BACKLIGHT MODULE AND DISPLAY DEVICE

The integration of a light blocking layer on the optical film set in the backlight module addresses light leakage and halo issues in narrow-frame display devices, ensuring uniform illumination and improved screen quality.

JP7597284B2Active Publication Date: 2024-12-10CORETRONIC CORPORATION
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Patent Information

Application Number
JP2020031150
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2019-03-11
Filing Date
2020-02-27
Publication Date
2024-12-10
Estimated Expiration
2040-02-27

AI Technical Summary

Technical Problem

Existing display devices with narrow frames suffer from light leakage and halo issues due to scattered light from the edges of the optical film, which affects the uniformity of the display panel's visible region.

Method used

Incorporating a light blocking layer on the end faces of the optical film set within the backlight module to absorb or block scattered light, ensuring uniform illumination across the display panel.

Benefits of technology

Reduces light scattering and prevents halo formation at the edges of the visible region, enhancing the uniformity and quality of the display panel's screen, even with a narrow frame design.

✦ Generated by Eureka AI based on patent content.

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Abstract

To provide a backlight module and a display device.SOLUTION: A backlight module includes a light guide plate, a light source, an optical film group, and at least one light shielding layer. The light guide plate comprises an incident surface, and an emitting surface adjacent to the incident surface. The light source is arranged near the incident surface. The optical film group comprises a first surface, a second surface, and at least one end surface. The first surface is opposed to the second surface. The at least one end surface is connected to the first surface and the second surface. The optical film group is installed on the emitting surface of the light guide plate. The first surface faces the emitting surface. The at least one light shielding layer is installed on the at least one end surface.SELECTED DRAWING: Figure 1
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Description

[Technical field]

[0001] The present invention relates to a light source module and a display device, and in particular to a backlight module and a display device having the backlight module. [Background technology]

[0002] With the rapid development of display devices (such as computer screens and mobile phone screens), consumers attach more importance to more attractive designs, among which the appearance feature of narrow borders is one of the factors that stimulates consumers' purchasing motivation. A narrow border display device is one that expands the visible area of ​​the display panel by reducing the left and right or surrounding edges of the display panel.

[0003] In addition, a general display device is mainly composed of a display panel and a backlight module, and the backlight module is used to provide backlight to the display panel. The backlight module usually has an optical film, which faces the display panel and can provide uniform flat light to the display panel. However, most of the light flux after optical processing by the optical film is provided to the display panel by the optical film facing the display panel, but a small part may be scattered from the edge of the optical film. Therefore, when the display panel has a structure with a narrow frame, the light flux scattered from the edge of the optical film cannot be effectively blocked, which may cause the problem of halo (a faint light umbrella seen around something shiny) at the edge of the screen in the visible region.

[0004] Note that the "Background Art" section is intended only to aid in understanding the present invention, and therefore the contents disclosed in the "Background Art" section may include techniques not known to those skilled in the art. Therefore, the contents disclosed in the "Background Art" section do not mean that the contents or the problems that one or more embodiments of the present invention are intended to solve were already known to those skilled in the art prior to the filing of the present invention. Summary of the Invention [Problem to be solved by the invention]

[0005] The objective of the present invention is to provide a backlight module and a display device to reduce the light leakage of the backlight module caused by scattered light from the edges of the optical film group of the backlight module, and to solve the problem of halo at the edges of the visible area of ​​the display panel.

[0006] Other objects and advantages of the present invention can be further understood from the technical features disclosed in the present invention. [Means for solving the problem]

[0007] In order to achieve one or some or all of the above objects or other objects, the backlight module according to the present invention includes a light guide plate, a light source, an optical film set, and at least one light blocking layer, the light guide plate has a light input surface and a light output surface adjacent to the light input surface, the light source is disposed near the light input surface, the optical film set includes a first surface, a second surface, and at least one end surface, the first surface and the second surface are opposite to each other, the at least one end surface is connected to the first surface and the second surface, the optical film set is disposed on the light output surface of the light guide plate, the first surface faces the light output surface, and the at least one light blocking layer is disposed on the at least one end surface.

[0008] In order to achieve one or some or all of the above objects or other objects, the display device according to the present invention includes a backlight module and a display panel. The backlight module includes a light guide plate, a light source, an optical film set, and at least one light-shielding layer. The light guide plate has a light input surface and a light output surface adjacent to the light input surface, the light source is disposed near the light input surface, the optical film set includes a first surface, a second surface, and at least one end surface, the first surface and the second surface are opposite to each other, the at least one end surface is connected to the first surface and the second surface, the optical film set is disposed on the light output surface of the light guide plate, the first surface faces the light output surface, and the at least one light-shielding layer is disposed on the at least one end surface. The display panel faces the second surface of the optical film set, and the optical film set is disposed between the display panel and the light guide plate.

