KR20040031570A - Read only information storage medium and method for reproducing data from the same - Google Patents

Abstract

PURPOSE: A playback only information storing medium and a method for playing data are provided to form a pattern needed for playing the data in at least one of a lead-in area and a lead-out area, and improve a playback characteristic by using the pattern. CONSTITUTION: The playback only information storing medium comprises a user data area(20) recording user data, the lead-in area(10) recording such as a disc related information by installing to an inner circumference of the user data area, and the lead-out area installed to an outer circumference of the user data area. The pattern is formed to at least one of the lead-in area and the lead-out area. The pattern is used for modulation degree measurement, asymmetry measurement, or PRML(Partial Response Maximum Likelihood) adaptation. It is desirable that the pattern is formed in a test zone(10d) included in the lead-in area. The lead-in area includes a control data zone(10a) recording the disc related information and the copy protection information, a buffer zone(10b), a reserved zone(10c), and an information zone(10e) recording the information related to a condition of a drive or a the disc.

Description

Read only information storage medium and method for reproducing data from the same}

The present invention relates to a high-density reproduction-only optical information storage medium and a data reproduction method in which a pattern required for data reproduction is formed in at least one of a lead-in area and a lead-out area to improve reproduction characteristics.

In general, an optical information storage medium, for example, an optical disk is widely used as an information storage medium of an optical pickup device that records / reproduces information in a non-contact manner, and may be a compact disk (CD) or a digital multifunction disk according to the information recording capacity. (DVD; digital versitile disk). As an optical disc capable of recording, erasing and reproducing information, 650MB CD-R, CD-RW, 4.7GB DVD + R / RW, random access memory (DVD-RAM), DVD-R / RW (rewritable), etc. Play-only discs include 650MB CD and 4.7GB DVD-ROM. Furthermore, high-density optical discs (HD-DVD) having a recording capacity of 20 GB or more are also being developed.

However, as the capacity of the optical information storage medium increases as described above, the length and width of the pit recorded on the read-only information storage medium decrease. As the length and width of the pit decrease as described above, since the signal of the minimum mark becomes very small, there is a problem in that it is difficult to measure the modulation degree. Modulation degree measurement is necessary for measuring the recording and / or reproducing performance of a data signal. For example, the modulation degree of an RLL (d, k) modulation scheme is measured as I _{(d + 1)} / I _{(k + 1)} . . Here, I represents the signal intensity in the eye pattern which is a data signal characteristic graph.

The RLL modulation scheme represents a modulation scheme according to how many 0 bits come between 1 bit and 1 bit. The RLL (d, k) has a minimum number of 0 bits between 1 bit and 1 bit. It means up to (k) individuals. For example, RLL (1,7) represents a method in which the number of 0 bits coming between 1 bit and 1 bit is 1-7 and 7 bits are 1-7 maximum. According to the RLL (1,7) modulation scheme, when d = 1, data of (1010101) is written, and has a length of 2T between one bit and one bit. Further, when K = 7, data of (10000000100000001) is recorded and has a length of 8T between one bit and one bit. Here, T represents the minimum mark, that is, the minimum pit length. Thus, in the RLL (1,7) modulation scheme, data is recorded in pits and spaces having a length in the range of (2T-8T).

As another example, according to the RLL (2,10) modulation scheme, data is recorded in pits and spaces having a length in the range of (3T-11T).

In the RLL (1,7) modulation scheme, the modulation degree is measured as I ₂ / I ₈ , and in the RLL (2,10) modulation scheme, the modulation degree is measured as I ₃ / I ₁₁ .

1 shows the structure of a lead-in area of a conventional read-only information storage medium. This lead-in area includes a control data zone 100a in which disk related information and copy protection information is recorded, a buffer zone 100b, and an information zone 100d in which drive or disk status related information is recorded. . In addition, although a content to be recorded is not currently determined, a reserved zone 100c may be further provided to be left as a free area for data to be added in the future.

As shown in FIG. 1, a conventional read only information storage medium is not provided with an area for measuring modulation degree, and a measurer directly measures modulation degree through an eye pattern of data recorded in a user data area.

2 illustrates eye patterns for random signals when data is recorded according to an RLL (1,7) modulation scheme. Here, the horizontal axis represents time and the vertical axis represents signal magnitude I. Conventionally, in order to measure the modulation degree using this eye pattern, a measurer measures I ₂ by moving the oscilloscope cursor on the floor of a signal pattern corresponding to 2T, which is the minimum foot, and measures the signal pattern corresponding to 8T, which is the maximum foot. I ₈ was measured by placing the cursor on the floor to measure modulation degree I ₂ / I ₈ .

