Why can’t fingerprints be used on privacy films?

The anti-privacy film cannot be used with fingerprints because the working principle of optical fingerprints under the screen is to obtain the light reflected by the user's fingerprint, and the design of the anti-privacy film will affect the penetrability and angle of light penetration. As a result, the signal acquired by the final device becomes weak and the unlocking is insensitive. Therefore, after the anti-privacy film is affixed, the in-screen fingerprint cannot be unlocked.

The operating environment of this tutorial: MIUI12.5 system, Xiaomi 11 mobile phone.

Why can’t fingerprints be used on the privacy film?

The impact of anti-privacy film on fingerprint recognition mainly affects mobile phones designed with under-screen fingerprint functions. The working principle of the under-screen optical fingerprint is to obtain the light reflected by the user's fingerprint. Simply put, it requires taking a photo of the fingerprint for comparison and then unlocking. The design of the anti-privacy film will affect the penetration angle of light, causing the signal acquired by the final device to become weaker and the unlocking to be insensitive. Therefore, after the anti-privacy film is applied, it is generally impossible to decode in-screen fingerprints.

Specific reasons:

1. The privacy film uses an optical technology called ultra-fine blinds, which can prevent the screen from being viewed from both sides and effectively protect personal privacy. . This technology actually makes use of the principle of physical optical polarization. After your LCD screen is covered with a privacy film, the screen will only have visibility within 30 degrees from the front and sides, which will affect the light transmittance and will Produces light refraction, affecting light propagation.

Most of the under-screen fingerprints currently use optical recognition technology. After illuminating the fingerprint area through the built-in light-emitting component, the fingerprint is photographed with the built-in ultra-macro sensor, and then compared with the data in the machine. , it can be unlocked after successful comparison. Since the privacy film affects the transmission of light and has a certain degree of reflection, the sensor data is abnormal and the light-sensitive fingerprint unlocking cannot be used normally.

Features of privacy film:

1. Prevent peeping: Using physical optical polarization principle technology, after using the privacy film on your LCD screen , the screen only has visibility within 30 degrees from the front and sides, and the screen content cannot be seen clearly from the sides beyond 30 degrees to the left and right.

2. Prevent scratches: The outer surface layer is treated with a super wear-resistant material coating with a hardness of 4-5H, which can effectively prevent scratches, stains, fingerprints and dust, and protect your phone from scratches to the greatest extent. Suffer external damage.

3. Flexible application: When the computer does not need to be protected from privacy, it can be easily removed and put aside as a computer accessory. Even if the laptop screen is not removed, the laptop can be closed freely.

4. Prevent warm reflection: Matt surface, anti-reflective, prevent dazzling caused by sunlight, fluorescent lights, etc., prevent strong glare up to 99.9%, eliminate eye fatigue, and protect your eyes!

5. UV protection up to 96%, radiation protection up to 99.9%, anti-static, enhanced contrast, better effect. Protected from prying eyes. For viewing only by those facing directly, the viewing area is 60 degrees. Anti-glare, anti-reflective, can control the incident direction of light. Anti-scratch, prevent the LCD surface from being scratched. It can be re-pasted without affecting the sensitivity of the touch screen. Easy to install and easy to remove. Available in various sizes to fit a variety of machine models. Easy to cut.

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