Backlight module

Abstract

The invention provides a backlight module, which is characterized by comprising a back plate, a light guide plate and a light guide plate, the first optical film is arranged on the back plate; the second optical film is arranged on the first optical film; wherein the first optical film comprises a plurality of first salient points, the plurality of first salient points protrude towards the second optical film, at least one of the plurality of first salient points has a first height, and the first height is greater than or equal to 4 [mu] m and less than or equal to 10 [mu] m.

Description

Technical Field

[0001] The invention relates to a backlight module, in particular to a backlight module with an optical film. Background Art

[0002] With the rapid advancement of liquid crystal display (LCD) manufacturing technology, LCDs are widely used in various electronic products such as tablet computers, notebook computers, digital cameras, digital camcorders, mobile phones, computer monitors and LCD TVs due to their advantages of being thin, light, power-saving and radiation-free. LCDs require a backlight module to provide light to display images.

[0003] However, the current backlight module still has disadvantages such as low assembly yield or high production cost. Therefore, it is necessary to provide a backlight module to improve the above defects. Summary of the invention

[0004] The present invention provides a backlight module, characterized in that it comprises: a back plate; a first optical film, which is arranged on the back plate; and a second optical film, which is arranged on the first optical film; wherein the first optical film comprises a plurality of first protrusions, the plurality of first protrusions protrude toward the second optical film, and at least one of the plurality of first protrusions has a first height, the first height is greater than or equal to 4 μm and less than or equal to 10 μm. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1A is a schematic diagram of an electronic device according to an embodiment of the present invention;

[0006] Figure 1B for Figure 1A A partially enlarged schematic diagram of

[0007] Figure 2A is a schematic top view of a first optical film according to an embodiment of the present invention;

[0008] Figure 2B is a schematic top view of a first optical film according to an embodiment of the present invention;

[0009] Figure 2C is a schematic top view of a first optical film according to an embodiment of the present invention;

[0010] Figure 3 is a bottom view schematically showing a first optical film according to an embodiment of the present invention;

[0011] Figure 4A A schematic diagram of an electronic device according to an embodiment of the present invention;

[0012] Figure 4B for Figure 4AA partially enlarged schematic diagram of .

[0013] In the above drawings, the meanings of the reference numerals are as follows:

[0014] 100- backlight module;

[0015] 200-panel;

[0016] 11- back plate;

[0017] 12-a first optical film;

[0018] 121- first convex point;

[0019] 122- second convex point;

[0020] 123-side wall;

[0021] 124-upper surface;

[0022] 125 - lower surface;

[0023] 13- second optical film;

[0024] 14- a third optical film;

[0025] 15- fourth optical film;

[0026] 16-light emitting unit;

[0027] 17- reflective sheet;

[0028] L-ray;

[0029] D1, D2, D3 - distance;

[0030] H1 - first height;

[0031] H2 - second height;

[0032] X, Y-direction;

[0033] Z-normal direction. DETAILED DESCRIPTION

[0034] The following describes the implementation of the present invention through specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways according to different viewpoints and applications without departing from the spirit of the present invention.

[0035] It should be noted that, in the present invention, unless otherwise specified, "having an element" is not limited to having a single element, but may have one or more elements. Furthermore, the ordinal numbers used in the specification and claims, such as "first" and "second", to modify the elements of the claims, do not themselves imply or represent any previous ordinal numbers of the claimed elements, nor do they represent the order of one claimed element and another claimed element, or the order of the manufacturing method. The use of these ordinals is only used to make a claimed element with a certain name clearly distinguishable from another claimed element with the same name.

[0036] Certain words are used in the description and claims of the present invention to refer to specific components. It should be understood by those skilled in the art that electronic equipment manufacturers may name the same components with different names. It is not intended to distinguish between components that have the same function but different names. In the following description and claims, the words "comprising", "containing", "having" and the like are open-ended words, and therefore should be interpreted as "containing but not limited to...". Therefore, when the terms "comprising", "containing" and / or "having" are used in the description of the present invention, they specify the existence of corresponding features, regions, steps, operations and / or components, but do not exclude the existence of one or more corresponding features, regions, steps, operations and / or components.

