KR20010090263A - Method for controlling RF signal of optical record/player and apparatus for the same - Google Patents

Abstract

PURPOSE: A method and apparatus for controlling an RF signal in an optical record player is provided to stably perform slice by detecting a portion at which a level of an RF signal is rapidly changed and controlling the RF level on the portion. CONSTITUTION: A switching is carried out according to a header mask signal(HDM). The first read channel signal or the second read channel signal allows a DC element to be removed from a DC removing part(201) by the switching. A switching part(202) selects the first read channel signal or the second read channel signal and outputs an RF signal. An RF level correcting part(203) corrects a level of the RF signal provided through the switching part by an RF control signal. The header mask signal(HDM) represents a header field by using the first read channel signal or the second read channel signal. A control signal generating part(206) generates the RF control signal. A slicing part(205) slices an equalized signal into a preset reference level and outputs a digitalized RF signal.

Description

Method for controlling RF signal of optical recorder and apparatus {Method for controlling RF signal of optical record / player and apparatus for the same}

The present invention relates to an optical recording and reproducing system, and more particularly, to a method and apparatus for controlling an RF signal in an optical recording medium having a header area.

In general, a rewritable optical recording medium, particularly a DVD-RAM, has a signal track having a structure of lands and grooves, and records information signals on tracks of lands and grooves to increase recording density. .

In this case, since the DVD-RAM described above has no information on the first disc, disc control and recording are impossible.

To this end, disc tracks are created in lands and grooves, information is recorded along the tracks, and control information for sector address, random access, rotation control, etc. is separately recorded on the disc, whereby no information signal is recorded. Allows tracking control even on the disc. For example, the control information may be recorded by pre-formatting the header area at the start of a sector for each sector. That is, in the DVD-RAM, a header area in which a physical address is recorded is recorded. This exists.

In the case of the DVD-RAM, the header area pre-formatted at the start of each sector is further composed of four header fields (header 1 field and header 4 field). Here, the header 1,2 field and the header 3,4 field are alternately arranged from the track center. FIG. 1 is an example of the structure of the header field for the first sector in one track.

In this case, the header area may be detected from the read channel 2 signal. For example, an optical detector in an optical pickup (not shown) is composed of four photodetecting elements that are specifically divided, i.e., divided into four, in the signal track direction and the radial direction of the optical disk, Let electrical signals proportional to the amount of light be a, b, c, d.

Then, the read channel 1 signal may be obtained by (a + b + c + d) the electrical signal output from the photo detector, and the read channel 2 signal may be the electrical signal output from the photo detector (a + d)-(b + c), and a tracking error (TE) signal can be obtained by processing the read channel 2 signal.

In addition, an RF signal is used for data recovery. The RF signal may be detected from the read channel 1 signal, or may be detected using both the read channel 1 signal and the read channel 2 signal. In other words, when only the read channel 1 signal is used, the RF signal in the user data area and the header area is detected from the read channel 1 signal. In the case where both the read channel 1 signal and the read channel 2 signal are used, the RF signal in the user data area is detected from the read channel 1 signal, and the RF signal in the header area is detected from the read channel 2 signal.

Therefore, in the latter case, the header area can be detected from the read channel 2 signal, which is reflected in the TE signal as a large disturbance factor in performing the actual track servo. In particular, in the DVD-RAM, the level of the RF signal (ie, read channel 2 signal) in the header area is higher than that of the RF signal (ie, read channel 1 signal) in the user data area, thereby generating an RF signal for data processing. Affects the slice level. Therefore, DC is removed from the actual RF signal and used as an RF signal for RF data detection.

FIG. 2 is a block diagram illustrating a general configuration of the RF signal control apparatus, and the DC removing unit 101 removes the DC component of the input RF signal and outputs the DC component to the equalizer (EQ) 102. The equalizer 102 removes the distortion and the like from the RF signal from which the DC component is removed and outputs it to the slicing unit 103. The slicing unit 103 slices the equalized signal to a predetermined reference level and outputs a digitized RF signal (eg, 3T, 4T, 5T, ...). The digitized RF signal is used for data reproduction and the like.

