Front light module and reflective display device

Abstract

The invention provides a front light module and a reflective display device. The front light module comprises a light guide plate, a light-emitting element and a barrier layer. The light guide plate has a light-in surface and a light-out surface adjacent to the light-in surface, and the light-emitting element emits light towards the light-in surface. The blocking layer is located on the light emitting face of the light guide plate, the blocking layer comprises a silicon chain material, and the water vapor transmission rate of the blocking layer is higher than that of the silicon chain material. WVTR) is less than 0.1 g / m2 / day. Therefore, the light guide plate can be prevented from deforming due to the influence of moisture.

Description

Technical Field

[0001] The invention relates to a front light module and a reflective display device using the front light module, in particular to a front light module with a water vapor blocking function. Background Art

[0002] In the light-emitting module of electronic paper, a barrier film is usually set between the light guide plate and the display panel to prevent moisture from contacting the light guide plate. Generally speaking, this barrier film is located between the light guide plate and the display panel, so the barrier film must be attached between the light guide plate and the display panel through at least two layers of optical glue. However, the thickness of the barrier film plus the thickness of the optical glue not only limits the lightness and thinness of the light-emitting module, but also greatly reduces the penetration rate of light entering the light guide plate, thereby affecting the luminous efficiency of the front light module. Summary of the invention

[0003] Therefore, an embodiment of the present invention provides a front light module, which can reduce the thickness of the front light module while having a moisture barrier function.

[0004] An embodiment of the present invention provides a front light module, which includes a light guide plate, a light emitting element, and a first barrier layer. The light guide plate has a light incident surface and a first light emitting surface adjacent to the light incident surface, and the light emitting element emits a light toward the light incident surface. The first barrier layer is located on the first light emitting surface of the light guide plate and includes a silicon chain material, and the water vapor permeability of the first barrier layer is less than 0.1 g / m 2 / day.

[0005] In at least one embodiment of the present invention, the main chain segment of the silicon chain material is selected from the group consisting of silicon-nitrogen linkage and silicon-oxygen linkage.

[0006] In at least one embodiment of the present invention, the thickness of the first barrier layer ranges from 200 nm to 1000 nm.

[0007] In at least one embodiment of the present invention, the refractive index of the first barrier layer is smaller than the refractive index of the light guide plate.

[0008] In at least one embodiment of the present invention, the refractive index of the first barrier layer ranges from 1.40 to 1.55.

[0009] In at least one embodiment of the present invention, the front light module further comprises a second barrier layer, and the second barrier layer is located on the second light emitting surface of the light guide plate. The second light emitting surface and the first light emitting surface are located on opposite sides of the light guide plate, and the second barrier layer comprises a silicon chain material, and the water vapor permeability of the second barrier layer is less than 0.1 g / m 2 / day.

[0010] In at least one embodiment of the present invention, the refractive index of the second barrier layer is smaller than the refractive index of the light guide plate.

[0011] In at least one embodiment of the present invention, the refractive index of the second barrier layer is higher than the refractive index of the first barrier layer.

[0012] In at least one embodiment of the present invention, the front light module further comprises two third barrier layers, which are respectively located on two opposite side surfaces of the light guide plate. The two side surfaces are respectively adjacent to the light incident surface and the first light emitting surface. The third barrier layer comprises a silicon chain material, and the water vapor permeability of the third barrier layer is less than 0.1 g / m 2 / day.

[0013] In at least one embodiment of the present invention, the front light module further includes a protection layer, and the protection layer is located on the first light emitting surface of the light guide plate.

[0014] In at least one embodiment of the present invention, the first barrier layer is formed on the light guide plate by wet coating.

[0015] An embodiment of the present invention provides a reflective display device, comprising the above-mentioned front light module and a reflective display panel, wherein the reflective display panel is disposed relative to the front light module.

[0016] In at least one embodiment of the present invention, the first barrier layer of the front light module faces away from the display surface of the reflective display panel.

[0017] In the above embodiment, the first barrier layer, the second barrier layer and the third barrier layer with the function of blocking water vapor are formed on the light guide plate by coating. Since the barrier layers do not need to be disposed on the light guide plate through optical adhesive, it helps to reduce the influence of the optical adhesive on the thickness and optical properties of the front light module, thereby preventing the light guide plate from being deformed by water vapor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be understood from the following detailed description and the accompanying drawings. It should be noted that various features are not drawn to the standard scale in industry practice. In fact, the size of various features may be arbitrarily increased or decreased for clarity of discussion.

