Backlight module and electronic device comprising the same

Abstract

This disclosure provides a backlight module and an electronic device including the same. The electronic device includes: a panel; and a backlight module disposed relative to the panel, and includes: a light guide plate; a first optical element; a second optical element; and a third optical element having a third prism structure and a surface relative to the third prism structure; wherein the third prism structure includes a plurality of sharp corner portions and a plurality of rounded corner portions, one of the plurality of rounded corner portions being disposed between two adjacent plurality of sharp corner portions, and in the normal direction of the panel, the height of one of the rounded corner portions to the surface of the third optical element is less than the height of one of the sharp corner portions to the surface of the third optical element.

Description

Technical Field

[0001] This disclosure relates to a backlight module and an electronic device comprising the same, and more particularly to a backlight module comprising specially designed optical elements and an electronic device comprising the same. Prior Technology

[0002] With the continuous development of technology, electronic devices are increasingly designed for privacy, low power consumption, high quality, or low cost. Currently, privacy is largely achieved by attaching privacy screen protectors or using collimated backlight modules to concentrate the light source. However, these methods still suffer from drawbacks such as high power consumption, high cost, or low yield rates.

[0003] Therefore, there is a need to provide a new backlight module and / or electronic device to improve the above-mentioned defects. Summary of the Invention

[0004] This disclosure provides an electronic device comprising: a panel; and a backlight module disposed relative to the panel, and comprising: a light guide plate; a first optical element disposed on the light guide plate and having a first prism structure; a second optical element disposed on the first optical element and having a second prism structure; and a third optical element disposed on the second optical element and having a third prism structure; wherein the first prism structure faces the light guide plate, and the second and third prism structures face the panel.

[0005] This disclosure further provides an electronic device comprising: a panel; and a backlight module disposed relative to the panel, and comprising: a light guide plate; a first optical element disposed on the light guide plate; a second optical element disposed on the first optical element; and a third optical element disposed on the second optical element, and having a third prism structure and a surface relative to the third prism structure; wherein the third prism structure comprises a plurality of sharp corner portions and a plurality of rounded corner portions, one of the plurality of rounded corner portions being disposed between two adjacent plurality of sharp corner portions, and in the normal direction of the panel, the height of one of the rounded corner portions to the surface of the third optical element is less than the height of one of the sharp corner portions to the surface of the third optical element. Simple diagram description

[0006] Figure 1 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. Figure 2 is a perspective view of an electronic device according to one embodiment of the present disclosure. Figures 3A and 3B are partial schematic diagrams of an electronic device according to one embodiment of this disclosure. Figures 4A to 4D show the optical analysis results of an electronic device under different backlight module conditions according to one embodiment of this disclosure. Figure 5 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. Figure 6 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. Figure 7 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. Figure 8 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. Figure 9 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. Figure 10A is a partial perspective view of an electronic device according to one embodiment of this disclosure. Figure 10B is a cross-sectional view of line segment I-I' in Figure 10A. Figure 11 is a perspective view of the third optical element of one embodiment of this disclosure. Implementation Method

[0007] The following describes the implementation of this disclosure through specific embodiments. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. This disclosure can also be implemented or applied through other different embodiments, and various details in this specification can be modified and changed for different viewpoints and applications without departing from the spirit of this invention.

[0008] It should be noted that, unless otherwise specified, the presence of an element is not limited to having a single element, but may include one or more of the same element. Furthermore, the use of ordinal numbers such as "first" and "second" in the specification and claims to modify the elements of the claims does not imply or represent any prior ordinal number of the claimed element, nor does it represent the order of one claimed element with another, or the order of manufacturing process. The use of these ordinal numbers is only to enable a claimed element with a certain name to be clearly distinguished from another claimed element with the same name.

[0009] Throughout this disclosure and in the appended claims, certain terms are used to refer to specific components. Those skilled in the art will understand that electronic device manufacturers may use different names to refer to the same component. This document is not intended to distinguish between components that have the same function but different names. In the following description and claims, words such as "comprising," "containing," and "having" are open-ended terms and should therefore be interpreted as "containing but not limited to...". Thus, when the terms "comprising," "containing," and / or "having" are used in the description of this disclosure, they specify the presence of the corresponding feature, area, step, operation, and / or component, but do not exclude the presence of one or more of the corresponding feature, area, step, operation, and / or component.

[0010] In this text, the terms "about," "approximately," "substantially," and "roughly" typically indicate that a given value or range is within 10%, 5%, 3%, 2%, 1%, or 0.5%. The given quantity is an approximate quantity; that is, even without specific mention of "about," "approximately," "substantially," or "roughly," the meaning of these terms is implied. Furthermore, the phrases "range from the first value to the second value" or "range between the first value and the second value" indicate that the range includes the first value, the second value, and other values ​​in between.

[0011] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. It is understood that these terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the relevant technology and the context of this disclosure, and should not be interpreted in an idealized or overly formal manner, unless specifically defined herein.

[0012] Furthermore, relative terms such as "below" or "bottom" and "above" or "top" may be used in the embodiments to describe the relative relationship of one element to another in the diagram. It is understood that if the device in the diagram is flipped upside down, an element depicted on the "below" side will become an element on the "above" side. When a corresponding component (e.g., a membrane or region) is referred to as "on another component," it can be directly on the other component, or there may be other components between them. On the other hand, when a component is referred to as "directly on another component," there are no components between them. Additionally, when a component is referred to as "on another component," there is a vertical relationship between them in the top-view direction, and this component can be above or below the other component, depending on the orientation of the device.

