Backlight module and display panel

Abstract

The utility model relates to the technical field of display, particularly provides a backlight module and a display panel, and aims to solve the problem of how to improve the phenomenon of uneven brightness of a liquid crystal display panel so as to improve the display quality of the display panel. In order to achieve the purpose, the backlight module comprises a substrate, the substrate comprises a bottom plate and a folded edge connected to the bottom plate, and the folded edge is arranged around the bottom plate so that a concave cavity can be defined between the folded edge and the bottom plate; the lamp strip comprises a PCB (Printed Circuit Board) and a light-emitting device arranged on the PCB; the reflector plate comprises a middle area and a peripheral area surrounding the middle area, the middle area is provided with an avoiding hole for the light-emitting device to penetrate through, the middle area covers the PCB and the bottom plate, and the peripheral area covers the folded edge; wherein a crease is formed between the middle area and the peripheral area, a first through hole is formed in the reflector plate along the extending direction of the crease, and the first through hole corresponds to the end part of the PCB. According to the display panel, the phenomenon of uneven brightness of emergent light of the backlight module can be improved, and the display quality of the display panel is improved.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically providing a backlight module and a display panel. Background Technology

[0002] Liquid crystal displays (LCDs) are widely used display devices. The backlight module, as a crucial component of an LCD, provides the light source. For direct-lit backlight modules, factors such as the backplate's structural features and the stacking of LED strips can affect the flatness of the backplate, leading to uneven brightness on the display panel and reducing its display quality. Utility Model Content

[0003] This application aims to solve the aforementioned technical problem, namely, how to improve the uneven brightness of liquid crystal display panels, thereby enhancing the display quality of the display panels.

[0004] In a first aspect, this application provides a backlight module comprising:

[0005] A substrate includes a base plate and a flange connected to the base plate, the flange being disposed around the base plate to define a cavity between the flange and the base plate;

[0006] A light strip, having multiple light-emitting devices arranged in an array within the cavity, the light strip comprising a PCB and light-emitting devices disposed on the PCB;

[0007] A reflective sheet includes a central region and a peripheral region surrounding the central region. The central region has a clearance hole for the light-emitting device to pass through. The central region covers the PCB and the base plate, and the peripheral region covers the folded edge.

[0008] A crease is formed between the central region and the peripheral region, and a first through hole is provided on the reflective sheet along the extension direction of the crease, the first through hole corresponding to the end of the PCB.

[0009] In one technical solution of the aforementioned backlight module, the length of the first through hole along the extension direction of the crease is greater than the width of the PCB.

[0010] In one technical solution of the aforementioned backlight module, the length of the first through hole along the extension direction of the crease is greater than twice the width of the PCB.

[0011] In one technical solution of the aforementioned backlight module, the base plate is provided with multiple grooves, and a first slit is provided in the middle area near the crease, the first slit being located between two adjacent clearance holes.

[0012] In one technical solution of the aforementioned backlight module, the first slit includes a first segment and a second segment connected to both ends of the first segment. The extension direction of the first segment is parallel to the extension direction of the crease, and the extension direction of the second segment intersects with the extension direction of the first segment.

[0013] In one of the technical solutions for the aforementioned backlight module, multiple first slits are arranged side by side between any two adjacent clearance holes.

[0014] In one technical solution of the aforementioned backlight module, the peripheral area is provided with a second slit at the top corner near the folded edge. The second slit divides the peripheral area into multiple independent parts. The first end of each independent part is provided with multiple third slits along the extension direction of the second slit. The third slit divides the first end of the independent part into multiple lobes.

[0015] In one technical solution of the aforementioned backlight module, a second through hole is also provided on the reflective sheet. The second through hole is located on the side of the second slit near the middle region and communicates with the second slit.

[0016] In one technical solution of the aforementioned backlight module, the third slit is located at the end of the independent portion away from the middle region.

[0017] In one technical solution of the aforementioned backlight module, the extension direction of the third slit is perpendicular to the extension direction of the second slit, and the length of the third slit is 4-6mm.

