RU2467407C2 - Apparatus for reproducing data from data medium - Google Patents

Abstract

FIELD: physics, acoustics.

SUBSTANCE: disclosed is an apparatus for reproducing data recorded on a data medium. The apparatus has a head which projects beams onto the medium, a signal processor and a controller which controls the head. The signal processor reproduces tracking signal polarity information relating to protruding or depressed recording elements.

EFFECT: shorter time for obtaining tracking polarity information.

12 cl, 13 dwg

Description

FIELD OF THE INVENTION

The present invention relates to an optical storage medium on which tracking polarity data corresponding to the shape of recording elements is recorded, as well as to a method and apparatus for recording data on an optical storage medium and / or reproducing data from an optical storage medium.

State of the art

Conventional optical discs, which are optical storage media, are classified as compact discs (CDs) or digital multi-purpose discs (DVDs) according to their information capacity. Optical discs can also be classified as mini discs (MDs) having a diameter of 65 mm or less. In addition, discs with a recording volume of 20 (GB) or more are under development.

Optical discs can be further classified as read-only discs or rewritable discs. Examples of read-only discs are read-only media on a compact disc (CD-ROM) and read-only memory on a DVD (DVD-ROM). Examples of rewritable discs are CD ± R / RW, DVD ± R / RW, and DVD-RAM (random access memory) discs. For CD-R and DVD-R discs, recording can only be performed once, for CD-RW and DVD-RW discs, recording and / or playback can be performed approximately 1000 times, and for DVD-RAM discs, recording and / or playback can perform several hundred thousand times.

In general, on discs intended for playback only or read-only, data is recorded as recording elements (“pits”). Since rewritable discs are coated with a material with a variable phase state, data is recorded on them in accordance with the phase change.

In a device for recording data on and / or reproducing data from an optical disc, the head accurately tracks the track on which user data is recorded and receives a laser beam reflected from the track, thereby reading user data. The signal used to track the track with the head is called the tracking signal (tracking). A tracking signal is obtained from a photodiode having several receiving parts, which receives a laser beam and sums or subtracts signals obtained based on the light received by the individual receiving parts. The tracking signal has the shape of an S-shaped curve in which the left and right polarities are opposite to each other with respect to the center of the curve.

The tracking signal has different polarities depending on the type of optical disc, that is, on the physical characteristics of the recording layer, for example, the physical form of the recording element, the physical form of the track, etc. For example, FIGS. 1A and 1B show paths G of grooves and paths L of pads located opposite. 1A, the tracking signal has a polarity that changes from positive (+) to negative (-). 1B, the tracking signal has a polarity that changes from (-) to (+). As described above, the polarity of the tracking signal is classified as a polarity changing from (-) to (+) and a polarity changing from (+) to (-). The tracking signal is processed differently depending on the polarity of the tracking signal. Therefore, if the polarity of the tracking signal is not recognized correctly, the data may not be reproduced correctly. Accordingly, when an optical disc is loaded, the known recording and / or reproducing apparatus recognizes the polarity of the tracking signal by trial and error and then tracks the track on which user data has been recorded based on the recognized polarity information. Thus, user data is read from the optical disc.

Disclosure of invention

Technical challenge

Thus, the known playback device spends some time to obtain information about the polarity of the tracking signal before reading user data. This prevents the immediate reproduction of user data.

The polarity of the tracking signal may vary in accordance with the physical form of the recording element. The physical form of the recording element may vary depending on the type of disc. However, according to the prior art, additional information about the polarity of the tracking signal depending on the physical form of the recording elements is not recorded on the disc, so that the reliability of data recording and / or playback is reduced. And also the known playback device spends some time to obtain information about the polarity of the tracking signal through trial and error, delaying recording and / or playback.

Technical solution

The present invention provides an optical information medium on which tracking polarity information is recorded depending on the shape of the recording elements, specifically reverse polarity information, as well as a method of recording data on an optical information medium and / or reproducing data from an optical information medium.

In accordance with an aspect of the present invention, there is provided a storage medium having at least one information storage layer in which data is recorded in the form of protruding or indented recording elements in a full or partial region of the information medium, and information relating to the protruding or indented elements is recorded records.

In accordance with an aspect of the present invention, information related to protruding or depressed recording elements is reverse polarity information.

In accordance with an aspect of the present invention, information related to protruding or depressed recording elements is recorded in or in front of the frame synchronization area.

