CN2624238Y - Area light source for LED - Google Patents

Abstract

The utility model relates to a light emitting diode surface light source with a small volume, evenly arranged light and relatively high light utilizing rate. The utility model comprises a light conducting plate, twp light reinforcing plates, two reflecting sheets and two light emitting diodes; wherein, the two light reinforcing sheets are respectively affixed onto the two opposing sidewalls of the light conducting plates. The two reflecting sheets are respectively arranged on the two opposing sidewalls of the light conducting plate. The two reflecting sheets and the two light reinforcing plates are clamped to form two hollow bodies, which is used for holding the two light emitting diodes.

Description

LED surface light source

【Technical field】

The utility model relates to a surface light source applied to a liquid crystal display, in particular to a light-emitting diode surface light source.

【Background technique】

Since the liquid crystal in the liquid crystal display panel itself does not have light-emitting characteristics, in order to achieve the display effect, it is necessary to provide a surface light source device for the liquid crystal display panel, such as a backlight or a front light source. Uniform flat light.

US Patent No. 6,502,948 published on January 7, 2003 discloses a light emitting diode surface light source. Please refer to Fig. 1 and Fig. 2 together, this light-emitting diode surface light source 1 comprises a light guide plate 12, a prism plate 17, a reflective plate 13, a base 14, two light-emitting diodes 15,16 and one surrounded by reflective plate 13 Light guide strip 18. Wherein, the prism plate 17 is located on the upper surface of the light guide plate 12, and the light emitting diodes 15, 16 are located on both sides of the light guide strip 18, and the light emitted by it enters the light guide strip 18, is reflected by the reflector 13 and enters the light guide plate 12, and finally enter the prism plate 17 from the upper surface of the light guide plate 12 and exit.

The light-emitting diode surface light source 1 disclosed in this patent has a light source part composed of two light-emitting diodes 15, 16, so the cost is low and the structure is simple. However, the reflector 13 can only improve the light utilization efficiency and cannot guide light The light emitted by the strip 18 is evenly distributed in all directions, and there is a distance between the light guide strip 18 and the prism plate 17, which is prone to light leakage and absorption loss.

【Content of utility model】

In order to overcome the defects of large volume and low light utilization rate of the LED surface light source in the prior art, the utility model provides a LED surface light source with small volume, uniform distribution of light in the light guide plate and high light utilization rate.

The technical solution adopted by the utility model to solve the technical problem is to provide a light-emitting diode surface light source, which includes two light-emitting diodes, two reflective sheets, two light-enhancing sheets, and a light guide plate including four sides and first and second The surface, the first surface of which is the light exit surface, and a pair of opposite sides thereof are the light input surface. Wherein, the two light enhancement sheets are attached to the light input surface of the light guide plate, and the two reflection sheets are arranged on one side of the light input surface of the light guide plate, and are respectively sandwiched with the two light enhancement sheets to form two cavities , the two cavities are used to accommodate the two light emitting diodes.

Compared with the prior art, the beneficial effect of the utility model is that the light-emitting diode surface light source adopts two light-emitting diodes and a reflector to form a light source. By rationally designing the structure of the reflector, the light can be evenly distributed in the cavity, and approximately The two line light sources further make the light in the light guide plate evenly distributed, and the brightness enhancement sheet is attached to two opposite sides of the light guide plate, which can improve the efficiency of light entering the light guide plate. The two light-emitting diodes are surrounded by two cavities formed by sandwiching two reflective sheets and two light-enhancing sheets, which produce less light leakage and absorption loss, and have a smaller volume.

【Description of drawings】

Fig. 1 is a perspective view of a light emitting diode surface light source in the prior art.

Fig. 2 is a cross-sectional view of the prior art LED surface light source.

Fig. 3 is a perspective view of the light emitting diode surface light source according to the first embodiment of the present invention.

Fig. 4 is a cross-sectional view along III-III direction of Fig. 3 .

Fig. 5 is a cross-sectional view of a light-emitting diode surface light source according to a second embodiment of the present invention.

Fig. 6 is a cross-sectional view of a light-emitting diode surface light source according to a third embodiment of the present invention.

Fig. 7 is a cross-sectional view of a light-emitting diode surface light source according to a fourth embodiment of the present invention.

Fig. 8 is a perspective view of a light emitting diode surface light source according to a fifth embodiment of the present invention.

【Detailed ways】

Please refer to FIG. 3 and FIG. 4 , which are the first embodiment of the light-emitting diode surface light source of the present invention. The LED surface light source 2 includes a light guide plate 21 , two brightness enhancement sheets 22 , 24 , two reflection sheets 23 , 25 , and two LEDs 27 , 29 . Wherein, the light guide plate 21 is a rectangle, which includes four sides and first and second surfaces, the first surface of which is a light exit surface (not marked), a pair of opposite sides 211, 212 are light input surfaces, and the other There is a reflective layer on the opposite side (not shown) and the second surface (not shown), the second surface is provided with V-shaped grooves or light diffusing dots (not shown). The two light enhancement sheets 22, 24 are attached to the light input surfaces 211, 212 of the light guide plate 21, the two reflective sheets 23, 25 are a groove structure, which are connected with the two light enhancement sheets 22, 24, and Two cavities 26 , 28 are formed, and the two cavities 26 , 28 are used to accommodate the two LEDs 27 , 29 and transmit the light emitted by the LEDs 27 , 29 .

Since the light emitting diodes 27 and 29 are arranged symmetrically, the light path of the light emitting diode surface light source 2 of the present invention will be described by taking the light emitting diode 27 as an example. The light-emitting diode 27 is arranged on the top of the cavity 26, and part of the light emitted by it enters the brightness enhancement sheet 22, and the other part enters the light guide plate 21 after being reflected by the reflection sheet 23 and transmitted by the brightness enhancement sheet 22. transmitted in different directions, and finally emitted from the upper surface of the light guide plate 21 .