[0037] In the present invention, the terms "about", "approximately", "substantially", and "roughly" generally mean within 10%, within 5%, within 3%, within 2%, within 1%, or within 0.5% of a given value or range. The number given here is an approximate number, that is, in the absence of specific instructions for "about", "approximately", "substantially", and "roughly", the meanings of "about", "approximately", "substantially", and "roughly" can still be implied. In addition, the terms "range is from a first value to a second value", "range is between a first value and a second value" mean that the range includes the first value, the second value, and other values ​​therebetween.

[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. It is understood that these terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the background or context of the relevant technology and the present invention, and should not be interpreted in an idealized or overly formal manner unless specifically defined herein.

[0039] In addition, 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 of the diagram to another element. It should be understood that if the device of the diagram is turned upside down, the element described on the "below" side will become the element on the "above" side. When a corresponding component (such as a film layer or area) is referred to as "on another component", it can be directly on the other component, or there can be other components between the two. On the other hand, when a component is referred to as "directly on another component", there is no component between the two. In addition, when a component is referred to as "on another component", the two have an up-and-down relationship in the top-down direction, and this component can be above or below the other component, so the up-and-down relationship depends on the orientation of the device.

[0040] In the present invention, the distance, diameter, height and density can be measured by an optical microscope, the height can be measured by a cross-sectional image in an electron microscope, and the distance, diameter and density can be measured by a top view or bottom view image in an electron microscope, but the present invention is not limited thereto. In addition, any two values ​​or directions used for comparison may have a certain error. If the first value is equal to the second value, it implies that there may be an error of about 10% between the first value and the second value; if the first direction is perpendicular to the second direction, the angle between the first direction and the second direction may be between 80 degrees and 100 degrees; if the first direction is parallel to the second direction, the angle between the first direction and the second direction may be between 0 degrees and 10 degrees.

[0041] It should be noted that the technical solutions provided in the following different embodiments can be replaced, combined or mixed with each other to form another embodiment without violating the spirit of the present disclosure.

[0042] Figure 1A FIG. 4 is a schematic diagram of an electronic device according to an embodiment of the present invention. Figure 1B for Figure 1A A partially enlarged schematic diagram of .

[0043] In one embodiment of the present invention, Figure 1AAs shown, the electronic device may include: a backlight module 100; and a panel 200, which is disposed on the backlight module 100. Therefore, the electronic device of the present invention may be an electronic device that requires a backlight module, such as a liquid crystal display, but the present invention is not limited to this. In addition, the panel 200 may be, for example, a flexible display panel, a touch display panel, a curved display panel, or a tiled display panel, but the present invention is not limited to this. The electronic device of the present invention is, for example, a display, a mobile phone, a laptop computer, a video camera, a camera, a music player, a mobile navigation device, a television, etc., but the present invention is not limited to this.

[0044] In the present invention, if Figure 1A , Figure 1B As shown, the backlight module 100 includes: a back plate 11; a first optical film 12, which is arranged on the back plate 11; and a second optical film 13, which is arranged on the first optical film 12; wherein the first optical film 12 includes a plurality of first protrusions 121, and the plurality of first protrusions 121 protrude toward the second optical film 13, and at least one of the plurality of first protrusions 121 has a first height H1, and the first height H1 is greater than or equal to 4μm and less than or equal to 10μm. The first height H1 measurement method is, for example, the length of the first protrusion 121 in the normal direction Z of the second optical film 13. The present invention can design the first height H1 of the first protrusion 121 within the above range through the arrangement of the first protrusion 121, thereby reducing the damage of foreign matter to the first optical film 12 and / or the second optical film 13, improving the assembly yield of the backlight module 100, and thus reducing the production cost of the electronic device. In the present invention, if Figure 1B As shown, the first protrusion 121 may be in direct contact with the second optical film 13 , but the present invention is not limited thereto.

