JPH11162115A - Recording medium and device and method for reproducing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To guard data from being copied or ensure the security of the data by arranging a plurality of recording areas on a recording medium and changing the recording directions of the recording areas, namely, the advancing directions of the recording tracks in each areas correspondingly to the areas and, at the same time, to suppress the run-out-of-control and breakage of an already existing player by reducing the possibility of accidentally reading out the data by an existing player. SOLUTION: A disk is divided into a first area which is provided on the inner peripheral side for recording formation in accordance with the already existing CD format and an outer peripheral second area which is provided on the outer peripheral side for recording information at a recording density which is twice as dense as that in the first area. In the first area, a clockwise track is formed of a pit train toward the outer peripheral side from the inner peripheral side and, in the second area, a counterclockwise track is formed in the opposite direction. When a uses an already existing CD-ROM player to reproduce the information recorded on the disk, the user is known that the player is not able to reproduce the information recorded in the second area, because the player issues an alarm, whereas the player can reproduce the information recorded in the first area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium having a plurality of recording areas, a reproducing apparatus thereof, and a reproducing method thereof.

[0002]

2. Description of the Related Art Conventionally, various inventions have been made in which a plurality of recording areas are arranged on a medium. For example, there is a type in which a plurality of recording areas are arranged in a radial direction of a disc, and a different program is recorded for each recording area. Recently, it is also possible to make the recording density different for each recording area by shortening the wavelength of a laser or the like.

[0003] As described above, with the development of the technology so far, it has become possible to configure a wide variety of media.

[0004]

However, when a newly developed medium is mounted on an existing player, the player runs away due to data read from the medium, and in the worst case, the player is damaged. There is also a risk of doing so. Therefore, it is preferable that data that does not match the existing player cannot be read out by the existing player. Further, from the viewpoint of copy guard and data security, it is necessary to prevent information on the area from being read by a player other than the dedicated player that can reproduce the medium. On the other hand, it is preferable that the dedicated player can also perform compatible reproduction of an existing medium.

An object of the present invention is to provide a recording medium, a reproducing apparatus and a reproducing method which can easily solve these problems.

[0006]

The most important feature of the present invention is that a plurality of recording areas are arranged on a recording medium, and the recording direction of each recording area, that is, the traveling direction of a recording track is made to correspond to each recording area. To change it. According to this, unless the information on the recording direction of each recording area is given to the reproducing apparatus in advance, the recording information of each area cannot be read, so that data copy guard and security can be performed. In addition, it is possible to reduce the possibility of data being read by an existing player by mistake,
Thus, runaway and damage of the existing player can be suppressed.

Hereinafter, the features of the recording medium according to the present invention will be described for each claim. A recording medium according to a first aspect is characterized in that the recording medium has a plurality of recording areas in which scanning directions of recording tracks are different. According to this, the above-mentioned data copy guard and data security can be realized in combination with the reproduction control on the reproduction apparatus side described later, and runaway of the existing player can be suppressed.

According to a second aspect of the present invention, the recording medium is a disk, wherein a plurality of recording areas are arranged in a radial direction of the disk. This represents one of the preferred embodiments of claim 1. The recording medium of claim 3 is claim 2.
In this case, two recording areas, an inner peripheral part and an outer peripheral part, are prepared, and the recording densities are different from each other.
This shows one of the preferred embodiments when the recording density is changed for the recording area.

According to a fourth aspect of the present invention, in the third aspect, the outer peripheral portion is a high-density recording area, main information is recorded on the outer peripheral portion, and information related to the main information is recorded on the inner peripheral portion. It is characterized by the following. According to this, since the outer circumference has a larger circumference than the inner circumference and is recorded at a high density,
In particular, when recording is performed at a constant linear velocity, the recording capacity of the main information can be significantly increased.

