Backlight module

Abstract

A backlight module including a substrate, a light guide plate, and multiple light sources. The light guide plate is disposed on the substrate and has a bottom surface, a top surface, and multiple accommodating recesses. The bottom surface and the top surface face away from each other. The bottom surface is located closer to the substrate than the top surface. The accommodating recesses are recessed inwards from the bottom surface. Each accommodating recess has a bottom surface and at least one light incident surface connected to the bottom surface. The normal direction of the light incident surface is non-parallel to the normal direction of the bottom surface. The light sources are electrically connected to the substrate and are disposed in the accommodating recesses of the light guide plate. Each light source emits light toward at least one light incident surface of one of the accommodating recesses.

Description

Technical Field

[0001] This invention relates to a light source device, and more particularly to a backlight module. Prior Technology

[0002] Generally speaking, backlight modules are roughly divided into direct-lit, edge-lit, and full-array types. Edge-lit backlight modules use light-emitting diodes that emit light from the side, along with a light guide plate, to guide the light to the display panel. Direct-lit and full-array types emit light directly from the back.

[0003] However, traditional direct-lit, edge-lit, and full-array backlight modules cannot simultaneously achieve thinness, low cost, and excellent local backlight adjustment. Specifically, direct-lit backlight modules require lenses, resulting in a thicker overall display; full-array backlight modules require LEDs to be placed throughout the entire backlight module, leading to higher costs; and edge-lit backlight modules, by placing the LEDs at the outermost edge, exhibit poor local backlight adjustment. Summary of the Invention

[0004] The present invention provides a backlight module in which a light source is disposed in a plurality of recesses arranged in multiple rows on the bottom surface of a light guide plate, so that the backlight module can achieve thinness, low cost and excellent local backlight adjustment effect.

[0005] An embodiment of the present invention discloses a backlight module comprising a substrate, a light guide plate, and a plurality of light sources. The light guide plate is disposed on the substrate and has a bottom surface, a top surface, and a plurality of receiving recesses. The bottom surface and the top surface face away from each other. The bottom surface is closer to the substrate than the top surface. The receiving recesses are recessed inward from the bottom surface. Each receiving recess has a groove bottom surface and at least one light-incident surface connected to the groove bottom surface. The normal direction of the light-incident surface is not parallel to the normal direction of the bottom surface. The light sources are electrically connected to the substrate and disposed in the receiving recesses of the light guide plate. Each light source emits light toward at least one light-incident surface of one of the receiving recesses.

[0006] According to the backlight module disclosed in the above embodiments, the receiving recess is recessed inward from the bottom surface of the light guide plate, and the light source is disposed in the receiving recess and emits light towards at least one light-incident surface of one of the receiving recesses. Therefore, the lens in a typical direct-lit backlight module can be eliminated, and the display using the backlight module can be made thinner by using the light guide plate as the light guiding medium for the light source. In addition, the light source disposed in the receiving recess can have excellent local backlight adjustment effect even if it does not fill the entire backlight module. In this way, the backlight module can achieve thinness, low cost, and excellent local backlight adjustment effect. Simple Explanation of the Diagram

[0007] Figure 1 is a side view of the display panel and the backlight module according to the first embodiment of the present invention. Figure 2 is a bottom view of the light guide plate, light shielding structure and light source of the backlight module in Figure 1. Figure 3 is a partial enlarged view of the light guide plate and light source in Figure 2. Figure 4 is a partially enlarged view of the side view of the light guide plate of the backlight module in Figure 1 from another perspective. Figure 5 is a partially enlarged view of the light guide plate and light source according to the second embodiment of the present invention from a lower perspective. Figure 6 is a partially enlarged view of the light guide plate according to the third embodiment of the present invention from a lower perspective. Figure 7 is a partially enlarged view of the light guide plate according to the fourth embodiment of the present invention from a lower perspective. Figure 8 is a partially enlarged view of the light guide plate according to the fifth embodiment of the present invention from a lower perspective. Figure 9 is a partially enlarged view of the light guide plate according to the sixth embodiment of the present invention from a lower perspective. Implementation

[0008] The following detailed description of the embodiments of the present invention outlines its features and advantages. This description is sufficient to enable anyone skilled in the art to understand the technical content of the embodiments of the present invention and to implement them accordingly. Furthermore, based on the disclosure, patent claims, and drawings in this specification, anyone skilled in the art can easily understand the relevant objectives and advantages of the present invention. The following embodiments further illustrate the points of the present invention but are not intended to limit the scope of the invention in any way.

