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
Method for controlling a motor
Semiconductor IC including pulse generation logic circuit
Real-image zoom viewfinder and imaging apparatus
Three-dimensional shape data processing apparatus and three-dimensional shape data processing method
Methods and compositions for improving photodynamic therapy through administration of lipids
Multi-radio coexistence
Method and arrangement for controlling semiconductor component
  Randomly Featured Patents
Device for reducing harmonics in three-phase poly-wire power lines
Method and apparatus for acoustic attenuation in variable speed compressors
Method for combining heat pipes with a fixing base
Fluid control unit
Real-time aggregation of data within an enterprise planning environment
Thin film optical switching device
Modular light system for automobiles
Touch keypad assembly
System and method for color dither matrix creation using human-vision-system gray matrix with cluster radii
Plug system in a dispenser that dispenses material from a roll of absorbent material