Phones with Fingerprint Scanner

How does a Mobile Phone with a Fingerprint Scanner Work and How do the Readers Differ?

Phones with a fingerprint reader use different sensing technologies to recognise your fingerprints.

Mobile Phones with a Fingerprint Scanner: The Optical Sensor

The oldest method is optical sensor scanning, which captures high-contrast 2D fingerprint images and then compares the unique patterns of each fingerprint. Mobile phones with a fingerprint reader using an optical sensor can easily be fooled and are therefore not secure.

Mobile Phones with a Fingerprint Scanner: The Capacitive Scanner

Capacitive scanners are a more modern and widespread option. A fingerprint scanner phone using this method compares the differences in electrical charge created by simply placing a finger on the reader. The more capacitors a scanner has, the safer it is and the more secure it is, thus eliminating the need to swipe your finger across the sensor.

Mobile Phones with Fingerprint Scanners: The Ultrasonic Scanner

The latest method is phones with ultrasonic fingerprint scanners. An ultrasonic pulse is transmitted against the finger that is placed over the scanner. Some of this pulse is absorbed and some of it is bounced back to the sensor, depending upon the ridges, pores, and other details that are unique to each fingerprint. Today, ultrasonic sensors are placed more and more under the screen of mobile phones.

Goodbye Physical Buttons - Hello Fingerprint Scanner Phones

Because of the increasing size of the displays on mobile phones, fingerprint readers are logically moving to the display in addition to or instead of the back of the phone. Currently, everything works on the principle of an older optical sensor or a newer ultrasonic sensor that can unlock the device even with a wet finger. The finger needs to be placed in the right place.

If you're wondering which display, processor or how big your phone's RAM should be, use our guide: How to choose a mobile phone.

Frequently Asked Questions before Choosing a Mobile Phone with a Fingerprint Scanner

Will Phones with Fingerprint Scanners work with a Finger Cut?

Modern phones with a fingerprint scanner do not compare the fingerprint of the whole finger, but fragments of it. Matching at least one part of the fingerprint is enough to unlock the phone. Multiple saved scans of the same finger can increase the scanning success rate. Wet fingers can reduce the success rate of capacitive readers.

Can a Mobile Phone with a Fingerprint Scanner be Fooled with a Photo or a 3D Scan?

Phones with a fingerprint scanner, whether capacitive or ultrasonic, are programmed to respond only to the human body. Even with an exact photocopy of the fingerprint, the reader will not work.

Some Fingerprint Scanner Phones have a Reader on the Front, others on the Back. Is There a Difference?

The location of the fingerprint sensor does not affect its functionality. It is only a design solution.