Curved backlight module and preparation method thereof

Abstract

The present invention provides a curved backlight module and a method for preparing the same. The curved backlight module comprises a backlight unit composed of a reflective plate, a light guide plate, an optical plate group, and a light source, and a fixing layer and a limiting layer sequentially arranged at the edge of the backlight unit. The method for preparing the curved backlight module comprises the steps of setting a buckle, setting a composite material sheet and a thermosetting resin, heating and applying pressure, and cooling. The curved backlight module and the method for preparing the same provided by the present invention solve the technical problems of the curved backlight module in the prior art, such as the difficulty in fully fitting the various parts, the easy separation, and the easy displacement of the position of the light source.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal display, and in particular to a curved backlight module and a preparation method thereof. Background Art

[0002] The curved backlight module is one of the key components of the curved liquid crystal display, which is used to supply sufficient brightness and evenly distributed light sources so that the curved liquid crystal display can display images normally. The basic structure of the curved backlight module is a reflector, a light guide plate, an optical plate group arranged in sequence, and a light source (LED light strip) arranged on the side of the light guide plate. Its common production process is to use a mold to pressurize the straight screen backlight module to make it curved. However, due to the stress difference between the various parts of the curved backlight module, there are problems such as difficulty in full fitting and easy separation.

[0003] In addition, in order to ensure that all the light emitted by the light source enters the light guide plate, the light source should be arranged as accurately as possible along the center line of the light guide plate. However, during the bending process, the position of the light source is very likely to shift, which will cause dark shadows or bright spots to appear at the straight-curved gradient of the light guide plate, seriously affecting the normal use of the curved backlight module. Summary of the invention

[0004] In order to solve the technical problems of the prior art that the parts of the curved backlight module are difficult to fully fit together, easy to separate, and the position of the light source is easy to shift, the present invention provides a method for preparing a curved backlight module that solves the above problems.

[0005] A curved backlight module comprises a reflective plate, a light guide plate, an optical plate group and a light source arranged on the side of the light guide plate in sequence, wherein the reflective plate, the light guide plate, the optical plate group and the light source constitute a backlight unit, wherein the edge of the backlight unit is wrapped with a circle of fixing layer, and the fixing layer is wrapped with a circle of limiting layer.

[0006] In a preferred embodiment of the curved backlight module provided by the present invention, the fixing layer is a thermoplastic resin; and the limiting layer is a thermosetting resin-based composite material.

[0007] A method for preparing a curved backlight module comprises the following steps:

[0008] Step 1: preparing the reflector, the light guide plate, the optical plate assembly, the light source, buckles, composite material sheets, thermosetting resin, and processing equipment;

[0009] Step 2: Assemble the reflector, the light guide plate, the optical plate group, and the light source into the backlight unit, and snap the buckles onto the edges of the backlight unit;

[0010] Step 3: Apply the thermosetting resin to the outer wall of the buckle away from the backlight unit, and lay the composite material sheet, repeating for multiple times until a suitable thickness is reached;

[0011] Step 4: placing the backlight unit provided with the buckle, the composite material sheet, and the thermosetting resin in the processing equipment, heating and applying pressure to soften the buckle, cure the thermosetting resin, and bend the backlight unit;

[0012] Step 5: After cooling, the curved backlight module is obtained.

[0013] In a preferred embodiment of the method for preparing the curved backlight module provided by the present invention, the buckle is a "C" shaped structure, the width of its opening is less than or equal to the thickness of the backlight unit, and the bottom surface of the opening is provided with a groove connected with the light source. It is made of thermoplastic resin.

[0014] In a preferred embodiment of the method for preparing the curved backlight module provided by the present invention, the outer wall of the buckle away from the backlight unit is made of thermoplastic resin.

[0015] In a preferred embodiment of the method for preparing a curved backlight module provided by the present invention, the thermosetting resin is a low-temperature curing thermosetting resin; and the softening temperature of the thermoplastic resin used in the buckle is lower than the curing temperature of the thermosetting resin.

[0016] In a preferred embodiment of the method for preparing the curved backlight module provided by the present invention, the processing equipment includes a heating chamber, a bending pressure device and a pressing device arranged in the heating chamber, and the backlight unit is arranged in the pressing device.

[0017] The pressing device comprises a square frame-shaped compacting tool, which is arranged around the edge of the backlight unit. A plurality of expansion bags are arranged on the inner wall of the compacting tool, that is, between the compacting tool and the backlight unit. The expansion bags are filled with thermal expansion materials.

[0018] The bending pressing device presses the backlight unit at an angle perpendicular to the pressing device and the backlight unit to bend the backlight unit.

[0019] Compared with the prior art, the curved backlight module provided by the present invention is coated with the fixing layer and the limiting layer at the edge of the backlight unit, which fixes the position of the light source and also fixes the various parts of the backlight unit, thereby solving the problems of difficulty in fully fitting and easy separation caused by the stress difference between the various parts of the curved backlight module.