In this case, the slicing unit 103 sets the automatic slice level to slice the equalized RF signal. That is, since the slicing unit 103 slices the RF signal while automatically following the center level of the RF signal, the transition is not fast.

Therefore, if the level of the RF signal is changed rapidly, there may be a problem in slicing. For example, an error such as 4T should be output but 5T is output.

In particular, an instant occurs when the level of the RF signal suddenly changes in the header area. When the DC remover 101 removes the DC component of the RF signal, the RF signal fluctuates at a transition point where the RF signal is rapidly changed by the high frequency component. Distance causes distortion of the RF signal. In this case, the slicing level is particularly difficult to set.

The present invention has been made to solve the above problems, and an object of the present invention is to detect a portion where the level of the RF signal changes rapidly and then control the RF level of the portion to perform the slice stably to the RF of the optical recorder The present invention provides a signal control method and apparatus.

1 shows an example of a header arrangement preformatted at the start position of each sector in a general rewritable disc.

2 is a block diagram illustrating a conventional RF signal control method

3 is a block diagram illustrating an RF signal control method according to the present invention.

4 is a detailed block diagram of a control signal generator of FIG. 3.

5A to 5G are waveform diagrams showing an example of a header region detection and RF control signal generation process using the read channel 2 signal;

6 (a) and 6 (b) are enlarged waveform diagrams of the original portions of FIGS. 5 (a) and 5 (b).

FIG. 7 is a waveform diagram illustrating an example of correcting an RF level by generating an RF control signal from the read channel 2 signal of FIG. 5.

8A to 8G are waveform diagrams showing an example of a header region detection and RF control signal generation process using the read channel 1 signal;

Explanation of symbols for main parts of the drawings

201: DC removing unit 202: switching unit

203: RF level correction unit 204: Equalizer

205: slicing unit 206: control signal generator

301: BPF 302: first slice portion

303: second slice portion 304: ora gate

305: Glitch Removal and Waveform Shapes

306: inverter

In the RF signal control method of the optical recorder according to the present invention for achieving the above object, the data area is composed of land and groove tracks, and can record data in each of the land and groove tracks, Detecting a header area from an optical recording medium providing information on a next data area, and identifying a section in which the signal change is greater than or equal to a predetermined reference by the header area; The method includes adjusting the output of the RF signal to a reference level.

In the section checking step, after filtering the read channel 1 or the read channel 2 signal to a predetermined band, slicing is performed at the upper slice level and the bottom slice level preset to the filtered signal, and the header region detection signal is obtained from the slicing result. It is characterized by generating.

In the section checking step, after filtering the read channel 1 or read channel 2 signal to a predetermined band, slicing is performed at the upper slice level and the bottom slice level preset to the filtered signal, and the RF signal change is constant from the slicing result. It is characterized in that for generating a RF control signal by detecting a section that changes over the reference.

In the RF signal control apparatus of the optical recorder according to the present invention, the data area is composed of lands and groove tracks, and data can be recorded in each of the lands and groove tracks, and a header area is provided for information on the next data area. A DC removing unit for removing a DC component of a read channel 1 or read channel 2 signal generated from an optical recording medium providing a signal; generating a header area detection signal by detecting a header area from the read channel 1 or read channel 2 signal; And a control signal generation unit for generating an RF control signal by checking a section in which the signal change is greater than or equal to a predetermined reference by the header area, and a lead which is switched by the header area detection signal output from the control signal generation unit to remove the DC. A switching unit for selectively outputting a channel 1 or lead channel 2 signal, and an RF output from the control signal generator If it is determined by the control signal that the signal change is greater than or equal to a predetermined reference period, the equalization is performed on the RF level correction unit for controlling the level of the RF signal output through the switching unit and the RF signal output through the RF level correction unit. It is characterized by including a slicing unit to digitize after.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention provides stable data reproduction by detecting a transition point rapidly changed by the header area and then adjusting the RF signal level of the detected portion to a reference level.

