Direct-lit backlight module capable of improving peripheral brightness, and display apparatus

Abstract

A direct-lit backlight module capable of improving peripheral brightness, the direct-lit backlight module comprising a back frame (100), which is provided with a bottom plate (100a) and a side wall (100b) surrounding the edge of the bottom plate (100a); a light panel (102), which is located on the bottom plate (100a) and has a plurality of light-emitting elements (104) arranged in an array pattern; a reflector member (106), which is located on the light panel (102) and has a plurality of reflector cups (106a), wherein the plurality of reflector cups (106a) are adjacent to each other and arranged in an array pattern, and the bottom surface of each reflector cup (106a) is provided with an opening (108), the plurality of light-emitting elements (104) being located in the plurality of openings (108); and a diffusion plate (110), which is arranged on the side wall (100b). The reflector member (106) further comprises a plurality of protrusions, each protrusion being higher than the side wall (106) and extending in a direction away from the bottom plate (100a), the bottom surface of each protrusion abutting against the top of the side wall (106). Further provided is a display apparatus comprising the direct-lit backlight module capable of improving peripheral brightness.

Description

Direct-lit backlight module and display device capable of improving peripheral brightness

[0001] This application claims priority to Chinese patent application No. 202310761269.0 filed on June 26, 2023, entitled “Direct-type backlight module and display device capable of improving peripheral brightness,” and all of its contents are incorporated herein by reference. Technical Field

[0002] The present invention generally relates to a direct-type backlight module, and more particularly to a direct-type backlight module capable of improving peripheral brightness and a display device using the direct-type backlight module. Background Art

[0003] Display panels and panel display devices using them have gradually become mainstream across various display devices. For example, various panel displays, home flat-screen televisions, flat-panel monitors for personal computers and laptops, and displays for mobile phones and digital cameras all utilize display panels. In recent years, market demand for liquid crystal display devices has grown significantly, and to meet the functional and aesthetic requirements of LCDs, the designs of backlight modules used in LCDs have also become increasingly diverse.

[0004] Common backlight modules on the market can be generally divided into two types: side-entry type and direct-down type, according to the difference in the incident position of the light source, so as to provide a uniform surface light source to the liquid crystal display module installed thereon. As the name suggests, the direct-down backlight module has a light source (such as LED chips or cold cathode fluorescent lamps CCFL) incident from the bottom surface of the panel, and a reflector is provided to reflect the light source emitted by the light-emitting component to the light-emitting surface, and a diffusion plate is provided to uniform the light source. However, in conventional technology, light is easily absorbed in the diffusion plate supporting area around the panel, resulting in a decrease in brightness, especially at the edges or corners of the light-emitting surface of the backlight module, thereby reducing the global uniformity of its surface scan (area scan) during detection, affecting the image quality that the panel can provide.

[0005] Summary of the Invention

[0006] In view of the problems encountered in the aforementioned conventional technology, the present invention proposes a novel backlight module structure, which is characterized in that a reflective sheet in the backlight module is formed with a raised portion near the periphery to reflect light, thereby preventing light from being absorbed at the periphery of the backlight module and causing a decrease in the brightness and global uniformity (area scan) or light output uniformity of the panel, and the raised portion of the reflective sheet can be used to position the diffuser plate arranged thereon.

[0007] The object of the present invention is to provide a direct-type backlight module that can improve peripheral brightness, comprising a back frame, which has a bottom plate and side walls surrounding the edge of the bottom plate; a light board, which is located on the bottom plate and has a plurality of light-emitting elements arranged in an array; a reflective sheet, which is located on the light board and includes a plurality of reflective cups, which are adjacent to each other and arranged in an array, each of which has an opening on the bottom surface, and the light-emitting element is located in the opening, and the reflective cup is used to reflect light emitted by the plurality of light-emitting elements; and a diffuser, which is arranged on the side wall; wherein the reflective sheet further includes a plurality of protrusions, each of which is higher than the side wall and extends in a direction away from the bottom plate, and the bottom surface of each protrusion abuts against the top of the side wall.