[0013] In the present disclosure, thickness, length, and width can be measured using an optical microscope, and thickness can be measured using cross-sectional images obtained through an electron microscope, but this is not limited to these measurements. Furthermore, any two values ​​or directions used for comparison may have a certain degree of error. If a first value is equal to a second value, this implies that there may be an error of approximately 10% between the first and second values. If a first direction is perpendicular to a second direction, the angle between the first and second directions may be between 80 and 100 degrees. If a first direction is parallel to a second direction, the angle between the first and second directions may be between 0 and 10 degrees.

[0014] It should be noted that the technical solutions provided in the different embodiments below can be substituted for, combined or mixed with each other to constitute another embodiment without violating the spirit of this disclosure.

[0015] Figure 1 is a cross-sectional view of an electronic device according to one embodiment of the present disclosure. Figure 2 is a perspective view of an electronic device according to one embodiment of the present disclosure. Figures 3A and 3B are partial schematic diagrams of an electronic device according to one embodiment of the present disclosure. As shown in Figures 1, 2, 3A, and 3B, the electronic device disclosed herein is characterized by comprising: a panel 100; and a backlight module 200 disposed relative to the panel 100, and comprising: a light guide plate 10; a first optical element 11 disposed on the light guide plate 10 and having a first prism structure 111; a second optical element 12 disposed on the first optical element 11 and having a second prism structure 121; and a third optical element 13 disposed on the second optical element 12 and having a third prism structure 131; wherein the first prism structure 111 faces the light guide plate 10, and the second prism structure 121 and the third prism structure 131 face the panel 100. In detail, as shown in Figures 2, 3A, and 3B, the first prism structure 111 may have a plurality of first strip structures 111a and a surface 111b relative to the plurality of first strip structures 111a; the second prism structure 121 may have a plurality of second strip structures 121a and a surface 121b relative to the plurality of second strip structures 121a; and the third prism structure 131 may have a plurality of third strip structures 131a and a surface 131b relative to the third strip structures 121a. The first prism structure 111 faces the light guide plate 10, and the first prism structure 111a is closer to the light guide plate 10 than the surface 111b. The second prism structure 121 faces the panel 100, and the second prism structure 121a is closer to the panel 100 than the surface 121b. The third prism structure 131 faces the panel 100, and the third prism structure 131a is closer to the panel 100 than the surface 131b.

[0016] It should be understood that although only panel 100 is shown in the accompanying drawings, panel 100 may include upper and lower substrates, display units, sealing elements, alignment films, polarizing plates, light-shielding layers, color filter layers and / or driving elements, but this disclosure is not limited thereto.

[0017] In this disclosure, as shown in Figures 1 and 2, the backlight module 200 may further include a reflective structure 40. The reflective structure 40 may be disposed below the light guide plate 10 and is used to reflect light emitted through the bottom of the light guide plate 10, so that the light travels toward the panel 100 to improve light utilization. In some embodiments, the material of the reflective structure 40 is not particularly limited, and may include metal, white ink, other reflective materials, or combinations thereof. The metal may include gold, silver, copper, aluminum, or combinations thereof, but is not limited thereto. The white ink may include white polyimide, resin, or combinations thereof, but is not limited thereto. Furthermore, the reflective structure 40 may include a single-layer or multi-layer reflective film.

[0018] As shown in Figures 1 and 2, the backlight module 200 may further include a light source 20, which may include a plurality of light-emitting elements 201, and the plurality of light-emitting elements 201 may be arranged, for example, along a first direction Y. In some embodiments, the light source 20 may include a light-emitting diode, which may include, for example, an organic light-emitting diode (OLED), a mini LED, a micro LED, or a quantum dot LED (including QLED, QDLED), fluorescence, phosphorescence, or other suitable materials, or combinations thereof, but is not limited thereto. In some embodiments, the backlight module 200 may include a frame F1 and / or a support frame F2, the frame F1 being used to accommodate the light source 20, the light guide plate 10, or the optical film layer (e.g., the first optical element 11, the second optical element 12, and / or the third optical element 13) and the support frame F2, but is not limited thereto. The panel 100 may, for example, be disposed on the support frame F2. In some embodiments, the material of the frame F1 and / or the support frame F2 may include metal, plastic, ceramic, other suitable materials, or combinations thereof, but is not limited thereto. In some embodiments, the backlight module 200 may include a circuit board CB, which may include a rigid circuit board (e.g., a printed circuit board (PCB)) or a flexible circuit board (e.g., a flexible printed circuit (FPC)). The circuit board CB may include active or passive driving elements, and the circuit board CB may be used to control the light emission of the light source 20, but is not limited thereto.

