Difference between 3D/2.5D Tempered Glass Screen Protector

It is very common to see 2.5D arc technique in tempered glass industry. iPhone 6 uses a 2.5D curved screen, mainstream smartphones also use 2.5D curved screen. What does the 2.5D curved screen mean? What is the difference between it and 3D curved screen?

What we usually called 2.5D screens are some smartphones that use a 2.5D glass screen. In 2011, Nokia launched the first 2.5D screen phone - Nokia N9. Simply speaking, the 2.5D screen means that the edge of the screen adopts a 2.5D curved surface design, except that the edge of the screen is curved, but the screen itself is still flat.

3D curved tempered glass screen protector is hot-bending by high temperature to achieve 3D curved effect. Hot-bending tempered glass screen protector and 3D curved tempered glass screen protector, which are more complicated than ordinary screen protector. To understand the difference between hot-bending glass protector and ordinary screen protector, please simply see below picture for your ref:

Simply put, normal phone screen is pure flat without any curved design, 2.5D phone screen is flat in the middle but the edge is curved. For 3D screen, it has a curved design in the middle and the edge.