[0008] The present invention further provides a display device, comprising: the direct-lit backlight module capable of improving peripheral brightness as described above; and a display panel disposed above the direct-lit backlight module capable of improving peripheral brightness.

[0009] The direct-lit backlight module of the present invention, which can improve peripheral brightness, utilizes a protrusion higher than the side wall at the edge or corner of the reflector to help reflect light from the position where shadows are likely to be generated to the optical film above, thereby achieving the effect of improving brightness, uniformity across the entire area, or uniformity of light output.

[0010] These and other objects of the present invention will become more apparent from the detailed description of the preferred embodiments described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings constitute a part of this specification so that those skilled in the art can further understand the embodiments of the present invention. These drawings depict some embodiments of the present invention and together with the description herein explain its principles, in which:

[0012] FIG1 is a cross-sectional schematic diagram of a direct-lit backlight module capable of improving peripheral luminance according to an embodiment of the present invention;

[0013] 2 is an enlarged cross-sectional view of a corner portion of a direct-lit backlight module capable of improving peripheral luminance according to an embodiment of the present invention;

[0014] FIG3 is a perspective enlarged schematic diagram of a corner portion of a direct-lit backlight module capable of improving peripheral brightness according to an embodiment of the present invention; and

[0015] FIG. 4 is a plan view of a diffusion plate of a direct-lit backlight module capable of improving peripheral luminance according to an embodiment of the present invention.

[0016] Please note that all the figures in this specification are of an illustrative nature. For the sake of clarity and convenience in describing the figures, the components in the figures may be exaggerated or reduced in size and proportion. Generally speaking, the same figure marks in the figures are used to indicate corresponding or similar component features after modification or in different embodiments. DETAILED DESCRIPTION

[0017] Below will be described in detail exemplary embodiments of the present invention, which will be illustrated with reference to the accompanying drawings so that those skilled in the art can understand and achieve technical effects. Those skilled in the art will appreciate that the description herein is merely illustrative of the present invention and is not intended to limit the present invention. Various embodiments of the present application and various features that do not conflict with each other in the embodiments may be combined or reset in various ways. Without departing from the spirit and scope of the present invention, modifications, equivalents or improvements to the present application are understandable to those skilled in the art and are intended to be included within the scope of the present application.

[0018] Those skilled in the art should be able to easily understand that the meanings of "on," "on," and "above" in the present invention should be interpreted in a broad manner, so that "on" not only means "directly on" something, but also includes the meaning of being "on" something with intervening features or layers, and "on" or "above" not only means "on" or "above" something, but also includes the meaning of being "on" or "above" something with no intervening features or layers (i.e., directly on something).

[0019] In addition, spatially relative terms such as "under," "beneath," "lower," "over," and "upper" are intended herein for convenience and may be used to describe the relationship of one element or feature to another element or features, as shown in the accompanying drawings.

[0020] Those skilled in the art can generally understand terms, at least in part, from usage in context. For example, depending at least in part on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or can be used to describe a combination of features, structures, or characteristics in a plural sense. Similarly, depending at least in part on the context, terms such as "a," "an," "the," or "said" can also be understood to convey singular usage or to convey plural usage. Additionally, the term "based on" can be understood to not necessarily be intended to convey an exclusive set of factors, but rather can allow for the presence of additional factors that are not necessarily explicitly described, again depending at least in part on the context.

[0021] Those skilled in the art will further understand that when words such as "include" and / or "contain" are used in this specification, they define the existence of the stated features, regions, wholes, steps, operations, elements and / or parts, but do not exclude the possibility of the existence or addition of one or more other features, regions, wholes, steps, operations, elements, parts and / or their combinations.

