Laptop screen completely blank, Works when connected to external monitor?

So, recently I decided to connect my laptop to my TV for something. Now, my laptop screen is gone and even the Lenovo logo when I turn on my computer turns up on the TV… Do you know how I can get my laptop back?

Shutdown the laptop, Disconnect the laptop from the TV and restart, your display may come back. If not look along the row of function keys for a key that switches the video output from laptop>TV, often F4 or F5. Look for a Fn key on the bottom left of th keyboard, hold down the Fn key and tap the F4 or F5 key.
Update your answer with model of Lenovo and operating system and we can be more specific

Press Win key- P and click on the options you want.

The graphics controls are found by right-clicking on the desktop

Connect the external monitor, then keep pressing the windows key + p until computer only is highlighted. It will either be in the middle of the screen, or on the right.