US 6,132,072 · Granted 2000-10-17
The Patent That Made Car Lights Glow Pure White
Imagine mixing blue and amber light so they overlap perfectly—you get pure white light that looks natural and bright. This patent describes how to arrange different colored LEDs on a car light so their beams blend together seamlessly, creating that clean white glow you see in modern headlights and interior lights.
The plain-English version
What it protects
The claim covers a specific arrangement of multiple LEDs mounted on a vehicular support member where lights of different colors (like blue-green and amber) are positioned so their beams overlap and optically mix. What's protected is the geometry and positioning that allows this color mixing to produce a metameric white light—a white that appears natural to the human eye—with enough brightness and color accuracy to serve as an effective illuminator in vehicles.
Why it matters
Before LEDs became cheap and efficient, most car lights used halogen or incandescent bulbs. This patent represents an early solution to a real problem: how to make LED light sources look like the warm, natural white light drivers and passengers expect, rather than the cold or colored light single-color LEDs produce. Gentex, a major supplier of automotive lighting and mirrors, patented this technique to control how others could combine LEDs for vehicle lighting applications.
Real-world use
When you sit in a modern car at night and the interior dome light or dashboard backlighting glows a warm, natural white, you're likely experiencing light that was mixed using a principle similar to what this patent describes.
Original USPTO abstract
An illuminator assembly, having a plurality of LEDs on a vehicular support member in a manner such that, when all of the LEDs are energized, illumination exhibiting a first perceived hue, e.g., blue-green, and projected from at least one of the LEDs overlaps and mixes with illumination exhibiting a second perceived hue, e.g., amber, which is distinct from said first perceived hue and which is projected from at least one of the remaining LEDs in such a manner that this overlapped and mixed illumination forms a metameric white color and has sufficient intensity and color rendering qualities to be an effective illuminator.
Patent details
- Publication number
- US 6,132,072
- Filing date
- 1998-09-04
- Grant date
- 2000-10-17
- Assignee
- Gentex Corporation
- Inventor(s)
- TURNBULL; ROBERT R., KNAPP; ROBERT C., ROBERTS; JOHN K.
- CPC class
- B60L1/14
Want to file your own patent?
If you're designing an automotive lighting concept, search IsItPatented to see what LED mixing patents already exist in your target vehicle segment.
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