Double-layer light guide plate and manufacturing method thereof

Abstract

The present disclosure provides a double-layer light guide plate and a manufacturing method thereof. The manufacturing method includes: preparing a screen printing plate having a frame glue pattern; covering the screen printing plate on a first light guide plate; filling an adhesive on the first light guide plate corresponding to the area of the frame glue pattern to form a frame glue layer; and bonding the first light guide plate and a second light guide plate through the frame glue layer, wherein the thickness of the frame glue layer is greater than a first threshold value.

Description

Technical Field

[0001] This disclosure relates to the field of displays, and more particularly to a double-layer light guide plate for displays and a method for manufacturing the same. Background Technology

[0002] In recent years, due to the advantages of thinness and lightness, flat panel displays such as LCDs, plasma displays, and LED displays have gradually replaced traditional cathode ray tube displays and become the mainstream in the display market, widely used in products such as televisions, laptops, and mobile phones.

[0003] Glasses-free 3D displays utilize the parallax effect of the human eye to provide a realistic stereoscopic image with spatial depth without the need for any auxiliary equipment (such as 3D glasses, helmets, etc.). A double-layered light guide plate can be used to realize glasses-free 3D displays. A double-layered light guide plate typically consists of two opposing light guide plates bonded together using an adhesive (such as edge-sealing glue).

[0004] However, since the sealing adhesive for double-layer light guide plates is usually made of free-flowing or semi-free-flowing liquid adhesive, it is difficult to produce a relatively large thickness. Traditional techniques can only achieve a maximum sealing adhesive thickness of 13µm. With a smaller sealing adhesive thickness, the gap between the upper and lower light guide plates is relatively small. If different parts of the light guide plates experience uneven stress during bonding, resulting in an uneven gap between the upper and lower light guide plates, a severe rainbow effect often occurs, significantly reducing product quality. Summary of the Invention

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art by increasing the thickness of the photoresist layer of the screen printing plate used to prepare the frame adhesive, thereby increasing the thickness of the sealing frame adhesive, to provide a double-layer light guide plate with a large air gap and its manufacturing method.

[0006] The first aspect of this disclosure provides a method for manufacturing a double-layer light guide plate, comprising: preparing a screen printing plate having a frame adhesive pattern; covering the screen printing plate onto a first light guide plate; filling an area on the first light guide plate corresponding to the frame adhesive pattern with an adhesive to form a frame adhesive layer; and bonding the first light guide plate and a second light guide plate through the frame adhesive layer, wherein the thickness of the frame adhesive layer is greater than a first threshold.

[0007] In some embodiments, preparing a screen printing plate with a frame adhesive pattern includes: forming a first photoresist layer on a screen; setting a fixture on the first photoresist layer; forming a second photoresist layer on the first photoresist layer; and exposing and developing the first and second photoresist layers to form the frame adhesive pattern on the screen, wherein the frame adhesive pattern has the same shape as the fixture, the thickness of the fixture is greater than the first threshold, and the thickness of the second photoresist layer is equal to the thickness of the fixture.

[0008] In some embodiments, the fixture has a rectangular frame structure and is made of a light-shielding material.

[0009] In some embodiments, the first threshold is in the range of 50µm to 80µm.

[0010] In some embodiments, forming a first photoresist layer on the screen includes: applying a photoresist material to the screen; and drying the photoresist material to form the first photoresist layer.

[0011] In some embodiments, forming a second photoresist layer on the first photoresist layer includes: applying a photoresist material to an area of ​​the first photoresist layer not occupied by the fixture; and drying the photoresist material to form the second photoresist layer.

[0012] In some embodiments, the photoresist material is a negative photoresist.

[0013] In some embodiments, the adhesive is filled with particles.

[0014] Another aspect of this disclosure provides a double-layer light guide plate, comprising: a first light guide plate; and

[0015] A second light guide plate is disposed opposite to the first light guide plate; wherein, a frame adhesive layer is disposed on the first light guide plate, and the first light guide plate and the second light guide plate are bonded together by the frame adhesive layer, and wherein, the thickness of the frame adhesive layer is greater than a first threshold.

[0016] In some embodiments, the frame adhesive layer has a rectangular frame shape.

[0017] In some embodiments, the first threshold is in the range of 50µm to 80µm.

