iPad screen not working but can hear sound

Over the last couple of days my iPad screen would stop responding and the screen would go a dark blue, I know it’s unlocked as when I press the lock button at the top the screen would go black like it would normally, I can’t get into my iPad, I’ve tried holding down the home button and the lock button but I can hold it down for a minute and still nothing happens, I’ve tried doing these separately and still nothing, it will normally come back after a couple of hours but I need help to fix the problem, also yes it is charged