[0009] Please refer to Figures 1 to 4. Figure 1 is a side view of the display panel and the backlight module according to the first embodiment of the present invention. Figure 2 is a bottom view of the light guide plate, light shielding structure and light source of the backlight module in Figure 1. Figure 3 is a partial enlarged view of the light guide plate and light source in Figure 2. Figure 4 is a partial enlarged view of the side view of the light guide plate of the backlight module in Figure 1 from another perspective.

[0010] In this embodiment, as shown in Figures 1 and 2, the backlight module 10 includes a substrate 100, a reflective layer 200, a light guide plate 300, multiple light sources 350, multiple first light-shielding structures 360, multiple second light-shielding structures 370, a top diffuser plate 400, a diffuser film 500, and two prisms 600 and 650. The backlight module 10 is used to transmit light to the display panel 20. The backlight module 10 and the display panel 20 can be housed in a housing (not shown) of the display.

[0011] The substrate 100 may be, for example, a circuit board. The reflective layer 200 is disposed on the substrate 100.

[0012] A light guide plate 300 is disposed on a substrate 100. Further, a reflective layer 200 is disposed between the light guide plate 300 and the substrate 100. That is, the light guide plate 300 is disposed on the substrate 100, for example, through the reflective layer 200. The light guide plate 300 has a bottom surface 301, a top surface 302, and a plurality of receiving recesses 303. The bottom surface 301 and the top surface 302 face away from each other. The bottom surface 301 is closer to the substrate 100 than the top surface 302. The receiving recesses 303 are recessed inward from the bottom surface 301 and arranged in multiple rows along an arrangement direction A1 (parallel to the X-axis direction). The arrangement direction A1 is not parallel to the normal direction N1 (parallel to the Z-axis direction) of the bottom surface 301, but rather perpendicular to each other. Each row of receiving recesses 303 includes at least two receiving recesses 303. In this embodiment, the receiving recesses 303 in each row are aligned with each other so that these receiving recesses 303 are arranged, for example, in a 3x13 array. That is, the receiving recesses 303 in this embodiment can be understood as being arranged in 3 rows along the arrangement direction A1, and each row of receiving recesses 303 contains 13 receiving recesses 303, or it can be understood as being arranged in 13 rows along the arrangement direction A2 (perpendicular to the arrangement direction A1 and parallel to the Y-axis direction), and each row of receiving recesses 303 contains 3 receiving recesses 303.

[0013] As shown in Figure 3, each receiving recess 303 has a groove bottom surface 304 and a plurality of light-incident surfaces 305 connected to the groove bottom surface 304. These light-incident surfaces 305 are adjacent to each other and are not parallel to each other. Furthermore, the normal direction N2 of the light-incident surfaces 305 is not parallel to the normal direction N1 of the bottom surface 301, but rather perpendicular to each other. In this embodiment, the receiving recess 303 is, for example, rectangular. Therefore, each receiving recess 303 has, for example, four light-incident surfaces 305. The normal directions N2 of two of the light-incident surfaces 305 are opposite to each other and parallel to the X-axis direction. The normal directions N2 of the other two light-incident surfaces 305 are opposite to each other and parallel to the Y-axis direction.

[0014] Light sources 350 are electrically connected to the substrate 100 and, for example, are disposed in the receiving recesses 303 of the light guide plate 300. That is, in this embodiment, one receiving recess 303, for example, accommodates one light source 350. Each light source 350 emits light toward at least one light-incident surface 305 of one of the receiving recesses 303. More specifically, in this embodiment, each light source 350, for example, has multiple emitting surfaces 351, and these emitting surfaces 351 of each light source 350 face these light-incident surfaces 305 in a corresponding receiving recess 303. That is, in this embodiment, each light source 350 emits light toward all light-incident surfaces 305 of the receiving recess 303 in which it is accommodated. Furthermore, these light sources 350 are, for example, light-emitting diodes (LEDs) and may have any color composition such as blue light, blue-green light, or ultraviolet light.

[0015] It should be noted that in other embodiments, a single recess may also accommodate multiple light sources.

[0016] Furthermore, in this embodiment, as shown in FIG4, the bottom surface 301 of the light guide plate 300 has, for example, a plurality of microstructures 3010. The microstructures 3010 are, for example, grooves, and are used to guide the light emitted by the light source 350 to a desired direction. In other embodiments, the bottom surface of the light guide plate may not need to have microstructures 3010.

