CN202125822U - Edge type LED backlight module - Google Patents

Abstract

The utility model provides an LED side-light backlight module, which includes a light guide plate, an LED light bar arranged on one side of the light guide plate, and an optical film covering the upper surface of the light guide plate: the optical film is close to the LED light bar One side protrudes from the light guide plate and is configured as a raised portion. With the utility model, the strength structure of this part is enhanced through the raised portion, thereby effectively resisting thermal expansion and reducing deformation caused by thermal expansion.

Description

LED edge-lit backlight module

technical field

The utility model relates to an LED side-light type backlight module.

Background technique

The LCD screen of an LCD TV is composed of a LCD panel and a backlight module. The LCD panel itself does not emit light. The backlight module provides a uniform and high-brightness light source for the LCD panel so that it can display images normally. Therefore, the backlight module is a key component of the LCD TV.

LED LCD TVs use LED light sources as the backlight for their backlight modules. Compared with traditional LCD TVs using fluorescent tubes as backlight, LCD TVs using LEDs as backlight can make the display screen consume less power, and the appearance can be thinner and more fashionable, while the brightness is more uniform to display more realistic color.

The backlight module includes an LED side-light backlight module, including a substrate, a reflective sheet arranged on the substrate from bottom to top, a light guide plate, an optical film, and a LED package packaged on the side of the light guide plate. LED strips. The optical film can be a multi-layer film, such as including upper and lower diffusion films, upper and lower light enhancement films, and the like.

The light source emitted by the LED light bar enters from the incident surface of the light guide plate, and the light source is emitted from the light exit surface of the light guide plate through the diffuse reflection of the reflector, and the light source is diffused through the optical film.

Among them, the thickness of the optical film is very thin. Due to the difference in thermal expansion coefficient from the light guide plate, when the LED light bar emits heat, the area of the diffusion sheet close to the LED light bar will warp or wrinkle due to thermal expansion. Cause changes in brightness in the backlight module or cause shadows. The above-mentioned conditions will be reflected on the surface shape of the LCD TV panel, seriously affecting the viewing effect of the LED LCD TV.

Utility model content

In view of this, the main purpose of the present utility model is to provide an LED edge-lit backlight module, so as to reduce the deformation of the optical film of the backlight module caused by the thermal expansion caused by the LED light strip emitting heat.

The LED side-light backlight module provided by the utility model includes a light guide plate, an LED light bar arranged on one side of the light guide plate, and an optical film covering the upper surface of the light guide plate:

The side of the optical film close to the LED light bar protrudes from the light guide plate and is provided with a raised portion.

From the above, by setting the part protruding from the light guide plate on the side of the optical film close to the LED light bar, and setting this part as a raised part, the strength structure of this part is enhanced, so that it can effectively resist heat absorption expansion and reduce the Deformation caused by thermal expansion.

Wherein, the optical film includes: a lower diffusion sheet and an upper diffusion sheet closely arranged in order away from the light guide plate;

The side of the lower diffusion sheet and/or the upper diffusion sheet close to the LED light bar protrudes from the light guide plate and is provided with the protrusion.

From the above, the protrusions are provided on the lower diffusion sheet and/or the upper diffusion sheet, which can realize the strengthening of the strength structure of the lower diffusion sheet and/or the upper diffusion sheet, so that it can effectively resist heat absorption expansion, and reduce thermal expansion. resulting deformation.

Optionally, both the lower diffusion sheet and the upper diffusion sheet are provided with the raised portion;

The raised portion of the lower diffuser is raised on the upper and lower sides of the downward diffuser;

The convex portion of the upper diffuser is convex downward.

From the above, the strength structure of the lower diffuser and the upper diffuser is enhanced, so that it can effectively resist heat absorption expansion, and reduce the deformation caused by the thermal expansion of the lower diffuser and the upper diffuser.

Optionally, the lower diffusion sheet or the upper diffusion sheet is provided with the raised portion;

The raised portion of the lower diffuser/upper diffuser is raised upward/downward to the side of the upper diffuser/lower diffuser.

From the top, the strength structure of the lower diffusion sheet or the upper diffusion sheet can be enhanced, and its protrusions can effectively block the heat transfer to the other diffusion sheet, so that not only itself can effectively resist heat absorption expansion, but also reduce the diffusion sheet. The deformation caused by thermal expansion also effectively blocks heat transfer to another diffusion sheet, reducing the deformation of the other diffusion sheet due to thermal expansion.

