CN103311399B - LED lighting device - Google Patents

Abstract

An LED light-emitting device comprises an LED chip, a reflecting cup and a fluorescent powder layer, and further comprises a reflecting layer, wherein the reflecting layer shields a forward light-emitting surface of the LED chip, the reflecting cup surrounds the LED chip and the reflecting layer, the fluorescent powder layer is coated on the inner surface of the reflecting cup, and light rays emitted by the LED chip in the forward direction are reflected to the fluorescent powder layer in the lateral direction by the reflecting layer. Light rays emitted by the LED chip are scattered to the lateral direction of the LED chip through the reflecting layer to be emitted, and therefore the fluorescent powder layer distributed on the lateral direction of the LED chip is excited. The phosphor layer is mixed with light emitted from the side of the LED chip, and then the mixed light is reflected by the reflecting cup until the mixed light is emitted from the opening of the reflecting cup. Because the light emitted by the LED chip is changed to the direction distributed with the fluorescent powder layer through the reflecting layer, the fluorescent powder layer can be better excited and mixed, and the problem of uneven emergent light color can be effectively solved.

Description

LED lighting device

technical field

The invention designs a light emitting device, especially an LED light emitting device.

Background technique

As shown in Figure 1, in the prior art, a traditional light source 11 (such as an incandescent lamp) is usually arranged at the focal point of an arc-shaped reflective cup 12 of a lamp, and a layer of phosphor layer is coated on the inner surface of the reflective cup 12 13. The light emitted by the light source 11 is converted by the phosphor layer 13 to mix different colors. As an emerging light source, LED (Light-Emitting Diode) will gradually replace traditional light sources in the future. However, due to the high directivity of LEDs, if LEDs are used to replace the above-mentioned light source 11 in the above-mentioned lamps, because the forward luminous intensity of the light source 11 is much greater than its lateral luminous intensity, only a few phosphor layers are excited, and the Part of the light will be emitted directly, causing the problem of uneven color of the emitted light.

Contents of the invention

In view of this, it is necessary to provide an LED lighting device with uniform light emission color.

An LED light-emitting device, including an LED chip, a reflective cup and a phosphor layer, the LED light-emitting device also includes a reflective layer, the reflective layer blocks the forward light-emitting surface of the LED chip, and the reflective cup surrounds the LED chip and the reflective layer , the phosphor layer is coated on the inner surface of the reflective cup, and the reflective layer reflects the light emitted by the LED chip in the side direction to the phosphor layer. Along the axial direction of the reflective cup, the phosphor layer The thicknesses at different positions on the inner surface are not equal, and the position of the phosphor layer corresponding to the outer periphery of the reflective layer forms a protrusion with the largest thickness, and the thickness of the phosphor layer gradually increases from the protrusion towards the bottom and top of the reflective cup. Thinned.

The light emitted by the LED chip is dispersed to the side exit of the LED chip through the reflective layer, thereby exciting the phosphor layer distributed on the side of the LED chip. After the phosphor layer is mixed with the light emitted from the side of the LED chip, it is reflected by the reflection cup until it exits from the opening of the reflection cup. Since the light emitted by the LED chip is changed to the direction where the phosphor layer is distributed through the reflective layer, the phosphor layer can be better excited and mixed, which can effectively improve the problem of uneven light color.

Description of drawings

Fig. 1 is a schematic diagram of an existing lamp.

Fig. 2 is a schematic diagram of the LED lighting device according to the first embodiment of the present invention.

FIG. 3 is a partial enlarged view of the LED lighting device of FIG. 2 .

Fig. 4 is a schematic diagram of an LED lighting device according to a second embodiment of the present invention.

Explanation of main component symbols

11 light source 12, 20 reflector cup 13, 21 Phosphor layer 211 protruding 30 lens 31 hole 32 microstructure 33 curved surface 34, 34a reflective layer 40 LED chips 41, 42 electrode 43 Substrate 100, 200 light emitting device

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

Detailed ways

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

Please also refer to FIGS. 2-3 , which show an LED lighting device 100 according to a first embodiment of the present invention. The light emitting device 100 includes an LED reflective cup 20 with a phosphor layer 21 , an LED chip 40 and a lens 30 used together.

