TW201816326A - Slim planar light source module - Google Patents

Abstract

A slim planar light source module comprises a light guide plate, a light reflecting film, and a number of edge-type light emitting diode (LED) elements. A lower surface of the light guide plate defines a number of grooves. The light reflecting film is located below the lower surface and covers the whole lower surface and the grooves, thereby forming an air gap between the reflecting film and the lower surface. The LED elements are received in the grooves. Each LED element comprises a LED chip, a wavelength transforming layer, and a light reflecting layer. The LED chip emits light. The wavelength transforming layer transforms the light into desired wavelength. The light reflecting layer reflects the light with desired wavelength towards the sidewalls of the wavelength transforming layer, thereby causing the light to travel towards the lower surface after leaving the sidewalls of the wavelength transforming layer. The light reflecting film reflects the light, which enters the air gap from the lower surface, towards an opposite upper surface of the light guide plate, thereby allowing the light to be uniformly emitted out from the upper surface.

Description

Thin planar light source module

The invention relates to a light source, in particular to a thin planar light source module.

Nowadays, light-emitting diode planar light source modules are widely used in lighting (such as general lighting or automotive lighting) or backlight modules. A conventional light emitting diode (LED) planar light source module generally includes an outer frame and a reflective sheet, a light guide plate, a diffuser plate, and a plurality of Optical reflective diaphragms. One side of the light guide plate is provided with a light emitting diode light source. However, since the light guide plate needs to be attached to the outer frame, the seam between the light guide plate and the outer frame is likely to have a dark line, which affects the appearance. Moreover, because of the presence of the outer frame, the light-emitting diode planar light source module cannot achieve the appearance without a border.

In view of this, it is necessary to provide a thin planar light source module that can solve the above problems.

The invention provides a thin planar light source module, comprising: a light guide plate comprising an upper surface and a lower surface opposite to the upper surface, wherein the lower surface is provided with a plurality of grooves, the grooves are spaced apart from each other; a reflection a diaphragm positioned below the lower surface and covering the entire lower surface and the recess to form an air layer between the reflective diaphragm and the lower surface; and a plurality of edge-lit LED units Each of the light-emitting diode units includes: a light-emitting chip, a bottom surface, a light-emitting surface disposed opposite to the bottom surface, and the bottom surface and the light-emitting surface The first side of the light emitting chip is configured to emit light through the light emitting surface; a color conversion layer is disposed on the light emitting surface of the light emitting chip and covers the first side surface, and has a surface disposed toward the light emitting surface a top surface and a second side disposed toward the first side, the color conversion layer is configured to convert light emitted by the light emitting chip into light of a specific wavelength; and a reflective layer is disposed at the a top surface of the color conversion layer, and the top surface is located between the light emitting wafer and the top of the groove, the reflective layer is for reflecting the light obtained after conversion to the second side of the color conversion layer Having the light incident through the second side and incident on a region of the lower surface other than the groove; wherein the reflective film is used to remove the groove via the lower surface The light incident from the outer region to the air layer is reflected toward the upper surface such that the light is uniformly emitted through the upper surface.

The thin planar light source module of the embodiment of the invention does not need to additionally provide an outer frame, thereby facilitating the problems of dark lines and unsightly seams in the seam when the outer frame is present, and forming an ultra-thin and borderless planar light source module. .

1 is a schematic structural view of a thin planar light source module according to a preferred embodiment of the present invention.

2 is a schematic structural view of a thin planar light source module according to another embodiment of the present invention.

3 is a schematic diagram showing the operation of the edge-lit LED unit in the thin planar light source module shown in FIGS. 1 and 2.

4 is a schematic diagram of the operation of the thin planar light source module shown in FIG. 1.

Referring to FIG. 1 and FIG. 2 , a thin planar light source module 100 according to a preferred embodiment of the present invention includes a light guide plate 10 , a plurality of edge light emitting diode units 20 , and a reflective film 30 .

The light guide plate 10 is substantially a rectangular plate body having an upper surface 11 and a lower surface 12 opposite to the upper surface 11 and extending in a direction substantially parallel to the upper surface 11. The upper surface 11 has a smooth planar shape. The lower surface 12 defines a plurality of grooves 121. The grooves 121 are arranged at equal intervals from each other. In this embodiment, the depth H of the top of the groove 121 is 0.4 mm to 1.2 mm. The ratio of the thickness A of the light guide plate 10 (ie, the distance between the upper surface 11 and the lower surface 12) and the pitch B of the adjacent two grooves 121 is 1:1 to 2:1. The cross-sectional shape of the groove 121 can be set as needed. In this embodiment, the groove 121 has a semi-elliptical cross section (as shown in FIG. 1). In another embodiment, the cross section of the groove 121 may also be quadrangular (as shown in FIG. 2). In other embodiments, the cross section of the groove 121 may also be hemispherical or other curved.

The edge-lit LED units 20 are respectively located in the recesses 121. The edge-lit LED unit 20 can be fabricated by a Chip Scale Package (CSP). Referring to FIG. 3 together, the edge-lit LED unit 20 includes a light-emitting chip 21, a color conversion layer 22, and a reflective layer 23. The light-emitting chip 21 includes a bottom surface 210, a light-emitting surface 211 disposed opposite the bottom surface 210, and a first side surface 212 connecting the bottom surface 210 and the light-emitting surface 211. The color conversion layer 22 is disposed on the light emitting surface 211 of the light emitting chip 21 and covers the first side surface 212 , and has a top surface 220 disposed toward the light emitting surface 211 and disposed toward the first side surface 211 . Second side 221. The reflective layer 23 is disposed on the top surface 220 of the color conversion layer 22, and the top surface 220 is located between the light emitting wafer 21 and the top of the recess 121. The material of the reflective layer 23 may be selected from one of titanium dioxide, cerium oxide, Teflon, and calcium carbonate.