[0018] In some embodiments, the frame adhesive layer is filled with particles. Attached Figure Description

[0019] Figure 1A A flowchart illustrating the manufacturing method of the double-layer light guide plate according to this disclosure is shown.

[0020] Figure 1BA process flow diagram of the manufacturing method of the double-layer light guide plate according to the present disclosure is shown.

[0021] Figure 2A A flowchart illustrating the operation of a method for manufacturing a screen printing plate according to this disclosure is shown.

[0022] Figure 2B A process flow diagram of the method for manufacturing a screen printing plate according to this disclosure is shown.

[0023] Figure 2C Another process flow diagram of the method for manufacturing a screen printing plate according to this disclosure is shown.

[0024] Figure 3 A schematic diagram of an example double-layer light guide plate according to this disclosure is shown. Detailed Implementation

[0025] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0026] It should be understood that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, method embodiments may include other steps and / or omit certain steps.

[0027] The adhesive used to seal the edges of a monitor is typically produced using screen printing. The quality of this adhesive directly affects the uniformity of the monitor's thickness. In the manufacturing process of a double-layer light guide plate, the thickness of the adhesive directly impacts the plate's display characteristics. Furthermore, the characteristics of the screen printing plate used to prepare the adhesive directly determine its thickness.

[0028] A screen printing plate is a printing plate with a pattern made of a screen template. In the screen printing process, the screen printing plate is typically attached to the substrate, and then a printing medium (e.g., ink, or the adhesive described in this application) is applied to the screen printing plate. Because the mesh openings of the patterned areas of the screen printing plate allow the printing medium to pass through, while the non-patterned areas do not, the printing medium can penetrate the mesh openings of the patterned areas and adhere to the substrate, leaving an imprint identical to the pattern on the substrate.

[0029] The thickness of the pattern printed on the substrate (e.g., the thickness of the sealing adhesive) is often determined by the thickness of the screen printing plate (e.g., the thickness of the portion of the image outside the printing medium that cannot pass through). As mentioned earlier, if the substrate is a light guide plate and the printed pattern on the substrate is a sealing adhesive, then if the thickness of the printed sealing adhesive is small, the gap between the upper and lower light guide plates will be relatively small. If different parts of the light guide plate are subjected to uneven stress during the bonding process, it can easily lead to uneven gaps between the upper and lower light guide plates, often resulting in a severe rainbow effect. Preparing a screen printing plate with a larger thickness, thereby increasing the thickness of the sealing adhesive, can effectively solve the above problem.

[0030] The embodiments of this disclosure provide a method for manufacturing a double-layer light guide plate. Figure 1A A flowchart illustrating the operation of a method 1000 for manufacturing a double-layer light guide plate according to the present disclosure is provided. To provide a clearer understanding of the method for manufacturing a double-layer light guide plate described in this disclosure, Figure 1B A process flow diagram of the manufacturing method of the double-layer light guide plate according to the present disclosure is shown.

[0031] like Figure 1A As shown, the manufacturing method 1000 of the double-layer light guide plate includes: preparing a screen printing plate having a frame adhesive pattern (S1100); covering the screen printing plate onto the first light guide plate (S1200); filling the area on the screen printing plate corresponding to the frame adhesive pattern with adhesive to form a frame adhesive layer (S1300); and bonding the first light guide plate and the second light guide plate through the frame adhesive layer (S1400).

[0032] The preparation of a screen printing plate typically involves processes such as coating with photosensitive emulsion, exposure, and development. For example, a patterned light-blocking template can be attached to a screen coated with photosensitive emulsion. The photosensitive emulsion covering the pattern can be removed by exposure and development, while the photosensitive emulsion outside the pattern is retained, thus forming a screen printing plate with a specific pattern.

[0033] Figure 2A A flowchart illustrating the operation of the screen printing plate manufacturing method 2000 according to this disclosure is shown. Figure 2B A process flow diagram of the method for manufacturing a screen printing plate according to this disclosure is shown. Figure 2A The steps in the method 2000 shown can be regarded as Figure 1A The detailed steps of step S1100.

[0034] like Figure 2AAs shown, the screen printing plate manufacturing method 2000 according to this disclosure includes the following steps: forming a first photoresist layer on a screen (S2100); setting a fixture on the first photoresist layer (S2200); forming a second photoresist layer on the first photoresist layer (S2300); and exposing and developing the first and second photoresist layers to form a frame pattern on the screen (S2400).

