US 6,320,176 · Granted 2001-11-20
The Camera Inside Your Windshield That Knows When It's Raining
Instead of using a traditional rain sensor with moving parts, this invention uses a tiny camera pointed at your windshield from inside the car to detect raindrops. The camera watches for water spots on the glass and tells your car when it's wet, so the wipers can turn on automatically without you touching anything.
The plain-English version
What it protects
The claim covers a rain detection system that uses an imaging sensor (essentially a small camera) mounted inside a vehicle to photograph the windshield surface and identify precipitation. What's protected here is the specific method of analyzing camera images to spot water droplets on glass, rather than relying on traditional mechanical or capacitive sensors. The control system uses spatial filtering of the camera's output to determine whether rain is present.
Why it matters
This patent moved rain sensing away from mechanical switches toward solid-state camera-based detection, which is more reliable and integrates easily with modern vehicle electronics and automatic wiper systems. By using imaging technology that was becoming more affordable in the early 2000s, Donnelly Corporation created a foundation for what became standard in many vehicles with smart climate features, eliminating the need for exposed sensor hardware that could fail or get dirty.
Real-world use
When you drive a modern car with auto-sensing wipers that turn on the moment rain hits without you flicking a switch, that's often this technology at work—a camera inside watching your windshield and signaling the wiper motor to engage.
Original USPTO abstract
A vehicular rain sensor which senses precipitation at a vehicle window. The rain sensor comprises an imaging array sensor and a control. The imaging array sensor is directed at the vehicle window from inside the vehicle and comprises a camera device capable of imaging precipitation at a surface of the window. The camera is operable to image the precipitation at least in response to ambient light present at the window. The control responds to an output of the imaging array sensor in order to indicate precipitation at the surface of the window. The control determines the presence of precipitation via spatial filtering of the image received by the camera device.
Patent details
- Publication number
- US 6,320,176
- Filing date
- 2000-06-22
- Grant date
- 2001-11-20
- Assignee
- Donnelly Corporation
- Inventor(s)
- SCHOFIELD KENNETH, LARSON MARK L., VADAS KEITH J.
- CPC class
- B60R21/01538
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