Resources Contact Us Home
Optical information recording and/or reproducing apparatus, optical information recording and/or reproducing method, optical information recording medium, and solid immersion lens

Image Number 4 for United States Patent #8130623.

An optical information recording and/or reproducing apparatus comprises: a focusing unit (11) which collects generated near-field light on an optical disc (1); a first detector (17) which receives light reflected by the optical disc (1) and outputs an electric signal according to the quantity of the received light; and a distance control circuit (22) which controls the distance between the focusing unit (11) and a light entrance surface of the optical disc (1), using the electric signal that is output from the first detector (17), and the optical disc (1) has at least N (N is an integer of 2 or greater) number of information layers, and a distance d0 from 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.gtoreq.d0.times.(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.

  Recently Added Patents
Soybean EF1A promoter and its use in constitutive expression of transgenic genes in plants
Circuit arrangement having a load transistor and a voltage limiting circuit and method for driving a load transistor
Fusing apparatus and image forming apparatus provided with the same, and heating apparatus
Baseball player stationery tab
Image forming apparatus and method for making density correction in a low resolution image based on edge determination
Performance apparatus, a method of controlling the performance apparatus and a program recording medium
Basket for a dishwasher
  Randomly Featured Patents
Word training interface
Anthrax and small Pox replikins and methods of use
Hydraulic tank access cover with self-centering and anti-rotation device
Black defect correction method and black defect correction device for photomask
Functionalized porous poly(aryl ether ketone) materials and their use
Bi-directional communication system
Water-dispersible hydrophobic thickening agent
Container having a built-in mill
Cylindrical lock
Electric power transmission system and method of asymmetric transmission of power to mitigate magnetic fields