WO2019119719A1

WO2019119719A1 - Bonding structure for light guide plate and reflective sheet, bonding method and liquid crystal display device

Info

Publication number: WO2019119719A1
Application number: PCT/CN2018/087393
Authority: WO
Inventors: 张继兵; 文喜平; 区可坚
Original assignee: 青岛海信电器股份有限公司
Priority date: 2017-12-18
Filing date: 2018-05-17
Publication date: 2019-06-27
Also published as: CN107831565A

Abstract

Provided are a bonding structure for a light guide plate and a reflective sheet, a bonding method, and a liquid crystal display device. The method comprises: stacking the light guide plate (23) and the reflection sheet (22); forming dots by high-temperature melting to-be-bond portions on the reflection sheet (22) and the light guide plate (23), so that the surface of the light guide plate (23) facing the reflection sheet (22) and the surface of the reflection sheet (22) facing the light guide plate (23) are relatively fixed only through the dots. With the above method, the utilization efficiency of the light source is improved, and the stability of the light guide plate (23) as well as the reflection sheet (22) after the bonding, meanwhile the manufacturing process is simplified, and production efficiency improved.

Description

Bonding structure of light guide plate and reflective sheet, bonding method and liquid crystal display device

This application claims the priority of the Chinese Patent Application filed on Dec. 18, 2017, the Chinese Patent Office, Application No. 201711366731.8, the application of the name of the "light-shielding plate and reflective sheet bonding method, backlight module and display device". The entire contents are incorporated herein by reference.

Technical field

The present disclosure relates to the field of laser display technologies, and in particular, to a bonding structure of a light guide plate and a reflective sheet, a bonding method, and a liquid crystal display device.

Background technique

At present, the ultra-thin design of LCD TVs has become mainstream. The liquid crystal display device shown in FIG. 1 includes a liquid crystal panel 1 and a side-entry backlight module 2. The liquid crystal panel 1 is disposed opposite to the light emitting surface of the side-entry backlight module 2 . The side-entry backlight module 2 includes a light emitting diode (LED) light bar 21, a reflective sheet 22, a glass light guide plate 23 and an optical film 24. The reflection sheet 22 is located below the glass light guide plate 23, and the optical film 24 is located on the light exit surface of the glass light guide plate 23, and is disposed opposite to the liquid crystal panel 1. In order to achieve an ultra-thin design, the glass light guide plate 23 and the reflective sheet 22 are generally combined to form an integrated structure to support the entire module screen, so as to reduce the thickness of the back sheet or cancel the back sheet, thereby achieving ultra-thin. This bonding is carried out by completely applying an adhesive to one surface of the glass light guide plate 23 or the reflection sheet 22, so that the adjacent two faces of the light guide plate 23 and the reflection sheet 22 can be bonded together.

Summary of the invention

Some embodiments of the present invention provide a bonding structure, a bonding method, and a liquid crystal display device for a light guide plate and a reflective sheet, which are used to simplify the bonding process of the light guide plate and the reflective sheet.

In one aspect, some embodiments of the present disclosure provide a conforming structure of a light guide plate and a reflective sheet. Wherein, a mesh dot is disposed between the light guide plate and the reflective sheet, wherein the mesh dot is used for relatively fixing the reflective sheet and the light guide plate; and the surface of the reflective sheet facing the light guide plate and the surface of the light guide plate facing the reflective sheet pass only through the mesh point Relatively fixed.

In another aspect, some embodiments of the present disclosure also provide a backlight module. The backlight module includes a bonding structure of the light guide plate and the reflection sheet.

In still another aspect, some embodiments of the present disclosure also provide a liquid crystal display device including a liquid crystal panel, a light guide plate, and a reflective sheet. Wherein, the liquid crystal panel and the reflective sheet are respectively disposed on two sides of the light guide plate; a mesh point is disposed between the light guide plate and the reflective sheet; the mesh point is for relatively fixing the reflective sheet and the light guide plate; and the surface and the guide on the reflective sheet facing the light guide plate The face of the light plate facing the reflection sheet is relatively fixed only by the halftone dots.