[0035] To better understand this disclosure, the following will be combined with Figure 2B The process flow diagram for manufacturing the screen printing plate is shown below to describe the above steps in detail. It should be understood that, for ease of description, Figure 2B Top views and corresponding cross-sectional views of the screen printing plate manufacturing process are shown in each process step. The various dimensions and relative dimensions shown are merely illustrative and are only intended to describe the design and concept of this disclosure, and are not intended to limit this disclosure.

[0036] like Figure 2B As shown in (a), a screen 201 is first provided. The screen 201 is a woven material used as a support for a screen printing plate, also known as silk screen, gauze screen, sieve, etc. The screen 201 described in this disclosure includes, but is not limited to, natural silk screen, synthetic silk screen, metal silk screen, special silk screen, etc. The screen 201 has mesh openings that allow the printing medium to pass through.

[0037] Next, as Figure 2B As shown in (b), a first photoresist layer 202 is formed on the screen 201. This step corresponds to Figure 2A The step S2100 is shown. In some embodiments, forming a first photoresist layer 202 on the screen 201 may include: firstly applying a photoresist material to the screen 201; and then drying the photoresist material to form the first photoresist layer 202. In this document, the photoresist material may be, for example, a photosensitive adhesive with added photosensitizer.

[0038] Furthermore, it should be understood that, despite Figure 2B In (b) of the diagram, the first photoresist layer 202 is shown as being attached to the upper surface of the screen 201, but this is merely for the purpose of describing the present disclosure. For example, in actual operation, since the screen 201 is a mesh structure with openings, the photoresist material may partially or completely penetrate the screen 201 during the application of the photoresist material, resulting in the first photoresist layer 202 and the screen 201 possibly overlapping partially or completely.

[0039] Next, as Figure 2B As shown in (c), a fixture 203 is disposed on the first photoresist layer 202. This step corresponds to Figure 2AThe step S2200 is shown. In some embodiments, the fixture 203 has a rectangular frame structure as shown and the fixture 203 is made of a light-shielding material. However, it should be understood that... Figure 2B The rectangular frame structure shown in (c) is merely an example of fixture 203 in the embodiments of this disclosure. Those skilled in the art can design fixtures of other shapes according to actual needs, including but not limited to square, circle, ellipse, rhombus, irregular polygon, etc.

[0040] Furthermore, it should be understood that, due to its light-blocking properties, the fixture 203 disclosed herein will prevent the area covered by the fixture 203 from being illuminated during exposure. Therefore, if a screen printing plate with the pattern of this fixture is to be formed, a negative photoresist material should be selected to form the aforementioned first photoresist layer 202. When a negative photoresist material is selected, the photoresist in the rectangular frame area covered by the fixture 203 will be dissolved by the developer, thereby forming the rectangular frame pattern shown in the figure on the screen 201.

[0041] However, the present invention is not limited thereto. Those skilled in the art can select other types of photoresist materials and corresponding fixture shapes as needed to form similar printed patterns. For example, a positive photoresist material can be selected to form the first photoresist layer 202 described above. In this case, the shape of the fixture 203 needs to be adjusted to match the shape of the first photoresist layer 202. Figure 2B The shapes shown in (c) are complementary, thus forming the same rectangular frame pattern on the screen 201.

[0042] Additionally, as shown in the figure, fixture 203 has a thickness H. As previously mentioned, the gap between the upper and lower plates of the double-layer light guide plate depends on the thickness of the frame adhesive, which in turn depends on the thickness of the photoresist layer on the screen printing plate. Therefore, the thickness H of fixture 203 needs to be designed for specific applications to enable the fabrication of the photoresist layer thickness required for the specific application. In this embodiment, the thickness H of fixture 203 should be greater than a first threshold, and the first threshold is in the range of 50 μm to 80 μm. A thickness of fixture 203 within this range allows for the fabrication of a double-layer light guide plate with a larger gap, thereby effectively suppressing the rainbow effect.

[0043] Next, as Figure 2B As shown in (d), a second photoresist layer 204 is formed on the first photoresist layer 202. This step corresponds to Figure 2A The step S2300 is shown. In some embodiments, forming a second photoresist layer 204 on the first photoresist layer 202 may include: applying a photoresist material to an area of ​​the first photoresist layer 202 not occupied by the fixture 203; and drying the photoresist material to form the second photoresist layer 204.