[0045] In the present invention, the material of the back plate 11 includes metal, alloy, polycarbonate (PC), polyimide (PI), polypropylene (PP), polyethyleneterephthalate (PET) or other plastic or polymer materials, or a combination thereof, but the present invention is not limited thereto. In the present invention, the first optical film 12 and the second optical film 13 are each independently a light guide plate, a diffuser plate, a brightness enhancement film, a prism sheet or a combination thereof, but the present invention is not limited thereto. The materials of the first optical film 12 and the second optical film 13 include poly(methyl methacrylate, PMMA), polycarbonate (polycarbonate, PC), polyimide (polyimide, PI), polyethylene terephthalate (polyethylene terephthalate, PET), polymer polyol (polyether polyol, POP), cycloolefin polymer (cycloolefin polymer, COP), rubber, glass, other suitable materials or the combination of the above, but the present invention is not limited thereto. In the present invention, the first protrusion 121 can be formed by injection molding, dot printing, dispensing, hot pressing, inkjet printing (Ink-jet Printing, IJP), other suitable methods or the combination of the above, but the present invention is not limited thereto. In one embodiment of the present invention, when the first protrusion 121 is formed by injection molding, the first optical film 12 and the first protrusion 121 can be integrally formed. The materials of the first protrusion 121 can include poly(methyl methacrylate, PMMA), polycarbonate (polycarbonate, PC), polyimide (polyimide, PI), polyethylene terephthalate (PET), polymer polyol (polyether polyol, POP), cycloolefin polymer (cycloolefin polymer, COP), rubber, glass, other suitable materials or the combination of the above, but the present invention is not limited thereto. The first protrusion 121 may be made of polyimide (PI), polymethacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyether polyol (POP), cycloolefin polymer (COP), rubber, glass, metal, other suitable materials or a combination thereof. In the present invention, the diameter of the first protrusion 121 is 40 μm to 60 μm, but the present invention is not limited thereto. When the protrusion diameter is 40 μm to 60 μm, better optical quality and manufacturing efficiency can be achieved.

[0046] In the present invention, if Figure 1AAs shown, the backlight module 100 further includes: a plurality of light-emitting units 16, which are disposed on one side of the first optical film 12; and a reflective sheet 17, which is disposed on the back plate 11. Specifically, the first optical film 12 may include a side wall 123, and the light-emitting unit 16 is disposed corresponding to the side wall 123 of the first optical film 12. Therefore, the light L provided by the light-emitting unit 16 can enter the first optical film 12 through the side wall 123 of the first optical film 12, and guide the light L through the first optical film 12 to provide it to the panel 200. Therefore, in one embodiment of the present invention, the first optical film 12 can be a light guide plate, and the side wall 123 can be the light incident side of the light guide plate, but the present invention is not limited thereto. The reflective sheet 17 can reflect the light L provided by the light-emitting unit 16 to the first optical film 12 to improve the utilization rate of the light L. In the present invention, the light-emitting unit 16 includes a light-emitting diode, such as an organic light-emitting diode (OLED), a sub-millimeter light-emitting diode (mini LED), a micro LED or a quantum dot light-emitting diode (quantum dot LED, including QLED, QDLED), fluorescence, phosphorescence or other suitable materials, or a combination thereof, but the present invention is not limited thereto. In the present invention, the material of the reflective sheet 17 also includes metal, white ink, other reflective materials or a combination thereof. Among them, the metal includes gold, silver, copper, aluminum or a combination thereof, but the present invention is not limited thereto. The white ink includes white polyimide, resin or a combination thereof, but the present invention is not limited thereto. In addition, the reflective sheet 17 may be a single-layer or multi-layer structure.

[0047] In one embodiment of the present invention, Figure 1AAs shown, the backlight module 100 may selectively include a third optical film 14 and / or a fourth optical film 15, which are disposed on the second optical film 13, wherein the third optical film 14 may be disposed between the second optical film 13 and the fourth optical film 15. The third optical film 14 and the fourth optical film 15 may be used to improve the light extraction efficiency of the backlight module 100 and / or enhance the display quality of the electronic device. In the present invention, the third optical film 14 and the fourth optical film 15 may be prepared using the same or different materials, and the materials of the third optical film 14 and the fourth optical film 15 are similar to those of the first optical film 12 and the second optical film 13, and are not described in detail herein. In addition, in the present invention, although not shown in the figure, an adhesive layer may be selectively included between the second optical film 13, the third optical film 14 and / or the fourth optical film 15, so that the second optical film 13, the third optical film 14 and / or the fourth optical film 15 are bonded to each other through the adhesive layer to form an optical film set, but the present invention is not limited thereto. The material of the adhesive layer may include 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 the present invention is not limited thereto.

