TW201428394A - Backlight module having light guide plate positioning design - Google Patents

Abstract

A backlight module having a light guide plate positioning design is provided. The backlight module includes a light guide plate, a positioning pin, and a frame. The frame encircles an inner space and has a supporting base at one side of the inner space. The light guide plate has a first surface disposed on a supporting surface of the supporting base. The peripheral of the first surface is disposed on the supporting surface wherein the supporting surface is parallel to the first surface. A positioning hole is formed on the supporting surface to accommodate the positioning pin. The positioning pin is disposed near one side of the first surface and passes through the positioning hole.

Description

Backlight module with light guide positioning design

The present invention relates to a backlight module; in particular, the present invention relates to a backlight module having a light guide plate positioning mechanism.

In the assembly process of the display device, the assembly of the backlight module is particularly important. The quality of the backlight module assembly affects the structural stability and display effect of the display device. As far as the positioning method of the light guide plate is concerned, there are mainly problems such as poor light output quality and poor fixing effect. The former may affect the consumer's willingness to purchase, while the latter directly affects the backlight module handling cost.

FIG. 1 is a schematic diagram of a positioning manner of a conventional light guide plate. As shown in FIG. 1 , the backlight module 10 includes a light guide plate 20 , a positioning pin 30 , and a frame 40 . The conventional positioning method is to punch holes in the back surface of the frame 40 for the positioning pins 30 to be disposed on the sides of the light guide plate 20, and the ear portions 22 have positioning holes corresponding to the positioning pins 30. The light guide plate 20 is fixed. Since the light guide plate 20 is heated and expanded after assembly, a gap must be reserved between the light guide plate 20 and the frame 40 and between the light guide plate 20 and the positioning pin 30 to accommodate thermal expansion. As shown in FIG. 1 , the light guide plate 20 and the positioning are provided. The pins 30 have a distance a, and the outer edge of the ear portion 22 of the light guide plate 20 has a distance b from the frame 40. In the manner that the current light guide plate 20 has a positioning design on both sides, since the left and right sides are reserved with the same size of thermal expansion receiving gap, when the backlight module 10 is transported, the distance between the light guide plate 20 and the left and right is twice as large. Distance a. In the case of a large-sized panel, excessive swaying during transportation may cause the light guide plate 20 to fall off from the positioning pin 30, and may even cause damage to the light guide plate 20. Although the current light guide plate 20 can increase the width of the ear portion 22, as shown in FIG. 1, the width of the ear portion 22 exceeds the positioning pin 30. More than half of the diameter, to prevent the light guide plate 20 from falling off from the positioning pin 30, but the distance a between the light guide plate 20 and the positioning pin 30 due to thermal expansion will still cause damage to the light guide plate 20 during transportation, even in the light guide plate 20 The third side is provided with the problem that the set pin 30 is swayed. However, such a method has a predetermined distance a between the light guide plate 20 and the positioning pin 30 in the horizontal and vertical directions, which will cause the light guide plate 20 to sway obliquely. . In addition, the method of positioning the three sides is not applicable to the models that enter the light on the upper and lower sides. Therefore, the addition of the set pin 30 on the third side does not effectively solve the above problem. In order to reduce the possibility of damage of the backlight module 10, the manufacturer has to pay more transportation costs, and therefore, the conventional fixing method still needs to be improved.

An object of the present invention is to provide a light guide plate positioning design to reduce the stroke of the light guide plate relative to the frame body.

Another object of the present invention is to provide a light guide plate positioning design to limit the moving direction of the light guide plate.

Another object of the present invention is to provide a light guide plate positioning design to limit the thermal expansion direction of the light guide plate.

The backlight module includes a light guide plate, a positioning pin and a frame body. The frame system encloses an interior space and has a support seat at the edge of the interior space. The light guide plate has a first surface disposed on the support surface of the support seat, and an edge of the first surface is mounted on the support surface, wherein the support surface is parallel to the first surface. A positioning hole is formed in the bearing surface to receive the positioning pin. The positioning pin is formed at an edge position of the first surface and protrudes into the positioning hole. The backlight module avoids shaking during handling to improve the stability of product delivery.

