Method for controlling laser power in a texturing process

摘要

A disk texturing tool is used, for example, to provide textured spots in an annular portion of both sides of a disk for a hard disk drive. Disks are moved into and out of the texturing process in cassettes, through two disk-handling stations. An optical system includes a laser directed at a beamsplitter to split the laser beam into two beams having approximately power, which are directed along parallel paths through a power control optics block to expose simultaneously opposite sides of a disk to be textured. The power level of each of these two beams is controlled by a program which operates in a teach mode to develop a look up table describing laser beam power as a function of a signal driving an attenuator, in a set point mode setting this drive signal to provide a certain laser beam power, in a run mode controlling this power through a feedback loop, and in a display mode showing laser beam power as a function of time.