| 摘要 |
PURPOSE:To remove disturbing sound waves other than the target bearing by using two kinds of pressure gradient type transducers. CONSTITUTION:A dynamic type vibrator 1 as a pressure gradient type transducer which electromagnetically performs electro-mechanical conversion and electrostrictive type bimorph vibrators 2a, 2b as pressure gradient type transducers which electrostatically perform electro-mechanical conversion are contained together with a medium of good sound wave transmittivity in a case of good sound wave transmittivity.Then the electric signal of the dynamic type vibrator 1 from output terminal 4a is removed of disturbing sound waves other than the target bearing as the electric signal being the difference of the two electrostrictive type bimorph vibrators 2a, 2b are outputted from output terminal 5a and at the same time the phase comparison for the purpose of bearing determination without phase shifter is made possible. |