[0009] The present invention provides a black or gray light-shielding layer on the end face of the optical film group of the backlight module, thereby reducing light scattering from the end face of the optical film group. Therefore, even when the display panel of the display device has a narrow frame structure, the light beam is not scattered from the end face of the optical film group, which causes the problem of haloing at the edges of the visible area, and the entire screen of the display panel can be made more uniform.

[0010] In order to make the above-mentioned features and advantages of the present invention more apparent, the present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is an exploded view of a display device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a structural diagram of a display device according to an embodiment of the present invention. [Diagram 3] 3 is a local cross-sectional view taken along line AA of the display device shown in FIG. 2. [Figure 4] 3 is a local cross-sectional view taken along line BB of the display device shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The above and other technical contents, features, functions and effects of the present invention will become clearer from the detailed description of the preferred embodiments based on the accompanying drawings. Note that the directional terms used in the following embodiments, such as up, down, left, right, front, back, etc., are merely the directions in the accompanying drawings. Therefore, the directional terms used are only for the purpose of explaining the present invention, and are not intended to limit the present invention.

[0013] Fig. 1 is a three-dimensional exploded view of a display device in an embodiment of the present invention, Fig. 2 is a structural diagram of the display device in an embodiment of the present invention, Fig. 3 is a local cross-sectional view taken along line AA of the display device shown in Fig. 2, and Fig. 4 is a local cross-sectional view taken along line BB of the display device shown in Fig. 2. As shown in Figs. 1 to 4, the display device 10 includes a backlight module 12 and a display panel 14 installed corresponding to the backlight module 12, and the backlight module 12 is used to provide backlight for the display panel 14. In one embodiment, the display panel 14 may be, for example, but is not limited to, a liquid crystal display panel.

[0014] The backlight module 12 includes a light guide plate 16, a light source 18, an optical film group 20, and a light-shielding layer 22. As shown in FIG. 3 and FIG. 4, the light guide plate 16 has a light entrance surface 161, a light exit surface 162, and a bottom surface 163, the light exit surface 162 faces the bottom surface 163, and the light entrance surface 161 is connected to the bottom surface 163 and the light exit surface 162. In one embodiment, the bottom surface 163 of the light guide plate 16 is provided with a number of microstructures (not shown). The light source 18 is disposed adjacent to the light entrance surface 161, and the light source 18 may be a light-emitting diode or other kinds of light-emitting elements. As shown in FIG. 3, the light source 18 provides a light flux L. In one embodiment, the light flux L enters the light guide plate 16 through the light entrance surface 161, and is guided to the light exit surface 162 by the microstructure of the bottom surface 163, and exits from the light exit surface 162.

[0015] The optical film set 20 also includes a first surface 201 (shown in FIG. 3 and FIG. 4), a second surface 202, and an end surface. In one embodiment, the optical film set includes four end surfaces, which are a first end surface 203a, a second end surface 203b, a third end surface 203c, and a fourth end surface 203d, respectively, as shown in FIG. 1. As shown in FIG. 3 and FIG. 4, the first surface 201 and the second surface 202 face each other, the first end surface 203a (shown in FIG. 3), the second end surface 203b, the third end surface 203c (shown in FIG. 4), and the fourth end surface 203d are connected to the first surface 201 and the second surface 202, the first end surface 203a and the second end surface 203b face each other, and the third end surface 203c and the fourth end surface 203d face each other and are adjacent to the first end surface 203a and the second end surface 203b. The optical film group 20 is disposed on the light output surface 162 of the light guide plate 16, where the first surface 201 faces the light output surface 162 and the first end surface 203a faces the light source 18. The number of the light-shielding layers 22 may be one or more, and the light-shielding layers 22 may be disposed on any one, two, three or all of the first end surface 203a, the second end surface 203b, the third end surface 203c and the fourth end surface 203d, respectively. In one embodiment, the light-shielding layer 22 may include an ink layer or an adhesive tape layer, and the color of the light-shielding layer 22 may include black or gray.

