The QR codes on some products weφ§ have seen are engraved by laseφ©r marking machines. The→≤ principle of laser marking techno" σ≈logy is to irradiateΩ€× the surface of the workpiece wi$ ↕¥th a high-energy laser beam, an'€‌d instantly vaporize to form ∞ ≠§a two-dimensional code. The♠∑←↕ non-contact processing ha♣​☆♣s little impact on tφ‍← he workpiece, and it can als★¶o be one object, one code, and the≥∞• marking has longevity. $↓←;