In accordance with an aspect of the present invention, the storage medium includes a BCA area (service area in which a code unique to the medium is entered during manufacture) and an input area, one of which stores information relating to the protruding or depressed recording elements.

In accordance with an aspect of the present invention, protruding or dented recording elements may be wobbling recording elements.

In accordance with an aspect of the present invention, data is decoded by performing an XOR operation with respect to reverse polarity information and data reproduced from protruding or dented recording elements.

In accordance with another aspect of the present invention, there is provided a method of recording data on a storage medium and / or reproducing data from a storage medium having at least one information storage layer, the method including recording data in the form of protruding or depressed recording elements in the full or partial area of the information carrier and recording information related to the protruding or depressed recording elements.

This method further includes reproducing reverse polarity information and recording data on the storage medium or reproducing data from the storage medium by performing tracking based on the reproduced reverse polarity information.

Additional aspects and / or advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned in accordance with the practice of the invention.

Beneficial effects

In the information carrier in accordance with the present invention, tracking polarity information (i.e. reverse polarity information) with respect to the protruding recording elements and indented recording elements is recorded so that the data can be easily recorded or reproduced without trial and error, designed to obtain tracking polarity information. Also, if the data is recorded in the form of recording elements, each of which may have different forms, similar to depressed or protruding recording elements.

List of drawings

The above and / or other features and advantages of the present invention will be more apparent as described in detail by exemplary embodiments with reference to the accompanying drawings, in which:

1A and 1B are different tracking polarities depending on the configuration of the groove tracks and the track tracks;

Figa - protruding recording elements formed on a substrate of a storage medium in accordance with an embodiment of the present invention;

2B is depressed recording elements formed on a substrate of a storage medium in accordance with an embodiment of the present invention;

3A is a graph of a curve showing the amplitudes of a differential phase detection (DFD) signal and a high-frequency (HF) signal versus time in a storage medium on which data is formed as protruding recording elements;

FIG. 3B is a graph of a curve showing the amplitudes of the DFD signal and the HF signal versus time in a storage medium on which data is formed as depressed recording elements;

Fig. 4A is a graph of a curve showing a reversal signal versus time in a storage medium on which data is formed as protruding recording elements;

Fig. 4B is a graph of a curve showing a reversal signal versus time in a storage medium on which data is formed as depressed recording elements;

5 is an example in which tracking polarity data is recorded in a synchronization structure on a storage medium in accordance with an embodiment of the present invention;

6A and 6B are various examples of organizing a storage medium in accordance with an embodiment of the present invention in which tracking polarity information is recorded in a special structure;

7A and 7B are various layout diagrams of a storage medium in accordance with another embodiment of the present invention;

Fig. 8A is a schematic view of a structure of an information area of a recordable information medium;

Figv is a schematic view of the structure of the information area of the information carrier, intended only for playback;

Figa is a straightforward set of recording elements, and

Figv is a wobbling set of recording elements;

10 is an example in which tracking polarity information is recorded on a storage medium in accordance with another embodiment of the present invention;

11A and 11B are views illustrating an XOR-based decoding method for tracking polarity data and data that is detected from a data frame in a storage medium in accordance with another embodiment of the present invention;

12 is a flowchart illustrating a method of recording and / or reproducing data in accordance with an embodiment of the present invention; and

13 is a schematic illustration of an apparatus for recording data in an information medium and / or reproducing data from an information medium in accordance with the present invention.

An embodiment of the invention

A detailed reference will now be made to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, with the same reference numerals referring to identical elements throughout the document. Embodiments are described below to illustrate the present invention by reference to the drawings.

As shown in FIG. 2A, in an optical information carrier according to an embodiment of the present invention, data is recorded as protruding recording elements 10 on a substrate 5. Alternatively, as shown in FIG. 2B, data is recorded as depressed recording elements 13 on substrate 5. Information about the protruding recording elements 10 or the depressed recording elements 13 is recorded in an optical information carrier.

Information about the protruding or depressed recording elements 10 or 13 may be tracking polarity information.

If the data is recorded in the form of protruding recording elements 10, the tracking signal may have a polarity that changes from (+) to (-). If the data is recorded in the form of depressed recording elements 13, the tracking signal may have a polarity that changes from (-) to (+). As described above, since the polarity of the tracking signal varies depending on the shape of the recording elements, the tracking signal must be performed in different ways depending on the shape of the recording elements so that the data can be normally recorded or reproduced.

