Ultrasonic vibrator
View Patent ↗A mobile electronic device including a casing, a signal generator housed within the casing, for generating a signal that has a frequency higher than the human audible range, at least one speaker housed within the casing and coupled with the signal generator, for producing analog output from the signal generated by said signal generator, wherein the analog output produced by the at least one speaker is (i) substantially inaudible, and (ii) causes the casing to vibrate at a frequency approximately equal to a resonant frequency of the casing.
1. A mobile electronic device comprising:
a casing;
a signal generator housed within said casing, for generating a signal that has a frequency higher than the human audible range;
at least one speaker housed within said casing and coupled with said signal generator, for producing analog output from the signal generated by said signal generator,
wherein the analog output produced by said at least one speaker is (i) substantially inaudible, and (ii) causes said casing to vibrate at a frequency approximately equal to a resonant frequency of said casing.
2. The mobile electronic device of claim 1 wherein the signal generated by said signal generator is a composite of at least two harmonics, each of which has a frequency higher than the human audible range.
3. The mobile electronic device of claim 1 wherein the at least two harmonics each has a frequency in the range of 20-30 KHz.
4. The mobile electronic device of claim 2 wherein the difference in frequencies for two of the at least two harmonics is approximately equal to the resonant frequency of said casing.
5. The mobile electronic device of claim 4 wherein the difference in frequencies for two of the at least two harmonics is in the range of 20-50 Hz.