[0044] As shown in the figure, the second photoresist layer 204 surrounds the fixture 203, and its thickness is equal to the thickness H of the fixture 203. In some embodiments, the material of the second photoresist layer 204 is the same as the material of the first photoresist layer 203, for example, both are negative photoresist materials as described above.

[0045] Finally, as Figure 2B As shown in (e), the first photoresist layer 202 and the second photoresist layer 204 are exposed and developed to form a frame adhesive pattern 205-1 on the screen 201. This step corresponds to Figure 2A Step S2400 is shown. (As shown) Figure 2B As shown in (e), the exposure and development process dissolves the area of ​​the first photoresist layer 203 beneath the fixture 203. After the fixture 203 is removed, a rectangular groove is formed in the screen printing plate 205, which corresponds to the frame pattern 205-1. For ease of description, in this document, we will refer to the overall structure formed in process (e) as screen printing plate 205, that is, the printing plate on which the frame pattern 205-1 has been printed.

[0046] Figure 2C Another process flow diagram of the method for manufacturing a screen printing plate according to this disclosure is shown. Figure 2C The process steps shown are Figure 2B The refinement steps corresponding to the exposure and development process.

[0047] like Figure 2C As shown in (a), after forming a first photoresist layer 202 on a screen 201, setting a fixture 203, and forming a second photoresist layer 204, the upper surface is irradiated from top to bottom with a light source (e.g., an ultraviolet UV lamp), and a development process is performed to dissolve the area of ​​the first photoresist layer 202 covered below the fixture 203, thereby forming a layer as shown in (a). Figure 2C The gap 202-1 is shown in (b) above. Then, the fixture 203 is removed to obtain the screen printing plate 205 as described above. Figure 2C (c)). The screen printing plate 205 has a rectangular frame-shaped groove, namely the frame adhesive pattern 205-1.

[0048] At this point, we have referred to Figure 2A-2C The entire process for preparing the screen printing plate 205 with the frame adhesive pattern 205-1 shown in the figure is described.

[0049] Next, we will return to Figure 1A-1B The method of using the screen printing plate 205 prepared as described above to manufacture the double-layer light guide plate of this disclosure will be further described.

[0050] like Figure 1BAs shown in (a), a first light guide plate 101 is first provided, and then a screen printing plate 102 is placed on the first light guide plate 102. Figure 1B (b) in the text, this process flow corresponds to Figure 1A The step S1200 is shown. The structure of the screen printing plate 102 is similar to that described above. Figure 2B-2C The structure of the screen printing plate 205 described herein will not be repeated here.

[0051] Next, as Figure 1B As shown in (c), adhesive is filled into the area on the screen printing plate 102 corresponding to the frame adhesive pattern 102-1 to form a frame adhesive layer 104. It should be understood that the adhesive in this disclosure is generally a fully fluid or semi-fluid resin adhesive, capable of penetrating the screen below the frame adhesive pattern 102-1 in the screen printing plate and adhering to the first light guide plate 101, thereby forming a... Figure 1B The frame adhesive layer 104 is shown in (c) in the figure.

[0052] Then, the screen printing plate 102 is peeled off from the first light guide plate 101, and the second light guide plate 103 is bonded to the first light guide plate 101 through the frame adhesive layer 104. Figure 1B (d) in the middle.

[0053] This concludes the description of a method for manufacturing a double-layer light guide plate using a screen printing plate. It should be understood that, due to the use of a fixture of a certain height during the screen printing plate preparation process, the thickness of the photoresist layer on the prepared screen printing plate is greater than the aforementioned first threshold. Simultaneously, due to the aforementioned... Figure 1B In (c), the groove-shaped frame adhesive pattern 102-1 is filled with adhesive, so that the height of the final frame adhesive layer 104 is also greater than the first threshold, thereby ensuring that the gap between the first light guide plate and the second light guide plate is greater than the first threshold.

[0054] Furthermore, to further increase the gap between the double-layer light guide plates, an adhesive with added particles can be used to form the frame adhesive layer. For example, polymer particles with a diameter of approximately 5-10 μm can be added to the adhesive to reduce its flowability, allowing it to better form the frame adhesive layer of the desired height.

[0055] However, the adhesives involved in this disclosure are not limited to the examples above, and other adhesives that do not contain polymer particles but are easy to mold can also be used to achieve the desired frame adhesive layer as needed.

