Please contact Media Sciences if your questions are not answered on these pages. Single-beam optical pickup heads were used in the first CD players for audio discs. A slight radial wobble enabled the radial tracking servo to accurately maintain radial position. This type is still used today in car CD players and also in some home audio players.
Radial position is maintained using side beams that sense pit or mark edges.
There is no radial wobble in these drives. These severe errors were not sensitive to media type. Similar uncorrectable errors have also been observed for discs written at 12X and 16X in high speed writers. Scientific tests have not yet precisely identified the source of defects responsible for uncorrectable errors in single-beam drives. Media Sciences believes they are related to vibrations during the recording process that approach mechanical resonance frequencies.