Backlight module and display device

Abstract

The invention provides a backlight module and display equipment. The reflecting cover in the light-emitting part in the edge area of the backlight module is provided with the fluorescent powder, so that the conversion efficiency of blue light is effectively improved, the residual quantity of the blue light which is not converted is further reduced, and the problem of blue light overflow in the edge area of the backlight module is solved. The display device comprising the backlight module can have better picture uniformity and display quality.

Description

Technical Field

[0001] The present invention relates to a backlight module and a display device, and in particular to a backlight module and a display device capable of reducing blue light overflow in edge areas. Background Art

[0002] With the increasing popularity of mobile devices, televisions, monitors, and automotive panels, consumer demands for display quality continue to rise, including higher color saturation, narrower bezels, and a superior visual experience. To meet these demands, the technological development of backlight modules, a core component of LCDs, has become increasingly critical. Currently, mainstream backlight modules can be categorized as direct-lit and edge-lit, depending on the light source configuration. Direct-lit backlight modules have been widely adopted in various display devices due to their advantages, including uniform light distribution, excellent viewing angles, simple structure, and lower cost.

[0003] However, direct-lit backlight modules have the problem of blue light overflow or blue light smearing in the edge areas. Therefore, it is urgent to provide a new backlight module and display device to improve the above-mentioned shortcomings. Summary of the Invention

[0004] One aspect of the present invention provides a backlight module having a reflective cover in the light-emitting portion of the edge area with phosphor, thereby effectively improving the blue light conversion efficiency and further reducing the amount of residual unconverted blue light, thereby improving the blue light overflow problem in the edge area of ​​the backlight module.

[0005] Another aspect of the present invention provides a display device, which includes the backlight module of the above aspect.

[0006] According to one aspect of the present invention, a backlight module is provided, comprising: a circuit board; a plurality of first light source arrays disposed on a central region of the circuit board, the first light source arrays being arranged along a first direction and a second direction, respectively, wherein the first direction and the second direction are not parallel to each other; the first light source arrays comprising a plurality of first light emitting portions, each of which comprising: a first bottom portion; a plurality of first side walls, wherein the first bottom portion is connected to the first side walls to form a first accommodation space; a first light emitting diode chip disposed in the first accommodation space; and a first reflector disposed on the first side walls. The backlight module further comprises a plurality of second light source arrays disposed on an edge region of the circuit board, the second light source arrays surrounding the first light source array along the first direction and the second direction; the second light source arrays comprising a plurality of second light emitting portions, each of which comprising: a second bottom portion; a plurality of second side walls, wherein the second bottom portion is connected to the second side walls to form a second accommodation space; a second light emitting diode chip disposed in the second accommodation space; and a second reflector disposed on the second side walls, the second reflector comprising phosphor.

[0007] According to one embodiment of the present invention, along the first direction, the distance between the outer edge and the inner edge of the edge area on the same side is 1 cm to 2 cm, and along the second direction, the distance between the outer edge and the inner edge of the edge area on the same side is 1 cm to 2 cm.

[0008] According to an embodiment of the present invention, the light sources of the first LED chip and the second LED chip are blue light.

[0009] According to an embodiment of the present invention, the wavelength of the second LED chip is greater than the wavelength of the first LED chip.

[0010] According to an embodiment of the present invention, the wavelength of the first light emitting diode chip is 447 nm to 451 nm.

[0011] According to an embodiment of the present invention, the wavelength of the second LED chip is 456 nm to 463 nm.

[0012] According to an embodiment of the present invention, the driving current of the second LED chip is smaller than the driving current of the first LED chip.

[0013] According to an embodiment of the present invention, the first reflective cover does not have fluorescent powder.

[0014] According to an embodiment of the present invention, the phosphor is yellow.

[0015] According to another aspect of the present invention, a display device is provided, which includes the backlight module of the above aspect.

[0016] The present invention provides a backlight module and a display device incorporating the same. In particular, the reflector within the light-emitting portion of the edge region of the backlight module comprises phosphor. This effectively improves the blue light conversion efficiency and further reduces the amount of residual unconverted blue light, thereby improving the blue light overflow problem at the edge region of the backlight module. Furthermore, the display device incorporating the aforementioned backlight module can achieve improved image uniformity and display quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following detailed description, when read in conjunction with the accompanying drawings, will provide a better understanding of the aspects of this disclosure. It should be noted that, as is standard practice in the industry, many features are not drawn to scale. In fact, for clarity of discussion, the dimensions of many features may be arbitrarily scaled.

