White light emitting diode using phosphor excitation

• US 7,382,091 B2
• Filed: 07/27/2005
• Issued: 06/03/2008
• Est. Priority Date: 07/27/2005
• Status: Expired due to Fees

• Current Assignee: Feng-Ku Chien, Lung-Chien Chen, Wen-How Lan
• Original Assignee: Feng-Ku Chien, Lung-Chien Chen, Wen-How Lan
• Inventors: Chen, Lung-Chien, Lan, Wen-How, Chien, Feng-Ku
• Primary Examiner(s): Patel; Ashok
• Application Number:
  US11/190,990
• Publication Number:
  US 20070024191A1
• Time in Patent Office: 1,042 Days
• Field of Search: 313/512, 313/113, 313/114, 362/235, 362/241, 362/242, 362/243, 362/247, 362/307, 362/260, 362/296, 362/297, 362/300, 362/310, 362/311, 362/341, 362/349, 362/351
• US Class Current: 313/512
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A white light emitting diode (LED) is provided, which includes a reflective mirror arranged on the light emitting path of a blue or an ultra violet LED die at an appropriate angle. Phosphors are coated on the reflective mirror, the emitting plane of the LED, or both so that the phosphors are excited by the blue or UV lights emitted by the LED die to produce white lights. The present invention provides a white LED having a long lifetime and a uniform light color by separating the phosphors from the LED die, and by allowing the lights emitted from the LED die to undergo several excitations with the phosphors.

Claims

1. A white light emitting diode using phosphor excitation, comprising:

a circuit board having a positive electrode, a negative electrode, and a light emitting diode die, the light emitting diode die being driven to emit specific color lights when an external voltage is applied onto the positive electrode and the negative electrode;

a reflective mirror arranged on an emitting path of the specific lights emitted by the light emitting diode die at an appropriate inclined angle, first phosphors being coated on an incident plane of the reflective mirror, the first phosphors configured so that white lights are produced by the specific lights'"'"' exciting the first phosphors; and

a cladding encapsulating the circuit board and the reflective mirror therein, lights reflected by the reflective mirror emitting out of the white light emitting diode through a emitting plane of the cladding,

wherein the light emitting diode emits the specific lights to the reflective mirror on the emitting path, and the first phosphors coated on the incident plane of the reflective mirror are excited by the specific lights to generate white lights, and the white lights are reflected by the reflective mirror and then emit through the emitting plane of the cladding.

2. The white light emitting diode using phosphor excitation as claimed in claim 1, wherein the light emitting diode die is one of a blue light emitting diode die and an UV light emitting diode die.

3. The white light emitting diode using phosphor excitation as claimed in claim 1, wherein the appropriate inclined angle of the reflective mirror is set so that an incident angle of the specific lights are between 15°

and 75°

.

4. The white light emitting diode using phosphor excitation as claimed in claim 1, wherein the reflective mirror is one of a metal film reflective mirror coated with a metallic material and a Bragg reflector made from a dielectric material.

5. The white light emitting diode using phosphor excitation as claimed in claim 4, wherein the metal material is selected from the group consisting of gold (Au), aluminum (Al), nickel (Ni), titanium (Ti), and chromium (Cr).

6. The white light emitting diode using phosphor excitation as claimed in claim 1, wherein an inner surface of the emitting plane is coated with second phosphors, and the second phosphors are configured so that white lights are produced by the specific lights'"'"' exciting the second phosphors.

7. A white light emitting diode using phosphor excitation, comprising:

a circuit board having a positive electrode, a negative electrode, and a light emitting diode die, the light emitting diode die being driven to emit specific lights when an external voltage is applied onto the positive electrode and the negative electrode;

a reflective mirror arranged on an emitting path of the specific lights emitted by the light emitting diode die at an appropriate inclined angle; and

a cladding encapsulating the circuit board and the reflective mirror therein, lights reflected by the reflective mirror emitting out of the white light emitting diode through a emitting plane of the cladding, an inner surface of the emitting plane being coated with first phosphors, the first phosphors configured so that white lights are produced by the specific lights'"'"' exciting the first phosphors,

wherein the light emitting diode emits the specific lights to the reflective mirror on the emitting path, and then to the emitting plane when reflected by the reflective mirror, and the first phosphors coated on the inner surface of the emitting plan is excited to generate white lights, and the white lights emits through the emitting plane of the cladding.

