I can't find the URL right now but this issue has been addressed well for the bizjet & above world, using a dedicated product which is basically just an LCD in a thin enclosure, with just one knob (a brightness control) and that's it.
It's cable-attached to a box in the plane (which is obviously some sort of PC running Jeppview) and the certified installation has two of these, one for each pilot.
Tablet computers (which is how GA pilots try to do it, not having any other choice) get close but not quite. The sunlight readable ones all use a special type of polariser over the LCD and most tablets on the market are not available with this. The Motion LS800 and the Xplore IX104 (a big brick - too big for this use) are, as are most ruggedised/milspec tablets (most of the latter are like the IX104 - too big and heavy; I used to fly with an IX104 for a year and it wore a hole in my shorts).
One could make a tablet computer say 10mm thick, weight 0.3kg, battery life 10hrs, sunlight readable, but it would not have a 3GHz processor which is what today's punters want...
Another problem I found is that at say FL180 (500mb) the cooling air is only half as thick so the thing overheats. Especially in sunlight, which is a feature of most airways flights. One has to fit a fan or do some other mods...
That said, I have used the LS800 entirely successfully to display plates which I needed in a hurry. Normally I print off dep, dest and alt but on a multi leg trip, perhaps changed around due to PPR or lack of avgas, one sometimes has to replan on the fly. A friend has a Fujitsu convertible tablet which is about 1280x900 and is wonderful; almost like paper, but not sunlight readable.