I suggest you look at the Standard Luggage Carry-On Backpack. It has a dedicated electronics compartment for laptop, tablet and accessories.
I did a review of it about a week ago but I'm not allowed to link to it. This is a well made, well though out bag designed for the business traveler who wants to go without wheels.
It is not completely checkpoint friendly as the computer does have to be taken out of the bag for security but with its easy access laptop compartment, this isn't very difficult. (And if you have TSA Precheck this isn't a problem.)
Off the top of my head, I don't know of any carry-on size bags that are completely checkpoint friendly. Mostly just laptop size bags.