[0018] Figure 1 is a schematic structural diagram illustrating a backlight module according to some embodiments of the present invention;

[0019] Figure 2A and Figure 2B3D schematic diagrams respectively illustrate a first light emitting portion and a second light emitting portion of a backlight module according to some embodiments of the present invention.

[0020] Reference numerals:

[0021] 100: Backlight module

[0022] 110: Circuit board

[0023] 120: First light source array

[0024] 125: First light-emitting unit

[0025] 130: Central area

[0026] 140: Second light source array

[0027] 145: Second light-emitting unit

[0028] 150: Marginal area

[0029] 152: Outer edge

[0030] 154: Inner edge

[0031] 156: Outer edge

[0032] 158: Inner edge

[0033] 210: First bottom

[0034] 215: First side wall

[0035] 220: First light-emitting diode chip

[0036] 225: First reflector

[0037] 230: First accommodation space

[0038] 235: Second bottom

[0039] 240: Second side wall

[0040] 245: Second light-emitting diode chip

[0041] 250: Second reflector

[0042] 255: Second storage space

[0043] L1: First direction

[0044] L2: Second direction

[0045] D1, D2, D3, D4: distance

[0046] W1, W2: width DETAILED DESCRIPTION

[0047] The following disclosure provides many different embodiments or examples for implementing different features of the present disclosure. Specific embodiments of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, in the subsequent description, the formation of a first feature above or on a second feature may include an embodiment in which the first feature and the second feature are formed in direct contact, and may also include an embodiment in which another feature may be formed between the first feature and the second feature so that the first feature and the second feature are not in direct contact. In addition, the present disclosure may repeat numbers and / or text in different instances. The purpose of repetition is to simplify and clarify the description, not to define the relationship between the different embodiments and / or configurations discussed.

[0048] Furthermore, spatially relative terms such as "beneath," "below," "lower," "above," and "upper" are used to facilitate describing the relationships of components or features depicted in the drawings to other components or features. Spatially relative terms encompass different orientations of components in use or operation in addition to the orientation depicted in the drawings. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

[0049] As used herein, “around,” “about,” “approximately,” or “substantially” generally means within 20 percent, or within 10 percent, or within 5 percent of the stated value or range.

[0050] Despite the advantages of direct-lit backlight modules, such as uniform illumination, wide viewing angles, simple structure, and high cost-effectiveness, they still face the problem of bluish tinting or blue light bleeding in practical applications, impacting overall display quality and visual quality. This phenomenon is caused by the following factors: First, due to the short wavelength of blue light (approximately 450nm to 480nm), it is easily scattered within the optical structure, leading to blue light bleeding in the edge areas. Second, blue light emitted by the light-emitting diode (LED) undergoes multiple reflections, refractions, and scattering between the film, diffuser, and reflector. It should be effectively converted to white light by the quantum dot film (QD film). However, at the module's edges, due to spatial limitations and unfavorable light emission angles, some blue light cannot be fully excited by the quantum dots and is not directly transmitted, resulting in blue light accumulation and color cast at the edge areas. Furthermore, some blue light, without being excited by the quantum dot film, is directly scattered from the diffuser and film sides, resulting in an insufficient ratio of red to green light and an excessive ratio of blue light, which in turn causes a bluish tint at the edge areas. Therefore, even though the direct-lit design performs well overall, the issue of blue light spillage from the edges remains an important issue that must be addressed and improved.

[0051] As described above, the present invention provides a backlight module and a display device incorporating the same. In particular, the reflector within the light-emitting portion of the edge region of the backlight module comprises phosphor. This effectively improves the blue light conversion efficiency and further reduces the amount of residual unconverted blue light, thereby alleviating the problem of blue light spillage in the edge region of the backlight module. Furthermore, the display device incorporating the aforementioned backlight module exhibits improved image uniformity and display quality.

