All premium flagship smartphones and most mid-range devices feature an in-display fingerprint sensor. You just need to play your fingerprint on the display and it unlocks your phone by verifying your fingerprint sensor. If you want to know how does in-display fingerprint sensor works, keep reading. In this article, I will explain in-display fingerprint scanning, the types of in-display fingerprint sensors, and how it differs from physical fingerprint scanners.
In-Display Fingerprint Scanning
In-display fingerprint scanning is a biometric authentication technology that allows you to unlock your smartphone by simply placing your finger on the screen. It works by embedding a fingerprint sensor under the display of the device, which can detect the unique ridges and patterns of your fingerprint.
In-display fingerprint scanning offers several benefits over traditional fingerprint sensors located on the back or the side of the device. It provides a more seamless and integrated look and feel, as the sensor is hidden under the screen and does not take up additional space on the device. It also allows for larger screen real estate, as the bezels can be smaller.
In-display fingerprint scanning technology is becoming increasingly popular among smartphone manufacturers, as it provides a convenient and secure way to unlock your device. It is also more convenient for users, as they do not have to reach for the back of the device or the side button to unlock it.
Types of In-Display Fingerprint Sensors
When it comes to in-display fingerprint scanning, there are two main types of technology available: optical and ultrasonic. Both technologies are used to capture an image of the fingerprint and allow the user to unlock their device with the touch of a finger. However, there are some key differences between the two technologies that are worth noting.
Optical In-Display Fingerprint Scanning
This technology uses a light-based system to capture an image of the fingerprint. An LED light is placed under the screen and shines through the display, illuminating the finger placed on the screen. The image of the fingerprint is then captured by the sensor and compared to the stored fingerprints in the device.
Optical in-display fingerprint scanning works by using a light-based system to capture an image of your fingerprint. A tiny sensor is placed under the screen, and when you place your finger on the screen, the sensor sends out light that goes through the screen and onto your finger. The light then reflects back to the sensor, creating an image of your fingerprint. The sensor then compares the image to the stored fingerprints in the device to determine if it is a match.
Optical in-display fingerprint scanner is less expensive and easier to manufacture compared to ultrasonic in-display fingerprint scanning, making it a more affordable option. Optical in-display fingerprint scanning can be impacted by moisture or oil, as these substances can interfere with the light used to capture the image of your fingerprint.
Pros:
- The optical in-display fingerprint sensor is less expensive and easier to manufacture. So, it is a cost-effective option for smartphone manufacturers.
- It is less likely to have issues with water or oil interfering with the fingerprint image, as the LED light illuminates the finger.
Cons:
- The image captured by the optical in-display fingerprint sensor is two-dimensional, which can lead to security concerns as it may be possible to recreate a fake fingerprint from the captured image.
- The optical in-display fingerprint sensor is less accurate and may take longer to unlock the device than ultrasonic in-display fingerprint sensors.
Ultrasonic In-Display Fingerprint Scanning
This technology uses high-frequency sound waves to create a 3D image of the fingerprint. The sound waves pass through the display and onto the finger placed on the screen, creating a detailed image of the fingerprint.
Ultrasonic in-display fingerprint sensor technology works by creating a 3D image of your fingerprint using high-frequency sound waves. When you place your finger on the screen, the sensor sends out sound waves that pass through the display and onto your finger. The sound waves then bounce back to the sensor, creating a detailed image of the ridges and valleys of your fingerprint.
The sensor then uses this 3D image to compare to the stored fingerprints in the device to determine if it is a match. Because the ultrasonic in-display fingerprint sensor creates a 3D image, it is more secure and difficult to fake compared to the 2D image captured by optical in-display fingerprint sensors.
Pros:
- The ultrasonic in-display fingerprint sensor creates a 3D image of the fingerprint, making it more secure and difficult to fake.
- The ultrasonic in-display fingerprint sensor is more accurate and faster than optical in-display fingerprint sensors, as it creates a more detailed image of the fingerprint.
Cons:
- The ultrasonic in-display fingerprint sensor is more expensive and difficult to manufacture, making it a more expensive option for smartphone manufacturers.
- It may have issues with water or oil interfering with the sound waves, which can impact the accuracy of the fingerprint image.
Optical vs Ultrasonic In-Display Fingerprint Scanner
Here is a table comparing the differences between optical and ultrasonic in-display fingerprint scanners:
| Feature | Optical In-Display Fingerprint Scanner | Ultrasonic In-Display Fingerprint Scanner |
|---|---|---|
| Technology | Light-based | Sound wave-based |
| Image Quality | 2D | 3D |
| Security | Less secure, as it’s easier to fake a 2D image | More secure, as it’s harder to fake a 3D image |
| Manufacturing cost | Less expensive, as it’s easier to manufacture | More expensive, as it’s more complex to manufacture |
| Impact by moisture and oil | More likely to be impacted, as these substances can interfere with the light | Less likely to be impacted, as sound waves can penetrate through these substances |
| Accuracy | Can be impacted by moisture or oil, making the unlocking process less reliable | Less likely to be impacted by moisture or oil, making the unlocking process more reliable |
Both optical and ultrasonic in-display fingerprint scanners have their own strengths and weaknesses, and it all comes down to personal preference and the specific needs and requirements of the user. The ultrasonic in-display fingerprint scanner is more secure and accurate, but it is also more expensive and complex to manufacture. The optical in-display fingerprint scanner is less expensive and easier to manufacture, but it’s less secure and less accurate.
Physical Fingerprint Scanners vs In-display Fingerprint Scanners
Budget smartphones still feature physical fingerprint scanners embedded on the home button, side button, or on back panel. Physical fingerprint sensors are found in low-end devices and laptops. Physical fingerprint scanners are straightforward and easy to use.
In-display fingerprint scanners, on the other hand, are located under the screen of the device. The main advantage of in-display fingerprint scanners is their convenience and sleek design, as you don’t need to physically touch a button or a sensor to unlock the device. However, in-display fingerprint scanners are typically more expensive and complex to manufacture compared to physical fingerprint scanners.
