| 摘要 |
PURPOSE:To prevent contact between an acoustic lens and a sample, by constituting so that at first, the sample and the acoustic lens are made to approach each other until an alarm is issued, and focusing can be executed while separating a distance between the sample and the acoustic lens from said state. CONSTITUTION:In a state that an acoustic lens 8 and a sample 10 have apparahed each other to an extreme, a detecting signal from the sample is feeble, therefore, it is amplified by an amplifier 13, and a gate part 14 is provided in order to fetch a signal from a necessary time area in the next place. This necessary time area is set between tb' (=tb+ta) in which detection of a detecting signal (b) from a boundary of the acoustic lens 8 and a liquid 9 ends, and tg in which a time area for fetching a detecting signal as a picture signal starts that is to say, an area between tf and tg. In order to decide whether a detecting signal from the sample exists or not in this area, a detector 10, etc. are provided, and in case when the detecting signal exists, it is formed by an alarm device 17. In this way, contact of the acoustic lens and the sample is prevented. |
