They're a scourge of nighttime driving: people who round a corner and forget to dip their headlights for oncoming cars. But thanks to efforts by Mazda, those concerns could soon be a thing of the past.
Mazda is developing a technology that automatically adjusts a car's headlights when it detects another car approaching. That will let people keep their high beams on and not be an annoyance to other drivers.
Detecting other cars is the easy part: Mazda uses the camera and lasers already fitted to its cars for collision avoidance. They can detect an oncoming car from 400 meters away, and detect the tail lights of a car in front from more than 120 meters, according to a Mazda representative at the Ceatec trade show in Japan, where the company is showing the technology.
The headlights themselves are divided into four blocks of LEDs that can be switched on and off independently. When the vehicle detection system spots a car up ahead, the system turns off the appropriate LED blocks until the other car has passed.
Dimming headlights automatically isn't new -- it's already offered on some premium brand cars such as BMWs. Those systems use a small motor to power a shutter that covers part of the headlight when needed.
Mazda says its system of turning lights on and off is cheaper than a mechanical system, and it claims it's easier on the eyes too. It says it will be the first automaker to bring auto-dimming headlights to non-premium brand cars - meaning the mass market.
The engineer at Ceatec wasn't willing to say yet when that will happen, though.
Other things Mazda is working on include automatically raising the headlight beam slightly when a car accelerates over a certain speed, because drivers need to see the road further ahead when they're on a freeway. It's also adding "wide distribution low beams" for spotting pedestrians or animals by the side of the road.
They're just a few ways that car headlights are evolving. More futuristic, Intel and Carnegie Mellon University have shown a technology under development that can make heavy rain or snow appear almost invisible to a driver, by not shining light on the raindrops as they fall.
Ceatec, taking place just outside Tokyo, is an annual conference where Japanese firms can show off their newest technologies. Robots, automotive technology and wearable computing are the three biggest themes here this week.