Sony computer User Manual

You can connect external displays to your computer while it is on. When you connect an external display (projector,
computer monitor, or TV) to your computer, you can switch the display between the computer screen (LCD), the external
display, or both, using shortcut keys. 

Fn+F7 Toggles the display between the computer screen (LCD), a connected TV, and both the LCD and TV. 

Select one display (LCD or TV) when playing a DVD. Connect the TV cable before you turn on the computer; otherwise, 
Fn+F7 will not work. You cannot use the Fn+F7 function to switch between LCD and TV once a DVD is inserted into the
optical drive. 

  

 You may not be able to display the computer screen (LCD) and an external display or projector at the same time,

depending on the types of computer displays and projectors you are using.