Backlight module and liquid crystal display device

The invention discloses a backlight module. The backlight module includes a light guide plate having an incident side; a mounting bracket including a vertical portion and a horizontal portion, wherein the vertical portion is opposite to the incident side, a gap exists between the vertical portion and the incident side, the vertical portion has a plurality of mounting holes, and the mounting holes pass through the vertical portion and the horizontal portion, thereby forming a plurality of grooves on the horizontal portion; a plurality of optical fibers, wherein the optical fibers are respectively disposed in the grooves and the mounting holes, emitting end faces of the optical fibers are attached to the incident side, and the optical fibers are used for guiding the ambient light into the light guide plate; and a plurality of slide assemblies, wherein the slide assemblies are respectively put around the optical fibers and fixed on the optical fibers, and the sliding assemblies are respectively disposed in the grooves and able to move with expansion or contraction of the light guide plate. The invention also discloses a liquid crystal display device having the backlight module.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention belongs to the technical field of liquid crystal display, in particular, to a backlight module and a liquid crystal display device.

Description of Related Art

Nowadays, most of backlight modules of liquid crystal display (Liquid Crystal Display, referred to LCD) device take the original light sources as backlights. The original light source emits light by the use of electricity, such as a light emitting diode (Light Emitting Diode, referred to as LED). LED has the advantage of energy-efficient, no it is widely used as a backlight source of backlight module. But as people pay more attention to energy saving in the future, the current power consumption of the backlight source of the backlight module needs to be further reduced, which needs to reduce the number of LEDs to achieve the reduction of power consumption of the backlight source, or use a new energy-saving source as the backlight source of the backlight module to achieve further energy saving.

Using ambient light (such as sunlight), as a backlight source of the backlight module is a new energy-saving program, which does not require the use of the original light source powered by electricity, or could reduce the proportion of the use of the original light sources, greatly reducing energy consumption. Currently, the backlight module using ambient light as a backlight source uses multiple optical fibers to conduct ambient light after collecting the ambient light, and by the emitting end face of the each optical fiber the collected ambient light is emitted into the backlight module.FIG. 1is a structural schematic diagram of a backlight module using ambient light as a backlight source according to a prior art. Referring toFIG. 1, the backlight module of the prior art includes a light guide plate110, an optical fiber120and a holder130fixing the optical fiber120. The light guide plate110includes an incident side111. The optical fiber120is fixed to the holder130, and the emitting end face121of the optical fiber120is attached to the incident side111. Thus, when the outside temperature or the self-heating temperature of the backlight module leads to expansion of the light guide plate110, due to the optical fiber120is rigidly fixed, cannot moved, the undesirable phenomena such as breaking the optical fiber120will appear.

SUMMARY OF THE INVENTION

In order to solve the above problems of the prior art, an object of the invention is to provide a backlight module including a light guide plate having an incident side; a mounting bracket including a vertical portion and a horizontal portion, wherein the vertical portion is opposite to the incident side, a gap exists between the vertical portion and the incident side, the vertical portion has a plurality of mounting holes, and the mounting holes pass through the vertical portion and the horizontal portion, thereby forming a plurality of grooves on the horizontal portion; a plurality of optical fibers, wherein the optical fibers are respectively disposed in the grooves and the mounting holes, emitting end faces of the optical fibers are attached to the incident side, and the optical fibers are used for guiding the ambient light into the light guide plate; and a plurality of slide assemblies, wherein the slide assemblies are respectively put around the optical fibers and fixed on the optical fibers, and the sliding assemblies are respectively disposed in the grooves and able to move with expansion or contraction of the light guide plate.

Further, the slide assembly includes a fiber jacket and an elastic element. The fiber jacket is put around the optical fiber and fixed on the optical fiber. The outer surface of the fiber jacket has a circumferential projection. The central portion of the groove has a receiving concave. The bottom of the receiving concave and the bottom of the groove form a first step and a second step. The fiber jacket is placed in the groove. The circumferential projection is against the first step. The elastic member is movably put around the fiber jacket and placed in the receiving concave. One end of the elastic member abuts the circumferential projection, and the other end of the elastic member abuts the second step.

Further, the backlight module farther includes a plurality of fixed covers, wherein the fixed cover includes a first arch and fixed portions respectively extending from two sides of the first arch, the fixed portion and a surface of the horizontal portion are fixedly connected to make the first arch fixed on the groove, and thereby the slide assembly is engaged between the first arch and the groove.

Further, the slide assembly includes a fiber jacket. The fiber jacket is put around the optical fiber and fixed on the optical fiber. The outer surface of the fiber jacket has a bump. The connection between a surface of the horizontal portion and the groove has an engaging recess. The bump is placed in the engaging recess to make the fiber jacket engaged in the groove. The bump is made of an elastic material.

Further, the backlight module further includes a fixing bar, wherein the fixing bar includes a plurality of convex portions and a second arch set among the convex portions, the fixing bar is fixed on the surface of the horizontal portion, the convex portion is fixed on the engaging recess to make the bump engaged between the convex portion and the engaging recess, and the second arch is fixed on the groove to make the fiber jacket engaged between the second arch and the groove.

Another object of the present invention is to provide a liquid crystal display device including a backlight module and a liquid crystal display panel on the backlight module. The backlight module provides light for the liquid crystal display panel, so that the liquid crystal display panel is able to display an image. The backlight module is as above.

In the backlight module and the liquid crystal display device of the present invention, during the thermal expansion or cooling contraction of the light guide plate, the slide assembly moves to drive the optical fiber so as to avoid the undesirable phenomena such as breaking the optical fiber.

DESCRIPTION OF THE EMBODIMENTS

Following exemplary embodiments with reference of figures are only used for describing the disclosure in detail. However, the disclosure can also be achieved through different implementations, which is not limited to the following embodiments. In the figures referred to herein, sizes and relative sizes of different layers are probably exaggerated for clarity of illustration and are not necessarily drawn to scale.

