White LED array

• US 20030147242A1
• Filed: 01/27/2003
• Published: 08/07/2003
• Est. Priority Date: 02/04/2002
• Status: Abandoned Application

• Current Assignee: Whelen Engineering Company Incorporated
• Original Assignee: Whelen Engineering Company Incorporated
• Inventors: Stopa, James L.
• Application Number:
  US10/352,263
• Publication Number:
  US 20030147242A1
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

An LED array is disclosed that provides white light having a warm hue by combining yellow LEDs and white LEDs in the array. The yellow LEDs are typically less expensive than the white LEDs, thereby improving the cost-efficiency of the LED array. A preferred ratio of one yellow LED for every two white LED is disclosed.

Claims

1. An illumination array comprising a first plurality of yellow LEDs and a second plurality of white LEDs, wherein the LEDs cooperate to provide a light output having a warm white hue.

2. The illumination array of claim 1, wherein a ratio of yellow LEDs to white LEDs is 1 to 2.

3. The illumination array of claim 1, wherein the white LEDs have a chromaticity center tolerance of substantially X=0.31 and Y=0.32 and produce an intensity of approximately 6 candelas at a 15°

viewing angle.

4. The illumination array of claim 1, wherein the yellow LEDs emit light having a wavelength at 592 nm and a chromaticity center tolerance substantially of X=0.57 and Y=0.42 and produce an intensity of approximately 6 candelas at a 15°

viewing angle.

5. The illumination array of claim 1, wherein the array produces a chromaticity center tolerance substantially of X=0.4 and Y=0.37.

6. A method for constructing an LED array having a warm white hue comprising the steps of:

arranging a first plurality of yellow LEDs in an array;

arranging a second plurality of white LEDs adjacent the yellow LEDs in the array.

7. The method of claim 6, wherein a ratio of a number of yellow LEDs in said first plurality to a number of white LEDs in said second plurality is 1 to 2.