TWI653492B - Display device, multilayer light guide plate structure and front light module - Google Patents

Abstract

A display device includes a display panel, a multilayer light guide plate structure, and a light source. The display panel has a display surface. The multi-layer light guide plate structure is disposed on the display surface of the display panel, and has a light incident surface and an upper surface and a lower surface opposite to each other, wherein the multilayer light guide plate structure comprises a plurality of light guide layer layers stacked on each other. The light source is disposed beside the light incident surface of the multilayer light guide plate structure and has a light emitting surface. In addition, a multilayer light guide structure and a front light module are also proposed.

Description

Display device, multilayer light guide plate structure and front light module

The present invention relates to a front light module and a display device, and more particularly to a front light module and a display device having a multilayer light guide plate structure.

Generally used in a front light illumination device of a display device, there is a light guide plate, which requires an outer protective element as a protection film to protect the light guide plate to prevent the user from scratching the light guide plate. On the other hand, the reflected light generated by the external light shining to the protective film may cause discomfort to the user's eyes, so the protective film will be subjected to anti-glare or hard coating treatment. The method is to bond or coat the protective film and the optical adhesive (OCA) in a whole roll, and cut into appropriate size sheets according to requirements, and attach them to the light guide plate in a manner of coating. . During the attaching process, a higher proportion of foreign matter is attached between the light guide plate and the optical glue, resulting in a decrease in overall yield.

The invention provides a front light module and a display device with a multi-layer light guide plate structure, and the front light module and the display device with the multi-layer light guide plate structure have high process yield.

The invention provides a display device comprising a display panel, a multilayer light guide plate structure and a light source. The multi-layer light guide plate structure is disposed on the display surface of the display panel, and has a light incident surface and upper and lower surfaces opposite to each other, wherein the multilayer light guide plate structure may include a plurality of light guide plate layers stacked on each other, or composed of a plurality of materials. A light guide layer. The light source is disposed beside the light incident surface of the multilayer light guide structure.

The present invention further provides a multilayer light guide plate structure including a first light guide plate layer and a second light guide plate layer. The first light guide plate layer has an upper surface and a lower surface opposite to each other. The second light guide plate layer is disposed on the upper surface of the first light guide plate layer, and has a light incident surface and upper and lower surfaces opposite to each other, wherein the first light guide plate layer and the second light guide plate layer are fabricated by a co-extrusion process.

The invention further provides a front light module comprising a first light guide layer, a second light guide layer and a light source. The first light guide plate layer has a light incident surface and an upper surface and a lower surface opposite to each other. The second light guide plate layer is disposed on the upper surface of the first light guide plate layer, and has a light incident surface and an upper surface and a lower surface opposite to each other. The first light guide layer and the second light guide layer are fabricated by a co-extrusion process. The light source is disposed on the light incident surface of the first light guide layer and the light incident surface of the second light guide layer, and has a light exit surface.

In an embodiment of the present invention, the multi-layer light guide plate structure includes a first light guide plate layer and a second light guide plate layer, wherein the first light guide plate layer is disposed on the display panel On the display surface, and having a light incident surface and an upper surface and a lower surface opposite to each other. The second light guide plate layer is disposed on the first light guide plate layer and has a light incident surface and upper and lower surfaces opposite to each other.

In an embodiment of the invention, the display device further includes an optical adhesive layer disposed between the first light guide plate layer and the display panel.

In an embodiment of the invention, the thickness of the first light guide plate layer is greater than the thickness of the second light guide plate layer.

In an embodiment of the invention, the ratio of the thickness of the first light guide plate layer to the thickness of the second light guide plate layer is between 1.05 and 2.2.

In an embodiment of the invention, the light incident surface of the first light guide layer and the light incident surface of the second light guide layer form a thickness range in a reference direction, and a central axis of the light exit surface of the light source is in a thickness. Within the scope.

In an embodiment of the invention, the material used for the first light guide plate layer has a first refractive index, the material used for the second light guide plate layer has a second refractive index, and the first refractive index is greater than the second refractive index.

In an embodiment of the invention, the material of the first light guide plate layer comprises a first polymer, the material of the second light guide plate layer comprises a second polymer layer, and the first polymer and the second polymer are different.

In an embodiment of the invention, the first polymer of the display device is polycarbonate (PC) and the second polymer is polymethyl methacrylate (PMMA).

In an embodiment of the invention, the first light shielding layer of the first light guide layer There is a dot structure.