A recording medium according to a fifth aspect is characterized in that, in the fourth aspect, sample information obtained by simplifying the main information is recorded on the inner peripheral portion. According to this, even if the main information of the outer peripheral area cannot be read, the outline of the main information recorded on the disc can be known by reading the inner peripheral area of the normal density. The recording medium according to claim 6 is the recording medium according to claim 4 or 5, wherein the medium is formed in accordance with the CD format, the outer peripheral portion is physically compressed as compared with a normal CD, and the spiral direction of the track is normal. C
D is the opposite direction. According to this, even in the case where the reproducing head accesses a high-density area in a normal CD (Compact Disc) player, the spiral direction of the track is opposite to the normal direction, so that the data Reading cannot be performed, so that the CD player does not run away or is damaged. In addition, since the normal density sample information and the like are arranged on the inner peripheral portion of the disc, when such a medium is mounted on a normal CD player, the sample information and the like are first read and reproduced, and thus, Can know the type of the disc and an overview of the main information. When such a medium is mounted on a dedicated player, the reproducing head can access the outer peripheral area and read and reproduce main information as in a reproducing apparatus described later.

A recording medium according to a seventh aspect is characterized in that, in the sixth aspect, a radial dimension of a start position of the outer peripheral area is set to a specific value in advance. According to this, by setting the radial dimension in the reproducing device in advance,
The head can easily access the outer peripheral area. An eighth aspect of the present invention is the recording medium according to the sixth or seventh aspect, wherein a transition region without pits is arranged at a boundary between the inner peripheral region and the outer peripheral region. According to this, at the time of access of the reproducing head, by detecting the non-pit area,
Since the transition of the area can be determined, the access between the areas becomes easy.

A recording medium according to a ninth aspect is characterized in that, in any one of the sixth to eighth aspects, the TOC information for the outer peripheral area is arranged at a start position of the outer peripheral area. According to this, since it is not necessary to access the inner peripheral portion and once read the TOC information, and then to start the reproduction of the outer peripheral portion by reversing the rotation direction of the disk, the reproduction of the main information of the outer peripheral portion can be performed quickly. It can be performed smoothly.

Next, the features of the reproducing apparatus for reproducing the recording medium will be described in each claim. According to a tenth aspect of the present invention, there is provided a reproducing apparatus for reproducing a recording medium according to any one of the first to ninth aspects, wherein a scanning direction determining means for determining a scanning direction of a recording track by a reproducing head; An access unit for allowing the reproduction head to access a recording track, wherein the access unit allows the reproduction head to access any one of the recording areas, and the scanning direction determination unit responds to the recording direction of the recording area. The reproducing head is caused to scan in the scanning direction. According to this, it is possible to read and reproduce the recording information for each recording area. The information on the scanning direction for each recording area is given in advance to a memory in the reproducing apparatus.

According to an eleventh aspect of the present invention, there is provided the reproducing apparatus according to the tenth aspect, further comprising a determining unit for determining whether the data read from the medium by the reproducing head is good or not, and the determining unit determines whether the read data is defective during the scanning. Is determined,
The read head is made to access another recording area by the access means, and the scanning direction is switched to a scanning direction according to the recording direction of the recording area by the scanning direction determining means. According to this, an unreadable area can be skipped and another area can be reproduced.

According to a twelfth aspect of the present invention, there is provided a reproducing apparatus for reproducing a recording medium according to the fourth or fifth aspect, wherein: a scanning direction determining means for determining a scanning direction of a recording track by a reproducing head; Access means for accessing the reproduction head to a track, wherein the access means allows the reproduction head to access a recording area on the outer peripheral side, and the scanning direction determining means corresponds to a recording direction of the outer peripheral area. The track is scanned in a scanning direction. According to this, the main information on the outer peripheral portion side can be smoothly read and reproduced.

According to a thirteenth aspect of the present invention, in the reproducing apparatus according to the twelfth aspect, a discriminating means for discriminating the quality of the data read from the medium by the reproducing head is provided. When a defect is determined, the reproducing unit accesses the inner peripheral area by the access unit, and switches to a scanning direction according to the recording direction of the inner peripheral area by the scanning direction determining unit. According to this, even when the main information in the outer peripheral portion cannot be read and reproduced, the reproduction of the sample information and the like in the inner peripheral portion can be performed. Further, when the disk is not divided into an inner peripheral portion and an outer peripheral portion and a recording track corresponding to the track form of the inner peripheral portion is formed over the entire surface of the disk, and the disk is mounted. However, since the reproducing head accesses the inner peripheral area from the outer peripheral area again, the recorded information can be read and reproduced.

