Ultrasonic guided wave transducer, terminal equipment and fingerprint identification method

Abstract

The embodiment of the invention relates to terminal equipment. The terminal equipment comprises a display screen and a processing circuit. The display screen comprises an ultrasonic guided wave transducer array, and the ultrasonic guided wave transducer array comprises at least one ultrasonic guided wave transducer. The at least one ultrasonic guided wave transducer can excite a Quasi-Rayleigh modal ultrasonic guided wave signal. The working frequency thickness product of the ultrasonic guided wave transducer is within the range of 5MHz. mm to 15MHz. mm. The at least one ultrasonic guided wavetransducer is used for transmitting an ultrasonic guided wave sound field signal. The processing circuit receives the scattered sound field signal, obtains a first fingerprint image according to thescattered sound field signal, and compares the first fingerprint image with a pre-stored second fingerprint image. When the first fingerprint image is matched with the second fingerprint image, an application operation is executed. The terminal excites an ultrasonic guided wave sound field with good characteristics and single mode on the display screen cover plate glass, weakens the influence of frequency dispersion characteristics of the sound field, eliminates coherent interference caused by multi-mode characteristics, improves the signal-to-noise ratio of a detection signal, and ensures thespatial resolution and contrast resolution of fingerprint imaging.

Description

technical field [0001] The invention relates to the field of fingerprint detection, in particular to an ultrasonic guided wave transducer, terminal equipment and a fingerprint recognition method. Background technique [0002] As a biometric identification technology, fingerprint recognition has lifetime validity, uniqueness and convenience, and has become a standard configuration of smartphones. Such as figure 1 As shown, full-screen fingerprint recognition has become the main trend in the current smartphone development. It can realize fingerprint recognition anywhere on the mobile phone display, which can effectively increase the screen-to-body ratio, provide users with a good fingerprint unlocking experience, and support more Safe, interactive applications. [0003] At present, the main technical problems faced by the full-screen fingerprint recognition technology include: display problems, the fingerprint sensor is integrated with the screen module, and the display func...

AI Technical Summary

Problems solved by technology

[0003] At present, the main technical problems faced by the full-screen fingerprint recognition technology include: display problems, the fingerprint sensor is integrated with the screen module, and the display function of the display screen cannot be affected at the same time; the cost problem is to expand the fingerprint detection area from the previous fixed area to the entire mobile phone display Screen, can not add too much cost to the existing screen module and fingerprint detection module; penetration problem, the display screen has a complex layered structure, it is necessary to penetrate the fingerprint signal on the surface of the mobile phone display screen to clearly image In the image detection layer

Among them, the ultrasonic fingerprint sensor in the ultrasonic solution cannot be transparent, and placing it on or in the display will affect the display, and it will be reflected by the multi-layer material of the display module under the display, which will make the signal-to-noise ratio of the receiving end very low. Low, while the yield rate of large-area ultrasonic sensors is low and the cost is very high

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