Many Apple (AAPL) fans who love the iPad mini but are disappointed by its display resolution may want to wait for the second-generation model. A recent report from Chinese website DoNews claims that Apple has chosen AU Optronics to build a Retina display for the second-generation iPad mini that will apparently have a pixel density of 324 pixels per inch. Needless to say, this would mark a significant upgrade from the current iPad mini display that sports just 163 pixels per inch, and that has been criticized for being inferior to other seven-inch tablets such as the Google (GOOG) Nexus 7.