Illumination Source

• US 20070291467A1
• Filed: 06/10/2005
• Published: 12/20/2007
• Est. Priority Date: 06/29/2004
• Status: Abandoned Application

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Nagai, Hideo, Mukai, Kenji
• Application Number:
  US11/596,034
• Publication Number:
  US 20070291467A1
• Time in Patent Office: Days
• US Class Current: 362/84
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

An illumination source is composed of a white LED of a first light source color and an orange LED of a second light source color, so that light is emitted in a color created as a result of mixing the first and second light source colors. The first and second light source colors are represented on the 1931 CIE chromaticity diagram by a first point P1 and a second point P2, respectively. The first point P1 is substantially on the Planckian Locus PL. The second point P2 is at such a position that a line segment L1 connecting the first and second points P1 and P2 is substantially in parallel with a tangent line L3 to the Planckian Locus PL. The tangent line L3 has a point of tangency on a line L2 that is normal to the Planckian Locus PL and passes through the first point P1.

Claims

1. An illumination source comprising:

a first light source operable to emit light of a first color represented by a first point on a 1931 CIE chromaticity diagram; and

a second light source operable to emit light of a second color represented by a second point on the 1931 CIE chromaticity diagram, a light intensity of the second light source being variable in accordance with a power supply, wherein

the first point is substantially on a Planckian Locus,

the second point is at such a position that a line segment connecting the first and second points is substantially in parallel with a tangent line to the Planckian Locus, the tangent line having a point of tangency on a line that is normal to the Planckian Locus and passes through the first point, and

the illumination source emits light of a mixture color of the first and second colors.

2. The illumination source of claim 1, wherein

the second light source includes a first light emitting element and a second light emitting element that are electrically connected in series or in parallel, the first and second light emitting elements having mutually different peak wavelengths.

3. The illumination source of claim 2, further comprising:

a third light source operable to emit light of a third light source color represented by a third point on the 1931 CIE chromaticity diagram, a light intensity of the third light source being variable in accordance with a power supply, wherein

the third point is located on an opposite side of the first point to the second point and at such a position that a line segment connecting the first and third points is substantially in parallel with the tangent line.

4. The illumination source of claim 3, wherein

the first light source includes:

a near-ultraviolet emitting element operable to emit near-ultraviolet light; and

blue, green, yellow, and red phosphors operable to convert the near-ultraviolet light to light of respective colors.

5. The illumination source of claim 4, wherein

the first light emitting element, the second light emitting element, and the near-ultraviolet emitting elements are LEDs.

6. The illumination source of claim 1, further comprising

a third light source operable to emit light of a third light source color represented by a third point on the 1931 CIE chromaticity diagram, a light intensity of the third light source being variable in accordance with a power supply, wherein

the third point is located on an opposite side of the first point to the second point and at such a position that a line segment connecting the first and third points is substantially in parallel with the tangent line.

7. The illumination source of claim 6, wherein

the first light source includes:

a near-ultraviolet emitting element operable to emit near-ultraviolet light; and

blue, green, yellow, and red phosphors operable to convert the near-ultraviolet light to light of respective colors.

8. The illumination source of claim 7, wherein

the near-ultraviolet emitting element is an LED.

9. The illumination source of claim 1, wherein

the first light source includes:

a blue light emitting element operable to emit blue light; and

green and red phosphors operable to convert the blue light to light of respective colors.

10. The illumination source of claim 9, wherein

the blue light emitting element is an LED.

11. The illumination source of claim 1, wherein

the first light source includes:

a near-ultraviolet emitting element operable to emit near-ultraviolet light; and

blue, green, yellow, and red phosphors operable to convert the near-ultraviolet light to light of respective colors.

12. The illumination source of claim 11, wherein

the near-ultraviolet emitting element is an LED.

13. The illumination source of claim 1, wherein

a light intensity of the first light source is variable in accordance with a power supply.