KR20060067742A - Data detecting system of pic area in blue-ray disc and method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reproducing an optical disc for high-density reproduction, comprising a lead-in area, a data area, and a lead-out area, wherein a high frequency is bi-phase modulated in a specific area of the lead-in area in the optical disc. An optical pickup unit for recognizing a recording pattern of a bi-phase modulated HFM groove and generating a signal thereof; An analog-to-digital converter for sampling and quantizing the high frequency modulated signal recognized by the optical pickup unit; A phase shift detector for determining a phase shift using a sign of the sampled value; A cyclic adder for continuously adding the sampled values; A sink length detector for detecting a length of a sync pattern included in the high frequency modulated signal recognized by the optical pickup unit and generating a cyclic value of the cyclic adder; And a bit detector for detecting a bit string recorded in the high frequency modulation groove when a phase shift is detected in the phase shift detector.

BD, PIC, HFM, Groove

Description

Data detection apparatus and method thereof in a PI area in an optical disk for high-density reproduction exclusively, and a method thereof TECHNICAL FIELD             

1 shows a disc structure for a general rewritable optical disc (BD-RW).

FIG. 2 shows the shape of an HFM groove modulated and recorded in a lead-in area of a general rewritable optical disc.

FIG. 3 shows a configuration of a push-pull tracking servo applied to a general rewritable optical disc device.

4 shows an embodiment of a disc structure for a typical high-density reproduction-only optical disc (BD-ROM).

Fig. 5 shows a block diagram of a PLL in a high density optical disc (BD-ROM) reproducing apparatus.

6 is a block diagram of an apparatus for reproducing HFM data in a high density optical disc according to an embodiment of the present invention.

7 is a flowchart illustrating a sink length detection method according to an embodiment of the present invention.

8 is an operation diagram of a cyclic adder and a bit detector according to an embodiment of the present invention.

9 is a flowchart illustrating a flow of a circulating adder according to an embodiment of the present invention.

10 is a flowchart illustrating a flow of a bit detector according to an embodiment of the present invention.

{Description of Major Symbols in Drawings}

602: analog-to-digital converter 603: phase shift detector

604: cyclic adder 605: sink length detector

606: bit detector 607: HFM bit data

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a data detection apparatus and method of a PIC (Permanent Information & Control data) area in an optical disc for high-density reproduction. In particular, in the high-density optical disc recording / reproducing system, the PIC area of the lead-in area of the high-density optical disc is HFM groove. The information is recorded in a manner that relates to a data restoration method using the characteristics of the HFM.

Recently, a new high-density rewritable optical disc capable of recording and storing high-quality video data and high-quality audio data for a long time, for example, a rewritable Blu-ray disc (hereinafter referred to as BD-RW) as shown in FIG. As the standardization of.) Progresses rapidly, related products are expected to be developed, released and commercialized.

On the other hand, in the case of the BD-RW as described above, the clamping area, the transition area, the BCA area, and the lead-in area are present in the inner circumferential surface of the disk, and the data is located on the center and outer circumferential surfaces of the disk. The disk structure includes a data area and a lead-out area, respectively.

In addition, the lead-in area may include a first guard (Guard 1) area and a permanent information amp (PIC) area, a second guard (guard 2) area, an information 2 (Info 2) area, and an OPC ( Optimum Power Control) and the like are separately allocated, wherein the first guard area and the PIC area are pre-recorded areas, while the remaining lead-in area and The data area and the lead-out area are areas where new data is rewritten.

In the PIC area, a high frequency modulated (HFM) groove is formed and recorded as the area where the main general information of the disk to be permanently stored is recorded. The HFM groove is shown in FIG. As described above, the data is modulated and recorded by a Bi-Phase Modulated method to record and store disk information.

For example, when HFM grooves of the same phase are recorded during the recording section of '36T', the value is '0', and when HFM grooves of different phases are recorded during the recording section of '36T'. , The value is '1'.

