Method for dynamically calibrating a fingerprint sensor

Abstract

The invention belongs to the technical field of capacitive fingerprint sensors, and provides a calibration method for improving the image quality by dynamically optimizing the working state of a sensor. According to the method, the whole semaphore range is reasonably estimated by selecting the representative lines or points in the dot matrix and counting the semaphore of the representative lines or points, so that the calibration time is shortened. The range of the semaphore is changed by modifying the working state of the sensor, the image contrast can be improved, and noise interference is reduced. When the fingerprint line depth difference is large, the sensor parameters can be dynamically adjusted to improve the image contrast. Completely adapting to the current environment, and enabling the sensor to automatically switch the optimal working state by dynamically adjusting the hardware parameters of the sensor so as to optimize the image acquisition effect; the problem of calibration data failure caused by process difference, fingerprint difference and module abrasion and smudginess is effectively solved, and the image acquisition yield of the fingerprint sensor is improved.

Description

technical field [0001] The invention relates to the technical field of fingerprint sensors, in particular to a method for dynamic calibration of fingerprint sensors. Background technique [0002] At present, fingerprint identification technology (fingerprinting) is the most mature, cheapest, and most widely used biometric identification technology. We can not only see fingerprint identification technology in access control and attendance systems, but also have more fingerprint identification applications in the market. : such as notebook computers, mobile phones, automobiles, and bank payments can all apply fingerprint recognition technology. A complete fingerprint recognition includes three modules: image collection, entry, and matching, among which the fingerprint sensor is responsible for completing the "image collection" function. However, the sensor itself is greatly affected by the environment, and the fingerprint data collected by different application devices or sce...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the deficiencies of the prior art, the present invention discloses a method for dynamic calibration of a fingerprint sensor, which is used to solve the problem of poor image quality caused by calibration data invalidation caused by changes in the surface thickness of the module due to the production process or the wear and tear of the module. Poor problem, aiming to provide a simple, efficient and stable method to ensure real-time update of calibration data, safe and reliable dynamic calibration method of fingerprint sensor

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