3 is a block diagram illustrating an RF signal control apparatus of an optical recorder according to an exemplary embodiment of the present invention, which is switched according to a header mask signal (HDM) and has a lead channel from which a DC component is removed from the DC removal unit 201 by switching. An RF level beam for correcting the level of the RF signal provided through the switching unit 202 by the switching unit 202 and the RF control signal RF_con that select one signal or the lead channel 2 signal and output the RF signal. The control unit generator 206 generating the header mask signal HDM and the RF control signal RF_con indicating the header area using the government unit 203 and the read channel 1 or read channel 2 signal are shown in FIG. 2. Is further provided. That is, the DC removing unit 201, the equalizer 204, and the slicing unit 205 are the same as those of FIG. 1.

4 is a detailed block diagram of the control signal generator 206, and receives the read channel 1 or read channel 2 signal to generate a header mask signal HDM and an RF control signal RF_con.

Referring to FIG. 4, a bandpass filter (BPF) 301 for bandpass filtering a read channel 1 (or read channel 2) signal and adding a DC bias voltage, and a preset upper slice level of the bandpass filtered signal. a first slice unit 302 to slice at a slice level), a second slice unit 303 to slice the output of the BPF 301 at a predetermined bottom slice level, and the first and second slices An OR gate 304 for logically combining the outputs of the units 302 and 303, a glitch removal and waveform generator 305 for generating a header mask signal indicating a header region after removing glitches from the output of the OR gate 304, and The inverter 306 generates an RF control signal RF_con by inverting the output of the OR gate 304.

Here, the glitch removal and waveform generator 305 can be easily configured using a multivibrator.

In addition, the BPF 301 may receive the read channel 1 signal and perform band pass filtering, or may receive the read channel 2 signal and perform band pass filtering. Can not be used).

Therefore, according to an exemplary embodiment of the present invention, the header mask signal HDM and the RF control signal RF_con are generated using the read channel 1 signal, and the header mask signal HDM and the RF control are performed using the read channel 2 signal. The case of generating the signal RF_con will be described separately.

5 to 7 illustrate an example of generating and controlling a header mask signal HDM and an RF control signal RF_con using the read channel 2 signal. In particular, Figs. 6A and 6B are enlarged portions of the circle of Figs. 5A and 5B. Therefore, the RF signal control process will be described in detail with reference to FIGS. 4 to 7.

That is, the BPF 301 outputs the read channel 2 signal to the first and second slice units 302 and 303 after the band pass filtering. Here, the BPF 301 may be configured by combining a low pass filter LPF and a high pass filter HPF.

At this time, when the read channel 2 signal as shown in FIGS. 5 and 6 passes through the BPF 401, the DC level is maintained at a constant DC bias voltage as shown in FIGS. 5 and 6 (b). For example, a large signal is generated at the transition point, for example, at the beginning and the end of the header area, and at the boundary between the header 1,2 field and the header 3,4 field. That is, since the header 1,2 field and the header 3,4 field are staggered from each other based on the track center in the header area, when the read channel 2 signal detected in the header 1,2 field and the header 3,4 field is bandpass filtered, As shown in (b) of FIG. 5 and FIG. 6, the signal is greatest at the phase shifting part, and the signal is next generated at the start of the header 1 and 2 fields and at the end of the header 3 and 4 fields. This is the point where the RF signal changes dramatically.

Accordingly, the first slice unit 302 slices the output of the BPF 301 at a preset upper slice level as shown in FIG. 5C, and outputs the result to the OR gate 304. 303 slices the output of the BPF 301 at a predetermined bottom slice level as shown in FIG. 5 (d) and outputs the same to the ora gate 304.

When the output of the first and second slice parts 302 and 303 is ringed by the OR gate 304, when only one header area is viewed, a high signal is generated at 3 parts as shown in FIG. 5E. At this time, depending on the circuit configuration, a low signal may be generated instead of a high signal. In the present invention, it is assumed that a high signal is generated in an embodiment.

On the other hand, the glitch removal and waveform generation unit 305 removes the high frequency components from the oraled signal as shown in Figure 5 (e) and shape the waveform to generate a header mask signal (HDM) as shown in Figure 5 (f) After that, output to the switching unit 202. In this case, assuming that the glitch removal and waveform generation unit 305 is configured as a multivibrator, the glitch removal and waveform generation unit 305 performs a high frequency component from the sliced signal by performing charge and discharge using an RC time constant. The header mask signal HDM is generated as shown in FIG.