[0022] Please refer to Figure 1, which is a cross-sectional schematic diagram of a direct-lit backlight module capable of enhancing peripheral brightness according to an embodiment of the present invention. As shown in Figure 1, the direct-lit backlight module proposed in the present invention generally comprises a back frame 100, a light panel 102, a reflective sheet 106, and a diffuser 110. The back frame 100 can be a plate made of a rigid material such as metal, which has a predetermined mechanical strength and support capacity. The light panel 102 is disposed on the back frame 100 and has a plurality of light-emitting elements 104 arranged in an array thereon to provide light. In an embodiment of the present invention, the light panel 102 can be a printed circuit board, and the light-emitting elements 104 disposed thereon can be light-emitting diodes (LEDs), but the present invention is not limited thereto. The reflective sheet 106 is a three-dimensional reflective sheet and is disposed around the light panel 102 and the periphery of the back frame 100. In an embodiment of the present invention, the reflective sheet 106 is made of a material with high reflectivity and low transmittance, such as PET (polyethylene terephthalate), to reflect light emitted by the light-emitting elements 104. The diffusion plate 110 is mounted on the back frame 100 , and its function is to further homogenize the light emitted by the light source through particles evenly distributed therein, so as to make the emitted light more uniform.

[0023] For example, the upwardly extending portion of the reflective sheet 106 can be located at the periphery of the overall direct-type backlight module, such as a corner position or any edge position. In another embodiment, the upwardly extending portion of the reflective sheet 106 can also be applied to the edge position of a non-rectangular (irregular) direct-type backlight module. In the direct-type backlight module of the present invention that can improve the peripheral brightness, the upwardly extending portion of the reflective sheet 106 is used for the diffuser plate 110 to support, which can reduce the situation in which the direct-type backlight module is easily absorbed by the diffuser plate 110 or other components. In other words, in edge areas or corner areas where shadows are easily generated, the present invention uses the reflective function of the reflective sheet 106 to reflect light upward to improve the brightness of the edge area or corner area, thereby achieving better uniformity of the entire area or uniformity of light output.

[0024] Now please refer to Figure 2, which is an enlarged cross-sectional schematic diagram of a corner portion of a direct-lit backlight module capable of improving peripheral brightness according to an embodiment of the present invention. As for the detailed features of the direct-lit backlight module capable of improving peripheral brightness of the present invention, as shown in Figure 2, the back frame 100 has a bottom plate 100a and a side wall 100b surrounding the edge of the bottom plate 100a, thereby forming an accommodating space S. The light board 102 is disposed on the bottom plate 100a of the back frame 100 and is located in the accommodating space S, and the reflective sheet 106 is disposed on the light board 102 and the back frame 100. In an embodiment of the present invention, the reflective sheet 106 includes a plurality of reflective cups 106a, a positioning portion 106b, a base 106c, and a support wall 106d, wherein the plurality of reflective cups 106a are adjacent to each other and can be arranged in an array on the bottom plate 100a of the back frame 100 (as shown in Figure 1). Furthermore, each reflector cup 106a has an opening 108 on its bottom surface. The light emitting element 104 on the light board 102 can extend into the reflector cup 106a through the opening 108. The inclined sidewall of the reflector cup 106a can reflect the light emitted by the light emitting element 104 toward the light emitting surface.

[0025] In the embodiment of the present invention, the portion of the reflective sheet 106 that is higher than the sidewall 100b of the back frame 100 is defined as the raised portion of the reflective sheet 106, which includes a positioning portion 106b and a base portion 106c. As shown in FIG2 , the positioning portion 106b of the reflective sheet 106 is connected to the base portion 106c and extends and projects away from the bottom plate 100a of the back frame 100 (as shown in FIG2 , it projects vertically upward relative to the bottom plate 100a of the back frame 100). The base portion 106c of the reflective sheet 106 extends laterally around the bottom plate 100a, such that the bottom surface of the base portion 106c rests against the top of the sidewall 100b of the back frame 100. Furthermore, the support wall 106d of the reflective sheet 106 extends from the base portion 106c along the sidewall 100b of the back frame 100 toward the bottom plate 100a. Through the base 106 c and the support wall 106 d , the reflective sheet 106 can be abutted against and positioned on the side wall 100 b of the back frame 100 .

