| 摘要 |
PURPOSE:To automatically execute focusing, by taking out a detecting signal at the time of focusing by prescribed timing from in a detecting signal of a reflected wave from a sample, comparing it with a prescribed threshold level, and obtaining a stop signal of a focusing mechanism. CONSTITUTION:An ultrasonic wave from a transducer 3 is made to pass through a lens 4, is hit against the surface of a sample 8 through a liquid 5, and a reflected wave is made to pass through a reverse path and is taken out as an output detecting signal from a signal processing circuit 9. Subsequently, a signal from a control pulse generator 14 is converted to a delay pulse 16, and a reflected wave detecting signal is held 15 as a sample and is supplied to a comparator 17. Subsequently, when the surface of the sample has been positioned in a focus of the lens 4, that is to say, only when a detecting signal corresponding to the largest reflected wave has been held, a pulse signal is outputted from the comparator 17, and a controller 13 is controlled so as to stop displacement in the direction Z of the lens 4 by a Z direction driving mechanism 12. |
