Why Fingerprint Locks Can't Be Recognized With Sweating Fingerprints
2019-04-11 01:08:29
If you have a fingerprint lock in your home, sometimes you may encounter the problem that fingerprints can't be identified. At this time, it may be a black question mark expression package. Then you begin to wonder if you have got a false fingerprint, which is not because your fingerprints are false, nor the fingerprint lock is invalid, but because your fingerprint input posture is wrong and it may be you. There is sweat on the finger, which makes the fingerprint lock unrecognizable.
At present, there are two main ways of fingerprint acquisition by fingerprint lock, optical and capacitive. Optical fingerprint head obtains fingerprint information by calculating the different distances of light rays between fingerprint groove and ridge and acquisition window. When finger has sweat stain or moisture in acquisition window, it may affect the transmission and distance of light, resulting in errors between the obtained fingerprint information and the original stored information. Recognition failure; capacitive fingerprint lock fingerprint identification sensor is coated with narrow electrodes. When finger is pressed to fingerprint acquisition window, because human body is an electric field, user fingerprint lines and sensor surface will form a coupling capacitance. For high frequency current, capacitance is a direct conductor, so finger will suck a very small current from the contact point. This current flows out of the peripheral electrodes, and the current flowing through the peripheral electrodes is proportional to the distance between fingerprints and the peripheral areas. The controller calculates the current proportion accurately and obtains the data related to the touch lines. When the fingers are sweaty or the collecting window is waterlogged, because the water is conductive, when the user uses fingerprint identification, the current will be affected, so the calculation above is not. Yes, natural recognition is out of order.
So if your fingerprint lock doesn't work, wipe your finger to see if it's sweating on your finger.
At present, there are two main ways of fingerprint acquisition by fingerprint lock, optical and capacitive. Optical fingerprint head obtains fingerprint information by calculating the different distances of light rays between fingerprint groove and ridge and acquisition window. When finger has sweat stain or moisture in acquisition window, it may affect the transmission and distance of light, resulting in errors between the obtained fingerprint information and the original stored information. Recognition failure; capacitive fingerprint lock fingerprint identification sensor is coated with narrow electrodes. When finger is pressed to fingerprint acquisition window, because human body is an electric field, user fingerprint lines and sensor surface will form a coupling capacitance. For high frequency current, capacitance is a direct conductor, so finger will suck a very small current from the contact point. This current flows out of the peripheral electrodes, and the current flowing through the peripheral electrodes is proportional to the distance between fingerprints and the peripheral areas. The controller calculates the current proportion accurately and obtains the data related to the touch lines. When the fingers are sweaty or the collecting window is waterlogged, because the water is conductive, when the user uses fingerprint identification, the current will be affected, so the calculation above is not. Yes, natural recognition is out of order.
So if your fingerprint lock doesn't work, wipe your finger to see if it's sweating on your finger.