In still another aspect, some embodiments of the present disclosure further provide a method of bonding a light guide plate and a reflective sheet, the method comprising: laminating a light guide plate and a reflective sheet; and melting the reflective sheet through a high temperature and/or a light guide plate to be attached The portion forms a mesh point such that the surface of the light guide plate facing the reflection sheet and the surface of the reflection sheet facing the light guide plate are relatively fixed only by the halftone dots.

DRAWINGS

1 is a schematic structural view of a liquid crystal display device in the related art;

2 is a schematic view showing a bonding structure of a light guide plate and a reflection sheet in the related art;

3 is a schematic flow chart of a bonding method according to some embodiments of the present disclosure;

4 is a schematic diagram of implementation of a bonding method according to some embodiments of the present disclosure;

5 is a schematic diagram of an optical path in a bonding type light guide plate formed by a bonding method according to some embodiments of the present disclosure;

FIG. 6 is a schematic diagram of distribution of an access point of a light guide plate in a bonding method according to some embodiments of the present disclosure; FIG.

FIG. 7 is a schematic diagram of applying pressure to facilitate bonding of a light guide plate and a reflective sheet to each other in a bonding method according to some embodiments of the present disclosure; FIG.

FIG. 8 is a schematic diagram of a bonding structure of a light guide plate and a reflective sheet according to some embodiments of the present disclosure.

Detailed ways

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. It is apparent that the embodiments described herein are only partial embodiments of the present disclosure, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments described herein without departing from the scope of the invention are the scope of the disclosure.

As shown in FIG. 1, in the related art, by using a bonding glue 25 between the glass light guide plate 23 and the reflection sheet 22, the glass light guide plate 23 and the reflection sheet 22 are bonded together to form an integral body. A full bonding method is often used between the glass light guide plate 23 and the reflection sheet 22. As shown in FIG. 2, the bonding glue 25 is disposed between the bottom surface of the light guide plate 23 and the reflection sheet 22 to bond the reflection sheet 22 and the light guide plate 23 together. In the actual production, the dot 231' and the drying dot 231' are printed on the bottom surface of the light guide plate 23, and then the reflective sheet 22 with the glue layer prepared in advance is attached to cover the light guide plate 23. . This method of bonding involves multiple steps and the manufacturing process is complicated. And after the light emitted by the LED lamp 21 enters the glass light guide plate 23, part of the light enters the glue layer due to the high refractive index of the glue 20, and a part of the light entering the glue layer is absorbed because the glue has a certain light absorption property. In turn, the utilization of the backlight is reduced. Further, the binder contained in the bonding glue 25 volatilizes or embrittles after long-term use, and there is a hidden danger in terms of stability.

Some embodiments of the present disclosure provide a method of bonding the light guide plate 23 and the reflective sheet 22. FIG. 3 is a schematic flow chart of the bonding method. As shown in FIG. 3, in step 301, the light guide plate 23 and the reflection sheet 22 are laminated. The light guide plate 23 can be located, for example, above the reflective sheet 22. In step 302, a dot is formed on the portion of the high-temperature molten reflection sheet 22 and/or the light guide plate 23 to be bonded so that the surface of the light guide plate 23 facing the reflection sheet 22 and the surface of the reflection sheet 22 facing the light guide plate 23 are formed. Only through the dots is relatively fixed.

In one embodiment, as shown in FIG. 4, the position of the laser focus point can be controlled such that the laser is incident on a portion of the surface of the reflection sheet 22 that is in contact with the light guide plate 23 to be bonded. After being incident on the reflective sheet 22, the energy of the laser light is focused on the surface of the reflective sheet 22 that is in contact with the light guide plate 23, and the laser light energy is converted into thermal energy, so that the portion of the reflective sheet 22 to be bonded is melted or The dots are melted to form a dot so that the reflection sheet 22 and the light guide plate 23 are bonded together.