In an embodiment of the invention, the upper surface of the second light guide plate layer is subjected to an anti-glare treatment, a surface hardening treatment or an anti-reflection treatment.

In an embodiment of the invention, the first light guide layer and the second light guide layer are fabricated by a co-extrusion process.

In an embodiment of the invention, the light source comprises one or more light emitting diodes, and the thickness of the light source in a reference direction is greater than, less than or equal to the thickness of the first light guide layer in the reference direction.

Based on the above, the display device and the front light module of the exemplary embodiments of the present invention include a multilayer light guide plate structure made of a composite material, which can reduce the use of the optical glue to reduce the attaching step and thereby improve the process yield.

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

100‧‧‧ display device

110‧‧‧ display panel

112‧‧‧ display surface

120‧‧‧First light guide layer

130‧‧‧Second light guide layer

122, 132‧‧‧ into the glossy surface

124, 134‧‧‧ upper surface

126, 136‧‧‧ lower surface

140‧‧‧Light source

142‧‧‧Glossy

150‧‧‧Optical adhesive layer

160‧‧‧Multilayer light guide plate structure

T1, T2, T3‧‧‧ thickness

X‧‧‧ horizontal direction

Y‧‧‧Vertical direction

AX‧‧‧ central axis

1 is a cross-sectional view showing a display device in accordance with an embodiment of the present invention.

1 is a cross-sectional view of a display device in accordance with an embodiment of the present invention. Please refer to Figure 1. The multilayer light guide plate structure 160 of the embodiment of the invention is disposed on the display surface of the display panel, and has a light incident surface and upper and lower surfaces opposite to each other, The mid-multilayer light guide plate structure 160 includes a plurality of light guide plate layers stacked on each other, or a light guide plate layer composed of a plurality of layers of materials. In the present embodiment, a plurality of light guide plate layers stacked on each other are, for example, two light guide plate layers of the display device 100. The display device 100 includes a display panel 110, a first light guide layer 120, a second light guide layer 130, and a light source 140. Herein, the combination of the first light guide layer 120, the second light guide layer 130 and the light source 140 serves as a front light module for providing a display light source of the display device 100. The display panel 110 has a display surface 112. The first light guide plate layer 120 is disposed on the display surface 112 of the display panel 110. The first light guide layer 120 has a light incident surface 122 and an upper surface 124 and a lower surface 126 opposite to each other. The second light guide plate layer 130 is disposed on the first light guide plate layer 120. The second light guide layer 130 has a light incident surface 132 and an upper surface 134 and a lower surface 136 opposite to each other. The first light guide layer 120 and the second light guide layer 130 are fabricated by a co-extrusion process, and the invention is not limited thereto. The light source 140 is disposed adjacent to the light incident surface 122 of the first light guide layer 120 and the light incident surface 132 of the second light guide layer 130 , and has a light exit surface 142 . Moreover, the display device 100 of the present embodiment may further include an optical adhesive layer 150 disposed between the first light guide plate layer 120 and the display panel 110 for bonding the display panel 110 and the first light guide layer 120.

In this embodiment, anti-glare treatment and surface hardening treatment are performed on the upper surface 134 of the second light guide plate layer 130 at least in order to reduce the reflected light generated by the external light to illuminate the light guide plate layer and to protect the light guide plate layer. (Hard-coating) or anti-reflection treatment can reduce the reflection light into the human eye on the one hand, and increase the surface hardness of the second light guide layer 130. In this embodiment After the surface-hardened second light guide plate layer 130, the surface hardness of the second light guide plate layer 130 is higher than the first light guide plate layer 120 by a pencil hardness test, thereby protecting the first light guide plate. Layer 120 and second light guide layer 130.

In detail, the display panel 110 of the embodiment is a reflective display panel, such as an electrophoretic display panel, but is not limited thereto. The first light guide layer 120 and the second light guide layer 130 are disposed on the display surface 112 of the display panel 110, that is, disposed on the front side of the display panel 110, so that the first light guide layer 120 and the second light guide layer 130 can be The combination of light sources 140 is considered a front light module. Here, the light source 140 is composed of, for example, a plurality of point light sources, such as a plurality of light emitting diodes. In other embodiments, the light source 140 may also be composed of a cold cathode fluorescent tube, which is not limited herein.

It is worth mentioning that the display device 100 of the present embodiment performs anti-glare, hard-coating or anti-reflection treatment directly on the upper surface 134 of the second light guide layer 130. -reflection), therefore, it is not necessary to make a protective film on the second light guide layer 130, and it is not necessary to bond or apply a layer of optical glue on the second light guide layer 130, thereby avoiding the A high proportion of foreign matter is adhered between the second light guide layer 130 and the optical glue, thereby improving the overall yield.