[0048] In the present invention, if Figure 1B As shown, the first optical film 12 may include a plurality of second protrusions 122, and the plurality of second protrusions 122 face the back plate 11 (eg, Figure 1A The second protrusion 122 protrudes from the backlight module 100 and / or enhances the display quality of the electronic device through the provision of the second protrusion 122, and at least one or more second protrusions 122 have a second height H2, and the second height H2 may be greater than or equal to 4 μm and less than or equal to 10 μm. The present disclosure can improve the light extraction efficiency of the backlight module 100 and / or enhance the display quality of the electronic device through the provision of the second protrusion 122. In one embodiment of the present invention, the second protrusion 122 may be in direct contact with the reflective sheet 17, but the present invention is not limited thereto. The second height H2 measurement method is, for example, the length of the second protrusion 122 in the normal direction Z of the second optical film 13.

[0049] In the present invention, the second bumps 122 are prepared by the same or different method as that of forming the first bumps 121, which will not be described in detail herein. In one embodiment of the present invention, when the second bumps 122 are formed by injection molding, the first optical film 12 and the second bumps 122 can be formed as one piece. The materials of the second bumps 122 can each include poly(methyl methacrylate, PMMA), polycarbonate (polycarbonate, PC), polyimide (polyimide, PI), polyethylene terephthalate (polyethylene terephthalate, PET), polyether polyol (polyether polyol, POP), cycloolefin polymer (cycloolefin polymer, COP), rubber, glass, metal, other suitable materials or a combination of the foregoing.

[0050] Figure 2A FIG. 4 is a schematic top view of a first optical film according to an embodiment of the present invention.

[0051] In one embodiment of the present invention, Figure 1A , Figure 1B and Figure 2A As shown, the first optical film 12 may include an upper surface 124, wherein the upper surface 124 is connected to the side wall 123, and the first protrusion 121 may be formed on the upper surface 124. Figure 2A As shown, the first protrusions 121 can be arranged in a rectangular pattern. Specifically, four adjacent first protrusions 121 can be connected to form a rectangle. In the present invention, the distances D1 and D2 between adjacent first protrusions 121 can be 2 mm to 10 mm. The "distance between adjacent first protrusions" can be, for example, the distance D1 between two adjacent first protrusions 121 (for example, the centers of two adjacent first protrusions 121) along direction X, or can be the distance D2 between two adjacent first protrusions 121 (for example, the centers of two adjacent first protrusions 121) along direction Y, wherein direction X is different from direction Y (for example, direction X can be perpendicular to direction Y). In one embodiment of the present invention, Figure 2A As shown, the distance D1 between adjacent first protrusions 121 along the X direction may be substantially equal to the distance D2 between adjacent first protrusions 121 along the Y direction, but the present invention is not limited thereto.

[0052] In addition, in the present invention, the density of the first bumps 121 may be 0.1% to 0.8%, for example, 0.1% to 0.5%, 0.1% to 0.3%, 0.3% to 0.5%, or 0.5% to 0.8%, or a combination thereof, but the present invention is not limited thereto. The "density of the first bumps" is, for example, the ratio of the total area of ​​the four first bumps 121 to the area enclosed by the four first bumps 121 in the top view direction (for example, in the Z direction) (taking the tangent line of the first bump 121, as shown by the dotted line).

[0053] Figure 2B FIG. 1 is a schematic top view of a first optical film according to an embodiment of the present invention. Figure 2B The first optical film and Figure 1A The first optical film is similar to the first optical film except that the arrangement of the first protrusions is different.

