An ultrasonic fingerprint scanner is a type of in-display fingerprint sensor that uses sound waves (ultrasound) to scan your finger.

⚙️ How It Works (Easy Steps)

You place your finger on the screen

The sensor sends ultrasonic waves

Waves bounce back from your fingerprint

It creates a 3D map of ridges & valleys

Phone unlocks if it matches

👉 So instead of just taking a photo (like optical), it reads depth → more accurate

✅ Advantages

🔒 More secure (3D scan, harder to fool)

⚡ Works even with wet or oily fingers

🌙 Works in dark / bright light (not dependent on light)

🎯 Better accuracy than optical sensors

❌ Disadvantages

💰 Found mostly in premium phones

🔧 Costlier technology

📱 Where You See It

Mostly in flagship phones 

Uses tech like Qualcomm 3D Sonic Sensor 

📱 Brand Example (Important Point ⭐)

👉 Many flagship smartphones, including premium models from iQOO, now use ultrasonic fingerprint scanners for faster and more secure unlocking.