The conditions and results of the simulation performed to establish the characteristics of the tracking signal are shown in Table 1.

Table 1 Disc laser wavelength (λ) 400 nm Numeric lens aperture 0.85 Groove structure pitch of recording tracks: 0.32 μm Minimum Label Length 0.149 μm Tag Width 0.15 μm Modulation method RLL (1,7) (encoding with limited recording field length)

In Table 1, the RLL modulation method is based on how many bits of '0' are present between two bits of '1'. RLL (m, k) represents that at least m bits of '0' are present between two bits of '1', and no more than k bits of '0' are present between them. For example, RLL (1,7) represents that at least one bit of '0' is present between two bits of '1', and no more than 7 bits of '0' are present between them. According to the modulation method RLL (m, k), if m is 1, the data is '1010101', and a 2T recording element is present between the two bits '1' If m is 7, the data is '1000000010000000l' writing, and an 8T recording element is between two bits of '1'. Moreover, T denotes the length of the minimum label, that is, the minimum record element. Therefore, in the RLL (1,7) modulation method, data is recorded in the form of recording elements varying in length from 2T to 8T and gaps.

3A shows a high frequency (HF) signal and a differential phase detection (DFD) signal when data is recorded in the form of protruding recording elements 10. 3B shows the RF signal and the DFD signal when data is recorded in the form of depressed recording elements 13. 3A and 3B, the DFD signal is independent of the shape of the recording elements.

Fig. 4A shows a reversal signal when data is recorded in the form of protruding recording elements 10, and Fig. 4B shows a reversal signal when data is recorded in the form of depressed recording elements 13. As for Figa and 4B, the reversal signal depends on the shape of the recording elements. Therefore, if data is reproduced or tracked using a reversal signal, then tracking polarity information should be recorded depending on the shape of the recording elements. Accordingly, the tracking polarity information may be reverse polarity information.

When recording tracking polarity information, as shown in FIG. 5, an optical information carrier according to an embodiment of the present invention includes a plurality of data frames 15 and tracking polarity information, i.e. reverse polarity information. Reverse polarity information can be recorded in the synchronization structure in the frame synchronization region 14 included in front of the region including a predetermined number of data frames 15. The synchronization structure may be a structure not used as a user data structure, or a combination of specific bits. An example of a synchronization structure is shown in FIG. 5.

For example, a synchronization structure may be generated based on the repetition of identical data to represent tracking polarity information. If the values '1' are read sequentially, this means that the data is recorded in the form of protruding recording elements. If the values '0' are read sequentially, this means that the data is written in the form of depressed recording elements.

Alternatively, tracking polarity information, i.e. reverse polarity information, may be recorded in a synchronization structure of a particular structure. For example, as shown in FIG. 6A, the data '010' is recorded in the frame synchronization region 14 and represents a polarity changing from (+) to (-). In this case, if the data '101' is reproduced after tracking, the polarity of the tracking signal is processed in the opposite way so that the data can be reproduced properly. 6A, tracking polarity information is recorded in the frame synchronization field 14. However, as shown in FIG. 6B, tracking polarity information may be recorded in a predetermined area 12 before the frame synchronization area 14. As described above, tracking polarity information may be recorded in a part corresponding to a frame synchronization region 14, or in a region other than a frame synchronization region 14.

7A and 7B show various arrangements of a storage medium in accordance with another embodiment of the present invention. This storage medium includes a fixing region C, a region B corresponding to a service area BCA, an input area LI, a user data area U, and an output area LO. The fixing region C denotes the region that the locking device presses to lock the disc.

Tracking polarity information can be recorded in the BCA region B. Unique disc information such as serial number, day / month / year of manufacture, etc., can also be recorded in the BCA region B. In FIG. 7A, the BCA β-region B lies between the fixation region C and the lead-in region LI. However, as shown in FIG. 7B, the BCA region B may be in front of the fixation region C.

If tracking polarity information is recorded in the BCA region B, it can be read before the disc is tracked after the disc is loaded into the drive device and focused on it. Thus, a servo servo system can be effectively implemented.

Tracking polarity information can also be recorded in the lead-in area LI instead of the BCA area B.

FIG. 8A shows a layout of a recordable storage medium. Data can be recorded in the form of recording elements in some part of the recordable information medium, for example, in the input area or in the output area. Information about the forms of the recording elements, that is, tracking polarity information, can be recorded in the input area, preferably in the area related to the information disc.

