Sughrue Mion, PLLC
Asymmetric error correction apparatus and method, and clock recovering apparatus for optical reading system employing the same
An asymmetric error correction apparatus and method, and clock recovering apparatus and data recovering apparatus for a system for reading data from an optical recording medium such as a CD or DVD that has a multi-level input signal and irregular characteristic of zero-crossing transition. The signal inputted from the optical recording medium is digitized, and a zero-crossing detector extracts four sequential samples and detects a zero-crossing point from the two intermediate samples. An asymmetric error detector judges an asymmetric state and asymmetric polarity of the digital signal from a sum of the two side samples among the four samples if the zero-crossing point is detected. A correction section accumulates the judged asymmetric polarities, judges an asymmetric error of the digital signal if the accumulated value exceeds a predetermined threshold, and corrects the asymmetric error of the read signal caused by an inaccurate pit length.
Samsung Electronics Co., Ltd.
H G H G G
H04L G11B H04L G11B G11B
inventional inventional inventional inventional inventional
Hyung-Jin Pan-Soo Jung-Hyun Seok-Jun
Choi Kim Lee Ko