CN1731251A - Backlight module structure - Google Patents

Abstract

The invention mainly discloses a backlight module structure. The backlight module structure comprises a rubber frame and a light guide plate which are integrally formed, wherein one side edge of the rubber frame is provided with a light guide plate glue inlet point, a shading film and a reflecting plate. The backlight module covers the light guide plate glue inlet point by using the light shielding film or the extending part of the reflecting plate, so that light cannot leak from the light guide plate glue inlet point to generate a dark area, and the problem of light leakage is solved.

Description

Backlight module structure

technical field

The invention relates to a backlight module, in particular to a backlight module which solves the problem of light leakage from an integrally formed plastic frame and a light guide plate.

Background technique

With the vigorous development of the optoelectronic industry, liquid crystal display modules (liquid crystal display; LCD) have been widely used in various notebook computers (notebook), personal digital assistant (personal digital assistant; PDA) and mobile phones (cell phone), etc. in the electronic device. However, the liquid crystal display is a non-self-illuminating flat panel display, which needs to be illuminated by an external backlight or side light. Therefore, a backlight module is always used as a light source in a liquid crystal display, and the high-brightness and high-uniformity illumination of the backlight module enables the liquid crystal display to efficiently display high-quality images.

Referring to FIG. 1A , it is an exploded perspective view of a conventional liquid crystal display. As shown in FIG. 1A , the LCD 100 includes a bezel 102 , an LCD panel 108 , a driver circuit 109 and a backlight module 120 . Referring to FIG. 1B, it is a cross-sectional view of a liquid crystal display 100, from which it can be known that a backlight module 120 is composed of a plastic frame (frame) 104, a plurality of layers of optical films 110, a light source 112, a light guide plate (light guide plate) 114, and a light-shielding tape. (shielding sheet) 106, reflecting plate (reflecting sheet) 116 and lamp holder (lamp holder) 118. The plastic frame 104 includes a plastic frame body 104 a and an accommodating chamber 105 . The accommodating chamber 105 accommodates the reflector 116 , the light guide plate 114 , the light source 112 , and the optical film 110 to form a backlight module 120 . And the reflection plate 116, the light guide plate 114 and the optical film 110 are stacked in the accommodating chamber 105 from bottom to top, and the gap between the light guide plate 114, the plastic frame 104 and the optical film 110 is covered by a light-shielding tape 106 to avoid light leakage , and the light source 112 is disposed in the lamp socket 118 and placed on one side of the housing chamber 105 in the plastic frame 104 . Moreover, the liquid crystal panel 108 is disposed on the backlight module 120 and fixed by an outer frame 102 .

The light guide plate 114 includes a protrusion 114 a, and the plastic frame 104 in the backlight module 120 is combined with the light guide plate 114 by using the protrusion 114 a. However, the cost of backlight modules in the manufacture of liquid crystal displays has always been high, and the cost of backlight modules is second only to color filters. Therefore, in order to reduce the cost of backlight modules, some manufacturers have adopted the following methods: The way of double injection molding forms the integrated light guide plate and plastic frame at the same time. Referring to FIG. 2A, it is a top view of a double-material injection molding module, which utilizes a double-material injection molding machine (not shown in the figure) to inject the plastic frame plastic and the light guide plate into the glue-in point 132 and the light-guide plate glue-in point 134 in a mold cavity 130 respectively. The plastic of the light guide plate, after being fixed and joined together, the integrated plastic frame and light guide plate can be taken out by opening the mold.

However, as shown in FIG. 2B , the integrally molded plastic frame 104 and light guide plate 114 formed in this double injection molding method need a light guide plate glue inlet 134 , and this light guide plate glue inlet 134 cannot be formed by the glue frame. 104 , thus forming a recessed light guide plate glue-in point 134 on the glue frame 104 . Therefore, when the light hits the glue inlet point 134 of the light guide plate, because there is no glue frame here to block the light, part of the light is lost from the recess 134, resulting in the inability to use the light effectively, and when the liquid crystal display is in operation, this There are shadows everywhere. This shadow will cause uneven brightness and poor picture quality of the LCD screen.

