CN104676350B - Light emitting device and backlight module - Google Patents

Abstract

The invention relates to a light-emitting device, which comprises a light source and a light-expanding unit. The light expansion unit comprises a light expansion lens and a light expansion ring. The light diffusion lens comprises a light incident surface, a light emergent surface and a side surface. The side surface is connected with the light incident surface and the light emergent surface. The light incident surface is provided with a containing cavity which is concave towards the light emergent surface, and the light source is positioned in the containing cavity. The light diffusion ring is arranged on the light emergent surface and corresponds to the light source so as to reflect part of light rays emitted from the light source and emitted through the light diffusion lens towards all directions. The invention also relates to a backlight module comprising the light-emitting device.

Description

Light emitting device and backlight module

technical field

The invention relates to a light emitting device and a backlight module including the light emitting device.

Background technique

Currently, large-size display panels mostly use direct-lit backlight modules. In a direct-lit backlight module, a light diffusing unit is usually added above a light emitting diode (LED) light source to diffuse the light, thereby reducing the number of LED light sources used.

The light emitted by the LED light source usually has an approximately circularly symmetrical light field after passing through the light expansion unit, as shown in Figure 1, which is a simulation diagram of the illuminance after the light emitted by the LED light source passes through the light expansion unit in the prior art, and the illuminance extends from the center to the surroundings The distribution is uneven, and the application of the light-emitting device with such illuminance in the backlight module will inevitably lead to poor uniformity of the light emitted by the backlight module.

Contents of the invention

In view of this, it is necessary to provide a light emitting device capable of improving the uniformity of light diffusion and a backlight module including the light emitting device.

A light-emitting device includes a light source and a light-diffusing unit. The light-diffusing unit includes a light-diffusing lens and a light-diffusing ring. The light expanding lens includes a light incident surface, a light exit surface and side surfaces. The side surface is connected with the light incident surface and the light output surface. The light incident surface is provided with an accommodating cavity concave toward the light emitting surface, and the light source is located in the accommodating cavity. The light-diffusing ring is installed on the light-emitting surface and corresponds to the light source to reflect part of the light emitted from the light source and emitted by the light-diffusing lens toward various directions.

A backlight module includes a light emitting device as described above and a diffuser plate. The diffusion plate is located on the side of the light-diffusing lens away from the light source. The diffuser plate is aligned with the diffuser lens for receiving and further diffusing the light emitted by the light emitting device.

The backlight module provided by the present invention and the light-emitting device use the light-diffusing ring to reflect the light incident on the light-diffusing ring in various directions, so that the light emitted from the light-emitting device is diffused uniformly, so that the light emitted from the backlight module is uniform.

Description of drawings

FIG. 1 is a simulation diagram of illuminance of a light emitting device in the prior art.

Fig. 2 is a schematic perspective view of the light emitting device provided by the first embodiment of the present invention.

FIG. 3 is an exploded schematic view of the light emitting device in FIG. 2 .

FIG. 4 is a schematic cross-sectional view of the light emitting device in FIG. 2 along line IV-IV.

FIG. 5 is a simulation diagram of illuminance of light emitted by the light emitting device in FIG. 2 .

FIG. 6 is a schematic cross-sectional view of a backlight module provided by a second embodiment of the present invention.

Description of main component symbols

light emitting device 100 light source 10 Diffusion unit 20 Diffusion lens twenty two Mount twenty four Diffusion ring 26 Accommodating cavity 220 Light incident surface 222 light emitting surface 224 side 226 annular groove 228 Bayonet 249 Card column 269 Backlight module 200 Diffusion plate 50 incident surface 52 exit surface 54

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

Detailed ways

The embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in FIGS. 2-4 , the light emitting device 100 provided by the first embodiment of the present invention includes a light source 10 and a light diffusing unit 20 .

The light emitted by the light source 10 is diffused through the light-diffusing unit 20 , and the illuminance of the light emitted from the light-diffusing unit 20 is uniform. In this embodiment, the light source 10 is a light emitting diode (light emitting diode, LED).

The light-diffusing unit 20 includes a light-diffusing lens 22 , a mounting part 24 and a light-diffusing ring 26 . The light-diffusing ring 26 is installed on the light-diffusing lens 22 through the mounting part 24 .

The light expanding lens 22 includes a light incident surface 222 , a light exit surface 224 and a side surface 226 . The side surface 226 connects the light incident surface 222 and the light output surface 224 . The light emitting surface 224 protrudes away from the light incident surface 222 . The light emitting surface 224 is an aspherical surface. The top of the light-emitting surface 224 is smoothly concave toward the direction of the light-incident surface 222 . The light incident surface 222 defines an accommodating cavity 220 recessed toward the light output surface 224 . The light-diffusing lens 22 has a central axis O, and the light-diffusing lenses 22 are symmetrically distributed about the central axis O. The light source 10 is located in the accommodating cavity 220 , and the light source 10 is also located on the central axis O. As shown in FIG. An annular groove 228 is disposed on the light emitting surface 224 . The annular groove 228 is center-symmetric about the central axis O of the light-diffusing lens 22 .

The mounting part 24 is annular. The mounting member 24 can be inserted into the annular groove 228 . A part of the installation part 24 protrudes from the annular groove 228 after being inserted into the annular groove 228 . A portion of the mounting member 24 protruding from the annular groove 228 is provided with a plurality of bayonet sockets 249 at an end far away from the diffuser lens 22 . The mounting part 24 and the dilation lens 22 can be made of the same material. In this embodiment, both the mounting part 24 and the light-diffusing lens 22 are made of polymethyl methacrylate (PMMA). It can be understood that the installation part 24 can also be integrally formed with the dilation lens 22 .

