US 7,492,677 B2
Method and device for playing optical discs and method for determining tracking quality
Anthonius Petrus Gerardus Emanuel Janssen, Eindhoven (Netherlands); and Jacobus Maarten Den Hollander, Eindhoven (Netherlands)
Assigned to Koninklijke Philips Electronics N.V., Eindhoven (Netherlands)
Appl. No. 10/571,626
PCT Filed Aug. 23, 2004, PCT No. PCT/IB2004/051527
§ 371(c)(1), (2), (4) Date Mar. 14, 2006,
PCT Pub. No. WO2005/027102, PCT Pub. Date Mar. 24, 2005.
Claims priority of application No. 03103408 (EP), filed on Sep. 16, 2003.
Prior Publication US 2007/0058512 A1, Mar. 15, 2007
Int. Cl. G11B 7/00 (2006.01)
U.S. Cl. 369—44.28  [369/44.32] 15 Claims
OG exemplary drawing
 
1. Method for reading data from a track (3) of a data carrier (2), comprising the steps of:
tracking the track (3) while reading data from the track (3);
using a tracking performance memory which contains information relating to a tracking quality of track portions of the data carrier (2), to determine, in situations where tracking has to be restored, which track portion to jump to for restoring tracking;
determining if a jump back to a previously read track portion is necessary;
if a jump back to a previously read track portion appears to be necessary, consulting said tracking performance memory to determine a closest target track portion (3P(x-n)) having a sufficient value of the tracking quality parameter (Q); and
jumping back (JB) to the target track portion (3P(x-n)) thus determined.