However, as the recording capacity increases, the eye pattern for the smallest pit becomes smaller and less clear as the length and width of the pit having the minimum length become smaller and smaller, and thus the modulation method for measuring the modulation degree as in the prior art may increase. There is no choice but to. In other words, as the amplitude of the eye pattern decreases, the accuracy of the degree of modulation decreases because the position of the cursor placed on the floor of the signal pattern corresponding to the minimum pit length varies according to the measurer. This problem is more serious as the capacity of the information storage medium increases. In addition, as the space spacing between the pits becomes narrower, crosstalk is severely generated, which makes it impossible to measure accurate modulation.

The modulation degree measurement described above is one of the requirements for reproducing data of a read-only information storage medium. In addition, a system adaptation process is required, and the data is smoothly reproduced when the requirements for reproducing the data are satisfied.

Accordingly, the present invention has been made to solve the above-described problem, and a pattern for a predetermined purpose necessary for reproducing data is formed in at least one of the lead-in area and the lead-out area, and the reproduction characteristic is made by using the predetermined pattern. It is an object of the present invention to provide a read-only information storage medium and a method for reproducing data that have been improved.

1 is a view showing a lead-in structure of a conventional read-only information storage medium.

2 shows an eye pattern of a signal for reproducing data recorded by the RLL (1,7) modulation method.

3 is a view schematically showing a data structure of a read-only information storage medium according to the present invention.

4A to 4D show examples of patterns for measuring modulation degrees recorded in a test zone provided in a read-only information storage medium according to the present invention.

5A to 5C show an equalizer for calculating expected values of a PRML system used in a read-only information storage medium according to the present invention.

6A shows a DPD signal and a push-pull signal for a single pattern.

6b shows a push-pull signal and an RF signal with good signal characteristics.

6C shows a DPD signal with good signal characteristics.

7 is a block diagram illustrating a signal generation process for measuring a modulation degree.

<Explanation of symbols for main parts of the drawings>

10 ... Lead-in area, 10a ... Control data zone

10b ... buffer, 10d ... test zone

10 e ... information zone, 20 ... data area

In order to achieve the above object, a reproduction-only information storage medium according to the present invention is a reproduction-only information storage medium including a data area, a lead-in area and a lead-out area in which user data is recorded.

A pattern for a predetermined purpose is formed in at least one of the lead-in area and the lead-out area.

The pattern is a test pattern for measuring modulation degree according to a data recording modulation scheme.

The test pattern may include at least the minimum and maximum feet within one period of the pit included in the data modulation scheme.

The test pattern is characterized in that it further comprises a pit having a length different from the minimum and maximum pit.

The test pattern is composed of a pattern in which the minimum and maximum feet of the pits included in the data recording modulation scheme are alternately repeated for each recording unit.

The test pattern includes a first pattern including a minimum pit among the pits included in the data recording modulation scheme and a pit having a length different from that of the minimum pit; The two patterns are alternately repeated for each recording unit.

In reproducing the test pattern, tracking is performed by a phase difference detection method (DPD) or a push-pull method.

The data write modulation scheme may be an RLL (d, k) modulation scheme.

The test pattern is configured such that the DC thumb of the signal characteristic graph is approximately zero.

The test pattern may include a first data pattern composed of a repeating pattern of (d + 1) T and a second data pattern composed of a repeating pattern of (k + 1) T.

The first data pattern and the second data pattern have a length of 2n (n is a natural number) times the least common multiple of (d + 1) and (k + 1), respectively.

The pattern is preferably used for the purpose of reproducing information of the information storage medium.

The pattern may be a pattern for measuring asymmetry.

A test zone is provided in at least one of the lead-in area and the lead-out area, and a pattern for the predetermined purpose is formed in the test zone.

In order to achieve the above object, a reproduction-only information storage medium according to the present invention is a reproduction-only information storage medium including a data area, a lead-in area and a lead-out area in which user data is recorded,

A pattern for PRML adaptation is formed in at least one of the lead-in and lead-out areas.

The pattern for the adaptation depends on the target channel of the PRML and the d of the RLL (d, k).

The pattern for the adaptation is 2T, 3T, and 5T or more and (k + 1) T or less for the PRML (a, b, b, b, a) system and the RLL (d, k) code with d = 1. It may have a pattern including at least one of the signals having.

The pattern for adaptation is a signal having a length of 3T, 5T or more and (k + 1) T or less for a PRML (1,2,2,2,1) system and an RLL (d, k) code with d = 1. It may be a pattern including at least one of.