[0052] See also Figure 1 , which is a schematic diagram illustrating the structure of a backlight module 100 according to some embodiments of the present invention. The backlight module 100 of the present invention includes a circuit board 110, a plurality of first light source arrays 120, and a plurality of second light source arrays 140. In some embodiments, each first light source array 120 includes a plurality of first light-emitting portions 125. In some embodiments, the plurality of first light source arrays 120 are disposed in a central region 130 of the circuit board 110, and the first light source arrays 120 are arranged along a first direction L1 and a second direction L2, respectively. Figure 1 The first direction L1 and the second direction L2 are shown to be perpendicular, but the present invention is not limited thereto. It should be noted that the first direction L1 and the second direction L2 are not parallel to each other and are preferably perpendicular to each other, but may also intersect at a non-perpendicular angle.

[0053] In some embodiments, a plurality of second light source arrays 140 are disposed on the edge region 150 of the circuit board 110 and surround the first light source array 120 along the first direction L1 and the second direction L2. In some embodiments, each second light source array 140 includes a plurality of second light emitting units 145.

[0054] In some embodiments, along the first direction L1, the distance D1 and the distance D2 between the outer edge 152 and the inner edge 154 of the edge region 150 on the same side are 1 cm to 2 cm respectively; along the second direction L2, the distance D3 and the distance D4 between the outer edge 156 and the inner edge 158 of the edge region 150 on the same side are 1 cm to 2 cm respectively. In some embodiments, along the first direction L1, the ratio of the width W1 of the first light source array 120 of the central region 130 to the width (D1+D2) of the second light source array 140 of the edge region 150 is 10:4 to 20:4, preferably 19:4; along the second direction L2, the ratio of the width W2 of the first light source array 120 of the central region 130 to the width (D3+D4) of the second light source array 140 of the edge region 150 is 5:4 to 10:4, preferably 9:4. Figure 1 As shown, along the first direction L1, the ratio of the width of the first light source array 120 in the central area 130 to the width of the second light source array 140 in the edge area 150 is 10:4; along the second direction L2, the ratio of the width of the first light source array 120 in the central area 130 to the width of the second light source array 140 in the edge area 150 is 5:4, but the present invention is not limited to this.

[0055] See also Figure 2A , which is a three-dimensional schematic diagram of the first light-emitting portion 125 of the backlight module 100 according to some embodiments of the present invention. In some embodiments, each first light-emitting portion 125 includes a first bottom 210, a plurality of first side walls 215, a first light-emitting diode chip 220 and a first reflector 225. In some embodiments, the first bottom 210 connects the plurality of first side walls 215 to form a first accommodating space 230. In this embodiment, the plurality of first side walls 215 are connected to the first bottom 210 at an angle. In some embodiments, the above-mentioned angle is about 30° to about 90°, but the present invention is not limited thereto. In some embodiments, the first light-emitting diode chip 220 is disposed in the first accommodating space 230, and the first reflector 225 is disposed on the plurality of first side walls 215. In some embodiments, the light source of the first light-emitting diode chip 220 is blue light. In some embodiments, the first reflector 225 does not have phosphor.

[0056] See also Figure 2B, which is a three-dimensional schematic diagram of the second light-emitting portion 145 of the backlight module 100 according to some embodiments of the present invention. In some embodiments, each second light-emitting portion 145 includes a second bottom 235, a plurality of second side walls 240, a second light-emitting diode chip 245 and a second reflector 250. In some embodiments, the second bottom 235 is connected to the plurality of second side walls 240 to form a second accommodating space 255. In this embodiment, the plurality of second side walls 240 are connected to the second bottom 235 at an angle. In some embodiments, the above-mentioned angle is about 30° to about 90°, but the present invention is not limited thereto. In some embodiments, the second light-emitting diode chip 245 is disposed in the second accommodating space 255, and the second reflector 250 is disposed on the second side wall 240. In some embodiments, the light source of the second light-emitting diode chip 245 is blue light.

[0057] In some embodiments, the second reflector 250 includes a phosphor. In one specific example, the phosphor can be sprayed onto the second reflector 250. In this embodiment, the phosphor is yellow. In some embodiments, the phosphor sprayed onto the second reflector 250 has different widths or concentrations. This effectively improves the blue light conversion efficiency at the edge of the backlight module and further reduces the amount of residual unconverted blue light, thereby improving the bluish cast at the edge of the backlight module.