Therefore, if the problem of light leakage of the integrally formed plastic frame and light guide plate produced by double injection molding is solved, the liquid crystal display has effective light use efficiency, high brightness and high uniformity.

Contents of the invention

In view of the above-mentioned background, the purpose of the present invention is to provide a backlight module structure, which can solve the problem of light leakage near the glue-in point due to the need to reserve the glue-in point for the integrated plastic frame and light guide plate produced by double-material injection molding, Further solve the problem of light leakage caused by dark areas on the screen of the liquid crystal display, resulting in uneven brightness and poor picture quality, so that better light use efficiency, higher brightness and higher uniformity can be achieved.

According to the above purpose, the present invention provides a better structure of the backlight module to solve the problem of light leakage caused by the glue inlet points required for the integral plastic frame and light guide plate produced by double injection molding. The backlight module includes a plastic frame with a concave structure, and has a plurality of protruding structures located around the outer side of the plastic frame, a light guide plate is located above the plastic frame, and a light-shielding film is located at the peripheral edge of the plastic frame. Of course, as in general, the existing backlight module includes a reflection sheet located below the light guide plate, multiple layers of optical films located above the light guide plate, and at least one light source located on one side of the plastic frame. The present invention is characterized in that the light-shielding film or the reflective sheet has an extension part that is bent at about 90 degrees and correspondingly covers the concave structure on the plastic frame. Therefore, the recessed structure that causes light leakage is covered by the light-shielding film or the reflective sheet, so that light cannot leak therefrom.

Description of drawings

FIG. 1A and FIG. 1B are respectively an exploded perspective view and a schematic cross-sectional view of a conventional liquid crystal display;

2A and 2B are respectively a top view and a perspective view of a plastic frame and a light guide plate formed by double injection molding;

3A to 3E are schematic perspective views and schematic cross-sectional views of an embodiment of the present invention;

4A to 4C are schematic perspective views and schematic cross-sectional views of another embodiment of the present invention; and

5A to 5C are schematic perspective views and cross-sectional views of still another embodiment of the present invention.

Detailed ways

Some embodiments of the invention are described in detail below. However, the invention can be broadly practiced in other embodiments than this detailed description. That is, the scope of the present invention is not limited by the presented embodiments, but by the present claims. Secondly, when each component or structure in the diagrams of the embodiments of the present invention is described as a single component or structure, it should not be regarded as a limited cognition, that is, when the following description does not particularly emphasize the limitation on the number, the present invention The spirit and scope of application can be extended to structures and methods in which multiple components or structures coexist. Furthermore, in this specification, different parts of each component are not drawn to scale. Certain dimensions have been exaggerated or simplified compared to other relevant dimensions to provide a clearer description and understanding of the present invention. However, the prior art used in the present invention is only cited here in an emphatic manner to facilitate the elaboration of the present invention.

Referring to FIG. 3A , it is a three-dimensional schematic diagram of a backlight module according to a preferred embodiment of the present invention. It includes a plastic frame 10, which has a plurality of protruding structures 10a on the outside around it, and a concave structure 10b on one side of the plastic frame 10; a light guide plate 12 is arranged on the plastic frame 10, and has An extension portion 14 a corresponds to the light-shielding film 14 of the recessed structure 10 b on the plastic frame 10 . The extension portion 14a, as shown in FIG. 3B , is bent downward at 90 degrees to cover the recessed structure 10b so that light cannot leak therefrom, so as to avoid the occurrence of dark areas caused by light leakage.

In addition, the plastic frame 10 and the light guide plate 12 are formed simultaneously by double-material injection molding, and the recessed structure 10b is the plastic inlet of the light guide plate not covered by the plastic frame to form the plastic inlet of the light guide plate in the aforementioned prior art. .

