Abstract: A laser marker enables efficient determination of an optimum condition for a printing pattern of a two-dimensional code and simplification of the evaluation operation of the printing pattern of the two-dimensional code. A printing pattern regarding a cell to be printed in each of reference cells of a two-dimensional code is generated. The two-dimensional code is printed in this cell printing pattern. The recognition rate of the two-dimensional code is calculated on the basis of the reference cells. When the recognition rate is a predetermined value or more, a present printing pattern is stored as an optimum condition (optimum printing pattern) in a database. In contrast, when the recognition rate is less than the predetermined value, the size of cells constituting the present printing pattern is changed. The two-dimensional code is printed in the changed cell printing pattern, and the recognition rate of the two-dimensional code is calculated again.

Abstract: A laser marker enables efficient determination of an optimum condition for a printing pattern of a two-dimensional code and simplification of the evaluation operation of the printing pattern of the two-dimensional code. A printing pattern regarding a cell to be printed in each of reference cells of a two-dimensional code is generated. The two-dimensional code is printed in this cell printing pattern. The recognition rate of the two-dimensional code is calculated on the basis of the reference cells. When the recognition rate is a predetermined value or more, a present printing pattern is stored as an optimum condition (optimum printing pattern) in a database. In contrast, when the recognition rate is less than the predetermined value, the size of cells constituting the present printing pattern is changed. The two-dimensional code is printed in the changed cell printing pattern, and the recognition rate of the two-dimensional code is calculated again.

Abstract: An optical scanner including a base body, a drive unit, a deflection status detector and a controller is provided. The base body has a non-linear frequency characteristic and has a first resonance frequency and a second resonance frequency. The controller includes a first upsweep unit which upsweeps a drive frequency from a frequency lower than the first resonance frequency; a dropping phenomenon detector which detects the dropping phenomenon; a target drive frequency determination unit which determines a frequency lower than a frequency at which the dropping phenomenon is detected, as a target drive frequency; a second upsweep unit which upsweeps the drive frequency toward the target drive frequency from a frequency lower than the first resonance frequency; and an adjustment unit which adjusts the drive frequency of the drive signal to keep the deflection status at the target drive frequency after the operation of the second upsweep unit.

Abstract: An optical scanner including a base body, a drive unit, a deflection status detector and a controller is provided. The base body has a non-linear frequency characteristic and has a first resonance frequency and a second resonance frequency. The controller includes a first upsweep unit which upsweeps a drive frequency from a frequency lower than the first resonance frequency; a dropping phenomenon detector which detects the dropping phenomenon; a target drive frequency determination unit which determines a frequency lower than a frequency at which the dropping phenomenon is detected, as a target drive frequency; a second upsweep unit which upsweeps the drive frequency toward the target drive frequency from a frequency lower than the first resonance frequency; and an adjustment unit which adjusts the drive frequency of the drive signal to keep the deflection status at the target drive frequency after the operation of the second upsweep unit.