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A Guide to Different Types of Fingerprint Scanners

Fingerprint Scanners

“Find an in-depth guide on the different types of fingerprint scanners available for use in the market. Learn their differences and technology.”

Biometric identification & security systems have been around for decades, gaining popularity with time. One of the most popular biometric technologies is fingerprint identification. Throughout the years, we have developed many different types of fingerprint scanners, suitable for a variety of applications. Using different sensors and scanning techniques, these devices provide a robust security solution for many devices & industries.

So, let’s check out the different types of fingerprint scanners available.


What are Fingerprint Scanners?

These are a type of biometric identification system that uses the fingerprints of a person to identify them. These scanners can use a variety of technology to scan the patterns of fingerprints. These scanners are used in a vast variety of technologies like smartphones, laptops, locks, attendance machines, ATMs, etc.

They can form an essential part of the security systems in smart home automation using IoT. However, when used in different applications, they may use different types of technologies to accomplish their tasks.

So, let’s discuss the types of scanners in the market.


Different Types of Fingerprint Scanners Available in the Market

There are many techniques that a device can use to identify the fingerprints of a user, as I pointed out above. Using these technologies, the scanners can record the distinctive shapes of the fingerprints and match them with the images already existing in the database. 

There are four classifications of fingerprint scanners-

(A). Optical Scanners

As the name suggests, this scanner uses optical recognition to work. The scanner consists of an illumination source (LED) that lights up the surface of the finger. An internal camera inside the scanner takes multiple up-close images of the finger and then uses image processing software to match it with the images in the database.

(B). Capacitive Scanners

Unlike optical scanners, these do not use a camera or light-sensing scanner of any kind. Rather, these scanners consist of an array of hundreds or even thousands of micro-capacitors under the surface layer. These capacitors are charged and measure the capacitance. Whenever a finger is put on the scanner surface, the tiny ridges and valleys of the fingers change the capacitance of the capacitors, based on their distance from it. 

The closer the finger surface is to the capacitor, the lower the capacitance. This data is then sent to an amplifier and then converted into a detailed digital representation of the subject’s fingerprints.

(C). Ultrasonic Scanners

As the name suggests, these scanners use sound instead of images or capacitors to read fingerprints. These scanners use a combination of tiny speakers to generate an ultrasonic soundwave. This wave goes towards the screen and reflects back after hitting the surface of the finger. The scanner has an array of mechanical stress sensors on its surface that can detect minute pressure.

The reflected waves hit these sensors, and using the time and the pressure of the waves the sensor can create a 3D image of the fingerprint.

(D). Thermal Fingerprint Scanner

There are many ways that we have developed to measure and detect biometrics, trying to find more efficient and robust ways of biometric security. One such method is to use thermal imaging technology to distinguish between fingerprints. These scanners utilize a pyro-electric sensor to generate a detailed image of fingerprints.

To simplify, pyroelectric refers to any technology that can convert heat/difference in temperature into electrical charge. These sensors work by converting the rise in temperature by encountering the ridges on a finger into an electrical charge. This allows the sensor to create an accurate shape of the fingerprints, based on the temperature difference zones on the sensor surface.

(E). In-Display Scanners

Lastly, the in-display technology. Unlike most screen devices (smartphones & wearables) where the scanners are located on the back or side, some of the devices have the scanners hidden inside the display. This allows the phones to be slimmer, have fewer buttons, and have bigger display surfaces. In-display scanners can use two types of sensors, namely: Ultrasonic, and Optical. The sensors are hidden behind the display of the device and use a small sensor to detect the fingerprint without hampering the aesthetic or functioning of the display.


Comparison Between Different Types of Fingerprint Scanners

If you’ve read this far then you know the basics of all the different types of scanners available in the market for use. But which one is the best, and why? Which type of scanner is the perfect one for your needs?

The only way to know the answers to these questions is to have a comparison between the different types of scanners.

(A). Cost

The cost of scanners can vary depending on many factors like the time it takes to produce a single unit, the cost of the materials required, the cost of all the manufacturing and fabrication processes, etc. 

