I. marking a certain range of contents with the use of off focus
Because each focusing mirror has a corresponding focal depth range, and the method of deviating from the focus will easily lead to the edge at the critical point of focal depth or beyond the focal depth range when the pattern is marked in a large range, so it is easier to cause the effect of nonuniformity. Therefore, the problem of laser energy should be considered in the method of offset marking.
2. The laser output spot is blocked, that is, the spot of laser beam passing through the galvanometer and field mirror is not round enough
The laser output head, fixed fixture and galvanometer are not adjusted properly, which results in part of the facula is blocked when the laser passes through the galvanometer, and the facula on the frequency multiplier after focusing through the field mirror is non-circular, which may also lead to uneven effect.
In another case, the deflection lens of the galvanometer is damaged, and when the laser beam passes through the damaged area of the lens, it cannot reflect out well. Therefore, the laser energy of the laser beam passing through the damaged area of the lens is inconsistent with that of the non damaged area of the lens, and the final laser energy acting on the material is also different, so that the marking effect is not uniform.