An optical fingerprint scanner works by taking a visible light image of your fingerprint. Here's a more detailed breakdown:
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Illumination: The process begins with illuminating your finger, typically placed on a glass plate. This is usually achieved using an array of light-emitting diodes (LEDs).
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Image Capture: The light reflected from the ridges and valleys of your fingerprint is captured by a Charged-Coupled Device (CCD) camera or a similar optical sensor. This sensor essentially acts as a digital "eye" that records the pattern of light and dark areas.
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Digital Image Processing: The CCD captures the image as a pattern of pixels, which is then converted into a digital representation. This digital image is then processed to enhance contrast and clarity.
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Pattern Matching: The processed image is then compared to a stored fingerprint template. The scanner analyzes specific features of your fingerprint, such as ridge endings and bifurcations (points where ridges split), and matches them against the stored template.
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Verification/Identification: If a sufficient number of matching features are found, the scanner verifies your identity (in the case of one-to-one matching, like unlocking a phone) or identifies you from a database of fingerprints (in the case of one-to-many matching).
In summary, optical fingerprint scanners use visible light to create a digital image of your fingerprint, which is then analyzed and compared to stored data for authentication.