[0016] In one embodiment, the optical film set 20 may include multiple optical films, which are stacked in sequence, with the first surface 201 of the optical film set 20 being, for example, stacked on the bottom surface of the lowest optical film, and the second surface 202 of the optical film set 20 being, for example, stacked on the top surface of the highest optical film. The optical films may also be, but are not limited to, diffusion sheets, prism sheets, etc., and the optical film set 20 may be, for example, a combination of one or more diffusion sheets and one or more prism sheets stacked together. In another embodiment, the optical film set 20 may be a single optical film, in which case the first surface 201 and the second surface 202 are, for example, the bottom surface and the top surface of the single optical film, respectively. During the cutting process of the optical film set 20, the first end surface 203a, the second end surface 203b, the third end surface 203c and the fourth end surface 203d are likely to be uneven or not smooth, so most of the first end surface 203a, the second end surface 202b, the third end surface 203c and the fourth end surface 203d are roughened. In one embodiment, as shown in Figures 1, 3 and 4, the light-shielding layer 22 is disposed on the first end surface 203a, the third end surface 203c and the fourth end surface 203d, but is not limited thereto, and the light-shielding layer 22 may be disposed on any one, two, three or all of the first end surface 203a, the second end surface 203b, the third end surface 203c and the fourth end surface 203d according to needs.

[0017] In addition, the light beam L emitted from the light source 18 is guided to the light output surface 162 of the light guide plate 16, and is emitted as planar light, and enters the optical film group 20. After the optical film group 20 performs optical processing such as homogenization and atomization on the planar light emitted from the light guide plate 16, most of the light beam L1 is emitted from the second surface 202 of the optical film group 20, so as to provide the display panel 14 with uniform planar light, of which a small part of the light beam L1 propagates to the first end surface 203a, the second end surface 203b, the third end surface 203c, and / or the fourth end surface 203d of the optical film group 20, and scattered light is generated by the roughened surface. At this time, the light-shielding layer 22 can effectively absorb or block the scattered light, so as to reduce the scattered light at the first end surface 203a, the second end surface 203b, the third end surface 203c, and / or the fourth end surface 203d of the optical film group 20.

[0018] 1 to 4, the backlight module 12 further includes a circuit board 19, a back plate 24, a reflective sheet 26, and a plastic frame 28. The circuit board 19 is, for example, a flexible printed circuit (FPC), and is disposed on the light output surface 162 of the light guide plate 16, and the circuit board 19 is electrically connected to the light source 18. The light guide plate 16 is disposed on the back plate 24, the reflective sheet 26 is disposed between the back plate 24 and the bottom surface 163 of the light guide plate 16, and the plastic frame 28 is attached to the back plate 24 and used for storing and fixing the light guide plate 16 and the optical film group 20. In an embodiment not shown, the plastic frame 28 may also be used for sandwiching the display panel 14.

[0019] 3 and 4 again. The display panel 14 is installed corresponding to the backlight module 12, where the display panel 14 faces the second surface 202 of the optical film group 20 of the backlight module 12, that is, the optical film group 20 is located between the display panel 14 and the light guide plate 16. In one embodiment, the display panel 14 includes a visible area 141 and an ineffective area 142, where the ineffective area 142 surrounds the visible area 141, where the ineffective area 142 refers to an area in the display panel 14 where the screen cannot be displayed. Take the display device 10 having a narrow frame as an example, the width of the ineffective area 142 is less than 3 mm. In one embodiment, the light blocking layer 22 is located within the range of the orthogonal projection of the ineffective area 142 on the light guide plate 16.

[0020] In the present invention, the light-shielding layer is provided on the end surface of the optical film group of the backlight module, which can reduce the light scattering from the end surface of the optical film group, and even when the display panel of the display device has a narrow frame structure, the light flux is not scattered from the end surface of the optical film group, which causes the problem of light halo at the edge of the visible area (i.e., the boundary between the visible area and the invalid area), and the entire screen of the display panel can be more uniform. In addition, the color of the light-shielding layer can be black or gray, and the color of the light-shielding layer can be selected between black, dark gray, and misty gray to fine-tune the light-shielding effect for the actual brightness of the edge of the visible area, so as to meet the light quality of the user of the display device.

