US IT giant Microsoft yesterday unveiled a low-price headset for "mixed reality," the cutting-edge technology that superimposes 3D computer images onto real scenes. Microsoft officials say the goggle-like device will cost around 300 dollars, about one-tenth the current price. <br/><br/>At a demonstration in Seattle, they used the device to create virtual settings on an empty stage. They say this will slash costs and time. Microsoft says it will sell the headset this year. Use of the technology has been limited due to high costs. In Japan, an aircraft maker uses it to train workers in engine maintenance