Discussion on FPC Fingerprint Module Technology
The FPC fingerprint module can be divided into: according to its fingerprint identification method:
1. The optical fingerprint module recognizes the fingerprint by the principle of light refraction and reflection;
2. The capacitive fingerprint module collects fingerprints by changing the value of the capacitor;
3, RF fingerprint module (scratch fingerprint module), using trace RF signals to detect texture.
Principle of FPC fingerprint module: The optical fingerprint module adopts the principle of light refraction and reflection. Light is emitted from the bottom towards the prism and is emitted by the prism. The angle at which the light is emitted is refracted on the uneven line of the finger's finger surface, and the brightness of the light reflected back and forth is different. CMOS or CCD optics collect image information at different brightness levels to complete fingerprint acquisition.
2, the semiconductor fingerprint module, whether it is capacitive or inductive, the principle is similar, on a "flat" integrated with thousands of semiconductor devices, the finger is attached to it and constitutes the other side of the capacitor (inductance) Since the finger plane is uneven, the actual distance between the bump and the concave contact plate is different, and the capacitance/inductance value is different. The device collects the different values according to this principle. The fingerprint collection is completed.
3. The radio frequency fingerprint module utilizes bio-radio fingerprint identification technology, and emits a small amount of radio frequency signals through the sensor itself, and penetrates the skin layer of the finger to control the inner layer texture to obtain the best fingerprint picture. The anti-counterfeiting fingerprint ability is strong, and the radio frequency identification principle only responds to human dermis skin, which fundamentally eliminates the problem of artificial fingerprint.