Sony Corp. announced Wednesday at IFA Berlin, one of the world’s largest consumer electronics trade shows in Europe, the release of the world’s first 4K smartphone. Sony said in a press release that the Xperia Z5 Premium’s 4K display has “four times the resolution of full HD,” and will allow users to watch any 4K content, including from Netflix Inc. and Google Inc.'s YouTube. “Smartphones are part of people’s lives,” Sony CEO Hiroki Totoki said in the release. “Since users already create, share and enjoy most of their content on the go, we’ve set out to bring Sony’s latest innovations in camera, design and display to ensure the Xperia Z5 series is the best possible lifestyle and entertainment platform." The Xperia Z5 series will launch globally in October,...