| 摘要 |
PURPOSE:To secure the quality of a picture with a high resolution with a view obtained in the overall length of an array by increasing or reducing the number of vibrators at the end of a vibrator array. CONSTITUTION:As the number of driving vibrators is increased to 2, 4, 6 and 8 at the left end of a vibrator array, signals are received or transmitted by each number. Then, after they are shifted by one, eight vibrators are driven. Thereafter, eight vibrators are simultaneously driven as shifted by one until the unit of eight vibrators reaches the right end of the array. Then, the number of the vibrators is reduced to 6. Likewise, each time it reaches the right end, the number thereof is reduced to 4 and 2 sequentially. As a result, the number of scan lines goes to (N-1) providing a view (M-2)d. Thus, an image can be obtained in substance covering the entire range of the vibrator array. |
