20080259770 | Optical Pick-Up for Use in a Multi-Disc Optical Player and Method for Correcting Optical Aberrations in Such an Optical Pick-Up Unit - The present invention concerns to an optical pick-up unit for use in a multi-disc system, for scanning a first type of record carriers and at least a second type of record carriers, the second type of record carriers having an information density different from an information density of the first type of record carriers, the optical pick-up unit comprising at least two optical branches ( | 10-23-2008 |