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US 6,212,144 B1Granted
Method and apparatus for reading data
AssigneeFujitsu Limited
InventorShigetaka Asano
Life of this patent
Estimating the term…
Abstract
A data reading unit reads analog data stored on a recording medium and converts the analog data to a digital signal synchronously with a clock signal. A waveform equalizer shapes the digital signal using a coefficient. The waveform equalizer also optimizes the coefficient synchronously with the clock signal using an intensity parameter. The waveform equalizer includes a control unit for setting an initial value of the intensity parameter and dynamically adjusting the intensity parameter. The data reader also includes a PLL circuit for generating the clock signal. The PLL circuit may generate the clock signal using a second intensity parameter. The PLL circuit includes a control unit for dynamically altering the second intensity parameter.
Claims43
A data reading apparatus for reading data recorded on a recording medium, the data reading apparatus comprising:
- an A/D converter that receives a read signal and a clock signal, the read signal including the recorded data and a control data for controlling a read out operation of the recorded data, and converts the read signal into a digital signal synchronously with the clock signal;
- and
- a waveform equalizer having a coefficient relate to a waveform of the digital signal and an intensity parameter, wherein the waveform equalizer receives the digital signal and the clock signal, optimizes the coefficient synchronously with the clock signal by an operation employing the intensity parameter and the digital signal, and shapes the waveform of the digital signal in accordance with the optimized coefficient to generate a reproduced signal, wherein:
- the intensity parameter has a predetermined initial value,
- the waveform equalizer includes a control unit for adjusting a value of the intensity parameter, and
- the control unit sets the value of the intensity parameter to a value larger than the initial value when the waveform equalizer optimizes the coefficient.
3 more elements
A data reading apparatus for reading data recorded on a recording medium, the data reading apparatus comprising:
- an A/D converter that receives a read signal and a clock signal, the read signal including the recorded data and control data for controlling a read out operation of the recorded data, and converts the read signal synchronously with the clock signal into a digital signal;
- a waveform equalizer for shaping a waveform of the digital signal and generating a reproduced signal;
- and
- a PLL circuit for generating the clock signal synchronized with the reproduced signal using an intensity parameter, wherein:
- the intensity parameter has an initial value,
- the PLL circuit includes a control unit for adjusting a value of the intensity parameter, and
- the control unit adjusts the value of the intensity parameter to a value larger than a predetermined value when the PLL circuit generates the clock signal synchronized with the reproduced signal.
4 more elements
A data reading apparatus for reading data recorded on a recording medium, the data reading apparatus comprising:
- an A/D converter that receives a read signal and a clock signal, the read signal including the recorded data and control data for controlling a read out operation of the recorded data, and converts the read signal to a digital signal synchronously with the clock signal;
- a waveform equalizer having a coefficient in relation to a waveform shaping of the digital signal and a first intensity parameter, receives the digital signal and the clock signal, optimizes the coefficient synchronously with the clock signal using the first intensity parameter and the digital signal, and performs waveform shaping of the digital signal in accordance with the optimized coefficient and the first intensity parameter to generate a reproduced signal, wherein the intensity parameter has an initial value;
- a first control unit for adjusting the first intensity parameter;
- a PLL circuit having a second intensity parameter relating to a synchronization of the clock signal for receiving the reproduced signal and for generating the clock signal synchronized with the reproduced signal based on the second intensity parameter, wherein the second intensity parameter has an initial value;
- and
- a second control unit for adjusting a value of the second intensity parameter;
- wherein the second control unit sets the second intensity parameter to a value larger than its value at the moment the clock signal is generated, and the first control unit sets the first intensity parameter to a value that is smaller than a predetermined value when the PLL circuit generates the clock signal synchronized with the reproduced signal.
4 more elements
A data reading apparatus for reading data recorded on a recording medium, the data reading apparatus comprising:
- an A/D converter that receives a read signal and a clock signal, the read signal including the recorded data and a control data for controlling a read out operation of the recorded data, and converts the read signal synchronously with the clock signal into a digital signal;
- a storage unit that stores a coefficient in relation to a waveform shaping of the digital signal and an intensity parameter, wherein the intensity parameter has an initial value;
- and
- a processing unit that receives the digital signal and the clock signal, optimizes the coefficient synchronously with the clock using the intensity parameter and the digital signal, performs waveform shaping of the digital signal using optimized coefficient to generate a digital signal, and adjusts a value of the intensity parameter, wherein the processing unit sets the value of the intensity parameter to a value larger than the initial value when the processing unit optimizes the coefficient.