[0018] In one technical solution of the aforementioned backlight module, ink dots are provided in the peripheral area; and / or

[0019] The intermediate area is provided with multiple printing zones at intervals, and each printing zone is provided with ink dots.

[0020] In one technical solution of the aforementioned backlight module, the backlight module further includes:

[0021] A support column is located within the recess and extends from the bottom plate toward the opening of the recess;

[0022] A diffuser plate is disposed at the top of the support column, and the diffuser plate is connected to the folded edge to close the cavity;

[0023] An optical film is disposed on the surface of the diffuser plate opposite to the support column.

[0024] In a second aspect, this application provides a display panel that includes the backlight module described in any one of the first aspects.

[0025] By employing the above technical solution, this application provides a first through hole on the reflective sheet, which disconnects the reflective sheet in the extension direction of the printed circuit board. This first through hole also blocks the transmission of tension between the middle and peripheral areas of the reflective sheet in the extension direction of the printed circuit board. Consequently, the tension is transmitted only on both sides of the printed circuit board. At this point, the tension on the portions of the reflective sheet located on both sides of the printed circuit board is essentially symmetrical, effectively improving the bulging phenomenon caused by uneven tension in various locations of the peripheral area. This enhances the fit between the peripheral area and the folded edge, improves the flatness of the peripheral area, and further improves the uneven brightness of the backlight module, thereby enhancing the display quality of the display panel. Attached Figure Description

[0026] The preferred embodiments of this application are described below with reference to the accompanying drawings, in which:

[0027] Figure 1 This is a longitudinal cross-sectional view of a backlight module according to an embodiment of this application;

[0028] Figure 2 This is a top view of a backlight module according to an embodiment of this application in a state without the reflector installed;

[0029] Figure 3 This is a top view of a backlight module according to an embodiment of this application after the reflector has been installed;

[0030] Figure 4 This is a schematic diagram showing the location of the peripheral area of ​​a reflective sheet near the end of a PCB according to an embodiment of this application;

[0031] Figure 5 This is a schematic diagram showing the location of the peripheral area of ​​the reflective sheet near the end of the PCB according to another embodiment of this application;

[0032] Figure 6 This is a top view of a reflective sheet after it has been attached to a substrate according to another embodiment of this application;

[0033] Figure 7 This is a partial schematic diagram of a reflective sheet at its apex corner position according to an embodiment of this application.

[0034] In the figure, the reference numerals refer to the following:

[0035] 1. Substrate; 11. Base plate; 111. Groove; 12. Folded edge; 2. LED strip; 21. PCB; 22. Light-emitting device; 3. Reflector; 31. Central area; 311. Clearance hole; 32. Peripheral area; 4. Support column; 5. Diffuser plate; 6. Optical film;

[0036] 100, concave cavity; 200, crease; 310, first through hole; 320, first slit; 321, first segment; 322, second segment; 330, second slit; 340, third slit; 350, second through hole. Detailed Implementation

[0037] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0038] It should be noted that in the description of this application, terms such as "upper," "lower," "left," "right," "inner," and "outer," which indicate direction or positional relationship, are based on the direction or positional relationship shown in the accompanying drawings. These terms are used merely for ease of description and do not indicate or imply that the relevant device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, ordinal numbers such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] Reference Figure 1 This is a longitudinal cross-sectional view of a backlight module according to an embodiment of the present application. The backlight module includes a substrate 1, a light strip 2, a reflector 3, a support column 4, a diffuser 5, and an optical film 6.

[0041] Combination Figure 1 , Figure 2 and Figure 3 ,in, Figure 2 This is a top view of a backlight module according to an embodiment of this application in the state without the reflector 3 installed. Figure 3 This is a top view of a backlight module according to an embodiment of the present application after the reflector 3 has been installed.

