TWI408462B - Backlight module and liquid crystal display - Google Patents

Abstract

A backlight module, including a light guide plate (LGP), a plurality of light emitting elements, a back frame and a supporting fixation element, is provided. The LGP has at least a through hole. The light emitting elements are disposed at a side surface of the LGP. The back frame has at least a hole corresponding to the through hole, and the LGP and the light emitting elements are disposed in the back frame. The supporting fixation element has a main body, a hooking portion and at least one pressing portion. The hooking portion is connected to one end of the main body. The pressing portion is connected to a side of the main body. The hooking portion and part of the main body pass through the through hole of the LGP and the hole of the back frame. The hooking portion is buckled on the back frame and the pressing portion presses the LGP. Besides, a liquid crystal display having the above backlight module is also provided.

Description

Backlight module and liquid crystal display device

The present invention relates to a backlight module and a liquid crystal display device, and more particularly to a backlight module and a liquid crystal display device capable of being pressed well against a whole piece of light guide plate or piece-coupled light guide plate .

In recent years, liquid crystal display devices have been widely used in electronic imaging products such as notebook computers, digital cameras, and televisions because of their characteristics of being light, thin, small, and low in power consumption.

Generally, a liquid crystal display device is composed of a liquid crystal panel and a backlight module. The liquid crystal panel changes the throughput of light in different pixel regions by the rotation of liquid crystal molecules and the action of the polarizing plate, and causes light and dark differences in different pixel regions to achieve the purpose of displaying images.

Since the liquid crystal itself does not have the illuminating property, it is necessary to rely on the backlight module to provide the surface light source. The backlight module can be roughly divided into a side-input type backlight module and a direct-lit backlight module. The direct-type backlight module requires a long mixing distance to achieve uniform light mixing, so the direct-lit backlight module The thickness is thicker and is not suitable for the fabrication of a thin display device; and the side-lit backlight module can be combined with a light-emitting diode, which has the advantage of being thinner.

As the liquid crystal display device gradually develops toward large size, high contrast and thinness, the side-lit backlight module has become the mainstream. In particular, the following backlight module is also proposed, that is, the backlight module can be utilized. More stitching A small-sized light guide plate can be used to obtain a large-area splicing light guide plate, and can also achieve a high dynamic contrast display effect of the liquid crystal display device by means of local area dimming.

However, the flatness of the spliced light guide plate will affect whether the surface light source provided by the backlight module is uniform. In other words, if the splicing light guide plate and the diaphragm below it are not well fixed, the splicing light guide plate and the diaphragm below it will be lifted, and a uniform surface light source cannot be provided.

In addition, in the side-lit backlight module, the light-guiding plate and the optical film above it do not have a sufficient light-mixing distance, which also causes a problem of insufficient uniformity of the surface light source.

In view of the above, the present invention provides a backlight module that not only can well fix the light guide plate and the diaphragm therebelow, but also has a sufficient light mixing distance between the light guide plate and the optical film above it to provide uniformity. Surface light source.

The present invention provides a liquid crystal display device having the above-described backlight module capable of displaying an image of good quality.

Based on the above, the present invention provides a backlight module comprising: a light guide plate, a plurality of light-emitting elements, a back frame and a support fixing element. The light guide plate has at least a uniform hole. The light emitting element is disposed on a side of the light guide plate. The back frame has at least one hole corresponding to the through hole, and the light guide plate and the light emitting element are disposed in the back frame. The supporting fixing component has a main body, a fastening portion and at least one pressing portion, the fastening portion is connected to one end of the main body, and the pressing portion is connected to one side of the main body, wherein the fastening portion and the partial body pass through the through hole of the light guide plate Broken holes with the back frame, The fastening portion is fastened to the back frame, and the pressing portion presses the light guide plate.

In an embodiment of the invention, the light guide plate is a single plate and has a plurality of through holes.

In an embodiment of the invention, the light guide plate is a spliced light guide plate formed by splicing a plurality of sub-light guide plates, and at least one corner of each of the sub-light guide plates is provided with a recess, and is spliced by a plurality of sub-light guide plates. Into a large number of through holes.