[0017] As shown in Figures 2 and 4, the first light-shielding structures 360 are arranged parallel to each other in the light guide plate 300. The second light-shielding structures 370 are also arranged parallel to each other in the light guide plate 300. These first light-shielding structures 360 and second light-shielding structures 370 are located between the bottom surface 301 and the top surface 302, and are formed in the light guide plate 300 by any suitable method, such as laser processing, machining, transfer printing, or embossing. The extension direction E1 (parallel to the Y-axis) of the first light-shielding structures 360 is not parallel (e.g., perpendicular to each other) to the extension direction E2 (parallel to the X-axis) of the second light-shielding structures 370, and the first light-shielding structures 360 and second light-shielding structures 370 intersect each other, thereby separating the light sources 350 from each other. In this way, the first light-shielding structures 360 and second light-shielding structures 370 can prevent the light emitted by different light sources 350 from mixing, thereby improving the effect of local dimming.

[0018] In this embodiment, the light transmittance of the first light-shielding structure 360 ​​and the second light-shielding structure 370 is, for example, less than 10%. Furthermore, in this embodiment, as shown in FIG4, the thickness T1 of the first light-shielding structure 360 ​​and the second light-shielding structure 370 is greater than or equal to 10% and less than or equal to 90%, such as 80%, of the thickness T2 of the light guide plate 300. Through the above-mentioned light transmittance design and / or the above-mentioned thickness design, the first light-shielding structure 360 ​​and the second light-shielding structure 370 can further prevent the light emitted by different light sources 350 from mixing with each other. It should be noted that the effect of local dimming can also be improved by controlling the light emitted by the light source 350 from different light-emitting surfaces 351. In such an embodiment, the backlight module may not need to include the first light-shielding structure 360 ​​and the second light-shielding structure 370. Furthermore, the thickness T2 of the light guide plate 300 is, for example, greater than or equal to 0.1 mm and less than or equal to 2 mm.

[0019] The top diffuser plate 400 is disposed on the side of the light guide plate 300 away from the substrate 100. Alternatively, the top diffuser plate 400 is disposed on the top surface 302 of the light guide plate 300. Furthermore, the top diffuser plate 400 is in contact with or adjacent to the top surface 302 of the light guide plate 300. Therefore, the optical distance (OD) of the backlight module 10 is minimized as much as possible (i.e., the distance between the light source 350 and the top diffuser plate 400 is minimized as much as possible), which allows displays using the backlight module 10 to easily achieve a thinner profile.

[0020] A diffuser film 500 is disposed on the top diffuser plate 400. A prism 600 is disposed on the diffuser film 500. A prism 650 is disposed on the prism 600. It should be noted that, in this embodiment, the backlight module 10 includes a reflective layer 200, a top diffuser plate 400, a diffuser film 500, and prisms 600 and 650 according to actual needs. In other embodiments, the backlight module 10 may not include the reflective layer 200, the top diffuser plate 400, the diffuser film 500, and the prisms 600 and 650.

[0021] Other embodiments will be listed below for illustration. It must be noted that the following embodiments use the component reference numerals and some content from the foregoing embodiments, with the same reference numerals representing the same or similar components, and descriptions of identical technical content omitted. For explanations of the omitted parts, please refer to the foregoing embodiments; these will not be repeated in the following embodiments.

[0022] This invention is not limited to the arrangement of the light-emitting surface of the light source. Please refer to FIG5, which is a partially enlarged view of the light guide plate and the light source according to the second embodiment of the present invention. In this embodiment, the light source 350a has only one light-emitting surface 351a. The light-emitting surface 351a of each light source 350a faces one light-incident surface 305 in one of the corresponding receiving recesses 303. Furthermore, the normal directions N2 of the light-incident surfaces 305 faced by the light-emitting surfaces 351a of adjacent light sources 350a are different from each other. It should be noted that the light source 350a of this embodiment can replace the light source 350 of the first embodiment and be included in the backlight module 10.

[0023] The present invention is not limited to the shape of the receiving recess. Please refer to FIG6, which is a partially enlarged lower view of a light guide plate according to a third embodiment of the present invention. In this embodiment, for example, the receiving recess 303b of the light guide plate 300b is circular and has a light incident surface 305b in the shape of an annulus.

[0024] Alternatively, please refer to FIG7, which is a partially enlarged view of a light guide plate according to a fourth embodiment of the present invention. In this embodiment, for example, the receiving recess 303c of the light guide plate 300c is hexagonal and has six light-incident surfaces 305c.

[0025] This invention is not limited to the arrangement of the accommodating recesses. Please refer to FIG8, which is a partially enlarged lower view of a light guide plate according to a fifth embodiment of the present invention. In this embodiment, the accommodating recesses 303d of the light guide plate 300d are arranged in multiple rows, for example, along the arrangement direction A2, and the accommodating recesses 303d in adjacent rows are staggered.

