KR100350678B1 - Encoded read data detecting device for disc driving recording system - Google Patents

Abstract

PURPOSE: A device for detecting encoded read data of a disc driving recording system is provided to recover data by a very small analog signal even though an amplitude of the analog signal is reduced by the noise or disc detection, and remove the noise generated by the disc noise, thereby realizing the precise data recovery. CONSTITUTION: A device for detecting encoded read data of a disc driving recording system includes a differentiation and time pulse generator(10) and a sampler(20). The differentiation and time pulse generator receives an analog signal abandoned from a disc via a head disk assembly, amplified by the predetermined level and filtered, and generates a time pulse corresponding to a point of inflection by differentiating the analog signal. The sampler is applied with the analog signal and the time pulse for sampling the analog signal by using the time pulse as a sampling frequency. First and second peak detecting and pulse width control elements(30,40) receive the output signal from the sampling element and respectively generate a positive or negative pulse signal corresponding to a maximum positive or negative value in each sampling section with reference to a predetermined reference level. A noise pulse removing element(50) removes a noise section by comparing the positive and negative pulse signals and outputs an ERD(Encloded Read Data) corresponding to the sum of the positive and negative pulse signals.

Description

An encoded read data detection device of a disc drive recording device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc drive recording apparatus, and more particularly to an apparatus for detecting encoded read data (hereinafter referred to as ERD) of a read channel for detecting data recorded on a disc.

In general, a conventional ERD detector in a read channel section for detecting ERD data from an analog signal induced in a head in a disc drive recording apparatus is a peak detection method. The signal read through the head is amplified to a predetermined level during data reproduction. After filtering, the ERD data is detected using a time channel and a qualification channel. The time channel is induced through the head and differentiates the filtered analog signal to generate timing information necessary for ERD detection. In addition, the limited channel sets a predetermined signal threshold level using a hysteresis comparator and compares the filtered analog input signal with the signal threshold level, thereby validating an input signal satisfying the comparison state. Data is judged and the ERD error is suppressed by ignoring the input signal that does not satisfy the comparison status. Such a conventional ERD detector and detection method is disclosed in Korean Patent Application No. 94-9013 filed by the applicant of the present application.

However, the above-described conventional ERD detector generates a time pulse by differentiating the analog signal induced by the head, and determines valid data using the analog signal. Therefore, the analog signal is changed by the speed change of the spindle motor or the noise generated from the head or the disk. Is misleading, causing data to be missed or produce incorrect data. In other words, if the peak point of the analog signal is changed by an external force, the time pulse is also changed, which may cause an error to generate an invalid extra ERD data, and the noise or disc defect may cause an error in the analog signal. When the amplitude decreases and falls below the signal threshold level of the hysteresis comparator, a missing error occurs that prevents data from being detected in the limited channel.

Accordingly, an object of the present invention is to provide an ERD detecting apparatus of a disk drive recording apparatus which suppresses occurrence of missing data and extra data by sampling and detecting ERD from the input signal as a time pulse obtained by differentiating an input signal read by the head. have.

In order to achieve the above object, the present invention provides a disc drive recording apparatus comprising: a derivative and a time pulse for differentiating an input signal amplified and inputted to a predetermined level induced from a disc through a head, and generating and outputting a time pulse corresponding to the result. Generating means,

Sampling means for receiving the input signal and sampling and outputting the input signal in synchronization with the time pulse;

First peak detection and pulse width adjusting means for receiving an output signal of the sampling means and generating and outputting a positive pulse signal corresponding to a positive maximum value in each sampling section based on a predetermined reference level;

Second peak detection and pulse width adjusting means for receiving an output signal of the sampling means and generating and outputting a negative pulse signal corresponding to a negative maximum value in each sampling section based on a predetermined reference level;

