Both methods are considered secure, but they differ technically. Ultrasonic fingerprint sensors capture a genuine 3D structure and are harder to fool than optical variants, while 3D facial recognition like Face ID also offers strong security through depth sensors. The choice often depends on the manufacturer's specific implementation.
Security & privacy
In-Display Fingerprint Sensor: Definition & explanation
In a nutshell
An in-display fingerprint sensor is a biometric scanner built directly beneath the screen. It reads fingerprints optically or via ultrasound, eliminating the need for a separate physical sensor on the device.
How does In-Display Fingerprint Sensor work?
In-display fingerprint sensors typically rely on one of two technologies: optical sensors use a miniature camera and light source to photograph the finger through the display, while ultrasonic sensors emit sound waves to create a 3D map of the fingertip's ridge pattern. Optical sensors are cheaper and faster but slightly more vulnerable to spoofing with photos or silicone molds. Ultrasonic sensors, such as those used in Samsung devices with Qualcomm chips, are considered more secure since they work through moisture or light dirt and capture genuine depth data.
For the sensor to function, the display must be transparent or semi-transparent at that specific point—something easier to achieve with AMOLED panels than LCDs, which is why this technology is almost exclusively paired with AMOLED screens. The scanning zone is usually marked visually and responds to light pressure. Compared to facial recognition, this method offers a reliable alternative in poor lighting or when wearing a mask, though it can be somewhat slower than traditional capacitive sensors mounted on the device body.
Advantages of In-Display Fingerprint Sensor
- Saves space, no separate sensor needed
- Enables sleek, uninterrupted display design
- Works better than face unlock when wearing a mask
- Ultrasonic versions are highly secure and moisture-resistant
- Large, easily accessible scanning area
Disadvantages of In-Display Fingerprint Sensor
- Often slower than capacitive sensors
- Optical variants are easier to fool
- Reduced accuracy with wet fingers (optical)
- Higher manufacturing cost
- Only practical with AMOLED displays
Frequently asked questions
Optical sensors need clear light reflections, which water disrupts. Ultrasonic sensors are more robust here since they rely on sound waves rather than light. If issues occur, drying your finger or applying firmer pressure usually helps.
The technology is now standard in many Android flagships, including Samsung Galaxy S and Note models as well as numerous devices from OnePlus, Xiaomi, and Oppo. Apple, in contrast, continues to rely on Face ID rather than an in-display sensor.
Guides with In-Display Fingerprint Sensor
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