Google next month will start cranking out prototypes of a 3-D tablet designed to give users immersive experiences that could include virtual reality, according to US media reports. The tablet will have a 7-inch display and an array of sophisticated cameras, sensors and software, the Wall Street Journal said in a story citing unnamed sources. Google on Friday said they had nothing to announce. The tablet was reported to be part of a Project Tango worked on by a special team at the California-based technology firm. The project was said to involve giving advanced mapping and virtual reality capabilities to mobile devices powered by Google's free Android software. Nearly 42 percent of people in the United States used tablets at least once a month last year and that figure was expected to top 46 percent this year, according to industry tracker eMarketer.