And a noise pulse removing means for receiving the positive pulse signal and the negative pulse signal, comparing the two input signals, removing the overlapping signal, and outputting an ERD corresponding to the sum of the two input signals.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a block diagram of an ERD detecting apparatus according to an exemplary embodiment of the present invention, in which the derivative and time pulse generator 10 is induced from a disk through an HGA (Head Disk Assembly) (not shown) and amplified to a predetermined level. After receiving the filtered analog signal, it is differentiated to generate and output a time pulse corresponding to the inflection point. A sampler 20 receives the analog signal and a time pulse, samples the analog signal using the time pulse as a sampling frequency, and holds a sampling result thereof. The first peak detection and pulse width controller 30 receives the output signal of the sampler and generates and outputs a positive pulse signal corresponding to the positive maximum value in each sampling section based on a predetermined threshold level. The second peak detection and pulse width controller 40 receives the output signal of the sampler and generates and outputs a negative pulse signal corresponding to the negative maximum value in each sampling section based on a predetermined threshold level. The noise pulse remover 50 receives the positive pulse signal and the negative pulse signal, compares the two input signals, removes the overlapping signal, and outputs an ERD corresponding to the sum of the two input signals. 2 is a signal waveform diagram of each component according to the configuration of FIG.

An operation example of a preferred embodiment of the present invention will now be described with reference to FIG. 2 based on the configuration of FIG. 1 described above.

First, the analog signal induced in the head from the disk in the HDA is first-amplified in the preamplifier, and then converted into a second-amplified and constant-level analog signal in a variable gain amplifier and filtered through a low pass filter. After the noise component is removed, it is input to the derivative and time pulse generator 10 and the sampler 20 in the waveform (a) of Fig. 2. The derivative and time pulse generator 10 then differentiates the analog signal. And generate and output a time pulse as shown in (b) of FIG. 2 corresponding to the inflection point of the differential analog signal, and the sampler 20 receives the filtered analog signal and the time pulse. The analog signal is sampled and held at a sampling frequency and output as shown in (c) of Fig. 2. The first peak detection and pulse width controller 30 then corresponds to the predetermined reference level. A positive pulse is generated and output corresponding to the maximum value of the positive sample (d in FIG. 2) of the output signal output from the sampler 30. The first peak detection and pulse width regulator 30 is, for example, a synchronizer. The pulse width of the positive pulse is adjusted and output at 1.5 times the clock cycle of Fig. 2 (f), while the second peak detection and the pulse width controller 40 correspond to the predetermined reference level. A negative pulse is generated and output corresponding to the maximum value of the negative sample (e) of the output signal outputted from the second signal, and the second peak detection and pulse width regulator 40 is, for example, in the clock cycle of the synchronizer. The pulse width of the negative pulse is adjusted by 1.5 times and outputted ((g) of FIG. 2).

Thereafter, the noise pulse remover 50 receives the positive pulse f and the negative pulse g from the first peak detection and pulse width controller 30 and the second peak detection and pulse width controller 40. Comparing to the second noise region (e.g. A in Fig. 2) that overlap occurs as shown in (h) of Fig. 2 and the two input pulses are synthesized and output as an ERD (Fig. 2 (i)).

Therefore, as described above, even if the amplitude of the analog signal decreases due to noise and disk detection, the present invention can recover data if only a small analog signal remains, and also eliminates noise generated by disk noise. There is an advantage to enable accurate recovery of the data.

1 is a block diagram of an encoded read data detection apparatus according to a preferred embodiment of the present invention.

2 is a timing diagram of each component according to an example of operation of FIG. 1.

Claims (3)

In a disc drive recorder: Derivative and time pulse generation means for differentiating an input signal amplified and inputted to a predetermined level induced from the disc through the head and generating and outputting a time pulse corresponding to the result; Sampling means for receiving the input signal and sampling and outputting the input signal in synchronization with the time pulse; First peak detection and pulse width adjusting means for receiving an output signal of the sampling means and generating and outputting a positive pulse signal corresponding to a positive maximum value in each sampling section based on a predetermined reference level; Second peak detection and pulse width adjusting means for receiving an output signal of the sampling means and generating and outputting a negative pulse signal corresponding to a negative maximum value in each sampling section based on a predetermined reference level; And a noise pulse removing means for receiving the positive pulse signal and the negative pulse signal, comparing the two input signals to remove a noise section, and outputting an ERD corresponding to the sum of the two input signals. Encoded lead data detection device of the device. The method of claim 1, And said differential and time pulse generating means generates and outputs a time pulse corresponding to the inflection point of the differential result. The method according to claim 1 or 2, The noise removing unit receives the positive pulse signal and the negative pulse signal, compares the two input signals, and compares the two input signals to convert the pulse sections each having a high overlap period into a low state to remove the noise section. An encoded read data detection device of a recording device.