公开(公告)号：EP0867023B1

公开(公告)日：2003-03-19

申请号：EP96939888.2

申请日：1996-11-22

申请人： DEUTSCHE THOMSON-BRANDT GMBH

发明人： DANG, Lieu, Kim

IPC分类号： G11B7/125 ,  G11B7/135

CPC分类号： G11B7/1381 ,  G11B7/1374 ,  G11B7/139 ,  G11B2007/0006

摘要： The present invention relates to a device for the reading and/or writing of optical recording media (AT) of various structures, which device operates with a single objective lens OL. The invention proposes to use a diaphragm varying in diameter, in particular a polarising filter arranged in the optical path in order to adapt the aperture to each type of optical recording medium (AT) used. The wavefront can be corrected using a divergent lens (SL) which can also be positioned in the beam path. The diaphragm formed by the polarising filter PF is linked to the objective lens (OL). The field of application of the invention relates to, in particular, devices for reading and/or writing optical recording media (AT) of various structure such as compact discs and digital video discs.

公开(公告)号：EP0900435A2

公开(公告)日：1999-03-10

申请号：EP97907045.0

申请日：1997-02-27

申请人： DEUTSCHE THOMSON-BRANDT GMBH

发明人： DANG, Lieu, Kim ,  ZUCKER, Friedhelm ,  SCHROEDER, Heinz-Jörg

IPC分类号： G11B7 ,  G11B19

CPC分类号： G11B19/12 ,  G11B7/08511 ,  G11B7/0945 ,  G11B7/1374 ,  G11B7/13922 ,  G11B19/00 ,  G11B2007/0006 ,  G11B2007/0013 ,  G11B2019/121

摘要： In order to identify the type of recording medium, a switch can be provided or alternatively a physical characteristic such as layer thickness can be defined. The changes of the focusing signal with time or the plausibility of the reproduction signal can be monitored. The reading beam is focused.

公开(公告)号：EP0900435B1

公开(公告)日：2001-11-14

申请号：EP97907045.5

申请日：1997-02-27

申请人： DEUTSCHE THOMSON-BRANDT GMBH

发明人： DANG, Lieu, Kim ,  ZUCKER, Friedhelm ,  SCHROEDER, Heinz-Jörg

IPC分类号： G11B7/085 ,  G11B7/09 ,  G11B19/12 ,  G11B19/02

CPC分类号： G11B19/12 ,  G11B7/08511 ,  G11B7/0945 ,  G11B7/1374 ,  G11B7/13922 ,  G11B19/00 ,  G11B2007/0006 ,  G11B2007/0013 ,  G11B2019/121

摘要： In order to identify the type of recording medium, a switch can be provided or alternatively a physical characteristic such as layer thickness can be defined. The changes of the focusing signal with time or the plausibility of the reproduction signal can be monitored. The reading beam is focused.

公开(公告)号：EP0867023A1

公开(公告)日：1998-09-30

申请号：EP96939888.0

申请日：1996-11-22

申请人： DEUTSCHE THOMSON-BRANDT GMBH

发明人： DANG, Lieu, Kim

IPC分类号： G11B7

CPC分类号： G11B7/1381 ,  G11B7/1374 ,  G11B7/139 ,  G11B2007/0006

摘要： The present invention relates to a device for the reading and/or writing of optical recording media (AT) of various structures, which device operates with a single objective lens OL. The invention proposes to use a diaphragm varying in diameter, in particular a polarising filter arranged in the optical path in order to adapt the aperture to each type of optical recording medium (AT) used. The wavefront can be corrected using a divergent lens (SL) which can also be positioned in the beam path. The diaphragm formed by the polarising filter PF is linked to the objective lens (OL). The field of application of the invention relates to, in particular, devices for reading and/or writing optical recording media (AT) of various structure such as compact discs and digital video discs.