100‧‧‧Backlight module

200‧‧‧Light guide plate

202‧‧‧ first surface

203‧‧‧Perforation

204‧‧‧Second surface

206‧‧‧ edge

300‧‧‧Locating pin

302‧‧‧ inside

304‧‧‧Outside

306‧‧‧Cap

308‧‧ ‧ pin body

400‧‧‧ frame

401‧‧‧ side wall

402‧‧‧ support

404‧‧‧Support surface

406‧‧‧floor

410‧‧‧Positioning holes

412‧‧‧ inner edge

414‧‧‧ outer edge

416‧‧‧ openings

500‧‧‧reflector

510‧‧‧ hole

A1, a2‧‧‧ distance

1 is a schematic view showing a positioning manner of a conventional light guide plate; 2A is a perspective view of an embodiment of a light guide plate positioning method according to the present invention; FIG. 2B is a cross-sectional view showing an embodiment of a light guide plate positioning manner according to the present invention; FIG. 2C is a top view of an embodiment of a light guide plate positioning manner according to the present invention; Figure 3 is a perspective view of another embodiment of the frame of the present invention; Figure 4B is a cross-sectional view of the embodiment of Figure 4A after assembling the light guide plate; Figure 4C is a top view of the embodiment of Figure 4A.

The backlight module of the present invention is preferably applied to a display device such as a smart phone, a liquid crystal television, a computer screen, etc., particularly a large-sized display device, but is not limited thereto.

2A is a perspective view of an embodiment of a positioning method of the light guide plate 200 of the present invention. The backlight module 100 mainly includes a light guide plate 200, a positioning pin 300, and a frame 400. The frame 400 is used as the outer casing of the backlight module 100 and may be made of metal or plastic. In this embodiment, the frame 400 has a side wall 401 extending from the bottom plate to define an inner space on the side of the frame 400. A support base 402 is located at the edge of the interior space. In other embodiments, the frame 400 may also be a bottomless structure. Compared to the perspective view shown in FIG. 2A, the frame 400 only has a square sidewall 401 surrounding the periphery. In the preferred embodiment illustrated in FIG. 2A, the support base 402 is formed from the side wall 401 and is bent toward the interior space. The manner in which the support 402 is machined can take a different approach depending on the material of the frame 400. For example, the metal frame 400 can be cut from the side wall 401 to the range of the support seat 402, and then bent inward; the frame 400 made of high-strength plastic can be formed into a support base 402 by heat molding or injection molding. The support base 402 has a bearing surface 404, that is, a top surface of the bent portion of the side wall 401. The light guide plate 200 and the reflection sheet 500 are supported by the support surface 404, wherein the edge 206 of the light guide plate 200 is The side wall 401 is surrounded, and the light guide plate 200 is mounted on the support surface 404.

On the other hand, the support surface 404 is formed with a positioning hole 410 to accommodate the positioning pin 300. As shown in FIG. 2A, the locating pin 300 is formed at an edge of the first surface 202 and passes through a locating hole 410 in the support surface 404. In this embodiment, the positioning hole 410 is preferably an elongated hole extending in a direction away from the internal space and having a function of guiding in the long direction and an upper limit in the short direction. In addition, a portion of the reflection sheet 500 disposed on the support surface 404 also forms a hole 510 in accordance with the shape of the positioning hole 410. The positioning pin 300 substantially opposes a portion that surrounds the circumference of the positioning hole 410 and is parallel to the direction in which the positioning hole 410 extends. In the preferred embodiment, the positioning hole 410 extends through the support base 402, and the positioning pin 300 penetrates the support base 402; however, in different embodiments, a shallower positioning hole 410, such as a positioning hole, may be used as needed. The 410 extends only into one half of the support base 402 without penetration, and the depth of the positioning hole 410 is less than the thickness of the support base 402 and accommodates the portion into which the positioning pin 300 extends. By this means, in addition to supporting the light guide plate 200 by the support base 402, when the reflection sheet 500 is mounted, the reflection piece 500 can be further restricted by the support base 402.