The cross-section of the light-diffusing ring 26 along the central axis O of the light-diffusing lens 22 is circular. The outer diameter of the light-diffusing ring 26 is smaller than the inner diameter of the mounting part 24 . A plurality of clamping posts 269 corresponding to the plurality of bayonet slots 249 are disposed on the periphery of the light-diffusing ring 26 . After the plurality of clamping posts 269 are engaged with the plurality of bayonet sockets 249 one by one, the light-diffusing ring 26 is installed on the mounting member 24 , so that the light-diffusing ring 26 is installed on the light-emitting surface 224 . Since the annular groove 228 is center-symmetric to the central axis O of the light-diffusing lens 22 , the light-diffusing ring 26 is also center-symmetric to the central axis O of the light-diffusing lens 22 . The outer surface of the light-diffusing ring 26 can reflect light. In this embodiment, there is a certain distance between the light-diffusing ring 26 and the light-emitting surface 224, and the distance between the light-diffusing ring 26 and the light-emitting surface 224 can be adjusted according to different conditions of light incident on the light-diffusing lens 22, In order to make the illuminance of the light emitted from the light emitting surface 224 more uniform after being reflected in all directions by the light diffusing ring 26 . In this embodiment, the light-diffusing ring 26 is formed by coating a circular-shaped substrate made of polymethyl methacrylate with a reflective film. It can be understood that, the light-diffusing ring 26 may adopt other structures whose outer surface has a reflective effect.

When the light emitting device 100 is in operation, the light emitted by the light source 10 enters the light-diffusing lens 22 from the light-incident surface 222 and exits from the light-emitting surface 224 . Part of the light emitted from the light-emitting surface 224 enters the light-diffusing ring 26 , and the light incident on the light-diffusing ring 26 is reflected in various directions by the light-diffusing ring 26 , so that the illuminance of the light emitted from the light emitting device 100 is uniform. As shown in FIG. 5 , the illuminance diagram of the light emitting device 100 provided in the first embodiment of the present invention, it can be seen by comparison that the illuminance of the light emitted by the light emitting device 100 is higher than that of the light emitted by the light emitting device in the prior art. (as shown in Figure 1) evenly.

Referring to FIG. 6 , the backlight module 200 provided in the second embodiment of the present invention includes the light emitting device 100 in the first embodiment and a diffuser plate 50 . The specific structure of the light emitting device 100 will not be repeated here.

The diffuser 50 includes an incident surface 52 and an outgoing surface 54 . The incident surface 52 and the outgoing surface 54 are respectively located on opposite sides of the diffusion plate 50 , and the incident surface 52 is parallel to the outgoing surface 54 . The diffuser 50 is located on a side of the light-diffusing lens 22 facing away from the light source 10 , that is, the diffuser 50 is located on a side where the light-emitting surface 224 of the light-diffusing lens 22 is located. The incident surface 52 is opposite to the light emitting surface 224 . The light emitted from the light emitting device 100 enters the diffuser 50 through the incident surface 52 and is further diffused by the diffuser 50 .

The backlight module 200 provided by the present invention adopts the light-emitting device 100, and the light-emitting device 100 installs a light-diffusing ring 26 on the light-emitting surface 224 of the light-diffusing lens 22 so that the light incident to the light-diffusing ring 26 is directed to all directions by the light-diffusing ring 26. Reflection, in this way, makes the diffusion of the light emitted from the light emitting device 100 uniform, and further makes the light emitted from the backlight module 200 uniform.

Although the present invention has disclosed a specific embodiment, it is not intended to limit the present invention. Any person skilled in the art may make equivalent structure or step replacements without departing from the concept and scope of the present invention, or follow the present invention. The equivalent changes and modifications made in the protection scope of the invention patent shall still fall within the scope covered by this patent.

Claims (8)

1. A light-emitting device, comprising a light source and a light-diffusing unit, its improvement is that the light-diffusing unit includes a light-diffusing lens and a light-diffusing ring, and the light-diffusing lens includes a light incident surface, a light exit surface and a side surface, and the side surface is connected to the light incident surface. surface and the light-emitting surface, the light-incident surface is provided with an accommodating cavity concave toward the light-emitting surface, the light source is located in the accommodating cavity, and the light-diffusing ring is installed on the light-emitting surface and corresponds to the light source so that the Part of the light emitted by the light source and emitted by the light-diffusing lens is reflected in various directions. An annular groove is provided on the light-emitting surface. groove and a part of the mounting part protrudes from the annular groove, the part of the mounting part is provided with a plurality of bayonets, the periphery of the light-diffusing ring is provided with a plurality of clamping posts, and the light-diffusing ring is installed on the mounting part, The plurality of clamping columns are respectively clamped in the plurality of bayonet slots. 2 . The light emitting device according to claim 1 , wherein the annular groove is center-symmetrical to the central axis of the light-diffusing lens. 3 . 3 . The light emitting device according to claim 2 , wherein a cross-section of the light-diffusing ring along the central axis of the light-diffusing lens is circular. 4 . 4. The lighting device according to claim 1, wherein the light-diffusing lens and the mounting part are made of the same material. 5. The light-emitting device according to claim 1, wherein the light-diffusing lens is made of polymethyl methacrylate. 6 . The light-emitting device according to claim 1 , wherein the light-diffusing ring is made by coating a circular-shaped substrate made of polymethyl methacrylate with a reflective film. 7. The light emitting device according to claim 1, wherein the light source is a light emitting diode light source. 8. A backlight module, comprising a light-emitting device as claimed in any one of claims 1 to 7 and a diffuser plate, the diffuser plate is located on the side of the light-diffusing lens away from the light source, the diffuser plate and the light-diffuser The lens is aligned for receiving and further diffusing light emitted by the light emitting device.