Light-emitting diode flash module with enhanced spectral emission

• US 7,404,652 B2
• Filed: 12/15/2004
• Issued: 07/29/2008
• Est. Priority Date: 12/15/2004
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Ng, Kee Yean, Cheng, Heng Yow, Kuan, Yew Cheong
• Primary Examiner(s): LEE, Y MY QUACH
• Application Number:
  US11/012,761
• Publication Number:
  US 20060126326A1
• Time in Patent Office: 1,322 Days
• Field of Search: 362/231, 362/84, 362/227, 362/230, 362/293, 362/555, 362/545, 362/800, 257 88- 89, 257/100, 257/787
• US Class Current: 362/231
• 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 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: G03B 15/03 Combinations of cameras with lighting apparatus; Flash units
• 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 2924/12041 LED
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H04M 1/22 Illumination; Arrangements for improving the visibility of characters on dials
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light-emitting diode (“LED”) device includes a plurality of LEDs. Each LED in the plurality of LEDs is adjacent to at least one other of the plurality of LEDs. At least one of the plurality of LEDs has a radiation with a full-width-half-maximum greater than 50 nm.

Claims

1. A light-emitting diode (“

LED”

) device comprising;

a plurality of LEDs including

a first LED emitting at least a first color having a first full-width-half-maximum greater than 50 nm, the first LED comprising a first LED chip and a first encapsulant containing a first wavelength-converting material, the first LED chip being covered by the first encapsulant, the first LED chip of the first LED including a first blue-emitting LED chip, and

a second LED adjacent to the first LED emitting at least a second color, the second LED comprising a second LED chip and a second encapsulant containing a second wavelength-converting material, the second LED chip being covered by the second encapsulant, the second LED chip of the second LED including a second blue-emitting LED chip.

2. The LED device of claim 1 wherein the second color is a first radiation of the second LED.

3. The LED device of claim 1 wherein the second color has a second full-width-half-maximum greater than 50 nm.

4. The LED device of claim 1 wherein the first color is a second radiation of the first LED and the first LED further emits a third color that is a first radiation of the first LED.

5. The LED device of claim 4 wherein the first wavelength-converting material emits a green radiation.

6. The LED device of claim 1 having a peak combined total emission, wherein a combined total emission of the LED device is at least 20% of the peak combined total emission from 470 nm to 650 nm.

7. The LED device of claim 1 wherein the plurality of LEDs further includes a UV LED with a third wavelength-converting material.

8. The LED device of claim 1 wherein the first wavelength-converting material emits a green radiation and the second wavelength-converting material emits a red radiation.

9. The LED device of claim 8 wherein the plurality of LEDs further includes a blue LED emitting a blue radiation, and wherein the LED device has a power ratio of red:

green;

blue light of about 3;

6;

1.

10. The LED device of claim 7 wherein the first wavelength-converting material emits a green radiation, the second wavelength-converting material emits a red radiation, and the third wavelength-converting material emits a blue radiation.

11. The LED device of claim 10 wherein the LED device has a power ratio of red:

green;

blue light of about 3;

6;

1.

15. The LED device of claim 1 emitting light having a color temperature of between 5,000 degrees Kelvin and 9,500 degrees Kelvin.

16. A flash module having an LED device in accordance with claim 1.

17. The flash module of claim 16 wherein a first bias is selectively applied to the first LED and a second bias is selectively applied to the second LED so as to produce a selected combined total emission from the flash module.

12. A light-emitting diode (“

LED”

) device comprising;

a plurality of LEDs including

a first LED emitting at least a first color having a first full-width-half-maximum greater than 50 nm, the first LED comprising a first LED chip and a first encapsulant containing a first wavelength-converting material, the first LED chip being covered by the first encapsulant, the first LED chip of the first LED being a first ultraviolet (“

UV”

) LED,

a second LED adjacent to the first LED emitting at least a second color, the second LED comprising a second LED chip and a second encapsulant containing a second wavelength-converting material, the second LED chip being covered by the second encapsulant, the second LED chip of the second LED being a second UV LED, and

a third UV LED with a third wavelength-converting material,

wherein the first wavelength-converting material emits a blue radiation, the second wavelength-converting material emits a green radiation, and the third wavelength-converting material emits a red radiation.

13. The LED device of claim 12 wherein a combined emission of the LED device has a power ratio of red:

green;

blue light of about 3;

6;

1.

14. The LED device of claim 12 having a peak combined total emission, wherein a combined total emission of the LED device is at least 20% of the peak combined total emission from 450 nm to 650 nm.