[0026] Alternatively, please refer to FIG9, which is a partially enlarged view of a light guide plate according to a sixth embodiment of the present invention. In this embodiment, the receiving recesses 303e of the light guide plate 300e are arranged in multiple rows, for example, along the arrangement direction A1, and the receiving recesses 303e in adjacent rows are staggered.

[0027] It should be noted that the light guide plate 300b of the third embodiment, the light guide plate 300c of the fourth embodiment, the light guide plate 300d of the fifth embodiment, or the light guide plate 300e of the sixth embodiment can replace the light guide plate 300 of the first embodiment and be included in the backlight module 10.

[0028] According to the backlight module disclosed in the above embodiments, the receiving recess is recessed inward from the bottom surface of the light guide plate, and the light source is disposed in the receiving recess and emits light towards at least one light-incident surface of one of the receiving recesses. Therefore, the lens in a typical direct-lit backlight module can be eliminated, and the display using the backlight module can be made thinner by using the light guide plate as the light guiding medium for the light source. In addition, the light source disposed in the receiving recess can have excellent local backlight adjustment effect even if it does not fill the entire backlight module. In this way, the backlight module can achieve thinness, low cost, and excellent local backlight adjustment effect.

[0029] Although the present invention has been disclosed above with reference to the foregoing embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of patent protection of the present invention shall be determined by the scope of the patent application attached to this specification.

[0030] 10: Backlight Module 100:Substrate 200: Reflective layer 300, 300b, 300c, 300d, 300e: Light guide plate 301: Bottom 3010: Microstructure 302: Top surface 303, 303b, 303c, 303d, 303e: accommodation recess 304: Bottom surface of the groove 305, 305b, 305c: Incident surface 350, 350a: Light source 351, 351a: Light-emitting surface 360: First light-shielding structure 370: Second light-shielding structure 400: Top diffuser plate 500: Diffusion membrane 600, 650: Prism lenses 20: Display panel A1, A2: Arrangement direction N1, N2: Normal direction E1, E2: Extension direction T1, T2: Thickness

Claims

1. A backlight module, comprising: a substrate; a light guide plate disposed on the substrate and having a bottom surface, a top surface, and a plurality of receiving recesses, the bottom surface and the top surface facing away from each other, the bottom surface being closer to the substrate than the top surface, the receiving recesses being recessed inward from the bottom surface, each of the receiving recesses having a groove bottom surface and at least one light incident surface connected to the groove bottom surface, the normal direction of the light incident surfaces being non-parallel to the normal direction of the bottom surface; and a plurality of light sources electrically connected to the substrate and disposed in the receiving recesses of the light guide plate, each of the plurality of light sources... The backlight module is used to emit light toward at least one light-incident surface of one of the accommodating recesses; wherein the backlight module further includes a plurality of first light-shielding structures and a plurality of second light-shielding structures, the first light-shielding structures being arranged parallel to each other in the light guide plate, the second light-shielding structures being arranged parallel to each other in the light guide plate, the extending directions of the first light-shielding structures and the extending directions of the second light-shielding structures being non-parallel, and the first light-shielding structures and the second light-shielding structures intersecting each other, thereby separating the light sources from each other.

2. The backlight module as claimed in claim 1, wherein the recesses are arranged in multiple rows along an arrangement direction, and the recesses in each row are aligned with each other such that the recesses are arranged in an array.

3. The backlight module as claimed in claim 1, wherein the accommodating recesses are arranged in multiple rows along an arrangement direction, and the accommodating recesses in adjacent rows are staggered.

4. The backlight module as claimed in claim 1, wherein each of the light sources has a light-emitting surface, the number of the at least one light-incident surface of each of the receiving recesses is multiple, the light-incident surfaces of each of the receiving recesses are adjacent to each other and not parallel to each other, and the light-emitting surface of each of the light sources faces one of the light-incident surfaces in one of the corresponding receiving recesses.

5. The backlight module as claimed in claim 1, wherein each of the light sources has a plurality of light-emitting surfaces, each of the accommodating recesses has a plurality of at least one light-incident surface, the light-incident surfaces of each of the accommodating recesses are adjacent to each other and not parallel to each other, and the light-emitting surfaces of each of the light sources face the light-incident surfaces in one of the corresponding accommodating recesses.

6. The backlight module as described in claim 1 further includes a top diffuser plate disposed on the side of the light guide plate away from the substrate.

7. The backlight module as described in claim 6, wherein the top diffuser plate is in contact with or adjacent to the light guide plate.

8. The backlight module as described in claim 1, wherein the bottom surface of the light guide plate has a plurality of microstructures.

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