Light emitting device having various color temperature

• US 7,679,281 B2
• Filed: 03/19/2008
• Issued: 03/16/2010
• Est. Priority Date: 03/19/2007
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Choi, Hyuck Jung, Kim, Do Hyung
• Primary Examiner(s): Vu; David Hung
• Application Number:
  US12/051,637
• Publication Number:
  US 20080231214A1
• Time in Patent Office: 727 Days
• Field of Search: 257/88, 257/89, 257/98, 257/E33.061, 257/E33.055, 313/498, 313/501, 313/502, 313/503, 313/504, 313/505, 315/246, 315/291, 362/84, 362/800
• US Class Current: 313/501
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: A61N 2005/0662 Visible light
• CPC Class Codes: A61N 5/0618 Psychological treatment
• 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: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/40 Details of LED load circuits

Abstract

A light emitting device capable of emitting light having various color temperatures is disclosed. The light emitting device includes a first light emitting part emitting a daylight color having a color temperature of 6000 K or more, a second light emitting part emitting white light having a color temperature less than 6000 K, and a third light emitting part emitting light in a visible range of 580 nm or more. The second and third light emitting parts are operable independently of the first light emitting part, and realize a warm white color having a color temperature of 3000 K or less with the white light emitted from the second light emitting part and the light emitted from the third light emitting part. The light emitting device realizes white light of various spectra and color temperatures corresponding to desired mood and utility. The light emitting device is controlled to emit light having a suitable wavelength or a suitable color temperature depending on the circadian rhythm of human, thereby enabling improvement of the user'"'"'s health.

Claims

1. A light emitting device, comprising:

a first light emitting part comprising a first LED chip and a first phosphor, and emitting a daylight color having a color temperature of 6000 K or more;

a second light emitting part comprising a second LED chip and a second phosphor, and emitting white light having a color temperature less than 6000 K;

a third light emitting part comprising a third LED chip and emitting light in a visible range of 580 nm or more,

wherein the second and third light emitting parts are operable independently of the first light emitting part, and realize a warm white color having a color temperature of 3000 K or less with the white light emitted from the second light emitting part and the light emitted from the third light emitting part.

2. The light emitting device according to claim 1, wherein the first or second light emitting part comprises a phosphor represented by the following Chemical Formula 1:

a(M^I O).b(M^II ₂O).c(M^II X).dAl₂O₃.e(M^III O).f(M^IV₂O₃).g(M^V_oO_p).h(M^VI_xO_y) 

 

<

Chemical Formula 1>

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

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

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

M^IV is at least one selected from the group consisting of Sc, B, Ga, and In;

M^V is at least one selected from the group consisting of Si, Ge, Ti, Zr, Mn, V, Nb, Ta, W, and Mo;

M^VI is at least one 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;

X is at least one selected from the group consisting of F, Cl, Br, and I; and

a, b, c, d, e, f, g, o, p, h, x, and y are respectively set in the ranges of;

0<

a≦

2, 0≦

b≦

2, 0≦

c≦

2, 0d≦

8, 0≦

e≦

4, 0≦

f≦

3, 0g≦

8, 1≦

o≦

2, 1≦

p≦

5, 0h≦

2, 1≦

x≦

2, and 1≦

y≦

5).

3. The light emitting device according to claim 1, wherein the first or second light emitting part comprises a phosphor represented by the following Chemical Formula 2:

a(M^I O).b(M^II₂O).c(M^II X).(4−

a−

b−

c)(M^III O).7(Al₂O₃).d(B₂O₃).e(Ga₂O₃).f(SiO₂).g(GeO₂).h(M^IV_xO_y) 

 

<

Chemical Formula 2>

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

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

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

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

X is at least one selected from the group consisting of F, Cl, Br, and I; and

a, b, c, d, e, f, g, h, x, and y are respectively set in the ranges of;

0<

a≦

4, 0≦

b≦

2, 0≦

c≦

2, 0≦

d≦

1, 0≦

e≦

1, 0≦

f≦

1, 0≦

g≦

1, 0<

h≦

0.5, 1≦

x≦

2, and 1≦

y≦

5).

4. The light emitting device according to claim 1, wherein the first or second light emitting part comprises a phosphor represented by the following Chemical Formula 3:

a(M^I O).b(M^II O).cAl₂O₃.d(M^III ₂O₃).e(M^IVO₂).f(M^V _xO_y) 

 

<

Chemical Formula 3>

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

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

M^III is at least one selected from the group consisting of B, Ga, and In;

M^IV is at least one selected from the group consisting of Si, Ge, Ti, Zr, and Hf;

M^V is at least one 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; and

a, b, c, d, e, f, x, and y are respectively set in the ranges of;

0<

a≦

1, 0≦

b≦

2, 0<

c≦

8, 0≦

d≦

1, 0≦

e≦

1, 0<

f≦

2, 1≦

x≦

2, and 1≦

y≦

5).

5. The light emitting device according to claim 1, wherein the first or second light emitting part comprises a phosphor represented by the following Chemical Formula 4:

a(M^I O).b(M^II O).c(M^III X).d(M^III₂O).e(M^IV ₂O₃).f(M^V_oO_p).g(SiO₂).h(M^VI_xO_y) 

 

<

Chemical Formula 4>

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

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

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

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

M^V is at least one selected from the group consisting of Ge, V, Nb, Ta, W, Mo, Ti, Zr, Hf, and P;

M^VI is at least one 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;

X is at least one selected from the group consisting of F, Cl, Br, and I; and

a, b, c, d, e, f, g, h, o, p, x, and y are respectively set in the 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).