The LED chip 40 includes two electrodes 41 , 42 insulated from each other, and the two electrodes 41 , 42 extend downward from the lower surface of the LED chip 40 . The LED chip 40 is connected to a substrate 43 through the two electrodes 41 , 42 through one of methods of eutectic, conductive wire connection, and flip-chip. The lens 30 covers the LED chip 40 and covers the upper surface and side surfaces of the LED chip 40 . The light emitting surface of the LED chip 40 faces directly above the lens 30 . The lens 30 includes an arc-shaped concave surface, which is recessed from the center of the lower surface of the lens 30 to the upper surface thereof, forming a cavity 31 at the center of the lens 30 with an open lower end. The cross-section of the cavity 31 is approximately semi-elliptical, its long axis is parallel to the vertical direction of the lens 30 , and its short axis is not larger than the width of the LED chip 40 . The side surface of the lens 30 includes a plurality of microstructures 32 . The plurality of microstructures 32 roughen the sides of the lens 30 . In this embodiment, the plurality of microstructures 32 are a plurality of ring-shaped microstructures 32 that are recessed toward the inside of the lens 30 , and their cross-sections are saw-toothed. The upper surface of the lens 30 is an upward convex arc surface 33 , and the curvature of the arc surface 33 in the middle of the lens 30 is smaller than that near the side of the lens 30 . The arc surface 33 is in contact with the microstructure 32 on the side of the lens 30 . The center of the curved surface 33 is covered with a reflective layer 34 , and the reflective layer 34 is a layer of high-reflectivity coating film on the direction toward the hole 31 . The size of the reflective layer 34 is slightly larger than the width of the LED chip 40 and blocks the forward light emitting position of the lens 30 . Further, the reflective layer 34 is made of metal with high reflectivity.

The LED chip 40 emits light after being powered on through the two electrodes 41 and 42 , and the light is mainly emitted from the light emitting surface, that is, the upper surface. After the light exits from the light emitting surface of the LED chip 40 , it first passes through the cavity 31 and then enters the lens 30 , the light is refracted at the interface between the cavity 31 and the lens 30 , and the light is bent toward the side of the lens 30 . The reflective layer 34 located directly above the lens 30 blocks the entire LED chip 40 directly above, so even if some light cannot pass through the interface refraction between the hole 31 and the lens 30 and bend to the side of the lens 30, it can still pass through the surface of the reflective layer 34. The reflection bends the light, so that most of the light generated from the LED chip 40 is emitted from the side of the lens 30 , and no forward light passes through the lens 30 . Furthermore, since the side surface of the lens 30 has a plurality of microstructures 32 to roughen the side surface, total reflection is not likely to occur when the light exits from the side surface of the lens 30 .

Referring to FIG. 2 again, a reflective cup 20 is provided to surround the lens 30 . The lens 30 and the LED chip 40 are located at the bottom of the reflection cup 20 . The sidewall of the reflective cup 20 extends slightly obliquely upward from the lower surface of the lens 30 to surround the lens 30 in a cup shape. Two electrodes 41 , 42 of the LED chip 40 protrude from the bottom of the reflective cup 20 to connect to the substrate 43 . The inner wall of the reflective cup 20 is coated with a phosphor layer 21 , and the phosphor layer 21 is arranged around the inner surface of the reflective cup 20 and has different thicknesses at different positions. The phosphor layer 21 is mainly distributed at the position of the reflective cup 20 corresponding to the side of the LED chip 40 , that is, the position corresponding to the side of the lens 30 in this embodiment. Wherein, the phosphor layer 21 forms a protrusion 211 with the largest thickness at the connection position corresponding to the curved surface 33 of the lens 30 and the plurality of microstructures 32 on the side of the lens 30 . The thickness of the phosphor layer 21 extends from the protrusion 211 to the bottom and the top of the reflective cup 20 and gradually becomes thinner. The height of the protrusion 211 is lower than the height of the highest point of the cavity 31 of the lens 30 . Wherein, the phosphor layer 21 extends to the bottom of the reflective cup 20 to the bottom of the reflective cup 20, extends to the top of the reflective cup 20 to the lowest height position of the reflective layer 34 of the reflective cup 20 roughly corresponding to the lens 30, that is, the phosphor The height of the powder layer 21 in the axial direction of the reflective cup 20 is equivalent to the height of the reflective layer 34 in this direction.