1 more element
A method of reading data recorded on a recording medium, the method comprising the steps of:
- converting a read signal including the recorded data and control data for controlling a read out operation of the recorded data into a digital signal synchronously with a clock signal;
- optimizing a coefficient relating to a waveform shaping operation using an intensity parameter;
- performing waveform shaping of the digital signal in accordance with the optimized coefficient to generate a reproduced signal;
- and
- adjusting a value of the intensity parameter, wherein the adjusting step sets the value of the intensity parameter to a value larger than its initial value at the moment of the coefficient being optimized.
2 more elements
A method of reading data on a recording medium, the method comprising the steps of:
- converting a read signal including the recorded data and a control data for controlling a read out operation of the recorded data into a digital signal synchronously with a clock signal;
- performing waveform shaping of the digital signal synchronously with the clock signal to generate a reproduced signal;
- generating the clock signal synchronized with the reproduced signal using an intensity parameter;
- and
- adjusting a value of the intensity parameter, wherein the adjusting step sets, in the clock signal generating step, the value of the intensity parameter to a value larger than a predetermined value.
2 more elements
A method of reading data recorded on a recording medium, the method comprising the steps of:
- converting a read signal including the recorded data and control data for controlling a read out operation of the recorded data into a digital signal synchronously with a clock signal;
- optimizing a coefficient relating to a waveform shaping synchronously with the clock signal using a first intensity parameter and the digital signal;
- performing waveform shaping of the digital signal in accordance with the optimized coefficient to generate a reproduced signal;
- generating the clock signal synchronized with the part of the reproduced signal originated from the control data, on the basis of a second intensity parameter;
- and
- adjusting values of the first and second intensity parameters, wherein in the step of generating the synchronized clock signal, the adjusting step includes the step of setting the value of the first intensity parameter to a value smaller than a predetermined value, and setting the value of the second intensity parameter to a value larger than a predetermined value.
3 more elements
A recording medium having a computer readable program for reading data, wherein the program code performs the steps of:
- converting a read signal including the read data and control data into a digital signal synchronously with a clock signal;
- optimizing a coefficient relating to a waveform shaping synchronously with the clock signal using an intensity parameter and the part of the digital signal originated from the control data;
- performing waveform shaping of the digital signal in accordance with the optimized coefficient to generate a reproduced signal;
- and
- adjusting a value of the intensity parameter, wherein the adjusting step includes the step of setting the value of the intensity parameter to a value larger than its initial value.
2 more elements
A recording medium having a computer readable program for reading data, wherein the program code performs the steps of:
- converting a read signal including the read data and control data into a digital signal synchronously with a clock signal;
- performing waveform shaping of the digital signal synchronously with the clock signal to generate a reproduced signal;
- generating the clock signal synchronized with the part of the reproduced signal originated from the control data using an intensity parameter;
- and
- adjusting a value of the intensity parameter, wherein the adjusting step sets, in the synchronized clock signal generating step, the value of the intensity parameter to a value larger than a predetermined value.
2 more elements
A recording medium having a computer readable program reading data, wherein the program code performs the steps of:
- converting a read signal including the read data and control data into a digital signal synchronously with a clock signal;
- optimizing a waveform shaping using a first intensity parameter and the digital signal originated from the control data;
- performing waveform shaping of the digital signal in accordance with the optimized coefficient to generate a reproduced signal;
- generating the clock signal synchronized with the part of the reproduced signal originated from the control data using a second intensity parameter;
- and
- adjusting the first and second intensity parameters, wherein, in the step of generating the synchronized clock signal, the adjusting step including the steps of:
- setting the value of the first intensity parameter to a value smaller than a predetermined value;
- and
- setting the value of the second intensity parameter to a value larger than a predetermined value.
6 more elements
Dependencies are inferred from the claim text.