[0019] In some embodiments, the backlight module 200 further includes a reflective element 126, which may be adjacent to the light incident surface ES of the light source 20 and the light guide plate 10, and may be disposed on the light source 20 and / or a portion of the light guide plate 10. In some embodiments, the reflective element 126 may contain a high reflectivity material, such as a material with a reflectivity between 70% and 99% (70% ≤ reflectivity ≤ 99%), but is not limited thereto. In some embodiments, the material of the reflective element 126 may include metal, white ink, white tape, other suitable reflective materials, or combinations thereof, but is not limited thereto. The reflective element 126 can be used to reflect the light generated by the light source 20 to the light guide plate 10, reducing light loss, reducing light leakage, or improving the brightness of the electronic device.

[0020] The detailed structures of the first optical element 11, the second optical element 12, and the third optical element 13 disclosed herein will be described in detail below.

[0021] As shown in Figure 2, the light source 20 may include multiple light-emitting elements 201, and the multiple light-emitting elements 201 may be arranged, for example, along a first direction Y. The extension direction of the first prism structure 111 may be, for example, perpendicular to the first direction Y, the extension direction of the second prism structure 121 may be, for example, parallel to the first direction Y, and the extension direction of the third prism structure 131 may be, for example, perpendicular to the first direction Y, but is not limited thereto. "Perpendicular" means that the angle between the extension direction of the aforementioned prism structure and the first direction Y is between 87° and 93° (87° ≤ angle ≤ 93°). "Parallel" means that the angle between the extension direction of the aforementioned prism structure and the first direction Y is between 0° and 6° (0° ≤ angle ≤ 6°).

[0022] More specifically, as shown in Figures 1 and 2, the first prism structure 111 may have a plurality of first strip structures 111a, and the extension direction of the so-called first prism structure 111 is the extension direction of the first strip structure 111a. Similarly, the second prism structure 121 may have a plurality of second strip structures 121a, and the extension direction of the so-called second prism structure 121 is the extension direction of the second strip structure 121a. Likewise, the third prism structure 131 may have a plurality of third strip structures 131a, and the extension direction of the so-called third prism structure 131 is the extension direction of the third strip structure 131a.

[0023] Figures 3A and 3B are partial schematic diagrams of an electronic device according to one embodiment of this disclosure. For ease of explanation, some structures of the electronic device, such as the light source 20, the light-emitting element 201, the reflective element 126, the circuit board CB, the frame F1, and / or the support frame F2, are omitted in Figures 3A and 3B. Figures 3A and 3B can be respectively compared to cross-sectional views in different directions of Figure 2.

[0024] As shown in Figures 2, 3A, and 3B, the extension direction of the first prism structure 111 may be, for example, perpendicular to the first direction Y; the extension direction of the second prism structure 121 may be, for example, parallel to the first direction Y; and the extension direction of the third prism structure 131 may be, for example, perpendicular to the first direction Y, but is not limited thereto. The first prism structure 111 (e.g., the first strip structure 111a) may have a first apex angle θ1, the second prism structure 121 (e.g., the second strip structure 121a) may have a second apex angle θ2, and the third prism structure 131 (e.g., the third strip structure 131a) may have a third apex angle θ3. In some embodiments, the first vertex angle θ1 and / or the third vertex angle θ3 may be between 87° and 93° (87°≦θ1≦93°; 87°≦θ3≦93°) or between 88° and 92° (88°≦θ1≦92°; 88°≦θ3≦92°), but are not limited thereto. In some embodiments, the first vertex angle θ1 and the third vertex angle θ3 may be the same or different. In some embodiments, the second vertex angle θ2 is between 50° and 60° (50°≦θ2≦60°) or between 52° and 58° (52°≦θ2≦58°), but is not limited thereto.

[0025] In some embodiments, the refractive index n1 of the first optical element 11, the refractive index n2 of the second optical element 12, and / or the refractive index n3 of the third optical element 13 may be between 1.45 and 1.60 (1.45 ≤ n1 ≤ 1.60; 1.45 ≤ n2 ≤ 1.60; 1.45 ≤ n3 ≤ 1.60) or between 1.48 and 1.58 (1.48 ≤ n1 ≤ 1.58; 1.48 ≤ n2 ≤ 1.58; 1.48 ≤ n3 ≤ 1.58), but are not limited thereto. In some embodiments, the refractive indices n1, n2, and / or n3 may be the same or different. In some embodiments, the materials of the first optical element 11, the second optical element 12, and / or the third optical element 13 may include transparent materials, but are not limited thereto. In some embodiments, the first optical element 11, the second optical element 12, and / or the third optical element 13 may include a substrate (not shown) and a corresponding prism structure (e.g., the first prism structure 111, the second prism structure 121, and the third prism structure 131). The materials of the substrate or prism structure may include polycarbonate (PC), polyimide (PI), polyethylene terephthalate (PET), polyether polyol (POP), polymethyl methacrylate (PMMA), cycloolefin polymer (COP), rubber, glass, other suitable materials, or combinations thereof, but are not limited thereto. In some embodiments, the materials of the prism structure may include photocurable adhesives, thermocurable adhesives, photothermal curable adhesives, moisture-curable adhesives, other suitable materials, or combinations thereof, but are not limited thereto. In some embodiments, the material of the prism structure may include optical clear adhesive (OCA), optical clear resin (OCR), acrylic resin, other suitable materials, or combinations thereof, but is not limited thereto. In some embodiments, the same or different materials may be used to fabricate the first optical element 11, the second optical element 12, and the third optical element 13.

