TW201643525A - Backlight module - Google Patents

Abstract

A backlight module includes a light guide plate, a first reflecting plate and a light source. The light guide plate has a light incident surface, a bottom surface and a light-emitting surface. The bottom surface is connected to the light incident surface, and the light emitting surface is opposed to the bottom surface and connected to the light incident surface. The first reflecting plate has a first surface, a second surface and at least one opening. The second surface is opposed to the first surface. A portion of the first surface disposed on the bottom surface, and the opening connects the first and second surfaces. The light source includes a circuit board and at least one light-emitting element. The circuit board has a first patterned conductive layer. The light emitting element disposed on the first patterned conductive layer is adapted to provide the light beam to the light guide plate from the light incident surface, wherein the light emitting element is disposed to pass through the opening.

Description

Backlight module

The present invention relates to a backlight module, and more particularly to a backlight module applied to a liquid crystal display.

Current electronic devices are moving toward versatility, aesthetics, and thinness. Since liquid crystal displays have advantages such as being thin and light, liquid crystal displays are widely used in various mobile electronic devices (for example, smart phones and tablets). Since the liquid crystal display panel does not have the function of active illumination, a backlight module must be disposed under the liquid crystal display panel as a side light source, so that the liquid crystal display panel can achieve the purpose of display.

1 is a schematic cross-sectional view of a conventional backlight module. Referring to FIG. 1 , the conventional backlight module 20 includes a light guide plate 21 , a reflective sheet 22 , a light source 23 , a back cover 25 , and a plastic frame 26 . The light guide plate 21, the reflection sheet 22, and the light source 23 are disposed in an accommodation space formed by the back cover 25 and the plastic frame 26. The light guide plate 21 has a light incident surface 213, a bottom surface 212, and a light exit surface 211. The bottom surface 212 is connected to the light incident surface 213, and the light exit surface 211 is connected to the light surface 213 with respect to the bottom surface 212. The light source 23 includes a circuit substrate 235 and The light-emitting element 232 is disposed on the circuit substrate 235 and adjacent to the light-incident surface 213 to provide light L1 into the light guide plate 21. The reflection sheet 22 is disposed on the bottom surface 212, and the reflection sheet 22 is bonded to the light guide plate 21 and the circuit board 235 via the fixing tape 27.

However, in the conventional backlight module 20, the fixing tape 27 is usually an opaque double-sided tape to prevent light leakage, but such a design reduces the utilization of the light L1 emitted from the light source 23. In addition, under the current trend of the pursuit of thinness and thinning of mobile electronic devices, how to make various components in the mobile electronic device (such as the backlight module of the liquid crystal display) more lightweight and thin has become an important issue. In the conventional backlight module 20, the circuit board 235 and the fixing tape 27 themselves have a certain thickness, so that the conventional backlight module 20 is difficult to achieve the purpose of slimming.

This "Prior Art" section is only intended to aid in understanding the present invention, and thus the disclosure of the "prior art" section may contain some conventional techniques that are not known to those of ordinary skill in the art. The matters disclosed in the "Prior Art" section, which do not represent the subject matter or the problems to be solved by one or more embodiments of the present invention, are known or recognized by those of ordinary skill in the art prior to the present application.

The invention provides a backlight module having a relatively thin thickness.

Other objects and advantages of the present invention will become apparent from the technical features disclosed herein.

To achieve one or a part or all of the above or other purposes, an embodiment of the present invention provides a backlight module including a light guide plate, a first reflective sheet, and a light source. The light guide plate has a light incident surface, a bottom surface, and a light exit surface. The bottom surface is connected to the light surface, and the light exit surface is connected to the light surface with respect to the bottom surface. The first reflective sheet has a first surface, a second surface, and at least one through hole. The second surface is disposed on the bottom surface with respect to the first surface, and the first surface and the second surface are connected by the through holes. The light source includes a circuit substrate and at least one light emitting element. The circuit substrate has a first patterned conductive layer. A portion of the second side of the first reflective sheet is disposed on the first patterned conductive layer. The illuminating element is adapted to provide light into the light guide plate from the light incident surface. Each of the light emitting elements is disposed on the at least one through hole of the first reflective sheet and disposed on the patterned conductive layer of the circuit substrate.

In an embodiment of the invention, the circuit substrate has an insulating layer, a second patterned conductive layer, and a protective layer. The insulating layer, the second patterned conductive layer and the protective layer are sequentially stacked on the first patterned conductive layer. The insulating layer is between the first patterned conductive layer and the second patterned conductive layer.

In an embodiment of the invention, the first reflective sheet and the insulating layer are respectively disposed on opposite surfaces of the first patterned conductive layer.

In an embodiment of the invention, the circuit substrate has flexibility.