By far, Capacitive scanners are the most expensive type of fingerprint scanners. Other scanners like ultrasonic, thermal, and optical sensors are relatively less expensive and affordable. 

(B). Tamper Resistance

An essential part of any security system is its ability to withstand tampering without compromising its functionality. Even though biometric systems are quite robust, yet they are not perfect and some of them can be fooled.

For instance, optical scanners rely on images of the fingerprint, thus, by using an imprint of an authenticated fingerprint, you can easily fool the system. On the other hand, scanners like capacitive ones, require the exact conductive surface shape to work, making tampering with it next to impossible. In addition, since capacitive requires a charged surface, dead flesh does not work with these scanners.

The only way to hack robust scanners like capacitive, and ultrasonic scanners, is to hack the system and override it.

(C). Speed

The one issue with fingerprint scanners is the speed and rare glitches due to external factors. When it comes to a security system, you want to keep it streamlined and functioning smoothly. Scanners like thermal and ultrasonic can have slow scanning speeds. Thermal scanners are also susceptible to outside temperatures affecting the accuracy of their scans, etc.


Workings of Fingerprint Scanning

We have discussed the types of fingerprint scanners and their differences. But we are yet to know how exactly fingerprint scanning works. How do we distinguish between different sets of fingerprints? To learn that we need to understand all the components of fingerprints.

The skin on our fingertips is not as smooth as the rest of our body. The skin there is folded into specific patterns. These folds allow us to have a better grip on objects & improved dexterity. The folds can be divided into two parts, the folds that extend outwards are known as the ridges. The fold inwards of the fingers are known as valleys.

The shapes & sizes of the ridges and valleys create distinct patterns on your fingertips. Ridges can be further divided into three types. These are known as Arc, Loop, and Whorl. The scanner uses specialized sensors to identify and map the exact positions, shapes, and sizes of these patterns to identify the difference between different fingers.


Benefits of Utilizing Fingerprint Scanners

There are a variety of identification & security systems available, like Passwords, PIN Codes, Electronic Access Keys/FOB, etc. However, biometric security is still the most popular form of security system used for valuable items.

Let’s discuss why that is the case.

(A). Security

The biggest advantage of using fingerprint scanners for authentication & identification is the exceptional security it offers. Unlike keys, FOBs, or other methods, biometrics are extremely difficult to replicate. It takes a lot of time and sophistication to capture and recreate a fingerprint. Even then, using the replicated fingerprint doesn’t work on scanners that use capacitive sensors.

(B). Faster

Fingerprint scanners are also very fast at identifying prints of different individuals. Unlike passwords, electronic keys, or cards, these scanners can work significantly faster, giving access to systems without causing delays. With the advancement in imaging technology and processing speeds, many scanners can identify prints in little as 0.2 seconds.

(C). Easy to Integrate

As we have developed this technology more and more, we have been able to reduce the size and thickness of the sensors. This has allowed us to integrate them into smaller spaces. The latest ultrasonic sensors can be as thin as 0.6 mm.


Frequently Asked Questions

Q1. What type of fingerprint scanner is best?

Of all the fingerprint scanner technology available, the best by far, keeping in mind factors like cost, speed, safety, etc., is the ultrasonic scanner.

Q2. What is the most common type of fingerprint sensor?

There are four primary types of fingerprint scanners, namely – optical, capacitive, ultrasonic, and thermal. They all use different types of sensors and technology to identify & differentiate between fingerprint biometrics.

The most common type of scanner used throughout the world is the optical fingerprint scanner.

Q3. Which biometric is most secure?

The reason that biometric systems offer the most security is the inability to be replicated. It is easy to find out and replicate passwords, and PINs. It’s even possible to steal encrypted data like RFID data, through spoofing techniques.

However, biometrics is a completely different game. You will find it quite impossible to replicate someone’s fingerprints, iris pattern, or retinal shape.


Disclaimer: The information presented here is for general information purposes only and true to best of our understanding. Users are requested to use any information as per their own understanding and knowledge. Before using any of the information, please refer to our Privacy Policy and Terms and Conditions.


  • Created on Aug 16, 2023
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