Abstract: An object is to provide an image display apparatus that outputs a voice by vibrating a display panel using a vibrator, in which a voice with sufficient sound pressure can be heard up to a high sound band. The object is achieved by including a display panel having a pixel pitch of 25 to 100 dpi and a vibrator mounted on a non-display surface of the display panel, in which, in a case where a length of a diagonal line of the display panel is denoted by A, a maximum length Lmax of the vibrator in a direction along a lateral direction of the display panel satisfies “Lmax?(A/0.15)1/2”.

Abstract: Provided is an electroacoustic transducer in which a decrease in sound pressure in a high sound band is suppressed and power consumption can be reduced, in an electroacoustic transducer in which a plurality of vibrators are arranged on a vibration plate. The electroacoustic transducer includes a vibration plate and a vibrator group consisting of a plurality of piezoelectric vibrators arranged on one surface of the vibration plate, in which the plurality of piezoelectric vibrators each belong to any one of a first group to an n-th group, an upper limit frequency of a frequency band of an input signal input to the piezoelectric vibrator is different for each group, and in a case where upper limit frequencies for each group are denoted by f1 to fn, the upper limit frequencies gradually decrease from the upper limit frequency f1 in the first group to the upper limit frequency fn in the n-th group.

Abstract: Provided are a piezoelectric element and an electroacoustic transducer, which can be made thinner while ensuring piezoelectric characteristics in a piezoelectric element.

Abstract: Provided are a laminated piezoelectric element and an electroacoustic transducer capable of obtaining high piezoelectric characteristics and easily ensuring an electric contact to an electrode layer. A plurality of layers of piezoelectric films, each of which is formed by laminating a first protective layer, a first electrode layer, a piezoelectric layer, a second electrode layer, and a second protective layer in this order, are laminated. Each of the piezoelectric layers is polarized in a thickness direction. In each of the piezoelectric films, the first electrode is disposed on an upstream side in a polarization direction of the piezoelectric layer, and the second electrode is disposed on a downstream side.

Abstract: An object of the present invention is to provide a piezoelectric film and a laminated piezoelectric element, in which, in a piezoelectric film including electrode layers and protective layers on both surfaces of a piezoelectric layer containing piezoelectric particles in a matrix containing a polymer material, changes in mechanical properties and electrical properties due to a humidity of an external environment can be reduced. The piezoelectric film includes a piezoelectric layer containing piezoelectric particles in a matrix containing a polymer material, electrode layers provided on both surfaces of the piezoelectric layer, and a protective layer provided on a surface of the electrode layer opposite to the piezoelectric layer, in which the protective layer has a resin substrate and at least one inorganic layer provided on the resin substrate, and a water vapor transmission rate of the piezoelectric film is 1×10?4 g/(m2×day) or less.

Abstract: An object is to provide a laminated piezoelectric element capable of preventing a short circuit between adjacent piezoelectric films and an electroacoustic transducer using the laminated piezoelectric element. The object is solved by laminating a plurality of layers of piezoelectric films polarized in a thickness direction, in which a piezoelectric layer is interposed between two thin film electrodes, and causing polarization directions of the adjacent piezoelectric films to be opposite to each other.

Abstract: An object is to provide a laminated piezoelectric element capable of preventing a short circuit between adjacent piezoelectric films and an electroacoustic transducer using the laminated piezoelectric element. The object is solved by laminating a plurality of layers of piezoelectric films polarized in a thickness direction, in which a piezoelectric layer is interposed between two thin film electrodes, and causing polarization directions of the adjacent piezoelectric films to be opposite to each other.

Abstract: Provided is a laminated piezoelectric element capable of suppressing heat generation while maintaining satisfactory piezoelectric characteristics. The laminated piezoelectric element is a laminated piezoelectric element including a piezoelectric film, in which the laminated piezoelectric element is obtained by laminating a plurality of layers of piezoelectric films each including a piezoelectric layer containing a polymer-based piezoelectric composite material that contains piezoelectric particles in a matrix containing a polymer material, and electrode layers formed on both surfaces of the piezoelectric layer, and in a case where a value obtained by dividing a capacitive reactance Xc of the piezoelectric film at a frequency of 1 kHz by an equivalent series resistance ESR is set to 1, a value XE20 obtained by dividing the capacitive reactance Xc at a frequency of 20 kHz by the equivalent series resistance ESR is in a range of 0.6 to 1.5.

Abstract: An object is to provide a piezoelectric film that has excellent flexibility in a high temperature environment at higher than 50° C. and exhibits good flexibility even at room temperature, a laminated piezoelectric element in which the piezoelectric films are laminated, and an electroacoustic transducer using the piezoelectric film or the laminated piezoelectric element. The object is solved by the piezoelectric film including: a polymer-based piezoelectric composite material in which piezoelectric particles are dispersed in a matrix including a polymer material; and electrode layers provided on both surfaces of the polymer-based piezoelectric composite material, in which a loss tangent at a frequency of 1 Hz according to dynamic viscoelasticity measurement has a maximal value of greater than or equal to 0.1 existing in a temperature range of higher than 50° C. and lower than or equal to 150° C., and has a value of greater than or equal to 0.08 at 50° C.

Abstract: An object is to provide a piezoelectric film that has excellent flexibility in a sub-zero environment and exhibits the required flexibility even at room temperature, a laminated piezoelectric element in which the piezoelectric films are laminated, and an electroacoustic transducer using the piezoelectric film or the laminated piezoelectric element. The object is solved by the piezoelectric film including: a polymer-based piezoelectric composite material in which piezoelectric particles are dispersed in a matrix including a polymer material; and electrode layers formed on both surfaces of the polymer-based piezoelectric composite material, in which a loss tangent at a frequency of 1 Hz according to dynamic viscoelasticity measurement has a maximal value of greater than or equal to 0.1 existing in a temperature range of higher than or equal to ?80° C. and lower than 0° C., and has a value of greater than or equal to 0.05 at 0° C.