The adaptation pattern is a repetitive pattern of 2T, 2T, 4T, and 4T for the PRML (a, b, b, a) system and the RLL (d, k) code with d = 1.

The pattern for adaptation is characterized by consisting of a repetitive pattern of 3T for the PRML (a, b, a) system and the RLL (d, k) code with d = 1.

The pattern for adaptation is preferably formed by a combination of a target channel of the PRML and at least one of signals having a length of 2T or more and (k + 1) T or less for an RLL (d, k) code.

In order to achieve the above object, the data reproduction method according to the present invention,

A method of reproducing data in a reproduction-only information storage medium including a data area in which user data is recorded, a lead-in area and a lead-out area,

Forming a pattern necessary for data reproduction in a partial region of at least one of the lead-in area and the lead-out area; Performing a test or adaptation necessary for data reproduction using the pattern; And reproducing data after the test or adaptation.

In the test step,

Performing tracking on the pattern for the test; Measuring the modulation degree using the signal characteristic graph for the test pattern; preferably includes.

Hereinafter, a reproduction-only information storage medium and a data reproduction method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 3, the read-only information storage medium according to the present invention includes a data area 20 in which user data is recorded, a lead-in area 10 provided on an inner circumference of the user data area, and records disc-related information and the like. And a lead-out area (not shown) provided on an outer circumferential side of the user data area.

The read-only information storage medium according to the present invention is characterized in that a pattern for a predetermined purpose is formed in at least one of the lead-in area 10 and the lead-out area.

It is preferable that the predetermined purpose is particularly for the purpose of reproducing the information storage medium. For example, the pattern may be a pattern for at least one of modulation degree measurement, asymmetry measurement, and PRML adaptation. The pattern for this predetermined purpose may be formed in a portion of at least one of the lead-in area and the lead-out area, and preferably in the test zone 10d provided in the lead-in area 10. have. The test zone may be provided not only in the lead-in area but also in the lead-out area, and may be repeatedly formed in the lead-in area and the lead-out area in order to increase the reliability of the pattern for a predetermined purpose.

Further, in the lead-in area 10, a control data zone 10a in which disc related information and copy protection information are recorded, a buffer zone 10b, a reserved zone 10c, and an information zone in which drive or disc status related information is recorded ( 10e) may be provided. Disc-related information includes, for example, information on types of storage media such as recordable discs, write once discs, and playback-only discs, information on the number of recording layers, recording speed information, and disc size information. have.

For example, a pit of a predetermined pattern for measuring modulation degree may be formed in the test zone 10d. Here, a method of measuring the modulation degree when data is recorded by the RLL (d, k) modulation method will be described.

As described above, the modulation scheme of the RLL (d, k) is a modulation scheme having a minimum number of (d) and a maximum number of (k) zero bits between 1 bit and 1 bit. In this case, a pattern including at least a minimum pit and a maximum pit is formed in a predetermined period P in the test zone 20c. For example, in the RLL (1,7) modulation scheme, since data is recorded in pits and spaces having a length in the range of 2T-8T, the test zone 20c includes at least 2T and 8T in one period P. The pattern can be recorded. Here, T represents the length of the minimum mark.

Specifically, as shown in FIG. 4A, a pattern including 2T and 8T is formed in one period P in the test zone 10d, where the period P is a recording unit such as an ECC block, a sector, or a frame. Can be An address is recorded at the head of each recording unit.

The pattern including 2T and 8T may be formed, for example, by forming a continuous pattern of 2T at the front and a continuous pattern of 8T at the back in one recording unit. Alternatively, the pattern may be composed of various combinations of 2T and 8T, such as a pattern in which 2T and 8T are alternately arranged or recorded in a pattern of 2T / 2T / 8T / 2T / 2T / 8T. Alternatively, one period may be two recording units. That is, 2T, which is the minimum pit in one of the two recording units, and 8T, which is the maximum pit in the other recording units, can be recorded. In other words, a pattern consisting of a minimum pit and a pattern consisting of a maximum pit can be recorded alternately for each recording unit.

On the other hand, a pattern including a minimum pit and a maximum pit and a pit having a length different from the minimum pit and the maximum pit in one period P may be configured. Here, the pit having a length different from the minimum pit and the maximum pit preferably has an intermediate length between the minimum pit and the maximum pit. For example, as shown in FIG. 4A, a pattern consisting of 2T, 5T, and 8T may be formed in one period P. FIG. Here, the period P may be a recording unit such as an ECC block, a sector, or a frame.