In an embodiment of the invention, the backlight module further includes a plastic frame and a back cover. The back cover and the plastic frame form an accommodation space for accommodating the light guide plate, the first reflection sheet and the light source.

In an embodiment of the invention, the backlight module further includes a second reflective sheet. The second reflective sheet is disposed between the edge of the light emitting surface of the light guide plate and the back cover.

In an embodiment of the invention, the first patterned conductive layer is not in direct contact with the bezel and the back cover.

In an embodiment of the invention, the first reflective sheet and the circuit substrate are parallel to each other.

In an embodiment of the invention, the light guide plate has a plurality of optical microstructures, and the optical microstructures are disposed on the bottom surface.

Based on the above, the embodiment of the present invention has at least one of the following advantages. In the above embodiment of the present invention, the first reflective sheet may be directly disposed on the first patterned conductive layer, and the first reflective sheet has a plurality of through holes. In addition, the light emitting element may be directly disposed on the first patterned circuit layer via the through hole of the first reflective sheet. Therefore, the backlight module of the present invention can directly replace the protective layer with the first reflective sheet disposed on the first patterned circuit layer to reduce the thickness of the circuit substrate, so that the mobile electronic device conforms to the current trend of thinning.

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

100‧‧‧Backlight module

110, 21‧‧‧ light guide

111, 211‧‧ ‧ light surface

112, 212‧‧‧ bottom

113, 213‧‧‧ into the glossy surface

120‧‧‧First reflection sheet

121‧‧‧ first side

122‧‧‧ second side

123‧‧‧Perforation

125‧‧‧First layer

130, 23‧‧‧ Light source

132, 232‧‧‧Lighting elements

135, 235‧‧‧ circuit board

135a‧‧‧First patterned conductive layer

135a1‧‧‧ surface

135a2‧‧‧ surface

135b‧‧‧Second patterned conductive layer

135c‧‧‧protective layer

135d‧‧‧Insulation

140‧‧‧Second reflector

150, 25‧‧‧ back cover

152‧‧‧ card slot

160, 26‧‧‧ plastic frame

162‧‧‧ hook

165‧‧‧Second layer

170‧‧‧Optical microstructure

20‧‧‧Study backlight module

22‧‧‧reflector

27‧‧‧Fixed tape

L, L1‧‧‧ rays

1 is a schematic cross-sectional view of a conventional backlight module.

2 is a schematic diagram of a backlight module according to an embodiment of the invention.

Figure 3 is an enlarged cross-sectional view of the backlight module of Figure 1 taken along line A-A'.

The foregoing and other objects, features, and advantages of the invention will be apparent from the Detailed Description The directional terms mentioned in the following embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only directions referring to the additional schema. Therefore, the directional terminology used is for the purpose of illustration and not limitation.

2 is a schematic diagram of a backlight module according to an embodiment of the invention. Figure 3 is an enlarged cross-sectional view of the backlight module of Figure 2 taken along line A-A'. Referring to FIG. 2 and FIG. 3 , in the embodiment, the backlight module 100 includes a light guide plate 110 , a first reflective sheet 120 , and a light source 130 . The light guide plate 110 has a light incident surface 113, a bottom surface 112, and a light exit surface 111. The bottom surface 112 is connected to the light incident surface 113, and the light emitting surface 111 is connected to the light surface 113, and the material of the light guide plate 110 is, for example, glass, PMMA (polymethylmethacrylate), PC (polycarbonate). Ester, Polycarbonate) or other suitable transparent material. The first reflective sheet 120 is, for example, a white reflective sheet, a silver reflective sheet, or other suitable reflective material. The first reflective sheet 120 has a first surface 121, a second surface 122, and a through hole 123. In this embodiment, the second surface 122 of the first reflective sheet 120 is opposite to the first surface 121 , and a portion of the first surface 121 is disposed on the bottom surface 112 of the light guide plate 110 . Furthermore, the through holes 123 of the first reflection sheet 120 are connected to the first surface 121 and the second surface 122 thereof. In this embodiment, the light source 130 includes a circuit substrate 135 and a light emitting element 132, wherein the light emitting element 132 is, for example, a light emitting diode (LED) or other suitable kind of light source. As shown in FIG. 3, the light-emitting element 132 is adjacent to the light-incident surface 113, and can provide light L from the light-incident surface. 113 enters the light guide plate 110.

