NEW YORK — Apple is expected to reveal a new iPad model today, with a sharper screen and perhaps an option for faster wireless broadband. The upgrades are relatively minor, but the iPad is secure in its position as the king of tablets.

As usual, Apple has kept the features of the new device secret. No matter what they are, analysts expect the new iPad to be a success, riding on the popularity of the previous models, as well as pent-up demand from consumers waiting for the new model.

The iPad 2 was a big step up from the original iPad, since Apple included a camera and reduced both the thickness and the weight of the device. But there isn’t that much Apple can do to jazz up the iPad 3.

Nearly a year ago, the iPad 2 went on sale nine days after it was revealed. Apple watchers expect similar timing this year.