[0019] Figure 1 A partial cross-sectional view of a front light module according to an embodiment of the present invention is shown;

[0020] Figure 2 A partial cross-sectional view of a front light module according to another embodiment of the present invention is shown;

[0021] Figure 3 A partial three-dimensional diagram of a front light module according to another embodiment of the present invention is shown;

[0022] Figure 4 A schematic diagram of a reflective display device according to an embodiment of the present invention is shown.

[0023]

Explanation of symbols

[0024] 100,200,300: front light module

[0025] 110: Light emitting element

[0026] 120: Light guide plate

[0027] 120a, 120b: light incident surface

[0028] 120c, 120d: side surface

[0029] 120f: First light emitting surface

[0030] 120s: Second light-emitting surface

[0031] 140: First barrier layer

[0032] 240: Second barrier layer

[0033] 340: The third barrier layer

[0034] 40: Reflective display device

[0035] 402: Optical adhesive

[0036] 430: Reflective display panel

[0037] 430s: Display surface

[0038] 450: Pixel array substrate

[0039] L1: Light DETAILED DESCRIPTION

[0040] The present invention will be described in detail with the following examples. It should be noted that the following description of the embodiments of the present invention is only for illustration and is not intended to exhaustively disclose all implementations or to limit the specific implementations of the present invention. For example, the description of "a first feature formed on a second feature" includes multiple implementations, including the first feature being in direct contact with the second feature, and also including additional features being formed between the first feature and the second feature so that the two are not in direct contact. In addition, the same element symbols used in the drawings and the specification will represent the same or similar elements as much as possible.

[0041] Spatially relative terms, such as "lower," "below," "beneath," "above," and related terms, are used herein to simply describe the relationship of an element or feature as shown in the figure to another element or feature. These spatially relative terms cover different orientations when using or operating the device in addition to the orientation depicted in the figure. In addition, when the element is rotatable (rotated 90 degrees or other angles), the spatially relative descriptors used herein can also be interpreted accordingly.

[0042] In the following text, in order to clearly present the technical features of the present invention, the dimensions (such as length, width, thickness and depth) of the elements (such as layers, films, substrates and regions, etc.) in the drawings will be enlarged in unequal proportions. Therefore, the description and explanation of the embodiments below are not limited to the dimensions and shapes presented by the elements in the drawings, but should cover the dimensions, shapes and deviations thereof caused by actual processes and / or tolerances. For example, the flat surface shown in the drawings may have rough and / or nonlinear features, while the acute angles shown in the drawings may be rounded. Therefore, the elements presented in the drawings of the present invention are mainly for illustration, and are not intended to accurately depict the actual shape of the elements, nor are they intended to limit the scope of the patent application of the present invention.

[0043] Furthermore, the words "about", "approximately" or "substantially" appearing in the present case not only cover the numerical values ​​and numerical ranges clearly recorded, but also cover the permissible deviation range that can be understood by a person with ordinary knowledge in the technical field to which the invention belongs, wherein the deviation range can be determined by the error generated during measurement, and the error is caused by, for example, the limitation of the measurement system or process conditions. In addition, "about" can mean within one or more standard deviations of the above numerical values, such as ±30%, ±20%, ±10% or ±5%. The words "about", "approximately" or "substantially" appearing in the present text can select the acceptable deviation range or standard deviation according to the optical properties, etching properties, mechanical properties or other properties, and not just one standard deviation can be applied to all the above optical properties, etching properties, mechanical properties and other properties.

[0044] Figure 1 The front light module 100 of one embodiment of the present invention comprises a light emitting element 110, a light guide plate 120 and a first barrier layer 140. The light guide plate 120 has a light incident surface 120a and a first light emitting surface 120f adjacent to the light incident surface 120a. The light emitting element 110 is located on one side of the light guide plate 120 and emits a light beam L1 toward the light incident surface 120a of the light guide plate 120.

[0045] like Figure 1As shown, the light L1 enters the light guide plate 120 from the light incident surface 120a and is transmitted in the light guide plate 120. Part of the light L1 leaves the light guide plate 120 from the first light exiting surface 120f, and part of the light L1 leaves the light guide plate 120 from the second light exiting surface 120s, wherein the first light exiting surface 120f and the second light exiting surface 120s are respectively located on opposite sides of the light guide plate 120.

