公开(公告)号：EP4102857A1

公开(公告)日：2022-12-14

申请号：EP21751010.6

申请日：2021-01-12

申请人： FUJIFILM Corporation

发明人： TAMADA, Yoshinori

IPC分类号： H04R17/00 ,  H01L41/09 ,  H01L41/18 ,  H01L41/257 ,  H01L41/313 ,  H01L41/317

摘要： An object of the present invention is to provide a piezoelectric film capable of realizing an electroacoustic conversion film or the like in which the durability is high and a sufficient sound pressure with respect to an input operating voltage is obtained. The object is achieved by providing a piezoelectric film including a polymer-based piezoelectric composite material which contains piezoelectric particles in a matrix containing a polymer material, and electrode layers which are provided on both surfaces of the polymer-based piezoelectric composite material, in which in a case where a cross section of the film in a thickness direction is observed with a scanning electron microscope, the polymer-based piezoelectric composite material is divided into ten equal regions in the thickness direction, area ratios of the piezoelectric particles in two most distant regions are measured, and the area ratio of the piezoelectric particles in the region with a lower area ratio is set as 1, the area ratio of the piezoelectric particles in the region with a higher area ratio is 1.2 or greater.

公开(公告)号：EP3993439A1

公开(公告)日：2022-05-04

申请号：EP20833055.5

申请日：2020-05-29

申请人： FUJIFILM Corporation

发明人： TAMADA, Yoshinori

IPC分类号： H04R7/20 ,  H04R17/00 ,  H01L41/047 ,  H01L41/09 ,  H01L41/18 ,  H01L41/43

摘要： Provided is a piezoelectric film capable of realizing an electroacoustic conversion film or the like in which the durability is high and a sufficient sound pressure with respect to an input operating voltage is obtained. The piezoelectric film is a piezoelectric film including a polymer-based piezoelectric composite material which contains piezoelectric particles in a matrix containing a polymer material, and electrode layers which are provided on both surfaces of the polymer-based piezoelectric composite material, in which in a case where a cross section of the piezoelectric film in a thickness direction is observed with a scanning electron microscope, the polymer-based piezoelectric composite material is divided into two equal regions in the thickness direction, and void volumes of the two regions are measured, a ratio of the void volume obtained by dividing the void volume of the region with a larger void volume by the void volume of the region with a smaller void volume is 1.2 or greater.