Laser-bump sensor method and apparatus

摘要: An apparatus for measuring the height and diameter of laser-zone texture bumps on a rigid magnetic disk substrate is disclosed. The has holder supporting rotating substrate, an optical beam-source assembly directing focused laser beam shifting position beam's illumination spot in tracking (radial) direction. detection measures deflection due to specular reflection by bumps, as function time, both scanning (circumferential) directions. A computational device functions (i) calculate values which characterize deflections directions, respectively, bump passing through produced (ii) select bump-height analysis, those whose are above selected threshold value below value, indicative condition textured each focus centered within said spot, (iii) determine heights diameters from Also disclosed method light power scattered substrate.