TWI591863B - Light-emitting device - Google Patents

Description

Illuminating device

The present invention relates to a light-emitting device, and more particularly to a light-emitting device in which a wavelength conversion layer covers a light upper surface.

A conventional light-emitting device includes a light-emitting diode and a phosphor powder layer, wherein the phosphor powder layer covers the light-emitting diode. However, due to the precipitation relationship, the phosphor powder in the phosphor powder layer generally cannot uniformly cover the light-emitting surface of the light-emitting diode, so that the light emitted from the light-emitting diode cannot be completely converted into a predetermined wavelength, thereby causing the light of the light-emitting device not to be emitted. Uniform phenomenon.

The present invention relates to a light-emitting device. In one embodiment, the problem of uneven light emission of the light-emitting device can be improved.

According to an embodiment of the invention, a lighting device is proposed. The light emitting device comprises a substrate, a light emitting element and a wavelength conversion layer. The light emitting element is disposed on the substrate and has a thickness Tc, a light exiting angle θ, and a light emitting upper surface. The wavelength conversion layer is disposed above the upper surface of the light exit and has a width Wp. The relationship between the thickness Tc, the light exit angle θ, and the width Wp is satisfied: Wp 2 × Tc × tan (θ/2).

According to another embodiment of the present invention, a light emitting device is provided, wherein The center point of the wavelength conversion layer is aligned with the center point of the light emitting element.

According to another embodiment of the present invention, a light emitting device is proposed in which the entire wavelength conversion layer is located above the light outgoing upper surface of the light emitting element.

According to another embodiment of the present invention, a light emitting device is provided, wherein the light emitting element further has a light emitting side surface, and the wavelength converting layer covers the light emitting upper surface and at least a portion of the light emitting side surface of the light emitting element.

According to another embodiment of the present invention, a light-emitting device is proposed in which a wavelength conversion layer covers at least a portion of a light-side side from which a light-emitting angle is covered.

According to another embodiment of the present invention, a light emitting device is proposed in which the outer contour of the wavelength conversion layer is a plane, a curved surface, or a combination thereof.

According to another embodiment of the present invention, a light emitting device is further provided, the light emitting device further comprising a light transmissive layer. The light transmissive layer is disposed on the wavelength conversion layer, and the wavelength conversion layer is located between the light transmissive layer and the light emitting element.

According to another embodiment of the invention, a lighting device is proposed. The light emitting device further includes a light transmissive layer. At least a portion of the light transmissive layer is formed between the wavelength conversion layer and the light outgoing upper surface of the light emitting element.

According to another embodiment of the present invention, a light emitting device is provided, wherein the light emitting element further has a light emitting side surface, and the light transmitting layer covers the light emitting upper surface and the light emitting side surface of the light emitting element.

According to another embodiment of the present invention, a light emitting device is proposed in which a refractive index of a light emitting element is greater than a refractive index of a light transmitting layer, and a refractive index of the light transmitting layer is greater than a refractive index of the wavelength conversion layer.

According to another embodiment of the present invention, a light emitting device is provided, wherein the wavelength conversion layer comprises a first wavelength conversion layer and a second wavelength conversion layer. The second wavelength conversion layer is disposed on the first wavelength conversion layer such that the first wavelength conversion layer is located between the second wavelength conversion layer and the light emitting element, wherein the first wavelength conversion layer and the second wavelength conversion layer have an interface therebetween .

According to another embodiment of the present invention, a light emitting device is provided, wherein the light emitting element further has a light emitting side surface, and the second wavelength converting layer covers the entire first wavelength converting layer and covers the light emitting upper surface and the light emitting side surface of the light emitting element.

100, 200, 300, 400, 500, 600, 700, 800, 900‧‧‧ illuminating devices

110‧‧‧Substrate

120‧‧‧Lighting elements

120s‧‧‧light side

120u‧‧‧Lighting upper surface

Section 120s1‧‧‧

130‧‧‧wavelength conversion layer

130b, 831b‧‧‧ lower surface

130u‧‧‧Outer contour

540‧‧‧Transparent layer

541‧‧‧Part 1

542‧‧‧Part II

831‧‧‧First wavelength conversion layer

8311‧‧‧First color light fluorescent particles

832‧‧‧second wavelength conversion layer

8321‧‧‧Second color light fluorescent particles

8322‧‧‧Part 1

8323‧‧‧Part II

C1, C2‧‧‧ Center

L1‧‧‧Light

N1, n2, n3‧‧‧ refractive index

P1, P2‧‧‧ curve

S1‧‧‧ cross section

S2‧‧‧ interface

Tc‧‧‧ thickness

Wp‧‧‧Width

θ‧‧‧Lighting angle

1 is a cross-sectional view of a light emitting device in accordance with an embodiment of the present invention.