[0026] The backlight module 200 disclosed herein can concentrate the light emitted from the backlight module 200 towards the positive viewing angle by means of the arrangement of the first optical element 11, the second optical element 12, and the third optical element 13, such as the angle relationship between the first prism structure 111, the second prism structure 121, and the third prism structure 131 and the first direction Y (the arrangement direction of the light-emitting elements 201), or the relationship between the first prism structure 111, the second prism structure 121, and the third prism structure 131 facing or moving away from the light guide plate 10. This will be explained in detail later in Figures 4A to 4D through optical analysis results. In addition, the effect of concentrating the light towards the positive viewing angle can be further achieved by designing the angles of the first apex angle θ1 of the first prism structure 111, the second apex angle θ2 of the second prism structure 121, and / or the third apex angle θ3 of the third prism structure 131. When the backlight module 200 disclosed herein is combined with the panel 100, an electronic device with a more concentrated light angle can be obtained. Therefore, privacy requirements can be met without the need for additional attachment or installation of privacy screens, or without the need to use collimated backlight modules with low yield and / or high cost.

[0027] In some embodiments, the surface 121b of the second optical element 12 may be a rough surface, and the haze of the surface 121b may be between 3% and 15% (3% ≤ haze ≤ 15%) or between 5% and 12% (5% ≤ haze ≤ 12%), but is not limited thereto. The haze design of the surface 121b can reduce the risk of mutual adsorption between the second optical element 12 and the first optical element 11, thereby improving quality defects.

[0028] As shown in Figures 1 to 3B, the backlight module 200 may further include a diffusion element 14, which may be disposed on the third optical element 13. In some embodiments, the backlight module 200 may further include a diffusion element 14-1 disposed between the first optical element 11 and the light guide plate 10, but is not limited thereto. In some embodiments, the haze of the diffusion element 14 and / or the diffusion element 14-1 may be between 5% and 50% (5% ≤ haze ≤ 50%) or between 30% and 50% (30% ≤ haze ≤ 50%), but is not limited thereto. In some embodiments, the diffusion element 14 may be used to disperse the light emitted by the light source 20 to make the brightness of the backlight module 200 more uniform. In some embodiments, the haze of the surface 121b of the second optical element 12 may be prepared by texturing, sandblasting or other suitable processes, but is not limited thereto.

[0029] Figures 4A to 4D show the optical analysis results of an electronic device under different backlight module configurations according to one embodiment of this disclosure. Specifically, Figures 4A to 4D show the optical analysis results of an electronic device with different optical film layers of the backlight module 200. These optical analysis results are, for example, measurements taken on the electronic device including the panel 100 and the backlight module. These optical analysis results can be obtained, for example, by measurement using a conoscopic lens, but are not limited thereto. For example, the optical analysis results can be measured or analyzed using a conoscope, BM5A, conometer 80U, or other suitable instruments, but are not limited thereto.

[0030] It should be noted that the optical analysis results in Figures 4A to 4D may include azimuth angles φ (azimuth angles from 0 degrees to 360 degrees in the figures) and tilt angles θ (tilt angles from 0 degrees to 80 degrees in the figures). Tilt angle θ is, for example, the angle with the normal direction of panel 100; a tilt angle of 0 degrees can represent the direction perpendicular to the upper surface of panel 100. Azimuth angle φ is, for example, the angle parallel to the upper surface of panel 100; an azimuth angle φ of 90 degrees can approximately correspond to the position of the light-incident surface ES of light guide plate 10 (as shown in Figure 2), and an azimuth angle φ of 270 degrees can approximately correspond to the position of the opposite surface BS of the light-incident surface ES of light guide plate 10 (as shown in Figure 2). Additionally, the color gradations on the right side of Figures 4A to 4D represent different ranges of luminance (cd / m²) per unit area. This range of luminance values ​​(cd / m²) per unit area is only to illustrate the results of one embodiment, but this disclosure is not limited thereto. The luminance value per unit area may vary depending on the design of the panel 100 or other factors.

[0031] As described above, Figures 4A to 4D show the optical analysis results of electronic devices with different optical film layers in the backlight module 200. For example, when the backlight module only includes the light guide plate 10, the measured optical analysis results of the electronic device are shown in Figure 4A; when the backlight module includes the first optical element 11 as described above in addition to the light guide plate 10, the measured optical analysis results of the electronic device are shown in Figure 4B; when the backlight module includes the first optical element 11 and the second optical element 12 as described above in addition to the light guide plate 10, the measured optical analysis results of the electronic device are shown in Figure 4C; when the backlight module includes the first optical element 11, the second optical element 12 and the third optical element 13 as described above in addition to the light guide plate 10, the measured optical analysis results of the electronic device are shown in Figure 4D.

