TW201421116A - Display device and back light module thereof - Google Patents

Abstract

A back light module includes a frame body, a light guide plate, a light source, and an optical films assembly. The light guide plate has a light-inlet surface and a light-exit surface. The light guide plate disposes in the frame body. The light source disposes in the frame body and faces to the light-inlet surface. The light emitting by the light source is a non-white light. The optical films assembly disposes on the light-exit surface. The optical films assembly includes a first color transformation layer and a second color transformation layer. Parts of the light emitting from the light source passes through the second color transformation layer but not the first color transformation layer. The first color transformation layer and the second color transformation layer transform the non-white light to a white light.

Description

Display device and backlight module thereof

The invention relates to an electronic device, in particular to a display device with a backlight module.

For the rapid advancement of the multimedia society, most of them benefit from the rapid development of semiconductor components or display devices. In terms of display elements, cathode display tubes (or cathode tubes, Cathode Ray Tube, CRT) have always dominated the display market due to their superior display quality and economy. However, CRT-type displays have the problem of excessive volume and excessive energy consumption. For high image quality, low power consumption, thin mass production, low voltage driving, and small size, CRT-type displays obviously cannot achieve this requirement. In view of this, liquid crystal display (LCD) will have great advantages, and LCD has been widely used in small and medium-sized portable TVs, video phones, video recorders, notebook computers, and tables. Top-size displays, tablets, and projection color TVs.

A conventional liquid crystal display includes a liquid crystal display panel and a backlight module located below the liquid crystal display panel. The backlight module comprises a light guide plate, a plurality of optical dies and a light source, and the light emitted by the light source passes through the light guide plate and the optical dies to the display panel to serve as a backlight of the display panel.

However, when the light is emitted from these optical dies, the peripheral edges of these optical dies are prone to light leakage, causing problems of darkness and even chromaticity unevenness. As such, the optical effect of the display and its backlight module will be poor.

The invention provides a display device and a backlight module thereof, thereby improving the brightness and chromaticity of the conventional backlight module.

The backlight module disclosed in the present invention comprises a frame, a light guide plate, a light source and an optical film set. The light guide plate has a light incident surface and a light exit surface, and the light guide plate is disposed in the frame body. The light source is located in the frame and faces the light incident surface, and the light emitted by the light source is a non-white light. The optical film set is disposed on the light exit surface. The optical film set includes a first color conversion layer and a second color conversion layer. At least a portion of the light emitted by the light source passes through the second color conversion layer and does not pass through the first color conversion layer. The first color conversion layer and the second color conversion layer are used to convert the light emitted by the light source from non-white light to white light.

The display device disclosed in the present invention comprises the backlight module as described above and a display panel. The display panel is stacked on the optical film set.

According to the display device and the backlight module thereof disclosed in the above, the light that has not passed through the first color conversion layer can pass through the second color conversion layer to ensure the light source is emitted by the second color conversion layer. All light can be converted from non-white to white. Thereby, the problem of the brightness and the chromaticity unevenness of the backlight module is improved.

The features, implementations, and utilities of the present invention are described in detail below with reference to the drawings.

Referring to FIG. 1, FIG. 1 is a cross-sectional view showing the structure of a display device according to an embodiment of the present invention.

The display device 10 of the present embodiment is exemplified by a display device in a tablet computer or a liquid crystal screen, but is not limited thereto. The display device 10 includes a backlight module 11 and a display panel 12.

The backlight module 11 includes a frame 111, a light guide 112, a light source 113, and an optical film set 114.

The frame body 111 includes a carrying bottom plate 1111 and at least one wall 1112 standing on the periphery of the carrying bottom plate 1111. The cross section of the wall 1112 is substantially a stepped shape. The wall 1112 has a first loading platform 1113 and a second loading platform 1114. The relative height of the first loading platform 1113 is higher than the relative height of the bearing bottom plate 1111. And the relative height of the first carrier 1113 is lower than the relative height of the second carrier 1114. The material of the frame 111 can be, but not limited to, plastic or rubber, that is, the frame 111 can be a plastic frame to provide the anti-shock effect of the backlight module 11. In addition, the appearance of the above-described housing 111 is merely illustrative and not intended to limit the invention.