Optionally, the raised portion is provided with more than one opening facing outward.

From the above, when the convex portion is slightly deformed due to thermal expansion, the gap structure can also ensure the expansion space of the convex portion of the diffusion sheet, and relieve the warping or wrinkling deformation caused by the expansion.

Description of drawings

Fig. 1 is the structural representation of the first embodiment of the utility model LED side-light backlight module;

Fig. 2 is a schematic structural view of the second embodiment of the LED edge-lit backlight module of the present invention;

FIG. 3 is a schematic structural view of a third embodiment of the LED edge-lit backlight module of the present invention.

Detailed ways

The LED edge-lit backlight module involved in the present invention will be introduced in detail below. The side-light LED backlight module includes: a reflection sheet 10, a light guide plate 20, an LED light bar 30 and an optical film. FIG. 1 shows a schematic structural diagram of a first embodiment of an LED edge-lit backlight module.

The reflection sheet 10 is in the shape of a rectangular plate with a thickness of 0.2mm, and is arranged at the lowermost end of the LED edge-lit backlight module. The reflective sheet 10 is used to reflect the light source leaking from under the light guide plate 20 and the light source not irradiated into the light guide plate 20 by the LED light bar 30 back to the light guide plate 20 to prevent leakage of the light source and increase the use efficiency of the light source.

The light guide plate 20 is in the shape of a rectangular plate with a thickness of 3 mm, and is disposed above the reflection sheet 10 .

The LED light bar 30 is disposed on a side of the light guide plate 20 . Evenly arranged LED light groups 301 are arranged on the LED light bar 30 . Used to provide light source to the LCD panel.

The light guide plate 20 is used to guide the irradiation direction of the light source, so as to improve the brightness of the light source and control the uniform brightness of the light source. Specifically, the light guide plate 20 receives the point or line light source emitted by the LED lamp group 301 , converts it into a surface light source, and emits it toward the diffusion sheet 40 . Wherein, the lower surface of the light guide plate 20 is provided with dot patterns 201, and the dot patterns 201 are densely distributed in the middle and sparsely distributed around. The purpose of setting the grid dots 201 is to destroy the total reflection of the light guide plate 20 , so that the light source irradiates the grid dots 201 to produce scattering, forming a diffuse reflection effect and entering the light guide plate 20 .

Optical films include diffusers and enhancement films.

Wherein, the diffusion sheet includes a lower diffusion sheet 401 and an upper diffusion sheet 402 .

As shown in FIG. 1 , the lower diffusion sheet 401 is disposed above the light guide plate 20 , and the part overlapping with the light guide plate 20 is in the shape of a rectangular plate with a thickness of 0.2 mm. The portion of the lower diffusion sheet 401 protruding from the light guide plate 20 near the side of the LED light bar 30 is thickened to form a raised portion. Specifically, the cross-section of the lower diffuser 401 is set as a T-shaped structure as shown in Figure 1. The ratio of the thickened part, that is, the protrusions to the top and bottom of it, is 1:1, that is, the ratio of the entire thickened part is 1:1. The thickness is 0.6mm.

The upper diffuser 402 is arranged in an L-shaped structure, that is, its thickened part, that is, the convex part protrudes downward, and the overall thickness is 0.6 mm. The thicknesses of the upper and lower brightness enhancement sheets mentioned later are both 0.2mm. Thus, after the optical film is assembled, the thickened parts of the upper and lower diffusion sheets, that is, the opposite surfaces of the raised parts are bonded together. Therefore, without affecting the thickness of the LCD TV, the deformation of the diffusion sheet due to the heat of the LED light can be reduced, and it can also be used to protect the brightness enhancement sheet described later and reduce its deformation caused by heat .

The lower diffusion sheet 401 is used to evenly diffuse the light source emitted from the light guide plate 20 , cover the network dots, and prevent the front surface from appearing scattering dots. The upper diffusion sheet 402 is used to correct the irradiation angle of the light source, so that the irradiation angle of the light source is perpendicular to the liquid crystal panel. In addition, another purpose of the upper diffusion film is to protect the brightness enhancement sheet described later and provide it with a fairly good shielding layer.