2B is a cross-sectional view showing an embodiment of a positioning method of the light guide plate 200 of the present invention. As shown in FIG. 2B, the light guide plate 200 has an opposite first surface 202 and a second surface 204. The first surface 202 is disposed on the support surface 404 bent from the frame 400 and near the edge of the first surface 202. A through hole 203 is formed in the position to penetrate the first surface 202, the second surface 204, and the reflection sheet 500. The support surface 404 is bonded to the reflection sheet 500 and the reflection sheet 500 is attached to the first surface 202 of the light guide plate 200 with respect to one surface of the support surface 404. The support surface 404 is parallel to the first surface 202, and the edge of the first surface 202 and the reflective sheet 500 are mounted on the support surface 404. The positioning pin 300 is placed in the through hole 203 to pass through the hole 510 of the light guide plate 200 and the reflective sheet 500. However, in different embodiments, the positioning pin 300 may be formed at other positions on the edge of the first surface 202, such as hot melt. Process or integral molding process. In the preferred embodiment illustrated in FIG. 2B, the locating pin 300 includes a pin body 308 and a cap 306 at one end. The cap 306 extends radially from one end of the pin body 308 and has a larger diameter The width of the perforation 203 diameter. The pin body 308 passes through the first surface 202 and the hole 510 of the reflective sheet 500 from the through hole 203 and protrudes out of the support surface 404, and the cap 306 is in contact with the second surface 204. In the preferred embodiment, the position of the positioning pin 300 and the through hole 203 is designed outside the visible area. In addition, in order to prevent the light from collecting or astigmatism through the positioning pin 300, the picture quality is disturbed, and the visible light field distribution is adjusted. The light penetration of the pin 300 is greater or smaller than the light penetration of the light guide plate 200. For example, the light penetration of the positioning pin 300 is preferably lower than that of the light guide plate 200 to avoid the occurrence of bright spots. Alternative means include, but are not limited to, the use of a black or gray material to make the locating pin 300 or cap 306 to reduce light penetration. In addition, the positioning pin 300 and the cap 306 can also be made of different light penetrating materials to increase the selectivity when adjusting the light field.

2C is a top view of an embodiment of a positioning method of the light guide plate 200 of the present invention. As shown in FIG. 2C, the positioning pin 300 has an inner side surface 302 facing the inside of the light guide plate 200 and a reverse outer side surface 304. In the case of the cylindrical positioning pin 300, the inner side surface 302 preferably refers to one side toward the inside of the light guide plate 200; the outer side surface 304 preferably refers to one side of the side of the light guide plate. The periphery of the positioning hole 410 has an inner edge 412 facing the inner side of the light guide plate 200 and a reverse outer edge 414, wherein the inner edge 412 preferably refers to one side facing the inner side surface 302; the outer edge 414 preferably means Facing one side of the outer side 304. The distance a1 between the inner side surface 302 and the inner edge 412 is smaller than the distance a2 between the outer side surface 304 and the outer edge 414. The distance a2 between the outer side surface 304 and the outer edge 414 is for housing the thermal expansion of the light guide plate 200. The distance a1 between the positioning pin 300 and the inner edge 412 of the positioning hole 410 is preferably only a tolerance gap reserved for the assembly of the positioning pin 300; in another angle, the inner side 302 and the inner edge 412 substantially interfere with each other. As shown in FIG. 2C, it is considered that the light guide plate 200 is heated and expanded after being assembled, and a gap must be reserved between the light guide plate 200 and the frame 400, that is, the distance a2. However, compared with the conventional fixing manner, the present embodiment is because the through hole 203 is Disposed on the light guide plate 200, during thermal expansion, the positioning pin 300 will move away from the inner edge 412 of the positioning hole 410 and move outward, and the conventional structure is that when the thermal expansion, the inner edge of the positioning hole will be directed to the frame. The positioning pin moves on the body; therefore, the design of the present invention eliminates the previous guidance An additional distance between the light plate 200 and the positioning hole 410 for accommodating thermal expansion is required. When the light guide plate 200 is thermally expanded, the positioning pin 300 extends toward the inner frame 400 as the light guide plate 200 expands away from the inner edge 412 of the positioning hole 410, and the extending direction thereof is limited to the supporting surface. The positioning hole 410 on the 404 does not arbitrarily sway in the non-extension direction. Please refer to Figure 2D for further reference. FIG. 2D is a schematic view showing the movement of the positioning pin 300 by the thermal expansion of the light guide plate 200. As shown in FIG. 2D, in the state of use, the light guide plate 200 is moved outward by thermal expansion. At this time, the positioning pin 300 disposed in the through hole 203 is also moved outward with the light guide plate 200. Therefore, according to the design of the present invention, since the distance reserved between the light guide plate 200 and the positioning pin 300 for thermal expansion is eliminated, the size of both sides of the backlight module 100 can be reduced, and on the other hand, the light guide plate 200 is not received during transportation. The thermal expansion, at this time, the positioning pin 300 substantially interferes with the inner edge 412 of the positioning hole 410, so that a better positioning effect can be provided, so that the light guide plate 200 does not arbitrarily shake, thereby improving the stability of product transportation.

