Abstract
This method is to use the multilevel recording in order to increase the storage capacity under the limited spot size. In this method, the multilevel recording is utilized by varying the diameter of circular marks, which are arranged like a two-dimensional lattice. When reading out the signal, multi-spot scan the marks on each track and the signal is obtained by canceling the inter-symbol interference and the cross-talk using the each detecting signals from each track. In this paper, the following items are reported. (1)The idea and concept of this method are proposed. (2)Marks that have different diameter are formed by a laser cutter. (3)The average and deviation of formed marks are measured.
