A global scanning fingerprint processing method

Abstract

The embodiment of the present invention discloses a global scanning fingerprint processing method, including: configuring the target scanning area; loading the default gains of PGA1 and PGA2; controlling the scanning of the target scanning area, and determining and configuring the offset circuit 1 based on the preset successive approximation strategy The first offset configuration signal; determine and configure the first target gain of PGA1 based on the ADC output range; determine and configure the second offset configuration signal of the offset circuit 2 based on the preset successive approximation strategy; determine and configure PGA2 based on the ADC output range The second target gain; controlling the sensing electrode array to scan the user's fingerprint to collect the user's fingerprint image; sending the user's fingerprint image to the fingerprint image buffer device. The embodiment of the present invention is beneficial to improving the resolution of the valley and ridge signals of the user's finger when collecting the user's fingerprint, and offsetting the offset noise generated in the signal processing process.

Description

technical field [0001] The invention relates to the technical field of fingerprint processing, in particular to a global scanning fingerprint processing method. Background technique [0002] Such as figure 1 as shown, figure 1 It is an example diagram of collecting user fingerprints by commonly used semiconductor fingerprint collection devices. Wherein, the fingerprint collection chip (that is, the sensor chip) is placed under the protective layer, and the middle is bonded together by glue. Such as figure 2 as shown, figure 2 based on figure 1 The fingerprint collection principle of the semiconductor fingerprint collection sensor shown. Among them, the finger and the metal electrode on the surface of the fingerprint collection chip form a parasitic capacitance. Due to the different distances from the valleys and ridges of the finger to the metal electrodes, the parasitic capacitances formed are also different, so the fingerprint pattern can be reflected by measuring...

AI Technical Summary

Problems solved by technology

[0004] The inventor of this technical solution found in the research process that the parasitic capacitance Cy between the surface of the protective layer and the metal electrode makes Cf shift significantly, that is, the valleys and ridges only account for a part of the total signal amount, especially in the case of wet fingers, Cx is very large, Cf is mainly dominated by Cy, and the resolution of the collected signals of the valleys and ridges of the user's finger is low

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