Portable navigation device

Abstract

A navigation device is configured to allocate display setting such as color schemes and screen contents to at least one ambient lighting condition, monitors and evaluates a signal indicative of ambient lighting conditions and determines whether display settings for the current ambient lighting conditions are already in use and to change display settings so that they suit current ambient lighting conditions if needed.

1 . A method for automatically adjusting visibility of a portable navigation device display, the method comprising the steps of: 
 allocating display settings for at least one ambient lighting condition,    monitoring a signal indicative of current ambient lighting condition, evaluating said signal,    selecting a display setting allocated to said current ambient lighting condition,    determining if a current display setting is the selected display setting, and    changing said current display setting to said selected display setting if said current setting is not said selected display setting.    
     
     
         2 . The method according to  claim 1 , wherein said at least one ambient lighting conditions comprises at least two ambient lighting conditions.  
     
     
         3 . The method according to  claim 1 , wherein said step of allocating display view settings comprises selecting at least one of an appropriate view, a backlight level, and a color scheme.  
     
     
         4 . The method according to  claim 3 , wherein one of said display settings is a day view.  
     
     
         5 . The method according to  claim 3 , wherein one of said display settings is a night view.  
     
     
         6 . The method according to  claim 3 , wherein one of said display settings comprises a three dimensional view of a map; and schematic representation of the sky at daytime.  
     
     
         7 . The method according to  claim 3 , wherein one of said display settings comprises a three dimensional view of a map; and a schematic representation of the sky at nighttime.  
     
     
         8 . The method according to  claim 3 , wherein one of said display settings comprises a high backlight level and a color scheme using brighter colors.  
     
     
         9 . The method according to  claim 3 , wherein one of said display settings comprises a low backlight level and a color scheme using darker colors.  
     
     
         10 . The method according to  claim 3 , wherein one of said display settings comprises a color scheme using inverted colors.  
     
     
         11 . The method according to  claim 3 , wherein said color scheme is stored as a plugin.  
     
     
         12 . The method according to  claim 1 , wherein the step of changing further comprises gradually changing backlight levels from a current backlight level to a level allocated to said selected display setting.  
     
     
         13 . The method according to  claim 12 , wherein the step of gradually changing backlight level comprises a predefined number of incremental jumps ranging from a backlight level for current display mode to another backlight level for said selected display mode.  
     
     
         14 . The method according to  claim 13 , wherein said gradually changing backlight level comprises five incremental jumps.  
     
     
         15 . The method according to  claim 1 , wherein said step of monitoring further comprises receiving a signal from a light sensor.  
     
     
         16 . The method according to  claim 15 , wherein said step of monitoring further comprises buffering said signal to filter temporary changes in ambient lighting conditions.  
     
     
         17 . The method according to  claim 16 , wherein said light sensor is located on a printed circuit board of said portable navigation device.  
     
     
         18 . The method according to  claim 1 , wherein said step of monitoring further comprises receiving a signal from a headlight sensor.  
     
     
         19 . The method according to  claim 18 , wherein said headlight sensor is wired to said portable navigation device directly or through its docking unit.  
     
     
         20 . The method according to  claim 19 , further comprising the step of confirming connection of said portable navigation device to said signal.  
     
     
         21 . The method according to  claim 18 , wherein said headlight sensor is wirelessly connected to said navigation device.  
     
     
         22 . The method according to  claim 1 , wherein said step of monitoring further comprises receiving a signal from a map matching function.  
     
     
         23 . The method according to  claim 22 , wherein said map matching function indicates current location of said navigation device is in a tunnel.  
     
     
         24 . The method according to  claim 22 , wherein said map matching function indicates loss of positioning signal.  
     
     
         25 . The method according to  claim 1 , wherein said display is a touch screen display with light emitting diode backlight.  
     
     
         26 . The method according to  claim 1 , wherein said step of changing further comprises presenting a confirmation dialog to the user of said portable navigation device.  
     
     
         27 . The method according to  claim 26 , wherein said step of changing is delayed until a confirmation is given by the user of said navigation device.  
     
     
         28 . The method according to  claim 1 , wherein said step of selecting a display setting is performed manually by the user of said navigation device.  
     
     
         29 . The method according to  claim 1 , wherein said step of changing comprises the step of enabling or disabling at least one function of said navigation device.  
     
     
         30 . The method according to  claim 29 , wherein said at least one function comprises one of a star map, points of interests, information relating to map items or a planned route, warning about speed limits, warning about driving breaks, displaying traffic information, displaying weather information, menu items, and menu color schemes.