In addition, the output of the OR gate 304 is output to the inverter 306, the inverter 306 inverts the output of the OR gate 304 to the RF control signal (RF_con) as shown in Figure 5 (g) After generating the output to the RF level correction unit 203.

In this case, the switching unit 202 is switched according to the header mask signal (HDM) to selectively output the read channel 1 or read channel 2 signal from which DC is removed by the DC removing unit 201 as an RF signal. That is, in a section in which the header mask signal HDM is turned on, for example, in the header region, the lead channel 2 signal is selected as an RF signal by switching and output to the RF level correction unit 203, and the header mask signal HDM is turned off. In the section, for example, in the user data area, the lead channel 1 signal is selected as an RF signal by switching and output to the RF level correction unit 203.

The RF level correction unit 203 adjusts the RF signal provided through the switching unit 203 to a reference level in a period where the RF control signal RF_con provided by the control signal generator 206 is low. .

In the present invention, when the RF control signal RF_con is low, it is regarded as a transition point, that is, a point where the RF signal changes rapidly. Accordingly, the RF level correction unit 203 charges an RF signal using an RC time constant, and then, at the transition point of the header area indicated by the RF control signal RF_con, converts the RF signal into a reference level as shown in FIG. Adjust to center level. At this time, the incoming AC signal is carried on the reference level. That is, when the RF control signal RF_con is low and the RF signal is turned off, and the RF signal is turned on only when the RF control signal RF_con is high, the RF signal level may be dropped to the reference level as shown in FIG. 7.

If the RF level correction unit 203 is designed to be adjusted to the reference level only when the RF control signal RF_con is low, the inverter 306 is required in FIG. 4, and conversely, is designed to be adjusted to the reference level only when the RF control signal RF_con is low. In FIG. 4, the inverter 306 is omitted.

8A and 8G illustrate a process of generating the header mask signal HDM and the RF control signal RF_con using the read channel 1 signal, and the hardware configuration is the same as that of FIG. 4.

That is, the BPF 301 outputs the read channel 1 signal to the first and second slice units 302 and 303 after the band pass filtering.

At this time, if the read channel 1 signal as shown in FIG. 8A passes through the BPF 401, the DC level is constantly maintained at the DC bias voltage provided as shown in FIG. 8B, and is a transition point, for example, a header region. The signal is generated largely at the beginning and the end.

The first slice unit 302 slices the output of the BPF 301 at a preset upper slice level as shown in FIG. 8C, and outputs the result to the OR gate 304, and the second slice unit 303. Slices the output of the BPF 301 at a predetermined bottom slice level as shown in FIG. 8 (d) and outputs the result to the OR gate 304.

At this time, when the output of the first and second slice units 302 and 303 is ringed by the OR gate 304, a high signal is generated at two points for one header region as shown in FIG. 8E. This is because the read channel 1 signal detected in the header area is in phase with respect to the header 1 and 2 fields and the header 3 and 4 fields. In other words, a large signal does not occur at the boundary between the header 1,2 field and the header 3,4 field.

Therefore, the glitch removal and waveform generator 305 removes the high frequency components from the oraled signal as shown in (e) of FIG. 8, and shapes the waveform to generate the header mask signal (HDM) as shown in (f) of FIG. 8. After that, output to the switching unit 202.

In addition, the output of the OR gate 304 is output to the inverter 306, the inverter 306 inverts the output of the OR gate 304 to the RF control signal (RF_con) as shown in Figure 8 (g) After generating the output to the RF level correction unit 203.

In this case, the switching unit 202 selects the read channel 1 signal as an RF signal in both the header area and the user data area and outputs the RF signal to the RF level correction unit 203. This is because the header mask signal HDM and the RF control signal RF_con are generated from the read channel 1.