[0042] The substrate 1 serves as the mounting base for the entire backlight module, supporting the aforementioned functional components. The substrate 1 includes a base plate 11 and a flange 12 connected to the base plate 11. Optionally, the base plate 11 has a square structure, and the flange 12 fixes the four edges of the base plate 11. The flange 12 can be integrally formed with the base plate 11. The flange 12 is set at an angle to the base plate 11, thereby defining a cavity 100 between the flange 12 and the base plate 11. The lamp strip 2, reflector 3, and support column 4 are all disposed within the cavity 100.

[0043] The light strip 2 includes a PCB 21 and light-emitting devices 22 spaced apart on the PCB 21. The light-emitting devices 22 are electrically connected to the PCB 21, and the light-emitting devices 22 include, but are not limited to, LED tubes and other devices. (See reference...) Figure 2 In one implementation, multiple light strips 2 are arranged side by side along the base plate 11 so that the light-emitting devices 22 are arranged in a linear array on the base plate 11, thereby filling the cavity 100. It should be noted that the backlight module of this application adopts a "direct-input light source", that is, the light-emitting surface of the light-emitting device 22 faces the opening of the cavity 100, and the light emitted by the light-emitting device 22 is perpendicular to the plane where the optical film 6 is located.

[0044] The reflector 3 includes a central region 31 and a peripheral region 32 surrounding the central region 31. The central region 31 covers the base plate 11, and the peripheral region 32 covers the folded edge 12. The central region 31 of the reflector 3 has a clearance hole 311. After the light strip 2 is fixed to the base plate 11, during the process of attaching the reflector 3, the clearance hole 311 is aligned with the light-emitting device 22, allowing the light-emitting device 22 to pass through the clearance hole 311. Since the plane of the base plate 11 intersects with the plane of the folded edge 12, a crease 200 is formed after the reflector 3 is attached to the base plate 11. The crease 200 divides the reflector 3 into the central region 31 and the peripheral region 32.

[0045] Multiple support pillars 4 are arrayed on the base plate 11, with each support pillar 4 distributed between adjacent light strips 2. The support pillars 4 can be made of transparent PC material. A diffuser plate 5 is disposed at the top of the support pillars 4, with its edge connected to the folded edge 12, enclosing the cavity 100. An optical film 6 is disposed on the surface of the diffuser plate 5 facing away from the support pillars 4. The support pillars 4 support the diffuser plate 5, creating a fixed-size space between the diffuser plate 5 and the cavity 100, allowing the light emitted by the light-emitting device 22 to mix thoroughly within the cavity 100. The diffuser plate 5 serves to uniformly distribute the light and support the relatively soft optical film 6. The optical film 6 serves to uniformly distribute the light and improve the brightness of the backlight module. The materials of the diffuser plate 5 and the optical film 6, and their functions in the backlight module, are common knowledge in the art and will not be elaborated upon here.

[0046] In one embodiment of this application, ink dots (not shown in the figure) are evenly distributed within the peripheral area 32, while multiple printing areas are spaced apart within the central area 31, each containing ink dots. These ink dots are used to absorb excess stray light, preventing excessively bright local lighting, thereby improving display quality.

[0047] Reference Figure 2 Due to the unevenness of the surface of the base plate 11, wrinkles are formed in some areas of the surface of the reflector 3 after installation, resulting in local "bulges". This unevenness of the reflector 3 surface will affect the uniformity of light output, ultimately resulting in uneven brightness and reducing the display quality of the display panel.

[0048] Specifically, the unevenness of the base plate 11 is manifested in the following aspects: First, it is due to the structural characteristics of the base plate 11 itself. In order to improve the overall structural rigidity of the base plate 11, a "keel" is usually provided on the base plate 11. The "keel" causes the surface of the base plate 11 facing the opening side of the cavity 100 to form a groove. At the same time, holes for fitting fasteners such as bolts are also provided on the base plate 11, or wire grooves for wiring. These will all form depressions on the surface of the base plate 11.

