Sony PCG-F540 Primary User Manual page 73

When you connect an external display to the monitor connector, you can
toggle the output between the Liquid Crystal Display (LCD), the external
monitor, or both devices.
Use the keys to select a display. See also "Selecting the Display
Fn+F7
Mode" in the online manual Customizing Your V AIO® Notebook for more
information.
Switch to an Fn+F7
external
display
Toggles between the LCD, the external display
connected to the Monitor connector, or both
the LCD and external display.