Side-lit light guide plate and optical module

Abstract

This application discloses a side-lit light guide plate and an optical module. The side-lit light guide plate includes two opposing light-emitting surfaces, one light-incident surface, two adjacent inclined surfaces, and multiple side surfaces. The two opposing light-emitting surfaces are adjacent to the opposing light-incident surface and the two inclined surfaces, as well as the multiple side surfaces, to form a closed cubic structure. The two adjacent inclined surfaces of the opposing light-incident surface have short sides of the same width and form an included angle, so that the light-incident surface forms a single isosceles triangular pyramid structure protruding outward on the side. In this application, the inclined surface of the single isosceles triangular pyramid structure can achieve total internal reflection of light, changing the light path and causing the light to be reflected back towards the incident light direction. This not only reduces the light loss in the side-lit light guide plate, but also enables the outgoing light to be completely reflected back into the light guide plate for reuse, improving the overall brightness of the side-lit light guide plate and increasing the utilization rate of electrical energy to light energy conversion.

Description

Technical Field

[0001] This application relates to a light guide plate, and more particularly to a side-lit light guide plate and an optical module. Background Technology

[0002] A light guide plate (LGP) is a high-tech product that uses optical principles to transform a line light source into a surface light source. It is widely used in LCD displays, lighting fixtures, ultra-thin advertising light boxes, medical equipment, and many other fields. Among them, edge-lit light guide plates are particularly favored due to their unique light-emitting characteristics and wide range of applications. They are often used in backlit flat panel displays, LCD TVs, and other devices to evenly distribute the backlight light across the entire screen surface, providing uniform brightness and a superior visual experience.

[0003] Traditional light guide plates typically have parallel planar structures for their light-incident and light-exit surfaces, meaning they are rectangular pyramidal structures. However, because LED light intensity has a certain directionality, approximately 67% of the maximum light intensity is concentrated within the 0-39° range. When this relatively straight light hits the light-exit side of an edge-lit light guide plate, it will not meet the total internal reflection condition (the refractive index of PC material is approximately 1.585, and the critical angle for total internal reflection is approximately 39°) and will exit the light guide plate. This will significantly reduce the brightness near the light-exit side, thus affecting the overall uniformity of the display. Consequently, this not only reduces the efficiency of the backlight system but may also interfere with the display effect, impacting the user's viewing experience. Utility Model Content

[0004] This application provides a side-lit light guide plate, which solves the problem of low light energy utilization caused by excessive light emission from the light-emitting side in traditional side-lit light guide plates.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, a side-lit light guide plate is provided, comprising two opposing light-emitting surfaces, one light-incident surface, two adjacent inclined surfaces opposite to the light-incident surface, and multiple side surfaces. The two opposing light-emitting surfaces, adjacent to the opposing light-incident surface and the two adjacent inclined surfaces, and adjacent to the multiple side surfaces, form a closed cubic structure. The two adjacent inclined surfaces opposite to the light-incident surface have short sides of the same width and form an included angle, such that the light-incident surface forms a single outwardly convex isosceles triangular pyramid structure on its sides.

[0007] In one embodiment, when one inclined plane reflects light incident through the incident surface to another inclined plane, the other inclined plane reflects the light in the direction of the incident surface.

[0008] In one embodiment, the included angle is 70° to 110°.

[0009] In one embodiment, the included angle is 80° to 100°.

[0010] In one embodiment, the included angle is 90° to 100°.

[0011] In one embodiment, the included angle is 90°.

[0012] In one embodiment, it further includes a reflective film or reflective coating disposed on the two inclined surfaces.

[0013] In one embodiment, it further includes a reflective film or reflective coating disposed on at least one of the plurality of sides.

[0014] In one embodiment, it further includes: a reflective film or reflective coating disposed on at least one of the two inclined surfaces and multiple side surfaces.

[0015] In a second aspect, an optical module is provided, comprising: a side-lit light guide plate as described in any of the first aspects and a light-emitting source. The light-emitting source is disposed on one side of the light-incident surface of the side-lit light guide plate, and the light-emitting source provides light to the side-lit light guide plate via the light-incident surface.