Alternatively, as shown in FIG. 4D, the pattern for modulation degree measurement may include a first pattern including a minimum pit and a pit having a length different from the minimum pit, and a maximum pit and a pit having a length different from the maximum pit. The containing second pattern may be alternately recorded for each recording unit. In this case, the period P may be composed of two recording units, and the recording unit may be an ECC block, a sector, or a frame.

For example, a first pattern composed of 2T and 5T and a second pattern composed of 8T and 5T are alternately recorded, and the first pattern is recorded in the nth ECC block, and (n + 1) The second pattern may be recorded in the first ECC block.

On the other hand, it is preferable that the test pattern recorded in the test zone is configured such that the DC thumb is zero to increase the reliability of signal reproduction.

As described above, a test pattern including at least the minimum feet and the maximum feet is periodically formed in the test zone 10d, and the modulation degree can be easily measured by using the signal for the pattern. The test zone in which the test pattern is formed may be provided not only in the lead-in area but also in the lead-out area in order to measure the reproduction performance of both the inner and outer regions of the information storage medium. Since the lead-out area is similar in structure to the lead-in area, its detailed description is omitted here.

Next, a pattern for adaptation of a partial response maximum likelihood (PRML) may be formed in the test zone 10d. The PRML method precodes an input signal to have controlled inter-symbol interference between the current data and the previous data, and then transforms the target signal into a target response to detect the data with a viterbi decoder. According to the PRML scheme, channel characteristics are compensated (distorted) through equalization, and error correction by jitter is performed through a bit ratio decoder.

For example, when the RLL (d, k) code is used for the PRML, the pattern for PRML adaptation may vary according to the target channel of the PRML system and the d value of the RLL (d, k) code. For example, in the PRML (a, b, b, b, a) system the values in parentheses indicate the target channel. Preferably, all of the expected values by the target channel of the PRML system may be represented, and at least one of signals having a length of (d + 1) T or more and (k + 1) T or less is selected to form a pattern for adaptation. do. More preferably, it is possible to represent all of the expected values by the target channel of the PRML system and to select and adapt the signals having the smallest possible length among the signals having a length of (d + 1) T or more and (k + 1) T or less. Form a pattern for

FIG. 5A shows an equalizer for obtaining an expected value that can be seen when using an RLL (d, k) code with d = 1 and a PRML (a, b, b, b, a) system. The expected values are summarized in the table as follows.

input Output (expected value) input Output (expected value) 1 1 1 1 1 2a + 3b -1 -1 -1 -1 -1 -2a-3b 1 1 1 1 -1 3b -1 -1 -1 -1 1 -3b 1 1 1 -1 -1 b -1 -1 -1 1 1 -b 1 1 -1 -1 -1 -b -1 -1 1 1 1 b 1 1 -1 -1 1 2a-b -1 -1 1 1 -1 -2a + b 1 -1 -1 -1 -1 -3b -1 1 1 1 1 3b 1 -1 -1 -1 1 2a-3b -1 1 1 1 -1 -2a + 3b 1 -1 -1 1 1 2a-b -1 1 1 -1 -1 -2a + b

Thus, when using a code of d = 1 and PRML (a, b, b, b, a) type PRML system, there are a total of 10 expected values. Here, when using the PRML (1,2,2,2,1) type, nine expected values are + 8, + 6, + 4, + 2,0, -2, -4, -6, -8. Has A pattern that can represent all nine expected values is a repeating pattern formed by selecting at least one of signals of 2T, 3T, and 5T or more and (k + 1) T or less. Preferably, the pattern for adaptation is formed in a pattern comprising at least 2T, 3T and 5T. For example, if you record with a repeating pattern of 3T / 2T / 2T / 3T / 5T / 5T or 2T / 2T / 3T / 3T / 5T / 5T, you can use it for the PRML (1,2,2,2,1) system during playback. It can be used for adaptation purposes. According to the pattern, the PRML (1,2,2,2,1) system can represent all expected values.

