Data reproduction apparatus for optical disc system

An apparatus to correct an asymmetrical signal, comprising:

• a digital to analog converter which converts a digital asymmetrical correction signal to an analog correction signal;
• an analog-to-digital converter which references an analog input RF signal to the analog correction signal and outputs a sampled digital signal;
• a blank detection signal generator which generates a blank detection signal if there is no change in the sampled digital signal over a predetermined interval of time;
• and
• a correction signal generator which calculates a digital sum value for the sampled digital signal and generates the digital asymmetrical correction signal, based on the digital sum value, and outputs the digital asymmetrical correction signal to said digital to analog converter, wherein if the blank detection signal is output, a calculation of a digital sum value is stopped for the predetermined interval of time.

A data reproduction apparatus comprising:

• an analog-to-digital converter (ADC) which samples an input RF and outputs a sampled signal;
• an adder which adds the sampled signal and an asymmetry correction signal and outputs an added signal;
• a blank/defect detector which receives the added signal and generates a blank detection signal if no variation in the data is detected from the received added signal over a predetermined interval of time;
• a correction signal generator which calculates a digital sum value (DSV) from the received added signal, generates the asymmetry correction signal based on the calculated DSV, and outputs the generated asymmetry correction signal to said adder;
• a waveform equalizer which waveform-equalizes the added signal;
• and
• a decoder which decodes the waveform-equalized signal and outputs the result,
• wherein if said blank/defect detector generates the blank detection signal, said correction signal generator temporarily stops the DSV calculation of the correction signal generator with respect to an interval of the added signal.

A data reproduction apparatus comprising:

• an analog-to-digital converter (ADC) which samples an input RF signal based on a reference voltage;
• a blank/defect detector which receives the sampled signal and generates a blank detection signal if a variation in data is not detected from the sampled signal over a predetermined interval of time;
• a correction signal generator which calculates a digital sum value (DSV) from the sampled signal, generates an asymmetry correction signal based on the calculated DSV, and outputs the generated asymmetry correction signal to said ADC as the reference voltage;
• a waveform equalizer which waveform-equalizes the sampled signal;
• and
• a decoder which decodes the waveform-equalized signal and outputs the result,
• wherein said correction signal generator temporarily stops the DSV calculation of said correction signal generator with respect to the interval of the corresponding sampled signal, if the blank/defect detector generates the detection signal.

A method for correcting an asymmetrical signal, comprising:

• adding an asymmetry correction signal to a digitally sampled input signal;
• generating a blank detection signal if there is no change in the added signal over a predetermined interval of time;
• and
• calculating a digital sum value for the added signal and outputting the asymmetry correction signal based on the digital sum value, wherein if the blank detection signal is output, calculating the digital sum value is stopped for the predetermined interval of time.

A method of reproducing data comprising:

• converting an input analog RF signal to a sampled digital signal;
• adding the sampled signal and an asymmetry correction signal and outputting an added signal;
• waveform-equalizing the added signal;
• selecting one of the added signal and the waveform equalized signal;
• calculating a digital sum value (DSV) based on the selected signal;
• and
• generating the asymmetry correction signal based on the calculated DSV.

A method of reproducing data comprising:

• converting a digital asymmetry correction signal to an analog reference voltage;
• sampling an input RF signal referenced to the analog reference voltage and outputting a sampled digital signal;
• detecting blanks/defects in the sampled signal and generating a blank detection signal if a variation in data is not detected from the sampled signal over a predetermined interval of time;
• and
• calculating a digital sum value (DSV) from the sampled digital signal, generating the digital asymmetry correction signal based on the calculated DSV, and temporarily stopping the calculating of the DSV for the predetermined interval of time if the blank/defect detection signal is generated.

A method of correcting an asymmetrical signal, comprising:

• adding an asymmetrical correction signal to a digitally sampled input signal, to generate an added signal;
• generating a blank detection signal if there is no change in the added signal over a predetermined interval of time;
• and
• calculating a digital sum value for the added signal and generating an asymmetrical correction signal, based on the digital sum value, and temporarily stopping the calculating of the digital sum value for the predetermined interval of time if the blank detection signal is generated.

A method of correcting an asymmetrical signal, comprising:

• adding an asymmetrical correction signal to a digitally sampled input signal, to generate an added signal;
• generating a blank detection signal if there is no change in the added signal over a predetermined interval of time;
• waveform equalizing the added signal;
• selecting one of the added signal and the waveform equalized signal;
• calculating a digital sum value based on the selected signal, generating the asymmetrical correction signal based on the digital sum value, and temporarily stopping the calculating of the digital sum value for the predetermined interval of time if the blank detection signal is generated.