[0046] The light emitting element 110 may be an electroluminescent element such as a light emitting diode. For example, in the present embodiment, the light emitting element 110 is a light bar formed by arranging a plurality of light emitting diodes. On the other hand, the material of the light guide plate 120 may include polymethylmethacrylate (PMMA), polycarbonate (PC), methylmethacrylate-styrene (MS) resin or other similar polymer materials.

[0047] Although the front light module 100 in the present embodiment includes only one light emitting element 110, and the light emitting element 110 is located on one side of the light guide plate 120, the present invention is not limited thereto. In other embodiments of the present invention, the front light module 100 may also include more than one light emitting element 110. For example, the front light module 100 may include two light emitting elements 110, and the two light emitting elements 110 are respectively located on opposite sides of the light guide plate 120. One of the light emitting elements 110 emits light L1 toward the light incident surface 120a of the light guide plate 120, and the other light emitting element 110 emits light (not shown) toward the other light incident surface 120b of the light guide plate 120.

[0048] Please refer to Figure 1 , the first barrier layer 140 is located on the first light emitting surface 120f of the light guide plate 120, and completely covers the first light emitting surface 120f. The first barrier layer 140 includes a silicon chain material, and the main chain segment of the silicon chain material may also include a silicon nitrogen link or a silicon oxygen link. Further, in this embodiment, the first barrier layer 140 can be directly formed on the first light emitting surface 120f of the light guide plate 120 by, for example, wet coating and surface modification. However, the method of forming the first barrier layer 140 in the present invention is not limited thereto, and the first barrier layer 140 can also be formed by other coating methods.

[0049] The material included in the first barrier layer 140 can form a high-density property like a ceramic material, and the water vapor transmission rate of the first barrier layer 140 is less than 0.1 g / m 2 / day. Therefore, it is possible to suppress the contact of moisture in the environment with the light guide plate 120, thereby preventing the light guide plate 120 from being deformed by moisture. On the other hand, the first barrier layer 140 also has the characteristic of high light transmittance. For example, in this embodiment, the light transmittance of the first barrier layer 140 can be greater than 85%. In this way, the light loss caused by the first barrier layer 140 can be reduced, thereby improving the luminous efficiency of the front light module 100.

[0050] It is particularly noted that in some embodiments of the present invention, the thickness of the first barrier layer 140 is in the range of 200 nm to 1000 nm, but the present invention is not limited thereto. In addition, the refractive index of the first barrier layer 140 is less than the refractive index of the light guide plate 120. For example, in this embodiment, the refractive index of the first barrier layer 140 may be in the range of 1.40 to 1.55, while the refractive index of the light guide plate 120 may be in the range of 1.49 to 1.59.

[0051] In this way, the probability of total reflection of the light L1 when passing through the interface between the first barrier layer 140 and the light guide plate 120 (i.e., the first light emitting surface 120f) can be increased to achieve a better light transmission effect. However, the refractive index of the first barrier layer 140 and the refractive index of the light guide plate 120 are not limited to the above embodiment.

[0052] Please refer to Figure 2 The front light module 200 of another embodiment of the present invention is similar to the front light module 100. The difference between the front light module 200 and the front light module 100 is that the front light module 200 further includes a second barrier layer 240. The second barrier layer 240 is located on the second light emitting surface 120s of the light guide plate 120, and the second light emitting surface 120s and the first light emitting surface 120f are respectively located on two opposite sides of the light guide plate 120. In other words, the first barrier layer 140 and the second barrier layer 240 are respectively located on two opposite sides of the light guide plate 120.

[0053] It is worth mentioning that the material of the second barrier layer 240 can be similar to that of the first barrier layer 140, or even the same as that of the first barrier layer 140. For example, the second barrier layer 240 can include a silicon chain material, and the silicon chain material can include a silicon-nitrogen chain, a silicon-oxygen chain, or a combination of the two. In addition, since the material of the second barrier layer 240 is similar to or the same as that of the first barrier layer 140, the water vapor transmission rate of the second barrier layer 240 can also be less than 0.1 g / m 2 / day.