2 is a cross-sectional view of a light emitting device in accordance with another embodiment of the present invention.

3 is a cross-sectional view of a light emitting device in accordance with another embodiment of the present invention.

4 is a cross-sectional view of a light emitting device in accordance with another embodiment of the present invention.

Figure 5 is a cross-sectional view of a light emitting device in accordance with another embodiment of the present invention.

Figure 6 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention.

Figure 7 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention.

Figure 8 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention.

Figure 9 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention.

Fig. 10 is a view showing optical characteristics of a light-emitting device according to an embodiment of the present invention.

1 is a cross-sectional view of a light emitting device in accordance with an embodiment of the present invention. hair The optical device 100 includes a substrate 110, a light emitting element 120, and a wavelength conversion layer 130.

The light emitting element 120 is disposed on the substrate 110. The light emitting element 120 has a thickness Tc, a light exit angle θ, and a light exit upper surface 120u.

The wavelength conversion layer 130 is disposed above the light outgoing upper surface 120u of the light emitting element 120 and has a width Wp. The relationship between the thickness Tc of the light-emitting element 120, the light-emitting angle θ of the light-emitting element 120, and the width Wp of the wavelength conversion layer 130 satisfies the relationship (1).

Due to the design of the relation (1), the light L emitted by the light-emitting element 120 in the range of the light-emitting angle θ can be converted into light having a predetermined wavelength by the wavelength conversion layer 130 to emit light.

As shown in FIG. 1, the center C1 of the wavelength conversion layer 130 is aligned with the center C2 of the light-emitting element 120. Under this design, the width Wp of the wavelength conversion layer 130 only needs to conform to the minimum width Wp in the relation (1) (ie, Wp=2×Tc×tan(θ/2)), so that the light outgoing light L in the light exit angle θ can be converted by the wavelength conversion layer 130, so that the material of the wavelength conversion layer 130 can be saved. Further, when the center C1 of the wavelength conversion layer 130 is aligned with the center C2 of the light-emitting element 120, and the width Wp of the wavelength conversion layer 130 is 2×Tc×tan(θ/2), the wavelength conversion layer 130 is opposite to the center C1. The symmetrical structure allows the light outgoing rays L in the range of the light extraction angles +θ/2 and -θ/2 to be converted by the wavelength conversion layer 130.

In this embodiment, the entire wavelength conversion layer 130 is located above the light outgoing upper surface 120u of the light emitting element 120. The embodiments of the present invention are not limited thereto, and the following are exemplified.

2 is a cross-sectional view of a light emitting device in accordance with another embodiment of the present invention. The light emitting device 200 includes a substrate 110, a light emitting element 120, and a wavelength conversion layer 130. Different from the light-emitting device 100 of the above embodiment, the light-emitting element 120 of the present embodiment further has a light-emitting side surface 120s, and the wavelength conversion layer 130 covers a portion of the light-emitting upper surface 120u and the light-emitting side surface 120s of the light-emitting element 120. Preferably, but not limited to, the wavelength conversion layer 130 covers at least the portion 120s1 covered by the light extraction angle θ of the light side surface 120s.

3 is a cross-sectional view of a light emitting device in accordance with another embodiment of the present invention. The light emitting device 300 includes a substrate 110, a light emitting element 120, and a wavelength conversion layer 130. Different from the light-emitting device 200 of the above embodiment, the wavelength conversion layer 130 of the present embodiment covers the light-emitting upper surface 120u of the light-emitting element 120 and the entire light-emitting side surface 120s.

In the above embodiment, the outer contour of the wavelength conversion layer 130 is exemplified by a plane. However, the outer contour of the wavelength conversion layer 130 may also be a curved surface or a combination of a curved surface and a plane, which is exemplified below.

4 is a cross-sectional view of a light emitting device in accordance with another embodiment of the present invention. The light emitting device 400 includes a substrate 110, a light emitting element 120, and a wavelength conversion layer 130. Different from the light-emitting devices 100, 200 and 300 of the above embodiment, the wavelength conversion layer 130 of the present embodiment has an outer contour 130u which is a curved surface such as a curved surface. In another embodiment, the outer contour 130u of the wavelength conversion layer 130 may also be a combination of a curved surface and a plane.

In this embodiment, the width Wp of the wavelength conversion layer 130 is defined as the outer contour width of the cross-sectional shape of the wavelength conversion layer 130 along a transverse plane S1, where The cross section S1 is coplanar with the light exit upper surface 120u. In this embodiment, the wavelength conversion layer 130 covers the entire light-emitting side 120s of the light-emitting element 120. In another embodiment, the wavelength conversion layer 130 of FIG. 4 covers a portion of the light-emitting side 120s of the light-emitting element 120 or does not cover the light-emitting element 120 at all. The light side is 120s.