On the other hand, the tracking servo for tracking the HFM groove recorded in the PIC region as described above is to use a well-known push / pull method, for this purpose, as shown in FIG. A two-divided light receiving element 12 for photoelectrically converting light received through the objective lens 10 and the collimated lens 11 into an electrical signal, and an electrical signal Ea, which is photoelectrically converted by the two-divided light receiving element, respectively; And a differential amplifier 13 for differentially amplifying Eb).

Accordingly, in the optical disk device, a tracking servo operation on the HFM groove is performed with reference to a tracking error signal (TE = Ea-Eb) output through the differential amplifier. For the wobble-shaped groove to be recorded, a tracking servo operation on the wobble-shaped groove is performed with reference to the tracking error signal TE = Ea-Eb output through the differential amplifier.

On the other hand, with the development of the BD-RW, a high-density playback-only optical disc, such as a BDROM, which is currently being discussed among related companies, has a clamping area and a lead-in area on the inner circumferential surface of the disc. And a disc structure in which a data area and a lead-out area exist respectively on the center plane and the outer circumferential surface of the disc, and in the lead-in area, disc information is recorded in the HFM groove manner as in the BD-RW. The data area and lead-out area have a disc structure in which data of pre-pit rows are recorded and stored as in a conventional CD-ROM or DVD-ROM or the like.

The high-density playable disc having the above structure can read the information of the disc itself only by recognizing the HFM groove recorded in the PIC area and restoring the data. In the bi-phase modulation scheme, as shown in FIG. 2, data is 0 when HFM grooves are in the same phase for 36T, and 1 when the phase is changed. Therefore, in general, a clock recovery method using a PLL is used as shown in FIG. 5 to detect a time of 36T. The recovered clock detects the phase change for 36T and detects the data.

As described above, the method using the PLL is common, but in order to share with the PLL used for data recovery in the data domain, a frequency design must be designed for another HFM groove, and additional pre-processing logic for sharing is required.

An object of the present invention is to provide a data recovery apparatus and method using the characteristics of the bi-phase modulation method in the high-density optical disk without using the PLL data of the PIC area in the high-density optical disk .

An apparatus for reproducing a high-density reproduction-only optical disc comprising a lead-in area, a data area, and a lead-out area of the present invention includes a bi-phase modulated high frequency modulation groove (Bi) in a specific area of the lead-in area in the optical disc. an optical pickup unit for recognizing a recording pattern of a -phase modulated HFM groove and generating a signal thereto; An analog-to-digital converter for sampling and quantizing the high frequency modulated signal recognized by the optical pickup unit; A phase shift detector for determining a phase shift using a sign of the sampled value; A cyclic adder for continuously adding the sampled values; A sink length detector for detecting a length of a sync pattern included in the high frequency modulated signal recognized by the optical pickup unit and generating a cyclic value of the cyclic adder; And a bit detector for detecting a bit string recorded in the high frequency modulation groove when a phase shift is detected in the phase shift detector.

A method of detecting data of a PIC area in a high-density playback-only optical disc including a lead-in area, a data area, and a lead-out area of the present invention is a high frequency bi-phase modulated with the PIC area (Permanent Information & Control data) area. Recognizing, digitizing, and quantizing a bi-phase modulated HFM groove pattern; Generating a cyclic value by using a sync pattern included in the high frequency modulated groove pattern; Determining the presence or absence of a phase shift idea among the sampled values; Continuously adding the sampled values; And detecting a bit of the high frequency modulated groove pattern based on when the phase shift occurs.

In the present invention, a method of generating a cyclic value divides the HFM grooved pattern in the permanent information & control data (PIC) region into at least one sync pattern, and divides the sync pattern among the sync patterns. After extracting the largest sink length in each division section within one section, margin value (M) is added to the average value of the remaining lengths except the minimum length and the maximum length among the maximum sink lengths extracted for each division section. It is preferable to calculate separately.

In the present invention, after the recursive value is generated, it is preferable to output the value to the recursive adder and set the operation flag of the recursive adder to '1'.