[0054] It is particularly noted that in some embodiments of the present invention, the thickness of the second barrier layer 240 is in the range of 200 nm to 1000 nm, but the present invention is not limited thereto. In addition, in the present embodiment, the refractive index of the second barrier layer 240 is less than the refractive index of the light guide plate 120, but is higher than the refractive index of the first barrier layer 140. Specifically, when the refractive index of the light guide plate 120 is in the range of 1.49 to 1.59 (e.g., 1.59), the refractive index of the first barrier layer 140 and the second barrier layer 240 may be in the range of 1.40 to 1.55, wherein the refractive index of the first barrier layer 140 may be 1.45, and the refractive index of the second barrier layer 240 may be 1.55.

[0055] In this way, the probability of total reflection of the light L1 when passing through the interface between the first barrier layer 140 and the light guide plate 120 (i.e., the first light emitting surface 120f) and the interface between the second barrier layer 240 and the light guide plate 120 (i.e., the second light emitting surface 120s) can be increased, so as to achieve a better light transmission effect. However, the refractive index of the first barrier layer 140, the refractive index of the second barrier layer 240, and the refractive index of the light guide plate 120 in the present invention are not limited to the above embodiment. For example, the refractive index of the first barrier layer 140 can also be the same as the refractive index of the second barrier layer 240.

[0056] Please refer to Figure 3 The front light module 300 of another embodiment of the present invention is similar to the front light module 100. The difference between the two is that the front light module 300 further includes two third barrier layers 340, and the two third barrier layers 340 are respectively located on two opposite side surfaces of the light guide plate 120. Specifically, one of the third barrier layers 340 is located on one side surface 120c of the light guide plate 120, and the other third barrier layer 340 is located on the other side surface 120d of the light guide plate 120. It is particularly mentioned that in this embodiment, the front light module 300 includes two light emitting elements 110, and the two light emitting elements 110 are respectively located on the light incident surface 120a and the light incident surface 120b of the light guide plate 120.

[0057] like Figure 3 As shown, the side surface 120c and the side surface 120d are respectively adjacent to the light receiving surface 120a (and the light incident surface 120b), and are respectively adjacent to the first light emitting surface 120f (and the second light emitting surface 120s). In other words, the first barrier layer 140, the second barrier layer 240, and the two third barrier layers 340 are respectively located on the four surfaces of the light guide plate 120 that are opposite to each other, and cover these four surfaces, while the above-mentioned barrier layers do not cover the light guide plate light incident surface 120a and the light incident surface 120b. Further, the six surfaces of the light guide plate 120 correspond to the four barrier layers and the two light emitting elements.

[0058] The material of the third barrier layer 340 may be similar to that of the first barrier layer 140, or even the same as that of the first barrier layer 140. For example, the third barrier layer 340 may include a silicon chain material, and the silicon chain material may include a silicon-nitrogen chain, a silicon-oxygen chain, or a combination of the two. In addition, since the material of the third barrier layer 340 is similar to or the same as that of the first barrier layer 140, the water vapor permeability of the second barrier layer 240 may also be less than 0.1 g / m 2 / day.

[0059] In some embodiments of the present invention, the thickness of the third barrier layer 340 is in the range of 200 nm to 1000 nm, but the present invention is not limited thereto. In addition, in the present embodiment, the refractive index of the third barrier layer 340 is less than the refractive index of the light guide plate 120. Specifically, when the refractive index of the light guide plate 120 is in the range of 1.49 to 1.59 (e.g., 1.59), the refractive index of the third barrier layer 340 may be in the range of 1.40 to 1.55. In this way, the probability of total reflection of the light L1 when passing through the interface between the third barrier layer 340 and the light guide plate 120 (i.e., the side surface 120c and the side surface 120d) can be increased, so as to achieve a better light transmission effect.

[0060] Although not shown in the figure, the front light module (such as the front light module 100) of some embodiments of the present invention may further include a cover lens. The cover lens is located on the first light emitting surface 120f of the light guide plate 120 to protect the first light emitting surface 120f of the light guide plate 120, thereby improving the scratch resistance of the front light module.