Referring to FIG. 3C , it is a schematic cross-sectional view of a liquid crystal display combined with the above-mentioned backlight module. It includes an integrally formed plastic frame 10 and a light guide plate 12, and one or several light sources 18, such as light-emitting diodes or cold cathode lamps, can be arranged inside the plastic frame 10. The location of the light source 18 is not limited. It is enough to provide the light source required by the liquid crystal display, and there is a recessed structure 10b on one side of the plastic frame 10 . In addition, there is a multi-layer optical film 20 and a light-shielding film 14 above the light guide plate 12 to cover the periphery of the plastic frame 10, and the light-shielding film 14 has an extension 14a that can be bent downwards to cover the recessed structure 10b , and a liquid crystal panel 22 is arranged on the light-shielding film 14 .

As shown in FIG. 3C , the plastic frame 10 described in this embodiment is a hollow structure, and there is a reflection plate 16 under the light guide plate 12 as a reflection light source. In addition, a back plate 24 is further included under the reflecting plate 16 for accommodating, fixing and protecting the reflecting plate 16 and the plastic frame 10 . The combination of the plastic frame 10 and the back plate 24 is as shown in Figure 3D. There are several grooves 24a around the back plate 24 corresponding to the plurality of protruding structures 10a on the side of the plastic frame 10, and the multiple protruding structures 10 a engages with a plurality of corresponding grooves 24 a to combine and fix the plastic frame 10 on the back plate 24 .

However, in a specific embodiment of the present invention, the structure of the plastic frame 10 is not necessarily a hollow structure. Referring to FIG. 3E is a schematic cross-sectional view of a liquid crystal display composed of a backlight module according to another embodiment of the present invention. The structure shown in it is substantially the same as the structure shown in FIG. 3C, except that in this embodiment, the plastic frame 10 is a one-piece structure, and the bottom 17 of the plastic frame 10 replaces the reflecting plate 16 (as shown in FIG. 3C ). (shown) to reflect light, and because the bottom 17 of the plastic frame 10 is used as a reflective plate, there is no need for a back plate 24 to accommodate and fix the plastic frame 10 and the reflective plate 16 . However, like other embodiments of the present invention, a back plate 24 can still be added to protect the backlight module.

Referring to FIG. 4A , it is a schematic perspective view of a backlight module according to another preferred embodiment of the present invention. It includes a plastic frame 10, with a plurality of protruding structures 10a on the surrounding sides of the plastic frame 10, and a concave structure 10b on one side of the plastic frame 10; a light guide plate 12 is arranged on the plastic frame 10, located A light-shielding film 14 surrounding the plastic frame 10 for shielding the light leaked from the gap of the backlight module, and a reflective plate 16 having an extension 16 a are located under the plastic frame 10 . This extension 16a, as shown in FIG. 4B, is bent upward at 90 degrees and covers the glue-in point (that is, the recessed structure) 10b of the light guide plate correspondingly, so that light cannot leak out of the recessed structure 10b, so that this area does not produce Occurrence of dark areas due to light leakage caused by light leakage. Of course, in this specific embodiment, the plastic frame 10 and the light guide plate 12 are integrally formed by double injection molding.

Referring to FIG. 4C , it is a schematic cross-sectional view showing a liquid crystal display combined with the above-mentioned backlight module. It includes an integral plastic frame 10 and a light guide plate 12, and one or several light sources 18, such as light-emitting diodes or cold cathode lamp tubes, are arranged in the plastic frame 10 to provide the light source required by the liquid crystal display, and The other side of the plastic frame 10 has a recessed structure 10b. In addition, there is a multi-layer optical film 20 above the light guide plate 12, and a light-shielding film 14 is used to cover the surroundings of the plastic frame 10, and a reflective plate 16 with an extension 16a is located below the plastic frame 10. This extension The portion 16 a is bent upwards to cover the recessed structure 10 b, and a liquid crystal panel 22 is disposed above the light-shielding film 14 . The plastic frame 10 described in this embodiment is a hollow structure, and a back plate 24 is located under the reflection plate 16 for accommodating, fixing and protecting the reflection plate 16 and the plastic frame 10 . The combination of the plastic frame 10 and the back plate 24 is as described in the previous embodiments, the plurality of grooves 24a on the back plate 24 are engaged with the corresponding plurality of protruding structures 10a on the side of the plastic frame 10, As shown in FIG. 3D , the fixed plastic frame 10 is combined on the back plate 24 .