The RF level correction unit 203 sets the RF level of the RF signal provided through the switching unit 203 as a reference level when the RF control signal RF_con provided by the control signal generator 206 is low. Adjust That is, since the RF control signal RF_con indicates low at the beginning and the end of the header area and highs at other portions, the RF level correction unit 203 charges the RF signal using the RC time constant. If the RF control signal RF_con indicates a transition point of the header area, the charged RF signal is adjusted to a reference level, for example, a center level. At this time, the incoming AC signal is carried on the reference level.

Similarly, if the RF level correction unit 203 is designed to adjust to the reference level only when the RF control signal RF_con is low, the inverter 306 is required in FIG. In FIG. 4, the inverter 306 is omitted.

As described above, since the point where the RF signal changes rapidly is adjusted to the reference level, the slicing unit 205 can stably set the slice level. That is, since the slicing unit 205 can always follow the RF signal, the RF signal is accurately digitized.

As described above, according to the RF signal control method and apparatus of the optical recorder according to the present invention, after detecting the point where the RF signal is rapidly changed, by controlling the RF signal level of the portion to the reference level, the RF signal in the header section It can eliminate the slice level instability caused by the rapid change. For this reason, the slice level at the time of digitizing an RF signal can be set stably, and especially the data reproduction quality can be improved.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (7)

The data area of the optical recording medium is composed of lands and groove tracks, data can be recorded on each of the land and groove tracks, and a header area is provided for the RF of the optical recorder providing information on the next data area. In the signal control method, Detecting the header area and identifying a section in which the signal change is greater than or equal to a predetermined reference by the header area; And And a step of adjusting the level of the input RF signal to a reference level in a section in which the signal change identified in the step is equal to or greater than a predetermined reference. The method of claim 1, wherein the step of checking the section After filtering the lead channel 2 signal to a predetermined band, slicing is performed at the upper slice level and the bottom slice level preset to the filtered signal, and a header region detection signal indicating the header region is generated from the slicing result. RF signal control method of optical recorder. The method of claim 1, wherein the step of checking the section After filtering the read channel 2 signal to a predetermined band, slicing is performed at the upper slice level and the bottom slice level preset to the filtered signal, and the RF control is detected by detecting a section in which the RF signal change is over a predetermined reference from the slicing result. An RF signal control method for an optical recorder, characterized in that for generating a signal. The method of claim 1, wherein the step of checking the section After filtering the read channel 1 signal to a predetermined band, slicing is performed at the upper slice level and the bottom slice level preset to the filtered signal, and a header region detection signal indicating the header region is generated from the slicing result. RF signal control method of optical recorder. The method of claim 1, wherein the step of checking the section After filtering the lead channel 1 signal to a predetermined band, slicing is performed at the upper slice level and the bottom slice level preset to the filtered signal, and the RF control is detected by detecting a section in which the RF signal changes by more than a predetermined reference from the slicing result. An RF signal control method for an optical recorder, characterized in that for generating a signal. The data area of the optical recording medium is composed of lands and groove tracks, data can be recorded on each of the land and groove tracks, and a header area is provided for the RF of the optical recorder providing information on the next data area. In the signal control device, A DC removing unit removing a DC component of the read channel 1 or read channel 2 signal; A control signal generator for generating a header region detection signal by detecting a header region from the lead channel 1 or lead channel 2 signal, and generating an RF control signal by checking a section where a signal change is greater than or equal to a predetermined reference by the header region; A switching unit which is switched by a header region detection signal output from the control signal generator to selectively output the read channel 1 or read channel 2 signal from which the DC is removed as an RF signal; An RF level correction unit adjusting the level of the RF signal output through the switching unit to a reference level when it is determined by the RF control signal output from the control signal generator that the signal change is greater than or equal to a predetermined reference period; And And an slicing unit for performing digital equalization after performing an equalization on the RF signal output through the RF level correcting unit. The method of claim 6, wherein the control signal generator A filtering unit configured to receive the read channel 1 or read channel 2 signal and perform band pass filtering; A first slice unit which slices the filtered signal to a preset upper slice level; A second slice unit which slices the filtered signal to a predetermined bottom slice level; A logic unit configured to logically combine the outputs of the first and second slice units to generate an RF control signal; And an glitch removal and waveform generation unit for generating a header region detection signal indicating that the header region is removed after removing the glitch from the output of the logic unit.