FIG. 8B shows a layout of a playback-only storage medium. Tracking polarity information may be recorded in an area related to a disc of information included in the lead-in area. Tracking polarity information includes reverse polarity information.

If the data is recorded in the form of recording elements, then the recording elements can be located either in a straight line, as shown in Fig. 9A, or along a wobble line, as shown in Fig. 9B. If the data is recorded in the form of a straight line from the recording elements, then the data recorded as the recording elements are reproduced using the sum channel, and the tracking can be controlled using the DFD technique or the reverse technique. If tracking is controlled using a reverse technique, then tracking polarity information, i.e., reverse polarity information, is required.

If the data is recorded in the form of a wobbling curve of recording elements (which is hereinafter referred to as wobbling recording elements), additional information can be recorded directly in the wobble. Data recorded as wobbling recording elements is reproduced using the sum channel, and additional information recorded in the wobble can be reproduced using the reverse channel.

Wobble recording elements can be grouped into a separate structure, which is composed of recording elements, each of which has the same lengths and spaces. In this separate structure of recording elements, recording elements have no data, and instead, wobble can have data. In this case, the reverse channel can be used as a channel for reproducing data stored in wobble recording elements.

When data is recorded in the form of wobbling recording elements, they can be recorded using various modulation techniques. For example, data may be recorded using at least one technique of phase modulation, frequency modulation, and amplitude modulation.

As for FIG. 10, in the information carrier in accordance with another embodiment of the present invention, tracking polarity information is recorded in the area before the predetermined data frame, and although the data is recorded in various forms, the data in various forms are decoded into identical data by performing the operation “ exclusive OR ”(XOR) with respect to tracking polarity information and data read using the tracking polarity information. Tracking polarity information can be recorded in the frame synchronization area.

A method for decoding data using the XOR operation will now be described if the data is recorded in the form of protruding recording elements or depressed recording elements. If the data recorded in the form of protruding recording elements is tracked, the tracking polarity information is read in the form, for example, '0', and the data is read in the form, for example, '11001 ...'. If the same data is recorded in the form of indented recording elements, the tracking polarity information is read in the form, for example, '1', and the data is read in the form, for example, '00110 ...'.

As for Fig. 11 A, if the tracking polarity information related to the depressed recording elements is recorded as data '0' and the data detected from the nth data frame is '11001 ...', then the tracking polarity data and data detected from the nth data frame is subjected to XOR operations to obtain decoded data '11001 ...'.

As regards Fig. 11B, if the tracking polarity information related to the protruding recording elements is recorded as data '1' and the data detected from the nth data frame is '00110 ...', then the tracking polarity data and data detected from the nth data frame, XOR operations are performed to obtain decoded data '11001 ...'.

As described above, since the data is decoded using the XOR operation with respect to the tracking polarity data and the data reproduced from the recording elements, the data can be properly reproduced and restored regardless of whether the recording elements are protruding or depressed. Also, decoded data can be obtained without further change in the control operation.

In addition, data read by using tracking polarity information, that is, reverse polarity information, as a selection signal, can be output as decoded data directly or output as decoded data after the polarity of the data is reversed. In other words, if the tracking polarity information is recorded in a predetermined structure and the read polarity information is the same as this predetermined structure, the data is decoded directly. However, if the tracking polarity information is recorded in a predetermined structure, and the read tracking polarity information is different from this predetermined structure, the data is decoded after their polarity is reversed.

The storage medium in accordance with the present invention is applicable to multilayer storage media having at least two layers of information storage, as well as to single-layer storage media.

12 is a flowchart illustrating a method for recording and / or reproducing data in accordance with an embodiment of the present invention. 12, in step 50, a storage medium is loaded into a drive device. In operation 55, the optical head included in the drive device reads tracking polarity information, i.e., reverse polarity information, from the loaded information medium. Tracking polarity information is recorded according to the embodiments described above, and is used as a basis for detecting a tracking signal or recording and / or reproducing data.

Since the tracking polarity varies depending on the protruding recording elements 10 of FIG. 2A or the depressed recording elements 13 of FIG. 2B, the tracking signal is processed differently in accordance with the tracking polarity information. If tracking polarity information is recorded in the BCA region B, the storage medium is first loaded into the drive and then focus control is performed and the tracking polarity information is read from the BCA region B before data is read from the loaded storage medium. Thus, tracking control and reproduction of information are reliable.