The light guide plate 112 of the embodiment is disposed in the frame 111 and located on the bearing bottom plate 1111. The light guide plate 112 has a light incident surface 1121, a light exit surface 1122, a side surface 1123, and a bottom surface 1124. The light emitting surface 1122 and the bottom surface 1124 are located on opposite sides of the light guide plate 112, and the bottom surface 1124 faces the bearing bottom plate 1111. The light incident surface 1121 and the side surface 1123 are located on opposite sides of the light guide plate 112, and the light incident surface 1121 and the side surface 1123 are interposed between the light emitting surface 1122 and the bottom surface 1124. Further, the light incident surface 1121 and the side surface 1123 of the light guide plate 112 of the embodiment are adjacent to opposite sides of the light emitting surface 1122, respectively. It can be seen from the relative positions of the light incident surface 1121 and the light exit surface 1122 that the backlight module 11 of the present embodiment is a side-lit backlight module. It should be noted that the backlight module 11 of the present embodiment is not limited to the side-lit type. In other embodiments, the backlight module may also be a direct-lit backlight module, that is, the light-incident surface and the light-emitting surface are located. The opposite sides of the light guide plate are not adjacent.

In addition, the light source 113 can be, but not limited to, a light emitting diode (LED, Light-emitting diode). The light source 113 is located in the frame 111 and is located on the carrying substrate 1111. The light emitting surface 1131 of the light source 113 faces the light incident surface 1121, and the light emitted by the light source 113 is a non-white light.

In addition, the backlight module 11 can further include a reflective sheet 115 between the light guide plate 112 and the carrying bottom plate 1111 of the frame 111.

The optical film set 114 includes a plurality of diaphragms, the optical film set 114 is disposed on the light emitting surface 1122, and a part of the optical film set 114 may be stacked on the first carrying stage 1113, but the optical film set 114 The feature that a portion of the diaphragm is stacked on the first carrier 1113 is not intended to limit the invention. In addition, the plurality of diaphragms included in the optical film group 114 further include at least a first color conversion layer 1141 and a second color conversion layer 1142. In this embodiment or other embodiments, the diaphragms of the optical film group 114 may further include a brightness enhancement sheet, a diffusion sheet, and the like, but are not limited thereto.

For the present embodiment, the first color conversion layer 1141 is located at the lowermost layer of the optical film group 114, and the first color conversion layer 1141 is directly attached to the light-emitting surface 1122 of the light guide plate 112.

It should be noted that the feature that the first color conversion layer 1141 is located at the lowermost layer of the optical film group 114 and is directly attached to the light-emitting surface 1122 is not intended to limit the present invention. In other embodiments, the first color conversion layer 1141 may also be located at an intermediate layer of the optical film set 114 to maintain a distance from the light exit surface 1122.

The second color conversion layer 1142 of the present embodiment may be, but not limited to, located at the uppermost layer of the optical film group 114 such that the second color conversion layer 1142 is kept at a pitch from the first color conversion layer 1141 without being in contact. Moreover, the second color conversion layer 1142 is substantially at the edge of the uppermost layer of the optical film group 114, and the second color conversion layer 1142 and the first color conversion The projection of the layer 1141 in the vertical direction at least partially overlaps, but is not limited thereto.

The first color conversion layer 1141 and the second color conversion layer 1142 are used to convert the light emitted by the light source 113 from non-white light to white light.

For example, the first color conversion layer 1141 and the second color conversion layer 1142 each include a plurality of first fluorescent quantum dots, and the first fluorescent quantum dots are excited (eg, irradiated with light) to emit a first color light. The so-called quantum dots (QDs) refer to semiconductor crystals of a nanometer size, and the quantum dots are excited by energy to emit fluorescence. Moreover, the color of the fluorescent light emitted by the excitation of different types of quantum dots is also different. Therefore, an appropriate kind of first fluorescent quantum dot can be selected such that the color of the first color light is complementary to the color of the non-white light emitted by the light source 113, so that the non-white light can pass through the first color conversion layer 1141 and the first The two-color conversion layer 1142 is converted into white light.

