Abstract: The invention relates to devices using transducer elements comprising a film of piezoelectric polymer arranged between electrodes. The transducer element in accordance with the present invention is in the form of a thermoformed protuberance. These devices are used for detecting and generating elastic compression waves, for infrared radiation, and for storing electrical energy.

Abstract: A piezoelectric transducer having at least one active element consisting of a film of polymer material is disclosed. Electrodes are formed on the two principal faces of the film after polarization of the film. The film is endowed with piezoelectric properties under the sole action of an electric field oriented along the normal to its principal faces and without any need for preliminary stretching. The anisotropy induced as a result of this orientation is solely electrical.

Abstract: This invention relates to the production of information carriers on which the information is recorded along a track; the process of making the information carrier comprises a first step of materializing the track itself before recording any information by forming a groove in an auxiliary layer, the track thus being capable of being optically detected, and a second step of recording the information in a photosensitive layer in contact with the auxiliary layer along the track previously formed.

Abstract: This invention relates to the production of information carriers on which the information is recorded along a track; the process of making the information carrier comprises a first step of materializing the track itself before recording any information by forming a groove in an auxiliary layer, the track thus being capable of being optically detected, and a second step of recording the information in a photosensitive layer in contact with the auxiliary layer along the track previously formed.

Abstract: The invention relates to devices using transducer elements comprising a film of piezoelectric polymer arranged between electrodes. The transducer element in accordance with the present invention is in the form of a thermoformed protuberance. These devices are used for detecting and generating elastic compression waves, for infrared radiation, and for storing electrical energy.

Abstract: This invention relates to the production of information carriers on which the information is recorded along a track; the process of making the information carrier comprises a first step of materializing the track itself before recording any information by forming a groove in an auxiliary layer, the track thus being capable of being optically detected, and a second step of recording the information in a photosensitive layer in contact with the auxiliary layer along the track previously formed.

Abstract: The invention relates to an arrangement for pressing flexible discs by compression under heat, comprising heating plates, each carrying a plate of flexible closed-cell foam similar in diameter to the engraved matrices. The flexible disc to be pressed is placed between an engraved matrix and a counter plate or a second engraved matrix, the assembly being placed between the plates of closed-cell foam in such a way that, during compression, these cellular foam plates act as a pneumatic compensator and enable the pressure to be uniformly distributed over the surface to be engraved.