In an embodiment of the invention, each of the sub-light guide plates has a light incident portion and a joint portion, and the light incident portion and the joint portion adjacent to each other are combined with each other to form a splicing light guide plate, and the light incident portion is formed. An accommodating space is formed at the junction with the splicing portion, and the illuminating element is disposed in the accommodating space and located at a side of the light incident portion.

In an embodiment of the invention, the pressing portion has two of the pressing portions, and the two pressing portions are coupled to both sides of the main body.

In an embodiment of the invention, the back frame comprises: a back plate and a bending element, the back plate has a hole, the bending element is adjacent to the hole and forms an angle with the back plate, and the bending element has a The engagement groove, the light guide plate abuts against the engagement groove, and the two pressing portions are pressed against the light guide plate.

In an embodiment of the invention, the side surface of the light guide plate has at least one lug, and the lug abuts against the engagement groove.

In an embodiment of the invention, the backlight module further includes an optical plate assembly that abuts the main body.

In an embodiment of the invention, the backlight module further includes a reflective sheet disposed under the light guide plate.

In an embodiment of the invention, the backlight module further includes a circuit board disposed under the reflective sheet, the light emitting element is electrically connected to the circuit board, and the reflective sheet is located between the circuit board and the light guide plate.

In an embodiment of the invention, the backlight module further includes: an insulating layer disposed under the circuit board, the circuit board being located between the reflective sheet and the insulating layer.

In an embodiment of the invention, the light guide plate has a plurality of grooves, and the light guide plate is divided into a plurality of light-emitting regions.

In an embodiment of the invention, the side surface of the light guide plate is provided with a microstructure.

The present invention further provides a liquid crystal display device comprising: the above backlight module and a liquid crystal panel. The liquid crystal panel is disposed on one side of the backlight module.

The invention adopts a supporting fixing component, which not only can well fix the light guide plate and the diaphragm below it, but also has an appropriate light mixing distance between the light guide plate and the optical film above the light guide plate to provide a uniform surface light source. . In addition, the bending member of the back frame can be used together with the supporting fixing member to further fix the light guide plate and the diaphragm therebelow.

The above described features and advantages of the present invention will be more apparent from the following description.

Backlight module [First Embodiment]

1A is a partial diagram of a component of a backlight module according to a first embodiment of the present invention; Three-dimensional explosion map. Referring to FIG. 1A , the backlight module 100 includes a light guide plate 110 , a plurality of light emitting elements 120 , a back frame 130 and a supporting fixing component 140 . The light guide plate 110 has at least a uniform hole 110A. The light emitting element 120 is disposed on a side surface of the light guide plate 110. The back frame 130 has at least one hole 132A corresponding to the through hole 110A, and the light guide plate 110 and the light emitting element 120 are disposed in the back frame 130. The support fixing component 140 has a main body 142, a fastening portion 144 and a pressing portion 146. The fastening portion 144 is connected to one end of the main body 142. The pressing portion 146 is connected to one side of the main body 142. The fastening portion 144 and the portion The main body 142 passes through the through hole 110A of the light guide plate 110 and the broken hole 132A of the back frame 130 , and the fastening portion 144 is fastened to the back frame 130 , and the pressing portion 146 presses the light guide plate 110 .

The support fixing member 140 shown in FIG. 1A is a partial cross-sectional view showing the connection relationship between the main body 142, the engaging portion 144, and the pressing portion 146. It may be noted that the number of the pressing portions 146 is exemplified herein. However, the number of the pressing portions 146 may be at least one, and the number and the set positions of the pressing portions 146 may be adjusted according to design requirements.

For example, FIG. 1B is a perspective exploded view of some components of a backlight module of another embodiment of the first embodiment. Referring to FIG. 1B, the component numbers are the same as those of FIG. 1A. It is noted that the number of the pressing portions 146 is two, and the two pressing portions 146 are connected to both sides of the main body 142. The two pressing portions 146 can more preferably press the light guide plate 110. Of course, the pressing portion 146 can be any suitable number. Hereinafter, the support fixing member 140 of FIG. 1B will be described as an example.

