iPhone 4s still works but has an unresponsive black screen

Today i was using an app on my iphone 4s and the screen just went black and i couldnt see anything. So i held the power button and turned off the phone by swipping at the top of the screen as you normally would if you could see the screen. I waited 2 minutes and turned it back on. This worked and i was able to see my screen again and it was not black. But a couple hours later and this happened again and i was not able to see my screen and it returned back to the black screen. Everything on the phone works (ex: siri, music, apps, touching the screen to get these) but i just cannot see it. So, i retried what i did earlier to fix this problem but it didnt work. I tried holding both the home and power button to restart my phone and the apple logo shows up but disappears after the phone restarts and returns to the black screen. Im just wondering if there is anything else i can try to get my screen back to its normal state.