Ultrasonic equipment for examinations using section displays

Claim 1

Ultrasonic equipment for examining an object by scanning a region of a preselectable section surface of the object near a surface of the object and comprising a scanning mechanism including a housing and two focussing sound transducer heads adapted to be adjusted to the preselected section surface of the object and mechanically operable to move a sound beam across the section surface, focussing of the sound beam transmitted by the transducer head improving the lateral resolution by constricting the sound beam in the preselected region compared with a sound beam transmitted by a comparable unfocussed sound transducer head, the length of the region being smaller than the depth of the scanned section surface in the object and said sound beams having respective relatively constricted length zones disposed in different depth zones of said object, and zone control means operable to activate only one of said sound transducer heads at a time, the equipment further comprising scanning depth control means for adjusting the region to different depths and successively scanning the section surface at said depths, a fluorescent screen arranged to receive and display signals derived from echoes generated in response to the transmitted sound beams at locations of the screen geometrically coordinated with the locations in the object where the echoes originated, selecting means for selecting only those echo signals for display on the screen which originated in the selected region, and means defining respective pre-entry zones for the sound beams transmitted by the transducer heads, the sound beams being transmitted through the pre-entry zones in the scanning meachanism housing before they enter the object, the pre-entry zone associated with one of the sound transducer heads having a predetermined length in the housing while the sound beam transmitted by the other transducer head passes through a pre-entry zone of shorter length.