Next, FIG. 5B shows an equalizer for obtaining an expected value that can be output when using an RLL (d, k) code having a d = 1 and a PRML (a, b, b, a) system. The expected values in this case can be summarized as follows.

input Output (expected value) input Output (expected value) 1 1 1 1 2a + 2b -1 -1 -1 -1 -2a-2b 1 1 1 -1 2b -1 -1 -1 1 -2b 1 1 -1 -1 0 -1 -1 1 1 0 1 -1 -1 -1 -2b -1 1 1 1 2b 1 -1 -1 -1 2a -2b -1 1 1 -1 -2a + 2b

Thus, when using a code of d = 1 and a PRML system of the PRML (a, b, b, a) type, there are 7 expected values. For example, when using the PRML (1, 2, 2, 1) type, there are seven expected values: +6, +4, +2, 0, -2, -4, -6. The pattern capable of representing these seven expected values may be a pattern formed by selecting at least one of signals of 2T and 4T or more and (k + 1) T or less. For example, recording with a repeating pattern of 2T 2T 4T 4T can represent both the expected values when using the PRML (1,2,2,1) system and the RLL (1, k) code. d, k) code and can be used for adaptation for PRML (a, b, b, a) systems. In other words, using the patterns including 2T and 4T, all expected values of +6, +4, +2, 0, -2, -4 and -6 can be represented.

Next, FIG. 5C shows an equalizer for calculating an expected value that may appear when using an RLL (d, k) code having a d = 1 and a PTML system of a PRML (a, b, a) type. The expected values in this case can be summarized as follows.

input Output (expected value) 1 1 1 2a + b 1 1 -1 b 1 -1 -1 -b -1 -1 -1 -2a-b -1 -1 1 -b -1 1 1 b

When using the RLL (d, k) code and the PRML (a, b, a) system with d = 1, there are four expected values. The pattern capable of representing all four expected values may be a pattern formed by selecting at least one of signals having a length of 3T or more and (k + 1) T or less, and using the pattern, RLL (d, k) code and An adaptation can be implemented for the PRML (a, b, a) system. For example, using the RLL (1, k) code and the PRML (1,2,1) system, there are four expected values: +4, +2, -2, -4. In this case, for example, all of the expected values may be expressed using a repeating pattern of 3T.

The pattern for PRML adaptation described above may be formed in at least one of the lead-in area 10 and the lead-out area, and more preferably in the test zone 10d of the lead-in area 10.

Meanwhile, the pattern for a predetermined purpose according to the present invention may be a pattern for measuring asymmetry. The pattern for measuring asymmetry is preferably a pattern comprising at least (d + 1) T and (k + 1) T in the RLL (d, k) code.

As described above, the read-only information storage medium according to the present invention includes at least one of a pattern for a predetermined purpose, for example, a pattern for measuring modulation, a pattern for PRML adaptation, and a pattern for measuring symmetry in the test zone 10d. A pattern is formed to improve the reproduction characteristics of the information storage medium.

Next, a data reproduction method of a read-only information storage medium according to the present invention will be described.

As described above, a test zone is provided in at least one of the lead-in area and the lead-out area, and a pattern for a predetermined purpose is formed in the test zone. This pattern is necessary for data reproduction, for example, including at least one of a pattern for measuring modulation, a pattern for PRML adaptation, and a pattern for measuring asymmetry.

For the pattern for measuring the modulation degree, the content described with reference to FIGS. 4A to 4D may be applied as it is. Tracking is performed to measure the degree of modulation using a test pattern including at least the minimum and maximum feet of the feet according to the data modulation scheme.

In performing tracking, tracking may be implemented by a differential phase detection (DPD) or push-pull method. The phase difference detection method is a method of implementing a tracking servo by the phase difference of an optical spot formed in a four-segment photodetector, and the push-pull method is a method of implementing servo by the left and right signal difference of an optical spot formed in the photodetector. Since it is known, a detailed description thereof will be omitted here.

However, according to the phase difference detection method when implementing tracking for a single pattern, tracking control is difficult. 6A shows a DPD signal and a push-pull signal for a single pattern of pit and space with a length of 2T. The graph at the lower part of FIG. 6A shows an enlarged view of some signals of the DPD signal and the push-pull signal. FIG. 6B shows the push-pull signal when the signal came out well and the RF signal obtained by tracking by the push-pull signal. 6A and 6B, the push-pull signal for a single pattern is good. Therefore, it is advantageous to use the push-pull method when tracking a single pattern.

Meanwhile, FIG. 6C illustrates an example of a well output DPD signal. Comparing this DPD signal with the DPD signal of FIG. 6A, it can be seen that the DPD signal for a single pattern cannot be detected normally because the triangle waveform is distorted. In contrast, DPD signals are advantageous in tracking for random patterns.

Accordingly, when tracking the pattern for measuring the modulation degree formed in the test zone 10d, tracking may be implemented by selecting a detection method advantageous for tracking among the DPD detection method and the push-pull method.

