Backlight module

Abstract

The invention provides a backlight module. The backlight module comprises a rubber frame, a light guide plate and an optical film. The rubber frame is arranged on the light-emitting surface of the light guide plate, and the light guide plate comprises a connecting part, a positioning column and a positioning concave part. The connecting part is adjacent to the light incident surface of the light guide plate, and the rubber frame covers the connecting part of the light guide plate. The positioning column and the positioning concave part are arranged on the connecting part of the light guide plate, and the positioning concave part surrounds the periphery of the positioning column. The optical film is overlapped on the light-emitting surface of the light guide plate and located between the light guide plate and the rubber frame. The optical film comprises a positioning hole, and the inner edge of the positioning hole is used for abutting against the periphery of the positioning column. Therefore, the assembly tightness between the light guide plate and the optical film in the backlight module can be improved, so as to reduce shaking abnormal noise.

Description

Technical Field

[0001] The invention relates to a backlight module. Background Art

[0002] During the assembly of the internal components of the backlight module, the optical film needs to be placed on the positioning posts on the light guide plate through the positioning holes on the optical film, so as to limit the relative displacement between the optical film and the light guide plate (especially in the horizontal direction). Generally speaking, the size of the positioning holes on the optical film needs to be larger than the positioning posts on the light guide plate, so that there is a gap between the positioning holes and the positioning posts for easy assembly. However, if the gap is too large, it is easy to cause the assembly between the optical film and the light guide plate to be not tight enough, so when the backlight module is shaken or vibrated, the optical film on the light guide plate will also shake more. A larger shaking amplitude will not only produce a louder collision noise, but also increase the risk of wear on the optical film or the light guide plate.

[0003] On the other hand, because the molding process of the light guide plate positioning column includes a demolding step, a rounded corner that is easy to demold will be formed at the bottom of the positioning column, so that the bottom of the positioning column will become wider. In the case of a rounded corner, in order to avoid interference, the positioning hole of the optical film cannot be completely fitted to the periphery of the bottom of the positioning column. Therefore, the gap between the positioning hole of the optical film and the positioning column of the light guide plate is difficult to reduce. Summary of the invention

[0004] Therefore, an embodiment of the present invention provides a backlight module, which helps to improve the tightness of the assembly between the light guide plate and the optical film in the backlight module, thereby reducing shaking and abnormal noise.

[0005] At least one embodiment of the present invention provides a backlight module, which includes a rubber frame, a light guide plate and an optical film. The rubber frame is arranged on a light emitting surface of the light guide plate, and the light guide plate includes a connecting portion, a positioning column and a positioning recess. The connecting portion is adjacent to a light incident surface of the light guide plate, and the rubber frame covers the connecting portion of the light guide plate. The positioning column and the positioning recess are arranged on the connecting portion of the light guide plate, and the positioning recess surrounds a periphery of the positioning column. The optical film is overlapped and arranged on the light emitting surface of the light guide plate, and is located between the light guide plate and the rubber frame. The optical film includes a positioning hole, and the inner edge of the positioning hole is used to abut against the periphery of the positioning column.

[0006] In at least one embodiment of the present invention, the positioning recess includes an opening and a bottom end. There is a depth between the bottom end and the opening, and five times of the depth is not greater than a thickness of the light guide plate.

[0007] In at least one embodiment of the present invention, the positioning recess includes an opening and a bottom end. There is a depth between the bottom end and the opening, and the ratio between a width of the opening and the depth falls within a range of 1.5 to 2.0.

[0008] In at least one embodiment of the present invention, the positioning recess includes an opening and a bottom end. There is a depth between the bottom end and the opening, and the ratio of a thickness of the optical film to the depth falls within a range of 1.0 to 1.7.

[0009] In at least one embodiment of the present invention, twice a height of the positioning post is smaller than a width of the positioning post.

[0010] In at least one embodiment of the present invention, an intersection angle between a bottom end of the positioning recess and a periphery of the positioning post is a rounded angle, and a radius of curvature of the rounded angle falls within a range of 0.2 mm to 0.3 mm.

[0011] In at least one embodiment of the present invention, the optical film includes a prism sheet and a diffusion sheet.

