the cover plate, the light-transmitting substrate and the light guide plate.

7. The display device according to claim 6, wherein: The light-transmitting substrate and the first adhesive layer are provided with a composite material side wall along the edge parallel to the second surface, and the light guide plate is provided with a plate side wall along the edge of the second surface. The orthographic projection of the composite material side wall on the second surface is located within the edge of the light guide plate and is separated from the edge of the light guide plate. The second adhesive layer covers the composite material side wall and a portion of the second surface.

8. The display device according to claim 6, wherein: The first adhesive layer has a plurality of openings, and the orthographic projections of the plurality of micro grooves on the light-transmitting substrate are located within the orthographic projections of the plurality of openings on the light-transmitting substrate.

9. The display device according to claim 8, wherein The orthographic projection profiles of the plurality of openings on the light-transmitting substrate are conformal to the orthographic projection profiles of the plurality of micro-grooves on the light-transmitting substrate.

10. The display device according to claim 6, wherein A percentage of a surface area of ​​a portion of the second surface not covered by the first adhesive layer and the second adhesive layer to a surface area of ​​the second surface is greater than or equal to 2.5% and less than or equal to 15%.

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