1. Mark the corresponding area using the content of the focus area: The method of marking the focus must take into account the problem of laser energy. This is because each focusing mirror has a matching depth of focus area and a method of using defocusing is used. It is easy to cause a large-area marking pattern, and the edge is at the depth of focus or beyond the depth of focus, which easily leads to the unevenness of the actual effect.
2. Thermal lens phenomenon: When light passes through the optical lens (refraction, reflection), the lens will be burned and cause slight deformation. This deformation causes the laser focus to rise and the focal length to be shortened. If the machine is fixed and the distance is adjusted to the focus, the laser energy density acting on the raw material changes after the laser is turned on for a period of time due to the thermal lens phenomenon.
3. The laser output point is hidden, ie the laser beam passes through the galvanometer and the objective lens, and the point is very short: the laser output head is not adjusted, the fixture and the galvanometer are fixed, which leads to a point where a part of the laser passes through the galvanometer timing to be hidden. . After the mirror is focused, the spots on the multiplying plate are non-circular, which may also result in uneven marking.
In another case, the galvanometer deflection lens of the laser marking machine is damaged and cannot be effectively reflected when the laser beam passes through the damaged area of the lens. Therefore, the laser beam passing through the damaged area of the lens and the undamaged area of the lens is uneven, resulting in different paying energy applied to the material, thereby making the marking uneven.
4. The horizontal working surface of the laser marking machine is not calibrated, ie the laser galvanometer or field of view mirror is not parallel to the processing table: this will cause the laser beam to pass through the objective lens and achieve inconsistencies in length. The processed object causes the laser beam to act on the object. The energy density of the energy is different, resulting in uneven marking effect.
5. Raw material factors, if the film thickness of the raw material surface is different or the physical and chemical properties change
This material is sensitive to laser energy reactions. Typically, laser energy can reach the same material damage threshold under the same material. However, when the thickness of the material coating is different, or when the physicochemical treatment process is uneven, the marking effect may be uneven.