[0016] In this embodiment, a single isosceles triangular pyramid structure protruding outward is provided on the reflective surface of a traditional side-lit light guide plate. When light enters through the light-incident surface of the side-lit light guide plate, the two inclined surfaces of the single isosceles triangular pyramid will achieve total internal reflection of the light, changing the light path and causing the light to be reflected in the direction of incident light. This not only reduces light loss in the side-lit light guide plate, but also enables the outgoing light to be completely reflected back into the light guide plate for reuse, improving the overall brightness of the side-lit light guide plate, increasing the utilization rate of electrical energy to light energy conversion, and solving the problem of low light energy utilization due to excessive light emission from the light-emitting side in traditional side-lit light guide plates. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 and Figure 2 This is a perspective view of a side-lit light guide plate according to one embodiment of this application;

[0019] Figure 3 This is a schematic cross-sectional view of an optical module and a schematic diagram of reflected light according to one embodiment of this application;

[0020] Figure 4 This is another perspective view of a side-lit light guide plate according to one embodiment of this application;

[0021] Figure 5 This is another perspective view of a side-lit light guide plate according to one embodiment of this application;

[0022] Figure 6 This is a cross-sectional schematic diagram of an optical module applied to a display panel according to one embodiment of this application.

[0023] The following explanation is based on the accompanying diagram:

[0024] 1, 2, 3: Side-lit light guide plate; 111, 112: Light emitting surface; 113: Light incident surface; 102, 103: Inclined surface; 114, 115, 116, 117, 118, 119, 120, 121, 122: Side surface; 2: Light source; A: Light ray; B: Single isosceles triangular pyramid structure; W: Short side; α: Included angle. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In the description of this application, it should be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0027] Please see Figures 1 to 5 , Figure 1 and Figure 2 This is a perspective view of a side-lit light guide plate according to one embodiment of this application. Figure 3 This is a schematic cross-sectional view of an optical module and a schematic diagram of reflected light according to one embodiment of this application. Figure 4 This is another perspective view of a side-lit light guide plate according to one embodiment of this application. Figure 5 This is another perspective view of a side-lit light guide plate according to one embodiment of this application. Figure 1 , 2As shown, the side-lit light guide plate 1 includes two opposing light-emitting surfaces 111 and 112, one light-incident surface 113, two adjacent inclined surfaces 102 and 103 opposite to the light-incident surface 113, and two side surfaces 114 and 115. The two opposing light-emitting surfaces 111 and 112 are adjacent to the light-incident surface 113 on opposite sides and the two adjacent inclined surfaces 102 and 103. The two opposing light-emitting surfaces 111 and 112 are also adjacent to the two side surfaces 114 and 115. The two opposing light-emitting surfaces 111 and 112, the opposing light-incident surface 113, the two adjacent inclined surfaces 102 and 103, and the two side surfaces 114 and 115 form a closed cubic structure. Specifically, the two adjacent inclined planes 102 and 103 on the opposite side of the incident light surface 113 have the same width of short side W, and the two adjacent inclined planes 102 and 103 form an included angle α, so that a single isosceles triangular pyramid structure B protruding outward is formed on the opposite side of the incident light surface 113. Figure 4 As shown, the side-lit light guide plate 2 includes two opposing light-emitting surfaces 111 and 112, one light-incident surface 113, two adjacent inclined surfaces 102 and 103 opposite to the light-incident surface 113, and three side surfaces including two adjacent side surfaces 116 and 117, and a side surface 118 opposite to the two adjacent side surfaces 116 and 117. The two opposing light-emitting surfaces 111 and 112, the opposing light-incident surface 113, the two adjacent inclined surfaces 102 and 103, and the three side surfaces 116, 117, and 118 form a closed cubic structure. Specifically, the two adjacent inclined surfaces 102 and 103 opposite to the light-incident surface 113 have the same width of short side W, and the two adjacent inclined surfaces 102 and 103 form an included angle α, such that a single outwardly convex isosceles triangular pyramid structure B is formed opposite to the light-incident surface 113. Figure 5As shown, the side-lit light guide plate 3 includes two opposing light-emitting surfaces 111 and 112, one light-incident surface 113, two adjacent inclined surfaces 102 and 103 opposite to the light-incident surface 113, and four sides including two adjacent sides 119 and 120 and another two adjacent sides 121 and 122, wherein sides 119 and 121 are opposite to each other, and sides 120 and 122 are opposite to each other. The two opposing light-emitting surfaces 111 and 112, the opposing light-incident surface 113, the two adjacent inclined surfaces 102 and 103, and the four sides 119, 120, 121, and 122 form a closed cubic structure. Specifically, the two adjacent inclined surfaces 102 and 103 opposite to the light-incident surface 113 have the same width of short side W, and the two adjacent inclined surfaces 102 and 103 form an included angle α, resulting in an outwardly convex single isosceles triangular pyramid structure B on the opposite side of the light-incident surface 113. It should be understood that the above description only uses two sides 114 and 115, three sides 116, 117, and 118, and four sides 119, 120, 121, and 122 as examples to illustrate multiple sides. However, this application is not limited to this. Those skilled in the art can select different numbers of sides according to actual needs, and then combine the above-mentioned light-emitting surface, light-incident surface, and outwardly convex single isosceles triangular pyramid structure to form a side-lit light guide plate.

