Fingerprint recognition may fail or be unreliable with screen protectors primarily because of how clearly and tightly the screen protector is attached to the device's screen.
When a screen protector or protective film is not attached clearly and tightly, it can create issues that interfere with the fingerprint sensor's ability to read your print accurately.
How Poorly Attached Screen Protectors Cause Issues
The main problems stem from imperfections between the screen protector and the actual display surface:
- Air Gaps: Small pockets of air trapped between the screen and the protector can distort the sensor's reading. The sensor relies on contact and subtle variations in the fingerprint ridges. An air gap prevents proper contact.
- Foreign Substances: Dust, dirt, or moisture trapped during installation can also create barriers or distortions that hinder the sensor's view of your fingerprint pattern.
According to device information, these air gaps or foreign substances between the protective film and screen may decrease the fingerprint recognition rate. This means the sensor finds it harder to get a clear, consistent image needed to match your stored fingerprint.
Ensuring Compatibility and Best Performance
While some screen protectors are specifically designed to work with ultrasonic or in-display optical fingerprint sensors, proper installation is crucial for any type.
Here's what helps:
- Use screen protectors explicitly stated as compatible with your device's fingerprint sensor type.
- Ensure the screen and the protector are thoroughly cleaned before installation.
- Follow installation instructions precisely to avoid trapping air bubbles or debris.
- Apply firm, even pressure when attaching the protector to eliminate gaps.
Ultimately, the exact answer based on the provided information is that fingerprint sensors may not work well with screen protectors because the protector is not attached clearly and tightly, leading to air gaps or foreign substances that decrease the fingerprint recognition rate.