6. The light emitting device according to claim 1, wherein the first or second light emitting part comprises a phosphor represented by the following Chemical Formula 5:

a(M^I O).b(M^II₂O).c(M^II X).d(Sb₂O₅).e(M^III O).f(M^IV_xO_y) 

 

<

Chemical Formula 5>

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

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

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

M^IV is at least one selected from the group consisting of Bi, Sn, Sc, Y, La, Pr, Sm, Eu, Tb, Dy, and Gd;

X is at least one selected from the group consisting of F, Cl, Br, and I; and

a, b, c, d, e, f, x, and y are respectively set in the ranges of;

0<

a≦

2, 0≦

b≦

2, 0≦

c≦

4, 0<

d≦

8, 0≦

e≦

8, 0≦

f≦

2, 1≦

x≦

2, and 1≦

y≦

5).

7. The light emitting device according to claim 1, wherein the first or second light emitting part comprises a phosphor represented by the following Chemical Formula 6:

a(M^I O).b(M^II₂O).c(M^II X).dGeO₂. e(M^III O).f(M^IV₂^O₃).g(M^V_oO_p).h(M^VI_xO_y) 

 

<

Chemical Formula 6>

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

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

M^III is at least one selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn, and Cd;

M^IV is at least one selected from the group consisting of Sc, Y, B, Al, Ga, In, and La;

M^V is at least one selected from the group consisting of Si, Ti, Zr, Mn, V, Nb, Ta, W, and Mo;

M^VI is at least one selected from the group consisting of Bi, Sn, Pr, Sm, Eu, Gd, and Dy;

X is at least one selected from the group consisting of F, Cl, Br, and I; and

a, b, c, d, e, f, g, h, o, p, x, and y are respectively set in the ranges of;

0<

a≦

2, 0≦

b≦

2, 0≦

c≦

10, 0<

d≦

10, 0≦

e≦

14, 0≦

f≦

14, 0≦

g≦

10, 0≦

h≦

2, 1≦

o≦

2, 1≦

p≦

5, 1≦

x≦

2, and 1≦

y≦

5).

8. The light emitting device according to claim 1, wherein the first or second light emitting part comprises a phosphor represented by the following Chemical Formula 7:

a(M^I O).b(M^II₂O).c(M^II X).dP₂O₅.e(M^III O).f(M^IV₂O₃).g(M^V O₂).h(M^VI_xO_y) 

 

<

Chemical Formula 7>

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

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

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

M^IV is at least one selected from the group consisting of Sc, Y, B, Al, La, Ga, and In;

M^V is at least one selected from the group consisting of Si, Ge, Ti, Zr, Hf, V, Nb, Ta, W, and Mo;

M^VI is at least one selected from the group consisting of Bi, Sn, Pr, Sm, Eu, Gd, Dy, Ce, and Tb;

X is at least one selected from the group consisting of F, Cl, Br, and I; and

a, b, c, d, e, f, g, h, x, and y are respectively set in the ranges of;

0<

a≦

2, 0≦

b≦

12, 0≦

c≦

16, 0<

d≦

3, 0≦

e≦

5, 0≦

f≦

3, 0≦

g≦

2, 0≦

h≦

2, 1≦

x≦

2, and 1≦

y≦

5).

9. The light emitting device according to claim 1, wherein the first or second light emitting part comprises a plurality of phosphors.

10. The light emitting device according to claim 1, wherein the first and second LED chips emit blue or UV light.

11. The light emitting device according to claim 1, further comprising:

a controller to control voltage applied to at least one of the first, second, and third light emitting parts.

12. The light emitting device according to claim 11, wherein the controller adjusts the externally input voltage according to time.

13. The light emitting device according to claim 12, wherein the controller adjusts the externally input voltage on a 24-hour cycle.

14. The light emitting device according to claim 1, wherein the first to third light emitting parts are formed in a single package.

15. The light emitting device according to claim 14,

wherein the package comprises a substrate upon which the first to third light emitting parts are mounted, and

wherein the phosphors of the first and second light emitting parts are disposed above the first and second LED chips, respectively.

16. The light emitting device according to claim 14,

wherein the package further comprises a heat sink to dissipate heat generated from the LED chips,

wherein the first to third LED chips are disposed above the heat sink, and

wherein the phosphors of the first and second light emitting parts are disposed above the first and second LED chips, respectively.

17. The light emitting device according to claim 14, wherein the second light emitting part is disposed nearer a center of the package than the first and third light emitting parts.

18. A light emitting device, comprising:

a first light emitting part comprising a first LED chip and a first phosphor, and emitting white light having a higher color temperature;

a second light emitting part comprising a second LED chip and a second phosphor, and emitting white light having a lower color temperature; and

a third light emitting part including a third LED chip emitting light in a visible range of 580 nm or more,

wherein the second and third light emitting parts are operable independently of the first light emitting part, and realize a warm white color having a color temperature of 3000 K or less with the white light emitted from the second light emitting part and the light emitted from the third light emitting part.