Figure 5 is a cross-sectional view of a light emitting device in accordance with another embodiment of the present invention. The light emitting device 500 includes a substrate 110, a light emitting element 120, a wavelength conversion layer 130, and a light transmissive layer 540. The light-emitting element 120 is disposed above the light-emitting upper surface 120u of the substrate 110, and the light-transmitting layer 540 is disposed above the wavelength conversion layer 130, and the wavelength conversion layer 130 is located between the light-transmitting layer 540 and the light-emitting element 120. The light extraction efficiency of the light-emitting device 500 can be improved by designing the light transmittance and/or the refractive index of the light-transmitting layer 540.

Figure 6 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention. The light emitting device 600 includes a substrate 110, a light emitting element 120, a wavelength conversion layer 130, and a light transmissive layer 540. The light-transmitting layer 540 of the present embodiment includes a first portion 541 and a second portion 542. The first portion 541 is formed between the light-emitting element 120 and the wavelength conversion layer 130 to cover the light-emitting upper surface 120u and the wavelength conversion layer 130 of the light-emitting element 120. The lower surface 130b covers the portion other than the lower surface 130b of the wavelength conversion layer 130 and the light exiting surface 120s of the light emitting element 120. The light transmissive layer 540 covers the entire wavelength conversion layer 130 and a portion of the light emitting elements 120.

Figure 7 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention. The light emitting device 700 includes a substrate 110, a light emitting element 120, a wavelength conversion layer 130, and a light transmissive layer 540. The entire light transmissive layer 540 of the present embodiment is formed between the wavelength conversion layer 130 and the light outgoing upper surface 120u of the light emitting element 120. In addition, the light emitting element 120 has There is a refractive index n1, the light transmissive layer 540 has a refractive index n2, and the wavelength conversion layer 130 has a refractive index n3, wherein the refractive indices n1, n2, and n3 satisfy the relationship (2). Since the refractive indices n1, n2 and n3 are gradually changed from large to small, the refractive angle of the light is gradually changed from small to large, so that the divergence of the light can be relatively uniform.

N1>n2>n3.............................(2)

In one embodiment, the refractive index n1 of the light-emitting element 120 is about 1.7, the refractive index n2 of the light-transmitting layer 540 is about 1.6, and the refractive index n3 of the wavelength conversion layer 130 is about 1.53. In terms of materials, the material of the light transmissive layer 540 includes glass, polycarbonate (Polycarbonate, PC), polymethylmethacrylate (PMMA), methyl methacrylate (MS) or polystyrene. (PS) or silicone, and the wavelength conversion layer 130 comprises a polymer and a phosphor, wherein the polymer is, for example, silicone. However, as long as the materials of the light-emitting element 120, the light-transmitting layer 540 and the wavelength conversion layer 130 are selected to conform to the refractive index relationship of the above relationship (2), the embodiment of the present invention does not limit the light-emitting element 120 and the light-transmitting layer 540. The material of the wavelength conversion layer 130 is selected.

Figure 8 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention. The light emitting device 800 includes a substrate 110, a light emitting element 120, a first wavelength conversion layer 831, and a second wavelength conversion layer 832. In this embodiment, the first wavelength conversion layer 831 is formed above the light-emitting upper surface 120u of the light-emitting element 120, and the second wavelength conversion layer 832 is disposed above the first wavelength conversion layer 831, so that the first wavelength conversion layer 831 is located at the second wavelength conversion layer 831. The wavelength conversion layer 832 is between the light emitting element 120 and the light emitting element 120. The first wavelength conversion layer 831 and the second wavelength conversion layer 832 are two independent wavelength conversion layers, so that the two are combined Thereafter, a distinct interface S2 is formed therebetween.

In this embodiment, different color light fluorescent particles are respectively doped to different wavelength conversion layers. For example, the first wavelength conversion layer 831 includes a plurality of first color light fluorescent particles 8311, and the second wavelength conversion layer 832 includes a plurality of second color light fluorescent particles 8321, wherein the first color light fluorescent particles 8311 and the second The colored fluorescent particles 8321 are respectively different colored fluorescent particles. In one embodiment, the first color light fluorescent particles 8311 and the second color light fluorescent particles 8321 are, for example, green, red or yellow fluorescent particles. If the first color light fluorescent particles 8311 and the second color light fluorescent particles 8321 are doped into the same wavelength conversion layer, the color lights converted by the first color light fluorescent particles 8311 and the second color light fluorescent particles 8321 are mutually absorbed. In turn, the light conversion efficiency is lowered, or more fluorescent particles need to be doped to be converted into a preset color light. Since the phosphor particles of different color lights are respectively doped to different wavelength conversion layers in this embodiment, the problem that the phosphor particles of different color lights absorb each other can be avoided, thereby improving the light conversion efficiency and/or reducing the doped fluorescent particles. The amount used.

