A high -precision fingerprint sensor with anti -parasitic capacitance effect

Abstract

A high-precision fingerprint sensor with anti-parasitic capacitance, comprising N detection units, the N detection units are distributed in an array, the detection unit includes a built-in built-in metal layer electrode, and a detection capacitor C can be formed between the built-in metal layer electrode and the finger plate , any two adjacent built-in metal layer electrodes are connected through switches. The sensor circuit adds a working mode, which can be switched with the traditional mode, and the output results of the two modes can also be compared with each other. By connecting the electrodes of the detection unit to each other through switches, the effect of enhancing the resolution of the sensor is achieved. The results of the enhanced mode can be compared with the results of the conventional mode to enhance the resolution and accuracy of the chip.

Description

technical field [0001] The invention relates to the field of fingerprint identification, in particular to a high-precision fingerprint sensor that is resistant to the influence of parasitic capacitance. Background technique [0002] With the advancement of society and the development of technology, in recent years, e-commerce services such as mobile banking, mobile wallets, and online shopping have been increasingly applied on smart mobile devices. In contrast, the public has higher and higher requirements for the performance of integrated electronic components and network information security. Fingerprints are an effective means of personal identification due to their uniqueness and stability. There are many types of fingerprint sensors, and there are currently three mainstream types: optical imaging fingerprint sensors, crystal capacitive (or pressure-sensitive) fingerprint sensors, and ultrasonic imaging fingerprint sensors. The optical device takes the principle of tot...

AI Technical Summary

Problems solved by technology

Therefore, the ESD discharge line network has a great impact on the accuracy of the sensor, especially for the sensor array at the edge, the ability to collect fingerprints is greatly weakened, and even cannot collect fingerprints, resulting in the loss of edge fingerprint images

[0005] At the same time, increasing the area of ​​the sensing electrode of the detection unit can effectively increase the accuracy of the fingerprint sensor, but considering various factors now, the size of a single fingerprint detection unit has a unified standard in the industry, so the current single built-in metal layer electrode , the maximum area is determined

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