| 摘要 |
PURPOSE: To make electric focusing in a plurality of directions possible by dividing an element of array into a plurality of sub-elements in height direction and setting an aspect ratio that varies corresponding to the distance from the central vertical axis of the array to each sub-element. CONSTITUTION: Array 16 comprises a plurality of elements e1 , e2 , and so on. Each element (for example element e1 ) is divided into a plurality of sub-elements (e1 A to e1 D) in height direction. The central sub-element has a size represented by 5-2 that means a width of 5 units in height direction and 2 units in vertical direction, and the sizes of the sub-elements on both sides thereof decrease gradually as being 4-2, 3-2, 2-2, and 1-2 sequentially. All the sub-elements have the same thickness T. Further, a plurality of active electrodes 21, 23, 26, 24 and 22 are all connected to each other by wire 28 soldered to each sub-element. |