[0026] Referring to Figures 2 and 3 , the positioning portions 106b and base portion 106c of the reflective sheet 106 are preferably located at corners of the back frame 100. The diffuser plate 110 is mounted on the sidewall 100b of the back frame 100, with the reflective sheet 106 spaced apart. More specifically, in an embodiment of the present invention, as shown in Figure 4 , the diffuser plate 110 has notches 110a formed at locations corresponding to the raised portions (i.e., the positioning portions 106b and base portion 106c) (e.g., at the corners of the back frame 100). The positioning portions 106b of the reflective sheet 106 are receivable within the notches 110a, thereby positioning the diffuser plate 110 thereon. Furthermore, as shown in Figure 3 , the reflective sheet 106 further includes a platform portion 106e located at a non-corner portion of the sidewall 100b of the back frame 100, extending laterally from the edge of the reflective sheet 106 to the top surface of the sidewall 100b. In this way, the brightness of the edge area can be improved by the reflective sheet 106 located below the edge of the diffuser, thereby achieving better uniformity or uniformity of light output across the entire area. The platform portion 106e of the reflective sheet 106 is laterally connected to the base portion 106c, and the top surfaces of the two can be at the same height and flush. In an embodiment of the present invention, in the non-corner area of ​​the back frame 100, the diffuser 110 rests on the platform portion 106e of the reflective sheet 106, and in the corner area of ​​the back frame 100, the diffuser 110 achieves a positioning effect with the corresponding positioning portion 106b of the reflective sheet 106 through the notch 110a. In this way, the brightness of the edge area and corner area can be improved by the reflective sheet 106 located below the edge of the diffuser, thereby achieving better uniformity or uniformity of light output across the entire area. In other embodiments, the positioning portion 106 b may also be formed on any side of the reflective sheet 106 , and a notch 110 a may be formed on the side of the diffuser 110 corresponding to the positioning portion 106 b .

[0027] Continuing with Figure 2 , the direct-lit backlight module of the present invention, which can enhance peripheral brightness, further includes at least one optical film 112, which is disposed on the diffuser plate 110 and similarly achieves a positioning effect via the positioning portion 106b of the reflective sheet 106. The optical film 112 may include a color conversion sheet and a prism sheet. The prism sheet deflects light toward the front viewing angle to achieve a concentrated and brightening effect, while the color conversion sheet converts the light waves emitted by the light-emitting element 104 to improve color reproduction and durability, but the present invention is not limited to this. In an embodiment of the present invention, the top of the positioning portion 106b of the reflective sheet 106 may be flush with the surface of the optical film 112, thereby achieving a better assembly and fixation effect. Furthermore, the direct-lit backlight module further includes a top frame 114. The top frame 114 may be made of a rigid material such as metal or a structurally strong plastic material. It has a predetermined mechanical strength and support capacity, and together with the back frame 100, it sandwiches the reflective sheet 106 and the diffuser plate 110 therebetween. More specifically, the top frame 114 covers the edge positioning portion 106b and the optical film 112, and the side can be combined with the side wall 100b of the back frame 100 to sandwich the reflective sheet 106, the diffuser 110 and the optical film 112 therebetween.

[0028] In the embodiment of the present invention, the reflective sheet is formed with four upwardly protruding positioning portions at the four corners of the direct-lit backlight module, which can improve peripheral brightness. These positioning portions are used to block light emitted from the sides of the diffuser plate 110 or the optical film 112, effectively reducing the distance the light travels. Furthermore, the highly reflective positioning portions reflect light into the diffuser plate 110 or the optical film 112, thereby achieving 74% full-area uniformity. Compared to the 70% full-area uniformity of conventional backlight modules, this embodiment can improve full-area uniformity by 4%. Therefore, the present invention can effectively achieve the effects of improving corner brightness and optimizing full-area uniformity.