[0021] The present invention has been disclosed above based on the preferred embodiment described above, but the preferred embodiment described above is not intended to limit the present invention, and a person skilled in the art may make minor modifications and adaptations to the present invention without departing from the technical spirit and scope of the present invention. Therefore, the scope of protection of the present invention is based on the scope of the attached claims. In addition, it is not necessary for any embodiment or claim of the present invention to achieve all of the objectives, advantages, or features disclosed in the present invention. In addition, a part of the abstract and the title of the invention are only intended to assist in searching the literature, and are not intended to limit the technical scope of the present invention. In addition, the terms "first", "second", etc., used in the present specification or claims are only intended to name elements or distinguish other embodiments or scopes, and are not intended to limit the upper or lower limits on the quantity of elements. [Explanation of symbols]

[0022] 10: Display module 12: Backlight module 14: Display panel 141:Visible area 142: Invalid area 16:Light guide plate 161: Light entrance surface 162:Idemitsu surface 163: Bottom 18:Light source 19: Circuit board 20: Optical film group 201: First surface 202:Second surface 203a: First end surface 203b: Second end face 203c: Third end face 203d: Fourth end surface 22: Light blocking layer 24: Back plate 26: Reflective sheet 28: Plastic frame AA: Line BB: Line L, L1: Luminous flux

Claims

1. A backlight module including a light guide plate, a light source, an optical film group, a backplate, a plastic frame and at least one light-shielding layer, the light guide plate has a light entrance surface and a light exit surface adjacent to the light entrance surface; The light source is disposed near the light entrance surface, The optical film set includes a first surface, a second surface, and at least one end surface, the first surface faces the second surface, and the at least one end surface is connected to the first surface and the second surface; the optical film set is disposed on the light output surface of the light guide plate, and the first surface faces the light output surface; The light guide plate is disposed on the back plate, the plastic frame is assembled to the back plate; the at least one light-shielding layer is disposed on the at least one end surface and does not extend to the first surface and the second surface; the at least one end surface is a first end surface, a second end surface, a third end surface and a fourth end surface, the first end surface and the second end surface are opposite to each other, the third end surface and the fourth end surface are opposite to each other and adjacent to the first end surface and the second end surface, the first end surface faces the light source, the at least one light-shielding layer is a plurality of layers, and the at least one light-shielding layer is disposed on any two or any three of the first end surface, the second end surface, the third end surface and the fourth end surface, respectively, the backplate and the plastic frame do not overlap the at least one light-shielding layer on one side where the optical film set leaves the light guide plate.

2. 2. The backlight module according to claim 1, The at least one light-shielding layer includes an ink layer or an adhesive tape layer.

3. 2. The backlight module according to claim 1, The backlight module, wherein the color of the at least one light-shielding layer includes black or gray.

4. 2. The backlight module according to claim 1, the light guide plate further has a bottom surface opposite to the light exit surface, the light input surface is connected to the bottom surface and the light exit surface, and a plurality of microstructures are disposed on the bottom surface.

5. 2. The backlight module according to claim 1, A backlight module, wherein the at least one end surface of the optical film set is a roughened surface.

6. A display device including a backlight module and a display panel, The backlight module includes a light guide plate, a light source, an optical film group, a back plate, a plastic frame, and at least one light-shielding layer; the light guide plate has a light entrance surface and a light exit surface adjacent to the light entrance surface; The light source is disposed near the light entrance surface, The optical film set includes a first surface, a second surface, and at least one end surface, the first surface faces the second surface, and the at least one end surface is connected to the first surface and the second surface; the optical film set is disposed on the light output surface of the light guide plate, and the first surface faces the light output surface; The light guide plate is disposed on the back plate, the plastic frame is assembled to the back plate; the at least one light-shielding layer is disposed on the at least one end surface and does not extend to the first surface and the second surface; the display panel faces the second surface of the optical film group, and the optical film group is located between the display panel and the light guide plate; the at least one end surface is a first end surface, a second end surface, a third end surface, and a fourth end surface, the first end surface and the second end surface are opposite to each other, the third end surface and the fourth end surface are opposite to each other and adjacent to the first end surface and the second end surface, the first end surface faces the light source, the at least one light-shielding layer is a plurality of layers, and the at least one light-shielding layer is disposed on any two or any three of the first end surface, the second end surface, the third end surface, and the fourth end surface, respectively, and the back plate and the plastic frame do not overlap the at least one light-shielding layer on one side where the optical film set leaves the light guide plate.

7. The display device according to claim 6, A display device, wherein the display panel includes a visible area and an ineffective area, the ineffective area surrounding the visible area, and a width of the ineffective area being less than 3 mm.

8. The display device according to claim 7, A display device, wherein the at least one light blocking layer is located within a range of orthogonal projection on the light guide plate of the invalid area.

Citation Information

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