PURPOSE: To make it possible to obtain a predetermined three-dimensional image by using an ultrasonic wave transmission system for transmitting a plane, by performing the transmission of the code between a rotary part and a stationary part by an optical means.

CONSTITUTION: For example, in taking the tomogram of the human body, the human body (a) is present on a stationary table and an ultrasonic wave transmission system is rotated. A rotary part (b) is connected to a housing through slide balls and the output source of the ultrasonic wave transmission system and a receiving plane are placed thereto. A transmission system for transmitting the output source of the ultrasonic wave transmission system to a file unit F is constituted of an optical mechanism and the disconnection of the physical connection between a stationary system and a motion system is prevented by said optical mechanism. In this case, by setting the code transmitting speed of a code transmitting system due to light to about 270Mb/s, all data are transmitted to the file unit F. By this mechanism, a predetermined three-dimensional image can be obtained by using the ultrasonic wave transmission system.