How Fingerprint Sensor in Smartphones or Laptops Works, The Technology Behind It & Its Types.

Introduction : A fingerprint sensor is an electronic device used to capture a digital image of the fingerprint pattern.
A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger.
Human fingerprints are detailed, nearly unique, difficult to alter, and durable over the life of an individual, making them suitable as long-term markers of human identity.
A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger.

Basically it recognizes patterns from the highs and lows from your finger. Each finger has a unique patter. Now how it does this in depth depends on which type of fingerprint scanner the phone uses.
Many technologies have been used including optical, capacitive, RF, thermal, piezoresistive, ultrasonic, piezoelectric, MEMS.

There are 3 Basic Types of Fingerprint Sensors:

Optical fingerprint sensor:
These type of sensors have a source light, which emits laser light to a prism. The prism is placed in such an angle to this light that due to total internal reflection, the light emitting from the source touches a side of the prism and reflects back. This reflected light is then captured by a sensor.
This captured light is then converted into a digital image and used for validation. When you place your finger on the sensor, you block the total internal reflection from the source, thereby helping the sensor to take a high resolution picture of your finger.

Capacitive fingerprint sensor:
These type of sensors discard the source light and the prism. They directly use the sensor and charge coupled device under metallic plate. They receive charges from your finger. The ridges of your finger conduct electricity and valleys don’t. This creates a charge pattern in the CCD, which can be used for validation.

Image Credit : Pixabay

Ultrasonic fingerprint sensor:
These sensors emit ultrasonic waves from a source which can travel through glass, metal, etc. but gets reflected by your finger. These reflected waves are captured back by its receiver and a 3D model of your fingerprint is created for validation.

These are the Basic Principles of any Fingerprint Sensor and how the sensors work is entirely dependent on the type of Fingerprint Sensor used in Electronic Devices such as Smartphones or Laptops by the Manufacturers.

Thanks For Reading.
Don't Forget To Leave Your Comments and Feedbacks & Do Like and Share This Post.