KR20070079200A - Method for regulating parameter of equalizer in optical disc driver - Google Patents

Abstract

A method for setting an equalizer parameter in an optical disc drive is provided to measure reproduction quality according to a position on an optical disc in an idle state of the optical disc drive and previously acquire the optimum value of the equalizer parameter. An optical pickup is performed for a certain position on an optical disc to acquire a reproduction signal(S201,S202). A reproduction error rate is measured for ECC(Error Correcting Code) blocks of a certain number from the certain position(S203). It is discriminated whether the measured reproduction error rate corresponds to a certain reference value range(S204). When the measured reproduction error rate does not correspond to a certain reference value range, a value of an equalizer parameter of an optical disc drive is adjusted(S205). The above process is repeatedly performed until the reproduction error rate corresponds to the certain reference value range. A currently set value of the equalizer parameter corresponding to the position where the optical pickup is performed is stored(S206). The position where the optical pickup is performed on the optical disc is moved by a certain unit, and the above process is repeatedly performed(S207).

Description

Method for regulating parameter of equalizer in optical disc driver

1 is a block diagram showing a structure for identifying data recorded on an optical disc in a typical optical disc drive.

2 is a flowchart illustrating a process of performing an embodiment of the present invention.

The present invention relates to a method of adjusting equalizer parameters of an optical disc drive.

In general, an optical disc drive for playing an optical disc such as a CD, DVD, BD, or the like, irradiates light onto an inserted disc using an optical pickup, and signals the result of the reflected light to identify the data recorded on the optical disc. .

1 is a block diagram showing a structure for identifying data recorded on an optical disc in a typical optical disc drive.

In FIG. 1, the optical disk drive irradiates light from the light source diode provided in the optical pickup 120 to the optical disk 110 so that the light is reflected from the optical disk 110. do. The RF block 130 generates a high frequency reproduction signal according to the photosensitive result of the photodiode, and the equalizer block 140 performs a waveform equalization operation such as reducing interference between codes with respect to the high frequency generation signal. The signal is converted into a digital signal, and the digital signal processor (DSP) 150 processes the converted signal to reproduce data or generate a servo signal.

The equalizer block 140 is a block that equalizes the RF signal generated by the RF block 130 and converts it into a digital signal and decodes it. The equalizer block 130 processes the RF signal by low band filtering, amplification and gain adjustment.

A predetermined equalizer parameter value is used for signal processing in the equalizer block 140, and the equalizer parameters include a cutoff frequency, a gaining gain, a group delay, and the like. There is a value.

According to the signal processing in the equalizer block 130 referring to the equalizer parameter, the digital signal processor 150 acquires error rate information of the data of the optical disc being reproduced, and based on this, servo adjustment of the optical pickup is performed. All. Therefore, since the servo quality, reproduction and recording quality vary according to the equalizer parameters, it is necessary to set the equalizer parameters to appropriate values.

In the conventional equalizer parameters, setting values according to the type of optical disc are stored in advance in the optical disc drive, and when the optical disc is loaded, the equalizing signal processing according to the stored equalizer parameter setting values is performed and reproduced. If the error rate is high, such as a data read failure occurs in a predetermined region during reproduction, an appropriate value of the equalizer parameter is obtained by repeating reproduction while adjusting the equalizer parameter for the region.

However, when the playback operation is interrupted to adjust and set the equalizer parameters, the playback time is delayed or the playback quality is deteriorated, and even when the adjusted and set equalizer parameters increase the error rate again during the reproduction of other areas of the optical disc. In many cases, there is a problem that the setting operation of the equalizer parameter must be repeated continuously.

An object of the present invention devised to solve the above problems is to set the equalizer parameter of the optical disc drive to obtain the optimum value of the equalizer parameter in advance by measuring the playback quality according to the position on the optical disc in the idle state of the optical disc drive. To provide a way.

