Sony Ericsson, NEC and Kyocera are among the other Japanese handset makers also betting on Android as their path to international sales.

While Android was initially overshadowed by the popular iPhone from Apple, its user numbers are now soaring. In 2010, global sales of Android phones reached 67.2 million units, ahead of iPhones, which sold 46 million units, according to the research company Gartner.

And Sharp, clearly hoping to edge onto Apple’s iPad turf, has introduced in the United States a lineup of tablet computers running a version of Android  the sort of competition Apple is hoping to stay well in front of with new versions of the iPad like the one it introduced Wednesday in San Francisco. For the Japanese phone makers, cashing in on Android’s popularity will mean learning some new skills, like marketing, while unlearning some old habits, like paying too much attention to the hardware and too little to the software.

Because Japan’s phone industry remains highly fragmented, no company so far has been large or savvy enough to make a strong overseas push. Instead, handset makers have long been content to serve as suppliers to Japan’s three largest mobile networks, which command a market of more than 100 million users, most of them on advanced 3G networks.

And in their hardware fixation, Japanese manufacturers have tended to bog down their handsets with clunky software platforms and fenced-in Web services that do not emphasize downloads of third-party applications.