3 is a schematic view of an embodiment of an external support 402. The foregoing embodiment cuts a portion of the side wall 401 and bends it into a support base 402, and the embodiment shown in Fig. 3 adds a support base 402 in an additional manner. As shown in FIG. 3, the support base 402 can be disposed on the side wall 401 or the bottom plate 406 in an external manner, and the arrangement can be fixed by hot melt or riveting.

4A is a perspective view of another embodiment of a frame 400 of the present invention. In this embodiment. The support 402 is formed by cutting an opening 416 from the bottom plate 406 of the frame 400 and the side wall 401, and then bulging upward toward the light guide plate 200 to form a raised support seat 402 on the side of the frame 400. As previously mentioned, the manner in which the support 402 is machined can take a different approach depending on the material of the frame 400. For example, the metal frame 400 can be formed into a range of the support seat 402 from the side wall 401 in a stamping manner. The frame 400 made of high-strength plastic can be formed into a support base 402 by heat molding or injection molding. The support base 402 has a bearing surface 404, i.e., a portion that is raised to form a platform. As shown in FIG. 4A, the support surface 404 is formed with an elongated positioning hole 410 which is formed to extend away from the internal space and has a function of guiding in the long direction and the upper limit in the short direction. In the preferred embodiment, the positioning hole The 410 series extends through the support base 402 and the locating pin 300 penetrates the support base 402; however, in various embodiments, the locating hole 410 can also extend into only one of the support seats 402 without penetration.

4B is a cross-sectional view of the embodiment of FIG. 4A after assembling the light guide plate. As shown in FIG. 4B, the light guide plate 200 has an opposite first surface 202 and a second surface 204. The first surface 202 is disposed on the support surface 404 raised from the bottom plate 406, and is located near the edge of the first surface 202. The through hole 203 is formed to penetrate the first surface 202, the second surface 204, and the reflection sheet 500. In addition, a portion of the reflection sheet 500 disposed on the support surface 404 also forms a hole 510 in accordance with the shape of the positioning hole 410. The positioning pin 300 is formed at the edge of the first surface 202 and is placed in the through hole 203 to pass through the hole 510 of the light guide plate 200 and the reflection sheet 500. However, in different embodiments, the positioning pin 300 may be formed in other manners. An edge location of a surface 202, such as a hot melt process or an integral molding process. In the preferred embodiment illustrated in FIG. 4B, the locating pin 300 passes through the bearing surface 404 from the perforation 203. The locating pin 300 includes a pin body 308 and a cap 306 at one end. The cap 306 extends radially from one end of the pin body 308 and has a width greater than the diameter of the perforation 203. The pin body 308 passes through the first surface 202 and the hole 510 of the reflective sheet 500 from the through hole 203 and protrudes out of the support surface 404, and the cap 306 is in contact with the second surface 204. In the preferred embodiment, the position of the positioning pin 300 and the through hole 203 is designed outside the visible area. In addition, in order to prevent the light from collecting or astigmatism through the positioning pin 300, the picture quality is disturbed, and the visible light field distribution is adjusted. The light penetration of the pin 300 is greater or smaller than the light penetration of the light guide plate 200. For example, the light penetration of the positioning pin 300 is preferably lower than that of the light guide plate 200 to avoid the occurrence of bright spots. Alternative means include, but are not limited to, the use of a black or gray material to make the locating pin 300 or cap 306 to reduce light penetration. In addition, the positioning pin 300 and the cap 306 can also be made of different light penetrating materials to increase the selectivity when adjusting the light field.