The equalizer parameter setting method of the optical disc drive of the present invention is to set a parameter for an equalizer for performing an equalization operation of a reproduction signal obtained from an optical disc in the optical disc drive, and performs the optical pickup to a predetermined position on the optical disc to reproduce the reproduction signal. Obtaining a first step; A second step of measuring a reproduction error rate for a predetermined number of error correcting code (ECC) blocks from the predetermined position; A third step of determining whether the measured reproduction error rate falls within a predetermined reference value range; Adjusting a value of an equalizer parameter of the optical disc drive when the reproduction error rate does not fall within the predetermined reference value range; A fifth step of repeating the steps of the first to fourth steps until the reproduction error rate corresponds to the predetermined reference value range; A sixth step of storing a value of an equalizer parameter currently set corresponding to a position where the optical pickup is performed; And a seventh step of repeating the processes of the first to sixth steps by moving the position where the optical pickup is performed on the optical disc in a predetermined unit.

The equalizer parameter setting method of the optical disc drive of the present invention further includes a step of determining whether the optical disc drive is in an idle state before the first step, and in the case where the optical disc drive is in an idle state, the first step It is preferable to carry out.

In the present invention, the equalizer parameter of the optical disc drive includes a cutoff frequency, a gaining gain and a group delay.

In the present invention, in the seventh step, it is preferable to move the position at which the optical pickup is performed on the optical disc by a logical block address (LBA) unit having a predetermined size.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In adding reference numerals to components of the following drawings, it is determined that the same components have the same reference numerals as much as possible even if displayed on different drawings, and it is determined that they may unnecessarily obscure the subject matter of the present invention. Detailed descriptions of well-known functions and configurations will be omitted.

2 is a flowchart illustrating a process of performing an embodiment of an equalizer parameter setting method of an optical disk drive of the present invention.

In the embodiment of Fig. 2, first, it is determined whether the optical disc drive is in an idle state (S201), and when the optical disc drive is in an idle state, optical pickup is performed at a predetermined logical block address (LBA) position on the optical disc. Obtain a reproduction signal (S202), obtain a reproduction error rate for a predetermined number of error correction code (ECC) blocks from the obtained reproduction signal (S203), and determine whether the reproduction error rate falls within a predetermined reference value range. It is determined (S204).

When the reproduction error rate does not fall within the predetermined reference value range, adjusting the value of an equalizer parameter of the optical disc drive (S205) to obtain the reproduction signal (S202). The process up to step (S204) of determining whether or not to correspond to the step is performed again, and in step (S204), adjusting the value of the equalizer parameter until the reproduction error rate falls within the predetermined reference value range (S205). ) And subsequent steps S202 to S204 are repeated.

If it is determined in step S204 that the reproduction error rate falls within the predetermined reference value range, the logical block address position where the acquisition of the reproduction signal and the measurement of the reproduction error rate are started in steps S202 and S203, and The value of the corresponding equalizer parameter is stored (S206). Subsequently, the logical block address position is moved by a predetermined unit on the optical disk (S207) and the whole process is repeated again.

The reproduction performance of the optical disc drive is influenced by the parameter value of the equalizer which performs waveform equalization processing on the reproduction signal obtained by the optical pickup. In the present invention, an optimum equalizer parameter value is obtained in advance for predetermined positions on the optical disc, thereby reducing the reproduction delay caused by resetting the equalizer parameter to the optimum value during reproduction.

In the present invention, particularly in the case where the optical disc drive is in an idle state in which the reproducing or recording operation is not performed, a test recording is performed on a predetermined position selected on the optical disc to find an optimal value of the equalizer parameter. .

In the above embodiment, if it is determined in step S201 that the optical disc drive is in the idle state, then the trial play and equalizer parameters are started to be adjusted to perform optical pickup for a predetermined position on the optical disc to obtain a reproduction signal (S202). And the reproduction error rate therefrom (S203).

The acquisition of the reproduction signal and the measurement of the reproduction error rate accordingly are performed from a predetermined position on the optical disc, in particular, a position corresponding to a predetermined logical block address, and is performed for a predetermined number of error correction code blocks.

By determining whether the reproduction error rate measured for a predetermined number of error correction code blocks from the predetermined logical block address falls within a predetermined reference value range (S204), it is determined whether the equalizer parameter value currently being used is an appropriate value. Able to know. If the reproduction error rate does not fall within the predetermined reference value range, the equalizer parameter value is adjusted (S205) to obtain a reproduction signal again (S202) and the reproduction error rate is measured (S203), and the reproduction error rate is the predetermined reference value. Adjustment of the equalizer parameter value (S205), acquisition of a reproduction signal (S202), measurement of reproduction error rate (S203) and determination of whether or not the reference value range of reproduction error rate are repeated (S204) until it falls within the range, Obtain equalizer parameters with appropriate values.

