A heat exchanging device includes first and second disk members coupled together to form a disk unit having a chamber. One embodiment of the method comprises focusing an image of an object onto a two-dimensional photosensor array, wherein an optical element is located between the object and the two-dimensional photosensor array. A synchronization burst is generated by a inverse fast Fourier transforming unit transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The invalidation means 22 changes a secondary match line 21 corresponding to a primary match line 13 in an invalid state into an invalid state to supply to an external source as a match line 11. As the cables wind onto the spools, variations in spool diameter are compensated for.