Figure 4C is a top view of the embodiment of Figure 4A. As shown in FIG. 4C, the positioning pin 300 has an inner side surface 302 facing the inside of the light guide plate 200 and a reverse outer side surface 304. With a cylinder For the locating pin 300, the inner side surface 302 preferably refers to one side of the inner side of the light guide plate 200; the outer side surface 304 preferably refers to one side of the side of the light guide plate. The periphery of the positioning hole 410 has an inner edge 412 facing the inner side of the light guide plate and a reverse outer edge 414, wherein the inner edge 412 preferably refers to one side facing the inner side surface 302; the outer edge 414 is preferably a finger surface. One side of the outer side 304. The distance a1 between the inner side surface 302 and the inner edge 412 is smaller than the distance a2 between the outer side surface 304 and the outer edge 414. The distance a2 between the outer side surface 304 and the outer edge 414 is for housing the thermal expansion of the light guide plate 200. The distance a1 between the positioning pin and the inner edge 412 of the positioning hole 410 is preferably only a tolerance gap reserved for the assembly of the positioning pin 300; in another angle, the inner side 302 and the inner edge 412 substantially interfere with each other. As described above, in the present embodiment, since the through hole 203 is disposed on the light guide plate 200, the positioning pin 300 will leave the inner edge 412 of the positioning hole 410 during thermal expansion, and outward. Moving, while the conventional structure is such that during thermal expansion, the inner edge of the positioning hole moves toward the positioning pin on the frame. Therefore, the design of the present invention eliminates the need to additionally reserve a distance between the light guide plate 200 and the positioning hole 410 for accommodating thermal expansion, and the direction in which the positioning pin 300 extends is limited to the positioning hole 410 on the support surface 404 without arbitrarily shaking. In addition, with the design shown in FIG. 4A to FIG. 4C, the support base 402 is only required to be processed in a single direction without folding, and there are fewer restrictions on the molding process, so this embodiment is more suitable for thinner thickness. The backlight module 100.

In summary, according to the design of the present invention, since the distance reserved between the light guide plate 200 and the positioning pin 300 for thermal expansion is eliminated, the size of both sides of the backlight module 100 can be reduced, and on the other hand, the positioning is performed during transportation. The pin 300 substantially interferes with the inner edge 412 of the positioning hole 410, so that a better positioning effect can be provided, so that the light guide plate 200 does not sway arbitrarily, and the stability of product transportation can be improved. In addition, the design of the present invention does not need to be additionally positioned on the third side, so that the adjustment of the brightness is also more flexible, so that the applicable light input form is wider.

The present invention has been described by the above-described related embodiments, but the above embodiments are merely examples for implementing the present invention. It should be noted that the disclosed embodiments do not limit the scope of the present invention. Wai. On the contrary, modifications and equivalents of the spirit and scope of the invention are included in the scope of the invention.

100‧‧‧Backlight module

200‧‧‧Light guide plate

202‧‧‧ first surface

206‧‧‧ edge

300‧‧‧Locating pin

400‧‧‧ frame

401‧‧‧ side wall

402‧‧‧ support

404‧‧‧Support surface

410‧‧‧Positioning holes

500‧‧‧reflector

510‧‧‧ hole

Claims (12)

A backlight module includes: a light guide plate having a first surface; a positioning pin formed at an edge of the first surface; and a frame enclosing an inner space and having a support An locating hole is formed on the support surface, and a locating hole is formed on the support surface; wherein the edge of the first surface is erected on the support surface, and The positioning pin extends into the positioning hole. The backlight module of claim 1, wherein the positioning pin has an inner side facing the inner side of the light guide plate and an outer side surface of the opposite end, and a circumference surrounding the positioning hole has an inner edge toward the inner side of the light guide plate. And an outer edge of the reverse phase, the distance between the inner side surface and the inner edge is smaller than the distance between the outer side surface and the outer edge. The backlight module of claim 2, wherein the positioning hole is formed as an elongated hole and extends away from the inner space. The backlight module of claim 3, wherein a portion of the periphery of the positioning hole that is parallel to the direction in which the positioning hole extends is substantially in contact with the positioning pin. The backlight module of claim 2, wherein the inner side surface substantially contradicts the inner edge system. The backlight module of claim 1, wherein the frame has a side wall, and the support seat is bent from the side wall toward the inner space. The backlight module of claim 6, wherein an edge of the light guide plate is surrounded by the sidewall. The backlight module of claim 1, wherein the frame has a bottom plate, and the support base is raised from the bottom plate toward the light guide plate. The backlight module of claim 1, wherein a perforation is formed at an edge of the first surface. Passing through to a second surface opposite to the first surface, the positioning pin includes a pin body; and a cap located at one end of the pin body and extending radially from one end of the pin body and having A width greater than the diameter of the perforation; the pin system protrudes from the perforation beyond the first surface, and the cap is in interference with the second surface. The backlight module of claim 9, wherein the cap has a lower light transmittance than the light guide plate. The backlight module of claim 9, wherein the pin body has a lower light transmittance than the light guide plate. The backlight module of claim 1, wherein the positioning pin has a lower light transmittance than the light guide plate.