Condition-dependent icon generation for vehicular information terminals

1. A computer storage medium encoded with a computer program, the program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising:

determining a strength of a signal used for identifying a location of a vehicle;

determining a road speed limit based upon the location of the vehicle;

determining a speed of the vehicle;

selecting at least first through third appearance characteristics of a single icon that represents the vehicle on a map displayed on a navigation interface, based upon the strength of the signal, the road speed limit, and the speed, respectively;

generating the icon including the selected appearance characteristics; and

displaying the icon representing the vehicle on the map of the navigation interface.

2. A system comprising:

one or more computers; and

a computer-readable medium coupled to the one or more computers having instructions stored thereon which, when executed by the one or more computers, cause the one or more computers to perform operations comprising:

determining a strength of a signal used for identifying a location of a vehicle,

determining a road speed limit based upon the location of the vehicle,

determining a speed of the vehicle,

selecting at least first through third appearance characteristics of a single icon that represents the vehicle on a map displayed on a navigation interface, based upon the strength of the signal, the road speed limit, and the speed, respectively,

generating the icon including the selected appearance characteristics, and

displaying the icon representing the vehicle on the map of the navigation interface.

3. A device comprising:

a storage medium configured to store a map;

a controller configured to:

determine a strength of a signal used for identifying a location of a vehicle,

determine a road speed limit based upon the location of the vehicle,

determine a speed of the vehicle,

select at least first through third appearance characteristics of a single icon that represents the vehicle on the map displayed on a navigation interface, based upon the strength of the signal, the road speed limit, and the speed, respectively, and

generate the icon including the selected appearance characteristics; and

a screen display unit configured to display the icon representing the vehicle on the map of the navigation interface.

4. The device of claim 3 , further comprising a voice output unit configured to output a guide voice based upon the icon.

5. The device of claim 3 , further comprising an antenna configured to receive global positioning system (“GPS”) signals as the signal used for identifying the location of the vehicle.

6. The device of claim 3 , further comprising a receiving unit configured to receive an inertial reference system (“IRS”) signal as the signal used for identifying the location of the vehicle.

7. A computer-implemented method comprising:

determining a strength of a signal used for identifying a location of a vehicle;

determining a road speed limit based upon the location of the vehicle;

determining a speed of the vehicle;

selecting at least first through third appearance characteristics of a single icon that represents the vehicle on a map displayed on a navigation interface, based upon the strength of the signal, the road speed limit, and the speed, respectively;

generating the icon including the selected appearance characteristics; and

displaying the icon representing the vehicle on the map of the navigation interface.

8. The method of claim 7 , further comprising comparing the speed to the road speed limit, wherein selecting the third appearance characteristic further comprises:

selecting a first internal shape indicator fill color as the third appearance characteristic if the speed exceeds the road speed limit, and

selecting a second, different internal shape indicator fill color as the third appearance characteristic if the speed does not exceed the road speed limit.

9. The method of claim 7 , further comprising storing upper and lower signal strength thresholds, wherein selecting the indicators further comprises:

selecting, as the first appearance characteristic, a first fill color for a region between an internal shape indicator and a circle that circumscribes the internal shape indicator if the strength of the signal does not exceed the lower signal strength threshold,

selecting, as the first appearance characteristic, a second, different fill color for the region between the internal shape indicator and the circle that circumscribes the internal shape indicator if the strength of the signal exceeds the lower signal strength threshold but does not exceed the upper second signal strength threshold, and

selecting, as the first appearance characteristic, a third, different fill color for the region between the internal shape indicator and the circle that circumscribes the internal shape indicator if the strength of the signal exceeds the upper signal strength threshold.

10. The method of claim 7 , further comprising selecting the map based upon the location of the vehicle, wherein the icon is displayed over the map.

11. The method of claim 7 , further comprising outputting a guide voice based upon the icon.

12. The method of claim 7 , wherein the signal is a global positioning system (“GPS”) signal.

13. The method of claim 7 , wherein the signal is an inertial reference system (“IRS”) signal.

14. The method of claim 7 , further comprising:

receiving a first user-initiated signal to enter a brief display mode, wherein the icon is selected, generated and displayed based upon the user-initiated signal to enter the brief display mode;

receiving a second user-initiated signal to enter a full display mode; and

based on receiving the second user-initiated signal:

selecting at least first through third separate icons to represent the strength of the signal, the road speed limit, and the speed, respectively, and

displaying the first through third separate icons on the map of the navigation interface.

15. The method of claim 7 , wherein the icon representing the vehicle is displayed on the map of the navigation interface within the vehicle.

16. The method of claim 7 , further comprising selecting the map based upon the determined location of the vehicle.

17. The method of claim 7 wherein regardless of the appearance characteristic selected, the single icon representing the vehicle exhibits a circular, colored outer shape circumscribing a pointed-shaped, colored inner shape.

18. The method of claim 7 , further comprising storing a road speed limit threshold, wherein selecting the second appearance characteristic further comprises:

selecting a first shape of an internal shape indicator as the second appearance characteristic if the road speed limit does not exceed the road speed limit threshold, and

selecting a second, different shape of the internal shape indicator as the second appearance characteristic if the road speed limit exceeds the road speed limit threshold.

19. The method of claim 18 , wherein the first shape comprises a triangle shape, and the second shape comprises an arrow shape.

20. The method of claim 18 , wherein the road speed limit threshold is based upon a local highway road speed limit.