[0029] In summary, the advantage of the present invention over conventional technology lies in that the reflector sheet is provided with upwardly protruding positioning portions near the periphery of the back frame (e.g., edges or corners), and these positioning portions correspond to the notches in the diffuser plate. This not only achieves the aforementioned positioning effect, but also improves the light reflection efficiency at the edges or corners. In contrast, conventional reflectors do not have a corner protrusion design. Therefore, light from the corners of the backlight module in conventional technology is easily absorbed there, resulting in a decrease in the panel's brightness and global uniformity (area scan). Therefore, compared to conventional technology, the present invention can indeed achieve the effect of improving corner brightness and optimizing overall uniformity.

[0030] In addition to the aforementioned embodiments, the present invention also provides a display device, as shown in FIG1 , which includes the direct-lit backlight module capable of enhancing peripheral luminance and all of its features described in the aforementioned embodiments, as well as a display panel 116 disposed above the direct-lit backlight module. Therefore, the display device of the present invention also exhibits improved uniformity across the entire area, resulting in superior optical quality.

[0031] The above descriptions are merely preferred embodiments of the present invention. All equivalent changes and modifications made within the scope of protection of the present invention should fall within the scope of the present invention.

[0032] Reference Signs 100 Back frame 100a Bottom plate 100b Side wall 102 Light board 104 Light emitting element 106 Reflection sheet 106a Reflection cup 106b Positioning portion 106c Base 106d Support wall 106e Platform portion 108 Opening 110 Diffuser plate 110a Notch 112 Optical film 114 Top frame 116 Display panel S accommodating space

Claims

1. A direct-type backlight module capable of improving peripheral brightness, comprising: A back frame having a bottom plate and side walls surrounding the edge of the bottom plate; A light board, which is located on the bottom plate and has a plurality of light-emitting elements arranged in an array; A reflector sheet, which is located on the light board, and includes a plurality of reflector cups, which are adjacent to each other and arranged in an array, each of which has an opening on the bottom surface, and the light-emitting element is located in the opening, and the reflector cup is used to reflect the light emitted by the plurality of light-emitting elements; as well as a diffusion plate, which is arranged on the side wall; The reflective sheet further includes a plurality of protrusions, each of which is higher than the side wall and extends in a direction away from the bottom plate, and the bottom surface of each protrusion abuts against the top of the side wall.

2. The direct-lit backlight module capable of improving peripheral brightness according to claim 1, wherein: A notch is formed at a position of the diffusion plate corresponding to the protrusion, and the protrusion is accommodated in the notch.

3. The direct-lit backlight module capable of improving peripheral brightness according to claim 2, wherein: The reflection sheet further has a platform portion, which extends from the edge region of the reflection sheet to the top surface of the side wall, and is located between the diffusion sheet and the side wall, and the diffusion plate abuts against the platform portion.

4. The direct-lit backlight module capable of improving peripheral brightness according to claim 3, wherein: The raised portion includes a positioning portion and a base, the positioning portion is connected to the base, and the bottom surface of the base is against the top of the side wall, the positioning portion is accommodated in the notch, and the base is connected to the platform portion on a side facing the diffuser plate, and the diffuser plate is against the base and the platform portion. 5 . The direct-lit backlight module capable of improving peripheral brightness according to claim 1 , further comprising an optical film, wherein the tops of the plurality of protrusions are flush with the surface of the optical film. 6 . The direct-lit backlight module capable of improving peripheral brightness according to claim 5 , further comprising a top frame, wherein the top frame covers the edges of the plurality of protrusions and the optical film.

7. The direct-lit backlight module capable of improving peripheral brightness according to claim 1, wherein: The reflective sheet further includes a supporting wall, and the supporting wall extends from the protruding portion along the side wall of the back frame toward the bottom plate.

8. The direct-lit backlight module capable of improving peripheral brightness according to claim 1, wherein: The plurality of protrusions of the reflective sheet are located at corners of the back frame.

9. A display device, comprising: A direct-lit backlight module capable of improving peripheral brightness according to any one of claims 1 to 8; and The display panel is arranged above the direct-type backlight module capable of improving peripheral brightness.

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