An ultrasonic camera having a high efficiency ultrasonic lens is coupled to a ultrasonic transmitter/receiver by a stretched membrane interface. The ultrasonic lens provides highly efficient transmission of ultrasound without introducing aberrations. The ultrasound system also uses a quasi incoherent source to reduce speckle noise in the image.

An ultrasonic camera having a high efficiency ultrasonic lens is coupled to a ultrasonic transmitter/receiver by a stretched membrane interface. The ultrasonic lens provides highly efficient transmission of ultrasound without introducing aberrations. The ultrasound system also uses a quasi incoherent source to reduce speckle noise in the image.

An ultrasonic probe for performing a scanning of an ultrasonic wave by a reflection mirror is disclosed. The probe comprises an ultrasonic wave generating means formed by a focusing element, an ultrasonic transducer, and an ultrasonic focusing element added to the ultrasonic transducer, a reflecting mirror being a convex ultrasonic mirror for reflecting the ultrasonic wave from the ultrasonic wave generating means or a concave ultrasonic mirror for reflecting the ultrasonic wave from the ultrasonic wave generating means, the distance between the convex ultrasonic mirror and the focusing element and ultrasonic transducer is made shorter than a focal length of the ultrasonic transducer, the distance between the convex ultrasonic mirror and the ultrasonic focusing element added to the ultrasonic transducer is made shorter than a focal length of the ultrasonic focusing element, the distance between the concave ultrasonic mirror and the focusing element and ultrasonic transducer is made longer than a focal length of the ultrasonic transducer, and the distance between the concave ultrasonic mirror and the ultrasonic focusing element added to the ultrasonic transducer is made longer than a focal length of the ultrasonic focusing element.

The disclosure is directed to a method and apparatus for non-destructive inspection of a solid workpiece, such as a steel workpiece. In accordance with the method of the invention, ultrasound is generated at an annular ring or portion thereof and focused into a hollow substantially cone-shaped beam, or sector thereof. The beam is directed at the surface of the workpiece so as to establish shear mode ultrasound energy in the workpiece. Ultrasound energy is then received from the workpiece (e.g. by reflection or transmission) and characteristics of the internal structure of the workpiece can be determined from the received ultrasound energy. In the preferred embodiment of the invention, the beam is configured such that the ultrasound energy impinging on the surface of the workpiece is at a sufficiently large angle with respect to the normal to the surface such that primarily shear mode of ultrasonic energy will be established within the workpiece. In a form of the invention, a second beam of ultrasound energy is generated and focused within the annular ring, this second beam being used to inspect the workpiece with a compressional mode of ultrasonic energy. In a form of the invention, an ultrasound-reflective surface is disposed in the path of the beam to correct for the inherent focusing effect of the curved surface contour of a workpiece to be inspected.

An acoustic lens system is constructed so that at least one surface of acoustic lenses constituting the acoustic lens system is an aspherical surface, which has such a shape that curvature moderates progressively in separating from the axis of the acoustic lens system, and an acoustic beam stop is provided therein. As a result, aberrations can be favorably corrected even when the angle of view and the numerical aperture are increased and this brings about the acoustic lens system suitable for an objective lens of an acoustic system for securing an image of an object having a two-dimensional size in particular.