In operation 60, the drive device writes data to the data area or reproduces data from the data area by controlling the tracking, without trial and error, based on the reproduced tracking polarity information, i.e. reverse polarity information. In other words, the optical head provides reproduced tracking polarity information to the drive device, and the drive device controls the optical head based on the received information, so that data is smoothly recorded on the storage medium or reproduced from the storage medium.

Data can be decoded by performing an XOR operation with respect to tracking polarity data and data reproduced from the recording elements. Thus, the data can be decoded regardless of the polarity of the tracking signal.

Data reproduced based on the tracking polarity information can either be directly output as decoded data, or output as decoded data after their polarity is reversed. In other words, if the tracking polarity information is recorded in a predetermined structure and the outputted read information of the tracking polarity is the same as this predetermined structure, then the data is decoded directly. On the other hand, if the tracking polarity information is recorded in a predetermined structure and the outputted read tracking polarity information is different from this predetermined structure, then the data is decoded after its polarity is reversed.

13 schematically illustrates an apparatus for recording data on a storage medium and / or reproducing data from a storage medium in accordance with the present invention. The device includes a head 50, a recording / reproducing signal processor 60, and a controller 70. More specifically, the head 50 includes a laser diode 51 for emitting light, a collimating lens 52 for converging rays of light emitted by the laser diode 51, a beam splitter 54 for changing a path incident light and an objective lens 56 for focusing the light transmitted through the beam splitter 54 on the information carrier D.

The light reflected by the information carrier D is reflected by a beam splitter 54 and received by a photodetector, for example a 4-section photodetector 57. The reflected light on a 4-section photodetector 57 is converted into an electrical signal when passing through an operating circuit 58. The RF signal, that is, the sum signal, is output through the first channel Ch1, and the difference signal used in the reverse recording method is output through the second channel Ch2.

When the storage medium D is loaded, the controller 70 controls the head 50 to project the beam onto the storage medium D, and reads the signal into which the beam reflected by the storage medium D is converted by the signal processor 60. More specifically, the beam reflected by the information carrier D is supplied to the photo detector 57 through the lens 56 of the lens and the beam splitter 54. The beam reflected to the photo detector 57 is converted into an electrical signal by means of an operating circuit 58, and this electrical signal is output as an RF signal.

The signal processor 60 processes the data signal in accordance with the tracking polarity information read from the information medium D. The controller 70 controls the head 50 based on a data signal processed by the signal processor 60.

Claims (12)

1. A device for reproducing data recorded on a storage medium containing
a head projecting a beam onto a storage medium on which data is recorded in the form of protruding or depressed recording elements in the full or partial area of the storage medium,
a reproducing signal processor reproducing polarity information of the tracking signal related to the protruding or depressed recording elements recorded in said full or partial region of the information carrier,
a controller controlling the head based on the polarity information of the tracking signal processed by the processor of the playback signals. 2. The device according to claim 1, in which the information related to the protruding or depressed recording elements is reversible polarity information. 3. The device according to claim 2, in which the processor of the playback signals reproduces information of reverse polarity and the controller controls the head to reproduce data from the storage medium by performing tracking based on the reproduced information of reverse polarity. 4. The device according to claim 1, in which information related to the protruding or depressed recording elements is recorded in the field of frame synchronization or in front of it. 5. The device according to claim 1, in which the service area is included in the storage medium, in which, during manufacture, a unique code for the medium (BCA) is entered to store information related to the protruding or depressed recording elements. 6. The device according to claim 1, in which an input region is included in the storage medium to store information related to the protruding or depressed recording elements. 7. The device according to claim 1, in which the protruding or depressed recording elements are wobble recording elements. 8. The device according to claim 7, in which additional information is recorded in the wobble of the wobbling recording elements. 9. The device of claim 8, wherein said additional information is recorded using at least one technique of phase modulation, frequency modulation, and amplitude modulation. 10. The device of claim 8, further comprising
a sum channel for reproducing data recorded in the form of wobble recording elements, and
a reverse channel for reproducing said additional information. 11. The device according to claim 1, in which the processor of the playback signals decodes the data by performing an exclusive-OR operation (XOR) with respect to the polarity information of the tracking signal and the data reproduced from the protruding or depressed recording elements. 12. The device according to claim 1, in which the processor of the playback signals reproduces data from the protruding or depressed recording elements and either outputs the data directly or outputs the data after the polarity of this data is reversed, in accordance with the polarity information of the tracking signal.

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