The display enters into standby after few seconds when displayed information is not crucial on the moment (if next turn is at 400m as an exemple).
This is made to save as much energy as possible with HAIKU's battery.
The information will come back to your screen automatically when a new notification has to be seen. For the navigation, the display will give you the info when at 50m of the turn.
If you want or need, when the display is off, you can just pass your hand over the product to reactivate the screen.