In the embodiment, the light guide plate 110 is, for example, a single plate and has a plurality of through holes 110A. The position of the through hole 110A corresponds to the broken hole 132A position. The light guide plate 110 and the back frame 130 can be easily combined by the support fixing member 140 passing through the through hole 110A and the broken hole 132A. Additionally, the body 142 supporting the fixation element 140 can also carry an optical film (shown in Figure 2) above it.

2 is a cross-sectional view of the backlight module of FIG. 1B. Referring to FIG. 1B and FIG. 2 together, in the backlight module 100, an optical film, a circuit board, and the like may be disposed under the light guide plate 110, that is, the backlight module 100 may include a reflective sheet 150, a circuit board 160, and The insulating layer 170; and an optical plate assembly 180 may be disposed above the light guide plate 110 to abut the main body 142. The optical plate assembly 180 can be any combination of the diffusion sheet 182, the gusset 184, the optical sheet such as the brightness enhancing sheet 186 and the protective sheet 188.

2, the reflective sheet 150 is disposed under the light guide plate 110, and the light emitted from the light emitting element 120 can be reflected upward; the circuit board 160 is disposed under the reflective sheet 150, and the light emitting element 120 is electrically connected to the circuit board. The reflective sheet 150 is disposed between the circuit board 160 and the light guide plate 110. The circuit board 160 controls the light emitting element 120 to be turned on or off. The insulating layer 170 is disposed under the circuit board 160. The circuit board 160 is disposed on the reflective sheet 150 and the insulating layer. Between 170, the insulating layer 170 prevents external conductive elements (not shown) from discharging the circuit board 160.

Similarly, in the position of the corresponding through hole 110A and the hole 130A on the reflective sheet 150, the circuit board 160 and the insulating layer 170, the through holes 150A, 160A and 170A may be respectively disposed so that the supporting fixing member 140 can also pass through the reflection. Sheet 150, circuit board 160 and insulating layer 170.

In particular, since the body 142 has an appropriate height, it can be guided An air gap AP is created between the plate 110 and the optical plate assembly 180. Thereby, the light emitted from the light guide plate 110 has an appropriate light mixing distance to be mixed into a more uniform surface light source.

According to the above, the support fixing member 140 can not only fix the light guide plate 110 and the diaphragm below it (the reflection sheet 150, the circuit board 160 and the insulating layer 170), but also ensure that the light guide plate 110 and the diaphragm below it are flattened, and It is also possible to support the optical plate assembly 180 with the body 142 that supports the fixation element 140, creating an air gap AP to provide a suitable light mixing distance. In this way, the backlight module 100 can provide a relatively uniform surface light source.

[Second embodiment]

FIG. 3 is a schematic diagram of a backlight module according to a second embodiment of the present invention. Referring to FIG. 3, the backlight module 102 of FIG. 3 is similar to the backlight module 100 of FIG. 1B. However, it can be noted that there are two differences: the first difference: the backlight module 100 of FIG. 1B uses a single plate. The light guide plate 110 of the backlight module 102 of FIG. 3 is a splicing light guide plate; the second difference is that the back frame 130 of the backlight module 100 of FIG. 1B has only the broken hole 132A, and FIG. 3 The back frame 130 of the backlight module 102 also has a bending element 134.

For the first difference, the light guide plate 110' is a spliced light guide plate which is formed by splicing a plurality of sub-light guide plates 110a. At least one corner of each sub-light guide plate 110a is provided with a recess G and is composed of a plurality of sub-guides. The recesses G of the light plate 110a are spliced into a plurality of through holes 110A. These spliced through holes 110A allow the support fixing member 140 to pass therethrough, so that the support fixing member 140 can fix the spliced light guide plate 110' to the back frame 130.

For the second difference, in detail, in the backlight module 102, the back frame 130 may include a back plate 132 and a bending element 134 having a hole 132A, and the bending element 134 is adjacent to the hole 130A and An angle θ is formed with the back plate 132. The bending element 134 has an engaging groove 134A. The light guiding plate 110 ′ abuts against the engaging groove 134A , and the two pressing portions 146 are pressed against the light guiding plate 110 ′. That is, the light guiding plate 110' can be further better fixed in the back frame 130 by the bending member 134 of the back frame 130 and the supporting support fixing member 140.

