Luminescent light source having blue light emitting diode chip and red light emitting diode chip

• US 8,563,996 B2
• Filed: 02/21/2012
• Issued: 10/22/2013
• Est. Priority Date: 11/09/2011
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Ke, Wei-Chih, Lin, Ruei-Teng
• Primary Examiner(s): Soward, Ida M
• Application Number:
  US13/401,777
• Publication Number:
  US 20130113003A1
• Time in Patent Office: 609 Days
• Field of Search: 257/89, 257/90, 257/E51.022
• US Class Current: 257/89
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• 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 2924/00014 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 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 33/502 Wavelength conversion materials

Abstract

A luminescent light source including a blue light emitting diode (LED) chip, a red LED chip, and a wavelength converting material is provided. The blue LED chip and the red LED chip respectively emit a first light and a second light. A ratio of peak intensity of the second light to peak intensity of the first light ranges from 0.36 to 0.56. The wavelength converting material is disposed around the blue LED chip or the red LED chip and emits a third light. A wavelength of the third light ranges from a wavelength of the first light to a wavelength of the second light.

Claims

1. A luminescent light source comprising:

a blue light emitting diode chip emitting a first light;

a red light emitting diode chip emitting a second light, wherein a ratio of peak intensity of the second light to peak intensity of the first light ranges from 0.36 to 0.56; and

a wavelength converting material disposed around at least one of the blue light emitting diode chip and the red light emitting diode chip, the wavelength converting material emitting a third light, a wavelength of the third light ranging from a wavelength of the first light to a wavelength of the second light.

2. The luminescent light source as recited in claim 1, further comprising a driver source outputting an electrical signal to drive the blue light emitting diode chip and the red light emitting diode chip.

3. The luminescent light source as recited in claim 1, wherein the first light, the second light, and the third light are mixed to generate a white light.

4. The luminescent light source as recited in claim 1, wherein a light emitting area of the blue light emitting diode chip is greater than a light emitting area of the red light emitting diode chip.

5. The luminescent light source as recited in claim 1, wherein the wavelength converting material is green phosphor powder, yellow phosphor powder, or a combination thereof.

6. The luminescent light source as recited in claim 1, wherein the wavelength converting material comprises an orthosilicate phosphor material, β

-SiAlON, an oxynitride-based phosphor material, an yttrium aluminum garnet phosphor material, a nitride phosphor material, a sulfate phosphor material, CaSc₂O₄, or a combination thereof.

7. The luminescent light source as recited in claim 3, wherein an NTSC color saturation of the white light is greater than 90%.

8. The luminescent light source as recited in claim 1, further comprising an encapsulant encapsulating the blue light emitting diode chip and the red light emitting diode chip.

9. The luminescent light source as recited in claim 8, wherein the wavelength converting material is doped into the encapsulant.

10. The luminescent light source as recited in claim 1, wherein the wavelength converting material is disposed on peripheries of the blue light emitting diode chip.

11. The luminescent light source as recited in claim 1, wherein the wavelength converting material is disposed on a light emitting surface of the blue light emitting diode chip.

12. The luminescent light source as recited in claim 1, wherein the blue light emitting diode chip and the red light emitting diode chip are connected in series or in parallel.

13. The luminescent light source as recited in claim 1, wherein the ratio of the peak intensity of the second light to the peak intensity of the first light ranges from 0.46 to 0.56.

14. The luminescent light source as recited in claim 1, wherein the ratio of the peak intensity of the second light to the peak intensity of the first light ranges from 0.36 to 0.44.

15. A display comprising:

a display panel having a color filter layer; and

a luminescent light source providing the display panel with a display light and comprising;

a blue light emitting diode chip emitting a first light;

a red light emitting diode chip emitting a second light, wherein a ratio of peak intensity of the second light to peak intensity of the first light ranges from 0.36 to 0.56; and

a wavelength converting material disposed around at least one of the blue light emitting diode chip and the red light emitting diode chip, the wavelength converting material being excited to emit a third light, wherein the first light, the second light, and the third light are mixed to generate the display light, the display light has an x-coordinate CIEx and a y-coordinate CIEy on a CIE 1931 chromaticity coordinate diagram after passing through the color filter layer, CIEx ranges from 0.265 to 0.328, and CIEy ranges from 0.273 to 0.344.

16. The display as recited in claim 15, wherein the display light has the x-coordinate CIEx and the y-coordinate CIEy on the CIE 1931 chromaticity coordinate diagram after passing through the color filter layer, CIEx ranges from 0.298 to 0.328, and CIEy ranges from 0.314 to 0.344.

17. The display as recited in claim 15, wherein the display light has the x-coordinate CIEx and the y-coordinate CIEy on the CIE 1931 chromaticity coordinate diagram after passing through the color filter layer, CIEx ranges from 0.265 to 0.295, and CIEy ranges from 0.273 to 0.303.

18. The display as recited in claim 15, wherein the ratio of the peak intensity of the second light of the luminescent light source to the peak intensity of the first light of the luminescent light source ranges from 0.46 to 0.56.

19. The display as recited in claim 15, wherein the ratio of the peak intensity of the second light of the luminescent light source to the peak intensity of the first light of the luminescent light source ranges from 0.36 to 0.44.