The equalizer parameters include a cutoff frequency, a gaining gain, a group delay, and the like of low band filtering. In the above embodiment, the equalizer parameter is adjusted by first adjusting the gain and measuring the reproduction error rate according to the adjustment to adjust the gain value to an appropriate value, and then adjust the gain in order of cutoff frequency and group delay. Adjust to an appropriate value by measuring the reproduction error rate according to the adjustment.

If the reproduction error rate falls within the predetermined reference value range, the equalizer parameter value currently used is an appropriate value for the position of the logical block address where the acquisition of the reproduction signal and the measurement of the reproduction error rate are made. The equalizer parameter value is stored so as to correspond to (S206). This obtains and stores an equalizer parameter value of an appropriate value for a given logical block address location on the optical disc.

Subsequently, the logical block address position on the optical disc is moved in a predetermined unit (S207), and the steps S201 to S206 are repeated for the moved logical block address position.

When the movement of the logical block address position in step S207 is shifted by 1000 to 10,000 units or more, an appropriate value of the equalizer parameter can be obtained for each logical block address classified into the predetermined unit. have. It is possible to estimate an appropriate value of the equalizer parameter for the logical block addresses of the entire area on the optical disc from the trend of the equalizer parameter changing with the change of the logical block address. If the change in the appropriate value of the equalizer parameter is stored and the optical disc is played back and the value of the equalizer parameter is set according to the stored change trend according to the logical block address, the reproduction performance according to the equalizer parameter for all the optical discs is set. It is possible to improve the performance and to reduce the delay of the playback to reset the equalizer parameters during the playback.

After moving the position of the logical block address, and before performing a series of processes of acquiring a reproduction signal, measuring a reproduction error rate, and adjusting equalizer parameter values, it is determined whether the optical disc drive is in an idle state. . When the optical disc drive needs to perform a play or record operation, the operation of adjusting the test play and equalizer parameters after the step S202 is stopped, and when the optical disc drive is in the idle state again, the test play and Resume adjustment of the equalizer parameters. In resuming the adjustment of the test reproduction and equalizer parameters, the initial position of the logical block address at which the acquisition of the reproduction signal and the measurement of the reproduction error rate is first performed is changed to a position different from that of the previous adjustment of the reproduction and equalization parameters. Preferably, in step S207, the operation of adjusting the test record and the equalizer parameters can be performed while moving the logical block address in the same units as in the previous operation of adjusting the test reproduction and equalizer parameters. Appropriate values of equalizer parameters for logical block address locations can be obtained.

As described above, it has been described with reference to the preferred embodiment of the present invention, but those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

As described above, according to the present invention, an appropriate value of the equalizer parameter of the optical disc drive can be obtained in advance by performing trial play and adjustment of the equalizer parameter for the optical disc, so that the optical disc can be reproduced using the equal value parameter of the appropriate value. The playback delay due to resetting equalizer parameters during playback is reduced.

Claims (4)

In setting the parameter for the equalizer which performs equalization operation of the reproduction signal obtained from the optical disc in the optical disc drive, A first step of performing an optical pickup to a predetermined position on the optical disc to obtain a reproduction signal; A second step of measuring a reproduction error rate for a predetermined number of error correcting code (ECC) blocks from the predetermined position; A third step of determining whether the measured reproduction error rate falls within a predetermined reference value range; Adjusting a value of an equalizer parameter of the optical disc drive when the reproduction error rate does not fall within the predetermined reference value range; A fifth step of repeating the steps of the first to fourth steps until the reproduction error rate corresponds to the predetermined reference value range; A sixth step of storing a value of an equalizer parameter currently set corresponding to a position where the optical pickup is performed; And a seventh step of repeating the processes of the first to sixth steps by moving the position where the optical pickup is performed on the optical disc in a predetermined unit. The method of claim 1, further comprising: determining whether the optical disc drive is in an idle state before the first step, and performing the first step when the optical disc drive is in an idle state. How to set equalizer parameters for an optical disc drive. The method of claim 1, wherein the equalizer parameter of the optical disc drive includes a cutoff frequency, a gaining gain, and a group delay. The method as claimed in claim 1, wherein the seventh step moves the position at which the optical pickup is performed on the optical disc in logical block address units of a predetermined size.

Images