JPS6462131A - Endoscope - Google Patents

Abstract

PURPOSE:To measure the inner diameter of a tubular body and to observe the interior of tissue, by internally mounting an ultrasonic transmitter-receiver, which transmits an ultrasonic wave to the outside from the leading end part of a tube in a specific direction and receives the reflected wave in the same direction, to the leading end part of the tube. CONSTITUTION:An ultrasonic transmitter-receiver 2 is constituted by forming electrodes to the inner and outer surfaces of a cylindrical piezoelectric body so that electrodes R1-R4, S1-S4 respectively divided into four in the circumferential direction in two upper and lower stages are formed to the outer surface and a common electrode B is formed to the inner surface. An ultrasonic wave transmitter is constituted of the four electrodes S1-S4, the common electrode B on the inner surface and the cylindrical piezoelectric body held between the electrodes on the outer and inner surfaces while an ultrasonic wave receiver is constituted of the electrodes R1-R4, the common electrode B and the cylindrical piezoelectric body held between said electrodes. At first, when an transmitting pulse is applied to the electrode S1, the piezoelectric body at the part of this electrode vibrates in a thickness mode to transmit wave reflected from the inner wall of a tube to be observed reaches the electrode R1 and the piezoelectric body at the part of this electrode vibrates to generate electromotive voltage in the electrode R1. The same processing is also performed with respect to the electrodes S2-S4 to perform measurement in the direction of the circumference 4 of the leading end part of the tube.