KR100938393B1 - High density read only optical disc, and apparatus and method for reproducing a data recorded on them - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-density reproduction-only optical disc, and an optical disc apparatus and method according thereto, wherein data stored in a lead-in area of a high-density reproduction-only optical disc such as a BD (Blu-ray Disc) -ROM or the like is associated with an HFM groove. By recording in a pre-pit column of a shape having a shape of a single high-density reproducing optical disc or a high-density rewritable optical disc, the same information as that of the disc information recorded in the HFM (High Frequency Modulated) groove method can be recorded. By allowing the same single tracking servo operation to be continuously performed for the entire area, it is possible to effectively prevent the complicated algorithms for the plurality of tracking servo controls and the consequent increase in size of the device. PLL circuit using pit can be operated to quickly It will be very useful inventions that are able to be stabilized.

BD-RE, BD-ROM, Push-Pull, DPD, Pre-pit Train, PIC Area, HFM Groove

Description

High density read only optical disc, and apparatus and method for reproducing a data recorded on them}             

1 shows a disc structure for a general rewritable optical disc (BD-RE),

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

FIG. 3 illustrates a configuration of a push / pull tracking servo applied to a general rewritable optical disk device.

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

FIG. 5 illustrates a configuration of a tracking servo of a DPD method applied to a general optical disk device.

Fig. 6 shows an embodiment of a disc structure for a high density reproduction-only optical disc (BD-ROM) according to the present invention.

FIG. 7 shows the shape of pre-pit rows recorded in the lead-in area of the high-density reproduction-only optical disc (BD-ROM) according to the present invention.

8 illustrates a configuration of a tracking servo of a push-pull type and a dipid type method applied to an optical disk apparatus and method according to the present invention.

9 to 12 show wobble-shaped spaces and marks recorded in the PIC area of the high-density reproduction-only optical disc (BD-ROM) according to the embodiment of the present invention.

※ Explanation of code for main part of drawing

10,20,50: objective lens 11,21,51: collimated lens

12,22,52: Light receiving element 13,25,55,65: Differential amplifier

23,24,30,31,53,54,63,64: summing amplifier

26,27,28,29,57,58,59,60: phase detector

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc for high-density reproduction in which a large amount of video and audio data is recorded and stored, and an optical disc apparatus and method accordingly.

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-RE) 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-RE as described above, the clamping area, the transition area, the BCA area, and the lead-in area exist in order on the inner circumferential surface of the disk. The disk structure includes a data area and a lead-out area, respectively.

The lead-in area may include a first guard (Guard 1) area and a permanent information & control data (PIC) area, a second guard (guard 2) area, an information 2 (Info 2) area, and an OPC (Optimum) area. Power control) area and the like, the first guard area and the PIC area are a pre-recorded area in which data is pre-recorded, whereas the remaining lead-in area and the data The 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, in the case of the high-density playback-only optical disc, for example, BD-ROM, which is currently discussed among related companies with the development of the BD-RE, as shown in FIG. 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-RE. The data area and lead-out area also have a disk structure in which data of pre-pit columns are recorded and stored as in a conventional CD-ROM or DVD-ROM or the like.

However, if the disc information is recorded in the lead-in area of the BD-ROM under discussion in the HFM method as in the BD-RE, a push-pull tracking servo for the tracking servo of the HFM groove is required. Differential phase detection (DPD) tracking servos for tracking servos of the pre-pit rows recorded in the data area and the lead-out area are both required at the same time.

In addition, when only the HFM groove is present in the lead-in area and no pre-pit shaped data is recorded, the operation of the PLL circuit using the RF signal cannot be performed, and connection reproduction between the lead-in area and the data area is prevented. The problem of disconnection occurs.

Accordingly, as shown in FIG. 5, the optical disk apparatus includes a quadrature light receiving element 22 for photoelectrically converting light received through the objective lens 20 and the collimating lens 21 into an electric signal, and A plurality of phase detectors 26 for detecting the phases of the photoelectrically converted electrical signals Ea, Eb, Ec, and Ed through the four-segmented light receiving elements, and then amplify and differentially amplify the electrical signals of the detected phases. 26, 27, 29, first and second summing amplifiers 23 and 24, and differential amplifier 25 are required, as well as for the same BD-ROM inserted and seated in the optical disc device. Since the tracking servo operation, that is, the push-pull tracking servo operation and the DPD tracking servo operation, must be performed separately, a complicated algorithm for controlling a plurality of tracking servos is necessary, and the device becomes large in size. Will occur.