[0012] In at least one embodiment of the present invention, the backlight module further comprises a light shielding layer disposed on the plastic frame, the light shielding layer covers the connecting portion of the light guide plate, and the plastic frame is located between the light shielding layer and the optical film.

[0013] In at least one embodiment of the present invention, the light shielding layer covers at least 0.5 times of a width of the positioning post.

[0014] In at least one embodiment of the present invention, the backlight module further includes a light source module disposed on the light incident surface of the light guide plate, and the light source module is used to emit a light toward the light guide plate.

[0015] In the above embodiment, a positioning recess is provided on the light guide plate in the backlight module. Since the bottom end of the positioning recess is recessed in the light emitting surface of the light guide plate, even if the inner edge of the positioning hole of the optical film abuts against the periphery of the positioning column, the inner edge of the positioning hole will not fit the intersection angle between the bottom end of the positioning recess and the periphery of the positioning column, so that interference of light emitted from the light emitting surface of the light guide plate can be avoided. Therefore, the inner edge of the positioning hole of the optical film can be as close as possible to the periphery of the positioning column of the light guide plate to reduce the gap between the positioning hole and the positioning column. In this way, the shaking amplitude between the conductive column and the optical film in the backlight module under shaking or vibration can be reduced, thereby improving the abnormal sound problem caused by shaking. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be understood from the following detailed description and the accompanying drawings. It should be noted that various features are not drawn to the standard scale in industry practice. In fact, the size of various features may be arbitrarily increased or decreased for clarity of discussion.

[0017] Figure 1 A partial top view of a backlight module according to at least one embodiment of the present invention is shown.

[0018] Figure 2 Draw Figure 1 A cross-sectional view of the backlight module along line segment AA.

[0019] Figure 3 A schematic diagram illustrating a backlight module disposed in a display device according to at least one embodiment of the present invention.

[0020] Wherein, the reference numerals are:

[0021] 100: Backlight module

[0022] 110: Light source module

[0023] 120: plastic frame

[0024] 140: Light guide plate

[0025] 140e: light-emitting surface

[0026] 140i: light incident side

[0027] 142: Connecting part

[0028] 144: Positioning column

[0029] 144p: Periphery

[0030] 146: Positioning recess

[0031] 146b: bottom

[0032] 146p: Opening

[0033] 150: Light shielding layer

[0034] 160: Optical film

[0035] 161,165: Prism

[0036] 162: Positioning hole

[0037] 162i: Inner edge

[0038] 163: Diffuser

[0039] 170: Back panel

[0040] 180: Covering layer

[0041] 190:Joint layer

[0042] 30: Display device

[0043] 301: LCD panel

[0044] AA: Line segment

[0045] A1: Angle of intersection

[0046] d1: depth

[0047] h1:Height

[0048] L1, L2: light

[0049] t1, t2: thickness

[0050] w1,w2: width DETAILED DESCRIPTION

[0051] The present invention will be described in detail with the following examples. It should be noted that the following description of the embodiments of the present invention is only for illustration and is not intended to exhaustively disclose all embodiments or to limit the specific embodiments of the present invention. For example, the description of "a first feature formed on a second feature" includes multiple implementations, including the first feature directly contacting the second feature, and also including additional features formed between the first feature and the second feature so that the two are not in direct contact. In addition, the same element symbols used in the drawings and the specification will represent the same or similar elements as much as possible.

[0052] Spatially relative terms, such as "lower," "below," "beneath," "above," and related terms, are used herein to simply describe the relationship of an element or feature as shown in the figure to another element or feature. These spatially relative terms cover different orientations when using or operating the device in addition to the orientation depicted in the figure. In addition, when the element is rotatable (rotated 90 degrees or other angles), the spatially relative descriptors used herein can also be interpreted accordingly.

[0053] In the following text, in order to clearly present the technical features of the present invention, the dimensions (such as length, width, thickness and depth) of the elements (such as layers, films, substrates and regions, etc.) in the drawings will be enlarged in unequal proportions. Therefore, the description and explanation of the embodiments below are not limited to the dimensions and shapes presented by the elements in the drawings, but should cover the dimensions, shapes and deviations thereof caused by actual processes and / or tolerances. For example, the flat surface shown in the drawings may have rough and / or nonlinear features, while the acute angles shown in the drawings may be rounded. Therefore, the elements presented in the drawings of the present invention are mainly for illustration, and are not intended to accurately depict the actual shape of the elements, nor are they intended to limit the scope of the patent application of the present invention.

