The particularity of the emission principle and generation process of lasers determines that lasers possess characteristics that ordinary light does not have: namely, three goods (good monochromaticity, good coherence, and good directionality) and one high (high brightness). Taking advantage of the good directivity and high brightness of lasers It can be widely applied in medical care, military, counterfeiting detection, security, stage (red, green, blue) lighting, various power tools, measuring devices, instruments, equipment, levels, positioning instruments, distance meters, thermometers, laser line marking devices (line projection devices), various sheet cutting and forming machines, stone machinery, woodworking machinery, metal sawing machines, packaging machinery for tool setting and line setting, and clothing (sewing machines). Products such as cutting machines, automatic and manual fabric cutting machines, bag opening machines, tying machines, fabric spreading machines, embroidery machines, printing machines, bead sewing machines, button sewing machines, riveting machines, die-cutting machines, electronic measuring tools, mice, USB flash drives, cameras, mobile phones, projection teaching page-turning pens, laser Pointers, handicrafts, indoor and outdoor decorations, flashlights, gifts, toys, etc. Convenient and fast, intuitive and practical, easy to install, stable and reliable. It can significantly improve work efficiency.