[0054] In one embodiment of the present invention, Figure 2B As shown, the first protrusions 121 are arranged in a diamond pattern. Specifically, four adjacent first protrusions 121 can be connected to form a diamond. In the present invention, the distances D1 and D2 between adjacent first protrusions 121 can be 2 mm to 10 mm. The "distance between adjacent first protrusions" can be, for example, the distance D1 between two adjacent first protrusions 121 (for example, the centers of two adjacent first protrusions 121) along direction X, or can be the distance D2 between two adjacent first protrusions 121 (for example, the centers of two adjacent first protrusions 121) along direction Y, wherein direction X is different from direction Y (for example, direction X can be perpendicular to direction Y). In one embodiment of the present invention, Figure 2B As shown, the distance D1 between adjacent first protrusions 121 along the X direction is not equal to the distance D2 between adjacent first protrusions 121 along the Y direction, but the present invention is not limited thereto.

[0055] In addition, in the present invention, the density of the first bumps 121 may be 0.1% to 0.8%, such as 0.1% to 0.5%, 0.1% to 0.3%, 0.3% to 0.5%, or 0.5% to 0.8%, or a combination thereof, but the present invention is not limited thereto. The "density of the first bumps" is, for example, the ratio of the total area of ​​the four first bumps 121 to the area enclosed by the four first bumps 121 in the top view direction (e.g., the Z direction) (taking the tangent line of the first bumps, as shown by the dotted line).

[0056] Figure 2C FIG. 1 is a schematic top view of a first optical film according to an embodiment of the present invention. Figure 2C The first optical film Figure 1AThe first optical film is similar to the first optical film except that the arrangement of the first protrusions is different.

[0057] In one embodiment of the present invention, Figure 2C As shown, the first protrusions 121 are arranged in a honeycomb pattern. Specifically, six adjacent first protrusions 121 can be connected to form a hexagon. In the present invention, the distance D3 between adjacent first protrusions 121 (for example, the centers of adjacent first protrusions 121) can be 2 mm to 10 mm. The "distance between adjacent first protrusions" is, for example, the length of one side of the hexagon. In one embodiment of the present invention, Figure 2C As shown, six adjacent first protrusions 121 can be connected to form a regular hexagon, and therefore, each side of the regular hexagon has the same length, but the present invention is not limited thereto.

[0058] In addition, in the present invention, the density of the first bumps 121 is 0.1% to 0.8%, for example, 0.1% to 0.5%, 0.1% to 0.3%, 0.3% to 0.5%, or 0.5% to 0.8%, or a combination thereof, but the present invention is not limited thereto. The "density of the first bumps" is, for example, the ratio of the total area of ​​the six first bumps 121 to the area enclosed by the six first bumps 121 in the top view direction (for example, in the Z direction) (taking the tangent line of the first bumps, as shown by the dotted line).

[0059] Figure 3 FIG. 4 is a bottom view of a first optical film according to an embodiment of the present invention.

[0060] In one embodiment of the present invention, Figure 1A , Figure 1B and Figure 3As shown, the first optical film 12 includes a plurality of second convex points 122, and the plurality of second convex points 122 protrude toward the back plate 11. Specifically, the first optical film 12 may include a lower surface 125, wherein the lower surface 125 is connected to the side wall 123, and the second convex points 122 may be formed on the lower surface 125. The light-emitting unit 16 is disposed on one side of the first optical film 12, wherein the density of the second convex points 122 adjacent to the side may be less than the density of the second convex points 122 away from the side. In the present invention, the density of the second convex points 122 is 1% to 50%, for example, the density of the second convex points 122 adjacent to the side may be 1% to 3%, and the density of the second convex points 122 away from the side may be 30% to 50% (for example, 35% to 45%, 30% to 40% or 40% to 50%), but the present invention is not limited thereto. Therefore, in the present invention, the density of the first convex points 121 is less than the density of the second convex points 122. The “density of the second bumps” is, for example, the ratio of the total area of ​​the adjacent plurality of second bumps 122 to the area surrounded by the plurality of second bumps 122 in the top view direction (e.g., the Z direction). In one embodiment of the present invention, the “density of the second bumps” is, for example, the ratio of the total area of ​​the second bumps 122 per unit area of ​​the lower surface 125 to the unit area.

