Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system
Reexamination Certificate
2005-12-27
2009-10-20
Nguyen, Hoa T (Department: 2627)
Dynamic information storage or retrieval
With servo positioning of transducer assembly over track...
Optical servo system
C369S044410
Reexamination Certificate
active
07606122
ABSTRACT:
In a layer jump and focusing control method, a first focusing error signal is generated according to the differential astigmatism method in a closed-loop focusing control manner when focusing on the first recording layer. A second focusing error signal is generated according to the astigmatic method in an open-loop focusing control manner when a first layer-jumping procedure is performed to shift a focusing position from the first recording layer to the second recording layer. Then, the completion of the first layer-jumping procedure is determined according to the second focusing error signal, for example when the second focusing error signal passes the zero crossing point and exceeds a threshold level. Afterwards, a third focusing error signal is generated according to the differential astigmatism method in a closed-loop focusing control manner when focusing on the second recording layer.
REFERENCES:
patent: 2003/0012092 (2003-01-01), Katayama
patent: 2003/0103424 (2003-06-01), Sun
Chen Fu-Hsiang
Fu Hsiang-Yi
Lee Tun-Chieh
Lee Yi-Chung
Frank Emily
King Justin I.
Lite-On It Corp.
Nguyen Hoa T
WPAT, PC
LandOfFree
Layer-jumping and focusing control method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Layer-jumping and focusing control method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Layer-jumping and focusing control method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4067022