Plastic Logic expects to begin making digital newspaper readers by the end of this year.

The iPod stemmed losses in the music industry. The Kindle gave beleaguered book publishers a reason for optimism.

Now the recession-ravaged newspaper and magazine industries are hoping for their own knight in shining digital armor, in the form of portable reading devices with big screens.

Unlike tiny mobile phones and devices like the Kindle that are made to display text from books, these new gadgets, with screens roughly the size of a standard sheet of paper, could present much of the editorial and advertising content of traditional periodicals in generally the same format as they appear in print. And they might be a way to get readers to pay for those periodicals — something they have been reluctant to do on the Web.