In the drawings, the same reference numerals will be used to denote the same elements. It will be understood that, although the term may be used herein “first”, “second”, and so on to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another separate.

FIG. 2is a partial schematic perspective view of the backlight module according to a first embodiment of the present invention.FIG. 3is a partial cross-section of the backlight module according to the first embodiment of the present invention.

Refer toFIG. 2andFIG. 3, the backlight module210of the first embodiment of the present invention includes a backplane210, a light guide plate220, a mounting bracket230, a plurality of optical fibers240, and a plurality of slide assemblies250.

Specifically, the light guide plate220is disposed above the backplate210, and has an incident side221. The mounting bracket230is fixedly disposed on the backplane210. The mounting bracket230includes a vertical portion231and a horizontal portion232. The vertical portion231is opposite to the incident side221. A gap with a distance exists between the vertical portion331and the incident side221. The vertical portion331has a plurality of mounting holes2311. Each mounting hole2311passes through the vertical portion231and the horizontal portion232, thereby forming a plurality of grooves2321on the horizontal portion232. Each optical fiber240is disposed in a corresponding groove2321and a corresponding mounting hole2311, and the emitting, end face241of each optical fiber240are attached to the incident side221. Each optical fiber240guides the ambient light collected by ambient light collecting means (not shown) into the light guide plate221by the incident side221. Each slide assembly250is put around a corresponding optical fiber240and fixed on the corresponding optical fiber240. Each sliding assembly250is disposed in a corresponding groove2321and able to move to drive the corresponding optical fiber240in the groove2321so as to avoid the undesirable phenomena such as breaking the optical fiber240during the thermal expansion or cooling contraction of the light guide plate220.

Each slide assembly250includes a fiber jacket251and an elastic element252. The fiber jacket251is put around the corresponding optical fiber240and fixed on the corresponding optical fiber240. In the embodiment, the fiber jacket251and the corresponding optical fiber240can be fixed together by glue or other adhesives. The outer surface of the fiber jacket251has a circumferential projection2511. In the embodiment, the circumferential projection2511may be disposed in the middle portion of the fiber jacket251, but the present invention is not limited thereto. The central portion of each groove2321has a receiving concave2322. The bottom of each receiving concave2322and the bottom of the corresponding groove2321form a first step2323and a second step2324. The fiber jacket251is placed in the groove2321. The circumferential projection2511is against the first step2323. The elastic member252is movably put around the fiber jacket251and placed in the receiving concave2322. One end of the elastic member252abuts the circumferential projection2511, and the other end of the elastic member252abuts the second step2324. When the light guide plate220is displaced by thermal expansion or cooling contraction, the displacement of light guide plate220makes the elastic member252of the slide assembly250contract or expand to drive the optical fiber240back or forward, so that the emitting end face241of the optical fiber240is always attached to the incident side221, avoiding the undesirable phenomena such as breaking the optical fiber120.

In order to better reinforce firmness of the fiber assembly240and the slide assembly250, the backlight module according to the embodiment of the invention further includes a plurality of fixed covers260. Each fixed cover260includes a first arch261and fixed portions262respectively extending from two sides of the first arch261. The fixed portion262and a surface of the horizontal portion232are fixedly connected to make the first arch261fixed on the groove2321, and thereby the slide assembly250and the optical fiber240are engaged between the first arch261and the groove2321.

FIG. 4is a partial schematic perspective view of the backlight module according to a second embodiment of the present invention.

The description of the second embodiment only discloses the differences with the first embodiment, and the similarities with the first embodiment are omitted. Referring toFIG. 4, the differences with the first embodiment are as below. Each slide assembly250includes a fiber jacket251. The fiber jacket251is put around the corresponding optical fiber240and fixed on the corresponding optical fiber240. In the embodiment, the fiber jacket251and the corresponding optical fiber240may be fixed together by an adhesive such as glue. The outer surface of the fiber jacket251has two bumps2512. In the embodiment, the two bumps2512may be set in the middle portion of the fiber jacket251, but the present invention is not limited thereto. The connection between a surface of the horizontal portion232and the groove2321has an engaging recess2325, meaning that the two sides of each groove2321each has an engaging recess2325. Each bump2512is placed in the corresponding engaging recess2325to make the fiber jacket251engaged in the groove2321. Each bump2512is made of an elastic material. When the light guide plate220is displaced by thermal expansion or cooling contraction, the displacement of light guide plate220makes each bumps2512made of the elastic material contract or expand to drive the optical fiber240back or forward, so that the emitting end face241of the optical fiber240is always attached to the incident side221, avoiding the undesirable phenomena such as breaking the optical fiber120. In the present embodiment, each of the bumps2512may be made of rubber or

In order to better reinforce firmness of the optical fiber240and the slide assembly250, the backlight module according to the embodiment of the invention further includes a fixing bar270. The fixing bar270has a plurality of convex portions271and a second arch272set among the convex portions271. The fixing bar270is fixed on the surface of the horizontal portion232. Each convex portion271is fixed on the corresponding engaging recess2325to make the corresponding bump2512engaged between the convex portion271and the engaging recess2325. The second arch272is fixed on the groove2321to make the fiber jacket251engaged between the second arch272and the groove2321.

FIG. 5is a schematic diagram of the liquid crystal display device according to an embodiment of the present invention.

Refer toFIG. 5. A liquid crystal display device according to the embodiment of the present invention includes a backlight module200and a liquid crystal display panel300on the backlight module200. The backlight module200provides light for the liquid crystal display panel300, so that the liquid crystal display panel300is able to display an image. The backlight module200is as the backlight module of the first or second embodiment above.