[0028] See also Figures 1 to 5 As shown, since the two adjacent inclined planes 102 and 103 have an included angle α, therefore... Figure 3 As shown, when the light source 2 is positioned on one side of the light incident surface 113 of the side-lit light guide plate 1, the light source 2 can provide light A to the side-lit light guide plate 1 via the light incident surface 113. When light A enters the inclined surface 102 via the light incident surface 113, the inclined surface 102 reflects light A to another inclined surface 103, which then reflects light A back towards the light incident surface 113. The light source 2 uses an LED light.

[0029] The LightTools software was used to simulate and verify a 6.0-inch traditional rectangular corner prism light guide plate, multiple triangular pyramid light guide plates, and the single isosceles triangular pyramid side-lighting light guide plate 1 of this embodiment. The effective display area of ​​122mm*95mm was divided into 122*95 equal parts, with each part having an area of ​​1mm*1mm=1mm. 2 Illuminance was extracted from each unit, with the center point data being the average illuminance of a 2mm x 3mm area at the very center of the effective display area. The simulation verification data is shown in the table below:

[0030]

[0031] As shown in the simulation verification data of Comparative Example 1 in the table above, for a conventional rectangular pyramidal side-light guide plate, the angle from which light A reaches the light-emitting side is less than 0.11°, which is similar to vertically incident on the inclined surface, resulting in weak overall brightness. In conjunction with the simulation verification data from Examples 1 to 9, taking the single isosceles triangular pyramid structure side-lighting light guide plate of this embodiment as an example, when the included angle α of the isosceles triangular pyramid is within 70° to 110°, the single isosceles triangular pyramid structure side-lighting light guide plate of this embodiment improves both the total illuminance of the effective display area and the illuminance at the center point compared to the conventional rectangular prism structure side-lighting light guide plate of Comparative Example 1; when the included angle α of the isosceles triangular pyramid is within 80° to 100°, the improvement effect on the total illuminance of the effective display area and the illuminance at the center point is significant; when the included angle α of the isosceles triangular pyramid is within 90° to 100°, the improvement effect on the total illuminance of the effective display area and the illuminance at the center point is the best, among which the average improvement effect is best when the included angle α is 90°. Meanwhile, the simulation verification data of Comparative Example 2 also shows that, for multiple triangular pyramidal side-lit light guide plates, although the average illuminance ratio of the effective display area is improved compared to the conventional rectangular corner pillar side-lit light guide plate of Comparative Example 1, the average illuminance ratio of the center point is reduced.

[0032] In detail, when the included angle α of the single isosceles triangular pyramid structure side-lit light guide plate is 90°, when light ray A enters through the light incident surface 113 of the side-lit light guide plate 1, the included angle between light ray A and the inclined surface of the isosceles triangular pyramid is about 45°, which is greater than the critical angle of total internal reflection of about 39°. Thus, the two inclined surfaces 102 and 103 of the single isosceles triangular pyramid will achieve total internal reflection of the light ray, changing the light path and causing light ray A to be reflected twice in the direction of incident light ray A. This not only reduces the leakage of light ray A in the side-lit light guide plate, but also enables the outgoing light ray A to be completely reflected back into the light guide plate for reuse, improving the overall brightness of the side-lit light guide plate, increasing the utilization rate of electrical energy to light energy conversion, and solving the problem of low light energy utilization rate when a lot of light is emitted from the light-emitting side of the traditional side-lit light guide plate. According to simulation verification data, the single isosceles triangular pyramid structure side-lighting light guide plate of this embodiment increases the total illuminance of the effective display area by about 3.91% and the illuminance at the center point (2mm*3mm) by 3.5% compared with the conventional rectangular corner prism structure side-lighting light guide plate of Comparative Example 1.

[0033] In one embodiment, the side-lit light guide plate is integrally formed using an injection molding process. The material of the side-lit light guide plate is PMMA or PC. The shape, size, and light guide point distribution of the side-lit light guide plate are designed according to the optical design structure, and a corresponding mold is designed and manufactured. Then, molten PMMA or PC material is injected into the mold and cooled to solidify, resulting in the desired shape of the side-lit light guide plate. In another embodiment, a single isosceles triangular pyramid is formed on the light-emitting surface of a traditional light guide plate (rectangular side-lit light guide plate) substrate through a polishing process. The side-lit light guide plate of this embodiment uses PMMA or PC material and employs either injection molding or polishing processes, both of which are existing mature materials and processes, requiring no additional R&D expenditure. This facilitates both improved luminous efficiency and mass production efficiency while maintaining economic viability.

