Automatic adaptation of display brightness

The automatic adaptation of display brightness prevents major sudden changes in the brightness of the head-up display when the vehicle moves between different ambient lighting conditions (e.g. from light to dark and from dark to light when driving through a tunnel).

The automatic adjustment of the display brightness depends on

• the ambient lighting conditions,
• the brightness adjustment setting,
• the dimmer setting for instrument lighting (only when the lights are on).

The surrounding brightness (day, night, twilight, sunshine, etc.) is recorded by the rain/light sensor. The value of the brightness adjustment (difference between base setting and individually set display brightness) is stored in the head-up display. When the lighting is switched on (terminal 58g, lights ON) the brightness of the headup display is also influenced by the dimmer setting of the instrument lighting.