In the present invention, the method of continuously adding the sampled values continuously accumulates the sampling values extracted from the high frequency modulation groove pattern input until the phase shift occurs, and if the phase shift occurs, the sign of the accumulated value and the current addition It is preferable to output the gradient sign of the sampling value to be obtained.

The data detection method of the PIC region in the high-density reproduction-only optical disc, characterized in that the cyclic flag is set to '1' when the added sampling value exceeds the cyclic value.

In the present invention, when the phase shift occurs, when the value of the cyclic flag is '1', it is preferable to set the current addition value of the cyclic adder to '0'.

In the present invention, a method of detecting a bit of the bi-phase modulated HFM groove pattern includes: when the phase shift occurs, when the cyclic flag is 1, looking at the result and the slope of the cyclic adder, the high frequency modulation It is preferable to determine the bit of the pattern as '0' and set the frame flag to '0'.

In the present invention, a method of detecting a bit of the bi-phase modulated HFM groove pattern includes: when the cyclic flag is '0' when the phase shift occurs, when the frame flag is '1'. The bit of the high frequency modulated bi-phase groove pattern is determined as '1'. If the frame flag is '0', the frame flag is set to '1' and no data is output.

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.

6 is a block diagram of a high density optical disc HFM data reproducing apparatus including a circular adder according to an embodiment of the present invention.

In the above embodiment, the HFM data reproducing apparatus includes an optical pickup unit 601, an analog-to-digital converter 602, a phase shift detector 603, a cyclic adder 604, a sink length detector 605, a bit detector 606. And HFM bit data 607.

In the above embodiment, an apparatus for reproducing data of a PIC area in a high density optical disc drive is schematically shown.

A PIC area exists in a lead-in area of the high density optical disc drive, and a high frequency modulated pit array is patterned in the PIC area. The pit train is recognized by the optical pickup unit in the optical disk drive and the recognized signal is reproduced as a signal of a high frequency sine wave. The reproduced signal is sampled at a fixed frequency via analog-to-digital converter 602. The analog-to-digital converter 602 quantizes the sampled signal to represent various bit values.

The phase shift detector 603 determines the presence or absence of a phase shift based on a sign of the sampled quantized bit value. That is, it is determined at any moment when the quantized bit value is changed from a positive value to a negative value or a negative value to a positive value. The phase shift occurrence signal is used as an input signal of the cyclic adder 604, the sink length detector 605, and the bit detector 605.

The sync length detector 605 extracts a sync pattern included in the HFM signal to generate a cyclic value of the cyclic adder 604. The HFM signal has a sync pattern of 54T / 54T length. The sink length detector 605 detects a length of 54T. The sampled value is accumulated until the phase shift occurs to find the largest value during the sync preliminary detection interval. The sink length can be detected by obtaining the average value of the remaining sink preliminary values except for the maximum and minimum values of the found sink preliminary values. The margin M is added to the average of the sink preliminary values and divided by half to obtain a circulation value of the cyclic adder 604. This process is continued during HFM data playback to keep the sync length updated for the current input. In an ideal environment, M = 0 and the cycle value corresponds to 27T. However, there is a noise component in the input HFM signal and the sample value moves to the 0 position. That is, since the center level is moved by the low frequency component, the circulation value is set to be between 20T and 25T using M value.

The process is described in detail with reference to FIG. 7 as follows.

First, set the sink reserve value N and the sink candidate value to '0'. The sync candidate value is continuously updated by adding the sampled value until the phase shift of the value sampled by the phase shift detector 603 occurs. When the phase shift of the sampled value is detected in the phase shift detector 603, the sink candidate value N is larger than the sync reserve value N. Replace with the candidate value and set the sink candidate value to '0', otherwise set the sink candidate value to '0' immediately. The process continues during the sync preliminary detection interval and outputs the sync reserve value N when the process is completed during the sync preliminary detection interval. The sync reserve value N is continuously output during the sync detection interval.