[0034] In one embodiment, the side-lit light guide plate further includes a reflective film or reflective coating (not shown in the figure). The reflective film or reflective coating is disposed on two adjacent inclined surfaces 102, 103. In another embodiment, the reflective film or reflective coating is disposed on at least one of the plurality of sides (114, 115, 116, 117, 118, 119, 120, 121, 122). In other embodiments, the reflective film or reflective coating is disposed on two adjacent inclined surfaces 102, 103 and at least one of the plurality of sides (114, 115, 116, 117, 118, 119, 120, 121, 122). The reflective film or reflective coating is an optical material whose function is to reflect the light A leaking through the light guide plate back, thereby further reducing the leakage of light A in the side-lit light guide plate and improving the overall brightness of the side-lit light guide plate. The reflectivity of the reflective film or reflective coating is typically required to be above 96%. The reflective film or reflective coating uses a high reflectivity material, which can be a metallic material (silver or aluminum) or a non-metallic material (titanium dioxide TiO2 or silicon dioxide SiO2).

[0035] Please see Figure 6 See also Figure 3 As shown, Figure 6 This is a cross-sectional schematic diagram of the optical module according to the second embodiment of this application applied to a display panel. The optical module 10 of this application can be applied not only to the front light or back light module of a display panel, but is also more suitable for application to the front light module of an electronic paper display (EPD) panel; such as... Figure 6 As shown, the optical module 10 of this embodiment includes a side-light guide plate 1 and a light source 2 as described in the first embodiment. The light source 2 is disposed on one side of the light incident surface 113 of the side-light guide plate 1. The light source 2 is configured to provide light A (e.g., light from the light incident surface 113) to the side-light guide plate 1 via the light incident surface 113. Figure 3 (As shown). In this embodiment, the light-emitting surface 111 of the side-lit light guide plate 1 is also attached to the display panel 3 by OCA adhesive (Optical Clear Adhesive) 4. The inclined surfaces 102 and 103 of the side-lit light guide plate 1 are not provided with OCA adhesive 4, and the length of the side-lit light guide plate 1 is less than the length of the EPD panel to avoid risks such as damage to the isosceles triangular pyramid.

[0036] In summary, this application provides a side-lit light guide plate and optical module, in which a single outwardly convex isosceles triangular pyramid is provided on the reflective surface of a traditional side-lit light guide plate. When light enters through the light-incident surface of the side-lit light guide plate, the two inclined surfaces of the single isosceles triangular pyramid will achieve total internal reflection of the light, changing the light path and causing the light to be reflected in the direction of incident light. This not only reduces light loss in the side-lit light guide plate, but also enables the outgoing light to be completely reflected back into the light guide plate for reuse, improving the overall brightness of the side-lit light guide plate, increasing the utilization rate of electrical energy to light energy conversion, and solving the problem of low light energy utilization due to excessive light emission from the light-emitting side in traditional side-lit light guide plates.

[0037] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0038] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. An edge-lit light guide plate, characterized by comprising: include: Two opposing light-emitting surfaces, one light-incident surface, two adjacent inclined surfaces opposite the light-incident surface, and multiple side surfaces; The two opposing light-emitting surfaces are adjacent to the opposing light-incident surface and the two adjacent inclined surfaces, as well as the plurality of side surfaces. The two opposing light-emitting surfaces, the light-incident surface, the two adjacent inclined surfaces, and the plurality of side surfaces form a closed cubic structure. The two adjacent inclined planes opposite the light-incident surface have short sides of the same width and form an included angle, so that the light-incident surface forms a single isosceles triangular pyramid structure that bulges outward on one side.

2. The side-lit light guide plate according to claim 1, characterized in that, When one of the inclined surfaces reflects light rays incident through the incident surface to the other inclined surface, the other inclined surface reflects the light rays toward the incident surface.

3. The side light type light guide plate according to claim 1, wherein The included angle is 70°~110°.

4. The side light type light guide plate according to claim 1, wherein The included angle is 80°~100°.

5. The edge-lit light guide plate of claim 1, wherein, The included angle is 90°~100°.

6. The edge-lit light guide plate of claim 1, wherein The included angle is 90°.

7. The edge-lit light guide plate of claim 1, wherein Also includes: A reflective film or reflective coating is disposed on the two inclined surfaces.

8. The edge-lit light guide plate of claim 1, wherein, Also includes: A reflective film or reflective coating is disposed on at least one of the plurality of sides.

9. The edge-lit light guide plate of claim 1, wherein Also includes: A reflective film or reflective coating is disposed on at least one of the two inclined surfaces and the plurality of side surfaces.

10. An optical module, characterized in that, include: The side-lit light guide plate as described in any one of claims 1-9; A light source is disposed on one side of the light incident surface of the side-lit light guide plate, and the light source provides light to the side-lit light guide plate through the light incident surface.

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