For example, if the non-white light emitted by the light source 113 is blue light, the first color light emitted by the first fluorescent quantum dot is required to be yellow light. If the non-white light emitted by the light source 113 is red light, the first color light emitted by the first fluorescent quantum dot is required to be Cyan light. If the non-white light emitted by the light source 113 is green light, the first color light emitted by the first fluorescent quantum dot is required to be magenta light.

It should be noted that the features of the first color conversion layer 1141 and the second color conversion layer 1142 including only one type of fluorescent quantum dots are not intended to limit the present invention. For example, in other embodiments, the first color conversion layer 1141 and the second color conversion layer 1142 may include a plurality of first fluorescent quantum dots and a plurality of second fluorescent quantum dots, that is, the first color conversion layer 1141 and The second color conversion layer 1142 includes two different kinds of fluorescent quantum dots. The first fluorescent quantum dot is excited to emit a first color light, and the second fluorescent quantum dot is excited to emit a second color light, the first color light and the second color light being different in color. With the proper combination of the first color light and the second color light, non-white light can still be converted to white light.

For example, if the non-white light emitted by the light source 113 is blue light, and the first color light emitted by the first fluorescent quantum dot is red light, the second fluorescent quantum dot is excited. The second color light emitted needs to be green light. If the non-white light emitted by the light source 113 is red light, and the first color light emitted by the first fluorescent quantum dot is green, the second fluorescent quantum dot is excited by the second light. The color light needs to be blue light. If the non-white light emitted by the light source 113 is green, and the first color light emitted by the first fluorescent quantum dot is blue light, the second fluorescent quantum dot is excited. The two-color light needs to be red.

In addition, the display panel 12 of the present embodiment is stacked on the optical film set 114. In detail, the display panel 12 is stacked on the optical film set 114 by being disposed on the second stage 1114.

Referring to FIG. 1 , when the light source 113 emits light of non-white light, most of the light is emitted through the light exit surface 1122 and penetrates the first color conversion layer 1141 to convert the non-white light into white light. However, some of the light L is not emitted by the light exit surface 1122, but is emitted by the side surface 1123. At this time, the light L emitted from the side surface 1123 is reflected by the wall surface 1110 of the frame body 111 and then penetrates the second color conversion layer 1142 to convert the non-white light into white light.

In other words, by proper setting of the second color conversion layer 1142, the light that has not passed through the first color conversion layer 1141 passes through the second color conversion layer 1142 to ensure the light source. All the light emitted by 113 can be converted from non-white light to white light. Thereby, the problem of the brightness and the chromaticity unevenness of the backlight module 11 is improved.

It should be noted that the position of the second color conversion layer 1142 of the present embodiment is not used to limit the present invention. It is familiar to those skilled in the art that the position of the second color conversion layer 1142 can be appropriately adjusted according to actual needs to ensure the light source 113. All light emitted can be converted from non-white light to white light.

Referring to FIG. 2, FIG. 2 is a cross-sectional view showing the structure of a display device according to another embodiment of the present invention. Since this embodiment is similar to the embodiment of Fig. 1, it is only explained for the difference.

The difference between the backlight module 11a of the display device 10a of the present embodiment and the backlight module 11 of the first embodiment is that the optical film group 114a includes the first color conversion layer 1141 and the second color conversion layer 1142, and the second The color conversion layer 1142 is extended by one end of the first color conversion layer 1141, and the second color conversion layer 1142 protrudes from the side surface 1123. That is, the second color conversion layer 1142 is connected to the first color conversion layer 1141.

Therefore, the light that is not set by the side 1123 without passing through the first color conversion layer 1141 will then penetrate the second color conversion layer 1142 to convert the non-white light into white light. In this way, it is also ensured that all the light emitted by the light source 113 can be converted from non-white light to white light.

According to the display device and the backlight module of the above embodiment, the light that has not passed through the first color conversion layer can pass through the second color conversion layer by the arrangement of the second color conversion layer to ensure that all the light source emits Light can be converted from non-white to white. Thereby, the problem of the brightness and the chromaticity unevenness of the backlight module is improved.

