Panasonic Corporation

Eiichi Ito

Masahiro Birukawa

Kenji Narumi

Rie Kojima

In optical recording and/or reproduction using an SIL optical system that performs a tilt servo using light for recording and/or reproduction, the SIL and an optical recording medium have a high probability of colliding with each other before the tilt servo is started. To prevent the collision, an optical recording/reproduction method performs a gap servo that controls a gap between a surface of an optical recording medium and a bottom surface of an SIL using reflected light that is generated from light traveling from the bottom surface of the SIL and reflecting on the optical recording medium, a focus servo that controls a distance between a focal point of the light and the bottom surface of the SIL, and a tilt servo that controls a tilt of the bottom surface of the SIL relative to the surface of the optical recording medium using the reflected light. The method includes acts which are performed sequentially: starting the gap servo with the gap being set larger than when optical recording and/or reproduction is performed, and shifting the focal point to an optical recording medium side from the bottom surface of the SIL, starting the tilt servo, and setting the gap smaller and arranging the SIL at a predetermined position.

Optical recording/reproduction method, optical recording/reproduction device, program, and optical recording medium

An optical information recording and/or reproducing apparatus comprises: a focusing unit () which collects generated near-field light on an optical disc (); a first detector () which receives light reflected by the optical disc () and outputs an electric signal according to the quantity of the received light; and a distance control circuit () which controls the distance between the focusing unit () and a light entrance surface of the optical disc (), using the electric signal that is output from the first detector (), and the optical disc () has at least N (N is an integer of 2 or greater) number of information layers, and a distance dfrom the light entrance surface to a first information layer which is most distant from the light entrance surface and a distance dn from the light entrance surface to an Nth information layer which is closest to the light entrance surface satisfy the relationship of dn&#x2267;d&#xd7;(1/25). As a result, servo control can be accurately performed regardless which information layer, out of a plurality of information layers of an optical disc, information is recorded to or reproduced from.

Optical information recording and/or reproducing apparatus, optical information recording and/or reproducing method, optical information recording medium, and solid immersion lens

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Niigata, Japan

Eiichi Ito