Without knowing the specific model I can only guess, but I would think the display cable connecting the screen to the motherboard has broken. With some care it should be possible to open up the laptop and check it to make sure.
The LCD screen guide for your laptop explains how to open up your laptop and find the cable (as it needs to be disconnected to replace the screen). In your case the screen will probably be fine.
Replacement cables can be bought online (I think I saw it in the ifixit parts store, although you may be able to find it cheaper elsewhere).
If you want to make sure the computer itself is still fine, find a tv or monitor and connect your computer to it using an HDMI cable. if your screen is visible on the external monitor, then the issue lies either with the cable or the screen. Since the screen did not take a hard hit the cable is the most likely bet.
Happy fixing!