Figure 9 is a cross-sectional view showing a light emitting device in accordance with another embodiment of the present invention. The light emitting device 900 includes a substrate 110, a light emitting element 120, a first wavelength conversion layer 831, and a second wavelength conversion layer 832. The second wavelength conversion layer 832 covers the entire first wavelength conversion layer 831 and covers the light-emitting upper surface 120u and the light-emitting side surface 120s of the light-emitting element 120. Further, different from the illuminating device 800 of the above embodiment, the second wavelength converting layer 832 of the embodiment includes a first portion 8322 and a second portion 8323, wherein the first portion 8322 is formed on the illuminating element 120 and the first wavelength conversion Between the layers 831 to cover the light-emitting upper surface 120u and the first wave of the light-emitting element 120 The lower surface 831b of the long conversion layer 831, and the second portion 8323 covers a portion other than the lower surface 831b of the first wavelength conversion layer 831 and the light exit side 120s of the light emitting element 120. Since the second portion 8323 covers the entire light-emitting side surface 120s, the light L emitted from any portion of the light-emitting side surface 120s can be converted by the second wavelength conversion layer 832.

Fig. 10 is a view showing optical characteristics of a light-emitting device according to an embodiment of the present invention. The curve P1 represents the optical characteristic curve of the conventional light-emitting device, and the curve P2 represents the optical characteristic curve of the light-emitting device 100 of the above embodiment. Compared with the curve P1, due to the design of the above formula (1), the color temperature of the light-emitting ray L in the range of the light-emitting angle θ of the light-emitting device 100 of the present embodiment is relatively uniform, that is, the light beam L emitted from the light-emitting angle θ. Produces a uniform light output. The illuminating device of other embodiments of the present invention also has optical characteristics similar to those of the illuminating device 100, and will not be described again.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧Lighting device

110‧‧‧Substrate

120‧‧‧Lighting elements

120u‧‧‧Lighting upper surface

130‧‧‧wavelength conversion layer

C1, C2‧‧‧ Center

L‧‧‧Light

Tc‧‧‧ thickness

Wp‧‧‧Width

θ‧‧‧Lighting angle

Claims (11)

A light-emitting device comprising: a substrate; a light-emitting element disposed on the substrate and having a thickness Tc, a light-emitting angle θ, and a light-emitting upper surface; and a wavelength conversion layer disposed above the light-emitting upper surface and having a a width Wp; wherein the relationship between the thickness Tc, the light exit angle θ, and the width Wp is satisfied: Wp 2 × Tc × tan (θ/2). The illuminating device of claim 1, wherein a center point of the wavelength conversion layer is aligned with a center point of the illuminating element. The illuminating device of claim 1, wherein the entire wavelength conversion layer is located above the light outgoing upper surface of the illuminating element. The light-emitting device of claim 1, wherein the light-emitting element further has a light-emitting side surface, the wavelength conversion layer covering the light-emitting upper surface of the light-emitting element and at least a portion of the light-emitting side surface. The light-emitting device of claim 4, wherein the wavelength conversion layer covers at least a portion of the light-emitting side covered by the light-emitting angle. The illuminating device of claim 1, wherein the outer contour of the wavelength conversion layer is a plane, a curved surface or a combination thereof. The illuminating device of claim 1, further comprising: a light transmissive layer disposed on the wavelength conversion layer, wherein the wavelength conversion layer is located between the light transmissive layer and the illuminating element. The light-emitting device of claim 1, further comprising: a light transmissive layer, at least a portion of the light transmissive layer being formed between the wavelength conversion layer and the light-emitting upper surface of the light-emitting element. The light-emitting device of claim 8, wherein the light-emitting element further has a light-emitting side surface, and the light-transmitting layer covers the light-emitting upper surface and the light-emitting side surface of the light-emitting element. The light-emitting device of claim 9, wherein the light-emitting element has a refractive index greater than a refractive index of the light-transmitting layer, and a refractive index of the light-transmitting layer is greater than a refractive index of the wavelength-converting layer. The illuminating device of claim 1, wherein the wavelength conversion layer comprises: a first wavelength conversion layer; a second wavelength conversion layer disposed on the first wavelength conversion layer, the first wavelength conversion layer being located between the second wavelength conversion layer and the light emitting element; wherein the first wavelength conversion layer and the second There is an interface between the wavelength conversion layers.