The bending element 134 is obtained, for example, by punching and then bending the backing plate 132. As shown in Fig. 3, a bending member 134 can be formed at a plurality of predetermined positions of the backing plate 132 for fixing a plurality of positions of the light guiding plate 110'. Subsequent Figures 9 and 10 will further illustrate the bonding state of the bending member 134, the supporting fixing member 140, and the light guide plate 110'.

4 is a perspective view of a sub-light guide plate according to a second embodiment of the present invention. FIG. 5 is an enlarged schematic view of a region A of FIG. 4. FIG. 6 is an enlarged schematic view of a region B of FIG. 4. FIG. 7 is an enlarged schematic view of a region C of FIG. 4.

Referring to FIG. 4, each of the sub-light guide plates 110a may have opposite light-incident portions 112 and splice portions 114. The light-injecting portions 112 and the splice portions 114 adjacent to each other may be combined with each other to form a spliced light guide plate 110'. Shown in Figure 3 and Figure 8). The light incident portion 112 and the joint portion 114 are formed in a stepped shape that cooperates with each other. The upper surface of the combined light incident portion 112 and the upper surface of the joint portion 114 are substantially at the same horizontal plane, and the lower surface of the combined light incident portion 112 and the lower surface of the joint portion 114 are substantially at the same horizontal plane. In this way, the reflective sheet 150, the circuit board 160, the insulating layer 170, and the like can be placed flat in the spelling. Below the light guide plate 110'.

Referring to the bending element 34 of FIG. 3, the sub-light guide plate 110a of FIG. 4 and the lug P of FIG. 5, it can be known that the side surface of the joint portion 114 of the light guide plate 110' (sub-light guide plate 110a) can have at least one lug. P, and the lug P can abut against the engaging groove 134A. Another lug P can also be made in the area A' of Fig. 4 (the corresponding position of the area A). The lug P is abutted in the engaging groove 134A of the bending element 134. Further, as is clear from Figs. 4 and 5, the recesses G are formed at at least one corner of the sub-light guide plate 110a, and recesses G may be formed in the regions A, A'. When the plurality of sub-light guide plates 110a are spliced, the recesses G of the different sub-light guide plates 110a can be spliced into the through holes 110A for passing the support fixing member 140.

Referring to FIG. 4 and FIG. 6, the light guide plate 110' (sub-light guide plate 110a) may have a plurality of grooves S, and the light guide plate 110' (sub-light guide plate 110a) is divided into a plurality of light-emitting regions R. The grooves S can separate the light rays of the different light-emitting regions R from each other, and can form an effect of emitting light at the same time or at different times. The groove S can be produced by injection molding the light guide plate 110' or by using a grooving tool (not shown).

Referring to FIG. 4 and FIG. 7, the side surface of the light incident portion 112 of the light guide plate 110' (the sub-light guide plate 110a) may be provided with a microstructure MS. This microstructure MS can be a plurality of fine trenches. The light from the light-emitting element 120 disposed on the side of the light incident portion 112 can be caused to enter the light guide plate 110' by the microstructure MS to improve light utilization efficiency.

FIG. 8 is a perspective view of the spliced light guide plate of FIG. 3. FIG. Referring to FIG. 8, each sub-light guide plate 110a has a light incident portion 112 and a counter. The joint portion 114, the light incident portion 112 and the joint portion 114 adjacent to each other are joined to each other to form a spliced light guide plate 110'. An accommodating space CS is formed at a junction of the light incident portion 112 and the splicing portion 114. The light emitting element 120 is disposed in the accommodating space CS and located on a side surface of the light incident portion 112. Further, the manner in which the sub-light guide plates 110a are spliced and the spliced through holes 110A can be more clearly seen from FIG.

FIG. 9 is a perspective view of a backlight module according to a second embodiment of the present invention. FIG. 10 is a cross-sectional view showing a backlight module according to a second embodiment of the present invention. Referring to FIG. 9 and FIG. 10, the light incident portion 112 of the sub-light guide plate 110a is spliced with the joint portion 114 of the other sub-light guide plate 110a. In particular, the lug P and the light incident portion 112 can be simultaneously engaged in the engaging groove 134A of the bending member 134 (refer to FIG. 3 at the same time). Thereby, the first operation of the light guide plate 110' is performed by the bending element 134.