[0058] In some embodiments, the wavelength of the second LED chip 245 is greater than that of the first LED chip 220. In some embodiments, the wavelength of the first LED chip 220 is approximately 447 nm to approximately 451 nm, and the wavelength of the second LED chip 245 is approximately 456 nm to approximately 463 nm. By using short-wavelength, non-low-blue light LEDs in the center of the backlight module and long-wavelength, low-blue light LEDs in the edge areas of the backlight module, the probability of blue light scattering in the edge areas can be reduced, thereby preventing blue light overflow from occurring in the edge areas of the backlight module.

[0059] In some embodiments, the driving current of the second LED chip 245 is lower than the driving current of the first LED chip 220. In one specific example, the first LED chip 220 has a higher driving current, such as 2 mA, while the driving current of the second LED chip 245 is 70% of the driving current of the first LED chip 220, such as 1.4 mA. This means that the backlight module of the present invention can reduce the driving current of the second LED chip 245 in the edge region 150 by approximately 30% compared to the driving current of the first LED chip 220 in the center region 130. By reducing the driving current of the LEDs in the edge region of the backlight module, the intensity of the blue light emitted by the LEDs in the edge region of the backlight module can be reduced, thereby preventing blue light accumulation and color cast in the edge region of the backlight module.

[0060] The present invention further provides a display device comprising the above-mentioned backlight module, thereby having better picture uniformity and display quality.

[0061] In summary, the backlight module of the present invention includes phosphor in the reflector of the light-emitting portion in the edge region, thereby effectively improving the blue light conversion efficiency and further reducing the amount of residual unconverted blue light, thereby improving the problem of blue light overflow in the edge region of the backlight module. The display device of the present invention, including this backlight module, thus has better image uniformity and display quality.

[0062] Although the present invention has been disclosed above in terms of embodiments, this is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the appended patent applications.

Claims

1. A backlight module, characterized in that: include: circuit boards; A plurality of first light source arrays are disposed on a central area of ​​the circuit board, and the plurality of first light source arrays are arranged along a first direction and a second direction, respectively, wherein the first direction and the second direction are not parallel to each other, and the plurality of first light source arrays include a plurality of first light-emitting portions, and each of the plurality of first light-emitting portions includes: First bottom; a plurality of first side walls, wherein the first bottom portion is connected to the plurality of first side walls to form a first accommodating space; A first light-emitting diode chip, wherein the first light-emitting diode chip is disposed in the first accommodation space; and a first reflector, wherein the first reflector is disposed on the plurality of first sidewalls; and a plurality of second light source arrays, disposed on an edge region of the circuit board, wherein the plurality of second light source arrays surround the plurality of first light source arrays along the first direction and the second direction, the plurality of second light source arrays including a plurality of second light emitting portions, and each of the plurality of second light emitting portions including: Second bottom; a plurality of second side walls, wherein the second bottom portion is connected to the plurality of second side walls to form a second accommodating space; a second light-emitting diode chip, wherein the second light-emitting diode chip is disposed in the second accommodating space; and The second reflective cover is disposed on the plurality of second side walls and has fluorescent powder.

2. The backlight module according to claim 1, wherein: Along the first direction, the distance between the outer edge and the inner edge of the edge area on the same side is 1 cm to 2 cm, and along the second direction, the distance between the outer edge and the inner edge of the edge area on the same side is 1 cm to 2 cm.

3. The backlight module according to claim 1, wherein: The light sources of the first LED chip and the second LED chip are blue light.

4. The backlight module according to claim 1, wherein: The wavelength of the second LED chip is greater than the wavelength of the first LED chip.

5. The backlight module according to claim 4, wherein: The wavelength of the first light emitting diode chip is 447 nm to 451 nm.

6. The backlight module according to claim 4, wherein: The wavelength of the second light emitting diode chip is 456 nm to 463 nm.

7. The backlight module according to claim 1, wherein: The driving current of the second LED chip is smaller than the driving current of the first LED chip.

8. The backlight module according to claim 1, wherein: The first reflective cover does not have the fluorescent powder.

9. The backlight module according to claim 1, wherein: The phosphor is yellow.

10. A display device, characterized in that: It comprises the backlight module according to any one of claims 1 to 9.

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