[0056] Furthermore, it should be understood that although the above method for manufacturing double-layer light guide plates describes the screen printing plate manufacturing process, this does not mean that a separate screen printing plate needs to be prepared first to manufacture each double-layer light guide plate. In practical applications, screen printing plates, as a type of printing mold, can be reused. For example, only one screen printing plate can be prepared for the same product, thus allowing for repeated use in the manufacturing process of each double-layer light guide plate.

[0057] Another embodiment of this disclosure provides a double-layer light guide plate.

[0058] Figure 3 A schematic diagram of an example double-layer light guide plate 3000 according to this disclosure is shown.

[0059] like Figure 3 As shown, the double-layer light guide plate 3000 includes a first light guide plate 301 and a second light guide plate 302 disposed opposite to the first light guide plate 301. A frame adhesive layer 303 is disposed on the first light guide plate 301, and the first light guide plate 301 and the second light guide plate 302 are bonded together by the frame adhesive layer 303.

[0060] In some embodiments, the thickness of the frame adhesive layer 303 is greater than a first threshold, and the first threshold is in the range of 50 μm to 80 μm.

[0061] like Figure 3 As shown, the frame adhesive layer 303 has a rectangular frame shape, and to facilitate the molding of the frame adhesive layer 303, particles are filled in the frame adhesive layer 303. These filling particles can be similar to those described above. Figure 1B The polymer particles discussed have a diameter of approximately 5µm-10µm, which can reduce the flowability of the adhesive, allowing it to better form a frame adhesive layer of the desired height.

[0062] It should be noted that the above text regarding Figure 1A-2B The details and additional technical features of the manufacturing method for the described double-layer light guide plate also apply to... Figure 3 The double-layer light guide plate of the embodiment is as described herein or is obviously not applicable in the context.

[0063] In the foregoing description, embodiments of the present disclosure have been described in conjunction with the accompanying drawings. It should be understood that the above embodiments are merely illustrative, and those skilled in the art should understand that the combination of constituent elements and processes of the present embodiments can be modified in various ways, and such modifications also fall within the scope of the present disclosure.

Claims

1. A method for manufacturing a double-layer light guide plate, comprising: preparing a screen printing plate having a frame glue pattern; covering the screen printing plate on a first light guide plate; filling an adhesive on the first light guide plate in an area corresponding to the frame glue pattern to form a frame glue layer; and bonding the first light guide plate and a second light guide plate through the frame glue layer, wherein an air gap between the first light guide plate and the second light guide plate depends on a thickness of the frame glue layer and is greater than a first threshold value in a range of 50 um to 80 um, wherein the preparing a screen printing plate having a frame glue pattern comprises: forming a first photoresist layer on a screen; providing a jig on the first photoresist layer; forming a second photoresist layer on the first photoresist layer; and exposing and developing the first photoresist layer and the second photoresist layer to form the frame glue pattern on the screen, wherein the frame glue pattern has a same shape as the jig, a thickness of the jig is greater than the first threshold value, and a thickness of the second photoresist layer is equal to the thickness of the jig. The jig has a rectangular frame structure, and the jig is made of a light shielding material.

2. The method of claim 1, wherein, 3.The method of claim 1, wherein the forming a first photoresist layer on a screen comprises: applying a photoresist material to the screen; and drying the photoresist material to form the first photoresist layer. 4.The method of claim 1, wherein the forming a second photoresist layer on the first photoresist layer comprises: applying a photoresist material to an area of the first photoresist layer not occupied by the jig; and drying the photoresist material to form the second photoresist layer. 5.The method of claim 3 or 4, wherein the photoresist material is a negative photoresist. 6.The method of claim 1, wherein the adhesive is filled with particles. 7.A double-layer light guide plate, comprising: a first light guide plate; and a second light guide plate disposed opposite to the first light guide plate, wherein the first light guide plate is provided with a frame glue layer, and the first light guide plate and the second light guide plate are bonded through the frame glue layer, and wherein an air gap between the first light guide plate and the second light guide plate depends on a thickness of the frame glue layer and is greater than a first threshold value in a range of 50 um to 80 um, wherein the double-layer light guide plate is manufactured using the method of claim 1. The frame glue layer has a rectangular frame shape. The frame glue layer is filled with particles. ​ ​ 8. The dual layer light guide plate according to claim 7, wherein, ​ 9. The dual layer light guide plate of claim 7, wherein, ​

Images