In the bonding method provided by the above-mentioned embodiments of the present disclosure, the light guide plate 23 and the reflection sheet 22 are laminated, and the energy of the laser beam is used to melt the portion of the reflection sheet 22 that is in contact with the light guide plate 23 to form a mesh point, thereby forming the reflection sheet. 22 and the light guide plate 23 are attached together by a halftone dot and are relatively fixed. The method avoids the problem that the light absorbed by the glue bonding in the related art is absorbed and the stability hazard caused by the embrittlement of the adhesive in the glue, and improves the light source utilization ratio of the bonding structure of the light guide plate and the reflection sheet. And stability. In addition, the method also reduces the steps of printing dots and drying dots in the related art, simplifies the manufacturing process, and improves the production efficiency.

In one embodiment, as shown in FIG. 4, the laser light may be incident from the surface of the light guide plate 23 away from the reflection sheet 22, and then incident through the light guide plate 23 to the portion of the reflection sheet 22 to be bonded. In another embodiment, the laser light may also be incident from the surface of the reflection sheet 22 away from the light guide plate 23 to the portion of the reflection sheet 22 to be bonded. The embodiments of the present disclosure do not limit this.

In one embodiment, the material of the light guide plate 23 is glass, and the material of the reflection sheet 22 is polyethylene terephthalate (PET). The energy of the laser used in step 302 needs to at least reach the melting temperature of the reflective sheet 22, such as 250 degrees. The energy of the laser light can also reach the softening temperature of the glass used to form the light guide plate 23, and then the portion of the light guide plate 23 to be bonded is melted, and the softening temperature of the glass used for the light guide plate 23 can be, for example, about 600 degrees.

In another embodiment, the material of the light guide plate 23 is polymethyl methacrylate (PMMA).

In one embodiment, in order to ensure that the laser energy meets the requirements of use, a (Nd3+:YAG) laser and a diode laser can be used to emit the laser, and the laser used can be a femtosecond pulse laser with a pulse width of 800-900 fs in the short-wavelength infrared region. The glass and PET can be melted during the pulse time with a pulse energy of about several tens of μJ.

As shown in FIG. 5, since the halftone dots 231 break the total reflection of the light in the light guide plate 23, the bonding and relative fixing of the light guide plate 23 and the reflection sheet 22 can be performed according to the density distribution of the set dots 231 (hereinafter referred to as soldering). ), thereby controlling the distribution of light on the light exit surface of the backlight module. In some embodiments, the diameter of the bottom surface of each of the dots 231 in contact with the reflective sheet 22 and/or the light guide plate 23 is equal, but the spacing between the different dots 231 may be the same or different. Figure 6 is a schematic illustration of the arrangement of dots 231 in one embodiment. The diameter of the bottom surface of the dot 231 can be determined by the size of the laser focused spot, and can be, for example, 0.05 mm to 1 mm.

When the laser welding is performed, if the light guide plate 23 and the reflection sheet 22 are in a free state of lamination, due to the flatness of the light guide plate 23 and the reflection sheet 22, there is a certain gap between the two, so that the predetermined sticker cannot be reached. Combined effect. Therefore, in one embodiment, in order to ensure that the light guide plate 23 and the reflection sheet 22 are closely adhered, the laminated light guide plate 23 and the reflection sheet may be used with a certain pressure before the reflection sheet 22 and the light guide plate 23 are welded by laser. 22 is extruded to bring the two into close contact to ensure the accuracy of the laser focus finding and the effect of fixing each dot through each other. In an embodiment, in the process of welding the reflection sheet 22 and the light guide plate 23 by laser, the reflection sheet 22 and the light guide plate 23 are pressed, and the pressure between the reflection sheet 22 and the light guide plate 23 is utilized. The welding is stronger. As shown in FIG. 5, the pressure of the opposite side can be applied to the reflection sheet 22 and the light guide plate 23 at the same time so that the two are brought closer to each other, and only one of the reflection sheet 22 and the light guide plate 23 can be pressed against the other side. And fix the other side so that the two are pressed together. The pressure can be reasonably selected according to actual needs, as long as the reflective sheet 22 and the light guide plate 23 are in close contact without damaging the light guide plate 23 and the reflection sheet 22, and the occurrence between the light guide plate 23 and the reflection sheet 22 is avoided. The conditions of the indentation may be, for example, 500 g to 10 kg.

