The creators of Android originally dreamed it would be used to create a world of "smart cameras" that connected to PCs, a founder said, but it was reworked for mobile handsets as the smartphone market began to explode.

"The exact same platform, the exact same operating system we built for cameras, that became Android for cellphones," said Android co-founder Andy Rubin, who spoke at an economic summit in Tokyo.

Rubin, who became a Google executive after the search giant acquired Android in August 2005, said the plan was to create a camera platform with a cloud portion for storing photos online.

He showed slides from his original pitch to investors in April 2004, including one with a camera connected "wired or wireless" to a home computer, which then linked to an "Android Datacenter."

But growth in digital cameras was gradually slowing as the technology became mainstream. Rubin's company revamped its business plan: A pitch from five months later declares it to be an "open-source handset solution."

Android kept its software core, including its Java core. The operating system's use of Java is at the heart of an ongoing multi-billion dollar lawsuit filed against Google by Oracle, around which an eight-week jury trial has just begun.

Back in 2005, the company added team members who had experience at companies like T-Mobile and Orange, and began to target rivals like mobile versions of Windows. Apple didn't enter the market until 2007.

IDGNS Android co-founder Andy Rubin, speaking in Tokyo.

"We decided digital cameras wasn't actually a big enough market," said Rubin. "I was worried about Microsoft and I was worried about Symbian, I wasn't worried about iPhone yet."

Rubin said there was an opportunity at the time because even as hardware costs fell steeply due to commoditization, software vendors were charging the same amount for their operating systems, taking up an ever larger part of manufacturers' budgets. As Android considered its product to be a platform for selling other services and products, the company aimed for growth, not per-unit income.

"We wanted as many cellphones to use Android as possible. So instead of charging $99, or $59, or $69, to Android, we gave it away for free, because we knew the industry was price sensitive," he said.

Handsets worked out better than cameras. An original "ambitious" projection by the company aimed for a 9 percent market share in North America and Europe by 2010; Android hit 72 percent last year. Google said in March that over 750 million Android devices have gone on line globally.

The Android operating system also eventually returned to its roots. Samsung has launched a Galaxy Camera that runs Android, along with similar offerings from makers including Nikon and Polaroid. The OS has been used in devices including tablets, TVs, espresso makers and refrigerators.

Rubin was a speaker at the Japan New Economy Summit held Tuesday in Tokyo. The summit was backed by a Japanese business group that aims to kick-start the country's economy.

In March, Google announced that Rubin had stepped down from his role leading Android in order to "start a new chapter" at the company.

Rubin said Tuesday he would continue to create products directed at end users.

"I can pretty much guarantee you that whatever I do next it's going to be something that delights consumers."