Self-driving cars are set to steal the show at the International CES in Las Vegas as big-screen ultra HD TV screens, smartphones and tablets move aside.

Two of the most awaited announcements aren't from big-name electronics companies but rather car manufacturers Toyota and Audi.

Each company plans to unveil prototype self-driving car technology here today.

Toyota offered a tantalising glimpse at its prototype through a five-second video clip published online of its "Advanced Active Safety Research Vehicle."

The video shows a Lexus car decked out with various sensors on the front grill, rear wheels and the roof, the most striking of which is a spinning cylinder on the roof. A similar device is used in a self-driving car prototype developed by Google and in city mapping cars operated by companies including Nokia.

Lasers point at the cylinder and through reflections from the car manage to map out an accurate image of the car's surroundings complete with depth information that would be unavailable from a conventional camera.

Toyota self-driving car

The unveiling of the cars at CES is especially notable because the electronics show comes just a week before the North American International Auto Show in Detroit. That event is one of the largest and most important global automotive shows and is typically where the world's car makers make major announcements.

Several other car makers are also researching self-driving and autonomous automotive technology.

At last year's Ceatec exhibition in Japan, Nissan unveiled a prototype car that could park itself, while Volvo is working on a vehicle platoon system that allows cars to automatically follow one another on long stretches of highway. Alongside Google in Silicon Valley, Stanford University has developed a prototype self-driving car based on an Audi TTS.