The brightness enhancement sheet is in the shape of a rectangular plate with a thickness of 0.2mm. The brightness enhancement sheet is arranged between the upper and lower diffusion sheets, including the lower brightness enhancement sheet 501 and the upper brightness enhancement sheet 502 . Wherein, the lower brightness enhancement sheet 501 is arranged above the lower diffusion sheet 401 ; the upper brightness enhancement sheet 502 is arranged above the lower brightness enhancement sheet 501 .

Both the upper and lower brightness enhancement sheets are used to increase the brightness of the light source. If a single layer of brightness enhancement sheets is used, the brightness of the light source can be increased by 60%, and if two layers of upper and lower brightness enhancement sheets are used, the brightness of the light source can be increased by 110% to 120%.

In addition, FIG. 2 shows a schematic structural diagram of the second embodiment of the LED edge-lit backlight module. The upper and lower ends of the thickened part of the lower diffusion sheet 401, that is, the upper and lower protrusions can also be arranged in an asymmetric structure, that is, the upper end of the thickened part of the lower diffusion sheet 401 extends to the side of the upper diffusion sheet 402, while the upper The diffusion sheet 402 is not thickened. In this way, the structure of the upper diffuser 402 can be simplified, and at the same time, the deformation of the optical film when heated is significantly reduced. It is not difficult to understand that the lower end of the thickened portion of the upper diffuser 402 may also extend to the side of the lower diffuser 401 , and the lower diffuser 401 is not thickened.

FIG. 3 shows a schematic structural diagram of a third embodiment of an LED edge-lit backlight module. The thickened part of the upper and lower diffusion sheets, that is, the outer side of the raised part is arranged in a zigzag shape formed by a plurality of notches. Compared with the T-shaped thickened structure or the L-shaped thickened structure, the zigzag thickened structure can effectively alleviate the deformation of the upper and lower diffusers due to heat on the one hand. On the other hand, even if the upper and lower diffusers are slightly deformed due to long-term thermal expansion, the gap structure can ensure the expansion space of the upper and lower diffusers without affecting the uniform light effect of the upper and lower diffusers. More preferably, the upper surface of the thickened portion of the lower diffuser 401 and the lower surface of the thickened portion of the upper diffuser 402 are set horizontally, so that after the optical film is assembled, the thickened portions of the upper and lower diffusers can be attached together.

The working principle of the LED edge-lit backlight module is introduced below: the point or linear light source emitted by the LED lamp group 301 is directly injected into and reflected from the reflector 10 into the light guide plate 20 . Using the optical function of the light guide plate 20, it is converted into a uniformly distributed surface light source. The surface light source passes through the lower diffusion sheet 401 to cover the dots, so that the light source can be evenly diffused. Thereafter, the brightness and uniformity of the light source are improved through the brightness enhancement sheet, and finally the irradiation angle of the light source is corrected through the upper diffusion sheet 402 so that the irradiation angle of the light source is perpendicular to the liquid crystal panel.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in the Within the protection scope of the present utility model.

Claims (5)

1. An LED side-lit backlight module, comprising a light guide plate (20), an LED light bar (30) arranged on one side of the light guide plate, and an optical film covering the upper surface of the light guide plate (20): it is characterized in that , The side of the optical film near the LED light bar (30) protrudes from the light guide plate (20) and is provided with a raised portion. 2. The LED edge-lit backlight module according to claim 1, wherein the optical film comprises: A lower diffusion sheet (401) and an upper diffusion sheet (402) closely arranged away from the light guide plate (20) in sequence; The side of the lower diffusion sheet (401) and/or the upper diffusion sheet (402) close to the LED light bar (30) protrudes from the light guide plate (20) and is provided with the protrusion. 3. The LED edge-lit backlight module according to claim 2, characterized in that, Both the lower diffusion sheet (401) and the upper diffusion sheet (402) are provided with the raised portion; The raised portion of the lower diffuser (401) is the upper and lower sides of the downward diffuser (401); The convex portion of the upper diffusion sheet (402) is convex downward. 4. The LED edge-lit backlight module according to claim 2, characterized in that, The lower diffusion sheet (401) or the upper diffusion sheet (402) is provided with the raised portion; The convex portion of the lower diffusion sheet (401)/upper diffusion sheet (402) is convex upward/downward to the side surface of the upper diffusion sheet (402)/lower diffusion sheet (401). 5 . The LED edge-lit backlight module according to any one of claims 1 to 4 , wherein the raised portion is provided with more than one opening facing outward. 6 .

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