By tracking the test pattern as described above, a signal characteristic graph, for example, an eye pattern may be obtained. The modulation degree is measured using this signal characteristic graph. According to the RLL (1,7) method among the RLL (d, k) modulation methods described above, the pattern for measuring the modulation degree includes 2T which is the minimum pit and 8T which is the maximum pit. Here, I _2T is measured by a signal corresponding to _2T , and I _8T is measured by a signal corresponding to _8T . At this time, since only the signal for the test pattern is detected, since the influence of other signals is less, signal detection for the minimum and maximum feet is easy.

In particular, as the recording capacity increases, detection of the minimum pit becomes difficult. In the present invention, since the pattern for measuring the modulation degree is composed of a simple pattern including the minimum pit and the maximum pit, there is an advantage in that the modulation degree is easily measured. On the other hand, crosstalk may occur between the minimum pits as the size of the minimum pits is reduced. However, since the minimum pits are regularly arranged in the pattern for measuring the modulation degree, the crosstalk is uniformly generated, and thus the modulation degree can be measured in consideration of the effect of the crosstalk. If the random pattern has crosstalk between neighboring pits, it may not be possible to measure the modulation degree in consideration of the effects of crosstalk.

On the other hand, in configuring a test pattern for measuring the modulation degree of the read-only data storage medium according to the present invention, at least the minimum and maximum feet of the pit used in the data modulation method, and the signal characteristic graph for the test pattern It is preferable to configure the DC thumb of 0 to be zero.

For example, in the RLL (d, k) modulation scheme, data is recorded in pits and spaces having a length in the range of (d + 1) T− (k + 1) T. In the RLL (d, k) modulation scheme, d is called a minimum run length and k is called a maximum run length. In order to eliminate the DC component in generating such a data signal, two specific constraints are selected that are within the range of the minimum run length d and the maximum run length k of the modulated code. That is, the specific constraint field i, j that satisfies d≤i, j≤k is selected. In generating a modulated signal as shown in FIG. 7, the random bit value generator 25 generates a random bit value, and the data pattern generator 27 uses the first data pattern to generate a random bit value. And generate a second data pattern. The NRZI encoding 30 of the first and second data patterns forms a bit stream.

The first data pattern and the second data pattern are each composed of a repeating pattern of (i + 1) T and a repeating pattern of (j + 1) T for i, j within a range of d ≦ i, j ≦ k. desirable. The DC component can be removed by making the total length of the first and second data patterns 2n times the minimum common multiple of (i + 1) and (j + 1), where n is a natural number.

Specifically, when i = 1 and j = 7, the first data pattern may be configured as a 2T repeating pattern, and the second data pattern may be configured as a 8T repeating pattern. The total length of the first data pattern and the second data pattern has a length that is 2n times 8, which is the least common multiple of 2 and 8. When n = 1, the first data pattern is repeated 2T eight times and the second data pattern is repeated 8T twice so that the total length of the first and second data patterns is 16T. In addition, when n = 2, the first data pattern is configured by repeating 2T 16 times and the second data pattern by repeating 4 times 8T so that the length of the pattern is 32T. In this way, the DC thumb can be made zero by configuring the first data pattern and the second data pattern with repetitive pits for predetermined i and j and forming the total length by an even multiple of their least common multiples.

In particular, it is preferable to include the minimum pit and the maximum pit in constructing the first data pattern and the second data pattern. In other words, in the RLL (d, k) modulation scheme, the first data pattern is configured with a repeating pattern of (d + 1) T, and the second data pattern is configured with a repeating pattern of (k + 1) T. The overall length is preferably 2n (n is a natural number) times the minimum common multiple of (d + 1) and (k + 1). When the minimum common multiple of (d + 1) and (k + 1) is I, the number of repetitions of (d + 1) is 2 np times and the number of repetitions of (k + 1) is 2 nq times. Here, p = I / (d + 1) and q = I / (k + 1).

The above is summarized as follows.

Bit value Repeat count First data pattern 0 2np repetition; p = I / (d + 1) Second data pattern One Repeat 2nq times; q = I / (k + 1)

By constructing a test pattern with a pattern according to Table 4, a DC thumb can be made 0 to generate a signal for modulation measurement, thereby accurately performing modulation measurement.

Next, a pattern for PRML adaptation is formed with the pattern described with reference to FIGS. 5A, 5B, and 5C. By implementing PRML adaptation using this pattern, data of a read-only information storage medium can be smoothly reproduced.

As described above, at least one of a pattern for modulation measurement, a pattern for PRML adaptation, and a pattern for measuring asymmetry is formed in at least one of the lead-in area and the lead-out area, and the data reproduction characteristics are optimized using these patterns. can do.