[0049] Secondly, the light strip 2 itself has a certain thickness. Although the light-emitting device 22 passes through the avoidance hole 311 on the reflector 3 and protrudes from the middle area 31 of the reflector 3, the PCB 21 is fixed on the base plate 11, and the middle area 31 of the reflector 3 covers the PCB 21. Therefore, there is a height difference between the part of the middle area 31 above the PCB 21 and the part of the middle area 31 that is attached to the base plate 11, making the middle area 31 uneven. However, considering that there is a certain "light mixing distance" between the middle area 31 and the diffuser plate 5 and the optical film 6, the light uniformity at the location of the middle area 31 will not be too bad. However, for the peripheral area 32, the distance between it and the diffuser plate 5 and the optical film 6 is relatively close. The end of the light strip 2 near the folded edge 12 will affect the flatness of the peripheral area 32 laid along the folded edge 12. Specifically, when installing the reflector 3, since the middle area 31 is bonded and fixed to the base plate 11, the middle area 31 exerts a pulling force on the peripheral area 32. However, since the heights of the part of the middle area 31 that is attached to the base plate 11 and the part of the middle area 31 that is attached to the PCB 21 are different, the pulling forces exerted by the two parts on the corresponding positions of the peripheral area 32 are also different. The peripheral area 32 corresponding to the position of the base plate 11 experiences a larger pulling force, while the peripheral area 32 corresponding to the position of the PCB 21 experiences a smaller pulling force. This causes the peripheral area 32 to be stretched and deformed, forming a "bulge" phenomenon at the position corresponding to the PCB 21.

[0050] Finally, considering the structural features of the substrate 1, there are intersecting planes at the four corners of the folded edge 12, which makes it difficult for the peripheral area 32 of the reflective sheet 3 to fit flat at this position. Especially when the peripheral area 32 is subjected to pressure during the assembly process, it will cause unevenness at this position.

[0051] Therefore, this application improves the reflective sheet 3 of the backlight module based on the above reasons to improve the unevenness of the surrounding area 32.

[0052] Reference Figure 4 This is a schematic diagram showing the location of the peripheral region 32 of the reflective sheet 3 near the end of the PCB 21 according to an embodiment of this application, in conjunction with... Figure 2 and Figure 4 During the assembly of the backlight module, in order to ensure the uniformity of the distribution of the light-emitting devices 22 and to meet the electrical connection between the PCB 21 and the external power supply, the end of the PCB 21 usually extends to the edge of the fold 12, that is, close to the location of the crease 200. Based on this, this application provides a plurality of first through holes 310 spaced apart on the reflective sheet 3 along the extension direction of the crease 200. The number of first through holes 310 is the same as the number of light strips 2 and corresponds one-to-one with the end of each PCB 21.

[0053] The first through hole 310 has an elongated cross-section and extends along the width direction of PCB21 (i.e., the extension direction of crease 200). The length of the first through hole 310 is greater than the length of PCB21. Optionally, in one embodiment, the length of the first through hole 310 is greater than twice the width of PCB21.

[0054] This application provides a first through hole 310 on the reflective sheet 3, which disconnects the reflective sheet 3 in the extension direction of the PCB 21. In this way, the first through hole 310 also blocks the transmission of tension between the middle region 31 and the peripheral region 32 of the reflective sheet 3 in the extension direction of the PCB 21. Thus, the tension is transmitted only on both sides of the PCB 21. At this time, the tension of the part of the reflective sheet 3 located on both sides of the PCB 21 is basically symmetrical, which effectively improves the bulging phenomenon caused by uneven tension in various positions of the peripheral region 32. This improves the fit between the peripheral region 32 and the folded edge 12, improves the flatness of the peripheral region 32, and further improves the uneven brightness of the backlight module, thereby improving the display quality of the display panel.

