Apparatus and method of forming localized vibration field, and method of disposing exciters
An apparatus and a method of forming a localized vibration field are provided. The apparatus includes: a plate; a plurality of exciters disposed at a plurality of locations in neighborhood of circumference of the plate and configured to excite the plate; and a driving controller configured to vibrate the plurality of exciters by using a substantially same excitation frequency, wherein the plurality of exciters excite a local region of the plate and suppress vibrations of a rest of regions except the local region of the plate.
1. An apparatus for forming a localized vibration field, the apparatus comprising:
a plate;
a plurality of exciters disposed around a circumference of the plate and configured to excite the plate at a substantially same excitation frequency, wherein the plate vibrates in the form of standing waves; and
a driving controller configured to set a location of a local region of the plate by independently controlling both of an amplitude and a phase of each of the plurality of exciters, wherein the local region of the plate is vibrated and vibrations of a region outside the local region of the plate are suppressed,
wherein the plurality of exciters are configured to excite the local region with a vibration energy greater than a vibro-tactile threshold, and to excite the region outside the local region of the plate with a vibration energy less than the vibro-tactile threshold, and
wherein the plurality of exciters are disposed at a node of vibration of the plate.
2. The apparatus of claim 1 , wherein the plurality of exciters are configured to excite the local region with a vibration energy substantially greater than the vibro-tactile threshold by about 2 dB or more, and excite the region outside the local region with a vibration energy substantially less than the vibro-tactile threshold by about 2 dB or more.
3. The apparatus of claim 1 , wherein the plurality of exciters are configured to excite the local region of the plate with a vibration energy substantially greater than a vibration energy of the region outside the local region of the plate by about 4 dB or more.
4. The apparatus of claim 1 , wherein the plurality of exciters are configured to excite the plate so as to vibrate the local region at a mid-range or a low-range frequency from among an audible frequency band.
5. The apparatus of claim 1 , wherein the plurality of exciters are configured to excite the plate such that the local region vibrates in a single mode having a constant a phase.
6. The apparatus of claim 1 , wherein the plurality of exciters comprise at least one of moving coil exciters, piezoelectric exciters, and off-center weight motors.
7. The apparatus of claim 1 , wherein the plate comprises a flat panel-type member or a curved panel-type member.
8. The apparatus of claim 1 , wherein the plate comprises a display panel or a housing of an electronic apparatus.
9. A method of forming a localized vibration field, the method comprising:
disposing a plurality of exciters around a circumference of a plate; and
exciting the plate by vibrating the plurality of exciters at a substantially same excitation frequency, wherein the plate vibrates in the form of standing waves;
setting a location of a local region of the plate by independently controlling both of an amplitude and a phase of each of the plurality of exciters, wherein the local region of the plate is vibrated and vibrations of a region outside the local region of the plate are suppressed; and
exciting the local region with a vibration energy greater than a vibro-tactile threshold, and exciting the region outside the local region of the plate with a vibration energy less than the vibro-tactile threshold,
wherein the plurality of exciters are disposed at a node of vibration of the plate.
10. The method of claim 9 , further comprising:
exciting the local region with a vibration energy substantially greater than the vibro-tactile threshold by about 2 dB or more, and exciting the region outside the local region with a vibration energy substantially less than the vibro-tactile threshold by about 2 dB or more.
11. The method of claim 9 , further comprising:
exciting the plate so as to vibrate the local region at a mid-range or a low-range frequency from among an audible frequency band.
12. The method of claim 9 , further comprising:
exciting the plurality of exciters to induce a single mode vibration having a constant phase in the local region.
13. A method of disposing exciters, which vibrate a local region of a plate by exciting the plate, around a circumference of the plate, the method comprising:
exciting a plurality of candidate locations around the circumference of the plate at a uniform excitation frequency, wherein the plate vibrates in the form of standing waves;
selecting independent candidate locations with respect to a localized vibration of the plate by calculating a correlation between the localized vibration of the plate and vibrations at the plurality of candidate locations; and
disposing the exciters at the selected independent candidate locations,
wherein a location of the local region of the plate is set by independently controlling both of an amplitude and a phase of each of the plurality of exciters,
wherein the local region of the plate is vibrated and vibrations of a region outside the local region of the plate is suppressed, and
wherein the plurality of exciters are disposed at a node of vibration of the plate.
14. The method of claim 13 , wherein the correlation between the localized vibration of the plate and the vibrations at the plurality of candidate locations is calculated by using an effective independence method (EfI).
15. The method of claim 13 , wherein the independent candidate locations with respect to the localized vibration of the plate are selected based on an achievement value set based on human tactile information.