Have you ever had a lane departure warning system start shouting at you, when you were absolutely sure you weren't venturing out of the lane? What if you had a head-up display that instead could relay that information to you in real time using augmented reality? That's what one of Toyota's recent patents looks to do.
Head-up displays as they currently exist push static images from the dashboard to your windshield using reflections. Toyota's system acts in that same way, but instead of just displaying data pulled from the instrument display, it takes readings from speed and steering-angle sensors to change the output in real time.
Combined with two cameras -- a front-mounted camera to identify lane markings, and an interior camera to track the driver's view -- the system can move and adjust information on the fly. For example, as you drive faster, you're presumably looking farther down the road; the displayed information like your speed or revs can move to a corresponding position to stay in easy sight.
Perhaps its main feature, or at least the feature most talked up in the patent itself, is the ability to display the vehicle's lane positioning in real time. As you move, you'll have an image that shows you where the edges of your car lie within the lane. Now, you'll never need to wonder exactly where your vehicle's extremes are -- you'll be able to see them right in front of you.
If this ever makes it to production (a good deal of automotive-patent tech tends to disappear into the ether), I'll finally understand why that damned chime keeps going off.