PRESTIGIO GEOVISION 450 - Manual (Page 6)

Settings
Tap on the Settings icon on the Main Menu, the following screen is
displayed.
Volume
Press 'Volume' you can modify the volume level of the voice prompts. You
can increase or decrease the level by clicking or . Click to
mute.
Display
Tap on the Display option to enter display submenu. There are 3 items to
adjust: Brightness, Backlight Timeout, and Screen Calibration.
Select Backlight Timeout to set idling time to shut down the display to
save battery consuming. Select “Never” to disable this option.
Select Screen Calibration to calibrate the unit to respond to your screen
taps. You will need to use this function only if the unit begins to respond
inconsistently to your screen taps. Tap on button to start. Follow the
on screen directions to tap on the center of the cross to calibrate. When the
steps are done, you will see the second figure, tap on screen to save and
apply the new calibration.