Piezoelectric accoustic sensor with multiple vibrating areas

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• the plurality of vibration regions include a deformation promoting structure that promotes a deformation of the first region as the improvement unit;
• and
• the plurality of vibration regions includes at least a part thereof having different resonance frequencies as the improvement unit.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• the support member has a support substrate and an insulation film arranged on the support substrate and on which the vibration unit is arranged;
• a recess portion for separating each of the plurality of vibration regions is arranged on the support substrate and on the insulation film;
• the recess portion disposed on the support substrate includes an opening on an opposite side of the insulation film as a first opening and an opening on a side of the insulation film as a second opening;
• and
• a side surface connecting the first opening and the second opening has a recessed structure as the improvement unit that is recessed with respect to a virtual line connecting the first opening and the second opening.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• in the electrode film and the piezoelectric film, a lower electrode film, a lower piezoelectric film, an intermediate electrode film, an upper piezoelectric film, and an upper electrode film are stacked in this order from a support member side;
• the intermediate electrode film is divided into a plurality of charge regions having a same area as the improvement unit;
• the plurality of charge regions are connected in series;
• and
• the vibration unit outputs the pressure detection signal according to a charge generated between the lower electrode film and the plurality of charge regions of the intermediate electrode film and another charge generated between the upper electrode film and the plurality of charge regions of the intermediate electrode film.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• the first region and the second region in the plurality of vibration regions include a plurality of virtual regions which are provided by dividing the plurality of vibration regions in a direction intersecting the one end portion;
• the plurality of virtual regions have a capacitance defined as C;
• the plurality of virtual regions have an average value of stress generated in the plurality of virtual regions and defined as σ;
• and
• the first region and the second region in the plurality of vibration regions are partitioned by a boundary line, as the improvement unit, connecting positions where a value of C×σ2 in each of the plurality of virtual regions is maximum.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• the first region and the second region in the plurality of vibration regions include a plurality of virtual regions which are provided by dividing the plurality of vibration regions in a direction intersecting the one end portion;
• the plurality of virtual regions have an area defined as S;
• the plurality of virtual regions have a sum of stress generated in the plurality of virtual regions and defined as σsum;
• and
• the first region and the second region in the plurality of vibration regions are partitioned by a boundary line, as the improvement unit, connecting positions where a value of (σsum)2/S in each of the plurality of virtual regions is maximum.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• the plurality of vibration regions have a planar triangular shape;
• each of the first region and the second region in the plurality of vibration regions provides three triangles prepared by dividing one vibration region of the plurality of vibration regions so as to divide the one end portion into three equal parts as the improvement unit;
• and
• the first region and the second region in the plurality of vibration regions are partitioned by a boundary line connecting positions of centers of gravity of the three triangles and both ends of the one end portion.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• in each of the plurality of vibration regions, the other end portion is warped with respect to the one end portion as the improvement unit;
• and
• the vibration unit outputs the pressure detection signal from each of the plurality of vibration regions as the improvement unit.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• each of the plurality of vibration regions has a reflection film that has a higher reflectance than the piezoelectric film, and is arranged in the second region as the improvement unit.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• the electrode film is disposed in the first region;
• and
• the piezoelectric element further comprising:
• an improvement unit for improving a detection accuracy of the pressure detection signal, wherein:
• in the electrode film and the piezoelectric film, a lower electrode film, a lower piezoelectric film, an intermediate electrode film, an upper piezoelectric film, and an upper electrode film are stacked in this order from a support member side;
• in the lower electrode film, the intermediate electrode film, and the upper electrode film as the improvement unit, a film thickness of the lower electrode film and a film thickness of the upper electrode film are thinner than a film thickness of the intermediate electrode film;
• and a rigidity of the lower electrode film is a same as a rigidity of the upper electrode film.

A piezoelectric element comprising:

• a vibration unit that outputs a pressure detection signal according to a pressure;
• and
• a support member, wherein:
• the vibration unit is arranged on the support member;
• the vibration unit includes a piezoelectric film and an electrode film that is connected to the piezoelectric film and is configured to extract an electric charge generated by a deformation of the piezoelectric film;
• the vibration unit further includes a support region supported by the support member and a plurality of vibration regions connected to the support region and separated from the support member;
• the vibration unit is configured to output the pressure detection signal based on the electric charge;
• each of the plurality of vibration regions has one end portion, which is a boundary with the support region and is a fixed end, and an other end portion, which is a free end;
• a part of each of the plurality of vibration regions on a one end portion side is defined as a first region;
• another part of each of the plurality of vibration regions on an other end portion side is defined as a second region;
• at least a part of the plurality of vibration regions have resonance frequencies which are different from each other;
• and
• the electrode film is disposed in the first region.