[0054] Furthermore, the words "about", "approximately" or "substantially" appearing in the present case not only cover the numerical values ​​and numerical ranges clearly recorded, but also cover the permissible deviation range that can be understood by a person with ordinary knowledge in the technical field to which the invention belongs, wherein the deviation range can be determined by the error generated during measurement, and the error is caused by, for example, the limitation of the measurement system or process conditions. In addition, "about" can mean within one or more standard deviations of the above numerical values, such as ±30%, ±20%, ±10% or ±5%. The words "about", "approximately" or "substantially" appearing in the present text can select the acceptable deviation range or standard deviation according to the optical properties, etching properties, mechanical properties or other properties, and not just one standard deviation can be applied to all the above optical properties, etching properties, mechanical properties and other properties.

[0055] Figure 1 A partial top view of a backlight module 100 according to an embodiment of the present invention ( Figure 1 Omit Figure 2 The plastic frame 120, the light shielding layer 150, the covering layer 180 and the bonding layer 190 are Figure 2 for Figure 1 The cross-sectional view of the backlight module 100 along the line segment AA is shown in FIG. Figure 1 and Figure 2 The backlight module 100 includes a plastic frame 120, a light guide plate 140, and an optical film 160. In addition, the backlight module 100 also includes a light source module 110, and the light source module 110 is used to emit light L1 toward the light guide plate 140. The light source module 110 includes a plurality of light-emitting elements (not shown) and a circuit substrate (not shown) for controlling the light-emitting elements. The light-emitting elements can be, for example, organic light-emitting diodes (OLED), micro light-emitting diodes (MicroLED), or other similar light-emitting elements.

[0056] like Figure 2 As shown, the light guide plate 140 has a light emitting surface 140e and a light incident surface 140i, wherein the plastic frame 120 is disposed on the light emitting surface 140e of the light guide plate 140, and the light source module 110 is disposed on the light incident surface 140i of the light guide plate 140. In detail, the light L1 emitted by the light source module 110 enters the interior of the light guide plate 140 through the light incident surface 140i of the light guide plate 140. The plastic frame 120 may include, for example, silicone, acrylic glue or similar materials, and the visible light transmittance of the plastic frame 120 may fall between 20% and 95%.

[0057] The light guide plate 140 includes a connection portion 142, a positioning post 144, and a positioning recess 146. The connection portion 142 is adjacent to the light incident surface 140i of the light guide plate 140, and the plastic frame 120 covers the connection portion 142 of the light guide plate 140. On the other hand, the positioning post 144 is disposed on the connection portion 142 of the light guide plate 140, and the positioning recess 146 is also disposed on the connection portion 142 of the light guide plate 140. The positioning recess 146 surrounds the periphery 144p of the positioning post 144, as shown in FIG. Figure 1 As shown, the positioning recess 146 may be an annular groove surrounding the periphery 144 p of the positioning post 144 .

[0058] Although the positioning post 144 of the present embodiment is in the shape of a truncated cone, the present disclosure is not limited thereto. In other embodiments, the positioning post 144 may also be in the shape of a polygonal frustum, such as a double triangular frustum or a double quadrangular frustum. Since the positioning recess 146 surrounds the periphery of the positioning post 144, the shape of the positioning recess 146 depends on the shape of the positioning post 144. For example, when the positioning post 144 is in the shape of a double quadrangular frustum, the positioning recess 146 may be a square ring groove surrounding the periphery 144p of the positioning post 144. In the present embodiment, twice the height h1 of the positioning post 144 is less than the width w1 of the positioning post 144. For example, the height h1 of the positioning post 144 may fall between 1 mm and 2 mm, and the width w1 of the positioning post 144 may fall between 2 mm and 4 mm, but the present disclosure is not limited thereto.

[0059] It is worth mentioning that the positioning recess 146 includes an opening 146p and a bottom end 146b, and a depth d1 is provided between the bottom end 146b and the opening 146p. In the present embodiment, five times the depth d1 is not greater than the thickness t1 of the light guide plate 140. For example, the depth d1 between the bottom end 146b of the positioning recess 146 and the opening 146p may be between 0.4 mm and 0.6 mm, and the thickness t1 of the light guide plate 140 may be between 2 mm and 3 mm. However, the present disclosure is not limited to the above-mentioned embodiment, that is, five times the depth d1 may also be greater than the thickness t1 of the light guide plate 140.