[0055] Reference Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the location of the peripheral region 32 of the reflective sheet 3 near the end of the PCB 21 according to another embodiment of the present application. The shaded area in the figure represents the location of the keel on the base plate 11 (the keel is the one closest to the crease 200), which is manifested as a groove 111 on the surface of the base plate 11. Figure 6 This is a top view of the reflector 3 after it has been attached to the substrate 1, and Figure 6 This illustrates the state of the reflector 3 when the middle area 31 of the reflector 3 is bonded to the base plate 11, and the middle area 32 corresponds to the groove 111 position and is subjected to downward pressure (during the assembly of the backlight module, due to human operation factors, the worker's hand or other environmental components may inevitably put pressure on the local position of the reflector 3).

[0056] Depend on Figure 6 As can be seen, when the middle region 31, corresponding to the groove 111, is subjected to downward pressure, the position will deform under pressure and generate tension on both sides. The force is transmitted along the middle region 31 to the peripheral region 32, causing the peripheral region 32 to move obliquely downward, causing the peripheral region 32 to bulge upward, forming an alternating undulating wave state.

[0057] Based on this, this application provides a first slit 320 in the middle region 31 near the crease 200, and the first slit 320 is located between two adjacent clearance holes 311. The first slit 320 extends in a direction parallel to the crease 200. The setting of the first slit 320 can prevent the tensile force from being transmitted along the middle region 31 to the peripheral region 32. When the middle region 31 is stressed due to the force at the groove 111, the first slit 320 expands to release the tensile stress. In this way, the peripheral region 32 can maintain its fit with the folded edge 12, thereby effectively improving the flatness of the peripheral region 32, thereby improving the uniformity of light emitted by the backlight module and improving the display quality of the display panel.

[0058] Reference Figure 5 Optionally, the first slit 320 includes a first segment 321 and a second segment 322 connected to both ends of the first segment 321. The extension direction of the first segment 321 is parallel to the extension direction of the crease 200, and the extension direction of the second segment 322 intersects the extension direction of the first segment 321. The second segment 322 extends toward the side where the groove 111 is located, thus making the first slit 320 as a whole bridge-shaped structure. As described above, the first slit 320 is set as a "bridge-shaped" structure, which has a better resistance to deformation than a single "straight line" structure. Therefore, it can withstand greater tensile force, and under the same tensile force value, its deformation is smaller, which is beneficial to maintaining the overall flatness of the reflector 3.

[0059] Furthermore, in one implementation, multiple first slits 320 are arranged side-by-side between any two adjacent clearance holes 311, so that the tensile stress generated when the reflective sheet 3 is compressed can be fully cut off and absorbed by the multiple first slits 320. For example, in Figure 5In the embodiment shown, two first slits 320 are provided between the two clearance holes 311, and the two first slits 320 have the same structure. One of the first slits 320 is closer to the groove 111, while the second segment 322 of the other first slit 320 is closer to the clearance hole 311. This can absorb excess stress and improve the flatness of the surrounding area 32.

[0060] Reference Figure 7 This is a partial schematic diagram of the reflective sheet 3 at its apex corner position according to an embodiment of this application. (In conjunction with...) Figure 2 and Figure 7 Since the folded edge 12 has intersecting planes at its top corners instead of continuous flat surfaces, the peripheral area 32 of the reflective sheet 3 has second slits 330 at its top corners. The extension direction of the second slits 330 is perpendicular to the extension direction of the fold 200. The second slits 330 divide the peripheral area 32 into multiple independent parts. Specifically, in the embodiments of this application, the reflective sheet 3 and the substrate 1 are generally square in structure. Therefore, the reflective sheet 3 has four top corners, and the number of second slits 330 is four, dividing the peripheral area 32 into four independent parts.