In some embodiments, in order to improve the welding speed and the welding effect, the bonding method shown in FIG. 3 further includes the following steps: pre-coating the reflective sheet 22 and the light guide plate 23 at the contact surface of the light guide plate 23 before the laser welding is performed. A coating that absorbs laser light. The coating may be applied to one surface of the reflection sheet 22, and then the surface of the reflection-coated sheet 22 coated with the coating may be in contact with the light guide plate 23. It is also possible to apply a coating on one surface of the light guide plate 23 first and then to contact the surface of the light-coated plate 23 coated with the coating material with the reflection sheet 22. The coating can be applied to a predetermined portion to be bonded. When the laser light is incident on the portion to be bonded, the coating absorbs thermal energy under the irradiation of the laser, rapidly generates heat and melts the material of the adjacent layer, and the molten material fixes the reflection sheet 22 and the light guide plate 23 together, thereby achieving welding.

In one embodiment, the coating may comprise silicon dioxide (SiO ₂ ), titanium dioxide (TiO ₂ ), triiron tetroxide (Fe ₃ O ₄ ), manganese dioxide (MnO ₂ ), copper oxide (CuO), germanium. At least one of cadmium (CdTe). The above materials are nano-materials, which have good absorption to laser light and can rapidly heat up after absorbing laser energy.

Some embodiments of the present disclosure also provide a backlight module. The backlight module includes a light guide plate and a reflective sheet. The light guide plate and the reflection sheet are bonded by the bonding method provided in the above embodiment. Of course, in addition, the backlight module may further include other components, such as a plastic frame for supporting or fixing the diaphragm, an optical film, and the like. The above components are well-known in the prior art and will not be described herein.

Some embodiments of the present disclosure also provide a liquid crystal display device including a liquid crystal panel, a light guide plate, and a reflective sheet. The liquid crystal panel and the reflective sheet are respectively disposed on two sides of the light guide plate, and the light guide plate and the reflective sheet are disposed with a mesh point therebetween; the surface of the reflective sheet facing the light guide plate and the surface of the light guide plate facing the reflective sheet are relatively fixed only by the mesh point.

Some embodiments of the present disclosure also provide a bonding structure of a light guide plate and a reflective sheet. As shown in FIG. 8, in the bonding structure, a mesh dot 231 is provided between the light guide plate 23 and the reflection sheet 22. The halftone dots 231 are used to relatively fix the reflection sheet 22 and the light guide plate 23, and the surface of the reflection sheet 22 facing the light guide plate 23 and the surface of the light guide plate 23 facing the reflection sheet 22 are relatively fixed only by the mesh point 231.

In one embodiment, the dots 231 are made of a viscous material. On the light guide plate 23 and/or the reflection sheet 22, no viscous material is provided except for the position of the halftone dot 231. The viscous material may, for example, comprise an ink and may also comprise scattering particles.

In one embodiment, the same material as the material of the reflective sheet 22 and/or the light guide plate 23 may be included in the viscous material.

In one embodiment, the dots 231 may be formed by melting the light guide plate 23 on the high temperature and/or the portion of the reflective sheet 22 to be bonded. For example, the halftone dots 231 are formed by melting the portion of the light guide plate 23 and/or the reflection sheet 22 to be bonded by laser irradiation. The ultra-thin display device thus produced is more stable and has higher light source utilization.