In the present embodiment, at least in order to improve the display quality, the refractive index n1 of the material used for the first light guide plate layer 120 is greater than the refractive index n2 of the material used for the second light guide plate layer 130. In addition, in this embodiment, the material of the first light guide plate layer 120 includes a first polymer, and the composition thereof is, for example, polycarbonate (PC), and the second light guide plate. The material of layer 130 comprises a second polymer, the composition of which is, for example, polymethyl methacrylate (PMMA). In this embodiment, the materials of the first polymer and the second polymer are not the same. In order to reduce the destruction of the material of the display panel 110 by ultraviolet (UV) light, an ultraviolet light absorbing material may be added to the first light guide layer 120 or the second light guide layer 130, and the two are coextruded. To make, but the invention is not limited thereto. In addition, in the embodiment, the thickness T1 of the first light guide plate layer 120 is greater than the thickness T2 of the second light guide plate layer 130. In the present embodiment, the ratio of the thickness T1 to the thickness T2 is, for example, between 1.05 and 2.2. This thickness design can conduct a greater proportion of the light emitted by the source 140 via the first light guide layer 120. Therefore, the light enters the first light guide plate layer 120 and the second light guide plate layer 130 via an appropriate incident angle, and the display panel display screen can provide good display quality.

In addition, in the embodiment, the light incident surface 122 of the first light guide layer 120 and the light incident surface 132 of the second light guide layer 130 form a thickness range in a reference direction. In this example, the reference direction is, for example, the vertical direction Y, and the thickness range is, for example, the total thickness T1+T2 of both the first light guide plate layer 120 and the second light guide plate layer 130. A central axis AX of the light exit surface 142 of the light source 140 is within the thickness range. For example, in the embodiment, the light source 140 may be parallel to the light incident surface 122 of the first light guide layer 120 and the light incident surface 132 of the second light guide layer 130 as a reference direction (ie, a vertical direction Y). The central axis AX of the light-emitting surface 142 is disposed in the lower surface 126 of the first light guide plate layer 120 and the upper surface 134 of the second light guide plate layer 130, that is, between the thickness ranges T1+T2. Further, in the present embodiment, the light source 140 is in the Y direction. The thickness T3 may be equal to, greater than, or smaller than the thickness T1 of the light incident surface 122 of the first light guide layer 120 in the Y direction to improve the light guiding efficiency of the first light guide layer 120 and the second light guide layer 130. In FIG. 1 , the thickness T3 of the light source 140 in the Y direction is greater than the thickness T1 of the light incident surface 122 of the first light guide layer 120 in the Y direction, and the remaining thickness relationship may be deduced by the invention. limit.

In the present embodiment, the lower surface 126 of the first light guide plate layer 120 has, for example, a dot structure. For example, the method of fabricating the dot structure can directly press the dot structure on the material of the first light guide layer 120 in a full roll manner by hot pressing. Alternatively, the dot structure may be formed by, for example, coating a UV-curable film layer material on the lower surface 126 of the first light guide plate layer 120, and curing the film layer by ultraviolet light irradiation after embossing the dot structure. Regarding the manner of fabricating the dot structure, the invention is not limited thereto.

In summary, in an exemplary embodiment of the present invention, the light guiding structure of the display device and the front light module includes a plurality of light guide plate layers, and the multilayer light guide plate structure is fabricated from a composite material. The upper surface of the second light guide plate layer is directly subjected to anti-glare treatment, surface hardening treatment or anti-reflection treatment, so that it is not necessary to bond the protective film to the second light guide plate layer, thereby improving product yield and reducing display device thickness of.

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

Claims (26)