Due to the nature of the HFM signal, the sink is longer than normal data. That is, the sink is 54T and the general data is 36T. This sink is detected repeatedly. In the sync preliminary detection interval, the interval is set so that at least one sink exists and the maximum value is found in this interval. The maximum value is then one sink preliminary value. That is, it is called S ₁ . The sync detection interval includes N sync spare intervals. Then, N values are detected from the total S ₁ to S _N.

If there are no errors on the disk, that is, no defects, the values of S ₁ ~ S _N will be almost the same, which is the sink length at the current speed. However, in reality, the combined function exists, so the minimum and maximum values of S ₁ to S _N are discarded and the sink length value is found among the remaining values. If there is no error, it is not necessary to distinguish the sync preliminary detection section and the sync detection section as described above.

As described above, when N sink reserve values are output, the minimum and maximum values are discarded and the average value is calculated. The average value is divided by half in addition to the margin M to derive the circulation value of the cyclic adder 604. After the series of processes, the sink length detector 605 outputs the cycle value to the cycle adder 604 and sets the cycle adder 604 operation flag to '1' so that the cycle adder 604 sets the cycle value. Use it.

The cyclic adder 604 adds the sampled HFM signal, initializes the cyclic value detected by the sink length detector 605, and resets the cyclic value whenever the cyclic adder 604 operation flag becomes '1'. Update to adapt to changes in input. The cyclic adder 604 continues to accumulate input HFM sample values until phase shift occurs. If a phase shift occurs, the sign of the result of the cyclic adder 604 and the sign of the slope are output. 8 shows the operation of the cyclic adder 604. At a length of 18T, the resultant value of the cyclic adder 604 cannot reach the cyclic value. At a length of 36T, the result of the cyclic adder 604 passes the cyclic value, and the cyclic flag is set to 1 at this time. If the cyclic flag is 1 when the phase shift occurs, the cyclic adder 604 is set back to zero. This serves to eliminate the accumulated error caused by the difference between the positive and negative lengths of the input HFM signal. In general, HFM bit data reproducing apparatus using a PLL requires additional logic to compensate for a case in which the lengths of (+) and (-) are different.

The operation of the cyclic adder 604 will be described in detail with reference to FIG. 9.

First, the cyclic adder 604 is set to '0'. The cyclic adder 604 continuously adds the sampling values until the phase shift detector 603 detects whether the sampling values are phase shifted. When the sampling value is added, cyclic addition is continuously detected. The cyclic addition exceeds the maximum or minimum of the cyclic value generated by the sink length detector 605 as the sampling value is continuously added. Say the case. In this case, set the recursion flag to '1'.

When the phase shift detector 603 detects the phase shift of the sampling value, the sign of the cyclic adder 604 and the slope sign of the cyclic adder 604 are output. The sign of the cyclic adder 604 means a sign of a sampling value added to the present, and the slope sign means a slope of a straight line with respect to the sampling value currently input as a linear function.

After outputting the value, the value of the operation flag of the cyclic adder 604 is searched, and if it is set to '1', it is set to '0'. Otherwise, the next operation is immediately performed.

Thereafter, if the value of the recursive flag is retrieved and set to '1', the recursive adder 604 operation flag and the recursive flag are set to '0', otherwise step 909 is executed immediately.

The cyclic adder 604 continuously adds the sampled and quantized values, the maximum of which does not exceed a positive cyclic value, and the minimum of which also does not exceed a negative cyclic value.

The bit detector 606 recognizes data on the high frequency deflection pattern recorded in the PIC region by the values of the phase shift detector 603 and the cyclic adder 604. The detailed method is illustrated in FIG. 10. If the cyclic flag is 1 when the phase shift occurs, the sink and the HFM data 0 are determined based on the result of the cyclic adder 604 and the gradient sign. The frame flag is set to zero. If the cyclic flag is 0, if the frame flag is 1, the HFM bit data 1 is output. If the frame flag is zero, set 1 to the frame flag and output nothing to the HFM bit data.

A detailed description thereof will be described with reference to FIG. 10.