According to a fourteenth aspect of the present invention, in the thirteenth aspect, the medium is formed according to the CD format, the outer peripheral portion is physically compressed as compared with a normal CD, and the spiral direction of the track is usually smaller. And the read head can read both data in the inner peripheral area and the outer peripheral area. This shows one preferred embodiment of the reproducing apparatus of claim 13. According to this, it is possible to smoothly read and reproduce the main information compressed and recorded on the outer peripheral portion. Further, even when an existing CD is loaded, information is automatically read and reproduced from the inner peripheral portion in response to a read failure of the outer peripheral portion, and thus, the existing CD can be reproduced compatible.

According to a fifteenth aspect of the present invention, in the fourteenth aspect, the radial size of the medium at the start position of the outer peripheral area is set to a specific value, and the access means performs the reproducing operation based on the radial size. Is accessed. According to this, the access of the head to the outer peripheral area becomes easy. According to a sixteenth aspect of the present invention, in the fourteenth or fifteenth aspect, a transition area without pits is arranged at a boundary between the inner peripheral area and the outer peripheral area of the medium, and the access unit detects the transition area. By doing so, the reproducing head is positioned in the outer peripheral area. According to this, the transition of the area can be determined by detecting the non-pit area when the reproducing head accesses, so that the reproducing head can easily access.

The reproducing apparatus according to claim 17 is the reproducing apparatus according to claims 14 to 1
6, in the start position of the outer peripheral area of the medium, TOC information for the outer peripheral area is separately arranged, and when reproducing the outer peripheral area, the TOC information of the outer peripheral area is stored in the memory. When reproducing the peripheral area, the TOC of the inner peripheral area
The information is stored in a memory. According to this, after reading the TOC information by accessing the inner periphery,
Since there is no need to reverse the rotation direction of the disc and start reproducing the outer peripheral portion, the main information on the outer peripheral portion can be reproduced quickly and smoothly.

[0020] The reproducing apparatus according to claim 18 is characterized in that, in claim 17, the TOC information of the inner peripheral portion and the TOC information of the outer peripheral portion are write-controlled by switching to a single memory. According to this, the memory capacity can be made more efficient. According to a nineteenth aspect of the present invention, there is provided a reproducing apparatus according to any one of the fourteenth to eighteenth aspects, wherein two types of internal circuits are provided for reproducing high-density information and for reproducing normal density information. , The internal circuit is switched. According to this, better reproduction of the inner peripheral portion and the outer peripheral portion can be performed.

Further, a reproducing method according to the present invention is a reproducing method for reproducing a recording medium according to any one of claims 1 to 9, wherein a step of causing a reproducing head to access a desired recording track; Scanning the reproducing head in a scanning direction corresponding to the recording direction of the area; determining whether the data read from the medium by the reproducing head is good; and determining whether the data is defective in the determining step. And causing the reproducing head to access another recording area and switching the scanning direction of the reproducing head to a scanning direction corresponding to the recording direction of the recording area. According to this,
It is possible to read and reproduce the recorded information for each recording area.

[0022]

FIG. 1 shows a preferred embodiment of a recording medium according to the present invention. In the present embodiment, the present invention
This is an example in which the present invention is applied to a D-ROM (Compact Disc-Read Only Memory) format disc. The disc is
It is divided into a first region on the inner periphery and a second region on the outer periphery. Information is recorded in the first area according to the existing CD format. On the other hand, in the second area, the track pitch, the pit length, and the pit width are compressed to 1 / √2 times that of the existing CD, and high-density recording is performed. That is, the recording density of the second area is twice the recording density of the first area.

In the first area, similarly to the existing CD-ROM, a clockwise track from the inner periphery to the outer periphery is formed by a pit row. On the other hand, the tracks in the second area are counterclockwise and in the opposite direction to the first area. Note that a transition area is provided between the first area and the second area. Such a transition region is a mirror surface region without pits.

The first area and the second area have a lead-in area, a user data area and a lead-out area, respectively. Each lead-in area has an existing C
Like the D-ROM, a TOC (Table of Contents) is provided. Therefore, the first area and the second area are independent of each other, and data reproduction control can be separately and independently performed.

The first region is set in a radial region with a radius of 25 mm to 28 mm, and the second region is set in a radial region with a radius of 30 mm to 58 mm. Therefore, the second area occupies most of the entire recording area and is recorded at twice the normal density, so that the recording capacity of the second area is extremely large. The transition region between the first region and the second region is a radial region having a radius of 28 mm to 30 mm.