Referring to FIG. 5A , it is a schematic perspective view of a backlight module according to another embodiment of the present invention. It includes a plastic frame 10, which has a plurality of protruding structures 10a around the plastic frame 10, and a light guide plate 12 is arranged on the plastic frame 10. Similarly, the plastic frame 10 and the light guide plate 12 are also double-molded. One piece. Therefore, a glue inlet for the light guide plate is reserved on the plastic frame 10 , that is, a recessed structure 10 b is formed on one side of the plastic frame 10 . The first light-shielding film 14 located around the plastic frame 10, and the second light-shielding film 15 that can be directly pasted on the recessed structure 10b cover the recessed structure 10b so that light cannot leak out from the recessed structure 10b, so that this area will not be affected by Light leaks, which causes light leakage and thus leads to the occurrence of dark areas. The second light-shielding film 15 can be an opaque adhesive tape, or an opaque film such as a reflective plate or a stainless steel plate, and an appropriate material can be selected according to design requirements.

In addition, the plastic frame 10 of this embodiment can also be a hollow structure as shown in FIG. 5B , the second light-shielding film 15 is directly pasted on the concave structure 10 b of the plastic frame 10 , and a back plate 24 can be accommodated or fixed. The plastic frame 10 and the reflection plate 16. This back plate 24 is combined with the plastic frame 10 by engaging the grooves 24a on it with the plurality of protruding structures 10a on the plastic frame 10, as shown in FIG. 3D. In addition, in other embodiments, this A second light-shielding film 15 can also be a part of the back plate 24, that is, to increase the height of the side of the back plate 24 to achieve the purpose of shielding the recessed structure 10b. Or, as shown in FIG. 5C , the plastic frame 10 can be a one-piece structure, on the recessed structure 10b of the plastic frame 10, a second light-shielding film 15 is directly pasted, and the bottom 17 of the plastic frame 10 is used as a reflector . The second light-shielding film 15 can be an opaque adhesive tape, or an opaque film such as a reflective plate or a stainless steel plate, and an appropriate material can be selected according to design requirements.

Therefore, the present invention uses the light-shielding film or the extension of the reflector, or directly attaches the light-shielding film to the glue-in point of the light guide plate reserved for the integrally formed plastic frame and the light guide plate formed by double injection molding. , to solve the light leakage problem of the backlight module. Therefore, the dark area caused by light leakage at the glue inlet point of the light guide plate is also solved at the same time, so that the backlight source can be used more effectively and its brightness is more uniform.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Changes can still be made and implemented within the scope of not departing from the essence of the present invention, and these changes should still belong to the scope of the present invention. Accordingly, the scope of the invention is defined by the appended claims.

Claims (9)

1. backlight modular structure comprises:

One glue frame has at least one side that a plurality of projective structures are positioned at this glue frame, and a sunk structure is positioned at a side of this glue frame;

One light guide plate is positioned at this glue frame top; And

One shading film is positioned at the edge of this glue frame, and this shading film has an extension correspondence and covers this sunk structure.

2. backlight modular structure as claimed in claim 1, wherein this glue frame and this light guide plate are to form simultaneously with extra quality injection molding way.

3. backlight modular structure as claimed in claim 1, wherein the extension of this shading film is to cover this sunk structure with the about 90 bending correspondences of spending.

4. backlight modular structure as claimed in claim 1 comprises that more a reflecting plate is positioned at the below of this glue frame.

5. backlight modular structure as claimed in claim 4, wherein this reflecting plate has an extension correspondence and covers this sunk structure.

6. backlight modular structure as claimed in claim 1, wherein this glue frame is the whole piece structure.

7. backlight modular structure as claimed in claim 1 comprises that more a backboard is positioned at the below of this reflecting plate, and this backboard around outer side edges have that most grooves are corresponding with those projective structures to engage mutually, to fix this reflecting plate and this glue frame.

8. backlight modular structure as claimed in claim 1, wherein this shading film is between this glue frame and this light guide plate.

9. backlight modular structure as claimed in claim 1, wherein this glue frame has a hollow structure.

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