Device for the detection of an acoustic image
AssigneeU.S. Philips Corporation
InventorCornelis Martinus van der Burgt
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Abstract
Apparatus for the detection of an acoustic image by means of an election tube including a face plate and an electronically scanned transducer made of a thin foil of polymer material whose acoustic wave velocity of propagation is less than 1.8 that of a liquid imaging medium. The face plate also is made of a polymer material having a velocity of propagation less than 1.8 that of said liquid. Preferably, the transducer foil is much thinner than the face plate and has a thickness approximately 0.5 times the acoustic wavelength.
Claims9
An electron vacuum tube comprising a face plate which is capable of withstanding the pressure difference between the inside and outside of the tube and which is made of a polymer material having a low velocity of acoustic propagation, a transducer for converting an acoustic image into a corresponding electric charge image and located inside of the tube adjacent the face plate, said transducer being formed of a stretched thin foil made of a polymer material which also has a low velocity of acoustic propagation and has a remanent electrical polarization, the velocity of acoustic propagation of the face plate and transducer material each being less than 1.8 times that of a liquid medium used to image the acoustic wave image onto the transducer via said face plate, the transducer being thinner than the face plate and approximately 0.5 times the acoustic wavelength, and means for electronically scanning the transducer charge image.
Apparatus for the detection of an acoustic image comprising, an electron vacuum tube including a non-piezoelectric face plate, a transducer for converting an acoustic image into a charge image and means for electrically scanning the transducer charge image, acoustic imaging means including a liquid medium and an acoustic lens for imaging acoustic waves of said image onto the transducer, the transducer being separated from the liquid medium by the electron tube face plate which is capable of withstanding the difference in pressure that exists between the vacuum inside the tube and the surrounding liquid, wherein the face plate is made of a polymer material having a velocity of propagation for acoustic waves which in relation to that of the liquid is less than 1.8, the transducer comprises a thin foil of polymer material applied to the face plate and is appreciably thinner than the face plate and has a thickness approximately 0.5 times the acoustic wavelength, and the velocity of propagation for acoustic waves in the transducer material in relation to that of the liquid is less than 1.8.
Apparatus for the detection of an acoustic image of an object comprising, a liquid medium for the propagation of acoustic wave energy, a source of acoustic wave energy for irradiating the object via the liquid medium, an electron tube having a non-piezoelectric face plate the outer surface of which is adjacent the liquid medium and the inner surface supporting a transducer for converting acoustic energy into an electric charge image, means for focusing the acoustic image reflected from the object onto said transducer via the liquid medium and the tube face plate, said electron tube including means for electronically scanning a charge image formed on the transducer, wherein the improvement comprises a face plate made of a polymer material having a velocity of propagation for acoustic waves which is less than 1.8 the acoustic wave velocity of propagation of the liquid medium, a transducer made of polymer material whose velocity of propagation for acoustic waves is less than 1.8 the acoustic wave velocity of propagation of the liquid medium, the thickness of the transducer being less than that of the face plate and approximately 0.5 times the acoustic wavelength.
Dependencies are inferred from the claim text.