[0020] Compared with the prior art, the preparation method of the curved backlight module provided by the present invention adopts a combination of thermoplastic resin, thermosetting resin and thermal expansion material. At a suitable temperature, the three processes of bending the curved backlight module, fixing the light source and fixing the various parts of the backlight unit can be completed at one time. The process is simple and fast, and the product quality is good.

[0021] In the preparation method of the curved backlight module provided by the present invention, by providing the buckle, the light source can be stably fixed during the assembly process before processing, the bending process during processing, and the use process after processing, thereby ensuring product quality.

[0022] In the method for preparing the curved backlight module provided by the present invention, the fixing frame of the backlight unit is prepared by arranging the composite material sheet and the thermosetting resin, which has better fit and stability than the traditional frame fixing method. In addition, the softened buckle can achieve the effect of binding reinforcement and has good impact resistance.

[0023] In the method for preparing the curved backlight module provided by the present invention, the composite material sheet and the thermosetting resin are compacted by using the thermal expansion material. Compared with traditional mechanical compaction, air pressure compaction and other solutions, the operation is simpler and the equipment requirements are lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of a backlight unit in a curved backlight module;

[0025] Figure 2 It is a schematic diagram of the structure after the backlight unit is provided with some buckles;

[0026] Figure 3 yes Figure 2 A partial enlarged view of

[0027] Figure 4 It is a schematic diagram of the structure of a backlight unit after being provided with buckles, composite material sheets, and thermosetting resin;

[0028] Figure 5 It is a schematic diagram of the structure of a backlight unit provided with buckles, composite material sheets, thermosetting resin, and a partial pressing device;

[0029] Figure 6 yes Figure 5 A partial enlarged view of

[0030] Figure 7 yes Figure 5 Cross-sectional view of medium pressure pressing equipment. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] Embodiment 1:

[0033] See also Figure 1 , is a schematic diagram of the structure of the backlight unit 1 in the curved backlight module provided by the present invention. It includes a rectangular reflector 11, a light guide plate 12, an optical plate group 13, and a light bar 14 arranged on a long side wall of the light guide plate 12. This part is basically the same as the backlight module of the prior art, and its specific structure will not be described in detail.

[0034] The method for preparing the curved backlight module comprises the following steps:

[0035] Step 1: Provide the backlight unit 1.

[0036] Provide a buckle 2, a carbon fiber sheet, an epoxy resin curing agent (initial curing temperature 70-130°C), processing equipment, and expanded graphite (initial expansion temperature 70-150°C). The processing equipment includes a heating chamber, a bending and pressing device, and a pressing and pressing device 3.

[0037] Please also see Figure 2 and Figure 3 , respectively, are a schematic diagram of the structure of setting a buckle 2 on the basis of the backlight unit 1, and a partial enlarged diagram thereof.

[0038] Step 2: Arrange a plurality of the buckles 2 at equal intervals along the edge of the backlight unit 1. The figure only shows a small part of the buckles 2 at the corner.

[0039] The buckle 2 is a "C" shaped structure made of PET material (initial softening temperature 70-90°C), and the opening is stuck on the edge of the backlight unit 1. Other materials with similar softening temperatures can also be used to further obtain other properties such as heat dissipation and impact resistance.

[0040] The buckle 2 includes two configurations. One configuration has a smooth inner wall, which is clamped on the three sides of the backlight unit 1 where the light bar 14 is not set; the other configuration has an inner wall with two clamping grooves, which is clamped on the side of the backlight unit 1 where the light bar 14 is set, and the two clamping grooves just position the light bar 14 at the center of the side wall of the light guide plate 12.

[0041] See also Figure 4 , is a schematic diagram of the structure in which the carbon fiber sheet and the epoxy resin curing agent are arranged on the basis of the structure in step 2.

[0042] Step 3: Wrap the carbon fiber sheet along the edge of the backlight unit 1 and apply the epoxy resin curing agent, repeating the process multiple times until the buckle 2 is completely covered.

[0043] Step 4: An isolation film (not shown in the drawings) is coated on the entirety of the backlight unit 1 , the buckle 2 , the carbon fiber sheet, and the epoxy resin curing agent.

[0044] See also Figure 5 and Figure 6 , respectively, are schematic diagrams of the structure of the pressing device 3 set up on the basis of the structure in step 4, and a partial enlarged diagram thereof.

[0045] Step 5: The pressing device 3 is arranged along the edge of the whole formed by the backlight unit 1, the buckle 2, the carbon fiber sheet, the epoxy resin curing agent and the isolation film. Only a small part located at the corner is drawn in the figure.

[0046] The pressing device 3 is a square frame structure, wherein the wide side is an integral structure and the long side is a multi-section split structure. The long side includes a plurality of trapezoidal pressing units 31, all of which are isosceles trapezoidal structures, and are movably connected to another pressing unit 31 or the wide side through a rotating shaft at the bottom surface of the trapezoid. The two wide sides are disconnected in the middle and connected by a bayonet (not shown in the drawings), that is, the pressing device 3 is composed of two parts spliced ​​together.

[0047] See also Figure 7 , is a cross-sectional view of the pressing device 3.

