Apple CEO Steve Jobs emerged briefly from medical leave and walked on stage to a standing ovation yesterday to unveil the second-generation iPad.

Jobs, 56, looked frail as he appeared at the Yerba Buena Center for the Arts Theater in San Francisco, Calif., in his signature black mock turtleneck, jeans and wire-rimmed glasses.

“We’ve been working on this product for a while, and I just didn’t want to miss today,” Jobs said. “Thank you for having me.”

The iPad 2 tablet computer has a faster processor than the original’s. It comes with two cameras for taking photos and video chatting. The battery life is the same, about 10 hours of use and a month on standby. It’s also thinner: 8.8 millimetres as opposed to the original’s 13.4 millimetres.

“The new iPad 2 is actually thinner than your iPhone 4,” Jobs said.

He also introduced a new accessory for the iPad that lets people connect the tablet to a high-definition TV. Updated software turns iPhones and iPads with 3G cellular connections into personal Wi-Fi hotspots, so you can share the connection with computers or other devices.

The iPad 2 goes on sale in Canada on March 25. Pricing is not yet available.

Jobs announced in January that he would take a third leave of absence to focus on his health. In the past decade, he has survived a rare but curable form of pancreatic cancer and undergone a liver transplant.