A display device includes: a display panel having a display surface; a multi-layer light guide plate structure disposed on the display surface of the display panel, and having a light incident surface and an upper surface and a lower surface opposite to each other, The multilayer light guide plate structure includes a plurality of stacked light guide plate layers, the multilayer light guide plate structure includes a first light guide plate layer and a second light guide plate layer, and the first light guide plate layer is disposed on the display surface of the display panel And having a light incident surface and an upper surface and a lower surface opposite to each other, and the second light guide layer is disposed on the first light guide layer and has a light incident surface and an upper surface and a lower surface opposite to each other The upper surface of the second light guide plate layer is subjected to an anti-glare treatment, a surface hardening treatment or an anti-reflection treatment; and a light source disposed beside the light-incident surface of the multilayer light guide plate structure and having a light-emitting surface. The display device of claim 1, further comprising: an optical adhesive layer disposed between the first light guide plate layer and the display panel. The display device of claim 1, wherein the thickness of the first light guide plate layer is greater than the thickness of the second light guide plate layer. The display device of claim 3, wherein a ratio of a thickness of the first light guide layer to a thickness of the second light guide layer is between 1.05 and 2.2. The display device of claim 3, wherein the light incident surface of the first light guide layer and the light incident surface of the second light guide layer form a thickness range in a reference direction, the light source a central axis of the illuminating surface is in the thickness range Inside. The display device of claim 1, wherein the first light guide plate layer has a first refractive index, the second light guide plate layer has a second refractive index, and the first refractive index is greater than the second Refractive index. The display device of claim 1, wherein the material of the first light guide layer comprises a first polymer, the material of the second light guide layer comprises a second polymer, and the first polymer Not the same as the second polymer. The display device of claim 7, wherein the first polymer is polycarbonate (PC). The display device of claim 7, wherein the second polymer is polymethyl methacrylate (PMMA). The display device of claim 1, wherein the lower surface of the first light guide layer has a dot structure. The display device of claim 1, wherein the first light guide layer and the second light guide layer are fabricated by a co-extrusion process. The display device of claim 1, wherein the light source comprises a light emitting diode, and the thickness of the light source in a reference direction is greater than, less than or equal to the first light guide layer in the reference direction. thickness. A multilayer light guide plate structure comprising: a first light guide plate layer having an upper surface and a lower surface opposite to each other; and a second light guide plate layer disposed on the upper surface of the first light guide plate layer, and An upper surface and a lower surface opposite to each other, wherein the first light guide layer and the second light guide layer are fabricated by a co-extrusion process, and the upper surface of the second light guide layer is subjected to anti-glare treatment and surface hardening treatment Or anti-reflective treatment. The multilayer light guide plate structure of claim 13, wherein the lower surface of the first light guide plate layer has a dot structure. The multilayer light guide plate structure of claim 13, wherein the thickness of the first light guide plate layer is greater than the thickness of the second light guide plate layer. The multilayer light guide plate structure of claim 13, wherein a ratio of a thickness of the first light guide plate layer to a thickness of the second light guide plate layer is between 1.05 and 2.2. The multilayer light guide plate structure of claim 13, wherein the first light guide plate layer has a first refractive index, the second light guide plate layer has a second refractive index, and the first refractive index is greater than the Second refractive index. The multilayer light guide plate structure of claim 13, wherein the material of the first light guide plate layer comprises polycarbonate (PC), and the material of the second light guide plate layer comprises polymethyl methacrylate ( Polymethyl methacrylate, PMMA). A front light module includes: a first light guide layer having a light incident surface and an upper surface and a lower surface opposite to each other; and a second light guide layer disposed on the upper surface of the first light guide layer And having a light incident surface and an upper surface and a lower surface opposite to each other, wherein the upper surface of the second light guide layer is subjected to anti-glare treatment, surface hardening treatment or anti-reflection treatment; And a light source disposed on the light incident surface of the first light guide layer and the light incident surface of the second light guide layer, and having a light exit surface, wherein the first light guide layer and the second light guide The layers are produced in a co-extrusion process. The front light module of claim 19, wherein the lower surface of the first light guide layer has a dot structure. The front light module of claim 19, wherein the thickness of the first light guide layer is greater than the thickness of the second light guide layer. The front light module of claim 19, wherein a ratio of a thickness of the first light guide layer to a thickness of the second light guide layer is between 1.05 and 2.2. The front light module of claim 19, wherein the light incident surface of the first light guide layer and the light incident surface of the second light guide layer form a thickness range in a reference direction, A central axis of the light exiting surface of the light source is within the thickness range. The front light module of claim 19, wherein the first light guide plate layer has a first refractive index, the second light guide plate layer has a second refractive index, and the first refractive index is greater than the Second refractive index. The front light module of claim 19, wherein the material of the first light guide layer comprises polycarbonate (PC), and the material of the second light guide layer comprises polymethyl methacrylate ( Polymethyl methacrylate, PMMA). The front light module of claim 19, wherein the light source package The light-emitting diode is included, and the thickness of the light source in a reference direction is greater than, less than or equal to the thickness of the first light guide layer in the reference direction.