[0032] In detail, as shown in Figure 4A, when the backlight module 200 only includes the light guide plate 10, it can be seen that the portion of the light luminance per unit area above 2.5E+04 cd / m² is approximately located between an azimuth angle φ of 240 degrees and 310 degrees, and an tilt angle θ of approximately 60 degrees and 80 degrees, but is not limited to these. In other words, when the light source 20 emits light to the light guide plate 10, the light can, for example, be concentrated at the position opposite the incident light surface ES to the surface BS. When the first optical element 11, the second optical element 12, and the third optical element 13 are sequentially arranged on the light guide plate 10 in the backlight module 200, the optical analysis results can be modulated sequentially, for example, as shown in Figures 4B to 4D. In detail, as shown in Figure 4B, after the light passes through the light guide plate 10 and the first optical element 11, the light can be roughly dispersed into two parts by the first optical element 11 (the lower left part and the lower right part in Figure 4B). The portion of the lower left part with a brightness value per unit area greater than 2.5E+04 cd / m2 can roughly correspond to a position with an azimuth angle φ of approximately 230 degrees to 250 degrees and an inclination angle θ of approximately 60 degrees to 80 degrees. The portion of the lower right part with a brightness value per unit area greater than 2.5E+04 cd / m2 can roughly correspond to a position with an azimuth angle φ of approximately 300 degrees to 320 degrees and an inclination angle θ of approximately 60 degrees to 80 degrees, but is not limited to these. As shown in Figure 4C, after the light passes through the light guide plate 10, the first optical element 11, and the second optical element 12, the beam splitting of the two parts (lower left and lower right) as shown in Figure 4B can, for example, change towards the position of the positive viewing angle (i.e., the tilt angle θ is closer to 0 degrees). For example, the two parts as described in Figure 4B can roughly correspond to a position with a tilt angle θ of about 60 to 80 degrees, while the positions of the two parts shown in Figure 4C change to a position with a tilt angle θ of about 20 to 40 degrees, but are not limited to this. In other words, after the light passes through the second optical element 12, the beam splitting of the two parts will be concentrated towards the positive viewing angle. In addition, as shown in Figure 4D, after the light passes through the light guide plate 10, the first optical element 11, the second optical element 12, and the third optical element 13, the beam splitting of the above two parts can, for example, be concentrated together, so that the light is concentrated at the position of the positive viewing angle of the electronic device. By utilizing the relative design of the light guide plate 10, the first optical element 11, the second optical element 12 and the third optical element 13 in the backlight module 200 disclosed herein, the electronic device can have the characteristic of concentrating light towards the frontal viewing angle. This backlight module can be used for privacy protection purposes, or it can increase the brightness of the frontal viewing angle to reduce power consumption or increase contrast, etc.

[0033] Figure 5 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. The electronic device in Figure 5 is similar to that in Figure 1, except for the following differences.

[0034] The backlight module 200 shown in Figure 5 may further include at least one adhesive layer 30, which may be disposed between the first optical element 11 and the second optical element 12, or between the second optical element 12 and the third optical element 13. In some embodiments, the adhesive layer 30 may be selectively disposed between the third optical element 13 and the diffusion element 14, but is not limited thereto. In some embodiments, the backlight module 200 may include at least one adhesive layer 30, which may be selectively disposed between the first optical element 11, the second optical element 12, the third optical element 13 and the first diffusion element 14, respectively. In some embodiments, the first optical element 11, the second optical element 12, the third optical element 13 and / or the diffusion element 14 may be bonded together through the adhesive layer 30 to form an optical film assembly, but is not limited thereto.

[0035] In some embodiments, the adhesive layer 30 comprises a light-curing adhesive, a thermosetting adhesive, a photothermal-curing adhesive, a moisture-curing adhesive, tape, other suitable materials, or combinations thereof, but is not limited thereto. In some embodiments, the adhesive layer 30 may comprise polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU), optical clear adhesive (OCA), optical clear resin (OCR), other suitable materials, or combinations thereof, but is not limited thereto. The adhesive layer 30 can reduce the relative positional misalignment between the layers or simplify the assembly process.

[0036] Figure 6 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. The electronic device in Figure 6 is similar to that in Figure 1, except for the following differences.

[0037] As shown in Figure 6, the backlight module 200 may further include a grating element 16, which may be disposed between the third optical element 13 and the panel 100. For example, a diffuser element 14 may be disposed between the grating element 16 and the third optical element 13. In other embodiments (not shown), an adhesive layer may be selectively disposed between the grating element 16 and the diffuser element 14 to bond them together. In some embodiments, the grating element 16 may include an advanced light control film (ALCF), a view control film (VCF), or other suitable light control layers, but is not limited thereto. In some embodiments, the grating element 16 can be used to control the viewing angle of an electronic device.

[0038] Figure 7 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. The electronic device in Figure 7 is similar to that in Figure 6, except for the following differences.

[0039] As shown in Figure 7, the backlight module 200 may further include a reflective composite layer 17, which may be disposed, for example, between the third optical element 13 and the panel 100. In some embodiments, the aforementioned diffusion element 14 and / or grating element 16 may be selectively disposed between the reflective composite layer 17 and the third optical element 13, and the grating element 16 may be disposed, for example, between the reflective composite layer 17 and the diffusion element 14. In other embodiments (not shown), an adhesive layer may be selectively disposed between the reflective composite layer 17 and the grating element 16 or between the grating element 16 and the diffusion element 14 to bond them together, but this is not limited to these embodiments. In some embodiments, the reflective composite layer 17 may include a dual brightness enhancement film (DBEF) or an advanced polarizer film (APF), but is not limited to these. The reflective composite layer 17 can be used to improve the utilization rate of the light source and reduce the energy consumption of electronic devices.

[0040] Figure 8 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. The electronic device in Figure 8 is similar to that in Figure 1, except for the following differences.