The illuminating wafer 21 is for emitting light through the illuminating surface 211. The color conversion layer 22 is configured to convert light emitted by the light-emitting chip 21 via the light-emitting surface 211 into light of a specific wavelength. The reflective layer 23 is configured to reflect the light obtained after the conversion to the second side surface 221 of the color conversion layer 22 such that the light is incident on the lower surface 12 after being emitted through the second side surface 221 An area outside the groove 121. In the embodiment, the color conversion layer 22 is made of a fluorescent material.

The reflective film 30 is located below the lower surface 12 and covers the entire lower surface 12 and the groove 121 such that an air layer 40 is formed between the reflective film 30 and the lower surface 12. Referring to FIG. 4 together, the reflective film 30 is configured to reflect light incident on the air layer 40 through a region other than the groove 121 through the lower surface 12 toward the upper surface 11, so that The light is uniformly emitted through the upper surface 11. The reflective film 30 is an independent diffused reflective film, and the material thereof may be selected from one of titanium dioxide, cerium oxide, Teflon and calcium carbonate.

In the embodiment, the lower surface 12 is further formed with a microstructure layer 122 in a region other than the groove 121. The microstructure layer 122 includes a plurality of microstructures (not labeled) for scattering light rays that may be recessed or convex relative to the lower surface 12.

Wherein the plurality of microstructures are gradually distributed in a region between two adjacent grooves 121 on the lower surface 12, and the density of the plurality of microstructures near the groove 121 is smaller than The density away from the groove 121 is further increased to further increase the uniformity of the light emitted by the upper surface 11. The cross-sectional shape of the microstructure may be set as needed, for example, the cross section of the microstructure may be triangular or semi-elliptical. It can be understood that in this case, the reflective film 30 is located below the microstructure layer 122 and covers the entire microstructure layer 122 and the groove 121.

The reflective film 30 can be fixed to the lower surface 12 by screwing or other mechanical fixing. For example, a screw is disposed at each of the four corners of the reflective film 30, and the lower surface 12 corresponds to The position is provided with a screw hole, so that the reflective diaphragm 30 can be fixed to the lower surface 12 when the screw is locked to the screw hole.

The thin planar light source module 100 of the embodiment of the present invention does not need to additionally provide an outer frame, thereby avoiding problems such as dark lines and unsightly seams, and forming an ultra-thin and frameless thin planar light source module 100. .

It is to be understood that those skilled in the art can make various other changes and modifications in accordance with the technical concept of the present invention, and all such changes and modifications are intended to fall within the scope of the appended claims.

100‧‧‧Small planar light source module

10‧‧‧Light guide plate

11‧‧‧ upper surface

12‧‧‧ Lower surface

121‧‧‧ Groove

122‧‧‧Microstructure layer

20‧‧‧Side-light LED unit

21‧‧‧Lighting chip

210‧‧‧ bottom

211‧‧‧Lighting surface

212‧‧‧ first side

22‧‧‧Color conversion layer

220‧‧‧ top surface

221‧‧‧ second side

23‧‧‧reflective layer

30‧‧‧Reflective diaphragm

40‧‧‧ air layer

no

Claims (8)

A thin planar light source module comprising: a light guide plate comprising an upper surface and a lower surface opposite to the upper surface, wherein the lower surface is provided with a plurality of grooves, the grooves being equally spaced from each other; a reflective film positioned below the lower surface and covering the entire lower surface and the recess to form an air layer between the reflective diaphragm and the lower surface; A plurality of edge-lit LED units are respectively located in the recesses, and each of the side-emitting LED units comprises: An illuminating chip includes a bottom surface, a light emitting surface disposed opposite to the bottom surface, and a first side surface connecting the bottom surface and the light emitting surface, wherein the illuminating wafer is configured to emit light through the light emitting surface; a color conversion layer disposed on the light emitting surface of the light emitting chip and covering the first side surface, having a top surface disposed toward the light emitting surface and a second side surface disposed toward the first side surface, the color conversion a layer for converting light emitted by the luminescent wafer into light of a specific wavelength; a reflective layer disposed on a top surface of the color conversion layer of the edge light emitting diode, wherein the top surface is located between the light emitting wafer and a top of the groove, and the reflective layer is used for The light obtained after the conversion is reflected toward the second side of the color conversion layer, such that the light is emitted through the second side and then incident on a region of the lower surface other than the groove; Wherein the reflective film is configured to reflect light incident to the air layer via an area of the lower surface other than the groove toward the upper surface, such that the light is uniformly emitted through the upper surface . The thin planar light source module of claim 1, wherein a region of the lower surface other than the groove is further formed with a microstructure layer, the microstructure layer comprising a plurality of microstructures, It is concave or convex with respect to the lower surface. The thin planar light source module of claim 2, wherein the plurality of microstructures are gradually distributed in a region between two adjacent grooves on the lower surface, the plurality of micro The density of the structure near the groove is less than its density away from the groove. The thin planar light source module of claim 1, wherein the top of the groove has a depth of 0.4 mm to 1.2 mm. The thin planar light source module of claim 1, wherein a ratio of a distance between the upper surface and the lower surface to a spacing between two adjacent grooves is 1:1 to 2:1. The thin planar light source module of claim 1, wherein the groove has a cross section of one of a hemispherical shape, a quadrangular shape, and a semi-elliptical shape. The thin planar light source module of claim 1, wherein the reflective film is a diffused reflective film, the material of which is selected from the group consisting of titanium dioxide, cerium oxide, Teflon and calcium carbonate. One. The thin planar light source module of claim 1, wherein the reflective layer is made of a material selected from the group consisting of titanium dioxide, cerium oxide, Teflon, and calcium carbonate.