Abstract: An object of the present invention is to provide an electroacoustic transducer and an image display device, each of which can be rolled up and does not need a mechanical mechanism and a driving source. The object is accomplished by providing a vibration plate or display element which can be rolled up, and a convex leaf spring having an arc-shaped cross section in the lateral direction and having a concave side disposed facing one surface of the vibration plate or a non-image-displaying surface of the display element.

Abstract: Provided is a laminated piezoelectric element is formed by folding back and laminating a piezoelectric film having an electrode layer and a protective layer on both sides of a piezoelectric layer in which piezoelectric particles are dispersed in a matrix. In the laminated two layers of the piezoelectric film, in a case where a thickness of a central portion thereof is a center thickness and a position up to twice the center thickness in a direction from the folded side end part toward the center is the folded-back portion, there is a position at which the thickness is greater than the center thickness in the folded-back portion, and there is an air gap in the folded-back portion or the air gap is filled with a cementing agent. The laminated piezoelectric element is able to prevent peeling of the electrode layer and the like in the folded-back portion in the laminated piezoelectric element in which the piezoelectric film is folded back and laminated.

Abstract: Provided are a laminated piezoelectric element and an electroacoustic transducer capable of obtaining high piezoelectric characteristics and easily ensuring an electric contact to an electrode layer. A plurality of layers of piezoelectric films, each of which is formed by laminating a first protective layer, a first electrode layer, a piezoelectric layer, a second electrode layer, and a second protective layer in this order, are laminated. Each of the piezoelectric layers is polarized in a thickness direction. In each of the piezoelectric films, the first electrode is disposed on an upstream side in a polarization direction of the piezoelectric layer, and the second electrode is disposed on a downstream side.

Abstract: Provided are an electroacoustic transduction film capable of reproducing a sound with a sufficient sound volume at a high conversion efficiency, a manufacturing method thereof, an electroacoustic transducer, a flexible display, a vocal cord microphone, and a sensor for a musical instrument.

Abstract: An object of the present invention is to provide a polymer-based piezoelectric composite material including lead zirconate titanate particles in a matrix consisting of a polymer material, the polymer-based piezoelectric composite material having a high piezoelectric characteristic; and a method for producing raw-material particles for a composite, the raw-material particles being used in the polymer-based piezoelectric composite material. The object is accomplished by a configuration in which the lead zirconate titanate particles include a polycrystalline material, a crystal structure of primary particles constituting the polycrystalline material of the lead zirconate titanate particles includes tetragonal particles, and a volume fraction occupied by the tetragonal particles is 80% or more.

Abstract: Provided is a stethoscope including: a support base that has an opening portion; a piezoelectric film that is supported by the support base in a state in which a surface exposed from the opening portion is convexly curved, and that detects a vibration caused by a sound which is generated from an object to be measured; and a protective layer that is disposed on a surface of the piezoelectric film on a side which comes into contact with the object to be measured, and that has an acoustic impedance between an acoustic impedance of the object to be measured and an acoustic impedance of the piezoelectric film.

Abstract: An object is to provide a piezoelectric film that has excellent flexibility in a high temperature environment at higher than 50° C. and exhibits good flexibility even at room temperature, a laminated piezoelectric element in which the piezoelectric films are laminated, and an electroacoustic transducer using the piezoelectric film or the laminated piezoelectric element. The object is solved by the piezoelectric film including: a polymer-based piezoelectric composite material in which piezoelectric particles are dispersed in a matrix including a polymer material; and electrode layers provided on both surfaces of the polymer-based piezoelectric composite material, in which a loss tangent at a frequency of 1 Hz according to dynamic viscoelasticity measurement has a maximal value of greater than or equal to 0.1 existing in a temperature range of higher than 50° C. and lower than or equal to 150° C., and has a value of greater than or equal to 0.08 at 50° C.

Abstract: An object is to provide a piezoelectric film that has excellent flexibility in a sub-zero environment and exhibits the required flexibility even at room temperature, a laminated piezoelectric element in which the piezoelectric films are laminated, and an electroacoustic transducer using the piezoelectric film or the laminated piezoelectric element. The object is solved by the piezoelectric film including: a polymer-based piezoelectric composite material in which piezoelectric particles are dispersed in a matrix including a polymer material; and electrode layers formed on both surfaces of the polymer-based piezoelectric composite material, in which a loss tangent at a frequency of 1 Hz according to dynamic viscoelasticity measurement has a maximal value of greater than or equal to 0.1 existing in a temperature range of higher than or equal to ?80° C. and lower than 0° C., and has a value of greater than or equal to 0.05 at 0° C.

Abstract: An object is to provide an electroacoustic transducer consisting of a vibration plate and an exciter and having good flexibility. The object is solved by providing a vibration plate and an exciter, in which a maximal value of a loss tangent of the exciter at a frequency of 1 Hz according to dynamic viscoelasticity measurement is 0.08 or more in a temperature range of 0° C. to 50° C., and a product of a thickness of the exciter and a storage elastic modulus at a frequency of 1 Hz and 25° C. according to the dynamic viscoelasticity measurement is at most three times a product of a thickness of the vibration plate and a Young's modulus.

Abstract: Provided are an electroacoustic transduction film capable of reproducing a sound with a sufficient sound volume at a high conversion efficiency, a manufacturing method thereof, an electroacoustic transducer, a flexible display, a vocal cord microphone, and a sensor for a musical instrument.