It is apparent that those skilled in the art can make various modifications and variations to the embodiments of the present disclosure without departing from the scope of the present disclosure. Thus, it is intended that the present invention cover the modifications and the modifications

Claims

A bonding structure of a light guide plate and a reflection sheet, characterized in that:

a mesh point is disposed between the light guide plate and the reflective sheet;

The mesh point is used for relatively fixing the reflective sheet and the light guide plate; and a surface of the reflective sheet facing the light guide plate and a surface of the light guide plate facing the reflective sheet are only passed through the mesh point. fixed.
The conforming structure according to claim 1, wherein:

The dots are formed by melting the reflective sheet on the high temperature and/or the portion to be bonded on the light guide plate.
The conforming structure according to claim 2, wherein:

The dots are formed by melting the reflection sheet on the reflection sheet and/or the portion to be bonded on the light guide plate by laser irradiation.
A liquid crystal display device comprising a liquid crystal panel, a light guide plate and a reflection sheet, wherein

The liquid crystal panel and the reflective sheet are respectively disposed on two sides of the light guide plate;

a mesh point is disposed between the light guide plate and the reflective sheet;

The mesh point is used for relatively fixing the reflective sheet and the light guide plate; and a surface of the reflective sheet facing the light guide plate and a surface of the light guide plate facing the reflective sheet are relatively fixed only by the mesh point.
A liquid crystal display device according to claim 4, wherein:

The dots are formed by melting the reflective sheet on the high temperature and/or the portion to be bonded on the light guide plate.
A liquid crystal display device according to claim 5, wherein said dots are formed by melting laser light on said reflection sheet and/or a portion to be bonded on said light guide plate.
A method for bonding a light guide plate and a reflection sheet, characterized in that the method comprises:

Laminating the light guide plate and the reflective sheet;

Forming dots on the reflective sheet and/or the portion to be bonded on the light guide plate by high temperature so that the surface of the light guide plate facing the reflective sheet and the surface of the reflective sheet facing the light guide plate are only The dots are relatively fixed by the dots.
The method according to claim 7, wherein the forming of the dots on the reflective sheet and/or the portion to be bonded on the light guide plate by high temperature melting comprises:

The laser is controlled to be incident on the portion to be bonded and to melt the portion to be bonded.
The method of any of claims 7-8, further comprising:

Applying a pressure directed to the opposite side to the laminated reflection sheet and the light guide plate to fit the reflection sheet and the light guide plate; or

Applying a pressure directed to the light guide plate to the laminated reflective sheet, and fixing the light guide plate to fit the reflective sheet and the light guide plate; or

A pressure directed to the reflection sheet is applied to the laminated light guide plates, and the reflection sheet is fixed to fit the reflection sheet and the light guide plate.
A method according to any one of claims 7-8, characterized in that before the incident of the laser to the portion to be bonded is controlled, the reflective sheet and/or the light guide plate are to be attached. The surface of the portion is coated with a coating capable of absorbing the laser.
The method according to claim 10, wherein said coating comprises silica (SiO 2 ), titania (TiO 2 ), triiron tetroxide (Fe 3 O 4 ), manganese dioxide (MnO 2 ), At least one of copper oxide (CuO) and cadmium telluride (CdTe).
The method according to any one of claims 7-11, wherein the light guide plate is made of glass or polymethyl methacrylate (PMMA), and the reflective sheet is made of polyparaphenylene. Polyethylene terephthalate (PET).
A method according to any one of claims 8-11, wherein the laser is a femtosecond pulsed laser having a pulse width of 800-900 fs in the short-wavelength infrared region.
The method according to claim 8, wherein a diameter of the bottom surface of the dot which is in contact with the reflection sheet and/or the light guide plate is 0.05 mm to 1 mm.