As described above, according to the read-only information storage medium and the data reproducing method according to the present invention, at least one of the lead-in area and the lead-out area is separately provided with a test zone having a pattern for reproducing data, thereby reproducing the data. Can improve.

Moreover, the decrease in the pit length as the recording capacity increases prevents the signal measurement for the smallest pit from becoming difficult. By accurately measuring the modulation degree as described above, more reliable data reproduction performance can be ensured.

In addition, according to the data reproducing method of the present invention, it is possible to form a test pattern in the test zone that can easily measure the modulation degree, and measure the modulation degree reliably by using the signal characteristic graph for this pattern. Furthermore, the test pattern can be configured to eliminate DC components, allowing for more accurate modulation measurements.

In addition, by forming an optimized pattern for PRML adaptation, it is possible to easily improve playback performance through PRML adaptation.

Claims (52)

In a reproduction-only information storage medium including a data area, a lead-in area and a lead-out area in which user data is recorded, And a pattern for a predetermined purpose is formed in at least one of the lead-in area and the lead-out area. The method of claim 1, The pattern is a read-only information storage medium, characterized in that the test pattern for measuring the modulation degree according to the data recording modulation scheme. The method of claim 2, wherein the test pattern, A read-only information storage medium, characterized in that it comprises at least the minimum and maximum feet within one period of the pit included in the data modulation scheme. The method of claim 3, wherein the test pattern, And a pit having a length different from the minimum and maximum pit. The method according to any one of claims 2 to 4, wherein the period of the test pattern is A reproduction-only information storage medium, characterized in that the ECC block, sector or frame. The method of claim 2, wherein the test pattern, A reproduction-only information storage medium, characterized by a pattern in which the minimum and maximum feet of the feet included in the data recording modulation scheme are alternately repeated for each recording unit. The method of claim 2, wherein the test pattern, A recording unit includes a first pattern including a minimum pit and a pit having a length different from the minimum pit among the pit included in the data recording modulation scheme, and a second pattern including a maximum pit and a pit having a length different from the maximum pit. Replay-only information storage medium, characterized in that arranged in turn alternately. The method according to claim 6 or 7, And the recording unit is an ECC block, sector or frame. The method according to claim 2, 3, 4, 6 or 7, Replay only information storage medium characterized in that the tracking is performed by a phase difference detection method (DPD) or a push-pull method in reproducing the test pattern. The method of claim 2, And the data recording modulation method is an RLL (d, k) modulation method. The method of claim 10, And the test pattern comprises a pit having a length of at least (d + 1) T and a pit having a length of (k + 1) T in one period. The method of claim 10, The test pattern includes a pit having a (d + 1) T length, a pit having a (k + 1) T length, and a pit having a length different from these lengths in one period. media. The method of claim 11 or 12, And the period is one recording unit or two recording units. The method of claim 13, And the recording unit is an ECC block, sector or frame. The method according to claim 2, 3, 4, 6, 7, 7, 10, 11 or 12, And the test pattern is configured such that the DC thumb of the signal characteristic graph is approximately zero. The method according to claim 10, 11 or 12, The test pattern includes a first data pattern composed of a repeating pattern of (d + 1) T and a second data pattern composed of a repeating pattern of (k + 1) T. The method of claim 16, And the first data pattern and the second data pattern have a length of 2n (n is a natural number) times the least common multiple of (d + 1) and (k + 1), respectively. The method of claim 1, And the pattern is used for the purpose of reproducing the information of the information storage medium. The method according to claim 1 or 2, The pattern is a reproduction-only information storage medium, characterized in that the pattern for measuring asymmetry (assymmetry). The method according to claim 1, 2, 3, 4, 18 or 19, A test zone is provided in at least one of the lead-in area and the lead-out area, and a pattern for the predetermined purpose is formed in the test zone. In a reproduction-only information storage medium including a data area, a lead-in area and a lead-out area in which user data is recorded, And a pattern for PRML adaptation formed in at least one of the lead-in area and the lead-out area. The method of claim 21, And the pattern is formed in a test zone provided in at least one of the lead-in area and the lead-out area. The method of claim 21 or 22, The pattern for adaptation is a reproduction-only information storage medium, characterized in that depends on the target channel of the PRML and d of the RLL (d, k). The method of claim 21 or 22, The pattern for the adaptation is 2T, 3T, and 5T or more and (k + 1) T or less for the PRML (a, b, b, b, a) system and the RLL (d, k) code with d = 1. A reproduction-only information storage medium comprising a pattern including at least one of signals. The method of claim 21 or 22, The pattern for adaptation is a pattern comprising at least 2T, 3T, 5T for a PRML (a, b, b, b, a) system and an RLL (d, k) code with d = 1. Information storage medium. The method of claim 25, And the pattern for adaptation is a repeating pattern of 2T / 2T / 3T / 3T / 5T / 5T. The method of claim 21 or 22, The pattern for adaptation is a signal having a length of 3T, 5T or more and (k + 1) T or less for a PRML (1,2,2,2,1) system and an RLL (d, k) code with d = 1. Replay-only information storage medium, characterized in that consisting of a pattern comprising at least one of. The method of claim 27, The pattern for adaptation is a reproduction pattern of 3T / 3T / 5T / 5T for a PRML (1,2,2,2,1) system and an RLL (d, k) code with d = 1. Information storage medium. The method of claim 21 or 22, The pattern for adaptation is a combination of a PRML (a, b, b, a) system and a pattern of 2T, 4T or more and kT or less for an RLL (d, k) code having d = 1. Storage medium. The method of claim 29, The pattern for adaptation is a repetitive pattern of 2T, 2T, 4T, 4T for the PRML (a, b, b, a) system and the RLL (d, k) code with d = 1. media. The method of claim 21 or 22, The pattern for adaptation is a combination of a PRML (a, b, a) system and a pattern of 3T or more (k + 1) T or less for an RLL (d, k) code with d = 1. Information storage medium. The method of claim 31, wherein The pattern for adaptation is a reproduction-only information storage medium, characterized in that the PRML (a, b, a) system and a repeating pattern of 3T for the RLL (d, k) code of d = 1. The method of claim 23, wherein The pattern for adaptation may be a pattern formed by a combination of a target channel of the PRML and at least one of signals having a length of 2T or more (k + 1) T or less for an RLL (d, k) code. Playback-only information storage medium. A method of reproducing data in a reproduction-only information storage medium including a data area in which user data is recorded, a lead-in area and a lead-out area, Forming a pattern necessary for data reproduction in a partial region of at least one of the lead-in area and the lead-out area; Performing a test or adaptation necessary for data reproduction using the pattern; Reproducing data after the test or adaptation. The method of claim 34, wherein in the testing step: Performing tracking on the pattern for the test; Measuring a degree of modulation using a signal characteristic graph for the test pattern. The method of claim 35, wherein the test pattern, At least a minimum foot and a maximum foot within one period of the pit included in the data modulation scheme. The method of claim 35, wherein the test pattern, A minimum foot, a maximum foot, and a foot having a length different from the minimum and maximum feet. 38. The method of claim 36 or 37, wherein the period is And an ECC block, sector or frame. The method of claim 35, wherein the test pattern, A repetitive arrangement of the smallest pit and the repetitive arrangement of the maximum pit among the pits included in the data recording modulation scheme is characterized in that the pattern is alternately repeated for each recording unit. The method of claim 35, wherein the test pattern, A recording unit includes a first pattern including a minimum pit and a pit having a length different from the minimum pit among the pit included in the data recording modulation scheme, and a second pattern including a maximum pit and a pit having a length different from the maximum pit. The method characterized in that the arrangement is repeated alternately. The method according to any one of claims 34 to 37, Tracking by the phase difference detection method (DPD) or push-pull in the step of tracking the test pattern. The method of claim 34, Wherein said data write modulation scheme is an RLL (d, k) modulation scheme. The method of claim 42, Wherein said test pattern comprises a pit having a length of at least (d + 1) T and a pit having a length of (k + 1) T in one period. The method of claim 42, Wherein said test pattern comprises a pit having a (d + 1) T length, a pit having a (k + 1) T length and a pit having a length different from these lengths in one period. The method of claim 43 or 33, The period is one recording unit or two recording units. The method according to claim 34, 35, 36, 37, 39, 40, 43 or 44, The test pattern is configured such that the DC thumb of the signal characteristic graph is approximately zero. The method according to any one of claims 34 to 37, And the test pattern comprises a first data pattern composed of a repeating pattern of (d + 1) T and a second data pattern composed of a repeating pattern of (k + 1) T. The method of claim 47, And the first data pattern and the second data pattern have a length of 2n (n is a natural number) times the least common multiple of (d + 1) and (k + 1), respectively. The method of claim 34, And forming a pattern for PRML adaptation in at least one of the lead-in and lead-out areas. The method of claim 49, The pattern is formed in a test zone provided in at least one of the lead-in and lead-out area. The method of claim 49 or 50, The pattern for adaptation is characterized in that it depends on the target channel of the PRML and the d of the RLL (d, k). The method of claim 34, The pattern is a pattern for measuring asymmetry.