Main information to be recorded on the disc is assigned to the second area. For example, when recording game software on a disc, this is recorded in the second area.
On the other hand, information related to the main information recorded in the second area is recorded in the first area. For example, when the game software is recorded in the second area as described above, the information recorded in the first area includes screen information of one scene for a game and information of an initial introduction part of the game. 5). In addition, alarm information when the disc is mistakenly mounted on an existing CD-ROM player is also recorded in the first area.

When such a disc is reproduced by an existing CD-ROM player, reproduction is started from the first area as usual, and since the first area is recorded according to the normal CD format, the data is recorded in the first area. Reproduction of information is performed. Thereby, the user can see the screen of one scene for the game described above and can confirm the initial introduction part of the game. In addition, when the player issues an alarm, it is possible to know that the disc cannot be reproduced by an existing player. As such an alarm, a description of the type of the disk may be displayed on a screen or outputted as audio along with a predetermined warning.

The manufacture of such a disc can be achieved by partially improving an existing cutting device. The recording of the first area may be performed in the same manner as the existing CD-ROM disc. In the recording of the second area, the rotation speed of the disk is reversed to 1 / √2 times, and the radial feed speed of the write head is 1 / に す る 2 times. Further, the spot diameter of the writing beam is set smaller than that in the normal density recording. The reduction of the spot diameter is as follows.
This can be achieved by shortening the wavelength of the writing beam or changing the numerical aperture of the objective lens. Other details of the disc manufacturing device are within the scope of diversion of known technology,
Here, the description is omitted.

Next, a reproducing apparatus for the disc will be described. FIG. 2 is a circuit block diagram of the reproducing apparatus. 1 is a disk, 2 is a spindle motor for driving a turntable holding the disk, 3 is a rotation speed control unit for controlling the rotation speed of the spindle motor, 4 is a rotation direction control unit for controlling the rotation direction of the spindle motor, 5 is A pickup 6, a reproducing unit for shaping a read signal from the pickup into a pulse signal, and a demodulation unit 7, for demodulating a pulsed code signal. The data from the demodulation unit 7 is sent to a reproduction processing system (not shown).

Reference numeral 8 denotes a sub-code separation unit for separating and extracting sub-code data from the demodulated data by the demodulation unit 7. Reference numeral 9 denotes a TOC separation unit which extracts TOC data from the subcode data separated and extracted by the subcode separation unit 8 and writes the extracted TOC data into the memory 10. Note that TOC data in either the first area or the second area is selectively written in the memory 10 in response to a command from the CPU 12.

Numeral 11 denotes a pickup servo for performing pickup adjustment, tracking adjustment and focus adjustment of a reproduction beam, and 12 a CPU. The CPU 12 controls each part of the playback apparatus. Also, in the CPU 12,
Information about the disk rotation drive direction of the first area and the second area is stored. Here, the rotation speed control unit 3 receives the pulse signal from the reproduction unit 6, and controls the motor 2 so that the reproduction clock based on the pulse signal has a constant frequency.
Is controlled by the PLL. In addition, the rotation direction control unit 4
The rotation direction of the spindle motor is counterclockwise when reproducing the first area and clockwise when reproducing the second area, as viewed from the disk reproducing surface. The setting of the rotation direction is described in CP
Responds to a command from U12.

Incidentally, the spot diameter of the read beam of the pickup 5 is set smaller than usual so that both the first area of normal density and the second area of double density can be reproduced. As for tracking, the first
Two types of servo systems are prepared in the pickup servo 11 so that the servo capacity can be switched between when reproducing the area and when reproducing the second area. Further, in the reproducing section 6, two kinds of equalizers are prepared so that the waveform shaping ability is switched between the reproduction of the first area and the reproduction of the second area. Switching between the servo system and the equalizer is performed in response to a command from the CPU 12.

Next, the operation of the reproducing apparatus will be described with reference to the flowchart of FIG. When the disc 1 is mounted on the reproducing apparatus and the reproduction is started, the motor 2 is controlled by the rotation speed control unit 3 and the rotation direction control unit 4 so that the disk 1 rotates clockwise as viewed from the reproduction surface ( S
1). At the same time, the pickup servo 11
Thereby, the pickup 5 accesses the start position (lead-in) of the second area of the disk 1 (S1).

