Portable navigation device and method with active elements

1. A portable navigation device comprising:

a housing having a substantially rectangular shape;

a first active element disposed at one corner of the housing;

a second active element disposed at a second corner of the housing;

a third active element disposed at a third corner of the housing;

a fourth active element disposed at a fourth corner of the housing;

a position detecting section that detects a current position;

an input section that receives an input for specifying a destination;

a destination direction detecting section that detects a destination direction to the destination from the current position;

a terminal direction detecting section that detects a terminal direction of the housing;

an angular difference calculating section that calculates an angular difference between the destination direction and the terminal direction; and

an active element control section that determines respective tactile sensation intensities of each of the first, second, third and fourth active elements based on the angular difference to control each of the first, second, third and fourth active elements in accordance with the tactile sensation intensities, wherein the active element control section controls at least three of the first, second, third and fourth active elements to simultaneously be activated at non-zero intensities based on the angular difference.

2. The portable navigation device of claim 1 , wherein

said first, second, third and fourth active elements are vibration elements, and

said active element control section is a vibration control section that determines respective vibration intensities of each of the first, second, third and fourth vibration elements to control each of the first, second, third and fourth vibration elements in accordance with the vibration intensities.

3. The portable navigation device of claim 2 , further comprising:

a distance calculating section that calculates a distance between the current position and the destination position, wherein

the vibration control section varies attributes of each of the first, second, third and fourth vibration elements based on the calculated distance.

4. The portable navigation device of claim 2 , further comprising:

a display section that displays a map for inputting the destination.

5. The portable navigation device of claim 4 , wherein

said display section displays the destination direction.

6. The portable navigation device of claim 2 , wherein

said input section sets said destination as an initial waypoint along a segment of a multi-segmented path.

7. The portable navigation device of claim 6 , wherein

said destination direction detecting section changes said destination direction at different turns along said multi-segmented path so as to provide turn-by-turn vibrational instructions to traverse said multi-segmented path.

8. The portable navigation device of claim 2 , wherein

said first, second, third and fourth vibrational elements are disposed about said housing such that when said housing is grasped the respective vibration intensities of the first, second, third and fourth vibration elements impart a phantom sensation to a user.

9. The portable navigation device of claim 2 , wherein

said vibration control section causes said phantom sensation to be aligned with said destination direction.

10. The portable navigation device of claim 2 , wherein

said housing being a mobile telephone housing.

11. The portable navigation device of claim 1 , wherein

said first, second, third and fourth active elements include at least one of a heating element, a constrictive element, and an electrical stimulation element.

12. The portable navigation device of claim 2 , wherein

said angular difference calculating section calculates

an angle θ 1 between the terminal direction and a reference direction,

and angle θ 2 between the destination direction and the reference direction, and

calculates the angular difference θ based on angle θ 1 and angle θ 2 .

13. The portable navigation device of claim 2 , wherein

said vibration control section calculates vibration intensity ratios between respective of the first, second, third and fourth vibration elements as part of determining said respective vibration intensities.

14. The portable navigation device of claim 2 , wherein

said first, second, third and fourth vibration elements consist essentially of four vibration elements.

15. A tactile sensory navigation method comprising:

detecting a current position of a portable navigation device with a position detecting section of said portable navigation device;

receiving an input for specifying a destination;

detecting a destination direction to the destination from the current position;

detecting a terminal direction of the portable navigation device, said portable navigation device including first, second, third and fourth active elements disposed at different corners of a substantially rectangular-shaped housing of the portable navigation device;

calculating with a processor an angular difference between the destination direction and the terminal direction;

determining with an active element control section respective tactile sensation intensities of each of the first, second, third and fourth active elements on the basis of the angular difference; and

driving at least three active elements in accordance with the determined tactile sensation intensities such that at least three of the first, second, third and fourth active elements are simultaneously be activated at non-zero intensities based on the angular difference.

16. The method of claim 15 , wherein

said first, second, third and fourth active elements are vibration elements,

said determining includes determining respective vibration intensities of each of the first, second, third and fourth vibration elements, and

said driving includes driving each of the first, second, third and fourth vibration elements in accordance with the respective vibration intensities.

17. The method of claim 16 , further comprising:

calculating with the processor a distance between the current position and the destination position, wherein

said driving varies attributes of each of the first, second, third and fourth vibration elements based on the distance calculated by the processor.

18. The method of claim 16 , further comprising:

displaying a map on a display of the portable navigation device for inputting the destination.

19. The method of claim 18 , wherein

said displaying includes displaying the destination direction.

20. The method of claim 15 , further comprising

setting said destination as an initial waypoint along a first segment of a multi-segmented path.

21. The portable navigation device of claim 12 , wherein

said active element control section calculates the respective vibration intensities v 1 (θ), v 2 (θ), v 3 (θ) and v 4 (θ) of the first, second, third and fourth vibration elements using the angular difference θ by the following equations:

v 1(θ)=(¼)×{1+sin θ sin(π/4)+cos θ sin(π/4)}

v 2(θ)=(¼)×{1+sin θ sin(π/4)−cos θ sin(π/4)}

v 3(θ)=(¼)×{1−sin θ sin(π/4)+cos θ sin(π/4)}

v 4(θ)=(¼)×{1−sin θ sin(π/4)−cos θ sin(π/4)}, wherein

v 1 (θ) to v 4 (θ) represent values of mutual proportions, a sum of which is 1.