Question

what are biometric sensor

Answer 1

Devices and sensors are any mechanical or electronic system used to enroll and capture raw biometric samples in a form that can be digitized and converted to a biometric template. For fingerprints, face, iris, and voice, these are fingerprint sensors, digital cameras, iris cameras, and microphones, respectively. Most fingerprint sensors are based upon either optical or capacitive techniques, but light emitting sensors and multispectral approaches are gaining adoption. Capacitive sensors can be either full-finger or swipe. It is critical to the performance of matchers for fingerprint images to be captured at sufficient resolution (500 ppi) and contrast, be compressed properly with WSQ, and be free of distortion. An optical sensor uses a prism, light source, and light sensor to capture images of fingerprints. Capacitive sensors are based on a silicon chip that detects electrical currents when the finger ridges make contact. Swipe sensors do not generate image quality sufficient for one-to-many identification. Generally speaking, the quantity and consistency of the biometric samples required is a function of the size of the database that must be searched

Answer 2

A biometric sensor is a transducer that converts a biometric treat (fingerprint, voice, face, etc.) of a person into an electrical signal. Generally, the sensor reads or measures pressure, temperature, light, speed, electrical capacity or other kinds of energies.