Patent ID: 8089826

Claim:
A ultrasonic device for detecting a direction to an object comprising: a transmitting element for transmitting a transmission ultrasonic wave; first and second receiving elements for receiving a reflection wave, which is reflected on the object, wherein the first and second receiving elements are arranged in an array manner; a diffraction wave phase detector for detecting a phase of a diffraction wave penetrating into each of the first and second receiving elements, wherein the diffraction wave is generated in such a manner that a part of the transmission wave is diffracted and penetrates into the first and second receiving elements; an initial phase memory for storing the phase of the diffraction wave as an initial phase under a predetermined sound speed; a sound speed detector for detecting a sound speed; a phase correction amount calculator for calculating a phase shift of the diffraction wave received by each of the first and second receiving elements, wherein the phase shift is caused by a sound speed change, and for calculating a phase correction amount in each of the first and second receiving elements based on the phase of the diffraction wave, the initial phase of the diffraction wave and the phase shift of the diffraction wave; a phase correction element for correcting a phase of the reflection wave received by each of the first and second receiving elements based on the phase correction amount; and a direction detector for detecting the direction to the object based on a difference between a corrected phase of the reflection wave received by the first receiving element and a corrected phase of the reflection wave received by the second receiving element, a distance between the first and second receiving elements, and a wavelength of the transmission ultrasonic wave corresponding to the sound speed.