When the two electrodes 41 and 42 are energized with the external power supply through the substrate 43, the LED chip 40 emits light, and the light is dispersed to the side of the lens 30 through the lens 30 to emit light, thereby exciting the phosphor layer 21 distributed near the side of the lens 30. Part of the light emitted through the lens 30 is converted by the phosphor layer 21 to change color, and the other part of the light is directly reflected by the reflective cup 20 without interacting with the phosphor layer 21 after passing through the phosphor layer 21 . The light converted in color by the phosphor layer 21 is mixed with the light not converted by the phosphor layer 21 , and exits through the opening of the reflective cup 20 . Since the light emitted by the LED chip 40 is changed to the direction where the phosphor layer 21 is distributed through the lens 30, the phosphor layer 21 can be better excited and mixed, which can effectively improve the problem of uneven color of the emitted light. And at the position where the light is the strongest (that is, at the connection position between the curved surface 33 of the lens 30 and the side surface with a plurality of microstructures 32), the coating of the phosphor layer 21 has the maximum thickness, which can further improve the excitation efficiency and Brightness of light. Moreover, the height of the fluorescent powder layer 21 in the axial direction of the reflective cup 20 is equivalent to the height of the reflective layer 34 in this direction, that is, only the part that can be directly irradiated by light is coated with the fluorescent powder layer 21, then it can be The phosphor layer 21 is saved.

Please refer to FIG. 4 again, which shows an LED lighting device 200 according to a second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the LED lighting device 200 does not include a lens 30 . In addition, the cross section of the reflective layer 34 a has a hump-shaped undulation, which includes two peaks, and the trough in the middle of the two peaks is located on the forward optical axis of the LED chip 40 . Since the forward light output of the LED chip 40 is strong, the design of the trough of the reflective layer 34a located on the forward optical axis of the LED chip 40 can effectively avoid the back and forth reflection problem of vertical light irradiation and vertical reflection that may occur on the optical axis . Of course, the reflective layer 34 a may also include other even-numbered peaks, and the middle trough of these peaks is located on the forward optical axis of the LED chip 40 . The height of the reflective layer 34a in the axial direction of the reflective cup 20 is equivalent to the height of the phosphor layer 21 in this direction. The reflective layer 34a is fixed directly above the LED chip 40 through a bracket (not shown) or other connection means. The reflective layer 34a blocks the forward light-emitting surface of the LED chip 40, and reflects the light emitted by the LED chip 40 to the side, thereby exciting the phosphor layer distributed at the position of the reflective cup 20 corresponding to the side of the LED chip 40. twenty one. The light emitted by the excited phosphor layer 21 is mixed with the original light emitted by the LED chip 40 , and then reflected by the reflective cup 20 and emitted to the opening of the reflective cup 20 . The LED lighting device 200 of this embodiment can also effectively improve the problem of uneven color of emitted light.

Claims (8)

1. a LED light emission device, comprise LED chip, reflector and phosphor powder layer, it is characterized in that: this LED light emission device also comprises reflector, the forward exiting surface of this LED chip is blocked in this reflector, this reflector is around this LED chip and this reflector, this phosphor powder layer is coated on the inner surface of this reflector, the light of LED chip forward direction transmission is laterally reflexed to phosphor powder layer by this reflector, along the axis of this reflector, this phosphor powder layer is unequal at the thickness at reflector inner surface diverse location place, the position that this phosphor powder layer corresponds to these reflector outer peripheral edges forms the maximum projection of a thickness, the thickness of this phosphor powder layer from this projection towards the bottom of reflector and top thinning gradually.

2. LED light emission device as claimed in claim 1, is characterized in that: this phosphor powder layer is distributed in the position of the corresponding LED chip side of reflector.

3. LED light emission device as claimed in claim 1, it is characterized in that: also comprise lens, these lens comprise end face, side and bottom surface, these lens cover the exiting surface of this LED chip, this reflector covers the center position of end face, this reflector is around these lens, and the inner surface that this phosphor powder layer is coated on this reflector is to should the position of side of lens.

4. LED light emission device as claimed in claim 3, is characterized in that: described projection is positioned at this phosphor powder layer to should the end face of lens and the Side attachment locations place of lens.

5. LED light emission device as claimed in claim 3, it is characterized in that: this lens interior has a hole be recessed to form to this end face from its bottom surface, this LED chip is contained in this hole, and the height of this projection is lower than the height of the peak in the hole of lens.

6. LED light emission device as claimed in claim 3, is characterized in that: the side of these lens has multiple micro-structural.

7. LED light emission device as claimed in claim 5, is characterized in that: this hole is a half elliptic, and its long axis direction is parallel with the vertical direction of lens, and its minor axis length is not more than the width of this LED chip.

8. LED light emission device as claimed in claim 1, is characterized in that: the tangent plane in this reflector be hump shape fluctuating, and the middle trough in this reflector is positioned on the forward optical axis of LED chip.