Signal reproduction block
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHirokuni Fujiyama, Takashi Morie
Life of this patent
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Abstract
In a signal reproduction block of a DVD reproduction apparatus, an output signal line for outputting a characteristic information signal representing a characteristic of a filter incorporated in the signal reproduction block to the outside is additionally provided on the output side of an A/D converter. In this way, it is possible to prevent an analog data signal from deteriorating during a data signal reproduction process due to a parasitic effect of the output signal line. Moreover, the filter characteristic information signal is output through the output signal line after it is convened to a digital signal by the A/D convener, thereby avoiding the deterioration the characteristic information signal and thus improving the measurement precision.
Claims8
A signal reproduction block, comprising:
- a filter for waveform equalization of an analog input signal;
- an A/D converter for converting an output signal from the filter to a digital signal;
- a digital signal processing section for reproducing an output signal from the A/D converter;
- and
- an output signal line through which a characteristic information signal that is obtained by inputting a test signal to the filter is output to an outside of the signal reproduction block during a characteristic measurement process of measuring a characteristic of the filter,
- wherein the output signal line is provided on an output side of the A/D converter;
- wherein an input signal to the filter is a differential signal;
- a bypass signal line for taking out an unfiltered signal to be input to the filter;
- and
- a signal selection circuit for receiving the unfiltered signal taken out by the bypass signal line
- and a filtered signal output from the filter, and for simultaneously outputting the unfiltered signal and the filtered signal to the A/D converter during the characteristic measurement process while outputting only the filtered signal to the A/D converter during a signal reproduction process.
Dependencies are inferred from the claim text.