Introduction to APF (Advanced Polarizing Film)

3M’s APF (Advanced Polarizing Film) is not a traditional “absorptive polarizer.” Instead, it is an on‑glass reflective polarizer laminated to the rear absorbing polarizer of the LCD panel. Its primary functions are to improve backlight efficiency, increase brightness, reduce module thickness, and enhance display performance from wide viewing angles.

As shown in the picture below, APF allows the polarization direction required by the LCD to pass through, while reflecting the orthogonal polarization back into the backlight system. The reflected light undergoes multiple scatterings inside the backlight cavity, and part of it returns with a rotated polarization state that can be reused. In other words, APF recycles light that would otherwise be wasted, thereby improving brightness and energy efficiency.

Reference: https://www.3m.com/3M/en_US/p/d/b5005047084/

Advantages of APF

• Brightness Enhancement (by around 30%)

Reduces optical loss and improves both on‑axis and wide‑angle brightness.

• Power Savings

By increasing backlight efficiency, APF reduces backlight power consumption, helping achieve lower energy usage and longer battery life.

• Thinner Module

Since APF is laminated directly to the panel’s rear polarizer, it can replace part of the BEF/DBEF stack, simplifying the optical structure.

• Better Viewing‑Angle Performance

The reflective polarizer structure improves brightness uniformity and wide‑angle brightness.

• Higher Environmental Robustness

More stable than “free‑standing reflective films,” with lower thermal load and better durability.

Comparison Between APF and DBEF

Based on the comparison above, we will recommend APF when you need thinness, efficiency, and wide‑angle performance, and DBEF when you need maximum brightness at lower cost.

Should you have any questions, please consult our engineering.