Accordingly, the present invention was devised to solve the above problems, and pre-pit (Pre-shaped) having data associated with the HFM groove is recorded and stored in the lead-in area of an optical disc for high-density reproduction such as a BD-ROM. A high-density reproducing optical disc and an optical disc according to which the same tracking servo operation can be continuously performed for the entire area of the same single high-density reproducing optical disc or the high-density rewritable optical disc It is an object of the present invention to provide an apparatus and method.

An optical disc for high-density reproduction according to the present invention for achieving the above object is a high-density reproduction-only optical disc including a lead-in area, a data area, and a lead-out area. Marks and spaces having a recording pattern of modulated bi-phase grooves, or pit rows of spaces and marks are recorded and the level transition points of the high frequency modulated bi-phase grooves are level shifted relative to the center of the space. It features.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of an optical disc for high-density reproduction and an optical disc apparatus and method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 6 shows an embodiment of a disc structure for an optical disc for high-density reproduction according to the present invention. In the case of the optical disc for high-density reproduction, for example, a BD-ROM (Blu-ray Disc-ROM), FIG. As described above, a clamping area and a lead-in area exist on the inner circumferential surface of the disk, and a data area and a lead-out area on the center and outer circumferential surfaces of the disk. Out Area) each have a disk structure,

On the other hand, in the data area and the lead-out area, pre-pit row data is recorded and stored as in a conventional CD-ROM or DVD-ROM, and the lead-in area is a PIC area of the lead-in area of the BD-RE. Pre-pitched data of a shape similar to the HFM groove previously recorded in the recording is recorded and stored.                     

That is, in the lead-in area, data of pre-pit rows are recorded as in the data area and lead-out area, and in the optical disc device for reproducing the same, for the same BD-ROM entire area inserted and seated in the device, DPD tracking servo control operation can be applied collectively.

On the other hand, in the shape of the pre-pit rows recorded in the lead-in area, as shown in Fig. 7, the pit rows are continuously recorded on the same track line during a predetermined recording period, or the pit rows are the same track during the predetermined recording period. Are discontinuously recorded at different locations within.

For example, as shown in FIG. 7, when a data sequence having a value of '0101' is recorded in the lead-in area, a total of 36T sections in which six 3T pit rows are continuously recorded on the same track line ('0') and a total of 36T sections ('1') in which three 3T pit rows are discontinuously recorded at different positions in the same track, respectively. That is, the same information recording recorded by the HFM method while being arranged in the pre-pit rows as described above is possible.

On the other hand, the reflected light reflected by the pit rows continuously or discontinuously recorded in the lead-in area as described above is photoelectrically converted by a quadrature light-receiving element (not shown) applied to a conventional servo servo of DPD method. The photoelectrically converted electric signals Ea, Eb, Ec, and Ed are, as shown in FIG. 7, a plurality of phase amplifiers 33, 34, 35, 36 and first and second summation amplifiers 30, 31. And the differential amplifier 32, a DPD tracking error signal (TE = (Ea + Ec)-(Eb + Ed)) is finally detected and output from the differential amplifier.                     

Accordingly, in the lead-in area, the DPD tracking servo operation can be performed by the pre-pit, and the recorded data sequence of '0101' can be detected and decoded by filtering the DPD signal according to the corresponding frequency. In the optical disk device, only the tracking servo operation of the DPD method is successively performed, so that the tracking servo operation for the entire area of the same BD-ROM can be normally performed, and the same information as the disk information recorded by the HFM method is recorded. This allows the same PLL operation to be performed from the lead-in area.

On the other hand, the length of each pit formed and recorded in the lead-in area as described above may have the same pit length, and may be formed and recorded in various kinds of pit lengths, for example, two or three kinds of pit lengths. have.

Further, by using a unique shape in which the pit rows are formed and recorded, other information can be expressed, and the depth of the pit is deeper or shallower than 'λ / 4' where the push-pull signal is detected small. For example, in the case of a BD-ROM, the depth of the pit is formed and recorded as' 3λ / 4 ', and in the case of the BD-RE, the pit depth of the lead-in area and the pit depth of the data area are respectively' λ. / 8 'and' λ / 4 'may be recorded differently.

The pit string may use a modulation code method used in the data area, and the modulation code may be used continuously or in combination by selecting any one of '3T', '2T', or a predetermined length. In addition, different data may be additionally recorded in each pit.                     

Meanwhile, in the optical disk apparatus according to the present invention, when an optical disk of any one of the BD-RE or the BD-ROM is inserted and seated in the apparatus, a tracking servo operation corresponding to the optical disk can be selectively performed. As shown in FIG. 5, the objective lens 50, the collimating lens 51, the quadrature light receiving element 52, and the plurality of summation amplifiers 53, 54, 63, 64 and the differential amplifiers 55, 65, And the selection switch 56 may be included, which will be described in detail as follows.