As can be seen from Figure 3, the holes 132A are present on both sides of the bending element 134 and form a "concave shape". As shown in FIG. 9 and FIG. 10, a portion of the main body 142 supporting the fixing member 140 can be sequentially passed through the through hole 110A of the light guide plate 110', the through hole 150A of the reflection sheet 150, and the lower portion of the backlight module 102. The through hole 160A of the circuit board 160, the through hole 170A of the insulating layer 170, and the through hole 132A located to the right of the bending element 134. Thereafter, the light guide plate 110 ′ and the diaphragm (the reflection sheet 150 , the circuit board 160 , the insulating layer 170 , and the like) under the light guide plate 110 ′ are fixed to the back frame 130 by the fastening portion 144 , and the pressing portions 146 on both sides of the main body 142 are used. The light guide plate 110', the bending element 134, and a diaphragm thereunder (reflecting sheet 150, circuit board 160, insulating layer 170, etc.) are pressed. That is to say, the second support can also be performed by the support fixing member 140. Fixed action.

In addition, since the body 142 has an appropriate height, an air gap AP can be created between the light guide plate 110 and the optical plate assembly 180. Thereby, the light emitted from the light guide plate 110 has an appropriate light mixing distance to be mixed into a more uniform surface light source.

The structure of the backlight module of the present invention is not limited to the backlight module 100 of the first embodiment and the backlight module 102 of the second embodiment. In more detail, the backlight module 100 is formed by combining the light guide plate 110 of a single plate with the back frame 130 having no bending element 134; and the backlight module 102 is formed by using the spliced light guide plate 110' and the bending element. The back frame 130 of the 134 is combined. However, it is also possible to use a combination of a single sheet of light guide plate 110 and a back frame 130 having a bending element 134, or a combination of a spliced light guide plate 110' and a back frame 130 having no bending element 134. These combinations are all included in the inventive spirit of the present invention.

Liquid crystal display device

FIG. 11 is a schematic diagram of a liquid crystal display device according to an embodiment of the present invention. The liquid crystal display device 200 can include a backlight module 210 and a liquid crystal panel 220. The liquid crystal panel 220 is disposed on one side of the backlight module 210. The backlight module 210 can adopt any of the above backlight modules. This liquid crystal display device 200 is capable of providing an image of good quality.

In summary, the backlight module and the liquid crystal display device of the present invention have at least the following advantages: by using a supporting fixing member, not only can the light guide plate be well fixed and the lower portion thereof The square diaphragm also has an appropriate mixing distance between the light guide plate and the optical film above the light guide plate to provide a uniform surface light source. In addition, the bending member of the back frame can be used together with the supporting fixing member to further fix the light guide plate and the diaphragm therebelow. A liquid crystal display device having the above backlight module can provide an image of good quality.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100, 102, 210‧‧‧ backlight module

110,110’‧‧‧Light guide plate

110a‧‧‧Sub-light guide

110A, 150A, 160A, 170A‧‧‧through holes

112‧‧‧Into the Department of Light

114‧‧‧Splicing Department

120‧‧‧Lighting elements

130‧‧‧ Back frame

132‧‧‧ Backplane

132A‧‧‧ hole

134‧‧‧Bending components

134A‧‧‧ snap groove

140‧‧‧Supporting components

142‧‧‧ Subject

144‧‧‧Withholding department

146‧‧‧ Pressing Department

150‧‧‧reflector

160‧‧‧ boards

170‧‧‧Insulation

180‧‧‧ Optical plate combination

182‧‧‧Diffuser

184‧‧‧ Picture

186‧‧‧Bright sequins

188‧‧‧protection film

200‧‧‧Liquid crystal display device

220‧‧‧LCD panel

AP‧‧‧Air gap

CS‧‧‧ accommodating space

G‧‧‧ Sag

P‧‧‧ 耳耳

S‧‧‧ trench

MS‧‧‧Microstructure

1A is a perspective exploded view of some components of a backlight module according to a first embodiment of the present invention.