[0041] As shown in Figure 8, the backlight module 200 may further include a light-absorbing layer 401 and a fourth optical element 402. The light-absorbing layer 401 may be disposed, for example, below the light guide plate 10, that is, the light guide plate 10 may be disposed, for example, between the light-absorbing layer 401 and the panel 100. In some embodiments, the fourth optical element 402 may be disposed, for example, between the light guide plate 10 and the light-absorbing layer 401. In some embodiments, air may be present between the fourth optical element 402 and the light guide plate 10. In some embodiments, the light guide plate 10 may be disposed between the fourth optical element 402 and the panel 100. In some embodiments, the fourth optical element 402 may have a fourth prism structure 4021, and the fourth prism structure 4021, for example, faces the light guide plate 10. More specifically, the fourth prism structure 4021 may have a plurality of fourth strip structures 4021a and a surface 402b relative to the plurality of fourth strip structures 4021a, and the so-called fourth prism structure 4021 facing the light guide plate 10 means that the fourth strip structure 4021a is closer to the light guide plate 10 than the surface 402b. In some embodiments, the light-emitting elements 201 are arranged along a first direction Y, and the extension direction of the fourth prism structure 4021 is, for example, perpendicular to the first direction Y, but not limited thereto. The term "perpendicular" means that the angle between the extension direction of the prism structure and the first direction Y is between 87° and 93° (87° ≤ angle ≤ 93°). More specifically, the fourth prism structure 4021 may have a plurality of fourth strip structures 4021a, and the extension direction of the so-called fourth prism structure 4021 is the extension direction of the fourth strip structure 4021a of the fourth prism structure 4021. In some embodiments, the fourth strip structure 4021a of the fourth prism structure 4021 may have a fourth apex angle θ4, which may be between 87° and 93° (87°≦θ4≦93°) or between 89° and 91° (89°≦θ4≦91°), but is not limited thereto. In some embodiments, the material or fabrication method of the fourth optical element 402 may be similar to, for example, the first optical element 11, the second optical element 12, and / or the third optical element 13, and will not be described in detail here.

[0042] As shown in Figure 8, in some embodiments of the backlight module 200, the reflectivity of the light-absorbing layer 401 may range from 0% to 25% (0% < reflectivity ≤ 25%) or from 0% to 10% (0% < reflectivity ≤ 10%), but is not limited thereto. In some embodiments, the absorptivity of the light-absorbing layer 401 may range from 75% to 100% (75% ≤ absorptivity < 100%) or from 90% to 100% (90% ≤ absorptivity < 100%), but is not limited thereto. In some embodiments, the material of the light-absorbing layer 401 may comprise a high-absorbent material, a low-reflective material, or a combination thereof, but is not limited thereto. In some embodiments, the material of the light-absorbing layer 401 may comprise particles, coatings, adhesives, other suitable materials, or a combination thereof, but is not limited thereto. In some embodiments, the light-absorbing layer 401 may comprise a black organic material, a black inorganic material, polyethylene terephthalate, black ink, black tape, other suitable materials, or a combination thereof, but is not limited thereto. In some embodiments, the light-absorbing layer 401 may be formed through chemical vapor deposition, coating, evaporation, electroplating, sputtering, lamination, printing, baking, or other suitable processes, but is not limited thereto. In some embodiments, the light-absorbing layer 401 may be used to reduce the chance of stray light emitted from the bottom surface of the light guide plate 10 (i.e., the side near the light-absorbing layer 401) being reflected back to the light guide plate 10, thereby reducing the brightness at a wide viewing angle, or increasing the contrast or brightness at a forward viewing angle. For example, the normal direction Z of the panel 100 may be, for example, 0 degrees, and the forward viewing angle may be within approximately ±30 degrees (or 40 degrees) of the normal direction Z of the panel 100, but is not limited thereto.

[0043] Figure 9 is a cross-sectional view of an electronic device according to one embodiment of this disclosure. The electronic device in Figure 9 is similar to that in Figure 1, except for the following differences.

[0044] As shown in Figure 9, the backlight module 200 may include a reflective structure 40 and a fourth optical element 402. The reflective structure 40 may be disposed below the light guide plate 10, that is, the fourth optical element 402 may be disposed between the reflective structure 40 and the light guide plate 10. The reflective structure 40 may include a single-layer structure or a composite layer structure. The material of the reflective structure 40 can be referred to as described in Figure 1 above, and will not be repeated here. In some embodiments, the reflective structure 40 may include an advanced polarizer film (APF), but is not limited thereto. In some embodiments, the fourth optical element 402 between the reflective structure 40 and the light guide plate 10 may have a fourth prism structure 4021, and the fourth prism structure 4021, for example, faces the light guide plate 10. More specifically, the fourth prism structure 4021 may have a plurality of fourth strip structures 4021a and a surface 402b relative to the plurality of fourth strip structures 4021a, and the so-called fourth prism structure 4021 facing the light guide plate 10 means that the fourth strip structure 4021a is closer to the light guide plate 10 than the surface 402b. The fourth strip structure 4021a of the fourth prism structure 4021 may have a fourth apex angle θ4, and the structure or material of the fourth apex angle θ4 may be as described in Figure 8 above, and will not be repeated here.