[0061] Each independent section is elongated, corresponding to one side of the reflector 3. Each independent section has a first end and a second end. The first end of each independent section has multiple third slits 340 extending along the direction of the second slit 330. The direction of each third slit 340 is perpendicular to the direction of the second slit 330, and the length of each third slit 340 is 4-6 mm. The third slits 340 divide the first end of each independent section into multiple lobes. It should be noted that in any two adjacent independent sections, the first end of one independent section connects to the second end of the other independent section. Thus, during the assembly of the backlight module, when the top corner of the reflector 3 is deformed by external force and then the force disappears, the second end of one independent section can be inserted into one end of the adjacent independent section through the third slit 340, preventing the joint of the two independent sections from jamming due to deformation and causing warping. Therefore, by setting the second slit 330 and the third slit 340, not only can the unevenness of the surrounding area 32 at its top corner be improved, but also when subjected to external force, the adjacent independent parts are connected as one, which can also improve the structural rigidity of the surrounding area 32 and enhance the integrity of the reflector 3.

[0062] It should be noted that when the peripheral area 32 is subjected to force, the deformation of the part further away from the middle area 31 is greater. Therefore, the third cut 340 may be located at the end of the independent part that is far away from the middle area 31.

[0063] Optionally, the reflector 3 is further provided with a second through hole 350, which is located on the side of the second slit 330 near the middle region 31 and communicates with the second slit 330. In this way, the root of the second slit 330 can be prevented from tearing due to stress concentration.

[0064] This application also discloses a display panel that includes the backlight module in any of the above embodiments.

[0065] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A backlight module, characterized in that, include: A substrate includes a base plate and a flange connected to the base plate, the flange being disposed around the base plate to define a cavity between the flange and the base plate; A light strip, having multiple light-emitting devices arranged in an array within the cavity, the light strip comprising a PCB and light-emitting devices disposed on the PCB; A reflective sheet includes a central region and a peripheral region surrounding the central region. The central region has a clearance hole for the light-emitting device to pass through. The central region covers the PCB and the base plate, and the peripheral region covers the folded edge. A crease is formed between the central region and the peripheral region, and a first through hole is provided on the reflective sheet along the extension direction of the crease, the first through hole corresponding to the end of the PCB.

2. The backlight module according to claim 1, characterized in that, The length of the first through hole along the direction of the crease is greater than the width of the PCB.

3. The backlight module according to claim 2, characterized in that, The length of the first through hole along the direction of the crease is greater than twice the width of the PCB.

4. The backlight module according to claim 1, characterized in that, The base plate is provided with multiple grooves, and a first slit is provided in the middle area near the crease. The first slit is located between two adjacent clearance holes.

5. The backlight module according to claim 4, characterized in that, The first slit includes a first segment and a second segment connected to both ends of the first segment. The extension direction of the first segment is parallel to the extension direction of the crease, and the extension direction of the second segment intersects the extension direction of the first segment.

6. The backlight module according to claim 5, characterized in that, Multiple first cuts are arranged side by side between any two adjacent clearance holes.

7. The backlight module according to claim 4, characterized in that, The peripheral area has a second slit at the top corner near the folded edge, which divides the peripheral area into multiple independent parts. The first end of each independent part has a multiple third slit along the extension direction of the second slit, which divides the first end of the independent part into multiple lobes.

8. The backlight module according to claim 7, characterized in that, The reflective sheet is also provided with a second through hole, which is located on the side of the second slit near the middle region and communicates with the second slit.

9. The backlight module according to claim 7, characterized in that, The third cut is located at the end of the independent portion away from the intermediate region.

10. The backlight module according to claim 7, characterized in that, The extension direction of the third slit is perpendicular to the extension direction of the second slit, and the length of the third slit is 4-6 mm.

11. The backlight module according to claim 1, characterized in that, The surrounding area is provided with ink dots; and / or The intermediate area is provided with multiple printing zones at intervals, and each printing zone is provided with ink dots.

12. The backlight module according to any one of claims 1 to 11, characterized in that, The backlight module also includes: A support column is located within the recess and extends from the bottom plate toward the opening of the recess; A diffuser plate is disposed at the top of the support column, and the diffuser plate is connected to the folded edge to close the cavity; An optical film is disposed on the surface of the diffuser plate opposite to the support column.

13. A display panel, characterized in that, Includes the backlight module according to any one of claims 1 to 12.

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