[0061] In one embodiment of the present invention, Figure 3 As shown, a plurality of light emitting units 16 may be arranged along a direction Y, wherein the density of the second protrusions 122 adjacent to the light emitting unit 16 is less than the density of the second protrusions 122 away from the light emitting unit 16. The density of the second protrusions 122 adjacent to the light emitting unit 16 is 1% to 3%, and the density of the second protrusions 122 away from the light emitting unit 16 is 30% to 50%. The terms "adjacent" and "away" as used herein are relative. When the second protrusions 122 are compared, the second protrusion 122 with the smaller shortest distance to the light emitting unit 16 is adjacent, and the second protrusion 122 with the larger shortest distance to the light emitting unit 16 is away. Figure 3 For example, the shortest distance between the second protrusion 122 and the light emitting unit 16 is the distance between the second protrusion 122 and the light emitting unit 16 in the X direction.

[0062] Figure 4A FIG. 4 is a schematic diagram of an electronic device according to an embodiment of the present invention. Figure 4B for Figure 4A A partial enlarged schematic diagram of the Figure 4A Electronic devices and Figure 1A Similar, except for the following differences.

[0063] In one embodiment of the present invention, Figure 4A , Figure 4BAs shown, a plurality of light emitting units 16 are disposed on the reflective sheet 17, and the plurality of light emitting units 16 may be disposed between the first optical film 12 and the reflective sheet 17 or the back plate 11. Specifically, the light emitting units 16 are disposed on the plane of the direction X and the direction Y, so that the light L provided by the light emitting units 16 may enter from the lower surface 125 of the first optical film 12 and be provided to the panel 200. In one embodiment of the present invention, the backlight module 100 may be a direct-type backlight module, but the present invention is not limited thereto.

[0064] In one embodiment of the present invention, Figure 4A , Figure 4B As shown, when the backlight module 100 is a direct-lit backlight module, the first optical film 12 may not have the second protrusion 122 (eg, Figure 1B As shown in FIG. 1 , the manufacturing steps can be simplified or the cost can be saved. In addition, other features of the first optical film 12 can be as described above and will not be repeated here.

[0065] The above specific embodiments should be interpreted as merely illustrative and not limiting the rest of the present invention in any way, and the features of different embodiments can be mixed and matched as long as they do not conflict with each other. The scope of rights claimed by the present invention is not limited thereto, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A backlight module, characterized in that: Include: a back plate; a first optical film, disposed on the back plate; and A second optical film, disposed on the first optical film; The first optical film includes a plurality of first protrusions, the plurality of first protrusions protrude toward the second optical film, and at least one of the plurality of first protrusions has a first height, the first height is greater than or equal to 4 μm and less than or equal to 10 μm.

2. The backlight module according to claim 1, characterized in that: The diameter of the first protrusion is 40 μm to 60 μm.

3. The backlight module according to claim 1, characterized in that: The density of the first bumps is 0.1% to 0.5%.

4. The backlight module according to claim 1, characterized in that: The distance between adjacent first protrusions is 2 mm to 10 mm.

5. The backlight module according to claim 1, characterized in that: The first optical film comprises a plurality of second protrusions, and the plurality of second protrusions protrude toward the back plate.

6. The backlight module according to claim 5, characterized in that: At least one of the second protrusions has a second height, and the second height is greater than or equal to 4 μm and less than or equal to 10 μm.

7. The backlight module according to claim 5, characterized in that: The density of the first bumps is less than the density of the second bumps.

8. The backlight module according to claim 5, characterized in that: It also includes a plurality of light-emitting units disposed on one side of the first optical film, wherein the density of the plurality of second protrusions adjacent to the side is smaller than the density of the plurality of second protrusions away from the side.

9. The backlight module according to claim 8, characterized in that: The density of the second bumps adjacent to the side is 1% to 3%.

10. The backlight module according to claim 8, characterized in that: The density of the second bumps away from the side is 30% to 50%.

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