[0045] Figure 10A is a partial perspective view of an electronic device according to one embodiment of the present disclosure. Figure 10B is a cross-sectional view along line segment I-I' of Figure 10A. The electronic device of this embodiment is similar to that of Figure 1, except for the following differences.

[0046] In this embodiment, as shown in FIG10A, the third optical element 13 has a third prism structure 131 facing the panel 100 (as shown in FIG1), and the third prism structure 131 may have a plurality of third strip structures 131a and a surface 131b relative to the third strip structure 131a, wherein the extension direction of the third prism structure 131 may, for example, be perpendicular to the first direction Y.

[0047] More specifically, as shown in Figure 10A, the third strip structure 131a may include a plurality of pointed strip structures S1 and a plurality of rounded strip structures S2, wherein the pointed strip structures S1 and the rounded strip structures S2 are arranged along the first direction Y, and one of the plurality of strip structures S2 is disposed between two adjacent plurality of pointed strip structures S1. In some embodiments, one to eight pointed strip structures S1 may be disposed between two adjacent rounded strip structures S2. For example, in Figure 10A, two pointed strip structures S1 are disposed between two adjacent rounded strip structures S2, but this is not the only possibility. In other words, in a cross-sectional view, as shown in FIG10B, the third prism structure 131a may include a plurality of sharp corner portions P1 and a plurality of rounded corner portions P2, the sharp corner portions P1 and the rounded corner portions P2 are arranged along the first direction Y, and one of the plurality of rounded corner portions P2 is disposed between two adjacent plurality of sharp corner portions P1, wherein the sharp corner strip structure S1 may correspond to the sharp corner portion P1, and the rounded corner strip structure S2 may correspond to the rounded corner portion P2. In some embodiments, one to eight sharp corner portions P1 may be disposed between two adjacent rounded corner portions P2. For example, in FIG10B, two sharp corner portions P1 may be disposed between two adjacent rounded corner portions P2, but it is not limited thereto.

[0048] Furthermore, as shown in Figures 10A and 10B, in the normal direction Z of panel 100, the height of the rounded corner strip structure S2 (i.e., the height from the top end T2 of the rounded corner portion P2 to the surface 131b of the third optical element 13) is less than the height of the pointed corner strip structure S1 (i.e., the height from the top end T1 of the pointed corner portion P1 to the surface 131b of the third optical element 13). In some embodiments, there is a height difference H1 between the height of the rounded corner strip structure S2 (i.e., the height from the top end T2 of the rounded corner portion P2 to the surface 131b of the third optical element 13) and the height of the pointed corner strip structure S1 (i.e., the height from the top end T1 of the pointed corner portion P1 to the surface 131b of the third optical element 13), wherein the height difference H1 is greater than 0 micrometers (µm) and less than or equal to 2 micrometers (µm) (i.e., 0µm < height difference H1 ≤ 2µm), but is not limited thereto.

[0049] In some embodiments, as shown in FIG10B, the sharp corner portion P1 may each have a fifth vertex angle θ5, wherein the fifth vertex angle θ5 may be between 87° and 93° (87° ≦ fifth vertex angle θ5 ≦ 93°) or between 88° and 92° (88° ≦ fifth vertex angle θ5 ≦ 92°), but is not limited thereto. The rounded corner portion P2 may each have a radius of curvature R, wherein the radius of curvature R may be greater than or equal to 3 micrometers (µm) and less than or equal to 5 micrometers (µm) (i.e., 3µm ≦ radius of curvature R ≦ 5µm). Furthermore, in some embodiments, the spacing PI between two adjacent third strip structures 131a may be between 18 micrometers and 50 micrometers (18µm ≦ spacing PI ≦ 50µm), wherein the "spacing between two adjacent third strip structures" refers to the distance in the first direction Y between the top end T1 of the pointed corner portion P1 and the top end T1 of the adjacent pointed corner portion P1, or the distance in the first direction Y between the top end T1 of the pointed corner portion P1 and the top end T2 of the adjacent rounded corner portion P2.

[0050] In some embodiments, the surface 131b of the third optical element 13 may be a rough surface with a haze between 1% and 10% (1% ≤ haze ≤ 10%), but is not limited thereto. In some embodiments, the haze of the surface 131b of the third optical element 13 may be prepared by texturing, sandblasting, or other suitable processes, but is not limited thereto. Furthermore, in some embodiments, the surface 131b of the third optical element 13 may be a smooth surface, which may be formed by a hard coating or a PET surface.

[0051] In this embodiment, as shown in FIG1, the backlight module 200 may further include a diffusion element 14 disposed on the third optical element 13, wherein the haze of the diffusion element 14 may be between 1% and 30% (1% ≤ haze ≤ 30%). In some embodiments, although not shown in the figures, the backlight module 200 may not include the diffusion element 14 shown in FIG1. ​​Furthermore, in other embodiments, the backlight module 200 may not include the diffusion element 14 shown in FIG1, but includes a diffusion element 14-1 as shown in FIG3A and FIG3B, wherein the diffusion element 14-1 is disposed between the first optical element 11 and the light guide plate 10, wherein the haze of the diffusion element 14-1 may be between 80% and 100% (80% ≤ haze ≤ 100%). In some embodiments, the diffuser element 14 can be used to disperse the light emitted by the light source 20 to make the brightness of the backlight module 200 more uniform; the diffuser element 14-1 can be used to concentrate the light at the normal viewing angle position of the electronic device, but is not limited thereto.

