To quickly change the brightness of the monitor to the minimum possible value, use the shortcut. One of the buttons combinations the Fn (located in the lower left corner of the keyboard) and the other depending on your model of laptop. This "stranger" will surely belong to the function keys (F1..F12 on the top row of the keyboard), and which is specifically you need to check the manual of your computer or out "at random". So, in laptops usually use the Fn+F7, the Samsung - Fn+F5 Acer - Fn+F6, etc.
There is a way "for the lazy" - just wait until the screen itself will turn off. Each time not to wait too long once you set the settings any reasonable time. If the laptop is running Windows 7, to do this, click the icon "power options" in the system tray showing battery. In the pop-up menu, choose "setting power options". Then click on "configure display off" and select the desired time interval in the fields "Dim the display" and "Disable display". At the conclusion of the procedure, click "Save changes".
Method for the lazy and impatient at the same time: close the lid of the laptop. On the one hand, the screen will cease to illuminate all around almost immediately, and with another - it goes out by itself after a specified time. How to indicate this, the time described in the previous step.
In laptops, running Mac OS - "Makbukah" - shortcut to quickly turn off screen also exists. Usually this combination of keys Control+Shift+Eject. In addition, you can assign this function to one of the corners of the screen - "active corner" - and then it will be enough to have this angle the pointer to the brightness of the screen immediately dropped to zero.