Light-emitting device

• US 20050099808A1
• Filed: 11/12/2003
• Published: 05/12/2005
• Est. Priority Date: 11/12/2003
• Status: Abandoned Application

• Current Assignee: June Pin Cheng, Kun-Chui Lee, Tzu Chi Cheng
• Original Assignee: June Pin Cheng, Kun-Chui Lee, Tzu Chi Cheng
• Inventors: Lee, Kun-Chui, Cheng, June Pin, Cheng, Tzu Chi
• Application Number:
  US10/705,508
• Publication Number:
  US 20050099808A1
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/502 Wavelength conversion materials

Abstract

A light-emitting device comprises at least one blue light emitting diode as a blue light source; at least one red light emitting diode as a red light source; and a fluorescent layer formed by mixing fluorescent powders with transparent resin; the fluorescent layer being glued to the blue light emitting diode and the red light emitting diode; the blue light emitting diode and the red light emitting diode emitting lights of different colors which are then mixed; the blue light being used to excite the fluorescent layer to emit light with wavelengths different from the blue light and red light. In another structure, a fluorescent layer is formed by mixing fluorescent powders with transparent resin; and the fluorescent layer encloses the blue light emitting diode. A transparent resin layer encloses the fluorescent layer and red light emitting diode.

Claims

1. A light-emitting device comprising:

at least one blue light emitting diode as a blue light source;

at least one red light emitting diode as a red light source; and

a fluorescent layer formed by mixing fluorescent powders with transparent resin;

the fluorescent layer being glued to the blue light emitting diode and the red light emitting diode;

the blue light emitting diode and the red light emitting diode emitting blue light and red light, respectively, which are then mixed;

the fluorescent layer absorbing radiation having a blue light to emit light with wavelengths different from the blue light and red light.

2. The light-emitting device as claimed in claim 1, wherein the light emitted from the fluorescent layer due to the excitation of the blue and red light is mixed with the red light and the blue light so as to present white light.

3. The light-emitting device as claimed in claim 1, wherein the wavelength of the light from the fluorescent layer is between 500 and 585 nm.

4. The light-emitting device as claimed in claim 1, wherein the blue light from the blue light emitting diode has a wavelength between 360 and 480 nm and the red light from the red light emitting diode is between 585 and 780 nm.

5. The light-emitting device as claimed in claim 1, wherein the fluorescent powders of the fluorescent layer 30 are selected from one of Yttrium Aluminium Garnet, and SmOn4−

, and BxOy3−

.

6. The light-emitting device as claimed in claim 1, wherein the blue light emitting diode and red light emitting diode are connected to a recess in a reflecting cover;

the fluorescent layer is filled in the recess.

7. The light-emitting device as claimed in claim 1, wherein the blue light emitting diode and red light emitting diode are connected to a groove above a main lead frame;

and the fluorescent layer is filled in the groove.

8. The light-emitting device as claimed in claim 1, wherein material of the fluorescent powders of the fluorescent layer is selected from one of a follow group containing YAG (yttrium aluminum garnet) activated by cerium and containing Y (yttrium) and Al (Aluminum) (YAG:

Ce³⁺);

YAG activated by europium (YAG;

Eu²⁺/Eu³⁺); and

YAG activated by Terbium (YAG;

Tb3⁺) and the combination thereof.

9. A light-emitting device comprising:

at least one blue light emitting diode as a blue light source;

at least one red light emitting diode as a red light source;

a fluorescent layer formed by mixing fluorescent powders with transparent resin; and

the fluorescent layer enclosing the blue light emitting diode; and

a transparent resin layer enclosing the fluorescent layer and red light emitting diode;

the blue light emitted from the blue light emitting diode stimulating the fluorescent layer to emit light with wavelengths different from the blue light and red light;

the light emitted from the transparent resin layer so that the light from the fluorescent layer is mixed with blue light and red light to present light of another color.