[0048] The cross section of the pressing device 3 is a "C"-shaped structure similar to the buckle 2, made of steel with strong pressure resistance, and welded with a layer of mesh plate 32 on the inner wall. The solid sheet of expanded graphite is inserted into the inner gap of the mesh plate 32.

[0049] Step 6: Place the whole composed of the backlight unit 1, the buckle 2, the carbon fiber sheet, the epoxy resin curing agent, the isolation film, and the pressing device 3 in the bending pressing device, and the bending pressing device is arranged in the heating chamber.

[0050] The bending and pressing device presses the whole downward to bend the backlight unit 1 into a target shape. During the bending process, the buckle 2 keeps the light bar 14 fixed to prevent its position from shifting.

[0051] At the same time, the heating chamber heats the entire structure, and the epoxy resin curing agent begins to cure while the buckle 2 begins to soften, and the light bar 14 is fixed by the epoxy resin curing agent and the carbon fiber sheet to prevent its position from shifting.

[0052] When the buckle 2 starts to soften and the epoxy resin curing agent starts to cure, the expanded graphite also starts to expand, pressing the epoxy resin curing agent and the carbon fiber sheet to improve the strength after curing; at the same time, the softened buckle 2 is forced to flow to fill the gap between the edge of the backlight unit 1 and the carbon fiber sheet.

[0053] Step 7: After exceeding the initial softening temperature of the buckle 2, the initial curing temperature of the epoxy resin curing agent, and the initial expansion temperature of the expanded graphite, the heating chamber continues to increase the temperature slightly and maintains the temperature, and the bending pressure device maintains the pressure, so that the changes recorded in step 6 continue until complete softening, curing, and expansion.

[0054] Step 8: Cool down and take out the whole body consisting of the backlight unit 1, the buckle 2, the carbon fiber sheet, the epoxy resin curing agent, the isolation film, and the pressing device 3. Remove the pressing device 3 and the isolation film in turn, trim the small amount of PET that overflows, and obtain the finished product of the curved backlight module.

[0055] The curved backlight module includes the backlight unit 1, a fixing layer (formed by softening the buckle 2) covering the backlight unit 1, and a limiting layer (the cured carbon fiber sheet and the epoxy resin curing agent) covering the outside of the fixing layer.

[0056] Embodiment 2:

[0057] The difference from Example 1 is that the inner wall of the buckle 2, that is, the part in contact with the backlight unit 1 and the light bar 14, is made of heat-resistant material, and the outer wall is made of the same material as in Example 1. When placed in the heating chamber for processing, only the outer wall softens and fills the gap at the edge of the backlight unit 1, including the gap between the backlight unit 1 and the unsoftened part of the buckle 2, and the gap between the backlight unit 1 and the carbon fiber sheet.

[0058] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a curved backlight module, characterized in that: The following steps are involved: Step 1: Prepare reflector, light guide plate, optical plate assembly, light source, buckle, composite sheet, thermosetting resin, and processing equipment; Step 2: Assemble the reflector, the light guide plate, the optical plate group, and the light source into a backlight unit, and snap the buckles onto the edges of the backlight unit; Step 3: Apply the thermosetting resin to the outer wall of the buckle away from the backlight unit, and lay the composite material sheet, repeating for multiple times until a suitable thickness is reached; Step 4: placing the backlight unit provided with the buckle, the composite material sheet, and the thermosetting resin in the processing equipment, heating and applying pressure to soften the buckle, cure the thermosetting resin, and bend the backlight unit; Step 5: After cooling, the curved backlight module is obtained.

2. The method for preparing a curved backlight module according to claim 1, characterized in that: The buckle is a "C"-shaped structure, the width of its opening is less than or equal to the thickness of the backlight unit, and the bottom surface of the opening is provided with a groove connected with the light source.

3. The method for preparing a curved backlight module according to claim 2, characterized in that: The buckle is made of thermoplastic resin.

4. The method for preparing a curved backlight module according to claim 2, characterized in that: The outer wall of the buckle away from the backlight unit is made of thermoplastic resin.

5. The method for preparing a curved backlight module according to claim 3 or 4, characterized in that: The thermosetting resin is a low-temperature curing thermosetting resin; the softening temperature of the thermoplastic resin used in the buckle is lower than the curing temperature of the thermosetting resin.

6. The method for preparing a curved backlight module according to claim 1, characterized in that: The processing equipment comprises a heating chamber, a bending and pressing device and a pressing device arranged in the heating chamber, and the backlight unit is arranged in the pressing device.

7. The method for preparing a curved backlight module according to claim 6, characterized in that: The pressing device comprises a square frame-shaped compacting tool, which is arranged around the edge of the backlight unit. A plurality of expansion bags are arranged on the inner wall of the compacting tool, that is, between the compacting tool and the backlight unit. The expansion bags are filled with thermal expansion materials.

8. The method for preparing a curved backlight module according to claim 7, characterized in that: The bending pressing device presses the backlight unit at an angle perpendicular to the pressing device and the backlight unit to bend the backlight unit.

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