First, when an optical disc of any one of the BD-RE or the BD-ROM is inserted and seated in the optical disc device, the reflected light received through the objective lens 50 and the collimated lens 51 is divided into the four light receiving elements 52. Photoelectric conversion of the photoelectrically converted electric signals Ea, Eb, Ec, and Ed by the first and second summation amplifiers 53 and 54 and the first differential amplifier 55. The detection signal is output as an error signal TE_DPD = (Ea + Ec)-(Eb + Ed).

In addition, the electrical signals Ea, Eb, Ec, and Ed that are photoelectrically converted by the four-segment light-receiving element 52 may be formed by the third and fourth summation amplifiers 63 and 64 and the second differential amplifier 65. The tracking error signal TE_P / P = (Ea + Eb)-(Ec + Ed) of the push-pull method is detected and output.

Meanwhile, in a micom (not shown) or a servo controller (not shown) included in the optical disk device, when the type of the optical disk inserted and seated in the device is a BD-ROM, the selection switch 56 ), So that the DPD-type tracking error signal TE_DPD detected and output from the first differential amplifier 55 is selectively outputted, and when the type of the optical disc inserted and seated in the device is BD-RE, the selection is performed. By operating the switch 56, the push-pull tracking error signal TE_P / P detected and output from the second differential amplifier 65 is selectively outputted.

Accordingly, in the case of the BD-RE, the push-pull tracking servo operation is normally performed, and in the case of the BD-ROM, the tracking servo operation of the DPD method can be controlled.

For reference, when the BD-ROM-only reproduction optical disc device is developed and released, only the DPD tracking servo operation can be used as described above.

On the other hand, in order to more accurately decode the main general information of the disc permanently recorded in the PIC area of the read-in Blu-ray disc (BD-ROM), a wobble type space repeatedly recorded in the PIC area ( Space and Mark, or the push-pull signal detected by the mark and space should be detected continuously without disconnection. This will be described in detail below.

First, in the PIC region of a reproduction-only Blu-ray disc (BD-ROM) according to the present invention, main general information of the disc is a pit row having a recording pattern of a high-frequency modulated bi-phase groove (Bi-phase modulated HFM groove). The level transition point of the high frequency modulated bi-phase groove, which is recorded, is formed based on the center of the space.

In addition, 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'.

For example, as shown in Figure 9, the level transition point of the high-frequency modulated bi-phase groove, the level transition is made with respect to the center of the space, recording a high level '18T' corresponding to 'Data 1' In the section, the mark 3Tm and the space 3Ts of 3T length are repeatedly recorded, and the mark 3Tm and the space 3Ts of 3T length can be sequentially and repeatedly recorded even in a low level '18T' recording section. have.

In addition, in the high level '36T' recording section corresponding to 'Data 0', the 3T length mark 3Tm and the space 3Ts are sequentially recorded, and the low level '36T' recording section also has a 3T length. The mark 3Tm and the space 3Ts may be sequentially recorded repeatedly.

On the other hand, since the level transition point of the high-frequency modulated bi-phase groove is shown as shown in FIG. 10, the level transition is made based on the center of the space, so that the level transition point is the zero crossing point of the push-pull signal. Point), the data value detected based on the zero crossing point of the push-pull signal can be accurately detected.

In addition, the space and the mark may be recorded to a minimum 2T length or 3T or more, as shown in Figure 9, by recording the mark of the same length symmetrical with respect to the level transition point, push-pull After slicing the level of the signal, the restored signal can be detected with a more accurate data value.

On the other hand, when the length of the mark and the space is 5T or more, the level of the push-pull signal corresponding to the mark and the space is increased, so that the level transition point may be incorrectly detected. It is necessary to limit the length of the mark and the space to 2T, 3T, and 4T lengths, and also to select the combination of the length of the mark and the space where the digital sum value (DSV) becomes zero or minimum for accurate servo control. You need to record it.

For example, as shown in Fig. 11, marks of pit rows are recorded by combining marks of 2T, 3T, and 4T lengths, and marks at which the DSV (Digital Sum Value) of the pit rows becomes zero or minimum. Record by selecting and space.

In addition, BDPP's 17PP (Parity Preserve) modulation code 'Prohibit Run Limited Transition (RMTR)' condition limits the 2T of the minimum recording size to be repeated up to 6 times to detect the RF signal normally. In order to satisfy the mark, marks and spaces of 2 T length are not continuously recorded more than seven times.

The shorter the length of the space where the level transition is made, the sharper the level transition waveform of the push-pull signal is. Therefore, the length of the space is limited to within 4T length and recorded.