8. The white light emitting diode using phosphor excitation as claimed in claim 7, wherein the light emitting diode die is one of a blue light emitting diode die and an UV light emitting diode die.

9. The white light emitting diode using phosphor excitation as claimed in claim 7, wherein the appropriate inclined angle of the reflective mirror is set so that an incident angle of the specific lights is between 15°

and 75°

.

10. The white light emitting diode using phosphor excitation as claimed in claim 7, wherein the reflective mirror is one of a metal film reflective mirror coated with a metal material and a Bragg reflector made from a dielectric material.

11. The white light emitting diode using phosphor excitation as claimed in claim 10, wherein the metal material is selected from the group consisting of gold (Au), aluminum (Al), nickel (Ni), titanium (Ti), and chromium (Cr).

12. The white light emitting diode using phosphor excitation as claimed in claim 7, wherein an incident plane of the reflective mirror is coated with second phosphors, and the second phosphors are configured so that white lights are produced by the specific lights'"'"' exciting the second phosphors.

13. A white light emitting diode using phosphor excitation, comprising:

a circuit board having a positive electrode, a negative electrode, and a light emitting diode die, the light emitting diode die being driven to emit a specific light when an external voltage is applied onto the positive electrode and the negative electrode;

a first reflective mirror having an incident plane coated with first phosphors, the first phosphors configured so that white lights are produced by the specific lights'"'"' exciting the first phosphors;

a second reflective mirror having an incident plane coated with second phosphors, the second phosphors configured so that white lights are produced by the specific lights'"'"' exciting the second phosphors;

a beam splitter arranged on an emitting path of the specific lights emitted by the light emitting diode die at an appropriate inclined angle, the beam splitter allowing part of the specific lights on the emitting path to pass through and proceed toward the first reflective mirror and reflecting part of the specific lights toward the second reflective mirror; and

a cladding encapsulating the circuit board and the reflective mirrors therein, lights reflected by the reflective mirrors emitting out of the white light emitting diode through an emitting plane of the cladding,

wherein the first phosphors coated on the incident plane of the first reflective mirror is excited by the specific lights falling on the first reflective mirror to generate white lights, and the white lights emits through the emitting plane of the cladding after reflected by the first reflective mirror and the beam splitter; and

the second phosphors coated on the incident plane of the second reflective mirror is excited by the specific lights falling on the second reflective mirror to generate white lights, and the white lights emit through the emitting plane of the cladding after reflected by the second reflective mirror and passing through the beam splitter.

14. The white light emitting diode using phosphor excitation as claimed in claim 13, wherein the light emitting diode die is one of a blue light emitting diode die and an UV light emitting diode die.

15. The white light emitting diode using phosphor excitation as claimed in claim 13, wherein the first reflective mirror is one of a metal film reflective mirror coated with a metal material and a Bragg reflector made from a dielectric material.

16. The white light emitting diode using phosphor excitation as claimed in claim 13, wherein the second reflective mirror is one of a metal film reflective mirror coated with a metal material and a Bragg reflector made from a dielectric material.

17. The white light emitting diode using phosphor excitation as claimed in claim 16, wherein the metal material is selected from the group consisting of gold (Au), aluminum (Al), nickel (Ni), titanium (Ti), and chromium (Cr).

18. The white light emitting diode using phosphor excitation as claimed in claim 13, wherein the emitting plane is coated with third phosphors, and the third phosphors are configured so that white lights are produced by the specific lights'"'"' exciting the first phosphors.