Various methods can be adopted for such access. For example, if the radial size of the disk at the start position of the second area is fixed in advance, a potential switch is arranged at that size position, and the pickup 5 moves from the innermost standby position to that size position. At this timing, the transfer of the pickup can be stopped. Also, if the reproduction signal of the reproduction unit 6 is monitored by the CPU 12, the passage of the transition area (mirror surface) can be easily detected by a change in the reproduction signal. Can also be stopped. Further, the pickup may be temporarily transferred to the outer peripheral side of the disk, and thereafter, the start position of the second area may be searched based on the address information in the second area.

When the pickup 5 accesses the start position of the second area in this way, it is next determined whether or not reproduction of the start position is possible (S2). This determination is made based on whether or not the CPU 12 has correctly received the subcode data within a certain period after the start of the reproduction. If it is determined that reproduction is possible, the reproduction of the second area is continued (S
3). At this time, the TOC data in the second area is simultaneously written into the memory 10.

On the other hand, if it is determined that the reproduction of the second area is impossible, the CPU 12 executes the reproduction of the first area.
The rotation direction of the disk 1 is reversed, and the pickup 5 is made to access the start position of the first area (S
4). Then, when the pickup 5 accesses the start position of the first area, the TOC data of the first area is read and written to the memory 10.

Here, the flow of S2 → S4 → S5 is mainly for enabling a normal CD-ROM disc to be reproduced when it is erroneously mounted on the reproducing apparatus. In other words, if the CD-ROM is incorrectly mounted, the CD-ROM is driven to rotate in the direction opposite to the proper direction. Therefore, even if the pickup 5 is moved to the start position of the second area, the CPU 12 Does not correctly receive subcode data. Thereby, the CPU 12
Detects the possibility that the disc is an existing CD-ROM disc, changes the rotation direction of the disc to a direction appropriate for the CD-ROM in S4 and S5, and moves the pickup 5 to the inner circumference of the disc 1 again. Transfer to department. CP
By performing such control by the U12, although the control operation such as transfer to the second area is performed, the reproduction of the CD-ROM disk can be automatically executed together with the disk of FIG.

The embodiment according to the present invention has been described above, but the present invention is not limited to this embodiment. For example, in the above-described embodiment, there are only two recording areas, the first area and the second area. However, three or more recording areas may be used. In such a case, a table indicating the relationship between the rotation direction of the disc and the recording area in accordance with the spiral direction of the track in each recording area may be stored in the CPU 12 so that the rotation direction of the disc may be controlled. . Instead of storing the table in the CPU 12, the table may be recorded, for example, at the innermost circumference of the disc, and read at the beginning of reproduction to be stored in a predetermined memory. When the number of recording areas is three or more, the access to each area start position of the pickup is performed as follows.
The above-described method using a potential switch, a method for detecting (counting) a transition region, and the like can be adopted.

In the above-described embodiment, the recording density of the second area is twice as large as that of the first area. Alternatively, the recording density may be more than twice. However, if the difference between the recording densities is large, it becomes difficult to read and reproduce data unless the diameter of the beam spot is changed according to the recording density. It is necessary to provide a means for changing to. It is of course possible to keep the same recording density over all the regions without changing the recording density for each region.

Further, in the above-described embodiment, a CD-format disk is taken as an example. Instead, a magneto-optical disk such as a mini disk, a phase change disk, and a tape or drum other than a disk may be used. The present invention can be applied to a medium. It goes without saying that various embodiments are possible within the scope of the technical idea of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing a disk according to an embodiment;

FIG. 2 is a block diagram showing a playback device according to the embodiment;

FIG. 3 is a view showing a flowchart according to the embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc 4 Rotation direction control part 5 Pickup 6 Reproduction part 9 TOC extraction part 10 Memory 11 Pickup servo 12 CPU

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // G11B 7/24 561 G11B 7/24 561B

Claims (20)

