Light emitting device including optical lens

• US 8,487,525 B2
• Filed: 05/02/2008
• Issued: 07/16/2013
• Est. Priority Date: 05/04/2007
• Status: Expired due to Fees

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Lee, Chung Hoon
• Primary Examiner(s): Williams, Joseph L
• Application Number:
  US12/598,891
• Publication Number:
  US 20100141109A1
• Time in Patent Office: 1,901 Days
• Field of Search: 313498-512
• US Class Current: 313/501
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7731 with alkaline earth metals
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/77344 Aluminosilicates
• CPC Class Codes: C09K 11/77347 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence

Abstract

According to the present invention, there is provided a light emitting device that includes at least one laser diode configured to emit light in at least one first wavelength region selected from spectrum regions including ultraviolet light, blue light, and green light; and a light emitting material for emitting light in a second wavelength region by the light emitted from the laser diode, the second wavelength region being different from the first wavelength region. A color-mixed light is made by the light in the first wavelength region and the light in the second wavelength region. Since the laser diode is used as a light emission source, the color-mixed light implemented by the light emitting device has high linearity, so that it may be effectively used for long-distance illumination and flash.

Claims

1. A light emitting device, comprising:

a substrate comprising a recessed region formed in an upper surface thereof;

a laser diode disposed in the recessed region and configured to emit ultraviolet light, blue light, or green light;

a first layer disposed over the laser diode and comprising a first light emitting material configured to emit light of a first wavelength when excited by the light emitted from the laser diode, and

an optical lens disposed on the substrate and configured to support the first layer,

wherein the first layer extends laterally only within the perimeter of the recessed region.

2. The light emitting device of claim 1, wherein the light emitting material comprises a compound containing copper as a host lattice component.

3. The light emitting device of claim 2, wherein the light emitting material comprises a material represented by a Chemical Formula of

a(M^IO).b(M^IIO).c(M^IIIA).d(M^III₂O).e(M^IV₂O₃).f(M^V_oO_p).g(SiO₂).h(M^VI_xO_y)

where M^I comprises at least one element selected from the group consisting of Pb and Cu;

M^II comprises at least one element selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn, Cd and Mn;

M^III comprises at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Au and Ag;

M^IV comprises at least one element selected from the group consisting of Al, Ga and In;

M^V comprises at least one element selected from the group consisting of Ge, V, Nd, Ta, W, Mo, Ti, Zr and Hf;

M^VI comprises at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu;

A comprises at least one element selected from the group consisting of F, CI, Br and I; and

a, b, c, d, e, f, g, h, o, p, x and y are set in ranges of 0≦

a≦

2, 0≦

b≦

8, 0≦

c≦

4, 0≦

d≦

2, 0≦

e≦

2, 0≦

f≦

2, 0≦

g≦

10, 0≦

h≦

5, 1≦

o≦

2, 1≦

p≦

5, 1≦

x≦

2 and 1≦

y≦

5, respectively.

4. The light emitting device of claim 3, wherein the light emitting material comprises a material represented by a Chemical Formula of

((Br,Sr,Ca)₁₋

x,(Pb,Cu)_x)₂SiO₄;

Eu,B

where B comprises at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu;

x is set in a range from 0 to 1; and

Eu and B are set in a range from 0 to 0.2.

5. The light emitting device of claim 1, wherein the light emitting material comprises at least one selected from the group consisting of sulfide, nitride, oxynitride, thiogallate, silicate, orthosilicate, and garnet.

6. The light emitting device of claim 1, wherein the substrate comprises a heat sink and a lead terminal.

7. The light emitting device of claim 1, wherein the first layer is disposed on the lower or upper surface of the optical lens.

8. The light emitting device of claim 7, further comprising a second layer disposed on the first layer and comprises a second light emitting material configured to emit light of a second wavelength when excited by the light emitted from the laser diode.

9. The light emitting device of claim 8, wherein:

the optical lens comprises an optical pattern disposed on the upper surface of the optical lens; and

the first and second layers are disposed on the lower surface of the optical lens.

10. The light emitting device of claim 8, wherein;

the optical lens comprises an optical pattern disposed on the lower surface of the optical lens; and

the first and second layers are disposed on the lower surface of the optical lens.

11. The light emitting device of claim 8, wherein:

the optical lens comprises;

a lower portion disposed on the substrate and comprising an optical pattern disposed on the lower surface thereof; and

an upper portion disposed on the lower portion and comprising an optical pattern disposed on the upper surface thereof; and

the first and second layers are disposed between the upper and lower portions of the optical lens.

12. The light emitting device of claim 11, wherein the first and second layers are disposed within a recessed region formed in the upper surface of the lower portion of the optical lens.

13. The light emitting device of claim 1, further comprising a member to couple the optical lens with the substrate.

14. The light emitting device of claim 8, wherein:

the first layer is disposed between the second layer and the laser diode; and

the first wavelength is longer than the second wavelength.

15. The light emitting device of claim 9, wherein the first and second layers are disposed within a recessed region formed in the lower surface of the optical lens.

16. The light emitting device of claim 10, wherein the first and second layers are disposed within a recessed region formed in the upper surface of the optical lens.

17. The light emitting device of claim 7, wherein the first layer is disposed on the lower surface of the optical lens and substantially covers the recessed region of the substrate.

18. The light emitting device of claim 7, wherein the first layer is disposed on the upper surface of the optical lens and substantially covers the recessed region of the substrate.