Meanwhile, the mark lengths recorded on the left and right sides of the space where the level transition is made are equally symmetrically recorded, and the mark lengths are determined in consideration of the diameter size of the laser beam spot formed on the optical disk. For example, when the wavelength and numerical aperture (NA) of the laser beam used for the BD-RE are 400 nm and 0.85, respectively, the diameter of the beam spot formed on the optical disk is about 580 nm (= 1.22 x (400 nm x 0.85)), and the diameter of the effective beam spot is about 450 nm.

Therefore, the length corresponding to 1T is 80 nm, and the 450 nm corresponding to the diameter of the effective beam spot is about 6T. Thus, as shown in FIG. 12, the mark length recorded symmetrically with the space where the level transition is made is shown. Record the sum so that it is 6T long.

Meanwhile, the sum of the space of the level transition point and the mark length recorded symmetrically may be recorded as 6T or more. However, when the mark is recorded symmetrically with a space and mark length smaller than the diameter of the effective beam spot, or when the mark is asymmetrically recorded, an offset is generated in the push-pull signal, and thus the jitter characteristic is greatly reduced.

As mentioned above, the above-mentioned preferred embodiment of the present invention has been published for the purpose of illustration, and in particular, the push-pull tracking servo and the DPD tracking servo are well known and well-known techniques. It is easy enough to refer to an example. In addition, within the spirit and scope of the present invention disclosed in the appended claims, various other embodiments may be improved, changed, replaced or added.

The high-density reproduction-only optical disc and the optical disc apparatus and method according to the present invention constructed and constructed as described above have data associated with HFM grooves recorded and stored in the lead-in area of the high-density reproduction-only optical disc such as BD-ROM. By recording in the shape of Pre-Pit columns in the shape, the same information as the disc information recorded in the HFM groove method can be recorded, but the same one for the entire area of the same high-density reproduction-only optical disc or a high-density rewritable optical disc By allowing the tracking servo operation to be performed continuously, it is possible to effectively prevent the complicated algorithms for controlling the plurality of tracking servos and the increase in size of the device, and to operate the PLL circuit using the pre-pit from the lead-in area. Can be used to quickly regenerate the reference clock It is a very useful invention that can be stabilized.

Claims (21)

delete delete delete delete delete delete delete delete delete delete In a recording medium comprising a lead-in area, a data area and a lead-out area, In a specific area of the lead-in area, a wobble pit sequence is bi-phase modulated for control information and formed along a specific recording pattern, The specific recording pattern may include a section in which a level transition point exists in a predetermined section, and a section in which a level transition point does not exist in a predetermined section, The wobble pit column is used for reading control information of the specific recording pattern and determining whether to reproduce data in the data area based on the control information. The method of claim 11, And the specific recording pattern is included in a lower area of a lead-in area of the recording medium in which control information is recorded and stored. The method of claim 12, The wobble pit array is formed according to a specific recording pattern in a PIC (Permanent Information & Control) area of a lead-in area defined in a Blu-ray Disc. The method of claim 12, The wobble pit sequence defines a plurality of recording sections, each recording section having a length of 36 T, wherein T corresponds to the length of the channel bit. The method of claim 14, Wherein each recording section has a mark and a space or a space and a mark repeatedly formed within a specific length. A method for reproducing a recording medium having a lead-in area, a data area, and a lead-out area, Using wobble pits, which are bi-phase modulated for control information and formed along a specific recording pattern, in a specific area of the lead-in area, The specific recording pattern may include a section in which a level transition point exists in a predetermined section, and a section in which a level transition point does not exist in a predetermined section, Using the wobble pit row, Reading control information of the specific recording pattern; And determining whether to reproduce data in the data area based on the control information. delete An apparatus for reproducing a recording medium having a lead-in area, a data area, and a lead-out area, A pickup device for reading wobble pits which are bi-phase modulated for control information and formed along a specific recording pattern in a specific area of the lead-in area; And a controller for controlling reproduction of data read from the pickup device. The specific recording pattern may include a section in which a level transition point exists in a predetermined section, and a section in which a level transition point does not exist in a predetermined section, And the wobble pit column is used to read control information of the specific recording pattern and determine whether to reproduce data in the data area based on the control information. The method of claim 18, And the pickup device reproduces the control information of the specific recording pattern. The method of claim 19, And the controller controls reproduction of the data area based on the control information reproduced by the pickup device. A method of forming a recording medium having a lead-in area, a data area, and a lead-out area, Forming wobble pits in a specific area of the lead-in area, which are bi-phase modulated for control information and formed along a specific recording pattern, The specific recording pattern may include a section in which a level transition point exists in a predetermined section, and a section in which a level transition point does not exist in a predetermined section, And the wobble pit column is used to read control information of the specific recording pattern and determine whether to reproduce data in the data area based on the control information.

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