An apparatus for improving decoding accuracy of an equalized signal having a direct current level obtained from an optical disk is provided. In one embodiment, the LDSLM assembly includes a linear array of diffractive MEMS elements. In the UHF band operation, only a UHF signal in a signal provided from an ANT terminal is output to a UHF input tuning circuit. The memory also includes plural bit-lines that are aligned with the plural columns. Since the upper side of the polygon is, only in part of its segment length, most adjacent to polygon within distance, this side is divided into segment that corresponds to the part adjacent to the polygon, and segment that is the rest.