Panasonic Corporation

Yorikazu Takao

Youichi Ogura

Tatsushi Hiraki

Noriyuki Masunari

An instantaneous jitter information detection section detects, based on first and second digital values indicating different polarities relative to a predetermined reference value, an instantaneous gradient value corresponding to a difference value between the first and second digital values, and an instantaneous deviation value corresponding to a difference value between an intermediate value between the first and second digital values and the reference value. An information conversion section converts, based on an inversely proportional conversion table, the instantaneous gradient value to an inversely proportional value. An arithmetic section detects an instantaneous variance value by multiplying the instantaneous deviation value and the inversely proportional value together, and squaring a value obtained by the multiplication, and detects an integrated value by accumulating the instantaneous variance value. A standard deviation detection section detects a square root of a mean value of the integrated value as the absolute jitter value.

Optical disc reproduction apparatus

A digital signal reproducing apparatus includes an analog to digital converter for sampling and quantizing a signal read from an optical recording medium in accordance with a reproduced clock having a frequency which is one-half of a channel bit frequency and outputting an obtained digital RF signal, an offset compensation circuit for reducing an offset component in an amplitude direction from the digital RF signal, and a simplified interpolation filter for reconstructing a signal indicating a predetermined pattern recorded in the optical recording medium from the output signal of the offset compensation circuit and outputting the reconstructed signal. A control operation is performed to reduce the magnitudes of respective values shown by first phase error information on a section with the predetermined pattern and by second phase error information on a section other than the section with the predetermined pattern.

Growing community of inventors

Osaka, Japan

Yorikazu Takao