In addition, the light emitting element 132 of the light source 130 is disposed on the first patterned conductive layer 135a of the circuit substrate 135. The light emitting element 132 can be disposed in the through hole 123 of the first reflective sheet 120, and the light emitting element 132 can be directly connected to the first patterned conductive layer 135a. In this embodiment, a portion of the first reflective sheet 120 is disposed on the first patterned conductive layer 135a. Compared with the conventional backlight module 20 of FIG. 1, the protective layer on the conventional circuit substrate 235 can be omitted. Not shown), and by the first reflective sheet 120 to achieve a protective effect of preventing deterioration of the first patterned conductive layer 135a and insulation. Therefore, the thickness of the backlight module 100 of the present embodiment can be further reduced compared with the thickness of the conventional backlight module 20 to conform to the current trend of thinning the display device.

The light source 130 is, for example, a light-emitting diode strip light source, and the light-emitting elements 132 of the light source 130 are a plurality of light-emitting diodes sequentially arranged on the circuit board 135. In addition, referring to FIG. 3, the circuit substrate 135 of the present embodiment further includes an insulating layer 135d, a second patterned conductive layer 135b, and a protective layer 135c in addition to the first patterned conductive layer 135a. In this embodiment, the insulating layer 135d, the second patterned conductive layer 135b, and the protective layer 135c are sequentially stacked on the first patterned conductive layer 135a, and the insulating layer 135d is located on the first patterned conductive layer 135a and the second. Between the patterned conductive layers 135b. In other words, in the laminated structure of the circuit substrate 135, the first patterned conductive layer 135a, the insulating layer 135d, the second patterned conductive layer 135b, and the protection are sequentially arranged from the top to the bottom in the thickness direction of the circuit substrate 135. Layer 135c. In addition, in the embodiment, the first patterned conductive layer can also be configured by the insulating layer 135d. The conductive paths of the layer 135a and the second patterned conductive layer 135b are insulated from each other to avoid a short circuit of the circuit substrate 135. The first patterned conductive layer 135a and the second patterned conductive layer 135b are made of, for example, a metal material, which is, for example, a copper foil conductive layer.

Referring to FIG. 3 again, the first reflective sheet 120 of the embodiment is disposed on the first patterned conductive layer 135a. Therefore, a portion of the first reflective sheet 120 and the insulating layer 135d are disposed on the opposite surfaces 135a1 and 135a2 of the first patterned conductive layer 135a, respectively. In addition, the circuit board 135 and the first reflection sheet 120 of the present embodiment are disposed in parallel with each other, and the circuit board 135 is, for example, a printed circuit board or a flexible printed circuit board (Flexible Printed Circuit). The protective layer of the Board (FPCB) is removed, and the present invention does not limit this.

As shown in FIG. 3, the backlight module 100 may include a plastic frame 160 and a back cover 150. The material of the back cover 150 is, for example, metal. The material of the plastic frame 160 is, for example, plastic. The invention is not limited thereto. The back cover 150 and the plastic frame 160 together form an accommodating space for accommodating the light guide plate 110, the first reflection sheet 120, and the light source 130. The back cover 150 and the plastic frame 160 can shield and absorb some of the light L emitted from the light source 130 in addition to the above-mentioned components, so as to reduce the light leakage phenomenon of the backlight module 100.

In addition, the backlight module 100 may include a second reflective sheet 140. As shown in FIG. 3, the cross-sectional shape of the back cover 150 of the present embodiment is, for example, a U-shape, and the notch faces the light guide plate 110. Therefore, the embodiment can also selectively configure the second reflective sheet 140 to guide the light. The edge of the light-emitting surface 111 of the plate 110 is between the upper plate of the back cover 150. The second reflective sheet 140 can be used to reflect the light L from the light-emitting element 132 into the light guide plate 110 to further improve the light utilization efficiency of the light source 130, and can prevent the light L from being emitted from the edge of the light-emitting surface 111 and the back cover 150. In addition, the light guide plate 110 of the present embodiment further has a plurality of optical microstructures 170 arranged on the bottom surface 112 of the light guide plate 110 to increase the light extraction efficiency of the light source 130 and the light exit path for the backlight module 100. Controllability. The optical microstructures 170 are uniformly distributed on the bottom surface 112 of the light guide plate 110. However, the present invention is not limited thereto, and the arrangement density of the optical microstructures 170 may be gradually increased as the distance from the light source 130 is further increased. In order to improve the light uniformity of the light guide plate 110.

The present invention does not limit the manner of bonding between the first reflective sheet 120 and the first patterned conductive layer 135a. The first reflective sheet 120 may be directly disposed on the first patterned conductive layer 135a. Alternatively, as shown in FIG. 3, the first reflective sheet 120 is also adhered to the first patterned conductive layer 135a through the first adhesive layer 125, thereby increasing the positioning effect between the first reflective sheet 120 and the circuit substrate 135 to prevent Damage caused by friction between these components. In addition, the short circuit can be caused by the arrangement of the first adhesive layer 125 avoiding the direct contact between the first patterned conductive layer 135a and the back cover 150 and the plastic frame 160.