First, the frame flag is set to '0' and the phase shift is detected. When the phase shift detector 603 detects the phase shift of the sampled value, the circular shift flag is searched for. If the value of the cyclic flag is set to '1', the result of comparing the cyclic adder 604 result code and the cyclic adder 604 gradient sign is not equal, and outputs a value of '0' as HFM bit data. Outputs the HFM bit data sink.

If the value of the circular flag is not set to '1', the frame flag is retrieved and if the value is set to '1', '1' is output as HFM bit data, otherwise the frame flag is set to '1'. .

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, HFM bit data of a high density optical disk can be reproduced using a simple circular adder 604 without using a conventional PLL.

In addition, the present invention has the same reproducibility and has the effect of reducing the logic required for implementation by simply using an adder rather than the existing complex PLL structure.

Claims (9)

An apparatus for reproducing an optical disc for high-density reproduction comprising a lead-in area, a data area, and a lead-out area, An optical pickup unit for recognizing a recording pattern of a bi-phase modulated HFM groove in a specific area of a lead-in area of the optical disc and generating a signal thereof; An analog-to-digital converter for sampling and quantizing the high frequency modulated signal recognized by the optical pickup unit; A phase shift detector for determining a phase shift using a sign of the sampled value; A cyclic adder for continuously adding the sampled values; A sink length detector for detecting a length of a sync pattern included in the high frequency modulated signal recognized by the optical pickup unit and generating a cyclic value of the cyclic adder; And a bit detector for detecting a bit stream recorded in the high frequency modulation groove when a phase shift is detected in the phase shift detector. A method for detecting data in a PIC area in an optical disc for high-density reproduction comprising a lead-in area, a data area, and a lead-out area, Recognizing, digitizing, and quantizing a bi-phase modulated HFM groove pattern in the permanent information & control data (PIC) region; Generating a cyclic value using a sync pattern included in the high frequency modulated groove pattern; Determining the presence or absence of a phase shift idea among the sampled values; Continuously adding the sampled values; And detecting a bit of the high frequency modulated groove pattern on the basis of when the phase shift occurs. The method of claim 2, wherein the method of generating a cyclic value divides the HFM grooved pattern in the permanent information & control data (PIC) area into a section including at least one sync pattern, and the sync pattern. After extracting the largest sink length in each divided section among the divided sections, the margin value (M) is added to the average value of the remaining lengths except the minimum length and the maximum length among the maximum sink lengths extracted for each divided section. A method for detecting data in a PIC region in an optical disc for high-density reproduction, characterized by dividing by two. 4. The data of the PIC area in the high-density playback-only optical disc according to claim 3, wherein after the cyclic value is generated, the cyclic adder outputs the value and sets the operation flag of the cyclic adder to '1'. Detection method. The method of claim 2, wherein the method of continuously adding the sampled values And accumulating the sampling values extracted from the input high frequency modulation groove pattern until the phase shift occurs, and outputting the sign of the accumulated value and the slope sign of the currently added sampling value when the phase shift occurs. A data detection method of a PIC area in an optical disk for high density reproduction only. 6. The data detection method of a PIC region in a high density reproduction-only optical disc according to claim 5, wherein the cyclic flag is set to '1' when the added sampling value exceeds the cyclic value. 7. The data detection method of a PIC region in a high density reproduction-only optical disc according to claim 6, wherein when the phase shift occurs, if the value of the circular flag is '1', the current addition value of the circular adder is set to '0'. . The method of claim 6, wherein the detecting of the bit of the bi-phase modulated HFM groove pattern is performed. When the phase shift occurs, when the cyclic flag is 1, the bit of the high frequency modulation pattern is determined to be '0' and the frame flag is set to '0' based on the result and the slope of the cyclic adder. Data detection method of PIC area in disk. The method of claim 6, wherein the detecting of the bit of the bi-phase modulated HFM groove pattern is performed. When the cyclic flag is '0' when the phase shift occurs, when the frame flag is '1', the bit of the high frequency modulated bi-phase groove pattern is determined as '1', and when the frame flag is '0', the frame is A data detection method of a PIC area in an optical disc for high-density reproduction, characterized by setting a flag to '1' and outputting no data.

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