Light-emitting device

• US 8,901,811 B2
• Filed: 08/27/2013
• Issued: 12/02/2014
• Est. Priority Date: 08/27/2012
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Yao, Chiu-Lin, Hsu, Ming-Chi, Liaw, Been-Yu
• Primary Examiner(s): WALFORD, NATALIE K
• Application Number:
  US14/011,242
• Publication Number:
  US 20140055980A1
• Time in Patent Office: 462 Days
• Field of Search: None
• US Class Current: 313/501
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 19/003 Fastening of light source holders, e.g. of circuit boards or substrates holding light sources
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21Y 2113/10 of different colours
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An embodiment of the present invention discloses a light-emitting device including a first light source, a second light source, and an optical element. The first light source is configured to emit a first light at a first low temperature and a first high temperature, and has a first hot/cold factor. The second light source is configured to emit a second light at the first low temperature and the first high temperature, and has a second hot/cold factor. The optical element is configured to generate a third light by the excitation of the first light, and reach a second high temperature higher than the first high temperature under the irradiation of the first light.

Claims

1. A light-emitting device, comprising:

a first light source configured to emit a first light at a first low temperature and a first high temperature, and has a first hot/cold factor;

a second light source configured to emit a second light at the first low temperature and the first high temperature, and has a second hot/cold factor; and

an optical element configured to generate a third light by an irradiation of the first light, and reach a second high temperature higher than the first high temperature under the irradiation of the first light.

2. The light-emitting device of claim 1, wherein the first light, the second light, and the third light can be mixed into a mixed light which has chromaticity coordinate differences of (Δ

x, Δ

y) between the first low temperature and the first high temperature, wherein Δ

y/Δ

x>

−

0.2.

3. The light-emitting device of claim 1, wherein the first light, the second light, and the third light can be mixed into a mixed light which has a first chromaticity coordinate point at the first low temperature and a second chromaticity coordinate point at the first high temperature, wherein the first chromaticity coordinate point and the second chromaticity coordinate point are located on two sides of a black-body radiation curve.

4. The light-emitting device of claim 1, wherein the first light, the second light, and the third light can be mixed into a mixed light which has a first chromaticity coordinate point at the first low temperature and a second chromaticity coordinate point at the first high temperature, wherein the first chromaticity coordinate point and the second chromaticity coordinate point are located on the same side of a black-body radiation curve.

5. The light-emitting device of claim 1, wherein the first light, the second light, and the third light can be mixed into a mixed light which has a first chromaticity coordinate point at the first low temperature and a second chromaticity coordinate point at the first high temperature, a line from the first chromaticity coordinate point to the second chromaticity coordinate point is substantially parallel to a black-body radiation curve.

6. The light-emitting device of claim 1, wherein the first light, the second light, and the third light can be mixed into a mixed light which has a first correlated color temperature at the first low temperature and a second correlated color temperature at the first high temperature which is greater than the first correlated color temperature.

7. The light-emitting device of claim 1, wherein κ

difference between the first high temperature and the second high temperature is of 30°

C.˜

40°

C.

8. The light-emitting device of claim 1, therein the first light comprises a blue light, the second light comprises a red light.

9. The light-emitting device of claim 1, wherein the optical element comprises a wavelength conversion material which is distant from the second light source.

10. The light-emitting device of claim 1, wherein the optical element comprises a frustum.