[0061] Figure 4 is a schematic diagram of a reflective display device 40 of at least one embodiment of the present invention. The reflective display device 40 includes a front light module 100 and a reflective display panel 430, wherein the reflective display panel 430 is arranged relative to the front light module 100. The reflective display panel 430 may include, for example, an electrophoretic display panel, a cholesterol liquid crystal display panel, or a similar display panel. In addition, the front light module in the reflective display device 40 is not limited to the front light module 100. In other words, the front light module in the reflective display device 40 may also be the front light module 200 or the front light module 300.

[0062] The reflective display device 40 further includes a pixel array substrate 450, and the pixel array substrate 450 may be, for example, a thin film transistor (TFT) substrate or a similar electronic component driving substrate. Figure 4 As shown, the reflective display panel 430 is disposed on the pixel array substrate 450 and is located between the pixel array substrate 450 and the front light module 100 .

[0063] In this embodiment, the first barrier layer 140 of the front light module 100 faces away from the display surface 430s of the reflective display panel 430. In addition, the front light module 100 is attached to the display surface 430s of the reflective display panel 430 by optical clear adhesive (OCA) 402.

[0064] In summary, the present disclosure provides a barrier layer (such as the first barrier layer 140, the second barrier layer 240 and the third barrier layer 340) with low water vapor permeability on the light guide plate to reduce the contact of water vapor in the environment with the light guide plate, thereby preventing the light guide plate from absorbing water vapor and deforming. In addition, since the above-mentioned barrier layer can be formed on the surface of the light guide plate by coating, it is possible to omit the use of optical adhesive to adhere the barrier layer to the light guide plate. In this way, the thickness of the front light module will not be greatly increased due to the provision of the waterproof barrier layer. On the other hand, the above-mentioned barrier layer also has a relatively high light transmittance (for example, a light transmittance of more than 85%), which also helps to reduce the impact of the waterproof barrier layer on the luminous efficiency of the front light module.

[0065] Although the embodiments of the present invention have been disclosed as above, they are not intended to limit the embodiments of the present invention. Any person with ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, the protection scope of the embodiments of the present invention shall be determined by the definition of the attached claims.

Claims

1. A front light module, characterized in that: Include: A light guide plate having a light incident surface and a first light emitting surface adjacent to the light incident surface; a light emitting element, emitting a light toward the light incident surface; and A first barrier layer is located on the first light emitting surface of the light guide plate, wherein the first barrier layer comprises a silicon chain material, and the water vapor permeability of the first barrier layer is less than 0.1g / m 2 / day.

2. The front light module according to claim 1, characterized in that: The main chain segment of the silicon chain material is selected from the group consisting of silicon-nitrogen linkage and silicon-oxygen linkage.

3. The front light module according to claim 1, characterized in that: The thickness of the first barrier layer ranges from 200 nm to 1000 nm.

4. The front light module according to claim 1, characterized in that: The refractive index of the first barrier layer is smaller than the refractive index of the light guide plate.

5. The front light module according to claim 4, characterized in that: The refractive index of the first barrier layer ranges from 1.40 to 1.

55.

6. The front light module according to claim 1, characterized in that: Also includes: A second barrier layer is located on a second light emitting surface of the light guide plate, wherein the second light emitting surface and the first light emitting surface are respectively located on two opposite sides of the light guide plate, and the second barrier layer comprises the silicon chain material, and the water vapor permeability of the second barrier layer is less than 0.1 g / m 2 / day.

7. The front light module according to claim 6, characterized in that: The refractive index of the second barrier layer is smaller than the refractive index of the light guide plate.

8. The front light module according to claim 7, characterized in that: The refractive index of the second barrier layer is higher than that of the first barrier layer.

9. The front light module according to claim 1, characterized in that: Also includes: Two third barrier layers are respectively located on two opposite side surfaces of the light guide plate, wherein the side surfaces are respectively adjacent to the light incident surface and the first light emitting surface, wherein the third barrier layers contain the silicon chain material, and the water vapor permeability of the third barrier layers is less than 0.1 g / m 2 / day.

10. The front light module according to claim 1, characterized in that: Also includes: A protective layer is located on the first light emitting surface of the light guide plate.

11. The front light module according to claim 1, characterized in that: The first barrier layer is formed on the light guide plate by wet coating.

12. A reflective display device, characterized in that: Include: A front light module as claimed in any one of claims 1 to 11; and A reflective display panel is arranged relative to the front light module.

13. The reflective display device according to claim 12, wherein: The first barrier layer of the front light module faces away from a display surface of the reflective display panel.

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