US 6,648,477 · Granted 2003-11-18
The Rearview Mirror That Became Your Dashboard's Second Screen
Imagine your rearview mirror displaying useful information—like turn signal alerts or lane warnings—right where you're already looking. This patent protects the clever optics that bounce light from LEDs down to your eyes without blocking your view of the road behind you.
The plain-English version
What it protects
The claim covers a rearview mirror assembly that integrates a display system using a refractive light-directing element (like a prismatic lens) to angle light from LED sources downward and sideways toward the driver's line of sight. What's protected here is specifically the optical geometry and mounting structure that allows information to be shown on or through the mirror glass while preserving the mirror's reflective function.
Why it matters
This patent represents an early attempt to bring smart-mirror technology into vehicles—merging safety information and convenience displays into a component drivers already rely on. Rather than adding more dashboard screens or head-up displays, embedding data into the rearview mirror reduces driver distraction and simplifies the cockpit layout. It opened the door for modern driver-assistance features integrated into mirrors.
Real-world use
When a modern vehicle alerts you about a blind-spot vehicle or flashing turn signal via a subtle glow or symbol in the rearview mirror, you're seeing the real-world outcome of this optical innovation.
Original USPTO abstract
An interior rearview mirror assembly provides a display system for displaying light or information to a driver of a vehicle. The display includes a refractive light directing element, which may include a prismatic display lens which refracts and directs the light of the display message downwardly and/or sidewardly toward a driver of the vehicle for improved viewing of the display message by the driver of the vehicle. The display system is mountable to a printed circuit board positioned within the case of the mirror assembly. The printed circuit board may also be connected to a pair of illumination sources positioned at a lower portion of a casing of the mirror assembly.
Patent details
- Publication number
- US 6,648,477
- Filing date
- 2001-07-05
- Grant date
- 2003-11-18
- Assignee
- Donnelly Corporation
- Inventor(s)
- HUTZEL BARRY W., MOUSSEAU RICK, DEWIND DARRYL P.
- CPC class
- B60R1/12
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