[0052] Figure 11 is a perspective view of a third optical element according to one embodiment of the present disclosure. The third optical element in Figure 11 is similar to that in Figure 10A, except for the following differences.

[0053] As shown in Figure 10A, the third strip structure 131a of the third prism structure 131 can be a regular structure. More specifically, the third strip structure 131a can have a top edge e1, which can be a straight line and can be perpendicular to the first direction Y. In other words, the top edge e1 can be parallel to the extension direction of the third prism structure 131a.

[0054] In this embodiment, as shown in FIG11, the third strip structure 131a of the third prism structure 131 can be an irregular structure. More specifically, the third strip structure 131a can have a top edge e2, which may not be a straight line, but may include an arc or other irregular lines. In other words, there may be an angle between the top edge e2 and the extending direction of the third prism structure 131a.

[0055] In Figure 10A, the top edge e1 of the third strip structure 131a refers to the continuation line of the tip T1 of the pointed corner portion P1 or the tip T2 of the rounded corner portion P2 in Figure 10B along the direction X perpendicular to the first direction Y. Similarly, the top edge e2 of the third strip structure 131a in Figure 11 refers to the continuation line of the tip T1 of the pointed corner portion P1 or the tip T2 of the rounded corner portion P2 in Figure 10B along the direction X perpendicular to the first direction Y.

[0056] The backlight module 200 disclosed herein can be applied to various electronic devices that require a display panel, and the display panel can be, for example, a flexible display panel, a touch display panel, a curved display panel, or a tiled display panel, but is not limited thereto. The electronic devices disclosed herein can be, for example, monitors, mobile phones, laptops, cameras, camcorders, music players, mobile navigation devices, televisions, and other electronic devices that require image display, but this disclosure is not limited thereto.

[0057] The specific embodiments described above should be interpreted as merely illustrative and not as limiting the remainder of this disclosure in any way.

[0058] 100: Panel 200: Backlight module 10: Light guide plate 11: First optical element 111: First Prism Structure 111a: First strip structure 111b: Surface 12: Second optical element 121: Second Prism Structure 121a: Second strip structure 121b: Surface 13: Third optical element 131: Third Prism Structure 131a: Third strip structure 131b: Surface 14: Diffusion element 14-1: Diffusion element 16: Grating element 17: Reflective composite layer 20: Light source 201: Light-emitting element 30: Adhesive layer 40: Reflective Structure 401: Light-absorbing layer 402: Fourth optical element 402b: Surface 4021: Fourth Prism Structure 4021a: Fourth stripe structure S1: Sharp-angled strip structure S2: Rounded corner strip structure P1: Sharp corner part P2: Rounded corners T1, T2: Top e1, e2: Top edge H1: Height difference R: Radius of curvature PI: Spacing θ1: First vertex angle θ2: Second vertex angle θ3: Third vertex angle θ4: Fourth vertex angle θ5: Fifth vertex angle X: direction Y: first direction Z: View from above F1: Frame F2: Support Frame CB: Circuit Board 126: Reflective element θ: inclination angle φ: Azimuth ES: Light-receiving surface BS: Opposite side

[0059] none

Claims

1. An electronic device comprising: a panel; and a backlight module disposed relative to the panel, and comprising: a light guide plate; a first optical element disposed on the light guide plate and having a first prism structure, the first prism structure having a first apex angle between 87° and 93°; a second optical element disposed on the first optical element and having a second prism structure, the second prism structure having a second apex angle between 50° and 60°; and a third optical element disposed on the second optical element and having a third prism structure and a surface opposite to the third prism structure; wherein, The third prism structure includes a plurality of sharp corner portions and a plurality of rounded corner portions, one of which is disposed between two adjacent sharp corner portions. In the normal direction of the panel, the height of one of the rounded corner portions to the surface of the third optical element is less than the height of one of the sharp corner portions to the surface of the third optical element. The second optical element has a first surface adjacent to the light guide plate that is a rough surface, and the haze of the first surface is between 3% and 15%.

2. The electronic device as described in claim 1, wherein, There is a height difference between the height of one of the rounded portions to the surface of the third optical element and the height of one of the sharp corner portions to the surface of the third optical element, wherein the height difference is greater than 0 micrometers (µm) and less than or equal to 2 micrometers (µm).

3. The electronic device as described in claim 1, wherein, Each of these rounded corner portions has a radius of curvature greater than or equal to 3 micrometers (µm) and less than or equal to 5 micrometers (µm).

4. The electronic device as described in claim 1, wherein, One to eight of these sharp corner portions are positioned between two adjacent rounded corner portions.

5. The electronic device as claimed in claim 1, wherein, The surface of the third optical element is a rough surface, and the haze of the surface of the third optical element is between 1% and 10%.

6. The electronic device as claimed in claim 1, wherein, The backlight module further includes a diffusion element disposed on the third optical element, wherein the haze of the diffusion element is between 1% and 30%.

7. The electronic device as claimed in claim 1, wherein, The backlight module further includes another diffusion element disposed between the first optical element and the light guide plate, wherein the haze of the other diffusion element is between 80% and 100%.

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