This application provides an ultrasonic fingerprint recognition module including: a base substrate; at least one ultrasonic wave signal receiver and at least one ultrasonic wave signal transmitter on the base substrate, which are on a same side of the base substrate and spaced apart from each other in a first direction parallel to the base substrate; a piezoelectric sensing layer on a side of the at least one ultrasonic wave signal transmitter and the at least one ultrasonic wave signal receiver distal to the base substrate; and an electrode layer on a side of the piezoelectric sensing layer distal to the base substrate.

A filtering apparatus formed by a plurality of channel systems. Each of the channel systems include an inlet port formed on an inlet side of the plate; no more than one outlet port formed on an outlet side of the plate; and a channel formed in the plate, the channel coupled to the inlet port and to the outlet port, wherein the ratio of the product of the capture area of the inlet ports of a channel system with the first transmissivity associated with the inlet ports to the product of the capture area of the outlet ports of a channel system with the second transmissivity associated with the outlet ports is greater than one. The channel system is configured to interact with objects of interest on a scale which is smaller than a value several orders of magnitude larger than the mean free path of an object of interest. Some plate embodiments are configured to interact with particles, such as air molecules, water molecules, or aerosols. Other plate embodiments are configured to interact with waves or wavelike particles, such as electrons, photons, phonons or acoustic waves.

An ultrasonic sensor and a display device and may drive a plurality of sensing pixels disposed in the ultrasonic sensor simultaneously to transmit an ultrasonic wave, may make a first electrode disposed in a sensing pixel to be floated at a timing receiving a reflected signal to store the signal, and then may perform a sensing sequentially. Therefore, as an accurate sensing may be possible while reducing a duration and a number of an ultrasonic wave transmitting, a sensitivity and an accuracy of a sensing may be maintained while improving a driving efficiency of the ultrasonic sensor.

A method for preparing a polymer composite material is provided. The method includes steps of mixing and heat-treating a first polymer, a second polymer, and a third polymer to obtain a first mixture, adding a light-transmitting material to the first mixture to obtain a second mixture, adding a nano material to the second mixture to obtain a third mixture, performing subsequent processing on the uniformly mixed third mixture to obtain the polymer composite material. The polymer composite material is configured to replace conventional protective glass in ultrasonic fingerprint recognition technology, and to improve accuracy of fingerprint recognition.

A vibration signal generation apparatus includes an absolute value signal generator configured to generate an absolute value signal by detecting an absolute value of amplitude of an acoustic signal, an envelope signal generator configured to generate an envelope signal by detecting an envelope of the absolute value signal, a differentiator configured to differentiate the envelope signal, an amplitude limiter configured to generate an amplitude-limited signal by limiting amplitude of the envelope signal so that an amplitude value of the differentiated envelope signal becomes zero or greater, and a vibration signal generator configured to generate a vibration signal by multiplying the amplitude-limited signal by a reference signal having a frequency that allows a human to perceive a vibration.

A multilayer body includes a piezoelectric body and a first acoustic matching layer in direct or indirect contact with the piezoelectric body. The first acoustic matching layer includes a plastic foam containing a plurality of closed pores. An average pore size of the closed pores is not smaller than 1 μm and not larger than 100 μm. The first acoustic matching layer has a density of not less than 10 kg/m.sup.3 and not more than 100 kg/m.sup.3.

The invention relates to a device for transmitting mechanical vibrations to flowable media. The device is characterized in that the normal amplitudes of the effective surface points of a resonator are substantially uniform during a resonant vibration, and an amplitude vector in the effective surface points of more than 50 percent of an effective surface is not substantially parallel to the normal vector of these effective surface points.

Prior to manufacturing a product by additive manufacturing, a stress relief profile including frequency and amplitude parameters of an ultrasonic input is determined based on physical properties of the product, including resonant frequencies of the product and a material from which the product is manufactured. Successive layers of a material are added and energy is applied to incorporate the material of each layer into the product. A processor accesses stress relief profile parameters for each layer, determines whether a layer requires stress relief and determines a frequency and a power level for the stress relief at the layer. An ultrasonic input is applied with the determined parameters to relieve stress as the product is built up.

A fingerprint recognition module, a display panel and driving method, and a display device are provided. The fingerprint recognition module includes a first electrode layer including a plurality of first electrodes, and a piezoelectric layer disposed on a side of the first electrode layer. The fingerprint recognition module also includes a second electrode layer disposed on a side of the piezoelectric layer facing away from the first electrode layer. The second electrode layer includes a plurality of second electrodes that are arranged along a first direction, and one second electrode overlaps at least two first electrodes. Moreover, the fingerprint recognition module includes a flexible circuit board bonded and connected to the plurality of second electrodes. In a plane parallel to the first electrode layer, the plurality of second electrodes and the flexible circuit board are arranged along a second direction, and the first direction intersects the second direction.

Some disclosed implementations include an ultrasonic sensor stack and an acoustic resonator. The acoustic resonator may be configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in an ultrasonic frequency range that is suitable for ultrasonic fingerprint sensors. In some examples, the acoustic resonator may include one or more low-impedance layers residing between a first higher-impedance layer and a second higher-impedance layer. Each of the one or more low-impedance layers may have a lower acoustic impedance than an acoustic impedance of the first higher-impedance layer or an acoustic impedance of the second higher-impedance layer. At least one low-impedance layer may have a thickness corresponding to a multiple of a half wavelength at a peak frequency of the acoustic resonator. The peak frequency may be within a frequency range from 1 MHz. to 20 MHz.