A year after flexing its R&D muscles with a rollable laptop that expanded its screen with a simple button push, Lenovo is back at Mobile World Congress in Barcelona, Spain, with another somehow even more sci-fi concept device. This is the ThinkBook Transparent Display Laptop, a 17.3-inch notebook with a screen you can peer straight through.The key draw is its bezel-less 17.3-inch MicroLED display, which offers up to 55 percent transparency when its pixels are set to black and turned off. But as ...