Terminology » Other Wireless » Fingerprint Sensor Basics and Types

Fingerprint Sensor Basics and Types

sensor fingerprint biometric identification scanner

This page covers the basics of fingerprint sensors and describes different fingerprint sensor types. It also includes specifications from Fingerprint Cards AB.

Definition: A fingerprint sensor is an electronic device used to capture the fingerprint pattern. This sensor is a key component of a fingerprint scanner.

The captured biometric sample of a finger is used for identification purposes. Different technologies are employed in fingerprint sensors for sensing, leading to various types of sensors, as mentioned below.

Based on the underlying technology, the following fingerprint sensor types are available:

Optical
Thermal
Pyroelectric
Piezo-electric
Ultrasound
Capacitive
Piezoresistive
MEMS etc.

fingerprint sensor used in fingerprint scanner

Figure 1 shows how a fingerprint scanner works.
As shown in the block diagram, a person places their finger on the scanner device.
The sensor captures the finger image.
An ADC (Analog-to-Digital Converter) converts this captured analog data into digital data.
The digital data is then transferred to a PC or laptop via a suitable interface cable.
Once the live data is available in the system, it’s compared against a previously stored database of fingerprints.
Based on this comparison, the system determines whether the captured finger image is valid or not.

Fingerprint Sensors from Fingerprint Cards, AB

Fingerprint Cards AB has developed various types of fingerprint sensors, including touch-based, swipe-based, and area-based sensors.

Here are the specifications of their fingerprint sensors:

Touch-based fingerprint sensor: This type operates on the principle of capacitive sensing. It captures images in 256 true grayscale levels.
Swipe-based fingerprint sensor: This type utilizes 3D sensing technology. It captures images with very high resolution and 256 grayscale values.
Area-based fingerprint sensor: This type works by using a reflective method of measurement.