[0060] In addition, in this embodiment, the ratio of the width w2 of the opening 146p of the positioning recess 146 to the depth d1 is in the range of 1.5 to 2.0. In other words, the width w2 of the opening 146p of the positioning recess 146 can be in the range of 0.6 mm to 1.2 mm.

[0061] On the other hand, the optical film 160 is overlapped and disposed on the light emitting surface 140e of the light guide plate 140, and the optical film 160 is located between the light guide plate 140 and the plastic frame 120. The optical film 160 includes a positioning hole 162, and the inner edge 162i of the positioning hole 162 is used to abut against the periphery 144p of the positioning column 144, wherein the positioning hole 162 and the positioning column 144 are clearance-matched. For example, in this embodiment, although the inner edge 162i of the positioning hole 162 is used to abut against the periphery 144p of the positioning column 144, when the inner edge 162i of the positioning hole 162 abuts against the periphery 144p of the positioning column 144, the inner edge 162i does not completely fit with the periphery 144p of the positioning column 144. In other words, a portion of the inner edge 162i of the positioning hole 162 is in contact with the periphery 144p of the positioning column 144, while another portion is separated from the periphery 144p of the positioning column 144.

[0062] In particular, the optical film 160 has a thickness t2, and the ratio of the thickness t2 to the depth d1 is within a range of 1.0 to 1.7. In other words, the thickness t2 of the optical film 160 can be between about 0.4 mm and 1.0 mm. According to the ratio between the depth d1 between the opening 146p and the bottom end 146b of the positioning recess 146 and the width w2 of the opening 146p and the thickness t2 of the optical film 160, the inner edge 162i of the positioning hole 162 can be prevented from falling into the positioning recess 146.

[0063] In addition, in the present embodiment, the intersection angle A1 between the bottom end 146b of the positioning recess 146 and the periphery 144p of the positioning post 144 is a rounded angle (R angle). The radius of curvature of the rounded angle falls within the range of 0.2 mm to 0.3 mm. However, the present disclosure is not limited thereto, and in various embodiments, the intersection angle A1 may also be a bevel angle.

[0064] In some embodiments, the optical film 160 may include a prism sheet 161 and a diffuser sheet 163. After the prism sheet 161 is adjusted, the light field pattern of the light L2 emitted from the backlight module 100 can be changed. On the other hand, after the diffuser sheet 163 is adjusted, the light L2 emitted from the backlight module 100 can be diverged to improve the uniformity of the light. In addition, the number of prism sheets included in the optical film 160 is not limited to one. For example, in this embodiment, the optical film 160 also includes another layer of prism sheet 165.

[0065] Please refer to Figure 3In the cross-sectional view of the display device 30, the backlight module 100 can be disposed opposite to a liquid crystal display panel 301 and is used to emit light L2 toward the liquid crystal display panel 301. The liquid crystal display panel 301 can be, for example, a vertical alignment (VA) liquid crystal display panel, an in plane switching (IPS) liquid crystal display panel, or a similar liquid crystal display panel, but the present invention is not limited to the above.

[0066] Please refer to Figure 2 and Figure 3 , the backlight module 100 may further include a light shielding layer 150. The light shielding layer 150 is disposed on the plastic frame 120 and covers the connecting portion 142 of the light guide plate 140. The plastic frame 120 is located between the light shielding layer 150 and the optical film 160, and the light shielding layer 150 does not cover the light emitting surface 140e of the light guide plate 140. In detail, the light shielding layer 150 may cover at least 0.5 times of the width w1 of the positioning column 144, so that the light L1 emitted by the light source module 110 can be prevented from passing through the connecting portion 142 of the light guide plate 140 and entering the liquid crystal display panel 301.

