Abstract: An apparatus for detecting defects on a disk surface includes a light source that generates a light beam and a beamsplitter that splits the light beam into a first light beam portion and a second light beam portion. The first light beam portion illuminates the surface of the disk and produces a reflected light beam. An acoustic-optic deflector deflects the reflected light beam and the second light beam portion producing a deflected output beam having a deflection angle. A detector detects an incident beam translation signal corresponding to reflected light beam angular deflection and acoustic-optic deflector beam angular deflection from the deflected output beam.

Abstract: A double pass apparatus for detecting defects on a disk surface includes a light source that generates a light beam and a beamsplitter that splits the light beam into a first light beam portion and a second light beam portion. A modulator is provided that modulates the second light beam portion into a frequency shifted modulated light beam for illuminating the surface of the disk. The frequency shifted modulated light beam is twice reflected from the surface of the disk, thus doubling the frequency shift of the reflected light beam. A polarizing beamsplitter combines the first light beam portion with the reflected light beam portion providing an interference signal.

Abstract: A spinstand includes a baseplate, a spindle mounted to the baseplate and a platform connected to the baseplate. A first component and a second component are mounted to the platform. An actuator moves the platform in a first direction relative to the baseplate, and mechanism moves the second component in approximately the first direction relative to the platform. The actuator moves the platform to position the first component at any radius of a disc placed on the spindle. The mechanism positions the second component at the same radius on an opposite surface of the disc according to a predetermined position adjustment. The first and second components are selected from a group consisting of: a burnish head, a glide head, a read head, a write head, and a read/write head. Embodiments provide automatic alignment of two components for simultaneous testing of both sides of a disc on the spinstand.

Abstract: Techniques are described in which a hard disc media tester uses busses conforming to a single bus format to connect control components within a control system of the hard disc media tester. A hard disc media tester may include several control components such as a testing control module, a motion interface, a defect analyzer, a write controller, a motion controller, head loaders, and so on. Busses conforming to a single bus format, such as the Universal Serial Bus (USB) or FireWire formats, may facilitate the communication of control messages among each of these control components. Furthermore, the hard disc media tester may include one or more bus hubs to allow many components to be controlled through a single cable.

Abstract: An apparatus for detecting defects on a disk surface includes a light source that generates a light beam and an acoustic-optic deflector that continuously dithers the light beam transmitted by the light source back and forth, producing a dithered output beam. The apparatus also includes at least one lens that forms a scan line on a disk surface from the dithered output beam with the scan line generating multiple scans and a detector that detects scattered light from defects on the disk surface passing through the dithered output beam of the scan line.

Abstract: An apparatus for detecting defects on a disk surface includes a light source that generates a light beam and a beamsplitter that splits the light beam into a first light beam portion and a second light beam portion. The first light beam portion illuminates the surface of the disk and produces a reflected light beam. An acoustic-optic deflector deflects the reflected light beam and the second light beam portion producing a deflected output beam having a deflection angle. A detector detects an incident beam translation signal corresponding to reflected light beam angular deflection and acoustic-optic deflector beam angular deflection from the deflected output beam.

Abstract: A double pass apparatus for detecting defects on a disk surface includes a light source that generates a light beam and a beamsplitter that splits the light beam into a first light beam portion and a second light beam portion. A modulator is provided that modulates the second light beam portion into a frequency shifted modulated light beam for illuminating the surface of the disk. The frequency shifted modulated light beam is twice reflected from the surface of the disk, thus doubling the frequency shift of the reflected light beam. A polarizing beamsplitter combines the first light beam portion with the reflected light beam portion providing an interference signal.