US 6,276,821 · Granted 2001-08-21
The Mirror That Talks Back: Donnelly's Signal-Light Mirror Patent
Imagine your car's side mirror not just reflecting what's behind you, but also flashing a signal light to warn other drivers you're about to turn or change lanes. This patent covers a mirror assembly with built-in LED or light-pipe signals that beam a pattern outward to approaching traffic—without blinding your own eyes with the glare inside the car.
The plain-English version
What it protects
The patent covers an exterior mirror housing that contains both a reflective mirror element and at least one signal light positioned inside. What's protected here is the specific design of a light conduit member—a channel that directs light from a remote source outward through the mirror housing in a controlled pattern, while blocking that light from reaching the driver's eyes inside the vehicle. The claims also cover the powerfold variant, which changes the light pattern depending on whether the mirror is in normal or folded position.
Why it matters
This patent addresses a real safety gap: traditional turn signals mounted elsewhere on the vehicle may be obscured or missed by drivers in adjacent lanes. By integrating a signal directly into the exterior mirror, Donnelly created a solution that makes lane-change intentions visible from more angles. The patent issued in 2001 and became foundational technology for modern advanced driver-assistance and active-safety mirror systems that automakers now include on premium vehicles.
Real-world use
When you're driving a modern luxury vehicle and notice the side mirror glowing or pulsing with an amber light as the driver ahead signals a lane change, you're seeing this patented technology in action.
Original USPTO abstract
An exterior mirror assembly for a vehicle includes a signal light that provides an advanced notification system to approaching vehicles that the driver of the vehicle intends to turn or make a lane change. The exterior mirror assembly includes a housing with a reflective element and a positioning device for adjusting the position of the reflective element in the housing, and at least one signal light positioned in the housing. The signal light includes a light source and a light conduit member which is adapted to project a pattern of light from the housing and yet restrict light from extending into the vehicle so that a driver seated in the vehicle does not directly observe the pattern of light. The light source may be provided by a light pipe which is optically coupled to a remote light source located, for example, in the vehicle. Preferably, the pattern of light extends at least rearwardly and laterally from the vehicle. In one form, the light conduit member includes a light input surface on one end and at least one light emitting surface for directing light outwardly from the housing of the exterior mirror assembly. In another form, the exterior mirror assembly includes a powerfold mirror system which incorporates a security light which directs light in a first light pattern when mirror assembly is in its normal use position and a second pattern when the mirror assembly is in its folded position.
Patent details
- Publication number
- US 6,276,821
- Filing date
- 1999-06-17
- Grant date
- 2001-08-21
- Assignee
- Donnelly Corporation
- Inventor(s)
- PASTRICK TODD W., VAN DE VEN MICHIEL P., WHITEHEAD PETER J., MOUSSEAU RICK, LYNAM NIALL R.
- CPC class
- B60Q1/2665
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