Navigation device and data update system

A navigation device that operates according to a plurality of application programs including at least a first program and a second program, reference map data of a reference data format referred to by the application programs being updatable, the navigation device comprising:

• a conversion unit that converts data in a predetermined update data format into data in the reference data format;
• and
• a reference map data update unit that updates the reference map data with the data in the reference data format after conversion by the conversion unit;
• wherein
• the reference map data is formed of a common map data frame commonly referred to by the plurality of application programs, a first map data frame referred to by the first program, and a second map data frame referred to by the second program;
• the data in the update data format is formed by storing in each data frame divided for each data type, at least one of:
• a first group of one or more common map data records to be stored according to the data type of each data frame in the common map data frame after conversion by the conversion unit;
• a second group of one or more first map data records to be stored according to the data type of each data frame in the first map data frame after conversion by the conversion unit;
• and a third group of one or more second map data records to be stored according to the data type of each data frame in the second map data frame after conversion by the conversion unit;
• and
• data stored in the common map data frame includes data relating to a road network formed by including a link and a node, and is commonly referred to by the plurality of application programs.