In order to make the plastic frame 160 and the back cover 150 of the embodiment more securely coupled, the plastic frame 160 of the embodiment has a hook 162, and the back cover 150 is further provided with a card slot 152 that can engage with the hook 162. The plastic frame 160 is fixed to the back cover 150 in a snapping manner. Furthermore, the first reflective sheet 120 of the embodiment may be directly disposed on the plastic frame 160, or As shown in FIG. 3, the second adhesive layer 165 is selectively disposed between the first reflective sheet 120 and the plastic frame 160 to adhere the first reflective sheet 120 to the plastic frame 160 to prevent the first reflective sheet 120 from being glued. The frames 160 rub against each other to cause damage.

In summary, the embodiment of the present invention has at least one of the following advantages. In the above embodiment of the present invention, the first reflective sheet can be directly disposed on the first patterned conductive layer, and the first reflective sheet has multiple perforation. The plurality of light emitting elements may be respectively disposed on the first patterned circuit layer via the through holes of the first reflective sheet. Therefore, the backlight module of the present invention does not need to additionally provide a protective layer between the first patterned circuit layer and the light-emitting element, so as to reduce the thickness of the circuit substrate of the overall backlight module, and is advantageous for the mobile electronic device to be thinned. development trend. In addition, the first reflective sheet may also be adhered to the first patterned conductive layer through the first adhesive layer to prevent damage caused by friction between the components, and the first patterned layer may be avoided by the setting of the first adhesive layer. The direct contact between the conductive layer and the back cover and the plastic frame causes a short circuit.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention. In addition, the terms "first", "second" and the like mentioned in the specification or the scope of the claims are only used to name the elements or distinguish different embodiments or ranges, and are not intended to limit the number of elements. Upper or lower limit.

100‧‧‧Backlight module

110‧‧‧Light guide plate

111‧‧‧Glossy surface

112‧‧‧ bottom

113‧‧‧Into the glossy surface

120‧‧‧First reflection sheet

121‧‧‧ first side

122‧‧‧ second side

123‧‧‧Perforation

125‧‧‧ glue layer

130‧‧‧Light source

132‧‧‧Lighting elements

135‧‧‧ circuit board

135a‧‧‧First patterned conductive layer

135a1‧‧‧ surface

135a2‧‧‧ surface

135b‧‧‧Second patterned conductive layer

135c‧‧‧protective layer

135d‧‧‧Insulation

140‧‧‧Second reflector

150‧‧‧Back cover

152‧‧‧ card slot

160‧‧‧ plastic frame

162‧‧‧ hook

165‧‧ ‧ glue layer

170‧‧‧Optical microstructure

L‧‧‧Light

Claims (9)

A backlight module includes: a light guide plate having a light incident surface, a bottom surface, and a light exiting surface, wherein the bottom surface is connected to the light incident surface, and the light emitting surface is connected to the light incident surface relative to the bottom surface; a reflective sheet having a first surface, a second surface, and at least one through hole, wherein the second surface is opposite to the first surface, a portion of the first surface is disposed on the bottom surface, and the at least one perforation is connected to the first surface And a light source comprising: a circuit substrate having a first patterned conductive layer, wherein a portion of the second surface of the first reflective sheet is disposed on the first patterned conductive layer And at least one illuminating element, configured to provide a light from the light incident surface into the light guide plate, wherein each of the light emitting elements is disposed in the at least one through hole of the first reflective sheet and disposed on the circuit substrate A patterned conductive layer. The backlight module of claim 1, wherein the circuit substrate further comprises an insulating layer, a second patterned conductive layer and a protective layer, the insulating layer, the second patterned conductive layer and the protection The layers are sequentially stacked on the first patterned conductive layer, and the insulating layer is located between the first patterned conductive layer and the second patterned conductive layer. The backlight module of claim 2, wherein the first reflective sheet and the insulating layer are respectively disposed on opposite surfaces of the first patterned conductive layer. The backlight module of claim 1, wherein the circuit substrate has flexibility. The backlight module of claim 1, further comprising: a plastic frame; and a back cover, and the plastic frame forms an accommodating space for accommodating the light guide plate, the first reflective sheet and the light source. The backlight module of claim 5, further comprising: a second reflective sheet disposed between an edge of the light emitting surface of the light guide plate and the back cover. The backlight module of claim 5, wherein the first patterned conductive layer is not in direct contact with the plastic frame and the back cover. The backlight module of claim 1, wherein the first reflective sheet and the circuit substrate are parallel to each other. The backlight module of claim 1, wherein the light guide plate has a plurality of optical microstructures, and the optical microstructures are disposed on the bottom surface.