US 2,002,159,270 · Filed 2002-01-22
The LED Welcome Light That Replaced Incandescent Bulbs in Car Doors
Instead of using old-fashioned hot filament bulbs that waste energy as heat, this invention uses a single super-bright LED to light up the ground around your car door or the interior cabin. It's designed to be efficient, run cool with a heat sink, and work safely with your car's electrical system.
The plain-English version
What it protects
The claim covers a vehicle lighting assembly powered by a single high-intensity LED (light emitting diode) that operates at at least 100 milliamps and produces at least 1 lumen of light per watt of power consumed. What's protected is the specific combination of a high-power LED paired with a heat dissipation element (heat sink or heat dissipater) and electrical components like a series resistor or DC-to-DC converter that step down the vehicle's battery voltage to safe operating levels for the LED.
Why it matters
This patent captures an early shift in automotive lighting from traditional incandescent bulbs to LEDs. LEDs are far more energy-efficient, longer-lasting, and generate less heat than filament bulbs, which matters in cars where space is tight and battery power is limited. By securing the design of a practical, heat-managed LED solution for vehicle entry and cabin lighting, the patent staked out intellectual property in a technology that would eventually become standard across the auto industry.
Real-world use
Every time you open your car door at night and the ground lights up to guide your feet, or the cabin gently illuminates before you turn on the main lights, you're likely encountering an LED assembly descended from designs like this one.
Original USPTO abstract
An improved vehicle lighting system for a vehicle is provided. The lighting system includes a light assembly, which is configured so as to illuminate, for example, a ground area adjacent an entrance to the vehicle or an interior portion of the vehicle. The light assembly includes a single non-incandescent light source, which comprises a single high-intensity power light emitting diode. The single high-intensity power light emitting diode preferably has a luminous efficiency of at least about 1 lumen per watt when the single high-intensity power light emitting diode is operated and wherein the single high-intensity power light emitting diode is preferably operated at a forward current of at least 100 milliamps. The single high-intensity power light emitting diode is preferably provided with a heat dissipation element, which functions as at least one of a heat sink and a heat dissipater for the power dissipated by the single high-intensity power light emitting diode. The single high-intensity power light emitting diode operates at an operational voltage that is less the battery/ignition voltage of the vehicle. Preferably the light assembly is provided with at least one of a series power resistor and a DC voltage to DC voltage converter.
Patent details
- Publication number
- US 2,002,159,270
- Filing date
- 2002-01-22
- Grant date
- Application — not yet granted
- Assignee
- Lynam Niall R. / Lindahl John O.
- Inventor(s)
- LYNAM NIALL R., LINDAHL JOHN O.
- CPC class
- B60K35/10
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