[0067] The backlight module 100 further includes a back plate 170 for carrying the plastic frame 120, the light guide plate 140 and the optical film 160, wherein the light guide plate 140, the optical film 160 and the plastic frame 120 are sequentially stacked on the back plate 170. In addition, in order to prevent the plastic frame 120, the light guide plate 140 and the optical film 160 in the backlight module 100 from being damaged by the compression of the liquid crystal display panel 301, the backlight module 100 further includes a covering layer 180. The covering layer 180 covers the plastic frame 120, the light guide plate 140 and the optical film 160 to protect the plastic frame 120, the light guide plate 140 and the optical film 160.

[0068] In addition, the backlight module 100 further includes a bonding layer 190. The bonding layer 190 is located between the cover layer 180 and the optical film 160, and the cover layer 180 is connected to the light shielding layer 150 through the bonding layer 190. The cover layer 180 can be a light-transmitting substrate, such as a glass plate or other similar substrates. The bonding layer 190 can include, for example, optical clear adhesive (OCA) or similar light-transmitting materials. In addition, the light shielding layer 150 can be a light-shielding double-sided tape, and is used to bond the glue frame 120 and the bonding layer 190.

[0069] In summary, a light guide plate with a positioning recess is provided in the backlight module. Since the bottom end of the positioning recess is recessed in the light emitting surface of the light guide plate, even if the inner edge of the positioning hole of the optical film abuts against the periphery of the positioning column, the inner edge of the positioning hole will not fit the intersection angle (for example, the rounded corner) between the bottom end of the positioning recess and the periphery of the positioning column, so that interference of light emitted from the light emitting surface of the light guide plate can be avoided. Therefore, in the case of a positioning recess, the inner edge of the positioning hole of the optical film can be as close as possible to the periphery of the positioning column of the light guide plate to reduce the gap between the positioning hole and the positioning column. In this way, the shaking amplitude between the conductive column and the optical film in the backlight module under shaking or vibration can be reduced, thereby improving the abnormal sound problem caused by shaking.

[0070] Although the embodiments of the present invention have been disclosed as above, they are not intended to limit the embodiments of the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, the protection scope of the embodiments of the present invention shall be determined by the scope of the attached patent application.

Claims

1. A backlight module, characterized in that: include: A plastic frame; A light guide plate, wherein the plastic frame is disposed on a light emitting surface of the light guide plate, and the light guide plate comprises: a connecting portion, adjacent to a light incident surface of the light guide plate, wherein the plastic frame covers the connecting portion of the light guide plate; a positioning post, disposed at the connecting portion of the light guide plate; and a positioning recess, disposed at the connecting portion of the light guide plate and surrounding a periphery of the positioning post; and An optical film is overlapped on the light emitting surface of the light guide plate and is located between the light guide plate and the plastic frame, wherein the optical film includes a positioning hole, and an inner edge of the positioning hole is used to abut against the periphery of the positioning column.

2. The backlight module according to claim 1, wherein: The positioning recess includes an opening and a bottom end, and a depth is defined between the bottom end and the opening, wherein five times of the depth is not greater than a thickness of the light guide plate.

3. The backlight module according to claim 1, wherein: The positioning recess includes an opening and a bottom end, and a depth is defined between the bottom end and the opening, wherein a ratio between a width of the opening and the depth falls within a range of 1.5 to 2.

0.

4. The backlight module according to claim 1, wherein: The positioning recess includes an opening and a bottom end, and a depth is defined between the bottom end and the opening, wherein a ratio of a thickness of the optical film to the depth falls within a range of 1.0 to 1.

7.

5. The backlight module according to claim 1, wherein: Two times of a height of the positioning post is smaller than a width of the positioning post.

6. The backlight module according to claim 1, wherein: An intersection angle between a bottom end of the positioning recess and the periphery of the positioning column is a rounded angle, and a curvature radius of the rounded angle falls within a range of 0.2 mm to 0.3 mm.

7. The backlight module according to claim 1, wherein: The optical film includes a prism sheet and a diffusion sheet.

8. The backlight module according to claim 1, wherein: Also includes: A light shielding layer is arranged on the plastic frame and covers the connecting portion of the light guide plate, wherein the plastic frame is located between the light shielding layer and the optical film.

9. The backlight module according to claim 8, wherein: The light shielding layer covers at least 0.5 times of a width of the positioning post.

10. The backlight module according to claim 1, wherein: Also includes: A light source module is disposed on the light incident surface of the light guide plate, and the light source module is used to emit a light toward the light guide plate.

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