1B is a perspective exploded view of some components of a backlight module according to another embodiment of the present invention.

2 is a cross-sectional view of the backlight module of FIG. 1B.

FIG. 3 is a schematic diagram of a backlight module according to a second embodiment of the present invention.

4 is a perspective view of a sub-light guide plate according to a second embodiment of the present invention.

FIG. 5 is an enlarged schematic view of a region A of FIG. 4.

FIG. 6 is an enlarged schematic view of a region B of FIG. 4.

FIG. 7 is an enlarged schematic view of a region C of FIG. 4.

FIG. 8 is a perspective view of the spliced light guide plate of FIG. 3. FIG.

FIG. 9 is a perspective view of a backlight module according to a second embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a backlight module according to a second embodiment of the present invention.

FIG. 11 is a schematic diagram of a liquid crystal display device according to an embodiment of the present invention.

100‧‧‧Backlight module

110‧‧‧Light guide plate

110A‧‧‧through hole

120‧‧‧Lighting elements

130‧‧‧ Back frame

132A‧‧‧ hole

140‧‧‧Supporting components

142‧‧‧ Subject

144‧‧‧Withholding department

146‧‧‧ Pressing Department

Claims (9)

A backlight module includes: a light guide plate having at least a uniform hole; a plurality of light-emitting elements disposed on a side surface of the light guide plate; and a back frame having at least a hole corresponding to the through hole, the light guide plate and the light guide plate The light-emitting elements are disposed in the back frame; a support fixing component has a main body, a fastening portion and at least one pressing portion, the fastening portion is connected to one end of the main body, and the pressing portion is connected to the side of the main body The fastening portion and the portion of the body passing through the through hole of the light guide plate and the hole of the back frame, the fastening portion being fastened to the back frame, wherein the pressing portion presses the light guide plate, wherein The pressing portion is an arm-shaped structure connected to both sides of the main body, and the engaging portion has two inverted fork blocks extending toward the arm-like structures on both sides of the main body, and the engaging portion is integrally In the shape of an arrow, the two inverted fork blocks are close to the central axis of the body, so that the fastening portion passes through the through hole and the broken hole, after the fastening portion passes through the through hole and the broken hole The two inverted fork blocks are displaced away from the central axis of the body, and Restored to a position corresponding to both sides of the main body of the arm-like structure to absorb the tolerance of the thickness of the light guide plate. The backlight module of claim 1, wherein the light guide plate is a single plate and has a plurality of the through holes. The backlight module of claim 1, wherein the light guide plate is a spliced light guide plate formed by arranging a plurality of sub-light guide plates, and at least one corner of each of the sub-light guide plates is provided with a recess, and The sub-light guides The depression of the plate is spliced into a plurality of the through holes. The backlight module of claim 3, wherein each of the sub-light guide plates has a light incident portion and a joint portion, and the light incident portion and the joint portion adjacent to each other are combined with each other to form a backlight module. The splicing light guide plate forms an accommodating space at a junction of the light incident portion and the splicing portion, and the light emitting elements are disposed in the accommodating space and located at a side surface of the light incident portion. The backlight module of claim 1, wherein the back frame comprises: a back plate and a bending element, the back plate has the hole, the bending element is adjacent to the hole and The back plate is formed at an angle, the bending element has an engaging groove, and the light guiding plate abuts against the engaging groove, whereby the arm of the pressing portion on both sides of the main body after the supporting fixing member is inserted The structure is pressed against the light guide plate, and the main body of the support fixing member and the bending element push against each other, so that the angle is retracted to generate a reset stress acting on the bending element to form a push-fixing fixed stress Between the bending element and the body. The backlight module of claim 5, wherein at least one lug is formed on a side surface of the light guide plate, and the lug abuts against the engaging groove. The backlight module of claim 1, wherein the light guide plate has a plurality of grooves, and the light guide plate is divided into a plurality of light-emitting regions. The backlight module of claim 1, wherein a side surface of the light guide plate is provided with a microstructure. A liquid crystal display device comprising: the backlight module according to any one of claims 1 to 8; and a liquid crystal panel disposed on one side of the backlight module.