[Claims] 1. A recording medium having a plurality of recording areas in which scanning directions of recording tracks are different. 2. The recording medium according to claim 1, wherein the recording medium is a disk, and a plurality of recording areas are arranged in a radial direction. 3. The recording medium according to claim 2, wherein two recording areas, an inner peripheral part and an outer peripheral part, are prepared and recording densities are different from each other. 4. The high-density recording area according to claim 3, wherein the main information is
A recording medium wherein information related to main information is recorded on an inner peripheral portion. 5. The recording medium according to claim 4, wherein sample information in which main information is simplified is recorded on an inner peripheral portion. 6. The medium according to claim 4, wherein the medium is formed in accordance with a CD format, the outer periphery is physically compressed as compared with a normal CD, and the spiral direction of the track is different from that of a normal CD. A recording medium characterized by being in the opposite direction. 7. The recording medium according to claim 6, wherein a radial dimension at a start position of the outer peripheral area is set to a specific value. 8. The recording medium according to claim 6, wherein a transition region without pits is arranged at a boundary between the inner peripheral region and the outer peripheral region. 9. The recording medium according to claim 6, wherein TOC information for the outer peripheral area is arranged at a start position of the outer peripheral area. 10. A reproducing apparatus for reproducing a recording medium according to claim 1, wherein: a scanning direction determining means for determining a scanning direction of a recording track by a reproducing head; Access means for accessing a reproduction head, wherein the access means allows the reproduction head to access any one of the recording areas, and the scanning direction determination means performs the scanning in a scanning direction corresponding to a recording direction of the recording area. A reproducing apparatus for causing a reproducing head to scan. 11. The method according to claim 10, further comprising: determining means for determining whether the data read from the medium by the reproducing head is good or bad. Means for causing the reproducing head to access another recording area by means, and switching to a scanning direction according to the recording direction of the recording area by the scanning direction determining means. 12. A reproducing apparatus for reproducing a recording medium according to claim 4 or 5, wherein: a scanning direction determining means for determining a scanning direction of a recording track by the reproducing head; And an access unit for causing the reproducing head to access a recording area on an outer peripheral side by the access unit, and the scanning direction determining unit sets the track in a scanning direction corresponding to a recording direction of the outer peripheral area. A reproducing device characterized by scanning. 13. The method according to claim 12, further comprising: determining means for determining whether the data read from the medium by the reproducing head is good or bad. Means for causing the reproducing head to access an inner peripheral area by means, and switching to a scanning direction according to the recording direction of the recording area by the scanning direction determining means. 14. The medium according to claim 13, wherein the medium is formed in accordance with a CD format, the outer peripheral portion is in a form that is physically compressed as compared with a normal CD, and the spiral direction of the track is opposite to that of the normal CD. A reproducing head capable of reading data in both the inner peripheral region and the outer peripheral region. 15. The medium according to claim 14, wherein a radial dimension of the medium at the start position of the outer peripheral area is set to a specific value, and the access means causes the reproducing head to access based on the radial dimension. Playback device. 16. A transition area according to claim 14, wherein a transition area without pits is arranged at a boundary between the inner peripheral area and the outer peripheral area of the medium, and the access means detects the transition area. A reproducing apparatus characterized in that a reproducing head is positioned in an outer peripheral area. 17. The medium according to claim 14, wherein a start position of the outer peripheral area of the medium is set to a TO for the outer peripheral area.
C information is separately provided, and when reproducing the outer peripheral area, the TOC information of the outer peripheral area is stored in the memory, and when reproducing the inner peripheral area, the TOC information of the inner peripheral area is stored in the memory. Playback device. 18. The reproducing apparatus according to claim 17, wherein the writing of the TOC information of the inner peripheral portion and the TOC information of the outer peripheral portion are controlled by switching to a single memory. 19. The internal circuit according to claim 14, wherein the internal circuit is for reproducing high-density information and for reproducing normal-density information.
A reproducing apparatus, wherein types are prepared, and the internal circuit is switched according to whether a reproducing head is at an outer peripheral portion or an inner peripheral portion. 20. A reproducing method for reproducing a recording medium according to claim 1, wherein the reproducing head accesses a desired recording track, and scanning according to a recording direction of the recording area. Scanning the read head in the direction; determining whether the data read from the medium by the read head is good; and determining that the data is defective in the determining step, the data is read to another recording area. Reproducing the read head and switching the scan direction of the read head to a scan direction corresponding to the recording direction of the recording area.