Although the present invention has been disclosed above in the foregoing preferred embodiments, it is not intended to be limiting. In the present invention, the scope of the patent protection of the present invention is defined by the scope of the patent application attached to the present specification, without departing from the spirit and scope of the present invention. quasi.

10‧‧‧ display device

10a‧‧‧Display device

11‧‧‧Backlight module

11a‧‧‧Backlight module

111‧‧‧ frame

1110‧‧‧ wall

1111‧‧‧ carrying base plate

1112‧‧‧ wall

1113‧‧‧First carrier

1114‧‧‧Second carrier

112‧‧‧Light guide plate

1121‧‧‧Into the glossy surface

1122‧‧‧Glossy surface

1123‧‧‧ side

1124‧‧‧ bottom

113‧‧‧Light source

1131‧‧‧Light emitting surface

114‧‧‧Optical diaphragm group

114a‧‧‧Optical diaphragm group

1141‧‧‧first color conversion layer

1142‧‧‧Second color conversion layer

115‧‧‧reflector

12‧‧‧ display panel

1 is a cross-sectional view showing the structure of a display device according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing the structure of a display device according to another embodiment of the present invention.

10‧‧‧ display device

11‧‧‧Backlight module

111‧‧‧ frame

1110‧‧‧ wall

1111‧‧‧ carrying base plate

1112‧‧‧ wall

1113‧‧‧First carrier

1114‧‧‧Second carrier

112‧‧‧Light guide plate

1121‧‧‧Into the glossy surface

1122‧‧‧Glossy surface

1123‧‧‧ side

1124‧‧‧ bottom

113‧‧‧Light source

1131‧‧‧Light emitting surface

114‧‧‧Optical diaphragm group

1141‧‧‧first color conversion layer

1142‧‧‧Second color conversion layer

115‧‧‧reflector

12‧‧‧ display panel

Claims (15)

A backlight module includes: a frame; a light guide plate having a light incident surface and a light exiting surface, wherein the light guide plate is disposed in the frame body; a light source is located in the frame body and faces the light incident surface, the light source The emitted light is a non-white light; and an optical film set is disposed on the light emitting surface, the optical film set includes a first color conversion layer and a second color conversion layer, and the light source emits at least Part of the light passes through the second color conversion layer and does not pass through the first color conversion layer, and the first color conversion layer and the second color conversion layer are used to convert the light emitted by the light source from the non-white light to a white light. . The backlight module of claim 1, wherein the light guide plate comprises a side surface adjacent to the light exiting surface, and at least part of the light emitted by the light source sequentially passes through the side surface and the second color conversion layer. . The backlight module of claim 1, wherein the second color conversion layer is extended by one end of the first color conversion layer. The backlight module of claim 1, wherein the second color conversion layer maintains a distance from the first color conversion layer. The backlight module of claim 1, wherein the projection of the second color conversion layer and the first color conversion layer in a vertical direction at least partially overlaps. The backlight module of claim 1, wherein the first color conversion layer contacts the light exit surface. The backlight module of claim 1, wherein the first color conversion layer and the second color conversion layer comprise a plurality of first fluorescent quantum dots, and the first fluorescent quantum dots are excited to emit a first color light. . The backlight module of claim 7, wherein the non-white light is blue light, and the first color light is yellow light. The backlight module of claim 7, wherein the non-white light is red light, and the first color light is cyan light. The backlight module of claim 7, wherein the non-white light is green light, and the first color light is magenta light. The backlight module of claim 1, wherein the first color conversion layer and the second color conversion layer comprise a plurality of first fluorescent quantum dots and a plurality of second fluorescent quantum dots, and the first fluorescent quantum dots are subjected to Exciting to emit a first color light, the second fluorescent quantum dots are excited to emit a second color light, and the first color light is different from the color of the second color light. The backlight module of claim 11, wherein the non-white light is blue light, the first color light is red light, and the second color light is green light. The backlight module of claim 11, wherein the non-white light is red light, the first color light is green light, and the second color light is blue light. The backlight module of claim 11, wherein the non-white light is green light, the first color light is blue light, and the second color light is red light. A display device comprising: the backlight module of claim 1; and a display panel stacked on the optical film set.