In order to improve the light utilization efficiency and the uniformity of light distribution, the reflection sheets 23, 25 form an included angle with the light input surfaces 211, 212 of the light guide plate 21, which changes the reflection angle of the light transmitted in the cavity, so that the light passes through the cavity. 26 and 28 are more evenly distributed, thereby improving the uniformity of the light entering the light guide plate 21, and the light enhancement sheets 22 and 24 are attached to the light input surfaces 211 and 212 of the light guide plate 21, so that the light is concentrated into the light guide plate 21 and increases Luminous brightness.

In order to produce a more uniform outgoing light, the reflective sheets 23, 25 can have a dot design to scatter the incident light of the light emitting diodes 27, 29, so that the light entering the brightness enhancement sheets 22, 24 is more uniform, so that the outgoing light of the light guide plate 21 The light is more even. The network dots can be of the same size and uniformly distributed, or distributed more densely along the direction away from the light emitting diodes 27, 29, and each area is larger.

In order to reduce the volume of the surface light source 2, the light emitting diodes 27, 29 and the reflectors 23, 25 are all arranged on the side of the light guide plate 21, and the position of the light emitting diodes 27, 29 is closely attached to the side surface of the light guide plate 21 to enhance the brightness. Sheets 22, 24 and reflectors 23, 25, which cooperate with reflectors 23, 25 and brightness enhancement sheets 22, 24, make the light reflect and transmit in the cavities 26, 28 formed together by them, by rationally designing reflectors 23, 25 structure, the light can be evenly distributed in the cavities 26 and 28, and two side light sources similar to line light sources can be formed to achieve the effect of small volume and good light uniformity.

The light guide plate 21 is made of transparent materials such as acrylic resin, polycarbonate, polyethylene resin or glass. The reflective sheets 23, 25 can be made of high light reflectivity materials, and reflective films can also be directly coated on them.

The second, third, fourth, and fifth implementations of the light-emitting diode surface light source of the present invention are all related to the structural improvement of the reflector, because their structures are different, and the light guiding effects achieved are also different.

The second embodiment of the light-emitting diode surface light source of the utility model is shown in Figure 5. The light-emitting diode surface light source 3 includes a light guide plate 31, two light-enhancing sheets 32, 34, two reflection sheets 33, 35, two light-emitting Diodes 37,39. Wherein, the ends of the two reflective sheets 33 and 35 are arc-shaped, which has a better reflection effect compared with the flat plate shape of the first embodiment.

The third embodiment of the light-emitting diode surface light source of the utility model is shown in Figure 6. The light-emitting diode surface light source 4 includes a light guide plate 41, two light-enhancing sheets 42, 44, two reflection sheets 43, 45, two light-emitting diodes 47, 49. Wherein, the two reflecting sheets 43 and 45 are arc-shaped as a whole.

The fourth embodiment of the light-emitting diode surface light source of the utility model is shown in Figure 7. The light-emitting diode surface light source 5 includes a light guide plate 51, two light-enhancing sheets 52, 54, two reflection sheets 53, 55, and two light-emitting diodes. 57,59. Wherein, the reflective surfaces (not shown) of the two reflectors 53 and 55 are provided with V-shaped grooves to facilitate light reflection and uniform light distribution.

The fifth embodiment of the light-emitting diode surface light source of the utility model is shown in Figure 8. The light-emitting diode surface light source 6 includes a light guide plate 61, two light-enhancing sheets 62, 64, two reflection sheets 63, 65, two light-emitting diodes 67,69. Wherein, the two reflectors 63, 65 are arc-shaped grooves, and the two light-emitting diodes 67, 69 are arranged at the focus of the arc-shaped grooves. After the light is emitted by the light-emitting diodes 67, 69, it passes through the two reflectors. Reflected by 63 and 65, it is incident on the brightness enhancement sheets 62 and 64 at approximately parallel angles, and finally enters the light guide plate 61, which can improve the uniformity of light distribution in the light guide plate 61.

Claims (9)

1. LED surface light source, it comprises: two light emitting diodes and a light guide plate, this light guide plate comprises four sides and first, second surface, its first surface is a light-emitting face, its a pair of opposite flank is an optical input surface, it is characterized in that: this LED surface light source also comprises two reflector plates and two brightening pieces, these two brightening pieces are attached to the optical input surface of this light guide plate, these two reflector plates are arranged on optical input surface one side of this light guide plate, it folds with these two brightening pieces respectively and forms two cavitys, and these two cavitys are used for holding this two light emitting diodes.

2. LED surface light source as claimed in claim 1 is characterized in that: this light guide plate cross section is a rectangle.

3. LED surface light source as claimed in claim 1 is characterized in that: the optical input surface of these two reflector plates and this light guide plate has angle.

4. LED surface light source as claimed in claim 1 is characterized in that: this light guide plate also comprises a plurality of sites, and it is positioned on the second surface of this light guide plate.

5. LED surface light source as claimed in claim 1 is characterized in that: these two reflector plates are a groove shape or arc or arc groove or terminally are arc.

6. LED surface light source as claimed in claim 1 is characterized in that: these two reflector plates are provided with V-shaped groove.

7. LED surface light source as claimed in claim 1 is characterized in that: another of this light guide plate has the reflection horizon to opposite flank and second surface.

8. LED surface light source as claimed in claim 1 is characterized in that: two reflector plates have the site design.

9. LED surface light source as claimed in claim 8 is characterized in that: the site of two reflector plates is closeer along the direction distribution away from light emitting diode, each area is bigger.

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