ULTRASONIC RECEIVING DYNAMIC FOCUSING CIRCUIT

摘要

PURPOSE:To prevent the mixing of switching noise and to simplify circuit constitution, by employing constitution for gradually changing over the delay line equipped with the tap. CONSTITUTION:A delay line 1 equipped with a tap is one for changing over a delay time and this change-over of the tap is performed by switching elements 2. Tap change-over is performed by either one of the switching elements 2 on the basis of the gradually changing selection signal generated by a selection signal generation circuit 3 and the current corresponding to the ultrasonic receiving signal supplied from a current source 4 is supplied to the tap of the delay line 1 equipped with the tap to give a receiving dynamic focus.