| 摘要 |
PURPOSE:To automatically adjust the focus of an ultrasonic mirocsope by applying the focus detecting method employed by conventional optical equipment. CONSTITUTION:When a reflected-wave detection signal at some movement position in the X-axis direction of a sample table 7 is Vn, the evaluated value D of an ultrasonic image of one X-axis line at each position in the Z-axis direction is found by the evaluation function equation in the figure, so that the value D is maximized when an acoustic lens 4 at a focusing Zf for a sample 8. The acoustic lens 4 is moved intermittently to the sampele 8 in the 1st direction on the Z axis and the evaluated values D of the ultrasonic image of one X-axis line at successive positions are found and compared; when their great-small relation is inverted, the acoustic lens 4 is moved in the 2nd direction opposite to the 1st direction until the position where the last evaluated value is obtained, thus placing the acoustic lens 4 at the focusing position for the sample. |
