US 6,326,613 · Granted 2001-12-04
How Donnelly Hid a Rain Sensor Inside Your Rearview Mirror
Imagine your rearview mirror wasn't just for looking behind you — it's also a Swiss Army knife packed with a rain sensor and other electronics tucked neatly inside. Donnelly's design cleverly splits the mirror housing into two secret compartments: one that senses when it's raining on your windshield, and another that could hold a compass or future gadgets, all hidden from view.
The plain-English version
What it protects
The claim covers a rearview mirror assembly where the internal housing is divided into two separate compartments by an internal wall. One compartment holds a rain sensor positioned to touch the windshield, while a second compartment houses additional electrical components like a compass sensor. The design also protects the specific method of routing electrical leads under a removable cover that extends toward the vehicle header, keeping wires hidden and organized.
Why it matters
This patent solved a real problem in the late 1990s: how to integrate increasingly smart automotive sensors without cluttering the dashboard or windshield with visible components. By hiding the rain sensor directly inside the existing rearview mirror housing, Donnelly created a cleaner, more integrated design that other manufacturers could copy — which is exactly why they needed patent protection. It's an example of how smart packaging can hide complexity.
Real-world use
Every modern car with automatic windshield wipers that detect rainfall is likely using technology descended from this patent — the rain sensor hidden inside that black box mounted on your rearview mirror.
Original USPTO abstract
A vehicle interior rearview mirror assembly comprises a housing having a front end releasably attached to the interior surface of the vehicle windshield and a rear end having a ball and socket joint for a rearview mirror unit. An internal wall subdivides the interior of the housing into first and second compartments. The first compartment contains a rain sensor which is preferably biased into contact with the windshield, and the second compartment contains a further electrical component such as a compass sensor accessible through a side opening. A removable cover mates with the housing around the opening and extends along the windshield towards the vehicle header. Electrical leads for the rain sensor and the component are routed under the cover to the header.
Patent details
- Publication number
- US 6,326,613
- Filing date
- 1999-11-04
- Grant date
- 2001-12-04
- Assignee
- Donnelly Corporation
- Inventor(s)
- HESLIN PATRICK, LYNAM NIALL R.
- CPC class
- B60R1/04
Want to file your own patent?
Thinking about embedding sensors into car accessories? Search our patent database for existing automotive gadget designs to see what's already locked down before you invent.
Free patentability scan